Complete Works, Volume Four

The first sign of each of these groups of three—Aries (♈), Cancer (♋), Libra (♎), and Capricorn (♑)—are called Cardinal signs. This is because the seasons of the year and the four quarters begin when the Sun enters them. They are also called Movable signs because the qualities of the seasons change at that time. The middle signs—Taurus (♉), Leo (♌), Scorpio (♏), and Aquarius (♒)—are called Fixed signs, because the seasons are then established and stable. The final signs—Gemini (♊), Virgo (♍), Sagittarius (♐), and Pisces (♓)—are called Common signs, in comparison to the Movable and Fixed signs. They are also known as Double-bodied signs. This is because Gemini and Pisces are clearly double figures; Sagittarius consists of both a horse and a man; and Virgo carries a spike of grain in her hand. The "spike of grain" refers to the star Spica, which Virgo is traditionally depicted holding, representing the harvest.

There are also various other names assigned to the signs, mostly by astrologers. For instance, if one takes Aries and skips every three signs, Aries (♈), Leo (♌), and Sagittarius (♐) are called Fiery signs. They are considered Hot, Dry, and Choleric. Taurus (♉), Virgo (♍), and Capricorn (♑) are Earthy, Dry, and Melancholic. Gemini (♊), Libra (♎), and Aquarius (♒) are Airy, Moist, and Sanguine. Cancer (♋), Scorpio (♏), and Pisces (♓) are Watery, Cold, and Phlegmatic. Thus, Aries, Leo, and Sagittarius are said to constitute the Fiery Triplicity Trigonum: a group of three signs belonging to the same element, also known as a triplicity; Taurus, Virgo, and Capricorn form the Earthy; Gemini, Libra, and Aquarius the Airy; and Cancer, Scorpio, and Pisces the Watery.

In the same way, they call some signs Masculine and others Feminine; some Human and others Brute Brute signs refer to those represented by animals, such as Aries the Ram or Leo the Lion.; some Fertile and others Sterile; some Beautiful and others Deformed. They also designate some as Diurnal and others Nocturnal. Some are the Houses of planets, others their Exile, others their Exaltation, others their Fall, and many other such things which are not necessary to address here.

It is worth noting that the Sun enters a specific sign each month. For example, it enters Aries in March, Taurus in April, Gemini in May, and so on, until it enters Pisces in February.

To know on approximately which day this entry occurs in any month, these verses can be noted:

Malice hiding in the mind insults honors, it dreads
Great deeds, clinging to those marked by distinguished praise. original: "Liuor mente latens insultat honoribus, horret / Grandia gesta, harens insigni laude notatis." This is a mnemonic poem where the first letter of each word provides a code for calculating the solar calendar.

Indeed, if you assign these twelve words to the twelve months—the first to March, the second to April, the third to May, and the rest to the others in order—and observe the position of the first letter of each word in the alphabet, you subtract that number from 30. The remaining number will indicate the day the Sun enters that sign.

For example, because the word Liuor corresponds to March and its first letter L is the tenth in the alphabet In the Latin alphabet used by the author, L is treated as the 10th letter, likely by excluding J and treating I as the 9th letter., subtract 10 from 30. The remaining 20 indicates that the Sun enters the sign of Aries on the 20th day of March. By the same logic, the letter M of the second word, which corresponds to April, will show that if 11 is subtracted from 30, the Sun enters Taurus on the 19th day of April. Similarly, the letter N of the last word, corresponding to February, suggests that if 12 is subtracted from 30, the Sun enters Pisces on the 18th day of February, and so on for the others.

Furthermore, if one asks which degree of the Zodiac the Sun is currently in on any day of the month, one only needs to add the number designated by the letter to the proposed day.

If the resulting number exceeds 30, the excess (with one added) will indicate the degree of the sign the Sun enters that month. If the number is less than 30, it will indicate the degree of the sign the Sun had entered in the previous month.

For example, if one asks where the Sun is on the 28th day of September, add 7 to 28 because of the letter G in the word Grandia. G is the seventh letter in the alphabet and corresponds to September. The total is 35. Subtract 30, and the excess of 5 plus one—which is 6—indicates that the Sun is in the 6th degree of Libra, which the Sun enters in that month. If one asks where the Sun is on the 12th day of the same month, add 7 to 12 again. The result is 19. This number indicates that the Sun is in the 19th degree of Virgo, which it entered in the previous month.

CHAPTER XIII.

On certain other circles understood in the Sphere, such as those called Vertical, of Altitude, Distance, Position, or Celestial Houses.

In addition to the circles described so far, other circles can be understood in the Sphere or the celestial globe (and thus also in the Heavens) which are frequently used by astronomers.

A diagram depicts an armillary sphere or celestial globe. It shows various intersecting circles, including meridians and parallels, contained within a circular frame. Points are labeled with letters such as A, B, E, F, G, H, I, K, and M. The sphere features a vertical axis and a horizontal equator, illustrating the projection of celestial coordinates used for measuring the positions of stars and planets.