Ptolemy - Ptolemy's Tetrabiblos - Ch. 18 lyrics

CHAPTER XVIII SIGNS BEHOLDING EACH OTHER, AND OF EQUAL POWER 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.