Yol. 50.] GLACIAL GEOLOGY OF MOUNT KENYA. 519 



in von Hohnel's sketch from Ndoro ; its nature appeared to me rather 

 puzzling, as there were points in it which did not accord with the 

 theory of its being a crater-wall. Its moutonne surface, however, 

 showed that it had been greatly worn by glaciers, and it doubtless 

 represents the site of the old ice-fall that once occurred here when 

 an ice-cap covered the upper part of the mountain. 



In the whole of the alpine zone of Mount Kenya there is abundant 

 evidence of former gbaciation. The rocks on the face of the rock- 

 slope, the bosses that rise from the peat-swamp above it or are 

 exposed on the flanks of the valleys, are all moutonnees. Erratics 

 and perched blocks are numerous on the sides of the valleys and 

 even on the summits of the ridges that separate them. Three 

 final proofs were the discovery in the higher parts of the valleys 

 of glaciated lake-basins, of a series of terminal moraines, and finally 

 of well-preserved striae. It is, I think, desirable to describe ex- 

 amples of each of these in detail, so that the foregoing statements 

 may be the more readily checked by future visitors to the mountain. 



(1) Lake-Basins. — The example of these which best shows a 

 glacial origin is that which I have named Lake Hohnel (see fig. 3). 



Fig. 3. — Section through the cirque, on the W. side of Mount 

 Hohnel, and its lake-basin. 



[Natural scale: g inch = l mile.] 



Lake 

 Hohnel 

 13,980 feet, 



Glaciated i 



Rock-barrier 



with Erratics"- 



It is situated in a cirque on the western face of Mount Hohnel, and 

 has its longer diameter running north and south. Between the base 

 of the cliffs of the cirque and the lake is a swampy plain formed by 

 the tumbling of talus from the crags above. The lake is nevertheless 

 at its deepest near the eastern shore, and apparently shallows gradu- 

 ally to the west. On this side it is bounded by a bare rocky barrier, 

 the whole of which is moutonnee, while some enormous andesite 

 erratics are perched upon it, in positions which they could not 

 possibly have held unless transported by glaciers. For the sake 

 of avoiding unnecessarily controversial topics, it may be advisable 

 to leave untouched the subject of the possible glacial origin of cirques, 

 alrhough the alternative theory of waterfall action is clearly inap- 

 plicable here. I do not think that anyone could contest the glacial 



