Short Radio Waves Act Like Light. Exploring that region of radio waves so short that they approach the invisible heat and infra-red rays, engineers of the General Electric Company have discovered interesting and unexpected phenomena. An experimental 5-meter radio sending set was recently put into operation a t South Schenectady where the experimental radio work of the company is done. Previous tests with sending stations on 15 to 30 meters, wave-lengths far below those usually used in broadcasting, had caused the engineers to expect somewhat unusual results, such as comulete fading close t o the station and extremely satisfactom reception a t extreme distances. But in the preliminary tests with the 5-meter set, i t was found that radio signals of that higb frequency had a shadow effect very much like light. A small hill prevented reception in the valley beyond. T o give the light-like radio waves as long a reach as possible the small transmitting set was hoisted t o the top of two fifty-foot towers. Under these conditions i t was possihle to pick up the signals 32 miles away, using 60 watts power. All tests so far have been made during the day, but night tests with 500 watts power are scheduled. A receiving set for the short waves will he placed in the top of the Woolworth Building in New York City, some 135 miles away, inorder to test further the properties of the 5-meter waves. This tall New Yark building was selected because maps show that there is a n unintempted line of "vision" between it and the Schenectady sending set. wave-length, The ex~erimentalradio station, 2XAF. operating on a slightly . longer 32.77 meters, has been heard all over the world. Using an antenna only 25 feet long i t has been picked up and rebroadcast in Australia. One peculiarity of this sort of radio wave is that i t skips over considerable distances, heing inaudible, for instance. between 10 and 1000 miles from the station.-Science Service Gas Speeds Growth of Plants. Ethylene, one of the ingredients of common illuminating gas, is workimg a revolution in the fruit and vegetable industries. Poisonous to plants when present in higb concentrations, in small quantities it acts as a stimnlant, and advantage is being taken of this recently discovered fact. Dr. F. E. Denny of the Bayce Thompson Institute, Yonkers, N. Y., discussed fruit ripening by gas before the recent meeting of the American Chemical Society. It had lonr. - been known that, when the roams where citrus fruits were stored were heated with kerosene stoves, the usual time requiredfor changing the green rind to the desired golden hue was reduced to about one-fourth. Dr. Denny's experiments in 192223 indicated that the active agent in the combustion gases was ethylene. Now this gas is used instead of the old oil stove in the treatment of hundreds of carloads of oranges and lemons, thus avoiding fire rlsk and , n ~ o k yodor. Dr. Denny said tudny: "Surprisingly low cunzcntrations of etllylcne added to thc air wrranding the fruit are able to bring about hastened coloration. If precautions are taken to prevent the loss of ethylene by diffusion, the process is successful with 1 part ethylene to 10,000 parts of air, 1 part in 100,000, or even 1 part in 1,000,000. In practical operation a somewhat higher original concentration is used in order to take care of losses of gas, but i t has not been necessary t o use a greater concentration than about 1 cubic foot of ethylene t o about 5000 cubic feet of air."-Science Service
