ORIGIN OF DRIFT. G3 



together at one operation. On the surface of the country where the 

 woods have been removed, this arrangement is sometimes equally- 

 evident ; thus hundreds of granite boulders may be seen to cumber 

 one limited spot, while in its neighbourhood they are compara- 

 tively rare. It is also well known to the farmers in the more rocky 

 districts, that many spots which appear to be covered with boulders 

 have, when these are removed, a layer of soil comparatively free from 

 stones beneath. These appearances may in some instances result 

 from the action of currents of water, which have in spots carried off 

 the sand or clay, leaving the boulders behind ; but in many cases this 

 is manifestly the original arrangement of the material. 



Boulders or travelled stones are often found in places where there 

 is no other drift. For example, on bare granite hills, about 500 feet 

 in height, near the St Mary's River, there are large angular blocks 

 of quartzite, derived from the ridges of that material which abound in 

 the district, but are separated from the hills on which the fragments 

 lie by deep valleys. 



In Canada and the Northern States, as well as in Scotland, marine 

 shells are sometimes found in the boulder formation as well as in the 

 clays overlying it ; and it is worthy of remark that these shells are of 

 such species as indicate a colder or more arctic climate than that 

 which at present prevails in those countries. In Nova Scotia I have 

 observed nothing of this kind ; and the only evidence of organic life, 

 during the boulder period, or immediately before it, that I have noticed 

 is a hai'dened peaty bed which appears under the boulder clay on the 

 north-west arm of the River of Inhabitants in Cape Breton. It rests 

 upon gray clay similar to that which underlies peat bogs, and is over- 

 laid by nearly twenty feet of boulder clay. Pressure has rendered it 

 nearly as hard as coal, though it is somewhat tougher and more earthy 

 than good coal. It has a glossy appearance when rubbed or scratched 

 with a knife, burns with considerable flame, and approaches in its 

 characters to the brown coals or more imperfect varieties of bituminous 

 coal. It contains many small roots and branches, apparently of 

 coniferous trees allied to the spruces. The vegetable matter composing 

 this bed must have flourished before the drift was spread over the 

 province, so that it belongs to some part (probably one of the later 

 parts) of the great tertiary group of rocks of which the drift is the 

 latest member. 



If we ask what has been the origin of this great mass of shifted and 

 drifted material, which overspreads the surface not only of the district 

 we are now describing, but the greater part of the land of the northern 

 hemisphere, we raise one of the most vexed questions of modern go- 



