Ragnarok : the age of fire and gravel

THE ORIGIN OF THE DRIFT NOT KNOWN. 9

“From the foregoing facts, it seems to me that we are justified in concluding :

“1, That however simple and plausible the Lyellian hypothesis may be, or however ingenious the extension or application of it suggested by Dana, it is not sustained by any proof, and the testimony of the rocks seems to be decidedly against it.

“9. Though much may yet be learned from a more extended and careful study of the glacial phenomena of all parts of both hemispheres, the facts already gathered seem to be incompatible with any theory yet advanced which makes the Ice period simply a series of telluric phenomena, and so far strengthens the arguments of those who look to extraneous and cosmical causes for the origin of these phenomena.” *

The reader will therefore understand that, in advancing into this argument, he is not invading a realm where Science has already set up her walls and bounds and landmarks; but rather he is entering a forum in which a great debate still goes on, amid the clamor of many tongues.

There are four theories by which it has been attempted to explain the Drift.

These are :

I. The action of great waves and floods of water. Il. The action of icebergs.

Til. The action of glaciers.

TV. The action of a continental ice-sheet.

We will consider these several theories in their order.

* “Popular Science Monthly,” July, 1876, p. 290.