d to exercise
their intended function. This is a safety precaution of inestimable
value.

The Parseval is probably the easiest dirigible to handle, inasmuch as it
involves no more skill or knowledge than that required for an ordinary
free balloon. Its movements in the vertical plane are not dissimilar
to those of the aeroplane, inasmuch as ascent and descent are normally
conducted in a "screwing" manner, the only exception being of course
in abrupt descent caused by the ripping of the emergency-valve. On one
occasion, it is stated, one of the latest machines of this type,
when conducting experimental flights, absolutely refused to descend,
producing infinite amusement both among the crowd and those on board.

The development of the Parseval is directly attributable to the
influence and intimate interest of the Kaiser, and undoubtedly this
represents the wisest step he ever made in the realm of aeronautics. It
certainly has enabled the German military machine to become possessed of
a significant fleet of what may be described as a really efficient and
reliable type of dirigible. The exact number of military Parsevals in
commission is unknown, but there are several classes thereof, in the
nature of aerial cruisers and vedettes.

The largest and most powerful class are those known as the B type,
measuring about 240 feet in length by 40 feet maximum diameter,
of 223,000 cubic feet capacity, and fitted with two motorsand two
propellers. This vessel carries about 10 passengers, can climb to a
maximum height of approximately 8,500 feet, and is capable of remaining
in the air for twenty hours upon a single fuel charge. While this is
the largest and most serviceable type of Parseval designed for
military duties, there is another, the A class, 200 feet in length with
accommodation for six passengers in addition to the crew of three, which
is capable of attaining a maximum altitude of 6,700 feet, and has an
endurance capacity of 15 hours. This class also is fitted with twin
propellers and motors. In addition there are the C and E classes,
carrying from four to eight passengers, while the vedettes are
represented by the D and F classes, which have a maximum altitude of
2,000 feet and can remain aloft for only five hours upon a single fuel
charge. These smaller vessels, however, have the advantage of requiring
only one or two men to handle them. The present military Parseval
dirigible is made in one of these five standardised cla