three envelopes and two cars were built by Messrs. Vickers on the
design of the original ship. These were delivered somewhat late
in the war, and on account of the production of the North Sea
airship with its greater speed were not persevered with. The
dimensions of the envelopes were somewhat increased, giving a
cubic capacity of 325,000 cubic feet. Twin Maybach engines
driving swivelling propellers were installed in the car, which
was completely covered in, but these ships were slow in
comparison with later designs, and were only used for the
instruction of officers and men destined for the crews of rigid
airships then building.

An experimental ship was made in 1917 which was known as Parseval
5; a car of a modified coastal pattern with two 240 horse-power
Renault engines was rigged to one of envelopes. During a speed
trial, this ship was calculated to have a ground speed of 50 to
53 miles per hour. The envelope, however, consumed an enormous
amount gas and for this reason the ship was deflated and struck
off the list of active ships.

This digression on Parseval airships has anticipated events
somewhat, and a return must now be made to earlier days.

Two more Astra-Torres were ordered from France, one known as No.
8, being a large ship of 4,00,000 cubic feet capacity. She was
fitted with two Chenu engines of 240 horse-power, driving
swivelling propellers. This ship was delivered towards the end
of the year 1914. The second Astra was of smaller capacity and
was delivered, but as will be seen later, was never rigged, the
envelope being used for the original coastal ship and the car