ast coasts of these islands.

The first ship, when completed and put through her trials, was voted a
success, and the others building were rapidly pushed on with. When
several were finished and experience had been gained, after long
flights had been carried out, the North Sea airship suffered a partial
eclipse and people were inclined to reconsider their favourable
opinion. Thus it was that for many months the North Sea airship was
decidedly unpopular, and it was quite a common matter to hear her
described as a complete failure. The main cause of the prejudice was
the unsatisfactory design of the propelling machinery, which it will be
seen later was modified altogether, and coupled with other improvements
turned a ship of doubtful value into one that can only be commended.

The envelope is of 360,000 cubic feet capacity, and is designed on the
Astra-Torres principle for the same reasons as held good in the cases
of the Coastal and C Star. All the improvements which had been
suggested by the ships of that class were incorporated in the new
design, which was of streamline shape throughout, and looked at in
elevation resembled in shape that of the S.S. airship. Six ballonets
are fitted, of which the total capacity is 128,000 cubic feet,
equivalent to 35.5 per cent of the total volume. They are fitted with
crabpots and non-return valves in the usual manner.

The rigging is of the Astra-Torres system, and in no way differs from
that explained in the previous chapter. Nine fans of the internal
rigging support the main suspensions of the car, while similar fans
both fore and aft provide attachment for the handling guys. Auxiliary
fans on the same principle support the petrol tanks and ballast bag.

Four gas and six air valves in all are fitted, all of which are
automatic.

Two ripping panels are embodied in the top lobe of the envelope.

The N.S. ship carries four fins, to three of which are attached the
elevator and rudder flaps. The fourth, the top fin, is merely for
stabilizing purposes, the other three being identical in design, and
are fitted with the ordinary system of wiring and kingposts to prevent
warping.

The petrol was originally carried in aluminium tanks disposed above the
top ridges of the envelope, but this system was abandoned owing to the
aluminium supply pipes becoming fractured as the envelope changed shape
at different pressures. They were then placed inside the envelope, and
this rearrange