Also called the Zenith House System. A pseudo-House System in which the lunes (pseudo- houses) are formed by great circles which pass through the Zenith and Nadir (rather than the North and South points along the Horizon), beginning with the Meridian and progressing toward the eastern half of the Prime Vertical. Each pseudo-house is of the same size; i.e., each lune is exactly 30° in size. The MC and 10th cusps are the same. But, the ASC is not the cusp of the 1st house; instead, the intersection of the Ecliptic with the eastern half of the Prime Vertical is used. This point is known, variously, as the Vertex, or Electrical Ascendant. American astrologer Charles Jayne preferred the Campanus House System, but advised serious investigation of the Zenith (or Horizon) System. A Campanus Table of Houses may be used the compute the house cusps for the Horizon System: Add 12h to the given Sidereal Time, determine the tabular values for the colatitude of the given place, and add 180° to the longitudes obtained.

See also:
  - Pseudo-house Circle
  - Jayne, Charles
  - Zenith
  - House System
  - Meridian
  - House Cusp
  - Prime Vertical
  - Zenith House System
  - Ecliptic
  - Anti-vertex
  - Vertex
  - Great Circle
  - Nadir
  - Lune
  - Mc
  - Asc

E x a m p l e:

Given that:
   obl = +23.45°
   LAT = +37.00°
   ST  = 07:32:00 = 113.00°
Then,
   ST' = 19:32:00 = 293.00°
   COLAT = 90° - LAT = +53.00°
and from a Campanus Table of Houses:
   10: CAP 21°16.6'
   11:
   12:
    1:
    2:
    3:
And, the Horizon System cusps are:
MC  = 10: CAN 21°16.6'
      11:
      12:
VTX =  1:
       2:
       3:

See also:
  - Pseudo-house Circle
  - Jayne, Charles
  - Zenith
  - House System
  - Meridian
  - House Cusp
  - Prime Vertical
  - Zenith House System
  - Ecliptic
  - Anti-vertex
  - Vertex
  - Great Circle
  - Nadir
  - Lune
  - Mc
  - Asc

     Also called the Zenith house system. This is a "pseudo" house system in which lunes (pseudo-houses) are formed by great circles that pass through the zenith and nadir -- rather than the north and south points along the horizon -- starting at the meridian and progressing toward the eastern half of the prime vertical. Each pseudo house is the same size; i.e. each lune is 30°. The MC is the 10th-house cusp, but the ASC is not the 1st-house cusp; instead, the intersection of the ecliptic with the eastern half of the prime vertical is used. This point is also known as the anti-vertex and is opposite the vertex or electrical ascendant. The American astrologer Charles Jayne advised serious investigation of the Zenith (Horizon) system, although he preferred the Campanus house system. A Campanus Table of Houses may be used the compute the house cusps for the Horizon system: - add 12 hours to the given Sidereal Time; - determine the tabular values for the colatitude of the given place; - add 180° to the longitudes obtained. ^

See also:
  - Pseudo-house Circle
  - Jayne, Charles
  - Zenith
  - House System
  - Meridian
  - House Cusp
  - Prime Vertical
  - Zenith House System
  - Ecliptic
  - Anti-vertex
  - Vertex
  - Great Circle
  - Nadir
  - Lune
  - Mc
  - Asc