Fifteen or twenty years ago, the penniless inventors who carried with them plans for construction of steerable balloons or flying machines approached the leaders of the peace movement. Help us to conquer the air, they said, and war will be overcome. The reasons they gave were more or less the following: borders would be obliterated, since neither barriers, nor toll fences, nor fortifications can be erected in the air; traffic, simplified and accelerated tenfold, would bring nations even closer than railroads and steamers already do; through this closeness, hostilities would vanish; and through the general rejoicing that such a wonderful achievement would arouse, people would rise above their petty hatreds and jealousies.