LAND AND WATER 
December 12, 1914. 
reason. They know that these airships possess a great speed, 
are capable of being well armed, hare a wide radius of action, 
and oan carry a large supply of explosives and of projectiles. 
The limitations of the Zeppelins, as a weapon of war, are also, 
no doubt, known to them ; and, in these notee, their qualities 
and shortcomings will, without any prejudice, be examined in 
turn. This is the only way we can form a fair idea of the 
Zeppelin menace— if such menace exists— and have a clear 
conception of how it can be checked. We shall also be in a 
position to understand why the German airships have not up 
to the present been very conspicuous at the front, and to what 
special uses they may possibly be put as tlie war develops. 
As is well known, the Zeppelin airship belongs to the nffid 
type of airships. This means that its outer shape is always 
tho same. This property of permanency of shape under all 
normal circumstances is not possessed by tho two other types 
of airships in existence: tho non-riffid and the semi-riffid. 
Count Zeppelin, who designs tho airships bearing his name, 
is not the inventor of the rigid typo of airships; but he has 
the distinction of having perfected it and of having brought 
it to its present stage of development. In his work ho has 
shown great courage, admirable persistency, and profound 
mechanical skill. The designing and construction of a rigid 
airship is very complex and delicate. Several eminent engi- 
neers, both here and abroad, have recently met with complete 
failure in their attempts to produce a rigid airship which 
would vie with those designed by Count Zeppelin. This re- 
mark is made solely with the idea of showing the value to Ger- 
many of Count Zeppelin's experience, and of enabling us to 
examine later on some objections that are often made to the 
Zeppelin method of construction. Roughly speaking, the 
general shape of the Zeppelin airship is that of a cylinder, 
with its axis resting horizontally, rgainst each end of which 
is placed a cone — the axes of the two cones being in Uie same 
straight line as that of the cylinder. Thisi is the reason that 
the shape of the Zeppelin airship is generally described as 
being " cylindrical, with conical ends." As a matter of fact, 
however, the central portion of the Zeppelin airship is not 
exactly cylindrical, that is circular in section. It is a large 
prism with sixteen sides, or faces, and so the conical ends of 
tho Zeppelin airship have not a circular base. The exact 
shape of the base is that of a regular 16-eided figure. 
The largest portion of a Zeppelin airship is, therefore, a 
rigid structure, the central part of which is a 16-sided prism, 
and the ends of which are cones having a regular 16-sided base. 
That structure, which must be rigid and yet light, is of alu- 
minium. The length from tip to tip of the aluminium struc- 
ture is divided vertically into a number of parts by light 
aluminium struts. The number of parts, or compartments, 
into which a Zeppelin airship is divided depends upon the 
size of the airship, but it is usually seventeen. Each of these 
compartments is completely shut oS from the neighbouring 
ones by means of gas-proof cloth, and contains an almost 
spherical balloon of aero-cloth filling the greater part of the 
compartment. As the number of compartments is usually 
seventeen, so the number of balloons containing the hydrogen 
gas which provides the necessary lifting power is also usually 
seventeen. Each, of these balloons has at its extremity an 
open appendix which enables the enclosed hydrogen to be in 
equilibrium with the air. In the Zeppelin airship, therefore, 
the lifting hydrogen contained in the difierent balloons inside 
the aluminium framework is not under pressure. This is an im- 
portant fact which must be borne in mind. Its full signifi- 
cance will Be realised when the vulnerability of the airship 
is considered. 
The outside of the aluminium framework of "cylindrical 
shape with conical ends " of the Zeppelin airship is itself 
covered with aero-cloth, and the whole of the framework thus 
covered is spoken of as the rigid envelope of the airsliip. It 
is designed and constructed so as to ensure, under all foreseen 
circumstances, the permanency of the external shape of the 
airship. This is necessary, because on it depends tlie regular 
propulsion of tlie airship through the air ; the existence of de- 
formations or of pockets in the envelope would have a very 
bad influence on the speed and on the steering qualities of the 
vessel. 
The speed of an aircraft is a matter of primordial im- 
portance. On it depends its der/ree of dirigihility, and it is 
only when the speed of an airship is greater tlian that of the 
existing wind that it can be steered in any desired direction 
In following the evolution of tho Zeppelin airships one notes 
that their speeds are alwaysi l^eing made greater and greater 
At present it is about 50 to 55 miles an hour. The driviiitr of 
an airship through the air, by means of screw propellers 
worked by motors, gives it its speed. 
In the Zeppelin airship the aluminium framework, al- 
ready described, has, along the whole length of its under por- 
tion, a V-shaped keel which serves a treble purpose: Firstly 
It strengthens the framework; secondly, it steadies the airship,' 
and, very much after the manner of a ship's keel, prevents it 
from rolling too much; and thirdly it offers a good means of 
rigidly connecting the cars, or nacelles, of the airship to the 
envelope. It will thus be seen that tli© whole structure of the 
Zeppelin airship is rigid. 
■ Towards the forepart of tlie V-shaped keel there is the 
fore nacelle, and towards its aftpart is the aft nacelle. A 
passage runs along the V-shaped keel, and. by means of two 
small aluminium ladders leading up to tlie passage access from 
one nacelle to the other is obtained. In a military Zeppelin 
the flooring of tho passage is of aluminium slieets about 18 
inches wide. At regular distances inside the keel, are sus- 
pended a number of tanks containing the fuel and the oil 
necessary for tho working of the motors. The contents of 
these tanks arc used progre.'jsively, starting from each ex- 
tremity so as to maintain undisturbed tlio balance of the air- 
ship. 
In the middle of the passage inside the keel there is a 
small room for the crew in which hammocks are suspended, 
and at a short distance from it is the officers' cabin in which 
are to be seen some of the instruments necessary for the naviga- 
tion of the airship, such as barometcis, altimeters, and regis- 
tering thermometers. Next to the officers' cabin there is a 
darkroom for developing photographic plates, and adjoining 
it another small cabin in which are placed various instruments 
connected with wireless telegraphy and in which wireless mes- 
sages are received and sent out. In a modern Zeppelin tho 
range of the wireless installation is from 125 to 150 miles. 
The Zeppelin airship, as at present constructed, is 600 feet 
long and 75 feet in diameter. The volume of its envelope is 
776,600 cubic feet. It is driven by three Maybach motors of 
170 h.p. each; its speed is from 50 to 55 miles per hour, and 
it can navigate at a height of 7,000 feet for several hours. 
In the fore nacelle is placed one of the three motors which 
works two 2-bladed propellers, one on each eide of the envelope 
The transmission of the power from the motor-shaft to the' 
propeller-shaft is obtained by means of bevel wheels. The two 
other motors are in the aft-nacelle, and work two 4-bladed pro- 
pellers, one on each side of the envelope. A quadruple clutch 
enables the engineer to work one of the two propellers by 
either motor, or a single propeller by both motors running 
simultaneously. Right at tho end of tho aft-nacelle is placed 
a wheel, the manipulation of which works the elevators and 
rudders of tlie vessel. 
The signalling of manoeuvres can be made from the fore to 
the aft nacelle by means of wire connections running along 
tho inside of the V-shaped passage. 
Towards the rear of the fore-nacelle is an oval vertical 
chimney going right through the rigid envelope in a space 
between two balloons. By climbing up that chimney access 
can be had to an aluminium platform about 10 feet square. 
On it are mounted two mitrailleuses!, each commanding a semi- 
circular field on one side of the airship. These guns can be 
used simultaneously for the needs of either pursuit or retreat. 
Three mitrailleuses are also placed in the cai-s, one in the foro 
and two in the aft nacelle. A modern military Zeppelin has, 
thus, for defensive and offensive, purposes, five machine guns 
which together command a complete spherical field. 
The supply of bombs and of explosives is placed, during 
a raid, in the cabin wliich is usually occupied by the crew. 
A modern Zeppelin can carry about 2 tons of explosives and 
yet still possess a radius of action of about 300 miles. 
Two searchlights enable a Zeppelin crew to examine 
during tlie night any particular spot on the ground, and by 
means of a system of luminous -signals to communicate with 
other airships or with tlic earth's surface. 
It will b© gathered from tjio foregoing description that ■ 
the Zeppelin, as a weapon of war, is by no means a negligible 
quantity. It has, however, certain defects, and with these it 
is proposed to deal in a subsequent article. 
(To be continued.) 
THE BLUE CROSS. 
The Blue Cross Fund is undertaking worit of the utmost import- 
ance, and one that must appeal not only to Jovcrs of animals but also 
to those who recognise the value of horses in the various strategic and 
t.ictical operations involved. This branch of Our Dumb Friends' 
League has received full recognition by the Government of the French 
Republic, and has undertaken to establish a number of base hosjxitals 
for the benefit of horses wounded in the war. Funds are urgently 
needed to carry on this good work, and cheques should be made pay- 
able to the Secretary of Our Dumb Friends' Lea^'ue, 58, Vietoria 
Street, Westminster, S.W., and the envelopes marKe<l "Blue Cross 
Fund." 
Tlie Buhy of RajnH'han, by R. E. Forrest, published by East and 
West, Ltd., at six shillings, ought to command a largo public at the 
present time, since it is concerned with India and written by a man 
whose knowledge of the inner workings of Indian life is indisputable. 
It is a story of tho earlier days of the great Emperor Akbar, and, 
while of extreme interest a.s a story, is distinctly valuable for its 
pictures of Indian life and customs. Here is old Ind, well presented. 
12" 
