IV. Trout Fishing with Fly and Bait (part 2 of 2)
The person who cares for things unusual will find the candle sconce made of a cowhorn a suitable fixture for the den. A well shaped and not too large cowhorn is selected, and prepared by first partly filling it with paper, packed in tightly, then filling it to the top with plaster of Paris, in which a candle socket is formed.
The bracket is made of strips of metal, formed as shown and riveted together where they touch each other, the back piece being fastened with screws to a wall board. The metal may be brass or copper and finished in nickel, antique, bronze, or given a brush finish. The wooden wall piece can be finished in any style desired.
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White spots on furniture can be removed by rubbing the wood with ammonia.
How to Make a Copper Stencil for Marking Laundry
A stencil suitable for marking laundry may be easily made as follows:
First procure a small sheet of "stencil sheet copper," about 1 in. wide and 4 in. long. Dip this sheet of copper in a vessel containing some melted beeswax, so that both sides will be evenly covered with a thin coat of the wax when it cools. The design--name, monogram or figure--that is wanted in the stencil should now be drawn upon a piece of thin white paper, the reverse side of the paper blackened with graphite, and then laid on the stencil plate with the design in the center of the plate, whereupon the design is lightly traced with a blunt point on the thin wax coating. After the paper is removed, trace the design on the wax surface with a pointed instrument, but not completely, the lines being broken at more or less regular intervals, to form "holders" so that, after etching, the design cannot fall out.
Next lay the stencil in a small shallow dish and pour a small quantity of fresh nitric acid over it. Keep the air bubbles removed from the surface by means of a piece of soft feather. The design will be eaten away in a very short time, where the wax has been removed, and this may be readily observed by holding the stencil plate up to the light. The acid should then be rinsed off with water, and the wax removed by heating and wiping it off with a cloth. The stencil may be given a final cleaning in a dish of benzine or gasoline, which will remove any remaining wax.
A Brass Pin Tray
A novelty pin tray can be easily made of a piece of No. 24 gauge sheet brass or copper, 5 in. in diameter. The metal is annealed and polished with fine emery cloth, which is given a circular motion to produce a frosted effect. The necessary tools are a 1-in. hardwood board with a 2-1/2-in. hole bored in it, and a round piece of hard wood, 1-7/8 or 2 in. in diameter, with the ends sawn off square.
Place the sheet metal centrally over the hole in the board and set one end of the round stick in the center of the metal. Drive the stick with a hammer until a recess about 1 in. deep is made in the center. The edge of the metal will wrinkle up as shown in the sketch. It is scarcely possible to make two trays alike, as the edge almost invariably will buckle in a different manner.--Contributed by F. Van Eps, Plainfield, N. J.
A Homemade Exerciser
A weight machine for exercising the muscles of the arms is easily constructed by using two screw hooks, 5 in. long, and two small pulleys, 2-1/2 in. in diameter. An awning pulley can be used for this purpose. The hole at the top of the hanger will allow the pulley to freely turn at almost any angle. A paving brick or a piece of metal can be used as a weight for each rope.--Contributed by Sterling R. Speirs, St. Louis, Mo.
A Book Covering
New books can be quickly and neatly covered to keep them clean by cutting a paper large enough to cover the back and sides when the book is closed, allowing 1 in. extra at each end to be turned over the front and back edges, then pasting on corners cut from used envelopes. The paper jacket can be slipped on or off easily when the book is opened, and it will keep a new cover clean while the book is being handled.--Contributed by Dr. John A. Cohalan, Philadelphia.
A Tilting Inkstand
An ink-bottle stand, that can be tilted or adjusted so that the pen will always be filled with a sufficient quantity of ink even when little of it remains in the bottle, as shown in the sketch, can be easily made by the amateur. The base may consist of a square piece of sheet brass, which has soldered or riveted to its center two pieces of spring brass, placed crosswise and bent upward so as to form clips to hold the bottle firmly. The legs are made of two lengths of wire, of sufficient stiffness, and are shaped to form holders for lead pencils and penholders. One pair of the legs may be soldered to the brass plate and the opposite side of the latter rolled over the other pair so as to allow them either to stand upright or be depressed in order to tilt the stand, when the ink supply in the bottle gets low.
A Ring Trick
The trick to be described is one of the simplest and at the same time one of the most effective, and but little "make-ready" is required to perform it. The magician, while sitting in a chair, allows his hands to be tied together behind the back of the chair. A ring is placed between his lips which he claims to be able to slip on his finger without untying his hands. This, to the audience, seems practically impossible, but it is easily accomplished.
A screen is placed in front of the performer before the trick is started, so that the audience will not see how it is done. As soon as he is hidden from view, he tilts his head forward and drops the ring in his lap. He then allows the ring to drop to the seat of the chair between his legs. The chair is tilted backward slightly, and he raises himself to allow the ring to slip to the back part of the chair seat, where he catches it in his hands and slips it on the finger. Any one finger may be mentioned, as he can slip the ring as readily on one as on another. Use a leather-bottom chair, if possible, as the least noise will then be made when the ring is dropped.--Contributed by Abner B. Shaw, N. Dartmouth, Massachusetts.
Removing Old Putty
A very effective way to remove old putty from window panes or other articles is to apply a red-hot iron, as follows: The iron should be made of a broken file or cold chisel and the point heated quite hot. This is run over the surface of the putty, which will crack and fall off. Be careful not to let the hot iron touch the glass, as the heat may cause the latter to break.
How to Make a Water Wheel
The materials used in the construction of this water wheel are such as the average amateur mechanic may pick up or secure from a junk pile. The drawings in Fig. 1 clearly show the way the wheel is built. The nozzle, Fig. 2, is made of pipe and fittings and is adjustable to concentrate the stream so as to get the full efficiency of the weight and velocity of the water. The cap on the end of the nipple is drilled to receive the pin point filed on the end of the 1/4-in. rod. The parts of this nozzle are a 1/2-in. tee, connected to the source of water supply; a plug, drilled to snugly fit the 1/4-in. rod, and fitted into one end of the straight part of the tee; and a 1/2-in. nipple of sufficient length to make the dimension shown in the sketch. The nipple has a long thread to receive two 1/2-in. locknuts, which clamp the nozzle to the sheet-metal covering, as shown in Fig. 1.
The buckets, Fig. 3, are formed of some easily melted, but not too soft metal alloy which can be cast in plaster molds. They are attached with rivets to the circumference of 1/16-in. thick sheet-metal disk of the diameter given in Fig. 1. This disk is fastened to a 1/4-in. shaft, 6 in. long, with two collars, one on each side of the disk, both being riveted to the disk and pinned to the shaft. The bearings AA are made of 3/4-in. pipe, each 2-1/4 in. long. Long threads are cut on these to turn through the two 3/4-in. waste nuts BB, which provides a way to adjust the buckets centrally with the stream of water, and to take up any side motion. The pipe is babbitted and drilled for oil holes. The runner or wheel must be well balanced, as the speed will be from 2,000 to 2,500 revolutions per minute with ordinary city pressure. In balancing the wheel, instead of adding an extra weight, a part of the disk is filed out on one edge. The inclosing sides are made of wood--cypress preferred--having the dimensions given, and two 7/8 by 1-1/2-in. pieces are attached to the bottom outside surfaces for mounting the wheel. The curved part is covered with galvanized sheet metal.
The drawing shows a wheel of small diameter, but having considerable power. Greater power may be obtained by increasing the size of the jet and the diameter of the wheel, but the use of too many buckets results in decrease of power. One bucket should be just entering the stream of water, when the working bucket is at a point at right angles to the stream. The water should divide equally exactly on the center of the bucket and get out of the way as soon as possible. Any stagnant water in the case, or dead water in the bucket, is detrimental to the power. A free exit for the water is made at the bottom of the case, as shown.
The construction of the case may be varied and, instead of wood, metal sides and frame may be used. Where the builder cares to make a more substantial wheel and has access to a foundry, the metal parts can be made as shown in Fig. 4. The parts are in this instance fastened together with machine screws. Patterns are made and taken to a foundry for the castings, which are then machined to have close fitting joints.--Contributed by R. H. Franklin, Unnatosa, Wis.
An Interesting Experiment
Take an ordinary board, 2 or 3 ft. long, such as a bread board, and place it on the table so that about one-third of its length will project over the edge. Unfold a newspaper and lay it on the table over the board as shown in the sketch. Anyone not familiar with the experiment would suppose the board could be knocked off by hitting it on the outer end. It would appear to be easy to do, but try it. Unless you are prepared to break the board you will probably not be able to knock the board off.
The reason is that when the board is struck it forces the other end up and the newspaper along with it. This causes a momentary vacuum to be formed under the paper, and the pressure of the air above, which is about 15 lb. to the square inch, prevents the board from coming up. This is an entertaining trick to play at an evening party, and also makes a simple and interesting school experiment.
Ironing-Board Holder
An ironing board that had been used on two chairs was cut off square on one end and a piece of heavy sheet metal cut and bent into the shape shown in Fig. 1. The square end of the board was fitted into the socket formed by the sheet metal. After attaching the socket to the wall with screws the board was easily put in place as shown in Fig. 2. The brace is hinged to the under side of the board.--Contributed by L. G. Swett, Rochester, N. Y.
How to Make a Water Motor By Edward Silja
After making several different styles of water motors I found the one illustrated to be the most powerful as well as the simplest and most inexpensive to make. It can be constructed in the following manner: A disk, as shown in Fig. 1, cut from sheet iron or brass, 1/16 in. thick and 9-3/4 in. in diameter, constitutes the main part of the wheel. The circumference is divided into 24 equal parts, and a depth line marked which is 8-1/4 in. in diameter. Notches are cut to the depth line, similar to the teeth of a rip saw, one edge being on a line with the center of the wheel and the other running from the top of one tooth to the base of the preceding tooth.
A 1/4-in. hole is drilled in the center of the disk and the metal strengthened with a flange, placed on each side of the disk and fastened with screws or rivets. A 1/4-in. steel rod is used for the shaft.
The cups, or buckets, are shaped in a die which can be cast or built up of two pieces, as desired. Both of these dies are shown in Fig. 2. The one at A is made of two pieces riveted together.
If a foundry is near, a pattern can be made for a casting, as shown at B. The die is used in the manner shown in Fig. 3. A strip of galvanized metal is placed over the depressions in the die and a ball-peen hammer used to drive the metal into the die. Cups, or buckets, are thus formed which are soldered to the edge of the teeth on a line with the center of the disk, as shown in Fig. 4. As there are 24 notches in the disk, 24 cups will be necessary to fill them.
The cups are made in pairs or in two sections, which is a better construction than the single cup. The water from the nozzle first strikes the center between the cups, then divides and produces a double force.
When this part of the work is finished it is well to balance the wheel, which can be done by filing off some of the metal on the heavy side or adding a little solder to the light side. This will be necessary to provide an easy-running wheel that will not cause any unnecessary wear on the bearings.
The housing for the wheel consists of two wood pieces, about 3/4-in. thick and cut to the shape shown in Fig. 5. Grooves are cut in one surface of each piece, to receive the edges of a strip of galvanized metal, as shown at A. The grooves are cut with a specially constructed saw, shown in Fig. 6. It consists of a piece of wood, 6 in. long, 1-1/2 in. wide and 1/2 in. thick, the end being cut on an arc of a circle whose diameter is 10 in. A piece of a broken hacksaw blade is fastened with screws to the curved end. A nail is used as a center pivot, forming a 5-in. and a 5-3/4-in. radius to swing the saw on in cutting the groove. After inserting the strip of galvanized metal, A, Fig. 5, the sides are clamped together with bolts about 3-1/4 in. long.
A piece of pipe, B, Fig. 5, having an opening 3/8-in. in diameter, is soldered onto the metal strip A. An ordinary garden-hose coupling, C, is soldered to the end of the pipe.
A bearing, D, shaped as shown, is fastened to one of the wood sides with screws, the wheel shaft is run into it, and the parts assembled. A wheel, either grooved or flat, 2-1/2 or 3 in. in diameter, is placed on the shaft. The hose coupling makes it easy to connect the motor directly to the water faucet.
An Application for Small Wounds
Pure wintergreen oil makes a good local application for all small wounds, bites, scratches, abrasions, etc. There is no germ or microbe, animal or vegetable, dead or living, that can withstand this oil, and at the same time it is not injurious to living tissues. A few drops gently rubbed in where there is apt to be any infection is sufficient.
An infection always follows the wound of a bullet or the scratch of a brass pin, with irritation extending up the limb or part threatening tetanus or lockjaw. These symptoms are manifested by spasmodic pains which shoot upward, but are quickly subdued, if the oil is applied along the track of the pain or infection. This oil is equally effective when locally applied to tendons or ligaments which have been unduly strained.
An ounce of the pure oil does not cost much, and it should be kept in every shop and household. If 5 or 10 per cent of olive oil is added to it, the oil will have more body and will last longer.--Contributed by Dr. E. R. Ellis, Detroit, Mich.
Cores for Use in Babbitt Metal
It is often necessary in making things of babbitt metal to core out some of the parts. A very good core is made of common salt and glue. Mix just enough of the glue into the salt to make a stiff paste, which is then formed into the desired shape or molded in a core box and allowed to harden. This kind of a core can be removed from the casting by soaking it in warm water, which will dissolve the salt and leave the desired hole.--Contributed by H. F. Hopkins, N. Girard, Pa.
How to Build a Wind Vane with an Electric Indicator
Quite often it is practically impossible to ascertain the direction of the wind by observing an ordinary wind vane on account of the necessity of locating the vane at such a height that it may give a true indication. By means of the device shown in Fig. 2, the position of the vane may be determined without actually looking at the vane itself and the indicating device may be located almost anywhere and independently of the position of the wind vane.
The principle upon which the device operates is that of the Wheatstone bridge. The position of the moving contact A, Fig. 1, is controlled by the wind vane. This contact is made to move over a specially constructed resistance R, Fig. 2. A second movable contact, B, is controlled by the observer and moves over a second resistance, identical with that over which the contact A moves. These two resistances are connected so as to form the two main branches of a Wheatstone bridge; the points A and B are connected to the current-detecting device, which may be a galvanometer or telephone receiver, and current is supplied by a number of dry cells.
In order to obtain a balance--that is, no current through the receiver--the points A and B must occupy corresponding positions on their respective resistances. If the two resistances over which the points A and B move are mounted in the same position with respect to the cardinal points of the compass, then the points themselves will always be in the same position with respect to the cardinal points when a balance is obtained. The arrow head on the wind vane and the point A are made to occupy corresponding positions, and hence the position of the point B, when no current passes through the receiver, is an indication of the direction in which the wind vane is pointing.
The principal parts in the construction of the device are shown in the illustration, and the following description of their construction may be of interest to those who contemplate building the indicator.
Procure two pieces of 1/16-in. hard rubber, 1-1/2 in. wide by 24 in. long. Clamp these, side by side, between two boards and smooth down their edges and ends, and then file small slots in the edges with the edge of a three-cornered file. These slots should all be equally spaced about 3/32 in. apart. Have the pieces clamped together while filing the slots and mark one edge top and one end right so that the pieces may be mounted alike. Now procure a small quantity of No. 20 gauge bare manganin wire. Fasten one end of this wire to one end of the pieces of rubber by winding it in and out through three or four small holes and then wind it around the piece, placing the various turns in the small slots that were filed in the edges. After completing the winding, fasten the end just as the starting end was attached. Wind the second piece of rubber in a similar manner and make sure to have the length of the free ends in each case the same. Obtain a cylinder of some kind, about 8 in. in diameter, warm the pieces of rubber by dipping them in hot water, bend them around the cylinder and allow them to cool.
A containing case, similar to that shown in cross section in the upper portion of Fig. 2 should now be constructed from a good quality of tin or copper. The inside diameter of this case should be about 1 in. more than the outside diameter of the resistance ring R, and it should be about 3 in. deep. The top C may be made curved as shown in the illustration, and should be fastened to the case proper by a number of small machine screws. The base of this case may be made so that the whole device can be mounted on the top of a pole.
Mount a piece of 1/4-in. steel rod, about 1/2 in. long, with a conical hole in one end, in the center of the bottom of the case as shown by M. A number of supports, similar to the one shown, should be made from some 1/4-in. hard rubber and fastened to the sides of the case, to support the resistance ring. The dimensions of these supports should be such that the ends of the piece of rubber, forming the ring, are against each other when it is in place. The upper edge of the ring should be about 2 in. above the bottom of the case.
Next, mount a piece of brass tube, D, in the exact center of the top and perpendicular to it. A washer, E, may also be soldered to the top so as to aid in holding the tube. Procure a piece of steel rod, F, that will fit in the tube D and turn freely. Sharpen one end of this rod and mount a brass wind vane on the other end. A small metal cup, G, may be soldered to a washer, H, and the whole mounted on the steel rod F in an inverted position as shown, which will prevent water from getting down inside the case along the rod. The cup G may be soldered directly to the rod. Make a small arm, J, of brass, and fasten a piece of light spring, K, to one side of it, near the outer end, then mount the arm on the steel rod so that it is parallel to the vane and its outer end points in the same direction as the arrow on the vane. The free end of the light spring on the arm J should be broad enough to bridge the gap between adjacent turns of wire on the resistance ring. Four bindings should then be mounted on the inside of the case and all insulated from it with the exception of number 1. Numbers 2 and 3 are connected to the ends of the winding and number 4 is connected to number 3.
A second outfit should now be constructed, identical with the one just described except that it should have a flat top with a circular scale mounted on it, and the arm L should be controlled by a small handle in the center of the scale. The position of the contact B may be indicated on the scale by a slender pointer, attached to the handle controlling the arm L.
Four leads of equal resistance should be used in connecting the two devices and the connections made as shown. An ordinary buzzer placed in the battery circuit will produce an interrupted current through the bridge circuit and a balance will be obtained by adjusting the contact point B until a minimum hum is heard in the telephone receiver.
Planting Seeds in Egg Shells
When growing flower plants from seeds, start them in halves of shells from hard-boiled eggs. When the time comes to transplant them, they can be easily removed by allowing the dirt in the shell to become hard and then breaking off the shell, whereupon the plant is placed in the ground.
A pasteboard box provided with holes large enough to support the egg shells can be used to hold them, unless egg crates are at hand. Two large seeds such as nasturtiums and sweet peas can be planted in one shell, and four seeds of the smaller varieties.--Contributed by Katharine D. Morse, Syracuse, N. Y.
Locating Drip Pan under a Refrigerator
In replacing the drip pan of an ice box or refrigerator it is often necessary to bend over in locating it under the drip pipe. This trouble may be done away with by fastening two strips of wood in a V-shape to the floor beneath the refrigerator. When the pan is shoved under, it will strike one strip and slide along until it strikes the other. Then the pan is sure to be under the drip pipe.--Contributed by Lloyd A. Phelan, Beachmont, Mass.
Windmill for Light Power
The windmill shown in the sketch is one that will always face the wind, and it never requires adjustment. It consists of a vertical shaft, A, provided with a number of arms, B, on which are hinged square sails, C. These sails are preferably made of wood frames covered with canvas. They are provided with hinges, D, attached to the ends of the arms in such a way that they offer resistance to the wind on one side of the wheel, while they move edgewise against the wind on the other side, as shown. The shaft of the mill can either be run in bearings set on an upright post, the lower end of the shaft turning on a conical bearing, or collars may be used on the bearings to keep it in position. The power can be transmitted with gears or by a flat belt over a pulley.
A wheel of this kind is not adapted for high speed, but direct-connected to a pump or other slow-working machinery will prove very efficient.--Contributed by Edward Hanson, Kane, Pennsylvania.
A Small Bunsen Burner
An excellent bunsen burner for small work can be made as follows: Draw a glass tube to the shape shown, to produce a fine hollow point. Mark carefully with a file and break at A and then at B. Bore or burn a hole in a cork to fit the tube. Cut a V-shaped notch in the side of the cork extending to the hole. Bend the lower tube at right angles and insert it in a wood block, previously slotted with a saw to make a snug fit. A little glue will hold the glass tubes, cork and base together. The air mixture can be adjusted by sliding the upper tube before the glue sets.
The burner is especially adapted to continuous work, such as sealing packages, etc. The flame will not discolor the wax.--Contributed by E. P. Fert, Spokane, Wash.
The Hindoo Sand Trick
This is one of the many tricks for which the Hindoos are famous, and was long kept a secret by them. It consists of placing ordinary sand in a basin full of water, stirring the water and taking out the sand in handfuls perfectly dry. It need scarcely be said that without previous preparation, it is impossible to do so.
Take 2 lb. of fine silver sand, place it in a frying pan and heat well over a clear fire. When the sand is thoroughly heated, place a small piece of grease or wax--the composition of a paraffin candle preferred--in the sand, stirring it well to get it thoroughly mixed, then allow the sand to cool. When this sand is placed in a basin of water, it will be apparently dry when taken out. It is very important that only a small portion of the adherent be used so that it cannot be detected when the sand is examined by the audience. The explanation is that the grease or wax coating on each sand particle repels the water.--Contributed by Mighty Oaks, Oshkosh, Wis.
A Kite-Line Cutaway for Toy Parachutes
The cutaway is made of a small piece of board, a cigar-box lid, an old yardstick or a piece of lath, which should be about 6 in. long. Common carpet wire staples are used to hold it on the string. The under side has a wire bent into such a shape as to form a loop at the forward end over the kite string, then running back through the two staples at the one side and through two staples at the other side.
The parachute should have a small wire ring fastened at the weight end so as to fasten in the carrier, and should be put between the two staples that are closest together on the under side of the carrier. A small nail or button--anything larger than the loop in the wire--should be attached to the kite string a few feet from the kite. When the parachute is carried up the kite string, the knob on the string will strike the loop of the wire on the carrier, which releases the parachute and allows it to drop. The carrier will return of its own weight to the lower end of the string.--Contributed by I. O. Lansing, Lincoln, Neb.
A Cherry Pitter
Procure an ordinary quill feather and cut the tip off to form a small hole. Do not remove so much of the end that the cherry stone can stick in it. The hole must be slightly smaller than the cherry stone. Push the quill through the center of the cherry and the stone will come out easily.--Contributed by Harold Wynning, Chicago, Ill.
To Hold a Fish while Removing the Scales
Insert a screwdriver or ice pick in a fish as shown, and the scales can be removed much better and quicker than in any other way. The handle of the screwdriver affords an efficient grip so that the fish can be held firmly on the board and every scale can be removed.
Carrying Stone Jars
The handholds on stone jars are usually not large enough to carry the jars safely when they are full. If the handles of an old galvanized tub are riveted to a leather strap long enough to reach under the bottom and almost to the top on each side, the jar can be handled without danger of being dropped. The fingers are placed in the handles to carry the weight, while the thumbs are used to keep the jar from tipping. By placing a buckle near one end, the strap may be used for carrying a jar of any size.--Contributed by C. H. Floyd, Elwood, Ind.
Vibrator for a Spark Coil
If you do not have the time to make a vibrator or electrolytic interrupter for a spark coil, a common electric door-bell makes a good substitute. Connect one of the primary wires to the binding-post of the bell that is not insulated from the frame, and the other primary wire to the adjusting screw on the make-and-break contact of the bell, as shown in the sketch. The connections are made from the batteries to the bell in the usual manner.--Contributed by Ralph Tarshis, Brooklyn, N. Y.
Head Rest for a Chair
While seated in a chair a person very often desires to lay the head back in resting. A support for the head is lacking in the low-back rockers and ordinary chairs. A detachable, padded support can be easily made at home for placing on any low-back chair and used as a head rest.
The support standards can be made of wood or metal as desired. If metal is used, the rest will have some springiness, which combined with the pad will insure much greater comfort than the hard rigid back. A cloth or paper is placed over the back of the chair to prevent marring of the varnish or wood.
Lighting a Lawn Mower for Use at Night
Those who desire to do so, or must, for lack of time during the day, may use their lawn mower at night and light the front of their machine with an ordinary bicycle lamp. The arm to hold the lamp can be attached with screws to the handle as shown in the sketch. It is easily made from a piece of hoop or bar iron.--Contributed by Samuel F. Reid, Minneapolis, Minn.
Tying a Rosette in a Couch-Cover Corner
In the accompanying illustration is shown a very simple method of tying a rosette in the corner of a couch cover. The use of the average couch cover as a throw-over leaves a large corner which drags upon the floor. To dispose of this extra length and at the same time make an artistic corner, the Upholsterer suggests the following method:
Spread the couch cover on the couch so that the surplus is evenly divided between the sides and ends, and pass a pin through the cover to show each corner as in Fig. 1. Measure the distance from each corner of the couch to the floor, Fig. 2, and measuring from the point of the corner, mark the same distance by the insertion of another pin, repeating in all four corners. The distance between the two pins at each corner now defines the amount of surplus that is to be taken up. Chalk a circle to include the portion between these two pins, as shown in Fig. 3, and with a circular needle and stout stitching twine run a shirring thread around the circle, and when this is drawn tightly and tied, the surplus is formed into a rosette, while the corner may be draped into an artistic cascade, as shown in Fig. 4.
Driving Screws
A wood screw having the threads hammered flat on two sides can be easily driven in with the flattened sides parallel to the grain of the wood. When the screw is turned a quarter turn the remaining threads cross the grain and hold as well as if they had been turned in all the way. This is an especial advantage where something is wanted which is easily inserted and will hold better than a nail.--Contributed by P. D. Merrill, Chicago.
A Power Windmill
The windmill shown is somewhat different from the ordinary kind. It is not a toy, nor does it approach in size the ordinary farm windmill, but is a compromise between the two, and in a good strong wind, will supply power enough to run a washing machine, a small dynamo, an emery wheel, or any other device used in the home workshop. The wheel is about 5 ft. in diameter, with eight blades. The over-all length is about 6 feet.
The windmill is easily made and the cost is within the means of the average boy. There is not a part used in its construction that cannot be found about an ordinary manual-training shop. The most difficult parts of the construction will be described in detail. Symmetry and smoothness of design should be preserved and the parts made as light as possible consistent with strength and durability.
The Wheel
As shown in the drawings, the wheel has eight blades. Ordinarily the use of eight blades makes it difficult to construct a hub of sufficient strength to carry them. Where so many blades radiate from a common center it is almost impossible to provide an anchorage for each blade. To provide a maximum of strength coupled with simplicity of design, the plan of using two hubs of four arms each was adopted in the construction of this mill. The ordinary hub of four arms is simple to make and quite strong. Four pieces of straight-grained oak, each 16 in. long and 1-7/8 in. square, are used in constructing the hubs. The manner of notching each pair of pieces together is shown in Fig. 1. The slope for the blades is made to run in opposite directions on the ends of each crosspiece. The slope is formed by cutting out a triangular piece, as shown.
The two hubs, thus formed, are mounted on the shaft, one behind the other, in such positions that the arms will be evenly divided for space in the wheel circle. These details are shown in Fig. 2. The blades, Fig. 3, are made of thin basswood or hard maple, and each is fastened in its place by means of two 3/8-in. bolts, in addition to which a few brads are driven in to prevent the thin blades from warping.
The Gears
This windmill was designed to transmit power by means of shafts and gear wheels, rather than with cranks and reciprocating pump rods, such as are used on ordinary farm mills. To obtain this result, an old sewing machine head was used. Such a part can be obtained from a junk dealer or a sewing-machine agent. The head is stripped of its base plate with the shuttle gearing; likewise the needle rod, presser foot, etc., are taken from the front end of the head along with the faceplate. The horizontal shaft and gear wheel are taken out and the bearings reamed out for a 1/2-in. shaft, which is substituted. The shaft should be 2 ft. in length, and 8 or 10 in. of its outer end threaded for the clamping nuts which hold the two hubs in place, as shown at A and B, Fig. 2. The gear wheel is also bored out and remounted on the new shaft.
The supporting standard is constructed of oak, with mortise-and-tenon joints, as shown in Fig. 4. The width of the pieces will depend on the kind of sewing-machine head used. It may be necessary also to slightly change the dimensions. The machine head is fastened on the support with bolts. A sleeve and thrust spring are mounted on the shaft, as shown. The sleeve is made of brass tubing, of a size to fit snugly on the shaft. A cotter will keep it in place. The sleeve serves as a collar for the thrust spring, which is placed between the sleeve and the standard. This arrangement acts as a buffer to take up the end thrust on the shaft caused by the varying pressure of the wind on the wheel.
The Vane
To keep the wheel facing the wind at all times, a vane must be provided. It is made of basswood or hard maple, as shown in Fig. 5. It is not built up solid, air spaces being left between the slats to reduce the wind resistance. Unless built in this manner, the vane is liable to twist off in a gale. The horizontal slats are 1/4 in. thick, and the upright and cross braces 3/8 in. thick, while the long arm connecting the vane to the supporting standard is 1/2 in. thick.
The supporting standard, carrying the wheel and the vane, must revolve about a vertical axis with the changes in the wind, and this vertical axis is supplied in the form of a piece of gas pipe which runs through the supporting standard at the points marked C and D, Fig. 4. Ordinary pipe fittings, called flanges, are bolted to the frame at these points. The coupling in the gas pipe beneath the supporting standard serves as a stationary collar to support the weight of the whole mill. The vane should be placed correctly to balance the weight of the wheel.
The shaft passes through the framework of the mill on the inside of the pipe, as shown at E. A 3/8-in. soft-steel or wrought-iron rod is satisfactory for the shaft, as no weight is supported by it and only a twisting force is transmitted. The use of a larger rod makes the mill cumbersome and unwieldy. The upper end of the shaft is fastened to the shaft that projects from the under side of the machine head by means of a sleeve made of a piece of 3/8-in. pipe. Two cotters hold the shafts and sleeve together.
At the lower end of the shaft, inside the workshop, the device shown in Fig. 6 is installed. The purpose of this appliance is to provide a horizontal shaft upon which pulleys or driving gears may be mounted. The device is constructed of another sewing-machine head similar to the one already described. The head is cut in two and the separate parts mounted on suitable supports. The gap between the sawed portions permits a pulley to be fastened on the shaft to serve as the main drive. The wheel propelled by the treadle of the sewing machine will make a good drive wheel. The small handwheel, originally mounted on the machine-head shaft, is left intact. This arrangement gives two sizes of drive wheels. Heavy sewing-machine belts will serve to transmit the power.
The Tower
The tower can be built up in any manner to suit the conditions. Ordinarily sticks, 2 in. square, are suitable. These are well braced with wire and fastened securely to the roof of the shop. The arrangement of the tower with the mill is shown in Fig. 7.
Telegraph Code on Typewriter Keys
A very simple and practical method of transcribing wireless time and other messages on the typewriter without having such perfect knowledge of the Morse system as to be able to immediately translate it into the common alphabet is the following: The characters of the Morse system are inscribed on small slips of paper--thus, three dots (...), for the letter S; two dashes (--), for the letter M, etc.--and these slips are pasted on the corresponding keys of the typewriter. The operator puts on his receiver, and the proper key is struck as he hears the corresponding Morse letter. As there are no capitals, spacing between words, or even punctuation, the manipulation of the typewriter is much simplified, and it is easily learned to record the signals as fast as they are heard.
An Aid in Sketching Profiles
The means usually employed by most beginners to obtain the correct outline of an object, such as tracing or a pantograph, make them dependent on mechanical help rather than train the eye to form and proportion a drawing correctly. The device shown not only greatly assists the beginner, but actually trains him toward a point where he can dispense with any such device and correctly sketch by free hand. It also has the effect of encouraging the beginner, because his first efforts will not be complete failures, as is usually the case.
The device consists of a rather fine wire bent in the shape of a human profile and supported on a stand or base. The stand may be dispensed with, however, and the wire held in the hand. In use, it is placed near the model or person whose profile is to be drawn; then, after closing one eye, it is set at a position where it will correspond to the features of the model. This enables one to note the variations between the wire and the model's features. For instance, the forehead may recede from the wire at the top, or the nose may have a different slant or shape.
The paper on which the drawing is to be made should have a faint outline drawn by laying the wire upon it and marking around it with a soft pencil. Having noted the variations between the wire and the features, proceed to draw the profile, observing the same variations, and when the sketch is completed, erase the faint outlines. Then compare the drawing with the model without using the wire, and make final corrections. The dotted line indicates the outline to be erased.
The drawing may be made larger or smaller than the bent wire, but the outline on the paper must be kept in exactly the same proportion. It is not necessary that the wire be bent so that it represents perfect features. With the use of this device one forms a habit of comparing and proportioning, which applies to the correct sketching of all objects.--Contributed by Will L. Burner, Columbus, Ohio.
A Small Hydroelectric-Power Plant
Wherever a water pressure of over 30 lb. is available a small hydroelectric-power plant will produce sufficient electric current for any light work, such as charging storage batteries, operating sewing and washing machines, toys, etc. The design is for a 6-in. hydraulic motor of the Pelton type, which will operate well on almost all city-water pressures, and at 80 lb. will drive a 100-watt generator to its full output.
The castings may be procured from any foundry cheaply, so that these parts need not trouble the builder. The patterns can be constructed easily and are not so complicated that they will tear the molds when being removed. They are made from well seasoned white pine, 1/4 in. thick. Fill in all sharp corners with small fillets. All the patterns should taper slightly from the parting line.
The motor casing is shown in Fig. 1. It is made with a wide flange so that the cover plate can be bolted to it. The lug A is to give additional strength and thickness to the side so that it may be drilled and tapped for the nozzle. The legs B and C are for bolting the case to a base or support. The outlet pipe is of lead, 1-3/4 in. outside diameter, and the hole for it in the case can be either drilled or cored. Solder the pipe flush with the inside of the casing. Drill and tap the holes around the flange for 8,32 bolts. The shaft hole must be drilled very carefully. Drill 1/4-in. holes in the feet. The oil holes are 1/8 in. in diameter. File the surface of the flange smooth and also the inside shoulder of the bearing lug. Drill and tap the nozzle hole for a 3/4-in. pipe thread.
The cover plate is shown in Fig. 2, This is bolted to the casing with 8,32 brass bolts, 1/2 in. long. The holes for them are drilled 3/16 in. in diameter. A shallow hole, for the end of the shaft to fit in, is drilled in the lug, as shown. It does not pass all the way through the plate. File the inside face of the lug smooth and also the edge of the plate where it joins the casing.
The wheel, with brackets attached, is shown in Fig. 3. This style of wheel need not be followed out closely. Bore the hub centrally for a 1/4-in. shaft and fit in two setscrews. Drill and tap the rim for the buckets with a 1/4-in. standard tap. The buckets must be evenly spaced and bolted on to make the wheel balance.
The buckets are shown in Fig. 4. They may be cast from iron or babbitt. The sharp ridge in the center provides for a deviation of the water jet as it flows on the bucket. The ridge divides the bucket into two equal lobes which turn each division of the jet through almost 180 deg., using all the kinetic energy in the jet. This is shown at D. The dividing ridge must lie in the plane of the revolution, so that each bucket will enter the center of the jet. The buckets being evenly spaced on the periphery of the wheel, only one at a time receives the force of the jet, the one in front and the one behind clearing the jet.
The nozzle is shown in Fig. 5. It can be made of iron or brass. The inside gradually tapers from 3/4 to 3/16 in. It has a 3/4-in. pipe thread and is screwed into the hole in the case from the inside and is secured with a lock nut. Enough additional threaded portion is left protruding to allow the supply pipe to be connected.
When assembling the motor, fasten the wheel to the shaft with the two setscrews, and place a metal washer, E, on each side of the wheel. Place the wheel in the casing and screw the cover plate in place. A thin rubber gasket should be placed between the cover and the casing to provide a water-tight joint.
The general arrangement of the plant is shown in Fig. 6. The motor and dynamo are mounted on a heavy wood base, which in turn is firmly bolted to a concrete foundation. Level up the two machines by the use of thin washers on the bolts between the base and machine. A heavy sleeve and setscrews are used to connect the two shafts. The connection to the water supply is made with 3/4-in. pipe, with a globe valve in it to regulate the flow of water. Any dynamo of about 100-watt output can be used.
Paper Shades for Electric-Light Globes
The appearance of an electric-light globe can be very prettily improved by making a shade of crêpe paper of any desired color for each one. Canary-colored crêpe produces a soft, mellow effect. Pale blue, yellow, red and, in fact, all the colors can be used, making a very pleasing variety.
The body of the shade is made of a piece of paper about 5-1/2 in. wide and 3-1/2 ft. long. The width will vary with the length of the globe to be covered, and it is best to have it full, as the edge can be trimmed even with the lower end of the globe afterward. Another piece of the same color is cut 2-1/2 in. wide and of the same length. This piece makes the ruffle.
The smaller piece is placed on the larger centrally, and both are stitched together with a running stitch, using a needle and cotton thread. A plain running stitch is also made 1/4 in. from one edge of the larger strip. The material is gathered along both threads. This operation makes the material shrink in length. Wrap it around the globe, pulling the threads taut so that the ends of the paper will just meet. Tie the threads and clip off the extending ends. If the paper extends beyond the end of the globe, trim it off with the shears. Ruffle the two edges of the narrow strip and the lower edge of the larger one. This operation is simply stretching the edge of the crêpe to cause it to stand out.--Contributed by Jas. A. Hart, Philadelphia, Pa.
Renewing the Markings on Graduates
Graduates that have been in use a long time, especially for measuring alkalies, become unreadable. The graduations are easily restored in the following manner: Moisten a small piece of absorbent cotton with a solution of white shellac, cut in alcohol. Rub this well into all the etched parts and allow to dry for about two minutes, then rub in a fine whiting or litharge with an old toothbrush. If red is desired, use rouge; if black is preferred, use lampblack or powdered graphite. When dry, wipe off the excess pigment with a cloth moistened in alcohol.--Contributed by A. C. Norris, Rockford, Ill.
Repairing a Broken Ball-Clasp Purse
Having occasion to repair a purse of the ordinary ball-clasp kind where one of the stems was broken off and lost, I first had some trouble in finding a way to repair it. I started to take off the remaining stem in an attempt to replace the locking device with another kind, and in bending it down toward the opposite side, I happened to close the purse and found that it locked just as well as if there had been two balls on it. I have since repaired two other purses in the same manner and found that they worked well.
The idea is to bend the remaining clasp over until it is low enough to come in contact with and to spring over the other side, thus giving the same snap and holding qualities as before.--Contributed by W. C. Loy, Rochester, Ind.
Automatic Valve for a Funnel
Where liquid is run through a funnel into an opaque bottle or earthen jug, the filling cannot be watched, and if not watched constantly, the vessel will overflow. This can be obviated by applying the automatic valve to the funnel stem, as shown. A washer support is soldered or otherwise fastened in the upper end of the stem, or at the base of the sloping part, and a crossbar is fastened to its upper surface across the hole. The crossbar is centrally drilled to receive a small rod or wire, to which is attached a valve that will cover the hole in the washer. A cork is stuck on the lower end of the rod. The location of the cork on the rod should be at a point a little below the level to which the bottle or vessel is to be filled.--Contributed by H. W. Hilton, Hopington, B. C.
Chisel Holder for Whetting
To obtain the proper slope and apply a fine cutting edge, the plane iron or chisel must be held at the proper slope while grinding, and especially so when whetting. The illustration shows a holder to keep the iron or chisel at the proper slope. It consists of a block of wood with a sloping cut at the right angle to make two pieces. One of these pieces is permanently fastened to the strip at the back, while the other is held with a bolt passing through a notch in the strip for adjusting or clamping. The rear end of the back piece is fitted with a large screw hook or L-hook to provide a slide to keep the rear end of the holder at the right height. The iron or chisel is inserted between the sloping edges of the blocks and clamped in place, then the L-screw is adjusted for height to secure the proper angle on the stone. It is then only necessary to move the block and tool back and forth over the stone.
A Large Hole in a Small Piece of Paper
It would seem impossible to cut a hole in a piece of paper, 2 in. wide and 3 in. long, large enough to allow a person's body to pass through it, but if carefully cut as shown by the lines in the sketch, one will find with surprise that the paper can be extended so that the feat is easily accomplished. Make the cuts about 1/8 in. apart and these will allow the paper to expand several times its size.--Contributed by H. Martine Warner, E. Orange, N. J.
Homemade Bunsen Burner
The amateur craftsman, at some time or other, needs a hot flame for certain kinds of work, and a Bunsen or alcohol flame is brought into service. The gasoline and alcohol flames have their drawbacks, one of which is the starting of the burner and the waiting for the heat. They are also unhandy in directing the flame on parts of the work. As I desired a burner for quick work and one whose flame I could direct at any angle, for repoussé and chasing on copper and silversmith's work, I made the one shown in the sketch to attach to a hose and connected it with the gas pipe of the illuminating system in the house. It consists of a hose connection into which a piece of pipe, 5 in. long, is fitted. The hose connection is also fitted with a small nozzle, A, for the gas, and the pipe has an opening through it at the end of the nozzle.--Contributed by John Koestner, Brooklyn, N. Y.
Cane-Seat Cleaner
A rapid and practical method of removing stains and discolorations from the cane seats of chairs, wickerwork, etc., is to use oxalic acid and powdered pumice.
Dissolve oxalic-acid crystals in hot water and saturate a small stiff brush in it, then dip the brush in the powdered pumice and rub the discolored cane briskly with the brush.--Contributed by W. F. Jaquythe, Richmond, California.
Shade-Roller and Curtain-Pole Bracket
The main advantage of this shade bracket is that a person can lower it for adjusting the shade or in changing curtains while standing on the floor, thus eliminating the use of a step ladder and the danger possibly attending such use.
The front elevation of a window with bracket attachment in position is shown in Fig. 1, and a cross section in Fig. 2. The position of the curtain pole when the brackets are lowered is shown by the dotted lines. A detail sketch of the support end is given in Fig. 3 and one bracket is shown in Fig. 4.
The curtain pole A is fastened to the brackets B with 1/4-in. dowel pins, C. These pins and the pole keep the brackets from spreading at the top, so that a shade roller, D, may have its attachments fastened to the inner sides of the brackets. A small pulley, E, is attached to the window casing above the right bracket and a double pulley is located above the left, cords being passed through them, down along the casing to a point within easy reach, and fastened in any manner desired.
All that is necessary to change the curtains or fix a shade is to loosen the cord and allow the brackets to drop down until they may be easily reached.--Contributed by James F. Napier, Montreal, Can.
Planing Arrow Sticks
While making some bows one day I discovered I had no suitable dowel sticks for the arrows, so I started to make them out of 1/4-in. square stock. I found it rather difficult to plane these pieces until I hit upon the scheme shown in the sketch. I procured a piece of ordinary tongue-and-groove flooring and clamped it in the bench vise, then drove a nail in the groove to act as a stop, and in no time I had the sticks planed into arrows.--Contributed by J. F. Culverwell, Washington, District of Columbia.
To Clean Shellac from a Brush
Put the brush in a strong, warm solution of borax and water, and then wash in clean, warm water. If the bristles have become hard, allow the brush to remain in the solution until soft, keeping the solution warm in the meantime; then wash it out in warm water.--Contributed by N. J. Shattuck, Woburn, Mass.
Lathe Dogs
In the absence of a full equipment of lathe dogs the amateur can make them cheaply from pieces of iron pipe. One of these is shown in the sketch. A section of pipe, 1-1/2 in. to 3 in. long, is partly cut away, as shown, leaving a projection of metal 1 in. wide. One or more setscrews are fitted in the round part, and the dog is complete.
A dog, or driver, may also be made of two U-clamps and two bolts as shown. This is especially useful for large work, where the cost of a dog would be prohibitive. After these two clamps are bolted on the work to be turned a bolt is attached in the faceplate that bears against the clamp, thus turning the work.
To Remove a Splinter from the Flesh
Quite frequently small particles of steel, splinters, or thorns are run into the flesh and cannot be removed with the fingers. These can be readily removed in the following manner: Press the eye of an ordinary needle over the protruding end, then turn the needle until the edges bind or clinch. While in this position, raise the needle and out comes the splinter.
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A fine luster can be given to zinc by rubbing it with kerosene or a weak solution of sulphuric acid.
Holders for Displaying Magazines
Papers and magazines often are sold in drug stores where the display space usually is limited, especially in the window. The method used by one druggist gave space for the magazines in the window without interfering with the other goods.
The back of the window was arranged with rows of hooks, three hooks for each magazine, two at the top edges and one in the center at the bottom. The magazine is easily slipped into these holders, and the whole presents a tidy appearance. The hooks are the ordinary screwhooks that can be obtained from a hardware or furniture store.--Contributed by T. F. Monaghan, Philadelphia, Pa.
Waste-Paper Basket
The covering of a broken demijohn was used in the manner shown as a waste-paper basket. The glass was broken out and the covering soaked in water, after which the splints were turned down and tied with a cord. This I found to make a first-class waste-paper basket.--Contributed by A. S. Thomas, Gordon, Canada.
Lettering Photographs
Amateur photographers often write, or print, the names of the subjects on the mounts, or in the albums, with white ink or scratch it on the negative so that it will print in the picture.
A very good method is to take ordinary black ink and do the lettering on the sensitive paper before it is printed under the negative, being careful not to scratch the paper. After printing the paper to the proper shade the toning and fixing baths will wash away the ink and leave the lettering in white.
The lettering is easily accomplished and a post card can be sent with any message desired on any negative, the inscription being printed on the paper so that the negative is unharmed for other printing.--Contributed by Henry J. Marion, Pontiac, Mich.
A Stamp Moistener
A handy stamp moistener and envelope sealer can be made by procuring a small medicine bottle or glass vial and inserting a piece of felt or other wicking material in the place of the stopper, and filling it with water.
This moistener will be found handy for a small office where the mail is quite heavy, but not big enough to warrant the purchasing of a sealing machine. This moistener is sanitary and replaces the wet sponge.--Contributed by Theo. J. Becker, Kansas City, Mo.
A Window Lock
A very neat window lock can be made of sheet steel, 1/2 in. wide. One piece, shaped like a saw tooth, is fastened to the sash, and the other, which is bent to form a catch over the tooth projection and ends in a curved top for a finger hold, is attached to the window casing. The illustration clearly shows how the lock is attached.--Contributed by Lee B. Green, Cleveland, O.
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Georgia pine should be filled with white shellac.
Varnished Candles Burn Longer
The heated tallow or wax of a candle runs down the sides and this results in a considerable waste. This waste can be stopped by coating the new candles with white varnish and laying them aside for a few days to harden. The varnish will keep the melted tallow or wax from running away and it is used in the wick.
Guides for a Mill File
Having a large number of wires to file true on the end I devised a way to do this with the use of some old worn-out and discarded files that had good cutting edges. A piece of sheet copper, about the same length as the files, was bent to fit over one edge and both sides of the file, allowing both edges to project about 1/4 in. This made a guide that prevented the edge of the file from slipping off the end of the wire. The guide was held in place on the file by cutting a slit in the projecting edges, about 1/4 in. from the end, and turning these separated parts back on the file.
If such a guide is fitted tightly on a file, the edges of worn-out files can be used for such work, and the file cannot slip off and mar the sides of the work.--Contributed by A. R. Drury, Hampton, Ill.
A Simple Motion-Picture Machine
The drum A is a piece of wood, 1-3/4 in. long and 1-3/16 in. in diameter, supported on the end of a round stick, B, which can be made in one piece with the drum, if a wood lathe is at hand, but a piece cut from a curtain pole and a lead pencil inserted in a hole bored in the end will answer the purpose. Be sure to have the diameter of the drum 1-3/16 inches.
Provide a base piece, C, 1/2 in. thick and 2 in. square, and fasten a piece of cardboard having a slit E, as shown. The cardboard should be 2 in. wide and 2-1/2 in. high, the slit being cut 1/2 in. in width, 1/4 in. from the top and 3/4 in. from the bottom. A hole is bored in the center of the block to admit the standard B easily.
The next step is to provide the picture and attach it to the drum. A picture of a boy pounding cobblestones is shown in the sketch, at F, which should be made on a strip of paper 4-3/8 in. long. This is glued or attached with rubber bands to the drum. The drawing can be enlarged in pen and ink, or can be reproduced as it is, if a hand camera is at hand, and a print used on the drum.
It is only necessary to put the parts together, grasp the base in one hand and turn the support B with the other, when, looking through the slot E, the boy is seen pounding the stones. Various pictures can be made and the strips changed.--Contributed by C. C. Fraser, Saginaw, Mich.
Substitute for Cleats on Boards
The necessity for using more than one cleat for fastening two boards together may be done away with by using the device shown in the sketch. The center cleat prevents the boards from buckling while the sides are tightly held by these simple flat fasteners. The fasteners are made of tin cut as indicated, slipped between the edges of the boards and the parts bent over and tacked. Where the strain is not too great the holders may be used without a cleat, making an effective flat fastening.--Contributed by W. O. Nettleton, Washington, D. C.
Attaching Door Knobs to Locks
When putting a lock on a door it is often difficult to press the two knobs together tightly enough to prevent them from rattling and still be able to insert the screw into the shank. By using a piece of board, 1 in. thick, 6 in. wide and 1 ft. or more in length, with a V-shaped piece cut out of one side, the knobs can be easily forced and held together while the screw is inserted.--Contributed by H. Musgrave, Sidney, British Columbia.
A Finger-Nail Buffer
The flywheel on a sewing machine is usually turned with a semicircular face and this makes a good base on which to apply a piece of chamois skin for use in buffing nails. A strip of the chamois is cut the length of the wheel's circumference and small holes pierced in its edges, through which strings are run to hold it to the rim of the wheel. The chamois can then be removed or left on the wheel as desired. Run the machine and hold the nail on the buffer. When there is a free wheel on the machine this makes an excellent buffing device.
Grinding Chisel Edges
A cold chisel ground with a rounding edge, as shown, will last twice as long and do better work than one that is ground straight, because it will not wedge, and the cutting edge, having a better support, will not chip off.--Contributed by F. G. Marbach, Cleveland, O.
Reducing Amperage of a Fuse Wire
It is sometimes necessary to use an electrical fuse of smaller amperage than those at hand, and for experimental work this is often the case. A smaller amperage may be readily made from a larger-size wire by making a nick in it with the cutting edge of pliers, or with a knife. The illustration shows how to reduce the size of a 10-ampere fuse to make it five amperes.--Contributed by Louis Litsky, Brooklyn, N. Y.
Dip-Plating Process
The various ways of doing dip plating are practically the same method, the coating fluid consisting of essentially the same materials.
The tank or crucible, as it may be called, consists of a piece of 3-in. gas pipe, 9 in. long, threaded at both ends, one end being fitted with a screw cap and the other with a pipe flange. This part is shown in Fig. 1. A piece of sheet metal is cut in the shape shown in Fig. 2 and bent to form a cone, so that the smaller end will fit snugly around the pipe and the base be 9 in. in diameter. The joined edges are riveted together. The assembled parts will appear as shown in Fig. 3.
The metal used for plating consists of bismuth, 4 oz.; antimony, 4 oz., and pure block tin, 10 lb. Place the antimony in the crucible and melt it, then add the tin and bismuth. A flame from an ordinary gasoline burner will be sufficient to heat the crucible.
Clean the article to be coated by rinsing it in strong caustic potash, which will remove all grime and grease, then dip it in a strong solution of sal ammoniac and water. Dry it and then dip it in the melted metal, allowing it to remain there about 1 minute, then remove and plunge it in a bath made of 1 lb. of sal ammoniac and 1 gal. of water. The article is then dried in sawdust.
The coating put on in this manner is a nice, shiny plate that will stand a lot of wear. No polishing or grinding is necessary.--Contributed by A. H. Waychoff, Lyons, Colo.
A Model Steam-Turbine Boat
A piece of thin board, or shingle, is cut to the shape of a boat and two standards are fastened to it. The standards have notches cut in them to hold an ordinary baking-powder can which is used for the boiler. The lid of the can is soldered on, and a small hole punched in one side with an awl. Two candles are used to heat the water.
The turbine is constructed on an axle made of a hatpin which runs through the top of the standards for bearings. The paddles are made of cardboard, or better still, pieces of thin sheet tin, cut and bent as shown at A, and three of these are attached to a three-cornered block of wood fastened to the shaft, as shown at B. The manner of attaching the shaft for the propeller is shown at C. The propeller consists of a piece of tin, slightly twisted and attached to the shaft with solder. The pulleys are located as shown and connected with a string band. The hole made in the can should be pointed to one side of the turbine shaft so that the escaping steam will strike one side of the paddles on the turbine.--Contributed by McKinley Wood, Ava, N. Y.
Plant Shelf for a Window
An ingenious and simple method of putting up window shelves for winter plants so that the window casing and facing are not marred is shown in the sketch. The materials required are one shelf, about 8 in. wide, 1-1/2 yd. of picture wire, two screweyes, two fence staples, and two strips of wood, to raise the shelf slightly from the window sill. The board for the shelf is cut to fit the window frame and casing. The picture wire, screweyes and staples are attached as shown. When cleaning the window the shelf can be drawn out of the way.--Contributed by H. C. Dixon, Johnstown, Pa.
A Camera Support
A device which, in many instances, will take the place of a tripod, can be made of a brass wood screw and can be carried in the pocket as easily as a pencil. The screw should be 3 or 4 in. long and 1/4 in. in diameter. Cut off the head and thread the end about 1/2 in. to fit the socket in the camera. Drill a 1/8-in. hole through the metal just below the threaded part and insert a short piece of 1/8-in. wire. Slip a washer over the end, down to the wire, and fasten it with solder.
The device can be turned into a tree, post or a stick thrust into the ground, and the camera screwed onto it and adjusted to any angle.--Contributed by O. D. Turner, Seattle, Wash.
Combination Tool for Amateur Draftsmen
A common 6-in. mill file can be converted into a very useful tool for an amateur draftsman. Grind the end of the file as shown in the sketch and use it for prying out thumbtacks that are driven in too tightly. Grind the base of the tang into a knife blade for sharpening pencils, shaving chalk, opening envelopes, etc. Shape, by careful grinding, the part A for cutting and trimming sheets. Grind one edge of the file round and polish it for smoothing and burnishing purposes. Grind a sharp point on the tang for perforating sheets. A piece of rubber stuck on the tang end answers the double purpose of a protector and eraser. The file part is used for finishing points on pencils.
Varnishing Bases for Electric Apparatus
It is quite difficult to keep from making finger marks on freshly varnished boards used as bases on electric devices. It is easily avoided, however, by procuring a large spool and fastening it to the bottom of the base with a wood screw. The spool will serve as a handle while the varnish is applied, and also makes a stand for the board while the varnish dries.--Contributed by Jacob Laudan, Louisville, Ky.
Waterproof Shoe Dressing
Melt some tallow and, while it is hot, put in some scraps of rubber from old rubber shoes or boots. Be careful to select rubber that is free from cloth. Put in as much of the rubber as the tallow will absorb. Stir freely while it is melting, and keep it away from any flames. Allow it to cool and set away for future use. Take enough for immediate use and warm it sufficiently so that it may be applied with a brush.--Contributed by F. S. Cummings, Detroit, Mich.
An Adjustable Bench Stop
A simple adjustable bench stop for light work may be made from a piece of 1-in. broom handle and a piece of piano wire. Plane a flat surface on the broom stick and drill two 1/16-in. holes, about 1/4 in. deep, 1/4 in. from each end. Bend the ends of the wire to enter the holes and have the wire of such length as to give it a slight curve between the ends when it is in place on the stick.
Bore a 1-in. hole through the bench top where it is desired to use the stop and cut several grooves, as shown, in the walls of the hole with a compass saw. The spring wire will slide into a groove and hold the stick wherever it is set. The position of the face can be changed by inserting the stick so that the wire will enter the right groove.--Contributed by Alan H. Andrews, Fall River, Mass.
A Crochet Hook
In making some kinds of lace work different-sized hooks must be used as the work proceeds. Considerable time will be lost in changing from one hook to another, if they are separate. The best way is to mount all the hooks necessary on one handle, as shown in the sketch. The handle part is made of a large wire or small rod, bent to the shape shown and with holes drilled through the ends for a small rivet. The ends of the hooks are drilled or bent to fit on the rivet. A small tin ferrule is made to slip over the handle and the hooks not in use. All hooks but the one in use are turned back into the handle and the ferrule slipped into place.--Contributed by Miss Nita S. Ingle, W. Toledo, O.
Writing Board for Children
A writing desk for a child can be easily made as shown in the sketch. The materials necessary are a board of suitable size, two screwhooks, four screweyes and a pair of rods for braces. The hooks are screwed into the back of a chair and the screweyes into the board, as shown. This desk is instantly attached or taken down when desired. If the chair is light and apt to tip over, make the rods long-enough to reach to the floor.--Contributed by John V. Loeffler, Evansville, Ind.
Geometric Principle in Line Division
When sketching a plan, if any one of the first few lines drawn is found to be the proper length, then this line can be made into a scale by the geometric rule for dividing a given line into equal parts.
Suppose, for example, the line AB, which is to represent 12 ft., is found to be 1 ft. long. Draw a line, AC, at any angle from the point A and step off on it 12 equal parts, beginning at A. The last point, or the one at C, is connected to the end B, then eleven other lines are drawn parallel with CB. Thus AB will make a scale of 1 in. to each 1 ft.--Contributed by James M. Kane, Doylestown, Pa.
Repairing a Broken Whip
Procure a piece of thin tin--the metal taken from a discarded fruit can will do--and cut it about 2-1/2 in. long and wide enough to encircle the break. Notch the ends like saw teeth and remove any sharp edges with a file. Place the tin on the break and tie temporarily. Wind the whole from end to end with a waxed linen thread, such as used by harness makers. The threads lying alternately on the whip and on metal at the notched ends eliminate any possibility of the parts working loose. A break near the small and flexible end of a whip is repaired in the same manner, using a quill instead of the tin. In either case, do not let the edges of the splicing material meet, and it will clamp tightly on the whip.--Contributed by W. S. Kingsley, W. Gouldsboro, Me.
Repairing a Worn Thimble
Silver thimbles are easily worn through at the end, and they can be quickly repaired by soldering from the inside. A very neat repair can be made with an alcohol lamp and a blowpipe by using a little silver solder. Borax or resin is used as a flux.
A Small Torch
A small torch, that will give a very fine and hot smokeless flame, can be made from a piece of glass tube, about 4 in. long, and 4 ft. of rubber tubing. The glass tube is heated in the center until it is red, then the ends drawn apart so that the tube will have a small diameter. After the glass has cooled, make a small scratch with a file on the thin part and break it. One of the pointed ends is connected to a straight piece of glass tube with a short piece of the rubber tube, as shown in the sketch. A small hole is cut in the side of the piece of rubber to admit air to the gas. The torch is connected to an ordinary gas jet.--Contributed by E. K. Marshall, Oak Park, Ill.
Fountain Attachment for an Ordinary Pen
A quite efficient fountain pen may be quickly made by bending an ordinary pen, as shown at A, and inserting it in the holder opposite to the regular pen, as shown at B. For best results, the point of the auxiliary pen should just touch the regular pen.--Contributed by Thos. L. Parker, Wibaux, Mont.
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A little water added to oil paint will make a flat or lusterless finish and will do no harm to the paint, as the water evaporates in time.
Homemade Cut Press
The person who has a little ability in making wood cuts with a knife will find it very interesting to make the press shown in the sketch. A fair job of printing can be done with the press, using printer's ink spread on a piece of glass with a hand ink roller, such as can be purchased cheaply of any dealer in printing supplies.
The press may have a base, A, of any size to suit, but one 1-1/2 in. thick, 6 in. wide, and 12 in. long will be found to serve best for most purposes. It must be smooth and level. Hard wood, such as maple, beech, or birch, is best for all parts. The post B is 1-1/4 in. thick, 2 in. wide, and 5 in. long. Before setting it, slot the upper end for the end of the lever. This is done by making a saw cut, 1-3/4 in. deep, 5/8 in. from either side and cutting out the core to make a slot 3/4 in. wide. A 1/4-in. hole is then bored through the prongs to receive a stove bolt that connects them with the lever. The post is fastened with screws and glue in a notch cut in the center of the base end.
The lever C is made of a piece of wood 1/4 in. square and 10 in. long. At the forward end the sides are pared away to form a tongue, or tenon, that will pass between the prongs of the upright, and a hole is bored through it to match those in the prongs. The entire upper surface of the lever is rounded and the under surface is rounded, beginning 6 in. from the tenon end. Glue to the under side of the lever a block, D, at the end of the under, flat surface. The block should be about 1-1/4 in. square by 1-1/2 in. long. If the under side of the base is crowning, either level it with a plane or nail cleats across the ends for feet. A washer is used with the stove bolt in connecting the lever and post.
The cuts are made of small blocks of wood, about 3/4 in. thick and of a size to take the characters desired. These blocks must be level and the printing side made smooth with very fine sandpaper, or a scraper, before the characters are laid out. Boxwood is best for cuts, but pearwood, applewood, birch, or maple will do very well. Mark out the characters backward, using the pencil very lightly. Then, with the small blade of a knife, made as sharp as possible, cut around the outlines, holding the knife slanting, and remove the adjacent wood by cutting in at a reverse angle to meet the boundary cut. Gradually deepen the cuts around the characters until they stand in relief about 1/8 in., then score V-shaped grooves, checkerboard fashion, across the remaining high surface that is not a part of the design, and chip out the resulting small blocks to bring the entire secondary surface of the block to a uniform level with the portions adjoining the characters.
A touch of glue to the back of the cut will set it securely enough to the bottom of the block D for printing, and allow its removal without injury when desired. To get a uniform impression in printing, place paper on the base, as at E, to the thickness required. For controlling the printing position on the stock paper, pins or tacks can be stuck into the base and each sheet to be printed laid against these guides.--Contributed by Chelsea Curtis Frazier, Saginaw, Mich.
An Electrical Testing Instrument for Experimenters
The amateur having an ordinary flash light can make an instrument that will serve for a variety of purposes. It is only necessary to solder a piece of lamp cord to the spring of the battery which comes in contact with the lamp, and pass the end through a hole drilled in the top of the case. The end can be fitted with a cord tip.
To test batteries, take the flash light in the right hand and press the button, lighting the lamp, then place the bottom of the flash light on one binding post and the cord on the other. If the light burns brilliantly, the battery is dead, but if it burns dimly or goes out the battery is good.
It may happen that the experimenter's telegraph line is out of order and the trouble cannot be found. The sounder may be tested out by disconnecting the wires from the instrument and placing the bottom of the flash light on one binding post and the cord on the other. If the light goes out, the trouble does not lie in the sounder, but in some other part of the line. The line may be tested in a similar manner if one end is short-circuited and the flash light connected to the other.
A tester of this kind cannot be used on long lines, or on instruments of much resistance, as their resistance will overcome that of the light. Keep in mind the fact that the lamp will always burn on an open circuit and go out on a closed circuit.
Softening the Tone of a Talking Machine
An effective mute, for use on any disk talking machine, can be made by clamping an ordinary wood clothespin on the head of the setscrew that holds the needle. Thus the tone will be softened a great deal more than by the use of a wood needle. The record of a stringed instrument, such as a violin, will be almost exactly reproduced. It will also eliminate almost all the scratching sound caused by a steel needle.--Contributed by C. M. Reeves, Los Angeles, Cal.
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An antenna should be made of wire larger than No. 14 gauge.
A Musical Doorbell By H. Marcelle
In the construction of this doorbell it is best to purchase a small instrument known as the "tubaphone." It consists of a rack with several pieces of brass tubing cut to different lengths to give the proper tones as they are struck. Such an instrument with eight tubes will play almost any tune, and can be purchased from 50 cents up, depending on the size. Brass tubes can be purchased, cut, and toned, but the time taken in doing this is worth more than the price of the instrument, and no changes are necessary in it to make the doorbell.
Several strips of pine, 2 in. wide and 7/8 in. thick, are procured for the framework. The tubes are placed on a table top, 1 in. apart and with their lower ends on a line at right angles to their length. Allow a space of 1 in. outside the first and last tube, and cut a piece of the wood to this length, allowing sufficient additional material to fasten on the ends of two uprights, which are cut long enough to admit the longest tube and allow sufficient room for a large roller and space at the top to swing the tubes.
A base is cut from a board, 7/8 in. thick and of sufficient size to admit the roller and tube rack, together with a small battery motor. The tube rack is fastened to the back of this base by making a tenon on the lower end of each upright, and a mortise in the baseboard to receive it.
A roller is turned from a piece of soft pine, large enough to provide room on its surface for a number of horizontal lines equal to the number of notes in the composition to be played. These lines should not be too close together. Supposing the music it is desired to play has 15 notes in its composition, then 15 horizontal lines must be spaced evenly on the surface of the roller. The length of the roller should be a free-working fit between the uprights. A 1/4-in. steel rod is run through its center for a shaft, allowing sufficient ends for the bearings, and, in addition, at one end sufficient length for a pulley.
The motor is lined up on the base, so that its pulley wheel will run a belt on the large wheel of the roller. The current is turned on after making belt and wiring connections, a lead pencil is held directly centering the place where each tube hangs, and a line is drawn on the circumference of the roller.
A 1/8-in. hole is drilled through each tube, near one end, and a piece of catgut string run into it to make a hanger. A piece of board, long enough to fit between the uprights when placed on the slope formed by the upper ends of the tubes after their lower ends are set straight on a line at right angles to their length, and wide enough to swing the tubes clear of the frame, is fastened in place, as shown. Small screw eyes are turned into the under side of this board, at even spacings of 1 in., and used to swing the tubes by the catgut strings. Another piece of board, the same width as the former, is placed, perfectly horizontal, between the uprights a short distance above the lower ends of the hanging tubes. Evenly spaced holes are bored in this crosspiece to admit the ends of the tubes. The holes should be of such size that when they are lined with a piece of felt, the tubes will have a little play without touching the sides at any point.
The hammers are each made of a strip of sheet brass, having a length that will extend from the base to a short distance above the lower ends of the tubes. A hole is drilled in each end of the strip, the lower one being of a size to fasten it to the base crosspiece with a round-head wood screw. The hole in the upper end is used to fasten a small block of wood with a screw, for the hammer head. A small strip of felt is glued to the striking side of the block. Another piece of brass, used for a trip, is fastened to the center part of each long piece with rivets, so that its upper end will be near the center of the roller for height, and strike the end of a small peg driven into the roller. The length of these pieces, in fact, of all pieces, will depend on the length of the tubes in the tubaphone and the size roller required for the music.
The setting of the pegs in the roller requires some patience in order to get the tune correct, but one mistake will be of more value than an hour's description. The pegs can be procured from a shoemaker. If the roller is of pine, they can be driven into the wood of the roller with a hammer.
With ordinary connections to the push button and motor, the mechanism will only run while the push button is being pressed. A device that will cause the piece of music to be played through to the finish after the push button is pushed for a short time, consists of a turned piece of wood fastened to the outside surface of the driving wheel on the roller. This piece of wood should be carefully set, so that its outside surface will be true as it revolves. Three brushes, made of copper strips, are fastened to the base. The length of these brushes will depend on the size of the roller and height of the block of wood. They should be evenly spaced and fastened, so that they will be insulated from each other. One strip of brass, or copper, is fastened around the turned piece of wood. This strip must be as wide as two brushes, except for a short distance to make a break in the electrical circuit. The notch in the strip, to make this break, should be on the outside edge where it will disconnect the center brush, and its location on the turned piece of wood should be on a line with the end and the beginning of the pegs for the music. Another short strip is fastened to the turned piece of wood, where it will make a contact with the first brush when the second or middle brush is in the notch, or disconnected, and is connected to the other notched strip with a piece of wire run beneath the wood.
The wiring shown will make it possible to start the motor with the push button which will turn the roll far enough to connect the center brush; then the roller will turn until the music is played, at which point it will stop and remain in rest until the push button again makes the contact.
The entire mechanism can be made to set on the mantel or shelf, incased like a mission clock, and the wires running to it may be concealed.
Replacing Buckle Tongues
Having several buckles without tongues I tried to repair them with pieces of wire, but could not get them to bend short enough to fasten around the buckle frame. Some cotters were at hand and seeing them gave me the idea of using one leg, with the eye part, as a tongue. By using the proper-sized cotter, a substantial and quickly made repair will be the result.--Contributed by Everett Hoar, Bowmanville, Ont.
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Bread crumbs thoroughly rubbed over a pencil drawing will remove most of the dirt and without disturbing the pencil lines.
Drying Towels in Photographer's Dark Room
In doing a large amount of photographic work the towel becomes wet, and to dry the hands on it is impossible. To obviate this annoyance, I made a galvanized-iron pipe, about 2 ft. long and 8 in. in diameter, with a disk, or circular piece, of metal about 10 in. in diameter soldered on each end to form flanges. One flange was fastened to the wall of the dark room in a convenient place to support the device. On the inside of the spool, or towel support, an ordinary incandescent electric globe was placed. The heat of the lamp would easily dry 12 in. of the towel, and when the dry part was pulled down for use another wet portion was brought into position for drying.
Those who have tried to handle gelatin dry plates with moist hands will readily appreciate the value of this simple contrivance. The lamp in the spool is connected on the switch with the ruby light, so that it is not forgotten, when leaving the room, to turn it out.--Contributed by T. B. Lambert, Chicago.
An Electric Chime Clock By John E. Mahlmeister
In the construction of this clock one perfectly good and accurate alarm clock and the works of an old or discarded one are used. The clock for the accurate time is set into a frame, or casing, made of thin boards which have a circular opening cut in them to fit snugly on the outside casing of the clock. The back of the clock and casing are shown in Fig. 1. A circular line is drawn on the casing, about 1 in. larger in diameter than the clock, and brass machine screws with two nuts clamping on the wood back, as shown at A, are set at intervals so as to be opposite, or just back of, the hour marks 2, 3, 5, 6, 8, 9, 11, and 12. A contact spring, B, is shaped as shown and soldered to the knurled knob on the back of the clock used for setting the hands in a position where it will travel or be parallel with the minute hand. The end of the contact spring should be shaped so that it will slide over the points of the screws easily, but in good contact. The ends of the screws should be filed to a slightly rounding point. The wiring diagram for this part of the apparatus is clearly shown, and the terminals are connected to binding posts C and D. The binding post E is connected to the metal part of the clock.
The chime part is made entirely separate and can be located at any reasonable distance from the clock. It is propelled by the works from an old clock, as shown at F, Fig. 2. The old clock is prepared for use by removing the hands, balance wheel and escapement so that the wheels will turn freely. To prevent the works from running too fast, a piece of sheet brass, G, is soldered to the shaft running at the highest speed. The brass should be as large as the space will admit. It forms a fan to catch the air and retard the speed, and also provides a means of stopping the works by the electric mechanism.
The parts for the gongs and electrical apparatus are supported on a baseboard, 3/4 in. thick, 6 in. wide, and 18 in. long. The automatic switch is located at one end of the base, and consists of two sets of magnets, H and J, with an armature, K, to which is attached a stiff contact wire, L. This wire is to make contact with the spring M when the armature is drawn by the magnets J, and with N when drawn by the magnets H. The springs M and N are made of thin sheet brass, bent as shown, and mounted on the base.
A piece of wood, O, on which to mount the works of the old clock is mortised into the base. Another standard, P, of the same height as O, is also mortised into the base to provide a bearing for the end of the shaft which carries the wood disk Q, the opposite end of the shaft being connected by means of a ferrule and soldered to the end of the minute-hand shaft. The shaft should be well lined up, so that it will turn freely. The wood disk is 1/4 in. thick and about 6 in. in diameter.
Mark four circles on the face of the disk, near the outside edge and 1/4 in. apart. Step off the outside circle into 150 parts and draw a radial line from each mark across the four circular lines with the straight edge on the center of the disk. An arc of the disk is shown in Fig. 3, where trip pins are driven in for making the electric contacts. This part of the arc shows the method of locating the pins for the hour from 3 to 4 o'clock, with the intermediate pins for the quarter, half, and three-quarter-hour contacts. The intermediate pins are arranged in the same manner for all hours, but the hour pins, on the second circle, run from 1 pin to 12 pins consecutively. Ordinary pins, with the heads cut off, are used and should be driven in accurately on the division lines to secure proper results.
The arrangement of the springs is shown in Fig. 4. These springs, when pressed together, will close the circuit for ringing the gongs. They are made of thin sheet brass, bent as shown at R, and fastened to a piece, or block, of hard wood with screws, as shown at S. The springs numbered 3, 5, 7, and 9 are the ones made as shown at R for sliding over the pins in the disk Q, and their ends should clear the face of the disk about 1/8 in. The springs 1, 2, 4, 6, and 8 are about 1/2 in. shorter and have their ends bent up at right angles so that they will almost touch the long ones. The spring 1 should be a little shorter than 2. When fastening the springs to the block of wood, be sure that no two springs touch and that each one is separated from the other to form no contact until the pins in the wheel force them together. The block is then fastened to the base under and parallel with the shaft carrying the disk Q, as shown.
The starting and stopping of the clockwork F is accomplished by means of a set of bell magnets, arranged, as shown at T, Fig. 2, with the wire attached to the armature bent to touch the brass wing of the fan G. The armature must not vibrate, but stay against the magnet cores while the current is flowing through them, thus allowing the clock wheels to turn, and as soon as the current is cut off, the armature will spring back and stop the wheels.
Arrange four gongs, U, V, W, and X, as shown in Fig. 2, and also three bell magnets with clappers 1, 2 and 3. These gongs should be selected for tone as in a chime clock. The connections to the bell magnets 1, 2, and 3 should be direct to the binding posts so that the armature will not vibrate, but give one stroke. For instance, bell magnet 1 should produce one stroke on the gong U when the current is on, and one stroke on the gong V when the current breaks. The magnets 2 should cause the clapper to strike once on the gong V when the current is on, and to make one stroke on the gong W when the current is broken. The magnets 3 produce only one stroke on the gong X at a time, which is used to sound the hours.
The parts are connected up electrically as shown in Fig. 5. The lines between the clock, Fig. 1, and the bell-ringing part, Fig. 2, are connected from C to C, D to D, and E, Fig. 1, to the zinc of a battery and from the carbon to E, Fig. 2. Two dry cells will be sufficient for the current.
The working of the mechanism is as follows: Suppose the time is 6 minutes of 3 o'clock and the contact spring on the back is near the 11 pin. As soon as it touches the pin, the armature K of the switch will be drawn in contact with the spring N, then when the contact spring touches the 12 pin, the current will flow into the magnets T and release the wheels of the clockwork F, which turns the disk Q, and the three pins in the second row will pass over the spring 5 and press it in contact with the spring 4 three times, causing the gong X to toll out 3 o'clock. As the contact spring B will be on the contact pin 12 for about 1 minute, the wheels of the clockwork F would continue to turn and the bells ring, if it were not for the stop pin located on the outside, or first, circle of the disk Q, which pin is set in line with the last pin in the set of pins for the hour, or, in this instance, in line with the third pin. When the stop pin has passed the spring, the connection through the magnets T is broken and the clockwork F stops instantly. When the spring B strikes the 2 o'clock pin, or 10 minutes after 3 o'clock, the armature K is drawn over to N, and at the 3 pin, or 15 minutes after 3 o'clock, the bells U, V, and W will ring and then the stop pin will break the current, and so on, at every 15 minutes of the 12 hours.
Hinges Used to Substitute Night Bolt
One of the safest devices for bolting, or locking, a door against intruders is to use two sets of hinges. The extra set is fastened to the door and frame in the same way but directly opposite the regular hinges. It may be necessary to file the extra hinges and pins in order to separate and bring the parts together easily. The usual door lock need not be used with this arrangement, as the hinges are exposed only on the inside of the room and cannot be tampered with from without.
Propellers for a Hand Sled
Desiring to propel my hand sled with power transmitted by cranks and wheels, I set about to procure the necessary materials. Two medium-sized buggy wheels were found in the back yard of a blacksmith shop, which were procured for a nominal price. The fellies of these wheels were removed, the tenons cut from the spokes and nails substituted, which were driven in their ends so that about 1/2 in. of the body with the head projected. The heads were then removed and the nail ends sharpened.
The hubs were plugged with pieces of wood, whittled to tightly fit the holes. A hole was then bored exactly central through each plug for a 1/2-in. rod. This size rod was procured and bent to form a crank, the bearing end being threaded for a distance equal to the length of the hub.
Two pieces or blocks of wood, 2 in. square and 4 in. long, were used as bearings. These were bored centrally through the long way, to receive the 1/2-in. rod just loose enough to make a good bearing. These bearings were supported by a pair of braces made of strap iron, about 1/4 in. thick and 3/4 in. wide. The length of the iron will depend on the size of the wheels and the height of the sled runner. The braces were shaped as shown. The center of the bearing hole must be as high from the surface of the ground as the distance the spoke ends are from the center of the hub hole.
The crank is then run through the bearing hole and a nut run on the threads and a washer placed against the nut. The wheel is then slipped on the axle, and another washer and nut run on tightly. Both wheels, bearings, cranks, and brackets are made alike. The brackets are fastened with small bolts to the sled top.--Contributed by Justin Stewart, Wallingford, Conn.
A Self-Feeding Match Box
With the addition of the simple device here illustrated, any match box can be converted into one of the self-feeding type. A piece of tin, or cardboard, is cut, as shown at A, the exact size depending on the match box used. The piece cut out is folded on the dotted lines, the cover on the match box is removed, and the part B pushed into the end of the box beneath the matches. The part B is twice as long as the depth of the box, therefore it enters the box as far as the line C. The flaps D rest against the outside of the box, and are held in place by the box cover. The matches feed into the box formed of the tin or cardboard as fast as used, while the burnt ones can be placed in the upper part E.
Corks-in-a-Box Trick
Procure a pill box and a clean cork. Cut two disks from the cork to fit in the box, and fasten one of the pieces centrally to the inside bottom of the pill box with glue.
To perform the trick, put the loose disk in with the one that is fast, and then open the box to show both corks. Close the box and in doing so turn it over, then open and only one cork will be seen. Be careful not to show the inside of the other part of the box with the cork that is fastened.--Contributed by Fred B. Spoolstra, Yonkers, N. Y.
A Disk-Armature Motor
One of the simplest motors to make is the disk motor, its construction requiring a wood base, a brass disk, a 3-in. horseshoe magnet, and some mercury.
The base is made of hard wood, in the proportions shown in the sketch. The leading-in wires are connected to the binding posts A and B, and from these connections are made, on the bottom of the base, from A to the groove C cut in the upper surface of the base for the mercury, and from B to one screw, D, of one bearing. The end of the former wire must be clean and project into the end of the groove, where it will be surrounded with mercury.
The bearings consist of thin sheet brass, cut to the dimensions shown, the bearing part being made with a well-pointed center punch, as at E. The disk wheel is made of sheet brass, 2 in. in diameter, and a needle, with the eye broken off and pointed, is used for the shaft. The needle shaft can be placed in position by springing the bearings apart at the top.
When the current is applied, the disk will revolve in a direction relative to the position of the poles on the magnet. The reverse can be made by turning the magnet over.--Contributed by Joseph H. Redshaw, Homestead, Pa.
Repairing Marble
With a little practice any mechanic can repair holes, cracks or chipped places on marble slabs, so that the patched place cannot be detected from the natural marble. Use the following mixture as a base for the filler: Water glass, 10 parts; calcined magnesite, 2 parts, and powdered marble, 4 parts. These should be mixed thoroughly to a semifluid paste. Fill the crack or hole and smooth off level, then with a camel's-hair brush and colors, made of aniline in alcohol, work out the veins, body colors, etc., as near to the natural marble as possible. It will depend on the application of the colors whether the repair can be seen or not. Artificial-marble slabs can be formed from this mixture.--Contributed by A. E. Soderlund, New York City.
The Construction of a Simple Wireless Telephone Set By A. E. Andrews In Two Parts--Part I
Among the various methods for the transmission of speech electrically, without wire, from one point to another, the so-called "inductivity" system, which utilizes the principles of electromagnetic induction, is perhaps the simplest, because it requires no special apparatus. Since this system is so simple in construction, and its operation can be easily understood by one whose knowledge of electricity is limited, a description will be given of how to construct and connect the necessary apparatus required at a station for both transmitting and receiving a message.
Before taking up the actual construction and proper connection of the various pieces of apparatus, it will be well to explain the electrical operation of the system. If a conductor be moved in a magnetic field in any direction other than parallel to the field, there will be an electrical pressure induced in the conductor, and this induced electrical pressure will produce a current in an electrical circuit of which the conductor is a part, provided the circuit be complete, or closed, just as the electrical pressure produced in the battery due to the chemical action in the battery will produce a current in a circuit connected to the terminals of the battery. A simple experiment to illustrate the fact that there is an induced electrical pressure set up in a conductor when it is moved in a magnetic field may be performed as follows: Take a wire, AB, as shown in Fig. 1, and connect its terminals to a galvanometer, G, as shown. If no galvanometer can be obtained, a simple one can be made by supporting a small compass needle inside a coil composed of about 100 turns of small wire. The terminals of the winding on the coil of the galvanometer should be connected to the terminals of the conductor AB, as shown in Fig. 1. If now the conductor AB be moved up and down past the end of the magnet N, there will be an electrical pressure induced in the conductor, and this electrical pressure will produce a current in the winding of the galvanometer G, which will cause the magnetic needle suspended in the center of the coil to be acted upon by a magnetic force tending to move it from its initial position, or position of rest. It will be found that this induced electrical pressure will exist only as long as the conductor AB is moving with respect to the magnetic field of the magnet N, as there will be no deflection of the galvanometer needle when the motion of the conductor ceases, indicating there is no current in the galvanometer winding, and hence no induced electrical pressure. It will also be found that the direction in which the magnetic needle of the galvanometer is deflected changes as the direction of motion of the conductor changes with respect to the magnet, indicating that there is a change in the direction of the current in the winding of the galvanometer, and since the direction of this current is dependent upon the direction in which the induced electrical pressure acts, there must have been a change in the direction of this pressure due to a change in the direction of motion of the conductor. The same results can be obtained by moving the magnet, allowing the conductor AB to remain stationary, the only requirement being a relative movement of the conductor and the magnetic field created by the magnet.
It is not necessary that the magnetic field be created by a permanent magnet. It can be produced by a current in a conductor. The fact that there is a magnetic field surrounding a conductor in which there is a current can be shown by a simple experiment, as illustrated in Fig. 2. If a wire be placed above a compass needle and parallel to the direction of the compass needle and a current be sent through the wire in the direction indicated by the arrow I, there will be a force acting on the compass needle tending to turn the needle at right angles to the wire. The amount the needle is turned will depend upon the value of the current in the wire. There is a definite relation between the direction of the current in the wire and the direction of the magnetic field surrounding the wire, because a reversal of current in the conductor will result in a reversal in the direction in which the compass needle is deflected. Remembering that the direction of a magnetic field can be determined by placing a magnetic needle in the field and noting the direction in which the N-pole of the needle points, this being taken as the positive direction, if one looks along a conductor in which there is a current and the current be from the observer, the direction of the magnetic field about the conductor will be clockwise. Imagine a conductor carrying a current and that you are looking at a cross-section of this conductor (see Fig. 3), and the direction of the current in the conductor is from you (this being indicated in the figure by the cross inside the circle), then the lines of force of the magnetic field will be concentric circles about the conductor, they being nearer together near the conductor, indicating the strength of the field is greatest near the conductor. A compass needle placed above the conductor would place itself in such a position that the N-pole would point toward the right and the S-pole toward the left. If the needle be placed below the conductor, the N-pole would point to the left and the S-pole to the right, indicating that the direction of the magnetic field above the conductor is just the reverse of what it is below the conductor.
The strength of the magnetic field produced by a current in a conductor can be greatly increased by forming the conductor into a coil. Figure 4 shows the cross-section of a coil composed of a single turn of wire. The current in the upper cross-section is just the reverse of what it is in the lower cross-section, as indicated by the cross and dash inside the two circles. As a result of the direction of current in the two cross-sections being different, the direction of the magnetic field about these two cross-sections will be different, one being clockwise, and the other counter-clockwise. It will be observed, however, that all the lines of force pass through the center of the coil in the same direction, or the magnetic field inside the coil is due to the combined action of the various parts of the conductor forming the complete turn. This magnetic field can be increased in value, without increasing the current in the conductor, by adding more turns to the coil.
A cross-section through a coil composed of eight turns placed side by side is shown in Fig. 5. The greater part of the magnetic lines created by each turn pass through the remaining turns as shown in the figure, instead of passing around the conductor in which the current exists that creates them. This results in the total number of lines passing through the coil per unit of cross-sectional area being greater than it was for a single turn, although the value of the current in the conductor has remained constant, the only change being an increase in the number of turns forming the coil.
If a conductor be moved by the end of a coil similar to that shown in Fig. 5, when there is a current in the winding of the coil, there will be an electrical pressure induced in the conductor, just the same as though it were moved by the end of a permanent magnet. The polarity of the coil is marked in Fig. 5. The magnetic lines pass from the S-pole to the N-pole through the coil and from the N-pole to the S-pole outside the coil, just as they do in a permanent magnet.
How to Lock a Tenoned Joint
A tenon placed in a blind mortise can be permanently fastened, when putting the joints together, by two wedges driven in the end grain of the wood. In some cases, where the wood to be used is very dry and brittle, it is advisable to dip the tenon in warm water before applying the glue. The glue must be applied immediately after the tenon is removed from the water, and then inserted in the mortise. The sketch shows the application of the wedges. The bottom of the mortise drives the wedges as the tenon is forced in place.
Fitting a Large Cork in a Small Bottle
When necessary, a large cork may be made to fit a small bottle, if treated as shown in the sketch. Two wedge-shaped sections are cut from the cork, at right angles to each other, as shown in Fig. 1. The points are then squeezed together (Fig. 2) and the end inserted in the bottle (Fig. 3). Wet the cork slightly and the operation will be easier.--Contributed by James M. Kane, Doylestown, Pa.
A Homemade Wet Battery
Procure a large water bottle and have a glass cutter cut the top off so that the lower portion will form a jar about 8-1/2 in. high. Next obtain two pieces of carbon, about 8 in. long, 4 in. wide and 1/4 in. thick. Melt up some old scrap zinc and mold a piece having the same dimensions as the pieces of carbon. The mold for casting the zinc may be made by nailing some 1/4-in. strips of wood on a piece of dry board, forming a shallow box, 4 in. wide and 8 in. long. Remove all the impurities from the surface of the zinc when it is melted, with a metal spoon or piece of tin. Before filling the mold with the metal, place a piece of No. 14 gauge bare copper wire through a small hole in one of the end pieces forming the mold, and allow it to project several inches inside, and make sure the mold is perfectly level. The zinc will run around the end of the wire, which is to afford a means of connecting the zinc plate to one of the binding posts forming the terminals of the cell.
Cut from some hard wood four pieces a little longer than the outside diameter of the glass jar, two of them 1/2 by 1/2 in., and two, 1/2 by 5/8 in. Drill a 1/8-in. hole in each end of all four pieces, the holes being perpendicular to the 1/2-in. dimension in each case, and about 3/8 in. from the end. Boil all the pieces for several minutes in paraffin and stand them up on end to drain. Procure two 1/8-in. brass bolts, 3-1/2 in. long, which are to be used in clamping the elements of the cell together. The two smaller pieces of wood should be placed on each side of one end of the zinc, then the carbon pieces and the larger pieces of wood outside the carbon pieces. The carbon plates should be connected together and then connected to a binding post which forms the positive terminal of the cell. If unable to obtain pieces of carbon of the required dimensions, a number of ordinary electric-light carbons may be used. Get about ten 1/2-in. carbons, without the copper coating, if possible; if not, file all the copper off. Cut these carbons off, forming 8-in. lengths. File the top ends of the carbons flat and so that they all become equal in thickness, and clamp them in place by means of the brass bolts. If rods are used, they should all be connected together by means of a piece of copper wire and then to a binding post.
The plates may now be hung in the jar, the wooden pieces resting on the top of the jar and acting as a support. The solution for this cell is made by dissolving 1/2 lb. of potassium bichromate in 1/2 gal. of water, and then adding very slowly 1/2 lb. of strong sulphuric acid. More or less solution may be made by using the proper proportion of each ingredient.
This cell will have a voltage of two volts, a rather low internal resistance, and will be capable of delivering a large current. If it should begin to show signs of exhaustion, a little more acid may be added.
A chemical action goes on in this cell regardless of whether it supplies current to an external circuit or not, and for this reason the elements should be removed from the solution and hung directly over the jar when the cell is not in use. A simple device for this purpose may be constructed as shown. A cord may be passed through the opening in the crossbar at the top and its lower end attached to the elements. When the elements are drawn out of the solution, the upper end of the cord may be fastened in some manner. This frame can, of course, be made longer, so it will accommodate a number of cells.
The Construction of a Simple Wireless Telephone Set By A. E. Andrews In Two Parts--Part II
If two coils of wire be placed parallel to each other as shown in Fig. 6, and a current be passed through the winding of one of them, say A, a part of the magnetic lines of force created by this current will pass through the other coil B. These lines of magnetic force must cut across the turns of wire of the coil in which there is no current as the magnetic field is being created, and as a result there will be an electrical pressure produced in the winding of the coil carrying no current. When the current in coil A is discontinued, the magnetic field created by this current is destroyed or it contracts to zero, and the magnetic lines again cut the various turns composing the winding of coil B. The direction in which the magnetic lines of force and the winding of coil B move with respect to each other is just the reverse, when the current in the winding of coil A is increasing, to what it is when the current in the winding of the coil A is decreasing. Any change in the value of the current in the winding of coil A will result in a change in the number of magnetic lines of force linked with the winding of the coil B, and as a result of this change in the number of lines linked with the winding of coil B there will be an induced electrical pressure set up in coil B. The direction of this induced electrical pressure will depend upon whether the current in the winding of coil A is increasing or decreasing in value. When the current in the winding of coil A is increasing in value, the electrical pressure induced in the winding of coil B will be in such a direction that the current produced by this induced electrical pressure will pass around the winding of coil B in the opposite direction to that in which the current passes around the winding of coil A. Or the current produced by the induced electrical pressure tends to produce a magnetic field opposite in direction to the one created by the current in the winding of coil A. When the current in the winding of A is decreasing in value, the induced pressure in the winding of the coil B is just the reverse of what it was in the previous case and the current produced by this induced pressure passes around the winding of the coil B in the same direction as the current passes around the winding of coil A. The current produced by the induced electrical pressure aids the current in the winding of coil A in producing a magnetic field. In general the current resulting from the induced pressure always passes around the circuit in such a direction as to produce a magnetic effect which will oppose a change in the value of the magnetic field causing the induced electrical pressure.
There will be an induced pressure in the winding of coil B, due to a change in the value of the current in the winding of coil A, as long as the coil B remains in the magnetic field of the coil A and its plane is not parallel to magnetic lines; or, in other words, coil B must always be in such a position that some of the magnetic lines created by the current in coil A will pass through the winding of coil B.
If a telephone transmitter and a battery be connected in series with the winding of coil A, a fluctuating or varying current can be made to pass through the winding by causing the diaphragm of the transmitter to vibrate by speaking into the mouthpiece of the transmitter. This varying current will set up a varying magnetic field and there will be an induced electrical pressure set up in coil B, if it be properly placed with respect to coil A. A receiver connected in series with the winding of coil B will be subjected to the action of a varying current due to the induced electrical pressure in the winding of coil B and as a result, the diaphragm of the receiver will vibrate in unison with that of the transmitter, and speech can thus be transmitted. The connection just described should be somewhat modified and a little more equipment used in order to give the best results.
Figure 7 shows the complete sending and receiving equipment, a complete outfit of this kind being required for each station. The transmitter T and the receiver R may be an ordinary local battery transmitter and receiver, although a high-resistance receiver will give better results. The induction coil with the windings, marked P and S, may be any commercial type of induction coil as used in a magneto telephone instrument, but a coil with a high-wound secondary will give better results. The push button K is to be used in closing the transmitter circuit when the set is being used for transmitting, the key being depressed, and for shorting out the high resistance secondary winding when the set is used in receiving, the key being in the normal position. Ten dry cells should be connected in series and used to supply current to the transmitter circuit, as shown by B in the figure. The receiver R, secondary winding of the induction coil S, and the winding of coil A used in transmitting and receiving the magnetic effects, are all connected in series. The winding of the coil A consists of two parts, D and E, as shown in the figure, with two of their ends connected together by means of a condenser, C, having a capacity of about 2 micro-farads. Each of these parts should consist of about 200 turns of No. 22 gauge silk-covered copper wire, wound on an ordinary bicycle rim. The inside end of one winding should be connected to the outside of the other by means of the condenser, the two coils being wound in the same direction. The condenser C can be procured at a small cost from almost any telephone company.
To talk, two of the instruments are placed 25 or 30 ft. apart, and they may be placed in different rooms as walls and other ordinary obstructions that do not interfere with the production of the magnetic field about the transmitting coil, have no effect upon the operation. Pressing the button K at the transmitting station, closes the transmitter circuit and removes the shunt from about the secondary winding of the induction. Any vibration of the transmitter will cause a varying current to pass through the primary winding P, which in turn induces an electrical pressure in the secondary winding S, and this pressure causes a varying current to pass through the coil A. The varying current in the winding of the coil A produces a varying magnetic field which acts upon the receiving coil, inducing an electrical pressure in it and producing a current through the receiver at the receiving station.
A filing coherer, adapted to close a local relay circuit and ring an ordinary bell, may be used with the sets just described for signaling between stations.
An Electric Incubator
Where electric current is available, it can be used to heat an incubator much better and cleanlier than the kerosene lamp. The materials are inexpensive and the cost should be no more than for the ordinary kind of heater.
First of all the box part must be made of very dry wood, 1/2 in. thick. The material should be matched, as the cost of the operation depends upon the construction of the box. The proper size for an 80-egg incubator is 2 ft. square and 1 ft. high. If a larger one is desired, the dimensions may be varied to suit, but it is not necessary to make it any higher for a larger one. If it is desired to have a window in the door, care must be taken to make it a good fit. The top, as shown in the sketch, is made without hinges so that it can be readily set on and removed. This makes it handy in case of repairing the heater and cleaning the box. The inside of the box, with the exception of the bottom, should be covered with asbestos paper.
After the box is finished, fit it with a tray, 1-1/2 ft. by 1 ft. 10-3/4 in. A tray having these dimensions will slide easily in the box. This is an essential feature of the hatching. The frame of the tray D, Fig. 1, consists of wood, 3/4 by 3/4 in., with a bottom made of wire mesh. The mesh should be firmly attached, so that it will not give away when full of eggs. Runners for the tray are placed 4-1/2 in. from the bottom of the box. When the tray is put in place, it will not touch the back. This small space is left for the chicks to fall into the nursery below. About 4 in. below the tray four holes are bored, AA, 1/8 in. in diameter, one on each side of the box. These holes admit fresh air to the eggs.
The electric heater is just large enough to allow a space about 1/2 in. on all edges. This makes it 23 in. square. A piece of 1/4-in. asbestos of the above size should be secured, on which to place the heating wire. The amount of wire depends on the size and kind. As it is not necessary to heat the wire very hot, iron or steel wire may be used. The length of wire may be determined by the following method:
Wind the wire on a long stick, making sure that no one coil touches its neighbor. Connect one wire of the current supply at one end of the coil and run the other end of the current supply along the coils, starting at the extreme opposite end and drawing toward the center until the iron wire gets too hot to hold with the bare hand. This will be the right length of wire to use. The length being known, a number of tacks are placed in the asbestos board to hold the wire, as shown in Fig. 2. Cover the wire with a sheet of asbestos and attach binding-posts, E and F, at each end.
The asbestos inclosing the heating wires is covered with a thin piece of sheet iron, which is made to fit tightly over the bottom and sides. This will spread the heat evenly. Be careful to have the binding-posts insulated from the sheet metal. In the cross section of the heater, Fig. 2, A represents the 1/4-in. asbestos board; B, the heater wire; C, the asbestos paper, and D the sheet-metal covering.
The most important part of the incubator is the thermostat which regulates the current to maintain a steady heat. It is not advisable to make this instrument, as a good one can be purchased for less than $1. Place the thermostat in the end of the box at B, Fig. 1. A small door, E, is made in the box for easy adjustment of the thumbscrews.
Suspend the heater from the cover of the box with bolts 2-3/4 in. long, as shown in Fig. 1. A base receptacle, G, and a snap switch, H, are fastened on top of the cover and connected up to the thermostat B, the condenser C, the heater F, and lamp I, as shown. Another snap switch, J, is used on the light only. The condenser C is to prevent sparking, thus saving the platinum points on the screws. Do not use more than a 2-cp. lamp for lighting purposes, as a brighter light blinds the young chicks.
The incubator should be run for a day or two so that the current may be well regulated before placing the eggs in the tray. The incubator is operated the same as with lamp heat.--Contributed by M. Miller, Lansing, Mich.
A Cover for Magazines
As soon as Popular Mechanics, or any other magazine of similar size, arrives and before any member of the family looks through it, strip off the front cover and carefully remove the narrow strip on the back as shown in Fig. 1. Strengthen the back with a piece of bookbinding tissue, A, Fig. 2, and then paste a piece of heavy manila paper, B, over the covers and back. Over this paste a piece of dark blue cambric, Fig. 3, carefully turning the edges even with the book. The picture from the cover and the date added to the left corner of the picture are neatly pasted on, Fig. 4, and the narrow strip is glued to the back.
The book is put under a heavy weight for several hours. Thus a neat, strong cover, which looks well in a bookcase, is secured at very little expense. The eager handling by every member of the family cannot soil or deface the cover.--Contributed by Katharine D. Morse, Syracuse, N. Y.
An Optical Illusion
A very deceiving illusion can be contrived with a bit of wire, a rubber band and a toothpick. An ordinary straight hairpin will serve instead of the wire. The hairpin or wire is bent as shown in the illustration, and the rubber band then placed on the inverted U-shaped part. A toothpick is inserted through the rubber band and a few turns taken by slipping the toothpick back and forth so it will pass the wire.
Hold the wire straight in front of the eyes, and, using the forefinger of the right hand, turn the end of the toothpick A, Fig. 1, down until it almost reaches the opposite point A, Fig. 2, and let the finger slip off. It will appear as if the toothpick passed through the wire.--Contributed by H. H. Windsor, Jr.
Temperature Alarm
The falling temperature of a room during the night may result in a very bad cold for the occupant. This may be prevented by the use of an alarm to awaken the sleeper and warn him to close the window. An alarm can be made as follows: Take a glass tube about 4 in. long and 1/4 in. in diameter and close one end, used for the bottom, with sealing wax, in which the bare end of a No. 20 gauge magnet wire is inserted. The tube is almost filled with mercury. On the mercury a float of wax is placed in which a bare piece of the same magnet wire is inserted and bent as shown in the sketch. The tube of mercury is fastened to a base with two clips of metal. At the upper end of this base the adjustable lever A is attached. The electric connections are made as shown in the sketch.
Should the temperature fall during the night, the mercury will contract, the float descend and the circuit close, so that the bell will ring. The adjustable lever allows setting the alarm for various differences of temperature.--Contributed by Klyce Fuzzelle, Rogers, Ark.
Paper Smoother and Penwiper
A convenient paper smoother and penwiper can be easily made as follows: Procure a common celluloid harness ring, A, about 1-1/2 in. in diameter and fasten a penwiper, B, to it. The wiper is made of arts-crafts leather, doubled and filled with pieces of chamois. They are held in place with a ribbon or cord tied as shown. The roughened paper caused by erasing can be easily smoothed with the ring.--Contributed by G. H. Holter, Jasper, Minn.
Stereoscopic Pictures with an Ordinary Camera
Make a small table as wide as the camera is long and 3 in. longer than the camera is wide. Sink a screw nut in the center of the under side to engage the regular tripod screw. Fasten a double or two-way spirit level on the front left-hand corner. Nail strips on both ends and on the rear side, to form a shallow box with three sides. The illustration shows the construction quite plainly. This device was used by a correspondent of Camera Craft as follows: The table was fastened to the tripod and carefully leveled. The camera is placed at one side, bringing the back snugly into the corner on that side. Make the exposure, change the film, slide the camera over to the other side and make another exposure. The table being 3 in. longer than the camera is wide, the lens will be moved exactly 3 in. when the camera is moved over to the other side. Three inches is the separation of the lenses in stereoscopic cameras and the negatives made as above will be the same.
As the negatives must be sized, it is necessary to use films. A camera using films 3-1/2 by 3-1/2 in. will make negatives that can be trimmed 1/4 in. on each side to make prints 3 by 3-1/4 in. Each two negatives making a pair are fastened together, properly transposed, by folding a narrow strip of black paper like a long, V-shaped trough, pasting it, and putting one on the bottom of the two negatives, as they lie side by side, and one at the top; saddle fashion. This can be done still easier by using strips of passe-partout binding, or strips used for binding lantern slides. If so desired, the use of black paper can be carried farther by cutting the top strip of binding paper in such a way that it gives the round corners to the top of the prints. A narrow strip through the center and a binding of black paper along the two end edges make a mask unnecessary in printing.
How to Make a Paper Drinking Cup
Every person should understand the simple method of making a paper drinking cup. It may be necessary at times to make quick use of medicine and with no cup or spoon convenient, the pyramid-shaped cup shown in the sketch is a useful emergency utensil.
The paper cup is made as follows: Cut the paper into a square and crease it on the dotted lines, A G, F B, and C D E, as shown in Fig. 1. Fold the paper in half through the line C D E to form a rectangle, Fig. 2. Fold points C and E inward until they meet inside the triangle to form the shape shown in Fig. 3. This makes four distinct corners, F, G, A and B. Fold the paper over on the dotted line and bring the points A and B together as in Fig. 4. The extreme edges meet in the central line indicated. Reverse the paper and fold the points G and F in like manner. Turn the points A B and F G inward and fold on the dotted line, and you will have a perfect pyramid-shaped cup as shown in Fig. 5.--Contributed by Miss Margaret S. Humphreville, Mt. Pleasant, O.
A Hand Corn Sheller
A very handy device for shelling corn, and especially popcorn, can be made of a 1-in. board on which is fastened a piece of metal lath. The edges of the metal lath are bound with a strip of wood nailed to the board.--Contributed by Ulysses Flacy, Long Beach, California.
A Shaft Coupling
In connecting a small 1/8-hp. motor to a small air pump where both shafts were 3/8 in. in diameter, I quickly made a coupling that would save the wear on the machines, as follows. The coupling was made of a piece of 3/4-in. brass rod with a 3/8-in. hole drilled through its center. One end of the hole was enlarged to 7-16 in. for about 7/8 in. The end of the coupling having the small hole was slipped on the pump shaft and fastened with two setscrews. The other end was drilled to take a pin loosely, the pin fitting tightly in a hole drilled in the motor shaft. The pin was bent at one end so as to keep it from falling out and the other end fitted with two nuts. The motor shaft being a little loose in the coupling, gave it a chance to work free without binding.--Contributed by Leo J. Werner, New York City.
Reading the Date of a Worn Coin
The date and denomination of a coin worn smooth can be determined in the following manner: Take an ordinary coal shovel, or a piece of sheet metal, and place it in a hot fire. Allow it to become red hot, then remove, and place the coin on the hot surface of the metal. Any figures or letters can be readily seen when heated in this manner. This test seldom fails even when the inscriptions have been worn so smooth that they are invisible to the naked eye.
Making a Knife an Easy Opener
The large blade of my knife being so hard to open placed me in constant risk of breaking my thumbnail. To overcome this difficulty, I ground a notch in the handle as shown in the sketch. After smoothing it up with a round file and fine sandpaper, I had just as good a job as if the knife had been made that way, and it is very easy to open it, as it can be done with the thumb and forefinger. Anyone can improve his knife in this way, but be careful not to cut the notch back of the point of the small blade.--Contributed by C. M. Mahood, Warren, Pa.
Construction of a Small Bell-Ringing Transformer By A. E. Andrews
I. Fundamental Principles
The transformer in its simplest form consists of two separate and electrically independent coils of wire, usually wound upon an iron core.
Figure 1 shows two coils, P and S, placed upon an iron ring, R. One of these coils is connected to some source of energy, such as an alternating-current generator, or an alternating-current lighting circuit, receiving its energy therefrom. The other coil is connected to a load to which it delivers alternating current. The coil of the transformer that is connected to the source of energy is called the primary coil, and the one that is connected to the load, the secondary coil.
The electrical pressure (voltage) at which current is supplied by the secondary bears a definite relation to the electrical pressure at which current is supplied to the primary. This relation, as will be explained later, is practically the same as the relation between the number of turns in the secondary and primary coils. If there are a smaller number of turns in the secondary coil than there are in the primary, the secondary voltage is less than the primary, and the transformer is called a step-down transformer. If, on the other hand, there are a larger number of secondary turns than of primary, the secondary voltage is greater than the primary voltage, and the transformer is called a step-up transformer.
The transfer of electrical energy from the primary coil to the secondary coil of a transformer is based upon the fundamental principles of electromagnetism and electromagnetic induction, and it will be necessary to investigate these principles before we can understand the operation of the transformer.
A magnet is a body, which, when freely suspended, assumes approximately a north and south position. The end of the magnet that points north is called the north pole, while the end that points south is called the south pole. The region surrounding a magnet is called a magnetic field. In this field the magnetism is supposed to flow along a large number of imaginary lines, called lines of force, and these lines are all supposed to emanate from the north pole of the magnet, pass through the medium surrounding the magnet and enter the south pole. The magnetic field surrounding a bar magnet is shown in Fig. 2. The strength of any magnetic field depends upon the number of these lines of force per unit area (square centimeter), the area being taken perpendicular to the direction of the lines.
In 1812, Oersted discovered that a compass needle, which is nothing but a permanent magnet freely suspended or supported, when placed near a conductor in which there was a direct current, was acted upon by a force that tended to bring the needle into a position at right angles to the conductor. This simple experiment proved to Oersted that there was a magnetic field produced by the current in the conductor. He also found that there was a definite relation between the direction of the current in the conductor, and the direction in which the north pole of the compass needle pointed. If the compass needle is allowed to come to rest in the earth's magnetic field, and a conductor is placed above it, the conductor being parallel to the needle, and a current then sent through the conductor, the needle will be deflected from its position of rest. Reversing the current in the conductor, reverses the direction in which the needle is deflected. If the needle be allowed to come to rest while there is a current in the conductor, and this current is then increased, it will be found that the deflection of the needle will be increased, but not in direct proportion to the increase in the current. Hence the strength of this magnetic field surrounding the conductor depends upon the value of the current in the conductor, and the direction of the field depends upon the direction of the current.
If a conductor be passed through a piece of cardboard, as shown in Fig. 3, and a current sent through it in the direction indicated by the arrow A, a compass needle, moved about the conductor in the path indicated by the dotted line, will always assume such a position that the north pole points around the conductor in a clockwise direction as you look down on the cardboard. If the current be reversed, the direction assumed by the compass needle will be reversed. Looking along a conductor in the direction of the current, the magnetic field will consist of magnetic lines encircling the conductor. These lines will be concentric circles, as a general rule, except when they are distorted by the presence of other magnets or magnetic materials, and their direction will be clockwise.
The strength of the magnetic field at any point near this conductor will depend upon the value of the current in the conductor, and the distance the point is from the conductor. The magnetic field surrounding a conductor is shown in Fig. 4. The plus sign indicates that the direction of the current is from you. The strength of a magnetic field due to a current in a conductor can be greatly increased by forming a coil of the conductor. Each turn of the coil then produces a certain number of lines, and the greater part of these lines pass through the center of the coil, as shown in Fig. 5. The field strength inside such a coil is dependent upon the number of turns in the coil, and the value of the current in these turns. Increasing the number of turns in the coil increases the number of magnetic lines passing through the center of the coil, as shown in Fig. 6. If the current be decreased in value, the field strength is decreased, and if the current be reversed in direction, the magnetic field is reversed in direction. The number of magnetic lines passing through the solenoid depends also upon the kind of material composing the core of the solenoid, in addition to the number of turns and the value of the current in these turns. The number of lines per unit area inside a solenoid with an air core can be multiplied several times by introducing a soft-iron core. If this core be extended as shown in Fig. 7, the magnetic circuit (the path through which the magnetic lines pass) may be completed through it. The larger part of the total number of lines will pass through the iron, as it is a much better conductor of magnetism than air.
In 1831, Michael Faraday discovered that there was an electrical pressure induced in an electrical conductor when it was moved in a magnetic field so that it cut some of the lines forming the field. If this conductor be made to form part of a closed electrical circuit, there will be a current produced in the circuit as a result of the induceds electrical pressure. The value of this induced electrical pressure depends upon the number of magnetic lines of force that the conductor cuts in one second. If 100,000,000 lines are cut in one second, an electrical pressure of one volt is produced. The direction of the induced pressure depends upon the direction of the movement of the conductor and the direction of the lines of force in the magnetic field; reversing either the direction of the magnetic field or the motion of the conductor, reverses the direction of the induced pressure. If both the direction of the magnetic field, and the direction of the motion of the conductor be reversed, there is no change in the direction of the induced pressure, for there is then no change in the relative directions of the two. The same results can be obtained by moving the magnetic field with respect to the conductor in such a way that the lines of force of the field cut the conductor.
If a permanent magnet be thrust into a coil of wire, there will be an electrical pressure set up in the coil so long as the turns of wire forming the coil are cutting the lines of force that are produced by the magnet. When the magnet is withdrawn, the induced electrical pressure will be reversed in direction, since the direction of cutting is reversed. A magnetic field may be produced through a coil of wire by winding it on the magnetic circuit shown in Fig. 8. Now any change of current in the coil P will cause a change in the number of magnetic lines passing through S and hence there will be an induced electrical pressure set up in S so long as the number of lines passing through it is changing. The pressure induced in each of the turns comprising the coil S depends upon the change in the number of magnetic lines through it.
Let us now consider a condition of operation when there is no current in the secondary coil and the primary coil is connected to some source of electrical energy. When this is the case the current in the primary coil is not determined by Ohm's law, which states that the current is equal to the electrical pressure divided by the resistance, but is considerably less in value, for the following reason. The magnetic lines of force produced by the current in the primary induces an electrical pressure in the primary winding itself, the direction of which is always opposite to the impressed pressure, or the one producing the current. As a result of this induced pressure being set up in the primary, the effective pressure acting in the circuit is decreased. At the same time there is an electrical pressure induced in the secondary winding in the same direction as that induced in the primary.
If the secondary circuit be connected to a load, there will be a current in the secondary winding, which will pass around the magnetic circuit in the opposite direction to the primary current, and as a result will decrease the number of lines passing through the primary coil. This will in turn decrease the electrical pressure induced in the primary coil, and a larger current will exist in the primary winding than there was before any current was taken from the secondary coil. The decrease in induced pressure is small, but it is always ample to allow the required increase in primary current. There is, at the same time, a small decrease in the secondary pressure.
When the transformer is operating on no load, with no current in the secondary coil, the induced pressure in the primary coil is practically equal to the impressed pressure and hence a very small current will be taken from the source of energy. It is apparent now that if the primary and secondary coils have the same number of turns, the induced electrical pressure in each of these coils will be the same, assuming, of course, that all the magnetic lines that pass through the primary also pass through the secondary coil, and vice versa, or the secondary pressure is practically the same as the pressure impressed on the primary. If the number of turns in the secondary coil is greater or less than the number of turns in the primary, the magnetic lines will be cut a greater or less number of times by the secondary coil, and hence the induced pressure will be greater or less, depending upon the relation of the number of turns in the two coils.
Spirit Photographs
Print some photographs in the usual way on printing-out paper, then fix them in a solution of 1 oz. hyposulphite of soda and 8 oz. of water, and wash them thoroughly. While the prints are still wet, immerse them in a saturated solution of bichloride of mercury. Be very careful to wash the hands and trays after using the mercury solution, as it is poisonous. When the print is placed in the mercury solution, the picture vanishes completely. Leave the prints in this bath just long enough for the image to disappear, and then wash and dry them thoroughly. Soak some clean blotting paper in the hyposulphite-of-soda solution and allow it to dry. You are now ready to perform the magic-photograph trick.
To cause the spirit photograph to appear, cut a piece of blotting paper the same size as the prepared print and moisten it, then hold the apparently blank piece of paper in contact with it. The picture will come out clear and plain, and if thoroughly washed out it will remain permanently.
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Saturate a small piece of cotton batting in glue and wrap it around a nail, then place it in a hole previously made in a plaster wall. When the glue dries, the nail will remain permanently.
Construction of a Small Bell-Ringing Transformer By A. E. Andrews