MAMMOTH SMOKE RINGS DOWN ENEMY BOMBERS! MONSTER MACHINE CREATES MAN-MADE TORNADOES! It was a fantastic idea, and it approached reality during World War II. The client? The U.S. government.

In recent decades wingtip vortices generated by jumbo jets have been known to disrupt the flights of smaller aircraft following nearby, turning them upside down in seconds. Imagine hostile pilots in close formation and laden with armaments and explosives encountering such whirlwinds.

That was the goal of a wartime plan hatched by the U.S. Army Chemical Warfare Service (USACWS) at the Dugway Proving Ground in Utah. The department did research not only on chemical agents but also on the means of delivering them. That’s where vortices came in, because they can improve the penetration of a gas charge through the air. A Colonel Esmond of the USACWS hired Thomas Shelton to work on the idea with Philip Leighton of Stanford University. Shelton was a genius inventor and aerodynamicist noted for his twin-boom, twin-engine 1935 Crusader, an aircraft that cruised at 200 miles per hour on just 312 horsepower. Its efficiency stemmed from Shelton’s careful wind-tunnel-tested streamlining. At cruising speed the teardrop-shaped cabin alone generated substantial lift. And fuselage-to-wing filleting prevented the interference drag that plagued other, later twin-boomed aircraft. (For example, early Lockheed P-38 Lightnings suffered from tail buffeting until fairings were added to their wing roots.)

Shelton quickly developed a clever vortex maker. A bellshaped chamber, acted on by a piston or an explosion, would send a packet of gas out its narrow end as a highvelocity vortex. The vortex enhanced the speed, distance, accuracy, and penetration through crosswinds of any vapor being shot out of the bell, just as rifling improves bullet performance. It could be used with vapor-based herbicides and insecticides, as well as with chemical and biological weapons.

Shelton envisioned another way to use his device: Vortices from a huge generator might disrupt aircraft in flight, and the equivalent of a giant smoke ring might break up high-altitude enemy bomber formations. To test his thesis, he built a scale model. Powered by a shotgun shell, it shot an 18-inch smoke ring 150 yards. And it made an eerie howling sound—potent psychological weaponry.

According to Shelton, the Army Air Corps brass at Wright Field, in Dayton, Ohio, seriously considered a version with highexplosive power and a business end yards wide. It would rocket a deadly accurate and invisible ring of air at near-supersonic speed thousands of feet skyward. There the vortex would wreak havoc, spinning target aircraft wildly out of control, crashing into other craft, and falling to earth.

This top-secret stratagem died unfulfilled as offensive weapons garnered war-research resources. But after the war Shelton patented miniature versions of his vortex generator as children’s toys. The Flash Gordon Air Ray Gun, manufactured by the Hudson Company of Chula Vista, California, knocked over targets with a puff of air and cost only $2.49. It was named “Toy of the Year” in 1949 by Popular Mechanics magazine.

Later, with backing from an investor named Paul Zifrin, Shelton developed the Magic Ray Gun, for the Nu-Age Company. It shot miniature smoke rings from small pellets developed by the Lion Match Company. The pellets, in book-match form, neither flamed nor flared but safely smoked prodigiously. Shelton based his idea on a toy made from a cylindrical oatmeal carton by his father, who was himself an industrialist and inventor of no small repute. When filled with cigarette smoke and tapped on one end, it would eject a ring from a hole in the other end. In the 1960s Wham-O Manufacturing revived the Hudson gun as the Air Blaster, cleverly configured with targets built into the cardboard box it came in.

Today “death ray” fantasies are back as prototypes for ground- and satellite-based laser and particle-beam weapons. Tom Shelton’s idea—which also projected disruptive, destructive energy—looked forward almost half a century. Perhaps it was merely too far ahead of its time.