Invisible Death

H. Grindell-Matthews, inventor of a method of controlling motorboats at sea by wireless, for which the British Government awarded him $125,000, has perfected a principle by which airplane or other engines can be stopped in full operation through an invisible ray. He has demonstrated its efficacy with but a quarter kilowatt of power on engines in the laboratory, and needs only to strengthen its current for operation at a greater distance to bring airplanes in flight to a full stop and send them crashing to earth. No insulation is proof against this weapon, for if the carburetor were sufficiently protected, the ray could be so intensified as to set the wing fabric afire. Said he: "I believe that in the near future machine guns will be found only in museums."

Nikola Tesla, Professor Bergen Davis, Columbia physicist, and other American scientists have been working on similar projects, and believe Grindell-Matthews' method thoroughly feasible. Practical aviators are inclined to scoff at the idea, but a number of such devices have been developed with partial success. The Britisher's invention will be offered to the British Government first, but, if not accepted, then to other nations. The French and German experimenters have not yet reached the efficiency of the Englishman's machine. It can also be used against infantry, either to kill or disable.

Niela Assen, Norwegian inventor in the French service, has developed still another type of war machine, consisting of nests of explosive and gas bombs, operated by radio from a distance. These "mechanical soldiers" could hold a front of several hundred miles against enemy invaders with a small staff of engineers. Mr. Assen expects to present his scheme to the U. S. War Department.