C 123 1

LETTER VIII,

Of the Nature of the Tides.

I N my last letter I have unfolded to you thegrand principle of attraction, and the mannerin which it operates. We have seen the geniusof Newton in the heavens, and travelled withhim to the fun and the planets. Let us now de-scend, and follow him into the world of waters,through tste depths of the ocean. By whatpower or cause is it, that this vast liquid bodyrises and falls alternately, twice a day, in a man-ner so constant and regular. The ancients con-sidered it as one of the greatest mysteries innature, and were utterly at a loss to accountfor it.

Aristotle, the great oracle of antiquity, is re-presented as having thrown himself into the sea,because he was unable to explain its motions ;and when he was in India, with Alexander theGreat, it is said that he wanted to follow thetide in its reflux, to fee where it would go.The story is sufficiently absurd; but not moreso than the following one related of Kepler. He,in one of his reveries, considered the earth as a|iving being, and thought the flux and reflux

of