The airship,
being provided with engines to propel it through the air, and
with rudders and elevators to control it for direction and
height, can be steered in whatever direction is desired, and
voyages can be made from one place to another--always provided
that the force of the wind is not sufficiently strong to overcome
the power of the engines. The airship is, therefore, nothing
else than a dirigible balloon, for the engines and other weights
connected with the structure are supported in the air by an
envelope or balloon, or a series of such chambers, according to
design, filled with hydrogen or gas of some other nature.