"A large balloon successfully equipped with a powerful oil engine, a propellor, and a rudder."

Dirigible Balloon

"A large balloon successfully equipped with a powerful oil engine, a propellor, and a rudder."

"A body whose average density is so much less than that of air that the body will rise, lifting not only itself, but a considerable load."

Spherical Balloon

"A body whose average density is so much less than that of air that the body will rise, lifting not…