BALDWIN U. S. “DIRIGIBLE NO. 1”
The German inventors settled the problem by making the envelope rigid, either with a solid covering or with a covering of fabric stretched over an inner framework. Thus the rigid type of airship was evolved.
The French inventors solved the same problem by placing inside the envelope a large empty bag of fabric, into which air could be pumped when necessary to fill the balloon out and hold the envelope firm. The air could not be pumped directly into the envelope itself as it would produce an explosive mixture with the gas already there. From this method of dealing with difficulty, the non-rigid type of dirigible was evolved.
THE BRITISH ARMY “BABY” DIRIGIBLE
But the non-rigid dirigible presented a new difficulty: how could the car be suspended from it in such a way that it would not swing? For only with a rigid connection between the car and the envelope could the greatest speed be obtained. The Lebaudy solved this problem by attaching to the base of the envelope a rigid steel flooring, from which the car could then be suspended by an immovable connection. And so was evolved the semi-rigid type of airship.
In recent years another solution of this problem of preventing the car from swinging has been employed to some extent: By making the car almost as long as the envelope, the connecting cables by which the car is suspended hang almost perpendicular, and there is not the same tendency to swerve as with cables slanting down to a comparatively small car. This type of airship is called the demi-semi-rigid.
These then are the four general classes of dirigibles which were used in the Great War.