The Boy Mechanic, Volume 1: 700 Things for Boys to Do (part 3 of 3)
Procure a block of wood, 1-1/2 in. long, 1 in. wide and 1/2 in. thick, add saw a kerf square with the face of the block, as shown at A. Attach a piece of fine emery cloth in the kerf, at B, with glue, taking care to have it flat on the sloping surface only and allowing no part of the cloth to turn the sharp corner and lie on the back side. Apply the block to the scissor blade as shown and draw it back and forth from one end to the other, being careful to keep the back side of the blade flat against the block. Without being familiar with scissors grinding, anyone can sharpen them correctly with this block. --Contributed by Harriet Kerbaugh, Allentown, Pa.
** Counter Brush for a Shop [419]
A very serviceable brush for use around a shop can be made from a discarded or worn-out push broom as shown at A. Pull out the bristles from one-half of the brush and shape the wood of that end with a knife or spokes have to the form of a handle, and the brush will be formed as shown at B. --Contributed by James T. Gaffney, Chicago.
** A Curtain Roller [419]
Procure a window-shade roller, an umbrella rib and two strips of oilcloth, each 1 in. wide and 4 in. long. Cut the roller off so that it will be 6 in. longer than the distance across the window, then cut a groove in it to insert the rib. Sew the pieces of oilcloth so that they will just fit over the ends of the roller. When this is done lay the curtain across the groove, then press the rib and curtain into the groove and push the oilcloth bands over the ends of the rib to keep it in place. --Contributed by E. L. McFarlane, Nashwaakees, N. B.
** Shade-Holder Bracket for a Gas Jet [419]
An old umbrella rib makes a very effective shade-holder bracket for a gas jet. The ends of the rib are bent to fit around the pendant upright and the support end is shaped into a hook. It can be quickly applied or removed. The outer end is bent into a hook to hold the shade. The rib can be cut to fit a pendant arm of any length. --Contributed by Edward Keegstra, Paterson, N. J.
** To Longer Preserve Cut Flowers [419]
A good way to keep cut flowers fresh is to place a small amount of pure salt of sodium in the water. It is best to procure this salt at a drug store because commercial salt will cause the flowers to wither, due to the impurities in the soda. Call for pure sodium chloride.
** Glass Blowing and Forming [420]
Fortunate indeed is the boy who receives a stock of glass tubing, a Bunsen burner, a blowpipe, and some charcoal for a gift, for he has a great deal of fun in store for himself. Glass blowing is a useful art to understand, if the study of either chemistry or physics is to be taken up, because much apparatus can be made at home. And for itself alone, the forming of glass into various shapes has not only a good deal of pleasure in it, but it trains the hands and the eye.
Glass, ordinarily brittle and hard, becomes soft and pliable under heat. When subjected to the action of a flame until dull red, it bends as if made of putty; heated to a bright yellow, it is so soft that it may be blown, pulled, pushed or worked into any shape desired. Hence the necessity for a Bunsen burner, a device preferred to all others for this work, because it gives the hottest flame without soot or dirt. The Bunsen burner, as shown in Fig. 1, is attached to any gas bracket with a rubber tube, but the flame is blue, instead of yellow, as the burner introduces air at its base, which mixes with the gas and so produces an almost perfect combustion, instead of the partial combustion which results in the ordinary yellow flame. All gas stoves have Bunsen burners, and many oil stoves.
If gas is not available, an alcohol lamp with a large wick will do almost as well. The blowpipe, shown in Fig. 2, is merely a tube of brass with the smaller end at right angles to the pipe, and a fine tip to reduce the size of the blast, which is used to direct a small flame. Besides these tools, the glass worker will need some round sticks of charcoal, sharpened like a pencil, as shown in Fig. 3, a file, and several lengths of German glass tubing.
To bend a length of the tubing, let it be assumed for the purpose of making a syphon, it is only necessary to cork one end of the tube and heat it near the top of the Bunsen flame, turning the tubing constantly to make it heat evenly on all sides, until it is a dull red in color. It will then bend of its own weight if held in one hand, but to allow it to do so is to make a flat place in the bend. The heating should be continued until the red color is quite bright, when the open end of the tube is put in the mouth and a little pressure of air made in the tube by blowing. At the same time, the tube is bent, steadily but gently. The compressed air in the tube prevents it from collapsing during the process.
To make a bulb on the end of a tube, one end must be closed. This is easily done by heating as before, and then pulling the tube apart as shown in Fig. 4. The hot glass will draw, just like a piece of taffy, each end tapering to a point. This point on one length is successively heated and pressed toward and into the tube, by means of a piece of charcoal, until the end is not only closed, but as thick as the rest of the tube, as in Fig. 5. An inch or more is now heated white hot, the tube being turned continually to assure even heating and to prevent the hot end from bending down by its own weight. When very hot, a sudden puff into the open end of the tube will expand the hot glass into a bulb, as in Fig. 6. These can be made of considerable size, and, if not too thin, make very good flasks (Fig. 7) for physical experiments. The base of the bulb should be flattened by setting it, still hot, on a flat piece of charcoal, so that it will stand alone.
To weld two lengths of, glass tubing together, heat the end of a tube and insert the point of a piece of charcoal in the opening, and twirl it about until the end of the tube has a considerable flare. Do the same to the end of the other tube, which is to be joined to the first, and then, heating both to a dull red, let them touch and press lightly together as in Fig. 8. As soon as they are well in contact, heat the two joined flares together, very hot, and, pulling slightly, the flares will flatten out and the tube be perfectly joined. Tubes joined without previous flaring have a constricted diameter at the joint.
To make a T-joint in two pieces of tubing, it is necessary to make a hole in the side of one piece, as shown at A in Fig. 9. This is accomplished by the aid of the principle of physics that gases expand when heated. Both ends of the tube, which should be cold, are corked tightly. The whole is then gradually warmed by being held near the flame. When warm, a small flame is directed by the blowpipe from the Bunsen flame to a spot on one side of the closed tube. As it heats, the air within the tube expands and becomes compressed, and as soon as the hot spot on the side of the tube is soft enough, the confined air blows out, pushing the hot glass aside as it does so, leaving a small puncture. This is to be enlarged with pointed charcoal until it also flares as shown at B. This flare is then connected to the flared end of a straight tube, C, and the T-joint, D, is complete.
Using the blowpipe is not difficult. The lips and cheeks should be puffed out with a mouthful of air, which is ample to blow a flame while the lungs are being refilled. In this way, it is possible to use the blowpipe steadily, and not intermittently, as is necessary if the lungs alone are the "bellows."
Small glass funnels, such as are used in many chemical operations, are made by first forming a bulb, then puncturing the bulb at the top, when hot, with a piece of charcoal, and smoothing down or flaring the edges. Very small and fine glass tubes, such as are used in experiments to demonstrate capillary attraction, water or other liquid rising in them when they are plunged into it, are made by heating as long a section of tubing as can be handled in the flame--2 in. will be found enough--and, when very hot, giving the ends a sudden vigorous pull apart. The tube pulls out and gets smaller and smaller as it does so, until at last it breaks. But the fine thread of glass so made is really a tube, and not a rod, as might be supposed. This can be demonstrated by blowing through it at a gas flame, or by immersing it in colored liquid. The solution will be seen to rise some distance within the tube, the amount depending on the diameter of the tube.
The file is for cutting the glass tubing into lengths convenient to handle. It should be a three-cornered file, of medium fineness, and is used simply to nick the glass at the place it is desired to cut it. The two thumbs are then placed beneath the tube, one on each side of the nick, and the tube bent, as if it were plastic, at the same time pulling the hands apart. The tube will break off squarely at the nick, without difficulty.
The entire outfit may be purchased from any dealer in chemical or physical apparatus, or any druggist will order it. Enough tubing to last many days, the Bunsen burner, blowpipe, file and charcoal should not exceed $2 in cost.
** Cadmium and Solder [421]
The addition of cadmium to soft solder composed of tin and lead, lowers its melting point and increases its strength.
** Telegraph Codes [422]
** How to Make a Cruising Catamaran [423]
A launch is much safer than a sailing boat, yet there is not the real sport to be derived from it as in sailing. Herein is given a description of a sailing catamaran especially adapted for those who desire to sail and have a safe craft. The main part of the craft is made from two boats or pontoons with watertight tops, bottoms and sides and fixed at a certain distance apart with a platform on top for the passengers. Such a craft cannot be capsized easily, and, as the pontoons are watertight, it will weather almost any rough water. If the craft is intended for rough waters, care must be taken to make the platform pliable yet stiff and as narrow as convenient to take care of the rocking movements.
This catamaran has been designed to simplify the construction, and, if a larger size than the dimensions shown in Fig. 1 is desired, the pontoons may be made longer by using two boards end to end and putting battens on the inside over the joint. Each pontoon is made of two boards 1 in. thick, 14 in. wide and 16 ft. long, dressed and cut to the shape shown in Fig. 2. Spreaders are cut from 2-in. planks, 10 in. wide and 12 in. long, and placed 6 ft. apart between the board sides and fastened with screws. White lead should be put in the joints before turning in the screws. Cut the ends of the boards so they will fit perfectly and make pointed ends to the pontoons as shown in Fig. 3, and fit in a wedge shaped piece; white lead the joints and fasten well with screws.
Turn this shell upside down and lay a board 1/2 in. thick, 12 in. wide and 16 ft. long on the edges of the sides, mark on the under side the outside line of the shell and cut to shape roughly. See that the spreaders and sides fit true all over, then put white lead on the joint and nail with 1-3/4 -in. finishing nails as close as possible without weakening the wood. Slightly stagger the nails in the sides, the 1-in. side boards will allow for this, trim off the sides, turn the box over and paint the joints and ends of the spreaders, giving them two or three coats and let them dry.
Try each compartment for leaks by turning water in them one at a time. Bore a 5/8-in. hole through each spreader in the center and through the bottom board as shown. The top board, which is 1/4-in. thick, 12 in. wide and 16 ft. long, is put on the same as the bottom.
After finishing both pontoons in this way place them parallel. A block of wood is fastened on top of each pontoon and exactly over each spreader on which to bolt the crosspieces as shown in Fig. 4. Each block is cut to the shape and with the dimensions shown in Fig. 5.
The crosspieces are made from hickory or ash and each piece is 2-1/2 in. thick, 5 in. wide and 6-1/2 ft. long. Bore a 5/8-in. hole 3 in. from each end through the 5-in. way of the wood. Take maple flooring 3/4 in. thick, 6 in. wide, 74-1/2 in. long and fasten with large screws and washers to the crosspieces and put battens across every 18 in. Turn the flooring and crosspieces upside down and fasten to the pontoons with long 5/8-in. bolts put through the spreaders. Put a washer on the head of each bolt and run them through from the under side. Place a thick rubber washer under and on top of each crosspiece at the ends as shown in Fig. 4. This will make a rigid yet flexible joint for rough waters. The flooring being placed on the under side of the crosspieces makes it possible to get the sail boom very low. The sides put on and well fastened will greatly assist in stiffening the platform and help it to stand the racking strains. These sides will also keep the water and spray out and much more so if a 12-in. dash is put on in front on top of the crosspiece.
The rudders are made as shown in Fig. 6, by using an iron rod 5/8 in. in diameter and 2 ft. long for the bearing of each. This rod is split with a hacksaw for 7 in. of its length and a sheet metal plate 3/32 in. thick, 6 in. wide, and 12 in. long inserted and riveted in the split. This will allow 3/4 in. of the iron rod to project from the bottom edge of the metal through which a hole is drilled for a cotter pin. The bottom bracket is made from stake iron bent in the shape of a U as shown, the rudder bearing passing through a hole drilled in the upper leg and resting on the lower. Slip the top bracket on and then bend the top end of the bearing rod at an angle as shown in both Figs. 6 and 7. Connect the two bent ends with a crosspiece which has a hole drilled in its center to fasten a rope as shown in Fig. 1.
Attach the mast to the front crosspiece, also bowsprit, bracing them both to the pontoons. A set of sails having about 300 sq. ft. of area will be about right for racing. Two sails, main and fore, of about 175 to 200 sq. ft. will be sufficient for cruising. --Contributed by J. Appleton, Des Moines, Iowa.
** Alligator Photo Mounts [424]
Rough alligator finished photograph mounts will not receive a good impression from a die. If a carbon paper is placed on the mounts before making the impression, a good clear imprint will be the result.
** How to Attach a Sail to a Bicycle [425]
This attachment was constructed for use on a bicycle to be ridden on the well packed sands of a beach, but it could be used on a smooth, level road as well. The illustration shows the main frame to consist of two boards, each about 16 ft. long, bent in the shape of a boat, to give plenty of room for turning the front wheel. On this main frame is built up a triangular mast, to carry the mainsail and jib, having a combined area of about 40 sq. ft. The frame is fastened to the bicycle by numerous pieces of rope.
Sailing on a bicycle is very much different from sailing in a boat, for the bicycle leans up against the wind, instead of heeling over with it as the boat. It takes some time to learn the supporting power of the wind, and the angle at which one must ride makes it appear that a fall is almost sure to result. A turn must be made by turning out of the wind, instead of, as in ordinary sailing, into it; the boom supporting the bottom of the mainsail is then swung over to the opposite tack, when one is traveling at a good speed.
** Removing Iodine Stains [425]
A good way to chemically remove iodine stains from the hands or linen is to wash the stains in a strong solution of hypo sulphite of sodium, known as "hypo," which is procurable at any photographic-supply dealer's or drug store.
There is no danger of using too strong a solution, but the best results are obtained with a mixture of 1 oz. of hypo to 2 oz. of water.
** Drying Photograph Prints without Curling [425]
Having made some photograph prints at one time that I wanted to dry without the edges curling, I took an ordinary tin can and a strip of clean cotton cloth, as wide as the can was long, and wound it one turn around the can and then placed the prints, one after the other, while they were damp, on the cloth, face downward, and proceeded to roll the cloth and prints quite close on the can. I then pinned the end of the cloth to keep it from unwinding and set the whole in a draft for drying.
The curvature of the can just about counteracted the tendency of the coating on the paper to make the prints curl and when they were thoroughly dried and removed they remained nice and flat. --Contributed by W. H. Eppens, Chicago.
** Piercing Glass Plates with a Spark Coil [426]
Anyone possessing a 1-in. induction coil and a 1-qt. Leyden jar can easily perform the interesting experiment of piercing glass plates. Connect the Leyden jar to the induction coil as shown in the diagram. A discharger is now constructed of very dry wood and boiled in paraffine for about 15 minutes. The main part of the discharger, A B, is a piece of wood about 6 in. long and to the middle of it is fastened a wood handle by means of one or two wood screws. A binding-post is fastened to each end of the main piece or at A and B as shown in the diagram.
Two stiff brass wires of No. 14 gauge and 6 in. long, with a small brass ball attached to one end of each, are bent in an arc of a circle and attached one to each binding-post. A plate of glass, G, is now placed between the two brass balls and the coil set in action. The plate will soon be pierced by the spark. Larger coils will pierce heavier glass plates. --Contributed by I. Wolff, Brooklyn, N. Y.
** A Home-Made Still [426]
Remove the metal end of an old electric light globe. This can be done by soaking a piece of twine in alcohol and tying it around the globe at the place the break is to be made. Light the string and after it is burned off, turn cold water on the globe. The result will be a smooth break where the string was placed. Purchase a piece of glass tubing from your druggist and secure a cork that will fit the opening in the glass bulb. Bore a hole in the cork the right size for the glass tube to fit in tightly. If you cannot get a glass tube with a bend in it, you will have to make a bend, as shown in the illustration, by heating the tube at the right place over an alcohol lamp and allowing the weight of the glass to make the bend while it is hot.
Insert the short end of the tube in the cork and place the other end in a test tube that is placed in water as shown. The globe may be fastened in position by a wire passed through the cork and tied to a ring stand. If you do not have a ring stand, suspend the globe by a wire from a hook that is screwed into any convenient place.
A neat alcohol lamp may be made of an old ink or muscilage bottle. Insert a wick in a piece of the glass tubing and put this through a hole bored in a cork and the lamp is ready to burn alcohol or kerosene. Alcohol is cleaner to use as a fuel. Fill the globe about two-thirds full of water or other liquid and apply the heat below as shown. The distilled liquid will collect in the test tube. --Contributed by Clarence D. Luther, Ironwood, Mich.
** Old-Time Magic
** Balancing Forks on a Pin Head [427]
Two, three and four common table forks can be made to balance on a pin head as follows: Procure an empty bottle and insert a cork in the neck. Stick a pin in the center of this cork so that the end will be about 1-1/2 in. above the tap. Procure another cork about 1 in. in diameter by 1-3/4 in. long. The forks are now stuck into the latter cork at equal distances apart, each having the same angle from the cork. A long needle with a good sharp point is run through the cork with the forks and 1/2 in. of the needle end allowed to project through the lower end.
The point of the needle now may be placed on the pin head. The forks will balance and if given a slight push they will appear to dance. Different angles of the forks will produce various feats of balancing. --Contributed by O. E. Tronnes, Wilmette, Ill.
** The Buttoned Cord [427]
Cut a piece of heavy paper in the shape shown in Fig. 1 and make two cuts down the center and a slit as long as the two cuts are wide at a point about 1 in. below them. A string is put through the slit, the long cuts and back through the slit and then a button is fastened to each end. The small slit should not be so large as the buttons. The trick is to remove the string. The solution is quite simple. Fold the paper in the middle and the part between the long cuts will form a loop. Bend this loop down and pass it through the small slit. Turn the paper around and it will appear as shown in Fig. 2. One of the buttons may now be drawn through and the paper restored to its original shape.
** Experiment with an Incandescent Lamp [427]
When rubbing briskly an ordinary incandescent lamp on a piece of cloth and at the same time slightly revolving it, a luminous effect is produced similar to an X-ray tube. The room must be dark and the lamp perfectly dry to obtain good results. It appears that the inner surface of the globe becomes charged, probably by induction, and will sometimes hold the filament as shown in the sketch. --Contributed by E. W. Davis, Chicago.
** How to Make a Small Motor [428]
The accompanying sketch shows how to make a small motor to run on a battery of three or four dry cells and with sufficient power to run mechanical toys. The armature is constructed, as shown in Figs. 1 and 2, by using a common spool with 8 flat-headed screws placed at equal distances apart and in the middle of the spool. Each screw is wound with No. 24 gauge iron wire, as shown at A, Fig. 1. The commutator is made from a thin piece of copper, 1 in. in diameter and cut as shown in Fig. 3, leaving 8 points, 1/8 in. wide and 1/8 in.- deep. The field is built up by using 8 strips of tin, 12 in. long and 2 in. wide, riveted together and shaped as shown at B, Fig. 4. Field magnets are constructed by using two 3/8-in. bolts, 1-1/2 in. long. A circular piece of cardboard is placed on each end of the bolt, leaving space enough for the bolt to pass through the field B, and to receive a nut. Wind the remaining space between the cardboards with 30 ft. of No. 22 double-wound cotton-covered copper wire. A light frame of wood is built around the magnets, as shown at C, Fig. 4. Holes are made in this frame to receive the axle of the armature. Two strips of copper, 1/4 in. wide and 3 in. long, are used for the brushes. The armature is placed in position in its bearings and the brushes adjusted as shown in Fig. 4, one brush touching the shaft of the armature outside of the frame, and the other just touching the points of the commutator, which is placed on the shaft inside of the frame. Connect the outside wire of one magnet to the inside wire of the other, and the remaining ends, one to the batteries and back to the brush that touches the shaft, while the other is attached to the brush touching the commutator. In making the frame for the armature bearings, care should be taken to get the holes for the shaft centered, and to see that the screws in the armature pass each bolt in the magnets at equal distances, which should be about 1/8 in.
** Aluminum Polish [428]
An emulsion of equal parts of rum and olive oil can be used for cleaning aluminum, says Blacksmith and Wheelwright. Potash lye, not too strong, is also effective in brightening aluminum, and benzol can be used for the same purpose.
A good polish for aluminum consists of a paste formed of emery and tallow, the finish luster being obtained by the use of rouge powder and oil of turpentine.
** Homemade Blowpipe [428]
Procure a clay pipe, a cork and a small glass or metal tube drawn to a small opening in one end. Make a hole in the cork just large enough to permit the tube to pass through tightly so no air can pass out except through the hole in the tube. Put the tube in the hole with the small opening at the top or projecting end. Push the cork into the bowl of the pipe and the blowpipe is ready for use. --Contributed by Wilbur Cryderman, Walkerton, Onto
** Substitute Sink or Bathtub Stopper [429]
Milk-bottle caps make good substitutes for the regular rubber stoppers in sinks and bathtubs. The water soon destroys them, but as a new one usually is had each day, they can be used until a regular stopper is obtained.
A good permanent stopper can be made by cutting a hollow rubber return ball in half, using one part with the concave side up. It will fit the hole of any sink or bathtub. One ball thus makes two stoppers at a cost of about 5 cents.
** Safety Tips on Chair Rockers [429]
Some rocking chairs are so constructed that when the person occupying it gives a hard tilt backward, the chair tips over or dangerously near it. A rubber-tipped screw turned into the under side of each rocker, near the rear end, will prevent the chair from tipping too far back.
** How to Make a Toy Flier [429]
While a great many people are looking forward to the time when we shall successfully travel through the air, we all may study the problem of aerial navigation by constructing for ourselves a small flying machine as illustrated in this article. A wing is made in the shape shown in Fig. 1 by cutting it from the large piece of an old tin can, after melting the solder and removing the ends. This wing is then given a twist so that one end will be just opposite the other and appear as shown in Fig. 2. Secure a common spool and drive two nails in one end, leaving at least 1/2 in. of each nail projecting after the head has been removed. Two holes are made in the wing, exactly central, to fit on these two nails. Another nail is driven part way into the end of a stick, Fig. 4, and the remaining part is cut off so the length will be that of the spool. A string is used around the spool in the same manner as on a top. The wing is placed on the two nails in the spool, and the spool placed on the nail in the stick, Fig. 5, and the flier is ready for action. A quick pull on the string will cause the wing to leave the nails and soar upward for a hundred feet or more. After a little experience in twisting the wing the operator will learn the proper shape to get the best results.
Be very careful in making the tests before the wings are turned to the proper shape, as the direction of the flier cannot be controlled and some one might be injured by its flight.
** How to Make an Ironing-Board Stand [429]
Secure some 1 by 3-in. boards, about 3 ft. long, and plane them smooth. Cut the two pieces A and B 30 in. long and make a notch in each of them, about one-third of the way from one end, 1 in. deep and 3 in. long. These notches are to receive the piece D, which has a small block fastened to its side to receive the end of the brace C. The brace C is 36 in. long. The upper ends of the pieces A, B and C are fastened to a common ironing board by using iron hinges as shown in Fig. 1. As the piece D is fitted loosely, it may be removed and the brace, C, with the legs, A and B, folded up against the board. --Contributed by Bert Kottinger, San Jose, Cal.
** A Home-Made Electric Plug [430]
A plug suitable for electric light extension or to be used in experimenting may be made from an old electric globe. The glass is removed with all the old composition in the brass receptacle, leaving only the wires. On the ends of the wires, attach two small binding posts. Fill the brass with plaster of paris, and in doing this keep the wires separate and the binding-posts opposite each other. Allow the plaster to project about 3/4 in. above the brass, to hold the binding-posts as shown. --Contributed by Albert E. Welch, New York.
** How to Make an Electric Fire Alarm [430]
On each end of a block of wood, 1 in. square and 1 in. long, fasten a strip of brass 1/4 by 3 in., bent in the shape as shown in the sketch at A, Fig; 1. These strips should have sufficient bend to allow the points to press tightly together. A piece of beeswax, W, is inserted between the points of the brass strips to keep them apart and to form the insulation. A binding post, B, is attached to each brass strip on the ends of the block of wood. The device is fastened to the wall or ceiling, and wire connections made to the batteries and bells as shown in the diagram, Fig. 2. When the room becomes a little overheated the wax will melt and cause the brass strips to spring together, which will form the circuit and make the bell ring. Each room in the house may be connected with one of these devices, and all on one circuit with one bell.
** Home-Made Boy's Car [430]
The accompanying cut shows how a boy may construct his own auto car. The car consists of parts used from a boy's wagon and some old bicycle parts. The propelling device is made by using the hanger, with all its parts, from a bicycle. A part of the bicycle frame is left attached to the hanger and is fastened to the main board of the car by blocks of wood as shown. The chain of a bicycle is used to connect the crank hanger sprocket to a small sprocket fastened in the middle of the rear axle of the car. The front axle is fastened to a square block of wood, which is pivoted to the main board. Ropes are attached to the front axle and to the back part of the main board to be used with the feet in steering the car. To propel the auto, turn the cranks by taking hold of the bicycle pedals. --Contributed' by Anders Neilsen, Oakland, Cal.
** Photographs in Relief Easily Made [431]
Relief photographs, although apparently difficult to produce, can be made by any amateur photographer. The negative is made in the usual way and, when ready for printing, a positive or transparency is made from it in the same manner as a lantern slide or window transparency, says the Sketch, London. Use the same size plate as the negative for the transparency. To make the print in relief place the positive in the frame first with the film side out and the negative on top of this with the film side up in the usual manner. Put in the paper and print. This will require a greater length of time than with the ordinary negative on account of printing through double glass and films. In using printing-out papers care should be taken to place the printing frame in the same position and angle after each examination.
** Wireless Tip [431]
Place the transmitting instruments of a wireless outfit as close together as possible.
** How to Make a Wireless Telephone [432]
A noted French scientist, Bourbouze, was able to keep up communication with the outside during the siege of Paris by making practical application of the earth currents. The distance covered is said to have been about 30 miles. Another scientist was able to telephone through the earth without the aid of wires. Nothing, however, has been made public as to how this was accomplished.
It is my object to unveil the mystery and to render this field accessible to others, at least to a certain degree, for I have by no means completed my researches in this particular work.
In order to establish a wireless communication between two points we need first of all a hole or well in the ground at each point. In my experiments I was unable to get a deep well, but the instruments worked fine for a distance of 200 ft., using wells about 25 ft. deep. As in ordinary telephone lines, we require a transmitter and receiver at each point. These must be of the long-distance type. If a hole is dug or a well is found suitable for the purpose, a copper wire is hung in the opening, allowing the end to touch the bottom. To make the proper contact an oval or round--but not pointed--copper plate is attached to the end of the wire. If a well is used, it is necessary to have a waterproof cable for the part running through the water. The top end is attached to the telephone transmitter and receiver, as in the ordinary telephone, to the batteries and to a zinc plate, which is to be buried in the earth a few feet away from the well or hole, and not more than 1 ft. under the surface. A battery of four dry cells is used at each station.
Both stations are connected in the same way, as shown in the sketch. This makes it possible for neighbors to use their wells as a means of communication with each other. --Contributed by A. E. Joerin.
** Eyelets for Belts [432]
If eyelets, such as used in shoes, are put into the lace holes of a belt, the belt will last much longer. The eyelets, which may be taken from old shoes, will prevent the lace from tearing out. I have used this method on several kinds of belts, always with entire satisfaction. --Contributed by Irl R. Hicks.
** How to Make a Life Buoy [432]
Any boy may be able to make, for himself or friends, a life buoy for emergency use in a rowboat or for learning to swim. Purchase 1-3/4 yd. of 30-in. canvas and cut two circular pieces, 30 in. in diameter, also cutting a round hole in the center of them, 14 in. in diameter. These two pieces are sewed together on the outer and inner edges, leaving a space, about 12 in. in length, open on the outer seam. Secure some of the cork used in packing Malaga grapes from a grocery or confectionery store and pack it into the pocket formed between the seams through the hole left in the outer edge. When packed full and tight sew up the remaining space in the seam. Paint the outside surface and the seams well with white paint to make it water-tight. --Contributed by Will Hare, Petrolea, Onto
** A Home-Made Microscope [433]
A great many times we would like to examine a seed, an insect or the fiber of a piece of wood but have no magnifier handy. A very good microscope may be made out of the bulb of a broken thermometer. Empty out the mercury, which is easily done by holding the bulb with the stem down over a lamp or candle. A spirit lamp is the best, as it makes no smoke and gives a steady heat. Warm the bulb slowly and the mercury will be expelled and may be caught in a tea cup. Do not heat too fast, or the pressure of the mercury vapor may burst the glass bulb, cautions the Woodworkers' Review. To fill the bulb with water warm it and immerse the end of the tube in the water. Then allow it to cool and the pressure of the air will force the water into the bulb. Then boil the water gently, holding the bulb with the stem up; this will drive out all the air, and by turning the stem or tube down and placing the end in water the bulb will be completely filled. It is surprising how much can be seen by means of such a simple apparatus.
** A Novel Electric Time Alarm [433]
All time alarms run by clockwork must be wound and set each time. The accompanying diagram shows how to make the connection that will ring a bell by electric current at the time set without winding the alarm. The bell is removed from an ordinary alarm clock and a small metal strip attached, as shown at B. An insulated connection is fastened on the clapper of the bell, as shown at A. The arm holding the clapper must be bent to have the point A remain as close to the strip B as possible without touching it. The connection to the battery is made as shown. When the time set for the alarm comes the clapper will be moved far enough to make the contact. In the course of a minute the catch on the clapper arm will be released and the clapper will return to its former place.
** How to Make a Phonograph Record Cabinet [433]
The core, Fig. 1, consists of six strips of wood beveled so as to form six equal sides. The strips are 3 ft.
long and 3 in. wide on the outside bevel and are nailed to three blocks made hexagon, as shown in Fig. 2, from 7/8-in. material. One block is placed at each end and one in the middle. A 1/2-in. metal pin is driven in a hole bored in the center of each end block. The bottoms of the pasteboard cases, used to hold the wax records, are either tacked or glued to this hexagon core, as shown in Fig. 3, with their open ends outward.
Two circular pieces are made of such a diameter as will cover the width of the core and the cases attached, and extend about 1/2 in. each side. A 1/2-in. hole is bored in the center of these pieces to receive the pins placed in the ends of the core, Fig. 1. These will form the ends of the cabinet, and when placed, one on each end of the core, heavy building paper or sheet metal is tacked around them for a covering, as shown in Fig. 4. A small glass door is made, a little wider than one row of cases, and fitted in one side of the covering. The outside may be painted or decorated in any way to suit the builder.
** Experiments with a Mirror [434]
Ask your friend if he can decipher the sign as illustrated in the sketch, Fig. 1, which you pretend to have read over the shop of an Armenian shoemaker.
He will probably tell you that he is not conversant with Oriental languages. He will not believe it if you tell him it is written in good English, but place a frameless mirror perpendicularly on the mysterious script, right across the quotation marks, and it will appear as shown in Fig. 2. We understand at once that the reflected image is the faithful copy of the written half.
With the aid of a few books arrange the mirror and the paper as shown in Fig. 3 and ask your friend to write anything he chooses, with the condition that he shall see his hand and read the script in the mirror only. The writer will probably go no farther than the first letter. His hand seems to be struck with paralysis and unable to write anything but zigzags, says Scientific American.
Another experiment may be made by taking an egg shell and trimming it with the scissors so as to reduce it to a half shell. In the hollow bottom roughly draw with your pencil a cross with pointed ends. Bore a hole, about the size or a pea, in the center of the cross. Place yourself so as to face a window, the light falling upon your face, not upon the mirror which you hold in one hand. Close one eye. Place the shell between the other eye and the mirror, at a distance of 2 or 3 in. from either, the concavity facing the mirror as shown in Fig. 4. Through the hole in the shell look at the mirror as if it were some distant object. While you are so doing the concave shell will suddenly assume a strongly convex appearance. To destroy the illusion it becomes necessary either to open both eyes or to withdraw the shell away from the mirror. The nearer the shell to the mirror and the farther the eye from the shell the more readily comes the illusion.
** Miniature Electric Lamps [434]
After several years' research there has been produced a miniature electric bulb that is a great improvement and a decided departure from the old kind which used a carbon filament. A metallic filament prepared by a secret chemical process and suspended in the bulb in an S-shape is used instead of the old straight span. The voltage is gauged by the length of the span. The brilliancy of the filament excels anything of its length in any voltage.
Of course, the filament is not made of the precious metal, radium; that simply being the trade name. However, the filament is composed of certain metals from which radium is extracted.
The advantages of the new bulb are manifold. It gives five times the light on the same voltage and uses one-half of the current consumed by the old carbon filament. One of the disadvantages of the old style bulb was the glass tip which made a shadow. This has been obviated in the radium bulb by blowing the tip on the side, as shown in the sketch, so as to produce no shadow.
** How to Make a Magazine Clamp [435]
This device as shown in the illustration can be used to hold newspapers and magazines while reading. Two pieces of wood are cut as shown, one with a slot to fit over the back of a magazine and the other notched to serve as a clamp. The piece, A, may be slotted wide enough to insert two or three magazines and made long enough to hold several newspapers.
** Pewter Finish for Brass [435]
A color resembling pewter may be given to brass by boiling the castings in a cream of tartar solution containing a small amount of chloride of tin.
** Drowning a Dog's Bark with Water [435]
The owner of two dogs was very much annoyed by the dogs barking at night. It began to be such a nuisance that the throwing of old shoes and empty bottles did not stop the noise. The only thing that seemed to put a stop to it was water.
Being on the third floor of the house, and a little too far from the kennel to throw the water effectively, a mechanism was arranged as shown in the sketch.
A faucet for the garden hose was directly below the window. An 8-in. wooden grooved pulley was slipped over an axle which had one end fitted on the handle of the faucet. A rope was extended to the window on the third floor and passed around the pulley several times, thence over an iron pulley fastened to the wall of the house and a weight was attached to its end. By pulling the rope up at the window the large pulley would turn on the water and when released the weight would shut off the flow. The nozzle was fastened so as to direct the stream where it would do the most good. --Contributed by A. S. Pennoyer, Berkeley, Cal.
** Cost of Water [435]
The average cost of supplying 1,000,000 gal. of water, based on the report of twenty-two cities, is $92. This sum includes operating expenses and interest on bonds.
** How to Make a Wondergraph [436] By F. E. TUCK
An exceedingly interesting machine is the so-called wondergraph. It is easy and cheap to make and will furnish both entertainment and instruction for young and old. It is a drawing machine, and the variety of designs it will produce, all symmetrical and ornamental and some wonderfully complicated, is almost without limit. Fig. 1 represents diagrammatically the machine shown in the sketch. This is the easiest to make and gives fully as great a variety of results as any other.
To a piece of wide board or a discarded box bottom, three grooved circular disks are fastened with screws so as to revolve freely about the centers. They may be sawed from pieces of thin board or, better still, three of the plaques so generally used in burnt-. wood work may be bought for about 15 cents. Use the largest one for the revolving table T. G is the guide wheel and D the driver with attached handle. Secure a piece of a 36-in. ruler, which can be obtained from any furniture dealer, and nail a small block, about 1 in. thick, to one end and drill a hole through both the ruler and the block, and pivot them by means of a wooden peg to the face of the guide wheel. A fountain pen, or pencil, is placed at P and held securely by rubber bands in a grooved block attached to the ruler. A strip of wood, MN, is fastened to one end of the board. This strip is made just high enough to keep the ruler parallel with the face of the table, and a row of small nails are driven part way into its upper edge. Anyone of these nails may be used to hold the other end of the ruler in position, as shown in the sketch. If the wheels are not true, a belt tightener, B, may be attached and held against the belt by a spring or rubber band.
After the apparatus is adjusted so it will run smoothly, fasten a piece of drawing paper to the table with a couple of thumb tacks, adjust the pen so that it rests lightly on the paper and turn the drive wheel. The results will be surprising and delightful. The accompanying designs were made with a very crude combination of pulleys and belts, such as described.
The machine should have a speed that will cause the pen to move over the paper at the same rate as in ordinary writing. The ink should flow freely from the pen as it passes over the paper. A very fine pen may be necessary to prevent the lines from running together.
The dimensions of the wondergraph may vary. The larger designs in the illustration were made on a table, 8 in. in diameter, which was driven by a guide wheel, 6 in. in diameter. The size of the driver has no effect on the form or dimensions of the design, but a change in almost any other part of the machine has a marked effect on the results obtained. If the penholder is made so that it may be fastened at various positions along the ruler, and the guide wheel has holes drilled through it at different distances from the center to hold the peg attaching the ruler, these two adjustments, together with the one for changing the other end of the ruler by the rows of nails, will make a very great number of combinations possible. Even a slight change will greatly modify a figure or give an entirely new one. Designs may be changed by simply twisting the belt, thus reversing the direction of the table.
If an arm be fastened to the ruler at right angles to it, containing three or four grooves to hold the pen, still different figures will be obtained. A novel effect is made by fastening two pens to this arm at the same time, one filled with red ink and the other with black ink. The designs will be quite dissimilar and may be one traced over the other or one within the other according to the relative position of the pens.
Again change the size of the guide wheel and note the effect. If the diameter of the table is a multiple of that of the guide wheel, a complete figure of few lobes will result as shown by the one design in the lower right hand corner of the illustration. With a very flexible belt tightener an elliptical guide wheel may be used. The axis may be taken at one of the foci or at the intersection of the axis of the ellipse.
The most complicated adjustment is to mount the table on the face of another disc, table and disc revolving in opposite directions. It will go through a long series of changes without completing any figure and then will repeat itself. The diameters may be made to vary from the fraction of an inch to as large a diameter as the size of the table permits. The designs given here were originally traced on drawing paper 6 in. square.
Remarkable and complex as are the curves produced in this manner, yet they are but the results obtained by combining simultaneously two simple motions as may be shown in the following manner: Hold the table stationary and the pen will trace an oval. But if the guide wheel is secured in a fixed position and the table is revolved a circle will be the result.
So much for the machine shown in
Fig. 1. The number of the modifications of this simple contrivance is limited only by the ingenuity of the maker. Fig. 2 speaks for itself. One end of the ruler is fastened in such a way as to have a to-and-fro motion over the arc of a circle and the speed of the table is geared down by the addition of another wheel with a small pulley attached. This will give many new designs. In Fig. 3 the end of the ruler is held by a rubber band against the edge of a thin triangular piece of wood which is attached to the face of the fourth wheel. By substituting other plain figures for the triangle, or outlining them with small finishing nails, many curious modifications such as are shown by the two smallest designs in the illustrations may be obtained. It is necessary, if symmetrical designs are to be made, that the fourth wheel and the guide wheel have the same diameter.
In Fig. 4, V and W are vertical wheels which may be successfully connected with the double horizontal drive wheel if the pulley between the two has a wide flange and is set at the proper angle. A long strip of paper is given a uniform rectilinear motion as the string attached to it is wound around the axle, V. The pen, P, has a motion compounded of two simultaneous motions at right angles to each other given by the two guide wheels. Designs such as shown as a border at the top and bottom of the illustration are obtained in this way. If the vertical wheels are disconnected and the paper fastened in place the well known Lissajou's curves are obtained. These curves may be traced by various methods, but this arrangement is about the simplest of them all. The design in this case will change as the ratio of the diameters of the two guide wheels are changed.
These are only a few of the many adjustments that are possible. Frequently some new device will give a figure which is apparently like one obtained in some other way, yet, if you will watch the way in which the two are commenced and developed into the complete design you will find they are formed quite differently.
The average boy will take delight in making a wondergraph and in inventing the many improvements that are sure to suggest themselves to him. At all events it will not be time thrown away, for, simple as the contrivance is, it will arouse latent energies which may develop along more useful lines in maturer years.
** How to Make a 110-Volt Transformer [439]
Secure two magnets from a telephone bell, or a set of magnets wound for 2,000 ohms. Mount them on a bar of brass or steel as shown in Fig. 1. Get an empty cocoa can and clean it good to remove all particles of cocoa and punch five holes in the cover, as shown in Fig. 2. The middle hole is to be used to fasten the cover to the brass bar with a bolt. The other four holes are for the wire terminals. A piece of rubber tubing must be placed over the wire terminals before inserting them in the holes. Fill the can with crude oil, or with any kind of oil except kerosene oil, and immerse the magnets in it by fitting the cover on tight (Fig. 3). The connections are made as shown in the diagram, Fig. 5. This device may be used on 110-volt current for electro-plating and small battery lamps, provided the magnets are wound with wire no larger than No. 40. --Contributed by C. M. Rubsan, Muskogee, Okla.
** Experiment with a Vacuum [439]
Take any kitchen utensil used for frying purposes-an ordinary skillet, or spider, works best-having a smooth inner bottom surface, and turn in water to the depth of 1/2 in. Cut a piece of cardboard circular to fit the bottom of the spider and make a hole in the center 4 in. in diameter. The hole will need to correspond to the size of the can used. It should be 1 in. less in diameter than that of the can. Place this cardboard in the bottom of the spider under the water. A 2-qt. syrup can or pail renders the best demonstration, although good results may be obtained from the use of an ordinary tomato can. The edge of the can must have no indentations, so it will fit perfectly tight all around on the cardboard. Place the can bottom side up and evenly over the hole in the cardboard. Put a sufficient weight on the can to prevent it moving on the cardboard, but not too heavy, say, l lb.
Place the spider with its adjusted contents upon a heated stove. Soon the inverted can will begin to agitate. When this agitation finally ceases remove the spider from the stove, being careful not to move the can, and if the quickest results are desired, apply snow, ice or cold water to the surface of the can until the sides begin to flatten. The spider with its entire contents may now be lifted by taking hold of the can. When the vacuum is complete the sides of the can will suddenly collapse, and sometimes, with a considerable report, jump from the spider.
The cause of the foregoing phenomenon is that the circular hole in the cardboard admits direct heat from the surface of the spider. This heat causes the air in the can to expand, which is allowed to escape by agitation, the water and the cardboard acting as a valve to prevent its re-entrance. When the enclosed air is expelled by the heat and a vacuum is formed by the cooling, the above results are obtained as described. --Contributed by N. J. McLean.
** The Making of Freak Photographs [440]
An experiment that is interesting and one that can be varied at the pleasure of the operator, is the taking of his own picture. The effect secured, as shown in the accompanying sketch, reproduced in pen and ink from a photograph, is that made by the photographer himself. At first it seems impossible to secure such a picture, but when told that a mirror was used the process is then known to be a simple one.
The mirror is set in such a way as to allow the camera and operator, when standing directly in front of it, to be in a rather strong light. The camera is focused, shutter set and plate holder made ready. The focusing cloth is thrown over your head, the position taken as shown, and the exposure made by the pressure of the teeth on the bulb while held between them.
** Hand Car Made of Pipe and Fittings [440]
Although apparently complicated, the construction of the miniature hand car shown in the accompanying illustration is very simple. With a few exceptions all the parts are short lengths of pipe and common tees, elbows and nipples.
The wheels were manufactured for use on a baby carriage. The sprocket wheel and chain were taken from a discarded bicycle, which was also drawn upon for the cork handle used on the steering lever. The floor is made of 1-in. white pine, 14 in. wide and 48 in. long, to which are bolted ordinary flanges to hold the framing and the, propelling and steering apparatus together. The axles were made from 3/8 in. shafting. The fifth wheel consists of two small flanges working on the face surfaces. These flanges and the auxiliary steering rod are connected to the axles by means of holes stamped in the piece of sheet iron which encases the axle. The sheet iron was first properly stamped and then bent around the axle. The levers for propelling and steering the car work in fulcrums made for use in lever valves. The turned wooden handles by which these levers are operated were inserted through holes drilled in the connecting tees. The working joint for the steering and hand levers consists of a 1/2 by 3/8 by 3/8 in. tee, a 1/2 by 3/8 in. cross and a piece of rod threaded on both ends and screwed into the tee. The cross is reamed and, with the rod, forms a bearing.
The operation of this little hand car is very similar in principle to that of the ordinary tricycle, says Domestic Engineering. The machine can be propelled as fast as a boy can run. It responds readily to the slightest movement of the steering lever.
** How to Make a Rustic Seat [441]
The rustic settee illustrated in Fig. 1 may be made 6 ft. long, which will accommodate four average-sized persons. It is not advisable to exceed this length, as then it would look out of proportion, says the Wood-Worker. Select the material for the posts, and for preference branches that are slightly curved, as shown in the sketch. The front posts are about 3-1/2 in. in diameter by 2 ft. 4 in. long. The back posts are 3 ft. 4 in. high, while the center post is 3 ft. 8 in. in height. The longitudinal and transverse rails are about 3 in. in diameter and their ends are pared away to fit the post to which they are connected by 1-in. diameter dowels. This method is shown in Fig. 4. The dowel holes are bored at a distance of 1 ft. 2-1/2 in, up from the lower ends of posts. The front center leg is partially halved to the front rail and also connected to the back post by a bearer, 4 in. deep by 1-1/2 in. thick. This bearer is tenoned to the back post.
Fig. 3 shows a sectional view of the bearer joint to front leg, and also the half-round seat battens resting on the bearer, also showing them with their edges planed. It is advisable to have a space between the edges of each batten, say about 1-8 in., to allow rainwater to drain. The ends of the seat battens are pared away to fit the transverse rails neatly as shown in Fig. 2. The struts for the post range in diameter from 1-1/2 in. to 2 in. The ends of the struts are pared to fit the posts and rails, and are then secured with two or three brads at each end.
Select curved pieces, about 2-1/2 in. in diameter, for the arm rests and back rails; while the diagonally placed filling may be about 2 in. in diameter. Start with the shortest lengths, cutting them longer than required, as the paring necessary to fit them to the rails and posts shortens them a little. Brad them in position as they are fitted, and try to arrange them at regular intervals.
** Heated Steering Wheel [441]
Motorists that suffer with cold hands while driving their cars may have relief by using a steering wheel that is provided with electric heat. An English invention describes a steering wheel with a core that carries two electrically heated coils insulated one from the other and from the outer rim.
** Homemade Workbench [442] By C. E. McKINNEY, Jr.
The first appliance necessary for the boy's workshop is a workbench. The average boy that desires to construct his own apparatus as much as possible can make the bench as described herein. Four pieces of 2 by 4-in. pine are cut 23 in. long for the legs, and a tenon made on each end of them, 1/2 in. thick, 3-1/2 in. wide and 1-1/2 in. long, as shown at A and B, Fig. 1. The crosspieces at the top and bottom of the legs are made from the same material and cut 20 in. long. A mortise is made 1-1/4 in. from each end of these pieces and in the narrow edge of them, as shown at C and D, Fig. 1. The corners are then cut sloping from the edge of the leg out and to the middle of the piece, as shown. When each pair of legs are fitted to a pair of crosspieces they will form the two supports for the bench. These supports are held together and braced with two braces or connecting pieces of 2 by 4-in. pine, 24 in. long. The joints are made between the ends of these pieces and the legs by boring a hole through each leg and into the center of each end of the braces to a depth of 4 in., as shown at J, Fig. 2. On the back side of the braces bore holes, intersecting the other holes, for a place to insert the nut of a bolt, as shown at HH. Four 3/8 by 6-in, bolts are placed in the holes bored, and the joints are drawn together as shown at J. The ends of the two braces must be sawed off perfectly square to make the supports stand up straight.
In making this part of the bench be sure to have the joints fit closely and to draw the bolts up tight on the stretchers. There is nothing quite so annoying as to have the bench support sway while work is being done on its top. It would be well to add a cross brace on the back side to prevent any rocking while planing boards, if the bench is to be used for large work.
The main top board M, Fig. 2, may be either made from one piece of 2 by 12-in. plank, 3-1/2 ft. long, or made up of 14 strips of maple, 7/8 in. thick by 2 in. wide and 3-1/2 ft. long, set on edge, each strip glued and screwed to its neighbor. When building up a top like this be careful to put the strips together with the grain running in the same direction so the top may be planed smooth. The back board N is the same length as the main top board M, 8-1/2 in. wide and only 7/8 in. thick, which is fitted into a 1/2/-in. rabbet int back of the board M. Thes boards form the top of the bench, and are fastened to the top pieces of the supports with long screws. The board E is 10 in. wide and nailed to the back of the bench. On top of this board and at right angles with it is fastened a 2-1/2-in. board, F. These two boards are 7/8 in. thick and 3-1/2 ft. long. Holes are bored or notches are cut in the projecting board, F, to hold tools.
Details of the vise are shown in Fig. 3, which is composed of a 2 by 6-in. block 12 in. long, into which is fastened an iron bench screw, S. Two guide rails, GG, 7/8 by 1-1/2 in. and 20 in. long, are fastened into mortises of the block as shown at KK, and they slide in corresponding mortises in a piece of 2 by 4-in. pine bolted to the under side of the main top board as shown at L. The bench screw nut is fastened in the 2 by 4-in. piece, L, between the two mortised holes. This piece, L, is securely nailed to one of the top cross pieces, C, of the supports and to a piece of 2 by 4-in. pine, P, that is bolted to the under sides of the top boards at the end of the bench. The bolts and the bench screw can be purchased from any hardware store for less than one dollar.
** Forming Coils to Make Flexible Wire Connections [443]
When connections are made to bells and batteries with small copper wires covered with cotton or silk, it is necessary to have a coil in a short piece of the line to make it flexible. A good way to do this is to provide a short rod about 3/16 in. in diameter cut with a slit in one end to hold the wire and a loop made on the other end to turn with the fingers. The end of the wire is placed in the slit and the coil made around the rod by turning with the loop end.
** Photographing the North Star [443]
The earth revolving as upon an axis is inclined in such a position that it points toward the North Star. To an observer in the northern hemisphere the effect is the same as if the heavens revolved with the North star as a center. A plate exposed in a camera which is pointed toward that part of the sky on a clear night records that effect in a striking manner. The accompanying illustration is from a photograph taken with an exposure of about three hours, and the trace of the stars shown on the plate by a series of concentric circles are due to the rotation of the earth.
The bright arc of the circle nearest the center is the path of the North star. The other arcs are the impressions left by neighboring stars, and it will be noticed that their brightness varies with their relative brilliancy. Many are so faint as to be scarcely distinguished, and, of course, telescopic power would reveal myriads of heavenly bodies which leave no trace on a plate in an ordinary camera. The North or pole star is commonly considered at a point directly out from the axis of the earth, but the photograph shows that it is not so located. The variation is known astronomically to be 1-1/4 deg. There is a slight irregularity in the position of the earth's axis, but the changes are so slow as to be noticed only by the lapse of a thousand years. Five thousand years ago the pole star was Draconis, and in eighteen thousand years it will be Lyrae. We have direct evidence of the change of the earth's axis in one of the Egyptian pyramids where an aperture marked the position of the pole star in ancient times, and from this it is now deviated considerable.
This experiment is within the reach of everyone owning a camera. The photograph shown was taken by an ordinary instrument, using a standard plate of common speed. The largest stop was used and the only requirement beyond this is to adjust the camera in a position at the proper inclination and to make the exposure for as long as desired. On long winter nights the exposure may be extended to 12 hours, in which event the curves would be lengthened to full half-circles.
The North star is one of the easiest to locate in the entire heavens. The constellation known as the Great Dipper is near by, and the two stars that mark the corners of the dipper on the extremity farthest from the handle lie in a line that passes across the North star. These two stars in the Great Dipper are called the pointers. The North Star is of considerable brilliancy, though by no means the brightest in that part of the heavens. --Contributed by O. S. B.
** How to Relight a Match [444]
A match may be a small thing on which to practice economy and yet a great many times one wishes to relight a match either for economy or necessity. The usual method is to place the burnt portion of the match in the flame to be relighted as shown in Fig. 1. It is very hard to relight the charred end and usually burnt fingers are the result of pushing the match farther in the flame. Hold the burnt end in the fingers and place the other end in the flame as shown in Fig. 2. A light will be secured quickly and the flame will only follow the stick to the old burnt portion.
** Home-Made Hand Drill [444]
In the old kitchen tool box I found a rusty egg beater of the type shown in Fig. 1. A shoemaker friend donated a pegging awl, Fig. 2, discarded by him due to a broken handle. With these two pieces of apparatus I made a hand drill for light work in wood or metal. By referring to Fig. 3 the chuck, A, with stem, B, were taken from the awl. The long wire beater was taken from the beater frame and a wire nail, 0, soldered to the frame, D, in the place of the wire. The flat arms were cut off and shaped as shown by E. The hole in the small gear, G, was drilled out and a tube, F, fitted and soldered to both the gear and the arms E. This tube, with the gear and arms, was slipped over the nail, 0, then a washer and, after cutting to the proper length the nail was riveted to make a loose yet neat fit for the small gear. The hand drill was then completed by soldering the stem, B, of the chuck to the ends of the flat arms E. Drills were made by breaking off sewing-machine needles above the eye as shown in Fig. 4 at A, and the end ground to a drill point. --Contributed by R. B. J., Shippensburg, Pa.
** How to Make a Stationary Windmill [445]
A windmill that can be made stationary and will run regardless of the direction of the wind is here illustrated. Mills of this kind can be built of larger size and in some localities have been used for pumping water.
Two semi-circular surfaces are secured to the axle at right angles to each other and at 45 deg. angle with that of the axle as shown in Fig. 2. This axle and wings are mounted in bearings on a solid or stationary stand or frame. By mounting a pulley on the axle with the wings it can be used to run toy machinery.
** Electric Anesthesia [445]
It is a well known fact that magnetism is used to demagnetize a watch, and that frost is drawn out of a frozen member of the body by the application of snow. Heat is also drawn out of a burned hand by holding it close to the fire, then gradually drawing it away. The following experiment will show how a comparatively feeble electric current can undo the work of a strong one.
I once tried to electrocute a rat which was caught in a wire basket trap and accidentally discovered a painless method. I say painless, because the rodent does not object to a second or third experiment after recovering, and is apparently rigid and without feeling while under its influence.
To those who would like to try the experiment I will say that my outfit consisted of an induction coil with a 3/8-in. iron core about 3 in. long. The primary coil was wound with four layers of No. 20 wire and the secondary contains 4 oz. No. 32 wire, and used on one cell of bichromate of potash plunge battery. The proper amount of current used can be determined by giving the rodent as much as a healthy man would care to take. Fasten one secondary electrode to the trap containing the rat and with a wire nail fastened to the other terminal, hold the vibrator of the coil with your finger and let the rat bite on the nail and while doing so release the vibrator. In three seconds the rat will be as rigid as if dead and the wires can be removed.
Now connect your wires to the primary binding-posts of the coil and wind the end of one of them around the rat's tail and start the vibrator. Touch the other terminal to the rat's ear and nose. In a few minutes he will be as lively as ever. --Contributed by Chas. Haeusser, Albany, N. Y.
** A Simple Battery Rheostat [445]
A spring from an old shade roller is mounted on a board 4 in. wide, 9 in. long and 3/8 in. thick. A binding-post is fastened to this board at each end, to which is attached the ends of the spring, as shown in Fig. 1. The temper of a small portion of each end of the spring will need to be drawn. This can be accomplished by heating over an alcohol lamp or in a fire and allowing it to cool slowly. The ends are then shaped to fit the binding-posts. A wire is connected to one of the binding-posts and a small square piece of copper is attached to the other end of the wire, as shown in Fig. 2. When this device is placed in a circuit the current can be regulated by sliding the small square copper piece along the spring. --Contributed by H. D. Harkins, St. Louis, Mo.
** A Frame for Drying Films [446]
No doubt many amateur photographers are troubled about drying films and to keep them from curling. The problem may be solved in the following way:
Make a rectangular frame out of pine wood, 1/4 by 1/2 in., as shown in the sketch. It is made a little wider and a little shorter than the film to be dried. This will allow the end of the film to be turned over at each end of the frame and fastened with push pins. Do not stretch the film when putting it on the frame as it shrinks in drying. The film will dry quicker and will be flat when dried by using this frame. --Contributed by Elmer H. Flehr, Ironton, Ohio.
** A Home-Made Novelty Clock [446]
This clock that is shown in the accompanying engraving is made in scroll work, the cathedral and towers being of white maple, the base is of walnut with mahogany trimmings, all finished in their natural colors. It has 11 bells in the two towers at the sides and 13 miniature electric lamps of different colors on two electric circuits. The clock is operated by a small motor receiving its power from dry cell batteries. This motor turns a brass cylinder over which runs a continuous roll of perforated paper similar to that used on a pianola. A series of metal fingers, connected by wires to the bells, press lightly on this brass roll and are insulated from the roll by the perforated paper passing between. When a perforation is reached a finger will make a contact with the brass roll for an instant which makes a circuit with the magnet of an electric hammer in its respective bell or forms the circuit which lights the electric bulbs as the case may be.
At each hour and half hour as the clock strikes, the motor is started automatically and the chimes sound out the tunes while the colored lights are turned on and off; two small doors in the cathedral open and a small figure comes out while the chimes are playing, then returns and the doors are closed. --Contributed by C. V. Brokenicky, Blue Rapids, Kansas.
** Fourth-of-July Catapult [447]
Among the numerous exciting amusements in which boys may participate during the Fourth-of-July celebration is to make a cannon that will shoot life-sized dummies dressed in old clothes. Building the cannon, as described in the following, makes it safe to fire and not dangerous to others, provided care is taken to place it at an angle of 45 deg. and not to fire when anyone is within its range. The powder charge is in the safest form possible, as it is fired with a blow from a hammer instead of lighting a fuse. If the cannon is made according to directions, there cannot possibly be any explosion.
The materials used in the construction of the catapult may be found in almost any junk pile, and the only work required, outside of what can be done at home, is to have a few threads cut on the pieces of pipe. The fittings can be procured ready to attach, except for drilling a hole for the firing pin.
Secure a piece of common gas pipe, 4 to 6 in. in diameter, the length being from 18 to 24 in. Old pipe may be used if it is straight. Have a machinist cut threads on the outside of one end, as shown in Fig. 1, and fit an iron cap, Fig. 2, tightly on the threaded end of the pipe. The cap is drilled and tapped in the center for a 1-in. pipe. Thread both ends of a 1-in. pipe that is 4 in. long, Fig. 3, and turn one end securely into the threaded hole of the cap. This pipe should project 1/4 in. inside of the cap. Fit a cap, Fig. 4, loosely on the other end of the 1-in. pipe. A hole is drilled into the center of this small cap just large enough to receive a 6-penny wire nail, B, Fig. 4.
This completes the making of the cannon and the next step is to construct a dummy which can be dressed in old clothes. Cut out two round blocks of wood from hard pine or oak that is about 3 in. thick, as shown in Fig. 5. The diameter of these blocks should be about 1/8 in. less than the hole in the cannon, so they will slide easily. In the center of each block bore a 1/4-in. hole. Secure an iron rod, about 4 ft. long, and make a ring at one end and thread 4 in. of the other. Slip one of the circular blocks on the rod and move it up toward the ring about 14 in. Turn a nut on the threads, stopping it about 3-1/2 in. from the end of the rod. Slip the other circular piece of wood on the rod and up against the nut, and turn on another nut to hold the wooden block firmly in its place at the end of the rod. If the rod is flattened at the place where the upper block is located, it will hold tight. These are shown in Fig. 5. Take some iron wire about 1/8 in. in diameter and make a loop at the top of the rod for the head. Wire this loop to the ring made in the rod and make the head about this loop by using canvas or gunny cloth sewed up forming a bag into which is stuffed either excelsior, paper or hay. The arms are made by lashing with fine wire or strong hemp, a piece of wood 1 in. square and 20 in. long, or one cut in the shape shown in Fig. 6, to the rod. Place the wood arms close to the bottom of the head. Make a triangle of wire and fasten it and the cross arm securely to the top of the rod to keep them from slipping down. A false face, or one painted on white cloth, can be sewed on the stuffed bag. An old coat and trousers are put on the frame to complete the dummy. If the clothing is not too heavy and of white material so much the better. To greatly increase the spectacular flight through the air, a number of different colored streamers, 6 or 8 in. wide and several feet in length made from bunting, can be attached about the waist of the dummy. The complete dummy should not weigh more than 6 lb.
The cannon is mounted on a board with the cap end resting against a cleat which is securely nailed to the board and then bound tightly with a rope as shown in Fig. 8. Lay one end of the board on the ground and place the other on boxes or supports sufficiently high to incline it at an angle of about 45. deg. Enough of the board should project beyond the end of the cannon on which to lay the dummy. When completed as described, it is then ready to load and fire. Clear away everyone in front and on each side of the cannon, as the dummy will fly from 50 to 100 ft. and no one must be in range of its flight. This is important, as the rod of the frame holding the clothes will penetrate a board at short range. An ordinary shot gun cartridge of the paper shell type is used for the charge and it must be loaded with powder only. Coarse black powder is the best, but any size will do. When loading· the rod with the wooden blocks, on which the dummy is attached, do not place the end block against the breech end of the cannon, leave about 2 or 3 in. between the end of the cannon and the block. Insert the cartridge in the 1-in. pipe. The cartridge should fit the pipe snug, which it will do if the proper size is secured. Screw on the firing-cap, insert the wire nail firing pin until it rests against the firing-cap of the cartridge. If the range is clear the firing may be done by giving the nail a sharp rap with a hammer. A loud report will follow with a cloud of smoke and the dummy will be seen flying through the air, the arms, legs and streamers fluttering, which presents a most realistic and life-like appearance. The firing may be repeated any number of times in the same manner.
** How to Make a Miniature Volcano [448]
A toy volcano that will send forth flames and ashes with lava streaming down its sides in real volcanic action can be made by any boy without any more danger than firing an ordinary fire-cracker. A mound of sand or earth is built up about 1 ft. high in the shape of a volcano. Roll up a piece of heavy paper, making a tube 5 in. long and 1-1/2 in. in diameter. This tube of paper is placed in the top of the mound by first setting it upon a flat sheet of paper and building up the sand or earth about the sides until it is all covered excepting the top opening. This is to keep all dampness away from the mixture to be placed within.
A fuse from a fire-cracker, or one made by winding some powder in tissue paper, is placed in the paper tube of the volcano with one end extending over the edge. Get some potash from a drug store and be sure to state the purpose for which it is wanted, as there are numerous kinds of potash that will not be suitable. An equal amount of sugar is mixed with the potash and placed in the paper tube. On top of this put a layer of pure potash and on this pour some gun powder. This completes the volcano and it only remains for the fuse to be lighted and action will begin with an explosion which sends fire, smoke and sparks upward. Flames will follow and the lava pours down the sides of the mound.
** Wire Loop Connections for Battery Binding-Posts [449]
The trouble with battery binding post connections can be avoided by winding the bare end of the connecting wire around the binding-post screw and then back around its extending length as shown in the sketch. Always screw down permanent connections with pliers.
** Melting Metal in the Flame of a Match [449]
The flame of an ordinary match has a much higher temperature than is generally known and will melt cast-iron or steel filings. Try it by striking a match and sprinkle the filings through the flame. Sputtering sparks like gunpowder will be the result of the melting metal.
** Russian Squirrels [449]
The squirrel slaughter of Russia amounts to 25,000,000 per year.
** Landscape Drawing Made Easy [449]
With this device anyone, no matter how little his artistic ability may be, can draw accurately and quickly any little bit of scenery or other subject and get everything in the true perspective and in the correct proportion.
No lens is required for making this camera-just a plain mirror set at an angle of 45 deg., with a piece of ordinary glass underneath, a screen with a peek hole and a board for holding the drawing paper. The different parts may be fastened together by means of a box frame, or may be hinged together to allow folding up when carrying and a good tripod of heavy design should be used for supporting it. In order to get the best results the screen should be blackened on the inside and the eyepiece should be blackened on the side next to the eye. A piece of black cardboard placed over the end of the eyepiece and perforated with a pin makes an excellent peek hole.
In operation the rays of light coming from any given object, such as the arrow AB, strike the inclined mirror and are reflected downward. On striking the inclined glass a portion of the light is again reflected and the rays entering the eye of the operator produce the virtual image on the paper as shown. The general outlines may be sketched in quickly, leaving the details to be worked up later. This arrangement may be used for interior work when the illumination is good.
** Irrigating with Tomato Cans [450]
The following is an easy and effective way to start plants in dry weather: Sink an ordinary tomato can, with a 1/8-in. hole 1/2 in. from the bottom, in the ground so that the hole will be near the roots of the plant. Tamp the dirt around both plant and can, and fill the latter with water. Keep the can filled until the plant is out of danger. --Contributed by L. L. Schweiger, Kansas City, Mo.
** Fountain for an Ordinary Pen [450]
Take two steel pens, not the straight kind, and place them together, one above the other, in the penholder.
With one dip of ink 60 or 70 words may be written. This saves time and the arrangement also prevents the ink from dropping off the pen. --Contributed by L. M. Lytle, Kerrmoor, Pa.
** Homemade Mousetrap [450]
Bore a 1-in. hole, about 2 in. deep, in a block of wood and drive a small nail with a sharp point at an angle so it will project into the hole about half way between the top and bottom, and in the center of the hole, as shown.
File the end very sharp and bend it down so that when the mouse pushes its head past it in trying to get the bait at the bottom of the hole, the sharp point will catch it when it tries to back out. Almost anyone can make this trap in a short time, and it will catch the mice as surely as a more elaborate trap.
** Clear Wax Impressions from Seals [450]
A die must be slightly damp to make clear impressions on sealing wax and to keep it from sticking to the wax. A very handy way to moisten the die is to use a pad made by tacking two pieces of blotting paper and one of cloth to a wooden block of suitable size, and saturate the blotters with water before using. Stamp the die on the pad and then on the hot wax. The result will be a clear, readable impression. --Contributed by Fred Schumacher, Brooklyn, N. Y.
** A Window Stick [450]
Although the windows in factories and houses are usually provided with weights, yet the stick shown in the sketch will be found very handy in case all of the windows are not so equipped. It is made of a piece of pine wood long enough to hold the lower sash at a height even with the bottom of the upper, and about 1-1/2 or 2 in. wide. Notches may be cut in the stick as shown, each being wide enough to firmly hold the sash. Thus, with the stick illustrated, the sash may be held at three different heights on the side A, and at still another on the side B. --Contributed by Katharine D. Morse, Syracuse, N. Y.
** How to Make a Canoe [451]
A practical and serviceable canoe, one that is inexpensive, can be built by any boy, who can wield hammer and saw, by closely following the instructions and drawings, given in this article.
It is well to study these carefully before beginning the actual work. Thus an understanding will be gained of how the parts fit together, and of the way to proceed with the work.
Dimensioned drawings of the canoe and molds are contained in Fig. 1. The boat is built on a temporary base, A, Fig. 2, which is a board, 14 ft. 1 in. long, 3 in. wide and 1-1/2 in. thick. This base is fastened to the trestles and divided into four sections, the sections on each side of the center being 4 ft. long.
The next thing to be considered are the molds (Fig. 3). These are made of 1-in. material. Scrap pieces may be found that can be used for these molds. The dimensions given in Fig 1 are for one-half of each form as shown in Fig. 3, under their respective letters. The molds are then temporarily attached to the base on the division lines.
Proceed to make the curved ends as shown in Fig. 4. Two pieces of straight-grained green elm, 32 in. long, 1-3/4, in. wide and 1 in. thick, will be required. The elm can be obtained from a carriage or blacksmith's shop. The pieces are bent by wrapping a piece of wire around the upper end and baseboard. The joint between the curved piece and the base is temporary. Place a stick between the wires and twist them until the required shape is secured. If the wood does not bend readily, soak it in boiling water. The vertical height and the horizontal length of this bend are shown in Fig. 4. The twisted wire will give the right curve and hold the wood in shape until it is dry.
The gunwales are the long pieces B, Fig. 2, at the top of the canoe. These are made of strips of ash, 15 ft. long, 1 in. wide and 1 in. thick. Fasten them temporarily to the molds, taking care to have them snugly fit the notches shown. The ends fit over the outside of the stem and stern pieces and are cut to form a sharp point, as shown in Fig. 5. The ends of the gunwales are fastened permanently to the upper ends of the bent stem and stern pieces with several screws.
Two other light strips, C and D, Fig. 2, are temporarily put in, and evenly spaced between the gunwales and the bottom board. These strips are used to give the form to the ribs, and are removed when they have served their purpose.
The ribs are now put in place. They are formed of strips of well seasoned elm or hickory, soaked in boiling water until they bend without breaking or cracking. Each rib should be 1-1/2 in.
wide, 3/8 in. thick and long enough to reach the distance between the gunwales after the bend is made. The ribs are placed 1 in. apart. Begin by placing a rib in the center of the base and on the upper side. Nail it temporarily, yet securely, and then curve the ends and place them inside of the gunwales, as shown in Fig. 6. Fasten the ends of the rib to the gunwales with 1-in. galvanized brads. This method is used in placing all the ribs. When the ribs are set, remove the pieces C and D, Fig. 2, and the molds.
A strip is now put in to take the place of the base. This strip is 1-3/4 in. wide, 1/2 in. thick and long enough to reach the entire length of the bottom of the canoe. It is fastened with screws on the inside, as shown in Fig. 7, and the ends are lap-jointed to the stem and stern pieces as shown in Fig. 4. When this piece is fastened in place, the base can be removed. The seats are attached as shown in Fig. 8, and the small pieces for each end are fitted as shown in Fig. 9.
The frame of the canoe is now ready to be covered. This will require 5-1/2 yd. of extra-heavy canvas. Turn the framework of the canoe upside down and place the canvas on it. The center of the canvas is located and tacked to the center strip of the canoe at the points where ribs are attached. Copper tacks should be used. The canvas is then tacked to the ribs, beginning at the center rib and working toward each end, carefully drawing the canvas as tightly as possible and keeping it straight. At the ends the canvas is split in the center and lapped over the bent wood. The surplus canvas is cut off. A thin coat of glue is put on, to shrink the cloth and make it waterproof.
The glue should be powdered and brought into liquid form in a double boiler. A thin coat of this is applied with a paintbrush. A small keel made of a strip of wood is placed on the bottom to protect it when making a landing on sand and stones in shallow water. When the glue is thoroughly dry the canvas is covered with two coats of paint, made up in any color with the best lead and boiled linseed oil. The inside is coated with spar varnish to give it a wood color.
The paddles may be made up in two ways, single or double. The double paddle has a hickory pole, 7 ft. long and 2 in. in diameter, for its center part. The paddle is made as shown in Fig. 10, of ash or cypress. It is 12 in. long, and 8 in. wide at the widest part. The paddle end fits into a notch cut in the end of the pole (Fig. 11).
A shield is made of a piece of tin or rubber and placed around the pole near the paddle to prevent the water from running to the center as the pole is tipped from side to side. The complete paddle is shown in Fig. 12. A single paddle is made as shown in Fig. 13. This is made of ash or any other tough wood. The dimensions given in the sketch are sufficient without a description.
** Thorns Used as Needles on a Phonograph [453]
Very sharp thorns can be used successfully as phonograph needles. These substitutes will reproduce sound very clearly and with beautiful tone. The harsh scratching of the ordinary needle is reduced to a minimum, and the thorn is not injurious to the record.
** Tool Hangers [453]
A tool rack that is serviceable for almost any kind of a tool may be made by placing rows of different-size screw eyes on a wall close to the workbench, so that files, chisels, pliers and other tools, and the handles of hammers can be slipped through the eyes.
A place for every tool saves time, and besides, when the tools are hung up separately, they are less likely to be damaged, than when kept together on the workbench.
** Child's Footrest on an Ordinary Chair [453]
Small chairs are enjoyed very much by children for the reason that they can rest their feet on the floor. In many households there are no small chairs for the youngsters, and they have to use larger ones. Two things result, the child's legs become tired from dangling unsupported or by trying to support them on the stretchers, and the finish on the chair is apt to be scratched. The device shown in the sketch forms a footrest or step that can be placed on any chair. It can be put on or taken off in a moment. Two suitable pieces of wood are nailed together at an angle and a small notch cut out, as shown, to fit the chair stretcher.
** Drying Photo Postal Cards [453]
A novel idea for drying photo postal cards comes from a French magazine. The drying of the cards takes a long time on account of their thickness, but may be hastened by using corrugated paper for packing bottles as a drying stand. Curve the cards, printed side up, and place the ends between two corrugations at a convenient distance apart. They will thus be held firmly while the air can circulate freely all around them.
** Preserving Key Forms [454]
After losing a key or two and having some difficulty in replacing them, I used the method shown in the sketch to preserve the outlines for making new ones. All the keys I had were traced on a piece of paper and their forms cut out with a pair of shears. When a key was lost, another could thus be easily made by using the paper form as a pattern. --Contributed by Ernest Weaver, Santa Anna, Texas.
** Renewing Typewriter Ribbons [454]
Roll the ribbon on a spool and meanwhile apply a little glycerine with a fountain-pen filler. Roll up tightly and lay aside for a week or ten days. Do not apply too much glycerine as this will make the ribbon sticky--a very little, well spread, is enough. The same application will also work well on ink pads. --Contributed by Earl R. Hastings, Corinth, Vt.
** Drinking Trough for Chickens [454]
A quickly made and sanitary drinking trough for chickens is formed of a piece of ordinary two or three-ply roofing paper. The paper is laid out as shown, and the edges are cemented with asphaltum and then tacked to the side of a fence or shed.
** Ordinary Pen Used as a Fountain Pen [454]
It is a very simple matter to make a good fountain pen out of an ordinary pen and holder. The device is in the form of an attachment readily connected to or removed from any ordinary pen and holder, although the chances are that when once used it will not be detached until a new pen is needed.
Take the butt end of a quill, A, from a chicken, goose or turkey feather--the latter preferred as it will hold more ink--and clean out the membrane in it thoroughly with a wire or hatpin. Then make a hole in the tapered end of the quill just large enough to pull through a piece of cotton string. Tie a knot in one end of this string, B, and pull it through the small end of the quill until the knot chokes within, then cut off the string so that only 1/4 in. projects. Shave out a small stopper from a bottle cork for the large end of the quill. This completes the ink reservoir.
Place the quill on top of the penholder C, so that its small end rests against the pen immediately above its eye. Pull the string through this eye. Securely bind the quill to the pen and holder with a thread, as shown, first placing under it a wedge-shaped support of cork or wood, D, hollowed on both sides to fit the curved surfaces of the quill and holder. The illustration shows the detail clearly.
To fill the reservoir place the pen upright on its point and dip a small camel's-hair brush or cloth-bound toothpick into the ink bottle and "scrape" off the ink it will hold on the inner edge of the quill. Cork tightly, and the device is ready for use. When not in use place the holder at an angle with the pen uppermost. --Contributed by Chelsea C. Fraser, Saginaw, Michigan.
** How to Construct a Small Thermostat [455] By R. A. McCLURE
It is a well known fact, that there is a change in the dimensions of a piece of metal, due to a change in its temperature. This change in dimensions is not the same for all materials; it being much greater in some materials than in others, while in some there is practically no change.
If two thin, narrow strips of different metals, that contract or expand at different ratio due to a variation in temperature, be rigidly fastened together at their ends, and the combination then heated or cooled, the combined piece will have its shape changed. One of the pieces will increase in length more than the other, due to a rise in temperature, and this same piece will decrease in length more than the other when subjected to a decrease in temperature.
If one end of this combined piece be rigidly clamped to a support, as shown in Fig. 1, and the combination then have its temperature changed, the free end will move to the right or left of its original position, depending upon which of the pieces changes in length the more. If there is a rise in temperature and the right-hand piece B increases in length faster than the left-hand piece A, the free end of the combined piece win move to the left of its original position. If, on the other hand, there is a decrease in temperature, the right-hand piece will decrease in length more than the left-hand piece, and the upper or free end will move to the right of its original position.
Such a combination of two metals constitutes a simple thermostat. If the movement of the free end of the combination be made to actuate a needle moving over a properly calibrated scale we have a simple form of thermometer. If two electrical contacts, CC, be mounted on the right and left-hand sides of the upper end of the combined piece, as shown in Fig. 1, we have a thermostat that may be used in closing an electrical circuit when the temperature of the room in which it is placed rises or falls a certain value. These contacts should be so arranged that they can be moved toward or away from the combined piece independently. By adjusting the position of these contacts, the electrical circuit will be closed when the temperature of the thermostat has reached an experimentally predetermined value.
The following description is that of a thermostat, constructed by the author of this article, which gave very satisfactory results. First obtain a piece of steel, 6 in. long, 5/8 in. wide and 2/100 in. thick, and a piece of brass, 6 in. long, 5/8 in. wide and 3/100 in. thick. Clean one side of each of these pieces and tin them well with solder. Place the two tinned surfaces just treated in contact with each other and heat them until the solder on their surfaces melts and then allow them to cool. A better way would be to clamp the two thin pieces between two heavy metal pieces, and then heat the whole to such a temperature that the solder will melt, and then allow it to cool. This last method will give more satisfactory results than would be obtained if no clamps are used, as the thin metal pieces are liable to bend out of shape when they are heated, and as a result they will not be in contact with each other over their entire surfaces. After these pieces have been soldered together forming one piece, which we shall for convenience speak of as the couple, two small holes should be drilled in one end to be used in mounting it, and a notch cut in the other end, as shown in Fig. 2.
Cut from some thin sheet brass, about 2/100 in. in thickness, two pieces, 1/4 in. wide and 1/2 in. long. Bend these pieces of brass over a piece of hatpin wire, thus forming two V-shaped pieces. Cut off a piece of the hatpin, 5/8 in. long, and fasten it across the notched end of the couple by means of the U-shaped piece of brass, which should be soldered in place as shown in Fig. 3. All superfluous solder should then be cleaned from the couple and the steel pin. Now bend the couple so as to form a perfect half circle, the brass being on the inside.
The base upon which this couple is to be mounted should be made as follows: Obtain a piece of brass, 7 in. long, 3/4 in. wide, and 1/4 in. thick. In this piece drill holes, as indicated in Fig. 4, except A, which will be drilled later. Tap the holes B, C and D for 1/8-in. machine screws.
Cut from some 1/8-in. sheet brass a piece, 1-7/8 in. long and 3/4 in. wide, to be used as a support for the couple. In one end of this piece drill two small holes, as indicated in Fig. 5, and tap them for 3/16-in. machine screws. In the opposite end cut a slot, whose dimensions correspond to those given in Fig. 5. Now bend the piece, at the dotted line in Fig. 5, into the form shown in Fig. 6, making sure that the dimension given is correct. This piece can now be mounted upon the piece shown in Fig. 4, by means of two brass machine screws placed in the holes B. The slot in the support for the couple will permit its being moved along the mounting strip, the purpose of which will be shown later.
Next cut another piece of 1/8-in. brass, 2-3/4 in. long and 5/8 in. wide. In this piece drill two 1/8-in. holes, as indicated in Fig. 7, and then bend it at the dotted lines into the form shown in Fig. 8. Mount this strip upon the main mounting strip by means of two brass machine screws placed in the holes C, so that the upper part is over the center-punch mark for the hole A in the main mounting strip.
You are now ready to drill the hole A, which should be done as follows: Remove the piece you last mounted and then clamp the main mounting strip in the drill press so that the center-punch mark for the hole A is directly under the point of the drill. Then remount the piece you just removed, without disturbing the piece you clamped in the drill press, and drill a small hole through both pieces. This hole should be about 3/64 in. in diameter. After this small hole has been drilled through both pieces, a countersink should be placed in the drill chuck and the hole in the upper piece countersunk to a depth equal to half the thickness of the metal in which it is drilled. Unclamp the pieces from the drill press, turn them over, and countersink the small hole in what was originally the lower piece. The object of countersinking these holes is to reduce the bearing surface of a small shaft that is to be supported in the holes and must be as free from friction as possible.
We may now construct the needle, or moving portion of the thermostat, which should be done as follows: The shaft that is to carry the moving system must be made from a piece of steel rod, about 3/32 in. in diameter. Its dimensions should correspond to those given in Fig. 9. Considerable care should be used in turning this shaft down, to make sure that it fits perfectly in the small holes in the supporting pieces. The shaft should turn freely, but it must not be loose in the holes, nor should it have but a very small end play.
Cut from some 1/32-in. sheet brass a piece whose dimensions correspond to those given in Fig. 10. Drill a 1/8-in. hole, A, in this piece, and cut a slot, B, from one side of the piece into this hole, and a second slot, C, along the center of the piece as indicated in the figure. Considerable care should be exercised in cutting the slot C, so that its breadth is exactly equal to the diameter of the piece of steel wire fastened on the end of the couple. Also make sure to get the sides of this slot perfectly smooth. Cut from some 1/8-in. brass a disk having a diameter of 1/2 in., and solder it to the end of the needle. The dotted line in Fig. 10 indicates the proper position of the disk. Now drill a hole, D, through the disk and needle, of such a diameter that considerable force must be applied to the steel shaft you have already made, in order to force it through the hole. Force the shaft through this hole until the needle is exactly in the center of the shaft.
The parts of the thermostat thus far made can now be assembled. Place the steel shaft in its bearings and see that it turns perfectly free. Then place the steel pin, on the end of the couple, in the slot C, and fasten the other end of the couple, by means of two machine screws, to the support made for the couple. Increase or decrease the temperature of the thermostat and note the results. If everything is working all right, the end of the needle should move when the temperature of the thermostat is changed. The amount the end of the needle moves can be easily changed by moving the support or the couple toward or away from the shaft supporting the needle, which changes the position of the steel pin in the slot C. The nearer the steel pin is to the shaft supporting the needle, the greater the movement of the end of the needle due to a given change in temperature.
A small piece of white cardboard can be mounted directly under the end of the needle by means of small brass strips, that in turn can be attached to the lower ends of the main mounting holes D, Fig. 4. A scale can be marked on this piece of cardboard by noting the position of the needle corresponding to different temperatures as determined by a thermometer. When this scale has been completed, you can use the thermostat as a thermometer.
Two contacts may be mounted, one on each side of the needle, in a manner similar to the method suggested for mounting the cardboard. These contacts should be so constructed that the end of the needle will slide over them with little friction, and so that their position with respect to the end of the needle may be easily changed.
Both contacts must be insulated from the remainder of the thermostat, and may or may not be connected together, depending on how the thermostat is to be used.
It would be advisable, if possible, to have the part of the needle that touches the contact points, as well as these points, of platinum, as the arc that is likely to be formed will not destroy the platinum as easily as it will the brass. A small wooden containing case can now be made and the thermostat is complete. There should be a large number of holes drilled in the sides, ends and back of the case so that the air inside may be always of the same temperature as the outside air.
In adjusting, testing, or calibrating your thermostat, make sure that it is in the same position that it will be in when in use.
The connections of the thermostat for ringing one bell when the temperature rises or falls to a certain value, are shown in Fig. 11. The connections of the thermostat for ringing one bell when the temperature rises to a certain value and another bell when the temperature falls to a certain value, are shown in Fig. 12. The complete thermostat is shown in Fig. 13.
** A Tailless Kite [458]
The frame of a 3-ft. kite is made of two sticks, each 3 ft. long. These are tied together so that the cross stick will be at a distance of 15 per cent of the full length of the upright stick, from its end, or in this case 5.4 in. The sticks may be made of straight grained pine, 3/8 in. square, for small kites, and larger hardwood sticks, for larger kites.
The cross stick is bent into a bow by tying a strong cord across from end to end. The center of the bend should be 4-1/2 in. above the ends. The bend is shown in the sketch. Connect all four ends or points with a cord, being careful not to pull the bend of the cross stick down, but seeing that it remains straight across the kite. When this is done the frame is ready for the cover.
The cover will require 2-1/2 sheets of tissue paper, 20 by 30 in., which should be pasted together as the sketch indicates. Cut out the paper, allowing 2 in. margin for lapping over the cord on the frame. Place the frame on the cover with the convex side toward the paper and paste the margin over the cord, allowing the paper to bag a little to form pockets for the air to lift the kite. The corners should be reinforced with circular pieces of paper pasted over the ends of the sticks.
The flying cord is attached to the points A and B of the frame. There is no cross cord. The kite will fly at right angles to the flying cord. It is easily started flying from the ground by laying it with the head toward the operator and pulling it up into the wind. --Contributed by Chas. B. Damik, Cooperstown, N. Y.
** The Levitation - A Modern Stage Trick [459]
This illusion has mystified thousands of the theater-going public, in fact, it has been the "piece de resistance" of many illusion acts. The ordinary method of procedure is as follows: The person who is to be suspended in the air, apparently with no support--usually a lady--is first put in a hypnotic (?) sleep. She is placed on a couch in the middle of the stage, and in most cases the spotlight is brought into play. The performer then takes a position close to the couch and with dramatic effect makes a few hypnotic passes over the subject. She then slowly rises from the couch until she has attained a height varying from 4 to 5 ft. above the stage, as shown in Fig. 1. The couch is then taken a way and a hoop is passed over the floating lady. The performer now causes the lady to float back to the couch or board that she may have been resting on, after which the so-called hypnotic spell is withdrawn.
In spite of the claims that the illusion owes its origin to Hindoo magic, it is nothing more nor less than a clever mechanical contrivance, the construction of which will be readily understood by a glance at the accompanying illustrations.
The bottom of the couch, if one is used, contains a cradle-like arrangement which fits the recumbent form of the lady and is connected to a heavy sheet of plate glass by means of a rod, D, Fig. 2, attached to one end, and running parallel to the side of the cradle. When the glass is lifted, the body of the subject is also raised, seemingly at the will of the performer. This is accomplished by the aid of an assistant beneath the stage floor. The plate of glass, E, Fig. 3, passes perpendicularly through the stage down to a double block and tackle. The end of the cable is attached to a drum or windlass and the plate glass held steady with guides at the sides of the slot in the stage floor, through which it passes. The winding up of the cable naturally forces the plate glass and cradle up, causing the lady to rise.
Some illusionists place the lady on a board on two ordinary trestles and cause the board to rise with the lady on it, as shown in the illustration, thus obviating the use of heavy paraphernalia as in the cradle attachment. The cradle attachment is also generally accompanied by a 2-in. iron bar, used in the place of the plate glass, the performer or operator standing at the rear of the couch to conceal the bar as it comes from beneath the stage. However, the method illustrated is the one generally used.
The solid hoop is passed over the body in the following manner: Start at the end, B, Fig. 2, passing the hoop as far as C with the hoop on the outside of the back horizontal rod. The side of the hoop toward the audience is then turned and swung clear around over the feet at A and entered between the rod and board on which the lady rests. The hoop is then carried as far as it will go back toward the end B. Then the side nearest the operator is passed over the head of the body apparently the second time and passed off free at the feet. Thus to the closest observer the impression is given that the hoop has encircled the lady twice. The illustrations give in detail the working of the illusion above the stage floor. No set rule is used for the tackle and drum below the floor.
CONTENTS
A Accelerometer, Simple 93 Acid Burns, Treating 126 Acetylene Gas Generator, Homemade 57 Acetylene Lamp, Lighting 401 Aerating Water in a Small Tank 241 Aeroplane, Paper, How to Make 329 Aeroplanes, Model, Equilibrator for 11 Alarm, Burglar, How to Make 368 Alarm, Callers' Approach 87 Alarm Clock Chicken Feeder 79 Alarm Clock to Pull Up Furnace Draft 107 Alarm, Electric 94 Alarm, Electric, Door Bell and 114 Alarm, Electric Fire, How to Make 430 Alarm, Electric, That Rings Bell and Turns On Light 337 Alarm, Electric Time 433 Alarm, Fire 47, 359 Aluminum Polish 428 Aluminum, Satin Finish on 198 Aluminum Wire, Insulating 306 Ammeter, How to Make 49, 203 Amusement-Boys Representing the Centaur 173 Amusement Device--Merry-Go-Round Thriller 209 Amusement Device--Merry-Go-Round, To Build 359 Amusement Device--Teeter Board. Revolving 297 Anesthesia, Electric 445 Animals, Small, Trap for 82 Annealing Chisel Steel 362 Annunciator, How to Construct 57, 416 Aquarium, How to Make 64, 210 Arbor, Grape, How to Build 73 Arc Lamp, Homemade 132 Arc Searchlight, Self Lighting 9 Arms and Armor, Imitation: Part I 235 Part II 242 Part III 248 Part IV 263 Part V 271 Part VI 279 Part VII 284 Arms, Drip Shield for 258 Arrowhead, Flint, How to Make 23 Asbestos Table Pads, Homemade 212 Athletes, Weights for, How to Make 274 Atomizer, How to Make 158 Automobile, Boys' Homemade 402, 430 Automobile Engine, Cooling Water for 236 Automobile, Greasing the Front Wheels of 320 Automobile Headlights, Adjusting 217 Automobile, Painting 357 Automobile with Sails 326 Axle, Cart without 291
B Babbitt Ladle, Emergency 264 Babbitt, Ladle for Melting 173 Bag, Changing, for Plate Holders 212 Bag, Sewing, How to Make 386 Bags, Paper, Use for 19 Balloon Ascension Illusion 300 Balloon, Pilot, How to Make 118 Balloons, Paper, How to Make 215 Barometer, Homemade 151 Barometer, How to Make 188 Barrel Stave Hammock 75 Barrel Stave Sled 383 Baseball, Playing with a Pocket Knife 250 Baseball Throwing Practice, Device for 312 Bath. Shower, To Make 15 Bathtub Stopper, Substitute 429 Batteries, Connecting Up to Give Any Voltage 93 Batteries, Dry, To Obtain Cheaply 410 Batteries, Dry, To Renew 369, 378, 401 Batteries, Gravity, Why Fail 115 Battery Binding Posts, Wire Loop Connections for 449 Battery Cell. Dry, Making 160 Battery Connections, Wire Terminals for 168 Battery, Grenet, How to Make 83 Battery Motor, Controller and Reverse for 72 Battery Motor, Reversing 405 Battery, Non-Polarizing, How to Make 151 Battery Rheostat 80, 445 Battery, Small Storage, How to Make 121 Battery Switch 99 Battery, Thermo-Electric, How to Make 59, 140 Battery Voltmeter 153 Battery Zincs, Old, To Use 87 Bed Warmer. Electric, How to Make 338 Beeswax, Substitute for 129 Bell, Cracked, Restoring Tone to 71 Bell, Return Call, with One Wire 101 Bell Ring Register 316 Bell, Ringing by Touching a Gas Jet 403 Belt, Eyelets for 432 Belt Lace Caution 239 Belt, Round, To Make without Ends 243 Bench Lathe Made of Pipe Fittings 316 Bicycle Catamaran 145 Bicycle Coasting Sled, How to Make 231 Bicycle Frame, Enameling 385 Bicycle, Runners on 157 Bicycle, To Attach a Sail to 425 Bicycle, Trailer for 397 Bicycle Trouser Guards for Sleeve Bands 283 Bicycle. Water, How to Make 335 Bill File Made of Corkscrews 315 Bind Magazines, To 40, 56, 406 Bird House, Proper Design for 201 Bird Houses, Clay Flower Pots Used for 277 Bit, Gouge Used as 411 Blotter Pad, Corner Pieces for 8 Blotting Pad, Desk 17 Blowpipe, Homemade 428 Blueprint Lantern Slides, How to Make 120 Blues, prussian and Chinese 401 Boards, Joining 268 Boat-Bicycle Catamaran 145 Boat-Canoe, How to Make 451 Boat-Catamaran, Cruising 423 Boat, Ice, How to Build 357, 382 Boat, Paddle, How to Make 100 Boat, Paper, How to Make 321 Boat-Punt, Homemade 123 Bobsled, Homemade Yankee 408 Bolts, Rusted 151 Book Cover, Paper, How to Make 126 Book Holder 32 Book, Removing Grease Stains from 230 Book Rest 292 Bookcase Doors, To Keep Closed 377 Bookmark 379 Bookmark, Brass 18 Bookmark, Paper Clip 241 Books. How to Carry 409 Boomerangs, How to Make 4, 202 Bore a Square Hole, How to 179 Boring Holes In Cork 8 Bottle, Cutting Thread inside of 179 Bottle, Diving 331 Bottle, Inverted, Withdrawing Paper from Under 33 Bottle, Photographing Man in 74 Bottle Pushing on the Ice 409 Bottles, Round End. Base for 29 Bottle Stopper, New Way to Remove 224 Bowl, Copper, How to Make 185 Box Cover. Sliding, Fastener 256 Box, Fishhook 379 Box, Magic 7 Box, Water Color 257 Boxes, Rustic Window 30 Bracket Saw, Cheap, How to Make 42 Brass Bookmark 18 Brass, Cleaning 407 Brass Flag, Ornamental, How to Make 266 Brass Frame In Repoussé 237 Brass Furnace, How to Build 115 Brass, Piercing Punch for 19 Brass Plaques, Photo Silhouette, Making 217 Brass Surface, Flat, Polishing 229 Brass Work-Candlestick, How to Make 325 Bread, Loaf, Cutting 36 Bronze Liquid 329 Brooder for Small Chickens 343 Broom Holder 13 Broom Holder Made of a Hinge 33 Broom, Old, Crutch Made of 352 Brush, Counter, for a Shop 419 Brush, To Keep from Spreading 367 Brushes, Paint, Care of 267 Bulb on a Glass Tube, To Make 324 Bunsen Cell, How to Make 206 Burglar Alarm, Simple, How to Make 368 Burning Inscriptions on Trees 45 Burns, Carbolic Acid 126 Button, Changing into a Coin 234 Button. Removing from Child's Nostril 237 Buttonhole Trick 234
C Cabinet for Pot Covers 16 Cabinet for Phonograph Records 483 Cabinet, Music, How to Make 77 Cabinet, Phonograph Disk Cabinet 79, 433 Calendar, Handy 196 Calliope, Steam, How to Make 418 Camera, Box, Repairing 379 Camera, Enlarging from Life in 111, 117 Camera, Homemade Kits for 159 Camera, Making Light proof 58 Camera, Practical, for Fifty Cents 365 Camp Stool, How to Make 222 Camp, Tin Drinking Cup for 379 Camper's Lantern, Makeshift 266 Camps and How to Build Them 341 Camps, Keeping Food Cool in 21 Can Covers, Tool for Lifting 352 Candle Shade, How to Make 191 Candlestick, How to Make 240, 281, 325 Candlestick, Water 406 Cane Chairs, How to 259 Cane in Furniture, Tightening 230 Cannon Balls, 36, Removing from Handbag 256 Cannon, Gas 197 Cannon, How to Make 42 Cannon, Lead, How to Make 338 Cannon, Toy, To Discharge by Electricity 59 Canoe, How to Make 451 Canoe, Sailing, How to Make 199 Cans, Tomato, Irrigating with 450 Canvas Cot, Folding, How to Make 154 Canvas, Waterproofing 146 Carburetor Difficulties 208 Card Trick, Rising 256 Card Trick with a Tapered Deck 70 Cardboard Spiral Turned by Heat 226 Cardboard Squares. Gun for Throwing 269 Cardcase, Lady's, How to Make 350 Cards, Mechanical Trick with 63 Carpenter's Gauge 19 Carpenter's Vise, Homemade 36 Carpet Sweeper Wheels, New Tires for 266 Cart, Dog 60 Cart without an Axle 291 Catamaran, Bicycle 145 Catamaran, Cruising 423 Catapult, Fourth of July 447 Cats, Shocking, Device for 411 Cell, Bunsen 206 Cell, Daniell 252 Centaur. Boys Representing 173 Centering, To Make Unnecessary 319 Chain Made from a Match 377 Chair, Child's Footrest on 453 Chair Legs. Rubber Tip for 229 Chair, Porch Swing 128 Chair Rockers, Safety Tips on 429 Chair Sleighs 383 Chairs, Balancing on 131 Chairs, To Cane 259 Checker Board Puzzle 189, 233 Cheese box Cover, Tea Tray 18 Chemicals. Protecting Fingers from 283 Cherry Seeder 29 Chicken Coop. Keeping Rats from 352 Chickens, Drinking Trough for 454 Chickens, Feed Box for 292 Chickens. Small, Brooder for 343 Chisel, Ice 61 Chisel, Steel, Annealing 362 Chopping Board 19 Christmas Tree Decorations, Repairing 11 Churn, Homemade Small 192 Clamp, Magazine, How to Make 435 Clamping a Cork 33 Clamps, Homemade Soldering 137 Cleaner for Gloves 302 Cleaner for White Shoes 239 Cleaning Brass 407 Cleaning Discolored Silver 344 Cleaning Furniture 185 Cleaning, Glass, Solution 31 Cleaning Jewelry 353 Cleaning Leather on Furniture .13 Cleaning Silver 305 Cleaning Walls 375 Cleaning Woodwork 315 Cleats, Insulating, Substitute for 348 Clock, Electric, How to Make 268 Clock, Homemade Novelty 446 Clock, How to Clean 119 Clock, Novelty, for the Kitchen 360 Clock, Old, Use for 367 Clothes Rack 14 Clothesline, Double, Support for 318 Coaster, Roller, Illusion 298 Coaster, Trolley, How to Make 387 Coasters and Chair Sleighs 383 Cock, 'l'hree Way, for Small Model Work 50 Coil. Jump Spark 113 Coils, Forming to Make Flexible Wire Connections 443 Coin and Card on the First Finger 175 Coin and Tumbler Trick 378 Coin, Changing Button Into 234 Coin, Disappearing 176, 193 Coin In a Wine Glass Trick 167 Coin, Moving under a Glass 214 Coin Purse, How to Make 354 Coin, Sticking against Wall 176 Coin, Sticking to Wood by Vacuum 287 Coins, Display Rack Shows Both Sides of 220 Coins, Sending by Mail, Safe Method of 287 Compass, Mariner's 170 Compass Needle, Floating 160 Compass, Substitute for 289 Compressed Air Phenomenon 111 Concrete Kennel 23 Concrete Swimming Pool 178 Conservatory, Window 103 Controller for a Small Motor 42 Cook Fish, One Way to 206 Copper Bowl, How to Make 185 Copper, Hardening 206 Copper Picture Frame, Etched, How to Make 414 Copper Trays, How to Make 180 Copper Work--Corner Pieces for a Blotter Pad 8 Cord. Buttoned 427 Cork, Boring, Holes in 8 Cork, Clamping 33 Cork Extractor 300 Corks, How to Fit 368 Corkscrews, Bill File Made of 315 Corner Pieces for a Blotter Pad, How to Make 8 Cot. Canvas, How to Make 154 Counter Brush for a Shop 419 Crossbow and Arrow Sling, How to Make 339 Crutch. Homemade 369 Crutch Made of an Old Broom 352 Crystallization, Instantaneous 288 Cup and Saucer Rack, How to Make 105 Cup, Tin Drinking, for the Camp 379 Current Reverser 107, 111 Curtain Roller 419 Curtain Roller Spring, How to Tighten 79
D Dance, Miniature War 255 Darkroom Lantern, Homemade 14, 340 Darkroom, Photographic, Building 26 Demagenetizing a Watch 166 Desk Blotting Pad 17 Developing Box, How to Make 220 Developing Tray, Cracked Composition, To Repair 260 Developing Tray. Photographic 269 Dish Holder, Hot 7 Dogcart, Homemade 160 Dog, How to Chain 257 Dog's Bark, Drowning with Water 435 Dogs, To Drive Away 106 Door Bell and Electric Alarm 114 Door Lock, Secret 6 Door Opener, Electric 78 Door Opener for a Furnace 83 Door, Sliding, Electric Lock for 89 Dovetail Joint 29 Dovetail Joint Puzzle 236 Draft Opener, Automatic 102 Draftsman. Spline for 406 Draftsmau's Ink Bottle Cork, Steel Pen Used In 117 Drawers, Several, Locking with One Lock 314 Drawing, Aid In 270 Drawing Instrument-Wondergraph, How to Make 436 Drawing, Landscape, Made Easy 449 Drill Gauge, Handy 252 Drill, Hand, How to Make 444 Drinking Cup, Tin, for the Camp 379 Drinking Trough for Chickens 454 Drip Shield for the Arms 258 Dry Batteries, Another Way to Renew 378 Dry Batteries, Cheap, How to Obtain 410 Dry Batteries, Old, To Renew 401 Dry Batteries, Renewing 367 Dry Battery Cell, How to Make 160 Duplicator for Box Cameras 363 Duplicator, Homemade 240
E Easel, How to Make 415 Egg-Beater, How to Make 291 Eggshell Funnel 93 Eggshells, How to Preserve 288 Elderberry Huller, Homemade 323 Electric Alarm 94 Electric Alarm, Door Bell and 114 Electric Alarm That Rings a Bell and Turns On a Light 337 Electric Anesthesia 445 Electric Apparatus-Ammeter, How to Make 49, 203 Electric Apparatus-Annunciator, Homemade 57 Electric Apparatus-Annunciator, How to Construct 416 Electric Apparatus-Batteries, Connecting Up to Given Any Voltage 93 Electric Apparatus-Battery Rheostat 80 Electric Apparatus-Battery Voltmeter 153 Electric Apparatus-Bell, Return Call, with One Wire 101 Electric Apparatus-Cats, To Shock 411 Electric Apparatus-Cell, Daniell 252 Electric Apparatus-Circuit Breaker for Induction Coils 101 Electric Apparatus-Controller and Reverse for Battery Motor 72 Electric Apparatus-Controller for a Small Motor 42 Electric Apparatus-Current Reverser 107, 111 Electric Apparatus-Galvanometer, Tangent 150 Electric Apparatus-Induction Coil, How to Make 138 Electric Apparatus-Induction Coils, Mercury Make and Break Connection for 187 Electric Apparatus-Jump Spark Coil 113 Electric Apparatus-Medical Induction Coil, How to Make 63 Electric Apparatus-Motor, Single Phase Induction 124 Electric Apparatus-Motors, Direct Connected Reverse for 60 Electric Apparatus-Rheostat, Lead Pencil 145 Electric Apparatus-Shocking Machine 139 Electric Apparatus-Thermo Battery, How to Make 59 Electric Apparatus-Thermostat, Small 455 Electric Apparatus-Transformer, 110-Volt 439 Electric Apparatus-Voltammeter, Pocket 330 Electric Battery Massage, Homemade 144 Electric Bed Warmer, Homemade 338 Electric Bell, Relay Made from 94 Electric Blue Light Experiment 47 Electric Clock, Homemade 268 Electric Charges, Detector for 281 Electric Door Opener 78 Electric Engine 276 Electric Experiment, Interesting 377 Electric Experiment, Reversing Switch for 92 Electric Fire Alarm, How to Make 430 Electric Furnace Regulator, How to Make 388 Electric Furnace, Small, How to Make 48 Electric Heat Regulator, Automatic 344 Electric Horn, How to Make 218 Electric Hydrogen Generator 54 Electric Illusion Box 135 Electric Indicator for a Wind Vane 348 Electric Lamp Experiment 53, 120, 131 Electric Lamp Sockets, Miniature, How to Make 270 Electric Lamps, Miniature 434 Electric Lamps, Testing 314 Electric Light Circuit, Experiments with 50 Electric Lighting, Miniature 104 Electric Lights, Turned On and off from Different Places 205 Electric Lock 60, 110 Electric Lock for Sliding Door 89 Electric Lock, Simple 60 Electric Locomotive, Miniature, How to Make 165 Electric Motor 401 Electric Motor, Novel 395 Electric Motor, Small 214, 222, 345 Electric Pendant Switch, How to Make 310 Electric Piano, How to Make 247 Electric Plug, Homemade 430 Electric Postcard Projector 195 Electric Rat Exterminator 358 Electric Shock, To Give While Shaking Hands 133 Electric Shocker for Garbage Cans 94 Electric Stove. Homemade 31, 273 Electric Terminals, Varnish for 376 Electric Time Alarm 433 Electric Toaster, How to Make 37 Electric Walking Stick 413 Electric Wires, Flexible, Adjuster for 386 Electricity, To Discharge Toy Cannon by 59 Electricity; To Explode Powder with 53 Electricity, Writing with 74 Electrodeposition, Copies Made from Wax Molds by 157 Electrolytic Rectifier, How to Make 197 Electromagnet, Floating 152 Electroplating, Easy Method of 88 Electroscope, How to Make 103 Electrostatic Illumination 299 Emery Wheel Arbors, Washers for 359 Enameling a Bicycle Frame 385 Engine, Electric 276 Engine, Gasoline, How to Make 207 Engine, Model Steam 1 Engine, Steam, Made from Gas Pipe and Fittings 184 Engine, Toy Steam, How to Make 73 Engine, Turbine, How to Make 355 Equatorial, Homemade 204, 253 Equilibrator for Model Aeroplanes 11 Experiment, Center of Gravity 302 Experiment, Electric 377 Experiment, Electric Blue Light 47 Experiment, Heat and Expansion 124 Experiment, Phonograph 105 Experiment, Telephone 137 Experiment with a Vacuum 439 Experiment with Colored Electric Lamps 53 Experiment with Heat 134 Experiment with Incandescent Lamp 427 Experiment with Two Foot Rule and Hammer 106 Experiment, X-Ray 190 Experiments, Electric Lamp 120, 131 Experiments, Electrical, Reversing Switch for 92 Experiments with a Mirror 434 Experiments with Electric Light Circuit 50 Eye, Blind Spot in, To Find 129 Eyeglasses, Holding Firm 315
F Fan, Wooden, How to Make 332 Faucet Used as an Emergency Plug 343 Feed Box for Chickens 292 File, Chalking 19 File, Sharpening Skates with 306 File Soft Metals, How to 406 Film Washing Trough 331 Films, Drying 412 Films, Frame for Drying 446 Filter, Simple and Effective 278 Filtering with a Small Funnel 25 Finger Mathematics 181 Finger, Removing Tight Fitting Ring from 361 Fingers, Protecting from Chemicals 283 Fire Alarm, Cheap 47 Fire Alarm, Electric, How to Make 430 Fire Alarm, Simple, How to Make 359 Fire Extinguisher, Homemade 351 Fire, Making with the Aid of Ice 338 Fire Screen, How to Make 82 Fire Screen. Leaded Glass 295 Fish Bait 152 Fish, One Way to Cook 206 Fishhook Box 379 Fishing through Ice, Signals for 10, 281, 380 Flag, Brass, How to Make 266 Flatiron Rest 19 Flier, Toy, How to Make 429 Flint Arrowhead, How to Make 23 Floor Polisher, Homemade 10, 350 Flour Sifter 7 Flower, Magic Growing 244 Flower Pot Stand 33 Flower Pots, Clay, Used for Bird Houses 277 Flower Pots, Window Shelf for 292 Flower Stand, Iron 353 Flowers, Cut, To Longer Preserve 419 Flowers, Decoloration of 288 Flush Valve, Repairing a Washer on 344 Fob, Shoestring Watch, How to Weave 285 Fob, Watch, How to Make 12, 223 Food. Keeping Cool in Camps 21 Football, Tying Knot for 133 Footrest, Child's, on an Ordinary Chair 453 Footwear, Drier for 229 Forks, Balancing on a Pin Head 427 Foundry Work at Home 95 Fountain for an Ordinary Pen 450 Fountain Pen, Ordinary Pen Used as 454 Fountain Pen Used as a Ruler 319 Fountain Pens, Leaking, Remedy for 390 Frame, Brass, in Repoussé 237 Frost, To Keep Windows Free from 354 Fuming of Oak 196 Funnel. Eggshell 93 Funnel, Filtering with 25 Funnel, Glass 412 Funnel, Horn Used as 7 Funnel, Temporary 275 Funnel, Venting a 318 Furnace, Brass, How to Build 115 Furnace, Door Opener for 83 Furnace Draft. Alarm Clock to Pull Up 107 Furnace Draft Opener, Automatic 102 Furnace, Electric, How to Make 48 Furnace Regulator, Electric, How to Make 388 Furniture, Cleaning 185 Furniture, Cleaning Leather on 13 Furniture, Drawing of 294 Furniture--Library Set in Pyro-Carving 407 Furniture--Rustic Seat 441 Furnlture--Table, Mission Library, How to Make 141 Furniture, Tightening Cane In 230
G Galvanometer, Tangent, How to Make 150 Galvanoscope, How to Make 68 Game-Baseball, Playing with a Pocket Knife 250 Game-Bottle Pushers 409 Game, Chinese Outdoor 176 Game Played on the Ice 216 Garbage Can, Keeping Animals Away from 94 Gas Cannon 197 Gas Jet, Ringing a Bell by Touching 403 Gas Jet, Shade Holder Bracket for 419 Gas, To Light without Matches 394 Gasoline Burner for Model Work 55 Gasoline Engine, Homemade 207 Gauge, Carpenter's 19 Gauge, Drill 252 Gauge, Rain, How to Make 64 Gauntlets on Gloves 266 Gear Cutting Attachment for Small Lathes 167 Gear for Model Work 225 Gear Wheels, Small, To Make without a Lathe 46 Geissler Tuhe, How to Make 154 Glass Blowing and Forming 420 Glass Cleaning Solution 31 Glass, Effect of Radium on 116 Glass, Emergency Magnifying 305 Glass, Fire Screen, Leaded 295 Glass Funnel, Emergency 412 Glass, Ground, Imitating 294 Glass, Ground, Substitute 255 Glass Letters, Removing from Windows 319 Glass, Magnifying, How to Make 397 Glass, Photograph Prints Mounted on 231 Glass Plates, Piercing with a Spark Coil 426 Glass Tube, To Make a Bulb on 324 Gilder, How to Make 171 Gloves, Cleaner for 302 Gloves, Gauntlets on 266 Gold Leaf, Covering Signals with 189 Gouge Used as a Bit 411 Gramophone Records, Cracked, Repairing 24 Grape Arbor, How to Build 73 Gravity Batteries, Why Fail 115 Gravity Experiment 302 Grease Stains, Removing from Book 230 Grease, To Remove from Machinery 216 Greasing the Front Wheels of an Automobile 320 Grills, Rope, How to Make 277 Ground Glass, Imitating 294 Guitar That Is Easy to Make 320 Gummed Paper, Substitute for 315 Gun Barrels, Bursting of 304 Gun, Toy, for Throwing Cardboard Squares 269 Gymnasium. Outdoor: Part I-The Horizontal Bar 298 Part II-Parallel Bars 301 Part III-The Horse 303
H Hacksaw Blade, Knife Made from 293 Hammock, Barrel Stave 75 Hammock, How to Make 410 Hand Car Made of Pipe and Fittings 440 Hand, Magic Spirit 2 Handbag, Ladies', How to Make 213 Handbag, Removing 36 Cannon Balls from 256 Handkerchlef Mended after Being Cut and Torn 198 Handkerchief Trick, Vanishing 319 Handle, Opengng, for a Stamp Pad 23 Handle, Tying Paper Bag to Make 10 Hanger, Trousers, How to Make 143, 369 Hangers, Tool 453 Hardening Copper 206 Harmonograph, Line 34 Hat. To Hang on a Lead Pencil 133 Hatpins, Sealing Wax, How to Make 175 Hats, Felt, Packing Cut from 207 Heat and Expansion 124 Heat, Cardboard Spiral Turned by 226 Heat, Experiment with 134 Heat Regulator, Electric 344 Hectograph, Homemade 240, 326 Hinge, Broom Holder Made of 33 Hinges, Imitation Fancy Wings on 224 Hinges, Leather, Metal Covering for 41 Hole, Square, How to Bore 179 Hole, Threaded, Sizing 295 Holes, Boring In Cork 8 Holes, Circular. Cutting In Thin Sheet Metal 35 Holes, Different Shaped, Fitting Plug in 122 Horn, Electric, How to Make 218 Horn, Paper Phonograph, How to Make 71 Horn Used as Funnel 7 Horsepower of Small Motors, Finding 238 House, Building In a Tree Top 146 Hydrogen Generator, Constant Pressure 70 Hydrogen Generator, Small Electrical 54 Hygrometer, How to Make 71, 140
I Ice Boat, How to Build 357 Ice Boating 382 Ice, Bottle Pushing on 409 Ice Chisel, Handy 61 Ice, Fish Signal for Fishing through 10 Ice, Fishing through 281 Ice, Game Played on 216 Ice, Making a Fire with the Aid of 338 Ice, Merry-Go-Round Whirl on 380 Ice, Peculiar Properties of 100 Ice, Signals for Fishing through 380 Ice Skates, Hollow Grinding 231 Ice Yacht. How to Build 307 Illusion, Balloon Ascension 300 Illusion Box, Electric 135 Illusion for Window Attraction 239 Illusion. Miniature "Pepper's Ghost" 52 Illusion, Roller Coaster 293 Illusion, Rolling Uphill 361 Illusions, Optical 74, 99, 130, 183, 206, 348, 364 Incandescent Lamp, Experiment with 427 Indian Clubs, Weighting 318 Indicator, Electric, for a Wind Vane 348 Induction Call, How to Make 138 Induction Coil, Lighting an Incandescent Lamp with 112 Induction Call, Small Medical, How to Make 63 Induction Coils, Circuit Breaker for 101 Induction Calls. Mercury Make and Break Connections for 187 Induction Motor, Single Phase, How to Make 124 Ink Bottle Cork, Steel Pen Used in 117 Ink Spots, Removing 131 Inkstand, Ornamental Metal 315 Insulating Aluminum Wire 306 Insulating Cleats, Substitute for 348 Insulation, Removing from Wire 213 Interrupter, How to Make 51 Iodine Stains, Removing 425 Iron Castings, Putty for 269 Iron Flower Stand, Ornamental 353 Iron Polisher 286 Iron Rest for an Ironing Board 288 Iron Work, Ornamental, Easy Designs in 370 Ironing Board Stand, How to Make 17, 429 Irrigating with Tomato Cans 450
J Jelly Making Stand 290 Jewelry, How to Clean 353 Jig Saw Puzzle, Photographic 361 Joint, Dovetail 29 Jump Spark Coil, How to Make 113
K Kennel, Concrete 23 Kennel Door, Automatic Closing 32 Kerosene, Used in Polishing Metals 364 Kettle, Spoon holder On 24 Kettles, Spoon Rest for 304 Key Forms, Preserving 454 Key, Removing from a Double String 179 Kiln, Pottery 62 Kitchen, Novelty Clock for 360 Kitchen Utensil--Baking Pan 13 Kitchen Utensil--Cherry Seeder 29 Kitchen Utensil--Chopping Board 19 Kitchen Utensil--Egg-Beater, How to Make 291 Kitchen Utensil--Elderberry Huller 323 Kitchen Utensil--Flour Sifter 7 Kitchen Utensil for Removing Pies from Pans 275 Kitchen Utensil--Homemade Toaster 139 Kitchen Utensil--Hot Dish Holder 7 Kitchen Utensil--Hot Plate Lifter 318 Kitchen Utensil--Jelly Making Stand 290 Kitchen Utensil--Knife Sharpener 379 Kitchen Utensil--Ladle and Strainer, Combined 302 Kitchen Utensil--Pot Cover Closet 16 Kitchen Utensil--Pot Covers, Homemade 297 Kitchen Utensil--Querl, Versatile 28 Kitchen Utensil--Salad Dressing Mixer 16 Kitchen Utensil--Spoon Rest for Kettles 24, 304 Kitchen Utensil--Tool for Lifting Can Covers 352 Kitchen Utensil--Vegetable Slicer 413 Kite Balancing Strings, Rubber Bands in 270 Kite, Box, How to Make 58 Kite, Chinese, How to Make and Fly 210 Kite Reel. Homemade 156 Kite, Tailless 458 Kites of Many Kinds and How to Make Them 391 Knife Blade, Worn, Repairing 228 Knife Made from Hacksaw Blade 293 Knife, Pocket, Playing Baseball with 250 Knife Sharpener, Kitchen 379 Knot, Magic 198 Knot Trick 167 Knot, Tying for Football 133
L Ladle and Strainer, Combined 302 Ladle, Babbitt 264 Ladle for Melting Babbitt 173 Lamp, Acetylene, Lighting 401 Lamp, Arc 132 Lamp Cord, Flexible, Holder for 317 Lamp Cords, Flexible, Clasp for Holding 267 Lamp, Flash, How to Make 174 Lamp, Homemade Pocket 149 Lamp, Incandescent, Experiment with 427 Lamp, Incandescent, Lighting with an Induction Coil 112 Lamp, Quickly Made 329 Lamp Sockets, Miniature Electric. How to Make 270 Lamp Stand and Shade, How to Make 147 Lamps, Electric, Testing 314 Lamps, Miniature Electric 434 Lamps, To Make Burn Brightly 364 Lantern, Camper's Makeshift 266 Lantern, Darkroom, How to Make 14, 340 Lantern, Homemade 163 Lantern, Magic, How to Make 328 Lantern, Magic, Using Sun's Light in 251 Lantern Slide Masks, Cutting 245 Lantern Slides, Blueprint, How to Make 120 Lantern Slides, How to Make 127, 220 Lantern Slides, Tinted, How to Make 144 Lathe, Bench, Made of Pipe Fittings 316 Lathe, How to Make 86 Lathe, Making Gear Wheels without 46 Lathe, Wood Turning, To Make Out of an Old Sewing Machine 403 Lathe Work, Calipering 258 Lathes, Small, Gear Cutting Attachment for 167 Laundry Device--Clothes Rack 14 Laundry Device--Clothesline, Double, Support for 318 Laundry Device--Iron Rest 19 Laundry Device--Iron Rest for an Ironing Board 288 Laundry Device--Ironing Board Stand 17, 429 Laundry Device--Sad Iron Polisher 286 Laundry Device--Washboard Holder 39 Lavatories, Sleeve Holders for 17 Lead Cannon, How to Make 338 Lead, Melting in Tissue Paper 185 Lead Pencil Rheostat, How to Make 145 Leaf, Photograph Printed on 362 Leather Card case, How to Make 350 Leather Hinges, Metal Coverings for 41 Leather on Furniture, Cleaning 13 Leather, Softening 140 Leather Spectacle Case, How to Make 228 Leather, Table Mat of, How to Make 286 Leather Work, Arts and Crafts 168 Letter Holder of Pierced Metal 294 Lettering on a Dark Ground, Paint for 170 Lettering with a Carpenter's Pencil 306 Letters, Glass, Removing from Windows 319 Levitation-Modern Stage Trick 459 Library Set in Pyro-Carving 407 Life Buoy, How to Make 432 Life preserver, Homemade 4 Light Gas without Matches, To 394 Light, Post or Swinging, Homemade 189 Light Trick, Invisible 251 Lightning Arrester, How to Make 122 Lightning, Photographing 124, 176 Lights, Turning On and Off from any Number of Places 310 Linoleum, How to Repair 273 Liquids-Splashes, Study of 164 Lock, Automatic 106 Lock, Electric 60, 110 Lock, Electric, for a Sliding Door 89 Lock, Homemade Pneumatic 65 Lock, Lubricating 151 Lock, Secret Door 6 Lock, Spring, Protection of 72 Lock, Trunk, How to Attach 134 Lock, Window 397 Locking Several Drawers with One Lock 314 Locomotive, Miniature Electric, How to Make 165 Log, To Cross Stream on 94 Lubricant for Wood Screws 137 Lubricate Sheet Metal, To 69 Lubricating a Lock 151
M Machinery, To Remove Grease from 216 Magazine Binder, To Make 406 Magazine Clamp, How to Make 435 Magazine, How to Bind 40, 56 Magic Box Escape 7 Magic-Electric Illusion Box 135 Magic Lantern, Homemade 328 Magic, Old Time 167, 175, 176, 179, 193, 198, 234, 244, 251, 256, 427 Magic, Parlor, for Winter Evenings 90 Magic Spirit Hand 2 Magic-Violin, Making Spirits Play 295 Magnet for the Work Basket 292 Magnifying Glass, Emergency 305 Magnifying Glass, Homemade 397 Mahogany, Filler for 139 Mail Photographs, How to 312 Mail, Sending Coins by 287 Marble, Rolling 191 Massage, Electric Battery 144 Mat, Wrestling 330 Match, Chain Made from 311 Match Holder of Wood and Metal. How to Make 282 Match, How to Relight 444 Match Safe, Homemade 194 Mathematics, Finger 181 Mattresses, Handling 19 Measuring the Height of a Tree 376 Medical Induction Coil, How to Make 63 Mercury Make and Break Connections for Induction Coils 187 Merry-Go-Round, How to Build 359 Merry-Go-Round Swing. How to Make 131 Merry-Go-Round Thriller 209 Merry-Go-Round Whirl on Ice 380 Metal Coverings for Leather Hinges 41 Metal Inkstand, Ornamental 315 Metal, Melting in the Flame of a Match 449 Metal, Pierced, Letter Holder of 294 Metal, Sheet, Sawing 291 Metal, Sheet, To Lubricate 69 Metal, Thin Sheet, Cutting Circular Holes in 35 Metal Whisk Broom Holder 221 Metals, Soft, How to File 406 Metals, Use of Kerosene In Polishing 364 Mice and Rats, Killing 293 Micrometer, Homemade 130 Microscope, Homemade 433 Microscope, Small, How to Make 408 Microscope without a Lens 76 Minnow Trap, How to Make 390 Mirror, Experiments with 434 Model Aeroplanes. Equilibrator for 11 Model Steam Engine 1 Model, Steamboat 216 Model Work, Gasoline Burner for 55 Model Work, Gear for 225 Model Work, Three Way Cock for 50 Mold, Removing from Wallpaper 320 Monoplane Weather Vane 390 Moon, New, photographing 174 Motor, Battery, Controller and Reverse for 72 Motor, Battery, Reversing 405 Motor, Electric 214, 345, 395. 401 Motor, Reversing 105 Motor, Single Phase Induction 124 Motor, Small, Controller for 42 Motor, Small, How to Make 428 Motor, Water 66, 311 Motorcycle Drives Washing Machine 219 Motors, Small, Finding Horsepower of 238 Mouse Trap 112, 198, 293, 395, 450 Music Cabinet, How to Make 77 Music, Furnace, To Transmit to a Distance 107
N Nail Holes, Filling 85 Nail, To Hang Heavy Things on 323 Nails, Iron Shingle, Life of 244 Necktie Holder, Homemade 369 Negatives. Broken, Restoring 377 Nickel, Polish for 112 Nostril, Child's, Removing Button from 237 Nut Cracking Block 290 Nuts, Tightening 155 Nutshell Photograph Novelty 24
O Oak, Fuming of 196 Optical Illusion 74, 99, 130, 183, 206, 348, 364 Optical Top 69 Ornaments, Christmas Tree, Repairing 11
P Packing, Cut from Felt Hats 207 Paint Brushes, Care of 267 Paint, Cause of Sagging 340 Paint for Lettering on a Dark Ground 170 Paint, Old, Removing 396 Paint, Sealing Up 363 Painting an Automobile 357 Painting Over Putty 136 Painting Yellow Pine 151 Paints, To Prevent from Crawling 55 Paints--Water Color Box 257 Pan, Baking 13 Paper Aeroplane, How to Make 329 Paper Bag, Tying to Make a Handle 10 Paper Bags, Use for 19 Paper Boat, How to Make 321 Paper, Gummed, Substitute for 315 Paper, Smoothing after Erasing 29 Paper, To Remove from Stamps 234 Paper under an Inverted Bottle, Withdrawing 33 Parachutes and Darts, Toy 352 Paraffin Wire, How to 161 Pen, Fountain, Ordinary Pen used as 450, 454 Pen, Fountain, Used as a Ruler 319 Pen, Steel, Used in Ink Bottle Cork 117 Pencil, Carpenter's, Lettering with 306 Pens, Corrosion of, Preventing 257 Pens, Leaking Fountain, Remedy for 390 "Pepper's Ghost" Illusion, Miniature 52 Percolator, Plant Food 258 Perfume Making Outfit 363 Phoneidoscope 407 Phonograph Experiment 105 Phonograph, Homemade 289 Phonograph Horn, Paper, How to Make 71 Phonograph Music, To Transmit to a Distance 107 Phonograph Record Cabinet 79, 433 Phonograph Reproducer, Relieving Weight of 245 Phonograph Spring. Broken, Repairing 316 Phonograph, Steadying 214 Phonograph, Thorns Used as Needles on 453 Photograph Letters, Spelling Names with 232 Photograph Mounts, Rough AIligator 424 Photograph Novelty, Nutshell 24 Photograph of a Clown Face 180 Photograph Postcards, Drying 453 Photograph Print Washing Tank 136 Photograph Printed on a Leaf 362 Photograph Prints, Drying Flat 38 Photograph Prints, Drying Without Curling 425 Photograph Prints, Mounting on Glass 231 Photograph Prints, Stretcher for Drying 275 Photographic Jig-Saw Puzzle 361 Photographing a Man in a Bottle 74 Photographing Lightning 124, 176 Photographing the New Moon 174 Photographing the North Star 443 Photographs, Freak, Making of 110, 440 Photographs, How to Mail 312 Photographs in Relief Easily Made 431 Photographs, Mounting in Plaster Plaques 287 Photographs on Watch Dials, Making 386 Photographs. To Print on Silk 396 Photography--Background Frame, Take Down, How to Make 156 Photography--Changing Bag for Plate Holders 212 Photography--Copying Stand 149 Photography--Darkroom Lantern, How to Make 340 Photography--Darkroom, Small, Building 26 Photography--Developing Box, How to Make 220 Photography--Developing Tray 269 Photography--Developing Tray, Cracked, Repairing 260 Photography--Duplicator for Box Cameras 363 Photography--Enlarging from Life in the Camera 111, 117 Photography--Film Negatives, How to Keep 194 Photography--Film Washing Trough 331 Photography--Films, Drying 412 Photography--Films, Frame for Drying 446 Photography-Green Prints, Paper That Makes 157 Photography-Kits for the Camera 159 Photography-Negative Washer, Adjustable, How to Make 143 Photography-Negatives, Broken, Restoring 377 Photography-Paper Stuck to Negative, To Remove 250 Photography-Pictures, Four, on One Plate 46 Photography-Printing Frame Stand 123 Photography-Prints, Overexposed Developing, Saving 16 Photography-Proofs, Making before Negative Dries 33 Photography-Ray Filter, Substitute for 120 Photography-Toning Blue On Bromide and Platinum 31 Photography-Tripod Holder, Homemade 284 Piano, Electric, How to Make 247 Picture Frame, Etched Copper, How to Make 414 Pies, Removing from Pans 275 Pin Ball, How to Make 314 Pine, Yellow, Painting 151 Pipe and Fittings, Hand Car Made of 440 Pipe and Fittings, Hand Sled Made of 305 Pipe Fittings, Bench Lathe Made of 316 Pipe Fittings, Uses for 61 Pipe, Gas, and Fittings, Steam Engine Made from 184 Pipe Rack, Bent Iron 305 Planing Octagonal Wood Pieces, Block for 293 Plant Food Percolator 258 Plaques, Photo Silhouette Brass 217 Plaques, Plaster, Mounting Photos in 287 Plaster of Paris, How to Mix 110 Plaster, Porous, Removing 41 Plate Lifter, Hot 318 Plug, Electric, How to Make 430 Plug, Emergency, Faucet Used as 343 Plug, Fitting in Different Shaped Holes 122 Plumb-Bob Line, Adjusting 229 Pocket Lamp, Homemade 149 Pockets for Spools of Thread 13 Polish, Aluminum 428 Polish for Nickel 112 Polish, Stove 133, 252 Polisher, Floor 10, 350 Polishing Cloths for Silver 32 Polishing Flat Surfaces 229 Polishing Metals, Use of Kerosene in 364 Porch Swing Chair 128 Portfolio, How to Make 225 Portieres, Japanese, How to Make 265 Postcar Holder, How to Make 363 Postcard Projector, Electric 195 Postcard Rack 25 Postcards, Photograph 453 Postcards, Unreadable, Key Card for Writing 35 Pot Cover, Closet 16 Pot Covers, Homemade 297 Pottery Kiln, Homemade 62 Poultry, Feed Box for 292 Poultry Feeder, Alarm Clock 79 Powder, to Explode with Electricity 53 Propelling Vehicle, How to Make 402 Pulley, Grooved, Made from Sheet Tin 412 Pump, Rotary, How to Make 81 Punch. Piercing, for Brass 19 Punching Bag Platform, Adjustable 267 Punt, Homemade 123 Purse, Coin, How to Make 354 Putty, Blacking 376 Putty for Iron Castings 269 Putty Grinder 191 Putty, Painting over 136 Putty, To Preserve 121 Puzzle, Checker Board 189, 233 Puzzle, Dovetail Joint 236 Puzzle, Photographic Jig Saw 361 Puzzle, Wire 378 Pyro-Carving, Library Set in 407
Q Quartz Electrodes Used in Receiving Wireless Messages 170 Querl, Versatile 28 Quilting Frames, Folding 258
R Rabbit Trap, Homemade 233 Rabbit Trap, Self Setting, How to Make 158 Rabbits, Trap for 395 Rack, Bent Iron Pipe 305 Rack, Clothes 14 Rack, Cup and Saucer 105 Rack for Displaying Coins 220 Rack, Postcard 25 Rack, Shoe 146 Radium Affects Glass 116 Rain Gauge, How to Make 64 Rat Exterminator, Electric 358 Rat Traps 290, 395 Rats and Mice, Killing 293 Rats, Keeping from a Chicken Coop 352 Ray Filter, Substitute for 120 Reel, Kite 156 Relay Made from an Electric Bell 94 Rheostat, Battery 80, 445 Rheostat, Lead Pencil, How to Make 145 Rheostat, Water 78 Rheostat, Water, How to Make 43 Ring, Finger, How to Make 39 Ring, Tight Fitting, Removing from Finger 361 Roller Coaster Illusion 293 Roller Skates, Homemade 386 Rope Grills, How to Make 277 Rubber Bands in Kite Balancing Strings 270 Rubber Stamps, How to Make 393 Rubber Tip for Chair Legs 229 Rule and Hammer, Experiment with 106 Ruler, Fountain Pen Used as 319
S Sack Trick 251 Sail, To Attach to a Bicycle 425 Sailomobile, How to Make 326, 415 Sails, Boat, Revolving a Wheel with 152 Sails for Skaters 381 Salad Dressing, Aid in Mixing 16 Sandpaper, To Keep from Slipping 376 Saw, Bracket, How to Make 42 Saw, Homemade Scroll 11 Sawing Sheet Metal 389 Scissors, Removing from a Card 175 Scissors, Sharpening 419 Sconce, How to Make 325 Scoop, Shot 230 Screen, Fire, How to Make 82 Screw, Tightening with Lead 233 Screws, Inserting in Hardwood 318 Screws, Wood, Lubricant for 137 Sealing Wax Bent While Cold 61 Sealing Wax Hatpins, How to Make 175 Seals, Clear Wax Impressions from 450 Searchlight, Self Lighting Arc 9 Searchlight, Small, How to Make 336 Seat, Rustic 441 Settee, Homemade 385 Sewing Bag, How to Make 386 Sewing Machine, Old Wood Turning Lathe Made Out of 403 Screw, To Hold on a Screwdriver 337 Scroll Saw, Homemade 11 Shade, Candle, How to Make 191 Shade, Fastening to a Roller 413 Shade Holder Bracket for a Gas Jet 419 Shaving Mug, Traveler's 9 Shelf Arrangement, Convenient 413 Shelf, Mission Bracket 39 Shelf, Turn Down, for a Small Space 144 Shelf, Window, for Flower Pots 292 Shellac Gum, Dissolving 124 Shocking Machine, Homemade 139 Shoe Horn, Substitute 25 Shoe Rack, Homemade 146 Shoe Scraper 413 Shoes, Skating, How to Make 158 Shoes, White, Cleaner for 239 Shoestring Watch Fob, How to Weave 285 Shot Scoop 230 Shower Bath, Homemade 15 Signals, Covering with Gold Leaf 189 Signals for Fishing Through Ice 10, 380 Silhouette Brass Plaques, Making 217 Silhouettes, How to Make 68 Silk, To Print Photographs on 396 Silver, Cleaning 305, 344 Silver Plating Outfit, Small, To Make 360 Silver, Polishing Cloths for 32 Sink or Bathtub Stopper, Substitute 429 Sizing a Threaded Hole 295 Skate Sharpener, Pocket, How to Make 166 Skater, Winged 381 Skates, Ice, Hollow Grinding 231 Skates, Roller, How to Make 386 Skates, Sharpening with a File 306 Skating Shoes, How to Make 158 Ski, Norwegian 384 Skidoo-Skidee Trick, Scientific Explanation of 162 Skis and Ski-Toboggans, Making 3 Sled, Barrel Stave 383 Sled, Bicycle 157 Sled, Bicycle Coasting, How to Make 231 Sled, Hand, Made of Pipe and Fittings 305 Sled, Toboggan, How to Make 44, 384 Sled, Yankee 408 Sleds, Coaster, Rocker Blocks on 223 Sleeve Bands, Bicycle Trouser Guards as 283 Sleeve Holders for Lavatories 17 Sleigh, Chair 383 Sleigh, Running 381 Sling, Crossbow and Arrow, How to Make 339 Snow House, Eskimo, How to Make 5 Snowshoes, Homemade 9 Solder with Low Melting Point 421 Soldering Clamps, Homemade 137 Soldering for the Amateur 38 Soldering Tool, Emergency 28 Spark Coil, Piercing Glass Plates with 426 Spectacle Case, Leather, How to Make 228 Spit Turned by Water Power 102 Splashes, Study of 164 Spine for Draftsman 406 Spoon Rest for Kettles 24, 304 Sport-Skis and Ski-Toboggans, Making 3 Sports, Winter, Devices of 380 Spring Board for Swimmers 237 Spring, Curtain Roller, How to Tighten 79 Sprocket Wheels, Small, To Make 15 Stage, Miniature, How to Make 159 Stains, Iodine, Removing 425 Stains on Book Leaves, Removing 31 Stamp Pad, Handle for Opening 23 Stamps, To Remove Paper from 234 Star, North, Photographing 443 Static Machine, How to Make 177 Steam Calliope, How to Make 418 Steam Engine Made from Gas Pipe and Fittings 184 Steam Engine, Model 1 Steam Engine, Toy, How to Make 73 Steam Turbine, Homemade 20 Steamboat Model, Simple 216 Steel, Chisel, Annealing 362 Steering Wheel, Heated 441 Stereograph, Principles of 186 Stick Pin, How to Make 164 Still, Homemade 426 Still, Simple, How to Make 170 Stool, Camp, How to Make 222 Storage Battery, Small, How to Make 121 Stove, Electric, How to Make 31, 273 Stove Polish 133, 252 Stovepipe, Cleaner for 230 Stoves, Cleaning 155 Strainer and Ladle, Combined 302 Stream, Crossing on a Log 94 Street Car Line, Imitation, How to Build 374 Sundial, How to Lay Out 261 Sunlight, Using in Magic Lantern 251 Swimmers, Spring Board for 237 Swimming Pool, Concrete 178 Swing and Turning Rings Combined 283 Swing Chair, Porch 128 Swing, Homemade Round 192 Swing, Merry-Go-Round, How to Make 131 Swing Seat, Child's Homemade 276 Switch, Automatic Time 80 Switch, Battery 99 Switch, Electric Pendant, How to Make 310 Switch, Reversing for Electrical Experiments 92 Switch, Simple, for Reversing a Current 111
T Table, Lifting 99 Table Mat of Leather, How to Make 286 Table, Mission Library, How to Make 141 Table Pads, Asbestos 212 Talking Machine Reproducer, Relieving Weight of 245 Tank, Small, Aerating Water in 241 Target, Illuminated 291 Tarnish, Removing 17 Tea Tray, Cheesebox Cover 18 Teeter Board, Revolving 297 Telegraph and Telephone Line, Combination 332 Telegraph Codes 422 Telegraph Instrument and Buzzer, How to Make 334 Telegraph Key and Sounder, How to Make 76 Telegraph Key, Homemade 21, 283 Telegraph Line, One Wire 78 Telegraph, Line, Simple Open Circuit 59 Telephone and Telegraph Line, Combination 332 Telephone Experiment 137 Telephone Receiver, Homemade 55, 353 Telephone, Receiving Wireless Telegraph Messages with 92 Telephone, Singing 75 Telephone Transmitter, Homemade 398 Telephone, Wireless, How to Make 432 Telescope, How to Make 108 Telescope Stand and Holder 218 Telescope, Water, How to Make 410 Tent, Bell, How to Make 190 Tent, Lawn, Quickly Made 398 Tents, Weatherproofing for 389 Thermo Battery, How to Make 59 Thermo-Electric Battery, How to Make 140 Thermometer, Air 152 Thermometer Back in Etched Copper. To Make 246 Thermostat. Small, How to Construct 455 Thorns Used as Needles In a Phonograph 453 Thread, Cutting Inside Glass Bottle 179 Thread Spools, Pockets for 13 Time Alarm, Electric 433 Time Switch, Automatic 80 Tin, Sheet, Grooved Pulley Made from 412 Tinware, Rustproof 347 Tire Repair, Emergency 33 Toaster, Electric, How to Make 37 Toaster, Homemade 139 Toboggan Sled, How to Make 44, 384 Toboggans and Skis, Making 3 Tool, Cutting Point of 278 Tool for Lifting Can Covers 352 Tool Hangers 453 Tool, Soldering 28 Top, Austrian 12 Top, Optical 69 Toy, Child's Rolling, How to Make 224 Toy Darts and Parachutes 352 Toy Flier, How to Make 429 Toy-Skidoo-Skidee, Scientific Explanation of 162 Trailer for a Bicycle 397 Transformer, 110-Volt. How to Make 439 Trap for Rabbits, Rats and Mice, How to Make 395 Trap for Small Animals 82 Trap, Minnow, How to Make 390 Trap, Mouse 112, 198, 450 Trap, Rabbit 233 Trap, Rat 290 Trap, Self Setting, How to Make 158 Trays, Copper. How to Make 180 Tree, Measuring the Height of 376 Tree Top, Building House in 146 Trees, Burning Inscriptions on 45 Trick, Balancing on Chairs 131 Trick, Bottle, Diving 331 Trick, Buttonhole 234 Trick, Cannon Balls, 36, Removing from Handbag 256 Trick, Card. with Tapered Deck 70 Trick, Coin and Card on the First Finger 175 Trick, Coin and Tumbler 378 Trick--Coin, Changing into a Button 234 Trick--Coin, Disappearing 176, 193 Trick--Coin, Moving Under a Glass 214 Trick--Coin, Sticking against Wall 176 Trick--Coins, Dropping in a Glass Full of Water 231 Trick--Coins, Making Stick to Wood 287 Trick--Cord, Buttoned 427 Trick--Electric Illusion Box 135 Trick--Electric Shock, To Give While Shaking Hands 133 Trick--Flowers, Growing 244 Trick--Forks. Balancing on a Pin Head 427 Trick--Handkerchief Mended after Being Cut and Torn 198 Trick--Hat, To Hang on a Lead Pencil 133 Trick--Key, Removing from a Double String 179 Trick, Knot 167 Trick--Knot. Magic 198 Trick--Light, Invisible 251 Trick--Magic Box Escape 7 Trick--Magic Spirit Hand 2 Trick--Marble, Rolling 197 Trick, Mechanical, with Cards 63 Trick--Miniature "Pepper's Ghost" Illusion 52 Trick--Optical Illusions 74 Trick-Paper, Withdrawing from Under an Inverted Bottle 33 Trick-Photograph of a Clown Face 180 Trick, Rising Card 256 Trick, Sack 251 Trick--Scissors. Removing from Card 175 Trick, Skldoo-Skldee 116 Trick, Stage-Levitation 459 Trick-Table, Lifting 99 Trick-Thread, Cutting Inside a Glass Bottle 179 Trick, Vanishing Handkerchief 319 Trick-Violin, Making Spirits Play 295 Trick, Watch 313 Trick, Water and Wine 244 Trick with a Coin in a Wine Glass 167 Tripod Holder, Homemade 284 Trolley Coaster, Homemade Overhead 387 Trousers, Hanger for 143, 369 Trunk Lock. Combination, How to Attach 134 Turbine Engine, How to Make 355 Turbine, Steam 20 Turning Rings and Swing, Combined 283 Turpentine In Cutting Oil 302 Typewriter Ribbons, Renewing 454
V Vacuum Cleaner, New Use for 25 Vacuum, Experiment with 439 Valve, Flush, Repairing a Washer on 344 Varnish for Electric Terminals 375 Vegetables, Preventing Burning in a Pot 14 Vegetable Slicer 413 Vehicle-Automobile, Boy's Homemade 430 Vehicle-Hand Car Made of Pipe and Fittings 440 Vehicle, Propelling, How to Make 402 Vehicle-Wind Propeller, How to Make 415 Violin, Making Spirits Play 295 Vise, Carpenter's Homemade 36 Vise. Hand. How to Make 201, 211, 226, 280, 340 Volcano. Miniature. How to Make 448 Voltammeter, Pocket 330 Voltmeter, Battery 153 Vulcanizing Press for Rubber Stamps 394
W Walking Stick. Electric 413 Wall, Cleaning 375 Wall, Waterproofing 229 Wallpaper, Moldy, Cleaning 320 War Dance, Miniature 255 Washboard Holder 39 Washer on a Flush Valve, Repairing 344 Washers for Emery Wheel Arbors 359 Washing Machine, Driving with Motorcycle Power 219 Watch, Demagnetizing 166 Watch Dial. Illuminating at Night 149 Watch Dials, Making Photographs on 386 Watch Fob, How to Make 12, 223 Watch Fob, Shoestring, How to Weave 285 Watch Trick, Mystifying 313 Water, Aerating In Small Tank 241 Water and Wine Trick 244 Water Bicycle, How to Make 335 Water Candlestick 406 Water Colors, To Prevent from Crawling 54 Water, Drowning a Dog's Bark with 435 Water. Freezing in Pipes 409 Water Motor, Homemade 66, 311 Water Power, Spit Turned by 102 Waterproofing a Wall 229 Water Rheostat 43, 78 Water Supply, Cost of 435 Water Telescope. How to Make 410 Water Wheel Does Family Washing 129 Water Wheel, How to Make 374 Water Wings, How to Make 202 Wax Impressions from Seals 450 Wax Molds, Copies Made by Electrodeposltion 157 Weather Vane, Monoplane 390 Weatherproofing for Tents 389 Weights for Athletes, How to Make 274 Wheel, Revolving with Boat Sails 152 Wheels, Front, of an Automobile, Greasing 320 Wheels, Sprocket, To Make 15 Whisk Broom Holder, Sheet Metal 221 Wind Propeller, How to Make 415 Wind Vane, Electric Indicator for 348 Windmill for Practical Purposes, How to Make 399 Windmill, Miniature, How to Make 333 Windmill, Musical 74 Windmill, Stationary, How to Make 445 Window Attraction--Fish and Birds Illusion 239 Window Boxes, Rustic 30 Window Conservatory 103 Window Display 22 Window Lock 397 Window Shade, Fastening to a Roller 413 Window Shade, Repair for 229 Window Shelf for Flower Pots 292 Window Stick 450 Windows, Removing Glass Letters from 319 Windows, To Keep Free from Frost 354 Wings, Water, How to Make 202 Winter Sports, Devices of 380 Wire, Aluminum, Insulating 306 Wire Connections, Flexible, Forming Coils to Make 443 Wire Loop Connections for Battery Binding Posts 449 Wire, Paraffin, How to 161 Wire Puzzle 378 Wire, Removing Insulation from 213 Wire Terminals for Battery Connections 168 Wireless Coherer, Easily Made 77 Wireless Messages, Quartz Electrodes Used In Receiving 170 Wireless Systems, Simple 54 Wireless Telegraph, How to Make 84, 121 Wireless Telegraph Messages, To Receive with a Telephone 92 Wireless Telegraph, Short Distance 102 Wireless Telephone, How to Make 432 Wires, Drawing Into Fixtures 13 Wires, Flexible Electric, Adjuster for 386 Wondergraph, How to Make 436 Wood Pieces, Octagonal Wood, Block for 293 Wood, Staining 221 Woodwork, Cleaning 315 Work Basket, Homemade 22 Work Basket, Magnet for 292 Workbench for the Amateur 226 Workbench, Homemade 442 Wrestling Mat 330 Writing with Electricity 74
X X-Ray Experiment 190 X-Ray Instrument, Homemade 151
Y Yacht, Ice, How to Build 307
Z Zincs, Old Battery, To Use 87