In 1812, Leppig built an airship at the cost of the State at
Woronzowo in Russia. This was of the shape of a fish with a
rigid framework beginning at the height of the longitudinal axis.

The lower keel-shaped part of the same formed the car. Two fans
were attached to the sides and a tail piece was provided behind
to act as a rudder. The ship was inflated, but structural damage
occurred during this operation and rendered it incapable of
flight.

In 1836, Georg Rebenstein, of Nurnburg, was considering the use
of the fall of inclined planes to obtain horizontal motion.

Nothing of importance was produced until a much later date. when
in 1885 M. Wolf constructed an envelope of 26,500 cubic feet. An
engine and propeller were fixed in a triangular framework in
front of the airship, supported by the steam pipe of a steam
engine fixed under the body of the envelope. The framework
lacked rigidity, and the envelope tore during inflation and the
airship failed to ascend.

In the following year Dr. Woelfert, of Berlin, produced a
cigar-shaped envelope, to which was attached rigidly a long
bamboo framework containing the car. An 8 horse-power benzine
Daimler motor drove a twin-bladed aluminium propeller, and
another propeller for vertical movement was provided beneath the
car. Four trial flights were attempted, but on each occasion the
motor gave unsatisfactory results, and Woelfert sought to improve
it with a benzine vaporizer of his own pattern. This improvement