Geological Society. 21 7 



needle would correspond to great elevations in the atmosphere, and 

 points near the earth's surface, respectively, the character of tiie 

 deviations turns out to be the same in both cases, so that in this 

 respect the hypothesis, so far as is known, agrees with observation. 



One general effect of some experiments with a hollow copper 

 shell filled with bismuth, afforded a striking correspondence with 

 nature. The whole equator being heated, and one part more than 

 the rest, he uniformly found that the elevated pole being towards 

 the north, the north end of the needle deviated when the place of 

 heat was on the meridian above the horizon, and south when below, 

 which is precisely the character of the diurnal variation in north 

 latitudes. 



A paper "On the variation of the needle," by Capt.Sabine,F.R.S., 

 and another " On a new vegetable principle," by Mr. Frost, F.L.S., 

 having been read, the Society adjourned over the long vacation, to 

 meet again on the second Thursday in November next. 



GEOLOGICAL SOCIETY. 



May 18.— G. J. Roupell, Esq. M.D. of Caroline Street, Bedford 

 Square ; and Isaac Lyon Goldsmid, Esq., of Dulwich Hill House, 

 Camberwell, — were elected Fellows of the Society. 



A notice was read " On a Whin dyke in Cooper Colliery, near 

 BIythe, Northumberland," drawn up from the information of Mr. 

 Bryham, agent at the Cooper Coal Works, by W. C. Trevelyan, 

 Esq. F.G.S.&c. 



The total length to which this dyke has been traced is 1577 yards. 

 It increases in breadth from 8. to N. ; being 4 J yards wide near the 

 most southern point, where it has been cut through, and 21^ yards 

 wide at the most northern spot hitherto observed. It is formed of 

 two walls of greenstone, each from two to four feet in thickness ; 

 and these walls contain between them a breccia, composed of frag- 

 ments of shale and whin, cemented by calcareous and argillaceous 

 matter. Carburetted hydrogen and pure water issue from a narrow 

 fissure in the broadest part of the dyke. The coal of the beds through 

 which the dyke passes is charred, and deteriorated in quality, to the 

 distance of about forty yards on each side. 



The reading of a paper was begun, " On the fixed rocks of the 

 Valley of the St. Lawrence, in North America," by John J. Bigsby, 

 Esq. M.D. F.G.S. &c. 



June 1. — Henry Campbell White, Esq. of Comer-Hall, Hemel 

 Hempstead ; and Samuel Sharpe, Esq. of New Ormond Street, Lon- 

 don, — were elected Fellows of the Society. 



The reading of Dr. Bigsby's paper, begun at the last meeting, 

 was concluded. 



The observations of the author in person were made principally 

 in the Canadas, and on the northern shores of the great Lakes ; and 

 he connects with them a sketch from various authorities, of the re- 

 gions which border the Valley of the St. Lawrence upon the S.W. 

 and the lakes on the south and west of Upper Canada. 



The north-western side of the St. Lawrence Valley consists 

 NtTO6V;7Vi-. Vol. 2. No. y. 6V7J/. 1827. 2F princi- 



