war, when the defeat of the German submarine campaign had become a
matter of life or death for the British Commonwealth.

The small airship called the 'S.S.', or Submarine Scout, was an
invention of the first year of the war. On the 28th of February 1915
Admiral Fisher sent for Commander E. A. D. Masterman and Wing Commander
N. F. Usborne, and told them that he wanted some small, fairly fast
airships to operate against the German submarines, and that he wanted
them at once. There was no time for experiment or the elaboration of new
designs; speed in production was essential, and speed could not be
attained except by the adaptation of existing types and the use of
standard parts. The navy is seen at its best when it has to rise to an
unforeseen occasion; within three weeks the first of the now famous
S.S.'s was ready for service. For the design of this airship it is as
difficult to apportion credit among the small band of naval officers who
had a hand in it as it is to divide the praise for the first flying
machine between the brotherhood of the Wrights. The idea seems to have
been struck out during a conversation in the mess at Farnborough at
which there were present the late Wing Commander N. F. Usborne, Flight
Lieutenant T. R. Cave-Browne-Cave, and Mr. F. M. Green of the Royal
Aircraft Factory. In the result the body, or fuselage, of a B.E. 2c
aeroplane was slung on to the envelope of a Willows airship, and the job
was done. The success of this airship was as great as its design was
simple. It fairly fulfilled the main requirements--to remain aloft for
eight hours in all ordinary kinds of weather, with a speed of from forty
to fifty miles an hour, and carrying a load which should include a
wireless telegraphy installation for the purposes of report and a
hundred and sixty pounds' weight of bombs for more immediate use. The
first twenty-five of these ships to be produced were fitted with the 70
horse-power Renault engine. Variations and improvements of the design
followed in steady succession, providing greater endurance, and more
comfortable cars for the crew. One of these variants, the C. 1 or
coastal type, used an Astra-Torres envelope and a car made from two Avro
fuselages with the tails cut off; a later and larger design, the N.S. 1,
or North Sea type, in use at the end of the war, had an endurance, on
occasion, of from two to three days.

Airship work against submarines, an authority on the subject has
remarked,