3When the sun has entered the sign of Aries, and run through about an eighth part of it, it is the vernal equinox. When he has arrived at the tail of Taurus and the Pleiades, for which the fore part of the Bull is conspicuous, he has advanced in the heavens more than half his course towards the north. From Taurus, he enters into Gemini, at the time when the Pleiades rise, and being more over the earth increases the length of the days. From Gemini entering into Cancer, which occupies the smallest space in the heavens, and coming to the eighth division of it he determines the solstice, and moving forward arrives at the head and breast of Leo, which are parts properly within the division assigned to Cancer.
3The sun, after entering the sign Aries and passing through one eighth of it, determines the vernal equinox. On reaching the tail of Taurus and the constellation of the Pleiades, from which the front half of Taurus projects, he advances into a space greater than half the firmament, moving toward the north. From Taurus he enters Gemini at the time of the rising of the Pleiades, and, getting higher above the earth, he increases the length of the days. Next, coming from Gemini into Cancer, which occupies the shortest space in heaven, and after traversing one eighth of it, he determines the summer solstice. Continuing on, he reaches the head and breast of Leo, portions which are reckoned as belonging to Cancer.