3 articles for "Porphyry"

(3rd century AD) Astrologer. A Neoplatonist, he introduced a method of house division.

See also:
♦ Porphyry House System

Named for Porphyry.

A pseudo-House System which uses pseudo-house circles which pass through the poles of the Ecliptic and the house cusps. The MC and ASC are equal, respectively, to the 10th and 1st house cusps. The intervening house cusps are located by trisecting the Ecliptic arc between the MC and ASC, and between the ASC and IC.

	  L10 = MC, L1 = ASC, L4 = IC = MC+180o
	  U = ASC-MC, V = IC-ASC
	  L11 =  MC + U(1/3)
	  L12 =  MC + U(2/3)
	  L2  = ASC + V(1/3)
	  L3  = ASC + V(2/3)
	Example: Given that:
	  obl = +23.45°
	  LAT = +37.00°
	  ST  = 07:32:00 = 113.00°
	Then,
	  MC  = L10 = 111.2768° = CAN 21°16.6'
	  ASC = L1  = 198.8521° = LIB 18°51.1'
	  IC  = L4  = 291.2768° = CAP 21°16.6'
	          U =  87.5753°,  U/3 = 29.1918°
	          V =  92.4247°,  V/3 = 30.8082°
	        L11 = 140.4686° = LEO 20°28.1'
	        L12 = 169.6604° = VIR 19°39.6'
	        L2  = 229.6603° = SCO 19°39.6'
	        L3  = 260.4685° = SAG 20°28.1'

See also:
♦ Pseudo-house Circle ♦ Ecliptic ♦ House Cusp ♦ Ascendant ♦ Mc ♦ Midheaven ♦ Asc ♦ Ic ♦ Equal House System

One of several house systems.

This is a quadrant system dating from the third century A.D. and attributed to Porphyry, a Neoplatonist who lived around 233-303 A.D. The ascendant is placed on the first-house cusp and the midheaven on the cusp of the tenth house. The intermediate house cusps are equal divisions of each quadrant, measured along the ecliptic.

This system creates two pairs of three equally small houses in opposite quadrants and two pairs of large houses in the other quadrants. It is a variation of the Equal house system and attempts to divide the quadrants of the horoscope in a more equal manner. There are problems at extreme latitudes, but many astrologers like this system because it is relatively easy to calculate by hand.

See also:
♦ Pseudo-house Circle ♦ Ecliptic ♦ House Cusp ♦ Ascendant ♦ Mc ♦ Midheaven ♦ Asc ♦ Ic ♦ Equal House System