292 R. BELL — GLACIAL PHENOMENA IN CANADA. 



of the hills have been alike rounded and smoothed — no place seems to have 

 iped. The proofs are innumerable thai the denuding agency could have 



bee thing bul land ice acting as a semi-fluid. There is no evidence that 



ice-bergs or other forms of floating ice had anything to do with the erosion. 

 The general contours of the surface slope in various directions and the 

 differences in level are very considerable, so that if this had once been the 

 bottom of the sea there would be corresponding differences in depth. 



h should be remembered by those whose imagination pictures ice-bergs 

 performing the work of glaciers that, as a matter of fact, when a berg takes 

 the bottom it Btop'fi i atirely and often remains for years stranded at the same 

 spot. The ice-grooves and furrows on the surface of the rocks constantly 

 show that the yielding force, while producing them, must have been slowly 

 forced round projecting knobs, through crooked channels of varying width, 

 up hill and down dale, the upward slope being often very steep indeed ; that 

 perpendicular walls and even the under sides of overhanging rocks are 

 frequently grooved horizontally; and, altogether, that this force must have 

 acted in a manner quite impossible for ice-bergs. To those who have seem 

 much of the glacial phenomena in Canada, it seems incomprehensible that 

 any man calling himself a geologist could believe these phenomena to have 

 been produced by ice-bergs, provided he had had opportunities of observing 

 at all. Such totally unsupported views could only be held on the'' authority " 

 of some of the older geologists who paid more attention to theory than 

 observation, and who happened to jump to the conclusion that the ice- 

 gTOOVes and furrows had been produced by the rubbing of bergs on the 

 bottom of the ocean, and that the transported bowlders had been dropped 

 from such bergs a- they passed along. This latter notion may be equally 

 fallacious with the first, for the ice-bergs of modern time-, at any rate, trans- 

 port very lilt le earthy or rocky material. Field or floe ice is a more im- 

 portanl transporting agent, but it is the finer materials, such as mud, sand, 

 and gravel, which are carried by this means. 



It i- probable that nol only were vast quantities of loose material;-, derived 

 from the decayed Burface, pushed forward under and in front of the ice-sheete 

 of the drift period, but that a large amount of similar d€bris was incorporated 

 in the substance of the ice itself. The latter would have a much more 

 powerful effect in abrading the rocky surface than materials which were \'v>'<- 

 to move and seek shelter wherever the pressure was least. Two points which 

 have sometimes been overlooked require consideration in this connection : 

 First, i he eif, ci of the i em perat u re of the ice itself, because, of course, ice is 

 capable of any temperature from that of the melting point down to the lowest 

 possible di ond, the hydrostatic pressure of the great superin- 



curnbenl mass upon the lower layer-, for ice on the lame scale would obey 

 the same laws as a fluid. Those who have noticed the slight effect of modern 



