ON the basis that it is impossible to state the case for either the airship or the heavier-than-air machine without some comparison of the two, the author discusses relatively features, points of merit or superiority and the fields of usefulness thus far disclosed in the rapid development of the craft. Progress since 1914 is outlined, a brief history to date is included and the way prepared for consideration of the possibilities of long-distance flight.A comparison of the features given emphasizes strongly the point that the airplane is mainly a high-speed, short-distance carrier, while the large rigid airship is essentially a medium-speed long-distance carrier. Each type has a distinct sphere of activity; the airship in transcontinental, transoceanic traffic; the airplane in feeding the terminals of the airship with passengers and, possibly, certain kinds of freight. The salient features of the airship are great endurance, large cargo capacity, ability to remain aloft in bad weather, and space and comfort for passengers.The secondary position of the United States in the rank of development is stated frankly. The non-inflammable lifting gas, of which we have an almost unlimited supply, should place us in the forefront for speedy, long-distance transport.