Benjamin Martin /Regiomontanus

1
In Benjamin Martin's second volume of Trigonometry Part 2 Chapter2 he explains how to calculate a chart using Regiomontanus system.My question is about the cusp of the eleventh house.There are 2 triangles made of great circles.First gives the pole above circle of position.Circle of position of 11 is indicated by the letter A.2 angles are then formed with A (1 for each triangle) In second triangle angle A is equal to pole + 90 degrees.In a chart where MC is north(ecliptic circle above equator) angle A is formed above equator with circle of position.In the case of my chart of north declination I am only sure of 1 side Equinox from Libra to OA of 11 along the equator 32 07 33 and 1 angle obl 23 27 11.cusp of 11 is at 1 59 virgo 28 01 ? for 1 side? I have tried the half angle formulas he uses but have gotten nowhere.I wasnt sure if I could use declination as a possible side .So far only result is a wrong triangle Harold

reply

2
I am not sure if anyone is familiar with this book but spherical astronomy applied to the astrology chart interests me.My ascendant is Libra which gives an MC of Cancer (North Declination).In calculating the cusp of 11 house Martin uses 2 angles and 1 side to find Ecliptic Longtitude.Since my last post on Skyscript I realized 90-pole along with obl 23 27 were the 2 angles needed for northern MC /90+ pole and obl for southern.I don't know if anyone shares my interest in Martins book but for me it has been an important resource.The above post is for the Regiomontanus system Regards-Harold