Four engines and four propellers. One engine in forward
car driving pusher propeller. Three engines in after
car driving two wing and one pusher propeller.

To the second stage belongs naval airship L 2, which was destroyed by
fire a month after completion in 1913. In 1916 a fourth stage made its
appearance, of which the first ship was L 30, completed in May, and to
which the ill-fated L 33 belonged. This type is known as the
super-Zeppelin, and has been developed through various stage until L
70, the latest product before the armistice. In this stage the
following are its main features:

Stage 4.

Short parallel portion of hull, long rounded bow and
long tapering stern. In all respects a good
streamline shape.
Internal keel walking way.
Balanced monoplane rudders and elevators.
Five cars. Two forward (combined as in Stage 3),
one aft, and two amidships abreast.
Six engines and six propellers. The after one of the
forecar and the sidecars each contain one engine
driving direct a pusher propeller. The after car
contains three engines, two of which drive two wing
propellers; the third, placed aft, drives direct a
pusher propeller.
In this stage the type of girders was greatly altered.

A company known as the Schutte-Lanz Company was also responsible for
the production of rigid airships. They introduced a design, which was
a distinct departure from Zeppelin or anyone else. The hull framework
was composed of wood, the girders being built up of wooden sections.
The shape of these ships was much more of a true streamline than had
been the Zeppelin practice, and it was on this model that the shape of
the super-Zeppelin was based. These ships proved of use and took part
in raids on this country, but the Company was taken over by the
Government and the personnel was amalgamated with that engaged on
Zeppelin construction during the war.

ITALY

In 1908, Italy, stimulated by the progress made by other continental
nations, commenced experimental work. Three types were considered for
a commencement, the P type or Piccolo was the first effort, then
followed the M type, which signifies "medium sized," and also the
semirigid Forlanini.

In the Forlanini type the envelope is divided into several compartments
with an internal rigid keel and to-day these ships are of considerable
size, the most modern being