234 SIR HENRY H. HOWORTH^ D.C.L.^ F.R.S., ON ICE OR WATER. 



above the sea level, it climbs the Hainmoor pass (about 1,400-1,500 

 feet), descending thence along the Tees valley to Darlington (about 

 150-160 feet). From Darlington the Shap boulders are carried in 

 two directions, first to the mouth of the Tees, and to the south- 

 west along the Yorkshire coast, from Saltburn to Flamborough 

 Head and Spurn Point; and secondly, along the Vale of York, 

 through which they have been traced as far south as Barnsley and 

 Doncaster. 



Let me give another case from East Anglia, equally interesting. 

 There are found in Lincolnshire on the west slope of the Wolds, as 

 at Market-Rasen, and elsewhere, some peculiar erratics of Neo- 

 comian age, which are as easily identified as Shap granite. Boulders 

 of the same kind are exceedingly common in West Norfolk, not 

 only on the low ground bordering the Wash, but also on the higher 

 land of the chalk escarpment. From this region I have traced 

 them in a south-east direction, forming a broad but well-defined 

 trail, which crosses the valley of the Little Ouse (50 feet), and then 

 climbs the boulder-clay plateau of central Suffolk (over 200 feet), 

 finally reaching lower ground to the north of Ipswich. It is 

 difficult to understand how the distribution of these two groups 

 of erratics, in regions open on all sides to the sea, to which flood 

 water would naturally flow along the easiest route, could be ex- 

 plained in any reasonable manner by Sir Henry's hypothesis. If, 

 however, all the similar cases which might be given had to be 

 considered together, the difficulty would ]:>e, I think, insuperable. 



Yours very truly, 



F. W. Harmer. 



