Ptolemy

Note that Ptolemy’s method always results in a Hyleg being found, whereas Omar’s and Bonatti’s may not.

This calculation uses rulerships and all other options specified in the 3rd and 4th definitions in the HYLEG.ALM file - these may be edited by the user, but by default they are the same as follows...

•Traditional rulerships

•Ptolemy Triplicities

•Ptolemy Terms

•Signs start at 0 degs

•Default houses

•5,5,5 degree house cusp offsets (for ang, suc, cad houses)

•Different Day/Night Part of Fortune

•5 points for rulerships

•4 points for exaltations

•3 points for (all three) triplicity rulers

•2 points for term ruler

•1 point for face ruler

•No points for any other items

3rd definition

•Summation Points: Sun, Ascendant, Pre-natal NM

•Minimum Honours: 3

•Applies to Diurnal charts

4th definition

•Summation Points: Moon, Part of Fortune, Pre-natal FM

•Minimum Honours: 3

•Applies to Nocturnal charts

"Prorogative" houses are the 1st, 7th, 9th, 10th, 11th

1.If a daytime chart then check if Sun is in a prorogative house (apply house cusp offsets specified in HYLEG.ALM). If so, then the Sun is the Hyleg. If not then check if Moon is in a prorogative house. If so, then the Moon is the Hyleg. If the Hyleg was not found, then go to next the step.

2.If a night-time chart then check if Moon is in a prorogative house. If so, then the Moon is the Hyleg. If not then check if Sun is in a prorogative house. If so, then the Sun is the Hyleg. If the Hyleg was not found, then go to next the step.

3.If a daytime chart then find the almuten according to the 3rd definition, and if a nighttime chart, then us the 4th definition instead. If this results in a point being found with a non-zero score, then that is the Hyleg. If the Hyleg was not found, then go to next the step.

4.If the Moon is waxing, then the Ascendant is the Hyleg. If the Moon is waning, then the Part of Fortune is the Hyleg.