Glaciers and Glacial Radiants — Clai/polc. 91 
signs of extensive glaciation and change of level which we 
found on the coasts that we previously examined. But our 
knowledge of the glacial geologj of these regions is so imperfect 
that they may be dismissed without further discussion. 
There only now remains in the northern hemisphere for con- 
sideration the vast, dreary, desolate plain of Siberia without a 
mountain to break the monotonous level from the Ural mount- 
ains to the Lena, from the Altai to the Arctic ocean, — a region 
of permanently frozen soil, of scanty vegetation, of vast north- 
ward flowing rivers and of annual floods on a vast scale, — the 
widest plain and the coldest country on the face of the earth — 
the convict-prison of Russia. Cold as is the present climate of 
Siberia it nevertheless yields to the geologist none of those 
traces of severe and long-continued glaciation which are af- 
forded by many other countries of happier climate and more 
fertile soil. This has been a standing puzzle to glacialists ever 
since the fact first came to light. No erratic blocks, no true 
drift, no striated rock-surfaces occur there to testify to the for- 
mer presence and action of glaciers. Had a polar ice-cap ever 
existed it surely ought to have strewn evidence of its presence 
in a land where if glaciers were born mainly of cold the condi- 
tions for their birth were so eminently favorable. Hut if the 
chief conditions for the development of glaciers are, as here 
maintained, high ground and abundant prec pitation, we find 
the result in Siberia in perfect accord with what might be ex- 
pected. Small glaciers very likely fringed the slopes of the 
northern Urals and moved eastward; others probably flowed 
northward from the Altai range and the high table-land of 
central Asia; a third group probably radiated from the Stanovoy 
and Tukulan mountains that skirt the Aldan river but these 
were apparently insignificant in size when compared with the 
vast plain into which they debouched. The fact remains that 
except along the borders of these ranges we find no evidence of 
ice-action over the great plain of Siberia. Obviously the reason 
is that there was no gathering-ground for the formation of 
glaciers in so level a district while the open ocean to the north- 
ward equally prevented their development in that direction. 
The glaciers were therefore cut off at their very source and their 
formation rendered impossible. On no other view are we able 
to explain the anomaly that the coldest area on the surface of 
