324 The Drift or Boulder Formation, 



constitute the hills. He would also soon observe that the flat 

 floors of limestone or sandstone which terminate at the base of 

 the mountain are encumbered by fragments of rock identical in 

 composition with that of the precipice, and the proof that they 

 had been broken off" and rolled down to their present position 

 would be sufficiently convincing to satisfy any reasonable mind. 

 But let him turn towards the south, and travel away from the 

 hills across Canada, and proceed several hundred miles into the 

 United States, and he will be able to trace fragments of the same 

 rock, in the shape of more or less rounded boulders, the whole 

 distance. It will be observed also that towards the south they are 

 smaller and much more worn than they are near the point of their 

 departure, a necessary consequence of the greater length of their 

 journey. The States of New York, Ohio, Pennsylvania, Michi- 

 gan, Illinois, and in fact all the country north of the Appalachian 

 Mountains are covered over with boulders that have travelled 

 from the Lawrencian regions, across Upper Canada and the great 

 lakes. That these rocks have been transported from the north 

 towards the south is almost self evident, from the facts that they 

 rest upon fossiliferous strata, and also, that no rock of the same 

 kind exists in any place in the Western States, but only in the 

 northern regions. 



The same formation occurs not only in this country but in the 

 north of Europe and Asia, and also in the southern hemisphere. 

 In fact, the drift surrounds both the north and the south poles of 

 our planet, while in the tropical regions there is a broad belt 

 completely encircling the earth, where no drift is found. Sir 

 Charles Lyell states, of the European drift, that, " In tracing this 

 remarkable deposit through the borders of the Baltic, we some- 

 times find frao-ments of rock which must have travelled hundreds 

 of miles from their point of departure; and as a general thing, we 

 find that they grow larger in size as we approach the region from 

 which they were derived. This I found to be the fact in going 

 north from the margin of the Rhine to Holstein and Den- 

 mark, where I found fragments of Scandinavian Rocks, from 

 Sweden, nine and sometimes forty feet in diameter ; and at last, 

 the whole country was made up of these rocks."* The rocks to 

 which he alludes have all been transported bodily across the 

 Baltic Sea. 



* Ly ell's Lectures on Geology, page 49. 



