lieviews. — British Association Reports. 177 



terminal moraines are formed chiefly from matter transported on tho 

 surface of the ghxcier. 



5th. If tho foregoing methods are correct, they might afterwards 

 be ap})licd to all the ghiciors of the Alps, and the rate of waste and 

 transport by glacier action might ho approximately determined ; and 

 in like manner they might also be used for well-known and com- 

 paratively accessible mountain-ranges like the Scandinavian chain, 

 the Himalayas, the mountains of New Zealand, and in time to the 

 Rocky Mountains, the Andes, and others. 



6th. But the above only forms part of the subject, and to attempt 

 to estimate the existing importance of " ice as an agent of geological 

 change," the glacier and glacial phenomena generally, as regards 

 erosion and terrestrial and marine transport of material, must be 

 taken into account in such regions as Si^itzbwgen, Greenland, and 

 Victoria Laud in the southern hemisphere. Something on a small 

 scale may be done in Spitzbergen and the southern part of Green- 

 land ; but at present we see no likelihood of definite observations 

 being made on the western side of Greenland further north, and in 

 the extreme north of that continent, or on its eastern shores, either 

 in respect to the erosion produced by its great glaciers, the eifect of 

 floe and shore ice, or the transporting work done by the icebergs 

 that float southwards from its shores. 



Something is known of the general result, but it seems very im- 

 probable, with regard to the number and size of icebergs, and the 

 quantity of matter they bear southwards, that anything definite is 

 likely to be ascertained at present. The same remarks bear yet more 

 strongly on the glacial phenomena of Victoria Land. 



7th. But when so much remains to be done on the Alps, and on 

 other accessible mountain areas, such difficult points can afford to 

 wait for the present, and we are of opinion that, perhaps, it is possible, 

 after the subject has been investigated with regard to the existing 

 glaciers of the Alps, to apply approximately the same method to the 

 older extension of the Alpine glaciers during the last glacial period, 

 and to invent a process by which we may be able, in some degree, 

 to estimate the amount of erosive waste, and of transport of moraine 

 matter on the surface of the great glaciers of that epoch. Accurate 

 surveys of old moraines of that epoch would be essential to this end, 

 such, for example, as that of the great moraine of Ivrea. The ex- 

 tent of the glacier has been shown by Gastaldi, and the area occupied 

 by, and cubic contents of, the moraine must be estimated ; and if it 

 be possible to feel our way towards data, attempts must be made to 

 estimate the amount of waste of the moraine going on at the time it 

 was deposited by the streams flowing from the end of the glacier. 

 Numerous other considerations arise from this extended view of the 

 question, one of which is, that, perhaps, it may be applied to other 

 glaciated regions where glaciers no longer exist, such as the Vosges, 

 the Black Forest, Wales, the North of England, Scotland, &c., thus : 

 — Given an area such as the Alps and the Lowlands of Switzerland 

 covered with glacier-ice ; if an approximate estimate can be formed 

 of the amount of waste suffered by that land, due to glacier-action, 



VOL. VII. NO. LXX. 12 



