Chapter XXII: Part IV: Trout Fishing with Fly and Bait (15)

The electric heater is just large enough to allow a space about 1/2 in. on all edges. This makes it 23 in. square. A piece of 1/4-in. asbestos of the above size should be secured, on which to place the heating wire. The amount of wire depends on the size and kind. As it is not necessary to heat the wire very hot, iron or steel wire may be used. The length of wire may be determined by the following method:

Wind the wire on a long stick, making sure that no one coil touches its neighbor. Connect one wire of the current supply at one end of the coil and run the other end of the current supply along the coils, starting at the extreme opposite end and drawing toward the center until the iron wire gets too hot to hold with the bare hand. This will be the right length of wire to use. The length being known, a number of tacks are placed in the asbestos board to hold the wire, as shown in Fig. 2. Cover the wire with a sheet of asbestos and attach binding-posts, E and F, at each end.

The asbestos inclosing the heating wires is covered with a thin piece of sheet iron, which is made to fit tightly over the bottom and sides. This will spread the heat evenly. Be careful to have the binding-posts insulated from the sheet metal. In the cross section of the heater, Fig. 2, A represents the 1/4-in. asbestos board; B, the heater wire; C, the asbestos paper, and D the sheet-metal covering.

The most important part of the incubator is the thermostat which regulates the current to maintain a steady heat. It is not advisable to make this instrument, as a good one can be purchased for less than $1. Place the thermostat in the end of the box at B, Fig. 1. A small door, E, is made in the box for easy adjustment of the thumbscrews.

Suspend the heater from the cover of the box with bolts 2-3/4 in. long, as shown in Fig. 1. A base receptacle, G, and a snap switch, H, are fastened on top of the cover and connected up to the thermostat B, the condenser C, the heater F, and lamp I, as shown. Another snap switch, J, is used on the light only. The condenser C is to prevent sparking, thus saving the platinum points on the screws. Do not use more than a 2-cp. lamp for lighting purposes, as a brighter light blinds the young chicks.

The incubator should be run for a day or two so that the current may be well regulated before placing the eggs in the tray. The incubator is operated the same as with lamp heat.--Contributed by M. Miller, Lansing, Mich.

A Cover for Magazines

As soon as Popular Mechanics, or any other magazine of similar size, arrives and before any member of the family looks through it, strip off the front cover and carefully remove the narrow strip on the back as shown in Fig. 1. Strengthen the back with a piece of bookbinding tissue, A, Fig. 2, and then paste a piece of heavy manila paper, B, over the covers and back. Over this paste a piece of dark blue cambric, Fig. 3, carefully turning the edges even with the book. The picture from the cover and the date added to the left corner of the picture are neatly pasted on, Fig. 4, and the narrow strip is glued to the back.

The book is put under a heavy weight for several hours. Thus a neat, strong cover, which looks well in a bookcase, is secured at very little expense. The eager handling by every member of the family cannot soil or deface the cover.--Contributed by Katharine D. Morse, Syracuse, N. Y.

An Optical Illusion

A very deceiving illusion can be contrived with a bit of wire, a rubber band and a toothpick. An ordinary straight hairpin will serve instead of the wire. The hairpin or wire is bent as shown in the illustration, and the rubber band then placed on the inverted U-shaped part. A toothpick is inserted through the rubber band and a few turns taken by slipping the toothpick back and forth so it will pass the wire.

Hold the wire straight in front of the eyes, and, using the forefinger of the right hand, turn the end of the toothpick A, Fig. 1, down until it almost reaches the opposite point A, Fig. 2, and let the finger slip off. It will appear as if the toothpick passed through the wire.--Contributed by H. H. Windsor, Jr.

Temperature Alarm

The falling temperature of a room during the night may result in a very bad cold for the occupant. This may be prevented by the use of an alarm to awaken the sleeper and warn him to close the window. An alarm can be made as follows: Take a glass tube about 4 in. long and 1/4 in. in diameter and close one end, used for the bottom, with sealing wax, in which the bare end of a No. 20 gauge magnet wire is inserted. The tube is almost filled with mercury. On the mercury a float of wax is placed in which a bare piece of the same magnet wire is inserted and bent as shown in the sketch. The tube of mercury is fastened to a base with two clips of metal. At the upper end of this base the adjustable lever A is attached. The electric connections are made as shown in the sketch.

Should the temperature fall during the night, the mercury will contract, the float descend and the circuit close, so that the bell will ring. The adjustable lever allows setting the alarm for various differences of temperature.--Contributed by Klyce Fuzzelle, Rogers, Ark.

Paper Smoother and Penwiper

A convenient paper smoother and penwiper can be easily made as follows: Procure a common celluloid harness ring, A, about 1-1/2 in. in diameter and fasten a penwiper, B, to it. The wiper is made of arts-crafts leather, doubled and filled with pieces of chamois. They are held in place with a ribbon or cord tied as shown. The roughened paper caused by erasing can be easily smoothed with the ring.--Contributed by G. H. Holter, Jasper, Minn.

Stereoscopic Pictures with an Ordinary Camera

Make a small table as wide as the camera is long and 3 in. longer than the camera is wide. Sink a screw nut in the center of the under side to engage the regular tripod screw. Fasten a double or two-way spirit level on the front left-hand corner. Nail strips on both ends and on the rear side, to form a shallow box with three sides. The illustration shows the construction quite plainly. This device was used by a correspondent of Camera Craft as follows: The table was fastened to the tripod and carefully leveled. The camera is placed at one side, bringing the back snugly into the corner on that side. Make the exposure, change the film, slide the camera over to the other side and make another exposure. The table being 3 in. longer than the camera is wide, the lens will be moved exactly 3 in. when the camera is moved over to the other side. Three inches is the separation of the lenses in stereoscopic cameras and the negatives made as above will be the same.

As the negatives must be sized, it is necessary to use films. A camera using films 3-1/2 by 3-1/2 in. will make negatives that can be trimmed 1/4 in. on each side to make prints 3 by 3-1/4 in. Each two negatives making a pair are fastened together, properly transposed, by folding a narrow strip of black paper like a long, V-shaped trough, pasting it, and putting one on the bottom of the two negatives, as they lie side by side, and one at the top; saddle fashion. This can be done still easier by using strips of passe-partout binding, or strips used for binding lantern slides. If so desired, the use of black paper can be carried farther by cutting the top strip of binding paper in such a way that it gives the round corners to the top of the prints. A narrow strip through the center and a binding of black paper along the two end edges make a mask unnecessary in printing.

How to Make a Paper Drinking Cup

Every person should understand the simple method of making a paper drinking cup. It may be necessary at times to make quick use of medicine and with no cup or spoon convenient, the pyramid-shaped cup shown in the sketch is a useful emergency utensil.

The paper cup is made as follows: Cut the paper into a square and crease it on the dotted lines, A G, F B, and C D E, as shown in Fig. 1. Fold the paper in half through the line C D E to form a rectangle, Fig. 2. Fold points C and E inward until they meet inside the triangle to form the shape shown in Fig. 3. This makes four distinct corners, F, G, A and B. Fold the paper over on the dotted line and bring the points A and B together as in Fig. 4. The extreme edges meet in the central line indicated. Reverse the paper and fold the points G and F in like manner. Turn the points A B and F G inward and fold on the dotted line, and you will have a perfect pyramid-shaped cup as shown in Fig. 5.--Contributed by Miss Margaret S. Humphreville, Mt. Pleasant, O.

A Hand Corn Sheller

A very handy device for shelling corn, and especially popcorn, can be made of a 1-in. board on which is fastened a piece of metal lath. The edges of the metal lath are bound with a strip of wood nailed to the board.--Contributed by Ulysses Flacy, Long Beach, California.

A Shaft Coupling

In connecting a small 1/8-hp. motor to a small air pump where both shafts were 3/8 in. in diameter, I quickly made a coupling that would save the wear on the machines, as follows. The coupling was made of a piece of 3/4-in. brass rod with a 3/8-in. hole drilled through its center. One end of the hole was enlarged to 7-16 in. for about 7/8 in. The end of the coupling having the small hole was slipped on the pump shaft and fastened with two setscrews. The other end was drilled to take a pin loosely, the pin fitting tightly in a hole drilled in the motor shaft. The pin was bent at one end so as to keep it from falling out and the other end fitted with two nuts. The motor shaft being a little loose in the coupling, gave it a chance to work free without binding.--Contributed by Leo J. Werner, New York City.

Reading the Date of a Worn Coin

The date and denomination of a coin worn smooth can be determined in the following manner: Take an ordinary coal shovel, or a piece of sheet metal, and place it in a hot fire. Allow it to become red hot, then remove, and place the coin on the hot surface of the metal. Any figures or letters can be readily seen when heated in this manner. This test seldom fails even when the inscriptions have been worn so smooth that they are invisible to the naked eye.

Making a Knife an Easy Opener

The large blade of my knife being so hard to open placed me in constant risk of breaking my thumbnail. To overcome this difficulty, I ground a notch in the handle as shown in the sketch. After smoothing it up with a round file and fine sandpaper, I had just as good a job as if the knife had been made that way, and it is very easy to open it, as it can be done with the thumb and forefinger. Anyone can improve his knife in this way, but be careful not to cut the notch back of the point of the small blade.--Contributed by C. M. Mahood, Warren, Pa.

Construction of a Small Bell-Ringing Transformer By A. E. Andrews