[ 131 ] 

 XXV. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



Aiiniversary Meeting, Nov. SO, 1838 (cow&z^ec?).— The following 

 Report of the Council respecting the awards they have made of two 

 Copley Medals, two Royal Medals, and one Rumford Medal, was 

 read. 



The Council have awarded a Copley Medal to Professor Gauss, 

 for his researches and mathematical researches on Magnetism. 



Professor Gauss's labours on the subject of magnetism, published 

 at various periods, and continued with increasing activity up to the 

 present time, have given to our knowledge of that subject very va- 

 luable and striking additions. In his dissertation entitled, " Inten- 

 sitas vis magneticae terrestris ad mensuram absolutam revocata*," 

 (Gottingen, 1833,) he showed how, by a skilful combination of ex- 

 periment with mathematical calculation, several of the most difficult 

 problems belonging to the subject may be solved ; namely, the de- 

 termination of the magnetic axis of a needle; the exact determination 

 of the moment of inertia of an oscillating needle ; the deviation pro- 

 duced in the direction of the horizontal needle by the neighbour- 

 hood of a magnet ; and the determination of the absolute intensity 

 of the horizontal magnetic force of the earth. A combination of 

 magnetic observers in different places had been set on foot by M. 

 von Humboldt in 1828 ; a magnetic observatory was erected at Got- 

 tingen in 1833 ; and in consequence of these circumstances the cu- 

 rious discovery was made in 1834', that the minute momentary 

 changes in tiie position of the horizontal needle are simultaneous 

 and corresponding at distant places. This led M. Gauss to direct 

 the attention of men of science more particularly to this subject ; 

 and the operations of the " Magnetic Union" of observers were car- 

 ried on with great activity under his guidance. The " Results of 

 the observations of the Magnetic Union" for 1836 and for 1837, 

 published by MM. Gauss and W. Weber, contain an account of the 

 consequences of these exertions. They also contain descriptions of 

 instruments invented by M. Gauss for the purpose of these obser- 

 vations, namely, the magnetometer, and other magnetical apparatus 

 of his construction, which has already been sent to the observatories 

 of Bonn, Dublin, Freiberg, Greenwich, Kasan, Milan, Munich, Na- 

 ples, Upsala, Krakow, Leipzig, and Marpurg. Also the Bifilar 

 Magnetometer, which determines directly the variation of horizontal 

 intensity. Tlie "Results" further contain various mathematical 

 calculations of great importance, on the sulyect of the above instru- 

 ments, and of the observations made by them. And it appears by 

 observations made in March, 1838, at Gottingen and three other 

 places, with the Bifilar ajjparatus, that tliere is the same corrcspond- 



• An abstract of Prof. Gauss's dissertation was given in Lend, and Edinb. 

 Phil. Mag., vol. ii. p. 291 ; and a translation of the " Results" published 

 by him and Weber, also mentioned in the above report of the Council, is 



Sreparing for immediate publication in the Fifth Number of the Scientific 

 IcMoias. — Edit. 



K2 



