December I2, 19 14 
LAND AND WATER 
WIRELESS TELEGRAPHY in WARFARE 
By "AN ENGINEERING CORRESPONDENT" 
I 
THE extent to which recent scientific knowledge is 
being employed in the great war is one of the 
characteristics of the great struggle. Owing to 
the world-wide field of operations it is necessary 
to use every possible form of intercommunication, 
and although ordinary wire telegraphy is not likely to be 
superseded, there are several cases in which wireless telegraphy 
has proved to be of great use in the Army, while in the Navy 
it is as indispensable as in the mercantile marine. 
Wireless telegraphy has probably revolutionised naval 
warfare. No longer is it necessary for a commander to sail 
away with sealed orders, for he is always in touch with 
headquarters, either direct or through some other ship. It is 
a well-known fact that the wireless station of the Admiralty at 
Whitehall has a range of over one thousand miles, and that the 
naval authorities are in constant touch with every ship and 
are informed of every move. The whole of the Fleet is now 
provided with " wireless," from the biggest battleships to 
submarines, although, of course, the range of torpedo boats 
and submarines is only some twenty or thirty miles. 
On land wireless is used on a very large scale by all 
armies, and is demonstrating its great usefulness in cases 
where no ordinary telegraphy exists between two places or 
where the telegraphic communication has been destroyed. 
Again, rapidly moving columns can keep in communication 
with the main army ; and a fortress, even when completely 
besieged, can stiU communicate with the outside world ; 
while an army and navy, when carrying out combined 
operations, can keep in close touch with one another. 
The importance of portable wireless apparatus for 
military purposes was grasped at an early date in the develop- 
ment of wireless telegraphy, and some of the first-made 
portable sets were used extensively by the Russian Army 
during the Russo-Japanese War. The early wireless stations 
were only adapted for wheel transport, and were thus of 
limited application. The Marconi Company has developed a 
series of portable wireless sets for military' purposes according 
as the transport is by cart, motor car, or cavalry. 
The cavalry type of station is capable of working over a 
distance of twenty to thirty miles in ordinary country. Four 
horses are necessary for transport, the load per saddle being 
about 160 lb., while everything has been designed with a 
view to easy manipulation, and on that account the station 
can be worked within ten minutes after a stop has been made. 
One horse carries the small petrol engine and electric 
generator, which are mounted on opposite sides of a pack- 
saddle, as well as a two-gallon tank of petrol and other 
accessories. A second horse carries the receiving set, the 
sending transformer, and all accessories ; the third horse 
carries masts, sections, and spreaders ; while the fourth 
horse carries the mast, stays, aerial wires, and the primary 
oscillating circuit of the transmitter. 
The motor car and cart stations are very much alike. 
In the motor car type of field station the electric generator 
is driven by the main engine through a silent chain gearing 
which can be thrown into or out of action as required. The 
entire apparatus is carefully arranged inside the car, while 
the masts are carried on either side of the car. The range 
of such a station is about seventy miles ; but the Telefunken 
Company has provided the German Army with heavier motor 
car stations, having a range of about two hundred miles. 
The Germans favour the use of a steel telescopic mast, having 
a length of about one hundred feet when erected. 
Another type of portable station which has been recently 
developed is the knapsack station, which is intended primarily 
to be employed by scouts and to replace to a large extent 
visual signalling. The distance over which it will work is 
about from five to seven miles, and the station can be divided 
into four loads of approximately 20 lb. each, while two men 
ran erect it in about five minutes. A single mast of extremely 
light construction is used, while the aerial wires act as stays 
for the mast. The source of energy may be either a primary 
or secondary battery. The accumulator consists of three 
two-volt cells carried in a light portable aluminium case. 
.Mo elaborate system .of tuning is provided or is necessary, as 
the wave length employed is very short and widely different 
from that in ordinary use ; consequently this type of set is 
practically immune from interference. 
The use of " wireless " in aircraft is the most recent 
application. Wireless communication between airship or 
aeroplane and military headquarters is of great service, as 
information obtained can be immediately communicated. 
while the headquarter staff can give instructions to the crew 
of the aircraft to reconnoitre special positions. Also, in case 
of accident — due to motor failure or in the event of being shot 
down by the enemy — the infoimation obtained need not be 
lost if " wireless " is carried. 
The operator is usually carried as a passenger, and 
transmits signals at the same time as he makes observations. 
The difficulty of installing wireless telegraphy on aeroplanes 
is very great, owing to the absence of sufficient space to 
provide an adequate aerial, and due to the limitations of 
weight and space to which the apparatus must conform. 
The current to work the apparatus is obtained from a 
generator driven by friction off the fly-wheel of the engine or 
from storage batteries, while experiments have also been 
made with wind motors for driving the generator. Portable 
stations manufactured by the Marconi Company, and especially 
adapted for aeroplane work, weigh 50 lb., and have a radius 
of about ten miles, while another set weighs 200 lb., and has 
a sending radius of fifty miles. 
Several foreign governments have adopted the aeroplane 
sets made by the Lorenz Company, of Berlin. The outside 
dimensions of the set are 15 in. by 15 in. by 21 in., not 
including the generator, and the weight is about 100 lb. 
This type of apparatus uses what is " technically " known as 
a quenched discharge gap. The Telefunken Company 
manufactures also aeroplane sets, having a sending radius of 
from fifteen to twenty miles. 
For aeroplane work several governments have gone back 
to the old days of untuned wireless waves, and for this kind 
of work there are several points in its favour. In transmitting 
a sharply tuned signal it takes a longer time to adjust the 
receiver, and as messages are sent in code it does not matter 
whether the enemy receives them or not. Again, if the 
signals are not sharply tuned a great deal of hindrance can 
be done to the enemy by flying in close proximity to their 
larger stations and causing a great deal of interference, as it 
will be difficult for them to cut out the untuned waves. 
In airships, especially of the Zeppelin type, large aerials 
can be employed, and consequently much greater distances 
can be covered. Since 1910 all Zeppelin airships have been 
fitted with wireless telegraphy. The electric generator is 
either driven by an independent petrol motor or is coupled 
to the motor driving the airship screw. The aerial on board 
a Zeppelin is almost 600 feet long, while the wave length 
varies from 400 to 1200 metres. It has been reported that 
some of the Zeppelins have a sending radius of 200 miles, 
while the Zeppelin airships, which used to make public 
passenger trips in Germany before the war broke out, carried 
regular wireless installations, the same as are used on liners. 
The greatest danger attached to airships from wireless 
installations is the fact that the gas may become ignited by 
sparks produced by induced currents occurring between 
metal parts. This danger can be eliminated to a certain 
extent by covering all metal parts, such as valves, etc., 
thoroughly with a thick coating v.1 some form of insulating 
varnish. 
As the ether is common property, and all wireless 
messages use the ether as the transmitting medium, it is im- 
possible to prevent the enemy from intercepting messages. 
The inability to send secret messages is a great drawback, 
and secrecy is obtained merely by conversing in code. 
Owing to the ease with which wireless messages can be 
intercepted — only an aerial and some cheap apparatus being 
required — a large number o{ amateur stations have sprung up 
in recent years. It is, however, necessary to have a Govern- 
ment licence to install a receiving station ; but as it is a very 
easy matter to hide the apparatus it is a very difficult matter 
to prevent spies from using such receiving stations. In this 
country it is impossible to transmit messages without being 
discovered by the numerous post office stations, which are 
always on the watch for unauthorised wireless messages. 
The danger is, however, that spies can receive messages in 
code from Germany without the authorities knowing 
anything about it. The use which spies make of wireless 
telegraj^liy may be judged from the fact that it is reported 
that when war broke out one hundred and fifty German 
wireless stations were discovered in Brussels alone. 
Mr. E. a. Brown, the manager of Devonshire Park, Eastbourne, 
lias engaged Mr. Hilaire Bclloc to deliver two lectures on " The 
Strategy of the War, " on Friday next, the i8th inst. During the 
Christmas holidays tht-re will be a special Christmas programme in 
the Winter Garden at Devonshire Park. 
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