ceeded all expectations, a company was formed for the construction
of dirigibles in the Zeppelin works on Lake Constance, and in 1909 an
enormous air-ship was produced.

In shape a Zeppelin dirigible resembled a gigantic cigar, pointed at
both ends. If placed with one end on the ground in Trafalgar Square,
London, its other end would be nearly three times the height of the
Nelson Column, which, as you may know, is 166 feet.

From the diagram here given, which shows a sectional view of a typical
Zeppelin air-ship, we may obtain a clear idea of the main features of
the craft. From time to time, during the last dozen years or so, the
inventor has added certain details, but the main features as shown in
the illustration are common to all air-craft of this type.

Zeppelin L1 was 525 feet in length, with a diameter of 50 feet. Some
idea of the size may be obtained through the knowledge that she was
longer than a modern Dreadnought. The framework was made of specially
light metal, aluminium alloy, and wood. This framework, which was stayed
with steel wire, maintained the shape and rigidity of her gas-bags;
hence vessels of this type are known as RIGID air-ships. Externally the
hull was covered with a waterproof fabric.

Though, from outside, a rigid air-ship looks to be all in one piece,
within it is divided into numerous compartments. In Zeppelin L1 there
were eighteen separate compartments, each of which contained a balloon
filled with hydrogen gas. The object of providing the vessel with these
small balloons, or ballonets, all separate from one another, was to
prevent the gas collecting all at one end of the ship as the
vessel travelled through the air. Outside the ballonets there was a
ring-shaped, double bottom, containing non-inflammable gas, and the
whole was enclosed in rubber-coated fabric.

The crew and motors were carried in cars slung fore and aft. The ship
was propelled by three engines, each of 170 horse-power. One engine was
placed in the forward car, and the two others in the after car. To steer
her to right or left, she had six vertical planes somewhat resembling
box-kites, while eight horizontal planes enabled her to ascend or
descend.

In Zeppelin L2, which was a later type of craft, there were four motors
capable of developing 820 horse-power. These drove four propellers,
which gave the craft a speed of about 45 miles an hour.

The cars were connected by a gangway built within the framework. On the