Geological Society. 525 



the cavity had been ground. On the surface of the rock were north 

 and south lines similar to those on the mountains, and they inter- 

 sected the east and west furrows mentioned above ; Professor Nord- 

 enskiold therefore infers that the lines were made subsequent to the 

 formation of the Giants' Pot. 



With respect to the level of the water in the Finnish Gulf, the 

 following changes are shown to have taken place. On the little 

 island of Fussaro, some miles from Hangovdd, and in the open sea, 

 a mark which was made in the year 1754 is now twenty Swedish 

 (19|- English) inches above the medium height of the water; an- 

 other which was cut in 1800 is about nine inches; and a third 

 excavated in 1821 is about five Swedish inches. At St. Petersburg 

 and Cronstadt it is believed that no change has taken place since 

 1645. 



A letter, addressed to Dr. Buckland by Mr. Thomas Bailey, " On 

 the Gravel Deposits in the Neighbourhood of Basford," was next 

 read. 



The parish of Basford is situated in a valley ranging nearly north 

 and south where it enters the great Trent vale. On the eastern 

 boundary, which is- a very elevated district, commences an extensive 

 argillaceous bed containing comparatively few pebbles ; on the west 

 are the coal-fields of Radford and Bilborough ; on the north-west 

 occurs the magnesian limestone which extends beyond Mansfield ; 

 and on the north is the elevated tract or ancient forest of Hurwood, 

 occupied by great accumulations of gravel and sand, agreeing in cha- 

 racter with those in the neighbourhood of Basford. In the midst of 

 the valley in which Basford is situated are lower ridges of hills, 

 mostly ranging in the direction of the valley, and containing beds of 

 gravel quite as thick (two to eight feet), and interspersed with boul- 

 ders as large as those found in the hollows or lower parts. Mr. 

 Bailey is of opinion that none of these deposits were accumulated by 

 fluviatile action, or by any uniform agent operating during long pe- 

 riods, but by a tumultuous commotion, when the surface of the earth 

 was in a different state to that which now prevails with respect to 

 hill and dale — the deposits being very unequal in thickness, con- 

 torted in position, and composed of materials very irregularly asso- 

 ciated as regards nature and size. The transport of the drift in one 

 direction, the author says, appears to have been sometimes checked 

 by a rush from an opposite point, by which means the materials were 

 forced into ridges having an axis of loose sand. Some of these 

 ridges, he conceives, may have been produced by intermediate hol- 

 lows having been scooped out, and subsequently filled with gravel. 



Mr. Bailey does not offer any positive opinion respecting the di- 

 rection by which the detritus arrived at its present situation, but he 

 thinks it could not have been transported from the S. or S.E., as it 

 contains no pebbles of Charnwood and Mount Sorrel sienite, or of 

 lias or lias-fossils, or of gypsum ; nor from any point between S.W. 

 and N.W., on account of the absence of mountain-limestone pebbles, 

 and as the fragments of chert which it contains differ from the chert 

 of the Derbyshire strata. Had the drift come from the west, he 



