It is now generally admitted that the balloon as a means of transit from place to place is essentially uncontrollable, and this remark applies in an almost equal degree to buoyant gas bags of whatever form. The main reason of this is obvious, viz., that, as regards horizontal, or even oblique progression, it is due to the great bulk offered to the wind (so much sail surface really), with which the vehicle must drift helplessly. This inevitable drifting no motor nor mechanism that the balloon will lift can counteract or cope with.