I. KINEMATICS.--PRELIMINARY ELEMENTARY MOVEMENTS OF INVARIABLE POINTS AND SYSTEMS
LESSONS 1-2.
Object of kinematics, under the geometrical and experimental point of view. Its principal divisions.
Re-statement of the notions relative to the motion of a point, its geometrical representation, and more especially the determination of its velocity.
Simultaneous Velocities of a Point and the Increments of its Velocities.
Ratio of the elementary displacement and the velocity of a point to the displacement, and velocity of its projection upon a straight line or plane. Use of infinitesimals to determine these ratios. Example:--Oscillatory motion of the projection upon a fixed axis of a point moving uniformly upon the circumference of a circle.
Analogous considerations for polar co-ordinates. Relations of the velocity of a point, of its velocity of revolution and its angular velocity about a fixed pole; of its velocity in the direction of the radius vector; of the velocity of increase of the area which this radius describes.
Simple Motions of Solids, or Rigid Systems.
1. Motion of rectilinear or curvilinear translation; simultaneous displacements, and velocities of its different points.
2. Motion of rotation about a fixed axis; relation of the velocities of different points to the angular velocity.
Geometrical notions and theorems relative to the instantaneous center of rotation of a body of invariable figure and movable in one plane, or to the instantaneous axis of rotation of a rigid system situated in space, and movable parallel to a fixed plane. Relation of the velocities of different points to their common angular velocity. Use of the instantaneous center of rotation for tracing tangents; examples--and amongst others--that of the plane curve described by a point in a straight line of given length, whose extremities slide upon two fixed lines. Rolling of a curve upon another fixed curve in a plane. Descartes’ theorems upon the intersection of the normals at the successive points of contact: cycloids, epicycloids, involutes, and evolutes. Extension of the preceding motions to the instantaneous axis of rotation of a rigid system movable about a fixed point.
COMPOSITION OF MOTIONS.
LESSONS 3-6. Composition of the Velocities of a Point.
Polygon of velocities. Example of movements observed relatively to the earth. Particular cases; composition of velocities taken along three axes; composition of the velocity of a point round a fixed pole, and its velocity along the radius vector. Method of Roberval for tracing tangents.
Composition of the Simple Motions of a Solid System.
Composition of any number of translatory displacements of a solid. Composition of two rotations about two intersecting axes. Composition of any number of rotations about axes cutting one another at the same point; parallelopiped and polygon of rotations. Composition of two simultaneous rotations about parallel axes; case where the rotations are equal and of opposite kinds. Decomposition of a rotation about an axis into an equal rotation about any axis whatever parallel to the first, and a translation perpendicular to the direction of this axis. Direct and geometrical decomposition of the most general motions of a body into a rotation about, and a translation along, an axis called the instantaneous axis. Composition of any two motions whatever. Every movement of an invariable system is at each instant of time decomposable into three movements of rotation, and three movements of translation with respect to three axes, which are neither parallel nor lying in the same plane, but otherwise arbitrarily chosen.
Relative or Apparent Motions.
Relative motion of two points whose absolute motions are given graphically à priori. Trajectory of the relative motions, relative velocities, and displacements upon curves or upon the direction of the mutual distance of the two points; use of the parallelogram to determine its amount. Relative motion of a point in motion in respect of a body turning about a fixed axis; relative motion of two bodies which turn about parallel or converging axes, and in general of two rigid bodies or systems impelled by any motions whatever. How this problem is immediately reduced to that of the composition of given motions.
The most general continued motion of an invariable figure in a plane is an epicycloidal motion, in which the instantaneous center describes a curve fixed in relation to absolute space, and traces relatively to the proposed figure a movable curve, which is rigidly connected with that figure and draws it along with it in its motion of rolling upon the other fixed curve. Case of space or spherical figures.
ON THE ACCELERATED MOTION OF A POINT.
LESSONS 7-9. Accelerated Rectilinear Motion.
Re-statement of the motions acquired relatively to the acceleration in the variable rectilinear motion of a point. Brief indication of the solution of six problems arising out of the investigation of the laws of the motion in terms of the space, time, velocity, and accelerating force. For the most part these solutions may be brought to depend on exact or approximate quadratures. Numerical exercises.
Accelerated Curvilinear Motions.
Re-statement of the notions acquired relative to the composition of accelerating forces; the resulting acceleration, the normal and tangential acceleration animating a point in motion on a curve. The total acceleration of a point upon an axis or plane is the projection upon this axis or plane of the acceleration of the moving body in space. In uniform curvilinear motion the total or resultant acceleration becomes normal to the curve. Particular case of the circle; value of the normal acceleration in terms of the velocity of revolution or the angular velocity of the radius vector. Case of any curve whatever; geometrical expression of the total or resultant acceleration.
Accelerated Compound and Relative Motions.
Geometrical investigation of the simple and compound accelerations arising out of the hypothesis in which the motion of any system of points whatever is referred to another system of invariable form, but also in motion. Geometrical and elementary explanations of the results obtained by means of the transformation of co-ordinates.
Examples or Exercises chosen from among the following Questions:--
Projection of circular and uniform motion upon a fixed straight line or plane; motion of a circle which rolls uniformly on a straight line; comparison of the motions of the planets relatively to each other, treating them as circular and uniform: comparison of the accelerating force on the moon with that of bodies which fall to the earth.
GEOMETRICAL THEORY AND APPLICATION OF MECHANISMS OR CONTRIVANCES FOR THE TRANSFORMATION OF MOTION.
LESSONS 10-19.
Succinct notions on the classification of elementary motions and organs for transmission of motion in machines after Monge and Hachette, Lanz and Bétancourt.
The most essential details upon this subject are set forth in the following order, and made clear by outline drawings previously distributed among the pupils.
Organs fitted to regulate the direction of the circular or rectilinear motion of certain pieces.
Axle; trunnions, gudgeons; pivots and bearings; couplings of axes; adjustment of wheels and of their arms. Joints with hinges, &c.; sheaves and pulleys; chains, ropes, and straps; means of securing them to the necks. Grooves and tongue-pieces. Eyelet-holes sliding along rectilinear or curvilinear rods. Advantages and disadvantages of these different systems of guides under the point of view of accuracy.
Rapid indication of some of their applications to drawbridges and to the movable frames or wagons of saw-works and railways.
Transmission at a Distance of Rectilinear Motion in a determinate Direction and Ratio.
Inclined plane or wedge guiding a vertical rod. Wedge applied to presses. Rods, winch-handles, &c. Disposition of drums or pulleys in the same plane or in different planes; geometrical problem on this subject. Fixed and movable pulleys. Blocks to pulleys. Simple and differential wheel and axle moved by cords. Transmission through a liquid. Ratios of velocities in these different organs.
Direct Transformation of circular progressive motion into progressive and intermittent rectilinear motion.
Rod conducted between guides: 1º, by the simple contact of a wheel; 2º, by cross-straps or chains; 3º, by a projecting cam; 4º, by means of a helicoidal groove set upon the cylindrical axis of the wheel. To-and-fro movement, and heart-shaped or continuous cam, waves, and eccentrics. Simple screw and nut. Left and right handed screws; differential screw of Prony, called the micrometric screw. Ratio of the velocities in these different organs.
The example of the cam and pile-driver will be particularly insisted upon; 1º, in the case where this cam and the extremity of the rod have any continuous form given by a simple geometrical drawing; 2º, in the case where this form is defined geometrically by the condition, that the velocity is to be transmitted in an invariable ratio, as takes place for cams in the form of epicycloids or involutes of circles.
Transformation of a circular progressive motion into another similar to the first.
1º, by contact of cylinders or cones, the two axes being situated in the same plane; 2º, by straps, cords, or endless chains, the axes being in the same situation; 3º, by cams, teeth, and grooves, at very slight intervals; 4º, by the Dutch or universal joint. Case, where the axes are not situated in the same plane; use of an intermediate axis with beveled wheels or a train of pulleys; idea of White or Hooke’s joint in its improved form. Endless screw specially employed in the case of two axes at right angles to one another. Combinations or groupings of wheels. Idea of differential wheels. Relations of velocities in the most important of these systems of transmission.
Transformation of circular progressive Motion into rectilinear or alternating circular motion.
Ordinary circular eccentric. Eccentrics with closed waves or cams. Examples and graphical exercises in the class-rooms relative to the alternate action of the traveling frames of saw-mills, of the slides or entrance valves of steam-engines. Cams for working hammers and bellows.
Transformation of alternating circular motion into alternating rectilinear motion, or into intermittent and progressive circular motion.
Pump rods with or without circular sectors, &c. Examples taken from large exhausting pumps, fire-engines, and common pumps. Suggestions as to the best arrangement of the parts. Lagarousse’s lever, &c. Application of the principle relative to the instantaneous center of rotation to give the relations of the velocities in certain simple cases.
Transformation of alternating circular or rectilinear motions into progressive circular motion.
The knife-grinder’s treadle. System of great machines worked with connecting rods, fly-wheel, &c. Watt’s parallelogram, and the simplest modifications of it for steamboats, for instance. The most favorable proportions for avoiding the deviation of piston-rods. Simplification of parts in the modern steam-engines of Maudsley, Cavé, &c. Variable ratios of the velocities.
Of organs for effecting a sudden change of motion.
Suspendors or moderators, &c. Dead wheels and pulleys, &c. Mechanisms for stretching cords or straps, and make them change pulleys during the motion. Brakes to windmills, carriages, &c., &c. Case where the axes are rendered movable. Means for changing the directions and velocity of the motions. Coupled and alternate pulleys; alternate cones; castors moving by friction and rotation upon a plate or turning-cone; eccentric and orrery wheels. Means of changing the motion suddenly and by intervals; wheels with a detent pile-drivers; Dobo’s escapement for diminishing the shock, &c.
Geometrical Drawing of Wheel-work.
General condition which the teeth of toothed wheels must satisfy. Consequence resulting from this for the determination of the form of the teeth of one of two wheels, when the form of the teeth of the other wheel is given.
Cylindrical action of toothed wheels or toothed wheels with parallel axes. External engagement of the teeth; internal engagement. Particular systems of toothed wheels; lantern wheels, flange wheels, involutes of circles. Reciprocity of action; case where the action can not be rendered reciprocal. Pothook action. Details as to the form and dimensions given in practice to the teeth and the spaces which separate them.
Conical action of toothed wheels, or toothed wheels with converging axes. Practical approximate method of reducing the construction of a conical to that of a cylindrical engagement of toothed wheels.
Means of observation and apparatus proper for discovering experimentally the law of any given movement.
Simple methods practiced by Galileo and Coulomb in their experiments relative to the inclined plane and the motion of bodies sliding down it. Various means of observing and discovering the law of the translatory and rotatory motion of a body according as the motion is slow or rapid. Determination of the angular velocity, &c. The counter in machines. Apparatus of Mattei and Grobert for assigning the initial velocity of projectiles (musket balls.) Colonel Beaufoy’s pendulum apparatus. Chronometrical apparatus for continuous indications by means of a pencil. Eytelwein’s apparatus with bands, and its simplest modifications. Apparatus with cylinders or revolving disks. Use of the tuning-fork for measuring with precision very small fractions of time.
(The principal sorts of the apparatus above described are made to act under the eyes of the pupils.)
II. EQUILIBRIUM OF FORCES APPLIED TO MATERIAL SYSTEMS
LESSON 21.
Résumé of the notions acquired upon the subject of forces, and their effects on material points.
Principle of inertia, notion of force, of its direction, of its intensity. Principle of the equality of action and reaction. What is meant by the force of inertia? Principle of the independence and composition of the effects of forces. Forces proportional to the acceleration which they produce on the same body. Composition of forces. Relation between the accelerating force, the pressure, and the mass. Definition of the work done by a force. The work done by the resultant is equal to the sum of the works done by the components. Moment of a force in relation to an axis deduced from the consideration of the work of the force applied to a point turning about a fixed line. The moment of the resultant of several forces applied to a point is equal to the sum of the moments of the components. Corresponding propositions of geometry.
LESSONS 22-25.
Succinct Notions upon the Constitution of Solid Bodies.
Every body or system of bodies may be regarded as a combination of material points isolated or at a distance, subject to equal and opposite mutual actions. Interior and exterior forces. Example of two molecules subject to their reciprocal actions alternately, attractive and repulsive, when the forces applied draw them out of their position of natural equilibrium. Different degrees of natural solidity, stability, or elasticity; they can only be appreciated by experience.
Equilibrium of any Systems whatever of Material Points.
General theorem of the virtual work of forces applied to any system whatever of material points. It is applicable to every finite portion of the system, provided regard be had to the actions exercised by the molecules exterior to the part under consideration. Determination of the sum of the virtual works of the equal and reciprocal actions of two material points. Demonstration of the six general equations of equilibrium of any system whatever. They comprise implicitly every equation deduced from a virtual movement compatible with the pre-supposed solidification of the system.
Theorem on the virtual work in the case of systems where one supposes ideal connections, such as the invariability of the distance of certain points of the system from one another, and the condition that certain of them are to remain upon curves either fixed or moving without friction.
Equilibrium of Solid Bodies.
The six general equations of equilibrium are sufficient as conditions of the equilibrium of a solid body. Theory of moments and couples.
APPLICATIONS.
LESSONS 26-29. Equilibrium of Heavy Systems.
Recapitulation of some indispensable notions for the experimental determination of the center of gravity of solids when the law of their densities is unknown. Re-statement of the theorem relative to the work done by gravity upon a system of bodies connected or otherwise. In machines supposed without friction submitted, with the exception of their supports, to the action of gravity alone, the positions of stable or unstable equilibrium correspond to the highest or lowest points of the curve which would be described by the center of gravity of the system when made to move. Influence of defect of centering in its wheels, upon the equilibrium of a machine. Case where the center of gravity always remaining at the same height the equilibrium is neutral. Examples relative to the most simple drawbridges, &c.
Equilibrium of Jointed Systems.
Equilibrium of the funicular polygon deduced from direct geometrical considerations: Varignon’s theorem giving the law of the tensions by another polygon whose sides are parallel and proportional to the forces acting upon the vertices of the funicular polygon. Case of suspension bridges; investigation of the curve which defines the boundary of the suspension chain; tensions at the extremities.
Equilibrium of systems of jointed rigid bodies without friction. Determination of the pressure upon the supports and the mutual actions at the joints.
Equilibrium and stability of solid bodies submitted to the action of stretching or compressing forces.
Permanent resistance and limiting resistance of prisms to longitudinal extension and compression. Equilibrium and stability of a heavy solid placed upon a horizontal plane and submitted to the action of forces which tend to overset it. Resultant pressure and mean pressure; hypothetical distribution of the elements of the pressure on the base of support. Conditions of stability, regard being had to the limit of resistance of solid materials, co-efficient of stability deduced from it.
III. ON THE WORK DONE BY FORCES IN MACHINES
LESSONS 30-39. General Notions.
Principle of work in the motion of a material point. Extension of this principle to the case of any material system whatever in motion. Considerations relative to mechanical work in various operations, such as the lifting of weights, sawing, planing, &c. It is the true measure of the productive activity of forces in industrial works. It may always be calculated either rigorously or approximately when the mathematical or experimental law which connects the force with the spaces described is given. Uniform work, periodical work, mean work, for the unit of time. Horse-power unit. Examples and various exercises, such as the calculation of the work corresponding to the elasticity of gases on the hypothesis of Mariotte’s law, the elongation of a metallic prism, &c.
Dynamometrical Apparatus.
Dynamometer of traction by a band or rotating disc or register. Dynamometer of rotation with simple spring, with band or register. Dynamometer of rotation with multiple springs and with register for the axles of powerful machines. Improved indicator of Watt.
(These pieces of apparatus are made to act under the eyes of the pupils.)
Work of Animal Prime Movers upon Machines.
Results of experience as to the values of the daily work which animal motors can supply under different circumstances without exceeding the fatigue which sleep and nourishment are capable of repairing.
Theory of the Transmission of Work in Machines.
Principal resistance. Secondary resistances. Two manners in which bodies perform the duty of motors. Ratio of work done to work expended always inferior to unity. Different parts of machines; receiver; organs of transmission; tools as machines.
Calculation of the Work due to the passive resistances in machines.
Résumé of the notions previously acquired on friction. Application to the inclined plane, to the printing-press, to guides or grooves, to the screw with a square thread; different cases of uniform motion being impossible under the action of forces of given directions. Friction of trunnions, pivots, eccentrics, and insertions of winch-handles. Prony’s dynamometrical brake; conditions of its application. Resistance to rolling; its laws according to experiment. Use of rollers and friction-wheels; their practical inconveniences.
Mixed friction of toothed wheels; the Dobo escapement: friction of the teeth in the endless screw.
Stiffness and friction of cords. Results of experience. Friction of cords and straps running round drums. Different applications; brakes; transmission by cords, endless straps, or chains.
Examples and exercises; effects of passive resistances in the capstan, the crane, pulleys, &c.
LESSON 40. Revision.
SECOND YEAR.
I. DYNAMICS.-- DYNAMICS OF A MATERIAL POINT
LESSONS 1-2. Completion of the Notions acquired on this Subject.
Differential equations of the motion of a material point submitted to the continued action of one or more forces. The acceleration of the projection of a point upon any axis or plane is due to the projection of the forces on this axis or plane. The acceleration along the trajectory is due to the tangential force. Relation of the curvature to the centripetal force. Introduction of the force of inertia into the preceding enunciations.
The increase of the quantity of motion projected upon an axis or taken along the trajectory is equal to the impulsion of the projected resultant, or to that of the tangential force. The total impulsion of a force is got by methods of calculation and of experiment analogous to those which relate to work. The increase of the moment of the quantity of motion in relation to any axis is equal to the total moment of the impulsions of the forces during the same interval of time; direct geometrical demonstration of this theorem. In decomposing the velocity of the moving body into a velocity in the plane passing through the axis of the moments, and a velocity of revolution perpendicular to this plane, we may replace the moment of the quantity of motion in space by the quantity of motion of revolution. Particular case known under the name of the principle of areas.
Extension of the preceding theorems to the case of relative motions. Apparent forces which must be combined with the real ones that the relative motion of a point may be assimilated to an absolute motion. Particular case of relative equilibrium. Influence of the motion of the earth upon the accelerating force of gravity.
DYNAMICS OF ANY MATERIAL SYSTEMS.
LESSONS 3-8.
Principle or general rule which reduces questions in dynamics to questions in equilibrium by the addition of the forces of inertia to the forces which really act on the system. Equation of virtual work which expresses this equilibrium; it comprises in general the external and internal forces.
General Theorems.
These theorems, four in number, are founded upon the principle of the equality of action and reaction applied to internal forces. They may be deduced from the preceding rule, but the three last are obtained more simply by extending to a system of material points analogous theorems established for isolated material points.
General theorem of the motion of the center of gravity of a system. Particular case called principle of the conservation of the motion of the center of gravity.
General theorem on the quantities of motion and impulsions of exterior forces projected on any axis.
General theorems of moments of quantities of motion and impulsions of exterior forces, projected on any axis whatever.
General theorems of the moments of quantities of motion and impulsions of exterior forces about any axis. Analogy of these two theorems with the equations of the equilibrium of a solid, in which the forces are replaced by impulsions and quantities of motion.
Composition of impulsions, of quantities of motion, or the areas which represent them. All the equations which can be obtained by the application of the two theorems relative to quantities of motion and impulsions, reduce themselves to six distinct equations. Particular case called principle of the conservation of areas. Fixed plane of the resulting moment of the quantities of motion called plane of maximum areas.
General theorem of work and vis viva. Part which appertains to the interior forces in this theorem. Particular case called principle of the conservation of vires vivæ, where the sum of the elements of work done by the exterior and interior forces is the differential of a function of the co-ordinates of different points of the system. Application of the theorem of work to the stability of the equilibrium of heavy systems.
Extension of the preceding theorems to the case of relative motions. Particular case of relative equilibrium. Motion of any material system relative to axes always passing through the center of gravity, and moving parallel to themselves. Invariable plane of Laplace. Relation between the absolute vis viva of a material system, and that which would be due to its motion, referred to the system of movable axes above indicated.
Examples and Applications.
The following examples, amongst others, to be taken as applications or subjects of exercises relative to the general principles which precede.
Walking. Recoil of guns. Eolypile. Flight of rockets.
Pressure of fluid veins, resistance of mediums, &c. Direct collision of bodies more or less hard, elastic, or penetrable. Exchange of quantities of motion. Loss of vis viva under different hypotheses. Influence of vibrations and permanent molecular displacements.
Pile driving; advantage of large rammers. Comparison of effects of the shocks and of simple pressures due to the weight of the construction. Oblique collision, and ricochet. Data furnished by experiment.
Oscillations of a vertical elastic prism suspended to a fixed point, and loaded with a weight, neglecting the inertia, and the weight of the material parts of this prism. Case of a sudden blow. What is meant by the “resistance vive” of a prism to rupture? Results of experiments.
Work developed by powder upon projectiles, estimated according to the vis viva which it impresses on them, as well as upon the gun and the gases upon hypothesis of a mean velocity.
SPECIAL DYNAMICS OF SOLID BODIES.
LESSONS 9-12. Simple Rotation of an invariable Solid about its Axis.
In applying to this case the first general rule of dynamics, the theorem of the moments of the quantities of motion, and the theorem of work, we are led to the notion of the moment of inertia; explanation of the origin of this name. The angular acceleration is equal to the sum of the moments of the exterior forces divided by the moment of inertia about the axis of rotation. Sum of the moments of the quantities of motion relative to this axis. Vis viva of a solid simply turning about an axis. What is meant by radius of gyration?
Remind of the geometrical properties of moments of inertia, of the ellipsoid which represents them, of the principal axes at any point, of those which are referred to the center of gravity.
Pressure which a rotating body exercises on its supports. Reduction of the centrifugal and tangential forces of inertia to a force which is the force of inertia of the entire mass accumulated at the center of gravity, and a couple.
Particular case where the forces of inertia have a single resultant; different examples. Center of percussion. Compound pendulum; length of the corresponding simple pendulum. Center of oscillation; reciprocity of the centers or axes of suspension and oscillation. Pressure upon the axis. Influence of the medium; experience proves that the resistance, varying with the velocity, changes the extent of the oscillations, but does not sensibly affect the time. Experimental determination of the center of oscillation and the moment of inertia about an axis.
Motion of an invariable Solid subject to certain Forces.
General notions on this subject. Motion of the center of gravity; motion of rotation about this point.
LESSONS 13-19. Various Applications.
Motion of a homogeneous sphere or cylinder rolling upon an inclined plane, taking friction into account.
Motion of a pulley with its axis horizontal, solicited by two weights suspended vertically to a thread or fine string passing round the neck of the pulley, the axle of which rests upon movable wheels. Atwood’s machine serving to demonstrate the laws of the communication of motion.
Motion of a horizontal wheel and axle acted on by a weight suspended vertically to a cord rolled round the axle, or upon a drum with the same axis, and presenting an eccentric mass. To take account of the variable friction of the bearings, and the stiffness of the cord, with recourse, if necessary, to approximation by quadratures. Oscillations of the torsion balance.
Balistic pendulum. Condition that there may be no shock on the axis. Experimental determination of the direction in which the percussion should take place.
Theory of Huyghen’s conical pendulum considered as a regulator of machinery. How to take account of the inertia and friction of the jointed rods, as well as of the force necessary to move the regulating lever, &c.; appreciation of the degree of sensibility of the ball apparatus with a given uniform velocity.
Windlass with fly-wheel. Dynamical properties of the fly-wheel. Reduced formulæ for a crank with single or double action. Advantages and disadvantages of eccentric masses. Tendency of the tangential forces of inertia to break the arms. Numerical examples and computations.
Mutual action of rotating bodies connected by straps or toothed wheels in varying motion.
The wedge and punching-press. Stamping screw or lever used in coining, cams, lifting a pile or a hammer. To take account of the friction during the blow, and afterwards to estimate the loss of vis viva in cases which admit of it.
II. SPECIAL MECHANICS OF FLUIDS.--HYDROSTATICS
LESSONS 20-22.
Principle of the equality of pressure in all directions. Propagation of the pressures from the surface to the interior of a fluid, and upon the sides of the vessel. Equations of equilibrium for any set of forces. Pressure exerted in the containing orifices. Measure of the pressure upon a plain portion of surface inclined or vertical (sluice-gate, embankments, &c.) Center of push or pressure. Pressure against the surfaces of a cylindrical tube. Effect, and resistance to oppose to the pressure. Manometer and piezometer. Equilibrium of a body plunged in a heavy fluid or floating at its surface. Stability of floating bodies. Metacenter. Laws of the pressure in the different atmospheric strata.
HYDRAULICS.
LESSONS 23-27. Flow of Fluids through small Orifices.
Study of the phenomena which accompany this flow in the case of a thin envelop and a liquid kept at a constant level. Conditions of this constancy in the level, and the permanence of the motion in general. Motion of the lines of fluid; form; contraction; reversal and discontinuity of liquid veins. Fundamental formulæ for liquids and gases based upon the principle of vis viva, and Bernoulli’s hypothesis of parallel sections or Borda’s of contiguous threads. Torricelli’s theorem relative to small orifices. What is called the theoretical expenditure, effective expenditure, and co-efficient of geometrical contraction. Co-efficient deduced from the effective expenditure. Its variations with the volume of the fluid contents, and the form of the inner surfaces of the reservoir. Results of the experiments of Michelotti, Borda, Bossut, &c. Phenomenon of adjutages. Venturi’s experiments; influence of atmospheric pressure; loss of vis viva; reduction of the velocity and augmentation of the expenditure. Results of experience relative to the co-efficient of expenditure, the form and range of the parabolic jets, showing the initial vis viva, and the loss of vis viva.
Large orifices.--Sluice holes and floodgates; reservoirs or open orifices; expenditure; practical formulæ and results of experiment. Influence of the proximity of the sides and the walls. Arrangement to avoid the effects of contraction or the losses of vis viva.
Flow through conducting Pipes and Open Canals.
Practical formulæ relative to the case of uniform sections of great length. Measure of the pressures at different points of a conduit-pipe. Expression for the losses of effect due to corners and obstructions. Flow of gases. Principal methods of measuring the volume consumed adopted in practice. Floats. Pitot’s tube. Woltman’s mill. Register mill in air or gas. Waste in such instruments. Modulus and scale for water-supply.
III. DIFFERENT MACHINES CONSIDERED IN THE STATE OF MOTION
LESSON 28. General Considerations. Résumé of the Notions acquired on this Subject.
Equation of vis viva, and transmission of work in machines, account being taken of the different causes of power and resistance. Physical constitution of machines; receiver, communicators, and operator. Influence of the weights, of frictions, of shocks, and any changes in the vis viva. Parts with continuous or uniform motion, with alternating or oscillating motion. Laws of the motion on starting from rest, and when the stationary condition is established. The positions to which the maximum and minimum of the vis viva correspond are those in which there is equilibrium between all the forces, exclusive of the forces of inertia. Advantage of uniform or periodic motion. General methods for regulating the motion; symmetrical distribution of the masses and strains; flys and various regulators. Brakes and moderators; their inconveniences. Object and real advantages of machines.
LESSONS 27-35. Hydraulic Wheels.
Vertical wheels with float-boards, with curved ladles, and with spouts. Figure of the surface of the fluid in these latter. Horizontal wheels working by float-boards, buckets, and reaction. Turbines. Description, play, and useful effects compared according to the results of experiment. Vertical wheels of windmills and steamboats. Screw propeller.
Windmills.
Description. Result of Coulomb’s observations.
On the principal kinds of Pumps.
Special organs of pumps. Valves and pistons, force pump, sucking pump; limit to the rise of the water. Sucking and force pump. Dynamical effects. Indication as to the losses of vis viva and the waste in different pumps. Explanation of the hydraulic ram. Air vessel. Fire pumps. Double action pumps.
Various Hydraulic Machines.
Hydraulic press. Water engine. Exhausting machines; norias; under and overshot wheels; Archimedes’ screw, construction and experimental data.
LESSONS 36-39. Steam Engines.
Succinct description of the principal kinds of steam-engine with or without detent. Effects and advantages of the detent. Condenser. Air Pump. Furnace and feeding-pump.
Variable detent. Formulæ and experimental results.
LESSONS 40-42. Revision.
Reflections on the totality of the subjects of the course.
IV. PHYSICS.--FIRST YEAR.
GENERAL PROPERTIES OF BODIES.--HYDROSTATICS.--HYDRODYNAMICS.
LESSONS 1-5. Preliminary Notions.
Definitions of physics. Phenomena. Physical laws. Experiments are designed to make them spring out of the phenomena. Method of induction. Physical theories; different character of the experimental and mathematical methods.
General Properties of Bodies.
Extension. Measure of lengths. Vernier. Cathetometer. Micrometer screw. Spherometer. Dividing engine.
Divisibility. Porosity. Ideas generally received on the molecular constitution of bodies. These conceptions, which are purely hypothetical, must not be confounded with physical laws. Elasticity. Mobility. Inertia. Forces; their equilibrium, their effects, their numerical estimation.
Weight or Gravity.
Direction of gravity. Plumb-line. Relation between the direction of gravity and the surface of still water.
Weight. Center of gravity.
Experimental study of the motion produced by weight. In vacuum, all bodies fall with the same velocity. Disturbing influence of the air. Inclined plane of Galileo. Atwood’s machine. To prove by experiment; 1º the law of the spaces described; 2º the law of velocities. Morin’s self-registering apparatus with revolving cylinder.
Law of the independence of the effect produced by a force upon a body, and the motion anteriorily acquired by this body. Law of the independence of the effects of forces which act simultaneously upon the same body. Experimental demonstration and generalization of these laws. Law of the equality of action and reaction.
Mass. Acceleration. For equal masses the forces are as the accelerations which they produce. Relation between the force, mass, and acceleration. Collision.
General laws of uniformly accelerated motion. Formulæ.
Pendulum. Law of the isochronism of small oscillations and law of the lengths deduced from observation.
Method of coincidences or beats. Use of the pendulum as the measure of time. Simple pendulum; formulæ. Compound pendulum: the laws of the oscillations of a compound pendulum are the same as the laws of the oscillations of a simple pendulum whose length may be calculated.
Determination by means of the pendulum of the acceleration produced by gravity. This acceleration is independent of the nature of the body.
Remark that the formulæ for the motion of oscillation apply to the comparison of forces of any kind, that may be regarded as constant and parallel to themselves in all positions of the oscillating body.
Identity of gravity and universal attraction.
Measure of weights. Balance. Conditions to be attended to in making it. Absolute sensibility; proportional sensibility. Method of double weighing. Details of the precautions necessary in order to obtain an exact weight.
Different States of Bodies. Hydrostatics.
Solids. Cohesion. Transmission of external pressures.
Elasticity. The true laws of elasticity are unknown. Empirical laws in certain simple cases, and for a very small action. Elasticity of compression, extension, torsion. Experimental determination of the co-efficients of elasticity. Limits of elasticity. Limits of tenacity.
Ductility. Temper. Cold hammering. Annealing.
Liquids. Fluidity. Viscosity. Physical laws which form the basis of hydrostatics:--1º the transmission of external pressures is equal in all directions; 2º the pressure exercised in the interior of a liquid upon an element of a surface is normal to that element, and independent (as to amount) of its direction. These principles are demonstrated by the experimental verification of the consequences drawn from them.
Application to heavy liquids. Free surface, and surface de niveau. Pressure upon the parts of the containing vessel, and upon the bottom in particular; hydrostatic paradox; verificatory experiments. Haldat’s apparatus. Hydrostatic press.
Application to immersed or floating bodies (principle of Archimedes;) verificatory experiments. (In treating of the equilibrium of floating bodies, the conditions of stability are not gone into.)
Superposed liquids.
Communicating vessels. Water level. Spirit level; its use in instruments.
Densities of solids and liquids. Anemometers.
Compressibility of liquids. Piezometer. Correction due to the compressibility of the solid envelop.
Gas. Expansibility. Other properties common to liquids and gases. Principle of the equal transmission of pressures in all directions. Weight of gases. Pressure due to weight (principle of Archimedes.) Weight of body in air and in vacuum. Aerostation.
Superposed liquids and gases.
Communicating vessels. Barometer.
Detailed construction of barometer. Barometers of Fortin, Gay-Lussac, Bunten. Indication of the corrections necessary.
Mariotte’s law. Regnault’s experiments.
Manometer with atmospheric air--with compressed air. Bourdon’s manometer.
Law of the mixture of gases.
Air pump. Condensing pump.
Primary Notions of Hydrodynamics.
Toricelli’s principle. Mariotte’s vessel and syphon. Uniform flow of liquids. The same of gases.
Molecular Phenomena.
Cohesion of liquids. Adhesion of liquids to solids. Capillary phenomena. Apparent attractions and repulsions of floating bodies.
Adhesion of drops.
Molecular actions intervene as disturbing forces in the phenomena of the equilibrium and motion of liquids.
HEAT.
EFFECTS OF HEAT ON BODIES.
LESSONS 6-9. Generalities.
General effects. Arbitrary choice of one of these effects to define the thermometric condition of a body. Conventional adoption of a thermometer. Definition of temperature.
Dilating Effects.
Definition of the co-efficients of linear, superficial, and cubic dilatation. Approximate relation between the numerical values of these three co-efficients. The value of the co-efficient of dilatation depends upon the thermometric substance and the temperature selected as the zero point. It becomes nearly independent of the zero point when the co-efficient is very small.
Relation between volume, density, and temperature. Linear dilatation of solid bodies. Ramsden’s instrument. Cubical dilatation of liquids. Dulong and Petit’s experiments on mercury. Discussion. Regnault’s experiments.
Cubical dilatation of solids and of other liquids when that of mercury is given.
Relations between the volume, density, and elasticity of a gas, and its temperature.
Cubical dilatation of gases. Experiments of Gay-Lussac, Rudberg, and M. Regnault. Advantage of varying the methods of experimenting in these delicate researches.
Methods based upon the changes of volume under a constant pressure, and upon the changes of pressure for a constant volume.
The disagreement of these two methods is due to deviations from the law of Mariotte.
The constancy of the co-efficients of dilatation previously defined is only approximately true.
Necessity of employing two different co-efficients of dilatation according as consideration is being had to the variations of volume to a given pressure, or of pressure to a given volume.
Empirical formulæ for the dilatation of liquids.
Graphical constructions.
LESSON 10. Thermometers.
Construction of thermometers. Mercurial thermometer. Details of construction. Fixed points. Different scales; their relation. Arbitrary scales. Change which takes place in the zero point. Different precautions to be observed in using the mercurial thermometer.
General want of comparability of mercurial thermometers with tubes of different material.
Air thermometers. They are comparable with one another within the limits of the errors of experiment, whatever the nature of the tube employed. This property entitles the air thermometer to a preference for all accurate measures. Comparison of the air and mercurial thermometers.
THERMOSCOPE, DIFFERENTIAL THERMOMETER, PYROMETERS, BREGUET’S THERMOMETER.
LESSONS 11-13. Changes of State produced by Heat.
Exposition of the phenomena which accompany the liquefaction of solids and the solidification of liquids. Constancy of the temperature whilst the phenomenon is going on.
Sudden melting and freezing. Persistance of the liquid state beneath the melting point.
Influence of pressure.
Exposition of the phenomena which accompany the conversion of liquids or solids into vapor, and the inverse passage from the gaseous to the liquid or solid state. Constancy of the temperatures whilst the phenomenon is going on.
Influence of pressure.
Phenomena of ebullition in free space. Augmentation of the temperature and pressure in a confined space. Papin’s digester.
Properties of vapors in spaces and in gases. Saturated vapors. Their tension does not depend upon the space which they occupy, but only upon their temperature.
Effects of a diminution or increase of pressure without change of temperature; the same without change of pressure. Effects of lowering the temperature in a limited region of space occupied by vapor.
Tension of a saturated vapor at the boiling point of its liquid.
Measure of the tensions of the vapor of water. Experiments of Dalton, Gay-Lussac, Dulong, and Arago, and of M. Regnault.
Tables of the tensions of steam. Empirical formulæ. Graphical constructions.
It is assumed that non-saturated vapors are subject to the same laws as gases.
APPLICATIONS. CORRECTION OF THE BOILING-POINT IN THE CONSTRUCTION OF THERMOMETERS. BAROMETRICAL THERMOMETERS.
LESSONS 14-16. Various Applications of the Laws previously established.
A phenomenon can not always be separated from the accessory phenomena which concur with it in producing the final result. Necessity of corrections to render complex results comparable inter se.
Density of solids when regard is had to the temperature and weight of the gases displaced by them.
Precautions to be attended to in the experiments. Empirical formulæ for the density of liquids. Maximum density of water. The temperature corresponding to the maximum must be determined graphically, or by interpolation.
Corrections for measures of capacity, for barometric measures.
The uncertainty of the corrections can not, in any considerable degree, affect the densities of solids and liquids.
Density of gases. Biot and Arago’s experiments. Special difficulties of the question. The uncertainty of the corrections may sensibly affect the results. Regnault’s method.
The same method may be applied to the determination of the co-efficient of dilatation for gases.
Density of vapors. Definition founded on the hypothetical application of the same laws to gases and vapors. Formulæ. Experimental method of Gay-Lussac and of Dumas. Corrections. Comparison of the two methods. Necessity of conducting the experiments at a distance from the saturation point. Latour’s experiments. Relations between the weight and volume of a gas, and its temperatures; between the weight and volume of a gas mixed with vapors, and its temperature. Various problems.
Hygrometry. Chemical hygrometry. Hygrometry by the dew-point. Psychrometry.
PROPAGATION OF HEAT.
LESSONS 17-18. Propagation at a Distance.
Rapid propagation of heat at a distance, in vacuum, in gases, in certain liquid or solid mediums. Experiments which establish this.
Rays of heat. Velocity of propagation. Intensity of heat received at a distance. Intensity of heat received or emitted obliquely. Emitting power, power of absorption, reflection, diffusion. The emitting and absorbing power are expressible by the same number in terms of their proper units respectively.
Analysis of calorific radiations by absorption. Different effects of deathermanous or thermochroic medium. Different influences of increasing thicknesses of the combination of different mediums. Radiations proceeding from different sources, various effects of different mediums on these radiations.
The calorific radiations emanating from different sources, have all the characters of differently colored heterogeneous rays of light.
THEORY OF RADIATION AND OF THE DYNAMICAL EQUILIBRIUM OF TEMPERATURES. APPARENT REFLECTION OF COLD.
LESSON 19. Law of Cooling.
Definition of the rate of cooling. Many causes may conspire in the cooling of a body.
Cooling in space. Newton’s law only an approximation. Experimental investigation of the true law. Method to be followed in this investigation. The velocity of cooling is not a datum directly observable. It must be deduced provisionally from an empirical relation between the temperature and the time. Preliminary experiments. Course of the definitive experiments. Elementary experimental laws.
Hypothetical form of the function which expresses the velocity of cooling. To determine by means of the preceding experimental laws the unknown form of the function which expresses the law of radiation. Relation between the temperatures and the times. This relation only contains data immediately observable, and may be verified à posteriori.
The contents which enter into the preceding relation depend upon thermometric constants and the nature of the radiating surface.
The contact of a gas modifies the law of cooling.
LESSONS 20-21. Propagation by Contact.
Slow propagation of heat in the interior of bodies, in solids, liquids, and gases. Confirmatory experiments. Hypothesis of partial radiation. Theoretical law resulting from this hypothesis upon the decrease of temperatures in a solid limited by two indefinite parallel planes maintained at constant temperatures. Determination of the co-efficient of conductibility by the experimental realization of these conditions. This experiment determines a numerical value of the co-efficients; it is not of a nature to serve as a check upon the theoretical principles. Enunciation of the law resulting from the same theoretical principles upon the decrease of temperatures in a thin bar heated at one end.
CALORIMETRY.
LESSONS 22-23. Specific Heats.
Comparison of the quantities of heat. The quantities of heat are not proportioned to the temperatures. Definitions of the unity of heat. General method of mixtures to estimate the quantities of heat. Experimental precautions and corrections.
Application of the general method of mixtures. Specific heats of solids and liquids. Law of the specific heat of atoms. Heat absorbed by expansion, restored by the compression of bodies. Experiments on gases. Specific heats of gases under constant pressure. Measure of specific heats of gases under constant pressure. Special difficulties of the question. Succinct indication of one of the methods. Specific heats to a constant volume.
LESSON 24. Latent Heat.
Component heat of liquids absorbed into the latent state during fusion, restored to the free state during solidification.
Influence of the viscous state. Latent heat of ice. Ice calorimeter; its defects.
Component heat of vapors, absorbed into the latent state during vaporization, restored to the free state during condensation. Measure of the latent heat of vapors. Regnault’s experiments.
Empirical laws on the latent heat of vaporization.
Applications of Calorimetry.
Means of producing heat or cold; 1, by changes in density; 2, by changes of state. Freezing mixtures. Vaporization of liquids. Condensation of vapors.
Steam-boilers. Warming by hot air and hot water. Various problems. Sensations produced by a jet of vapor.
Different physical and chemical sources of heat; percussion, friction, chemical combinations, animal heat, natural heat of the globe, solar heat, &c. It will be remarked that mechanical work may become a source of heat, and heat a source of mechanical work.
STATICAL ELECTRICITY.--MAGNETISM.--STATICAL ELECTRICITY.
LESSONS 25-27.
General phenomena. Distinction of bodies into conductors and non-conductors. Distinction of electricity into two kinds. Separation of the two electricities by friction. Hypothesis of electric fluids. Effects of vacuum of gases and vapors of points. Electrical attractions and repulsions. Electrization by influence. Case where the influenced body is already electrized. Sparks; power of points. Electrization by influence preceding the motion of light bodies.
Electroscopes.
Electrical machines of Van-Marum, Nairne, Armstrong.
Condenser. Accumulation of electricity upon its surface. Leyden jar. Batteries. Electrical discharges. Effects of electricity.
Condensing electroscope. Electrophorus.
Velocity of statical electricity.
Atmospherical electricity. Phenomena observed with a serene sky. Electricity of clouds. Storms. Lightning. Thunder. Effects of thunder. Return-shock. Lightning conductor.
Different sources of statical electricity.
MAGNETISM.
LESSONS 28-30.
Natural magnets. Action upon iron and steel. Artificial magnets. The attractive action appears as if it were concentrated about the extremities of magnetic bars. First idea of poles.
Direction of a magnetized bar under the earth’s action. Reciprocal action of the poles of two magnets. Names given to the poles.
Phenomena of influence. Action of a magnet upon a bar of soft iron; upon a bar of steel. Coercive force. Effects of the rupture of a magnetized bar. Theoretical ideas on the constitution of magnets. More precise definition of the poles.
Action of the earth upon a magnet. The earth may be considered as a magnet. Its action may be destroyed by means of a magnet suitably placed. Astatic needles. The magnetic action of the earth is equivalent to a couple. Three constants define the couple of terrestrial action. Declination. Inclination. Intensity. Measure of the declination; of the inclination.
Magnetic metals. Influence of hammering, tempering, &c. Methods of magnetizing. Saturation. Loss of magnetism. Influence of heat. Magnetic lines. Armatures.
Magnetization by the earth’s influence. Means of determining the magnetic state of a body.
Measure of Magnetism and Electricity.
LESSONS 31-32.
Coulomb’s balance. Distribution of magnetism on a magnetized bar; distribution of electricity at the surface of isolated conductors. Comparative discussion of the conditions of the two problems and the methods of experiment.
Laws of the magnetic attractions and repulsions. Law of electric attractions and repulsions. Comparative discussion of the conditions of the two problems, and the methods of experiment.
Determination of the law of magnetic attractions and repulsions by the method of oscillations.
Comparison of the magnetic intensity at different points of the earth’s surface.
LESSONS 33-34. Revision.
Considerations on the totality of the subjects of the course.
SECOND YEAR.
DYNAMICAL ELECTRICITY.--GALVANISM.
LESSONS 1-2.
Chemical sources of electricity. Experimental proofs. Arrangement devised by Volta to accumulate, at least in part, at the extremities of a heterogeneous conductor the electricity developed by chemical actions.
Pile. Tension at the two isolated extremities; at one single isolated extremity; at the two extremities reunited by a conductor. Continuous current of electricity. Poles. Direction of the current, &c.
Various modifications of the pile of Volta. Woollaston’s pile, Münch’s pile, &c. Dry piles; their application to the electroscope.
Principal effects of electricity in motion, and means of making the currents perceptible. Experiment of Oersted. Galvanoscopes.
Currents produced by heat in heterogeneous circuits. Thermo-electric piles. Thermometric graduation of thermo-electric piles.
Currents produced by the sources of statical electricity.
PROPERTIES OF CURRENTS.
LESSON 3. 1. Chemical Actions.
Definitions. Phenomena of decomposition and transference. Reaction of the elements transferred upon electrodes of different kinds.
Principles of electrotyping.
Causes of the variation of the current in ordinary piles; means of remedying this; Daniell’s pile. Bunsen’s pile.
LESSONS 4-8. 2. Mechanical Properties.
Reciprocal actions of rectilinear or sinuous currents parallel or inclined. Reaction of a current on itself.
Reciprocal actions of helices or solenoids. Continuous rotation of currents by their mutual action; by reaction. Analogy of magnets and solenoids. Electro-dynamical theory of magnetism. Action of magnets upon currents and solenoids. Action of currents upon magnets. Experiments of Biot and Savart. Continual rotation of a current by a magnet; of a magnet by a magnet.
Action of the earth upon currents; it acts as a rectilinear current directed from east to west, perpendicularly to the magnetic meridian.
Continual rotation of a current by the action of the earth.
Astatic conductors.
LESSONS 9-10. 3. Magnetic Properties.
Action of an interposed conductor upon iron filings.
Electro-magnets. Magnetization temporary or permanent. Principles of the electric telegraph. Electrometers. Reference to diamagnetic phenomena.
4. Electro-motive Properties.
Phenomena of induction by currents, by magnets. Phenomena of magnetism in motion. Induction of a current upon itself.
Induction of different orders.
Interrupted currents. Clarke’s machine.
LESSON 11. 5. Calorific Properties.
Influence of the nature of the interposed conductor; of its section; of the intensity of the current. Unequal temperatures at the different junctions of a heterogeneous circuit.
6. Luminous Properties.
Incandescence of solid conductors. Spectrum of the electric light. Voltaic arc. Transfer of ponderable matter. Action of the magnet upon the Voltaic arc.
7. Physiological Action of Currents.
Some words on this subject. Muscles and nerves. Actions of discontinuous currents. Reotomic contrivances.
Reometry.
Compass of sines, of tangents. Experimental graduation of galvanometers.
The dynamical intensity of a current diminishes when the length of a current increases. Reostat.
Laws of the dynamical intensity of a current in a homogeneous circuit. Reduced length and resistance of a circuit. Specific co-efficients of resistance. Laws of the dynamic intensity of a current in a heterogeneous circuit.
The intensity of currents is in the inverse ratio of the total reduced length, and proportional to the sum of the electromotive forces. Formula of the pile. Discussion of the case of hydro-electric piles-- thermo-electric piles. Conditions for the construction of a pile, with reference to the effects to be produced. Conditions for the construction of a galvanometer with reference to its intended application.
Laws of secondary currents in the simplest cases. The chemical intensity of a current is proportional to its dynamical intensity.
ACOUSTICS.
LESSONS 12-15.
Noise, sound, quality of the sound, pitch, intensity, timbre. A state of vibration in a solid, liquid, or gaseous body is accompanied with the production of sound.
The pitch depends on the number of vibrations. Unison. Instruments for counting the vibrations:--1st. Graphic method. 2nd. Toothed wheels. 3rd. Lever. Feeling of concord. Musical scale. Gamut. Limit of appreciable sounds.
Study of vibrating motions in solids. Vibrating cords. Vibrations transversal, longitudinal. Experimental laws. Sonometer.
Spontaneous division of a cord into segments. Fundamental sounds. Harmonic sounds.
Straight and curved rods. Transversal and longitudinal vibrations. Experimental laws. Division into segments. Nodes. Ventral segments. Membranes.
Plane and curved plates. The vibrations divide them into “concamerations.” Nodal lines. Harmonic sounds.
Study of the vibrations in liquids and in gases.
Theoretical ideas upon the propagation of a vibratory motion in indefinite elastic media, on an indefinite cylindrical tube. Waves of condensation of dilatation. Progressive nodes and ventral divisions. Laws of the intensities of sound. Direct measure of the velocity of the propagation of sound in water. Measure of the velocity of the propagation of sound in air. Formulæ without demonstration. Comparison of the formulæ with experiment.
Sonorous waves reflected in an indefinite medium.
Fixed nodes and ventral divisions. Sonorous waves reflected in closed and open tubes. Fixed nodes and ventral divisions; the vibratory state and density thereat.
Series of sounds afforded by the same tube. Effect of holes.
Sonorous reflected waves in rods. Series of sounds afforded by the same rod vibrating longitudinally. Indirect measure of the velocity of sound in gases, liquids, and solids.
Experiments on the communication of vibrating motion in heterogeneous mediums, on the general direction of the vibrating motion communicated.
Intensification of sounds. Interferences. Beats. Different stringed and wind instruments. Means of setting them in vibration.
A few words on the organs of voice and hearing. Incompleteness of our knowledge on this subject.
OPTICS.
LESSONS 16-17. Propagation of Light.
Propagation of light in a straight line. Rays of light. Geometrical theory of shadows. Velocity of light. Rœmer’s observations. Laws of intensity of light. Photometers of Bouguer, Rumford. Intensity of oblique rays. Comparison of illuminating powers. Total brightness. Intrinsic brightness.
Reflection.
Reflection of light: its laws. Experimental demonstration. Images formed by one or more plane mirrors. To ascertain if a looking-glass has its two faces parallel.
Spherical mirrors. Foci, formulæ. Discussion. Images by reflection. Measure of the radius of a spherical mirror.
Definition of caustics by reflection. Definition of the two spherical aberrations in mirrors.
Woollaston’s goniometer.
LESSON 18. Refraction.
Refraction of light in homogeneous mediums. Descartes’ law. Experimental demonstration for solids and liquids.
Inverse return of the rays. Successive refractions. Indices of transmission in terms of the principal indices. Consequences of Descartes’ law. Total reflection. Manner of observing it.
Irregular refractions. Mirage.
Refraction is always accompanied with the accessory phenomenon of dispersion.
Geometrical consequences of the law of refraction. Focus of a plane surface. Focus of a medium bounded by two parallel plane surfaces; by two plane surfaces inclined in the form of a prism.
Foci of a spherical surface; of a medium limited by two spherical surfaces. Lenses.
Formula for lenses. Discussion. Varieties of lenses. Optic center. Images. Measure of the focal distance of lenses.
Definition of caustics by refraction. Definition of the two spherical aberrations of a lens.
LESSONS 19-20. Dispersion.
Unequal refrangibility of the differently colored rays which compose white light. Analysis of heterogeneous light by the prisms. Newton’s method. Solar spectrum. Homogeneity of the different colors. Second refraction of a homogeneous pencil. Experiment with crossed prisms. Precautions to be attended to in the experiments. The spectrum, obtained by Newton’s method, differs from the spectrum produced at the focus of a lens placed between the prism and the picture, according to the method of Fraunhofer. Reasons of the comparative purity of this latter spectrum. Fraunhofer’s lines. Different spectra of different sources of heterogeneous light. Marginal iridescence of a large pencil of natural light traversing a prism. Dispersion of light by lenses. Iridescence of focal images. Recomposition of light, by means of a prism at the focus of a spherical mirror or a lens, by the rapid rotation of a plane mirror, by the rotation of a disk with party-colored sectors. Compound colors.
Chemical and calorific radiations accompany luminous radiations.
Analysis of light by absorption. Characteristic action of transparent colored mediums upon different sorts of compound light. Different influences of increasing thickness. Effects of differently colored mediums upon heterogeneous light. Effects of differently colored mediums upon homogeneous rays separated by the prism.
LESSON 21. Measure of the Indices of Refraction.
Determination of the indices of refraction.
1. In solids. Measure of the refracting angles. Minimum of deviation. Measure of the corresponding deviation. Use of Fraunhofer’s lines.
2. In liquids.
3. In gases. Special difficulties of the question. Experimental method. Biot’s and Arago’s experiments.
Any power whatever of the index of refraction diminished by unit is sensibly proportional to the density of the gas. Method of Dulong founded on this remark.
LESSONS 22-23. Application of the preceding Laws.
Rainbow. Different orders of bow.
Achromatism.
Achromatic prisms. Diasperometer achromatism of lenses; how to verify it. Definition of secondary spectra: their nature gives the means of recognizing, whether flint or crown glass predominates, in an imperfectly achromatic lens.
Instruments essentially consisting of an achromatic lens. Magic lantern; megascope; solar microscope; camera obscura; collimators.
Vision.
Summary description of the principal optical parts of the eye. They act like the lens of a camera obscura to form an image upon the retina. Distinct vision; optometers; short sight; long sight; spectacles.
Binocular vision; perspective peculiar to each eye; estimation of distances; sensation of solidity; stereoscope; estimation of magnitudes.
PERSISTENCE OF IMPRESSIONS; DIVERS EXPERIMENTS.
LESSONS 24-26. Optical Instruments.
Camera lucida. A lens is necessary to reduce to the same apparent distance the two objects seen simultaneously. Instruments to assist the sight; simple microscope; the magnifying power; distinctness; field; advantage of a diaphragm; it modifies the field and the brightness variously according to its position.
Woollaston’s double glass; its advantages.
General principle of compound dioptrical instruments.
Compound microscope; experimental measure of its magnifying power, by means of the diaphragm, by means of the camera lucida.
Astronomical telescope; object glass; simple eye-glass. Necessity for a diaphragm; its place; the wires, their place; optic axis of a telescope. Parallax of the threads of the wires; magnifying power of the object-glass; of the eye-glass; field of view of a telescope.
Optic ring; different methods of measuring the magnifying power.
Distinctness of a telescope; night-glass.
Different distances of drawing out the eye-glass for short-sighted and long-sighted observers.
Different sorts of eye-pieces; positive eye-pieces; ordinary double eye-piece of the astronomical telescope. Ramsden’s eye-piece; treble eye-piece of the terrestrial telescope. Negative eye-pieces; simple eye-piece of Galileo. Compound ditto of Huyghens; advantages and disadvantages of these different combinations; general principle of catadioptrical instruments.
LESSONS 27-29. Double Refraction.
Crystallized mediums do not all act upon light like homogeneous mediums.
Double refraction of Iceland spar: the extraordinary image turns round the ordinary image. The ordinary and extraordinary rays cross at the interior of the crystal.
Huyghens’ construction; measure of the ordinary and extraordinary indices of refraction; attractive and repulsive crystals; a ray falling perpendicularly does not always bifurcate in a camera with parallel faces, nor in a prism. Definition of uniaxial and biaxial crystals.
The dispersion of the ordinary ray differs from that of the extraordinary ray.
The two rays are unequally absorbed in many colored mediums. Tourmaline.
Doubly-refracting prisms; their construction. Use of doubly-refracting prisms to measure apparent diameters, &c.
LESSONS 30-31. Polarization.
Successive refractions in doubly-refracting prisms. Special properties of the two rays emerging from the first doubly refracting crystal. Polarization by double refraction.
Reflection from transparent media polarizes the light partially or wholly according to the incidence. Brewster’s law. Reflection of polarized light from a transparent medium.
Simple refraction partially polarizes the light. Many successive refractions polarize it almost totally. Piles of glasses.
Different methods to obtain a ray of polarized light, 1st, by reflection; 2nd, by simple refraction; 3rd, by double refraction, by eliminating one of the refracted pencils;--by a screen,--by total reflection, Nicol’s prism, by absoption, tourmaline.
Distinctive characters of light completely or partially polarized.
LESSONS 32-34. Theory of Undulations.
Hypothesis of luminous undulations.
Vibratory state of a simple ray of homogeneous light. Vibratory state at the intersection of two simple rays of homogeneous light intersecting at a very small angle.
Experimental proofs in support of this hypothesis:
1st. Experiment with interferences, fringes. Their breadth is different for different colors; they give the various colors of the prism in white light. The alternately bright and dark sheets are hyperboloids of revolution. The measure of the fringes give the means of estimating the lengths of the undulations corresponding to different colors.
2nd. Colored rings of Newton, observed by reflection, by refraction. Law of the diameters; these vary in absolute length for different colors. Variously colored rings with white light. Reflected rings with a white spot at the center.
The theory of the undulations does not apply merely to theses phenomena. Explication of the laws of reflection and refraction. Definition of polarization in the system of waves. Elementary application of double refraction and the polarization which accompanies it in uniaxial crystals when the face of the crystal is parallel to the axis, and the plane of incidence normal or parallel to this axis.
Chemical and Calorific Radiations.
Chemical and calorific radiations are subject, like luminous radiations, to the laws of reflection, refraction, dispersion, double refraction, polarization, interferences.
LESSONS 35-36. Revision.
Considerations on the totality of the subjects of the course.
MANIPULATIONS IN PHYSICS.
The practical exercises which constitute the subject of this programme will be performed in part by the pupils under the direction of the professors and répétiteurs, in part by the professors and répétiteurs, with the coöperation of the pupils.
FIRST YEAR.
Use of various instruments, designed for measuring lengths. Experiments on weight with Atwood’s machine, the inclined plane, Morin’s apparatus, and the pendulum.
Some experiments on elasticity.
Various verifications of the principles of hydrostatics and hydrodynamics.
Construction of aerometers.
Construction of a barometer, of a manometer. Various verifications of the law of Mariotte.
Various experiments with the air-pump.
Determination the density of solids or liquids by different methods.
Construction of a thermometer.
Experiments on the dilatation of liquids and solids by means of the ordinary thermometer and by means of the statical thermometer.
Experiments upon the dilatation of air by various methods.
Experiments upon the tension of vapors by different methods.
Determination of the density of vapors and gases by various methods.
Leading experiments on calorific radiation.
Experiments on cooling.
Determination of specific heats, heats of fusion, heats at which bodies pass into vapor.
Cooling mixtures.
Use of the chemical hygrometer, the wet bulb hygrometer.
Rehearsal of the leading experiments on magnetism.
To magnetize a needle, to reverse its poles.
Rehearsal of the principal experiments of statical electricity.
Experiments verificatory of the laws of electricity and magnetism.
Use of compasses.
SECOND YEAR.
Experiments upon the chemical actions of poles.
Leading experiments in electro-dynamics.
Leading experiments upon the magnetic properties of currents.
Experiments on induction.
Experiments on the calorific and luminous actions of currents.
Quantitative experiments on the laws of currents.
Experiments on the propagation of sound; on the vibrations of rods of plane or curved plates, membranes, sonorous tubes.
Experiments on mirrors, plane or curved.
Experiments on lenses. Experiments on the decomposition of light by the prism--by absorption. Measures of the indices of the refraction of solids. Use of the magnifying glass and microscope; measure of the magnifying power. Use of different telescopes, with and without corrections. Measure of the magnifying power. Experiments on double refraction and polarization. Experiments on interferences and colored rings.
ORGANIZATION AND CONDITION IN 1869.
The organization of the school, which is fixed by a Decree dated Nov. 30th, 1863, is of a military character. There is a staff of military officers in addition to, and quite separate from, the staff employed in the duties of instruction. The pupils wear uniform, which, however, is more civil than military in appearance. They are formed into four companies which together constitute a battalion; and, although they are not actually subject to the penal code of the army, the discipline maintained and the punishments inflicted are entirety military in character.
The military establishment remains exactly as it was in 1856, and consists of:
The Commandant, a General Officer, usually of the Artillery or the Engineers, at present a General of Artillery.
A Second Commandant, a colonel or lieutenant-colonel, chosen from among the former pupils of the school; at present a colonel of Engineers.
Three captains of Artillery and three captains of Engineers, as inspectors of studies, chosen also from former pupils of the school.
Six adjutants (adjudants), non-commissioned officers, usually such as have been recommended for promotion.
Slight changes have been made in the civil establishment; it now consists of:--
1. A Director of Studies, at present a colonel of Engineers.
2. Seventeen professors,[12] (two additional professors for history) seventeen Répétiteurs and assistant Répétiteurs, and five drawing masters. Of the 17 professors, two are at present officers of Engineers, and one an officer of Artillery; the remainder are civilians, of whom three are members of the Academy of Sciences.
[Footnote 12: In 1856 there were only 15 professors; there are now two additional professors for history, the study of which has been recently introduced at the school.]
3. Five examiners for admission, and five for conducting the examinations at the school. All of these at present are civilians.
4. An administrative staff consisting of a treasurer, librarian, &c.; and a medical staff.
The general control or supervision of the school is vested, under the War Department, in four great boards or councils, viz.:--
1. A Board of Administration, composed of the Commandant, the Second Commandant, the Director of Studies, two professors, two captains of the military staff, and two members of the administrative staff. This board has the superintendence of all the financial business, and all the minutiæ of the internal administration of the school.
2. A Board of Discipline, consisting of the Second Commandant, the Director of Studies, three captains of the Military Staff, and one major of the army, selected from former pupils of the school.[13] The duty of this board is to decide upon cases of misconduct.
[Footnote 13: Formerly two professors of the school were also members of the Council of Discipline, but the professors have now no voice in matters of discipline.]
3. A Board of Instruction, whose members are, the Commandant, the Second Commandant, the Director of Studies, the Examiners of Students, the Professors, and two captains of the Military Staff; and whose chief duty is to make recommendations relating to ameliorations in the studies and the programmes of admission and of instruction in the school to--
4. A Board of Improvement (Conseil de Perfectionnement), charged with the general control of the studies, and formed of:--
The Commandant, president, The Second Commandant, The Director of Studies, Two delegates from the Naval Department, Two delegates from the Department of Public Works, One delegate from the Home or Finance Department, Three delegates from the War Department, Two members of the Academy of Sciences, Two examiners of students, Three professors of the school.
The delegates from the public departments are appointed by the respective ministers; the members of the Academy, the examiners, and the professors are selected by the Minister of War. The real management of the school, so far as the course of instruction is concerned, is in the hands of the Conseil de Perfectionnement; it will be seen that of the 18 members composing it more than half are entirely independent of the school, and are men of eminence in the various public services for which the instruction at the Polytechnic is preparatory. One of the chief duties of the Council is to see that the studies form a good preparation for those of the more special schools (Ecoles d’ Application) for the civil and military services; and the eminent character of its members gives great weight to the recommendations they make to the Minister of War.
The annual expenses of the school, as extracted from the Budget for 1869, are as follows:--
Francs. Pay of staff, professors, &c., 331,850 Instruction, maintenance, examination of candidates, clothing, books, &c., 321,073 Francs. Outfits for 30 new pupils at 600 francs each 18,000 Allowances (premières mises) to 25 exhibitioners on admission to the military services at 750 fr. each 18,750 ------ 36,750 Maintenance and repair of buildings, 30,000 ------- Total sum charged in the schools estimate, 719,673 Add regimental pay of 28 officers and non-commissioned officers employed at the school, 85,515 ------- Total expenditure 805,188 Deduct repayments from pupils, 237,000 ------- Cost to the State, 568,188
Or about 22,720_l._
The chief changes that have been made in regard to the course of instruction since 1856, may be summarized as follows:
1. The more elementary portions of chemistry and physics which are required in the entrance examination, but which were formerly repeated at the school, have been omitted. The course of instruction in these subjects is now confined to the more advanced portions which do not enter into the entrance examination.
2. The mathematical courses have in some points been slightly curtailed, and the number of lectures in French literature and German have been diminished. By the modifications thus made in the programmes, it has been found possible to shorten the whole course of study and to increase the length of the vacations.
3. The subject of “Military Art,” which formerly entered into the final examination is no longer taken into consideration in determining the order of merit of the pupils. In this respect the course of instruction may be said to have even less of a military character than formerly. Topographical drawing is the single military subject which has any influence on the final classification of the pupils, and this only to a very slight extent.
4. History has been introduced as a subject of instruction. This change was made in 1862. The course comprises general history, both ancient and modern, but more especially the history of France in modern times. The introduction of this subject appears to have arisen partly from a feeling that an acquaintance with history was a necessary element of a liberal education, and partly from a wish to meet, to some extent, an objection often made to the Polytechnic course of instruction, that it was too deficient in studies of a literary character. History, however, like military art, is evidently still regarded as a subject of only secondary importance and has no influence on the final classification.
5. A diminution has been made in the number of examinations during the course, by the suppression of one of the half-yearly examinations by the professors (interrogations générales, as distinct from the interrogations particulières) in each year. Further reference will be made to this point when speaking of the examinations at the school.
6. The importance of written exercises in determining the respective merits of the pupils has been decreased, apparently from the difficulty of establishing a security that such compositions were the unaided work of the individual.
The following table shows the present course of instruction during the two years, and the alterations which have been made in the number of lectures in each subject since 1856:--
Subject.--First Year’s Course. Lectures in--1868. 1856.
Analysis {Differential calculus, 25 28 {Integral calculus, 18 20 Descriptive geometry and geometrical drawing, 32 38 Mechanics and machinery, 40 40 Physics, comprising heat and electricity, 30 34 Chemistry:--The metals, 30 38 Astronomy and geodesy, 30 35 French composition and literature, 25 30 History, 25 0* German, 25 30 Figure and landscape drawing, 48 50
Second Year’s Course.
Analysis:--Integral calculus, 32 32 Stereotomy:--Geometrical drawing of constructions in timber and masonry, 28 32 Mechanics:--Dynamics, hydrostatics, and machinery, 40 42 Physics:--Acoustics, optics, and heat, 30 36 Chemistry:--Continuation of the metals and organic chemistry, 30 38 Architecture and buildings, construction of roads, canals, and railways, 40 40 French composition and literature, 25 30 History, 25 0* German, 25 30 Military art, 20 20 Topography, 2 10 Figure and landscape drawing, 48 48
[* Introduced in 1862.]
In connection with several of the courses, such as descriptive geometry, stereotomy, machinery, and architecture, much drawing is done by the pupils; hand sketches are taken of the diagrams shown in the lecture-room, and finished drawings are afterwards executed in the salles d’étude. In addition to this, 30 attendances of two or three hours each, distributed over the two years, are especially devoted to drawing more elaborate plans and elevations of architectural constructions and machinery. The practical applications of the theoretical instruction are limited to manipulations in the laboratory in connection with the course of lectures on chemistry and physics. Towards the close of the second year the pupils are also taken to visit some of the large manufacturing establishments in Paris, in order to gain a practical acquaintance with machinery.
All the subjects taught at the school are obligatory, but history and military art, as already stated, have no influence in determining the order of merit of the pupils in the final result.
The only instruction in practical military exercises, which is compulsory upon all, is that in drill. The pupils are exercised under arms in company drill, and are also occasionally drilled as a battalion; but very little importance is attached to this point--the only really military portion of their training. Drill goes on only for about three months in each year during the spring and summer, and even during this brief period only takes place about twice a week. By the regulations of the school the pupils should be exercised in musketry practice, but although they are armed with the Chassepot rifle this regulation is never carried out. Instruction is given in fencing and gymnastics, but attendance at both is voluntary, and scarcely more than half the pupils take advantage of it. Neither riding nor swimming are taught at the school.
The school year commences about the 1st of November, and terminates about the first of August. Some seven months of the year are given up to lectures and the ordinary routine of study; about two months are occupied with the annual examinations and private preparation for them; the remaining three months--August, September, and October--are the vacation. In addition to this long vacation, from eight to twelve days are allowed after the periodical examination, which takes place near the end of February, at the close of the first portion of each year’s study.
One peculiarity in the arrangements of the school is that the subjects of each year’s course are not all studied simultaneously. The lectures in the main subjects of instruction--those which, as a rule, present the most difficulty--are divided into courses which continue only during a certain portion of each year. Thus in the junior division, analysis and descriptive geometry are the mathematical subjects studied during the first three months, or three months and a half. The course in them is then concluded; an examination by the professors (interrogation générale) is held in these subjects, and they are laid aside for the remainder of the year, though they enter into the examination at the close of the year. Their place is then taken by a course of lectures in mechanics and geodesy. Similarly in the second year, analysis and mechanics are the subjects of the first course of lectures, at the termination of which there is an examination; and for the remainder of the year no further lectures in them are given, stereotomy and military art taking their place.
The subjects involving as a rule less difficulty--such as history, French literature, German, and drawing--are spread over the whole year, forming generally the evenings’ occupation.
THE SPECIAL MILITARY SCHOOLS OF FRANCE.
SCHOOL FOR ARTILLERY AND ENGINEERS AT METZ.
HISTORY AND GENERAL DESCRIPTION,
The first French Artillery School was founded in the time of Louis XIV. (in 1679) at Douai. It had but a short existence: and it was only in 1720 (under the Regency,) when the Royal Regiment of Artillery received a new organization, that schools of theory were permanently founded in each of the seven towns where there were garrisons of artillery. But no academy properly so called was established before that founded by D’Argenson at La Fère, in 1756, with a staff of two professors of mathematics, and two of drawing. This was transferred to Bapaume, near the Flemish frontier, in 1766, re-transferred to La Fère, and suppressed, among other schools, at the beginning of the Revolution.
Of early Engineer Schools there was only one, the very distinguished School of Mézières, near the northern frontier. This was founded in 1749, also under the ministry of D’Argenson; Monge was a professor there; and it had a very high reputation down to its suppression in the Revolution.
When the wars of the Revolution broke out, Provisional Schools for giving a brief course of rapid instruction was established at Metz for the engineers, and at Chalons-sur-Marne for the artillery. These had to supply, at a great disadvantage, the officers needed for the protection of the invaded frontier.
It was intended originally that the Polytechnic, established in 1794, should send engineers direct to the army; but it was quickly found to be a better plan to allow the pupils destined for this service first to spend some little time at Metz; which thus, in October, 1795, became a School of Application for Engineers. The artillery pupils in like manner went to Châlons. This separate system of two Schools of Application continued till 1802, when the establishment at Châlons was united with that of Metz, and Metz became what it has since continued to be, the seat of the United School of Application for the two services. The Polytechnic students who select the Artillerie de terre, Artillerie de mer, or the Génie militaire, enter here to receive the special and professional instruction deemed requisite to fit them for actual employment.
The students quitting the Polytechnic in the manner described in the account of that school, at the average age of twenty-one, enter the School of Application, with the provisional rank, the uniform, and the pay of sub-lieutenants (sous-lieutenants.) The ordinary term of residence is two years. Under special circumstances this may be shortened; and in case of illness or want of application individual students are occasionally retained for a third year. Each new body of students, each admission or promotion, is classified at the end of the first year, and the students composing it are arranged in order of merit in accordance with the reports of the professors, but without an examination; at the close of the second year they pass a final examination before the Board of Officers, and are definitively placed in the corps they have chosen, the artillery or engineers, according to the order of merit. They are allowed to count, as regards retirement from the service and towards military decorations, four year’s service on account of the two years passed at the Polytechnic School, and of the time passed in preparing for admission to it, reckoning from the day of their admission to the School of Application.
Metz is a fortified place on the Prussian frontier, the seat of war at the time of the school’s first foundation; it is on the line of railway to Mannheim, about thirty miles from the point where this branch diverges from the main line to Strasburg. The Moselle flows through the town, and is employed, with its little affluent the Seille, in the military defenses. The garrison numbers 10,000 men; there is an Arsenal, a school of Pyrotechny for the manufacture of rockets, two Regimental Schools, one of Artillery and the other of Engineers. The School of Application occupies buildings erected on the site, and partly the original buildings themselves, of a suppressed Benedictine monastery. Three sides of the cloistered monastic quadrangle are devoted to the offices, lecture-rooms, galleries and halls of study. A fourth, formerly the ancient church, is converted into a salle des manœuvres. There is an adjoining residence for the commandant; and a separate modern building, four stories in height, affords lodging to the young men.
The salle des manœuvres is a large area under a lofty roof, rising to the whole height of the buildings of the quadrangle; it contains artillery of various descriptions, mortars, field and siege guns placed as in a battery, and is amply large enough to allow cannon to be moved and exercises performed when the state of the weather may make it desirable.
The amphitheaters or lecture rooms, much on the same system as those at the Polytechnic, are two in number, one for each of the two divisions. Officers of the artillery and engineers who are in garrison, are entitled, if they please, to attend the lectures, and other officers also may be admitted by permission.
The galleries, partly on the ground floor, partly on the first floor, contain very good collections of models of artillery, ancient and modern, of sets of small arms, of tools, of locks, barrels and other portions of muskets in various stages of the process of their manufacture, of specimens of carpentry and roofing, of minerals, of models of fortifications, bridges, coffer-dams, locks, &c.
The library on the first floor has an adjoining reading room; and near it is the examination room, of which further mention will be made. The three halls of study (salles d’étude) on the first floor are on a different plan from those of the Polytechnic, each one being large enough to accommodate a whole division (seventy students.) Three rooms are also provided for the professors to prepare their lectures in.
The barracks, on the opposite side of the open space used for drill and exercises, form a lofty and handsome building, entered by separate staircases, the ground-floor rooms of each being assigned to a servant, who undertakes to provide attendance for all the young men lodging in the rooms above. The rooms are comfortable, mostly double-bedded, the bedroom serving also as a sitting room, and a small adjoining closet being used for washing, &c. Twenty or twenty-two appear to be thus accommodated on each staircase; there are lodgings altogether for one hundred and forty-five. A certain number of the senior sub-lieutenants would, probably, on the arrival of the new cadets from the Polytechnic, be removed to lodge in the town.
There is a riding-school adjoining the court; stables, for thirty-three horses, which are kept for the use of the pupils, and lodgings for the attendants are provided in the neighborhood.
The mere description of the buildings shows at once that the system is different in many respects from that of the Polytechnic. Young men of twenty-one and twenty-two years of age, already holding provisional commissions in the service, receiving the pay and wearing the uniform of sub-lieutenants, are naturally allowed much greater freedom of action. They live, and partly also study, not in the halls of study, but in their own rooms; they take their meals in the town, where they frequent the cafés and restaurants of their choice. The rappel summons them every morning to rise and attend a roll-call at half-past five or six; military exercises, riding, or interrogations, similar to the interrogations particulières, require the presence of a portion of the number, but the rest are free to return to their rooms. At ten they have to attend either the day’s lecture, followed by employment in the halls of study, till four o’clock P.M., or they proceed at once to the halls of study, and set to work on the drawings, designs, projects, &c., which are described hereafter in the account of the studies. From four to half-past five P.M.; drill, exercises, and riding occupy a portion of the number, probably those who were not called for in the morning. After half-past five they are left to themselves.
This ordinary routine of studies is interrupted in the summer months by the occurrence of expeditions for making surveys, and for measuring and sketching machines in manufactories. The young men are sent, two together, to survey (lever à boussole;) singly for the reconnaissance sketch _(lever à vue _;) and generally, a certain number are distributed about a district not too large for an officer to make his round in it, and see each day that all are at work. The railways afford considerable facilities; the expeditions never occupy more than ten days at a time, but they may be extended as far as Strasburg.
There are no répétiteurs in the school; but the system of interrogations particulières is carried on; and an examination by the professor and an assistant professor takes place after, about, every eight or ten lectures.
THE STAFF AND GOVERNMENT.
The Staff of the Institution consists of--
1 General Officer, at present a General of Brigade of Artillery, as Commandant. 1 Colonel or Lieutenant-Colonel, Second in Command and Director of Studies, at present a Lieutenant-Colonel of Engineers. 1 Major of Artillery. 1 Major of Engineers. 5 Captains of Artillery. 8 Captains of Engineers. 1 Surgeon (Médecin-Major.)
The Commandant is taken alternately from the Artillery and Engineers, and the command lasts for five years only.
The Second in Command is always chosen from that arm of the service which does not supply the Commandant.
The inferior officers of each rank are taken in equal numbers from the two arms.
The Staff of Instructors is as follows:--
1 Professor of Artillery, at present a Captain of Artillery. 1 Assistant ditto also a Captain of Artillery. 1 Professor of Military Art, charged also with the Course of Military Legislation and Administration (a Captain of Engineers.) 1 Professor of Permanent Fortification and of the Attack and Defense of places (a Captain of Engineers.) 1 Assistant ditto ditto (a Captain of Engineers.) 1 Professor of the Course of Topography and Geodesy (a Captain of Engineers.) 1 Professor of Sciences applied to the Military Arts. 1 Professor of Mechanics applied to Machines (a Captain of Artillery.) 1 Professor of the Course of Construction (a Captain of Engineers.) 1 Assistant ditto. 1 Professor of the German language (a civilian.) 1 Professor of Veterinary Art and Riding (a Captain of Artillery.) 1 Assistant ditto (a civilian.) 1 Drawing Master, Chief of the Drawing Department (a civilian.)
In all, nine Professors, four Assistant Professors, and one Drawing Master.
The School employs in addition an administrative staff, consisting of--
A Treasurer, } both of whom must have been Officers in the A Librarian, } Artillery or Engineers. A Principal Clerk. An Assistant Librarian. Two Storekeepers, intrusted with the materiel belonging to the two arms. One skilled Mechanic. One skilled Lithographer. One Fencing Master.
Clerks and draughtsmen are provided as required.
The school is under the general superintendence of two hoards or councils, the Superior Council and the Administrative Council.
The Superior Council consists of the General Commandant, as President, the Second in Command, the Director of Studies, as Vice-President; the Major of Artillery, and the Major of Engineers, as permanent members; two Captains of the Establishment, one of each arm; two Military Professors, one of each arm; and one Captain of the Establishment; these five last being all removable at the General Inspections.
The Superior Council has the duty of drawing up the programme of the studies of the year, of suggesting changes in the regulations relating both to studies and discipline, all subject to the approval of the Minister of War; of preparing at the end of the year the classified list of the students, drawn up according to their conduct and progress in their studies, and of pointing out to the Jury of Examiners any students who should go again through the courses of the year, and stay in consequence an additional year at the school.
When questions relating to the instruction are brought before the Superior Council, the whole body of military professors attend and take part in the proceedings, and the Council is thus said to be constituted as a Board or Council of Instruction. Improvements are here suggested, and are subsequently submitted to the Jury of Examiners, and to the Minister of War; the value to be attached, in the system of marks or credits, to each particular course of study is determined; a statement is drawn up showing what printed works, models, &c., are wanted. The budget itself, to be submitted to the Minister of War, is finally drawn up by the Superior Council in its ordinary sittings.
The Administrative Council, composed of the Second in Command as President, the two Majors of Artillery and of Engineers, one Captain and one Military Professor, and the Treasurer as Secretary without the right of voting, takes cognizance of all the financial and other business matters of the school.
SUBJECTS AND METHOD OF STUDY.
The studies at Metz consist of topography and geodesy, including military drawing and surveying under special circumstances; field fortification, military art and legislation, permanent fortification, and the attack and defense of fortified places, accompanied by a sham siege, without, however, executing the details practically on the ground; architecture, as applicable to military buildings and fortifications; the theory and practice of construction, and artillery. The programmes of these studies are inserted at length in the Appendix.
The instruction is given principally (as at the Polytechnic) by means of a series of lectures, and the knowledge which the students have acquired is first directly tested by requiring them to execute various kinds of surveys of ground, either with or without the use of instruments; to prepare drawings of buildings, workshops, and machines in full detail (plan, elevation, and sections) from the measurements they have recorded in their note-books or on their sketches, and to accompany such drawings with descriptive memoirs of all particulars and calculations that may be necessary to exhibit their purpose or efficiency; to draw up projects and lay out works of field and permanent fortification, or of those of attack or defense of a particular place on certain given data, or according to the nature of the ground; to design a military building, bridge, machine, or piece of ordnance, accompanied by estimates and descriptive memoirs, showing in what manner the instructions and conditions under which it was drawn up have been complied with; and to prepare a project for the amelioration of the works of defense of a specified portion of a fortified place known to be defective in some respects.
The instruction during the first year’s residence is common to the two arms; and the time is appropriated in the following manner, namely:--
Days. Military art and legislation, 33 Topography and geodesy, 47 Field fortification, 39 Permanent fortification, 88 Theory and practice of construction, 77 --- Total, 284
The sous-lieutenants who complete their first year’s work are allowed nearly a month’s vacation during November.
The instruction given to the Artillery and Engineers during the second year’s residence is not entirely the same, as will be seen by comparing the accompanying table of the year’s study:--
Artillery. Engineers. Days. Days. Military art and legislation, 2 2 Topography and geodesy, 28 28 Attack and defense of places, 44 44 Permanent fortification, 44 129 Artillery, machines, &c., 81 -- Theory and practice of construction, 46 42 --- --- 245 245 Brought forward from first year, 284 284 --- --- Total, 529 529
We should not omit to state that there is a short course on the Veterinary Art.
The lectures, as before said, begin at 10 A.M., and they last usually an hour and a half, and are followed by work in the halls of study. It would appear, however, that very frequently the day’s occupation consists simply of work in the halls of study (or occasionally out of the school buildings, when the students are sent on some excursion;) and, accordingly, in giving the account of the studies, a day or day’s work will sometimes mean a lecture followed by drawing or other employment, sometimes this drawing or other employment without any lecture preceding. Taking a general average, the proportion appears to be about two lectures to five séances, i.e., sittings without lectures.
The system will be better understood by referring to the accompanying tables, which are translated from the Project for the Employment of Time for the year 1851-2, submitted for the approval of the Minister of War. The dates in the first column indicate the days of the commencement of each particular study. The school year, it should be said, begins on the 1st of December.
EMPLOYMENT OF TIME FOR THE YEARS 1851-1852.
[KEY] Att Attendances. LbW Lectures before Work. TL Total of Lectures.
-----------+------------------------------------------+-------------- Month and | Second Division. | Number of Date. | +----+----+---- | First Year’s Instruction. | Att| LbW| TL -----------+------------------------------------------+----+----+---- December 1 | Lectures on Military Art in | | | “ 2 | Topography--Conventional Tints, | 2 |....|.... “ 4 | Study of Hill Drawing | | | | (in sepia with contour lines,) | 2 |....|.... | { Plate 1 .. 5} | | | | { Plate 2 .. 5} | | | “ 6 | Military Art,{ Plate 3 .. 5} | | | | { Plate 4 .. 5} | | | | { Plate 5 .. 9} | 29 | 4 | 39 January 12 | Front of Cormontaige | 24 | 3 | 13 | | | | February 9 | Project of Field Fortification, | | | | { Plate 1. Plan of the whole, 3} | | | | { Plate 2. Organization of a work, 8} | | | | { Plate 3. Details of Construction, 4} | | | | { Memoir 4} | 19 | 5 | 7 March 3 | Plan of Stability of Revetments, &c., | 9 | 9 | 9 “ 13 | Study of the Drawing showing the effect, | 8 | 1 | 1 “ 23 | Plan of a Building, | | | | { Out-of-door work, 9} | | | | { Laying down and drawing, Memoir, 23} | 32 |....|.... April 29 | Topographical Triangulation, | 4 | 4 | 6 May 5 | Defilement and Profiling on the Ground, | 3 |....|.... | Project of a Building, | | | | { Sketches, 14} | | | | { Drawing, 24} | | | | { Memoir, 4} | | | | { Estimate, 3} | 45 | 12 | 22 June 28 | Survey with a plane-table, | | | | { Out-of-door work 0} | | | | { Laying down and drawing, 3} | 13 | 1 |.... | One day free in case of bad weather, | 1 |....|.... July 14 | To find the Variation of the Needle, | 1 | 1 |.... “ 17 | Survey of Ground with the Compass, | | | | { Out-of-door work, 8} | | | | { Laying down and drawing, 2} | 10 | 1 |.... | One day free in case of bad weather, | 1 |....|.... August 2 | Reconnaissance Plan--Out-of-door work, | 6 | 1 |.... | One day free in case of bad weather, | 1 |....|.... “ 10 | Study of Shaded Drawing | | | (Hachures and colored.) | 8 | 1 |.... “ 18 | Laying down and drawing the Survey | | | made with the Compass, | 2 |....|.... | Project of Fortification on Level Ground,| | | | { Plate 1 6} | | | “ 20 | { Plate 2 30} | | | | { Memoir, 6} | 42 | 3 | 19 September | | | | October 8 | Project of Fortification on Hilly Ground,| | | | { Plate 1 19} | | | | { Memoir, 3} | 22 | 8 | 10 Nov. 3 | Last day of week, | | | “ 6 | Leave for their Vacation, | | | There remains therefore in this division:--1st. Three free days in case of bad weather; one after each survey. 2nd. Two days at the end of the year, the 4th and 5th November. Total five free day. -----------+------------------------------------------+----+----+---- Total of the days employed 279 + 5 days free, |284 | | -----------+------------------------------------------+----+----+----
EMPLOYMENT OF TIME FOR THE YEAR 1851-1852.
-----------+------------------------------------------+-------------- Month and | First Division. | Number of Date. | +----+----+---- | Second Year’s Instruction. | Att| LbW| TL -----------+------------------------------------------+----+----+---- | Brought forward, |284 |....|.... December 6 | Laying down the First Survey | | | | by Reconnaissance, | 8 |....|.... “ 16 | Attack and Defense:--Plate, | | | | Batteries, with Plan and | | | | Sections of Detail, | 4 | 5 | 6 | Ditto, { Plate 1, 25 } | | | “ 20 | { Journal, 2 } | | | | { Plate 2 13 } | 40 | 6 | 20 January | | | | February 7 | Designs and Constructions of | | | | Revetments, Arches, &c., | 9 | 9 | 9 “ 18 | Project and Permanent Fortification | | | | in Hilly Ground, { Plate 1 19 } | | | | { Memoir, 3 } | | | | { Plate 2 8 } | 30 | 8 | 19 | | | | | SPECIAL WORKS: | | | | Artillery. | | | | Engineers. | | | | | | | March 25 | Measurement and Drawings | | | | of a Cannon, 12 | 12 |....|.... | Project of Fortification in | | | | hilly ground, Plate 2 cont., 12 | | | April 8 | Measurement of a Workshop, | | | | Out-of-door Work, | 9 | 30 | 30 “ 19 | Laying down the Measurement, 28 | | | | Laying down the Measurement, 24 | | | May 18 | Project of Fortification in hilly | | | | ground, Plate 3, 14 | | | “ 24 | Project for Machines, 14 | | | June 4 | Abstracting and calculating | | | | Measurements, 3 | | | “ 8 | Plate 4, 11 | | | “ 9 | Questions in Artillery, 5 | | | | 1st. Measurement of Matériel, | | | | Gun Carriages, &c., 8 | | | | Register of the removal of Earth, 3 | | | | Laying down ditto, 10 | | | | Estimate, 2 | | | | Memoir, 2 | | | | Project for Improvements, | | | | {Plate 1, 30 | | | | {Plate 2, 6 | | | | {Memoir, 2 | | | July 6 | 2nd. Measurement of Matériel, 8 | | | “ 15 | Project for a Cannon, 24 | 97 | 2 | 2 | | | | August 12 | Second Reconnaissance Survey, | | | | Out-of-door Work and Tracing of the | | | | Lines on the Reconnaissance Plan, | 7 |....|.... | One day free in case of bad weather, | 1 |....|.... “ 21 | Geodetical Calculations, | 4 |....|.... “ 26 | Laying down the Reconnaissance Survey, | 8 |....|.... September | | | | 4 | Memoir on Entrenched Lines, | 1 |....|.... “ 6 | Tracing or laying out Camps, | 1 |....|.... “ 7 | Operations of a Sham Siege, | 13 |....|.... | One day free, | 1 |....|.... “ 19 | Preparing for the Examination, |....|....|.... October | | | | November 1 | Examination for leaving, |....|....|.... | |----|....|.... Total of the days employed, 522 + 7 days free |529 | | -----------+------------------------------------------+----+----+----
EXAMINATION AND CLASSIFICATION.
FINAL EXAMINATION.
About six weeks of free or voluntary study is allowed, immediately prior to the Final Examination, for the sub-lieutenants to prepare for their last effort.
The examination which takes place prior to their leaving the School of Application, is entirely conducted by a board of six officers, under the presidency of a general officer alternately of the artillery or engineers, the remaining members of the board consisting of a general officer of each corps and three field officers of these corps; the last three being specially charged with the duty of examining. It takes place in a room set apart for the purpose, with a small interior room in connection with it, into which the members of the board retire to deliberate at the end of each student’s examination. The jury assembles each year at the period fixed by the minister of war.
The three examining members conduct the examination of the students in three different branches of study; the first more particularly relating to artillery science, the second to engineering science, and the third to mechanical science in its connection with the art of war. The whole of the students who are to leave the school are first examined in such one or other of these branches of study as may be determined on.
The student under examination is specially questioned by the examining officer in his subject, and occasionally by the president or any other member of the board that may wish to do so, for three-quarters of an hour. As soon as the examination of the student has been concluded, the board retire to the adjoining room and compare their notes of the credits they have severally awarded to the student under examination, and they also examine his drawings, sketches, and memoirs relating to the subjects on which he has been questioned, and prepared during his two years of residence in the school. They severally note the credits to which they consider him to be entitled for them, and adopt the general mean.
As soon as the examination of the whole of the students in this particular study has been finished, the examination in the next branch is commenced, so that five or six days elapse between the first and second examinations of the same student; and the same interval of time occurs between the second and third examinations.
The credit allotted to each student by the board of examiners represents, on the scale of 0 to 20, the manner in which he has replied to the questions, or executed the drawings, sketches, memoirs, &c., belonging to each course. The importance attached to each particular branch of study is estimated very nearly by the amount of time allowed for its execution divided by 20; and the definitive marks which each student obtains for that branch of study is obtained from the products of the numbers respectively representing the credit for answering, and that for the importance of the subjects on which he has been examined.
The final classification of the order of merit, in each arm of the service, is arranged after a comparison of the total of the marks obtained by each student. This total is the sum of the definitive marks gained by each student in the sciences bearing on artillery, engineering, and mechanics in connection with the art of war, for the talent displayed in drawing, sketching, and writing memoirs, and for skill in practical exercises, as determined by the results of the examination conducted by the jury of examiners, added to the marks due to the previous classification in the school, with the weight or influence equal to one-third of that allowed for the examination by the jury.
The co-efficients of influence for the present year are--
For those particularly relating to Artillery Science, 39.29 “ “ “ Engineering Science, 53.75 “ “ “ Mechanical Science, 43.00 For talent in drawing, sketching, writing memoirs, &c., 6.80 For practical exercises, 16.75 Previous classification in the school, 45.30
So that the examination conducted by the jury of examiners exercises an influence on the position of the students very nearly approaching to two-thirds of the whole amount.
It is this final classification which determines their seniority in the respective services. We were permitted to be present during the examination, which was entirely oral, of two of the sous-lieutenants, before the jury of examiners.
The questions were replied to with great fluency and readiness, but it seemed to us that the examination was somewhat limited for the object in view, viz., that of awarding a credit representing the progress which each student had made in the particular science on which he had been questioned, especially as that credit would have very great weight in determining the candidate’s future position.[14]
[Footnote 14: The examination chamber is a small room in the school buildings, near the library, ornamented with portraits of Vauban, and of D’Argenson, under whose ministry the original schools at La Fère and Mézières were founded. At a large table under these portraits, and extending across the room, General Morin, President, and four officers, members of the jury, were seated. The sixth member sat at a small table in front, near the blackboard, at which the student stood. The Commandant, the Director of Studies, and the other officers of the school were seated also in this part of the room.
The student who was first examined was questioned partly by the examiner, partly by the president, and gave his answers, working problems and drawing illustrations on the board as he went on. He was asked questions as to the details of the steam-engine, and as to the method of casting cannon. The German teacher of the School put him on to construe from a German book, and tried him in speaking; he succeeded just passably in both. The whole occupied about three-quarters of an hour.
The second student, after answering similar scientific questions, had opportunity given him to show his knowledge, which was considerable, of the geology of the neighborhood; and having lived in foreign countries, he was able to make a very good display of his knowledge of German, Spanish, Italian, and English.
After each examination the jury retired into the inner cabinet, by a door opening to it from behind their seats.]
On quitting the School of Application at Metz, the sub-lieutenants of artillery and engineers respectively join the regiments, to which they are then definitely assigned as second lieutenants, and continue to be employed in doing duty, and in receiving practical instruction with them, until they are promoted.
SUBSEQUENT INSTRUCTION AND EMPLOYMENT.
The lieutenants of the artillery are employed on all duties that will tend to make them efficient artillery officers, and fully acquainted with all details connected with the drill, practice, and manœuvres of the artillery, and also with the interior economy and discipline of a regiment of artillery.
After the officers of artillery are promoted to the rank of second captain, but not before, they are detached from their regiments and successively sent into the various arsenals, cannon foundries, powder mills, and small arm manufactories, pyrotechnic establishments, and workshops, in order that they may become practically acquainted with the whole of the processes connected with the manufacture and supply of artillery, rockets, small arms, powder, material of all kinds, tools, &c., and also with the construction and repair of the buildings and factories required for these purposes. Sometimes they are employed as assistants in these establishments. The inspectors of the arms of regiments are selected from among those who have become acquainted with the manufacture of small arms.
When promoted to first captains they again rejoin their regiments, so that they may not lose the qualifications and knowledge required from a good practical artillery officer.
Field-officers of artillery are employed as superintendents and directors, and captains as sub-directors, of the important works intrusted to their arm.
In time of war, the officers of artillery have the construction of their own batteries, and the direction of the ordnance in battles and sieges, together with the formation of movable bridges and passages by boats.
It must be noticed, in contradistinction to the practice which prevails in England, that the artillery and engineer services manufacture their own tools.
The young engineer officers are employed with the men of their regiments, and with them pass through courses of practical instruction in the field, in sapping, mining, field fortification, sham-sieges, bridges, and castrametation. During this practical instruction one of the lieutenants belonging to each company is always present, and the captain of the company visits the work once in the course of the day.
The duties of the officers of engineers in time of peace are the construction, preservation, and repairs of fortresses and military buildings, and the command and instruction of the engineer soldiers.
In time of war, the officers of engineers are intrusted with the construction of works of permanent fortification, of the general works in the attack and defense of fortresses, and the reconnaissance connected therewith.
They may also be charged--
With the construction of such works of field fortifications as the commander-in-chief or the generals of division consider necessary; such as épaulments, trenches, redoubts, forts, blockhouses, bridgeheads, intrenched camps, as well as the opening of communications, the establishment of bridges resting on fixed supports, and the formation and destruction of roads.
After the officers of engineers have been promoted to the rank of second captain, and not before, they are mostly employed apart from their regiments, on the état major of the engineers in fortified towns and places, either in charge of the existing military buildings and fortifications, or with the duty of carrying on, or assisting to carry on, such new works as are in course of construction from time to time.
We have already stated that by the law in France one-third of the officers of the army is obtained from the military schools; one-third from the non-commissioned officers who have been raised to that grade from the ranks; while the remaining third is placed at the disposal of the supreme executive power. As regards the artillery and engineers this last third is in actual practice obtained, like the first third part, from the Polytechnic School, so that only one-third of the officers of those arms are promoted from among the non-commissioned officers, and these seldom rise above the rank of captain. Much attention is, however, paid to the improvement of the education of these latter officers, and we found that four officers of engineers and one officer of artillery so promoted were, by order of the minister of war, on the recommendation of the inspectors-general, passing through the School of Application at Metz, the course of instruction for them being modified on their account. And it was confidently expected that a large number of those officers who had been promoted in this way during the war would be ordered to the School of Application at Metz.
We should not omit to mention that occasional exchanges of service take place, during the first year of residence at Metz, among the pupils destined for the artillery, and those destined for the engineers.
The pay of officers of the artillery and of the engineers is the same. A small additional allowance is granted to officers of artillery when mounted.
REGIMENTAL SCHOOLS.
ARTILLERY REGIMENTAL SCHOOLS.
There are ten regimental artillery schools established in places or towns that are usually garrisoned by the troops of this arm, and one of these schools exists at Metz.
ENGINEER REGIMENTAL SCHOOLS.
The soldiers of the engineers appear to be very well taught in their regimental schools, of which there are three, one for each regiment, established at Metz, Arras, and Montpellier, where the regiments are usually in garrison. The strength of each regiment is 4,500 men.
The instruction given in these schools has for its object to afford, to its full extent, to the officers, sous-officiers, and soldiers of the engineers, the requisite theoretical and practical knowledge to enable them satisfactorily to fulfill the duties of their various ranks, and to qualify them for promotion to higher rank.
It is so regulated that at the end of the first year the men have learnt the nature of the service and duties of a soldier; and that at the close of the second year, the practiced sapper is cognizant of mining, and the practical miner is acquainted with sapping.
In the lowest classes the men begin with learning to read and write; this if followed by arithmetic, grammar, writing from dictation, and composition. The next subjects are special mathematics, landscape, plan, topographical and architectural drawing. We attended a class in which a corporal of sappers was explaining to the mathematical teacher (a civilian) the theory of the inclined plane, and we saw a large number of their drawings, topographical and architectural, many of which were very well executed.
The theoretical instruction is given between the months of November and March, the practical instruction in the field, (already noticed) occupies the rest of the year. The combined courses are completed in two years.
REGULATIONS AND PROGRAMMES OF INSTRUCTION
OF THE
IMPERIAL SCHOOL OF APPLICATION FOR THE ARTILLERY AND ENGINEERS AT METZ.
(Abridged.)
I. POLICE REGULATIONS.
The chief Regulations for the Police of the Establishment are as follows:--
I. BARRACKS.--The Students are lodged in Barracks in the School, under the command of a Captain of the Staff, with the title of Commandant of the Quarter. They take their meals, however, out of the Barracks, in the town. They are allowed free egress and ingress from and to their Barracks, from the call at 6 in the morning to 10 at night, excepting during the hours devoted to lectures and the studies in the rooms. During these hours they must give special notice o£ their times of going out and coming in.
II. ORGANIZATION INTO BRIGADES AND SECTIONS.--Each Division is arranged in Brigades of thirty Students at the utmost, and each Brigade in two sections. The Students of Artillery and those of the Engineers constitute, as far as possible, separate Brigades. A Captain of the Staff is attached to each Brigade for its superintendence. The students in these Brigades and Sections are arranged in the order of merit which they held on entrance, and the first Student on the list of each Brigade and of each section of a Brigade is called its Chief. This arrangement is preserved at their messes, which are held at the Restaurateurs’, each section of fifteen having its own table, and its chief being the head of the mess. Private bills or private additions to the mess are forbidden, the maximum price for the daily fare being fixed by the Commandant of the School.
III. CONDUCT OF THE STUDENTS.--All games of chance are forbidden; and any debts discovered are punished. If a Student continues long without paying such, he is reported to the Minister of War.
IV. INSPECTION OF WORK DONE WITHIN THE HOUSE.--No work or drawing may be done out of the rooms of study, except in cases of illness.
All works to be executed by the Students are considered as service ordered to be done, which must be completed at the hours and within the period fixed in the order of the day. Students who are in arrears of work at the end of their first year are required to finish them during the time of vacation.
V. SUPERINTENDENCE OF OUT-OF-DOOR WORK.--After describing facilities afforded to the Students for working in the country, and stating minutely the method to be followed, the directions add that “on bringing back their plans, Students must present their sketches, and all the notes taken by them, in their rough state, to the Officer of the Staff intrusted to inspect them. They can not begin to put their work into shape till this Officer’s visa has been affixed to the sketches, notes,” &c.
VI. VACATION.--There is one vacation at the end of the first year. Any class, or any single student, under punishment, may be deprived of this. Any work to which the Professor gives a mark below 7, must be considered incomplete, and to be done again. Students are kept up in vacation to finish their work; but if it is done within fifteen days, and marked by the Professor’s visa, they are allowed to go away for the rest of the vacation.
Young Officers, after their final examination, are subject to all the Regulations of the School, down to the moment of their leaving the town.
II. REGULATIONS FOR ESTIMATING THE VALUE OF THE WORK EXECUTED.
The time devoted to each of the courses in the School, to the works of every kind which belong to it, to the exercises, drill, theoretical instructions, &c., is fixed in accordance with programmes approved by the Minister of War; and the Table similar to that given at pages 180-181, exhibiting the employment, is each year submitted for his approbation by the Superior Council of the School.
Every kind of work, such as the out-door operations, sketches, drawings, memoirs, calculations, interrogations, manipulations, manœuvres, drill, &c., is valued by the Professor or Officer of the Staff charged with its direction, by the product of two numbers, one representing the merit of its execution, and the other the importance of the work.
The numbers representing the merit of the execution or instruction are regulated by the scale of 0 to 20, as at the Polytechnic School.
The co-efficient of importance is found by dividing the number representing the maximum value allowed for the execution of any work by 20, the maximum credit for merit; and the number representing the maximum value, allowed for the execution of any work has reference to all the circumstances bearing upon its execution. It is regulated by the number of hours appropriated to its execution; and in estimating this number of hours, regard is had, not only to the time occupied in making the drawing, but also to that which is necessary for the calculations, essays, and sketches indispensable to its execution. The lectures are reckoned at one and a half hours, and the sittings in the Halls of Study at four and a half hours.
The number of hours inserted in the Table giving the distribution of the time employed, being insufficient for the composition of the memoirs, specifications, estimates, &c., the value given for this kind of work, of which a great part is performed out of the Halls of Study, is fixed at twice the number of hours inserted in the Table showing the distribution of the time employed.
The interrogations are the subject of a special credit, the maximum being equal to the number of hours devoted to the lectures, multiplied by one and a half hour, the length of each lecture.
The credit given for a work performed outside the school is divided into two parts: one, equal to one-third of the total credit, is in the hands of the Officer charged with the superintendence of the work, who estimates the zeal and aptitude of the student; the other, equal to two-thirds, is applied by the Professor, and given according to the merit of the work.
The sum of the credits, given for work of all kinds in a course of study, forms the maximum credit for the course.
The method of fixing the credit for the execution of works, according to the time devoted to them, is equally applicable to the exercises, practice, and drill.
When the time granted for the execution of any work has expired, the Director of Studies sends this work to the Professor for his examination, who establishes the number or credit, showing its importance, and returns it to the Director of Studies.
Every work which has been finished and examined, is marked by the Professor by a number representing its merit, which number may be fractional.
This is multiplied by the number representing its importance, and the nearest whole number resulting from this product expresses the value of the examined work.
Every unfinished work receives a provisional value, and is then returned to the person executing it, and as soon as it has been completed a second evaluation is made, but only two-thirds of the difference between the first and second evaluations is added to the first; the same principle is applied to the works which have been valued below seven, or to those which have been amended or recommenced.
Every work which has not been executed by the student is marked 0; but the grounds for its non-execution are placed before the Jury of Examination.
In the event of two papers being so similar that it is evident one must have been copied from the other, and that it is not possible to decide which has been copied from the other, both are marked 0.
And on the other hand, if it is proved that there was no complicity between the authors of the two papers, the copied paper is the only one canceled.
At the end of each year’s study, the Council of the School makes a classification of the students of the two divisions.
Each of these classifications is formed of the following elements:--
1st. Notes of conduct given by the General commanding and the Colonel Second in Command.
2nd. Notes of appreciation given by the General Commanding, and the Colonel Second in Command, and by the Officers of the Staff of the School.
3rd. Tables of credits given by two Field Officers of the Artillery and Engineers on the theoretical and practical instruction with which they are charged.
4th. Tables of credits given by each Professor for the works of all kinds, interrogations, &c., of his course.
The classification of the first year comprehends all the works, drill, and practice, executed during the first year, which have been valued, as well as the notes of appreciation and of conduct.
The number appropriated to these notes at the end of the first year is equal to the moiety of the total number allowed for the two years of study.
The classification of the students of the second year presents the reunion of the works executed by them since their entrance into the school.
The maximum number of credits appropriated to all the Officers of the Staff, as a note of appreciation, is equal to one-sixth of the total of all the courses taken together.
The same number, divided into two equal parts, is assigned to the notes of appreciation given by the General commanding and the Second in Command.
Lastly, the notes of conduct given by the General commanding and the Second in Command form one-fiftieth of the total value.
For the classification of each division the Director of Studies abstracts into a Table, for each arm, all the elements which should enter into this classification. Below the name of each student are inserted all the credits which belong to him, and the total, reduced in the ratio of the maximum 20, is the definitive number of the classification of each student.
The Director of Studies appends to these Tables a report containing everything which affords a means of estimating the work, the conduct of each student, the delays, and the causes, &c. In giving the names of the students whose credits are less than 7, he proposes, conformably with the Regulations, the measures that should be taken with regard to them.
The Superior Council of the School being assembled, the different Tables furnished by the Professors and by the Officers of the Staff, as well as those in which they are summed up, are collated, and the list of classifications for each division and for each arm is fixed separately, with the definitive numbers representing the credits.
These classified lists indicate for each arm the new rank of the Students, their rank at admission to the School of Application and of passage to the first division, the sum of the values for the works executed by them, and all the elements which would tend to enable a proper judgment to be formed of their merits and conduct.
The Superior Council adds to it, if there be any necessity for it, notes, exposing the grounds which have contributed to the principal alterations in the relative position of the Student, and points out those whose credit is less than 7, as well as those who by their bad conduct deserve to become the object of exceptional measures.
Examination for Leaving.
Each year the General commanding the School determines by lot, at least one month in advance, the order in which the examinations for the promotions in the Artillery and Engineers are to take place. The Students belonging to the same arm can change among themselves, but eight days after the lots have been drawn the list of the order of examination is definitely closed. The General commanding the School makes known at the same period the order of the examinations and the division of the subjects between these examinations.
The General commanding the School places before the General of Division, President of the Jury of Examination, the following:--
1st. The division of the subjects between the three examinations.
2nd. The order of examination of the Arms, and of the students of each Arm.
3rd. The provisional classification of the students of the first division made by the Superior Council.
4th. The particular reports relating to each student made by the General commanding the School.
5th. The list of the propositions made by the Superior Council and the proceedings of the sitting at which it was agreed to.
6th. The classification of the Students of the second Division.
7th. Tables of questions established for each course.
8th. The abstracts of the sittings of the Superior Council held since the last examination.
The Student Sub-lieutenants are successively examined in all the branches composing the theoretical and practical instruction of the School. The theoretical knowledge is grouped in three series, each of which is the object of a particular trial.
The drill and practice are executed in the presence of the Jury, who cause the command to be given to the Sub-lieutenant, in order to satisfy themselves of the amount of their instruction, and to assign marks of merit to them individually.
The subjects of the three examinations are divided in the following manner:
First. Examination, made by the Field Officer of Artillery in the--
Course of Military Art. Course of Artillery. Course of Veterinary Art. Sham Siege (part relating to Artillery.) Course of Military Law and Administration.
Second. Examination, held by the Field Officer of Engineers.
Course of Permanent Fortification and the Attack and Defense of Places. Course of Construction. Sham Siege (part relating to the Engineering.)
Third. Examination, held by the third Examiner, taken either from the Artillery or Engineers, in the--
Course of Mechanics. Course of Applied Sciences. Course of Topography and Geodesy. German Language.
Every Student, on presenting himself before the Examiners, submits for their approbation the drawings and manuscripts relating to the subjects on which the examination is to bear. Independent of the questions which are placed before him by the Examiners, the Student Sub-lieutenant must reply to any objections or questions which the members of the Jury may think fit to address to him.
The German Master directly questions the Students, if the Jury wish it. The Professors or their Assistants must be present at the examinations relating to their course.
As soon as the examination is ended, the members of the Jury retire to an adjoining room with closed doors, to determine on the amount of marks to be given to the Student examined.
When the trials of all kinds are finished, the Jury proceed to the definitive classification of the Students belonging to each arm. In making this classification, regard is had to the following considerations:--
1st. Each examination has a co-efficient of importance equal to the sum of all the different courses which are included in it.
2nd. The co-efficient of importance for drawing is equal to the 1/20 of the sum of the co-efficients of the three examinations.
3rd. The co-efficient of importance of the practice, drill, &c., is, as for the courses, the sum of the co-efficients appropriated to the works taught in the School.
By multiplying the co-efficients of importance by the mean number of marks of merit obtained by the Students in the different examinations, the definitive credit which must be assigned to each Student in the Table of Classification is obtained.
The classification of the School enters into the definitive classification for a value equal to one-third of the total number of the three examinations, without comprising the valuation of the drawings; this value is added to the credits determined above.
The Jury give an account of the proceedings of the examinations in a “procès-verbal” addressed to the Minister by the General acting as President.
III. PROGRAMME OF THE ARTILLERY COURSE.
FIRST PART.--INTRODUCTION.
Twenty-six Lectures common to Students of both Arms.
First Lecture.--(1.) Definition of the word Artillery. Material, personnel, science. Object and division of the course.
FIRST SECTION.--EFFECTS OF POWDER.
Ideas on the origin of powder and its use in fire-arms; mealed or pulverized powder; powder in grain. General conditions which powder ought to satisfy; action of each of its component parts. Proportion of component parts used in France. Fulmi-ligneux.
Considerations on the physical properties of powder. Size of the grains expressed by the number of grains to the gramme. Density of the grains and specific density of the powder; circumstances causing them to vary. Effects of damp upon powder.
Second Lecture.--(2.) Combustion of powder. Different modes of ignition of powder. Research respecting the laws of its combustion, process of observation employed, laws discovered. Influence of the density, the composition, the mode of manufacture, the damp, the tension and temperature of the surrounding gases.
Combustion of the grains of powder. Calculation applied to the spherical grain. The formula is applicable to the irregular grains of ordinary powder.
Calculation of the density of the gases of powder in a fixed space, on the hypothesis of a simultaneous ignition of the grains. Discussion of the formula obtained; influence of the density of the grains, of the duration of their combustion and of the space in which the powder is inclosed.
Inquiry into the rapidity of ignition of charges of powder. Experiments made upon trains of powder, and upon gun-barrels filled with powder. Conclusions drawn from the results obtained.
Third Lecture.--(3.) Calculation of the density of the gases of the powder on the hypothesis of successive ignition.
Results of the application of the formula to charges of a spherical and a truncated form.
Tension of the gases of powder. Impossibility of determining it by considerations of a purely theoretical nature. Experimental solution of this question. Experiments by Rumfort; description of his apparatus. Results obtained. Formula representing them. Observations on these results.
Fourth Lecture.--(4.) Effects of powder in a fixed space.
Hollow projectiles. The readiest bursting of a hollow sphere takes place in the direction of the plane of a great circle. Determination of the minimum bursting charge; law by which this charge varies with the thickness of the envelope. Influence of the fuse-hole of hollow projectiles; weakening of the envelope of the shell, diminution of the charge; loss of gas, increase of the charge. Effects of the shock of the exploding gases; means of estimating it. Influence of the vivacity of the powder in burning. Number and rapidity of the explosions.
Hollow cylinders burst more easily longitudinally than transversely. Consequences of this principle relatively to the employment of a fibrous metal for the manufacture of arms. Thickness necessary to resist bursting.
Fifth Lecture.--(5.) Effects of powder in cannon.
Analytical theory of the effects of powder in cannon.
Equation of the problem. General expressions of the quantity of force exercised by the expansion of the gases,--of the density of the different sections of gas and of their tension. Differential equations of the motion of the gases, of the projectile, and of the gun. Equation of condition leading to the establishment of the general formula which determines the position of a stratum of gas in the terms of the function of its original position, and of the other data of the question. General relations between the velocity of the projectile and that of the gun.
Density of the stratum of gas at a given moment. Position of the stratum which has a maximum density.
Sixth Lecture.--(6.) Approximative solution applicable to the cases ordinarily met with in practice. Hypothesis relating to the velocity and the tension of different strata of gas.
Relations between the velocity of the projectile and that of the gun. Approximate expression of the amount of force due to the expansion of the gases; line to be followed in the execution of the arithmetical calculations. Formula serving to determine the velocity of the projectile. General considerations on the state of the gases of powder during the burning of the charge. Influence of the motions of the projectile and of the bottom of the bore on the distribution of the gases at each instant. Influence of the successive generation of the gases combined with the enlargement of the space which incloses them on their density throughout the whole duration of the phenomenon.
Seventh Lecture.--(7.) Influence of the vent and of the windage of the projectile on the effects of powder in cannon.
Determination of the loss of velocity occasioned by the windage of the projectile. Influence of the weight of the piece upon the velocity of the projectile. Influence of the weight of the projectile on tension of the gases and upon the velocities of the two bodies set in motion. Influence of the weight of the charge of powder. Charge giving the maximum of velocity. Influence of the size and density of the grains of the powder as well as other circumstances which cause a variation in the law of generation of the gases. Advantage of very rapid combustion in short pieces and of slower combustion in long ones.
Eighth Lecture.--(8.) Influence of the length of bore; circumstances which modify it; length corresponding to the maximum of velocity. Comparison of the quantities of motion of the projectile and of the gun. Trial of a formula fitted to represent their relation. Determination of this relation with the help of the balistic pendulum.
Mean pressure exercised on the projectile during its passage through the bore. Injuries produced in guns by firing; enlargement of metal and cracks; lodgment and percussion of the projectile.
Different effects of the percussion; means tried to prevent injuries (in general.) Considerations on the metals employed in the manufacture of ordnance. Charging with elongated cartridge; use of wooden bottoms and wads.
Ninth Lecture.--(9.) Examination of the proper means for measuring the effects of powder. Eprouvettes of different sorts. Experimental processes founded on the measure of the velocity of the projectile. Grobert’s rotatory machine. Process of Colonel Debooz. Process based on the employment of an electric current. Method by ranges (mentioned here by way of note.)
Balistic pendulum. Pendulum of Robins, of d’Arcy, of Hutton. Improvements introduced in France into the construction of these apparatus. Description of the pendulums in use at the present day; cannon pendulum; musket pendulum.
Tenth Lecture.--(10.) Analytical theory of the balistic pendulum.
1. Receiver pendulum; formula which gives the velocity of the projectile. Determination of the elements which enter into the formula, and the degree of approximation necessary. Simplification of the calculation of the velocities in the case of firing several times consecutively.
2. Cannon pendulum. Amount of recoil in the gun. Percussion of the knife-edges of the pendulum. Case where there is none. Means of correcting the position of the center of percussion.
Eleventh Lecture.--(11.) Examination of the effects of the recoil upon guns and their carriages. The question may be considered as resolving itself into two others.
1. Percussions of the carriage upon the points supporting it; analytical solution. Determination of the percussions and of the force of the recoil in the case of carriages on wheels, and that of mortar beds. Graphic solution of the same question by an analysis of the force which acts upon the bottom of the bore. Modification of the sketch according to the different cases presented by the direction of fire relatively to the ground.
Twelfth Lecture.--(12.) Discussion of points relating to the percussion of the carriage upon its supports, and to the force of the recoil. Influence of the elevation of the line of fire; of the inclination of the ground or of the platform; of the length of the carriage in proportion to its height and of the friction which results from the contact of the trail with the ground. Velocity of recoil of the collective apparatus. Determination of the extent of the recoil on a given ground. Recoil of the different pieces of ordnance in use. Case in which the forepart of the carriage has a tendency to be lifted up; velocity of this motion; determination of the effect resulting from it.
Thirteenth Lecture.--(13.)
2. Percussions produced by the gun upon its carriage. Determination of the amount of percussion of the breech upon the elevating screw, and of that of the trunnions upon the trunnion holes. Discussion of points relative to the effects produced. Influence of the elevation; of the dimensions of the gun, and of the proportion of its weight to that of the entire apparatus.
Effect of the elasticity of the different parts of the apparatus. It diminishes the wear of the parts struck, and renders it necessary to take into account the velocity of the parts striking.
Fourteenth Lecture.--(14.) Effects of powder in mines. Historical notices. Dimensions of the boxes containing the powder. Considerations on the effects of the expansion of the gases in an indefinite or limited compressible medium.
Definitions having reference to craters and chambers of mines. Ordinary charge of the chamber. The old rule for miners; its entire alteration. Table relating to different kinds of medium. Overcharged chamber. Overcharged chamber or “camouflet.” Limit of the effects of compression which result from the action of the chambers. Use of gun cotton. Considerations on the effects of the petard. Dimensions of the cavity reserved for the powder. Means employed or proposed to diminish the charge of powder proportioned to a given effect.
SECOND SECTION.--MOTION OF PROJECTILES IN SPACE.
Fifteenth Lecture.--(15.) Science of projectiles. Historical notices. Utility of an acquaintance with the laws of the motion of projectiles in a vacuum. Definitions relating to the trajectory. Differential equations of the motion in vacuo. Equation of the trajectory. Inclination of its elements. Velocity of the projectile at any one point. Duration of its passage. Determination of the range and of the angle of greatest range. Relations between the ranges; the initial velocities; and the angles of projection. Examination of the cases where the theory of the parabola is applicable.
Preliminary ideas on the resistance of fluids; difficulties inherent in this question. Approximative formula of the resistance, established by the help of the principle of active forces; circumstances not taken into consideration by it.
Sixteenth Lecture.--(16.) Experiments relating to the determination of the resistance of the air.
1. Case of small velocities. Rotatory apparatus; results furnished by them in the case of thin planes; their essential defect. Apparatus with rectilinear movement. Mean value of the co-efficient of the theoretical resistance in the case of thin planes; modification of this value for the case of spheres, &c.
2. Case of great velocities. Direct determination of the resistance of the air by the aid of the balistic pendulum. Experiments of Hutton, their results. Experiments made at Metz in 1839 and 1840. General expression of the resistance based upon the total of the results obtained, and containing a function of the velocity in three terms. Search after a function in two terms fit to replace in each particular case the general expression.
Seventeenth Lecture.--(17.) Theory of the motion of projectiles in the air. Differential equations of the motion. Hypothesis on the relation of the element of the trajectory to its projection. Calculations based on this hypothesis, and leading to the final equation of the arc of the trajectory. Inclination of the element of the trajectory. Velocity of the projectile at a given point. Duration of the passage.
Eighteenth Lecture.--(18.) Examination of the functions employed in the formulas of the science of projectiles. Formation of the balistic co-efficient, and the series contained in the functions. Relations of the series and the functions to each other. Arithmetical tables designed to give their values. Determination of the relation of an arc of the trajectory to its projection. Error resulting from the introduction of the constant relation in balistic calculations.
Nineteenth Lecture.--(19.) Application of balistic theories to the movement of projectiles thrown at great angles. Analysis of the trajectory, and determination of all the circumstances of the movement. Trajectory of shells considered as a single arc. Solution of several problems involved in this hypothesis. Determination of the range. Velocity corresponding to a given range and angle of projection. Angle of projection corresponding to a known initial velocity and range. Angle of greatest range. Variation of the velocity of the projectile during the whole of its passage. Limit of velocity of projectiles falling vertically in the air.
Twentieth Lecture.--(20.) Application of balistic theories to the motion of projectiles thrown at low angles. Case where the relation of the arc to its projection can be supposed sensibly equal to unity. Problems relative to direct fire; distinction established between the angle of projection and the angle of fire. In ordinary cases in practice the angle of fire is very nearly independent of the height of the object aimed at. Relations between the angle of projection, the angle of elevation of the object aimed at, and the angle of descent. Problems relating to plunging fire. (Ricochet fire.) Determination of the initial velocity and the angle of projection for a projectile which has to pass, firstly, through two given points; secondly, through one given point, the trajectory having at this point a known direction. Case of practical impossibility.
Twenty-first Lecture.--(21.) Relations between the velocities, the spaces traversed, and the durations of passage in the rectilinear movement of projectiles. They are applicable to direct fire, and are independent of the function of the velocity which enters into the expression of the resistance of the air. Case where the resistance of the air can be supposed proportional to the square of the velocity. Establishment of balistic formulas in this hypothesis. Application of the formulas to the resolution of one of the problems connected with a plunging fire. Comparison of the results obtained with those arrived at by the use of general formulas. Indication of methods applicable to the resolution of several questions in projectiles.
Twenty-second Lecture.--(22.) Examination of disturbing causes which influence the motion of projectiles.
1. Disturbing causes acting on the projectile during its passage through the bore. Imperfections of form, such as want of straightness in the bore, faulty position of the line of sight and the trunnions.
Influence of the windage of the projectile and of the percussions which result from it. Deviation from the original direction; its consequence in the different kinds of fire. Effect of the recoil and the vibrations of the barrel in the fire of small-arms.
Influence of the various causes which are capable of modifying the initial velocity.
2. Disturbing causes acting upon the projectile during its passage through the air. Influence of the rotatory motion which results from the last percussion within the bore. Effects of the eccentricity of projectiles. Case where the rotation occasions no deviation. Influence of the proximity of the ground. Deviation produced by the wind (air in motion.) Influence of atmospheric changes.
THIRD SECTION.--MOTION OF CARRIAGES.
Twenty-third Lecture.--(23.) Importance of the question. Preliminary ideas. Resistance due to the motion of a carriage and determination of the effort necessary for drawing it in the case of uniform motion. Two-wheeled carriage on level ground; the effort of draught in a direction parallel to the ground; first, resistance referable to the friction of the wheels on the axle; secondly, resistance referable to their revolution upon the ground. Influence of the weight of the carriage. Advantage of large wheels over small ones, demonstrated in the two cases of a yielding soil and a hard soil scattered over with obstacles. Expression of the power of draught necessary to overcome the two resistances united.
Twenty-fourth Lecture.--(24.) General expressions of the effort of draught necessary for two-wheeled and four-wheeled carriages; case of a locked wheel. Influence of the direction of the traces and of the inclination of the ground upon the draught. Advantage of rolling over dragging for the transport of burdens. Examination of resistances which are developed in the passage from repose to motion. Considerations on the position of the fillet in the box, and determination of the co-efficient of friction for the case of the revolution of the wheel about the axle.
Influence of the length of the nave on the frictions when the axle is thrown out of a horizontal position.
Twenty-fifth Lecture.--(25.) Turning of carriages considered successively in the case of two-wheeled and four-wheeled carriages. Center and angle of the turn in four-wheeled carriages. Calculations of the angle of the turn and of the space required by the carriage to execute a half turn. Examination of the dimensions of the carriage which influence the angle of the turn. Diameter of the fore-wheels and height of the body of the carriage; distance between the wheels and breadth of the body of the carriage; position of the point of reunion of its fore and hind parts. Examination of the circumstances favorable or unfavorable to the action of the horse. Relation between the forces to which he is subjected, and the pressure of his feet on the ground. Sliding of the feet; influence of the weight of the animal; of the co-efficient of friction; and of the direction of the traces. Lifting of the fore-hand; influence of the weight of the horse, and of the increased distance between the points on which he rests; of the position of his center of gravity; and of the direction of the traces.
Twenty-sixth Lecture.--(26.) Considerations on the mode of action of the draught-horse. Effect of his weight, and of the inclination of the traces. Effort of draught of which the horse is capable, both momentarily and continuously; results of experiments. Composition of artillery harness. Harness à limonière (with shafts and cross-bar,) or on the French system; on the German system, with pole and support. Use and discontinuance of swing bars. Arrangement of the traces. General arrangement of harness. Bât-saddle.
SECOND PART.
CLASSIFIED ACCOUNT OF SMALL ARMS AND OF ARTILLERY MATERIAL.
Twenty Lectures, of which Fourteen are common to the Students of both Arms and Six confined to Artillery Students.
FIRST SECTION.--SMALL ARMS.
Twenty-seventh Lecture.--(1.) Classification of small arms. Arms not fire-arms. Classification of hand-weapons. Considerations on the profile and outline of cutting weapons. Effect of the curve. Division of the mass. Form of the hilt.
Considerations on the profile and outline of thrusting weapons.
Position of the center of gravity; form of the point. Description of arms other than fire-arms now in use. Sabres and swords. General ideas respecting their component parts; blade, hilt, and scabbard. Regimental arms. Infantry sword. Sword-bayonet of the artillery and chasseurs, cavalry sword; peculiar requisites. Sword of cavalry of reserve, of cavalry of the line, and of light cavalry. Horse artillery sword.
Officers’ and non-commissioned officers’ arms. Cavalry lance. Camping axe. Side-arms in use in the navy. Sword, pike, boarding-axe, dirk.
Defensive armor. Cuirassiers and carabineers’ cuirasses. Cuirass and helmet of the sapper.
Twenty-eighth Lecture.--(2.) Fire-arms. Historical notices. First attempts in fire-arms. Hand cannons. Arquebuses, culverines, &c. Poitrinal, matchlock, firelock, pistol, and blunderbuss.
Means employed successively for loading and ignition of the charge. Twisted match, wheel-lock, flint-lock, percussion-lock, (the two last mentioned here by way of note.) Classified account of fire-arms now in use. Muskets. Considerations on the weight and principal dimensions of muskets. Detailed description of the infantry musket. Action of the flint and the percussion lock.
Twenty-ninth Lecture.--(3.) Comparison of the flint and the percussion musket. Voltigeur’s, dragoon’s, and double-barreled musket. Gendarmerie and cavalry carbine. Cavalry and gendarmerie pistol. Arms in which precision of aim is studied. Means employed to prevent the deviations caused by the windage of the projectiles and their rotatory-movement in the air. Diminution and suppression of the windage; straight grooves in the barrel, spiral grooves, rifled arms. Rotation of the ball about its axis of flight.
Principles of arrangement of rifled arms. Charge of powder and inclination of the grooves; two modes of solution, powerful charge and long spiral, weak charge and short spiral. Length of the barrel: conditions which determine it; number and form of the grooves.
Thirtieth Lecture.--(4.) Loading of rifled arms; ramming the ball home; loading at the breech. Different methods tried. Loading with a flattened ball; effect of the flattening of the ball. Examination of the successive improvements to which this idea has served as a basis. Chambered arms; use of the short bottom and the patch. Arms à tige. Elongation of the ball; shortening of the spiral groove; diminution of the charge: advantages resulting from it. Pointed cylindrical ball; principles of its outline; effect of the notches of the ball; superiority of this projectile over the spherical balls. Summary examination of the different models of rifled arms which have been successively in use. Versailles rifles.
Wall-piece, pattern 1831. Common rifle, pattern 1842. Wall-piece, pattern 1840. Bored-up wall-piece, pattern 1842. Pistols for officers of cavalry and gendarmerie. Rifles à tige, pattern 1846, and artillery carbine à tige. Description of these two arms. Superiority of the rifle à tige over the arms for precise aim previously adopted. Trial relating to a new improvement in the construction of rifled arms. Disuse of the “tige.” Ball with cup. Comparative notice of the fire-arms of the different European powers.
SECOND SECTION.--PROJECTILES AND CANNON.
Thirty-first Lecture.--(5.) Principles of construction of projectiles.
Considerations on the substances which may be chosen for the manufacture of projectiles. Essential conditions, density, hardness, tenacity, cheapness. Projectiles of stone, lead, cast-iron, iron, copper, gun-metal. Forms of projectiles.
Exterior form; conditions which serve to determine it. The spherical form preferable to any other in the actual state of artillery. Advantage of elongated projectiles. Conditions relating to their use. First attempts. Interior form of hollow projectiles; howitzer shells, bombs, and grenades. Thickness of the metal; fuse-hole; charging-hole of naval hollow projectiles; lugs or handles of shells. Density of projectiles. Recapitulation of the balls; howitzer shells; shells and grenades in use, their nomenclature, dimensions, weight. Cannon-balls. Choice of metal and weights. Different arrangements for the use of shot, case-shot, canister or naval grape-shot. Spherical case; conditions relating to their use. Charge of spherical case. Bar-shot. Rescue shells.
Thirty-second Lecture.--(6.) Cannon. Historical ideas on the subject. Principle of arrangement of ancient arms and machines of war. Motive force employed; its inferiority compared to that furnished by the combustion of powder. Earliest cannon.
Historical view of the different systems of ordnance which have been successively in use in France.
1. Cannon. Calibres in use in the 16th century. Edict of Blois, 1572. Cannon employed in the reign of Louis XIV. Regulation of 1732. System of Vallière. Modifications introduced by Gribeauval in 1765. Cannon of the year XI. Cannon in use at the present day.
2. Ordnance adapted to hollow projectiles. Difficulties inseparable from the throwing of hollow projectiles; first attempts. Mortars. Double fire. Ancient calibres. Mortars in use at the present day. Stone mortar. Howitzers, their first use in the French artillery; howitzers of 1765; of the year XI. Calibres in use at the present day. Considerations on the calibres of different kinds of cannon. Siege, garrison, field, coast, and naval ordnance. Siege, garrison, field, mountain, coast, and naval howitzers. Mortars and stone mortars. Considerations on the metals which may be employed in the manufacture of cannon for siege, garrison, field, coast, and naval purposes. Interior form of ordnance.
1. Part of the bore traversed by the projectile, transverse section; trial of rifled cannon, longitudinal section.
2. Part of the bore occupied by the charge; influence of its form; the spherical, cylindrical, truncated form. Chambers of mortars; reason for their adoption. Cylindrical and truncated chambers; comparison of their effects. Spherical chamber; pyriform chamber: interior form of the naval mortar à semelle (cast in one piece with the bed.) Chamber of howitzers; experiments with reference to their adoption for field howitzers. Dimension. Howitzers without chamber. Chamber of carronades. Junction of the chambers with the rest of the bore: form of the bottom of the bore or of the chamber.
Thirty-third Lecture.--(7.) Vent; its object, its dimensions. Bushes inserted before casting, (masses de lumière;) after casting, (grains de lumière.) Considerations on the position of the vent relatively to the charge. Experiments made with the infantry musket, and with 24 and 16 pounder guns.
Arrangement of the vent in guns of 1732; portfire chamber. Vent of mortars. Priming pans. Windage of projectiles; conditions which determine it for the different services. Rules received with respect to ancient guns. Dimensions in use at the present day. Different characteristics resulting from the windage of projectiles. Length of the bore. Question of the length of the bore considered with reference to the projectile effect of the powder. The length of ordnance is determined by considerations unconnected with this effect.
Length of bore of siege and defensive artillery, of field, coast, and naval guns. Length of bore of mortars, and of the stone mortar. Length of bore of howitzers. Thickness of metal and external outline. Cannon:--Theoretical determination of the external outline necessary for resistance to the effect of the gases of the powder. Co-efficient of resistance, its value in the guns in use. Thickness in the chase necessary for resistance to the percussions of the projectile.
Swell or moulding of the muzzle. Thickness at the position occupied by the trunnions. Thickness of metal of the different systems of cannon which have been successively in use in France. Thickness of metal in howitzers. Form resulting from the diminution of internal diameter, at the position occupied by the chamber. Exceptional form of the siege howitzer. Outline of the interior of mortars.
Thirty-fourth Lecture.--(8.) Line of sight; its object and arrangement. Considerations on the inclination of the line of sight relatively to the axis of the gun. Trunnions; object and arrangement of trunnions and their shoulders. Position of trunnions relatively to the center of gravity of the gun. Preponderance of the breech over the chase; manner of estimating it; preponderance allowed in the different guns in use. General principle serving as the basis for its adoption. Position of trunnions relatively to the axis of guns. Reasons for their depression; circumstances which cause it to vary. Trunnions of mortars; their reinforces. Dolphins of ordnance. Weight of ordnance; necessary relation between the weight of a gun, and the quantity of movement of its projectile. Conditions serving to determine the weight of the different species of cannon, howitzers, and mortars in use. Examination of the weights adopted for the pieces of ordnance of all sorts, which have been successively employed. General recapitulation of the different species of ordnance in use. Nomenclature. Dimensions, weight. Land artillery. Siege, garrison, and field guns. Siege, garrison, field, and mountain howitzers, mortars, and stone mortars. Naval artillery. Cannon, carronades, howitzers, mortars, stone mortar, blunderbuss. Observations on ordnance. Exceptional ordnance. Villantroy’s howitzers. Belgian mortar of 60 c., &c. Description of the artillery petard.
THIRD SECTION.--WAR AND SIGNAL ROCKETS.
Thirty-fifth Lecture.--(9.) Historical ideas on the subject. Cause of the motion of rockets. Their exterior and interior form. Relation which should exist between the law of generation of the gases and the orifice for their escape. Measure of the tension of the gases in rockets. Results of experiments. Motion of the rocket. Variation of the velocity during its passage. Means of regulating the motion; effect of the directing stick. Influence of the wind upon the trajectory of the rocket.
Description of rockets in use.--1st. War rockets; calibres employed; body of the rocket; arrangement of the stick. Projectiles fitted to the head of the rocket; rockets without stick. 2d. Signal rockets; their calibres and composition.
FOURTH SECTION.--CARRIAGES.
Thirty-sixth Lecture.--(10.) Historical ideas on the subject. Arrangements originally in use for the service of ordnance. Successive improvements. Carriages on wheels. Introduction of limbers. General conditions which gun-carriages should satisfy.
General principles of their construction:--1st. With reference to the act of firing. 2dly. With a view to transport.
Mortar carriages. Particular requisites. Description of the carriages in use. Siege carriages; particular conditions. General arrangement of ancient siege carriages. Detailed description of the present siege carriage and its limber; its weight and different characteristics. Field carriage; particular requisites; general arrangement of the carriages employed before 1765. Field carriages of the system of Gribeauval; its defects. General arrangement and detailed description of the present field carriage and of its limber. Weight and different characteristics. Mountain carriages; particular requisites; description of the carriage and of the arrangement of its shafts (limonière.)
Thirty-seventh Lecture.--(11.) Garrison and coast carriages; particular requisites; object of the platform for the two systems; its principal dimensions; position of the pintle or working bolt (cheville ouvrière.) General arrangement of ancient garrison and coast gun-carriages. Description of the present garrison carriage; change of the carriage into a movable one on four wheels; weight and different characteristics. Replacement of the platform by a directing transom bed under certain circumstances of the service. Casemate carriage. Iron carriages; inconveniences of this kind of construction for siege purposes and on the field of battle; its advantages for the armament of coasts. Description of the coast carriage actually in use; weight and different characteristics. Naval carriages; particular requisites. General arrangement of naval carriages in use. Carriage on four small wheels for cannon. Bracket carriage (à échantignolle,) and carriage with double pivot platform for howitzers. Carronade carriage. Mortar bed, cast in one piece with the mortar, (à plaque.) Exceptional methods of construction. Depressing gun carriages for a very plunging fire. Villantroy’s howitzer beds, those of the Belgian mortar of 60 c., &c.
FIFTH SECTION.--CARRIAGES AND OTHER PARTS OF AN ARTILLERY TRAIN. ARTILLERY OF FOREIGN POWERS.
Thirty-eighth Lecture.--(12.) Battery carriages. Ammunition wagon. Historical ideas on the subject. Requisites for carriages used for the transport of munitions of war. General arrangement and description of the present ammunition wagon. Principles of arrangement of the ammunition chest. Loading of the chest with munitions of various kinds. Mountain ammunition chest. Loading of the chest with howitzer ammunition and infantry cartridges.
Battery wagon; object of this carriage; patterns successively adopted. Description of the wagon, pattern 1833. Field forge; object of this carriage. Description of the forge in use. Arrangement and play of the bellows. Mountain forge. Description and loading of it.
Thirty-ninth Lecture.--(13.) Park carriages and machines.
Park wagon. General arrangement and description of the park wagon and its limber. Carriages destined to the transport of heavy burdens. Ancient gun wagon. Truck. Block carriage. General arrangement and description of the carriage. Siege cart; its object and description. Devil carriages. Arrangement of the ancient devil carriages with perch and with screw. Devil carriage with roller. Description of the carriage and of its mechanism. Gin. General arrangement of the different patterns successively employed. Description of the gin at present in use. Handscrew; its use, general arrangement, and description.
Fortieth Lecture.--(14.) Pontoon equipages. Conditions which military pontoon equipages should satisfy. Considerations on the nature of the supports to be employed. Reserve pontoon equipage. Boat of the reserve equipage; its general form and dimensions. Description of the boat and skiff; use of the boat for navigation; its weight and different properties.
Tackle and machines employed for bridge-making. Balks, moorings, chesses, blocks, and balk collar. Framework, with movable head; different kinds of piles. Means of anchorage. Common anchor; its properties. Anchor basket and chest. Buoy. Cordage. Ideas on its arrangement and on the measure of its resistance. Capstan. Windlass. Tackling. Handscrew. Pile driver. Hand rammer. Grapnel and hooks.
General arrangement of the boat carriage. Description. Its weight and properties. Light equipage.
Forty-first Lecture.--(15.) General ideas on the artillery of the different European powers, and comparison with the French material.
Ordnance; description, species, and calibres. Gun-carriages, carriages, and other parts of the train. General arrangement; facility of movement; modes of harnessing, &c.
SIXTH SECTION.--DETAILS OF CONSTRUCTION OF GUN CARRIAGES AND ARTILLERY CARRIAGES, AND MEANS OF PRESERVATION OF MATERIAL.
Forty-second Lecture.--(16.) Knowledge of woods. Preliminary ideas. Structures and general properties of woods. Diseases and defects of woods. Description and properties of the principal substances employed in the construction of the material; uses to which the different kinds of wood are specially destined. Selection of standing timber; felling; transport; reception of woods; cubature. Cutting up in large and small sizes. Observations on the shrinking of wood. Preservation of woods. Drying in the air. Round, squared, and blocked-out timber. Preservation in store; preservation in water. Steeping. Influence of the contact of woods with other woods, and with metals.
Forty-third Lecture.--(17.) General considerations on the substances employed in the manufacture of gun and artillery carriages. Different properties of metals. Choice of kinds of wood; effects of their being dried. Classified account of axles and wheels. Axles; substance employed, their forms and dimensions. Wheels; essential requisites. Importance of the elasticity of wheels. Effects of the dishing of a wheel, form of the spokes, coupling of the spokes with the nave and the felloes. Tires. Form and number of the felloes determined by the effects of the drying. Form of the nave. Wheel-boxes.
Forty-fourth Lecture.--(18.) Means employed for the connection of the pieces which enter into the composition of gun-carriages, carriages, and other furniture of the train. Nails, clinch nails, rivets, bolts, screws, &c. Examination of the joinings employed in the construction of gun-carriages, carriages, and other furniture of the train.
General principles. Joinings of gun-carriages. Joint plates (“rondelles d’assemblage.”) Mortar beds, siege, field, and garrison carriages.
Forty-fifth Lecture.--(19.) Joining of other carriages and furniture. Hind parts, ammunition wagon, battery wagon, forge, park wagon, block carriage, cart, devil carriage, and drays. Boat and wherry. Fore parts, particular requisites. Fore parts of the field and siege carriage, of the park wagon, devil carriage, and drays. Barrels and cases.
Forty-sixth Lecture.--(20.) Means employed for the preservation of the material. Cost price of the principal parts of the material. Ordnance, projectiles, powder, carriages, and other furniture of the train. Small-arms. Preservation of ordnance in gun-metal and cast-iron. Preservation of projectiles. Formation and counting of piles. Rust-cleaning machine. Preservation of gun-carriages, carriages, and other furniture of the train. Different methods of stacking in use. Preservation of powder and made-up ammunition; stacking in powder magazines. Means proposed for avoiding the danger of explosion. Preservation of small-arms. Armories. Preservation of iron and cut wood.
THIRD PART.
FIRE OF ORDNANCE AND PORTABLE FIRE-ARMS. EFFECTS OF PROJECTILES.
Forty-seventh Lecture.--(1.) Fire of ordnance. Kinds of fire in use with ordnance. Choice of charges of powder. Charges of powder formerly in use; their progressive reduction. Charges of field, siege, garrison, coast, and ships’ cannon; of howitzers and mortars.
Arrangement of the charge. Shot cartridge for field guns. Loading of the other kinds of guns, of howitzers, mortars, and the stone mortar. Loading for fire with red-hot shot. Armaments for the service of ordnance. Methods of igniting the charges of powder; tubes formerly in use, friction tubes. Percussion system; Swedish tube. Ignition of the charge of hollow projectiles, fuses of hollow projectiles, fuse with several pipes for the fire of spherical case, hand grenade fuse. Rapidity of fire. Laying of ordnance. Principal methods of laying guns; laying them by the help of the line of sight. Determination of the elevation. Instruments in use to obtain elevations. Negative elevations, means of using them. Laying guns for fire parallel to the ground; for breaching fire at a short distance.
Forty-eighth Lecture.--(2.) Determinations of elevations by experiment; construction of practice tables. Laying guns when the axis of the trunnions is not horizontal. Laying guns with the help of the plumb-line and quadrant; plunging fire, rectification of the aim.
Fire of mortars, means for directing it in use; use of pickets, of the line, of the quadrant. Laying pieces in the case of a defective platform. Means of laying them for night-firing. Laying naval ordnance; use of the front sight. Initial velocities of projectiles with the different charges in use. Angles of sight, and point-blank ranges of ordnance. Ranges at different sights. Maximum ranges.
Forty-ninth Lecture.--(3.) Probabilities in the fire of ordnance; known laws, facts ascertained by experiment. Distribution of projectiles over an object aimed at of indefinite extent. Mean point of impact. Fire of canister; effects of the dispersion.
Fire of spherical case. Effects of the bursting of the projectile; dispersion of the balls and of the explosions. Fire of the stone mortar; use of mortars for the same purpose.
Fire of small arms: charges of powder adopted. Ball cartridge. Initial velocities of balls with the different arms. Angles of sight and point-blank ranges. Rules for fire according to distances, for muskets, carbines, and pistols. Fire of rifled arms; use of the tangent scale. Probability of the fire of small-arms; comparison of arms with smooth-bored and rifled barrels. Different means employed for the estimation of distances.
Fiftieth Lecture.--(4.) Effects of projectiles on the different substances fired at. Effects of concussion and penetration. Effects on earth. Theory of the penetration of a projectile into a resisting medium. Formula to express the penetration, based on the results of calculation and experiment. Effects of penetration into wood. Effects on metals, cast-iron, iron, lead. Effects on masonry and on rock. Application to a breaching fire delivered in a regular direction relatively to the revetment. Effects of the shock of projectiles upon living bodies. Effects of hollow projectiles bursting in different media; earth, wood. Method of bursting employed against troops.
Effects of spherical case. Incendiary effects. Effects of war rockets. Explosive rockets. Incendiary rockets. Effects of concussion.
FOURTH PART.
TRACE AND CONSTRUCTION OF BATTERIES.
Six Lectures, common to the Students of both Arms.
Fifty-first Lecture.--(1.) Definitions. Meaning attached to the word “battery.” Different denominations given to batteries: first, according to the circumstances of the war in which they are employed; secondly, according to their mode of construction; thirdly, according to the kind of ordnance with which they are armed; fourthly, according to the kind of fire for which they are intended; fifthly, according to the direction of their fire.
Principles of construction. General considerations on the elements which constitute the different kinds of batteries which have reference to them. Epaulment; its length, height, and thickness in different cases. Section of the epaulment. Ground-plan of the epaulment of the different kinds of batteries; returns at its extremities. Case where the battery is in advance of a parallel. Epaulment with redans; its trace.
Embrasures opened in the epaulment; their construction in different cases; slope of the bottom; interior opening; exterior opening; form of the cheeks.
Genouillère; fixing of its height for the different kinds of fire. Limit of the obliquity of the embrasures.
Fifty-second Lecture.--(2.) Terre-Plein; its position relatively to the ground; its length for the different kinds of batteries. Disposition of the part unoccupied by the platforms. Terre-plein of garrison, field, coast, and barbette batteries.
Ditch; cases in which it is employed. Its position with reference to the epaulment. Depth, breadth, section, and plan of the ditch.
Communications between the battery and the works, in its neighborhood; parallels or trenches; plan and construction. Communication between the battery and its ditch.
Powder magazines: their object. Discussion respecting their site and capacity with a view to the different kinds of batteries, viz., siege, garrison, and field batteries.
Traverses of crownwork and garrison batteries. Width between them and dimensions.
Fifty-third Lecture.--(3.) Details of construction. Different materials employed in the construction of batteries. First, materials for revetments, fascines, gabions, hurdles, sods, bags of earth, withy-bands, stakes, &c. Secondly, materials for platforms; hurtoir, sleepers, planks, beams, pickets. Construction of revetments of different kinds employed in batteries. First, revetment of the interior slope of a battery upon the natural ground. Secondly, revetment in use when the terre-plein is more or less sunken. Ordinary siege battery, battery in a parallel, battery in a crownwork. Third, revetment of the checks of embrasures in the different cases met with in practice; direct batteries with point-blank range; ricochet, breaching, garrison, and field batteries.
Fifty-fourth Lecture.--(4.) Construction of platforms. Ordinary siege platforms, movable platforms (à la Prussienne,) garrison and coast platforms, ordinary mortar platforms, platforms for coast mortars of great range. Peculiar case where the fire has to be elevated or greatly depressed. Construction of the communications from the battery to the parallel and to its fosse. Construction of powder magazines in batteries. Magazines of siege batteries, Nos. 1, 2, 3, 4. Case of breaching batteries; garrison battery and field battery. Magazines. Degree of resistance offered by blinded magazines. Modifications adopted for the strengthening of magazines whose construction is already fixed.
Fifty-fifth Lecture.--(5.) Number of workmen to be employed on the construction of the different parts of batteries: revetments, platforms, communications, powder magazines. Earthworks.
Duration of the total labor necessary for the construction of each kind of battery. Duration of the duty for the different parts of the personnel employed upon the construction; officers, gunners, assistants. Definitive number of workmen necessary for the construction of the different kinds of batteries. Tools of different kinds.
Simultaneous execution. Preliminary operations. Reconnaissance. Prolongations. Sketch of the plan of a battery. Formation of the working party. Transport of materials. Plan of the battery. First, battery having its terre-plein on the level of the ground. Disposition of the working party. Work of the first night, of the following day, of the second night. Second, a battery sunk outside a parallel. Third, battery in a parallel or trench of some kind already established. Day labor, night labor.
(4.) Particular case of crownwork batteries.
Fifty-sixth Lecture.--(6.) Exceptional constructions. Blinded batteries for cannon or howitzers; for mortars. Batteries of earth-bags. Batteries on stony ground, on the rock, or marshy soil. Floating batteries. Construction on sites deficient in space. Case where the fire of the place is too dangerous. Coast batteries. General arrangement.
Instruction preparatory to working at the plans of batteries. (Course.)
FIFTH PART.
UNIFORM ORGANIZATION AND SERVICE OF THE ARTILLERY.
Ten Lectures common to Students of both Arms.
FIRST SECTION.--UNIFORM ORGANIZATION OF THE ARTILLERY.
Fifty-seventh Lecture.--(1.) Historical résumé. Progress of modern artillery, from its origin down to our time. Artillery of Charles VII. and of Louis XI. Progress under Francis I. Effects of the wars of religion. Edict of Blois, 1572. Improvements by Sully. Creation by Gustavus Adolphus. State of the artillery under Louis XIV. Employment of artillery on the field of battle at the commencement of the 18th century. Regulation of 1732. Introduction of howitzers into the French artillery. Regimental pieces. Progress of the artillery in Prussia and in Austria in the Seven Years’ War. Reorganization of the French artillery in 1765. Résumé of the improvements owing to Gribeauval. System of the year XI. Present system.
Historical ideas on the personnel of the artillery. State of the personnel at the commencement of the use of fire-arms. Masters and grand-masters of the artillery, &c. Personnel employed originally on the service, and the guard of ordnance. Creation by Louis XIV. Account of the successive modifications in the personnel from this epoch down to 1765. Organization of 1765. Horse artillery. Pontoneers. Artillery train. Artillery of the Imperial Guard. Organization of 1829. Present state of the personnel. Regiments of artillery. Composition of the personnel of the different kinds of batteries. Companies of pontoneers, workmen, armorers, veteran gunners. Driver-corps (“train de pare.”) Naval artillery.
Fifty-eighth Lecture.--(2.) Committee and central depôt of artillery. Organization of artillery commands. Establishments for the instruction of the personnel; artillery schools. Creation in 1679. Present schools; personnel attached to them. Central school of military pyrotechnics. Establishments for the preservation of the material. Importance of the material of artillery. Its state in France at different epochs. Artillery directions. Division of the territory of France. Personnel of the directions.
Establishments for the manufacture of the material. Ideas on the subject of their management. Arsenals; their object, management, number, personnel. Forges; their object, management, districts, personnel, inspection. Foundries for land artillery; their number, management, personnel, inspection. Naval foundries. Manufactures of arms; their special management, number, personnel, inspection. Branch of the service connected with gunpowder and saltpetre. Powder manufactories and refineries; management, personnel. Direction of the service. Establishments existing in France. Percussion cap manufactory.
SECOND SECTION.--SERVICE OF THE ARTILLERY IN THE FIELD. ORGANIZATION OF THE FIELD ARTILLERY TRAIN, ETC.
Selection of ordnance, conditions which determine it; cannon, howitzers, relation between them. Proportion of the number of pieces of ordnance to that of the combatants. Mean proportion received in France; circumstances which may lead to a modification of it. Organization of ordnance in batteries. Account of the arrangements formerly adopted. Present system. Distribution of the batteries in the army. Principles received. Application of these principles to the artillery train of an army of a given strength. Infantry divisional batteries; cavalry divisional batteries; reserve batteries. Case of the formation of army corps. Composition and supply of batteries. Principles and details of the supply of batteries with ammunition for the guns and for the troops. Second supply distributed amongst the parks.
Fifty-ninth Lecture.--(3.) Field parks. Their composition, in carriages of all kinds. Application of the principles to the artillery train of an army of a given strength. Approximate relation of the number of the carriages and of the horses of the train to that of the pieces of ordnance. Means of renewing the supply of the parks.
Personnel of the field train. Personnel of the batteries; working companies. Companies forming part of the train. Personnel attached to the parks. Staff. Particular conditions, having reference to war in a mountainous country. Selection of pieces of ordnance. Proportion between their number and that of the combatants. Composition of some artillery trains employed in our African expeditions. Composition and supply of the mountain battery. Lading of the mules. Composition of pontoon trains. Reserve train, boats, wherries, tackle, carriages, and horses. Personnel of the train. Light train: material, personnel.
Sixtieth Lecture.--(4.) Marches of the artillery. Reception of a battery or of a park. Precautions to be taken before the departure. March at a distance from the enemy. Order of march. Distribution of the personnel; halts. Case of an accident to a carriage; ascents; descents; deep-bedded roads; passage through inhabited places; passage of bridges; of fords. Passage over ice. Night march. Transport of mountain artillery. March of pontoon trains. Transport of the trains by water; navigation by convoys; by isolated boats. Transport of ordnance, powder and projectiles in the boats. Transport of artillery trains by sea.
March in the vicinity of the enemy. Isolated convoys; rule with reference to their command; order of march; general measures of security; precautions to be taken during halts; manner of receiving an attack. Case where resistance becomes impossible; arrangements for the night.
Artillery in the march with other troops. Order of march. Relation of the different corps to each other. Exceptional difficulties which may occur on marches; privations of all kinds; bad weather; bad state of the roads; instances. March among high mountains; passes strongly occupied by the enemy; examples.
Encampments and bivouacs. Choice of ground convenient for a camp; disposition of the artillery camp. Establishment of artillery bivouacs. Disposition of the park; precautions relating to the superintendence. Different measures to be taken on arriving on the place of encampment or of bivouac. Attention to be paid to the horses: special precautions for the mules of the mountain artillery. Precautionary measures variable according to circumstances.
Sixty-first Lecture.--(5.) Artillery on the field of battle. Measures to be taken on arriving in the neighborhood of the enemy.
Choice of positions adapted for artillery.
1. Different considerations relative to the ground to be occupied; form of the ground; cultivated lands; nature of the ground; communications, &c.
2. Position of the artillery relatively to the enemy.
3. Position of the artillery relatively to the troops to be supported.
Execution of the fire. Choice of the different kinds of fire according to the nature of the object aimed at and the distance. Fire of cannon, with ball, with shot. Fire of field and mountain howitzers. Fire parallel to the ground.
Use of war rockets. General principles relating to the effects to be produced by artillery, and to the warmth of the fire. Proper use of stores; their replacement. Use of the prolong. Arrangements to be made after the engagement. Spiking and unspiking of ordnance.
Use of artillery in the principal circumstances of a campaign. General case of an offensive engagement. Part played by the artillery in supporting infantry and cavalry marching to the attack. Importance of the artillery for following up a first advantage which has been obtained. Examples. Use of the artillery in masses to strike a decisive blow. Examples. Defensive engagement.
Disposition and use of the artillery for the defense of fortified positions. Attack of entrenchments. Reconnaissance. Disposition and use of artillery; attack of lunettes by the gorge. Examples. Attack and defense of villages; disposition of the artillery under these two circumstances. Attack of squares. Importance of artillery towards preparing for it. Examples. Defense of squares; disposition of artillery. Examples. Case of a charge of cavalry upon artillery. Use of artillery in the advanced guard, in the rearguard, in a retreat.
Use of artillery in the passage of streams. Examples. Use of artillery to defend or force the passage of valleys or defiles. Examples.
THIRD SECTION.--SERVICE OF ARTILLERY IN THE ATTACK AND DEFENSE OF PLACES, AND IN THE DEFENSE OF COASTS.
Sixty-second Lecture.--(6.) Object to be attained with the use of artillery in the attack of places. Selection of ordnance, cannon, howitzers, mortars. Composition of the siege train. Method to be followed in order to determine it. Examples of trains employed in different sieges. Carriages of the train. Supply of the siege train with projectiles, powder, &c.
Personnel of the siege train; troops and staff. Transport of the siege train. Horses to be employed. Limit in either direction. Employment of watercourses. Examples. Establishment of the train before the place. Encampment of the artillery force. Organization of the parks. Workshops, powder magazines, trench-depots. Rules relating to the direction of artillery works.
Commanding officers of attack.
Sixty-third Lecture.--(7.) Considerations on the different kinds of batteries to be employed in the attack of fortified places. Position of the batteries relatively to the point to be breached. Direct battery within point-blank range; enfilading battery, for a plunging fire, for direct fire within point-blank range, for plunging fire. Mortar batteries. Composition of the different kinds of batteries. Position of the directing lines of an enfilading battery, relative positions of the cannon, the howitzers, or the mortars. Position of the batteries relatively to the parallels and the rest of the trenches. Examination of the circumstances which affect the power of a plunging fire, command of the work over the battery; distance between the height of the traverses. Slope of the crests of the work.
General principles relating to the order of the works of the artillery, commencing from the opening of the trenches.
Times for the construction of the first batteries. Batteries of the first and second parallels. Use of field artillery to defend the flank of the attacks. Replacement of the fire covered by the advance of the works; batteries of the third parallel. Use of vertical fire. Mortars of 15c. Throwing of grenades. Breaching and counter batteries. Considerations relating to their position. Batteries in the covered way.
Case of a breach into an interior work. Composition of the breaching and counter batteries. Calibres to be used. Number of pieces of ordnance.
Ideas upon the operation of arming batteries. Precautions to be taken. Passage out of the parallels or trenches. March in the trenches; examples of some operations of this kind. Supply of the different kinds of batteries. Rule relating to their daily service. Firing of siege batteries. Opening of the fire. Direct fire within point-blank range. Plunging fire. Fire of mortars. Warmth of the fire by day and by night; mean consumption of material. Fire of breaching batteries. Effects to be produced. Height of the horizontal cutting, number of the vertical ones. Execution of the fire; fall of the revetment. Fire upon the counter forts. Fire to render the breach practicable; balls, shells, war-rockets, facts ascertained by experiment.
Consumption of powder and projectiles, length of the operation. Breaching fire in a very oblique direction. Fire upon masked masonry. Breach into an unreveted work. Fire of counter-batteries. Bombardment. Case where it can be employed; manner of executing it.
Occupation of the place; arrangements which must be made by the artillery. Case of raising the siege. Case of its transformation into a blockade.
Sixty-fourth Lecture.--(8.) Service of artillery in the defense of places. Object to be attained with artillery. Selection of ordnance, guns, howitzers, mortars. Use of war-rockets and arms of precise aim. Field artillery. Basis of the supply of fortified places. Projectiles, powder, small-arms, various carriages. Personnel of the artillery. Troops. Staff.
Measures to be taken before the siege. Reconnaissances. Arrangement of the material. Organization of the personnel, of the duty by local divisions, of the workshops of all sorts. Precautionary armament. Basis of its organization. Supply of ordnance. Defensive armament. General principles relating to the armament of different kinds of works. Bastions, cavaliers, demilunes, approaches, &c. Organization of the armament. Traverses, embrasures, gun-carriages to be employed. Powder magazines. Supplies. Service of pieces.
Employment of the artillery against the first works of the besiegers, against the construction and armament of batteries; against the besieging artillery. Partial disarmament in case of inferiority. Part played by artillery in sorties. Modification of the defensive armament in proportion to the progress of the attack. Last defensive armament. Principles relating to its disposition. Armament of the flanking part of the fortification. Increased use of vertical fire. Use of war-rockets against works in close proximity. Crowning batteries, cavaliers of the trenches. Heads of saps, &c. Blinded batteries. Conditions of the establishment. Defense of breaches.
Service of artillery in the defense of coasts. General considerations on the degree of extension admissible in the armament of coasts. Principal points to be defended. Selection of ordnance intended for the armament of coast. Objects to be effected. Effects of balls (utility of large calibres;) of howitzer shells and of shells. Fire with red-hot balls. Material appropriated to the defense of coasts.
Position of coast batteries, conditions which determine it. Composition of coast batteries; their supply. Ideas upon the organization of the batteries and their small redoubts (réduits.) Use of the fleet and of field artillery. Personnel allotted to the service of artillery on the coasts.
FOURTH SECTION.--APPLICATION OF THE PRINCIPLES PREVIOUSLY SET FORTH TO THE ATTACK AND DEFENSE OF THE FORTRESS OF METZ, (SHAM SIEGE.)
Sixty-fifth Lecture.--(9.) Composition of the siege train necessary for the attack of Metz. Carriages of the train.
Supply of the train with projectiles, powder, &c. Personnel of the train, troops and staff. Transport of the siege train. Establishment of the train before the place; encampment of the artillery force. Organization of the parks. Work-shops, powder magazines and depôts.
Sixty-sixth Lecture.--(10.) Object, disposition, and armament of all the batteries from the first opening of the trenches to the capture of the place. Use of field artillery to flank the batteries, &c.
Service of artillery in the defense of the place. Supply of ordnance, projectiles, powder, small-arms, and different carriages.
Personnel of the artillery. Troops, staff. Organization of the personnel and of the duties by local divisions. Precautionary armament; supply of ordnance. Defensive armament. Armament of the different works. Service of the pieces. Last defensive armament.
Lectures Preparatory to the Labors of the Course.
1. Drawing and tracing of ordnance, 3 lessons. 2. Design for ordnance, 4 “ 3. Application of the theories of the course, 1 “ 4. Drawing of artillery material, 1 “ 5. Tracing of batteries, 1 “
The sixth lecture of the fourth part of the course (the fifty-sixth) is partly devoted to the communication of the instructions necessary for the execution of the work of tracing plans of batteries.
Studies in connection with the Artillery Course.
The practical studies which are connected with the artillery course, are,--
1. Drawing of ordnance, 12 days. 2. The designs for ordnance, 24 “ 3. The application of the theories of the artillery course, 6 “ 4. The drawings of artillery material, 26 “ 5. The tracing of batteries, 4 “ -- Total, 72 days.
The tracing of batteries is executed by the students of both arms, the other tasks by the artillery students alone.
I. DRAWING ORDNANCE (12 DAYS.)
The survey of ordnance consists in constructing accurate sketches of a gun, howitzer, and mortar, in measuring their dimensions, and in giving a description of each of the pieces drawn. It is on this occasion that the students are practiced in the management of instruments to insure precision, such as the étoile mobile, and the sliding compass, &c. One day is devoted to this work.
The tracing of ordnance consists in the execution of a drawing upon colombier paper, containing an exact and detailed representation of a gun, a howitzer, and a mortar, with their projectiles.
This work is performed with the help of the tables for the construction of ordnance. Eleven days are devoted to it.
Detailed Programme of the Drawing.
1. For each gun, howitzer, or mortar, a longitudinal section in the direction of the axis, and at right angles to the axis of the trunnions, and a plan parallel to the axis of the bore and of the trunnions.
Besides this, for those cannon and howitzers which have dolphins, a transverse section taken across the middle of the dolphins and the axis of the trunnions. For mortars, a transverse section made by a plane passing in front of the dolphins, the whole on a scale of one-fifth.
2. Detail of the button (comprising the cascable and breeching loop for naval ordnance) on a scale of two-fifths.
3. Detail of the tracing of a dolphin, on the scale of two-fifths.
4. Tracing of the bush of a gun, on a scale of two-fifths, and tracing of a priming-pan at the real size.
5. For garrison ordnance, in cast-iron, detail of the widening of the base ring on a scale of two-fifths.
6. Tracing of a cannon-ball, of a howitzer-shell, and of a shell, on a scale of one-fifth.
Tracing of the lugs of a shell, ring and lug at the real size.
All the parts of the drawing must be colored in uniform tints in conformity to the table of conventional colors; the annexation of the figures of measurement is not required.
This work is preceded by three or four lectures intended to make the students familiar with the tracings which they have to execute, and the solution of the problems in geometry and descriptive geometry, to which the representation on paper of pieces of ordnance and their projectiles give rise.
II. DESIGN FOR ORDNANCE (24 DAYS.)
The design for ordnance has for its object the complete determination of the nature of a projectile, and of a piece of ordnance in accordance with certain special conditions, inquiring into the laws of the motion of the projectile, and into its principal destructive effects, and the settlement of practice-tables for the gun. The general case for treatment is that of a howitzer, which comprehends the gun and the mortar as particular cases.
The data usually adopted are,--
1. For the projectile, its weight and the quantity of powder which it is capable of containing.
2. For the piece, the initial velocity of its projectile. This operation comprises calculations, a drawing, and a memoir.
The drawing, on colombier paper, which must be figured in all its parts, contains,--
1. The tracing of the profile of the piece, as it is determined by calculation, so as to satisfy the different conditions of resistance, on a scale of one-fifth.
2. The complete tracing of the piece executed in conformity with the rules laid down for the tracing of ordnance on a scale of one-fifth.
3. Tracing of the projectile on a scale of one-fifth.
4. Tracing of the wooden bottom and of the fuse of the projectile, executed in the case of each of these objects in two figures--the one on a large scale (two-thirds, or even the size of nature,) representing the inquiry into their forms and dimensions, the other giving on a scale of one-fifth the results of this inquiry. To this is added, for the mountain howitzer, or any other howitzer for which it is admissible, a tracing of the mounted howitzer carriage.
5. The representation in drawing of the laws of the motion of the projectile, the trajectory, inclinations, remaining velocities, durations of the passage.
In addition, the scale of the elevations and that of the angles of fire, for an object of aim placed at different distances.
6. An inscription showing all the essential elements by which the projectile and the piece are distinguished.
The final tracings of the gun, the projectile, the bottom, and the fuse, must be colored in uniform tints conformably to the table of conventional colors.
As to the tracing of the profile founded upon the calculation, it should receive merely an edging of the color which represents the metal used.
PROGRAMME OF THE MEMORANDUM ON THE DESIGN FOR ORDNANCE.