132 MR. E. HULL ON THE VESTIGES OF EXTINCT 



to examine iu detail the flanks and main valleys of the 

 mountain-groups^ and the rock-surfaces of the districts by 

 which those mountain-groups are surrounded. 



It will be necessary to record on accurate maps of suffi- 

 cient scale the directions of the striae, and the levels to 

 which they rise on the flanks of the valleys, the sites of the 

 moraines both lateral and terminal, and the upper limits 

 of the Northern Drift. 



When this has been accomplished for any of our moun- 

 tain-groups, it will then be possible to construct a map, 

 reproducing with approximate accuracy the glacial system 

 of the district, and the relative position of land and sea 

 during the period. I can answer for it, that to one en- 

 dowed with a love of nature, together with those essential 

 accessories, time and money, the inquiry would afford 

 ample enjoyment, and the scientific value of the results 

 would not be unimportant. It was in a detailed survey 

 of this kind that I was engaged during the summer ; and 

 as it is far from being complete, I hope to be able to 

 devote another season to the northern flanks of the great 

 central range which separates Westmoreland from Cum- 

 berland. 



As far back as the year 1821 M. Venetz first announced 

 his opinioa, founded on ample testimony, that the glaciers 

 of the Alps formerly extended far beyond their present 

 limits.* These views were subsequently confirmed by 

 MM. Charpentier and Agassiz, and are now universally 

 received. But it was not until the year 1842 that Dr. 

 Bucklandf published his reasons for believing that the 

 mountains of Caernarvonshire gave birth to glaciers which 

 descended along seven main valleys; and that to these 

 agents are to be attributed the polished, fluted and striated 

 rock-surfaces which may be traced at intervals along the 



* SibliotMgue universelle cle Geneve, torn. xxi. 



t Proceedinris of the Geological Society of London toI. iii. 



