ype of internal combustion engine for work
with aircraft; this type has the disadvantage of requiring either a
gas-producer or a large storage capacity for the gas, either of which
makes the total weight of the power plant much greater than that of
a petrol engine. The latter type also requires less attention when
working, and the fuel is more convenient both for carrying and in the
matter of carburation.

The first airship propelled by the present-day type of internal
combustion engine was constructed by Baumgarten and Wolfert in 1879
at Leipzig, the engine being made by Daimler with a view to working on
benzine--petrol as a fuel had not then come to its own. The construction
of this engine is interesting since it was one of the first of Daimler's
make, and it was the development brought about by the experimental
series of which this engine was one that led to the success of the
motor-car in very few years, incidentally leading to that fining down of
the internal combustion engine which has facilitated the development
of the aeroplane with such remarkable rapidity. Owing to the faulty
construction of the airship no useful information was obtained from
Daimler's pioneer installation, as the vessel got out of control
immediately after it was first launched for flight, and was wrecked.
Subsequent attempts at mechanically-propelled flight by Wolfert ended,
in 1897, in the balloon being set on fire by an explosion of benzine
vapour, resulting in the death of both the aeronauts.

Daimler, from 1882 onward, devoted his attention to the perfecting of
the small, high-speed petrol engine for motor-car work, and owing to
his efforts, together with those of other pioneer engine-builders, the
motorcar was made a success. In a few years the weight of this type of
engine was reduced from near on a hundred pounds per horse-power to less
than a tenth of that weight, but considerable further improvement had to
be made before an engine suitable for use with aircraft was evolved.

The increase in power of the engines fitted to airships has made
steady progress from the outset; Haenlein's engine developed about 6
horse-power; the Santos-Dumont airship of 1898 was propelled by a motor
of 4 horse-power; in 1902 the Lebaudy airship was fitted with an engine
of 40 horse-power, while, in 1910, the Lebaudy brothers fitted an
engine of nearly 300 horsepower to the airship they were then
constructing--1,400 horse-power was common in the airships