Remember, then, in the discussions which follow, that if the theories advanced are gigantic, the facts they seek to explain are not less so. We are not dealing with little things. The phenomena are continental, world-wide, globe-embracing.
[1. Dana's "Text-Book," p. 221.
2. Gratacap, "Ice Age," "Popular Science Monthly," January, 1878.]
CHAPTER II.
THE ORIGIN OF THE DRIFT NOT KNOWN.
WHILE several different origins have been assigned for the phenomena known as "the Drift," and while one or two of these have been widely accepted and taught in our schools as established truths, yet it is not too much to say that no one of them meets all the requirements of the case, or is assented to by the profoundest thinkers of our day.
Says one authority:
"The origin of the unstratified drift is a question which has been much controverted."[1]
Louis Figuier says,[2] after considering one of the proposed theories:
"No such hypothesis is sufficient to explain either the cataclysms or the glacial phenomena; and we need not hesitate to confess our ignorance of this strange, this mysterious episode in the history of our globe. . . . Nevertheless, we repeat, no explanation presents itself which can be considered conclusive; and in science we should never be afraid to say, I do not know."