THE recent successful trips of the Zeppelin airship make it appropriate to review and illustrate some of the less known attempts at aerial navigation. Somewhat similar in plan to Count von Zeppelin's enormous airship is the dirigible flying-machine shown in Fig. 1, with which at various times during 1897 and 1898 Dr. K. I. Danilewsky, of Charkov, Russia, made excursions. The object of making the balloon sausage-shaped was, of course, that its forward end might be brought toward the wind, and then, with the nose pointed upwards, as in the illustration, its under surface served somewhat as that of a kite. The wings were made about twelve feet in length, and it was found
possible to handle them so as to turn the balloon entirely around in the air. and also to keep it practically stationary in a moderate breeze.
M. de Santos Dumont has sailed about the Eiffel Tower in Paris in the dirigible balloon shown in Fig. 2. It was 65 feet long. 25 in diameter and contained 17,658 cubic feet of gas. He used a small petroleum engine for controlling the rudder and aeroplane. The reports are that he was able to navigate very much at will. Fig. 3 is another form of dirigible balloon tried by M. Dumont. This was also reasonably successful.
Fig. 4 represents a machine designed by Frederick P. Merritt, with windmill sails below and on both sides of his balloon, and a mechanism for feathering them in such a manner as to drive the craft either forwards or backwards.