Note A — PART II. CHIEFLY SCIENTIFIC. (continued 3)

"Imagine," writes Professor Forbes, "a long narrow trough or canal, stopped at both ends and filled to a considerable depth with treacle, honey, tar, or any such viscid fluid. Imagine one end of the trough to give way, the bottom still remaining horizontal: if the friction of the fluid against the bottom be greater than the friction against its own particles, the upper strata will roll over the lower ones, and protrude in a convex slope, which will be propagated backwards towards the other or closed end of the trough. Had the matter been quite fluid the whole would have run out, and spread itself on a level: as it is, it assumes precisely the conditions which we suppose to exist in a glacier." This is perfectly definite, and my equally definite opinion is that no glacier ever exhibited the mechanical effects implied by this experiment.