Class / 7 / ft. long is used for a keel, or backbone, and is cut tapering for about a third of its length, toward each end, and beveled on the outer edges (A, Fig. 2). The cross-boards (B, B, Fig. 2) are next sawed from a pine board 1 in. thick. Shape these as shown by A, Fig. 1, 13 in. wide by 26 in. long, and cut away in the center to avoid useless weight. Fas- ten them cross-wise to the bottom- board as shown in Fig. 1 and 2, with long stout screws, so as to divide the keel into three nearly equal parts. Then add the stem and stern pieces | ( . I , Fig. 2). These are belter, probably, when made of green elm. Screw the pieces to the bottom-board and bend them, as shown in Fig. 2, by means of a string or wire, fastened to a nail driven into the bottom. Any tough, light wood that is not easily broken when bending will do. Green wood is preferable, because it will retain the shape in which it has been bent better after drying. For the gunwales (a, a, Fig. :!), procure at a carriage factory, Details of F k Construction POPULAR MECHANICS or other place, some light strips of ash, % in. thick. Nail them to the cross- boards and fasten to the end pieces (C, C,) in notches, by several wrap- pings of annealed iron wire or copper wire, as shown in Fig. 3. Copper wire is better because it is less apt to rust. For fastening the gunwales to the crossboards use nails instead of screws, because the nails are not apt to loosen and come out. The ribs, which are easily made of long, slender switches of osier willow, or similar material, are next put in. but before doing this, two strips of wood d>, b. Fig. 3) should be bent and placed as in Fig. 3. They are used only temporarily as a guide in put- ting in the ribs, and are not fastened, the elasticity of the wood being suffi- cient to cause them to retain their po- sition. The osiers may average a lit- tle more than ] - in. in thickness and should be cut, stripped of leaves and bark and put in place while green and fresh. They are attached to the bottom by means of shingle nails driven through holes previously made in them with an awl, and arc then bent down until the}- touch the strips of ash (b, b. Fig. .'!). and finally cut off even with the tops of the gunwales, and notched at the end to receive them (B, Fig. 1). Between the cross-boards the ribs are placed at intervals of 2 or 3 in., while in other parts they are as much as 5 or fi in. apart. The ribs having all been fastened in place as described, the loose strips of ash (b, b, Fig. 3) are withdrawn and the framework will appear some- what as in Fig. 1. In order to make all firm and to prevent the ribs from changing- posi- tion, as they are apt to do, buy some split cane or rattan, such as is used for making chair- bottoms, and, after soaking it in water for a short time to ren- der it soft and pliable, wind it tightly around the gunwales and ribs where they join, and also interweave it among the ribs in other places, winding it about them and forming an irregular network over the whole frame. ( Isiers probably make the best ribs, but twigs of some other trees, such as hazel or birch, will answer nearly as well. For the ribs near the middle of the boat, twigs 5 or (i ft. long are re- quired. It is often quite difficult to get these of sufficient thickness throughout, and so, in such cases, two twigs may be used to make one rib, fastening the butts side by side on the bottom-board, and the smaller ends to the gunwales, as before described. In drying, the rattan becomes very tight and the twigs hard and stiff. The frame-work is now complete and ready to be covered. For this purpose buy about IS yd. of very strong wrap- ping-paper. It should be smooth on the surface, and very tough, but neither stiff nor very thick. Being made in long rolls, it can be obtained in almost any length desired. If the paper be 1 yd. wide, it will require about two breadths to reach around the frame in the widest part. Cut enough (1 f the roll to cover the frame and then soak it for a few minutes in water. Then turn the frame upside down and fasten the edges of the two strips of paper to it, by lapping them carefully on the under side of the bottom-board and tacking them to it so that the paper hangs down loosely on all sides. The paper is then trimmed, lapped and doubled over as smoothly as possible at the ends of the frame, and held in place by means of small clamps. It should be drawn tight along the edges, trimmed and doubled down over the gunwale, where it is firmly held by slipping the strips of asli (b, b) just inside of the gunwales into notches which should have been cut at the ends of the cross-boards. The shrinkage caused by the drying will stretch the paper tightly over the framework. When thoroughly dry, varnish inside and out with asphaltum varnish thinned with turpentine, and as soon as that has soaked in, apply a second coat of the same varnish, but with less turpentine; and finally cover the laps or joints of the paper with pieces of muslin stuck on with thick varnish. Now remove the loose strips (if ash and put on another layer of paper, fastening it along the edge of the boat by replacing the strips as be- fore. When the paper is dry, cover the laps with muslin as was done with the first covering. Then varnish the whole outside of the boat several times until it presents a smooth shining surface. Then take some of the split rattan and, after wetting it, wind it firmly around both gunwales and inside strip, pass- ing it through small holes punched in the paper just below the gunwale, until the inside and outside strips are bound together into erne strong gunwale. Then put a piece of oil-cloth in the boat between the cross-boards, tacking it to the bottom-board. This is done to protect the bottom of the boat. Now you may already have a canoe that is perfectly water-tight, and steady in the water, if it has been properly constructed of good material. If not. however, in a few days you may be disappointed to find that it is becoming leaky. Then the best remedy is to cover the whole boat with unbleached muslin, sewed at the ends and tacked along the gunwales. Then tighten it by shrinking and finally give it at least three coats of a mixture of varnish and paint. This will doubtless stop the POPULAR MECHANICS 1 caking entirely and will add but little ti i either the weight or cost. Rig the boat with wooden or iron rowlocks (B, B, Fig. 5), preferably iron, and light oars. You may put in several extra thwarts or cross-sticks, fore and aft, and make a movable seat (A, Fig. 5.) With this you will doubt- less find your boat so satisfactory that you will make no more changes. For carrying the boat it is convenient to make a sort of short yoke ( C, Fig. 5), which brings all the weight upon the shoulders, and thus lightens the labor and makes it very handy to carry. To Hang Heavy Things on a Nail lioys will find many places around the house, where a hook to hang things on will be a great convenience. Instead of buying hooks use wire nails, and if driven as shown in the cut, they will support very heavy weights. Drive the lower nail first. POPULAR MECHANICS A Home-Made Elderberry Huller As we had only one day to pick elderberries, we wanted to get as many of them as we could in that time. We could pick them faster than they could NATURAL. SIZE OF WIRE Details of the Elderberry Huller be hulled by hand so we made a huller to take along with us to hull the ber- ries as fast as they were picked. We procured a box and made a frame. Fig. 1, tci fit it easily, then made another frame the same size and put a piece of wire mesh between them as shown in Fig. '.'. allowing a small portion of the mesh to stick out of the frames. The top frame would keep the berries from rolling or jumping off, and the bottom frame kept the wire mesh and frame from being shaken off the box. The projecting edges of the mesh would keep the frame on the top edge of the box. The top view of the frame is shown in Fig. 1 and the end in Fig. 5, and the box on which the frame rests in Fig. 3. The actual size of the wire mesh used is shown in Fig. 1. One person could hull with this huller as many berries as two persons would pick. — Contributed by Albert Niemann, Tittsburg, Pa. How to Make a Bulb on a Glass Tube As a great many persons during the winter months are taking advantage of the long evenings to experiment in one way or another, the following method of forming bulbs on glass tubes may be of interest. A common method is to heat the part to be formed and by blowing in one end of the tube grad- ually expand the glass. This way has its drawbacks, as many are not suf- ficiently familiar with the work to blow a uniform blast, and the result is, a hole is blown through the side of the tube by uneven heating or blowing. A good way to handle this work, is to take the tube and 1 or 2 in. more in length than the finished article is to be and place one end over an alcohol flame, and by holding a spare piece of tubing against the end allow them both to come to a melting heat, then pull apart and instead of breaking off the long thread thus formed, simply hold it in the flame at an angle of 45 deg. and melt it down and close the end at the same time. Close the other end with the same operation ; this makes the tube airtight. Gradually heat the tube at the point where the bull) is to be formed, slowly turning the tube to get a uniform heat. The air inside of the tube becoming heated will expand, and the glass, be- ing softer where the flame has been applied, will be pushed out in the shape of a bulb. A great deal of care should be taken not to go to extremes, as the bulb will burst with a loud report if the heat is applied too long. The best results are obtained by heating the glass slowly and then the bulb can be formed with regularity. This is an POPULAR MECHANICS easy way to make a thermometer tube. After the bulb is formed, the other end of the tube can be opened by heating, drawing out and breaking the thread like glass. — Contributed by A. Oswald. center along concentric rings outward, then reverse. The candle holders may have two, three, four, or six arms, and are bent tn shape by means of the round-nosed How to Make a Sconce A sconce is a candlestick holder, so made that it has a reflector of brass or copper and is to hang upon the wall. The tools necessary are a riveting- hammer, hie, metal shears, rivet punch, flat and round-nosed pliers, screwdriver and sheet brass ur cupper No. 23 gauge. To make the sconce proceed as fol- lows :' First, cut off a piece of brass so that it shall have V2 ' n - extra metal all amund; second, with a piece of carbon paper, trace upon the brass Hues that shall represent the margin of the sconce proper, also trace the decorative de- sign ; third, with a nailset make a series of holes in the extra margin about :;/ ( in. apart and lar^e enough to take in a %-in. thin screw; fourth, fasten the metal to a thick board lu T inserting screws in these holes: fifth, with a twenty-penny wire nail that has had the sharpness of its point filed off, stamp the background of the design promiscuously. By holding the nail about ' 1 in. above the work and strik- ing it with the hammer, at the same time striving to keep its point at ' 1 in. above the metal, very rapid progress can be made. This stamping lowers the background and at the same time raises the design. Sixth, chase or stamp along the border of the design and background using a nail tiled to a chisel edge. This is to make a clean sharp division between background and design. Seventh, when the stamping is complete remove the screws and metal from the board and cut off the extra margin with the metal shears. File the edges until they are smooth to the ti null. The drip cup is a piece of brass cut circular and shaped In- placing the brass over a hollow in one end of a block. Give the metal a circular mo- tion, at the same time beat it with a round-nosed mallet. Work from the Completed Sconce Shaping the Holder; Riveting pliers. Tin' form of the brackets which support the drip cups may be seen in the illustratii m. I raving pierced the bracket, drip cup, and holder, these three parts are riveted together as indicated in the drawing. It will be found easier usually if the holder is not shaped until after the riveting is done. The bracket is then riveted to the back of the sconce. Small copper rivets are used. It is better to polish all the pieces before fastening any of them together. Metal pi ilish ( >f any kind will di >. After the parts have been assembled a lac- quer may be applied to keep (he metal from tarnishing. 10 POPULAR MECHANICS How To Make a Hectograph A hectograph is very simply and eas- ily made and by means of it many copies of writing can be obtained from a single original. Make a tray of either tin or paste- Making Copii ith the Hectograph board, a little larger than the sheet of paper you ordinarily use and about % in. deep. Soak 1 oz. of gelatine in cold water over night and in the morning- pour oil' the water. Meat 6% oz. of glycerine to about 200 deg. F. on a water hath, and add the gelatine. This should give a clear glycerine solution ■ if gelal ine. Place the tray so that it is perfectly I> vel and pour in the gelatinous com- position until it is nearly level with the edge of the tray. Cover it so the cover does not touch the surface of the composition and let it stand six hours, w hen it w ill l>e ready for use. Make the copy to be reproduced on ordinary paper with aniline ink; using a steel pen. and making the lines rather heavy so they have a greenish color in the light. A good ink may be made of methyl violet 2 parts, alcohol 2 parts, sugar 1 part, glycerine I parts, and wa- ter 24 parts. Dissolve the violet in the alcohol mixed with the glycerine; dis- solve the sugar in the water and mix 1h ith solutions. When the original copy of the writ- ing is ready moisten the surface of the hectograph slightly with a sponge, lay the copy face down upon it and smooth down, being careful to exclude all air bubbles and not shifting the paper. Leave it nearly a minute and raise one corner and strip it from the pad, where will remain a reversed copy of the in- scription. Immediately lay a piece of writing paper of the right size on the pad, smooth it down and then remove as be- fore. It will bear a perfect copy of the original. Repeat the operation until the number of copies desired is ob- tained or until the ink on the pad is exhausted. Fifty or more copies can he obtained from a single original. When through using the hectograph wash it off with a moist sponge, and it .will be ready for future use. If the surface is impaired at any time it can he remedied in a water hath and poured into a tray as before, if it has not ab- si irbed t< io much ink. How to Make a Sailomobile By Frank Mulford. Shiloh, N. J. I had read of the beach automobiles used on the Florida coast; they were like an ice boat with a sail, except they had wheels instead of runners. So I set to work to make something to take me over the country roads. I found and used seven fence pickets for the frame work, and other things as they were needed. I spliced two rake handles together for the mast, winding the ends where they came to- gether with wire. A single piece would he better if you can get one long enough. The gaff, which is the stick to which the upper end of the sail is fastened, is a broomstick. The boom, the stick at the bottom of the sail, was made of a rake handle with a broom- stick spliced to make it long enough. .Mother let me have a sheet, which I put down on the floor and cut in the shape of a mainsail. The wind was the cheapest power to he found, thus it was utilized ; the three wheels were cast-off bicycle wheels. I steer with the front wheel, which was the front wdieel of an old bicycle POPULAR MECHANICS 11 with the fork left on. The axle be- tween the rear wheels is an iron bar which cost me 15 cents, and the pulley were the tools used. Slats made the seat and a cushion from the house made it comfortable, and in a week every- which raises and lowers the --ail oust 5 cents. Twenty cents was all I spent, all the rest 1 found. A saw, hammer, and brace and bit Country Roads thing was ready for sailing. < 'nee it was started with only my lit- tle cousin in it and 1 had to run fast ti > catch up. 12 POPULAR MECHANICS Jug Line Fishing Jug line fishing is fine sport and often successful where other methods fail. It is more often used on rivers on ac- count of the current. Fasten two jugs to a strong line about 30 ft. long. Be sure that each jug is securely corked. To the long line attach a couple or more of short fish lines equipped with proper sinkers and baited hooks. This done, place the outfit in the water and watch it, ready to follow with a row boat, or let it float down stream at- tached to a line held in the hand. When one of the jugs sinks or commences to bobble, you can row out to the line and -=w. Jugs Bob Up nd Do n Catch pull in the fish. On the Mississippi river dozens of jugs are often thus tied together and the fisherman follows them in a row boat until he has a good boat load of fish. How to Make a Miniature Steam Turbine With an old toy steam engine boiler and a little work a steam turbine can easily be made. When you have the boiler the next thing to do is to make a disk of wood about Vt in. thick and 3 l /> in. in di- ameter. M ark twelve p o i nts around the edge of the cir- cle of wood, the points being at equal intervals all the way a r o u n d. Cut with a fine saw 3/1(1 in. at each of these points. Twelve paddles should then be made of s h e e t copper or brass and cut in the shape of the fig- ure shown at A in the sketch. Then wedge the paddles tightly into the saw cuts and bend them into the shape of a spoon. For the axle take a wire nail, cut off the head and sharpen each end to a fine point. Force the nail securely into a central hole in the disk. Now we may go back to the boiler. As there is generally a small piece of brass tubing left on the side of a boiler, which was formerly connected to the steam engine, this piece may now be joined to a 1 or 5 in. length of rubber tubing and bound with wire. The rub- ber pipe is then attached in the same manner to a piece of metal tube bent into the shape shown in the drawing and fastened to the base with a staple. In mounting the wheel make two blocks of wood each 3 in. high, 1 - in. thick and 1 in. wide. ( >n the flat end of one of the blocks screw a small plate of sheet brass and punch a very tiny hole which should fit the point of the axle. For the opposite bearing file off the point of a 1 -in. screw and also make a small hole in the end of this to fit POPULAR MECHANICS the other point of the axle. Then put the screw into the second block at the same height as the hole in the piece of brass on the first block. Fasten these bearings to a base made of a board 1 ft. long- and 6 in. wide. A fairly good idea of the way the wheel is to be mounted may be obtained from the sketch. The turbine is now complete and ready to run. Meat is obtained from an alcohol lamp or Bunsen burner and when under full steam the wheel will revolve with considerable rapidity. — Contributed by E. 11. Klipstein, East ( (range, N. J. How to Make a Pair of Dumb-Bells Any boy can make a pair of dumb- bells for himself and a lifting weight, also, which will do quite as well as any he could purchase, providing he does his work carefully. First procure two large tin cans, such as fruit is often canned in, and cut the ends out of each. Shape four round pieces nf wood just large enough to fit tightly in the ends of the cans and then cut a hole in the center of each piece of wood as shown in Fig. 1. Procure, also, a hardwood bar the length of the ordinary dumb-bell — a length of old broom handle will do very well. For filling the cans mix 1 part of ce- ment with 2 parts of sand and add wa- ter until it is soft, but still has a de- gree of firmness. Pack this closely length of rod between (Fig. 2). It is well to first string the two inner disks on the bar and then drive a few nails through each end of it before pushing into the cement, to give it a grip. The disks are then pushed along the rod to 0= stage let the bells stand for five days or until the cement is perfectly dry, then remove bits nf wood and tin until only the cement is left. Cement dumb-bells may be filed into shape as in Fig. •'!. anil painted, also, if desired. Figure I shows a lifting weight made of cement. Its construction is very simple. The cement is packed into a wooden mould previously prepared and an iron rod with a ring is thrust in at the top. When the cement is dry the wi oden mould is removed. A cocoanut mav be easily broken by making two holes in the shell, extract- ors! ^sr*--- Cemen-t L/_y_/ rV-~ ^\~/T~ ' Cerwf ot 3 Details of Dumb-Bell Constr into the cans and insert the wooden disks into the ends of the cans. Insert the hardwood bar through the holes in the inside disks so that it runs clear through the center of each can ment, and joins the cans with a proper ing the milk, applying air pressure by blowing in the holes and quickly throwing it to the floor. Never change a single ball in a bear- ig. Renew them all. POPULAR MECHANICS A Home-Made Magic Lantern The essential parts of a magic lantern are a condensing lens to make the beam of light converge upon the slide to illuminate it evenly, a projecting lens with which to throw an enlarged pic- ture of the illuminated slide upon a screen and some appliances for pre- serving the proper relation of these parts to each other. The besl ol materials should be used and the parts put together with care to produce a clear picture on the screen. The first to make is the lamp house oi box to hold the light. Our illustra- tion shows the construction for an electric light, yet the same box may be used for q;is or an oil lamp, provided the material is of metal. A tin box having dimensions somewhere near those given in the diagrammatic sketch may be secured from your local grocer, but if such a box is not found, one can be made from a piece of tin cut as shown in Fig. 1. When this metal is bent at right angles on the dotted lines it will form a box as shown in Fig. 2 which is placed on a baseboard, Y* to 3 /± in. thick, 8 in. wide, and 14 in. long. This box should be provided with a reflector located just back of the lamp. Procure a plano-convex or a bi-con- vex 6-in. lens with a focal length of from 15 to 20 in. and a projecting lens 2 in. in diameter with such a focal length that will give a picture of the required size, or a lens of 12-in. focus enlarging a 3-in. slide to about (i ft. at a distance of 24 ft. The woodwork of the lantern should be of '--in., well seasoned pine, white wood or walnut and the parts fastened together with wood screws, wire brads, or glue, as desired. The board in which to mount the condensing lens is 16 in. wide and 15 in. high, battened on both ends to keep the wood from warping. The board is centered both ways, and, at a point 1 in. above the center, de- scribe a 9-in. circle witli a compass and saw the wood out with a scroll or key- hole saw. If a small saw is used, and the work carefully done, the circular piece removed will serve to make the smaller portion of the ring for holding the condensing lens. This ring is made up fii mi two rings, A and B, Fig. 3. The inside and outside diameters of the ring B are % in. greater than the cor- responding diameters of ring A, so when fastened together concentrically an inner rabbet is formed for the recep- tion of the lens and an outer rabbet to tit against the board C in and against which it rotates being held in place by buttons, DD. Magic Lantern Details POPULAR MECHANICS A table, E, about 2 ft. long is fas- tened to the board C with brackets F and supported at the outer end with a standard. The slide support, G, and the lens slide, H, are constructed to slip easily on the table, E, the strips II serving as guides. Small strips of tin, J J, are bent as shown and fastened at the top and bottom of the rectangular opening cut in the support G for hold- ing the lantern slides. All the parts should be joined to gether snugly and the movable parts made to slide freely and when all is complete and well sandpapered, apply two coats of shellac varnish. Place the lamphouse on the bottom board be- hind the condensing lens and the lantern is ready for use. The proper light and focus may be obtained by slipping the movable parts on the board E, and when the righl position is found for each, all lantern slides will produce a clear picture on the screen, if the position of the lantern and screen is not changed. — Con- tributed by Stuart Mason Kerr, St. Paul, Mimi. A Quickly Made Lamp A very simple lamp can be made from materials which are available in practically every household in the fol- lowing manner: A cheap lTiss tumbler is partly filled with water and then about 1 L . in. of safe, light burning nil, placed on the water. Cut a thin strip from an ordinary cork and make a hole in the center to carry a short piece of wick. The wick should be of such a length as to dip into the oil, but not long enough to reach the water. The upper surface of the cork may be protected from the flame with a small piece of tin bent over the edges and a hole punched in the center for the wick. The weight of the tin will force the cork down into the oil. The level of the oil should be such as to make the flame below the top of the tumbler and the light then will not be blown out with draughts. The ar- rangement is quite safe as, should the glass happen to upset, the water at once extinguishes the flame. — Contrib- uted bv G.' P. B. How to Make a Paper Aeroplane A very interesting and instructive toy aeroplane can be made as shown in the accompanying illustrations. A sheet Folding the Paper of paper is first folded. Fig. 1, then the corners on one end are doubled over, Fig. ".', and the whole piece finished up and held together with a paper clip as in Fig. •'!. The paper clip to be used should be like the one shown in Fig. 4. If one of these clips j> not at hand, form a piece of wire in the same shape, as it will be needed for balancing pur- as well as for holding the paper together. Grasp the aeroplane between the thumb and forefinger at the place marked A in Fig. ■'!, keeping the paper as level as possible and throwing it as you would a dart. The aeroplane will make an easy and graceful flight in a room where no air will strike it. — Con- tributed bv T. H. Crawford, Schenec- tady, N. Y. Banana oil or amyl acetate is a bronze liquid. POPULAR MECHANICS How to Make Your Own Fishing Tackle If yuu want to fish and engage in siime other spurt at the same time, you Fig. 1— The Fishing S< should by all means have a fishing semaphore. This instantly shows from a distance when a fish is on the hook, and any boy c a n m a k e it. The line may be bailed and set, a n d the fisher can give his at- tention ti i other thin g s, with n n 1 y an i icca- sinnal glance at the signal. To make the semaphore lake a piece of board about 12 in. square and '.' in. thick. If a single piece cannot be obtained, build a block of this size i nit i if small stuff. Bore a hole in the center 1 in. in diameter and drive a piece of timber 3 in. square and 12 or 15 in. long into it. Now take a piece of wood 2 in. wide and ■"> in. long for the semaphore and round two of the cor- ners, as shown in the cut. Bore a small hole 2V2 i' 1 - from the tapered end and fasten the board to the scantling by Toy Fishing W%B "■■■ 5. JRWW XYJ> j&jfTM&y or JW&Z- mar: M."*— S- Fig. 3— Method of Making a Trout Rod driving a small round nail at A (Fig. 1). Drive another nail at 1'.. leaving the nail head protrude >-j in. from the upright to serve as a rest for the sema- phore. The board should be made to turn easily on the pivot nail. At C fasten a strip of thin sheet iron, bent flat at the top, so as to support the semaphore in place when it is sprung — ■ that is, when it rises to indicate a fish is caught. The free end of this strip or spring rests on the outside of the semaphore when it is down, and sup- ports it when it is up. It should not press too tightly against the signal. At D drive a small nail and attach the fish- ing line. When the fish takes the hook it will throw the signal up to a horizon- tal position and the spring C will hold it there. The semaphore may be painted red, or white, or to bear the 'vi ird "Fish." Bass and pickerel have an irresistible hankering for bait mi a hook trolled by toy boats. These boats serve the pur- pose, however rudely made, and one boy can operate a whole fleet of them, if lie has a large boat by which he can row to any one of the small boats imme- diately when he notes a fish is hooked. The lioats can be made of a piece of plank, say '.' ' L . ft. long. The board should be sharpened at one end and rigged up with a couple of cloth masts (Fig. "'). The most important part of the craft is the rudder. This should be very long, to prevent the boat from making leeway and to keep it from changing its course. Drive a couple of nails in the stern of the boat, to which tie the fish lines, hooked with spoon or live bait. The small boat does not scare the fish as a large one does, and the bait pulled along by it is wonder- fully attractive to members of the finny tribe, especially when trolled before the wind. If proper fishing tackle is not acces T sible, it is very easy to manufacture it yourself. To make a trout rod first secure a long, straight, elastic pole, such as can be found in nearly any wood. Then secure some pins and a small piece of wire. File off the heads of the pins and bend them in the shape of the letter U and drive them in the rod on the same side at regular intervals, be- POPULAR MECHANICS 17 ginning at about 2 1 /-. ft. from the butt end of the pole. Drive the pins just far enough in to permit the line to pass freely under the loop. To make the tip bend a circular loop in the center of a piece of wire and knot or bind the wire to the end of the pole, as shown in the illustration (Fig. 3). If you have plenty of wire, it will make better 1. h .ps than the pins. Cut the wire into short pieces about 3 in. long, loop each piece in the center. Then with more wire or with strong, waxed thread, bind the ends lengthwise on the rod, as shown in the illustration (Fig. •'!). After the binding is secure, twist each loop around to its proper position. A large wooden spool, an old tin can and a thick wire will serve to make an Al reel. Run the wire through the spool and wedge it tightly so that 1 in. protrudes at one end and 3 in. at the other. From a tin can cut a piece of tin of the shape shown in Fig. I. Two protruding parts are left on each side to be bent up for side pieces, to serve as rests for the axle. After the side pieces are bent up in the proper shape, punch a hole in each and insert the ends of the wires through the holes. See that the spool revolves freely, and then bend the long end of the wire in the shape of a crank. Hammer the tin over the rod until it takes the exact curve of the rod and fits snugly. Then bind it firmly to the rod with strong twine. It is difficult to make a fish hook, though many good perch and cats have been caught with bent pins. A strong steel wire can be bent and filed to a point and a notch filed above the point for the barb. Fish hooks have been made of birds' claws. The claw is bound to a piece of shell by vegetable fiber. None of these home- made hooks are satisfactory, however, Simple Minnow Net and it is better to carry a good supply with you. Inside the hat band is a good place to carry small hooks. Live minnows are the best bait for black bass, pickerel and many other kinds of fish, and to catch live min- nows you need a net. (Due of the sim- plest minnow nets is made by fasten- ing two sticks to the ends of a stout piece of mosquito bar. If desired, the net may lie provided with floats at the top edge and sinkers at the bottom, as in the illustration ( big. •">). ( >ld sieves and pieces of meshed wire can often be transformed into ideal minnow nets. A good landing net may be made from a forked stick and a piece of strong mosquito bar, or preferably a ball of twine. Mend the two ends of the fork until the ends overlap each other and bind them tightly together, as shown in the cut (Fig. 6). Waxed twine serves best in all such binding work in making reels, nets and other tackle. Xow, if the net is to lie made POPULAR MECHANICS of mosquito bar, sew the mosquito bar into the shape of a bag and fasten the mouth to the sides of the loop described by the connected forks of the stick. A better net is made from twine. Fasten Weaving the Scoop Net the pole in a handy place, with the hoop suspended vertically a little higher than your neck. Cut a number of pieces of twine each about 8 ft. long. Double each piece and slip it on the loop with the loose ends hanging down. Arrange the double strings this way all around the loop. Now begin from a convenient point, take a string from each adjoining pair and make a simple knot of them, as shown in the diagram (Fig. 7). Continue all the way around the loop, knotting the strings together in this manner. Now begin on the next lower row, and so on until a point is reached where you believe the net ought to commence to narrow or taper down. This is accomplished by knot- ting the strings a little closer together and cutting off one string of a pair at four equidistant points in the same row. Knot as before until you come to a clipped line ; here take a string from each side of the single one and knot them, being careful to make it come even with others in the same row. Be- fore tightening the double knot pass How to Fasten a Minnow on a Hook the single string through, and after tying a knot close to the double one, Continue as before until the row is finished, only changing from the first plan when a single string is reached. Proceed in the same manner with the next and the next rows, diminishing the number of strings remaining until the remaining ones meet at the bottom. Be careful not to let one drop mesh come directly under another of the same kind. A bucket or old tin can with the top and sides perforated b y means of a nail and hammer (Fig. 8), will serve as ami n n o w bucket. The illustra- tion (Fig. 9) shows the proper way to bait a live minnow. The mouth of the minnow no feeling in it, and when thus baited the minnow is not killed and swims about promiscuously, thus standing a much better chance of catching a fish than when cruelly mangled by the hook of the ignorant fisherman. a hook with cartilaginous has little or How to See Through Your Hand Roll a tube out of a piece of paste- board about 5 in. square, having one end just large enough to fit around the eye and the other slightly smaller. Take the tube between the thumb and finger of the right hand and put the large end close against the right eye. Hold your left hand against the other end of the tube and keep both eyes open. There will appear to be a hole through your hand and objects beyond it will be plainly visible. The left eye is actually doing all the seeing of ob- jects beyond, but it will seem like the right eye sees them, too, through the hand. Always put a washer on a lag-screw before turning it into the wood. cut the stnm close as at A. It is not economy to save emery wheels by neglecting to keep them true and sharp. POPULAR MECHANICS A Film Washing Trough The washing of films without scratch- ing them after they are developed and fixed is very difficult in hot weather. A convenient washing trough for washing full length films is shown in the accompanying sketch. The trough must be made for the size of the film to be washed. Cut a *4-in. board as long as the film and a trifle wider than the film's width. Attach strips to the edges of the board to keep the water from spilling over the sides. Cut a hole in one side of a baking- powder can about half way between the top and bottom, large enough to admit a fair-sized stream of water from a faucet. Then solder the cover to the can and punch a number of holes about % in. apart along the opposite side from where the large hole was cut. Place this can on one end of the trough, as shown, with the large hole up. Some heavy wire bent in the shape of a U and fastened to the under side of the trough at the can end will fur- nish supports to keep that end of the trough the highest and place the open- ing in the can close beneath the water faucet. A common pin stuck through C.Br :, *%\«r*t "5 * Am S v w r .i t- Bur glass a it wood work done with an ordinary reading nd the sun's rays. one end of the film and then in the trough close to the can will hold it in position for washing. Five minutes' washing with this device is sufficient to remove all traces of the hypo from the film.— Contributed by M. M. Hunt- ing, Dayton, O. Negative Film The Diving Bottle This is a very interesting and easily performed experiment illustrating the transmission of pressure by liquids. Take a wide-mouthed bottle and fill almost full of water ; then into this bot- tle place, mouth downward, a small vial or bottle having just enough air in the bottle to keep it barely afloat. Put a sheet of rubber over the mouth of the large bottle, draw the edge down over the neck and wrap securely with a piece of string thus forming a tightly stretched diaphragm over the top. When a finger is pressed on the rubber 20 POPULAR MECHANICS the small bottle is caused by the pres- sure transmitted through the water, thus causing the volume of air in the small tube to decrease and the bottle to descend and ascend when released as the air increases to the original volume. This experiment can be performed with a narrow-necked bottle, provided the bottle is wide, but not very thick. Place the small bottle in as before, tak- ing care not to have too much air in the bottom. If the cork is adjusted prop- erly, the bottle may be held in the hand and the sides pressed with the fingers, thus causing the small bottle to descend and ascend at will. If the small bottle used is opaque, or an opaque tube such as the cap of a foun- tain pen, many puzzling effects may be obtained. — Contributed by John Shahan, Auburn, Ala. How to Make an Inexpensive Wooden Fan Select a nice straight-grained piece of white pine about \\ in. thick. :t ( in. wide and -1 in. long. Lay out the design desired and cut as shown in Fig. 1, and then soak the wood in hot water to make it soft and easy to split. Cut the divisions very thin with a sharp knife down to the point A, as shewn in the sketch, taking care not to split the w 1 through the part left for the handle. The fan is then fin- ished by placing each piece over the other as in Fig. 2. This will make a very prettv ornament. — Contributed by Fred W. Whitehouse, Upper Troy, N. Y. Combination Telegraph and Tele- phone Line The accompanying diagrams show connections for a short line system Cutting the Wood and Complete Fan Wiring Diagram (metallic circuit) of telegraph where a telephone may be used in combination on the line. The telephone receivers can be used both as receivers and trans- mitters, or ordinary telephone trans- mitters, induction coils and battery may be used in the circuit with a receiver. If a transmitter is used, its batteries may be connected in circuit with a common push button which is held down when using the telephone. On a ]000-ft. line, four dry cells will be suffi- cient for the telegraph instruments and two cells for the telephone. — Contrib- uted by D. W. Miller. POPULAR MECHANICS How to Make a Miniature Windmill The following description is how a miniature windmill was made, which gave considerable power for its size, even in a light breeze. Its smaller parts, such as blades and pulleys, were constructed of 1-in. sugar pine on ac- count of its softness. The eight blades were made from pieces 1 by l 1 /' by 12 in. Two opposite edges were cut away until the blade was about l A in. thick. Two inches tended to the ground. The 2 '--in. ind- ie}-. I, Fig. 1, was keyed i" shaft C, as shown in Fig. I. The wire 1. was put through the hole in the axle and the two ends curved so as to pass through the two holes in the pulley, after which they were given a final bend to keep the pulley in place. The method by which the shaft C was kept from work- ing forward is shown in Fig. 5. The washer AI intervened between the 3wi vel Bearing 'Hut, ' C Details of Miniature Windmill Construction were left uncut at the hub end. They were then nailed to the circular face plate A, Fig. 1, which was 6 in. in di- ameter and 1 in. thick. The center of the hub was lengthened by the w len disk, 1!, Fig. 1, which was nailed to the face plate. The shaft C, Fig. 1, was ',4-in. iron rod, 5 ft. long, and turned in the bearings detailed in Fig. 2. J was a nut from a wagon bolt and was placed in the bearing to insure easy running. The bearing blocks were •'! in. wide, 1 in. thick and •'! in. high with- out the upper half. Both bearings wen- made in this manner. The shaft C was keyed to the hub of the wheel, by the method shown in Fig. 3. A staple, EC, held the shaft from revolving in the hub. This method was also applied in keying the 5-in. pulley F, to the shaft, G, Fig. 1, which ex- bearing block and the wire N, which was passed through the axle and then bent to prevent its falling out. Two washers were placed on shaft C, be- tween the forward bearing and the hub of the wheel to lessen the friction. The bed plate D, Fig. 1, was 2 ft. long, •! in. wide and 1 in. thick and was tapered from the rear bearing to the slol in which the fan F was nailed. This fan was made of -/4-in. pine 18 by 12 in. and was cut the shape shown. The two small iron pulleys with screw bases, II, Fig. 1, were obtained for a small sum from a hardware dealer. Their diameter was 1% in. The belt which transferred the power from shaft C to shaft G was top string, with a section of rubber in it to take up slack. To prevent it from slipping on the two POPULAR MECHANICS wooden pulleys a rubber Land was placed in the grooves of each. The point for the swivel bearing was determined by balancing the bed plate, with all parts in place, across the thin edge of a board. There a %-in. hole was bored in which shaft G turned. To lessen the friction here, washers were placed under pulley F. The swivel bearing was made from two lids of baking powder cans. A section was cut out of one to permit its being enlarged enough to admit the other. The smaller one, O, Fig. 6, was nailed top down, with the sharp edge to the underside of the bed plate, so that the ^-in. hole for the shaft G was in the center. The other lid, G, was tacked, top down also, in the center of the board P, with brass headed furniture tacks, R, Fig. 6, which acted as a smooth surface for the other tin to revolve upon. Holes for shaft G were cut through both lids. Shaft G was but VL in. in diameter, but to keep it from rubbing against the board P, a V^-in. hole was bored for it, through the latter. The tower was made of four 1 by 1- in. strips, 25 ft. long. They converged from points on the ground forming an 8-ft. square to the board P at the top of the tower. This board was 12 in. square and the corners were notched to admit the strips as shown, Fig. 1. Laths were nailed diagonally between the strips to strengthen the tower later- ally. Each strip was screwed to a stake in the ground so that by disconnecting two of them the other two could be used as hinges and the tower could be tipped over and lowered to the ground, as, for instance, when the windmill needed oiling. Bearings for the shaft G were placed 5 ft. apart in the tower. The power was put to various uses. How to Make a Telegraph Instrument and Buzzer The only expenditure necessary in constructing this telegraph instrument is the price of a dry cell, providing one has a few old materials on hand. Procure a block of wood about 6 in. long and 3 in. wide and take the coils out of an old electric bell. If you have no bell, one may be had at the dealers for a small sum. Fasten these coils on the blocks at one end as in Fig. 1. Cut a piece of tin 2 in. long and % in. wide and bend it so the end of the tin shown in the illustration. This com- pletes the receiver or sounder. To make the key, cut out another piece of tin (X, Fig. 1) 4 in. long and bend it as shown. P.efore tacking it to the board, cut off the head of a nail and drive it in the board at a point where the loose end of the tin will cover it. Then tack the key to the board and connect the wires of the battery as in Fig. 1. Now, move the coils back and forth until the click sounds just the way Home-Made Telegraph Instrument when fastened to the block will come just above the core of the coil. Cut another piece of tin 3 in. long and bend it as shown at A, Fig. 2. Tack these two pieces of tin in front of the coils as you wish and you are ready to begin on the Morse code. When tired of this instrument, con- nect the wire from the coils to the key to point A and the one connected at POPULAR MECHANICS the point under the key to B, leaving the other wire as it is. By adjusting the coils the receiver will begin to vibrate rapidly, causing a buzzing sound. — Contributed by John R. Mc- Connell. How To Make a Water Bicycle Water bicvcles afford fine sport, and, like many another device boys make, can be made of material often cast off by their people as rubbish. The prin- cipal material necessary for the con- struction of a water bicycle is oil bar- rels. Flour barrels will not do — they are not strong enough, nor can they be made perfectly airtight. The grocer can furnish you with oil barrels at a very small cost, probably let you have them for making a few deliveries for him. Three barrels are required for the water bicycle, although it can be made with but two. Figure 1 shows the method of arranging the barrels; after the manner of bicycle wheels. Procure an old bicycle frame and make for it a board platform about 3 ft. wide at the rear end and tapering to about 2 ft. at the front, using cleats to hold the board frame, as shown at Water Bicycle Complete the shaded portion K. The construc- tion of the barrel part is shown in Fig. 2. Bore holes in the center of the heads of the two rear barrels and also in the heads of the first barrel and put a shaft of wood through the rear barrels and one through the front barrel, adjusting the side pieces to the shafts, as indi- cated. Next place the platform of the bicy- cle frame and connections thereon. Go- ing back to Fig. 1 we see that the driv- ing chain passes from the sprocket driver L of the bicycle frame to the place downward between the slits in the platform to the driven sprocket on the shaft between the two barrels. Thus a center drive is made. The rear barrels are fitted with paddles as at M, consisting of four pieces of board nailed Barrel Float (or Bicycle and cleated about the circumference of tlie barrels, as shown in Fig. 1. The new craft is now ready for a first voyage. To propel it, seat yourself on the bicycle seat, feet on the pedals, just as you would were you on a bicycle out in the street. The steering is ef- fected by simply bending the body to the right or left, which causes the craft to dip to the inclined side and the affair turns in the dipped direction. The speed is slow at first, but increases as the force is generated and as one be- comes familiar with the working of the affair. There is no danger, as the air- tight barrels cannot possibly sink. Another mode of putting too-ether the set of barrels, using one large one in the rear and a small one in the front is presented in Fig. •'!. These two bar- rels are empty oil barrels like the others. The head holes are bored and the proper wooden shafts are inserted and the entrance to the bores closed tight by calking with hemp and putty or clay. The ends of the shafts turn in the wooden frame where the re- quired bores are made to receive the same. If the journals thus made are well oiled, there will not be much fric- POPULAR MECHANICS on. Such a frame can be fitted with platform and a raft to suit one's in- ividual fancy built upon it, which can Type of Float ; paddled about with ease and safety n any pond. A sail can be rigged up y using a mast and some sheeting; or ven a little houseboat, which will give n v amount of pleasure, can be built. low To Make a Small Searchlight The materials required for a small ;archlight are a 1-volt lamp of the iop variety, thin sheet brass for the vlindcr, copper piping and brass tub- lg for ba. bracket ; E, elec- tric bulb (31/0 volts) ; S. brass strip, t 1 i in. long, :! s in. wide and 1 16 in. thick; T, switch; F, wire from batteries to switch; G, wire from bell to switch; II, wire from light to switch; I, dry batteries; J. bell; X, point where a splice is made from the light to wire leading to batteries from brass strip under cluck. Push the switch lever to the right before retiring. To operate this, set alarm key as shown in diagram, after two turns have been made on the key. When alarm goes off, it turns till it forms a con- nection by striking the contact post and starts the electric bell ringing. Throw lever off from the right to center, which stops bell ringing. To throw on light throw levers to the left. The bell is then cut out but the light remains on till lever is again thrown in the center. Details of Alarm Construction In placing clock on shelf, after set- ting alarm, be sure that the legs "I clock are on the brass strip and that the alarm key is in position so it will come in contact with the contact post in back of clock. The contact post may be of 7 4-iii. copper tubing, or ^-in. brass rod. The advantage of this is that one can control the bell and light, while lying in bed, by having the switch on the baseboard, near the bed, so it can be reached without getting out of bed. — Contributed by Geo. C. Brinkerhoff, Swissvale, Pa. How to Hold a Screw on a Screwdriver A screw that is taken from a place almost inaccessible with the fingers re- quires considerable patience to return it with an ordinary screwdriver unless some holding-on device is used. I have found that by putting a piece of card- board or thick paper with the blade of 1 lie screwdriver in the screw head slot, the screw may be held and turned into places that it would be impossible with the screwdriver alone. — Contributed by C. Chatland, Ogden, Utah. 26 POPULAR MECHANICS How to Make a Lead Cannon Any l)ii>- who has a little mechanical ability can make a very reliable cannon for his Fourth <>f July celebration by following the instructions given here: =4 V A Fio.l Take a stick (a piece of curtain roller will do) ", in. long. Make a shoulder i- at A, Fig. 1, 1 in. from one end, mak- ing it as true and smooth as possible, 'is this is to he the muzzle of the can- non. Make the spindle as in Fig. 1, \\ in. in diameter. Procure a good [uality of stiff paper about G in. wide ind wrap it around the shoulder of the stick, letting it extend :; | in. beyond the end of the spindle, as at 1'.. Fig. 2. Push an ordinary shingle nail through die paper and into the extreme end of the spindle as at A. Fig. ".'. This is to form the fuse h, ile. Having finished this, place stick and all in a pail of sand, being careful not to get the sand in it and letting the opening at the top extend a little above the surface of the sand. Then fill the paper cylinder with melted lead and let cool. Pull out the nail and stick, scrape off the paper and the cannon is ready for mounting as in Fig. 3. — Con- tributed by Chas. S. Chapman, Lanes- boro, Minn. How to Waterproof Canvas The method used by the Pritish navy yards for waterproofing and painting canvas so it will not become stiff and cracked is as follows: One ounce of yellow- soap and ' - pt. of hot water are mixed with every ? lb. of paint you wish to use. The mixture is applied to the canvas with a brush. This is allowed to dry for two days and then a coat of the same paint without the soap is laid on. When this last coat is dry the canvas may he painted any color desired. After three days of dry- ing the canvas may be folded up with- out sticking together, and, of course, it is waterproof. The canvas water- proofed in this manner makes an ex- cellent covering for portable canoes and canvas boats. The color mixture for the soap and second application is made from 1 11 1. of lampblack and th sides, and then marked and cut as shown in Fig. 1. A groove is cut for the arrows in the top straight edge % in. wide and :; s in. deep. The tin is bent and fastened on the w 1 at the hack end of the groove where the cord slips out of the notch; this- is to keep the edges from splitting. A mortise is cut for the how at a point 'i 1 ■_. in. from the end oi the stock, and one for the trigger 12 in. from the Arrow Sling with two screws. The trigger, Fig. •">, which is \ >\ in. thick, is inserted in the mortise in the position when pulled hack, and adjusted so as to raise the spring to the proper height, and then a pin is put through both stock' and trigger, having the latter swing quite freely. When the trigger is pulled, it lifts the spring up, which in turn lifts rd off the tin notch. The stick for the how, Fig. I. is dressed down from a point '■'• \ in. on each side of the center line to U> in. wide at each end. Notches are cut in the ends for the cord. The how is not fastened in the stock, it is wrapped with a piece of canvas 1H in. wide on the center line to make a tight lit in the mortise. A stout cord is now tied in the notches cut in the ends of the how making the cord taut when the w< » id is straight. The design of the arrows is shown in Fig. 5 and they are made with the POPULAR MECHANICS blades much thinner than the round part. To shoot the crossbow, pull the cord back and down in the notch as shown in Fig. (i, place the arrow in the groove, sight and pull the trigger as in shoot- ing an ordinary gun. The arrow sling is made from a branch of ash about x /-> in. in diameter, the bark removed and a notch cut in one end, as shown in Fig. 7. A stout cord about 2\i> ft. long is tied in the notch and a large knot made in the other or loose end. The arrows are practically the same as those used on the crossbow, with the exception of a small notch which is cut in them as shown in Fig. 8. To throw the arrow, insert the cord near the knot in the notch of the arrow, then grasping the stick with the right hand and holding the wing of the arrow with the left, as shown in Fig. 0. throw the arrow with a quick slinging motion. The arrow mav be thrown several hundred feet after a little practice- Contributed by O. E. Trownes, Wil- mette, 111. A Home-Made Vise Cut two pieces of wood in the shape shown in the sketch and bore a %-in. hole through both of them for a com- mon carriage bolt. Fasten one of the pieces to the edge of the bench with a large wood screw and attach the other piece to the first one with a piece of leather nailed across the bottom of both pieces. The nut on the carriage licit mav be tightened with a wrench, or, better still, a key filed out of a piece of soft steel to fit the nut. The edges of the jaws are faced with sheet metal which can be copper or steel suitable for the work it is intended to hold. Temporary Dark Room Lantern Occasionally through some accident to the regular ruby lamp, or through the necessity of developing while out of reach of a properly equipped dark- room, some makeshift of illumination must be improvised. Such a temporary safe light may be made from an empty cigar box in a short time. Remove the bottom of the box, and nail it in p o s i t i o n as shown at A. Re- in o v e one end, a n d replace as shown at 1'.. Drive a short wire nail through the center of the op- posite end to serve as a seat for the candle, C. The lamp is finished by tacking two or more layers of yellow post-office paper over the aperture D, bringing the paper well around to the sides and bottom of the box to prevent light leakage from the cracks around the edges, says Photo Era. The hinged cover F, is used as a door, making lighting and trimming convenient. The dour may be fastened with a nail or piece of wire. It is well to reinforce the hinge by gluing on a strip of cloth if the lamp is to be in use more than once or twice. This lamp is safe, for the projecting edges of A and B form light-shields for the ventilation orifice and the crack at the top of the hinged cover, respectively. Moreover, since the flame of the candle is above A, only reflected and transmitted light reaches the plate, while the danger of igniting the paper is reduced to a minimum. Details of a Home-Made Bench Vise The paint will sag and run if too much oil is put in white lead. POPULAR MECHANICS Camps and How to Build Them For a short camping excursion, or for use while the permanent camp is being built, nothing is more novel and delightful than the temporary camp built of the materials ever ready in the woods. The simplest form of all perhaps is the Indian camp. To build this, cut an evergreen tree nearly through about 5 ft. above the base of the trunk, so that when the top falls the butt will still be attached to the stump. Hollow out the under side of the treetop by removing boughs and branches. Use the trunk of the fallen part as a ridge pole and bank boughs and branches from it to the ground on either side. The shelter thus formed will be very comfortable, but there are other kinds better calculated to protect from heavy rainstorms. A wigwam sheds rain well because its sides are so steep. Set up three long poles in the form of a pyra- mid and tie their tops together. Fill the open spaces with poles set at the same slant about 1 ft. apart at the ground and fastened at the t> ip as be- fore. Thatch the outside closely with branches and brush. There are several ways to build a brush camp, but they all have many similar points. The ridge pole for such a camp (about 8 ft. long) may be placed between two trees at a height of about 6 ft., or between two crotched poles set firmly in the ground for the purpose. Long branches may be used to form the sides, but the best method is to lay straight poles on a slant from the ridge- pole to tlie ground, about 8 in. apart. Begin at the bottom and thatch the sides to the top to a depth of about 1 ft. with hemlock or cedar boughs, lav- ing them with the feather side down ; by means of poles weight down the thatch. Such a shelter carefully made will withstand heavy rains. '-'^ Another camp in high favor among campers for temporary shelter is the lean-to; this may be an open lean-to — that is, without ends — or closed as de- sired and may lie thatched with either bark or brush. Select two crotched poles about ? ft. long and set in the ground. Lay another p. >le acn iss these, with its ends resting in the crotches of the other poles. From this pole slant three other poles to the ground. Push the ends of them well into the earth and fasten securely by means of crotched sticks placed over them and driven into the ground. Across these last three poles lay cross-sticks, on which pile brush and weight it down with other poles. Build up the sides in the same way. Where bark is used to thatch the lean-to the top side of the rafters should lie flattened so the bark can be nailed to them. Lark may also 30 POPULAR MECHANICS be used to thatch the wigwam, laying. it in overlapping courses, beginning at the bottom, and securing it by means of cord. To remove bark from trees, cut two circles 6 ft. apart completely around the tree and join the cuts thus made by a vertical cut and pry away the bark by means of an axe. It is must readily re- moved in the early summer. Lay the bark on the ground to dry for a few daws, weighting it down with stones, after which it is ready for use. Hemlock, spruce or cedar boughs, having all large boughs removed so that only fine branches are left, piled to a depth of 2 ft. and with the blankets or sleeping bag on these, make the best bed for the temporary shelter. An- other form of bed can be made by sew- ing deep hems in each side of a piece of heavy duck canvas about 40 in. wide and G ft. long. Set four forked poles in the ground, run poles "i ft. long and 2 in. in diameter through the hems of the canvas and set up on the forked poles so it is about a foot above the ground. Table and Cha fresh water within easy reach is essen- tial. Shade for the hottest part of the day should be considered also. Other considerations vary with the party, the duration of the outing, the country sur- rounding, etc. To make a crane set two green sticks 2 in. thick and 3 ft. long into the ground a foot from either end of the fire. Split the top ends with an axe and provide another stick as a support. A pair of tongs may be made from a piece of tough green wood, which should be ■p/o in. in diameter, 3 ft. long and of snme wood, such as elm, or hickory, which will bend easily. Cut it half way, In selecting a site for a cam]) always remember that above everything else Broom of Hemlock Twigs a distance of 1 ft. in the center, heat the center over a bed of coals until it will bend together without breaking, whittle into shape and fasten the two arms in position by means of a cross- piece. Shape the ends so they will catch hold of anything that has dropped into the fire. A round stick several feet lung will serve as a poker. To make a broom bind hemlock twigs around one end of a stick, using wire ur stout cord to hold them in place. Stools are easily made by sawing a 3-in. block from a log 1 ft. thick. Bore three holes in one side of the block, into which drive pegs. A back may be added if desired. For a rude table set four posts in the ground, nail /rtsssssS^^t^S. cross-pieces on %sSv"^.v- v ^XjL top, and ewer />0>\f >- J§ with slabs cut ^J^ ■^.^JJP' from soft wood log s. At the right height for seats nail pieces on t h e legs to extend out on each side and re- ceive slabs which will serve as seats. Many other articles of use about the temporary camp can be made from such materials as the timber affords. Such things as nails, cord, an axe, etc., ol Made of a Block POPULAR MECHANICS 3] are indispensable to the camping out- fit. No place could be more picturesque and cozy than the log cabin camp, es- pecially where care in choosing its site has been exercised. Aside from the boating, hunting and fishing advantages of the camp's loca- tion, the scenery surrounding it should be considered; it should not be near a swamp, but on high dry ground and. if possible, near a running stream, but always near pure, fresh water. Plan Cut all the others, save those at the ends between the corner posts, on a level with the first one. Those at the How the Logs Lock at the C the building to harmonize with its site. Clear away all decayed trees which might fall on the cabin, stake on I the structure according to the plans and clear off the place it is to occupy. For foundation posts use cedar if possible, but tamarack, pine or hemlock will do. Select sound timber about 1'.' in. in di- ameter and 5 ft. long. Dig post holes down to solid ground or rock, or about ."> ft. deep; set the posts, tamping the earth firmly around them. There should be a post under each angle and corner of the building and where these are quite a distance apart, as many in between as necessary. In a distance of 20 ft. there should be four posts, in- cluding those at the corners, and in 1 2 ft., three posts. After the posts are set, mark the one in highest ground 1<> in. above the ground and cut off squarely. Framing and Beveling the Rafters ends between the corner posts cut 1 in. higher. Stone foundation piers, instead of posts, may be made by digging pits :i ft. deep and 2 ft. in diameter, filling them up with small stones to -round level and laying large cobble-stones on top of these, chinking up with small stones any places that may remain i ipen. For building the cabin use straight, sound timber from 6 to in in. in diame- ter. Tamarack, balsam, pine, spruce and hemlock are all good for the pur- pose. Each log should be cut 2 ft. longer than the side of the building in which it is to be used. Where the (ops of the trees are straight and sound they may be used for rafters, joists, etc. If the timber is brought some distance to the building site, it should be placed on skids and thus hauled to camp. For the first tier of logs select the strongest, best shaped and largest of all. These sills, as the\ are called, should l>e flattened on the upper side from end to end and in a straight line, and at the narrowest part of the log the flattened space should be •"■ in. wide. Place them on the foundation piers so that the flattened surfaces are level with each other. All the other loes for the walls flatten on both sides. When the sills are laid cut notches in the logs and lay the floor sleepers. 32 POPULAR MECHANICS To join the logs at the corners, on the under side a foot from each end cut a hollow which will fit over the round side of the log beneath. Place Crosspieces Where Joists Are Cut for Openings the logs si i the large and small ends of them come alternately. Lay the logs carefully, being sure that each log is properly laid before proceeding with another. Continue laying the tiers un- til the height of the tops of the win- dows and doors is reached. At this point saw out the top log the proper width of each window and door to he made, lay the next tier of logs and then resume sawing out the openings for windows and doors. 1 rave ready door and window frames made of boards 1 in. thick and planed on one side. Xail them in the open- ings to hold the loose ends of the logs. Partition Made of Halved Logs Make the window sills slanting so they w ill shed water. If there are to he two floors to the cabin, at the height of the second floor lay peeled joists, which should he of straight sound timber 6 in. in diameter if the span is 12 ft.; thicker if the span is longer. Always place them so they will have the shortest span possible and about 3 ft. apart. Flatten their upper sides from end to end. using a chalk line and a broad axe for the purpose. To place the joists cut gains, as shown in cut, in the logs that receive the joists and make tenons on the ends of the logs. Use spikes to fasten them. Where partitions are to run the same way of the joist, place a strong joist under each one. At openings for stairs cut the joists at the proper places and put a crosspiece between two joists across the cuts, joining by means of gains and tenons as before. In putting up the rafters raise the gable rafters first. The best roof is a steep one. Select and flatten the rafters just as you did the joists. Frame their lower ends to fit the plate-logs The Door Latch and bevel their tops according to the slant of the roof. Use a ridge-pole to fasten the rafters to at the top. Lay them about '■>> ft. apart and spike them to the ridge-pole at the top. Select small timber about 4 in. in diameter, flatten one side and halve them on to the rafters, letting them extend over the gable ends about 6 in. Nail them in place. If shingles cannot be procured for a covering, bark will do very well. The bark should lie removed from large trees and laid on in long strips, over- lapping <1 in. For floors use matched and planed pine boards 1 in. thick and <> in. wide. For the second story floor they should be planed on both sides, unless two thicknesses are used, in which case the boards should be put on with the rough surfaces facing. To make partitions saw logs in longi- tudinal halves and nail them in form POPULAR MECHANICS with their flat sides facing and over- lapping just enough to hold firmly when nailed together. This will make each side of the partition consist of a round log surface and a flat one alternately. Place a log on top of the partition and spike into place. Window sash must be procured from Mime outside source of supply and they should be placed in the frames so, they will be waterproof. Windows that swing out are most convenient. Straps of old leather will do for hinges and a hardwood bar on the sash, having holes bored in it to fit over iron pins in the frame will be convenient for holding it open, while a leather strap to but- ton over the nail will hold it closed. Make doors of matched boards and use braces and crosspieces on them, nail- ing them securely. If hinges are not to be had, bore a large deep hole at one side of the door in the upper part of the frame, and another directly opposite in the lower part of the frame. In these holes slip the ends of a strong round stick which will turn in them the latch on the inside and pass it through a hole in the door to the out- side. Screens add much to the comfort The Fireplace with Rustic Mantel of a cabin and may be provided if de- sired. The fireplace should he built up with the cabin, laying stone foundations for it at the time the other foundations are laid, using cement mortar. The fire- place should he of firebrick, but may have a stone face. The opening should not be larger than .'! ft. high and ■"> ft. wide and be arched at the top. The fireplace should have a deep throat and the smoke flue should be about 16 in. square. Build the chimney of brick, and to prevent the roof from leaking around it lay pieces of tin in the brick work, letting one edge extend under the shingles at the top side of the chim- ney and over them at the lower and at the sides let the tin turn down against^ other pieces laid with the Bunk with Mattress of Springy Boughs easily. Nail the door on one side of the pole. To -fasten the door make a wooden catch and provide a strong bar to work as a latch. Fasten a string to To Hold the Windo shingles. If the chimney reaches above the ridge-pole it will have a good draft without capping it over, but if below the ridge-pole it should be capped. The POPULAR MECHANICS fireplace may be built up in a ledge to support a mantel, or wooden brackets mav be made. A crane may be made Rustic Stairway by bracing an iron bar to an upright piece. Sockets for the crane should be built in with the brick and the vertical piece should have pins to fit into them. Two Styles of Wood Box The arm should be provided with hi inks, on which to hang vessels, etc. Another kind of fireplace consists ''I a huge inverted sheet-iron funnel ■'! ft. wide at its lower part and tapering up to fit the smoke pipe about 1, in. in diameter. The top of the pipe extends above the roof; the funnel is suspended over a foundation of stone, brick or clay 8 in. dee]) and which supports the firebed which is held together by a An Inviting Window Seat frame of green logs. This is a good arrangement for warmth. In building a stairway the frame is built of poles, and as to the work put on it, one may suit his fancy. Halved logs may be used for steps and are convenient for many other purposes. Bunks may be made by placing small straight even poles on a frame work of poles at least 1 ft. above the floor and laying even- sized boughs and fine twigs to the depth of 2 ft., lay- ing pieces at sides, head and foot to hold the boughs in place and on these laying the blank- ets or sleeping b a g. A packing box can be used for a cupboard by hinging its cover and furnishing with a few shelves. For furnishings for the cabin there i^ a wide range for suiting individual tastes. Many articles, such as chairs, beds, wood boxes, tables, etc., may be built of poles and nails. Window- seats add to the appearance of comfort and Saplings ||||r .lydi: ! ■§ Canopied Couch Built rustic seats can be built for the ver- anda. For the disposal of garbage it is well to dig a hole a little distance from the ramp, sprinkling a little of the exca- vated material over any refuse that is placed in it. The cabin may be finished more in- side if thought best, but this detracts rather than adds to its appropriateness Calking should be done as late as possi- ble, so the logs can dry out a little. For calking use oakum or moss, pressing it in between the logs from both sides, POPULAR MECHANICS 35 using a wooden chisel and a mallet to force it in. Care in the details of the camp will afford a place as inviting and comfortable as can be desired. To Make an Electric Piano Make or buy a table about :i ft. long and 1 ft. or more wide, and about 2'- ft. high. Nail a board | A, Fig. 1 ) about 8 in. wide and of the same length as the table, to the table as shown in the illustration. Paint the table any color desired. may be either nailed or screwed down (G, Fig. I). Make two holes in the table for each button and its wires (II, Fig. 2). Nail or screw the buttons to the table as shown at Fig. 5 with the wires under- neath. The connections are simple: I in Fig. 5 is a wire running from one end of the table to the other end, at- tached tn a post at each end; J. is an- other wire attached in the same way; L is the carbon wire running from the batteries to I : M is the zinc wire run- ning from the batteries to wire T; O Purchase a dozen or so battery elec- tric bells (they are cheaper if bought by the dozen) and screw them to the board. (See Fig. 2.) Arrange the bells in the scab- as shown at B, Fig. 2. Bore two holes, near the posts of each bell for the wires to pass through. Buttons for the bells may be pur- chased, but it is cheaper to make them in the following way: Take a pier,- of wood and cut it round, about 2 1 - in. in diameter and v \ in. thick (Fig. 3) and bore two holes (C and D) through it. Then get two posts, about 1 in. long (battery posts will do) and put them through the holes as at Fig. I. Cul out a piece of tin, % in. wide, punch a hole through it and put in under post E, Fig. I, so that when it is pressed down, it will touch post F, Fig. 1. It indicates the'batteries; 1' i^ a wire run- ning from J to one j >. .-- 1 of a button; Q is another wire running from the other post of the button to one of the posts of the bell ; R is a wire running from 1 to unc post of the bell. When the but- ton S is pressed, the bell will ring. Each button should be connected with its bell in the same way. < )ne battery can be used with each bell if preferred. — Contributed by Vincent de Ybarrondo, 1 ,os Angeles, < 'al. Felt from an old hat makes good packing for automobile water circulat- ing pumps. Strips should be cut to tit snugly in the stuffing box. When the follower is screwed down, it will ex- pand the felt and make a watertight joint. POPULAR MECHANICS Another Optical Illusion After taking a look at the accompany- ing illustration you will be positive that the cords shown run in a spiral toward the center, yet it shows a series of per- The Cord Is Not a Spiral feet circles of cords placed one inside the other. You can test this for your- self in a moment with a pair of com- passes, or, still more simply, by laying a point of a pencil on any part of the cord and following it round. Instead of approaching or receding from the center in a continuous line, as in the case of a spiral, you will find the pencil returning to the point from which it started. Substitute for Insulating Cleats In wiring up door hells, alarms and telephones, as well as experimental work the use of common felt gun wads make a very good cleat for the wires. They are used in the manner illustrated in the accompanying sketch. The insulated wire is placed between two wads and fastened with two nails or screws. If one wad on the back is not thick enough to keep the wire away from the support, put on two wads behind and one in front of the wire and fasten in the same manner as described. Electrically Operated Indicator for a Wind Vane The accompanying photograph shows a wind vane connected with electric- wires to an instrument at considerable distance which indicates by means of a magnetic needle the direction of the wind. The bearings of the vane consist of the head of a wornout bicycle. A J^-in. iron pipe extends from the vane and is held in place by the clamp originally used to secure the handle bar of the bicycle. In place of the forks is attached an eight-cylinder gas engine timer which is slightly altered in such a manner that the brush is at all times in contact, and when pointing between two contacts con- nects them both. Nine wires run from the timer, one from each of the eight contacts, and one, which serves as the ground wire, is fastened to the metallic body. The timer is set at such a posi- tion that when the vane points directly north, the brush of the timer makes a connection in the middle of a contact. When the timer is held in this position the brush will make connections with each of the contacts as the vane re- volves. The indicating device which is placed in a convenient place in the house con- sists of eight 4-ohm magnets fastened upon a 1-in. board. These magnets are placed in a 10-in. circle, 45 deg. apart and with their faces pointing toward the center. Covering these is a thin, wood board upon which is fastened a neatly drawn dial resembling a mari- ner's compass card. This is placed over the magnets in such a manner that there will be a magnet under each of the eight principal points marked on the dial. Over this dial is a magnetic needle or pointer, 6 in. long, perfectly balanced on the end of a standard and above all is placed a cover having a glass top. The eight wires from the timer contacts connect with the out- side wires of the eight magnets sepa- rately and the inside wires from the magnets connect with the metal brace which holds the magnets in place. A wire is then connected from the metal POPULAR MECHANICS brace to a push button, two or three cells of dry battery and to the ground wire in connec- tion with the tinier. The wires are con- nected in such a man- ner that when the vane is pointing in a certain direction the battery will be connected in series with the coil under that part i if I lie dial representing t h e direction in which the vane is pointing, thus magnetizing the core of the magnet which attracts the opposite pole of the needle to- ward the face of the magnet and indicating the way the wind is blowing. The pointer end of the needle is painted black. If the vane points in such a direction that the tinier brush con- nects t vvi i ci mtaets. two magnets will be mag- netized and the needle will point midway be- 1 w i in the twi > lines represented on the dial, thus- giving Hi differ- ent directii ins. Around the pointer end of the needle is wound a fine ci ipper wire, i me end of which extends down to about ,'_. in. . if the dial. This wire holds the needle in place when the pointer end is di- rectly over the magnet attracting it ; the mag- net causing the needle to "dip" will bring the wire in contact with the paper dial. With- out this attachment, the needle would swing a few seconds before coming to a standstill. The Wind Vane, Magnets and Indicator 3.8 POPULAR MECHANICS The vane itself is easily constructed as can be seen in the illustration. It should be about 6 ft. long to give the best results. The magnets used can be purchased from any electrical store in pairs which are called "instrument magnets." Any automobile garage can supply the tinier and an old valueless bicycle frame is not hard to find. The cover is easily made from a picture frame with four small boards arranged to take the place of the picture as shi iwn. The outfit is valuable to a person who is situated where a wane could not be placed so as to be seen from a window and especially at night when it is hard to determine the direction of the wind. By simply pressing the push button on the side of the cover, the needle will instantly point to the part of the dial from which the wind. is blowing. — Contributed by lames L. Blackmer, Buffalo, X. Y. A Home-Made Floor Polisher An inexpensive finer polisher can be made as follows: Secure a wooden box with a base 8 by 12 in. and about 6 in. high, also a piece of new carpet, 1 I by 18 in. Cut 3-in. squares out of the four corners of the carpet and place the box squarely on it. Turn three of the flaps of the carpet up and tack them securely to the sides of the box. Before tacking the fourth side, fold a couple of newspapers to the right size and shove them in between the carpet and the bottom of the box for a cushion. Fill the box with any handy ballast, making it heavy or light, according to who is going to use it, and securely nail on the top of the box. The handle can be made from an old broom handle the whole of which will be none too long. Drive a heavy screweye into the big end of the handle and fasten to the polisher by a staple driven through the eve into the center of the cover, thus making a universal joint. The size of the box given here is the best although any size near that, if not too high, will answer the pur- pose just as well. The box is pushed or pulled over the floor and the padded side will produce a fine polish. How to Make a Lady's Card-Case A card-case such as is shown here makes a very appropriate present for any lady. To make it. secure a piece of "ooze" calf skin leather -I 1 '- by 1(>V1> in. The one shown in the accompany- ing picture was made of a rich tan ooze of light weight and was lined with a grey-green goat skin. The design was stenciled and the open parts backed with a green silk plush having a rather heavy nap. The lining of goat skin need in >t c< >ver more than the central part — not the flies. A piece 4 1 , j by 5 Design for the Cover of Lady's Card-Ca POPULAR MECHANICS in. will be sufficient. A piece of plush IV4 by 6 in. will he enough for the two sides. Begin work by shaping the larger piece of leather as shown in the draw- ing. Allow a little margin ai the top and bottom, however, to permit trim- ming the edges slightly after the parts have been sewed together. A knife or a pair of scissors will do to cul the leather with, though a special knife, called a chip carving knife, is mosl sat- isfactory. The next thing is to put in the marks fur the outline of the designs and the borders. A tool having a point shaped as in the illustration is commonly used. It is called a modeling tool for leather and may be purchased, or, one can be made from an ordinary nut pick by taking off the sharpness with fine emery paper so that it will not cut the leather. To work these outlines, first moisten the leather on the back' with as much water as it will take and still not show through on the face side. Place the leather on some level, non- absorbent surface and with the tool and a straightedge on the straight 1 1 1 1 1 indent the leather as shown. The easiest way is to place the paper pattern on the leather and mark on the paper. The indentations will be trans- ferred without the necessity of putting any lines on the leather. With the knife cut out the stencils as shown. Paste the silk plush to the inner side, being careful not to gel an) of the paste so far out that it will show. A good leather paste will be required. ordinary sewing-machine will do if a good stout needle is used. A silk thread that will match the leather should be used. Keep the ooze side of the lining Complete Card-Case out so that it will show, rather than the smooth side. With the knife and straightedge trim off the surplus ma- terial at the top and bottom and the boi ik is ready f< >r use. Leather Tools Next place the lining, fold the flies along- the lines indicated in the draw- ing. Hold the parts together and stitch them on a sewing-machine. An Home-Made Fire Extinguisher Dissolve 20 lb. of common salt and 10 lb. o| sal ammoniac in ] gal, of water, and put the solution in thin glass bottles, cork tightly and seal to pre\ enl e\ api iratii m. The In a t les should hold about 1 qt. If a tire breaks out, throw one of the bollle-. in or near the flames, or break off the neck and scatter the contents on the fire. It may be necessary to use several bot- tles tc i quench the flames. POPULAR MECHANICS How to Make Water Motors To make the pattern of a water motor shown in' Fig. 1, first get a disk con- structed like A, about 20 in. in diam- eter. This disk can be cut out of sheet metal, or it may be made of pine wood, using common boards. The sheet .4^=H£i Handy So metal will have to be cut at the tin- smith's. You can make the wood disk yourself if you marls out the shape on the boards in pencil and cut the mater- ial accordingly. After the disk is ready, the hub should be designed. This con- sists of the wooden wheel B. This wheel can be purchased ready made at a hardware or a general tool and ma- chinery store. The wheel is grooved, about 5 in. in diameter, and of ample width to fit the shaft and carry the rope C. The wheel is fitted to the wood shaft with a key or screw. Next comes the application of the water wings or paddles. These are made of curved sheet metal of the design shown. They Simple Type of Water Motor should be of sufficient width to receive the full blast of the jet of water from the nozzle or discharge pipe D. If the disk is of metal, the edge of the disk must be turned, so as to provide a shoulder to secure the paddles to either by soldering or by using little bolts passed through holes bored for the pur- pose. If there is a wooden disk used, the paddles are set-screwed to the rim direct. Thus we have the paddles in place, so that the discharge of water plays into each»as it comes around the circuit as at E. Considerable speed can be developed with the common hose pipe. The power generated in this way is used for running sewing machines, fan wheels, dust wheels, etc. The en- tire affair fits in boxed framework of wood, so that the water will be kept in. The water is drawn off through the base of the framework to the drain pipe. These devices may be seen in use for mechanical service in connec- tion with running automatic contriv- ances in show windows. The skeleton-like arrangement in Fig. 2 is made with the hub of small size as shown, to which the large wings or paddles are secured with set-screws. This hub is metal. It can be made by hack-sawing the same from a section of metal 3 let I in. in diameter and bor- ing for the hole. Sometimes a common cart wheel hub can be used for the pur- pose. The wings have to be of wrought or other stiff metal, so that they will retain t h e ir form under the pressure of the water. These p a d- d 1 e s are a 1) o ut .'! in. wide. C o m- nioii .'1-1 <> or 's-in. metal will answer the purpose. The wheel is set upon its shaft and the plan is made for the vol- ume of water to fall upon the paddles from an outlet as at F. The water force contacts with the paddle at G, as shown. The shaft which carries the wheel also carries the driving wheel, which is for a flat belt or round belt, as the case may lie. It is quite easy to POPULAR MECHANICS 41 get from y 2 to 3 hp. from these various types of home-made wheels. The wheel in Fig. '■) is calculated for use in direct contact with the water. A running stream of water is selected and the wheel is adjusted on its shaft so as to drop the lower portion of the wheel into the moving currents as shown. The water contacts with each box-paddle, as at II, in turn, and keeps the wheel revolving according to the velocity of the water. First we make the hid) or center of two pieces of hard- wood bolted together and protected with flanges on either side. The two pieces can be sawed from boards and fitted together with the hole for the shaft bored through. The hub is ap- plied to the shaft. The spokes for the paddle boxes are adjusted into holes bored around the circuit of the hub, same as spokes are fitted to the com- mon wheel hub. Then the paddle boxes of tin or of wood are secured to the end of each spoke. These boxes are about 4 in. square with side-- about 2 in. deep. Sometimes it is necessar) to run the wheel within a case of sheet metal, as in big. 4. The ease has an opening to let the water discharge in, as at I, and an opening to let the used water out, as at J, The case is usually set up on the brick masonry, as indi- cated. The affair is usually in the base- ment. The wheel is made with four plain paddles and the power is gen- erated by the water striking the pad- dle, as at K. The hub is of wood, or as before, a discarded carriage or wagon wheel hub will do. The paddles are wood, about 4 in. wide and 30 in. long. They are mortised into the hub. Figure 5 is another view of this wheel. The hid) is marked M. The section of paddles shown is marked X. The shaft extends through the hub, and is secured to the hub with pins or a key. To one end of the shaft there is fixed the pulley for carrying the belt P. The journals for supporting the shaft are adjusted between the wheel center and the shaft ends. Several who have made this pattern of wheel have been able to get satisfaction from it. It is simple and is capable of generating quite a degree of power, which mav be transmitted to some device through the agency of the licit I'. In Fig. 6 is shown another design, which can be constructed with mater- V * Fig 6 ials usually easily collected. The hub is made firsl as in the case of the other wheels, and this may again be a com- mon wheel hub, with the belt wheel fixed on the shaft adjoining it. < >r in case a wheel hid) is not at hand, the hub can be made of a hardwood block, bored and rounded to suit the conditions. Then the spokes are in- serted into holes made in the hub for the purpose. These spokes are of hard- wood and a good way to get them is to secure spokes of an old carriage wheel. In fact, a good way to do is to get a wheel from a blacksmith or wheel- wright and use it as it is, removing the rim, cutting the spokes to right length. 42 POPULAR MECHANICS and if necessary sawing off every other spoke. ( >r perhaps it will be necessary to saw off two of every three spokes. This gives you a very strung base to work with. The wheels can be bought for a very little money after they are cast tn the junk heap. Many times they arc given away. Thus if we were making the pattern of wheel in Fig. 6, all the spokes of the wheel would be sawed nil except the four shown. To these spokes, at the ends, the bowl- shaped tins are fixed. They are fas- tened with screws or rivets so that the spoke crosses direct over the front of the opening. The water force is from the pipe T, and the discharge forcibly meets tile bowl S. causing the wheel to revolve, bringing the next bowl in position, and so on. The rope belt is marked R, and is extended to the de- \ ire ti i be driven. A Barrel Boat for Sailing The barrel sailing boat is very easily constructed and it is one of the best devices known to instruct a young per- son in the art of managing sails. The barrel boat can lie put together in one day, and the only part that needs to be Sailing in a Barrel Boat bought is the material for the sail. Figure 6 shows the hull of the barrel boat. Jt consists of a bow barrel and a stern barrel, joined together by one strong plank" and a simple outrigger which extends from the plank. In or- der that the barrels may not present a tlat front, which would be difficult to push through the water, they are, as shown in the illustration of the com- pleted boat, fastened to the plank at an angle. The angle is made by placing between each barrel and the plank a triangular shaped brace, such as shown in Fig. f>. Both barrels must be covered with tar and painted so that they will be absolutely water-tight. The outrigger (Fig. i ). is a small SCOW-shaped affair, about 2% ft. long and 1 ft. wide. An ordinary oar or paddle is used for steering. A notched stick (Fig. S) or an iron rowlock can be fastened over the stern barrel to hold the steering oar. The barrel boat, when completed, will consist of two large air-tight com- partments and is, therefore, unsinkable, and because of the out-rigger is very difficult to tip over. Hence it is safe to carry quite a large spread of sail. In a stiff breeze the barrel boat is more seaworthy than rapid, because the waxes slap against the ends of the bar- rels, but in a light breeze when the gging of water is smooth, the barrel boat com- pares favorably in point of speed with the ordinary small sail boat. A little borax added to flour paste will double its adhesive power, and keep it from souring, also. When using a new file, on babbitt or aluminum, rub it with a piece of chalk or soapstone. This fills the teeth of the file so chips cannot stick in them and cut scores in the work. POPULAR MECHANICS Mechanics for Young America A Simple Steamboat Model The small boat shown in the accom- panying sketch may have a length of 12 to 18 in. and is constructed in the following manner: A small strain boiler, A, is supported by two braces over an alcohol lamp in the middle of the boat. A small pipe is fastened to the top of the boiler in such a way that the open end will be opposite the open end of another pipe. B, somewhat larger in size. The pipe B opens into the stern of the boat at C, as shown in Fig. 1. The steam, coming through Sectional View and Completed Boat the small pipe A, is driven forcibly through the largest pipe, 1'.. which car- ries with it a certain amount of air out through the opening C into the water. As the boat is driven forward by this force, the steam arises to the surface in the form of bubbles. The boat soon attains considerable speed, leav- ing behind a Ion- wake. Home-Made Blowpipe 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 hi >!e in the tube. Put the tube in the hole with the small opening at the top or projecting end. Push the cork into the A Pipe Blowpipe bowl of the pipe and the blowpipe i- ready for use. — Contributed by VVilbui Cryderman, Walkerton, ( >nt. Ornamental Iron Flower Stand The illustration shows an orna- mental iron stand constructed t>. 1ml. 1 a glass or china vase. This stand can be made by first drawing an outline of the vase on a heavy piece of paper. The vase is to have three supports. The shape of the scrolls forming each support should be drawn on the papei around the shape of the ease. A single line will lie sufficient, hut care must he taken to get the shapes of the scrolls true. Take a piece of string or, better still, a piece oi small wire, and pass it around the scroll shape on the paper. 1 1 POPULAR MECHANICS This will give the exact length of the iron required to make the scroll. As sheet metal is used for making the senilis, it can be cut in the right lengths with a pair of tinner's shears. Take a pair of round-nose pliers, begin with the smallest scrolls, and bend each strip in shape, using the flat-nose pliers when necessary to keep the iron straight, placing it on the sketch from time to time to see that the scrolls are kepi td the shape required. The scrolls are riveted and bolted together. The supports are fastened together with rings of strip iron % in. wide, to which tin- supports are fastened with rivets. The metal can be covered with any de- sired color of enamel paint. How to Make a Coin Purse The dimensions for a leather coin purse are as follows: from A to 1',, as shown in the sketch, 6% in.; from C to I), 1 1 '| in.; from E to F, 3% in. and A Leather Design for a Purse from G to II, 3V4 in. Russian calf modeling leather is the material used. A shade of brown is best as it does not soil easily, and does not require color- ing. Cut out the leather to the size of the pattern, then moisten the surface on the rough side with a sponge soaked in water. He careful not to moisten the leather too much or the water will go through to the smooth side. Have the design drawn or traced on the pattern. Then lay the pattern on the smooth side of the leather and trace over the design with the small end of the leather tool or a hard, sharp pencil. Trace also the line around the purse. Dampen the leather as often as is necessary to keep it properly mois- tened. After taking off the pattern, retrace the design directly on the leather to make it more distinct, using a duller point of the tool. Tress or model down the leather all around the de- sign, making it as smooth as possible with the round side of the tool. Work down the outside line of the design, thus raising it. Fold the leather on the line EF. Cut another piece of leather the size of the side ECBD of the purse, and after put- ting the wrong sides of the leather to- gether, stitch around the edge as designated by the letters above men- tioned. Do not make this piece come quite up to the line EF, so that the coins may be more easilv put in and taken out. About 1 in. from the lines EF on the piece, stitch in a strip of leather about 1 ( in. wide when stitch- ing up the purse, through which to slip the fly AGH. A window glass may be kept from frosting by rubbing over the inner sur- face a solution of 55 parts of glycerine and 1,000 parts of 60 per cent alcohol. The odor may be improved by adding a little oil of amber. This s< ilution will also prevent a glass from sweating in warm weather. POPULAR MECHANICS How to Make a Turbine Engine In the following article is described is even at the edge with the under a machine which anyone can make, square piece and place the wheel so and which will be very interesting, as that the space between the wheel and well as useful. It can be made without the use of a lathe, or other tools usu- ally out of reach of the amateur me- chanic. It is neat and efficient, and a model for speed and power. Babbitt metal is the material used in its con- struction, being cast in wooden molds. The casing for the wheel is cast in halves — a fact which must be kept in mind. First, procure a planed pine board 1 by 12 in. by 12 ft. long. Cut off six pieces 12 in. square, and, with a com- pass saw, cut (nit one piece as shown in Fig. 1, following the dotted lines, leaving the lug a, and the projections B and b to be cut out with a pocket knife. Make the lug ' ,4 in. deep, and the projections B, b, ^ in. deep. The entire cut should be slightly beveled. Now take another piece of wood, and cut out a wheel, as shown in Fig. 2. This also should be slightly beveled. When it is finished, place it on one of the square pieces of wood, with the largest side down, then place the square piece out of which Fig. 1 was cut, around the wheel, with the open side down. (We shall call that side of a mold out of which a casting is drawn, the "open" side.) Place it so that it o — ^\f B \ \ "4- o ° o the other piece of wood is an even % in. all the way around. Then nail the wheel down firmly, and tack the other piece slightly. Procure a thin board I4 in. thick, and cut it out as shown in Fig. 3 ; then nail it, with pins or small nails, on the center of one of the square pieces of wood. Fit this to the two pieces just finished, with the thin wheel down — but first boring a %-in. hole ' 1 in. deep, in the center of it; and boring a %-in. hole entirely through at the same place. Now put mold No. 1 (for that is what we shall call this mold) in a vise, and bore six %-in. holes through it. Be POPULAR MECHANICS careful to keep these holes well out in the solid part, as shown by the black dots in Fig. 1. Take the mold apart, and clean all the shavings out of it; then bolt it together, and lay it away to dry. Now take another of the 12-in. square pieces of wood, and cut it out as shown in Fig. I. slightly beveled. After it is finished, place it between two of the 12-in. square pieces of wood, one of which should have a %-in. hole bored through its center. Then bolt together with six Vt-in. bolts, as shown by the black dots in Fig. 4, and lay it away to dry. This is mold No. '.'. Now take mold No. 1 ; see that the bolts are all tight; lay it on a level place, and pour babbitt metal into it, until it is full. Let it stand for half an hour, then loosen the bolts and re- move the casting. Now cut out one of the 12-in. -square pieces of wood as shown in Fig. 5. This is the same as Fig. 1, only the one is left-handed, the other right-handed. Tut this together in mold No. 1, in- stead of the right-handed piece ; and run in babbitt metal again. The cast- ing thus made will face together with the casting previously made. Pour metal into mold No. 2. This will cast a paddle-wheel, which is in- tended to turn inside of the casting al- ready made. If there should happen to be any holes or spots, where the casting did in 't fill out, fill them by placing a small piece of wood with a hole in it, over the defective part, and pouring metal in to fill it up. If you cannot obtain the use of a drill press, take an ordinary brace, fasten a %-in. drill in it, and bore a hole through the end of a strip about 2 in. wide and Hi in. long; put the top of the brace through this hole, and fasten the other end of the strip to a bench, as shown in illustration. Find the center of the paddle-wheel, place it under the drill, true it up with a square ; and drill it entirely through. Find the centers of the insides of the other two castings, and drill them in the same manner. A piece of mild steel 5 in. long, and % in. in diameter must now be ob- tained. This is for a shaft. Commenc- POPULAR MECHANICS ing- 1^4 in. from the one end, file the shaft off flat for a distance of 1 in. Then cut a slot in the paddle-wheel, and place the shaft inside of the paddle- wheel, with the flat part of the shaft turned to face the slot in the wheel. Pour metal into the slot to key the wheel on to the shaft. The paddle-wheel is now ready to be fitted inside of the casing. It may he necessary to file some of the ends off the paddles, in order to let the pad die-wheel go into the casing. Aftei it is fitted in, so that it will turn easily, place the entire machine in a vise, and bore three 1 4-in. holes, one in the lug, one in the project]. m-. B, b, and the other in the base, as shown by the Mack dots in Fig. 6. Also bore the port-hole in projection B, and the exhaust hole in projection b. and two \ rin. holes at d, d. Fig. 6. Cut out a piece of gasket and lit it between the two castings. Then bolt the castings together, screw down, and connect to the boiler. Using the Brace The reader must either cast a pulley out of babbitt metal, or else go to a machinist and get a collar turned, with a b >ss and a set screw, and with three small screw hole- around the edge. Cut out a small wood wheel and screw the collar fast to it. fa-ten it to the shaft of the turbine and turn on the -team. Then take a knife or a chisel, and, while it is running at full speed, turn the wheel to the shape desired. Your turbine engine i- now ready foi work, and if instructions have been carefully followed, will do good service. When painting the automobile body and chassis be sure to stuff the oil holes with felt or waste before applying tin' paint. If this caution i- not observed the holes will become clogged with paint which will prevent any oil reach- ing the bearing. How To Build An Ice Boat The ice boat is each year becoming more popular. \n\ one with even small experience in using tools cai struct such a craft, and the ph. many limes repays the effort. Take two pieces of wood '.' by 6 in., mie 6 ft. and the other 8 It. Ion-. At each end of the G-ft. piece and at right angles to it, bolt a piece of hardwood V l.\ I h\ 1'.' in. Round off the lower edge of each piece to lii an old skate. Have a blacksmith bore holes through the top of tlie skates and screw • them to each of the pieces of hardwood. These skates must be exactly parallel or there will be trouble the first time, the craft is used. ( >ver the middle of the 6-ft. piece and 18 POPULAR MECHANICS at right angles to it, bolt the S-ft. plank, leaving 1 ft. projecting as in Fig. 1. The rudder skate is fastened to a piece of hardwood 3 by 2 by 12 in. as the runners were fastened. This piece should be mortised 3 by 3 by 4 in. in the top before the skate is put on. Figure '.' shows the rudder post. A piece of hardwood I by <> by 6 in. Figure 6 shows the way of rigging the gaff to the spar. Figure 7 shows the method of crotching the main boom and Fig. 8 a reef point knot, which may come in handy in heavy winds. Make your runners as long as possi- ble, and if a blacksmith will make an iron or steel runner for you, so much the better will be vour boat. Fig. 6 Details of Ice Boat Construction should lie screwed to the under side of the S-ft. plank at the end with the grain running crosswise. Through this bore a hole 1 ' •> in. in diameter in order that the rudder post may fit nicely. The tiller, Fig. :!, should be of hardwood, and about ft. long and "_" _■ in. in diameter at the base, tapering to 1 ' - in. at the top. This fits in the square hole. Fig. 1. The horn should be 5y L . ft. long, 2 by 3 in. at the butt and 1 in. at the end. Figure 1 gives the shape and dimen- sions of the mainsail which can be made of muslin. Run the seam on a ma- chine, put a stout cord in the hem and make loops at the corners. Electric Rat Exterminator Some time ago we were troubled by numerous large rats around the shop, particularly in a storehouse about 100 ft. distant, where they often did con- siderable damage. One of the boys thought he would try a plan of electri- cal extermination, and in order to carry out his plan he picked up an old zinc floor plate that had been used under a stove and mounted a wooden disk t> in. in diameter in the center. ( )n this disk he placed a small tin pan about 6 in. in diameter, being careful that none of the fastening nails made an electrical con- nection between the zinc plate and the tin pan. This apparatus was placed on the floor of the warehouse where it was plainly visible from a window in the shop where we worked and a wire was run from the pan and another from the POPULAR MECHANICS 49 zinc plate through the intervening yard and into the shop. A g 1 sized induc- tion coil was through connected with these wires and about six dry batteries were used to run the induction coil whenever a push button was manipu- lated. It is quite evident that when a rat put its two fore feet on the edge of the pan in order to eat the mush which it contained, that an electrical connection would be made through the body of the rat, and when we pushed the button up in the shop the rat would be thrown Electric Rat Trap 2 or 3 ft. in the air and let out a terrific squeak. The arrangement proved quite too effective, fur after a week the rats all departed and the boys all regretted that their fun was at an end. — Con- tributed by John D. Adams, Phoenix, Ariz. How to Make a Simple Fire Alarm A tire alarm which is both inexpen- sive and simple in construction is shown in the illustration. Its parts are as follows : A, small piece of wood; I'>, block of wood nailed to A ; S S, two pieces oi sheet brass about n \ in. wide, bent into a hook at each end; P, P, binding-posts fastening the springs S S, to block B, so that they come in contact at C. W is a piece of wax crayon just long enough to break the contact at C when inserted as shown in the illustration. When these parts have been put to- gether in the manner described, con- nect the device in circuit with an elec- tric bell, and place it behind a stove. -P rT > \ . TT Simple Fire Alarm When the stove becomes too hot the wax will melt at the ends, allowing the springs to contact at C, and the alarm bell will ring. — Contributed by J. lv. Comstock, Mechanicsburg, Pa. To Build a Merry-Go-Round This is a very simple device, but one that will afford any amount of amuse- ment. The center post rests in an auger hole bored in an old stump or in a post set in the ground. The stump makes the best support. The center pole should be 10 ft. high. An old wheel is mounted at the top of the pole, and the pole works in the wheel as an axle, says the American Boy. The wheel is anchored out by several guy Home-Made Merry-Go- Round wires. The seat arms may be any length desired. A passenger rides in each seat and the motorman takes his station at the middle. Emery wheel arbors sin mid be fitted with flanges or washers having a slight Ci mcave U < their taee. 50 POPULAR MECHANICS Novelty Clock for the Kitchen An inexpensive and easy way to make an unique ornament of a clock The Clock with Holder fur kitchen use is to take an old alarm cluck or a new one if preferred, and make it into a cluck to hang on the wall. Take the glass, dial and works i nit < if the shell and cut some piece-- i ml of the metal so that when the pieces left are turned hack it will have the appearance as in Fig. 1. Then get a 10-cent frying pan, ii in. in diameter, and drill a hole in the center so the shaft for the hands will easily pass through and extend out far enough to replace the two hands. Tut the works hack in the metal shell and solder it to the frying pan by the pieces turned out as in Fig. 2. Gild the pan all over, including the handle, and print black figures in the small circles. Calendar figures can he pasted on small circles and these pasted on the frying pan. The parts can he divided into minutes with small lines the same as shown in the drawing. Make new hands that are long enough to reach the figures from sheet brass or tin and paint them black. — Contributed by Carl P. Herd, Davenport, Iowa. How to Make a Small Silver Plating Outfit Take an ordinary glass fruit jar or any other receptacle in glass, not metal, which will hold 1 qt. of liquid and till it with rain or distilled water and then add :! i oz. of silver chloride and D- oz. of c. p. potassium cyanide. Let this dissolve and incorporate well with the water before using. Take an ordinary wet battery and fasten two copper wires to the terminals and fasten the other ends of the wires to two pieces of heavy copper wire or y±- in. brass pipe. The wires must be well soldered to the brass pipe to make a good connection. When the solution is made up and entirely dissolved the outfit is ready for plating. Procure a small piece of silver, a sil- ver button, ring, chain or anything made entirely of silver and fasten a small copper wire to it and hang on the brass pipe with connections to the car- bon of the battery. Clean the article to be plated well with pumice and a brush saturated in water. When clean- ing any article there should be a cop- per wire attached to it. Do not touch the article after you once start to clean it, or the places touched by your fin- ders will cause the silver plate to peel off when finished. When well scoured, run clear, cold water over the article and if it appears greasy, place in hot water. When well cleaned place in the plating bath and carefully watch the results. If small bubbles come to the surface you will know that you have too much of the anode or the piece of silver hansnngf in the solution and von and Battery must draw out enough of the piece un- til you can see no more bubbles. Leave the piece to be plated in the solution POPULAR MECHANICS for about one-half hour, then take the article out and with a tooth brush and some pumice, clean the yellowish scum off, rinse in clear water and dry in saw- dust. When thoroughly dry, take a cotton flannel rag and some polishing powder and polish the article. I he ar- ticle must have a fine polish before plating if it is desired to have a finely polished surface after the plate is put on. In order to see if your battery is working, take a small copper wire and touch one end to the anode pipe and the other end to the pipe holding the article to be plated. When these two parts touch there will be a small spark. Always take the- zincs out of the solu- tion when not in use and the batteries will last longer. This description ap- plies only to silver plating. Articles of lead, pewter, tin or any sofl metal can- not be silver plated unless the article is first ci ipper plated. Removing a Tight- Fitting Ring from a Finger When a ring cannot be removed eas- ily from the finger, take a string or thread and draw one end through be- tween the ring and the flesh. Coil the other end of the string around the finger covering the part from the ring to and over the finger joint. Uncoil the string by taking the end placed through the ring and at the same time keep the ring close up to the string. In this way the ring can be easily slip- Wrapp ped over the knuckle and i finger. — Contributed by J Marietta. Tenii. A Photographic Jig-Saw Puzzle Take any photographic print and mount it on heavy cardboard, or, if you Picture Marked for Cutting have a jig saw. a thin smooth w 1 board and mark out various shaped pieces as shown in the accompanying cut. If the picture is mounted on card- board, the lines can be cut through with a sharp pointed knife. It you have a jig saw. you can make a bro- mide enlargement from the negative you have selected and mount (he print on a smooth board that is not too thick. This wood-mounted picture can be sawed out making all shapes of blocks, which forms a perfect jig-saw puzzle. — Contributed by Erich Lehmann, New York City. >ff from the K. Miller Rolling Uphill Illusion This interesting as well as entertain- ing illusion, can be made by anyone having a wood-turning lathe. A solid, similar to two cones placed base to base, is accurately turned in a lathe, the sides sloping to an angle of \~> deg. The spindle can be turned out of the si -lid at the same time as the c< me ; i ir, after turning the cone, drive an iron or wood shaft through the center making a tight fit. The boards for the track are made with a sloping edge on which the cone is to roll. This slope will depend on the diameter of the com-, which can be POPULAR MECHANICS any size from :> to 12 in. The slope should not be too Hat, or the cone will not roll, and it should be such that the The Illusion one end will be higher than the other by a little less than half the diameter of the cone. Thus it will be seen that the diameter of the cone determines the length of the slope of the tracks. A notch should be cut in the tracks, as indicated, for the shaft to drop into at the end < if the course. The lower end of the tracks are closed until the high edge of the cone rests upon the inside edges of the tracks and the high end spread sufficiently to take the full width of the cone and to allow tlie shaft to fall into the notches. When the cone and tracks are viewed from the broadside the deception will lie more perfect, and will not be dis- covered until the construction ,<\ the model is seen from all sides. Should it be difficult to make the cone from wood, a good substitute can be made from two funnels. — Contributed by 1. (',. Bayley, Cape May Point, X. J. Annealing Chisel Steel Persons who have occasion to use tool or carbon steel now and then and do not have access to an assorted stock of this material find that the kind most readily obtained at the hardware store is the unannealed steel known as chisel steel. Machining or filing such steel is exceedingly slow and difficult, be- sides the destruction of tools; as a matter of fact this steel is intended for chisels, drills, and like tools which re- quire only forging and filing. If this steel is annealed, it can be worked as easily as the more expensive annealed steel. Annealing may be done by heating the steel to a cherry red, not any more, and burying it in a box of slaked lime, where it is allowed to remain until all the heat is gone. If well done, the metal will be comparatively soft and in a condition to machine easily and rapidly. In lieu of lime, bury in ashes, sand, loam, or any substance not in- flammable, but fine enough to closely surround the steel and exclude the air so that the steel cools very slowly. If possible, keep the steel red hot in the fire several hours, the longer the better. In certain processes, like that of file manufacturing, the steel blanks are kept hot for Is hours or more. Where it is impossible to wait so long as the foregoing method takes, then a cold water anneal may be used with less time. This method consists of heating the work as slowly and thor- oughly as the time will permit, then above photograph mtins a maple leaf or rk, then printing on top th gative, and finished the made by first paper, not too POPULAR MECHANICS 53 removing the steel from the fire and al- lowing it to cool in the air until black and then quenching in water. In addition to softening the steel, annealing benefits the metal by reliev- ing strains in the piece, .should a par- ticularly accurate job be called for, the steel should be annealed again after the roughing cuts have been taken and before machining to the final size. This will insure a true job and dimin- ishes the danger of Spring in the final hardening. — Contributed by Donald A. Hampson, Middletown, N. Y. How to Make a Post Card Holder This holder is designed to lay flat on the counter or to stack one on top of the other, keeping each variety of cards separate, or a number of them can be fastened on any upright surface to display either horizontal or vertical cards. The holders can be made from sheet tin, zinc, brass or aluminum. The dimensions for the right size are given in Fig. 1; the dotted line showing where the bends are made. The c<>m- Pattern for Cutting the Metal pleted holder is shown in Fig. 2 as fastened to a wall. — Contributed by John F. Williamson, Daytona, Fla. Do not allow paint that is left over from a job to stand uncovered. The can should lie tightly sealed and the paint will be found suitable for use for several days. Perfume-Making Outfit The real perfume front the flowers is not always contained in the liquid purchased for perfume. I It e most expensive perfume can be made at home for less than in cents an ounce. The i lUtfit neces- sary is a large bottle or glass jar with a small- er bottle to fit snugly into the open mouth of the large one. Secure a small piece < if very line spi mge and wash it clean to thor- ough!) remove all grit and sand. Saturate the sponge with pure olive oil, do not use strong oil, and place it inside of the smaller bottle. Fill the large bottle or jar with flowers, such as roses, carnations, pansies. honeysuckles or any flower having a strong and swei t odor. Place the small bottle containing the sponge upside down in the large one, as shown in the illustration. The bottle is now placed in the sun and kept there for a day and then the flowers are removed and fresh ones put in. Change the flowers each day as long as they bloom. Remove the sponge and squeeze out the oil. For each drop of oil add 2 oz. of grain al- cohol. Tf stronger perfume is desired add only ] oz. alcohol to each drop of Home-Made Duplicator for Box Cameras The projecting tube of the lens on a hand camera can be easily fitted with a duplicator while the box camera with its lens set on the inside and nothing but a hole in the box does not have such advantages. A small piece of heavy cardboard can be made to POPULAR MECHANICS produce the same results on a box camera as a first-class duplicator ap- plied to a hand camera. The card- Duplicator Attached to board is cut triangular and attached to the front end of the camera as shown in Fig. 1 with a pin about 1 in. above the lens opening. A rubber band placed around the lower end of the cardboard and camera holds the former at any position it is placed. A slight pressure of the finger on the point A, Fig. 2, will push the cardboard over and expose one-half of the plate and the same pressure at B, Fig. 3, will re- verse the operation and expose the other one-half. Pins can be stuck in the end of the camera on each side of the lens opening at the right place to stop the cardboard for the exposure. With this device one can duplicate the picture of a person on the same nega- tive. — Contributed by Maurice Han- dier, New Orleans, La. Optical Illusions The accompanying sketch shows two optical illusions, the first having a perfect circle on the outside edge ap- The Two Illusions pears to be flattened at the points A, and the arcs of the circle, 1'., appear to be more rounding. In the second fig- ure the circle appears to have an oval form with the distance from C to C greater than from D to D. A compass applied to the circles in either figures will show that they are perfectly round. — Contributed by Norman S. Brown, Chippewa Falls, Wis. Use of Kerosene in Polishing Metals Anyone who has polished a flat iron or steel surface with emery cloth knows how soon the cloth gums and fills up. The cloth in this condition will do little or no cutting. A simple remedy for this trouble is to use kerosene on the surface. The oil floats away a lar«;e part of the gumming substance and leaves the emery cloth sharp and clean to do the best work, also, it seems to act as a lubricant to keep particles of metal from collecting on the cloth and scratching or digging in the surface of the metal. A very light lard oil is equally good for this purpose, but not always easily obtained. A surface polished where oil or kerosene is used does not rust so easily as one polished dry. for the reason that a little oil re- mains on the metal. Kerosene is the best to use on oil stones, being better than heavier oil. This oil readily floats away all particles of the feather edge that are liable to become loosened and forced into the stone. These particles of metal when stuck to the stone are the cause of spoiling it, as well as nicking the tools that are being sharpened. Keep the surface of the stone well oiled at all times to make the cutting free. — Con- tributed by Donald A. Hampson, Mid- dletown, N. Y. How to Make Lamps Burn Brightly For a good, steady light there is nothing better than a lamp, but like most everything it must have attention. After cleaning well and fitting it. place a small lump of camphor in the oil vessel. This will greatly improve the light and make the flame clearer and brighter. If there is no camphor at hand add a few drops of vinegar oc- casionally. POPULAR MECHANICS A Practical Camera for Fifty Cents 55 By C. H. Claudy I say for fifty cents, hut really this is an outside estimate. If you possess a few tools and the rudiments of a shop, by which is meant a few odds and ends of screws, brass and nails, you can really make this camera for nothing. The camera box is the first considera- tion, and for this a cigar box answers every purpose. It is better to use one of the long boxes which contain a hun- dred cigars and which have square ends. This box should be cut down, by means of a saw and a plate, until the ends are 4 in. square. Leave the lid hinged as it is when it comes. Clean all the paper from the outside and in- i- advised, the box should measure that size in its internal dimensions. We now come to the construction of the most essential part of the camera — the pin hole and the shutter, which take the place of the lens and shutter used in more expensive outfits. This construction is illustrated in Fig. 4. Take a piece of brass, about 1/16 in. thick and 1'- in. square, liore a hole in each corner, to take a small screw, which will fasten it to the front of the camera. With 'i-in. drill bore nearly through the plate in the center, but be careful that the point of the drill docs not come through. This will produce Construction of C side of the box — which may be readily done with a piece of lTiss for a scraper and a damp cloth — and paint the in- terior of the box a dead black, either with carriage makers' black or black ink. Now bore in the center of one end a small hole, L in. or less in diameter. Finally insert on the inside of the box, on the sides, two small strips of wood, ] /s by Yi in. and fasten them with glue, Ys in. from the other end of the box. Examine Fig. 1, and see the location of these strips, which are lettered EE. Their purpose is to hold the plate, which may be any size desired up to 4 in. square. Commercially, [dates come 3 1 /-; by 3 x /2 in., or, in the lantern slide plate, 3*4 by 4 in. If it is desired to use the 3% by 3V 2 in. plates, which the recess shown in the first section in Fig. I. Now take a Xo. 1<> needle, in- sert the eye end in a piece of wood and very carefully and gently twirl it in the center of the brass where it is the thin- nest, until it goes through. This pin hole, as it is called, is what produces the image on the sensitive plate, in a manner which I shall presently de- scribe. 1"he shutter consists of a little swinging piece of brass completely covering the recess and pin hole, and provided with a little knob at its lower end. See big. ■'!, in which F is the front of the camera, I'. the brass plate and C the shutter. This is also illustrated in the second cross section in Fig. 4. In the latter I have depicted it as swung from a pivot in the brass, and in Fig. 3 as hung from a screw in the wood of 56 POPULAR MECHANICS the front board will be effective. either construction of your vision the little frame. ,-hen confined within Explanat Lastly, it is necessary to provide finder fur this camera in order to kno what picture you are taking. M a k e a little frame of wire, the size of the plate you are u s i n g, a n d m o unt it up- right (see Fig. • r >) on top of the camera as close to the end where the pin hole is as you can. At the other end, in the center, erect a little pole of wire half the height of the plate. If now you look along the top of this little pole, through the wire frame and see that the top of the little pule appears in the center of the frame, everything that you see beyond will be When you want to use this camera, take it into an absolutely dark room y w 11 ! a ;,o j c " F -B F.G3 - Hole and Shutte taken on the plate, as will be made plain by looking at the dotted lines in Fig. 5, which represents the outer limits Constructing a Finder for Camera and insert a plate (which you can buy at any supply store for photographers) in the end where the slides of wood are, and between them and the back of the box. Close the lid and secure it with a couple of rubber bands. See that the little shutter covers the hole. Ni iw take the camera to where you wish to take a photograph, and rest it se- curely on some solid surface. The ex- posure will be, in bright sunlight and supposing that your camera is 10 in. long, about six to eight seconds. This exposure is made by lifting the little brass shutter until the hole is un- covered, keeping it up the required time, and then letting it drop back into place. It is important that the camera be held rigid daring the exposure, and that it does not move and is not jarred ■ — otherwise the picture will be blurred. Remove the plate in the dark room and pack it carefully in a pasteboard box and several wrappings of paper to pro- tect it absolutely from the light. It is now ready to be carried to some one POPULAR MECHANICS 57 who knows how to do developing and printing. To explain the action of the pin hole I would direct attention to Fig. *.'. I lore F represents the front of the camera, D the pin hole, AA the plate and the letters RR, rays from a lighted candle. These rays of course, radiate in all di- rections, an infinite multitude of them. Similar rays radiate from every point of the object, from light reflected from these points. Certain of these rays strike the pin hole in the front of the camera, represented here by RRRR. These rays pass through the pin hole, and as light travels only in straight lines, reach the plate AA, forming an inverted image of the object, in this case a candle in a candlestick. Mil- lions of rays are given off by every point in every object which is lighted by either direct or reflected light. To all practical purposes only one of these rays from each point in an object can pass through a minute opening like a pin hole. This being so, any screen which interrupts these selected rays of light will show upon it a picture of the object, only inverted. If that screen happens to be a photographically sen- sitive plate, which is protected from all other light by being in a dark box, upon it will be imprinted a photographic image which can be made visible by the application of certain chemicals, when it becomes a negative, from which may be printed positives. This camera is not a theoretical possibility, but an actual fact. I have made and used one successfully, as a demonstra- tion of pin-hole photography. Use for an Old Clock Remove the hair spring of the clock, and fasten a spring to one end of the pawl and a small wire to the other end. Make a slit in the case of the clock opposite the pawl. Fasten the spring on the outside in anv convenient way and pass the wire through the slit to an eccentric or other oscillating body. To make the dial, paste a piece of paper over the old dial, pull the wire back and forth one hundred times, and make a mark where the minute hand Mops. Using this for a unit divide up the whole dial. The hour hand has an inner circle of its own. Put the alarm hand at a little before twelve and wind the alarm. 'When the alarm is un- wound the hour hand starts on a new trip. The clock I used was put on an amateur windmill and when the hour hand went around once 86,400 revolu- tions or jerks on the wire were made. while the minute hand recorded one- twelfth of tin- number, or 7,200.— Con- tributed by Richard II. Ranger, Indian- apolis, Ind. Renewing Dry Batteries Dry batteries, if not too far gone, can be renewed by simply boring a small hole through the composition on top of each carbon and pouring some strong salt water or sal ammoniac solu- tion into the holes. This kink is sent us by a reader who says that the pro- cess will make the battery nearly as good as new if it is not too far gone beforehand. If a round brush spreads too much, slip a rubber band over the upper part of the bristles. POPULAR MECHANICS How to Make a Simple Burglar Alarm Take a piece of any wood about 6 l>y 8 in. for the base. This may be fin- ished in any way desired. For the con- tact points use brass or any sheet metal door or window and any movement of it will pull it to the contact point on the right. If the string is cut or broken the spring will pull the lexer to the con- tact point on the left and thus complete the circuit. If the string is burned it will also act as a fire alarm. CONTACT MCTAL How to Fit Corks ( >ccasionally odd-sized bottles are re- ceived in stores which require corks cut to fit them. No matter how sharp a knife may be, it will leave some sharp edges after cutting the cork, which will cause leakage. The illustration shows three very effective methods of reduc- ing the size of corks. The one shown in Fig. 1 is made from two pieces of Yz-\u. wood fastened together at one end with a common hinge. Two or three grooves are cut cross-wise in sizes desired. The cork is put into the groove and both pieces are pressed to- gether, which will make the cork smaller. Rollins: the cork between two flat Simple Burglar Alarm which will l>e satisfactory. Take a piece about ;*'_• or '■'■ in. in length and bend the ends up about ' _■ in. in a ver- tical position as shown. Fasten this to the top of the hoard using screws or nails. Under this strip of metal fasten a copper wire which can he connected to a binding-post on the board if de- sired. Take another piece of metal about 4 ' _• in. in length and make a lexer of it in the shape shown in the diagram. Fasten this so that one end of it will swing freely, but not loosely between the ends of the oilier piece marked C-C. Near the end fasten a spiral spring, S, which can be obtained almost anywhere. Fasten the end oi this to the screw marked X. Also fasten to this screw a cupper wire lead- ing to the binding-post. Jn the lower end of the lever make a small hole to fa-ten a string through. This string may be fastened across a surfaces (big. 2) is simple and almost as good as pressing in the grooves. A cork rolled on the floor (Fig. 3) is a quick and effective way. A slower and equally as gi >> id way is to soak the cork in hot water for a short time. — Con- tributed by L. Szerlip, Brooklyn, N. V. Standing at the cylinder end and looking toward the flywheel of an en- gine, the wheel will be at the right if the engine is right-hand. POPULAR MECHANICS Home-Made Crutch While a fractured bone was healing in the limb of my boy he needed a pair of crutches and not being able to se- cure the right length, 1 set about to make the crutches from two broom handles. 1 split the handles to within 1 ft. of the end (Fig. 1 ) with a rip saw. and then stuck them in a barrel of water for three days to make the wood pliable fur bending. A grip fur each stick was made as long as the hand is wide and a hole bored through the cen- ter the size of a No. in gauge wire. These grips were placed between the two halves of each stick at the right distance for the length of the boy's arm and a wire run through both split 1 iu Handle Crutch pieces and the handle then riveted as shown in Fig. 2. Another piece was cut as shown at A, Fig. .">, and nailed to the upper ends of each half of the broom handle. — Contributed by Geo P. Grehore, Nashville, Term. Home-Made Necktie Holder The gas bracket is considered a g 1 place to hang neckties, even if it dues crowd them together. The illustration shows a better method, a curtain rod attached to one end of a bureau. Two 1< mg-shanked, square-hi » iked screws should be used, so they may be screwed beneath and close up to the pr< top. When removed they will 1 lectins; ea vc if e=^-s hgurin, , Xeiman, New Y How to Make a Trousers Hanger Secure from your tinsmith a piece of sheel metal : in. wide and 12 in. long. Cut the metal as shown in Fig. 1 ami make a cl ise bend at the point A, but not too close to cause it to break. The piece will then appear as shown in Fig. 2. Cut a piece from the waste mate- rial I o in. wide and ■>> , in. li mg ami bend it around the two pieces I',. Fig. 2, s, , it will slide freely on their length. Bend the edges < ! in for \ ' s in. to hold the trousers firmly. Drill a hole through the top end of B and attach a wire formed into a hook for use in hanging on a nail. The bottom end of the trousers is inserted between the jaws C and the small ferrule pushed Cut from Sheet Metal down to clamp them on the cloth. — Contributed by A. Levinson, Saginaw, .Michigan. POPULAR MECHANICS Easy Designs in Ornamental Iron Work Many an industrious lad has made money manufacturing the common forms of wood brackets, shelves, boxes, stands, etc., but the day of the scroll saw and the cigar-box wood bracket and picture frame has given way to the more advanced and more profitable work of metal construction. Metal brackets, stands for lamps, gates, parts of artistic fences for gardens, support- ing arms for signs, etc., are among the articles of modern times that come un- der the head of things possible to con- struct of iron in the back room or attic shop. The accompanying sketches pre- sent some of the articles possible to manufacture. First, it is essential that a light room be available, or a portion of the cellar where there is light, or a workshop may be built in the yard. Buy a mod- erate sized anvil, a vise and a few other tools, including bell hammer, and this is all required for cold bending. If you go into a forge for hot bending, other devices will be needed. Figure 1 shows how to make the square bend, getting the shoulder even. The strip metal is secured at the hardware store or the iron works. Often the strips can be secured at low cost from junk dealers. Metal strips about % in. wide and Ys in. thick are preferable. The letter A indicates a square section of iron, though an anvil would do, or the base of a section of railroad iron. The bend is worked on the corner as at B, cold. If a rounded bend is desired, the same process is applied on the circular piece of iron or the horn of an anvil. This is shown in Fig. 2, at C. This piece of iron can be purchased at any junk store, where various pieces are always strewn about. A piece about 20 in. long and 4 in. in diameter is about the right size. The bend in the metal be- gins at D and is made according to the requirements. Occasionally where sharp bends or abrupt corners are need- ed, the metal is heated previous to bending. Although the worker may produce various forms of strip-metal work, the bracket is, as a rule, the most profitable tn handle. The plain bracket is shown in Fig. 3, and is made by bending the strip at the proper angle on form A, after which the brace is adjusted by means of rivets. A rivet hole boring tool will be needed. A small metal turning or drilling lathe can be pur- chased for a few dollars and operated by hand for the boring, or a common hand drill can be used. Sometimes the bracket is improved in design by add- ing a few curves to the end pieces of the brace, making the effect as shown in Fig. 4. After these brackets are made they are coated with asphaltum or Japan ; or the brackets may be paint- ed or stained any desired shade. In some of the work required, it is necessarv to shape a complete loop or circle at the end of the piece. This may POP II LA 11 MECHANICS 61 be wrought out as in Fig. 5. The use of a bar of iron or steel is as shown. The bar is usually about 2 in. in diam- eter and several feet in length, so that it will rest firmly on a base of wood or stone. Then the bending is effected as at F, about the bar E, by repeated blows with the hammer. After a little practice, it is possible to describe al- most any kind of a circle with the ti m ils. The bar can be bought at an iron deal- ers for about 40 cents. From the junk- pile of junk shop one may get a like bar for a few cents. A convenient form for shaping strip- metal into pieces required for brackets, fences, gates, arches, and general trim- mings is illustrated at Fig. 6. First there ought to be a base block, G, of hard wood, say about 2 ft. square. With a round point or gouging chisel work out the groove to the size of the bar, forming a seat, by sinking the bar, II, one-half its depth into the wood as shown. In order to retain the bar se- curely in position in the groove, there should be two caps fitted over it and set-screwed to the wooden base. These caps may be found in junk dealers' heaps, having been cast off from 2-in. shaft boxes. ( )r if caps are not avail- able, the caps can be constructed from sheet metal by bending to the form of the bar, allowing side portions or lips for boring, so that the caps can be set- screwed to the wood. Thus we get a tool which can be used on the bench for the purpose of effecting series of bends in strips of metal. Since the introduction of the laws re- quiring that signs of certain size and projection be removed from public thoroughfares in cities, there has been quite a call for short sign brackets, so termed, of the order exhibited in Fig. 7. These sign-supporting brackets do not extend more than .'i ft. out from the building. A boy can take orders for these signs in almost any city or large town with a little canvassing. The sign supporting bracket shown is mere- ly a suggestion. < tther designs may be wrought out in endless variety. \ hook or eve is needed to sustain the ring in the sign. The young man who undertakes ti i construct any sort of bracket, supports, frames or the like, will find that lie will get many orders for lamp-supporting contrivances, such as shown at Fig. 8. It is hardly necessary to go into details Of3 H *,]v: ^^sms r^ for making these stands, as every part is bent as described in connection with the bending forms, and the portions are simply riveted at the different junc- tures. Both iron and copper rivets are used as at I, in Fig. 9, a cross sectional view. The best way is to bore straight through both pieces and insert the rivet. In some cases the rivet is head- ed up in the bore and again washers are used and the heading effected on the washer. Copper rivets are soft and easily handled, but are costly as com- pared with iron rivets. Good prices are obtained for the guard-, for open fireplaces made in many varieties in these days. The re- 62 POPULAR MECHANICS turn of the open fireplace in modern houses has created a demand for these guards and in Fig. 1<> we show a design for one of them. The posts are made sufficiently stiff by uniting two sides with rivets. The ends at top are looped as shown, while the ends or butts at the base are opened out to make the feet. Rings are shaped on forms and are then riveted to the base cross-piece as illustrated. Crosses are made to de- scribe to central design and the plan is worked out quite readily with the different shapes. The making of metal fire grate fronts has proven to lie a very interesting and profitable occupation for boys in recent times. Not long ago it was sufficient for the ingenious youth to turn out juvenile windmills, toy houses and var- ious little knickknacks for amusement. The modern lad wants more than this, lie desires to turn some of his product into cash. Therefore we present some of the patterns of fire grates which boys have made and can make again from scrap iron, with few tools and devices, and find a ready market for the same as soon as they are made. Figure 11 is a sketch of a form of fire grate bar or front that is constructed with a se- ries of circles of strip metal. The best way is to go to the hardware store or iron dealer's and buy a quantity of 1 i -in., '--in., and %-in. iron, about V$ to ,',,-in. thick. In fact t^-in. metal would do in many cases where the parts are worked out small in size. The 's-in. metal is very strong. Then after getting the supply of strip metal in stock, procure the usual type of metal worker's hammer, a cheap anvil, a !)-ll>. vise, a cold chisel, a file or two, and a round piece of shaft iron, about :> in. diameter and 2 to 3 ft. long. This piece of iron is represented at B, Fig. 12. The iron is held in position by means of the straps of metal C, C, which are bent over the shaft tightly and grip the hoard base with set or lag screws as shown. The wooden base should be about 2 in. thick and large enough to make a good support for the iron shaft. The pr' 'cess of bending the rings in this way is as shown. The piece of strip iron is grasped at D. Then with the hammer the iron is gradually worked cold about the mandrel as at F until the perfect form is acquired. After the form is finished, the strip at the ter- minus of the ring is cut off. In order to get a steady base the wooden part may be bolted to a bench. In Fig. 13 is shown the method of clipping off the completed ring. The cold chisel is held upright, and by delivering several blows with the hammer upon the same, the point is caused to chip through the metal and release the ring. The shaft or mandrel is marked G. The cold chisel is indicated at I and the position POPULAR MECHANICS where the hand grasps the strip is at II. The final operation in shaping the ring is by driving the protruding cut, lip down, to the common level of the oppo- site point, thus giving us the finished ring with the lips closed on the man- drel as at J, Fig. 1 1. These rings can be turned out in this way very speedily. The next operation involves the pri icess of uniting the rings in the plan to shape the design. The design work is often worked out ahead and followed. Some become so proficient that they can de- velop a design as they proceed. Figure 11 is a design of grate front used for various purposes in connection with grate fires. The series of rings are united by a rivet between each at the joining point. With thin metal the holes can be punched with an iron punch and hammer on an anvil where there is a hole to receive the point of the punch after the punch penetrates the metal. For the heavier forms of metal a drill is necessary. \ metal drill and brace can be purchased very cheaply for this work. After drilling the holes, the parts are erected and the rivets inserted and headed up as i addition is made. Thus the series of rings are united and then the side pieces are similarly riveted. The points a1 the top are then wi irked i ml and joined i m. These points are filed down to the nee essary taper after the union is efTet ted. The finishing work involves smoothing rough places with a file and painting. Asphaltum makes a good black finish. Some of the best designs of grates are bronzed. Some are silvered. The dif- ferent designs are finished as desired by customers. Figure 15 is another design of grate in which the process of shaping tin- rings is like that in the first design. There are some half circles in tins pat- tern and these are framed by shaping the same about the mandrel with the hammer. In order to get the shoulders close and the circle complete it is nec- essary to heat the metal. \ coke lire can be made in a hole in the ground. Then procure a tin blowpipe and blow the flame against the metal at the point to be bent. This metal will beci une red hot very soon, and can be bent readily against the anvil and the circular form. Let the metal cool off on the ground after heating. Fig. 16 is another design !» 1 M II m K • xj§ XH, ■ which can be wrought out. 'I he middle adjustment is wire screen work which may be bought at a hardware store and set into the position shown. Fig. 11 shows a chipping off device useful in connection with this work. Metal chip- pers can be bought at any tool store. The chipper is placed in the jaws of the vise as at K, and secured there The strip of metal in process of cutting is marked M. The hammer lit caused to strike the metal just over the cutting edge of the chipper. The quick, POPULAR MECHANICS hard blow causes the cutting edge to penetrate far enough to sever the piece. I '.ending cold with a wooden form is done as in Fig. is. The wooden form is marked 1' and is about 8 in. wide and ) in. high, forming a one-sided oval shape. There is a pin R set into the base board of the oval form and the strip of metal for bending is grasped at S and the other end is inserted back of the pin R. By applying pressure, the strip of metal is bent to the form. Figure 19 shows the hour-glass wood bending form, made by selecting a piece of hard wood block, about is another type of fireplace front, constructed by unit- ing the shaped metal pieces. In fact an almost endless variety of designs can be wrought out after the start is once made. A good way to figure the price on the grate is to add up the costs of the parts and charge about 12 cents per hour for the work. How to Make a Water Wheel Considerable power can be developed with an overshot water wheel erected as in Fig. 1. This wheel is made with blocks of wood cut out in sections as indicated by the lines, so as to form the circle properly. The wheel can lie Overshot and Undershot Wheels about 21 in. in diameter to produce re- sults and about 1<> in. wide. Get some tin cans and attach them around the wheel as shown. Bore the wheel cen- ter out and put on the grooved wood wheel, P, and a rope for driving, R. This rope runs to a wooden frame in the manner illustrated. The water is carried in a sluice affair, N, to the fall, O, where the water dippers are struck by the vol- ume and from 2 to I hp. will be pro- duced with this size of wheel if there is sufficient flow of water. This power can be used for running two or three sewing machines, fans, fret-saws, and the like. Another form of water wheel is shown in Fig. 2. This is driven by an underflow of current. This type of wheel can be made on lines similar to the other, only that the paddles are of win id and extend outward as shown. The wheel is supported in a bearing on the piece S. A belt, T, communicates the power to the wheel V and from here the power is carried to any desired point. How To Build An Imitation Street Car Line An imitation street car line may sound like a big undertaking, but, in fact, it is one of the easiest things a boy can construct, does not take much time and the expense is not great. A boy who lives on a farm can find many fine places to run such a line, and one in town can have a line between the house and tlie barn, if they are some distance apart. ( )ften all the boards and blocks re- quired can be had for helping a carpen- ter clear away the rubbish around a new building. Wheels and parts of old bicycles, which can be used in so many ways, can be found at a junk shop at very low prices, wheels in good repair are not expensive. For the car for the street car line try to find a set of wheels having axles, but if you cannot find such, make shafts of hard wood, about :i in. bv '.''-j in. and by means of a jack- knife turn, or shave down the ends to receive the hub bearings of the wheels. Fasten the wheel hubs securely over POPULAR MECHANICS the ends of the wood with pins or little bolts, or if the wheel bearing is of such a nature that it revolves on its own journal, the journal can be fastened to the end of the wood piece. Each of the wheels should be provided with a sprocket ; any chain sprocket of a bicycle may be used. Fasten these sprockets on the outside of the wheels as shown in Fig. 1. They can be set en over the bearing end and se- cured with a set .screw, or the original key can be employed. It is best in cases like this to use the original parts. Make the floor of the car of pieces of boards placed i hi the axles and nailed, screwed or bolted, as shown at A. To erect the frame, place uprights, ( C C C, in position as shown, fastening the ends to the base-boards, and making the roof line as at l'i, then put in t h e cross - pieces, GG. Seals, E E, are simply bi ixes. T h e drive of t h e car is effected by using the driving sprockets, D D, fitted to the crosspieces, G G, with the original bearings. The parts are there- by secured to the car and the chain placed on. Key the cranks for turning to the upper sprocket's shaft and all is ready. If there are sprocket gears and cranks on either side, four boys may propel the carat one time. Considerable speed can be made on smooth mads, but it is the best amusement to run a car line on wooden tracks with a brake con- sisting of a piece of wooden shaft, pass- ing through a bore in the car floor, and fitted with a leather covered pad as at H. A spiral spring holds up the brake until pressure is applied by font power, when the brake contacts with the wooden track and checks the car. The track plan is illustrated in Fig. ?. ( let some boards ami place them end for end on other pieces set as tics. The main boards or tracks, J J, can be about <; in. wide, to the edges of which nail strips about % in. wide and about the Construction of Car same height. The ties, I I, can be al- most any box boards. Wire nails are the best to use in putting the tracks together. The sprocket connection with the chain is shown in Fig. '.'<. This consists of the sprocket gear on the propelling shaft, and the crank. The pedals may be removed and a chisel handle, or any tool handle, substituted, so as to afford means for turning the U Section of the Track crank by hand power. Great fun can be had with the mad. and. furthermore, it can be made remunerative, as boys and girls can be given rides for a penny each. \pply a coal of raw starch water to a dirty wall before painting; this, when dry, may be brushed or wiped off. A good varnish for electric terminals is made of sealing wax dissolved in gasoline. To prevent brittleness add a little linseed oil. POPULAR MECHANICS How to Make a Bell Tent A bell tent is easily made and is nice for lawns, as well as for a hoy's camp- ing outfit. The illustrations show a plan of a tent U ft. in diameter. To make such a tent, procure unbleached tent duck, which is the very best ma- terial for the purpose, says the Cleve- land Plain Dealer. .Make 22 sections, shaped like Fig. 3, each 10 ft. (i in. long and 2 ft. 2 in. wide at the bottom, taper- ing in a straight line to a point at the top. These dimensions allow for the laid or lapped seams, which should be of the wall firmly to the bell cover at the point indicated by the dotted line, For the top of the tent have the blacksmith make a hoop of Vi-in. round galvanized iron, 6 in. diameter. Stitch the canvas at the apex around the hoop and along the sides. Make the apex into a hood and line it with stiff canvas. Have the tent pole ■'] in. in diameter, made in two sections, with a socket joint and rounded at the top to fit into the apex of the tent. double-stitched on a machine. The last seam sew only for a distance of 4 ft. from the top, leaving the rest for an opening. At the end of this seam stitch on an extra gusset piece so that it will not rip. Fold back the edges of the opening and the bottom edge of the bell-shaped cover and hind it with wide webbing, :! in. across and having eye- lets at the scams for attaching the stay ropes. Near the apex of the cover cut three triangular holes 8 in. long and 4 in. wide at the bottom and hem the edges. These are ventilators. Make the tent wall of the same kind of cloth 2 ft. 2 in. high, bind it at the upper edge with webbing and at the bottom with canvas. Also stitch on coarse canvas (I in. wide at the bottom, and the space between the ground and the wall when the tent is raised, fill with canvas edging. Stitch the upper edge In raising the tent, fasten down the wall by means of loops of stout line fastened to its lower edge and small pegs driven through them into the ground, Fig. 5. Run the stay ropes from the eyelets in the circular cover to stakes ( Fig. ■">) stuck in the ground. I'se blocks, as in Fig. 6, on the stay ropes for holding the ends and adjust- ing the length of the ropes. Simple X-Ray Experiment The outlines of the bones of the hand may be seen by holding a piece of rice paper before the eyes and placing the spare hand about 12 in. back of the rice paper and before a bright light. The bony structure will be clearly dis- tinguishable. — Contributed by G. J. Tress, Emsworth, Pa. POPULAR MECHANICS f,T Mechanics for Young America Novelty Chain Made from a Match The accompanying engraving shows what is possible to do with a penknife. A small chain composed of several Lay a Match on the Picture links was cut from the woo forms the match.- Made by Courath, Marietta, < lliio. A. C. An Interesting Electrical Experiment Any one possessing a battery having an e. m. f. of from 1 to 20 volts can perform the following experiment, which is particularly interesting on a< - count of the variation of results with apparently the same conditions. [mmerse two pieces of brass in a strong solution of common sail and water. ( lonnect one piece to the posi- tive wire and the other to the negative, taking care thai the brass pieces do not touch each other. After the current bus passed one or two minutes, the solution will be- co] lored, and i f t he process is con- tinued a colored pigment will be pre- cipitated. The color of the precipitant varies considerably and may be cither yellow, blue. orange, green or brow ii, and possibly others, depending on the strength of the current, the strength of the solul ion, and the com- position of the brass.— Contributed bv !■:. W. I).. Chicago. Restoring Broken Negatives W boever has the misfortune to break a valuable negative need not de- spair, for the damage can be i most effectively. In ease the negative he broken into many pieces, take a How Wires are Connected Before and Alter Mending (lean glass the same size as the broken negal ive, and put upon this the pieces, joining them accurately, says Camera ( 'raft. Put another clean glass on top of this and bind the three together with passe-partout binding or gumi 1 strips of ordinary paper, as one would a lantern slide, and cover the glass edges. Next make a transparency of this (in the camera, of course), and if done right the positive will only show the cracks as dark and light lines. The 68 POPULAR MECHANICS dark Lines are removed with the etch- ing knife and the light ones with the retouching pencil. From this trans- parency another negative can be made, or as many negatives as necessary, by either contact or in the camera, and if the work on the glass positive was done carefully, no trace of the break should be seen on the finished nega- tive. If the negative is broken in two or three larger puce- only, a contact positive may be made in the printing frame without binding, by using a clean glass in the latter, upon which the pieces are put together, face up, and a dry plate exposed in contact with them in the dark room. The accompanying engravings show a print before and after repairing a broken negative in this manner. Coin and Tumbler Trick The accompanying sketch show: how a good trick may he easily per formed ly any one. Lay a piece o This is a Good Trick heavy paper that i- free from creases mi a board or table. Secure i hree t um- blers that are alike ami stick a piece of I he same heavy paper over the open- ings in two id* them, neatly trimming it all around the edges so as to leave nothing of the paper for any one to see. Make three covers of paper as shown in fig. 1 to put over the tum- blers. Place three coins on the sheet of paper, then the tumblers with cov- er.- on top of the coins, the unprepared tumbler beina in the middle. Now lift the covers off the end tumblers, and you will see that the paper on the open- ings covers the coins. Replace the cov- ers, lift the middle one, and a coin will be seen under the tumbler, as the open- ing of this tumbler is not covered. Drop the cover back again and lift the other tumblers and covers bodily, so that the spectators can see the coins. remarking at the same time that you can make them vanish from one to the other. The openings of the tumblers must never be exposed so that any one can see them, and a safe way to do this is to keep them level with the table. Another Way to Renew Dry Batteries There are many methods of renew- ing dry batteries, and I have used sev- eral of them, but I found the follow- ing the best : Remove the paper cover and with a '4-in. drill make about six holes around the side of the zinc, about T S in. from the bottom. Then drill another row of holes about half way up the side and put the bat- tery to soak in a solution of sal am- moniac for 48 hours. Then remove and plug the holes up with hard soap, and replace in the paper box, when it will give nearly as strong a current as when new. Simply Made Wire Puzzle The object of this simply made wire puzzle is to get the ring oil', which is not easy unless you know how. To do so it is necessary to move the triangle with ring to ime of the hinge joints and fold the puz- zle. Then slip the ring off the triangle over the hinge joint and it will slip all around and off at the oilier hinge. Diabolo is pronounced Dee-ab-lo. POPULAR MECHANICS A Mechanical Ventriloquist And How To Make It An apparatus rigged up as shown in the illustration will afford any amount of amusement to the boy who cares to try it. The materials required are a watch case telephone receiver, a trans- mitter, a large phonograph horn, about 200 ft. of No. IS gauge wire and three or four batteries. Fasten the watch case receiver to the shaft is not in the center the engine will not run smoothly. Make the shaft to extend on each side of the two bearings, so that the commutator may be attached to one side and s, , the other side may be bent into the form of a crank. On the com- mutator side place a brush in such posi- tion that during every revolution the circuit will be alternately opened and closed. Arrange the commutator so that the circuit will be closed either A Simple A horn, being careful not to let it touch the diaphragm of the receiver. Run the line and attach the transmitter at its opposite end. When one talks into the transmitter a person '.'mi ft. distant from the receiver can plainly hear what is said. If the receiver and horn end is hidden in a clump of bushes near a road, people passing will be greatly puzzled at hearing a voice, seemingly out of uninhabited space. How to Build an Electric Engine This engine, if carefully made, pre- sents a neat appearance and is capable of running toy machinery on very low current strength — the one I made ran satisfactorily on 1 2 '< amperes. The coils may be those of an old electric bell, mounted on a light piece of angle-iron, at a height of not more than 1 in. from the baseboard. The fly-wheel standard, crank-rod and ar- mature may be made out of galvanized iron. No. 16 being most suitable. A small valve-wheel makes a very £ 1 fly-wheel, but care must be taken in mounting it upon the shaft, for if the when the handle is at the top or when it is at the bottom, which makes no difference, except for the direction in w Inch the engine will run. Let us suppose that the crank is pointed downward. The circuit is now- closed by the commutator and the ar- mature is attracted by the electro-mag- net, but. as ii approaches the magnet, the circuit is broken and the fly-wheel pulls it back again, only to he attracted when the circuit is again closed l'.\ adjusting the commutator, sev- eral different speeds may be obtained, as well as reversing the engine accom- Home-Made Electric Engine plished, which is done by placing the crank so that it points upward, then twisting the commutator around so that the circuit is closed. — Contributed by Warren B. Weyrick. Akron, ( ). POPULAR MECHANICS Devices of Winter Sports — How to Make and Use Them "Tip-Up Pole" In the north the red-cheeked boy digs a hole in the iee and while he amuses and invigorates himself at skat- ing, the fish underneath the icy sheet fasten themselves to the hi hiI< he has let down through a hole. The boy used to sit over the hole in the ice and wait for the fish to bite, but that became ti i. > slow and detracted too much from his pleasure at skating. So his in- ventive genius set it- self to work and the "tip up" and "sig- nal" shown in the illustration was the result. When the fish is not biting the flag lies flat on the ice, but as soon as a fish has swallowed the hook the flag- pole stands straighl up wafting its bright colored flag to the breezes and all the boys on the skating pond read the word "fish." The fish i- drawn up, the hook rebated and the youthful fish- erman resumes Ids pleasures on the ice. Often a score or more of these "tip tips" are planted about the edges of the ice pond, each boy bringing his fishing tackle with his skates and thus finding a double source of amusement. Maybe one boy will thus have a half do/en different lines in the water at once, it being easy to watch them all ti igel her. The d e v i e e by which the fish is made to give its own signal when caught is exceedingly simple and any boy can make it. Procure a light rod about 2 ft. in length and to i me end fasten a small flag, made of any bright colored cloth. Bind the rod at right angles to another stick which is placed across the hole, so that a short piece of the flag-rod pro- iver the cross stick. Ti i tins sh< >rt end fasten the fishing line. Be sure and "Tip-Up" Fish Caught use strong string in binding the two rods together, and also take care that the cross stick is long enough to permit several inches of each end to rest on the ice. After fastening the line to the short end of the rod, bait the hook with a live minnow or other suitable bait and let it down through the hole. When the fish is hooked the flag will instant- ly raise and wave about strenuously until the fish is taken from the water. "Jumping Jack" Fisherman If the small boy has a "jumping- jack" left over from Christmas he may make this do his fishing f o r h i m and serve as well as the "tip up," or he can easily make the jumping-jack himself independ- ent of Santa Claus. The string which is pulled to make the p lints move is tied securely to Jumping-Jack Fisherman jj le nsllill" line; the hook is 1 '.ailed and lowered into the water through a hole in the ice. The "jumping-jack" waxes his legs and arms frantically to notify the boys when the fish is biting. The "jump- in. j i: 1- i liso used lor fishing m summer time by placing it on a float which is cast into the water. Winter Velocipede Bicycles may be converted into novel sleighs by simply overhauling. The usual bicycle frame and pedals are used, and gearing transmits to contact wheels, in which are sharp spikes for catching in the snow' or ice. Instead of moving on wheels the machine is car- ried on runners. The Running Sleigh Another winter sport, very popular in Sweden, and that has already reached POPULAR MECHANICS VI America, is the "running sleigh," shown in the illustration. A light sleigh is equipped with long double runners and is pro- pelled by foot power. The person using the sleigh stands with one foot upon a rest attached to one of the braces connecting the run- ners and propels the sleigh by pushing backward with the other foot. To steady the body an upright support is attached to the runnel's. The contrivance can be used upon hard frozen ground, thin ice and snow-covered surfaces, and under favor- able conditions moves with remarkable speed. The "running sleigh" has a decided advantage over skis, because the two foot supports are braced so that they cannot come apart. Any boy can make the sleigh with a little pains. each end firmly to the hoop's sides. For CONSTRUCT. O* for Skater's Sails The Winged Skater With the actual speed of the wind a skater may be hurled along the ice if he is aided by sails. He has been known to travel at the rate of 10 miles an hour, and the sport while affording the limit of excitement, is not attended with dan- ger. The sails are easily made, as the illustrations and description will show. Secure two large thin hoops about 4 ft. in diameter. They may he obtained from an old hogshead or by bending thin strips. For each hoop selecl a piece of strong cane about :: i in. in di- ameter to constitute the fore and main masts or cross-yard--. Extend these across the center of the hoop and fasten Running Sleigh the middle of each cross-spar make a cleat and lash it on firmly. The main spar should also he made of two pieces of strong cane, each about 9V2 ft- long. Bind them together at each end so thai the large end of one is fastened to the small end of the 1 ither. Xexi comes the attach- ing of the sails in the sep- arate masts. Tin- sails should be made of strong sheeting or thin canvas. Tack the cloth to the hoop on tin- inner side after the cloth has been wrapped around the hoop two or three limes. X, IW the main spar si ould be at- ached >y ;pnngn g it IP irt and slip- >ing th e c rats m| the Cl 1 iss-spar be- Bicycle Sleigh tween the two pieces. Bind the inner sides of the hoops tightly together by means of a very strong double cord, as shown in the figure. Then your sail 72 POPULAR MECHANICS is ready for the ice pond. See that your skates are securely fastened, raise your sail and you will skim along the ice as lightly as a bird on the wing. With a little practice you will learn to tack and guide yourself as desired. Plan of I nd Rudde If the hoops cannot be easily obtained the sails may be made equally effective by using the main spar and fore and main masts as herein described, mak- ing the sails square shaped instead of round and leaving off the hoops. In this case the sails should be securely bound with strung tape. Attach a corner to each end of the cross-spar, and a corner to the outer end of the main spar. The remaining corner of each then appears oppo- site to each other, and should be fastened together by strong cord in the same man- ner as the hoops. In this case the sails may be left off until after the frame is entirely put together and then fastened on to the spars by buttons. A more simple sail may be made according to the plans illustrated in the lower drawing. It is made by binding together in the center the halves of two strong hogshead hoops, or two bent ] Miles are better. If possible the sail should be about 8 ft. long and 4 ft. wide. Fasten on the sail at the four corners. The rig will convey two persons and is more easily con- structed than any other. Ice Boating T.ut the sport that is greatest of all, the one that used to be part of the life of every northern boy, and which is being revived in popularity after years of stagnation, is ice boating. With the aid of old skates, pieces of board and an old sheet or a small bit of can- was, any boy possessed of ordinary mechanical genius may make an ice boat. The frame of the boat should be made something in the form of a kite. The center- board should be 4 or 5 ft. long, 6 in. wide and 2 in. thick. The cross board may be of a piece of 1 by 6-in. plank 3 ft. POPULAR MECHANICS 13 long-. Fasten these with braces of small stout strip, as shown in the draw- ing, and screw the cross-piece securely to the center-board. Bore a hole in the center of the intersection for the mast pole. The seat may be made of a piece of strong cloth or leather. Three skates are fastened on to either side of the cross-board and one to the rear end of the center-board, the latter of which is to operate as a rudder. In attaching the skates first make a couple of runner blocks, each in. wide. Bore holes in them fur the straps of the skates to pass through and f a s t e n them secure- ly. Xail the r u n 11 e r blocks firmly to the cross- In i;ird about Boy's Ice Boat -, i • r 1 ' •> in. from each end. In making the rudder hew down a piece of scantling 1 ft. long until it assumes the shape of a club with a tlat base. Xail a strip of wood firmly to this base, and to the strip fasten the skate. Run the top of the club through a hole bored in the stern of the center- board. Then make the helm by boring a hole in one end i if a strip i if s< 'ft 1 i iard about 1 ft. long, and through this hole pass the club or rubber-pole and fasten it so it may be shifted when desired. Make the sail out of .m old sheet, if it be strong enough, piece of canvas, or am- such substance and attach it to the mast and sprit as shown in the illus- tration, and guide it b\ a stout string- attached to the lower outer corner. As an ice boat will travel faster than the wind, some care and considerable skill is necessary. Unless you are accus- tomed to managing a sail boat, do not select a place in which to learn where there are air holes or open water. To stop tlie boat throw the head around into the wind, same as you would with boat. If the wind is strong the occupants of the boat should lie tlat on their stomach. Coasters and Chair Sleighs Make your own sled, boys! There is no use in buying them, because your hand-made sled is probabh better than any purchased one and then you can take s, , much more pride in it when you know it is of your 1 1 w n ci instruction. There are so many different designs of sleds that can be made by hand that the matter can be left almost entirely to your own ingenuity. You can make one like the bought sleds and face the runners with pieces of an iron hoop which will answer every purpose. A 3fl Chair Sleigh f 1:L 3 good sled for coasting consists simply of two barrel sta-\ es and three piei es oi board as shown in the picture. Fig. 1. No bought sled will equal it for coast- ing and it is also just the thing for car- rying loads of snow for building snow- houses. The method of its construc- tion is so simple that no other descrip- tion is needed than the picture. You Fig. 4— Folding . Sleigh Open 74 can make a chair-sleigh out of this by fitting a chair on the cross board in- stead of the long top board or it will be still stronger if the top board is allowed to remain, and then you will have a device thai can readily again be transform e d into a coast- ing sled. In making t h e chair - sleigh it is neces- sary, in or- der to h old the chair in place, to nail four L -shaped Mi M-ks on the cross boards, one for each leg of the chair. Skating along over the ice and pushing the chair in front of him the proud pos- sessor of a chair-sleigh may take his mother, grown siller or lady friend with him on his outings, and permit her to ride in the chair. Folding Chair Sleigh A folding chair sleigh is even more enjoyable and convenient than the de- vice just described. If the ice pond is far from home this may be placed un- der your arm and carried where you like." The illustrations. Figs. 2 and 3, show- all the parts as they should look before POPULAR MECHANICS Slei-h Closed bein^ joined together. The seat may be made of a piece of canvas or carpet. The hinges are of leather. Figure 4 shows the folding chair sleigh after it has been put together. Skates are em- ployed for the runners. The skates may be strapped on or taken off when- ever desired. When the chair is lifted the supports slip from the notches on the side bars and fall on the runner bars. The chair is then folded up so that it can be carried by a small boy. With regular metal hinges and light timbers a very handsome chair can be constructed that will also afford an ornamental lawn chair for summer. The Toboggan Sled When the snow is very deep a to- boggan sled is the thing for real sport. I lie runners of the ordinary sled break through the crust of the deep snow, blocking the progress, and spoiling the fun. The toboggan sled, with its broad, smooth bottom, glides along over the soft surface with perfect ease. To make the toboggan sled, secure two boards each in ft. long and 1 ft. wide and so thin that they can be easily bent. Place the boards beside each other and join them together with cross sticks. Screw the boards to the cross stick from the bottom and be sure that the heads of the screws are buried deep enough in the wood to not protrude, so Fig. 6 — The Toboggan that the bottom will present an abso- lutely smooth surface to the snow. Fasten two side bars to the top of the cross sticks and screw them firmly. In some instances the timbers are fastened together by strings, a groove being cut in the bottom of the boards so as to keep the strings from protruding and being ground to pieces. After the side bars are securely fastened, bend the ends , if the b> iards i >ver and tie them to the ends of the front cross bar to hold them in position. See Fig. 6. The strings for keeping the boards bent must be very strong. Pieces of stout wire, or a slender steel rod, are even hetter. The toboggan slide is the fa- vored device of sport among the boys in Canada, where nearly every boy knows how to make them. The Norwegian Ski. You have often read of the ski, the snowshoe used by the Norwegians and other people living in the far north. With them the men and women glide down the snow-covered mountain sides, leap across ditches, run races and have all kinds of sport. They are just POPULAR MECHANICS as amusing to the American boy who has ever learned to manipulate them, and it is wonderful how much skill can be attained in their use. Any buy with a little mechanical ingenuity can make a pair of skis (pronounced skees). They can be made from two barrel staves. Select staves of straight grained wood. Sharpen the ends of each and score each end by cutting grooves in the wood, as shown in the cut, Fig. '. . \ pocket knife or small gouge will suffice for this work. Then smear the cud of the staves with oil and hold them close to a hot fire until they can be bent so as to tip the toes upward, as shown in the picture, Fig. 7. Then with a cord bind the staves as they arc bent and permit them to remain thus tied until they retain the curved form of their own accord. Now screw ori top of each ski a little block", just broad and high enough to fit in front of the heels of your shoe. Fasten a strap in front of the other side of H another curd (J is fastened, which passes over the pulley N and termin- ates in any convenient place in the rooms above. This piece of iron H is held in place by the release A. Now C is a coil of wire from a door bell. R is an armature which works A on pivot minutes 1 concluded to make a self- acting device which would close the draft and leave the furnace safe, with- out any further attention mi my part, after putting in the coal ami opening it up to burn. As some other boys may like to build the same regulator I will tell just how to make one and how it operates. Referring to Fig. 1. you will see a straighl cord is attached to the draft dour of the furnace. I), and is run over the pulley I' ami finally is attached to a small piece of iron, H. This piece J. M is a U-tube, filled with mercury, one end being connected to a half liter glass flask F by the tube T, and the other end terminates in an overflow? tube I >. B is a battery of three bi- chromate cells which are connected up with the C and the platinum points 1 — '.', which are fused into the U-tube. ( )n fixing the furnace the iron piece II takes position X, this being the nor- mal position when draft door 1> is closed. On arriving upstairs I pull the cord G, which causes the piece H to become fixed in the vertical position POPULAR MECHANICS 79 by means of A. This opens the draft door at the same time. Now when the furnace heats up sufficiently it causes the air to expand in F, which causes the mercury in M to rise a little ah no the point 2. This immediately causes a current to flow through C which in turn draws R towards it, raises A and causes II to drop to position X. This shuts the furnace door. Now the fur- nace, of course, c ioIs down, thus caus- ing the air in F 1 > contract and const quently opening the circuit through ('. If at any time the furnace should over heat, the raising of A, "ii which is grounded a wire from a signal hell up- stairs, will make a circuit through the bell by means of the point /. and wire leading therefrom. Tin- lull also serves to tell me whether II lias dropped or not. This same device of regulating the draft I) can be used I i regulate the damper, found on the coal doors of most furnaces, by simply fus- ing a platinum p linl mi the other side of AI and changing the o ird v\ Inch is at- tached to D. A twi i-ci 'iit.'u i s\\ itch could also he inserted to throw con- nections from •.' to ::. It would work in this manner: The damper door, of course, which keeps a low lire, would he up in a p< >sit i hi similar to 1 > ; on the furnace cooling too much, connec- tion, due to contracting of air in !■', would be made through '■> and C, caus- ing H to drop, thus closing door. This simple device worked very well all last winter and gave me no trouble what- ever. If you cannot readily procure a U- tube, you can make one, as 1 did, and the work is interesting. The U-tube is constructed in the fol- lowing manner. A glass tube is closed at one end. This is done by holding the tube in one corner of a gas flame, somewhat near the dark area (A, Fig. 2), and constantly turning the tube when it will be found that the glass has melted together. Now, after it is cool, about 3 or 4 in. from the sealed end. the tube is held steadily so that the flame will heat one small portion (B, Fig, 2). After this small portion is heated blow into the tube, not very hard, but just enough to cause tube to bulge out. Allow to cool. Then re- heat the small bulged portion, blew quite hard, so that the glass will be blown out at this point, forming a small hole. Now insert about l/, in. ,,|' plat- inum wire and reheat, holding platinum Making the U-Tube wire by means of a small pliers so that it will be partly in the lube and partly without. The platinum will stick to the glass, and if glass is sufficiently heated one will be able to pull it, by mean-, of pliers, from i .ne side of the hole to the other, thus sealing the wire into the tube. Another wile i^ sealed in the same way about 1 in. from the first. Now. to bend the tube, one must hold it, with both hands, in the flame and turn constantly until soft. Quickly withdraw from flame and bend, just as you would a piece <>f copper wire. Allow to cool slowly. The several tubes are connected with a short piece of rubber tubing. The total cost of materials for con- structing the apparatus complete will not amount to mi re than one dollar.^ Contributed b) M. < 1. Kopf, Lewis In- stitute, Chicago. Weatherproofing for Tents Dissolve I oz. sulphate of zinc in lit gal. water; add l / 2 lb. sal-soda ; stir well until dissolved, and add ' [> oz. tartaric acid. Put the tent cover in this solu- tion and let lie 2 I Ins. Take out (do not wring it) and hang up to dry. — Grinnell's I land Book on Painting-. Sheet metal placed between two boards in the jaws of a vise and clamped tightly, can be sawed with a hacksaw. 80 POPULAR MECHANICS How to Make a Toy Battery Motor Lift A 10-lb. Weight The materials necessary are a small battery motor, three or four cells of batteries, an old clockwork, and a board motor will lift the weight up to the level of the clockwork without diffi- cult)-. This experiment demonstrates the power of gearing. — Contributed by W. J. Slattery, Emsworth, Pa. Axle oo wbicb H St, ring wind&X Pulley ^^^ String Belt/ T o p View 6 in. wide and 12 in. long. Remove the mainspring from the clockwork and make a small pulley and fasten it on the axle of the smallest wheel in the mechanism. Fasten the clockwork on one end of the board in such position that the large wheel will project over the edge. Place the motor on the board about 6 in. from the clockwork and connect the pulley of the motor with the pulley in the clockwork by a string belt. Now fasten a niece of strong cord or chalk- line to the axle of the large wheel of Sm^ll pulley a^ttevcbed "bo & meJIest wheel in clockworks How to Remove Glass Stoppers from Bottles Glass stoppers which are stuck in bottles may be quickly removed by holding the bottle at a slant of about l"> deg. and applying a burning match to the neck of the bottle around where the stopper seems the tightest and turning the bottle while the match is burning so the glass will be heated evenly all around. This will cause the neck of the bottle to expand before the stopper does and when the flame has B a.-t"b e. ry -bide View the clockwork and put a weight of well burned out, drop the match and about 10 or 12 lb. on the end of the quickly give the stopper a little twist string. and it will come out readily. — Contrib- uting three or four batteries, the uted by Jno. E. Cox, Halstead, Kan. POPULAR MECHANICS Kites of Many Kinds and How to Make Them Boy Kite One of the prettiest of all is the but- terfly kite. To make this get two thin kite sticks of equal length. I '.end each in an arc, tying one end of a strong string to one end of each stick and the other end of the string to a point about .') in. from the other end of the stick. This leaves one end of each stick free, hooking over the hemisphere de- scribed by the thread and the --tick. Now tie another thread to each of these free ends and tie the other end of the thread to a point near the other end of the stick, corresponding with the distance from the end at which the first strings were tied on the oppo- site side. This done, you should have two arched frames, each an exact c iun- terpart of the other in size, curvature and weight. Now fasten the two frames together so that the arcs will overlap each other as shown in the sketch. Bind the intersecting points securely with thread. To make the butterfly's head, secure two heavy broom straws or two short wires, and at tach them to the top p a r t of the w i n g frames near where the sticks intersect, so that the straws or w ires will en iss. These li inn 1 lie antennae, . ir the "smellers." Then select the color i if pa- per yi iu want, yellow, bn i\\ n, blue, w bite or any i it her ci 'lor ; lax- it on a fiat surface and place the frame i in t< ip of it. holding the frame down securely with a weight. Then with a pair of scissors cut the pa- per around the frame, leaving aboul a 1 --in. margin for pasting. ( 'ill slit- in the paper about V in. apart around the curves and at all angles to keep the paper from wrinkling when it is pasted Distribute the paste with a small brush and make the overlaps a little more than 14 in. wide and press them to- Buttcrfly Kite . gether with a soft cloth. When the kite is dry decorate it with paint or strips ot colored paper in any de- sign you may fancy. The best ef- fects are produced by pasting pi. colored paper on top of the other pa- per. Black paper decorations show up to line ad\ autage w hen the kite is in llight. Attach the "belly-band" to the curved sticks by pi a hole in the paper in the same m a li- ner as it j„ attached to the common hexagonal or coffin-shaped kite. With a tail, your kite is ready to fly. Ano t h e r interes ting design is the boy kite. \\ ith light colored coat and vest and fray striped trousers, the kite stand- ing high in the air always attracts at- Girl Kite POPULAR MECHANICS tention and affords splendid sport for the American youth in spring-time. In making a boy kite it should be remembered that the larger the boy is the better he will fly. To construct the frame, two straight sticks, say .'i 1 - ft. long, should serve for the legs and Frame for Boy Kite bod\ : another straight stick forms the spine and should be about 2 it. 1 in. long. For the arms, get a fourth straight stick about ■'! ft. 3 in. long. Make the frame for the bead by bend- ing a light tough stick in a circle about 7 in. in diameter. Bind it tightly with a strong thread and through its center run the spine. Then tack on the arm stick 3 in. under the circle so that the spinal column crosses the arm stick ex- actly in the center. Wrap tightly with strong thread and tack on the two Sticks that are to serve for the legs and body. The leg stick- should be fast- ened to the arm stick about 6 in. on either side of the spinal column, and crossed so that the other end- are 3 fl apart. Tack them and the arm stick together at the point where they inter- sect. Small hoops and cross stick oi the same material as the head frame should be fastened to both extremities of the arm stick and the lower ends of the leg stick for the bands and feet. See that both hand frames are exactly alike and exercise equal caution regard- ing the foot frames; also see that the arm stick i- at exact right angles with the spine stick and that the kite joints are all firmly tied and the kite evenly balanced ; otherwise it may be lopsided. Fasten on the strings of the frame, be- ginning at the neck at equal distances from the spine, as indicated by the dotted lines in the diagram. Extend a string slantingly from the armstick to the head on both sides of the spinal column, and run all the other strings as shown in the cut, being careful that both sides of the frame correspond in measurements. To cover the kite, select different colors of paper to suit your taste, and after pasting them together, lay the paper <^n the floor and placing the frame on it, cut out the pattern. Leave an edge of ' - in. all around and make a slit iu this edge every (> in. and at each angle ; make the slits 2 in. apart around the head. After the kite is pasted and dry, paint the buttons, hair, eyes, bands, feet, etc.. as you desire. Arrange the "belly band" and tail band and attach the kite string in the same manner as in the ordinary coffin-shaped kite. The "lady kite" is made on the same principle as the boy kite. The frame may lie made exactly as the boy kite and then "dressed" with tissue paper to represent a girl, or it may be made on the special frame, page 81. Remem- ber the dotted lines represent the strings or thread, and the other line- indicate the kite sticks. Be careful with your measurements so that each side of the kite corresponds exactly and is well balanced. Also see that every point where the .-ticks intersect is firmly tacked and bound. To cover the kite, first paste together pieces of tissue paper of different color to suit your taste. The paste should be made of flour and water and boiled. Make the seams or overlaps not quite :: s in- wide. 1 -ay the paper on the floor, using weights to hold il down, and place the frame of the kite upon it. Then cut out the paper around the frame, leaving an edge of 1 .. in. Don't forget to make a slit in the edge every 6 or 7 in. and at each angle. Around the head the slits are cut "2 in. apart, as in the case of the boy kite. After the kite is POPULAR MECHANICS 83 dry, paint the paper as your fancy dic- tates. To make the breast hand, punch hi lies through the paper, one upon each side of the leg sticks, just above the bottom, and one upon each side of the arm sticks at the sin udder. Run one end of the string through the hole at the bottom of the left limb and tie it to the leg stick; tie the other end at the right shoulder. Fasten one end of another string of the same length at the bot- tom of the right leg; pass the string up across the first band and tie the other end at the left shoulder. Attach the kite string to the breast band at the point where the two strings intersect. Tie the knot so that you can slide the kite string up or down until it is prop- erly adjusted. The tail band is made by tying a string to the leg sticks at the bottom of the breast band. I et the string hang slack below the skirt and attach the tail to the center. The same general rules apply in attaching the string and tail to the boy kite. You can make the lady look as if dancing and kicking in the clouds In- making the feet of stiff pasteboard and allowing them to hang loose from the line which forms the bottom of the skirt. The feet will move and sway with each motion of the kite. How to Make Rubber Stamps India rubber, especially prepared for stamp-making, sin mid be pn icurcd fn im a dealer or manufacturer, if g 1 re- sults are to be obtained. As an experi- ment, it is possible for an amateur to prepare the rubber, but, in such cases, it is always attended with uncertain results. The mixed uncured rubber comes in white sheets, strong, firm and about ' , s in. thick, and for its manipu- lation a press is indispensable, but can be home-made. For the base of the press use a i if in m. bavin- twi i hi des drilled in it at the middle of opposite sides, through which pass bolts, letting the thread ends extend upward and counter-sink- ing places li ir the bolt heads t, i keep the under side of the base level. Solder the bolts in place at the base. The up- per part of the press, or the platen, is also of iron, cut so it can be swung ott the bolts, lather than by removing the nuts and lifting it off. String a half dozen nuts, larger than those which screw on, on each bolt, so that when the upper nut on each is screwed to the extent of the thread the pressure will be communicated through the nuts wedged in between the platen and the upper nut. The bolt holes in the platen should be directly over those in the base. Distance pieces of an exact thick- ness should be provided for use on the base; these serve to keep the pressure even. In preparing the mould, if type is to be copied, use rather large type with wide spaces and set up with high quads and spaces, or the type faces may be tilled up by rubbing with either wax, or soap, lightly brushing off any that remains loose. The type so set should be locked into a frame. This may be made of two pieces of wood bolted to- gether at both ends, or of printer's fur- niture. Place it on a flat surface (mar- ble is good, but any perfectly smooth surface will do) and place distance ' * in. higher than its upper sur- Fa e on either side of it. Apply olive oil to the type faces and wipe off any excess. To form the matrix or reverse of the model, take a piece of iron largei than the inscription to be copied, and spread upon it to a depth of 'j in. a putty made by mixing plaster of paris 84 POPULAR MECHANICS and water to the right consistency. By means of a table knife spread the plas- ter smoothly and then invert the plate upon the model and press down until Vulcanizing Press for Rubber Stamps the distance pieces are struck. Let it set 10 minutes and then remove. If care has been taken the matrix will be perfect. After it has thoroughly dried, preferably in an oven, saturate it with an alcoholic solution of shellac to strengthen it. Cut a piece of smooth rubber, large enough to cover the matrix, from the sheet, throw this into a box of talc, or powdered soapstone, so that it receives a coating on both sides; dust a little of the powder over the matrix, also. Place the press on a support over a gas burn- er, or a kerosene lamp, and apply the heat. Place the matrix on the base of the press, dust off the piece of india rubber and place in the press upon the matrix and screw down the platen. Heat the press to °S I deg. F. and keep screwing down the platen so that the rubber, now soft and putty-like, is forced into every recess of the matrix. A thermometer is not necessary : some rubber always protrudes and the stage of the process can be told from that. At first it is quite elastic, then as the heat increases it becomes soft, then the curing begins and it again becomes elastic, so that, if a point of a knife blade is pressed against it, it resumes its shape when the point is removed. When this take-; place it is then thor- oughly vulcanized and the sheet can be removed from the matrix. Ten min- utes, under favorable conditions, is suf- ficient time for moulding the rubber. By means of common glue, or bicycle tire cement, fasten the rubber stamp to a wi " 'den handle. It is possible to dispense with, the press in making stamps, where the work is not done in quantities, and use a hot flat-iron. The matrix is placed on a stove at low heat, the rubber laid on and the hot iron applied. But a few moments are required to mould it. An old letter press if it be inclosed in a tin oven makes a good press, or all the necessary materials and appa- ratus can be purchased from a dealer. Any type such as all printers use will answer. To Light a Gaslight Without Matches It is probably well known that if you rub your feet briskly over a carpet on a dry, cold day and then touch any metal- lic object with your finger it will emit a small spark. The foil o w i n g amusing experi- ment m a y be di me on the same principle : Take any small piece of wire all' ait 2 in. long and twist it around a gas- burner as shown a t A in t h e sketch. Have the tip i if the burnei about 1 s in. below the end of the wire. The wire must be just far enough away from the center of the burner to keep it out of the flame, or else it will melt. Now get a friend to turn on the gas when you are ready for it. Go around the room once or twice rubbing your feet along the carpet. When you come anmnd to the gaslight touch the point of the wire and if the gas is turned on, the light will flare right up as if it had been lit with a match. This experiment cannot be done on a damp day or without shoes, and works best in cold weather. — Contributed by E. H. Klipstein. A o \J POPULAR MECHANICS 85 How To Make a Trap For Rabbits, Rats ard Mice From an old fi-in. pine fence board cut off four pieces '.''-j ft. long and one 6 in. square fur the end of the trap and another I in. by 8 in. for the door. I'se old boards, as new boards scare rab- bits. Figure 1 shows how the box i 1 - made. It should be 1 in. wide and G in. high 2, and fasten its loop into the loop of the hammer. Mount the bell on a small board as in Fig. '■'• and fasten the cogwheel almost on a line with it. Now press down the hammer and place a nail in the position shown in the dia- gram so that the catch touches one of the teeth. Fasten the board in an upright posi- tion and attach two dry batteries to the binding-posts. If properly connected, OOO/i ■ A Good Trap for Small Animal top and bottom on the inside. Tit boards project 1 in. beyond the side boards al the back and the end In iard is set in. The top board should be '-' in. shorter than the sides at the front. Xail a strip on the top board back of the door and one on the bottom board so the game cannot push the door open from inside the trap and gel out. In the middle of the top board bore a hole and put a crotched stick' in for the lever to rest on. Bore another hole in the top of the door for the lever to pa^s through. Two inches from the back of the box bore a hole for the trigger, which should he made out of heavy wire in the manner shown in Fig. '.'. The door of the trap must work easily and loosely. the fly-wheel will turn quite rapidly and witli amazing force for so small a machine. The machine, however, has a fixed direction as shown by the arrow, but the belting can be arranged so as to send the models in a reversed direc- tion if required. The materials for the motor should not cost more than Novel Electric Motor The materials necessary to make this motor are an old electric bell of the "buzzer" type and a cogwheel from an old clock. Remove the hammer-head and gong from the bell, then bend the end of the hammer into a loop, as in Fig. 1. Now make a little wire catch like Fig. Motor 25c for the bell and if yon have an old hell it will cost next to nothing. — Con- tributed by Fred C. Curry, Brockville, ( Intario. 86 POPULAR MECHANICS How to Build a Model Yacht Alex. E. Quinn Within the past few years the inter- esting and instructive spurt of model yachting lias become very popular in the sporting circles of San Francisco. This popularity has been caused prin- cipally by the efforts of a lately formed model yacht club, in the affairs of which some of the foremost citizens of San Francisco have taken a great in- terest. < hiite a few of these men are of San Francisco. then shaped exactly on the outside to template taken from the lines of the plan ; after which the inside must be hollowed out until the shell is about -i : ', ; -in. thick, except along the keel, where it is advisable to leave l /2 in. of wood for fastening the aluminum fin which takes the lead, and along the deck line where it is best to leave ' j in. thickness for fastening; the deck to the naval architects, marine engineers, etc. The yachts permitted to enter these races must not be over •"><> in. on the load waterline, with a corresponding sail aiea of generally not more than 2,500 sq. in., being classified according io -i e, etc.. in three classes. The following will give an outline of how to construct one of these yachts. The first step is to build the hull, the best wood for this being cedar, and the best metal aluminum, the cedar boat (which will he described) is cheaper, hut takes a longer time to build, as the wood has to be thoroughly seasoned, PLAN hull. In order to make the hull per- fectly watertight, it is best to first ijive it three coats of shellac on the inside, then to glue strips of light canvas or linen upon this and then give two or more coats overall. For a boat of 70- in. overall, 50-in. on the load waterline and a beam of ID in., the hull must not weigh more than ^ lb. after the alum- inum fin. Fig. 1 . is fitted ; the boat com- plete must not weigh more than 27 lb. For ease in transportation the mast should be made portable, at the same time, however, the opening in the deck for the mast must be watertight, and POITLAR MECHANICS 81 this result is 1>est obtained by placing a piece of %-in. brass tubing over a plug secured to the keel by a wood screw (See Fig. 2). This tube is made long enough to project through the deck. To prevent turning, a pin is put through tube and plug. The mast may then lie put in place or removed very easily. An aluminum flanged plate bedded in white lead is placed on the deck where the tube o Miles through in i irder u 1 make it watertight. The bow-sprit, ( Fig. I ) is best made portable also, and the must suitable wood for thi- part is oak. The bow- sprit can be fitted to the deck of the boat by means of two bracket-, the one at the end of the bow-sprit made with three legs, the other brackel need only be a common strap bracket. 'I he ma- terial most suitable for these brackets is aluminum, as this metal is lightest and is it' it affected b\ water. All the rigging fittings, such as rings, screw eyes, pins, etc., had best be made of aluminum also. Two aluminum travelers one for the gib and one for the mainsail, must be titled to the deck, so as to give the booms enough play. Both should be the same length, so the mainsail and gib will be on the same angle. This angle depends on the strength of the wind and can be found by experience in sailing boom stays to be fitted, so that they can be adjusted acci irdingly. The best material for the sails is Lonsdale cambric. If care is taken to have the edge of the sail running from the gaff to the end of the 1 m. in the selvage, no trouble will be experienced on account of slack or baggy sails. vt.rritNecannrc -■£ BRASS TlX ■£"//V5/flf The center of effort of the entire sail area must be about 2 in. or more for- ward of the center of buoyancy of the hull, because these model yachts are fitted without rudders and this is nec- essary for them to sail straight. The lead fur the size of boat men- tioned is best cast in cigar shape and Model Yacht Complete must have its center of buoyancy di- rectly under tile center of buoyancj of the hull, because if these two a in correct relation with each other, the vvaterline of the boat will change, mak- ing the hull dip cither forward or aft. The aluminum tin on which the lead is fastened is best attached to the hull of the boat (if boat is finished natural wood) by means of two aluminum all- eles :; | in b\ :; | in., or if the boat is to be painted or enameled, by cutting slots 1 in. deep and 1 in. apart, or a- wide apart as will come out even, in the upper edge of the tin and then bending the squares alternatel) to right and left. The hull can then In' recessed in way of these squares, in each of which three wood screws fastening it to the hull had best be put ; in this way a very smooth job can be done. The lead may be fastened to the aluminum fin by slotting it lengthwise about half the diameter deep, then boring two or more holes through lead and fin, and fasten- ing the lead to the fin. The claw of a hammer can be used for removing the insulation on copper wire, if not more than 1 in. is taken off at a time. POPULAR MECHANICS How to Make a Very Simple Steam Turbine A tin can of quart size or larger may serve for the boiler. The can must have a good lid, so that it will not leak. In the top of the can, near one edge, punch a small hole. Through this hole the steam is to come out and strike the paddles of a small wheel. Make the wheel of two pieces of wood, fastened together by cutting halfway through the middle of each and then fitting each into the other, as every boy knows how to do to form a four-paddle water wheel. Drive a pin in each side to A Simple Turbine Eng serve as a shaft. For the supports of the wheel use pieces of tin, bent into L-shape and soldered fast to the can. Place them in such position, with re- spect to the small hole punched, that the spurt of steam from the hole will strike the ends of the paddles of the wheel squarely. Fill the boiler three- fourths full of water, set it on a hot stove and as soon as steam is gener- ated fast enough to come out the es- cape hole with slight force the wheel will start to revolve. How to Make Paper Balloons Any boy who can make kites can make enough paper balloons for a Fourth of July celebration and can make and sell enough of them to pay for all the necessary materials, which are very few. Paper balloons may be of any size de- sired and have as many gores as one wishes in whatever colors one prefers. A very good size is 3 ft. in height with 32 gores, each gore being 3 in. wide at the bottom, 8 in. wide at its widest point, and 1 in. wide at the top. To make the balloon pear-shaped, the three widths mentioned when added together (3+8+1 = 12) should be one-third of the height of the balloon. Procure close-textured tissue paper in any contrasting colors you like ; red and white are good. Cut out a paste- board pattern exactly the shape and size the gores are to be and cut the gores out by it. Varnish each gore with boiled oil and hang it up on a line to dry, being careful not to let it come in contact with any other gore. When they are perfectly dry put them together by means of gum water, or clear thin paste. To do this gum about H in. of a gore and lay one edge of another gore midway across the gummed space and dab down very lightly by means of a clean cloth. In this manner unite all the gores in pairs until there are but 1C parts. Continue to unite them until you have two halves. Join these very carefully, closing the balloon at the top completely. Each time you paste a gore hang the part up until perfectly dry be- fore using it further. In the bottom of the balloon work a circle of wire 6 in. in diameter and fasten a wire with a piece of sponge strung on it across the circle of wire. When using dry cells in a damp place put them in a tight box and pour melted paraffine around them. A little graphite mixed in the oil used on lathe centers materially aids in obtaining proper lubrication. Sweet oil and tripoil form an excel- lent coating to prevent brass work from becoming tarnished. Oxalic acid or vinegar and salt are good to remove stains from the metal. POPULAR MECHANICS 89 Mechanics for Young America Trailer for a Bicycle Instead of using' a seat on the han- dlebars or frame of a bicycle for my little girl. I made a trader as shown in Fig. 1 tn attach to the rear axle. I made it from old bicycle parts. The handlebars, which form the hack of the seat, fasten into the seat post of an old bicycle attached to the trader axle. The trailer is attached to the rear axle of the bicycle with two arms or forks on the ends of which are two forgings, formerly used on the rear ends of a bicycle frame, brazed in, and one of the tube projections cut off from each to make a hock as shown in Fig. '.'. The piece marked E shows one of these forgings or hooks in section. The original axle "f the bicycle was re- moved and one supplied 1 5 lli in. longer, which was turned below the threads for clearance, as shown at A. A washer, D, with a hexagon hole was fitted over the regular nut, ( ', on the axle and filed tapering so the forging or hook, K, on the trailer attachment could be kept in position. The washer F is held tightly against the hook by When turning from right to left the left hook on the trailer forks slays in position, while the right hook pushes the washer F outward and relieves the HowTVailer isH to Bicycle flil-A Fig. 2— The Hook in Position strain on the fork. This attachment al^o makes it easy to remove the trailer from the bicycle. The washers F are pushed outward and the honk- raised "iT the axle. — Contributed by John F. Grieves, Providence, R. I. A Window Lock Bore a hole through the sash of the lower window' and halfway through the sash of the upper window where (hey meet in the center and insert a heavy nail or spike. This will fasten Fig. 1— T hed to a Bicycle a pressure from a spring. < i. The spring the sash together so well that nothing is held in place by a small nut. II, and short <>f a crowbar can pry them apart, cotter pin, 1. This attachment makes The nail can be easily removed when a flexible joint for turning corners, the windows are to be opened. '.Ill POPULAR MECHANICS hell. Home-Made Telephone Transmitter The parts for transmitting the sound are encased in a covering, 11, made from the gong of an old electric bell. A round button, D, is turned or tiled from the carbon electrode of an old dry cell and a hole drilled t h r o u g h the center to fit in a binding-post taken from the s a m e battery cell. This but- ton m ust be carefully insu- lated from the , IT, by running the binding-post through a piece of small rubber tube where it passes through the hole and placing a rubber or paper washer, F, under the carbon" button, and an in- sulating washer under the nut on the outside. This will provide one of the terminals of the instrument. Con- struct a paper tube having the same diameter as the button and with a length equal to the depth of the bell case, less ! s in. (due or paste this tube to the button so it will form a paper cup with a carbon bottom. The diaphragm, 1!, which is the es- sential part of the instrument, should be made as carefully as possible from ferrotype tin. commonly called tintype tin. Cut a circular piece from this metal the exact si/e of the outside of the shell. A hole is made in the center of the disk a little larger than a bind- ing-post that is taken from another old battery cell. When making the hole in the disk be careful not to bend in- crease the tin. Scrape the black coating from the tin around the outside about 14 in. wide and a place about 1 in. in diameter at the center. The second electrode, C, is made the same as 1 ), and fastened to the tin dia- phragm with the binding-post without using any insulation. A third binding- post, Ci. is fastened to the shell through a drilled hole to make the other ter- minal. The mouthpiece, A. may be turned from wood in any shape de- sired, but have a flange on the back side that will make a tight fit with the outside of the shell. Fill the paper tube with powdered carbon, E, which can be made by pounding and breaking up pieces of carbon to about the size of pin heads. Powdered carbon can be purchased, but if you make it be sure to sift out all the very fine particles. Assemble the parts as shown and the transmitter is ready for use. If speech is not beard distinctly, put in a little more, or re- move some of the carbon and try it out until yi m get the instrument work- ing nicely. — Contributed by Harold II. Cutter, Springfield, Mass. Quickly Made Lawn Tent A very simple way of erecting a lawn tent for the children is to take a large umbrella such as used on de- livery wagons and drive the handle into the ground deep enough to hold it solid. Fasten canvas or cotton cloth to the ends of the ribs and let it harg so that the bottom edge will touch the ground. Light ropes can be tied to the ends of the ribs and fastened to stakes driven in the ground in a tent-like manner to make the whole more substantial and to stand against a heavy wind. This makes an ex- ceptionally fine tent, as the umbrella Lawn Tent Complete is waterproof; also, there is more room to stand up in than in a tent that is in the shape of a wigwam. — Con- tributed by I. A. Whamer, Schenec- tady, N. Y". POPULAR MECHANICS How to Make a Windmill of One or Two Horsepower for Practical Purposes A windmill for developing from !{> to 3 lip. may be constructed at home, the expense being very small and the results highly satisfactory. The hub for the revolving fan wheel is first constructed. < >ne good way to get In 'th the hub, lining, shaft and spokes for the blades, is to go to a wheelwright's and purchase the wheel and axle of some old rig. There are always a number of discarded carriages, wagons or parts thereof in the rear of the average blacksmith's shop. Some- times for half a dollar, and often for nothing, you can get a wheel, an axle, and connected parts. Remove from the wheel, all but the four spokes needed for the fans as in Fig. 1. The same hub, axle and bearings will do. In case you cannot secure a wheel and shaft, the hub may be made from a piece of hard- wood, about 4 in. in diameter and (i in. long. A 2-in. hole should be bored through for a wooden shaft, or a 1 ' j-in. hole for a metal shaft. The hub may be secured by putting two or three metal pins through hub and shaft. Ad- just the spokes by boring holes for them and arrange them so that thev extend from the center \, like 1'.. The wheel is then ready for the blades. These blades should be of sheet metal or thin hardwood. The sizes may vary accord- ing to the capacity of the wheel and amount of room for the blades on the spokes. Each one is tilted so as to receive the force of the wind at an an- gle, which adjustment causes the wheel to revolve when the wind pressure is - vm i y F J§> E ,/w, ^r E ,r#r,n.fl I H wMm ~J i r^ i I i K F c 2 strong enough. Secure the blades to the spokes by using little metal cleats. C and 1 ». I '.end these metal strips to suit the form of the spokes and flatten against the blades and then insert the screws to fasten the cleats to the w 1. If sheet metal blades are used, rivets should be used f< >r fastening them. The stand for the wheel shaft is shown in Fig. ".'. Arrange the base piei e in platfi >rm i irder, (J i. This is more fully shown in Fig. 5. ( hi lop of this base piece, which is about 3G in. long, place the seat or ring for the re- volving table. The circular seat is in- dicated at I. Fig. 1. This ring is like an inverted cheese box cover with the center cut out. It can be made by a tinner. Size of ring outside, 35 in. The shoulders are I in. high and made of tin also. Form the shoulder by solder- ing the piece on. Thus we get a smooth surface with sides for the mill base to turn in si i as t. . receive the wind at each point to advantage. The X-shaped POPULAR MECHANICS piece H rests in the tin rim. The X- form, however, dues not show in this sketch, but in Fig. 5, where it is marked S. This part is made of two pieces of I M^ 537 A W 2-in. plank, about 3 in. wide, arranged so that the two pieces cross to make a letter X. When the pieces join, mor- tise them one into the other so as to. secure a good joint. Adjust the up- rights for sustaining the wheel shaft to the X-pjeces as shown at E, E, Fig. 2. These are I by 1 in. pieces of wood, hard pine preferred, planed and securely set up in the X -pieces by mortising into the same. Mala- the bearings for the wheel shaft in the uprights and insert the shaft. The gearing for the transmission of the power from the wheel shaft to the shaft calculated for the delivery of the power at an accessible point below musl next be adjusted. The windmill is in- tended fi ir installat i< in on top i if a build- ing, and the power maj be transmitted below, or to the top of a stand specially erected for the purpose. It is a good plan to visit some of the second-hand machinery dealers and get four gears, a pulley and a shaft. Gears about ■"> in. in diameter and beveled will be re- quired. Adjust the first pair of the beveled gears as at F and G. If the wheel shaft is metal, the gear may be set screwed to the shaft, or keyed to it. If the shaft is hardwood, it will be necessary to arrange fur a special con- nection. Tlie shaft may be wrapped with sheet metal and this metal fas- tened on with screws. Then the gear may lie attached by passing a pin through the set-screw hole and through the shaft. The upright shaft like the wheel shaft is best when of metal. This shaft is shown extending from the gear, G, to a point below. The object is to have the shaft reach to the point where the power is received for the service below. The shaft is shown cut < ■ 1 1 at K. Passing to Fig. •'! the shaft is again taken up at L. It now passes through the arrangement shown, which device is rigged up to hold the shaft and delivery wheel P in place. This shaft should also be metal. Secure the beveled gears M and X as shown. These transmit the power from the up- right shaft to the lower horizontal shaft. Provide the wheel or pulley, P, with the necessary belt to carry the p iwer from this shaft to the point of use. The tail board of the windmill is il- lustrated in Fig-. I. A good way to make this board is to use a section of thin lumber and attach it to the rear upright, E of Fig. 'J. This may be done by boring a hole in the upright and inserting the shaft of the tail-piece. In Fig. 1 is also shown the process of fastening a gear, R, to the shaft. The set screws enter the hub from the two sides and the points are pressed upon the shaft, thus holding the gear firmly in place. The platform for the entire wheel device is shown in Fig. . r >. The X-piecc S is bored through in the mid- dle and the upright shaft passes through. The tin run-way or ring is- marked T, and the X-piecc very readily revolves in this ring, whenever the wind alters and causes the wheel's position to change. The ring and ring base are secured to the platform, I r . The latter is made of boards nailed to the timbers of the staging for support- ing the mill. This staging is shown in Fig. 6, in a sectional view. The ring with its X-piece is marked V, the X- piece is marked W, and the base for the part, and the top of the stage is marked X. The stage is made of 2 by 1-in. stuck. The height may vary, ac- cording tn the requirements. It the affair is set up on a barn or shed, the staging will lie sufficient tn support the device. Bui if the stage is constructed direct from the ground, it will be nec- essary tn use some long timbers tn get the wheel up high enough tn receive the benefit of the force of the wind. Proceeding on the plan of the derrick stand, as shown in Fig. fi, a stage of considerable height can lie obtained. To Renew Old Dry Batteries Remove the paper thai covers the cell and knock several good-sized Ivies in the zinc shell. Place the battery in a glass jar, fill it two-thirds full of siting sal ammoniac (or salt) solution and connect the terminals tn whatever ap- paratus the current is tn be used for. A few drops of sulphuric acid quickens and improves the action. The output of the cell will be nearly as great as when the battery was first bought. ( nnti-iliuted by C. W. Arbitt, Austin Texas. Prussian blue and Chinese blue are both the same chemically but they do not cut or look the same. POPULAR MECHANICS Another Electric Motor When an acetylene lamp is in order it will light up slowly with a hissing noise followed by a pure white flame. Should the lamp light up quickly with a yellowish flame, it is a sj^n <<\ a leak somewhere. This form of electric motor is used largely in England in the form of an indicator. It is very easily made and if you have an old electro-magnet will cost practically nothing. A large soft-in m wheel is mounted mi an axle with a pulley-wheel mi one end and a circuit breaker mi the other end. I he teetli mi the circuit-breaker must be tlie same number as on the soft-iron wheel. The electro-magnet is mounted so that its cure is level with the axle and in a line with the wheel. ( )ne wire from it is attached tn one binding screw and the other end is grounded tn the iron frame that supports it. This frame is connected tn the frame sup- porting the wheel. A small brush presses ,,n the circuit-breaker and is en, me, -ted tn the other binding screw. In the diagram A represents the iron wheel : I'., the brush ; < '. the circuit- breaker: I), the magnet. The wire connecting the two frames is shown b) a di itted line. To start the motor, attach your bat- tery tn the screws and turn the wheel a little. The magnel attracts one of the teeth nil the wheel, but as soon as it is parallel with the cue oi the mag- net the circuit is broken and the mo- mentum of the wheel brings another tooth tn be attracted. Tn reverse the motor reverse the con- nections ami start the wheel the other way. He sure that the frames are si i cm ed ilnw ii W ell m- the motor will run jerkily .m,] destro) the connec tions.- Contributed by F. Crawford Curry. Brockville, ( hitario. POPULAR MECHANICS How to Make a Propelling Vehicle Any boy, with a little knack and a few odd tools, can rig up various con- trivances which will he a source of pleasure to himself and oftentimes can be sold, to ,B =n_ less inge- nious hoys, for a snug lit- tle sum. Any tool a boy can obtain is apt to be of use to him, chisel, bit, jack-knife or hammer. Figure 1 shows what two boys did with old cycle wheels. They went to some junk shops where the concerns had purchased cast-away bicycles and noticed that there were numerous wheels in very good order that could be selected from among the sets of wheels with broken or bent rims, spokes, hurst tires, etc. In fact, the lads had no trouble in getting several sets of bicycle wheels in good condition for very little money. These wheels were taken to the back-yard shop of the boys where the young fellows had rigged up a shed-like affair and put in a bench. The previous Christmas one of the boys received a box of tools as a gift, in which was included a little hand vise and the required tools for general boy's h a n d i- work. Four of the c y c 1 e wheels they used in in a k i n g t h e hand - propelled vehicle shown at Fig. 1. A w o o d e n body, A, made of S 111 o t ll boards rests upon s haft s. Fixed on this 1>' idy is an upright carrying the sprocket 1'.. The upright is a piece of wood about in in. high and I in. wide, fitted with one of the bearings from the cycle. The regular cycle chain sprocket is used at B as well as upon the shaft. The regular chain of the cycle is likewise employed, so, when buying the wheels, it is well to select one or more chains with cor- responding sprockets from the junk heap. The detail of the adjustment of the parts is shown in next views. The letter D signifies the seat which is a box. The steering gear is a bent iron rod, also found in the waste pile of the junk shop, and is bent to right form by heating and bending over on a rock or any solid matter. The steering rod is marked E. It fits into a socket in the shaft of the forward wheels. Figure 3 shows the construction of the cart below. The cog is keyed or set-screwed to the driving shaft of the wheels with either key or set-screw used in original fastening, as the case S*- 1 " Gear may lie. The chain is marked F, and there is a slot cut in the floor of the cart to let the chain pass up and through to the cos; on the propelling shaft crank. The disk which receives the steering rod is at G. The forward shaft bears only at the center upon a disk of metal, consisting of any circular piece found among the pieces of iron or brass at the junk store. One can gel nearly all the mechanical parts in junk establishments that purchase parts of out-of-date or cast-away bicy- cles. The detail of the driving shaft is shown at Fig. •'>. The sprocket wheel is at 11 and this is just as it is taken from the original bicycle shaft. The bearings consist of wires looped around the shaft and inserted into holes bored in metal plates as shown. These plates are screwed to the bottom of the cart. POPULAR MECHANICS 95 The shaft itself is found in rods or even cast-away metal axles which are com- monly found in most any carriage works, cycle shops or junk dealer's. Figure 4 shows the disk that receives the steering gear. The disk is bored around edges for the securing screws, while the center is open for the steer- ing rod. When put together, three boys usually ride. One steers and the other two turn the crank. Freight can be carried and some boys do quite an express business in their town with one of the carts like this that thev made. Ringing a Bell by Touching a Gas Jet The experiment of scuffling the feet over a carpet and then producing a spark which will light the gas by touch- ing the chandelier is described on an- other page. One of our correspondents says that if a wire is connected to the chandelier and led to one terminal of the coherer of a wireless telegraph out- fit the bell will ring every time the Tapper 6 Hi Zl Relay HiH Touch the Gas Jet and Ring the Bell spark is produced by touching the chandelier, and that, as the chandeliers are all connected by the gas-pipe, the bell will ring, no matter in which room the spark is produced. The covering quality will be greatly improved if some dry red lead is added to the shellac varnish used fur killing knots. How to Make a Wood-Turning Lathe Out of an Old Sewing Machine With a hack-saw, cut off the arm containing the needle on line AM, Fig. 1, leaving the shaft only. On the end of the shaft will be found a round plate, in which drill four 3/16-in. holes. Now secure, or have turned, a piece of iron or steel 1% in. in diameter, Fig. 2. Drill and countersink four 3/16-in. holes in it to fit the holes on the shaft plate. File a spur center 5/1 G in. long, and two side points 3/l(i in. long. Bolt this plate to the shaft plate with four flat-headed stove bolts, 3/16 in. in di- ameter by % or % in. long, Fig. 3. For the bed, use a board 32 in. long and as wide as the base of the machine arm. This gives a limit of 2 ft. be- tween spur and dead centers. Let this board be made level with the rest of machine table by making a pair of legs if needed. Next make a T-rail, Fig. 4, of two boards, one 5 by % by 33 in., the other iW* by % by 32 in. Three- quarter inch of the wider board pro- jects over each of the smaller boards. Nail firmly and clinch nails, or screw together. Screw this rail on the ma- chine board so that its center coincides exactly with the machine centers. Bore a number of %-in, holes with centers 2% in. apart along the center line of this rail, beginning 6 in. from the end nearest the machine. Make another T-rail for slide tool rest, of two pieces 32 by 3 by •"• i in., and 32 by V/ 2 by % in. Fasten this in front of the larger T-rail and parallel to it, the center lines being 6% in. apart. To make the tail-piece, that is. the part to hold wood to be turned, get a board 6% by 7 by % in., and on the edges, Fig. 5, A, screw two pieces 7 by % by iy L > in. so that the cap thus oo POPULAR MECHANICS made will fit snugly over the large T- threaded to fit the crank, on the head- rail. Fasten to these last two pieces, end of the crank block, and a plain nut o Spur Center End View Front with screws, two more pieces 7 by % by '■'■ i in., Fig. 5, 1!. This tail-piece should move smoothly no side motion. ack and forth with Now get a block of hardwood 4 by 2 1,4 in., and l :i 4 in- higher than the spur cen- t e r w h e n mounted on the middle of the tail- piece just de- scribed. At exactly the height of the spur center bore through this block a ■"• ! in. hoi e, Fig. 5. I lave a blacksmith make a crank S in. long, threaded fur •"> in. as shown. At the dead center end taper the crank and make a cup center, out of which allow a •'! 1 ".-in. point to project. The cup prevents the point from boring into to act as a bearing, on the crank end. I 'nc and one-half inches from the back of the tail-piece bore a %-in. hole. Make a peg % by ~ in. To put in a piece of wood to turn, move the tail- piece back until the head end is over the center of the hole nearest the end of the block, then the pen" will slip into second hole from the head end of the tail-piece, and into a corresponding T- rail hole, pinning the two together. In- sert wood and screw up dead center to hold it. For a tool rest make a second piece like the base of the tail-piece, 11 in. long and fitting the small T-rail. Cut out two blocks 1 ' 2 by '. M 4 by 3 /4 in. and screw them, one on each end of the base of the tool rest, covering the half farthest from the centers, and having an 8-in. space between blocks. On the loos of these blocks screw a strip 11 by \" ] by '"'i in. Now for the rest proper, cut out a board 8 by 11/16 by 9 in. to slide in the slot of the rest. Take a piece of oak 11 by 2 in., and high enough so that the top will lie level with the centers of the lathe, and bevel wood too rapidly. One inch from the outer end of tile crank block. Fig. •">, bore a 3/16-in. hole, and force a l /4-in. bolt to cut its thread in the wood. This is a sd screw to hold the crank in any position desired. Place a strap nut. as shown in Fig. ii. Screw on one end of tlie 8 bv 9-in. piece exactly in the middle. This piece will slide in and out, closer or farther from the centers as desired, and also along the T-rail. A center for turning rosettes, saucers, POPULAR MECHANICS 91 etc., may be made as follows : Remove the spur center and bolt in its place a 1-in. circular board of the same diamc- and 4. Hold the brass strips apart by means of the hard rubber strip and screws. Do not let the screws come ■f H 1 ; 1 ■f~~ mm^ J J- [ V ( -i ( — f.o '«*» j J i| h '** v -*- > H 101 T 1- o ter, using longer 3/16-in. stove bolts with heads countersunk. Rotate the lathe, and with a gimlet bore a hole at the exact center and through the board. Now take off the board and counter- sink on the back a place for the head of a coarse threaded screw. Turn in a 1%-in. screw, replace the board and any block held on the end of the rota- ting screw will turn on and be held while being turned. — Contributed by L. L. Winans, Mexico, Mo. all the way through the rubber strip or you are liable to get a shock in case you should touch both screws simul- taneously. Screw a rubber handle onto the rubber strip to move the lever back and forth with. Fig. 2 shows the ar- rangement of strips, handle, screws, etc., in detail. Fig. 3 is an end view of the same. — Contributed by Eugene F. Tuttle, lr., Newark, ( )hio. Bronze bearings may be cleaned with Reversing Small Battery Motor Make the switch out of a piece of slate (for the base) two strips of brass, a rubber strip and handle and some binding-posts from old dry batteries. Fasten the brass strips at 5 and 6, Fig. 1, so they can swing from 1 and 3 to 'i ution of washing powder and water run through the oil cups while the machine is running without any load. The solution, cutting out the dirt and grime, will come from the bearing very black. About 1 pt. of this mixture should be run through each bearing, then clean thoroughly with clear water. 98 POPULAR MECHANICS A Water Candlestick A glass of water makes a fine emer- gency candlestick. Weight one end of ,t 1 Ht'- o (.over 1 1 i\ 'i ' Je i 1 o ! i CO | 1 , 1 | a. Cover •> " ' " " " Plan of Magazine Binder the candle with a nail just large enough to hold the candle in the water so thai the water comes near its top edge, but does not touch the wick, and then light the candle. It will burn until the last vestige of wick is gone and the flame will not flicker. The melted tallow that runs down but serves to hold the candle mi ire statii mary. ± Magazine Binder Complete How to File Soft Metals When filing soft metals, such as solder or babbitt metal, the file, after a few strokes, will become filled with metal, causing scratches on the surface being filed. The surface may be filed smooth, provided the file has been well oiled. The oil prevents the cutters from clogging and also allows the metal to yield easily. Oil the file every few minutes and use a card frequently in cleaning and the work will be smooth. — Contributed by Jno. E. Ganaway, Paducah, Ky. To Make a Magazine Binder Get % yd. of cloth, one shoestring, a pasteboard box for covers, and some heavy paper. Cut the paste- board into two covers, Vi in. larger all around than the magazine, e x- cept at the back with w h i c h they should be even. Next cut a strip 1 in. wide off the back of each cover. Place the covers on the cloth, Fig. 1, with the back edges Vl in. far- ther apart than the thickness of the volume to be bound. Cut the cloth around the covers, leaving l 1 -; in. mar- gin. 1'aste the cloth on the covers as they lay, and turn over the 1 ' - in. mar- gin, [lasting down smoothly. Cut a piece of stiff paper to fit and paste on the back. Take a piece of cloth as wide as the cover, and long enough to extend over the back and l 1 ' L > in. be- yond e a c h "strip." Paste on to hold all together. Two pieces of paper the exact size of t h c m a g a z i n e, pasted on the inside of each cover protects the edges of the cloth, and adds to the appearance. Let dry slowly. With backs and edges of magazines even, place in a vise and set up tight allowing % in. from back to show above the vise. Pore three 3/16-in. holes V2 in. from the back, one in the middle, the other two 1 ' - in. from each end. Make corresponding holes in the strips of the binder and use the shoestring to complete as in Fig. 2. A piece of wire solder makes a good temporary spline for the draftsman. POPULAR MECHANICS 99 Mechanics for Young America A Library Set in Pyro-Carving By Helen Westinghouse The multitude of indifferently ex- ecuted small articles which followed the introduction of pyrography is begin- ning to disappear, people are consider- ing the art mi ire seriously and apply- ing it to more dignified uses. Pyro- carving is one of the new methods oi decorating furniture which is both beautiful and practical, two qualities which do not always go together. The library set illustrated consists of the stain to be applied directly to the wood without a filler. On the outside of the supports the design is drawn in with pencil, the background is then cut out smoothly with a chisel to the depth of an eighth of an inch, leaving the decoration in re- lief. It is then burned deeply, the back- ground in straight flat strokes, tin- out- lines having the effect of a sloping, dark edge. The shadows are burned in as ^ Table and Seat Decorated in Pyro-Carving a table 30 by 50 in. with two benches, 11 in. wide of the same length. The supports are made of selected white pine, which must he absolutely free from pitch. The pine is soft enough to work easily with the point and stands wear much better than basswood. The tops and braces are made of curly fir, all (if the material must he 2-in. lumber, which dresses to about an inch and a half. All surfaces, except the faces of the supports, are given a well-rubbed coat of oil with a little burnt umber, deeply as possible and the shading is put in with the flat of the point. A wax or egg-shell oil varnish finish is most suitable for this set. A Phoneidoscope The phoneidoscope has many and varied forms, hut the simplest can be made by bending the forefinger and thumb so as to form a circle and then drawing a soap film across them. This is done similar to blowing soap bubbles. POPULAR MECHANICS The angle with the direction of the light may be readily adjusted by turning the wrist, a motion of the elbow alters the distance from the mouth and the ten- sion of the film can be regulated by moving the thumb and forefinger. Singing or speaking at the film when under proper tension will cause beauti- ful figures to appear, which may be re- flected from the film directly on the screen. — Contributed by Robt. E. Brad- ley, Winchester, Mass. A Home-Made Yankee Bobsled A good coasting sled, which I call a Yankee bob, can be made from two hardwood barrel staves, two pieces of *"■ Runners Made of Barrel Staves 8 by 6-in. pine, a piece of hardwood for the rudder and a few pieces of boards. The 2 by 6-in. pieces should be a little longer than one-third the length of the staves, and each piece cut tapering from the widest part, 6 in., down to 2 in., and then fastened to the staves with large wood screws as shown in Fig. 1. Boards 1 in. thick are nailed on top of the pieces for a seat and to hold the runners together. The boards should be of such a length as to make the run- ners about 18 in. apart. A V-in. shaft of wood, Fig. 2, is turned down to 1 in. on the ends and put through holes that must be bored in the front ends of the 2 by 6-in. pieces. A small pin is put through each end of the shaft to keep it in place. The rudder is a l ] /2-in. hardwood piece which should be tapered to y 2 in. at the bottom and shod with a thin piece of iron. A ^-in. hole is bored through the center of the shaft and a lag screw put through and turned in the rudder piece, making it so the rudder will turn right and left and, also, up and down. Two cleats are nailed to the upper sides of the runners and in the middle lengthways for the person's heels to rest against. Any child can guide this bob, as all he has to do is to guide the rudder right and left to go in the direction named. If he wants to stop, he pulls up on the handle and the heel of the rudder will dig into the snow, causing too much friction for the sled to go any further. — Contributed by Win, Algie, Jr., Little Falls, X. Y. How to Make a Small Microscope Theoretically a simple microscope can be made as powerful as a com- pound microscope, but in practice the minute size required by the simple lens tn give the highest power makes it al- most impossible to be used. However, a lens having a reasonable magnifying power can be made in a few minutes for almost nothing. Take a piece of glass tubing, heat one place in a hot flame, hold one end and pull on'the other and draw the heated place down to a fine string as shown in Fig. 1. Take about ;i in. of this fine tube and heat one end which will form a glass bead as shown in Fig. 2. This bead is the lens. When in this form it can be used only in an artificial light coming from one direc- tion, but if you take a piece of card- F,5 1 o F.G 3 F,o 2 Lens Formed by Heat board and bore a hole in it a little smaller than the bead on the glass tube which is forced into the hole, Fig. 3, POPULAR MECHANICS you can use this mounted lens in or- dinary daylight. In this case a mirror must be used to reflect the light up through the lens. It is difficult to see anything at first, as the lens must be held very close to the eye. but in prac- tice you will soon learn to see the ob- ject as it appears enlarged. If you soak a little dried grass or hay in water for a few days and look at a drop of this water, germs in vari- ous life forms can be seen. The water must be put on the lens. One thing to remember is that the smaller the lens, the greater the magnifying power. — Contributed by Daniel Gray, Decatur, Illinois. The water in hot water supply pipes will freeze quicker than water that has nut been heated. This is because the air, which is a poor conductor of heat, has been driven out by the heat. How to Carry Books Almost all school children carry their books with a strap put around and buckled very tight. This will make dents i n the cover where the board over- laps the body of the book. If the strap is left loose, the bonks are liable to slip o u t. Place the cover of one book between the cover and fly leaf of its neighbor and the difficulty will be remedied. This will place the bunks in alternate directions. Books stacked in this manner do not require the strap buckled tight, or, they can be carried without any strap just as well. — Contributed by Thos. De Loof, Grand Rapids, Mich. ^V *y^3r^ ; " m* ^ St BOTTLE PUSHERS.— This is a game in which the competitors push bottles on the ice with hockey sticks. All the bottles must be the same size and make. The persons participating must keep their bottles upright at all times. The bottles are lined up for the start and at the word "go," each person pushes a bottle across the field for a distance that is agreed upon. POPULAR MECHANICS How to Make a Hammock Any one can make a hammock as good as can be bought and that at a cost so small that every member of the family can possess one providing there are places enough for hanging them. The materials required are a needle about 7 in. long, and with a big' eye, an iron ring for each end of the hammock, two long smooth sticks mi which to knit the hammock and two pounds of strong hemp cord or twine. The twine may be colored in any color cm' com- bination of e<'li>rs desired. A Roman stripe at each end of the hammock makes a pretty effect. A hammock 45 in. wide will not be too large for solid comfort. To knit it first thread the big needle and holding it in the left hand, hold the cord in place with the thumb until you have looped the cord over the tongue, then pass the cord under the needle to the opposite side and catch it over the tongue. Repeat this operation until the needle is full. Cut a 2-yd. length of cord and make a loop and fasten to the dour knob or to some other convenient place. Tie the cord on the needle to this loop 3 in. from the end of the loop. Place the small mesh stick under tin- cord with the beveled edge close to the loop, and, with a thumb on the cord to hold it in place, pass the needle around the stick and then, point downward, pass it through the loop from the top. them off the stick and proceed in the same way with the next row, passing the needle first through each of the 30 knots made for the first row. Make •"><> rows and then tie the last loops to the other iron ring. Stretchers may be made and put in place and the hammock, strong and durable, is fin- ished. The work must be carefully and evenly done. One is apt to have a little trouble getting the first row right, but after that the work proceeds quite rapidly. How to Obtain Cheap Dry Batteries Not very many people realize that good, serviceable dry cells can be ob- tained from an automobile garage very cheap. These cells having been "run out" beyond the required number of amperes for automobile use, will give excellent service, considering their cost. Mam- of them will give two-thirds of their original amperage. Six of such cells have been in use on my door-bell circuit for nearly a year. They can be used for other purposes just as well. — < outrilmted by If. II. Cutter. Water Telescope and then firing it over the stick so form- ing the first half of the knot. Pull this tight and hold in place with a thumb while throwing the cord over your hand, which forms the loop. Pass the needle fr> mi under through the loops and draw fast to fasten the knot. Hold this in place and repeat the operation. Make 30 of these knots and then push How to Make a Water Telescope Before you decide on a place to cast your hook it is best to look into the water to see whether any fish are there. Yes, certainly, you can look into the water and see the fish that are there swimming about, if you — ..infl iv have the proper equipment. What you need is a water tele- scope. This is a device made of wood or metal with one end of glass. When the glass end is submerged, by looking in at the open end, objects in . the water are made plainly visible to a considerable depth. In Norway, the fishermen use the wa- ter telescope regularly in searching for herring shoals or cod. All that is necessary to make a wooden water telescope is a long wooden box, a piece of glass for one POPULAR MECHANICS 103 nd end and some paint and putty for mak- ing the seams watertight. Fix the glass in one end of the box, and leave the other open to look through. A tin water telescope is more convenient than the wooden one, but more difficult to make. The principal essential for this is a circular piece of glass for the large end. A funnel shaped tin horn will do for the rest. Snider in the glass at the lar and the telescope is made. Sinkers con- sisting of strips of lead should lie sol- dered on near the bottom to counter- act the buoyancy of the air contained in the watertight funnel and also helps to submerge the big end. The inside of the funnel should be painted black to prevent the light from being reflect- ed on the bright surface of the tin. If difficulty is found in obtaining a cir- cular piece of glass, the bottom may be made square and square L;lass used. Use plain, clear glass; not magnifying glass. To picnic parties the water tel- escope is of great amusement, revealing numerous odd sights in the water which many have never seen before. along the top of the fence about 1 in. How to Rid Your Yard of Cats The following is a description of a device I built at my home in Brooklyn, which not only gave us relief from the Wooden Water Telescope apart, fastening them down with small staples, care being taken that they did not touch. To the ends of these wires I fastened ordinary insulated bell wire, running them to the house and con- necting them to the upper binding- posts of an induction coil; I then ran a wire from the lower binding-post of my coil through the batteries back to the other lower binding-post of coil, breaking the circuit by putting in an ordinary switch. The more batteries used, the stronger the current. The switch should always be left open, as it u^es up the current very rapidly. When "tabby" is well on the wires I close the switch and she goes the length of the fence in bounds, often coming back to see what the trouble is, thus receiving another shock. — Contributed by Charles L. Pultz. A gouge may be used as a substitute Wires Batteries Switch \ JL_J Electric Apparatus for Driving Away Cats nightly feline concerts, but also fur- bit if a proper sized bit is not at hand, nished much amusement to my friends. The gouge can lie placed in the brace I first ran two bare copper wires the same as a bit. 104 POPULAR MECHANICS Drying Films The drying of photographic film in full lengths without scratching or curl- ing is quite difficult. Various devices are used to keep the film straight, and Pins Keep the Film Straight push pins or thumb tacks are supplied with almost all of them. The illus- tration shows a simple and inexpensive device constructed of common wood clothespins without any metal pins to come in c< intact with the film and cause rust streaks. A pair of pins are fastened at each end of the film by pushing one pin over the other which in turn is clamped on the film. A string tied to the heads of one pair of pins provides a way to hang the whole on a nail. The lower pair of pins makes a weight to keep the film straight. — Con- tributed by J. Mac Gregor, Montreal, Canada. Grooved Pulley Made from Sheet Tin A grooved pulley which will run true and carry a round belt may be made without the use of other tools than a compass and pair of shears, with a drill or punch for making two rivet holes. Lay off a circle on the tin, of the di- ameter desired for the bottom of the groove. Then lay off a concentric circle of % in- greater radius. Cut out along the lines of the large circle. On the line of the small circle mark with a prick punch or nail a series of slight dents, about ^4 > n - apart, all the way around. Now make cuts from the line of the large circle to these dents, stopping when the shears give the lit- tle "click" on entering the dent. Bend the little tongues thus formed alter- nately to the right and left, then by shaping them with some care you will have a good running surface for the belt. It will not make any difference if there are more tongues on one side than the other, or if they are not equally spaced, within reason. For the hub, solder or rivet a "handle" across the center hole and drill a hole through it of the same size as the center hole. With the help of solder a grooved pulley which will answer almost every experimental purpose may be made, and it is re- markable with how slight care a per- fectly true wheel may be made in this manner. The same principle might in some way be applied to gear-wheels, for light and temporary use. — Contributed by C. W. Nieman, New York City. An Emergency Glass Funnel Secure a glass bottle having a small neck and tie a string saturated in kero- sene around the outside at A and B as shown in the sketch. Light the string a n d allow it to b u r n until the glass is heated, then plunge the bottle quickly into water. The top or neck will then come off easily. The sharp edges are ground or filed off smooth. This will make a good emergency funnel which serves the purpose well for filling wide necked bottles. — Contributed by Jos. W. Sorenson, Everett, Wash. POPULAR MECHANICS Two Boys Build an Automobile 105 accompanying show t h e The engravin^ completed work of twin boys, Wilford and Win- furd Goddard, 15 years of age. The boys started out with no other mate- rial than what they could collect around their own home. No suggestions were received by them and they de- signed a n d completed the work of building an automobile with the ex- ception of the gasoline engine. This engine they purchased f r o m their earnings. The automobile is about 8 ft. long, with a 40-in. tread. The driving arrangement from the en- gine to the rear axle is connected to a cone clutch, which in turn is connected to a chain drive. The wheels were made from large carriage wheels cut down to the proper size and fitted with 28-in. rims. The tires are standard bicycle tires with an extra cover. On a trial trio it carried four boys ('< The Twins and Their Machine miles, up and down bills and over sandy roads, at a speed of about ID miles an hour. A scientist has calculated that the eyelids of the average man open and shut no fewer than [,000,000 times in the course of a single year of his ex- istence. Seat Removed to Show Construction io« POPULAR MECHANICS How to Make an Etched Copper Picture Frame Secure a heavy piece of copper about 8 or Hi gauge, cut to 1 by 7% in. Make a design on a piece of paper. The ac- companying sketch offers a suggestion. Etched Copper If the design is to be symmetrical, draw a line down the middle of the paper, make one-half the fold and trace the remaining half by placing a piece of double-surfaced carbon paper be- tween the halves. Fasten this design with a little paste on the copper at two of its corners and trace it on the copper by means of the carbon paper Remove the paper, and, with a small brush and black varnish or asphaltum paint, cover the part not to be eaten by the acid of the bath into which the metal is to be immersed. Two or three coats will be necessary to withstand the acid. The conventional trees, the border as shown in the illustration, and the baclc are covered with the varnish or asphaltum. The etching solution should be put in a stone vessel of some kind and care should be taken not to allow it to get on the hands or clothes. A stick should be used to handle the metal while it is in the solution. This solu- tion is made by putting' in the stone jar the following: Water a little more than one-half, nitric acid a little less than one-half. Do not add the water to the acid. Leave the metal in this solu- tion three or four hours. The time will depend upon the strength of the acid and the depth to which you wish the etching to be done. An occasional ex- amination of the object will show when to take it out. When the etching has been carried as far as desirable, take the copper from the bath and remove the asphaltum by scraping it as clean as possible, using an old case knife. After doing this, put some of the solution, or pickle as it is called, in an old pan and warm it over a flame. Put the metal in this hot liquid and swab it with batting or cloth fastened to the end of a stick. Rinse in clear water to stop the action of the acid. When clean, cut the metal out from the center where the picture is to be placed, using a metal saw. Solder on the back several small clips with which to hold the picture in place. There must also be a support soldered in place to keep the frame upright. To further clean the metal before solder- ing, use a solution in the proportion of one-half cup of lye to 3 gal. water. Heat either the solution or the metal just before using. When soldering, care must be taken to have the parts to be soldered thor- oughly clean. Any grease or foreign matter will prevent the solder from running properly. On a piece of slate slab, heavy glass or other hard, non- absorbent substance that is clean, put a little water and grind a lump of borax around until the resultant is like thin cream. Thoroughly clean the parts that are to be soldered by scraping with a knife, and do not touch with the fingers afterward. Place a piece of thin silver solder between the parts after having coated them and the solder with the borax. Use a pair of tweezers to pick up the solder. Hold the parts firmly together and apply heat — slowly at first until all moisture has been ex- pelled and the borax crystallized, after which the flame may be applied more directly and the parts brought to a s< ildering heat. An alcohol flame will POPULAR MECHANICS 107 do. Heat applied too quickly will throw off the snider and spoil the attempt. painted in some pretty tint, or, if pre- ferred, may be enameled. — Contributed by G. J. Tress. LP =0 ^ L7 ^ r^; 2H3 Fig 4 Details of Easel Co There are various ways of finishing the metal. It may be polished by means of powdered pumice, chalk or charcoal, and then treated with a coat of French varnish diluted ten times its volume in alcohol. Another popular way is to give the background a bluish- green effect by brushing it over a great many times, after it has been cleaned, with a solution composed of muriate of ammonia. 1 part; carbonate of am- monia, •'! parts; water, •? I parts. The whole may then be treated with French varnish to preserve the colors. How to Make an Easel A strong and substantial easel may be made at home with very little ex- pense and no great difficulty. Smooth down with a plane, four pieces of pine, 1 in. thick, I in. wide and 1 ft. long, until suitable for legs. Make three cross-pieces, Fig. 1, and join the legs with them as shown in Fig. 2. With an auger 1m ire a hole in each leg about ■"> in. from the bottom, and fit into each a little peg, Fig. 2, for the picture to rest on. The peg should be of hardwood so it will not break. Cut the handle from an old broom, measure off the right length, and put a hinge on one end. Fasten this leg on the second cross-piece, thus forming a support for the two front legs, big. :!. The easel may be finished according to the individual taste. It may be sand- papered and stained and varnished, or How to Make a Wind Propeller A wind propeller may be constructed with four old bicycle wheels arranged with shafts pretty much like the shafts of a hand-propelled cart. The platform is flatter, how- ever, and the body one tier so that it is w e r. A framework of wood is built at M and this Wind Propeller is a support for several purposes. The sail is se- cured to the mast which is fixed into the body of the carl as shown. The sail is linen fabric. There are two cross- pieces to aid in keeping the sail prop- erly opened, 'flic steering arrangement is through tile rear shaft. The shaft is pivoted as in a hand-propelled cart, and the rod I extends from I lie middle con- nection of the shaft up to a point where the person seated on the wooden frame can handle it. There is a brake ar- ranged by making a looped piece J and hinging it as shown. This piece is metal, fitted with a leather face. The cord K is pulled to press the brake. I marks the support for the mast un- derneath the body of the cart. In a steady breeze this cart spins nicely alone the roads. Never change a single ball in a bear- ing. Renew them all. 108 POPULAR MECHANICS How to Construct an Annunciator Oftentimes a single electric bell may be connected in a circuit so that it can he operated from more than one push button. These push buttons are usually located in entirely different parts of the building and it is neces- sary to have some means of determin- ing the particular push button that was pressed and caused the bell to operate. The electric annunciator is a device that will indicate or record the various calls or signals that may be sent over the circuits to which the annunciator is connected. A very simple and inex- pensive annunciator may he made in the following way : Before taking up the construction of the annunciator it would he best to make a diagrammatic drawing of the circuit in which the annunciator is to operate. The simplest circuit that will require an annunciator is one where the bell may he operated from either of two push buttons. In this case the an- nunciator must he constructed to give only two indications. Fig. 1 shows how the various elements of such a circuit may he connected. 1'. is an ordinary vi- brating electric hell. Ml and M2 are the two electromagnets of the annun- ciator, A is a battery of several dry cells, and PI and P2 are the push hut- tons from either of which the bell may be operated. When the push button PI is pressed the circuit is completed through the winding of the magnet All and its core becomes magnetized. In a similar manner the core of the magnet M2 be- comes magnetized when the push hut- ton P2 is pressed and the circuit com- pleted through the winding of the mag- net M2. If an iron armature, that is supported by a shaft through its center and properly balanced, he placed near the ends of the cores of Ml and M2, as shown in Fig. 2, it may assume the position indicated by either the full or dotted lines, depending upon which of the magnets, All <»r M2, was last mag- netized. The position of this armature will serve to indicate the push button from which the bell was operated. The magnets should he placed inside a case and the indication may be made by a pointer attached to the shaft, support- ing the armature. If you are able to secure the electro- magnets from a discarded electric bell they will work fine for the magnets Ml and M2. They should be disconnected from their iron support and mounted upon some non-magnetic material, such as brass or copper, making the dis- tance between their centers as small as possible. The piece of metal upon which the magnets are mounted should now be fastened, by means of two wood screws, to the back of the board, shown in Fig. (>, that is to form the face of the annunciator. It should be about l/g in. thick, \ fa in. wide and long enough to extend a short distance be- yond the cores of the magnets Ml and M2. Drill a 1/1 ('.-in. hole through its center, as shown in Fig. 2. Drive a piece of steel rod into this hole, mak- ing sure the rod will not turn easily in the opening, and allow about ' •_. in. of the rod to project on"" one side, and l 1 /:; in. on the other side. Drill a hole in the hoard upon which the magnets are mounted so that when the long end of the rod carrying the armature is passed through the hole, the armature will be a little more than 1/16 in. from each magnet core. The short end of the rod should be sup- ported by means of a piece of strip brass bent into the form shown in Fig. 3. Frill a hole in the center of this piece, so the rod will pass through it. When the armature has been put in its proper place, fasten this strip) to the board with two small wood screws. You may experience some difficulty in locating the hole in the hoard for the rod, and it no doubt would be best to drill this hole first and fasten the magnets in place afterwards. Two small collars should he fastened to the rod to prevent its moving end- POPULAR MECHANICS wise. Fit the collars tightly on the rod to hold them in place. Cut the lone; end of the rod off so it projects through the face of the an- nunciator about % in. Take some very thin sheet brass and cut out a needle or indicator as shown in Fig. 4. In a small piece of brass drill a hole so it will fit tight on the other end of the rod. Solder the indicator to this piece and force it in place on the end of the rod. When the armature is the same dis- face of the case; three whose dimen- sions correspond to those of Figs. 7, 8. and 9 and are to form the lower and upper end of the case and the finish for the top. Secure a piece of window glass, 4^2 in. by 3% in. that is to lie used as the front. Before assembling the case cut on the inner surface of the pieces form- ing the sides and the lower end, a groove just wide enough to take the glass and 1/16 in. in depth. The outer edge of this groove should be % in. Fig 7 Fig 8 Details of the Annunciator tance from each core, the indicator should be parallel to the long dimen- sion of the face of the case. The case of the instrument may be made in the following way: Secure a piece of %-in. oak. or other hard wood, 3 in. wide and ;. ,1 L . ft. long. Then cut from this board the follow- ing pieces: two whose dimensions cor- respond to those of Fig. 5 and are to form the sides of the case; two whose dimensions correspond to those of Fig. 6 and are to form the back and the from the outer edge of the frame. After the case is fastened together there should be a slot between the piece forming the upper end and the piece that serves as a finish at the top, that will allow the glass to be slipped into place. A small strip of wood should be tacked over this slut, after the glass is put in place, to prevent the dust and dirt from falling down inside of the case. The piece upon which the works are to be mounted may be fastened in place POPULAR MECHANICS by means of four round-headed brass screws that pass through the sides of the case. It should be fastened about x /-2 in. back of the glass front. The back may be fastened inside of the case in a similar manner. Cut two pieces, from some sheet brass, whose dimensions correspond to those of Fig. 10. These pieces are to be used in supporting the case by means of some small screws. Fasten three binding-posts, that are to form the ter- minals of the annunciator, on the top of the upper end of the case. Mark one of these binding-posts C and the other two Ll and \:l. Connect one ter- minal of each of the magnet windings to the post marked C and the other terminal to the posts Ll and L2. You can finish the case in any style you may desire. Oftentimes it is desirable to have it correspond to the finish of the woodwork of the room in which it is to be placed. The distance the point of the indicator will move through de- pends upon the distance between the cores of the magnets and the distance of the armature from these cores. These distances are oftentimes such that the indications of the cell are not very defi- nite. If the armature is moved too far from the cores there is not sufficient pull exerted by them when magnetized, to cause the position of the armature to change. Mount on the shaft carrying the ar- mature a small gear wheel. Arrange another smaller gear to engage this on and fasten the indicator to the shaft of the smaller gear. Any movement now of the armature shaft will re- sult in a relative large movement of the indicator shaft. Figure 11 shows the ar- rangement of the gears just described. How to Make a Steam Calliope Secure ten gas jet valves, the part of the gas fixture shown in Fig. 1, and prepare to place them in a piece of 1 -in. pipe, 12 in. long. This is done l>v drilling and lapping in holes, each Details of the Calliope 1 in. apart, in a straight line along the pipe. The valves screwed into these holes appear as shown in Fig. 2. The whistles are made from pipe of a dia- meter that will fit the valves. No di- mensions can be given for the exact lengths of these pipes as they must be tried out to get the tone. Cut ten pieces of this pipe, each one of a dif- ferent length, similar to the pipes on a pipe organ. Cut a thread on both ends, put a cap on the end intended for the top, and fit a plug in the other end. The plug must have a small portion of its side filed out, and a notch cut in the side of the pipe with its horizontal edge level with the top of the plug. This part of each whistle is made sim- ilar to making a bark whistle on a green stick of willow. The pipes are then screwed into the valves. The whistles may be toned by trying out and cutting off pieces of the pipe, or by filling the top end with a little melted lead. The 1-in. pipe must have a cap screwed on one end and the other attached to a steam pipe. The steam may be supplied by using an old range boiler, placed horizontally in a fireplace made of brick or sheet iron. If such a boiler is used, a small safety valve should be attached. The keys and valve operation are shown in Fig. 3. This is so plainly illustrated that it needs no explanation. — Contrib- uted by Herbert Halm, Chicago. POPULAR MECHANICS Mechanics for Young America Home-Made Snowshoes Secure four light barrel staves ami sandpaper the outsides smooth. Take two "1(1 shoes that arc extra large and cut off the tops and heels so as to leave only the toe covering fastened to the sole. Purchase two long book straps and cut them in two in the middle and fasten the ends on the toe covering as shown in Fig. 1. The straps are used to attach the snowshoe to the regular shoe. When buckling up the straps be sure to leave them loose enough for the foot to work freely, Fig. 2. Fasten the barrel staves in pairs leaving a space of ! in. between them, as shown in Fig. 3, with thin strips of wood. Nail the old shoe soles to crosspieces placed one- F.o 3 Made from Barrel Staves third of the way from < me end a — Contributed by David Brown City, Mo. to\\ II. ansas A Velocipede Racer The small hoy shown in the accom- panying illustration found a way to make a new plaything out of his old one. When he became tired of his old- fashioned velocipede and thought he would prefer a "racing automobile" he simply disconnected the front wind and the fork from the rear wheels by removing the bolt. The back part of the machine was turned upside down and the bolt replaced to join the two pat Is The saddle, which had been pre- vious!) removed, was then attached to the rear axle with a piece of wire and the "racer" was ready for use. — Con- tributed by C. L. Edholm, Los Angeles, California. A Substitute for a Compass An easy way to make a pencil com- pass when one is not at hand, is to take a knife with two blades at one end, open one to the full extent and the other only one-half way. Stick the point end of the full open blade into the side of a lead pencil and use the half-open blade as the center leg of the compass. Turn with the — Contr tor, C knife handle t ibuted l>v E. 1 make . Cold the circle. , I... Vic- 112 POPULAR MECHANICS Glass Blowing and Forming Fortunate indeed is the boy who re- ceives a stuck of glass tubing, a Bun- sen burner, a blowpipe, and some char- coal 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 In he taken up, because much apparatus can he made at home. And fur itself alone, the forming of glass into various shapes has not only a good deal of pleasure in it. hut it trains the hands and the eye. (ilass, ordinarily brittle and hard, be- comes 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 he 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, hut the flame is blue, Mislead 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 par- tial combustion which results in the ordinary yellow flame. All gas stoves have Bunsen burners, and many oil •~t< ives. 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 lTiss worker will need some round sticks of charcoal, sharpened like a pencil, as shown in Fig. .'!. a file, and several lengths of German glass tubing. To bend a length of the tubing, let it be assumed for the purpose of mak- ing a syphon, it i> only necessary to ci irk one end of the tube and heat it near the top of the Bunsen flame, turn- ing 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 he 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, tlie tube being turned continually to assure even heating anil to prevent the lmt end from bending down by its own weight. When very hot, a sudden puff into the open end of the tube will ex- pand the hot glass into a bulb, as in Fig. 6. These can be made of con- siderable 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. S. 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 POPULAR MECHANICS 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 sin mid 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 tlame to a spot on one side of 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 <;ets 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 dem- onstrated by blowing through it at a gas flame, or by immersing it in t spot on the side of the tube is soft enough, the confined air blows out, pushing the hoi 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 pulled out with a mouthful of air, which is ample to blow a (lame 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 punctur- ing 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 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 tub- ing into lengths convenient to handle. It should be a t luce-cornered tile, of medium fineness, and is used simply to nick the glass at the place it is de- sired to cut it. The two thumb- 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 lime pulling the hands apart. The tube will break off squarely at the mil.. 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. The addition of cadmium to soft solder composed of tin and lead, lowers its melting point and increases its strength. 114 POPULAR MECHANICS A NOVEL BURGLAR ALARM Will Ring an Electric Bell, Flash an Electric Light, Shoot a Pistol Four Times and Call the Police A burglar alarm which will do all of these things may be made at small cost and with very little labor. Secure a piece of hard wood, a part of a tobacco box is best, about 8 or 1<) in. square. Cut a round piece like Fig. 1 out of it and on one edge cut a notch as at C. Take a strip of hard wood about 1 in. thick, shape it like B, Fig. 1, and nail it securely to the round piece. At A make a hole large enough to run a 20-penny nail through. Saw off 3 or l in. of the large end of ,^01" ' Construction of Un an old baseball bat, make a hole through this also and nail it to the back of Fig. 1. The 20-penny nail should pass thn iugb the hole at A. through the hole in the bat, and project far enough to drive into the wall. It should be fas- tened either to the wall in the room or the back hall. Figure 3 consists of a piece of ball bat, C, fastened to a strong cord, B, which has a weight. A, fastened to the other end. This is to be wound up on the piece of bat, C. Shape a piece of wood like Fig. 4, about 6 in. long. Make two holes A and B in it. The short arm of this piece is to project over the end of B, Fig. 1, and act as a trigger to keep the weight, A, Fig. 3, from dropping until wanted. The lower end of Fig. 4 is to be securely fastened to a piece of wood projecting from the wall so the short arm will slip over the end of B, Fig. 1. Now fasten a string in the hole. A, Fig. I, and run the string to the doors and windows. You can run a dozen or more strings to the hole, A. The best way is to put a hook, or eye, Rear in the door facing on one side of the door and a hook on the other side. Make a short hook out of a piece of hay wire and attach it to the end of the string. At night hook the end of string attached to trigger in eye on one side of door facing, draw it in front of door and put through the eye on other door facing. Leave the screen or other door unlocked and if any one attempts to go through the door he will put the ma- chinery to work and get a "warm re- ception." The string should be about 2 ft. above the floor. Remove the trigger guard from a POPULAR MECHANICS 115 double-acting cheap revolver, and fas- ten it so when the weight, A. runs down, the piece, P>, Fig. 1, will strike the trigger and fire the pistol. Blank cartridges <"//v should be used. They will prove effectual as the burglar will hardly stop to investigate. Take a small block of wood, B, Fig. 2, and fasten two springs on it so that they will nearly touch. Fasten this block of wood so when the weight is wound up the springs will he in the m itch, C. Fig. 1. When the weight falls the springs will lie pressed together, thus ringing the electric hell and fur- nishing an electric light. If you haw.' no electric lights in the house, yet a small electric hand lantern. The lull and light may both be connected on the same circuit. Fig. 2 shows how this is done: A A, are the springs; 1'.. block of w 1; C C C C, wire-; D, hell; K. lamp; F, batteries; <; (, I '. G, screws to which the wires are attached. Now in addition, if you want to call the police, get a small, cheap phon- i igraph and a record w ith " I '< ilii e," "Fire," "Murder," or anything else on it you wish. Make anything you please on it. Place it directly in front of your telephone transmitter and con- nect it with Fig. 1, and also connect the receiver of the phone with Fig. 1, so that when the weight falls it will start the phonograph and at the same time will drop the receiver of] it- hook-, consequently calling the police. Any one with a little ingenuity can connect the phonograph, and the receiver of the telephone so that when the weight falls they will do their part. It will cost very little to make this and it will prove a sure protection. If you w isli you can leave off calling the police, ringing the hell and flashing the light and only have it tire the pistol. Loosening Salt in a Shaker If a common salt shaker is filled to the top, the -alt sometimes becomes damp and so closel) packed that it can not he shaken through the perforated cap. This can he remedied by placing a piece of non-corrosive metal or hard- wood in the center of the shaker and attaching a small thumbpiece on the end through the center hole of the shaker cap. The upright is provided with two cross-pins at the bottom, two at the center, and one at the top, close to the holes in the metal cap. The salt For Loosening Salt can l>e loosened by rotating the upright with the thumbpiece. Keeping Matches Dry The camper knows how difficult it is to keep a supply of matches dry. I have found the following very simple 3s to he invaluable in such cases. Take some paraffin and melt it in a shallow pan in a water hath. Immerse the ordinary friction matches in it for an instant, withdraw, allow to cool, and the matches will have a thin coat of paraffin which protects them from water. I have left a match so pro- tected in a basin of water for half a dav and then lighted it by striking in the usual way.— < ontributed by Arvid W. Andersi m. ( mtaha, Nebr. How to Repair Tungsten Lamps Turn the lamp into a socket which is attached to a flexible cord, switch on the current, and hold the lamp so that you can see the broken ends inside of the ylass. Gently shake the globe so the ends will come in contact. This will cause the lain]) to light and the ends will often fuse together. — Con- tributed by R. P. Small, 1 Vtroit. Mich. \ crumpled wire may he quickly straightened by catching one end in a vise and giving the other several hard jerks, using pliers to hold the wire POPULAR MECHANICS TELEGRAPH CODES morse, used in the united states and canada. CONTINENTAL,used in Europe and elsewhere, phillipsused in the united states for"press"work. Dash -2 dots. Long dash -A dots. Space between elements of a letter -I dot Space between letters of a word -2 dots. Interval in spaced letters =2 dots Space between words -3 dots. LETTERS Morse Continental A E- H PUNCTUATION, ETC. Morse Continental . Period : Colon — ^Semicolon , Comma ? Interrogation — ! Exclamation — Fraction line -Hyphen 'Apostrophe £ PoundSterling •B Paragraph — Italics or underline ( )Parentheses C ] Brackets ) ""Quotation marks) Phillips Min. Minute. Msgr Messenger Msk. Mistake No. Number. Nre. Nothing. N.M.No more. O.K. All right. Ofs. Office. Opr. Operator . Period - : Colon ■.— Colon dash ; Semicolon -- , Comma ? Interrogation '. Exclamation ■ Fraction line -Dash ■ -Hyphen £ Pound Sterling / Shi/ling mark B> Dollar mark - d Pence Capitalized letter- - - -■ Colon followed by) quotation :" ) c Cents . Decimal point \ using two boards end to end and putting battens on the inside over the joint. Each pontoon is made i if t w< > bi iards 1 in. thick, 1 1 in. wide and Hi ft. long, dressed and cut Id the shape shewn in Fig. 2. Spread- ers are cut from 2-in. planks, 10 in. wide and 1 2 in. long, and placed 6 ft. apart between the board sides and fast- ened with screws. White lead should he put in the joints before turning in the screws. Cul the ends of the boards SO they will tit perfectly and make pointed ends to the pontoons as shown Turn this shell upside down and lay a board Vi; '"• thick, 12 in. wide and 16 ft. long on the edges of the sides, mark Completed Boat on the under side the outside line of the shell and cut to shape roughly. See that the spreaders and sides lit true all over, then put white lead on the joint and nail with 1%-in. finishing nails as close as possible without weakening the wood. Slightly stagger the nails in the sides, the I in. side hoards will allow for this, trim off the sides, turn the box over and paint the joints and Details of the Pon in Fi^. 3, and fit in a wedge shaped ends of the spreaders, giving them two piece; white lead the joints and fasten or three coats and let them dry. well with screws. Try each compartment for leaks by 118 POPULAR MECHANICS turning water in them one at a time. ISore a %-in. hole through each spreader in the center and through the Crosspiece and Rudder Details bottom board as shewn. The top board, which is ' j-in. thick, L2 in. wide and 16 ft. Inns;, is put on the same as the both mi. After finishing both pontoons in this way place them parallel. A block of wood is fastened on top of each pon- toon and exactly over each spreader on which to bolt the crosspieces as shown in Fig. I. Each block is cut to the shape and with the dimensions shown in Fig. 5. The crosspieces are made from hick- ory or ash and each piece is 2 ] '-j in. thick, 5 in. wide and li 1 '- ft. long. Bore a %-in. hole :: in, from each end through the 5-in. way of the wood. Take maple flooring : V, in. thick, li in. wide, 1'-\ ] » in. long and fasten with large screws and washers to the cross- pieces and put battens across every IS in. Turn the flooring and crosspieces upside down and fasten to the pon- toons with long %-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 side:', will also keep the water and spray out and much more so if a 12-in. dash is put on in front on top i if the en isspiece. The rudders are made as shown in Fig. 6, by using an iron rod % in. in diameter and 2 ft. long for the bearing of each. This rod is split with a hack- saw for " in. of its length and a sheet metal plate 3 '■'■'2 in. thick, 6 in. wide. and 1".' in. long inserted and riveted in the split. This will allow % 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 V 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 cross- piece, 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. Rough alligator finished photograph mounts will not receive a good impres- sion from a die. If a carbon paper is placed on the mounts before making the impression, a good clear imprint will be tin- result, POPULAR MECHANICS How to Train a Dog C. H. Claudy He's a good dog, a nice dog, we'll rather loosely with st tin admit at the outset, but he doesn't know much about minding you, does he? He'll come when you call him, because he knows v< iur voice and 1. w es you, but he won't go when you send him. lie cannot understand why you don't want him! As to fetching or carrying, or guarding, or lying down, or rolling over, or "playing dead," or standing up and begging, or carrying a message or anything like that — "Well, he never was taught those things!" you say, indignantly. But il, when you grew up, you couldn't read nor write nor talk, and some one said of you in defense, "Well, he never was taughl those things!" in that same indignant tone, on whom would the reflection he, you or your parents ? It is an easy matter to teach a dot; almosl anything. There is only one principle to master. A dog's mind re- sponds to the elementary moral law of reward and punishment. But, just as you don't expert your mother to punish your baby sister when she flings liei rattle and breaks something, so you mustn't punish a pup for doing some- thing he doesn't know is wrong, or fail- ing to do something which he hasn't mastered. Punishment should be rare, and only for disobedience, nevei foi failure to understand. that is the whole thing in a nutshell. For instance, your dog, just past the wobbly leg stage of puppyh I. will take anything in his mouth which he can get in it. along with a good many things which look entirely too big for mastication. Again, he will run after anything that moves, a hall, a stick, a stone. lie has in his mind the desire to do the first hall of tin- act of fetch- ing. All you have to do is to get into his head the Other half, the idea that what he runs after and picks up must l>e broughl i' i you. To do this requires some stout cord, a collar, some stale bread soaked in gravy, a soft hall made of rags wound ittle time every day, and a whole lot of patience and good nature. Fasten the collar on the dog and the string to the collar. Roll the ball away anil let the pup have his head. Ile'il chase it and mouth it— and drop it! Get the ball yourself, and roll it again, saying, "Fetch it, Dan!" (or whatever his name is. ) Let him have his head again. When he picks the ball up in his mouth, give a gentle pull on the string. I he chances are a hundred to one he'll drop the ball again. But the mere repetition of the rolling ball, the word-, "Fetch it, Dan," and the pulling of the string will, repeated day after day, make an impression. Some day the ball will either stay in Dan's mouth when he brings up at the end of the cord and returns to you. because his teeth have caught on the I wine wound around the ball, or he will turn towards you with it in his mouth before the pull on the cord reminds him. Then, bread and gravy in quantities ! It may be several days before this happens again, or it may be in the next five minutes. Some dogs learn much more quickly, and much younger, than other dogs. Thus, a fox terrior gels his first growth long before a mast iff, and so can be taught earlier. But it will happen again, and the con- stant commands, cord pullings, and gravy rewards will accomplish their purpose. Dan will learn that for some inscrutable reason, when that ball stays in his mouth until you take it out, bread and gravy results' And, once this is learned, a pat and a kind word satisfy him in place of the gravy ! The dog who answers to his name and can fetch for you can be taught anything. Me has learned that reward follows certain things he does. Never let linn forget it. Always reward the mastery of a new trick with something to eat, the performance of an old one with a pat and a word, and use the POPULAR MECHANICS whip only for disobedience, and then, sparingly. Il is undeniable that a dog can be taught more quickly by fear than by patience, but mure is sacrificed than is gained. You would not care to have a dog win 'so tail went between his legs every time he sav\ you coming, would yon? Hardly. The hearty, doggish greeting, the barks and yelps of wel- come, are worth more than the little patience you must use to teach him without the whip. So, when you get td. Teaching him to mil over is the same — -roll him over when you tell him to roll until he rolls himself, and "play- ing dead" is hut instructing him, by the same means, to lie on his hack", all lour legs up in the air, and motionless. Learning to "guard" is hut a doub- ling of "fetch it" and "lie down." If. lying down, he drops the object, put it between his paws. After a while, lie will put ii there. Then go off and leave him for short periods, and don't let him get up and walk oil' until you reappear and tell him he may. A dog has so much intelligence, once it is started, that il won't take the idea long to get into his head that this lying down busi- ness, with a hall between his paws, means something. He ma} never know' n'hat it means, hut he won't question it further than to know that he is doing what you want. Finally, get some one else to take the hall away. If this can he done, it is your turn to come and ask' Man for it, and turn away from him. lie won't like it. and he'll try to find out why. Tried again, immediately, and the same result may occur, hut some time, and soon, he who tries to take that hall away will he met with a growl— and the less, m is learned. It is a pleasant pastime, teaching a dot;, and the hoy who can do it, and at the i-iid of a month has some tricks to show, an unused whip, and a dog which still worships him, is a pretty good sort of a hoy — the sort of a boy a di il; likes t( . have as master ! CONTENTS Aeroplane, Taper, How lo Make 15 Alarm, Flectric, Rings Bell and Turns mi Light 25 Alarm, Novel Burglar Ill Alarm, Simple Burglar, How to Make 58 Alarm, Simple Fire. How to Make 4!> Annealing chisel Steel 52 Annunciator, How to Construct 108 Automobile, Two Boys Build 105 Balloons, Taper. How to Make 88 Barrel Moat for Sailing 42 Batteries, Cheap l>ry, How to Obtain 102 Batteries, l>ry, Another Way to Renew r,s Batteries, Dry, Renewing 57 Batteries, I>ry. To Renew 93 Batter; Motor, Small, Reversing 97 Batter; Motor, Toy, To Make l.irt Weight. . 80 Bell, Kinging by Touching Gas Jet 95 Bicycle Frame, Enameling 75 Bicycle, Trailer for 89 Bicycle, Water, How to Make 2.1 Binder, Magazine. To Make 98 Blowpipe, Home-Made 43 Roat. Barrel, for Sailing 42 Boat Cruising Catamaran, How to Make... 117 Roat. Ice, 1 low to Build 47 Roat. Taper. How to Make 5 Boating, Ice 72 Bobsled, Home. Made Yankee 100 Rooks, How to Carry 101 Rottle, Diving 19 Rottle Pushers 101 Bottles, To Remove Glass Stoppers from.... so Bronze Liquid, Oood 15 Bulb, To Make on Glass Tube 8 Rnrglar Alarm, Novel Ill Burglar Alarm. Simple, How to Make 58 Burnt Wood Work Done by Son 19 Calliope, Steam, How to Make. . 110 C '' Practical, for Fifty Cents 55 Cameras, Box, Home Marie Duplicator for. . r.:i Camps and How to Build Them 29 Candlestick. Water 98 Cannon. Lead. How to Make 26 Canvas. How to Waterproof 20 Card-Case, How to Make ,'!8 Catamaran. Cruising, Hew to Make 117 Cats. How to Rid Your Yard of 103 Chain, Novelty. Made from n Match (17 Chisel Steel. Annealing 52 Clock, Noveltv for the Kitchen 50 Clerk. Old, TTso for 57 Coaster. Home Made Overhead Trolley 77 Coronnut. To Rreak Open 1 H Coin and Tumbler Trick 68 Coin Purse, How to Make 44 Compass. Substitute for Ill Copp.r Picture Frame. Etched, How to Make. 106 Corks. How to Fit 58 Crossbow and Arrow Sling. How to Make. ... 27 Crutch, Home-Made 59 Dark Room Lantern, Temporary 28 DIabolo 68 Diving Rottle 10 Dog, How to Train 119 Dry Batteries, Another Way to Renew 68 Drv Batteries, Cheap, How to obtain 102 Dry Butteries, Old, To Renew 98 nrv Batteries, Renewing 57 Dumb-Belle, How to Make 1.1 Duplicator, Home-Made. for Box CameraB. ... 63 Easel, How to Make 107 Elderberry Huller, Home .Made g Electric Engine, How to Build 69 Electric Motor, Another ;>:t Elecl rlc Motor. Novel 85 Electric Piano, To Make 35 Electric Wires, Flexible, Adjuster for 76 Electrical Experiment, Interesting 07 Enameling a Bicycle Frame 75 Engine Electric, iiow to Build 69 Eyes, Opening 105 Pan, Inexpensive Wooden, How to Make 20 Film Washing Trough 19 Films, Drying 104 Finger. Removing Tlght-Flttlng Ring from. .. , :, 1 Fire Alarm, Simple, How to Make 40 Fire Extinguisher, Home-Made 39 Fishing, Jug Fine 12 Fishing Signals 70 Fishing Tackle, How to Make 16 Fisherman, '•.lumping .lack." How to Make.... 70 Floor Polisher, Home-Made rtK Flower Stand. Ornamental Iron 4:i Frosting, To Keep Window Class from 44 Furnace Regulator, Electric, How to Make. . . 78 Funnel. Emergency Class 104 Game Bottle Pushers 101 Gas Jet, Ringing Hell by Touching 95 Gaslight, To Llghl Without Matches 84 Class mowing and Forming 112 Class Funnel. Emergency 104 Class, To Keep from Frosting 4 1 Class Tube, How to Make a Bulb on 8 Hammock. How to Make 102 Hand. How to See Through 18 Hang Heavy Things on Nail, To 7 Hectograph, How to Make m Ice Boat. How to Build 47 Ice Boating 72 Illusion, Another Optical 86 Illusion. Rolling Uphill 61 Illusions. Optical 64 Indicator, Electrically Operated, for wind Vane 3fl Insulating Cleats. Substitute for 36 insolation on Wire, Removing 98 Iron Flower Stand. Ornamental 4,'l Iron Work. Ornamental, Easy Designs In 60 Jig Saw Puzzle, Photographic 51 Jug Line Fishing y> Kerosene. Use In Polishing Metals 64 Kites of Many Kinds and How to Make Them, 81 Lamp, Quickly Made 15 Damps, To Make Burn Brightly 54 Damps. Tungsten. How to Repair 115 Lantern, Home Made Magic 14 Lantern, Temporary Dark Room 28 Lathe, Wood-Turning, Making Out of Old s,w- lng-Machlne 95 Leaf. Photograph on 52 Library Set in Tyro Carving 09 Lock. Window 89 Magazine Binder. To Make 98 Magic Lantern, Home-Made 14 Match. Novelty Chain Made from 67 Matches, Keeping Dry 115 122 Merry-Go-Round, To Build 49 .Metal. Sheet, Sawing 103 Metals, Dse of Kerosene in Polishing 54 Microscope, Small. How to Make 10(1 Morse Code 116 Motor, Another Electric 93 Motor, N'ov.l Elect ri<- 85 Motor. Small Battery, Reversing 07 Motor. Toy Battery, To Make Lift Weight.... 80 Motors. Water, How to Make 40 Mouse Trap 85 Nail, To Hans Heavy Things on 7 Necktie Holder, Home-Made 50 Negatives, Restoring Broken 67 Optical illusion, Another 36 Optical Illusions 54 Paint Running 28 Paint, Sealed 53 Taper Boat, How to Make 5 Paste, Adhesive 42 Perfui Making Outfit 53 Phoneidoscope 99 Photograph Mounts. Alligator 11 s Photograph on Leaf 52 Photographic .1 Ig Sav, Puzzle 51 Photographs, Making on Watch Dials to Photography — Drying Films 104 Photography — Film Washing Trough 19 Piano, Electric, To Make 35 Picture frame. Etched Copper, How to Make 106 Plating Outfit, Small Silver. How to Make... 50 Polisher, Home-Made Floor 38 Polishing Metals. Use of Kerosene in 54 Post Card Holder, How to Make 53 Propelling Vehicles, Mow to Make 94 Pulley, Grooved, Made from Sheet Tin 104 Purse, Coin, How to Make 44 Puzzle, Photographic Jig-Saw 51 Puzzle. Wire. Simply Made 68 Pyro-Carving, Library Set in 99 Babbit Trap 85 Rat Exterminator, Electric 4 s Rat Trap 85 Ring, Tight-Fitting. Re vins from Finger... 51 poller Skates, II Made 70 Rubber Stamps. How to Make 83 Sailomobile, How to Make 10 Sails. Skater's 71 Stilt. Loosening in a Shaker 115 Sawing Sheet Metal 103 Sconce, How to Make S Searchlight. Small, How to Make 24 See Through Hand, How to Settee Homo Made Sewing Bag, How to Make Sewing-Machine. Old, Making W 1-Turnln Pall "!' . Silver Plating Outfit, Small. How to Make. . . Skat. r'S Sails Skates, Home-Made Roller is P.", Skis. Norwegian 74 Sled. Toboggan, How to Make 74 Sleds ami Chair Sleighs, To Build 73 Sleigh, Running 70 Sling, Crossbow and Arrow. How to Make... 27 Snowshoes, Home-Made Ill Steam Turbine. How to Make ss Steam Turbine, Miniature. How to Make 12 Steamboat Model, Simple 4.", Steel. Chisel. Annealing 52 Street tar Line, Imitation. How to Build 04 Telegraph and Teh]. hone Line. Combination . . 20 Telegraph Instrument and Buzzer, How to Make 22 Telegraphy- -Morse Code lit! Telephone and Telegraph Line. Combination.. 20 Telephone Tra tismi 1 1 or. Home Made 00 Telescope, Water. How to Make 102 Tent, Bell, How to Make Of. Tent. Quickly Made fawn 90 Tents, Weatherproofing for 70 Tin. Sheet. Grooved Pulley Made from 104 Toboggan Sled. How p. Make 74 Trailer for a Bicycle so Trap for Rabbits. Rats and Mice 85 Trick, foin and Tumbler 08 Trick— Diving Bottle 19 Trolley Coaster, Home-Made Overhead 77 Trousers Hanger, How to Make 50 Tungsten Lamps, How to Repair 115 Turbine Engine, How to Make 45 Turbine, Miniature Steam. How P, Make 12 Turbine, Simple Steam. lion- to Make 88 Vane. Wind, Electrically Operated Indicator for 36 Vehicli — How to Make a Wind Propeller.... 107 Vehicle, Propelling, How to Make 04 Vehicli — Sailomobile 10 Velocipede Racer Ill Velocipede, Winter 70 Ventriloquist, Mechanical, Hon- to Make. . . 00 Vise. Home-Made 28 Watch Dials. Making Photographs on 76 Water Bicycle, How to Make 23 Water Candlestick '-is Water in Pipes. Freezing 101 Water Motors, How to Make 411 Water Telescope. How to Make 102 Water Wl 1, How to Make 64 Weatherproofing for Tents 70 Wind Propeller. How to Make 107 Wind Vane, Electrically Operated Indicator for 30 Windmill for Practical Purposes. To Build. ... 91 Windmill. Miniature. How to Make 21 Window I.oek 89 Winter Sport. Devices for. How to Make 70 Wire Puzzle. Simply Made OS Wires. Flexible Electric, Adjuster for 76 X-Ray Experiment 615 Yacht, Model, How to Build 86 Popular Mechanics Practical Books = Written So You Can Understand Them = 25 CENT INDUSTRIAL HANDBOOK SERIES No. 1 . Mission Furniture, How to Make It— Part 1 This is Number 1 of the Popular Mechanii s25-cenl Series oi Industrial Handbooks. It t. lis plainly how to make twenty-one different articles of Mission Furniture, the instructions being accompanied by working drawings and hall tones of the finished articles. % pages, cloth cover. Price 25 cents. No. 2. Metal Spinning By PROF. F. D. CRAWSHAW, Assistant Dean, College of Engineering, University of Illinois. This bock consists of practical instructions in this fascinating art. and is the only book published on tins interest me subjei i. \\ ritten by a man well qualified on account of Ins thorough studv <>l all obtainable information . ,,n- cerning same. A working manual both fur those who desire to spin metal work as a trade. SO pages, cloth cover. 33 illustrations. OUR NEW BOOK JUST FROM THE PRESS Pattern-Making Price $1.00 Postpaid. By G. H. WILLARD. With Additional Chapters on Core-Making and Molding. A book for the man who has to do the work. Written bv a practical pattern maker of many yea! right down to business in the first chapter and keeps it up throughout the book. Full of kinks and actual working information Profusels illustrated- Every one following this trade, or intending to learn it should have a copy of this valuable book- 224 pages. 312 illustrations, cloth covers. Time and Its Measurement B y james arthur Reprinted from Popular Mechanics. So far as known is entirely different from anything previously written on the Mr Arthur is a great author it \ along this line having for years ma. I,- an ox tens ive MuJi oi clocks, watches and time-measuring devices. Contents: Chapter 1— Historic Outline. 2 lapancse Clocks. 3— Modern ( ocks. I Astronomical Foundation of Time. M pages, profusely illustrated. Size 7x10 inches. Printed on coated paper with handsome Mia i loth i overs. Price $1.50 Postpaid. SHOP NOTES SERIES OF YEAR BOOKS One of these books is issued the first of each year, and is a reprint of all the articles which have been published during : past 111 our "Shop Notes Department." Shop Notes for 1 90S Shop Notes for 1 908 200 Pages, Vol. I, 385 Illustrations. 212 Pages. Vol. IV, 536 Illustrations. Shop Notes for 1 906 Shop Notes for 1 909 228 Pages. Vol. II, 555 Illustrations. 216 Pages, Vol. V, 561 Illustrations. Shop Notes for 1 907 Shop Notes for 1 9 1 228 Pages. Vol. Ill, 580 Illustrations. 224 Pages Vol. VI, 543 Illustrations. These books are a perfect gold mine of information lor everyone inten -t d in mi . h inics, or who uses tools for pleas- an occupation. Of equal v. dm in. I help to the prolcssiom ch.nu, ami the amateur. 50 cents per volume. Complete Set, 6 Books in a Case, $3.00 Express Prepaid. 25 CENT MECHANICAL BOOKS Amateur Mechanics. No. 1 A loo page I k for old and young telling how to make useful articles. Size 6tfxW inches, containing 165 illus- trations. The descriptions ami illustrations enable anyone mechanically inclined to build at trifling expense all sorts oi things for the h e as well as foi use in outdoot sports. Price 25 cents. Amateur Mechanics. No. 2 Biggei and better than No. I Contains entirely different matter, yet along the same interesting, practical lines. Tellshowto make main more different articles ol riaiU use. among which are: Workbench. Pilot Balloon. Ft Photographs. \\ u. ! h. Boats .,1 Various Kinds. Induction Motor. 1. allien) slides \,, I.., nip. rhermoEli trii Batters Motorcycl. Batters Voltmeter, tie.ssler Tube Pevi.es lnUim.i - . m five. Glider, Flash Lamp. Static Machine. ( oncrete Swimming Pool. I , ,pper V. Pi , Tricksol ill Kinds and Illusions, etc. Interesting to the practical mind, both old and young. l.Np....- re, Wti- ... illustrations Price 25 cents. Mechanics for Young America wheels, electric burglar alarms, clocks, searchlights, wate .vlnch delight the heart ot the average hoi. loOpages. 170 illustra Price 25 < All above prices include postage or express. Order of your newsdealer or send direct to publisher POPULAR MECHANICS BOOK DEPT. 225 Washington Street, Chicago. Amateur Mechanics No. 1 A VALUABLE BOOK Of Exceeding Interest to the Practical Mind For both old and young Price 25 cents postpaid Ai i elerometer, Simple Acetylene ("..is ( .(-iterator, Home-Made i proach Ammeter. Ib.« to Make Ai.inin. i.itiewsaeaiers. 0rder from your News company. 25c Popular Mechanics Book Dept. 225 Washington Street, CHICAGO 25c 25c POSTPAID JUST PUBLISHED PART TWO 25c POSTPAID Mission Furniture 128 pages | JJ W tO Make It 1 Cloth cover 40 New and Approved Designs A large and varied selection of immensely popular pieces, among which are: Settee — Two China Closets — Three Arm Chairs — Rocker — Side Chair — Magazine Stand —Mantel Clock — Lamp Stand — -Two Foot Stools — Bookcase — Magazine Table — Smoking Stand —Wall Case — Waste Paper Basket — Music Stand — Hall Clock — Window Seat — Mission Table — Cedar Chest — Child's Dresser — Serving Table — Couch — Table — Oil Lamp — Grill — Two Writing Desks — Library Set— Hall Tree— Buffet— Bedstead— Dining Table— Wall Shelf- Medicine Cabinet — Magazine Rack — Tabouret — Pedestal — Umbrella Stand — Telephone Stand — Plate Rack — Screen — Folding Card Table Complete dimensioned working drawings, explicit instructions how to make, and halt-tone illustrations of the finished pieces. Special Features Are: Articles describing how to produce the different finishes and show- ing methods of making joints and bending wood. "Written So You Can Understand It" May be ordered of any newsdealer in the U. S. or will be sent to any address postpaid upon receipt of the price, 25 cents, by the publishers. 25c POSTPAID POPULAR MECHANICS COMPANY 225 Washington St., CHICAGO 25c POSTPAID SOc Each ENTIRELY NEW IN THIS COUNTRY SOc Each Separable-Parts Models of Steam Engine, Wireless Telegraph, Motor Car, Gas Engine, Dynamo, Steam Turbine Price 50c Each Postpaid Complete Set of 6 Models $2.50 Postpaid Illustration shows how parts separate THESE models are of great value as a means of graphically showing all the interrelated parts ot the above named mechanisms by virtue of their construction, which is similar to that of educational manikins of the human body and organs, with which nearly everyone is familiar. Beginning with the outermost or surface parts of the gas engine, for exam- ple, these are all differently colored and numbered to correspond to a printed key of names which comes with each model. By means of their hinge-like attachment, they may then be lifted, thereby disclosing to view the layer of parts next underneath, exactly as they would be in the engine itself, and so on until the innermost construction is shown. The models are carefully made by hand in Bavaria, and this is the first time they have been offered in this country. We are the sole rep- resentatives in the United States. As their value to engineers, students and, in fact, everyone having occasion to refer to the construction and working of the different mechan- isms mentioned, was at once apparent to us, we felt that they would be highly appreciated here. They are substantially made of heavy paper, and with ordinary care will last indefinitely. Supply Limited Order Now = ADDRESS = Popular Mechanics Book Dept., c 5 h i c ago