Lancaster Daily Intelligencer

The Ocean's "Undertow."
From Surf and Surf-Bathing in Scribner.
Doubtless we have all heard a great deal about this "undertow," as though it were some mysterious force working from the recesses of a treacherous ocean to draw unwary bathers to their doom. As a matter of fact, its presence is obviously natural and the explanation of it more than simple. As each wave rolls in and breaks upon the beach, the volume of water which it carries does not remain there and sink into the sand: it flows back again, and as the succeeding wave breaks over it the receding one forms an undercurrent flowing outward, of strength proportionate to the body of water contained in each breaker, and, again, proportionate in a great measure to the depth of the ditch. Where this latter is an appreciable depression, it can be readily seen that the water of receding waves will flow into it with similar effect to that of water going over a fall, and that a person standing near is very likely to be drawn over with it, and thus, if the ditch is deep enough, carried out of his depth. This is all there is to the much-talked-of "undertow" and the numerous accidents laid to its account.