The discovery of a method for obtaining helium in large quantities at a low cost from natural gas will have results of the highest consequence for air navigation. Being non-inflammable it makes the dirigible a safe means of transport by air and so greatly increases the possibilities of long distance flights above both oceans and continents. The propaganda balloons devised by the meteorological and other services of the United States were most useful in the dissemination of information in enemy countries, where the results were important in the undermining of morale. They also make possible the mapping of the air highways across the Atlantic and the observation of air temperatures and air currents--a service which will be of so much importance to the future of aviation that it can not yet be estimated. The ingenuity and resourcefulness which found a means of treating cotton fabric to make it as good as linen for the covering of airplane wings made a contribution of signal value to American effort in the war, for without it our air program would have been completely balked. Other nations had attempted to solve the same problem and had devised cotton substitutes for linen, but none of them had proved equal to the strain which airplane wings must bear. The American process gave a substitute as good as linen, and better in some respects, and it has already proved a contribution of very great value to the building of airplanes for commercial purposes, for it simplifies the obtaining of raw material and lessens the cost of production. Many problems connected with work in the air were under study by scientific experts in the army service when the armistice was signed and many smaller problems had been solved and contributions of less value had been made. Among them was the devising of a new and improved compass for air use; the developing of new and more serviceable cameras for airplanes; the construction of a leak-proof tank for airplanes which lessens the dangers of flying; the devising of several kinds of ingenious signaling lamps for both day and night use. Several new types of planes were developed under the urgency of the country’s needs that make important aeronautical advances. One of the most important of all the airplane improvements of the entire war was the developing and the successful application by members of the Bureau of Aircraft Production to American airplanes of the radio telephone. It made possible voice communication between planes in the air and between the ground and the planes. For some time before the armistice was signed squadrons of American planes at the front were being maneuvered and fought by radio telephone and German orders had been insistent that an American plane thus equipped should be shot down and brought to the rear for examination. Important for war purposes as was this development, the result of months of investigation and experiment, its possibilities and its value for peace time uses are even greater.