34«8 "Royal Society: Report of the Council: 



to those made on the four days, and in the manner recommended in 

 Sir John Herschel's instructions. 



A grant of 500/. from the public funds has since been obtained 

 from the Lords Commissioners of Her Majesty's Treasury, in aid of 

 the purchase of the necessary instruments for carrying on the mag- 

 netic observations, according to the plan proposed by the Committee, 

 and under the directions of the Royal Society. 



A statement having been also laid before the Council by Mr. 

 Christie of the importance of a more accurate determination than 

 has hitherto been made of the variation of the magnetic needle at 

 several points on the coasts and in the interior of Great Britain and 

 Ireland, and likewise of the dip and of the intensity of terrestrial 

 magnetism, the Council, fully concurring in these views, presented 

 to the Lords of the Admiralty a strong recommendation that steps 

 should be taken for carrying into effect the course of observations 

 pointed out by Mr. Christie ; and their Lordships have in conse- 

 quence appointed a Committee to meet and examine into this im- 

 portant subject. 



The Council having deemed it desirable that the difference of level 

 between the brass mark fixed by Capt. Lloyd on the north-east 

 landing stairs of the New London Bridge, and Mr. Bevan's mark on 

 the basement of the pilasters of the north-east landing stairs of 

 Waterloo Bridge, should be accurately determined, requested Sir 

 John Rennie to undertake this determination. Sir John Rennie has 

 reported to the Council that, after repeated trials, the greatest varia- 

 tion of which did not exceed two-tenths of an inch, he found that 

 the mark on Waterloo Bridge is 3 feet and 1*65 inches above that 

 on New London Bridge*. 



The Council have awarded the Copley Medal of this year to M. 

 Becquerel for his various Memoirs on the subject of Electricity, 

 published in the " Memoires de I'Academie Royale des Sciences de 

 ITnstitut de France", and particularly for those on the production of 

 Crystals of Metallic Sulphurets and of Sulphur, by the long-con- 

 tinued action of electricity of very low tension, and published in 

 the tenth volume of those Memoirs f . 



Among those who have been engaged in investigating the phae- 

 nomena of electricity, M. Becquerel holds an eminent rank, and 

 the Memoirs of the Royal Academy of Sciences of Paris bear 

 ample testimony to the success which has attended his researches 

 in this department of science. He appears early to have been sen- 

 sible that, for the detection of phsenomena which may occur at the 

 instant of incipient molecular attraction, and which become masked 

 by the more general effect of the transfer of the elements when 

 powerful electric currents are employed, it was necessar}"^ to sub- 

 stitute for these currents of very low tension J. Following out the 

 view, carefully adjusting the strength of the current to the power of 



♦ See p. 205. 



f See Scientific Memoirs, vol. i. p. 414. 



j: Annates de Chimie, torn, xxxiv. p. 152. Memoire lu a, I'Academie 

 Royale des Sciences^ &c., 21 Aout, 1826. 



