ANY two signs, equally distant from either tropical sign, are equal to each other in power; because the Sun, when present in one, makes day and night, and the divisions of time, respectively equal in duration to those which he produces when present in the other. Such signs are also said to behold each other, as well for the foregoing reasons, as because each of them rises from one and the same part of the horizon, and sets in one and the same part. 2
26:2 Whalley has a very lengthy note upon this and the preceding chapter, to show that Ptolemy here speaks of zodiacal parallels, or parallels of declination, and to point out the necessity of observing a planet's latitude, in order to ascertain its true parallels. It is, however, to be recollected, that the p. 27 parallels now alluded to are distinct from the mundane parallels, which are equal distances from the horizon or meridian, and are considered by Ptolemy in the 14th and 15th Chapters of the 3rd Book of this work; although not under the express name of mundane parallels.