Ptolemy's Tetrabiblos: Book the Second: Chapter V. Mode of Particular Prediction in Eclipses
CHAPTER V
MODE OF PARTICULAR PREDICTION IN ECLIPSES
AFTER having gone through the necessary preliminary topics, it is now proper to speak of the manner in which predictions are to be formed and considered; beginning with those which relate to general events, affecting either certain cities, or districts, or entire countries.
The strongest and principal cause of all these events exists in the
