THE next war, all agree, will be a war in the air; and the advantage will be with the force striking the first blow. Obviously, the attack will be made on the fixed air bases of the other army, since that will inflict most damage from a military point of view.
By "DUNNINGER" • RISING-CARD tricks are ever popular ill the program of the modern magician. The trick here described is perhaps the simplest in preparation, and the most effective of them all. Three cards are chosen (not forced) from a deck and, after being noted by the spectators, are returned individually to different parts of the pack.
Continents Have Stopped Sliding Down Hill • THE migration of continents, which some geologists think a continual process, while others deny it, is suggested by George W. Munro, of Purdue University, in a letter to Science, to have been an actual occurrence; but one which has happened only twice in two billions years of the earth's history, when sufficient heat was developed near the surface to start continental masses moving under pressure. He suggests that the American continent hit a snag, which broke its backbone.
Peacetime Tank for Swamps • The machine at the left was built by a member of a distinguished engineering family with the idea of using it for relief in case of hurricanes or floods in the Florida Everglades. Telescope—Anti-Aircraft • THE machine below shoots at balloons, but it is a camera, 16 feet long, and the longest outside astronomical observatories. It was used as another check on altitude flight.
A New Tricycle • THEY call the device at the upper left an aerocycle. It is said to be far more comfortable to propel than a bicycle, and it seems far more stable than a lot of the odd European bikes which we have been illustrating in recent months. It suggests a motor tricycle, but is foot-driven.
Projector for Artists • USED in a dark room, this simple picture projector gives a colored image which can be traced by even beginners, and does not require the blinking necessary with a "camera lucida." It is inexpensive. Rotating Clock • NOVEL, and ingenious, this drum-dial clock, which is easy to read, will grace a desk or table top. Improved Can Opener • THIS cuts out the top as a clean round disc, and makes emptying the can more easy. The new model has a suction cup which neatly lifts the resulting sharp-edged disc. Extra leverage of handle makes cutting easier.
Electrical Cradle Soothes Baby THE motor that rocks the baby now rules the world. Mamma can set the invention at the right to any tempo that best soothes the little stranger, and go about her work.
Pocket-Cleaning Device • A MAN'S pockets are a catchall, particularly if he smokes a pipe. Since many pockets cannot be turned inside out, the dry cleaner has difficulty in freeing them from particles which might make a stain. Here is a brush and suction cleaner which gets into the seams.
Now is your chance to get into a big new industry and grow up with it to an important position. Today there is practically no competition in the Diesel field, but the increasing use of Diesel engines will result in keen competition for jobs after a few years. If you start your training now and get established in this field, you need not worry about competition.
Revolving Hospital. • AT the left, the novel hospital built at Vallauris-le-Cannet, France, by the Institute of Actinology. (The actinic, or chemical rays of the sun, are no longer classified separately; but the term alludes to the effects such as on photographic plates, or reddening skin.) The hospital beds are in the upper portion, shown here from the rear, which turns to keep the sunlight shining through the windows, full on each bed.
By HUGO GERNSBACK IT is odd that automobile engineers, as a whole, for many years have concentrated on mechanical improvements of the automobile, but have done practically nothing toward improved design of cars, in the matter of reducing the hazards of the occupants, as well as of pedestrians. It is true that we now have better brakes and so-called safety glass, but these are about the only points to which automobile engineers have paid serious attention.
• NOT all patents are complicated; some, as shown here, are extremely simple. Their success depends on the manner in which they are merchandised to the public, and the public receives them. For instance, right, we have a very simple remedy for the habit of paper napkins to slip off your knee; a little sticker holds the napkin to table or clothing. (It is specified that it shall leave no marks when pulled off.) Left, a motorist's, and a sailor's idea.
• SCENES on this page, taken from the recent G-B (Gaumont-British) feature film, "Transatlantic Tunnel," represent a high degree of ingenuity in forecasting the inventions of the next quarter century, as will be seen. This is scientific and mechanical fiction, not science and mechanics; the film tells a story, without endeavoring to demonstrate its possibility mathematically.
ASTRONOMERS like to scare their hearers from time to time, like the old-fashioned nurse telling children about ogres, with pictures of the end of the world. It may be burnt up by the exploding sun, or frozen by the sun's extinction (though the latter is less probable); it may lose all its air by radiation into space, and chemical absorption into the earth. But, at the close, the audience is reassured that their fear of its happening in a million years is baseless—that the earth has at least ten million years of existence ahead—and they go away relieved.
• IN surveying the product of inventive genius, as it appears in the patents issued each week, it is interesting to notice the variety. Of the total, a great proportion are merely based upon previous practice, and are minor improvements, valuable, doubtless, from an economic standpoint, but of interest only to a technician. Others, which may be grasped at a glance are pictured here.
By HUGO GERNSBACK THE automobile, as a quick get-away instrument in crime, has assumed vast proportions during the past decade. Notorious gangsters and their henchmen are always using high-powered automobiles and, unfortunately, they are often able to outwit local police and state troopers after the crime has been engineered.