work up to 30 millimetres as a maximum and 15 millimetres as a
minimum flying pressure. During a descent the pressure should be
watched continuously, as it may fall so low as to cause the nose
to blow in. This will right itself when the speed is reduced or
the pressure is raised, but there is always the danger of the
envelope becoming punctured by the bow stiffeners when this
occurs.


HOUSING ACCOMMODATION FOR AIRSHIPS, ETC.

During the early days of the war, when stations were being
equipped, the small type of airship was the only one we
possessed. The sheds to accommodate them were constructed of
wood both for cheapness and speed of construction and erection.
These early sheds were all of very similar design, and were
composed of trestles with some ordinary form of roof-truss. They
were covered externally with corrugated sheeting. The doors have
always been a source of difficulty, as they are compelled to open
for the full width of the shed and have to stand alone without
support. They are fitted with wheels which run on guide rails,
and are opened by means of winches and winding gear.

The later sheds built to accommodate the rigid airship are of
much greater dimensions, and are constructed of steel, but
otherwise are of much the same design.

The sheds are always constructed with sliding doors at either
end, to enable the ship to be taken out of the lee end according
to the direction of the wind.