Ptolemy's Tetrabiblos · Ptolemy
THE NEW MOON OF THE YEAR
In every annual revolution made by the Sun, the first new Moon of the year is to be considered as the point of the commencement of his circuit; this is evident not only from its denomination, but from its virtue also.[98] The case stands thus: In the ecliptic, which, as circle, has in fact no actual or definite beginning, the two equinoctial and the two tropical points, marked by the equator and the tropical circles, are reasonably assumed as beginnings. And to obviate any doubt as to which of these four points should preferably be considered as the primary beginning (since in the regular simple motion of a circle no part of it has any apparent precedence), the appropriate quality naturally belonging to each of these four points has been taken into consideration by the writers on this subject. And the point of the vernal equinox has been consequently designated by them as the beginning of the year; because, from that time, the duration of the day begins to exceed that of the night, and because the season then produced partakes highly of moisture, which is always a predominant quality in all incipient generation and growth. After the vernal equinox comes the summer solstice; when the day attains its greatest length, and in Ægypt, at the same period, the rise of the Nile takes place and the Dog Star appears. Then follows the autumnal equinox, when all fruits are gathered in, and the sowing of seeds recommences anew; lastly, comes the winter solstice, when the day proceeds from its shortest duration towards its increase.
It therefore becomes necessary to explain, in the first instance, the particular natures and attributes exercised by each sign in influencing the several constitutions of the weather, as it exists at various times of the year; these natures and attributes shall now be immediately detailed. It will be recollected, that the particular properties of the planets and the fixed stars, as affecting the wind and the atmosphere, as well as the manner in which the entire signs hold familiarity with the winds and the seasons, have been already set forth. [99] That is to say, at the new and full Moon taking place during the Sun’s progress through each sign. [100] The passage marked thus “ ” is not in the Greek, but is found in two Latin translations.
Text from Project Gutenberg, public domain in the United States.