hull framework in section formed a
regular polygon of seventeen sides, and was built up of triangular
aluminium girders. The gasbags were eighteen in number. This ship was
fitted with three 170 horse-power Maybach engines, which were disposed
as follows--one in the forward car, driving two two-bladed propellers;
two in the after car, each driving a single four-bladed propeller. For
steering purposes she had six vertical and eight horizontal planes.
The total lift was 27 tons, with a disposable lift of 7 tons. Her
speed was about 50 miles per hour, and she could carry fuel for about
48 hours. Her normal crew consisted of fourteen persons, including
officers.

It will probably be remembered that the military Zeppelin Z III was
compelled to make a forced landing in France. This ship was of similar
construction to L 1, but of smaller volume, her capacity being 620,000
cubic feet. A trial flight was being carried out, and while above the
clouds the crew lost their bearings. Descending they saw some French
troops and rose again immediately. After flying for four hours they
thought they must be safely over the frontier and, running short of
petrol, made a landing--not knowing that they were still in France
until too late. The airship was taken over by the French authorities.

Until the year 1916 the Zeppelin may be considered to have passed
through three stages of design. Of the twenty-five ships constructed
before the war, twenty-four were of the first type and one of the
second. Each type possessed certain salient features, which, for
simplicity, will be set out in the form of a tabulated statement, and
may be useful for comparison when our own rigid airships are reviewed.

Stage 1.
Long parallel portion of hull with bluff nose and tail.
External keel with walking way.
Box rudders and elevators.
Two cars.
Four wing propellers.

Stage 2.
Long parallel portion of hull with bluff nose, tail portion
finer than in Stage I
Internal keel walking way.
Box rudders and elevators.
Three cars, foremost for control only.
Four wing propellers.

Stage 3.
Shorter parallel portion of hull framework, bluff nose and
tapering tail.
Internal keel walking way.
Balanced monoplane rudders and elevators.
Three cars, foremost for control only.
Two foremost cars close together and connected by
a canvas joint to look like one car.