Strength and Shape The strength of a substance, say in supporting a weight, depends on many factors. Pliability or its ability to bend is probably the chief factor of all. But there are other considerations which determine the strength of a substance beyond its own qualities. Shape is one of them. Here is a simple experiment to show that shape …

Music of Money When you jungle coins in your pocket what musical note do they give? This sounds rather like a riddle, but the answer is quite straightforward; see if you can guess the note and see if you are right by striking several notes on a piano. Of course, there is a good deal of confusion about the about …

An Experiment With Sound Waves Here is an experiment dealing with sound waves that is extremely illuminating. It is just the thing for a gathering of young friends who are scientifically inclined. Stretch a piece of string tightly across the room and on it pin a silk handkerchief or any other handy article made of silk-the larger the better. When …

A Hutch for Small Pets Most boys keep pets of some kind, and probably you are no exception to the rule. If you have rabbits, doves, guinea-pigs, or such-like creatures, you will know how important it is to house them well and comfortably. Here is a capital hutch which can be made easily. You will agree that it is just …

Making a Dog Kennel Some people think that anything will do for a dog to sleep in. As a matter of fact, a good kennel makes for a healthy dog, and a bad one does the animal harm. Therefore, if your own a canine friend, see that he has comfortable quarters. Below we describe the way to make an attractive …

Keeping Weekly Periodicals Tidy Probably you buy a boy’s paper every week and, though you may not wish to have the copies bound, you may like to keep them for reference. If so, stack up the parts in their proper order and then, thread a piece of tape through the wire stitches, as shown in the larger illustration. The small, …

Defying Gravity Get a round cardboard tube, such as people use for sending things through the post which they do not wish they do not wish to have ceased, and cut an inch off it, either with a fretsaw or a pocket-knife. Be careful that in doing this you do not flatten any part of the circumference, because it must …

A Matchbox Holder The accompanying sketch shows an easily made matchbox holder. The wooden base consists of an odd piece of thin material left over from some other job. It should be be about 7 by 3 inches. When the edges have been nicely trimmed up and smoothed, the metal tray is added. The larger sketch shows how the sides …

A Capital Puzzle Take two thin pieces of wood, of the size shown by the square. With your fretwork saw, cut out, from one of them, the X-shaped pattern, and glue the piece surrounding the X to the untouched square. Then, get four tiny ball-bearing the X to the untouched square. Then, get four tiny ball-bearing balls from the nearest …

A Boat Driven by Air If you are one of those boys who like to experiment with things, here is something that will assume you. Get a lightly built model rowing boat and put a small length of metal tubing through the stern end, so that it projects under water. Then blow up an air ballon and close the neck …