xxviii President's Address for the year 1877. 



through which a constant current from a galvanic battery 

 flows ; the induction brought about by the vibration of the 

 magnet so affects the battery current that the composite 

 characteristics of the sound are manifested on the receiving 

 apparatus, which, so far as one can judge from the descrip- 

 tions given, consists of an electro-magnet within an iron 

 box, the armature of which is a loose iron plate covering the 

 box, and which is set in vibration, approximately repro- 

 ducing the sound of the voice speaking against the mem- 

 brane at the sending station. 



I have, I am afraid_, already tried your patience too long, 

 but, before concluding, I wish to urge our younger members 

 to greater activity in the society ; there is plenty of work to 

 do, and broad fields of untouched ground for research. The 

 discoveries I have just spoken of ^ome principally from our 

 American cousins, who have done more than any other 

 nation for electric telegraphy, which even yet presents to 

 us an almost boundless field for research and useful dis- 

 covery ; and why should not some of it fall to Australians ? 

 Discovery and useful results of scientific work are not got 

 except by persistent and grooved application. The very 

 ground over which one must travel before he gets upon 

 " pastures new" with any hope of success has already be- 

 come long and weary; but those who steadily keep in one 

 path not only arrive on the new ground first, but have the 

 best chance of seeing any that has been left unturned on 

 the way. 



