Note 4 — ADDENDA.

It must be remembered, that I am here considering the effect of icebergs, in inland and protected sounds. Dr. Richardson tells me, that the great icebergs in the Arctic sea are packed together, and are driven with such force against the shore, that they push up before them, to the height of several feet, every pebble and boulder which lies on the bottom; and consequently the submarine ledges of rock are kept absolutely bare. If a fragment were to be wedged beneath one of these mountain-masses of ice, when forced upward with such overwhelming power, it is impossible to doubt that the underlying surface of solid rock would be deeply scored. As it is known that the shingle on most beaches has a tendency to travel in one direction, so must the icebergs; and hence we may conjecture, that the grooves, would generally be slightly oblique to the line of coast, and parallel to each other.