226 GEOLOGICAL TIME 



and Abbot on the ' Physics and Hydraulics of the 

 Mississippi,' published in 1 86 1 , might well serve as 

 a model for imitation, though these observers neces- 

 sarily occupied themselves with some questions which 

 are not specially geological, and did not enter into 

 others on which, as geologists, we should now gladly 

 have further information. 



Again, the action of Glaciers has still less been sub- 

 jected to prolonged and systematic observation. The 

 few data already obtained are so vague that we may be 

 said to be still entirely ignorant of the rate at which 

 glaciers are wearing down their channels and contribut- 

 ing to the denudation of the land. The whole of this 

 inquiry is eminently suitable for combined research. 

 Each stream or glacier, or each well-marked section of 

 one, might become the special inquiry of a single 

 observer, who would soon develop a paternal interest 

 in his valley and vie with his colleagues of other valleys 

 in the fulness and accuracy of his records. 



Nor is our information respecting the operations of 

 the Sea much more precise. Even in an island like 

 Great Britain, where the waves and tides effect so much 

 change within the space of a human life-time, the 

 estimates of the rate of advance or retreat of the 

 shore-line are based for the most part on no accurate 

 determinations. It is satisfactory to be able to 

 announce that the Council of this Association has 

 formed a Committee for the purpose of obtaining full 

 and precise information regarding alterations of our 

 coasts, and that, with the sanction of the Lords of the 

 Admiralty, the co-operation of the Coast-guard through- 

 out the three kingdoms has been secured. We may 



