Proceedings of Learned Societies. 477 



escarpment which overlooks the valley of the Severn, could not 

 possibly be formed by oceanic currents, except under very peculiar 

 conditions, which we have no reason to believe to have existed in 

 those localities. On the contrary, the formation of such escarp- 

 ments during the gradual emergence of the land would be a neces- 

 sary consequence of that emergence under conditions which must 

 have obtained in numerous instances. Hence the author concludes 

 that the escarpment of the wolds was formed subsequently to the 

 transport of the blocks which are now found in that region. He 

 conceives that, with respect to the theory of transport by currents, 

 difficulties founded on existing inequalities of surface have been far 

 too strongly contended for on the one hand, and too easily admitted 

 on the other. 



The author is anxious that his views should not be misunder- 

 stood as respects the glacial theory, or that which would refer the 

 transport of blocks to floating ice. He is quite prepared to believe 

 in the possible extension of glaciers beyond the boundaries to 

 which they now extend, wherever such greater extension can be ac- 

 counted for consistently with the conclusions of collateral branches 

 of physical science ; and also to believe that such more extensive 

 glaciers, where they have existed, may have been the means of 

 transport of erratic blocks, provided sufficient mechanical cause 

 can be assigned for their movement. With respect to the iceberg 

 theory, though he rejects its application to the case investigated in 

 this communication as altogether unnecessary to account for the 

 observed phaenomena, he conceives that floating ice may probably 

 have been the most efficient agent in transporting the larger blocks 

 of colder regions from their original localities. 



LXXXIII. Proceedings of Learned Societies. 



ROYAL ASTRONOMICAL SOCIETY. 

 [Continued from p. 401.] 

 March 1 1 , f ■ THE following communications were read : — 



1842. JL 1. On an Instrument adapted for observing Right 

 Ascensions and Declinations of Stars independently of time, accom- 

 panied by Drawings made with the Camera Lucida by Captain Basil 

 Hall, R.N. By M. Wettinger. Communicated, with a Letter of De- 

 scription, to Sir J. F. W. Herschel, Bart., by Capt. Basil Hall, R.N. 



The instrument contrived by M. Wettinger is so fully described 

 in Captain Hall's letter, that an independent abstract of M. Wettin- 

 ger's paper is unnecessary. The- following is a copy of the letter, 

 dated Malta, Dec. 6, 1841 :— 



" My dear Sir John, — I have had my attention lately called to 

 an invention which appears to me so ingenious, and grounded upon 

 such good principles, that I think a description of it may interest 

 you, and perhaps be considered by you as worthy of being brought 

 to the notice of the Astronomical Society. Of this, however, you 



