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Ptolemy's Tetrabiblos : $b or Quadripartite, being four books of the influence of the stars ... with a preface, explanatory notes, and an appendix containing extracts from the Almagest of Ptolemy and the whole of his Centiloquy, together with a short notice of Mr. Ranger's zodiacal planisphere and an explanatory platePtolemy

Religion

Ptolemy's Tetrabiblos : $b or Quadripartite, being four books of the influence of the stars ... with a preface, explanatory notes, and an appendix containing extracts from the Almagest of Ptolemy and the whole of his Centiloquy, together with a short notice of Mr. Ranger's zodiacal planisphere and an explanatory plate

Name: Ptolemy's Tetrabiblos : $b or Quadripartite, being four books of the influence of the stars ... with a preface, explanatory notes, and an appendix containing extracts from the Almagest of Ptolemy and the whole of his Centiloquy, together with a short notice of Mr. Ranger's zodiacal planisphere and an explanatory plate
Author: Ptolemy

Ptolemy

Astrology -- Early works to 1800

[144] The Latin translation, printed at Perugio in 1646, has here the
following passage in addition: “But it must be seen which luminary may
follow the other in the succession of the signs; for if the Moon should
so follow the Sun, the part of Fortune is also to be numbered from the
horoscope or ascendant, _according_ to the succession of the signs. But
if the Moon precede the Sun, the part of Fortune must be numbered from
the ascendant, _contrary_ to the succession of the signs.”

There is a long dissertation on the part of Fortune, in Cooper’s
Placidus, from pp. 308 to 318; and, among the directions there given
for computing its situation, the following seem the most accurate and
simple: viz. “In the diurnal geniture, the Sun’s true distance from
the east is to be added to the Moon’s right ascension, and in the
nocturnal, subtracted; for the number thence arising will be the place
and right ascension of the part of Fortune: and it always has the same
declination with the Moon, both in number and name, wherever it is
found. Again, let the Sun’s oblique ascension, taken in the ascendant,
be subtracted always from the oblique ascendant of the ascendant, as
well in the day as in the night, and the remaining difference be added
to the Moon’s right ascension; the sum will be the right ascension
of the part of Fortune, which will have the Moon’s declination.” It
is shown also by this dissertation, that the situation of the part
of Fortune must be necessarily confined to the lunar parallels;
that it can but rarely be in the ecliptic; and that its latitude is
ever varying. Cooper also adds, from Cardan’s Commentaries on the
Tetrabiblos, that “if the Moon is going from the conjunction to the
opposition of the Sun, then the Moon follows the Sun, and the part
of Fortune is always under the Earth, from the ascendant; but if the
Moon has passed the opposition, she goes before the Sun, and the part
of Fortune is before the ascendant, and always above the earth.” This
remark of Cardan’s is, in effect, exactly equivalent to what is stated
in the additional passage inserted in the Perugio Latin translation,
and given above.

Public-domain text, read in full here on John Shaqi.