GLACIAL PHENOMENA IN MAINE. 
119 
I may say, without exaggeration, that gla¬ 
cial phenomena extend over the whole length 
and breadth of the State of Maine, wherever 
there is no obvious cause for their disappear¬ 
ance. One word of explanation, that this 
assertion of their omnipresence may not seem 
overdrawn to those who follow me over the 
same ground, expecting, perhaps, to find the 
glacial writing at every step along the road¬ 
side, and to see the polished surfaces as shin¬ 
ing and slippery as a metallic plate or a mar¬ 
ble slab. In the first place, all kinds of rock 
do not admit the same degree of polish. Coarse 
and friable sandstone cannot be polished under 
any circumstances. Only the finer granitic 
rocks retain the striae and the polished sur¬ 
faces very distinctly, in this region; and even 
upon these they are frequently hidden by the 
accumulation of soil, or occasionally obliter¬ 
ated by decay, where the rock is not hard 
enough to resist the atmospheric influences. 
The loose materials themselves, which have 
served as emery to grind down, polish, and 
groove the surface of the soil, may eventually 
become a screen to cover it from observation. 
The skill of the geologist consists in tracing 
