An Electric Massage for Milady
MILADY’S complexion will benefit immensely from an application of “juice” from this little massaging device. There’s no danger of shock, and the complexion will not suffer a charring from the current, so it’s all quite safe. The only parts needed are: Four or five dry cells, preferably new and fresh; a short length of bell wire, two silver spoons and some tape. The hook-up of all this equipment is shown in the accompanying drawing. Note that the handles of the spoons are insulated with windings of tape, so that all danger of a jolt is eliminated. Apply the spoons to the face as illustrated in the drawing, patting them gently so as to get full benefit from the sparking. If need be, the operator can wear rubber gloves.â€” Walter Menyhart.
Toothpick Engineering Is Dentists Hobby
By FRANK CAPORAEL
MAKING scale models of giant engineering projects with flat wooden toothpicks and household cement serving as the structural materials, is the unusual spare-time occupation of Dr. M. Russell Stein, a New York City dentist. Ably assisted by his wife, Dr. Stein transforms boxes of toothpicks into architectural masterpieces that are accurate models of their prototypes, practically perfect in every detail.
Automatic Milk-Bottle Safe
By DONALD A. PRICE
THIS simply constructed milk bottle safe will obviate the pilfering of milk from the door or porch, by automatically locking itself when full bottles of milk are placed inside. In addition, it provides a shelter from the weather.
This is apparently the second article in the Modern Mechanix series: “How to kill yourself underwater”. The first being Build Your Own Diving Helmet.
They are seriously talking about getting in this thing and being towed 15-30mph at a depth of at least 30 feet. But don’t worry because “The air inside the boat will be sufficient for approximately half an hour’s stay under water”.
Take Thrilling Underwater Cruise in ONE-MAN SUB
YOU get all the keen thrills of deep-sea diving and underwater cruising in this one-man submarine. Towed by a motor-boat, the novel craft will take you down to a depth of at least 30 feet, where you can explore the river or lake bed. Through a special conning tower you can watch the fish as you dart among them, the while maneuvering about like a real submarine.
Our Color Camera Takes a Look Through a Kaleidoscope
By HARRY WALTON
Photographs by WILLIAM MORRIS and ROBERT SMITH
VISITORS to London about 1816 were amazed to see people in the streets gazing skyward through pasteboard tubes. But these watchers were peering at no eclipse or comet. They were fascinated by a scientific novelty that had taken London by stormâ€”the kaleidoscope, invented by Sir David Brewster. First regarded only as a toy, it was soon adopted by artists as an aid in originating new designs. Sir David named his invention by combining three Greek words: kalos, meaning beautiful; eidos, form; and skopeo, I see. Almost anyone who has looked through a kaleidoscope will agree that the name is appropriate.
It’s Fun to Play This Indoor Football Game
Played by two to six persons, this game provides endless fun for members of your family or your party guests. The object of the game is to drive a table-tennis ball into one of the two goal baskets at opposite ends of the box. This is done by hitting the ball with wooden paddles attached to dowel rods, which are turned and pushed back and forth by hand. There are eight rods; the two center ones have four paddles each, the next two toward each goal have three each, while the next pair have two paddles each and the last two next to the goals have only one paddle each.
BUILDING a DIVING Helmet
Improvement follows improvement in the design of home made diving helmets as amateur divers become more and more acquainted with their use. This one of Hoag’s is the last word in helmets so far published by good old M-M.
ALL the thrills of exploring the lake bottom are yours with this simply constructed diving helmet; and, if you do not dive too deep, you are in no particular danger, either. Besides its use in recovering lost outboard motors at a substantial profit, the helmet will give you one of the most interesting experiences of your life; for until you have breathed and walked at leisure under water, you have missed something. It will take a good deal of nerve to go down the first time, but after that it will just be fun.
PS Builds a LASER …and so can you
The incredible ruby ray is the hottest scientific discovery of the decade, but practical uses are still scarce. Here’s your chance to join the search
-June, 1960: Dr. T.H. Maiman, of the Hughes Aircraft Co., reports the development of the first successful ruby laser.
â€”November, 1964: Popular Science publishes plans for the first do-it-yourself ruby laser.
By Ronald M. Benrey
IT MAY sound like science fictionâ€” but it’s really science fact: You can build a working ruby laser. It could be the most challengingâ€”and rewardingâ€” home-workshop project that you have ever tackled.
A ruby laser is a source of coherent light. All of the light waves in the pencil-thin, bright-red ruby laser beam are in phaseâ€”or in stepâ€”with each other. This extraordinary property of the laser beamâ€”shared by no other light sourceâ€”has spurred a world-wide search for practical uses.
Ordinary light sourcesâ€”a light bulb, for exampleâ€”generate incoherent light; the light waves are out of phase with each other.
Drop a pebble into a still pond, and the waves ripple out smoothly in all directions. This represents a single light wave from a light source. All light sources produce more than a single wave, however.
They act as if you dropped a handful of pebbles at once: You get a jumbled clutter of waves one on top of another. This clutter of waves is analogous to incoherent light.
Suppose, though, you dropped your handful of pebbles one pebble at a time, each in exactly the same spot in the pond. The waves would continuously radiate from that point. All of the wave crests would be in phase. This is coherent radiation.
A ruby laser generates a coherent light beam by a similar process. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Inside the ruby laser rodâ€”heart of the ruby laserâ€”excited atoms are stimulated to emit light waves in phase with each other.
Light Harpoon Gun Spears Fish and Frogs
THIS efficient weapon operates on the same principle as the harpoon guns used in whaling in that it has a line uncoiling from a tank with which to retrieve the harpoon as well as the prey. Appearance and size (Fig. 3) are similar to a conventional gun with the exception of the tank for the line. The “barrel” (Fig. 1) consists of a length of cold-rolled steel channel secured to stock with 3 countersunk screws, and has a guide near “muzzle” with a-groove for harpoon shaft to raise one of the barbs above bottom of channel. Well or tank for line is one end of a 1 lb. fruit can, edges filed smooth and painted brown. Fit end of line with a ball or block; before firing wedge line in one of the forks as illustrated. To recoil line lift out end and, beginning at that end, wrap line loosely around your hand and replace in tank.