Part 22 (1/2)
The piston is made of a stove bolt, E, Fig. 2, with two washers, FF, and a cylindrical piece of hard wood, G. This is wound with soft string, as shown in Fig. 3, and saturated with thick oil. A slot is cut in the end of the bolt E, to receive the connecting rod H. The valve B is made of an old bicycle spoke, C, with the nut cut in half and filed down as shown, the s.p.a.ce between the two halves being filled with string and oiled.
The valve crank S, Fig. 1, is cut out of tin, or galvanized iron, and is moved by a small crank on the shaft. This crank should be at right angles to the main crank.
[Ill.u.s.tration: Engine in Operation]
The boiler, Fig. 4, can be an old oil can, powder can, or a syrup can with a tube soldered to it, and is connected to the engine by a piece of rubber tubing. The heat from a small gas stove will furnish steam fast enough to run the engine at high speed. This engine was built by W. G. Schuh and A. J. Eustice, of Cuba, Wis.
** Writing with Electricity [74]
Soak a piece of white paper in a solution of pota.s.sium iodide and water for about a minute and then lay it on a piece of sheet metal. Connect the sheet metal with the negative or zinc side of a battery and then, using the positive wire as a pen, write your name or other inscription on the wet paper.
[Ill.u.s.tration: Electrolytic Writing]
The result will be brown lines on a white background.
--Contributed by Geo. W. Fry, San Jose, Cal.
** To Photograph a Man in a Bottle [74]
Neither a huge bottle nor a dwarfed man is necessary for this process, as it is merely a trick of photography, and a very amusing trick, at that.
First, photograph the person to be enclosed in the bottle against a dark plain background and mark the exact position on the ground gla.s.s. Let the exposure be just long enough to show the figure distinctly. Then place an empty bottle against a dark background and focus so as to have the outlines of the bottle enclose those of the man. Let this exposure be about twice the length of the first, and the desired result is obtained.
** A Musical Windmill [74]
Make two wheels out of tin. They may be of any size, but wheel A must be larger than wheel B. On wheel A fasten two pieces of wood, C, to cross in the center, and place a bell on the four ends, as shown. The smaller wheel, B, must be separated from the other with a round piece of wood or an old spool. Tie four b.u.t.tons with split rings to the smaller wheel, B. The blades on the wheels should be bent opposite on one wheel from the others so as to make the wheels turn in different directions. When turning, the b.u.t.tons will strike the bells and make them ring constantly.
[Ill.u.s.tration: Musical Windmill]
** Optical Illusions [74]
By giving the page a revolving or rinsing motion the three circular figures printed on the next page appear to rotate. The best effect will be produced by laying the book down flat on the desk or table and revolving, first
[Ill.u.s.tration: Move These Figures Rapidly with a Rinsing Motion]
in one direction and then in the opposite direction, in such a way that any given point on the page will describe a circle of about 1/2 in. diameter. Fig. 1 then appears to rotate in the same direction as the revolution; Fig. 2 appears to revolve in the opposite direction, and Fig. 3 appears to revolve sometimes in the same direction and at other times in the opposite direction.
A curious effect can be produced with Fig. 1 by covering up Figs.
2 and 3 with a piece of plain paper and laying a coin or other small object on the paper. If the vision is then concentrated on the coin or other object while same is being revolved, Fig. 1 will be seen to rotate.
** Barrel-Stave Hammock [75]
A hammock made of barrel staves is more comfortable than one would think, considering the nature of the material employed in making it. Good smooth staves should be selected for this purpose, and if one cares to go to little trouble a thorough sandpapering will make a great improvement. Cut half circles out of each stave, as shown at AA, and pa.s.s ropes around