WIKELESS TELEGRAPHY. 
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militate a good deal against the employment of this system in the field. 
Of course dry cells can be used, but dry cells will not last very long 
and I do not think we have much experience as to how dry cells 
would stand the rough conditions of service in the field. 
When an interchange of messages between two stations is required 
there must be, of course, a transmitting and a receiving apparatus at 
each station, and it would appear that your own receiving apparatus 
would respond to your own signals. Where there are only two stations 
concerned that is not much disadvantage, but where there are more 
than one pair of stations established within a short distance of one 
another, and they are exchanging messages simultaneously, the signals 
would get hopelessly mixed unless by some process of tuning the re¬ 
ceivers can be made to respond only to waves of some selected and ad¬ 
justed wave length. Mr. Marconi, I believe, claims to have accom¬ 
plished this, but in what manner I must express my inability to tell 
you. 
When treating of the military possibilities of the system, I must be 
allowed to use the term military in a very wide sense. The navy, of 
course would be most benefitted. Fully equipped with electrical ap¬ 
pliances and provided with a mast as support for the vertical wire, 
communication of orders from a Flagship to ships of the squadron will 
be facilitated, while it should be possible for ships to receive intelli¬ 
gence from shore, say from a coast-guard station, without the neces¬ 
sity of coming into harbour. 
Unless the receivers can be tuned, the use in the presence of the 
enemy appears to be impracticable as the enemy would probably be 
able to confuse the signals. Consider also the danger of a false signal 
being sent, if there was no guarantee as to the source from which 
it emanated! The use of cypher will get rid of this disadvantage. 
Captain Jackson, of the Royal Navy, considers that one useful em¬ 
ployment of the system would be for a friendly torpedo boat entering 
a harbour to announce itself by a preconcerted signal and so prevent 
its being fired on as an enemy. Those who know the difficulties (in 
connection with our experiments for coast defence), in distinguishing 
friend from foe, will see that this is rather an important application 
(applause). I might add that Captain Jackson has been most actively 
experimenting with the system in the neighbourhood of Devonport. 
One most promising field for the employment of the system is in 
connection with coast defence. Very frequently it happens that com¬ 
munication must be established between the fortifications on both 
sides of a harbour or estuary. This is usually effected by a submarine 
cable, but those who have been charged with the duty of maintaining 
these cables know their liability to be picked up and broken by barges, 
ships, etc. anchoring or dragging anchors over them. Wireless tele¬ 
graphy as an alternative would, in such a case, probably maintain 
communication at a critical time. To give another instance it might 
be possible for a beleagured garrison, especially on the coast, to es¬ 
tablish communication outside. I fancy that many military men, en¬ 
gineers especially, have been getting a little frightened by the state* 
