FILLING UP OF FJORDS. 65 



quite unnecessary to say more in refutation of whal has nothing 

 whatever to do with the subject in hand. It does not at all follow 

 that, because ancient glaciers hollowed out the present fjords, the 

 sub-glacial stream flowing into them from modem glaciers may not 

 shoal them up. But the modern glacier, like the ancient one, whether 

 ending in the head of a fjord (the bed of an ancient glacier) or at 

 the open sea— as at the great " lisblink," 15 miles north of Frederiks- 

 haab — is, I believe, unquestionably excavating out the valley in 

 which it lies, to become hereafter, in some future period of Greenland 

 history — either through a change of climate or of coast-level — a deep 

 valley or a deeper fjord. I know — as does any one at all acquainted 

 with Greenland — that this great glacier, though it is not the only 

 one, reaches the sea without entering a fjord, and finding the sea 

 too shallow to buoy its seaward end up, and so break it off in the 

 form of icebergs (as in the deep fjords), it pushes its way along the 

 bottom for some distance, until getting into deeper water it will 

 again, like the others, discharge its icebergs. This, again, is quite 

 foreign to the subject of the formation of fjords. There are modern 

 glaciers. I spoke of ancient ones. Still even the great " lisblink " 

 spoken of, though it happens — accidentally it may be said — not to 

 enter a fjord, is, nevertheless, by the part of it which lies on land, 

 grinding down the infia-jacent country and acting the part of the 

 ancient glaciers which formed the present fjords. In regard to this 

 filling up of the fjords by the modern glaciers at their head, this is 

 due to the mud brought down by the sub-glacial stream, and which 

 is again due to the abrasion of the rocks by the incumbent glacier 

 moving over them. In another memoir, ' On the Physics of Arctic 

 Ice as explanatory of the Glacial Remains of Scotland, 1 1 have entered 

 into a full discussion of this and other points connected with Arctic 

 glaciers, so that it would be needless to take up space here with any 

 resume of my observations. In that memoir I have estimated that, 

 at the very lowest calculation, this glacial mud is accumulating at 

 the head of these fjords at the rate of not less than 25 feet thick in a 

 century. Accordingly it has closed some old fjords with ice, the 

 glacier at their head being no longer able to discharge its bergs, 

 owing to the shallowness of the water, and in some cases, as pre- 

 viously pointed out by Dr. Rink 2 and Mr. Taylor, 3 the glaciers arc 

 seeking new outlets, on the principle of ice seeking the plane of least 



1 ' Quarterly Journal of the Geological Society,' vol. xxiv. (1871) pp. C71-701 ; 

 and in a more condensed'form, reprinted at pp. 27-58 of this ' Manual, and "Das 

 Innere von Gronland," in Petermann's ' Geographische Mittheilungen.' October 

 1871. 



2 ' Gronland Geographisk og statistisk boskrevot,' &c. 



3 ' Proceedings of the ltoyal Geographical Society,' vol. v. p. 93 (18G1). 



