In point of fact the narrator represents the Deluge as prevailing for a whole year, which would be impossible in the case of a river inundation. He attributes it in part, at least, to the 'great deep'--that is, the ocean; and he represents the ark as drifting inland or toward the north. Such conditions can be satisfied only by the supposition of a subsidence of the land similar in kind, at least, to the great post-glacial flood of geology. Partial subsidences of this kind, local but very extreme, have occurred even in later times, as, for instance, in the Runn of Cutch, the delta of the Mississippi, and the delta of the Nile; and if the objectors are determined to make the Deluge of Noah very local and more recent than the post-glacial flood, it would be more rational to refer to subsidences like those just mentioned, and of which they will find examples in Lyell's _Principles_ and other geological books. It is, however, decidedly more probable that Noah's Flood is identical with that which destroyed the men of the mammoth age, the palæocosmic or 'palæolithic' men;[57] and in that case the recession of the waters would probably be gradual, but intermittent, 'going and returning,' as our ancient narrator has it; but there need not have been any violent _débâcle_.
[57] _Modern Science in Bible Lands_, chaps. iii. and iv.
It is also to be noted that a submergence of the land and consequent deluge may be cataclysmic or tranquil, according to local circumstances, and that it may have been locally sudden, while for the whole world it was gradual and of longer duration. Such differences must belong to all great submergences, which may in one place produce great disturbance and very coarse deposits, in another may be quiet and deposit the finest silt. Even the flood of a river or the action of a tide admits of variations of this kind. In narrow channels the great tides of the Bay of Fundy rush as torrents; in wide bays they creep in imperceptibly.
The traditions and Biblical history of the Deluge not only furnish important material for connecting the geological ages with the period of human history, and for enabling us to realise the fact that early man was a witness of some of the later physical and vital vicissitudes that have passed over the earth, but may be correlated with other ancient traditions which seem at first sight to have no immediate relation to it.