Note 178 — LETTERS ON SCIENCE.

Not in the “last letter,” but in the last but one—see ante, p. 177, “A stone at the bottom of a stream,” etc. The parts of “G. M.’s” letter specially alluded to by Mr. Ruskin are as follows:

“It is very evident that the nearer the source of the glacier, the steeper will be the angle at which it advances from above, and the greater its power of excavation.... Mr. Ruskin gets rid of the rocks and débris on the under side of the glacier by supposing that they are pressed beyond the range of action in the solid body of the ice; but there must be a limit to this, however soft the matrix.”