the ship.

The forward engines drove two four-bladed swivelling propellers through
gear boxes and transmission shafts, the whole system being somewhat
complicated, and was opposed to the Zeppelin practice at the time which
employed fixed propellers.

The after engine drove a large two-bladed propeller direct off the main
shaft.

The petrol and water ballast were carried in tanks situated in the keel
and the oil was carried in tanks beneath the floors of the cars.

The wireless cabin was situated as before mentioned in a cabin in the
keel of the ship, and the plant comprised a main transmitter, an
auxiliary transmitter and receiver and the necessary aerial for
radiating and receiving.

No. 9 was inflated in the closing days of 1916, and the disposal lift
was found to be 2.1 tons under the specification conditions, namely,
barometer 29.5 inches and temperature 55 degrees Fahrenheit. The
contract requirements had been dropped to 3.1 tons, which showed that
the ship was short by one ton of the lift demanded. The flight trials
were, however, carried out, which showed that the ship had a speed of
about 42 1/2 miles per hour.

The alterations previously mentioned were afterwards made, the bags of
the ship were changed and another lift and trim trial was held in
March, 1917, when it was found that these had had the satisfactory
result of increasing the disposable lift to 3.8 tons or .7 ton above
the contract requirements, and with the bags 100 per cent full gave a
total disposable lift of 5.1 tons.

Additional trials were then carried out, which showed that the speed of
the ship had not been impaired.

For reference purposes the performances of the ship are tabulated below.

Speed:
Full 45 miles per hour
Normal = 2/3 38 " " "
Cruising = 1/3 32 " " "

Endurance:
Full 18 hours = 800 miles
Normal 26 " = 1,000 "
Cruising 50 " = 1,600 "

No. 9 having finished her trials was accepted by the Admiralty in Mar.
1917, and left Barrow, where she had been built, for a patrol station.

In many ways she was an excellent ship, for it must be remembered that
when completed she was some years out-of-date judged by Zeppelin
standards. Apart from the patrol and convoy work which she
accomplished, she proved simply invaluable for the training of officers
and men selected to be the crews of future rigid airships. Many of
these receive