11.  On its variations depends also the condition of the air, as is proved by sudden disturbances which often come after the new moon, in the midst of a calm and of a stillness in the winds, to agitate the clouds and to hurl them against each other; as the flux and reflux in straits, and the ebb and flow of the ocean prove, so that those who live on its shores see it regularly following the revolutions of the moon.  The waters of straits approach and retreat from one shore to the other during the different phases of the moon; but, when she is new, they have not an instant of rest, and move in perpetual swaying to and fro, until the moon, reappearing, regulates their reflux.  As to the Western sea, i.e.the Atlantic.  cf. Ovid., Met. xi. 258, “Hesperium fretum.” we see it in its ebb and flow now return into its bed, and now overflow, as the moon draws it back by her respiration and then, by her expiration, urges it to its own boundaries. Pytheas, of Marseilles, is first named as attributing the tides to the moon.  Plut. περὶ ἀρεσκ. κ.τ.λ. iii. 17.  On the ancient belief generally vide Plin. ii. 99.