362 Proceedings of the British Association. 



With the diluvial gravel over the country we find associated organic 

 remains^, — a strong proof that the land must have been dry when 

 the transportation took place. — Mr. Murchison had observed these 

 boulders associated with recent shells at various elevations, — conse- 

 quently, the land must have been at one time under the sea, and" 

 have been subsequently elevated. There must have been a rela- 

 tive change of the level of land and sea ; and Prof. Esraark, in Nor- 

 way, had been the originator of the idea of the icebergs transporting 

 gravel. He referred to the valley of the Inn, in the Tyrolese Alps, 

 as illustrating this alteration of level : boulders of granite had been 

 found on calcareous mountains composing one of its sides, elevated 

 five or six thousand feet above the sea level ; and this valley could 

 not have been scooped out. — Dr. Buckland was of opinion that the 

 land must have been dry before the action of the water that had 

 transported these blocks. There was a great number of organic re- 

 mains mixed with the gravel derived from animals existing on dry 

 land ; and this was not only true in England, but confirmed by ob- 

 servations made on the continent of Europe. 



In the Statistical Section Dr. Lardner dehvered a lecture on steam 

 communication with India. 



In the Section of Mechanical Science, Mr. Whewell gave a short 

 account of the present state of the science of the tides. Though 

 there can be no doubt, that the tides are to be reckoned among the 

 results of the great law of universal gravitation, they differ from all 

 the other results of that law in this respect, that the facts have not, 

 in their details, been reduced to an accordance with the theory; and 

 the peculiar interest of the subject at the present moment arises from 

 this, that the researches now going on appear to be tending to an ac- 

 cordance of theory and observation ; although much in the way of 

 calculation and observation remains to be still effected before this ac- 

 cordance reaches its ultimate state of completeness. With regard 

 to observation, the port of Bristol offers peculiar advantages ; for, in 

 consequence of the great magnitude of the tides there, almost all the 

 peculiarities of the phenomena are magnified, and may be studied as 

 if under a microscope. With regard to the theory, one point mainly 

 was dwelt upon. By the theory, the tides follow the moon's 50M^A- 

 ings at a certain interval of time, (the lunitidal interval,) and this 

 mean interval will undergo changes, so as to leave less than the 

 mean when the moon passes three hours after the sun, equal to the 

 mean when the moon passes six hours after the sun, and greater 



