100 PROCEEDINGS COTTESWOLD CLUB 1908 
THURSDAY, December 12th, 1907 
W. R. CARLES, C.M.G., F.L.S., F.R.G.S., President, in the Chair. 
The following Lecture was given :— 
‘* WIRELESS TELEGRAPHY.” By /. 4. Hume-Rothery, M.A., 
Cantab., B.Sc., London. 
The lecturer was ez rapport with his subject, and by his clear ex- 
position and explanation of the occult science of electricity as applied 
to telegraphy, aided by a series of graphic experiments, he succeeded 
in conveying to his audience a thoroughly comprehensive and in- 
telligible understanding of the manner in which messages are trans- 
mitted by wireless telegraphy. 
On one end of a long table in front of the lecturer was placed a 
small apparatus for generating electricity, and to each end of the 
electric coil of the apparatus a small bright metal ball was connected 
by wires, the two balls facing each other and almost in contact. On 
sending a current through the connecting wires an electric spark was 
seen to pass between the two balls, and it was stated that the oscilla- 
tions caused by the passage of the current of electricity were 
communicated to the ‘‘ ether” in the surrounding atmosphere, by 
which the osciliations were dispersed or conveyed as a series of 
waves in various directions until they had spent themselves, just as 
when one disturbs a quiet pool or tank of water by moving his hand to 
and fro therein, or as when a horse drinks at a water-trough ; a series 
of waves or ripples are created, which spread with gradually dimin- 
ishing force until they reach the sides of the pond, or tank, or trough. 
If, then, repeated currents of electricity are created, greater disturb- 
ances are set up, and innumerable sets of waves follow each other 
into space. These waves resemble waves of light in that they can be 
reflected or refracted, and can be transmitted through great distances. 
At the other end of the lecture-room table a second small 
apparatus was placed, the prominent feature of which was a couple of 
copper plates attached by wires to the apparatus in a line parallel to 
the ‘‘oscillator.” It was then explained that the oscillations pro- 
duced by the generating apparatus, set up in the copper plates 
attached to the second or ‘‘ receiving ” apparatus a series of electric 
currents like those that produced the oscillations at first. This was 
illustrated by the ringing of a bell connected with the receiving ap- 
paratus by the current transmitted from the oscillator at the other 
end of the table. 
The lecturer next explained how, by producing a combination of 
Jong and short ringings of the bell, messages could be transmitted and 
read off in a manner similar to that adopted in ordinary telegraphy 
when the Morse code is used. One method of breaking and restoring 
the current, so as to produce the long and short strokes as in the 
Morse system, or the long and short ringings of the bell as in 
the experiment, was that of passing the current through a small tube 
