ADDRESS. 1 



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these branches of science were looked upon as cognate, and that the theory 

 of two opposite electric fluids was generally accepted. 



In magnetism, the investigations of Hansteen, Gauss, and Weber in 

 Europe, and the observations made under the Imperial Academy of Russia 

 over the vast extent of that empire, had established the existence of mag- 

 netic poles, and had shown that magnetic disturbances were simultaneous 

 at all the stations of observation. 



At their third meeting the Association urged the Government to 

 establish magnetic and meteorological observatories in Great Britain and 

 her colonies and dependencies in different parts of the earth, furnished 

 with proper instruments, constructed on uniform principles, and with 

 provisions for continued observations at those places. 



In 1839 the British Association had a large share in inducing the 

 Government to initiate the valuable series of experiments for determining 

 the intensity, the declination, the dip, and the periodical variations of the 

 magnetic needle which were carried on for several years, at numerous 

 selected stations over the surface of the globe, under the directions of 

 Sabine and Lefroy. 



In England systematic and regular observations are still made at 

 Greenwich, Kew, and Stonyhurst. For some years past similar observa- 

 tions by both absolute and self-recording instruments have also been made 

 at Falmouth — close to the home of Robert Were Fox, whose name is in- 

 separably connected with the early history of terrestrial magnetism in 

 this country — but under such great financial difficulties that the continu- 

 ance of the work is seriously jeopardised. It is to be hoped that means 

 may be forthcoming to carry it on. Cornishmen, indeed, could found no 

 more fitting memorial of their distinguished countryman, John Couch 

 Adams, than by suitably endowing the magnetic observatory in which he 

 took so lively an interest. 



Far more extended observation will be needed before we can hope 

 to have an established theory as to the magnetism of the earth. We 

 are without magnetic observations over a large part of the Southern 

 Hemisphere. And Professor Riicker's recent investigations tell us that 

 the earth seems as it were alive with magnetic forces, be they due to elec- 

 tric currents or to variations in the state of magnetised matter ; that the 

 disturbances affect not only the diurnal movement of the magnet, but 

 that even the small part of the secular change which has been observed, 

 and which has taken centuries to accomplish, is interfered with by some 

 slower agency. And, what is more important, he tells us that nime of 

 these observations stand as yet upon a firm basis, because standard instru- 

 ments have not been in accord ; and much labour, beyond the power of 

 individual effort, has hitherto been required to ascertain whether the 

 relations between them are constant or variable. 



In electricity, in 1831, just at the time when the British Association 

 was founded, Faraday's splendid researches in electricity and magnetism 

 at the Royal Institution had begun with his discovery of magneto- 



