Chap. 99.] CAUSE OF THE TIDES. 125 
always in the space of twenty-four hours. Eirst, the moon 
rising with the stars ^ swells out the tide, and after some time, 
having gained the summit of the heavens, she declines from 
the meridian and sets, and the tide subsides. Again, after she 
has set, and moves in the heavens under the earth, as she 
approaches the meridian on the opposite side, the tide flows 
in ; after which it recedes until she again rises to us. But 
the tide of the next day is never at the same time with that of 
the preceding ; as if the planet was in attendance^, greedily 
drinking up the sea, and continually rising in a different place 
from what she did the day before. The intervals are, however, 
equal, being always of six hours ; not indeed in respect of any 
particular day or night or place ^, but equinoctial hours, and 
therefore they are unequal as estimated by the length of com- 
mon hours, since a greater number of them^ fall on some cer- 
tain days or nights, and they are never equal everywhere 
except at the equinox. This is a great, most clear, and even 
divine proof of the dullness of those, who deny that the stars 
go below the earth and rise up again, and that nature pre- 
sents the same face in the same states of their rising and 
setting^ ; for the course of the stars is equally obvious in the 
one case as in the other, producing the same effect as when 
it is manifest to the sight. 
There is a difference in the tides, depending on the moon, 
of a complicated nature, and, first, as to the period of seven 
days. . Tor the tides are of moderate height from the new 
moon to the first quarter ; from this time they increase, and 
are the highest at the full: they then decrease. On the 
seventh day they are equal to what they were at the first 
^ " Mundo the heavens or visible firmament, to which the stars and 
planets appear to be connected, so as to bs moved along with it. 
2 " AnciUante ; " "Credas anciUari sidus, et induigere mari, ut non ab 
eadem parte, qua pridie, pastum ex oceano hauriat." Hardouin in 
Lemaire, i. 427. 
3 Not depending on the time of the rising and setting of the sun or 
the latitude of the place, but determinate portions of the diurnal period. 
^ By a conjectural variation of a letter, viz. by substituting " eos " for 
"eas," Dalechanip has, as he conceives, rendered this passage more clear j 
the alteration is adopted by Lemaire. 
* "In iisdem ortus occasusque operibus;" "Eodem modo utriaque 
orientibus occidentibusque sideribus," as interpreted by Alexandre iii 
Lemaii'e, i. 428. 
