Suppose it is desired to incline the bow of the craft upward,
then the ventilating fan would DEFLATE the fore ballonet and
INFLATE the aft one, so that the latter, becoming heavier, would
lower the stern and raise the bow of the vessel.

Along each side of the envelope are seen strips to which the car
suspension-cords are attached. To prevent these cords being
jerked asunder, by the rolling or pitching of the vessel,
horizontal fins, each 172 square feet in area, are provided at
each side of the rear end of the balloon. In the past several
serious accidents have been caused by the violent pitching of
the balloon when caught in a gale, and so severe have been the
stresses on the suspension cords that great damage has been done
to the envelope, and the aeronauts have been fortunate if they
have been able to make a safe descent.

The propeller and engine are carried by the car, which is slung
well below the balloon, and by an ingenious contrivance the car
always remains in a horizontal position, however much the balloon
may be inclined. It is no uncommon occurrence for the balloon to
make a considerable angle with the car beneath.

The propeller is quite a work of art. It has a diameter of about
14 feet, and consists of a frame of hollow steel tubes covered
with fabric. It is so arranged that when out of action its
blades fall lengthwise upon the frame supporting it, but when it
is set to work the blades at once open out. The engine weighs
770 pounds, and has six cylinders, which develop 100 horse-power
at 1200 revolutions a minute.