Holdups Thwarted by Burglar Trapdoor (Oct, 1931)

Sadly, there are all too few surprise trapdoors remaining in operation today.

Holdups Thwarted by Burglar Trapdoor

IMPRISONING bank burglars by suddenly opening up a yawning pit at their feet is the somewhat unique and highly effective means which a recently invented burglar trap employs to nip holdup schemes in the bud.

When a thief walks up to a cashier’s window and orders all hands elevated, the bank employee simply reaches down — very quickly, of course—and pushes a lever, which operates a trap door before the window. The bandit falls through the door and into the steel-walled cage below. He is ordered to hand out his arms and then turned over to the police.

The trap door in the floor is adapted to be dropped from a normal position, at the same time sliding back the top of the cage as illustrated in the accompanying diagram. When weight is removed the top automatically slides back to cover the cage.

World’s First Color Fax Machine – 1946 (Nov, 1947)

This is a pretty remarkable invention for it’s time. A color, plain paper, fax machine from 1946 that used colored pencils to print the output. The resulting image looks a lot like a printout from my first color inkjet printer. Sending a 7×10″ picture in full color took about 15 minutes, which seems pretty damn reasonable to me.

Tune In a Painting

PSM photos by Hubert Luckett

TAKE a good look at the front cover of this issue of your Popular Science Monthly. You are looking at something you have never seen before—a picture that was transmitted by radio in one operation and imprinted on a sheet of ordinary paper.

This is known as color facsimile. It is the product of years of effort to transmit an image by wire or radio and reproduce it perfectly on ordinary paper at the receiving point. It was developed by Finch Telecommunications. Inc., of Passaic, N. J. Finch labels it “Colorfax.”

Sensational THRILL RIDES Invented for N.Y. World Fair (Apr, 1939)

“one smart inventor has devised a ship that takes passengers to Venus, which is part of the way to the moon”
Wow, I had no idea Venus was so close!

And don’t forget: “These are no sissy rides, and if it’s a thrill you want, you’ll get it at the New York World’s Fair!”

Sensational THRILL RIDES Invented for N.Y. World Fair

HOW would you like to experience the thrill of a parachute jump— without the accompanying dangers of the ‘chute failing to open, of being blown out to sea or of landing in a tree? Well, that thrill will be yours if you are one of the lucky 60,000,000 expected to visit the New York World’s Fair after it opens on April 30. As a matter of fact, a safe parachute jump will be only one of the many sensations ingenious engineers have invented for the Fair visitor’s amusement. If the ‘chute jump seems tame, try the aerial ship which the rider can pilot himself. It’s safe, of course, because a cable keeps the ship anchored to a revolving pole, but you can turn or stall in a steep climb or experience the sensation of a power dive, if you are up to it.

LATEST BOATING SPORT… Sailing Midget Ships (May, 1938)

These are really cool. I love the idea of making scale models that you can actually sail around in.

LATEST BOATING SPORT… Sailing Midget Ships


AMATEUR boat builders in many parts of the world are going down to the sea in midget ships. They are putting off in men-of-war, square-rigged traders, ocean liners, and superdreadnoughts barely larger than rowboats, yet reproducing in every detail ships that are famous in nautical history.

Scientific Tricks of Master Spies (Oct, 1931)

Scientific Tricks of Master Spies

By Donald Gray

Amazing beyond belief are the scientific tricks employed by modern spies to help them carry out their dangerous work without detection. All the resources of chemistry and mechanics, ranging from secret inks to marvelous enciphering machines, are made to serve the master spy, as set forth in this startling article.

Portable Globe House for Well-Rounded Living (Jan, 1961)

Portable Globe House for Well-Rounded Living

Only 15 feet in diameter, low-cost home offers all the conveniences of a larger one. And, it can be delivered by boat, truck or even helicopter.

IT looks like a satellite that just fell out of orbit. But actually it is a down-to-Earth, low-cost portable home—with all the modern conveniences you would expect to find only in a more usual-looking (and usual-priced) house. Called the Kugelhaus (Kugel is German for “ball,” and haus means just what it sounds like), it is nothing more than a 15-ft.-diameter hollow ball. Its eggshell-like construction is of either lightweight reinforced concrete, metal or plastic. Just one inch of concrete gives good results, says the inventor, Dr. Johann Ludowici. The house can be completely assembled in the factory—with whatever furniture or other equipment is wanted—before delivery. As portable as a house could be, it can be flown to wherever you want it by helicopter, towed in by boat (it floats), or, more conventionally, carried on a truck.




by Samuel G. Hibben

Director of Applied Lighting, Westinghouse Lamp Division.

AGE-OLD mysteries of flourescence and phosphoresence are being solved today because the demands of war and the foretaste of post-war electrical living have spurred scientific research and development, formerly dormant for several generations. A great incentive has been given to extend scientific studies of this subject—generally termed “luminescence”—through recent developments of the practical methods of producing the chief ingredient, “black light.” True, black light, which is another name for invisible ultraviolet radiations just out of range of the human eye, does exist in sunlight, but it is overcome by the much more powerful visible radiations.

MOVIE CARTOONS Gain THIRD Dimension (Jul, 1936)


MAX FLEISCHER worked a full year to produce 250 feet of motion picture film on one of the first animated cartoons ever to reach the silver screen. Alone, he made thousands of drawings, wrote the story, and did the photography. The animated cartoon was “Out of the Ink Well.” It made movie history just after the World War.

Today he has a staff of 225 people who turn cut a 650-foot animated cartoon every ten days. All of them are in sound, many in color and, latest of all, with three dimensions. The famous “Popeye the Sailor” animateds are leaders in the field; “Betty Boop,” “Ko-Ko the Klown,” and the familiar Screen Songs with the famous bouncing ball are known to every movie-goer. They are released through Paramount Pictures Corporation.



Look down into the Well of Youth through these pages and see Biology’s most recent and amazing discoveries. For “booster” hearts and human cold storage are just two of many longevity miracles the doctor orders for your descendants.

YOUR great-great-great-great-great grandchildren may live for a thousand years!


Let us assume that it is the year 2136 and this far-off descendant of yours has reached the age of twenty-five. He summons a scientist and says:

“I have decided to retire from the world for a while. Put me in a storage vault and leave orders that I be restored to the world of living men one hundred years from today.”

Eyeglasses for Dogs (Apr, 1939)

There is actually a company called Doggles that sells prescription eyewear for your dog.

Eyeglasses for Dogs

BY MENTIONING that her dog seemed nearsighted, a girl customer started an optician of Geneva, Switzerland, on his way to becoming a specialist in fitting canines with glasses. Not only did he succeed in curing her pet, but now he has found a novel and profitable career in applying his newly discovered methods to other four-footed subjects.