Sir H. H. Hoicorth — Erratic Boulders in Drift. 153 



as those above noticed, there is evidence of some of these Tonga 

 Islands having been upheaved, for although the consolidated "coral 

 sand " may have been thrown up to its present level by the sea, 

 and have been indurated very recently in that position, yet it seems 

 highly probable that some of the rocks (Ia, Io, III, and possibly 

 IX and X) have been formed under water and afterwards elevated. 

 Mr. Harker, in concluding his paper, speaks of the possibility of 

 some of the rocks of the Tonga Islands proving eventually to 

 be of Tertiary age. None of the specimens we have examined 

 give any evidence of such an antiquity. 



IV. — On the Erratic Boulders and Foreign Stones in the 

 Drift Deposits of Eastern England, and their Lessons. 



By Sir Henry H. Howorth, E.G. I.E., M.P., F.R.S., F.G.S. 

 {Concluded from the March Xumber^ p. 130.) 



FOLLOWING in the wake of that admirable institution the Boulder 

 Committee of the British Association, whose M'ork ought to have 

 been done by the Geological Surveyors, we may divide the districts 

 from which the foreign boulders (that is, boulders extraneous to the 

 immediate district) have come to Eastern England into four, namely, 

 Charnwood Forest, the Hills of Derbyshire, Durham and Cleveland, 

 and lastly Norway. 



First, in regard to Charnwood Forest. Nearly all the boulders 

 which have travelled thence have travelled to the south-west, south, 

 south-east, or east, a small number only having been found to the 

 north of the parent rock. 



This district, wliere a considerable mass of crystalline rocks is 

 exposed, is particularly fitted to test the problem of local glaciers in 

 South-Eastern England. It is very curious that, with the exception 

 of a very small patch of smoothed rock found by Mr. Harrison, not 

 a trace of glacial action can be found here. Upon this Professor 

 Carvill Lewis is emphatic, and his conclusion is supported completely 

 by two such good observers as Professor Bonney and Mr. Hill. They 

 also support Mr. Lewis in attributing to other than glacial action 

 the local patch referred to by Mr. Harrison, which it must be 

 remembered is only about two yards long. Professor Carvill Lewis, 

 an extreme glacial champion, says of it that it is not an example 

 of true glacial stride, but is a very local smoothing due to moving 

 gravel or possibly an iceberg (" Glacial Geology of Great 

 Britain," p. 61). 



This conclusion is very important, for several reasons. If there 

 were no ice on the high ground of Charnwood Forest, which is over 

 800 feet high, how can we believe in its existence on the Lincoln- 

 shire and Norfolk Wolds, which are in the same latitude, and 

 very much lower? This is another argument to add to those 

 I used in a former paper with regard to the impossibility of 

 understanding the former existence of local glaciers on these 

 Downs. But a more important fact remains. If there are no 



