National Geographic : 1953 Aug
218 National Geographic Photographer John E. Fletcher Aerosol Sprays, Beltsville's Invention, Battle Insect Stowaways from Abroad A Public Health Service officer shows Pan American World Airways stewardesses proper bug-killing procedure. Beltsville entomologists, who gave the a method of distributing insecticides through aircraft striking improvement in seed germination and crop yields. Today several soil condi tioners give greener thumbs to millions of American garden lovers. In U. S. timberlands today insects rank with fire as destroyers of forests. Beltsville's insect fighters seek better weapons to control forest pests. Air Sprays Rout Timber Thieves From the Beltsville airport NATIONAL GEO GRAPHIC photographer Jack Fletcher and I took off with a forester-pilot in a bright-yellow Department of Agriculture aerial survey plane. We flew across the experimental forest which covers 3,000 acres of the Research Center. Below us, barely above the trees, flew a yellow biplane. Suddenly a purple cloud burst behind it. The mist settled slowly, trailing out behind like an unrolling carpet. "DDT," our pilot shouted over the engine world the push-button spray can, now are developing air-conditioning systems. roar. "For experimental purposes colored dyes are added to show where the spray goes. The goal is to apply as little as possible and still kill insects." Both planes swung back toward the airport, turning into a spray path marked by orange balloons bobbing on 50-foot lines. Colored in secticide spray drifted down across a grid of aluminum test panels on wooden stakes. Scientists learn the size and diffusion of the droplets by checking glass microscope slides on the panels (page 208). Such constant and careful research at Belts ville has no end. Pressed by all the will, in genuity, and boundless curiosity of agricul tural science, the experiments of this huge outdoor laboratory guard the Nation's price less forests and farms, its food and clothing, and its future health.* * For additional articles on agriculture, see the two-volume NATIONAL GEOGRAPHIC MAGAZINE Cumu lative Index, 1899-1952.