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It is certain that the moon, having her horns always turned from the sun, when she is waxing, looks towards the east; when she is waning, towards the west. Also, that, from the second day after the change, she adds 47 1/2 minutes1 each day, until she is full, and again decreases at the same rate, and that she always becomes invisible when she is within 14 degrees of the sun. This is an argument of the greater size of the planets than of the moon, since these emerge when they are at the distance of 7 degrees only2. But their altitude causes them to appear much smaller, as we observe that, during the day, the brightness of the sun prevents those bodies from being seen which are fixed in the firmament, although they shine then as well as in the night: that this is the case is proved by eclipses, and by descending into very deep wells.

1 In a subsequent part of the work, xviii. 75, the author gives a different rate of increase, viz. 51 1/2 minutes; neither of these numbers is correct; the mean rate of increase being, according to Alexandre, about 54′ or 55′; Lemaire, ii. 261, 262. See also Marcus in Ajasson, ii. 311–14.

2 It is scarcely necessary to remark, that the effect, as here stated, has no connexion with the supposed cause.

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