ends. A
long nacelle or framework, triangular in section and built up of light
steel tubes, was suspended beneath the envelope by means of diagonally
crossed suspensions.

A 7 horse-power Peugeot engine was fitted at the after end of the
nacelle which drove a 10-feet diameter propeller. In front were a pair
of swivelling tractor screws for steering the ship in the vertical and
horizontal plane. No elevators or rudders were fixed to the ship.

WILLOWS No. 2

The second ship was practically a semi-rigid. The envelope was over
twice the capacity of the earlier ship, being of 29,000 cubic feet
capacity. This envelope was attached to a keel of bamboo and steel,
from which was suspended by steel cables a small car. At the after end
of the keel was mounted a small rudder for the horizontal steering.
For steering in the vertical plane two propellers were mounted on each
side of the car, swivelling to give an upward or downward thrust. A 30
horse-power J.A.P. engine was fitted in this case. Several successful
flights were carried out by this ship, of which the most noteworthy was
from Cardiff to London.

WILLOWS No. 3

No. 2, having been rebuilt and both enlarged and improved, became known
as No. 3. The capacity of the envelope, which was composed of rubber
and cotton, was increased to 32,000 cubic feet, and contained two
ballonets. The gross lift amounted to about half a ton. As before, a
30 horse-power J.A.P. engine was installed, driving the swivelling
propellers. These propellers were two-bladed with a diameter of 61
feet. The maximum speed was supposed to be 25 miles per hour, but it
is questionable if this was ever attained.

This ship flew from London to Paris, and was the first British-built
airship to fly across the Channel.

WILLOWS No. 4

The fourth ship constructed by this firm was completed in 1912, and was
slightly smaller than the two preceding ships. The capacity of the
envelope in this instance was reduced to 24,000 cubic feet, but was a
much better shape, having a diameter of 20 feet, which was gradually
tapered towards the stern. A different material was also used,
varnished silk being tried as an experiment. The envelope was attached
to a keel on which was mounted the engine, a 35 horse-power Anzani,
driving two swivelling four-bladed propellers. From the keel was
suspended a torpedo-shaped boat car in which a crew of two was
accommodated. Originally a vertical fin and rudder