498 Sir Henry Howorth — Replies to Criticisms. 



If an ice-sheet crossing the North Sea is not possible as the porter 

 of these stones, how are we to account for them ? Icebergs seem to 

 me to be as difficult to explain on many grounds as an ice- sheet. 

 Inter alia, I presume the postulated ice must have collected the 

 Carboniferous stones from Durham, and the stones from the Cheviots, 

 where we have no evidence of continuous submergence. I therefore 

 suggested the possibility of these local deposits of northern stones 

 on the seaboard, all of which, so far as I have seen, are rounded and 

 water-iuorn, and not one of them has the flattened parallel sides of 

 undoubted glacier stones, being possibly ballast, which finds its way 

 into many strange places. 



This very year I heard, at Southwold, a most circumstantial 

 account of two cargoes of stones from wrecks which had been 

 scattered on the beach — one of them, a steamer from Guernsey with 

 Guernsey rocks, wrecked near Aldborough, and the other a cargo of 

 paving-stones from Scotland. Mr. Hulke writes to say that he 

 remembers a cargo of Elephants' tusks being similarly shipwrecked 

 in the Channel. I further pointed out that the Norse pirates, whose 

 ships were being continually wrecked on the Yorkshire and East 

 Anglian coasts, curiously enough chiefly came from Laurvig and its 

 neighbourhood, and not only must have carried ballast, but also 

 used stones for anchors. This explanation does explain simply, 

 completely, and absolutely the local character of the finds, and the 

 occurrence of the stones on the strand. It is on the strand the 

 great bulk of them occur. Mr. Harker says, however, that some 

 also occur in situ in the cliffs. He does not say he has found any 

 himself. If he has, and the question is very important, its im- 

 portance has certainly been overlooked in his former papers, which 

 I quoted. The question is not a simple one to decide, and we 

 should all be grateful for precise and definite details, and not 

 obiter dicta. 



It is very difficult sometimes on these coasts (and I confess to 

 having been myself misled the other day at Cove Hithe) to dis- 

 tinguish between boulders actually in the clay originally and those 

 driven into the face of the cliff by the high tides. The safest test 

 is to examine pits in the Boulder-clay some distance from the sea. 

 Has this been done ? Any details as to the exact facts of the finds 

 other than on the strand would be very useful. 



The issue is too interesting and too important to be left in doubt, 

 and now that the question has been raised in this way it ought to be 

 properly sifted, and by no one better than by Mr. Harker and Mr. 

 Lamplugh. The stones in question deserve to be more systematically 

 collected, and their external appearance as well as their internal 

 structure described, and the provenance of each properly marked. 

 Such a collection ought to be found in Jermyn Street, the best of 

 Geological Museums, but, unfortunately, the Yorkshire boulders are 

 badly represented there. I could only find two small specimens of 

 the rhomb porphyr. I am bound to add that from my own superficial 

 examination, the Yorkshire stones seem to differ both in colour and 

 in the shape and size and mode of occurrence of the imbedded 



