502 . Mr. T. Tate on the Elasticity of 



While correcting the erroneous statements of Sonnini and 

 others, the labours of Admiral Smyth have verified the existence 

 of a bar extending from Sicily to the opposite coast of Africa ; 

 and in the Adriatic it is well known that the depth of the bottom 

 between Otranto and the opposite coast, though considerable, is 

 much less than either north or south of the " narrows. " This 

 is not the occasion for discussing the probability of recent changes 

 in a region which has long been the seat of intense volcanic ac- 

 tion; it is enough to say that, if the rein be given to speculation, 

 it may take other directions than that in which it has been set 

 free by M. de Mortillet. 



The broad facts are simply these, that an enormous quantity 

 of mineral materials has somehow been transported from the 

 central portions of the Alps to the valley of the Po ; that the 

 older part consists of a waterworn deposit spread out over the 

 plain, while the newer portion assumes the shape of mounds of 

 unrolled or slightly worn materials disposed about the opening 

 of the main valleys. All are agreed that these mounds are mo- 

 raines, partially or exclusively deposited in their present site by 

 glaciers which descended the valleys and filled up the basins of 

 the lakes, where such were present in the path of the extinct gla- 

 ciers. The same vehicle was equally competent to convey the 

 materials of the diluvium ; but we have no direct evidence to 

 show how this was reduced to its present rolled and waterworn 

 condition, nor how it was spread out over the low country. It 

 is only by full discussion of the problems remaining to be solved 

 that we are likely to arrive at reliable solutions, and it is to this 

 end that I have offered the foregoing remarks. 



LXXI. On the Elasticity of the Vapour of Sulphuric Acid. 

 By Thomas Tate, Esq.* 

 [With a Plate.] 



THE method hitherto employed for finding the elasticity of 

 the vapours of different liquids fails when the liquid (such 

 as sulphuric acid) acts chemically on mercury. In the apparatus 

 Which I have used (Plate VII. fig. 8), the liquid does not come 

 into contact with the mercury employed in the experiments. 

 A B C D is a bent glass tube containing the acid, connected 

 with a brass tube D, from which proceeds the barometer-tube 

 D E, dipping into a cup of mercury E ; V a union joint ; K a 

 cock connecting the tube with an exhausting air-pump P ; A an 

 oil-bath, secured to the tube A B by means of a perforated cork ; 



* Communicated by the Author, having been read to the British Asso- 

 ciation at Newcastle-upon-Tyne in August 1 863. 



