. . .p, first gently washing, finally covering it entirely, and then, little by little, subsides again. If you wait long enough, you may see it thus alternately advance and recede three successive times."

Pliny suggests four or five explanations of this phenomenon, but is probably wide of the mark in all but the fourth one:—

"Or is there rather a certain reservoir that contains these waters in the bowels of the earth, and, while it is recruiting its discharges, the stream in consequence flows more slowly and in less quantity, but, when it has collected its due measure, runs on again in its usual strength and fullness."

There are several of these intermitting springs in different parts of the world, and they are perhaps all to be explained on the principle of the siphon.

In the Idyls of Theocritus there are frequent allusions to springs.
It was at a spring—and a mountain spring at that—that Cast. . . Read More