THE HAMILTON ASSOCIATION. 9 
electric waves, however, are longer, and of these only some 
hundreds of millions occur in a second. 
After referring to the methods by which ordinary tele- 
graphy is accomplished, the lecturer described the essential ap- 
paratus for wireless telegraphy, viz., the coherer, consisting of 
a glass tube into which two metallic plugs are fitted. A small 
space between the plugs is partially filled with clean metallic 
filings. One plug is electrically connected to the end of the 
wire, and the other to the earth or some large metallic body. 
The method by which the sparks are produced, which send out 
the electric waves traveling through the ether until they reach 
the receiver were illustrated. The rate already at- 
tained for messages has been fifteen to twenty words 
a minute, but Marconi claimed that he would soon be 
able to increase this to 40 words. Although Marconi did not 
deserve the credit for discovering these waves, or inventing the 
co-herer for detecting them, he was entitled to credit for per- 
fecting the instruments used in the system. One objection to 
the system is the lack of secrecy, but this is to be overcome by 
a system of tuning of the instruments so that they will respond 
only to waves of a certain length. Each transmitter can be 
made to radiate waves of anv reauired length. ‘The lecture was 
fully illustrated, not only by apparatus, but by lantern views. 
FEBRUARY 12th, 1903. 
The regular meeting held, with President J. M. Dickson in 
the chair. 
Several new members were elected. 
Reference was made to the late Thos. MclIlwraith, and a 
resolution expressing the feeling of the loss sustained, and ap- 
preciation of the work done by him in years past, was ordered 
to be entered on the minutes and conveyed to his family. 
A paper was read by Mr. EF. C. Murton on “ Reminiscences 
of Nome and Romance of Placer Mining,” which proved mosi 
interesting. 
