PART II--A Festooned Kite

More than one kite on the same framework is known as a compound kite. The one illustrated consists of three tailless kites on one long stick, called the spine. The upper one is 3 ft.; the center one, 2 ft., and the lower one, 1 ft. in width. There will be needed for the construction of this kite a stick of light wood--spruce is best, but it may be of pine or bass--7 ft. long by ¹⁄₄ by ¹⁄₂ in. If the wood breaks easily it will be better to increase the width from ¹⁄₂ in. to ³⁄₄ in., or the stick might be made ³⁄₈ in. thick without increasing the width, but with a good spruce stick the dimensions first given will be sufficient. The stick should be straight-grained and without a twist. If the spine is twisted, the kites will not lie flat or in a plane with each other, and if one is out of true, it will cause the kite to be unsteady in the air. The bow sticks are three, the upper one being 4 ft. long by ¹⁄₄ by ¹⁄₂ in.; the center one, 2 ft. long by ¹⁄₄ by ³⁄₈ in., and the lower one, 1 ft. long by ¹⁄₄ by ¹⁄₄ in. About five sheets of tissue paper will be required, but more may be needed for color combinations. The so-called French tissue paper is much better, as it comes in fine colors and is much stronger than the ordinary tissue. It costs a trifle more, but it pays in making a beautiful kite. The Chinese rice paper is the strongest, but it comes only in natural colors.

It will be seen that the kites do not extend to the top and bottom of the spine stick. The first bow stick is placed 13 in. from the top end of the spine, and each of its ends extends 6 in. beyond the kite for fastening the festoons. The bow sticks should be lashed to the spine, not nailed. Wind diagonally around the two sticks, both left and right, then wind between the two, around the other windings. This draws all windings up tightly to prevent slipping.

To string up the upper kite, drill a small hole through the spine, 6 in. from the top, at A, and also 6 in. from each end of the bow stick, at B and C. If a small drill is not available, notch the stick with a knife or saw to hold the string. Another hole is made in the spine 29 in. from the upper bow stick, or at D. Tie the outline string at A, then pass through the hole at C, then through D, up through B and back to the starting point at A. In tying the last point, draw up the string tightly, but not enough to spring the spine or bow. Measure carefully to see if the distance AC is the same as AB, and if CD is equal to BD. If they are not, shift the string until they are equal and wind at all points, as shown at E, to prevent further slipping. Proceed in the same way with the center and lower kite, and it will be ready for the cover.

The cover tissue should be cut about 1 in. larger all around than the surface to be covered, but turn over about half of this allowance. This will give plenty of looseness to the cover. For the fringe festoons, cut strips of tissue paper, 2¹⁄₂ in. wide, paste ¹⁄₂ in. of one long edge over a string, and cut slits with scissors at intervals of 1 in. along the loose edge. After the fringe has been made, attach it as shown in the illustration. Do not stretch it tightly, but give sufficient looseness to make each length form a graceful curve and keep the sides well balanced.

To bend the bows of the upper and center kites, attach a string from end to end of each bow on the back side of the kite and spring in short brace sticks in the manner usual for tailless kites.

Attach the upper end of the bridle at A. The length of the bridle string is 87 in. and the kite line is attached to it 30 in. from A, leaving the lower part from this point to F, where it is tied to the spine, 57 in. long.

The kite should fly without a tail, but if it dodges too much, attach extra streamers to the ends of the bow sticks of the lower kite, and to the bottom of the spine.

If good combinations of colors are used a very beautiful kite will be the result, and one that will fly well.

Simple Experiment in Electromagnetism

The following simple experiment, which may be easily performed, will serve to prove the theory that there is a magnetic field produced about a conductor carrying a current, and that there is a definite relation between the direction of the current in the conductor and the direction, or polarity, of the magnetic field produced by the current. The current in the experiment is to be produced by a battery consisting of a small copper and zinc plate fastened to the under side of a large flat cork, as shown in the sketch, the whole being placed in a glass or rubber vessel partly filled with diluted sulphuric acid. A small coil of wire is formed and mounted on top of the cork, and its terminals are connected to the copper and zinc plates. The electromotive force generated will cause a current to circulate through the coil from the copper plate to the zinc plate. If the poles of a permanent magnet be presented in turn to the same side of the coil it will be found that there is a force of attraction between one pole of the permanent magnet and the coil, and a force of repulsion between the other pole and the coil. If the same operation be performed on the opposite side of the coil, it will be found that the force between the poles of the magnet and the coil are just the reverse of what they were in the first case; that is, the pole that attracted the coil in the first case will now repel it, and the one that repelled it, will now attract it. Applying one of the fundamental laws of magnetism--like poles attract and unlike repel each other--it can be readily seen that the two sides of the coil are of opposite magnetic polarity.

If the direction of the current around the coil be changed, the action between the coil and the magnet will be opposite to what it was originally, and if the plates be placed in clean water, there will be no current and no attraction or repulsion between the coil and the poles of the magnet.

Double Lock for a Shed

Four boys using the same shed as their workshop wished to lock it so that any one of them could enter alone. Usually only two keys are supplied with a lock, so two locks were purchased and applied to the staples as shown. Each boy was provided with a key and could enter at his pleasure.--Contributed by George Alfred Moore, Versailles, O.

Ferrules for Tool Handles

Discarded metal caps from broken gas-mantle holders should be saved, as they will come in handy for several purposes, such as ferrules on wood handles, and the like. The wire screen is removed from the end, and the cap is fastened to the handle with a nail or screw.--Contributed by James M. Kane, Doylestown, Pa.

Mallet Made from Wagon-Wheel Felly and Spoke

When in need of a mallet and if an old broken and discarded wagon wheel is at hand, one can be made quickly as follows: Cut through the rim at A and B, and through the spoke at any distance desired, as at C, for instance. The spoke is dressed into the shape of a handle and sandpapered smooth. The section of the felly is used as head and is shaped properly and fastened to the handle with two nails.--Contributed by Mark Gluckman, Jersey City, New Jersey.

A Mystery Sounding Glass

Procure a thin, tapering drinking glass, a piece of thin, black thread, about 2 ft. long, and a long lead pencil. Cut a small groove around the pencil near one end. Make a slip noose in each end of the thread and slip one into the notch and place the thin glass in the other with the thread near the top. When the pencil is revolved slowly the thread will be wound on it slightly and it will slip back with a jerk that produces a ring in the glass. This may be kept up indefinitely. The movement necessary is so small that it is imperceptible. The glass can be made to answer questions by two rings for “yes” and one ring for “no.”

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¶A lighted match held to the outside of a fish-pole joint causes an expansion of the outer ferrule and allows the pole to be readily pulled apart.

Repairing a Broken Canoe Paddle

While paddling a rented canoe one day the paddle struck a rock and snapped in two a little below the center of the handle. The boatman laughed at the idea of trying to fix it, but after paying his price for the paddle I decided to try mending it. The barrel of an old bicycle pump was procured and I found that it fitted over the paddle at the break a trifle loosely. It was pushed on the handle out of the way. Then with a No. 8 bit I bored a hole 8 in. deep in the end of each broken part. Into these holes, which formed one cavity when the broken ends were brought together, was forced and glued a tight-fitting 16-in. dowel pin. The outside of the handle was then wrapped with tape for about 10 in. each side of the break, and the pump barrel was forced down over this tape until it completely and firmly enveloped the broken ends.--Contributed by Clarence G. Meyers, Waterloo, Iowa

Tightening Lever for Tennis Nets

Tennis nets are always sagging and to keep them at the proper height requires considerable attention, especially so where the posts are not solidly set in the ground. A very effective net tightener, and one that is easy to make is the lever shown in the illustration. One end of a piece of hardwood board is shaped into a handle the other end being left large. In the latter a hole is cut to fit loosely over the post for the net. The upper end of the post is notched and a sheave pulley is placed in it so that the groove will be in line with the net. The upper rope on the net is run over the pulley and is attached to the lever handle. A downward pressure on the handle draws the rope taut and locks it on the post. It is easily removed from the post and can be left attached to the rope and rolled up in the net when not in use.

A Desk Watch Holder

A watch holder for the desk is a great convenience for the busy worker, and many calendar devices are sold for this purpose, yet they are no more efficient than the one illustrated, which can be made from an ordinary spindle desk file. If the wire is too long it can be cut off and the bend made in it to form a hook for the watch ring.

Cleaning Silverware

To clean silverware or anything made of the precious metals, such as jewelry, etc., is very simple with the following method: Place a piece of zinc in a cup, dish, or any glazed ware; put in the articles to be cleaned, and pour over them a hot solution of water and carbonate of soda--washing soda--in proportions of one tablespoonful of soda to ¹⁄₂ gal. of water. This is a solution and method used by many jewelers for cleaning pins, rings, chains, and many other small articles made in gold and silver.

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¶A machine should never be stopped in the midst of a fine cut.

An Eight-Pointed Star Kite

BY CHARLES M. MILLER

Nearly every boy can make kites of the several common varieties without special directions. For the boy who wants a kite that is not like those every other boy makes, an eight-pointed star kite, decorated in an original and interesting manner, in various colors, is well worth while, even if it requires more careful work, and extra time. The star kite shown in Fig. 1 is simple in construction, and if carefully made, will fly to a great height. It is balanced by streamers instead of the common type of kite tail. Any regular-shaped kite should be laid out accurately, as otherwise the error appears very prominent, and unbalances the poise of the kite.

The frame for this star kite is made of four sticks, joined, as indicated in Fig. 5, with strings running from one corner to the second corner beyond, as from A to C, from C to E, etc. A little notching of each pair of sticks lessens the thickness of the sticks at the center crossing, and strengthens the frame, The sticks are ¹⁄₄ by ¹⁄₂ in. by 4 ft. long, They are set at right angles to each other in pairs, and lashed together with cord, and also held by a ³⁄₄-in. brad at the center. The strings that form the sides of the squares, A to G, and B to H, must be equal in length when tied. The points where the strings forming the squares cross each other and the sticks are also tied.

The first cover, which is put on with paste, laying it out on a smooth floor or table as usual in kite making, is plain light-colored paper. The darker decorations are pasted onto this. The outside edges of the cover are turned over the string outline, and pasted down. The colors may be in many combinations, as red and white, purple and gold, green and white, etc. Brilliant and contrasting colors are best. The decoration may proceed from the center out, or the reverse. The outside edge in the design shown has a 1¹⁄₂-in. black stripe. The figures are black. The next octagonal black line binds the design together. The points of the star are dark blue, with a gilt stripe on each. The center design is done in black, dark blue, and gilt.

The flags are tied on, and the tassels are easily made of cord. The outside streamers are at least 6 ft. long, and balanced carefully. Ribbons, or dark-colored lining cambric, are used for them. The funnel-shaped ends balance the kite. They are shown in detail in Figs. 2, 3, and 4, and have 1-in. openings at the bottom, through which the air passes, causing a pull that steadies the kite. They are of dark blue, and the cloth fringe is of light blue. A thin reed, or fine wire, is used for the hoop which stiffens the top. Heavy wrapping or cover paper is used to cover the hoops. It is cut as shown in Fig. 4 and rolled into shape.

A four-string bridle is fastened to the frame at I, J, K, and L, as shown. The upper strings are each 18 in., and the lower ones 32 in. long, to the point where they come together, and must be adjusted after the kite line is fastened at M.

Second Handle on Hoe or Rake Saves Stooping

Anyone who has used a hoe or rake for days at a time will appreciate the labor saved by the attachment for the handle shown in the illustration. It is adjustable to various-sized persons by means of the holes at the front end of the horizontal piece. The two parts are each made of strips joined at the middle portions, and arranged to clamp on the handle of the hoe or rake. In hoeing around shrubs and large plants, the handle may be set to one side.--A. S. Thomas, Amherstburg, Ont., Canada.

Photo-Copying Lens Increases Angle of Camera

Trying to take some indoor pictures I found the angle of my ordinary lens was insufficient to “get in” the various objects I desired. Not having a wide angle lens, I decreased the focal length of the lens by using a copying attachment. The results were quite pleasing and while there is some distortion and less of the plate is covered than usual, there is a remarkable increase in the angle of view. To obtain definition, it is necessary to stop the lens down, but the pictures are very clear.--Samuel L. Pickett, Denver, Colo.

Belt for Sprocket Drive Made of Brass Strips

Being unable to purchase a small driving chain for sprockets made by cutting out every other tooth in gears taken from a clockwork, I used a brass strip, properly punched, and found it satisfactory. The strip was .005 in. thick and the points where the holes were to be punched out were indicated by dividers set from the gears. I made a punch from a nail leaving a small center on it as shown and grinding the end to an oblong shape. I used a piece of sheet lead as a die, on which to punch the strips. The marks made by the dividers provided spots on which to set the center of the punch, making the result quite accurate.--Edward M. Davis, Philadelphia, Pa.

Rain Alarm with Drop-of-Water Contact

An annunciating device, which awakens a person sleeping in a room with the window open and warns him that it is raining, so that he may close the window, is an interesting bit of electrical construction. On the outside of the house, as detailed, is a funnel fixed to the wall. At its small end, two separate wires have their terminals. The wires enter the room at the frame of the window, and connect to an electric bell, and a dry cell. A drop of water entering the funnel, flows down to the small end, falling on the terminals of the wires, and acting as a conductor, completes the circuit, ringing the bell. A switch inside cuts out the circuit, stopping the bell’s ringing.--John M. Chabot, Lauzon, Quebec, Can.

Coaster Steering Gear Made from Cream-Freezer Drive

In rebuilding a wagon into an automobile coaster, I used the driving rod and gears from an old ice-cream freezer, and found that it worked so well that perhaps other boys might be interested in the job. The front of the coaster was covered with a hood, and the steering wheel was set back of it, as shown. The center rod of the freezer was used for the steering post F, and an old rubber-tired wheel was made into a steering wheel. The casting from the top of the freezer, with the gears in it, and the rod on which the turning crank was fastened were set on a block, H, and braced, as shown. The shaft where the crank was fastened, at B, was set through the wagon bed. A crosspiece of iron, A, was wired to the axle D with wires C. A heavy block was used for a turntable. The top end of the casting was fastened to the hood with a brace, G, and the block H steadies the rigging also.--L. Chester Bryant, El Dorado, Ark.

Pad for Glass Vessels Made of Corks

In the kitchen, shop, laboratory, and other places where glass or other fragile dishes or vessels are used, a convenient pad on which to rest them can be made by stringing corks on a strong cord or wire in the form of a ring. Several rings of corks may be used to make a mat, or rings slightly larger in diameter than the bottle or vessel may be made for certain sizes of containers. If desired, the corks may be cut to fit closely on the radial joints, making the resulting ring more secure.

A Shaving Lamp and Mirror for the Camp

To make shaving possible in camp at night, or with little daylight, a small mirror was provided with an electric flash light. The mirror was set to swing free, in a wooden support. The light was fastened slightly above and behind the mirror. and swings at its base, so that it can be tipped upward or downward, throwing the light correspondingly. A piece of wood, 1¹⁄₄ by 3¹⁄₂ in., and as long as the mirror frame is wide, serves as a base. The arms will hold the mirror far enough in front of the lamp to allow room in which to swing. The body of the lamp is set on a block, and held between two wooden pieces, into which a band of iron was set near the top. The uprights move in an arc, pivoting at their lower fastening, on screws.--C. L. Meller, Fargo, N. D.

Automatic Electric Light on Talking-Machine Cabinet

In many homes the phonograph is placed where little light is available in changing the records, setting the needle etc. An electric light which is lighted only while the cover of the phonograph is raised, is well worth installing. A metal arm, A, supports the open cover of the cabinet. When the cover is closed, this arm passes through a slot and takes the position shown by the dotted line. A strip of spring brass, B, is fastened to the inside wall of the cabinet, in the path of the arm, so that it will be pushed down to the off position, as indicated. When the arm releases the strip B, the latter presses against the contact C. A small electric lamp, D, is set in the corner, and electrical connection made to it through B and C, the plug connections passing through the back of the cabinet. When the cover is down, the electric circuit is open, and the moment it is raised, connection is made at C, and the lamp lights. The backs of most phonograph cabinets may be removed easily to make these changes.--M. C. Ball, Kansas City, Mo.

Device for Suspending Parcels from Overhead Hooks

To hang small sacks or other articles out of reach overhead, so that they may be easily taken down, I use a double-eye hook which I made of wire. A single piece of wire is used, and twisted into two loops as shown, and then formed into a twisted hook. I use a pole with a nail, hooking it into the lower loop, to raise the parcel; this leaves the upper loop free to be hooked on the nail above.--E. B. Warren, Garnet, Mont.

Steel Wool as Aluminum-Ware Cleaner

It takes little trouble to keep aluminium pots and pans shining if they are cleaned frequently with steel wool, water, and a nonalkaline soap. Use a very fine grade of the wool, and give the utensils a few rubs frequently rather than attempt to clean them only occasionally, when much soiled.--L. P. Langan, Denver, Colo.

How to Make a Model Old-Four Monoplane

BY RALPH M. BROWN

The old-four monoplane model, made famous by its wonderful flights, is one of the most graceful that has been built. Its large size and slow, even glide make it a much more desirable flier than the ordinary dartlike model. It gives one a true insight into the phenomena of heavier-than-air flight. This machine, when complete, should weigh 9 oz. and fly 1,200 ft., rising from the ground under its own power and landing lightly. Its construction is simple, and with careful reference to the sketches, an exact reproduction may be made.

For the motor bases, A, Fig. 1, secure two spruce sticks, each 48 in. long, ³⁄₈ in. wide, and ¹⁄₄ in. thick, and fasten a wire hook on one end of each stick with thread wound around after giving it a coat of glue. These hooks are to hold one end of the rubber bands that act as the motive power, and are designated by the letter B. At the opposite ends of the sticks, at C, bearings are provided, which consist of blocks of wood, each 1 in. long, 1 in. wide, and ³⁄₈ in. thick. These are also bound in place with thread after gluing them. Holes are drilled through the blocks lengthwise and then lined with bushings made of brass tubing, ¹⁄₁₆ in. in inside diameter. The two motor bases A are connected with four cross sticks, D, each 9 in. long and ³⁄₁₆ in. square. These are bound and glued on the under side, one near each end and the others equidistant each from the other and from the nearest end stick. The front bumper E is made of round rattan, ¹⁄₈ in. in diameter.

The alighting gear is next in order of construction. This is made as shown entirely of bamboo, ³⁄₁₆ in. square. The pieces marked F are 11 in. long; G, 9¹⁄₂ in. long, and the cross bar H, 11 in. long. At the rear, the pieces J are 13 in. long; K, 4¹⁄₂ in. long, and the cross piece L, 11 in. long. The distance between the points M and N, Fig. 2, is 6 in., and between O and P, 9 in. The bamboo is easily curved by wetting and holding it for an instant in the flame of a candle. It will hold its shape just as soon as it becomes cold. The wheels are made of tin, 1¹⁄₂ in. in diameter, borrowed from a toy automobile. The axles are made from wire, ¹⁄₁₆ in. in diameter.

The wing spars Q are made of spruce, ³⁄₁₆ in. wide and ¹⁄₄ in. thick. Those for the front are 30 in. long, and for the rear, 36 in. long. The ribs R are made of bamboo pieces, ¹⁄₁₆ in. square, 5 in. long for the front plane, and 6 in. for the rear. These are bound and glued on top of the spars, 3 in. apart. They are given a slight upward curve. The round ends are made of ¹⁄₁₆-in. rattan.

It is rather difficult to make good propellers, but with a little time and patience they can be shaped and formed into good proportions. Procure two clear, straight-grained blocks of white pine, 8 in. long, 1¹⁄₂ in. wide, and ³⁄₄ in. thick. Draw a diagonal line on one block from opposite corners, as shown at S, Fig. 3, then on the other block T, draw the line in an opposite direction. Turn the blocks over and draw opposite diagonals, as shown by the dotted lines. Draw a circle on each side exactly in the center, ¹⁄₂ in. in diameter. Drill ¹⁄₁₆-in. holes through the centers of the circles for the propeller shafts. The wood is then cut down to the lines drawn, leaving only enough material so that they will not break easily. The face of the blades should be flat and the back rounded. Leave plenty of stock near the hub. After the faces have been finished, the blades are shaped as shown at U. The propellers should be finished with sandpaper to make them perfectly smooth, as much of the success of the model will depend upon them. It will be a good plan to shellac them, and also the frame and the alighting gear. Aluminum paint costs but little, and it makes a fine finish for a model aeroplane.

The propeller shafts V, Fig. 1, 2, and 4, are cut from bicycle spokes. An eye for the rubber band is bent in the spoke, about 2 in. from the threaded end. The end having the threads is run through the bearing block C, Fig. 4, and the propeller fastened on with a small washer on each side of it by means of two nuts, W, cut from a bicycle nipple. These nuts may be turned up tightly with pliers.

The planes are covered with tissue paper put on tightly over the tops of the ribs, using a flour paste. The planes are movably fixed on the motor bases A by tying at the four points of contact with rubber bands. This makes it possible to adjust the fore-and-aft balance of the machine by changing the position of the planes.

The motive power, which is the most important part of the entire machine, consists of rubber bands. There are three ways of obtaining these bands. It is best, if possible, to purchase them from an aeroplane supply house. In this case, procure about 100 ft. of ¹⁄₁₆-in. square rubber, 50 ft. for each side. These are wound closely between the hooks X. This rubber can be taken from a golf ball. It will require about 40 strands of this rubber, which is removed by cutting into the ball, on each propeller. Another way of obtaining the bands is to purchase No. 19 rubber bands and loop them together, chain-fashion, to make them long enough to reach between the hooks without stretching. About 30 strands on each propeller will be sufficient. The hooks X are made in the shape of the letter “S,” to provide a way for taking out the rubber bands quickly. To prevent the hooks from cutting the rubber, slip some ¹⁄₁₆-in. rubber tubing over them. The rubber bands, or motor, when not in use, should be kept in a cool, dark place and powdered with French chalk to prevent the parts from sticking together.

With the model complete, flying is the next thing in order. With a machine as large as this one, quite a field will be necessary to give it a good flight. Test the plane by gliding it, that is, holding it up by the propellers and bearing blocks on a level with your head and throwing it forward on an even keel. Shift the planes forward or back until it balances and comes to the ground lightly.

Winding up the propellers is accomplished by means of an eye inserted in the chuck of an ordinary hand drill. While an assistant grasps the propellers and motor bearings the rubber is unhooked from the front of the machine and hooked into the eye in the drill. Stretch the rubber out for about 10 ft., and as it is wound up, let it draw back gradually. Wind up the propellers in opposite directions, turning them from 400 to 800 revolutions. Be sure to wind both propellers the same number of turns, as this will assure a straight flight.

Set the machine on the ground and release both propellers at once, and at the same time push it forward. If everything is properly constructed and well balanced, the mechanical bird will run about 5 ft. on the ground and then rise to 15 or 20 ft. and fly from 800 to 1,200 ft., descending in a long glide and alighting gracefully.

If the machine fails to rise, move the forward plane toward the front. If it climbs up suddenly and hangs in the air and falls back on its tail, move it toward the back.

After the novelty of overland flights has worn off, try flights over the water. To do this the wheels must be removed and four pontoons put in their place, as shown by the dotted lines in Fig. 2. The pontoons are made over a light frame, constructed as shown in Fig. 5. The frame pieces are bamboo, ¹⁄₈ in. square. Each one is 8 in. long, 4 in. wide, and 2 in. deep. The covering consists of writing paper glued in place, after which the whole surface is covered with melted paraffin to make it water-tight.

No doubt various methods will be suggested by the time such flights are made, such as smaller planes for racing, larger ones for altitude and duration, etc. To make the machine carry weights, build a duplicate set of planes and fasten them 6 in. above the others by means of struts, ³⁄₁₆ in. square, forming a tandem biplane, as shown by the dotted lines in Fig. 2.

Patience is the one thing necessary in model budding. Sometimes a machine carefully made will not fly, and no one can make it do so until some seemingly unimportant alteration is made.

How to Make a Pair of Trammels

The making of these trammels is a very nice workshop problem for a school, as it requires a very small amount of stock and a corresponding degree of skill, and at the same time adds a little something to the general shop equipment.

The brass is best procured in strips, which may be had in different widths, except the bar, which is ¹⁄₄ in. thick and not less than ³⁄₄ in. wide. The steel for the points may be the ordinary steel, or if the trammels are to be used on woodwork, very satisfactory points can be made of heavy nails.

Cut two pieces of brass, 4¹⁄₄ in. long, and straighten them with a wood or rawhide mallet on a surface plate. Draw center lines both ways through each piece and lay out the openings for the bar with a sharp scriber, and make a center-punch mark for the ¹⁄₈-in. hole that is to be drilled at the intersection of the center lines. Mark the lines where the piece is to be bent, and with a pair of dividers lay out the ends and shape them with a file.

The center hole and bar openings are next drilled, and the latter finished by filing. It is better to plane up a short piece of hard wood, ¹⁄₄ by ¹³⁄₁₆ in., and use it as a gauge in filing the rectangular openings than to try to make them by measurement. Polish the brass pieces with a piece of fine emery cloth or paper, rubbing it in straight lines lengthwise of the stock.

The bending is done by clamping the pieces in a vise and bending first one side and then the other on the lines indicated. This will require some care, as the upper ends should be 1¹⁄₄ in. apart on the inside when the bending is complete. To insure the same angle on both sides, a template of wood is used, and the pieces are carefully bent to fit it.

The holes for the points are reamed tapering from the inside, where they are riveted in place. The points are filed to shape and polished, which is best accomplished in a lathe. Clamp one of the points in an upright position in a vise with the shouldered end up. Slip one of the brass pieces in place and rivet by upsetting the projecting end with a light hammer.--Contributed by J. A. Shelly, Brooklyn, N. Y.

Seeding Bare Spots on Lawns

A lawn that shows patches of grass with bare spots, or only partly covered with grass can be sown with seed that will fill the uncovered places by using the tool illustrated. It is made of a block of wood, 1 in. thick, into which several large nails are driven so that their ends project about 1¹⁄₂ in. Another block is fastened on top of the nail heads to keep them from pushing out of their holes. A handle is attached to the latter block.

The tool is used by driving it into the earth where there is no grass, or in thin places, and the grass seed is sprinkled into the holes. In raking over the lawn the young grass is not so apt to be torn out and destroyed before it gets a good root.--Contributed by Edmund H. Trabold, Orange, N. J.

A Porch Swing

The seat of the swing consists of a board, 30 in. long, 14 in. wide, and 1 in. thick, with holes bored in each corner for the ropes. The rail at the top is made of four oak pieces, two of them 30 in. long, for the sides, and the other two 18 in. long, for the ends; all 3 in. wide and ⁷⁄₈ in. thick. The ends of these pieces are finished rounding, and holes are bored in them for the supporting ropes. The supports for the rails consist of four pieces of ³⁄₄-in. pipe, 15 in. long. The ropes are run through the holes in the ends of the rails, down through the pipes and through the holes in the seat board, where they are knotted.

A rope tied to a convenient post or screw hook makes a handy way to give motion by pulling. To get into the swing, raise one of the side rails on the rope.--Contributed by Ward M. Mills, Bakersfield, Cal.

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¶Cover the top and side of ice in a refrigerator with a piece of Canton flannel, and the ice will last longer.

Sheepshank Knot Used to Recover Rope

The knot shown has a peculiar characteristic which enables a person to recover the rope after letting himself down from some elevated position. After the rope has been tied firmly to some support, as a limb of a tree, tie this knot, or “sheepshank,” as high up as possible. Close inspection will show that one of the three sections of the knot holds no part of the weight below. This section is identified as the portion which projects through the loops A and B at both ends. The other sections project through at one end only. When the knot has been arranged, slide down carefully to a position just below it and cut the rope at C; then descend to the ground. By shaking the rope the knot may be loosened, and only a short piece will be left attached to the support.--Contributed by F. R. Gorton, Ypsilanti, Michigan.

Writing Two Colors on a Plain-Ribbon Typewriter

To write red, or any other color, on a one-color ribbon typewriter place a long enough piece of red carbon paper, or the color desired, between the ribbon and the paper. It will hold its place quite well, does the work as well as a two-color ribbon used on expensive machines, and does not cost very much.--Contributed by Leslie E. Turner, New York City.

A Simple Card Deception

The effect of this trick is not new, but the method is a new one. A card is selected by a spectator and noted, then returned to the pack, which is shuffled by the one drawing the card. Despite the thorough mixing the correct card is located by cutting the pack. The secret is this: When the card is chosen, the chooser is allowed to remove it from the pack. The performer then takes it and holds it up and asks the audience to fix it in their minds. While doing this, allow the thumb nail of the index finger to slightly graze the edge of the card. This will not show, nor can it be detected by the holder, and he suspects nothing of the kind. When returned to the deck and shuffled the pack is evened up for cutting. A glance at the edges will show a small white spot distinctly, as the scraped edge will contrast with the other soiled cards. It is simple to cut the pack from this key.--Contributed by John C. Moorehead, Minneapolis, Minn.

Catching Minnows for Bait

Instead of chasing the little fish up and down the stream to catch enough for bait, try putting a clean bit of shell in a wide-mouth jar and holding it in the water. The minnows will be attracted in great numbers, and it is an easy matter to dip them up. A bit of shell can be used also in a net. The white, shining shell seems to be a good lure for the little fellows.--Contributed by Miriam Colchester, Amherst, Can.

Grinding Writing and Lettering Pens

A fine or coarse writing or lettering pen can be produced quickly by means of an oilstone. By rubbing it at the sides of the nibs, the pen is made finer, and grinding across the ends makes it coarser. By grasping the penholder in the normal writing position, and writing lightly on the surface of the stone, the pen may be ground to the style of the user, making it write more smoothly. If the pen scratches, a slight touching up on the stone, which should be a fine hone, will remedy the difficulty.

Pneumatic Door Check Made of Bicycle Pump

A door was provided with a heavy coiled spring that caused it to slam shut, and in order to overcome this nuisance, a check was made from an old bicycle pump. The fittings being worked out neatly, did not mar the appearance of the woodwork. Band iron, ¹⁄₈ by 1¹⁄₂ in., was used for the fittings. A clamp, as detailed, was made to hold the end of the pump cylinder. A bracket, 5¹⁄₂ in. long, of similar iron was fastened to the door, as shown, with screws, and the clamp bolted to it. The end of the plunger was extended and bent at a right angle, so as to pivot in a small angle bracket attached to the trim, as shown in the front view. An air-release hole was provided, as indicated, so that the air was freed from the cylinder gradually as the door closed, thus preventing slamming.--P. P. Avery, Garfield, New Jersey.

Convenient Tool Drawer under Chair Seat

For the householder who does small repairing occasionally at home, a sliding drawer under his working chair will be found a convenience. The tools are always handy when he sits down to his work, and he can put them away again without arising from the chair. This arrangement is also useful in small shops where a chair or stool is used for tinkering and light bench work.--James M. Kane, Doylestown, Pa.

Red Windows in Daylight Photographic Workroom

Instead of the customary dark room, with the expense of red incandescent lamps or the evil-smelling oil lamp, the photographer who works during the day should have a red room, obtained by means of a window with panes of red glass. The amateur can cover the windows with red cloth, through which will penetrate a diffuse red light of the desired quality. This is far superior to the common practice of providing an opaque screen, blocking up the windows, etc., and the screen can be made of red cloth instead of black cloth, just as handily. Proper ventilation should, of course, be provided.--Alfred J. Miller, Albuquerque, N. M.

A Model Paper Monoplane That can be Steered

An interesting bit of paper construction is a small monoplane made from a 7-in. square of paper, folded as indicated in the diagram and provided with a paper tail. This little monoplane can be steered by adjusting the tail, and even made to loop the loop in the varying air currents. For the boy who enjoys experimenting with such a model this little construction offers much instruction and entertainment, and the grown-up who still has an interest in such things will also find it a worth-while job.

To make this model, fold a square of medium-weight paper on the dotted lines, as indicated in Fig. 1 in the diagram. Then unfold the sheet and refold it as in Fig. 2. Then bring the folded corners A and B into position, as shown at A and B in Fig. 3. Fold the corners C and D upward to the position C and D in Fig. 4. Fold corners G and H to the corresponding letters in Fig. 5. Fold points J and K to the corresponding letters in Fig. 6. Raise the points J and K, Fig. 6, and fold them in so that the corners which were below them in Fig. 6 now come above them, as at L and M in Fig. 7. Fold the corner N back along the line OP, Fig. 8, so that the shape of the main portion of the model is as shown in Fig. 9, at OP. Make the tail 1¹⁄₂ by 14 in. long, as shown in Fig. 10, and paste it into position. This completes the model, which can be steered by bending or twisting the tail.--George H. Stipp.

Roll-Film Spools Useful in Economizing Pencils

Now that everyone should economize, short lead pencils should receive attention. A convenient lengthener is easily made by removing the metal ends from used film-camera spools, the 3¹⁄₄-in. length being the best size to use. The pencil is cut to fit the unslotted end of the spindle tightly. An eraser may be fitted in the slotted end. In a school quite a saving was made by collecting the short pencils of the pupils and having them thus fitted up in the workshop.--A. T. Moss, Napa, Calif.

How to Use the Lawn Mower

Difficulty in the operation of a lawn mower is often caused by failure to use the machine properly. A lawn mower cuts like scissors except that one of the members is fixed. The cutters pass over the cutting bar at an angle and thus shear off the grass. The machine tends to throw the grass off to one side, usually toward the left; hence the machine should not be permitted to throw the cut grass back into the uncut patch. This may be prevented by passing around the lawn so that the uncut grass is at the right of the operator.--W. H. Kruse, Fort Wayne, Ind.

Telegraph Recorder with Spool-and-Pencil Indicator

A simple substitute for the somewhat complicated telegraph recorders of the inking type may be constructed of materials readily available to a boy. The instrument shown in the sketch was made in a short time and with no special outlay. The base and the upright support are of wood. The armature A was made of a strip cut from a tin box, and folded to a length of 4 in.

The recording device consists of a short piece of pencil, P, set in a spool, S. The electromagnet M is fixed to the base, and the armature A is actuated when current is permitted to pass through the magnet, causing the recording pencil to move vertically. A strip of paper is moved slowly under the pencil, and in order to make the record regular a small channel-shaped guide of metal may be arranged under the pencil.--William Warnecke, Jr., New York City.

Campers’ Bait Cache

Campers desiring a sure supply of angleworms for fishing will find the bait cache shown in the sketch convenient and practical. A box, about 18 in. long and 10 in. square on the end, is sunk into the ground in a shady place, and all the bait dug by the campers on their arrival is placed into it. The soil used to fill the box should be rich, black loam, quite moist but not wet enough to be sticky. A few inches of the top of the box is left unfilled and a double layer of green sod is fitted over it, as shown in the sectional view at the right. The upper sod is arranged level with the surface of the ground and should be cut carefully so that it will not be observed by prowlers. If the region where fishing is to be done is such that angleworms cannot be obtained easily, it is best to dig them before starting for the camp. The bait cache may then be made as a convenient place in which to keep the bait in good condition for fishing.

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¶After cleaning a shotgun, or a rifle, a cork large enough to be seen readily should be placed in the end of the barrel to prevent rusting. The cork should not be pressed into the end deeply as, if it is forgotten and the firearm discharged without removing it, a dangerous explosion may result.

A Sail-Rigged Wind Motor

BY E. R. HENDERSON

Ample power for driving light machines in a repair shop was obtained by the use of a wind motor like that shown in the sketch and in the detail drawings. The device has numerous other applications, particularly as a substitute for wind motors that require a high tower, as in the driving of a pump. As an interesting and inexpensive means of providing power for a home or boy’s workshop, or as an experimental device, the motor is also worth while making. The materials used are easily obtainable, and the construction can be carried out with ordinary tools, for the most part. The driving connections may be obtained from old machine parts. The dimensions given are for a motor of considerable size, and may, of course, be reduced proportionately for a lighter machine. If the device is made by boys, the framework and other parts should be made one-half as large as the sizes indicated. The wood used should then be three-fourths as thick as that shown. The roof of the structure upon which the device is mounted must be well braced and strong enough to stand the strain. The sails are headed toward the wind, like those on a sailboat, when the motor is at rest, by means of a control rod, F, shown in the working drawing.

The main structural portion is a vertical beam, or tower, tapered at the ends and built up of 1 by 1-in. rods, strongly braced, especially in the lower portion, as indicated. It is 14 ft. high, and built around an 18-in. square board, A, notched at the corners to receive the posts. A similar 14-in. square, B, is built into the lower portion. The lower end of the tower is pivoted on the ridge of the roof on a hollow shaft made from a section of iron pipe, D, and provided with a metal bearing washer, E. The pipe D is split at its upper end, as shown in detail, and fastened to the wooden plate B. The control rod F passes up through the pipe D, and is fixed to the control wires, reaching the sails, by means of a leather strap, from which an iron swivel, C, is suspended, as shown in the detail at the left. The ends of the strap pass over pulleys, fixed to the lower side of the plate A, and connect with the sail-control wires. Spiral wire springs are attached to the wire connected to each end of the strap, as shown only at the right sail beam, and aid in controlling the sails. These springs are adjusted so that when the control rod is drawn down to its lowest extent, the sails will be with the edge “into the wind,” thus neutralizing each other, and causing the sail beam to be at rest.

The sail beam extends 9 ft. out from the center of the tower, and is built up of three pieces. The center section extends through the tower, above the plate A, and the brace beam, which crosses it at right angles, as shown in the perspective sketch, and also at the detail of the strap arrangement. The center section is of 1 by 4-in. stock, and the end portions are of 1 by 2-in. stuff, fastened securely, as shown at detail G. The sails are supported on masts, 1 in. square, pivoted at their junctions with the sail beam, as shown at detail G, and in guy-wire plates at their extreme ends, as shown at detail J. The fastening and bracing of the gaffs at the mast ends is also shown at J.

The canvas sails are 4 by 4 ft., and mounted on the booms, gaffs, and masts. The ends of the booms nearest the masts are weighted with lead, as shown at detail G, and extend beyond the masts. The outer ends of the booms are joined in pairs, and connect to the spring and strap control. The guy wires N, of No. 18 wire, supporting the masts are fixed to the ends of the sail beam and to the ends of the brace beam, as shown in the sketch and the working drawing. The fastening at the ends of the sail beam is made as shown at detail H, which also shows one of the coil springs. All of the braces for the masts should be fitted carefully, so as to have the proper tension without interfering with the action of the sails, before the tower is set into its place. The device should be tested on the ground, with the pivot shaft set in a suitable support, before attempting to mount it on a roof, or other structure. The support for the bearing should be fitted into the roof, as shown. The power from the shaft is transmitted to the bevel gears, and from them to the drive shaft and the belted pulley.

The main tower is supported on the roof by means of strong guy wires, set over four built-up guy towers of 1 by 1-in. wood, and 12 ft. long, as shown in detail L. The towers must be set so that the sail beam has proper play and be secured firmly to the roof. The top of the main tower is fixed to the guy wires by means of a guy plate shown in detail K. A plan of the arrangement of the sail beam, brace beam, and sail booms is shown at detail M. The sail beam is braced by No. 12 guy wires, O, attached at the top of the main tower, at the junction of the two sections of the beam, and similarly at the bottom of the main tower. The fastenings of the wires and braces should be made carefully, and they should be examined thoroughly both before and after the device is mounted in place. Grease the pivoted and other moving parts, and start the device slowly, bringing the sails into the wind as required for the desired speed.

Lawn Benches Made from Old Bedsteads

Old bedsteads were converted into serviceable lawn, or porch, benches, as shown in the photograph reproduced, by the addition of a suitable seat, properly supported. The transformation was a simple one. Only the foot and headpieces of the bedsteads were used. The front legs and other pieces were made from other wood. The front legs are of square stock, about 2¹⁄₂ by 2¹⁄₂ in. The crosspieces, supporting the wide board seats, are mortised into the legs and fastened with glue and screws. The seat is fastened from the under side by cleats. The lumber was carefully planed and sandpapered so that the benches presented a smooth finish when painted green, to match other outdoor furniture.--F. E. Tuck, Nevada City, Calif.

Repairing Wood-Wind Instruments

Wood-wind instruments sometimes “leak” at the joints or keys and make playing of the instrument difficult. Many such instruments are made in sections, with ends that telescope to form a tight fit. This fit is maintained by the use of a cork band cemented around the tenon end of the telescoping joint. The renewal of these cork joints, and the addition of new pads on the keys, will make an old instrument nearly as good as it was when new, so far as playing is concerned, provided the work is correctly done and the wood of the sections themselves has not cracked. Many musicians have spare time and can do this work themselves. The outlay for materials for the job is from 75 cents to $1.00. A small alcohol, or even a kerosene, lamp and an old knife, or old file, are required.

All traces of the old cork on the joint can be removed with sandpaper, leaving it as shown at the left. The cork comes in strips of about the proper thickness, and wide and long enough to allow for trimming. The ends of the strip should be beveled to make a ¹⁄₄-in. lap joint.

A small quantity of the cement is heated over the lamp and six drops poured on the joint; then with the end of the file, which should be heated also, it is spread to give an even, thin coating. The beveled ends of the strip are similarly treated. By working quickly and carefully, the coating on the joint and strip are brought to a plastic state by holding in the flame, and the strip is quickly laid in place. Before the cement has time to harden, press the cork in, forming a neat joint. Bind a rag around the cork, leaving it until the cement is thoroughly set.

The corked joint will be too large to go into the joining section of the instrument. File and sandpaper it to a twisting fit. Though the cork should be truly cylindrical, it may be tapered a trifle smaller at the forward end. A coating of tallow applied to the joint will make it easy-fitting, but air-tight and moisture-proof.

The pads are disks of felt incased in thin sheepskin. After long usage, they become too hard to make an air-tight fit. Repadding should, therefore, be anticipated. Shellac will give good results in putting on pads. It is heated until liquid and poured into the key recess. The new pad is pressed into the liquid shellac, care being taken to have it well centered. For different keys, it will be necessary to use varying quantities of shellac to make the pad sit higher or lower, as required.--Donald A. Hampson, Middletown, N. Y.

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¶A simple method of bracing a screen door is to stretch a stout wire diagonally across the lower portion of it.

Rustic Trellis to Shade Door or Window

Proper preparation in the early spring will make it possible for the householder to shade doors and windows from the hot summer’s sun by means of inexpensive rustic trellises that add not a little to the beauty of the home. A suggestion for a trellis at a doorway and one for a window are shown in the illustration. They are made of straight tree trunks and small limbs, having the bark on them. The curved portions of the window trellis may be made easily by using twigs that are somewhat green. Morning-glories, or other suitable climbing plants, may be trained over the trellises.--J. G. Allshouse, Avonmore, Pa.

Making Scale Enlargements with a Rubber Band

For reducing or enlarging maps, and similar drawings of irregular design, the device shown in the illustration will replace the ordinary instruments, and enable the draftsman to turn out a given amount of work in much less time than required when proportional dividers are used. The materials needed are an eraser, a rubber band, two pins, two thumb tacks, and a few drops of rubber cement. From the eraser two pieces are cut, as shown in the sketch, about ¹⁄₄ by ¹⁄₂ by 1¹⁄₄ in. Cut deep slits in each end of these pieces. Insert the end of the rubber band, cut at the splice, in one of these slits and place a thumb tack in the other. A pin is thrust through the eraser and trimmed close, to prevent the thumb tack from tearing the eraser. Cement the slits with rubber cement, and place the assembled device under a book weight, until the cement has set.

Assuming that a contour map is to be enlarged, the rectangular divisions of the original map, ordinarily section lines or the boundaries of quarter sections, are drawn on the larger sheet as a base for the reproduction. Place the device on the original map, as indicated, the edge of the rubber band touching a “horizontal” section line between two “vertical” ones, the rubber band under slight tension. On the black surface of the band, dot white points, with water color, along the section line at which the contour lines intersect it. Also place a dot at each end of the band to indicate the position of the two “vertical” section lines between which the band is set.

Transfer the device to the same relative position on the enlargement, stretching the rubber band. Make dots at each end, denoting the “vertical” section lines, for the corresponding lines on the enlargement. The series of intermediate points along the band will be in the same relative position on the enlargement as they were on the original. They can be connected on the enlargement with as accurate a result as obtained by the use of proportional dividers, and more rapidly.

After the points are indicated upon the enlargement, the reproducing device is removed and the surface of the rubber band cleaned instantly by touching it with a moist cloth. The exposed part of the rubber band is a variable, and the device can be made with this dimension adapted to the work. It is capable of enlarging or reducing at a ratio not greater than six to one, above which the rubber band approaches its elastic limit.--H. L. Wiley, Seattle, Wash.

Signal Telegraph with Green and Red Lights

By arranging a circuit with batteries, lights, and keys, as shown in the diagram, a signal telegraph may be made that will afford much pleasure to boys and may be used for practical purposes. The keys A and B are wired into the circuit with a battery C and a red and a green incandescent lamp. A simple set of signals may be devised easily so that messages may be sent in the code.--James R. Townsend, Itasca, Texas.

A Circular Swing

BY DAVIS FOSS GETCHELL

While on the farm I constructed a circular swing which proved very attractive to my boys and their friends. By its side, and suspended from the same tree branch, was an ordinary swing. During the eight weeks of our stay the latter was seldom in use. The circular swing was a far greater favorite with all the young people, boys and girls alike.

Around a branch of a large elm and 18 or 20 ft. from the tree trunk was looped a 10-ft. length of chain and to the hanging end of this was made fast a 1-in. rope nearly 10 ft. longer than was needed to reach the ground. Directly beneath the point where the chain went around the limb, as determined by a plumb bob, was set a 6-in. piece of cedar post 3¹⁄₂ ft. into the ground. This was sawed off square 2¹⁄₂ ft. above the ground. Into the top of this post was set a ¹⁄₂-in. rod, to serve as a pivot for the swing. It was set in firmly about 6 in. and projected about 3 in. from the top of the post.

A straight-grained piece of pine board, 15 ft. long, 8 in. wide, and 1 in. thick, was procured and a hole bored in one end large enough to make it turn freely on the pin in the upper end of the post. Two holes were bored in the other end of the board large enough to admit the rope. The first hole was 6 in. from the end, and the second hole, 3 ft. The hanging end of the rope was passed down through one of these holes and back up through the other and then made fast to itself about 3 ft. above the board after the board had been adjusted so that it would swing throughout its length at the height of the post, or 2¹⁄₂ ft. from the ground. The swing was then complete except for a swivel, which was put in the rope within easy reach of one standing on the board, so that it could be oiled.

One good push would send the board with a boy on the end three or four times about the 90-ft. circle. The little fellows would like to get hold of the board in near the post and shove it around. Once started, it could be kept going with very little effort.

In putting up such a swing, make sure to have the post set solidly in the ground, as it has a tendency to work loose. Tie all the knots tightly. Do not look upon the swivel as unnecessary. The first swing I put up was without one, and the rope twisted off in a few days.

It is not necessary to climb a tree; just throw a stout cord over the limb by means of a stone or nut tied to the end, then haul the rope and chain up over the limb with the cord. Before the chain leaves the ground loop the end of it and pass the cord through the loop. The higher the limb from the ground the better the swing will work, but 25 ft. will be about right.

Hand-Operated Motorboat Whistle

Anyone with a power boat can construct a blower for the whistle very cheaply. The whistle is attached to a suitable length of pipe, threaded on each end. The blower is made of two white-pine boards, 1 in. thick, cut as shown at A; a thin piece of leather is cut like the pattern B, to form the bellows part, and after it is shaped, the edges of the boards are glued and the leather placed in position, where it is fastened with tacks driven in about 1 in. apart. The bellows are fastened to the under side of a seat with screws, and a tension spring is attached to the bottom of the bellows and the floor of the boat. A cord is fastened to the lower board of the bellows and run up through to the cabin roof over suitable pulleys to a handle within convenient reach of the operator.--Contributed by John I. Somers, Pleasantville, N. J.

Filling In Broken Places on Enamel

Ordinary putty will not do to fill in cracks or broken spots on an enameled surface, such as a clockface. Fine sealing wax is much better, as it hardens at once, takes color without absorbing the oil, and does not shrink like putty. Use a wax of the proper color to match the surface as closely as possible. Fit it in and smooth with a warm, flexible piece of metal, such as a palette knife. Give it one or two coats of thin color to exactly match the other surface, and varnish. If the article has not a high polish, the gloss of the varnish can be cut a little with pumice stone.

“Step right up; three twisting thrillers for a penny--a tenth of a dime!” was the familiar invitation which attracted customers to the delights of a homemade merry-go-round of novel design. The patrons were not disappointed, but came back for more. The power for the whirling thriller is produced by the heavy, twisted rope, suspended from the limb of a tree, or other suitable support. The rope is cranked up by means of the notched disk A, grasped at the handle B, the car being lifted off. The thriller is stopped when the brakeplate I rests on the weighted box L.

Manila rope, ³⁄₄ in. or more in diameter, is used for the support, and is rigged with a spreader, about 2 ft. long, at the top, as shown. The disk is built up of wood, as detailed, and notches, C, provided for the ropes. The rope is wound up and the car is suspended from it by the hook, which should be strong, and deep enough so that it cannot slip out, as indicated at H.

The car is made of a section of 2 by 4-in stuff, D, 10 ft. long, to which braces, E, of 1 by 4-in. stuff are fastened with nails or screws. The upper ends of the pieces E are blocked up with the centerpiece F, nailed securely, and the wire link G is fastened through the joint.

The seats J are suspended at the ends of the 2 by 4-in. bar, with their inner ends lower, as shown, to give a better seating when the thriller is in action. The seats are supported by rope or strap-iron brackets, K, set 15 in. apart. The box should be high enough so that the seats do not strike the ground.

Kinks for the Talking Machine

When short of fiber needles or when the jewel needle has broken, file down the tooth of a bone comb to the required point, and it will serve well. If the needle arm becomes loosened from the diaphragm, and no wax is handy, a bit of soft chewing gum makes an excellent temporary repair. Use a magnet to pick up steel needles from the receptacles on the machine, to save time and avoid punctured fingers. If the machine is too loud for the room, placing a piece of loose cotton in the tone arm, directly behind the reproducer, is more effective than muffling the sound at the horn end.--L. B. Robbins, Attleboro, Mass.

A Wire-Walking Toy

A daring wire-walking performer who, unmindful of the fact that a misstep may mean destruction, keeps on going, back and forth, so long as the motor runs, or the crank is turned, is a toy that boys can make easily. The wire is stretched, not across Broadway, but between two 1 by 1-in. standards, held upright by guy cords, or fixed to a baseboard. They are fitted with forked tops, at A and B, and pulley wheels, C and D. A wire, F, is fastened to two of the prongs, at E, and a black thread, G, runs over the pulley wheels. A carriage, I, is formed from a 12-in. length of stiff wire, and weighted, at L, to balance upon the tight wire. The figure K is cut from stiff paper, and made to turn upon the carriage upright J, and braced with thread, at H. Thus the figure is always drawn forward, revolving on the support J at the end of each trip. Power to turn the thread is transmitted from a hand crank or motor, M, by means of the double pulley wheel at D.--Edward R. Smith, Walla Walla, Washington.

Double Roofs Provide Ideal Shade for Poultry Coops

Having no native shade in our city chicken yard, we noticed one summer that the hens, especially those in the low brooder coops, became droopy and exhausted from the excessive heat. We studied the construction of the U. S. Weather Bureau thermometer shelter, which usually stands out in the sun, and is no larger than our brooder coops. It has a double roof with free air-circulation space between the roofs, hence the inclosed thermometers are exposed to a true-shade temperature. We then placed an extra roof on each of the brooder coops, leaving a 6-in. open air space between, the top roof being supported at the corners only. The arrangement proved so effective that the hens sought the coops, against the heat of unventilated inclosures on quiet, hot days.--J. Cecil Alter, Cheyenne, Wyo.

An Illuminated Indicating Target Box

The joys of target practice are often hampered by the delays in the settlement of hits. It takes time and is annoying to be constantly advancing to the target to examine it. To do away with this, an illuminated target was constructed that enables the shooter to locate every hit without leaving his post. To make the device, a square wooden box of convenient size is obtained. In one side of this, cut a round hole as large as the largest ring on the targets used. The side opposite this is fitted with a piece of sheet iron to stop the bullets. Paint this iron and the interior white. Inside the box, arrange four electric lights so their rays will be thrown on the hole, as shown. Candles may be used, if necessary. The lamps must be out of range of the bullets, that hit the target, and protected by an iron plate. The targets, painted on thin paper, are fastened over the front of the hole, and the lights are on, while shooting. Each shot punctures the paper, and the light streaming through the hole will show the location of the hit.--Thomas W. Benson, Philadelphia, Pa.

Kinks in Washing Photographic Negatives and Prints

Photographic defects, spots, stains, etc., are often due to inadequate washing. In the common method of washing negatives or prints under the tap, in a dish, the water is not changed quickly enough. If the negatives are placed film downward and supported at the edges, the washing is quicker and more thorough. Films as well as glass negatives are in the same class in the matter of washing. Films should not stick together, and the sharp edges must not be permitted to cause scratches.

Bird House Made of an Old Straw Hat

A bird house of an old straw hat is a practical and easily contrived affair. Cut a hole in the crown of the hat. Then nail the hat against a board of proper size. To protect the hat against the rain, put a roof over it, as shown. A perch is also provided. Such a bird house can be hung against the trunk of a tree, or nailed against a wall. Leaving the hat in its natural straw color, and painting the rest a dark brown, produces a satisfactory effect.--C. L. Meller, Fargo, N. D.

Camp Shelter Affords Protection from Mosquitoes

When it is undesirable to stay in a camping tent, on warm nights or during the day when a siesta is taken, a mosquito shelter can be made of materials readily available at most camping places. The arrangement, as shown, is made as follows: Procure a number of pliable switches, about ³⁄₄ in. in diameter, and 8 or 10 ft. long, willow or similar growths. Sharpen the butts, and force them into the ground in two rows, 3¹⁄₂ ft. apart. Bend the tops together, and tie them in arches of the same height, as indicated. Next, tie a ridge binder the entire length. Cover the frame with mosquito netting, providing an entrance at one end. The shelter shown is for one person, but may easily be made larger. The fly, supported on a rope between posts or trees, affords shade.--J. T. Trammell, Milwaukee, Wis.

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¶The annoyance of a chair rocking on a bare floor, especially a child’s rocking chair, may be overcome by tacking sections of garden hose along the curved rockers. If properly done this also adds to the comfort of the chair.

Rustic Well for a Bazaar or Fair Booth

A feature of a bazaar which attracted much attention was a rustic well from which a pretty girl dipped cool drinks with the aid of an “old oaken bucket.” The arrangement may also be used at an outdoor fair or lawn party.

A corner of the room was marked off by a rail fence and turnstile. The floor was covered with green cloth and green excelsior, for grass. The well was constructed as shown in the detail sketch. Half of a barrel, B, with the head removed, was inverted, and a mirror, C, was set in a shallow pan of water on the floor. The pan was surrounded with pebbles, D, and a framework, E, built over the barrel. The supply of lemonade was kept cool in the tub G, behind the partition. When the bucket A was lowered into the well, by means of the sweep, it was filled by pouring the beverage in the trough F. The bucket was then raised and the drinks served from it, a cocoanut-shell dipper being used.

So many persons became curious to learn how the well was constructed, that an admission fee was charged to pass the turnstile, and the reward was a peep at the reflection in the mirror at the bottom of the well.--Susan E. W. Jocelyn, New Haven, Conn.

Novel Masks for Printing Pictures

In printing pictures, I have made use of various masks, and those suited to the particular picture, for some special reason, have proved especially popular. For instance, in making a picture for a contractor and mason, a mask in the shape of a trowel was used; for a policeman, a star; an automobile for the motorist. Sometimes the special interests of persons in a picture, or the background, will suggest good outlines for masks.--Russell Waldo, Indianapolis, Ind.

Sheet-Metal Stand for Flatiron

Considerable energy is consumed in lifting a heavy flatiron to the stand which protects the ironing board. The device shown in the illustration was made to overcome this objection to most flatiron stands and proved efficient as well as easy to make. The iron is shoved onto the stand at one end, provided with an incline. The layout for the sheet metal is shown in detail. The piece A is cut 4¹⁄₂ by 9 in., and the stop B, the incline C, and the leg D, are cut as shown, and bent to shape The stand is fastened near the end of the ironing board by means of screws.--Ernest Ward, Detroit, Mich.

Water-Coasting Toboggan and Slide

BY D. J. HOUGH

Coasting down an incline and being projected through the air to plunge into the warm water of a summer lake, or other outdoor bathing spot, has thrills and excitement that appeal to the person seeking a new aquatic diversion. The illustration shows a slide, and the toboggan sled for use on it, that were built by a group of young men at a summer resort. While the slide shown is perhaps more extensive than most boys would care to undertake, the principle involved may be adapted easily to others one-fourth as long, less than 20 ft. The slide shown was strongly built of 2 by 4-in. material for the framework, 2 by 6-in. planks for the slide guides, and 2 by 12-in. planks for the bearing for the roller. Lighter material may be used for the guides and the roller bearing on a smaller slide, but the framework should be of 2 by 4-in. stock.

The high end of the slide illustrated is about 7 ft. from the ground, but a proportionately greater incline is provided because the beach slopes gradually to the water’s edge. It is reached by a ladder fixed to a tree, which acts as an end brace for the slide. If no such natural support is available, the end of the slide must be strongly braced on three sides, to insure safety. It is inadvisable to build the slide unduly high to provide the necessary incline since this may result in accidents. A location where the ground is suitable should be selected rather than assume danger or risk.

The end of the slide nearest the water may be given a slight upward turn, so that when the toboggan leaves it the rider is carried upward before striking the water. The hold on the toboggan should be retained when entering the water, as injury may result by failure to clear it in the plunge. With experience a dive may be made as the toboggan leaves the slide.

The construction of the slide is shown in detail in the lower sketch. The framework of 2 by 4-in. material should be only slightly wider than the guides, and the supports should be spread toward the ground to give rigidity. The supports A should be nailed firmly, or bolted, to the horizontal members B. If lighter stock is used, the pieces at B should be nailed in pairs, one on each side of the uprights. The guides C and D should be of smooth lumber, and the edges of these pieces, as well as of the bearing plank E, should be rounded off to remove splinters. The joints in the sections of the guides should be made carefully and placed over the framework supports. They should be reinforced from the lower side by plates of wood.

The bearing plank E is of 2-in. stock and 12 in. wide. It may be made of lighter material in a smaller slide. The joints in it should likewise be made carefully, to insure smooth riding over them. They should be set directly over the framework supports, but not on those over which joints have been made in the guides. The plank forming the bearing for the roller should not extend to the end of the slide at the lower end, but should be set back about 18 in. This permits the toboggan to slide off smoothly rather than to spring directly into the air from the bearing on the rollers. The bearing plank may be nailed into place, but care must be taken to set all nails below the surface. A better construction is to use screws or bolts. Bore holes for them through the plank, countersinking their heads.

The toboggan, as shown in the detail sketches, is built strongly, and is to be fitted over the 12-in. bearing plank, allowing ¹⁄₄-in. play on each side. The sides are of 1¹⁄₄-in. stock and high enough to accommodate the rollers, which should be about 3 in. in diameter. The dimensions of 15 in. in width and 30 in. in length, on the top surface, are suggestive only, and will vary with the materials used. The toboggan will not stand the necessarily hard wear unless good-quality oak, or other hard wood, is used. The top and foot brace should be fixed strongly with screws, their heads countersunk.

The rollers are fixed in the sides by means of screws, or a bolt may be set through the length of the roller. In either case the bearing should be in holes bored through the sidepieces. Washers should be fitted at the sides of the bearings, and the latter must be kept greased. All the edges and corners of the toboggan should be rounded off so that there is little possibility of injury from slivers or contact with the edges.

Tile Trap for Rabbits

Rabbits may be trapped in order to rid grounds of them, or for food purposes, by the use of the tile trap shown in the illustration. A tee, having a smaller opening of 6 in., is set in the ground with the large end projecting. Rocks are placed around it and it is provided with a cover. Several extensions are attached to the 6-in. opening and the end permitted to project slightly from the ground. Rocks are also placed about this opening. The rabbit enters the trap at the small opening and is free to come and go from the burrow. By closing the small opening, the quarry may be taken out at the large opening.

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¶Vaseline is a good cleaner for commutators while machines are in operation and under load.

A Woodsman’s Log Raft

BY A. M. PARKER

Making a raft for crossing a stream, or other small body of water, is often a diversion for campers, who have the usual supply of camp tools and materials. The woodsman is sometimes confronted with a different situation: He has only a hand ax as his tool equipment, and to construct a fairly safe raft of crude materials becomes necessary in order to pursue his course. Logs are readily available, and he may be fortunate enough to find willow withes, various stringy kinds of bark, or even coarse seaweed. If these are not available, the practical woodsman, particularly of the northern regions, builds a raft of logs, pinned together firmly with poles and pointed wooden spikes, cut on the spot. The method, as shown in the illustration, is simple and interesting. It may be of service in the woods even when other methods of binding the logs into a raft are possible, and as a practical test of woodcraft for the amateur or boy camper it is of interest. The sketch shows the completed raft, bound together by wooden pins notched into poles, and the inset details show the manner in which the poles are clamped by the crossed pins.

This method of construction may be applied to a variety of rafts, for carrying small or large loads. In selecting the material for the raft several points must be considered. Dry logs are preferable to wet or green ones, and if the latter are used, a relatively larger raft will be needed to carry a certain load. For one passenger, three logs, 9 to 12 in. in diameter, 12 to 16 ft. long, and spaced to a width of 5 ft., will provide a stable raft. Poles may be laid across it to give sufficient footing. For heavier loads the logs should be about the same length and diameter, but spaced closer together, and laid to form a raft of considerable width and of greater buoyancy.

Select a shore, sloping gently into the water, if possible, and cut the logs and poles as near this place as is convenient. Cut the logs and roll, them to the bank, alternating the butts, if there is any considerable difference in the diameter of the ends. Cut a supply of poles of about 3-in. diameter, and of the length necessary to reach across the proposed raft. Then cut a number of pins of hard wood, 1 ft. long, and sharpened on one end, as shown in the detailed sketch.

Roll the first log--one of the largest--into the water until it is nearly floating. If it is bowed or crooked, place the “humped” side toward the outer edge of the raft. Chop notches, 2 in. deep, in the top of the log about 1¹⁄₂ ft. from the ends, and squarely across. Place a pole in the notch, with its end projecting slightly beyond the log, and cut a double notch in the upper edge of the pole, as shown in the detail sketches, so that when the pins are driven into the log, they will rest diagonally in the notches cut into the poles. Make rifts in the log with the ax, cutting as though to split off a slab of bark and wood, rather than toward the center of the log, and drive two of the pins into place. Properly done, this will make a remarkably strong joint. Fasten a second pole at the other end of the log, and prop up both poles so as to permit the next log to be rolled into the water, under the poles.

Notch the second log before slipping it finally into place. Alternate ends only, of the inner logs, need be fastened, and if time is important, some of the logs may be left unfastened, provided they are held tightly between the logs that are pinned. Shove the raft out into the water as each log is added. If there is a strong current it is desirable to guy the raft with a pole to the bank, downstream. The last log, which should also be a large one, is then floated down and pinned at both ends.

The raft may then be floated, and is ready to be covered with light poles or brush, to provide a dry footing and a place for the dunnage. The dunnage is placed near the forward end of the raft, and the person controlling it sculls with a pole at the rear.

Curved Printing Surface for Sharp Focus in Bromide Enlargements

Practically all of my negatives are of post-card size, and, in making bromide enlargements, I experienced difficulty in getting a satisfactory focus on 6 by 10-in. or 8 by 12-in. prints. When the center of the picture was in focus the outer portions were usually blurred, and vice versa. Compromising between the two gave unsatisfactory results. By providing a curved surface, on which the bromide paper is mounted, results were obtained that are satisfactory except for architectural subjects. A wooden box was made as long as the desired print and 1 in. wider. The height may be made as is convenient, but a height of about 2 in. is satisfactory. A partition was fitted into the box, dividing its length into two compartments. The upper edges of the center partition and the ends of the box were cut in the shape of an arc, the curve being determined by the distance from the lens to the easel when the center of the picture is in focus. The bromide paper is fitted to the curves on the box. The device is fitted to the easel by means of two strips fixed to the bottom of the box, and extending beyond its ends. The curved surface may be covered with cardboard to give a better backing for the bromide paper, which is held in place by pins or small tacks. Where only a small portion of the negative is to be enlarged, this difficulty will not present itself, the flat surface being satisfactory.--Victor Woodland, Denver, Colo.

Playing Talking-Machine Records with the Finger Nail

Talking-machine records may be played with the finger nail, and a person skilled in the process can afford a party of spectators much amusement, creating no little surprise. The record is placed over a penholder, or pencil, and supported by the left hand as shown in the sketch. It is revolved by the fingers of the left hand, and the nail of the second finger of the right hand is applied to the record. Practice is required to obtain satisfactory results and an old record should be used.--George S. Nissen, Chicago, Ill.

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¶Finely powdered graphite dusted on the parts of a motorcycle clutch when repacking it after cleaning will act as an excellent lubricant.

Safety Chopping Block

Chopping of pieces of wood, which must be broken into short lengths, is often dangerous. The chopping block shown in the illustration was designed to overcome this element of danger and it may be used for chopping small kindling wood as well as for breaking up heavier pieces. When the blow is struck on the wood to be broken the pieces are thrown away from the person chopping. The sketch shows the device in use for the chopping of short pieces of wood, and the heavy portion may be used as a seat. The smaller sketch shows how the block is built up of 2-in. planks, bolted together--A. S. Thomas, Amherstburg, Canada.

Repairing a Broken Reed Handle

A strong repair for a broken reed handle, like those on market baskets, handbags, or workbaskets, may be made by joining the broken parts with a ferrule of tinned sheet metal, brads or wire being used to prevent the ends from working loose. After the metal fitting has been made, the handle is rewound with the ends of the material unwound from it, or if desirable, the entire handle may be re-covered with material of the original kind or other suitable substitute.--R. E. Brown, Portland, Ore.

Duck Decoys Mounted on Folding Frame

The duck hunter who wishes to economize by making some of his equipment will be interested in the folding frame for duck decoys, shown in the illustration. It is made of two strips, ³⁄₄ in. by 2 in. by 3 ft. 6 in., of soft wood, and fitted with a bolt at the middle, so that it may be folded, for convenience in carrying. The decoys are cut from a sheet of tinned metal, and are painted to resemble the game.--Carl A. Haberlein, McPherson, Kan.

Onlaying Script on a Trophy Cup

A novel method of inscribing names or other indications on trophy cups or medallions is to onlay copper, or other contrasting metal, upon the surface by the process illustrated. Beeswax, or paraffin, is fixed to the side of the cup and formed into a dish shape, the surface on which the onlaying is to be done being covered with only a thin layer of the wax. With a needle or other suitable instrument, scratch the markings desired through the thin layer of wax to the surface of the cup. Pour copper sulphate into the wax cavity if the onlay is to be of copper, and suspend a small piece of pure copper in the liquid, connected with the positive pole of a storage battery, or other similar electrical source. Attach a wire from the negative pole of the battery to the cup. The copper will be deposited on the surface of the cup where the thin layer of wax has been scratched off, exposing the metal. The thickness of the deposit will depend on the length of time that the current is permitted to flow. Ten hours of action will permit the depositing of a satisfactory onlay.--M. H. Edwards.

Economy in Motorcycle Tires

Caution in the use of motorcycle tires with a minimum of abuse will result in a considerable tire saving. Tremendous wear on a single spot results when the power is thrown in so suddenly that the driving wheel makes several revolutions before gripping the ground. The proper air pressure must be maintained in the tires in order to obtain good wear. Guessing is a poor method of determining the air pressure and the exact condition should be noted from time to time with a gauge. Ordinarily, a pressure of 45 to 50 lb should be maintained in the rear tire and about 20 per cent less in the front tire, in the case of 3-in. tires. Rim cutting from running motorcycle tires underinflated is the commonest abuse. Dents in the edge of the rims cause undue wear on the tire, the fabric being worn through by the constant rubbing. Bent rims are often caused by insufficient air pressure in tires, the liability to injury being increased when crossing tracks or bumps with an improperly inflated tire.

A Knock-Down Tennis-Court Backstop

BY EDWARD R. SMITH

Severe weather soon damages a tennis-court backstop that is built on posts set in the ground, and permitted to remain in place during the winter. The backstop shown in the illustration was designed to overcome this objection, and proved efficient on this score, as well as economical to build and maintain. Instead of setting the supports in the ground, they are set on the ground, and guyed by a system of wire braces. The wire netting is also held taut by wire braces, and the entire rigging is quickly taken down for storage, and easily set up when needed again. The lower edge of the wire is held down by hooks pinned to the ground with tent stakes, making it convenient to unhook the netting when the grass is to be cut around the backstop. The towers are 50 ft. apart, about 14 ft. high, and built up of 4 by 4-in. and 2 by 4-in. pieces of sound yellow-pine timber.

Foundations of brick, anchored into the ground, were made for the towers. End braces of heavy wire, fastened to the top, and guyed to the sunken anchors at the ground, support the towers against the weight of the netting and wire rigging. This is convenient in setting up the arrangement, as a ladder can be leaned against the end of the tower, guyed securely. To withstand side motion at the top edge of the netting, the supporting wires are carried on crossarms of 1 by 1-in. pieces of wood, 2 ft. long. This rigging is suspended between the towers and wired to the netting. When this is drawn up tightly, the netting is fairly taut. Additional supporting wires, with vertical leaders to the netting, are used to draw up the entire length of the netting tautly, as desired.

The netting extends under the towers, and is supported there by wires. As the netting extends nearly to the end guy wires, players cannot be harmed easily by running into the wires particularly if a white flag is attached to the guy wires, about 6 ft. from the ground. Number 20 gauge wire was used for the supporting cables, and No. 9 for the end braces extending to the anchored fastenings.

A Folding Ground Seat with Back Rest

Those who enjoy sitting or lying upon the grass while reading will find the device shown in the illustration convenient and comfortable. With this, one may enjoy the coolness of the ground without harm to the person or clothing. The adjustable back rest supports the body in various positions. The device is light, compact, and readily transported. It is useful also in the home and elsewhere. By placing it across the bed, or on a trunk, a good substitute for an extra chair is provided. The seat proper may be folded under and the back rest used as a prop for reading in bed.

Oak is a suitable wood, and other common woods may be used. First construct, according to the dimensions given, three rectangular frames, with mortise-and-tenon joints. Cover the seat and back frames with heavy duck, turning it in ¹⁄₂ in. at the edges. The base is an open frame, provided with adjusting notches, spaced 2 in apart. Next make the adjusting frame, as detailed. Hinge the back and the seat to the base, and fasten the adjusting frame to the back with screws, permitting it to fold, as shown.--T. H. Linthicum, Annapolis, Md.

Bicycle Carried on Automobile as Tender

Steam yachts often carry a motorboat tender, and an automobile may carry a bicycle for emergencies. An autoist whose duties require him to travel through rural districts, had numerous unhappy experiences with a stalled car until he hit upon this scheme. The bicycle is strapped on the running board of the car, its handlebars turned flat against the side, and its wheels in tire sockets in the running board. A tank in the bicycle frame holds several gallons, and if the owner runs out of gasoline, he uses the tender to get a supply, filling the auto tank by siphoning the gasoline through a flexible tube.--John Miller Bonbright, Philadelphia, Pa.

Heater Keeps Developer at Proper Temperature

Having had trouble with developer cooling down and failing to work properly, while developing in the dark room, I constructed the apparatus shown. A small light-tight box was made slightly larger than the tray, with a removable top having an opening to hold the tray. An electric-light socket was fastened inside at one end of the box and a lamp fitted to it. A wire was attached across the middle of the lower side of the box, so that the latter and the tray could be rocked. The box was lined with black paper and varnished black. The edges of the opening in the top were fringed with felt to guard against light leakage. A thermometer is used to determine the temperature. When the developer cools, turn on the light until it reaches the required temperature.--John Hoeck, Alameda, California.

Steam-Propelled Motorcycle Made by Mechanic

BY L. L. VOELEHERT

As an example of the application of steam power to the propulsion of a vehicle, the motorcycle shown in the illustration is interesting. While it does not embody the many refinements of gasoline motorcycles manufactured commercially, and makes no pretense of competing with them, the machine has a striking individuality. It was made by a mechanic in his spare time, with only the facilities of a small machine shop. Tests and hard usage over typical roads have shown it to be easy riding, partly by reason of its weight, and to give very steady power. The machine can be reversed quickly and no clutch is used. It has a wheel base of 75 in., and weighs about 350 pounds.

The upper portions of the frame are made of 1-in. steel tubing, strongly riveted at the fork and other joints. The lower section, from the fork to the rear axle, is made of a double bar of 1¹⁄₂ by ¹⁄₂-in. steel, spread and braced to carry the tank, engine, and boiler. The fork is forged from strips of steel, and fitted to standard motorcycle wheels. The handlebars, seat, transmission chains and gears, as well as other fittings, are of the ordinary motorcycle type. The seat may be moved and clamped at various places along the upper bar of the frame, and an extra seat may be installed, or a bundle carrier may be fitted behind the driver.

Gasoline, with which to heat water for the generation of steam, is carried in the long round tank, hung below the frame at the top. The water supply is contained in the square flat tank under the lower part of the frame. The engine is supported on the frame immediately above the water tank, and drives a shaft, which is geared to the rear wheel by a chain and sprocket.

The round boiler, with gasoline burners beneath it, is carried on the lower part of the frame, which is spread, immediately behind the front wheel. The boiler is 16 in. in diameter and 12 in. high. It is fitted with valves, whistle, water gauge, and the usual fittings of a boiler. The engine is of the horizontal type, and the working parts are largely inclosed, so as to protect them from dust and to avoid possible danger to the operator.

Sideboard Converted into Kitchenette

Living in rooms, in which it was necessary to use the small living room as a kitchen and dining room as well, the storage of the cooking equipment became a problem. It was unsightly in the room when not in use, and there was no convenient place in which to store it out of sight. The kitchenette, shown in the sketch, was made from an old sideboard, and served the purpose admirably, being useful also for other needs.

The top was removed and hinged to one end, the supports being removable, for storing them in the cabinet. The hinged top provided a support for the dishes while cooking. The partition between the top drawers was removed and the fronts of the drawers fastened in place with screws. The space thus made available was lined with asbestos, and a small gas stove was fitted into it. The gas line was connected to the stove and two pieces of asbestos sheeting were hinged to fold under the cover and to be leaned against the wall as a protection while cooking. The top could be hinged at the back to protect the wall, or cut in two and the parts hinged one at each end of the cabinet. The lower drawers of the kitchenette were fitted to hold the cooking materials and equipment.

When the kitchenette is closed it is useful as a stand or table, for dining, or for other purposes, including ironing. In the latter operation, it is often desirable to have the hinged top open to give free access around the end of the top.--J. S. Hagans, Toledo, Ohio.

Bee Feeder for Winter Use

The use of a feeder, like that shown in the sketch, makes the feeding of bees in winter convenient. Sirup is fed to the bees from inverted glass jars, the openings of which are covered with muslin, the jars being incased in a packing of chaff in a wooden covering. The wooden box is made to fit over the hive, as shown in the sketch, and a 2-in. strip is nailed over the joint.

The device is made as follows: Use wood smoothed on both sides; pine basswood, or other soft wood being satisfactory. Make two pieces, ⁷⁄₈ in. thick, and the same size as the top of the hive. Into one of these cut two round holes, as shown, to fit the necks of the jars. Make two pieces, 6³⁄₄ in. wide, for the sides, and two for the ends, the length being suited to the hive, the dimensions given in the sketch being suggestive only. Make four strips, 2 in. wide, and long enough to fit the four sides of the box. Nail the pieces of the box together, as shown, nailing the sides over the end pieces, and the top over the frame of sides and ends. Pack chaff into the box, and, after filling the jars with sirup and covering their openings with muslin, pack the jars into the box so that their openings will be level with the bottom through which the holes have been cut. Fasten the board, with holes for the jars, into place with screws, so that it may be removed when it is desired to remove the jars for refilling. Nail the 2-in. strips around the lower edge of the box so as to cover the joint between the box and the hive. The feeder is then fitted into place, the bees feeding from the surface of the muslin. The chaff prevents the sirup from congealing in cold weather and so it is always available for the bees. The use of this simple device will prove economical and practical in keeping bees over the winter, assuring them a good food supply, with little effort on the part of the keeper.--Gus Hansen, Peachland, B. C., Can.

Kink for Driving Nails

Nails, or spikes, may be driven into hard wood without causing them to buckle by applying a coating of vaseline, beeswax, and rosin, mixed in equal portions. A convenient method of applying the mixture is to bore a hole in the end of the hammer handle and fill it with the material. The nails may be pressed into the hole to coat them.--O. Root, Lorain, Ohio.

Porch Gate Folds into Hollow Pillar

The porch is a convenient play spot for the children, but must be properly safeguarded to prevent not uncommon accidents and injury by falls. The folding gate shown in the sketch provides substantial barrier to the head of the stairs, and may be quickly folded out of the way. It is hardly noticeable when set in the side of the pillar, and does not mar the finish or general effect of the latter.

The gate is made of strips of band iron, although wood may be used. The strips are fastened with bolts, or rivets, and the forward end is fitted to the section of the pillar, which forms the cover for the recess in which the gate is housed. The cover is hooked to the opposite pillar when the gate is opened. Any suitable height may be chosen for the gate, but, for the purpose suggested, 24 to 30 in. is satisfactory. The device may be adapted to a variety of other uses by providing a box or chamber for the collapsed gate, when no hollow recess is otherwise available.

A Homemade Book Holder

A piece of board and four finishing nails furnished me with the necessary materials to construct a book-holding apparatus when in a hurry. Each nail, being driven through the board, could be turned to release, and pulled out far enough to accommodate a thicker book. In fact the device was adjustable.

The Enchanted Card Frame

A mystifying card trick, in which the performer makes use of the enchanted card frame shown in detail in the illustration, is as follows: A pack of playing cards is given to one of the spectators, who selects a card, noting the number and suit. The card is then placed in an envelope and burned by the spectator. The performer takes the ashes and loads them into a pistol, which he aims at a small frame, shown as empty, and set upon a table a few feet distant. The frame is covered with a handkerchief, and the pistol is fired at the frame. On removing the handkerchief the selected and destroyed card appears in the frame, from which it is taken at the back.

The trick is performed as follows: A forced deck is prepared having 24 like cards, and the backs of the cards are held to the spectators when a card is selected. The frame is made of a molding 2 in. wide, mitered at the corners, and of the size indicated, the opening being 6³⁄₈ by 7¹⁄₂ in. The general views of the frame in normal position and inverted are shown in Figs. 1 and 5. A pocket is cut in the lower edge of the frame at the back, as shown in detail in Fig. 2. A pane of glass is fitted into the frame, and on the three edges other than the one having a pocket, strips of cardboard, ¹⁄₈ in. thick, are glued, as a bearing for a second piece of glass, as shown in Fig. 4. The back of the frame is fitted with a cover of thin wood, and a hinged door is arranged in the center of the back, as shown in Fig. 3.

A mat of black cardboard is fitted into the frame to form a background behind the card, Fig. 1. The pocket at the bottom is filled with black sand--that used by sign painters is satisfactory--and the frame is ready to receive the card for the performance of the trick. One of the cards from the forced deck is placed in the frame. By inverting the latter the sand is caused to run between the glass partitions, concealing the card on the black mat behind it. In this condition it is exhibited to the spectators and then placed upon the table. A handkerchief is thrown over it. The pistol is one of the toy variety and a cap is fired in it. In picking up the frame the performer turns it over, while removing the handkerchief, so that the black sand runs back into the pocket in the frame.--Harry Marcelle, Honolulu, H. I.

Portable Fence for Baby’s Play Area

BY L. N. ROBINSON

A child in the “toddler” stage should be provided with a safe place in which to play without disturbing the household routine of the busy mother too frequently. The folding wood-and-wire fence shown in the illustration meets this need in a practical and inexpensive manner. It may be used in the home or out of doors, the fence being especially useful in the latter case, since it protects the child, and likewise the lawn flowers, which a youngster, unguarded, may injure. The fence is 25 to 32 in. high, strong enough to support a grown person sitting on the edge of it, and incloses an area of about 4 by 6 ft. This is ample for the child, and the folded fence is thus not too bulky to be transported easily. The materials cost less than $3.50, including hardware for the making of the fence, as shown in the working drawings. The wood used for the main frames is ¹⁄₂ by 2 in., and they are covered with wire mesh, the edges of which are nailed under strips, on the outer side of the frames. Care should be taken to insure that none of the wire strands is exposed, thus endangering the child, or the clothes of passers-by. The frames are hinged together, as shown in the plan, and fold into compact form. Two long and four short frames are required. Cut the top and bottom rails of the long frames 6 ft. in length, and those of the shorter frames and the stiles 25 in. The corner joints are cross-lapped by cutting away one-half the thickness of each strip, as shown at A. The joints at the top and bottom of the center stile, or vertical piece, are made as shown at B, and the joints at the crossing of the center stiles and the cross braces, as at C. The braces only are notched to fit the stile. Each of the joints is fastened with flat-head screws, countersunk. The ends of the braces are cut to fit flush into the corners of the frames, and are nailed in place. This provides a flat nailing surface for the wire mesh and the strips that cover its edges.

Before putting on the wire mesh, all the exposed corners should be “broken” slightly with sandpaper, the wood wiped smooth, and finished with a coat of shellac. The wood may, of course, be left unfinished. In fixing the 1-in. wire mesh in place, fasten one end of the piece squarely at the end of the frame, nailing it with staples. Place a strip of wood under each end of the frame and bear down on the middle of the frame, or weight it, to produce a bowed effect. Then nail the other end of the wire securely; on removing the strips, the wire will be drawn taut. Tack the edges down, and repeat this process on the other frames. Next nail the covering strips on the front faces of the frames, mitering them at the corners, as shown at A.

The frames are then joined by means of hinges, as shown in the plan at A. Care should be taken that they are set so that the corners of the fence meet squarely and evenly when it is opened. Metal drawbolts should be fastened horizontally, one on the top of each folding joint between the end sections. These will prevent the child from folding the ends in, and possibly injuring its fingers. The completed fence is then given a final coat of shellac or varnish, the galvanized wire being left unfinished.

The materials required for the fence are as follows, the wood being listed in lineal feet, and smoothed on four sides to the dimensions indicated:

155 ft. ¹⁄₂ by 2-in. clear pine 50 ft. ¹⁄₄ by 1-in. clear pine 22 lineal ft. 1-in. mesh, 2-ft. wide wire fencing. 6 pairs 1¹⁄₂ in. iron plain butt hinges, with screws. 2 steel drawbolts, with screws. ¹⁄₂ pt. white shellac.

Water Rheostat for Small Electrical Devices

The rheostat shown in the illustration can be made quickly and at small expense. The base consists of a piece of wood, ¹⁄₂ by 2 by 12 in. A glass tube, 1 in. in diameter and 6 in. long, is fastened to this with strips of sheet metal. A large brass tack is driven into a cork, and the cork is inserted in the lower end of the tube. A wire runs from the brass tack to the binding post A. The lower part of the tube should be paraffined to make it water-tight. A brass or copper rod is placed through the binding posts B and C. The resistance can be changed by sliding the rod up or down. The tube is nearly filled with water having a small quantity of salt dissolved in it. The amount will depend upon the current to be reduced. The rheostat should be fastened to a wall, or other support, and may be used to regulate the speed of small motors and other electrical devices.--R. R. Wayt, Pittsburgh, Pa.

White Blotting Paper Improves Light Reflectors

In the lecture and classrooms of a large university it was found that reflections of the electric-light bulbs in the glazed porcelain reflectors were extremely annoying to the eyes of students, and concentration of sight on the blackboard was difficult. A number of tests were made, and the following method proved successful, eliminating the glare and the reflections. Large sheets of white blotting paper were cut to fit the inside of the reflectors, and then glued to their surface. The soft, somewhat rough surface of the blotting paper diffused the light, so that the glare was overcome.--C. M. Hall, St. Louis, Mo.

Two Simple Vises for the Home Workbench

Boys, and other amateurs, sometimes have need of a vise when a commercial article or one of standard type cannot be had readily. The devices shown in the illustration will give good service and can be made of material easily obtained. The vise shown in Fig. 1 was made of old machine parts, consisting of a bolt and a wing nut. The bolt A was flattened at one end and bent at a right angle. A hole to fit it was bored through the top of the bench B, and the washer C and wing nut D were put in place. The piece to be gripped is clamped under the end A. This device should be fitted near the end and front edge of the bench.

The vise shown in Fig. 2 grips the block E in the same manner as the first vise. The jaw F is bolted to a vertical piece, G, which is fitted into a mortise cut through the bench top. The wedge H passes through a mortise in the piece G and clamps against the lower side of the bench top.--James E. Noble, Toronto, Can.

Drinking-Glass Holders Easily Made

Several styles of holders for a drinking glass are suggested in the illustration. They may be made of durable materials easily obtained in the home workshop. The first is made by twisting a galvanized-iron or brass wire, as shown, with an eye and a loop for fastening it to the wall. A cork is fixed to the upper end, on which to rest the glass. The lower sketch shows a holder of the cup type made by riveting a metal cup to a diamond-shaped plate, the latter being fastened to the wall. The holder at the right is made from a piece of sheet metal cut to the shape indicated below. It is bent to the shape shown, and the lower end of the narrow strip is curved upward to provide a rest for the edge of the glass. The upper portion of the holder should be large enough so that the glass may be raised sufficiently to fit into the rest. The holes are provided for a fastening.--Frank L. Matter, Portland, Ore.

Emery Needle Cushion on Sewing Machine

A convenient emery pad and needle cushion may be made by inclosing the powder in a long sack, about 1 in. in diameter, and sewing it in place around the arm of the machine. It will thus be close at hand and needles and pins may be stuck in the cushion, free from rust, and will not be in the way.

The possibilities for practical use as well as novelty for play and experimental purposes make the compensated aerial cableway, shown in the illustrations, not only interesting but also worthy of study. The arrangement assembled in its simplest form with two towers, in the page plate, shows how the weight of the car is compensated, so that a fairly level course on the track cable is provided. The various positions of the load and cables, showing the application of the compensating principle, are indicated in Figs. 1 to 5, and a multiple system is shown in Fig. 6. The details of the constructional parts are also shown. The car may be driven by wind power, as shown in Fig. 7, or by a motor, as in Fig. 8, in addition to the simple application of hand power suggested in the page plate. Devices for automatically reversing the course of the cars both for the sail rigging and with the use of electrical power, are shown in Figs. 7 and 8. By their use it is unnecessary to have an operator at each end of the cableway. The constructional features were worked out first by experiments on models in a shop, and then applied to a large rigging spanning over 100 ft. between the A-frames. The sketch in the page plate was made from photographs of this construction. Application of the compensating principle to carrying and transportation problems affords opportunity for interesting engineering, in spanning streams, cañons, or gulleys.

In most types of cableways a considerable sag is allowed in the cable supporting the car in addition to that caused by its own weight. Even in systems of practically constant cable tension, in which the wire is stretched by enormous weights, the loaded car causes a sag in the track cable, and ascends and descends an incline when approaching and leaving a tower. The aim in the compensated cableway is to overcome this sag as much as possible, and to offer a minimum of resistance to the car in its course.

The simple form of compensated cableway shown in the page plate is made by setting up two A-frames, with wire braces supporting them, and mounting the track and traction cables upon them. A light, flexible compensating cable extends from one tower to the other and is fitted to grooved pulley wheels at the tops of the towers, as shown in the detail at the right. The ends of the cable are fixed to wire hooks, from which the track cable is suspended. The latter is anchored at the ends of the wire braces supporting the A-frames. In order to understand the operation of the system it is desirable that the course of a load be traced in its various stages, as indicated in the diagrams, Figs. 1 to 5. For diagrammatic purposes the load is shown passing from the west slope to the east. As the load passes under the first A-frame, as in Fig. 2, the track cable is drawn down at that point; the corresponding end of the compensating cable is also drawn down, raising the opposite end of the track cable, and taking out most of the sag in the center portion of the track cable. As the load passes to the center position, as shown in Fig. 3, the track cable resumes a more nearly horizontal position. When the second A-frame is reached the load draws the corresponding end of the compensating cable down with the track cable, Fig. 4, and the latter assumes its normal position as the load reaches the end of the course. It is evident from the diagrams that the course of the load is more nearly level than it would be if the sagging of the track cable were not counteracted.

For use with a multiple-frame system, the cables are arranged in units between supports, as shown in Fig. 6. The compensating action is similar, the tendency being to level the entire course of the load. The weight of the car and load only is compensated, and since the weight of the cable will cause a sag, the course cannot be level, but may approach this condition.

A model of the compensated cableway, as shown in the page plate, or on a smaller scale, may be made by a boy of fair mechanical skill. For experimental purposes the detail may, of course, be refined to a high grade of workmanship, if desired. The size and dimensions of the parts need not be proportioned precisely as shown, but may depend more or less upon the materials available. The track cable should be made of galvanized-iron wire, the compensating cable of fishline, and the towers of 1-in. stuff, the width of the pieces making up the A-frames being increased in proportion to the height. Grooved pulley wheels, set in housings fixed to the top of the A-frames, carry the compensating cable. These may be made of wood, built up in three sections, to provide a flange on each side of the cable groove. The A-frames should be joined strongly at the top, and braced to anchors, sunk into the ground as shown. The hooks from which the track cable is suspended are made of heavy wire, bent so as not to interfere with the H-frame hanger supporting the car, and looped around the cable.

Various types of hangers may be devised to house the two pulley wheels which ride on the track cable. A simple H-frame hanger is shown in the detail sketch in the page plate. The grooved pulley wheels are set on bolts, and a heavy wire is bent and set through the center block as a support for the car. For experimental purposes, or even for play, when it is not desired to make a more elaborate car, a wooden block or other object of sufficient weight may be used as a load. An interesting feature of the work, especially for a boy, is to devise a realistic coach model, as suggested in the sketch. A wooden block forms the base, and the roof and platforms are made of sheet metal. The windows and doors are painted on the metal. The inventive boy may, of course, build a car with a hollow metal or wooden body, and weight it properly to provide the necessary load.

The motive power is provided by means of a cord, or traction cable, carried around two large grooved pulleys, mounted in supports fixed to the landing stages at each end of the cableway. They are made of wood, a suitable groove being cut around the edge with a saw, and smoothed with a small round file, or sandpaper wrapped over a round rod. The traction pulley is turned by means of a crank, set on the bolt which is used as an axle. The traction cable must be drawn sufficiently taut to provide the necessary pressure on the grooved pulleys, or it will slip. Rosin applied to the pulleys and the cable will tend to prevent this.

If the frames and other fittings have been properly set up, the cableway will support a sail car, shown in Fig. 7, or a two-cell electric car, driven by a small motor, as shown in Fig. 8. The sailing-car arrangement is often feasible, since a stiff breeze is common in gorges, cañons, narrow valleys, or even in ravines where such a cableway might be set up. The hanger is an H-frame having the grooved pulleys bolted in it, and further reinforced by small blocks at the ends. A braced frame, supporting a deck on which a mast is set, is suspended from the hanger by four curved wires, as shown in the side view, Fig. 7. A sail with boom and gaff is supported by the mast. It is arranged to be shifted around the mast, which is accomplished automatically at the end of a run, or “tack,” by means of the trigger device shown in the top view. The sail is controlled in relation to the wind much as is the main sheet of a sailboat. The car can be operated in this manner only at right angles to the direction of the wind, or nearly so. For play purposes, a boy stationed at each end of the cableway can shift the sail, but the trigger device shown makes this unnecessary. A rubber band is attached to the boom, as indicated in the top view, and a cord and wire are arranged to engage a trigger. A stop for the trigger is fixed to the A-frame so that it is sprung when the car reaches the end of the run. The rubber band reverses the sail, the car having been set on the cable originally so that the forward end is in proper relation to the wind.

The electric car is especially interesting in that it provides self-contained motive power by means of a battery of dry cells, and a motor belted to the hanger, as shown in Fig. 8. The hanger is of the H-frame type with heavy blocks between the sidepieces to provide for the small grooved driving pulley set on the axle of one of the larger pulleys. A wooden deck, supported by four heavy wires set into the center block of the hanger, carries the motor, and the dry cells are fixed under it. The motor is of the small reversible battery type, and should be provided with a reversing lever. This will make it possible to reverse the car when it reaches the end of its course. The motor and cells should be disposed so as to balance, tests being made for this purpose before setting them in place finally. A cord or small leather belt connects the drive pulley of the motor with the proper pulley on the hanger. These pulleys should be in line, and that on the hanger should be five times the diameter of the one on the motor shaft. The power is shut off at the end of the course by a shut-off switch which strikes a stop crank attached to the A-frame. When the reversing lever and stop are used, the stop crank is unnecessary. A nonreversing motor can be made to drive the car in a reverse direction by removing the belt from the motor pulley and replacing it to make a figure-eight twist.

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¶When babbitt metal is heated some of the tin and antimony in it is burned out, making it unsuited for use in machinery bearings, and similar purposes, after several heatings. The oxidation of the metal is indicated by the formation of a scum on the surface.

Among the engines of war in action on land, probably none has created greater interest than the now famous “fighting tank,” which, according to reports, pours out missiles of destruction on the enemy from armored turrets, and crawls over trenches, shell craters, and similar obstructions, like a fabled giant creature of prehistoric ages. The tank described in this article, while not as deadly as those on the battle fields of Europe, performs remarkable feats of hurdling trenches, and crawling over obstructions, large in proportion to its size. The model, as shown in the heading sketches, is full-armored, and has a striking resemblance to these war monsters. The turret is mounted with a magazine gun, which fires 20 projectiles automatically, as the tank makes its way over the rough ground. The motive power for the tractor bands is furnished by linked rubber bands, stretched by a winding drum and ratchet device, on the rear axle, as shown in Fig. 1. When the ratchet is released, the rear axle drives the fluted wheels on it, and they in turn drive the tractor bands, as shown in the side elevation, Fig. 6. The wire-wrapped flywheel conserves the initial power of the rubber-band motor, and makes its action more nearly uniform.

The tank will run upward of 10 ft. on the rubber-motor power, depending on the size and number of the bands used. The gun is fired by a spring hammer, actuated by a rubber band. The trigger device is shown in Fig. 1. The pulley A is belted, with cord, to the front axle. Four pins on its inner side successively engage the wire trigger, drawing it out of the gun breech B, and permitting another shell to drop into place. As the pulley revolves, the trigger is released, firing the projectile. This process goes on until the motor runs down, or the supply of shells is exhausted.

The tank is guided by the pilot wheel, shown in Fig. 1. The sheet-metal armor, with its turret, is fitted over the mechanism, and can be removed quickly. It bears on angles bent up, as detailed in Fig. 2, to fit on the ends of the wooden center crosspiece of the main frame, and is held by removable pins at the ends of this frame. While the rubber motor is easy to make and install, the range of the tank can be increased by using a strong spring motor, the construction otherwise being similar.

The construction is best begun by making the wooden frame which supports the armor. The perspective sketch, Fig. 1, used in connection with the working and detailed drawings, will aid in making the latter clear. Make the frame C, as detailed in Figs. 5 and 6, ³⁄₈ by 1³⁄₄ by 11 in. long, with an opening cut in the center, 1 in. wide, 1 in. from the rear, and 1¹⁄₄ in. from the front end. Make the crosspiece D ³⁄₈ by 1³⁄₄ by 5⁷⁄₈ in. long; the gun support E, as detailed in Fig. 4, ³⁄₈ by 1⁵⁄₁₆ by 6¹⁄₄ in. long. Shape the support E as shown. Fasten the frame C and the crosspiece D with screws, setting the piece D 5³⁄₄ in. from the front, and its left end 3 in. from the side of the frame, as shown in Fig. 5. This is important, as the fitting of the other parts depends on the position of these wooden supports.

The drive-wheel axles are carried in sheet-metal hangers, F, shown in Figs. 1 and 5, and detailed in Fig. 6. These hangers also carry bearing wheels, G, Fig. 1, which are held between the hanger F and a metal angle, as detailed at G, Fig. 6. These wheels are cut on a broomstick, and mounted on nail axles. The metal for the hangers F is drilled as shown, and bent double at the ends to make a strong bearing for the drive-wheel axles. The upper portion is bent at a right angle and fits over the top surface at the end of the crosspiece D, and is fastened to it with small screws or nails. Cut the stock for the hangers 2 by 6³⁄₈ in. long.

Next make the sheet-metal support H, Fig. 1, for the flywheel, the rim of which is wrapped with wire to give it added weight. Cut the stock, as detailed in Fig. 6, 1³⁄₄ by 4³⁄₁₆ in. long, and notch it to form the spring arrangement, which holds the flywheel so that the belt will be tight. The other sheet-metal support may then be made also. Cut the stock for the front support J, for the rubber motor, 4¹⁄₈ by 3³⁄₄ in. long, and shape it as shown in the detail, Fig. 6. Make the support K from a piece of sheet metal, in general shape similar to that used for support H, the dimensions being made as required, and no spring arrangement being provided. Drill these metal fittings, as indicated, for the points of fastening, and mark the places for the holes in which shafts or axles run very carefully.

The driving mechanism can then be made, as shown in Fig. 1, and detailed in Figs. 5 and 6. The driving shafts and their parts, as well as the pulleys, can be turned in a lathe, or made from spools, round rods, etc. Make the front axle L, and wheels, joined solidly, 5³⁄₄ in. over all, the grooved wheels being ³⁄₄ in. thick, and 1⁷⁄₁₆ in. in diameter. Wires are used as bearings for shafts for the driving axles. If the rear axle is turned in a lathe, it is cut down to the shape indicated, thinner at the middle, to provide a place for the cord connected to the rubber motor. The grooved pulley and the fluted drive wheel at the winding-key end, shown in Fig. 5, are then cut loose; the drive wheel on the other end is cut loose, forming three sections, mounted on the wire axle, one end of which is the winding key. Ratchet wheels, M, are fitted between the ends of the center section and the adjoining pieces, the ratchet wheels being nailed to the center section and soldered to the wire axle. Pawls, U, are fitted to the inside of the two end sections, as indicated in Fig. 1 and in Fig. 5. When the rubber motor is wound up on the drum, the tractor bands are gripped until it is desired to start the tank on its trip. Then the power is communicated from the drum, or center section of the axle, to the drive wheels by means of the ratchet wheels, acting on the pawls.

Mount the hangers F on the center crosspiece D, fitting the axles of the drive wheels into place. Make the weighted flywheel, and mount it on its shaft, as shown, lining it up with the pulley on the rear drive shaft. Fit the supports J and K into place, setting spools for the rubber-motor cord in place, on wire axles. Arrange the belt from the flywheel to the drive shaft, and connect the rubber bands for the rubber motor as shown. Fasten one end in the hook of support J, and pass the winding cord through the spools, and fix it to the drive shaft. The device can then be operated with the fluted drive wheels, bearing on strips of wood for tracks.

The tractor bands N are fitted over the drive wheels, as shown in Fig. 6. They are built up of canvas strips, on which wooden shoes are glued and sewed, as detailed in Fig. 5. The stitches which reinforce the gluing are taken in the order indicated by the numerals. The pilot wheel is 2 in. in diameter, and sharpened at its circumference. Make a metal shell, O, for it, as detailed in Fig. 6. Solder the shell to the double wire, which supports the wheel and gives it a spring tension to take obstructions nicely. The wire is fastened to the crosspiece D, as shown in Fig. 5.

The gun and its mechanism can be made handily before the support E is fixed into place at the front of the crosspiece D. Shape the magazine P from sheet metal, making it 2⁵⁄₈ in. high, as detailed in Fig. 4. Make the gun Q from a piece of sheet metal, as detailed, cutting the metal to the exact dimensions indicated. Mount the magazine and the gun, and arrange the wire hammer R, and the rubber band that holds it. Fit the pulley A into place on its axle, supported by a small block of wood. Belt it to the front drive-wheel axle, as shown in Fig. 5, after the gun support is fastened into place with screws. Make the projectiles of wood, as shown, and the fighting tank is ready to be tested before putting on the armor.

The armor is made of one deck piece, S, Fig. 3, into which the covered turret is set, and two side pieces T, as detailed in Fig. 2. Make one left and one right sidepiece, allowing for the flanges all around, to be bent over and used for riveting or soldering the armor together. The bottom extension on the sidepieces is bent double to form an angle, on which the armor is supported, where it rests on the top of the hangers F. The turret is fitted to the deck by cutting notches along its lower edge, the resulting strips being alternately turned in and out along the point of joining, as shown in Fig. 3. When the armor is completed, it is fitted over the main frame, the gun projecting from the turret. Small pins hold the ends of the armor solid against the ends of the main frame C, so that the armor can be lifted off readily. The various parts of the fighting tank can be painted as desired, care being taken not to injure the points of bearing, on the axles and pulleys, which should be oiled. Silver bronze is a good finish for the exterior of the armor, which may be decorated with a coat of arms.

A Neat and Economical Baby Crib Made from a Clothes Basket

A clothes basket on a simple but strong wooden frame, mounted on castors, makes a cradle which is as convenient and sanitary as many which are sold for five times its cost. It is light enough to roll out on the porch without difficulty, and may be padded and fitted with pillows until the most exacting mother is satisfied. The basket and frame should be painted, preferably some light color. The whole cost, not including pads or pillows, should not be over $2.50.--A. Switzer, Denver, Colo.

A Small Rheostat for Experiments and Testing

A rheostat made as shown in the sketch has been used successfully for calibrating a large number of ammeters and wattmeters. One of the general designs suggested will be useful for many other purposes. The dimensions given were used for obtaining a variation of from ¹⁄₂ to 5 amperes with a 6-volt source of electromotive force. For other capacities the proportions may be increased or decreased proportionately. A piece of pine, 7 by 9¹⁄₂ in., forms the base. For resistance wire No. 16 gauge “Climax” was used, but wire of any material which will carry the maximum current without excessive oxidation may be employed instead. Nails support the resistance wire, which should be soldered to the nails to insure good electrical contact. Leads of flexible cord are arranged as shown. These are soldered to the first and last nails in the series. To provide connection between the free ends of the cord and the resistance wire or the nails, 5-ampere test clips are soldered to the cord ends. The teeth of the clip jaws are filed off, and in their stead a short piece of brass wire is soldered to each jaw, as indicated in the detailed view. A nick is filed in each of the brass wires so that they will hold firmly onto the resistance wire or nail. Suspender or display-case clips, suitably modified, may be substituted for the commercial test clips.

In using the device, one clip is moved along the front span. The other is gripped to a nail in the rear row. Sliding the front clip along the span wire insures a fine adjustment of resistance. Gripping the rear clip on the different nails provides the coarse adjustment--R. F. Binney, La Vina, Calif.

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¶Glue applied to door-knob screws will prevent them from loosening easily, yet they may be removed without difficulty.

Roll-Paper Feed for Typewriter

Typewriter paper may be fed from a roll where only one copy is necessary and where maximum speed of production is essential. Sections, not to exceed about 11 in. in length, of the typed paper are torn off as necessary. This practice is followed often in newspaper offices. The roll paper can be purchased at any paper-supply house, cut to the width required by the user. The construction of a roll-feed attachment which may be mounted on any of the standard typewriters will be described.

First make the two uprights. Both are cut from ¹⁄₆-in. sheet brass, as shown. After cutting, heat the pieces to anneal them before bending. A hole is provided for the paper-roll rod in the right-hand upright and a slot in the left-hand one. A rod, threaded on one end and equipped with two nuts, constitutes the paper holder. For a guide plate and cutter, cut a piece of sheet brass, 1¹⁄₂ in. wide and of a length equal to that of the carriage, as detailed in the drawing. Bend it as shown. A ¹⁄₈-in. slot is cut almost the entire length of the guide.

In mounting the holder on the typewriter, the uprights are drilled at the base to engage the two small screws at the side of the carriage back of the roller. The exact location of these holes will vary in machines of the different makes. Next, the uprights are clamped into place with the screws, one at each end of the carriage. Then determine the distance between the arms of the uprights, drill a corresponding hole at each end of the guide-and-cutter plate, and fasten the plate to the uprights with small stove bolts. The roll of paper is placed on the rod and fed between the machine platen and roller as with single sheets. When the article or memorandum being written is finished, the paper is held against the guide plate and the blade of a pocketknife inserted in the slot. Passing the blade the length of the slot cuts off the paper, or it may be torn off at the slot. The end of the paper roll is again fed into the machine, ready for another operation.

Handy Paring Knife Made from Old Hacksaw Blade

With a little work a hacksaw blade, or a portion of one, can be made into a paring knife that will prove very durable because of the excellent quality of the steel. Two pieces of hard wood should be cut into the shapes shown and riveted together with one end of the blade between them. After putting a paper mold about the end of the handle from which the steel projects, melted lead is poured into it, to form a collar that will hold the parts firmly together. The exposed part of the saw can then be ground as desired.

Washing Machine Equipped with Churn Attachment

The owner of a power-driven family washing machine has provided an attachment for it with which he churns cream at a little additional expenditure of energy. A wooden plunger was bolted to the outside of the flywheel and its upper end placed between two rollers set in a metal frame attached to the side of the tub. Enough play was allowed between the rollers to permit the plunger to move up and down freely. A framework large enough to hold a glass fruit jar was attached to the side of the plunger, a thumbscrew being provided in its upper end with which the jar is held firmly in place. As the flywheel revolves, the movement of the plunger thoroughly agitates the contents of the jar.--Dale R. Van Horn, North Loup, Neb.

Treating Closets with Cedar Oil

Apropos of the article in a recent issue of Popular Mechanics Magazine entitled “A Cedar-Lined Oak Chest,” readers who desire the advantages of a cedar-lined box or closet may accomplish it by the use of cedar oil. Painting the interior of a box with this oil will to all intents and purposes convert it into a cedar chest regardless of the kind of wood used. The cost of the oil is not great. A closet treated in the same manner will likewise keep out insects.--Robert E. M. Bain, St. Louis, Mo.

Barnyard Gate is Operated with the Foot

A gate which can be unlatched with the foot has proven a great convenience across a path on a farm where laborers frequently pass with both hands occupied carrying pails. Pivoted to the side of the gate, near its center, a beam, or foot lever, is hung in a vertical position, extending almost to the ground and having a shelf bracket fastened to its upper end. The horizontal arm of the bracket passes beneath a porcelain knob projecting from a pivoted bar that engages the elbow catch. By pushing the vertical beam to one side with the foot the bar is raised above the catch, allowing the gate to swing open. If the gate is properly hung it will close of itself, the elbow catch serving to prevent its being opened again, except when the bar is raised.--T. C. McDowell, Adrian, Michigan.

Improvised Post-Card Projector and Enlarging Camera

BY HARRY MARCELLE

An outfit which may be used for either projecting picture post cards or enlarging photographic negatives was assembled as delineated in the illustration. An ordinary camera, which provides the lens and bellows, is required, in combination with a dark box which can be built in the home workshop. The method of construction is this:

Make a box about 8 in. square out of ¹⁄₂-in. planed soft-wood stock. Nail the sides, but omit, for the present, the top and the bottom. The two openings thus left will be called the front and the back. Mount an 8 by 8 by ¹⁄₂-in. board, D, which constitutes a door, on the back with hinges and provide a hook to hold it shut. Cut a square hole, of the same size as that of the opening in the back of the camera which is to be used, in another 8 by 8-in. piece, E. This will constitute the front board. This front board is so cut that it fits in between the sides of the box instead of on the ends, as does the back. In the top, cut a square hole for ventilation. A hood is provided over this hole to prevent light being thrown forward.

When using the arrangement as a projector or magic lantern two 40-watt tungsten lamps, A, are required. Each lamp is mounted in a porcelain receptacle held on the floor with screws. A lamp cord, one end connecting the two lamps in multiple and the other fitted with an attachment plug, passes through a hole in the floor of the box. Form the two reflectors, B, of 8 by 7-in. bright tinned sheet-iron pieces, each having holes along one of its edges to admit of attachment. The reflectors are bent to a semicircular contour before mounting. The card holder is detailed at C. It is a piece of tinned sheet iron bent to the form shown so that it will hold a post card. A hole is drilled in its center for a screw pivot. It can then be fastened to the center of the back door and can be turned into position for either horizontal or vertical pictures. A washer is inserted on the screw between the holder and the door. The thickness of the camera body having been determined, a slide is fastened to the front board, as diagrammed, to support this body.

Before it can be used as a projector it must be adjusted to operate with the camera of the type and size available. The adjustment, which must be made in a darkened room, having on one of its walls a white screen on which the image will be projected, is effected thus: Remove the back from the camera and place the camera in the slide without extending the bellows. Open the shutter. Insert a card in the holder C. Light the tungsten lamps. Now move the front board, with the camera carried on it, back and forth within the box until the components are in focus, that is, until the most distinct image obtainable is reproduced on the screen. Then, illuminate the previously darkened room and nail the front board in the position thus determined. These adjustments having been made, paint the box, inside and out, a coat of dead black. Everything should be painted black except the reflecting surfaces of the tin reflectors and the incandescent-lamp bulbs. The front board having been fastened, subsequent focusing can be effected by shifting longitudinally the lens board of the camera. The image of any sort of a picture that will fit in the holder can be reproduced. Colored post cards will project in their natural tints.

To make enlargements with the same box, a few minor changes are necessary. When employed for enlargements the tungsten lamps, which are required for projection, are not used. They may, however, remain in the box and can be disconnected from circuit by unscrewing them a few turns. The negative, or film, which is to be enlarged, is held in the opening E. Where a film is to be reproduced, it is held between two pieces of glass which are fastened to the inside of the front board with small clips. If a glass negative is used, the two additional glass plates are unnecessary. If the negative does not fill the opening in the camera, a mask cut from heavy black paper will be required to cut off the light.

The light for the enlargement is furnished by another tungsten lamp mounted in a porcelain receptacle which is screwed to a board which constitutes a base. This light source is moved about in the house until it is directly back of the opening E in the front of the box and until the light is distributed equally over the entire negative. To focus, move the camera backward or forward. While focusing, use a yellow glass, or ray screen, to cover the lens. When focusing has been completed, the shutter is closed and the ray screen removed. Then stop down the lens to bring out detail, and expose.

Changing a Motor-Car Tire without a Jack

It occasionally happens that a motorist fails to have a jack at hand when a tire needs to be changed on the road. The situation is easily met with the aid of a strong board and a couple of blocks or rocks. Driving the desired wheel onto the incline, provided in the manner illustrated, and setting the brakes, a block is placed beneath the axle. The board is then knocked out of the way.--John Peters, Milwaukee, Wis.

Roller Truck for Use in Scrubbing

A little padded platform on wheels takes most of the drudgery away from scrubbing in hotels and office buildings. The platform carries the pail as well as the scrubber, and enables the scrubber to keep dry.--Florence L. Clark, McGregor, Ia.

Economical Use of Wood Alcohol in Small Cooking Stove

A couple eating breakfast and supper in their room used a chafing dish for cooking. A hard alcohol was used for fuel, and the expense seemed too high. So a fuel can was filled with pulverized asbestos pipe covering, and then saturated with wood alcohol. A quart of alcohol lasted about a month.--Charles A. King, Plymouth, N. H.

Attractive Table Stands for Hot Dishes

Attractive stands which will preserve the dining table from injuries, or heat marks made by hot dishes, can be easily made from thin pieces of board cut oblong or oval. After the board has been cut the proper size, cleats are fastened to the underside to which billiard-cue tips are attached to serve as supports. The stand should be varnished and waxed to match the table.--George L. Furse, St. Louis, Mo.

Cord Used as Spacer for Curtain Rings

To make the curtain rings space automatically along the curtain pole, tie a cord from one ring to the next, spacing the rings uniformly. Or the cord may be attached at uniform distances to the curtain. A pull at the edge of the curtain will space the rings evenly every time.--Frank L. Matter, Portland, Ore.

Device for Packing Earth in Transplanting

When tomato or cabbage plants are to be set out in considerable numbers, the simple implement shown here makes stooping over to press the dirt about the plants unnecessary. After a row of plants has been set in dibble holes and watered, the soil can be packed about their roots quickly while one is standing upright. The jaws of the device are actuated by means of the hinged lever.--A. S. Thomas, Amherstburg, Ont.

Cleat and Pulley Fastenings to Adjust Clothesline

The following kink will relieve the housewife of the trouble of sagging clotheslines, and hubby of constantly being asked to tighten up the line. The cost should not be over 25 cents, as all that is needed is a pulley cleat and hook, all of which may be had at any ten-cent store. When the line gets slack, it is pulled tight through the pulley and tightened up in the cleat.--S. H. Johnson, Westville, Conn.

Convenient Type of Mail Box for Home Use

A person having a mail box set flush in the outside wall of his home can, with a little alteration, make it accessible from inside the house: After removing the back side of the box a tin extension should be soldered to the box giving it sufficient length to reach through the wall in which an opening of the proper size has been cut. The enlarged container is completed by adding a glass door to the inner end which enables one to ascertain its contents at a glance.--A. Pertle, Chicago, Ills.

Block Plane Converted for Use on Circular Work

Few amateur craftsmen can afford to own a circular plane, yet this tool is decidedly necessary for such round work as table tops, half-round shelves, segments, and the like. Any ordinary block plane will accomplish such work if equipped as illustrated. A piece of half-round hard wood is cut the width of the plane and attached with countersunk machine screws, as indicated. The block elevates the rear end of the plane, causing it to follow the curve of the work on which it is used.

Pressure Spray Made of Old Oilcan

In making a spraying outfit for garden use, or similar purposes, a 3 or 5-gal. kerosene can and tire pump may be satisfactorily employed. The latter is attached rigidly at the rear of the container with iron straps, as shown. A ball check valve is fitted in the top of the receptacle and connection is made between it and the pump with the pump hose. A 6-ft. length of ¹⁄₄-in. rubber tubing is wired to the drain cock. An 8-in. piece of ¹⁄₄-in. brass pipe is filed down and wired in the spray end of the hose to serve as a nozzle.--P. P. Avery, Garfield, N. J.

Keeping Tools Bright and Free from Rust

Bright-finished tools can be preserved against rust by coating with linseed oil, and allowing the oil to dry as a film. If more body is desired, oxide of iron, very finely powdered, should be mixed with the oil. Another antirust coating is made by dissolving ¹⁄₂ oz. camphor in 1 lb. melted lard. The mixture is skimmed, and fine graphite added to make an iron color. Clean the tools and smear with this mixture. Let the tools stand 24 hours, and rub clean with soft cloth.

A good method of removing rust is to cover the metal parts with sweet oil, rubbing it in well. Let stand 48 hours; then rub with finely powdered, unslaked lime. Next immerse the article for a few seconds in a solution of ¹⁄₂ oz. potassium cyanide in a wine glass of water. Then clean with a paste of potassium cyanide, castile soap, whiting, and water, using a toothbrush. Potassium cyanide is a strong poison, and should be used carefully.--E. Standiford, Youngstown, Ohio.

Repairing Leaks in Pipes

Frequently a cast or malleable-iron pipe fitting will leak through its side, the water oozing, drop by drop, from a pinhole--ordinarily due to a sand hole in the casting. Sometimes the leak can be stopped by hammering the affected spot with the ball end of a hammer. If this fails, it is necessary to replace the fitting. Where the leak is around a thread, screwing the pipe or fitting tighter constitutes the only, and usually effective, corrective.--L. A. Merton, St. Louis, Mo.

Corn Popper Made from Coffee Can and Broom Handle

With an old coffee can, or similar tin receptacle, and a piece of a broom handle, 2¹⁄₂ or 3 ft. long, it is easy to make a corn popper that is preferable in many ways to a wire one. Take a strip of wood a little shorter than the height of the can to be used, and after boring two holes in it to prevent its splitting, nail it to the end of the handle. The latter is then fastened to the side of the can with two wire staples, as shown. Holes are made in the can top to admit air to the corn while it is popping.--James Crouse, Dixon, Ky.

An Easily Constructed Ball-Bearing Anemometer

BY THOMAS A. REYNOLDS

An anemometer is an instrument which measures the velocity of the wind. The anemometers used by the weather bureau consist of four hemispherical cups mounted on the ends of two horizontal rods which cross at right angles and are supported on a freely turning vertical axle. Since the concave sides of the cups offer more resistance to the wind than do the convex sides the device is caused to revolve at a speed which is proportional, approximately, to that of the wind. The axle, to which the rotary motion is transmitted from the cups, is connected to a dial mounted at the foot of the supporting column. This dial records automatically the rotations. The reproduction of such a registering mechanism would be rather complicated. Hence, in the arrangement to be described none will be employed. Therefore, one of these improvised anemometers, when mounted on a high building, will indicate by the changing rapidity of its revolutions only the comparative, not the real, velocity of the wind.

In constructing the instrument, straight, dished vanes will be used instead of hollow cups. The vanes operate almost as effectively and may be combined more readily into a sturdy rotating unit. A bicycle front hub is utilized to constitute a wear- and noise-proof bearing having minimum friction. Each of the four wings is formed from a piece of galvanized iron, measuring 4¹⁄₂ by 10 in., which has one end cut to a curve as shown. To each wing is fastened, with tinners’ rivets, a 4-in. length of ³⁄₄ by ¹⁄₁₆-in. strap iron. Form each of the strips into a trough-shaped vane, measuring 2¹⁄₄ in. from edge to edge--this being the distance between the spoke flanges of a bicycle hub. Some cylindrical object of suitable diameter will serve as a form for bending. Place the ends of the support strips between the spoke flanges and rivet them securely. The rivets pass through the spoke holes. Some trying out may be required to insure a symmetrical arrangement of the parts. Solder the curved end of each wing to the inner surface of the adjacent wing. Place a tin cap--a salve-box lid will do--under the upper locknut on the hub to exclude rain from the bearing.

The supporting upright may be a heavy wooden rod, or a piece of iron pipe. A yoke of 1 by ¹⁄₈-in. strap iron, held to the top of the upright with screws, is provided for the attachment of the hub. The locknut on the hub clamps it to the yoke. Apply a coat of metal paint to the iron parts which are exposed. Mount the device sufficiently high to give the wind free access to it from all directions. The curve at one end of each wing is an irregular one. Hence, its accurate construction involves a knowledge of sheet-metal pattern drawing. However, if it is made of a form similar to that shown it will fit sufficiently well to permit a good soldered joint.

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¶Boards exposed to the weather should be laid with the heart side down, as determined by examining the end grain.

[These directions will enable boys of varying skill with tools to make a pile driver, as a toy or model. Several simple methods of making the parts in the home workshop, with materials easily obtainable, are suggested.--Editor.]

The construction of small docks, wharves, piers, and foundations or bridges, buildings, and other structures, by the driving of piling is interesting out-of-door play, in which boys will find much fun. A pile driver for this work is shown in the page plate, Fig. 1. The hammer is raised by means of a winch, and is dropped automatically when it reaches the cap of the derrick, as indicated in Fig. 3. The drum is then released, and the weighted double-hook nipper drops down, picking up the hammer on the next upstroke. A single-hook nipper, that can be made easily of wire, is also shown in the detail sketch, Fig. 6. The small boy who cannot make the nippers or the winch, may tie the rope directly to the hammer, drawing it up by hand, and dropping it as desired. The hammer need not be fitted to the guides, but merely arranged to drop between them, and the derrick can be made of only a few main pieces. The larger parts of the hammer and nipper weight are best made of lead, babbitt, or white metal, as these may be cut or melted readily. Iron, brass, or copper, solid or in plates, may be used, if means for shaping them are at hand.

The making of the derrick may be undertaken first. Make two pieces for the bed A, ⁷⁄₈ by ⁷⁄₈ by 17 in.; two hammer guides B, ⁷⁄₈ by ⁷⁄₈ by 33¹⁄₈ in.; one bed piece, C, ³⁄₈ by ⁷⁄₈ by 20 in.; two bed pieces, D, ³⁄₈ by ⁷⁄₈ by 5¹⁄₄ in.; two posts, E, ¹⁄₂ by ¹⁄₂ by 34¹⁄₂ in.; two braces, F, ³⁄₈ by ³⁄₄ by 26¹⁄₂ in. Cut these pieces slightly over their finished lengths as given, allowing for trimming and fitting. Make strips, ¹⁄₄ by ¹⁄₂ in., for the bracing on the sides of the derrick and the ladder bracing on the back.

Notch the lower ends of guides B, ¹⁄₈ by ⁷⁄₈. and the lower ends of posts E, on an angle, ¹⁄₈ in. deep, to fit pieces A. Join the parts of the bed, as shown in the page plate, pieces A being set 3¹⁄₂ in. apart, fastening them with bolts or screws. Make braces G, of sheet metal, and bolt them in place. Fit the posts E into place, and fasten them at the bed and the top. Put on several ladder braces temporarily, to steady the frame. Fit the braces F carefully, and bolt them in place. Remove the piece C and the braces F, and nail the horizontal bracing to the sides of the frame. Then fit and nail the diagonal braces. The bolted construction is convenient in “knocking down” the derrick for storing it. Reassemble the parts, and make the cap for the headblock.

The headblock and cap are shown in detail in Figs. 2 and 3. Make two pieces, H, ¹⁄₄ by 1⁵⁄₁₆ by 1³⁄₄ in.; one piece, J, ¹⁄₄ by 1 by 1³⁄₁₆ in.; two braces, K, ¹⁄₄ by 1¹³⁄₃₂ by 1³⁄₄ in. Make the two beveled pieces of the cap ⁷⁄₈ by 1³⁄₄ by 1¹⁄₂ in., and provide a wooden strip or metal plate for the front and rear edges, as shown. Fasten strips of sheet metal to the bevel of the notch, to protect it from wear by the striking of the nipper hooks. Make the sheave 1¹⁄₂ in. in diameter and ³⁄₈ in. thick, with a groove for the rope. Assemble the parts, as shown.

The details of the winch are shown in Figs. 4 and 5, and the method of assembling the parts, in Fig. 1. The drum may also be driven without gears by fixing the crank directly to the shaft. Gears may be obtained from old machines, or purchased from dealers in model supplies. Make the supports L and M, Fig. 4, ³⁄₄ by 4 by 6⁵⁄₈ in., cutting patterns of paper, if desired.

The gear, Fig. 5, is 3¹⁄₂ and the pinion ³⁄₄ in. in diameter. The drum is of wood, 2 in. in diameter and 3⁵⁄₁₆ in. long. Its ends are 3¹⁄₂-in. metal disks, fastened with screws. The shaft is a ³⁄₈-in. bolt, 5³⁄₈ in. long, and bears in holes bored in the supports, as shown in the details of these parts. The crank N, Fig. 5, is made of a ³⁄₁₆-in. rod, bent as shown, and fitted with a washer to fit next to the pinion. The gear is set by means of the pawl O, which is bent from a strip of ¹⁄₁₆-in. sheet metal. The brace P is bent from a ¹⁄₁₆ by ³⁄₄ by 1⁵⁄₈-in. strip of sheet metal, and riveted to the pawl. Assemble the parts, fastening the gear to the drum end, and bolt the supports into place. Put the pinion into mesh with the gear at its proper place, and carefully mark the hole for the crank. Square the end of the crank and the hole in the pinion, and fit them to a driving fit. Fix the rope to the drum, and reeve it through the head block. The derrick is then ready for the hammer and the weighted nipper.

The hammer, shown in Fig. 6, may be made easily from a solid block of lead, 1¹⁄₄ by 2⁵⁄₈ by 2⁵⁄₈ in. Cut ³⁄₁₆ by ⁷⁄₈-in. grooves in the vertical edges to fit the guides. Make the circular ³⁄₁₆ by 1⁵⁄₈-in. hammer plate Q of iron or brass, and fasten it with screws. Rivet the wire lifting strap R, as shown.

The single-hook nipper, shown in Fig. 6, is made as follows: Flatten a piece of ³⁄₁₆-in. wire at the middle, and drill a ³⁄₃₂-in. hole for the bolt. Shape the lower end into a pointed hook, and bend the upper end to form the trip arm. This strikes the notch in the cap of the derrick, releasing the hammer. The rope is wired to the hook as shown. The nipper weight is made of a solid piece of lead, 1¹⁄₄ by 2⁵⁄₈ in., by 1 in. high, grooved at the ends to fit the guides. Cut a slot through it, for the hook, as shown in Fig. 6, and bolt the latter into place. The double-hook nipper is better mechanically, and may be made of two pieces of wire, or cut from sheet metal.

Test the action of the nippers, and bend or file the hooks to operate properly. The pile driver may then be painted, and work on “jobs” begun. If it is used at the water, fix metal guards at the lower ends of the guides, to prevent the hammer from falling into the water.

Split Needle Causes Echo on Talking Machine

An amusing stunt is to split the end of a fiber talking-machine needle carefully about ¹⁄₄ in., so as to make two points, slightly separated. The needle is then placed on the machine, preferably on an old record, so that the points play the record successively, producing an echo. If the work is carefully done, and the points are separated slightly, both reproductions will be fairly clear.--Frank Murphy, Faribault, Minn.

Weighting a Metal Base

Having to weight a shallow metal base to support a 4-ft. brass tube, I found that the easiest way was to fasten four screws on the base with nuts, as shown in the illustration, and pour in lead. The screws were taken out in polishing the base.--James M. Kane, Doylestown, Pa.

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¶In toasting bread over a camp fire, it is best to cover the fire with a tin pan.

Trunk Bookcase for Convenient Shipment

Mechanics, engineers, and other persons are sometimes engaged in work which keeps them at the same locality only a few months. Those who desire to carry with them a small library will find the trunk bookcase, as shown, convenient. It may be shipped as a trunk, and used as a bookcase in one’s hotel or dwelling. Other articles than books may be packed in it. The outside dimensions when closed are 31 by 18 by 18 in., providing for three shelves. It may be made of ³⁄₄-in. pine or whitewood, and stained, or covered with impregnated canvas. The outer corners are reinforced with metal corner plates, and suitable hardware is provided.--Lloyd C. Eddy, Jr., Buffalo, N. Y.

Bottle Carrier Made of Pipe Straps

Two metal pipe straps, fitted around the neck of a bottle and bolted together, form a convenient method of attaching a carrying handle to a large bottle. The handle proper is made by fixing a grip in a bail of wire similar to that on a bucket.

A Developing or Etching-Tray Rocker

An appliance that saves time for the worker in a photographic dark room is a tray rocker, made as follows: Fasten a bracket of strap iron, into which are riveted the pointed ends of two spikes, to the under side of a board, as shown in the detail sketch. Support this further with a double angle fastened at the end of the board. Fix a small can, weighted with lead, on the end of an iron rod, adjusted to a suitable curve, and fasten the rod to the bracket. The weighted end should extend under the edge of the table, as shown, and be balanced so that it will rock the board and tray without tipping the latter toward the bracket. The nails pivot on metal pieces, to protect the table top.--L. L. Llewellyn, Piedmont, Calif.

Combination Laundry Tub and Dishwashing Sink

A saving of space and time was effected in a home kitchen by the use of a sink developed in a large kitchen. Two ordinary laundry tubs were installed with the faucets raised above the tubs, as shown. A sink of sheet zinc was fitted in the upper part of one tub; it has handles, and a strainer set in the bottom. The strainer is closed by a rubber stopper, and the sink becomes a dishpan. The sink is easily lifted out for cleaning, or for washing clothes. Another use for the sink, between meals, is for washing and preparing vegetables and fruits. The second tub has a wire dish-draining rack, in which the china is rinsed and sterilized by hot water from the faucet.--Mrs. Avis Gordon Vestal, Chicago, Ill.

A Leather and Silk Bookmark

An artistic and useful bookmark was made from a silk ribbon passed through a buckle of leather, tooled with an inscription and a conventional design. Ribbon of various sizes may be used, and the leather left plain if desired. The ends of the ribbon are fringed, as shown. Monograms make interesting and individual decorations for the leather portion.--Will Chapel, Manchester, Ia.

Emergency Oarlock of Rope

An oarlock that will give considerable service may be made by fixing a loop of rope to the gunwale of a boat at the proper position. This kink is useful in an emergency, such as when an oarlock is dropped overboard.

Planing Thin Sticks Held in Flooring Groove

Boys who make thin sticks for arrows, kites, etc., as well as the mechanic, can make good use of the following suggestion: The difficulty of handling thin strips while planing them may be overcome by setting the strip in the groove of a piece of flooring, clamped in a vise. A peg or nail is driven into the groove and acts as a stop for the end of the strip.

Submarine photography should have great attractions for amateur photographers who have access to lakes, ponds, and other clear waters. While more careful work is demanded than in ordinary photography, the method of obtaining good results is not difficult, and the necessary equipment may be provided by constructing the device shown in the illustration. Submarine pictures can be taken in a considerable depth of water, providing it is reasonably free from foreign matter. This is a fascinating field of photography, and many pictures of educational and scientific value remain to be made of under-water life. The illustration shows the detailed construction of the camera chamber, and the method of suspending it from a bridge, or other place convenient to the body of water. Reproduced in the oval panel is a photograph of fish near baited hooks, on a fishline. The original was made from a negative exposed by the use of the camera chamber described.

The problem of making photographic exposures under water involves the provision of a strong water and pressure-proof container for the camera, a means for controlling the shutter, and a suitable opening in the container through which the exposures may be made. The arrangement described combines these features in a simple manner, and by the use of materials that can be obtained without difficulty. It was made for a camera taking 4 by 5-in. pictures, and the dimensions given are for a container for this size. The dimensions may be varied to adapt the device to various cameras, within reasonable limits. A 9-in. steel pipe was used for the chamber, and its ends were fitted with pipe caps. A heavy piece of plate glass was fitted into the forward cap, which was cut into the shape of a ring, to provide the exposure opening. The general arrangement of the camera in the chamber is shown in the sectional view, Fig. 1, as seen from the shutter end. The electrical device, by which the shutter is controlled, is shown in this view, and in Fig. 2 it is shown in detail.

The chamber was made as follows: A section of 9-in. steel pipe was cut to a length of 11¹⁄₂ in. and threaded on the ends to fit pipe caps. The forward pipe cap was chucked up in a lathe and the center portion cut away, to provide an exposure opening and a shoulder at the rim, on which the plate-glass window rests. A graphite paint was applied to the rim, then the glass was bedded solidly in it, and a rubber gasket was fitted to the joint, making it waterproof when the cap was drawn up tightly. The chamber assembled and in detail is shown in the illustration.

Holes were bored into the top of the chamber, and eyebolts were fitted into them. Between the eyebolts a hole was bored and fitted with a water-tight collar, through which the wires leading to the shutter-control device pass. The chamber is supported by the wires, which are fixed to the eyebolts and secured at the base of operations by the photographer.

A support for the camera was provided by bending a strip of ¹⁄₈ by 1-in. band iron to the shape indicated in Fig. 1, at A, and riveting it to the bottom of the chamber. Its upper surface is flat and was bored and threaded to fit the tripod thumbscrew B, on the lower surface of the camera. The camera is arranged on the support and clamped into place firmly by the thumb nut, as it might be on a tripod. The adjustment of the camera in the chamber is done from the rear, and the space beneath the thumbscrew should be large enough to make access easy. A camera of the size indicated, when fitted with its lens centering on the center of the window, will be raised sufficiently for convenience in clamping it. The threads on the back cap must fit snugly and no paint must be used on them. Hard oil, or vaseline, may be applied to insure a water-tight joint that permits easy removal of the cap.

The making and adjustment of the electrical shutter device requires care, but its operation is simple. An electromagnet, of the type used on doorbells, was fixed to the front of the camera, above the shutter, as shown in Fig. 1, and in detail in Fig. 2. It is actuated by current from two dry cells. The latter are kept in a convenient carrier at the base of operations, and are connected to the magnet by a single strand of double, waterproof wire. This is spread as it reaches the chamber and fastened to the two eyebolts in the top. The ends of the wires are conducted through the water-tight center opening between the eyebolts, and attached to the magnet. The release lever is fitted to a steel hook, pivoted at its upper end with a small nail, C, Fig. 2. A rubber band is fixed to the lower edge of the shutter lever and its other end is attached to the front of the camera. When the current is permitted to flow into the magnet by pressing a contact key, in the hand of the operator, the steel hook is drawn from the release lever, and the rubber band draws the lever down, making an exposure.

The double-wire cable carries the current as well as holds the chamber suspended in the water. The wire should be about 25 ft. long, and, in transporting the outfit, or when only partly used, is coiled. The chamber should be completed for picture-taking operations by giving it a coat of dull, black waterproof paint, both inside and outside. This will prevent rusting and also serves to make the object inconspicuous when in the water. It is important that the interior be painted in this manner, because reflections of light within the chamber may cause difficulty in obtaining satisfactory results. When the paint is thoroughly dry, the device may be tested for leakage and assembled ready for a test before making an actual trial in the water. The camera is fitted into the chamber so that it centers on the center of the plate-glass window, and is clamped into place. If the electrical device operates satisfactorily the plate may be inserted, the plate-holder slide withdrawn, the back cap replaced securely, and the outfit lowered into the water. It should be watched carefully until it reaches the proper depth, for, if it is permitted to touch the bottom, the sediment stirred up must be given time to settle before an exposure is made. The forward end of the chamber should be marked on its upper edge with a streak of white paint, to aid in identifying it at considerable depth in the water. This is important, since the operator must shift the chamber carefully until the window faces the objects to be photographed. When the chamber is in position, the contact key is pressed and the exposure is made.

The time of exposure for under-water photography depends on the clearness of the water, the depth at which the pictures are to be taken, and the light conditions on the surface. A bright day is, of course, desirable for this class of photography. A safe approximation on a sunny day, in clear water, and with the chamber lowered to a depth of 20 ft., is ¹⁄₂₅ sec. at the F 8 stop. The fastest plates or films obtainable should be used for this work, making possible a fairly rapid shutter speed. This tends to overcome the movement of the subject and possible movement of the camera.

The camera should be focused while in the chamber in order that the plate glass may not disturb the focus. The glass usually changes the focal length of the lens slightly, hence this precaution must be taken. The camera should be focused in the chamber for a distance of 10 ft., as this is the average at which under-water photographs will be taken ordinarily.

When attempting under-water photography in cloudy waters, or at a considerable depth, the necessary illumination may be provided by a charge of flash-light powder. For this purpose another submarine chamber, similar to that used for the camera, should be provided, with a plate glass, ¹⁄₂ in. thick, and a valve fitted into the top of the chamber, and opening outward, so that the gas may escape. Fifteen grains of powder will suffice, and this should be set off by a small electrical fuse connected to the current supply.

Every pond, lake, and river abounds in interesting and instructive subjects for submarine photography. Along the coast of Florida, and at many points along the Pacific coast, are waters of such clearness that pictures may be taken at a depth of nearly a hundred feet, without the use of artificial illumination. These localities abound in objects under water of great interest, such as shipwrecks. The fascinating art of taking pictures under water does not make it necessary for one to go to these places, for subjects are easily available. Whenever the submarine chamber is raised from the water there is an element of mystery involved, regarding what may be recorded on the plate or film, and this is an attractive feature of the diversion.

The Magic of Numbers

BY JAMES L. LANYON

That there are a great many magic squares; that the numbers in these squares are arranged according to a definite system; that squares with very remarkable properties are easily constructed, are facts not generally known.

Consider the magic square A of 16 numbers. Add up any four numbers straight across, up and down, or diagonally--10 ways in all--and the sum in each case will be 34. But that is not all: Take the four numbers in any one quarter of the square, as for example, 15, 10, 4, and 5, and the sum will be 34; or take the four central numbers, or the four corner numbers, and the result will be the same. But even this does not exhaust the magic of the square. Add any four numbers arranged symmetrically around the center, as 3, 10, 8, and 13, or 10, 4, 7, and 13, and the result will also be 34. In fact, it is really not necessary to have them arranged symmetrically, because it will be found that four numbers arranged as are 6, 10, 11, and 7, or 1, 4, 16, and 13 will produce the same magic number of 34.

There are two other combinations of the 16 numbers that will give the same result. They are shown at B and C. In fact the second one, B, not only exhibits some of the former combinations, but also includes such sets of four as 14, 5, 3, and 12, or 15, 8, 2, and 9, which places to the credit of this square numerous combinations. Such special features as this simply add another element of mystery and interest. Thus, while the square B has these two combinations exclusively to its credit, the first, A, and the third, C, have such special arrangements as 5, 16, 1, and 12, or 15, 6, 11, and 2. Also 10, 3, 5, and 16, or 4, 5, 14, and 11, making the total number of such combinations for the first square 34.

Magic squares of 25 numbers also have remarkable properties. Examine the square D and note the many possible combinations graphically set forth in the small diagrams. Not only do any five numbers in a row or along a diagonal make 65, but almost any four arranged around the center, with the center number 13 added, will give the same result.

This square is a good example by which to illustrate one of the methods of construction of these interesting devices. Thus, place 1 in the middle square of the top row, and then write the numbers down consecutively, always working in the direction of the arrows as indicated. When any number falls outside, as number 2 does at the start, drop down to the extreme square in the next row and insert the number there, as was done in this case. It will be observed that 4 falls outside, and so it is moved to the proper square as suggested, which will be at the extreme left of the next row above. Continuing, it is found that at 6 it is necessary to drop down one square and continue in the direction of the arrows. At 9 it is necessary to drop down to the proper extreme square as shown. The next number, 10, must again be provided for at the square on the left of the next higher row. The square ahead being already filled, 11 is placed below; after this there is “clear sailing” for a time. In this manner magic squares with seven or nine numbers to the side may be made easily. When puzzles and catch problems are under discussion, it is always mystifying to take one’s pencil and quickly make out a magic square according to this easily remembered method. The small diagrams at D suggest some of the combinations.

Another method of constructing a square of 25 numbers diagonally is shown at E. Place the outside numbers in the open spaces at the opposite side of the square, maintaining the same triangular relation, which results in the arrangement shown at F. While this combination is entirely different from the previous one, it exhibits the same mysterious properties.

Although they do not contain quite so many combinations, the three magic squares shown at G all add up to this same magic number of 65, straight across, diagonally, and many other ways. A square with seven numbers to the side, worked out according to the first method described, is illustrated at H. The magic number here is 175. Since the general principle is similar to that involved in the squares described in detail, the working out of the numerous combinations of the squares shown at G and H will be left to the interested experimenter.

Muffling the Ticking of a Watch or Clock

When a watch is used on a table in the sick room, the ticking may be eliminated by placing an ordinary tumbler over the watch. The face may be seen readily. A large glass vessel, or transparent jar, may be used in the same way to cover a small clock.--L. E. Turner, Jamaica, N. Y.

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¶To letter on prepared cloth, use colors ground in japan and thin the mixture with gasoline to the consistency of cream.

A Simple Cipher Code

Adapted for Use in Private Correspondence

BY CAPT. W. H. WALDRON, U. S. ARMY

Have you ever needed a secret code in which to couch the contents of a message intended for the eyes of one person alone? If you have, you will remember the difficulties that were experienced in making up the code and enciphering your letter. Here is a cipher code that may be mastered in a few minutes; one that is most difficult to decipher by any person other than those having the key words, and that is very simple when once understood.

It is commonly known as the “Play Fair” code and is in use in some of the foreign military services. It is a substitutive cipher which operates with one or more key words, two letters in the code being substituted for each two letters in the text of the message. In preparing the cipher code by this method the key words are selected by the correspondents and their location in the cipher square mutually agreed upon. A large square divided into 25 smaller squares is drawn, as shown in Fig. 1, and the letters of the key words entered into their proper spaces, the remaining spaces being filled by other letters of the alphabet. The key words must not contain duplicate letters. The letters I and J are considered as one and entered in the same space, the letter I being invariably used in enciphering.

Suppose that the two words “grant” and “field” have been selected for the key, the same to be entered respectively in the spaces on the first and third horizontal lines of the square. Then the basis of the construction would be as indicated in Fig. 1. Now fill in the remaining fifteen spaces of the square with other letters of the alphabet, beginning at the blank space at the left of the second line, entering the letters in rotation and not using any letter of the key words. The completed cipher would then appear as shown in Fig. 2.

The text of the message to be sent is then divided into groups of two letters each and the equivalent substituted for each pair. Where two like letters fall in the same pair the letter X is inserted between them and when the message is deciphered this additional letter is disregarded. If one letter is left over after the last pair, simply add an X to it and make a pair.

Suppose it is desired to send this message in the cipher: “Will you meet me as agreed.” Having three pairs of the same letter, it will be necessary to break them up by placing the letter X between them. The message will then be paired off as follows:

WI LX LY OU ME XE TM EA SA GR EX ED

The message may now be enciphered, after considering three simple rules for guidance: Every pair of letters in the square must be either in the same vertical line; in the same horizontal line; or at the diagonally opposite corners of a rectangle formed by the smaller squares within the large square.

In the first case, R and P are in the same vertical line (the second), and the next letter below, in each case, is substituted for R and P, which are C and W. If the pair consists of K and Y (fourth vertical), substitute L for K and go to the first horizontal line (fourth vertical) for Y, substituting N for Y. In the second case B and H are in the same horizontal line (the second), and thus substitute the next letters to the right, which are C and K. If the pair consists of P and U (fourth horizontal), substitute Q for P and then go back to the first vertical line (fourth horizontal) and substitute O for U. In the third case, R and S are at the opposite corners of a rectangle. Each letter of the pair is substituted by the letter in the other corner of the rectangle on the same horizontal line with it. Then R would be represented by N, and S would be represented by P. To illustrate further, NE would be represented by AL; BZ would be represented by MV; TP by RU.

The message may now be enciphered, applying the rules:

WI LX LY OU ME XE TM EA SA GR EX ED RP EY SN PO HD AQ MD QH QN RA QA LF

In sending this message, to make it more difficult for the inquisitive cipher expert, divide the substituted letters into words of five each and give him the added task of determining whether the cipher used is the transposition or the substitution method. The message ready to hand to the telegrapher would read:

RPEYS NPOHD AQMDQ HQNRA QALFX

In deciphering a message the method is reversed. Take the message as received, divide the letters into pairs, and disregard the final X, which was put in to make a five-letter word. Then apply the key reversed. Practice it on the above message to get the system with respect to letters occurring at the end of the lines. Where the letters of a pair are in the same vertical line, substitute for each the letter above; where they are in the same horizontal line, substitute the letter to the left; where they are in the corners of a rectangle, substitute the letters at the opposite corners on the same horizontal line. To test the understanding of the system, the message given in Fig. 3, with the key words “chair” in the first horizontal line and “optun” in the fourth line, may be deciphered. The message to be deciphered is as follows:

FQVUO IRTEF HRWDG APARQ TMMZM RBFVU PICXM TRMXM AGEPA DONFC BAXAX.

Cheese Grater and Ash Tray Made from a Tin Can

Being in need of a cheese grater and finding it inconvenient to go many miles to town, I constructed a satisfactory makeshift. I took a heavily tinned can and cut it in two, as shown in the sketch. By punching holes through it from the inside a practical grater resulted. From the remaining half of the can I made an ash tray, as shown at the right of the sketch. The semicircular ends were bent over to form a rest, and by cutting portions at the sides and bending them in, a convenient rest for a pipe or cigar was afforded.--Gus Hansen, Peachland, B. C., Canada.

An Improvised Typewriter Desk

Travelers and others who carry typewriters on their journeys frequently find it inconvenient to use the tables provided because they are usually too high for typewriters. A method of overcoming this difficulty is to withdraw the drawer from the table and invert it in the slide as shown. The typewriter may then be placed upon the bottom of the drawer and will be considerably lower than if placed upon the table top.

An Inexpensive Imitation Fire

Window decorations may frequently be made attractive by the use of an imitation fire in a stove or a fireplace, when an indoor setting is on display. To produce such an effect, put an electric fan below the place at which the imitation fire is to be arranged and run an electric-light cord, with a red globe attached to it, to the center of the “flame.” Cut a number of strips of Indian red tissue paper and fix the lower ends of these to form a circular mass above the globe. When the light is turned on permit the fan to direct a stream of air against the tissue-paper ribbons, forcing them upward to appear like tongues of flame. The sketch shows this method applied to a heater. The fan is placed in the ash box and the electric light is conducted through the grate.

Jardinière Made of Metal-Lamp Body

Some of the metal bodies of old lamps, and they are usually brass, are of such ample size and so neatly embossed that they can be readily used as jardinières instead of being handed to the junk man. It is only necessary to remove the lamp part, and set the plant pot into the bowl of the stand, as shown in the sketch.--H. N. Wolfe, Chicago, Ill.

Replacing a Broken Coffeepot Knob

A knob was broken from the lid of a coffeepot, which was valued by reason of its associations. Attempts to fasten the broken portions together were unsatisfactory, and the rough surface, where the earthenware was broken, was ground smooth and fitted with a carefully shaped wooden knob. A hole was drilled through the center of the lid with an old file and the wooden knob bolted into place. When stained appropriately, the repair was quite satisfactory.

Homemade Magnesium Printer

A convenient homemade printing device consists of a smooth board, A, 2 ft. long and 1 ft. wide, and an upright, B, which is 1 ft. square. Bore a hole in the center of the upright for the small tin holder E, to carry the magnesium ribbon, made by folding a piece of tin to fit it. Small pieces of wood, CC, are nailed across the board to hold the ground glass D and the printing frame G. The ground glass is 10 in. from the upright, and the printing frame is 10 in. from the ground glass. The latter is 1 ft. square and is used to diffuse the light from the magnesium ribbon F, which may be purchased from any dealer in photographic supplies. The length of exposure varies according to the length of ribbon which is permitted to burn. This should be tested out carefully before making exposures.--Gustave Straub, Albany, N. Y.

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¶In sandpapering a varnished surface between coats, especial care should be taken to avoid rubbing through at sharp edges.

Garden Plow Made of Pick-Up Material

BY T. T. STURGEON

The labor of spading a garden of even moderate size is sufficient to warrant the person who undertakes the job in making a hand plow like that shown in the illustration, for it will serve many years, with reasonable care. I made one worth about $5 at an outlay of 25 cents, gathering the necessary wood and metal from among old machine parts and pick-up material.

An old wheelbarrow provided the 16-in. wheel. The handles were made from a ⁷⁄₈ by 4-in. strip of spruce, 5 ft. long. They were marked on the strip so that one of the curved grips was at each end, on opposite edges. The curved parts of the grips were cut with a keyhole saw, and when a kerf long enough to admit a large ripsaw was cut, the board was ripped into the two handles. They were smoothed and the grips trimmed with a sharp knife. A section of broomstick was cut for the upper brace. The lower one is made of a strip of iron, ¹⁄₄ by 1¹⁄₄ by 12 in., drilled for ¹⁄₄-in. bolts, and bent at right angles, 1¹⁄₂ in. from each end. Drill a ¹⁄₄-in. hole at the middle, to engage a bolt on which the vertical strip is supported, and adjusted to the operator, as shown in Fig. 1.

Cut a strip, ¹⁄₄ by 1¹⁄₄ by 18 in., for the vertical support, shown in Fig. 5. Drill four ¹⁄₄-in. adjusting holes, 1 in. apart, at the upper end, and three ¹⁄₄-in. holes at the lower end for fastening the strip to the moldboard, as shown in Fig. 3. Drill a ⁵⁄₁₆-in. hole at the 7¹⁄₂-in. mark, for bolting the strip to the braces, the other ends of which are fitted on the ³⁄₈ by 10-in. bolt used as an axle. Cut the two braces 14 in. long, of ¹⁄₄ by 1¹⁄₄-in. strips, and drill a ³⁄₈-in. hole in the forward end of each, to fit the axle, and a ⁵⁄₁₆-in. hole in the opposite ends, 1 in. from the ends in each case. Cut a strip, ¹⁄₈ by ³⁄₄ by 12 in., for the landside, as shown in Fig. 2, bent under the moldboard, and bolted to it. The proper angle can best be bent after the moldboard is made and fitted.

The method of marking the shape of the moldboard on the blade of an old shovel is shown in Fig. 4. Make a pattern of cardboard, marking it into 1-in. squares. Draw the shape of the moldboard by tracing the outline through the corresponding squares, using the diagram as a guide. Mark the position of the bolt holes, for fastening it to the vertical support, indicated by the dash lines at the right. Cut out the pattern and trace around it on the shovel, using the thickest part for the point of the share. Cut out the outline, smooth the edges, and point up the cutting edge. Drill holes for fastening the moldboard to the vertical strap with ¹⁄₄-in. bolts, and for the fastenings to the landside, with ³⁄₁₆-in. bolts.

Curve the moldboard into shape and fit it to the various supports so that it sits properly, as shown in Fig. 1, seen from the furrow side, in Fig. 2, from the rear, and in Fig. 3, from the land side. Bend the 12-in. strip into shape, as shown in Fig. 3, and bolt it into place, to form the landside. Assemble the parts, being careful that the wheel and landside are set in line, as shown in Fig. 2, and that the rear edge of the latter is raised slightly, as in Fig. 3. The plow should be given a coat of paint, and the cutting parts made smooth, and oiled.

An Interesting Water Telescope

A water telescope is easy to make and will afford much pleasure in exploring plant or animal life in comparatively shallow water. The device is made by fitting a heavy glass disk into the end of a round metal tube, about 2 in. in diameter. The glass is fitted between two rings of metal, preferably with a small flange set against the glass. A waterproof cement is used to fix the glass between the rings. To use the “telescope,” rest it on the side of a boat or other convenient place at the water, and set the lower end, containing the glass, under the water. Remarkably clear views may be had in this way.--S. Leonard Bastin, Bournemouth, England.

Writing on a Moving Train

Writing legibly on a fast-moving train is difficult to a person unaccustomed to it. The railroad conductor knows the trick of it and manages to get along quite satisfactorily. He prefers to write in a standing position and holds his right elbow firmly against his side. The reason for this is that in a sitting posture there is too much lateral movement in the trunk of the body, while in a standing position this is more easily controlled. When the arm swings freely, as in ordinary writing, several joints of the body are affected in the process, each of which is capable of its own motion. Holding the elbow against one’s ribs “breaks” these motion tendencies, except that of the wrist, which movement is necessary in writing, and thus the pencil, or pen, is more easily controlled.

The same principles modified apply in using a typewriter on a moving train. Many traveling men, news correspondents, and others, carry portable typewriters and do much of their writing while traveling on trains, not to mention the various railroad and government men who travel in office cars and necessarily must get out their correspondence en route. It is extremely difficult to execute neat typewriting on a moving train with free-arm movement, even though the central portion of the car where the vibration and swing is less severe, is selected. As I am employed in such capacity, I had to evolve some plan to expedite the work. I am able to do typewriting quite rapidly by resting the palm of the hands, near the wrists, against the front edge of the typewriter frame surrounding the keyboard, and using the swing of the fingers instead of that of the whole arm, as in ordinary typewriting.--Victor Labadie. Dallas, Tex.

A Revolving Window Display

A jeweler attracted passers-by and not a few customers by placing a revolving display in his window which was kept in motion by means of the arrangement shown in the sketch. A 10-in. cut-glass bowl was placed, upside down, near the front of the show window. An inverted tumbler was set upon it and a small tin box was pivoted on the tumbler by means of a needle soldered inside of it. Six arms of wire were soldered to the box, and watches were suspended from them. The carefully balanced frame revolved easily on the point of the needle. It was kept in motion by the draft from a fan hidden behind a mirror.--H. S. Hart, Shreveport, La.

A Horse-Drawn Sod Cutter

The cutting of a considerable area of sod is tedious work when done by hand, and it is difficult to make the sections of uniform thickness and size. These important features are provided for by the use of the homemade sod cutter shown in the sketch. To start a cut across a meadow or lot, a notch is cut in the turf for the blade, and the device is set into place, stamping it down to give a good start. The operator stands on the plank in front of the blade, and a little practice will soon determine the best position for ease in operation. When a cut has been completed, the cutter is dragged to a fresh starting place, the driver turning it over on the upper side. The strips are cut into suitable lengths and piled conveniently for removal with a stone boat or wagon.

The device may be made of any suitable width; 15 in. between the inner edges of the blade, and the latter set to cut a depth of about 2¹⁄₂ in., being desirable. The board is a 2-in. plank, about 4 ft. long. The blade should be set with the cutting edge slanting slightly downward so as to make the device “bite” into the ground. A smaller cutter may be made for use by boys, several of whom may draw it.--F. H. Sweet, Waynesboro, Va.

A Match-Box Trick

All that is required to perform this trick is a box of safety matches. Four matches are removed and three of them arranged as shown in the sketch. The performer then tells his friends that he will light the fourth match and set the cross match on fire in the center, then asks which match of the standing ones will light first. Most persons will not stop to think and guess either one or the other. As a matter of fact, after the cross match is set on fire it soon burns the wood away, and the pressure of the two side matches will cause it to spring out so that neither catches fire.--Contributed by Abner B. Shaw, North Dartmouth, Massachusetts.

Cutting Glass Bottle with Electricity

Performing an experiment in a laboratory, it became necessary to have some apparatus which we did not possess at the time. A bell jar could have been used, but this we did not have, and as a substitute we used a large glass bottle, 8 in. in diameter, with the bottom removed. In order to do this, we first made a mark around the outside of the bottle near the bottom with a glass cutter. A piece of copper wire, ¹⁄₃₂ in. in diameter, was then wound around the outside on the mark and connected to the circuit.

As the wire would expand enough to make it slip off the bottle when heated red-hot, pliers were used to keep it taut about the bottle when the current was turned on. A current of 110 volts and 5 amperes was run through the wire, heating it red-hot, and this cracked the glass exactly on the line marked by the glass cutter.--Contributed by R. E. Hollis, Chicago, Ill.

Nail Cabinet with Muffin-Pan Trays

Muffin-pan trays used by the housewife in baking make serviceable containers for nails, screws, and other small articles used in a shop. The illustration shows the pans fitted into a box, and sliding in grooves cut into the sides with a saw.

The box is made with the end pieces lapping over the top and the bottom this being a better construction to carry the weight of the trays. The wood used in the sides is ⁷⁄₈ in. thick, in order that a saw cut may be made to a depth of ¹⁄₄ in. without weakening the support. Thinner wood may be used if instead of saw cuts small strips of wood are nailed against the side on which the trays may slide.--Contributed by Harry J. Blacklidge, San Rafael, Cal.

Waterproofing Matches

Dipping ordinary parlor matches into melted paraffin and permitting them to dry thoroughly will enable them to withstand water. The paraffin acts like a wax candle and is unaffected by the moisture. This should be of aid to campers and others who find it hard to keep matches dry.--Contributed by T. W. Lambert, Jr., New York, N. Y.