Page:The Natural History of Pliny.djvu/160

 126 plint's natural history. [Book IT. quarter, and iliej again increase from the time that she is at first quarter on the other side. At her conjunction with the sun they are equally high as at the full. IVhen the moon is in the northern hemisphere, and recedes further from the earth, the tides are lower than when, going towards the south, she exercises her influence at a less distance After an interval of eight years, and the hundredth revolu- tion of the moon, the periods and the heights of the tides return into the same order as at first, this planet always acting upon them; and all these effects are like^^ase in- creased by the annual changes of the sun^, the tides rising up higher at the equinoxes, and more so at the autumnal than at the vernal ; while they are lower^ about the winter solstice, and still more so at the summer solstice ; not indeed precisely at the points of time which I have men- tioned, but a few days after'' ; for example, not exactly at the full nor at the new moon, but after them ; and not immediately when the moon becomes visible or invisible, or has advanced to the middle of her course, but generally about two hours later than the equinoctial hours^ ; the eliect of what is going on in the heavens being felt after a short interval ; as we observe with respect to lightning, thunder, and thunderbolts. But the tides of the ocean cover greater spaces and produce greater inundations than the tides of the other seas ; whether it be that the whole of the universe taken together is more full of life than its individual parts, or that the large open space feels more sensibly the power of the planet, as it moves freely about, than when restrained within narrow bounds. ^ It is scarcely necessary to remark, that both the alleged fact and the supposed cause are incorrect. And tliis is the case with what our author says in the next sentence, respecthag the period of eight years, and the hundi'ed revolutions of the moon. 2 " Solis annuis causis." The circumstances connected wdth the revo- lution of the sun, acting as causes of the period and height of the tides, in addition to the effect of the moon. 3 " Inanes ;" " Deprcssiores ac minus tumentes." Hardouin in Le- maire, i. 429. "* According to the remark of Alexandre, " Uno die et dimidio altero, 3G circiter horis, m GaUia." Lemaire, i. 429. 5 Alexandi-e remarks on this passage, " Variat pro locis hoc intervallum a nullo fere tcmporis momcnto ad undecim horas et amphus :" Lemaire. L 429.