The young man and civil engineering

Front matter

OassZAiiL

COPXRIGHT DEPOSm

VOCATIONAL SERIES

Table Of Contents

CHAPTER rAOB

I Historical Introduction 1

II Branches of Civil Engineering .... 27

Chapter I Introduction

The field of engineering is so large, and its extent and limitations so little understood by the layman, that it is necessary at the outset to consider briefly the history of engineering and of the development of its various branches, in order that the reader may clearly perceive the proper meaning of the term "engineering," as well as of the narrower terms "civil engineering," "mechanical engineering," etc.

Engineering may perhaps- be most briefly and at the same time most broadly described as the science and art of construction. Whoever constructs a thing, whether it be a bridge, a railroad, a steam engine, or a watch, is in the broadest sense an engineer. But there are obvious limitations and extensions of this definition, and these, as we shall see, lead to a more accurate definition. Engineering involves not merely manual or mechanical skill, but intelligent application of the laws of nature. Something more is required than mechanical proficiency in the use of tools or materials. The man who runs the engines in a mill, or the workman who fashions the parts of a locomotive, is not an engineer in the true sense. A knowledge of the reasons why certain mechanical operations have to be performed, and an intelligent adaptation of the laws of nature to the attainment of those ends, is necessary, and this involves the distinction between an art and a science.

A science teaches us to know and an art to do. A scientific man studies the reasons for things, investigates the laws of nature, and designs the means of adapting them to the end in view. The merely mechanical routine work of performing the operations necessary for the production or construction of the object or agency desired, is not engineering. A skilled mechanic, therefore, is not an engineer ; neither is a skillful roadmaster of a railroad, though he superintends the laying and maintenance of the track ; unless these men, in addition to being skilled in doing, are also skilled in knowing, so that they understand the reason why, and can adapt means to ends ; modifying, if need be, their usual practice to meet particular emergencies.

In a similar manner, the scientist who, in the solitude of his study or laboratory, investigates the laws of nature, and perhaps discovers new ones, is not necessarily an engineer, unless he has the capacity of also showing how his discoveries may be made useful, though perhaps he may not himself have the mechanical skill necessary to put them into actual use, or to fashion the tools or instruments necessary for that purpose. An art, therefore, is, or should be, founded upon a science, the science teaching what to do, how to do it, and why, while the art develops the specific means of accomplishment.

Engineering is, therefore, both a science and an art. The engineer must know and must also be able to do. The important thing is the knowing, or the science. The engineer may not actually do a great deal with his hands, but he must at least know how to do it, should it be necessary; and, strictly speaking, he is not an engineer unless he is engaged to some extent in actually doing, whether with his own hands or by directing the hands of others. In a similar manner, the mechanic who is skillful with his hands, if he also knows the scientific principles governing the things which he does, and is able to coordinate intelligently the science and the art, may not be denied the title of engineer, provided he actually does use science and is not merely a workman, even a skillful one. The work of the engineer, therefore, involves the command and use of principles, and the ability to apply them in a way which will lead to the definite construction of some work. The engineer is not a mere mechanic or workman, though a mechanic or workman may well have the capacity to become an engineer if opportunity is offered.

What we know as the "learned professions" are those in which brain work is necessary and not merely skill. Engineering, therefore, should rightly be considered as one of the learned professions and not merely an art, since it requires for its exercise a knowledge of the laws of nature, and their application.

The profession of engineering is as ancient as any of the occupations of man. No doubt from the earliest times man has been subject to disease, and the healing art in more or less crude or imaginary form has long been practiced; man, naturally a quarrelsome animal, has also from the earliest time engaged in disputes with his neighbor, and in more or less imperfect form, the law has long had to be administered. Once more, from the most primitive times, man has realized the presence of some supernatural power which the priest, if only under the title of "medicine man," has endeavored to propitiate. But clearly, man has always required water and food, and has dug wells and employed crude means for raising water and for growing crops. He has also in the earliest stages of civilization required some sort of shelter and made use of some of the laws of nature for purposes of offense and defense, and for the fashioning of weapons, tools, and implements, even before the principles of law were formulated and perhaps before anything was known or even imagined with reference to the healing art; so that the engineer and architect (who so far as his work is constructive and not wholly artistic is also an engineer) may fairly claim that their profession is as old as any.

In the Lake Dwellers' village of Wangen, in Switzerland, fifty thousand piles are said to have been driven into the bed of the lake, to support the dwellings. This was in the Late Stone Age, between 10,000 and 3,000 years B. C. In Egypt, the pyramids were built about 2,900 years B. C, and great mechanical skill must have been possessed by the builders in quarrying, transporting, and raising the immense blocks of stone that were used. Buckle, quoting from Diodorus, says that "to build one of the pyramids required the labour of 360,- 000 men for 20 years," and that 2,000 men were occupied for three years in carrying a single stone from Elephantine to Sais. A little later, but fully 4,000 years ago, the Egyptians anticipated the construction of the Suez Canal by building a canal from the head of the Red Sea or Gulf of Suez westward to the easternmost branch of the Nile, so that vessels of that time could pass from the Mediterranean to the Red Sea by this route ; and this work is said by Buckle to have cost the lives of 120,000 Egyptians. Thus early were accomplished engineering works which to-day would be called great, though done with a prodigal waste of human life and labor. The wonder is, however, that they could have been accomplished at all, . considering the primitive state of scientific knowledge.

Many people, even those well informed, appear to have the idea that engineering is not a profession in the proper sense of the term, and that the engineer is neither a scientist nor professional man, nor yet a business man, strictly speaking, but that he is something betwixt and between, perhaps more nearly a mechanic. According to the dictionary, a profession is defined as "A vocation in which a professed knowledge of some department of science or learning is used by its practical application to the affairs of others, either in advising, guiding, or teaching them, or in serving their interests or welfare in the practice of an art founded on it. Formerly, theology, law, and medicine, were specifically known as the professions; but as the applications of science and learning are extended to other departments of affairs, other vocations also received the name. The word implies professed attainments in special knowledge, as distinguished from mere skill; a practical dealing with affairs, as distinguished from mere study or investigation; and the application of such knowledge to the uses of others as a vocation, as distinguished from its pursuit for one's own purposes." According to this definition engineering is clearly both a science and an art.

Up to the present time the art involved in the work of engineering has probably been more recognized than the science. The engineer has been considered rather a builder than a scientific man, pursuing an occupation or avocation, rather than a profession. As civilization developed, the work of the engineer and builder developed correspondingly. The Assyrians and Babylonians built canals and bridges; the inhabitants of India, great reservoirs ; the Egyptians, pyramids ; the Romans, roads, bridges, aqueducts, baths, and other important works, many of them of great extent, and requiring unusual skill. The builders of these works were engineers.

During the early development of the profession, engineering came to be divided into two kinds, civil and military; the latter being concerned with the construction of fortifications, and with all other means of defense and offense; while civil engineering included all other applications of the constructive art. The uncertainties, however, with regard to the precise meaning of the term civil engineering, and the desirability of having it accurately defined, led the Council of the Institution of Civil Engineers of Great Britain on December 29, 1827, to pass the following resolve :

"RESOLVED, That Mr. Tredgold be written to, requesting him to define the objects of the Institution of Civil Engineers.* and to give a description of what a civil engineer is, in order that this description and these objects may be embodied in a petition to the Attorney General in application for a charter."

At the following meeting of the Council on January 4, 1828, a communication from Mr. Tredgold was read and entered in the Minutes, bearing the title "Description of a Civil Engineer, by Thomas Tredgold, Hon. M. Inst. C.E.," as a result of which the charter of the Institution described the profession of the civil engineer as "the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states both for external and internal trade, as applied in the construction of roads, bridges, aqueducts, canals, river navigation, and docks, for internal intercourse and ex-

* The Institution of Civil Engineers of Great Britain was founded in 1818, and incorporated by Royal Charter in 1828; the Institution of Mechanical Engineers was formed nineteen years later, with George Stephenson as the first President.

8 THE YOUNG MAN AND CIVIL ENGINEEEING

change; and in the construction of ports, harbors, moles, breakwaters and light houses ; and in the art of navigation by artificial power for the purposes of commerce, and in the construction and adaptation of machinery, and in the drainage of cities and towns."

Tredgold's definition of Civil Engineering as "the art of directing the great sources of power in nature for the use and convenience of man," is the definition still generally given. It is suggestive in various ways ; it emphasizes, as has been done on a previous page, that engineering properly involves the application of the laws of nature. It also involves a concrete application of those laws "for the use and convenience of man" and not merely for abstract or useless purposes. It may be criticized, however, in defining engineering as an art. It would perhaps be proper to consider engineering to be an art founded upon some branch or branches of science, such as the science of mechanics or of physics or of chemistry, but the art and the science cannot always be clearly differentiated; it is not easy to tell where the science ends and the art begins. If we adhere strictly to the conception that engineering is an art and therefore limited strictly to the doing, this would lead us to conclude that a man is only an engineer when he is executing the work, and that while he is designing it or studying the principles governing its design, he is .a scientist. It seems more proper to consider engineering as both a science and an art, and not simply as an art depending upon a science.

Furthermore, engineering is concerned not only with directing the sources of power in nature, but in utilizing and applying all the laws of nature and all the materials of the external world. Tredgold's definition was formulated at a time when the minds of engineers were filled with the new discoveries relating to power, which will hereafter be briefly referred to — with the steam engine, the steam boat, and the steam locomotive. The subject of power was, therefore, foremost in men's minds, and it is natural that this should have been emphasized in the definition.

Recently, the late Mr. Henry G. Stott, in his address as President of the American Institute of Electrical Engineers, proposed as an improvement upon Tredgold's definition, the following:

"Engineering is the art of organizing and directing men, and of controlling the forces and materials of nature for the benefit of the human race."

This definition, however, is also incomplete in that it terms engineering an art. Furthermore, it would apply the term to any activity in organizing and directing men, such for instance, as in military or political operations, and while this use of the term is often suggested, as when we speak of "engineering a deal," such use is a corruption or slang expression. Furthermore, neither of the definitions quoted puts any emphasis on one of the most important functions of engineering, namely, the regard for economy. The organizing and directing of men does not seem to be properly engineering, though we may sometimes refer to it as such; nor should a clumsy and wasteful and useless application of the laws of nature be termed engineering, though perhaps we should recognize it as simply bad engineering. A man, who by no stretch of the imagination could be called an engineer, migiit, if he were given sufficient time, men, and money, construct works similar to or identical with some of those built by engineers. It is, of course, plain there will always be differences of efficiency between engineers, and both good and bad engineering, and yet it would seem that some emphasis should be laid upon economy. Indeed, an engineer has been wittily defined as a man who does with one dollar what any fool can do with two,

James Nasmyth, the great English engineer and inventor, defined engineering as "common sense applied to the use of materials."

In view of the above considerations the following definition is suggested, namely :

Engineering is the science and art of applying, economically, the laws, forces, and materials of nature, for the use, convenience, or enjoyment of man.

The proper practice of engineering clearly requires both knowing and doing, and it is this combination, together with the character of the work done by the engineer, that leads to the somewhat peculiar position of the profession. It is not, of course, an art in the sense of being one of the fine arts. The engineer, as such, has little or nothing to do with questions of beauty, although every member of the profession should aim to possess such knowledge of the canons of beauty as to lead him to construct works which are not only useful, but beautiful as well, with due regard to economy. The engineer must know the laws and forces of nature and the properties of materials, and must be able to apply them economically. The laws and forces of nature with which he must be familiar, will depend upon the specific branch of the profession which he practices. Tredgold, after giving his definition of civil engineering, in which he specified many branches of the profession, concluded with the prediction that the extent of the profession was "limited only by the progress of science, and that its scope and utility would be increased with every discovery in philosophy, and its resources with every invention of the mechanical or chemical arts, since its bounds are unlimited and equally so must be the resources of its professors."

This prediction has been abundantly justified. Since Tredgold's time great fields, then unsuspected, have been added to the profession of engineering, resulting in the development, from the original root of civil engineering, of numerous branches, each of which is now a profession by itself. A knowledge of these developments, as well as of some which took place even before Tredgold's definition was formulated, is essential in order that the reader may clearly see the relation of civil engineering to other branches of the profession.

Up to nearly the end of the eighteenth century the sources of power in nature were little understood and could be utilized only to a comparatively small degree. Up to that time engineering comprised mainly the construction of roads, canals and bridges, the improvement of harbors, river works, the construction of docks, and the supplying of towns and cities with water. The state of the art only allowed of the construction of bridges of very short span, either of stone or wood, since iron had not yet been brought into use, and ferries were generally employed in crossing streams too deep for fording. The steam engine was known only in a very crude and uneconomical form; the weaving of cloth was almost all done by hand; there was little transportation except by sea; cities were not drained, or lighted by gas ; the applications of electricity were, of course, unknown; navigation by water was entirely by means of sailing vessels or with oars ; and the only form in which iron was used to any large extent was in the form of cast iron.

But before the end of the eighteenth century there came a remarkable series of mechanical inventions — the spinning jenny by Hargreaves, the spinning frame by Arkwright, the mule by Crompton, the power loom by Cartwright, the modern steam engine by Watt, the puddling process for making wrought iron by Cort, and others. These were followed, in the first third of the eighteenth century, by the development of the steam locomotive by Stephenson, of the steamboat by Fulton, by the inauguration of the era of railroads, beginning for all practical purposes with the victory of the "Rocket" in the competition at Rainhill in 1829, and by further great improvements in manufacturing, and in the production of iron and steel.

It was just at this time, when the minds of all were

INTEODUCTION 13

filled with the inventions of Watt and of Stephenson, that Tredgold gave his definition, clearly showing the tremendous influence held at that time by the subject of power., These great developments much enlarged the field of engineering, and gave birth to a new class of engineer — the railroad engineer. They led also to the differentiation of the mechanical engineer from the civil engineer. Since that time the mechanical engineer has claimed as his special field the development and use of power in all its forms, including the generation of power from the combustion of fuel or the flow of water, by means of the various types of engines and water wheels, the transmission of that power from point to point by belting, shafting or other means, and the utilization of that power by machinery. There is hardly a field of human industry, therefore, which is not dependent upon the mechanical engineer, because all manufactured articles depend upon power in some application, and upon machinery operated by power.

The field of the modern mechanical engineer, however, not only covers the department of power and its applications — in manufacturing, in the steam locomotive, in the steamship — but it is also held to include the construction of mills, and all applications of steam and heat such as heating, ventilation, lighting, and so on.

But notwithstanding the diff*erentiation from it of the field of the mechanical engineer, the field of the civil engineer was itself enlarged by the progress of science and invention. The great impetus given to manufacturing rendered necessary the distribution of the raw material and of the manufactured products. Transportation engineering was enormously increased in its scope and the new profession of the railroad (civil) engineer was brought into existence. Roads, rail' roads, canals, harbors and docks, were built with unexampled rapidity, and river improvements were extensively carried on. At this time the increasing use of canals gave occasion for the celebrated remark of Brindley, the great canal engineer of England, himself an untutored genius, who, when asked what the use of a river was, replied "to supply canals with water." At the same time the economical production of wrought iron rendered possible the construction of bridges of considerable span.

By this time had begun one of the greatest sociological movements which characterizes the present time, namely, the increasing congregation of people in cities. At the beginning of the nineteenth century only three per cent, of the population of the United States lived in cities, while at the present time the urban population is over fifty per cent, of the total. This phenomenon, during the last half of the century just passed, has led to the differentiation of another field of engineering, namely, that of the sanitary engineer, whose specific province it is to deal with the problems of water supply, drainage, the disposal of refuse, the purification of water and sewage, the sanitation of dwellings, and the various other problems resulting from this congestion of population.

Improvements, also, in chemistry and in metallurgy, have given rise to still other distinct branches of engineering, namely, mining engineering and metallurgy, the scope of which it is not necessary here to sketch.

Again, the field of the mechanical engineer has during the past quarter of a century become subdivided, owing to the discoveries in electricity. Steam and water are no longer used simply to propel steam engines or water wheels, producing power to be used on the spot. Steam or other engines, and water wheels, now drive electric generators, the currents from which are transmitted long distances, sometimes as great as 200 or even 300 miles, by means of transmission wires, to be again transformed by electric motors and used for the production of light or for the operation of machinery. The telephone and the telegraph have been discovered, electric cars have replaced the horse cars, and the traffic of our steam railroads is in 'some cases being hauled by electric locomotives. Almost everything nowadays is done or can he done by electricity, even to preparing our food, washing our clothes and dishes, and heating our houses. The electrical engineer, with a field already so wide that it is divided into specialties, is a product of the last twenty-five years.

By the last third of the nineteenth century, therefore, there had grown out from the original stem of civil engineering, three professions so differentiated from it and from each other, that they have ever since been and are still regarded as separate professions, namely: (1) Mechanical engineering, (2) electrical engineering, (3) mining' engineering and metallurgy. A fourth stem, namely, architecture, may be said to have been differentiated from civil engineering at a still earlier date.

These five professions are represented by the five great national engineering societies in the United States, namely :

(1) The American Society of Civil Engineers (Instituted Nov. 5, 1852).

(2) The American Society of Mechanical Engineers (Organized 1880^ Incorporated 1881).

(3) The American Institute of Electrical Engineers (Organized 1884^ Incorporated 1895),

(4) The American Institute of Mining Engineers (Organized 1871).

(5) The American Institute of Architects (Incorporated 1857).

These professions have many points of contact and cannot be sharply differentiated from each other. There are overlapping or twilight zones which may be considered to belong to either of two or more. In the last analysis, members of all these professions belong to the one great profession of engineering, but for practical purposes it is desirable and usual to consider them as distinct. Indeed, each of these professions has, with the development of science, become divided into a number of specialties. This is particularly true of civil engineering for, notwithstanding the differentiation from it of the fields of architecture, mechanical engineering, electrical engineering, mining engineering and metallurgy, the field of the civil engineer keeps on ever increasing in scope. Coasts have to be protected from the sea, swamp and marsh lands reclaimed, large areas irrigated by artificial means, requiring the construction of great dams, the storing of immense quantities of water and the distribution of that water by means of canals into the uplands. Novel problems of urban transportation present themselves and must be solved by the construction of subways and tunnels ; great railroad terminals have to be provided ; and towering sky-scrapers are constructed by the engineer, who here trenches upon the domain of the architect. Also the possibility of electrical transmission, and the increasing scarcity and waste of fuel, have increased enormously the importance and value of water powers. The question of the discharge of rivers, the means of increasing it, of storing it so as to make it more regular from month to month, thus avoiding the damage due to floods, and increasing the power during dry seasons, the construction of dams and of the various works incident to the development of water powers, all these, together with other problems, now constitute a separate field, that of the hydraulic engineer. Water, at once the most valuable and necessary of the gifts of nature, and at the same time an enemy to be dreaded and feared, must be controlled and governed, so that communities may be supplied adequately with this necessity of life and the power generated by the rivers turned to the service of man. The laws of water flowing in conduits, through pipes and in open channels must be studied and experimented upon, and the science of the laws of water — ^hydraulics — is steadily increasing in value and in importance.

Of recent years, in addition to the five main branches of the profession of engineering above enumerated, others may fairly be said to have been developed. The increase in transportation by sea, the use of steel ships, and the ever increasing size of vessels, has led to the profession of the naval architect, itself a large field, dealing with the applications of steel and other materials to the construction of vessels. Another specialty of mechanical engineering is that of the marine engineer. The naval architect builds the vessels, the marine engineer equips them with machinery and provides them with ventilating and other apparatus necessary to fit them for use. Still another branch or specialty of mechanical engineering has been developed by the construction of large and high buildings, namely, the profession of the heating and ventilating engineers, which deals with the methods and means of heating and ventilating buildings of all kinds. Indeed, the architect may be said to produce the mere shell of a great building. The equipping it with machinery and apparatus for heating and ventilating, with elevators, water supplies, plumbing, and fire protection, is a large problem in itself, and belongs to engineering rather than to architecture.

Finally, investigations in the various fields of applied chemistry, as for instance in the production of gas and oil, in the manufacture of rubber goods, soap, glue and other materials too numerous to mention, have led in recent years to the formation of still another branch of the profession, namely, that of chemical engineering, which deals with the application of chemistry to the useful arts. To even enumerate the applications of this science would tax the patience of the reader.

From the above brief sketch it will appear that civil engineering is the parent stem which at first included all branches of the constructive art, with the exception of military engineering, which may perhaps be considered to be, in its objects, more destructive than constructive; that from this parent stem four to six new branches may be said to have grown, which now constitute professions in themselves and»are not the subject of further consideration, except incidentally, in this book. What remains in the field of civil engineering is, however, even now much larger than it was in Tredgold^s time, and it is continually growing as new applications of science are discovered and new lines of practice are founded upon them.

In its restricted meaning, civil engineering may be said to include the following branches, although some of these specialties may be claimed to be entitled to rank as separate professions :

(1) Surveying and Geodesy, which deals with the measurement and dehneation of large or small portions of the earth's surface and the objects found thereon.

(2) Hailroad Engineering, which deals with the location and construction of railways, and their maintenance and operation so far as engineering principles are concerned.

(3) Highway Engineering, which deals with the location, construction and maintenance of highways, including city streets and pavements.

(4) Hydraulic Engineering, which deals with the laws governing the flow of water in all kinds o£ channels, and with the principles governing the flow of water upon the surface of the earth, both in surface and underground channels; with the discharge of rivers, the methods of controlling it and of protecting banks and preserving navigable channels; with the location and construction of dams and their appurtenances, for retaining bodies of water, for the water supply of communities and for the production of power; with the construction of canals, harbors, light houses and other works in which the control of water is the main problem. This branch of the subject includes what is known as canal, river, and harbor engineering, water power engineering, irrigation engineering, and water-supply engineering.