Default House System

In the "Preferences" dialog, "Houses" tab you can select a house system which is the one used by default for all new tropical charts in Solar Fire, and optionally also for all re-opened charts as well.

You can also select a second house system which is the one used by default for all new charts which are cast with a sidereal zodiac. This may be the same, or different from the first house system.

The available house systems are as follows...

•Campanus - Uses the prime vertical as the fundamental circle, divided into 12 equal lunes. Derived in the 13th century by mathematician Johannes Campanus.

•Koch - One of the most commonly used systems. Similar to Alcabitius, except that the degree of the Midheaven is moved back to the ascendant before the ascendant is moved towards the Midheaven. Recently derived (1940s).

•Meridian - Also known as the Axial system.

•Morinus - Uses the equator as the fundamental circle, divided into 12 equal arcs starting from the projection of the ascendant onto the equator. Attributed to Jean Baptiste Morin in the 17th century.

•Placidus - One of the most commonly used systems. Derived by determining the points on the ecliptic whose semi-diurnal arcs exactly trisect their quadrant. Derived by Placidus de Tito in the 17th century.

•Porphyry - Each quadrant is dissected by longitude into three equal houses. Originated in the 3rd century AD.

•Regiomontanus - Similar to Campanus, but uses the celestial equator as the fundamental circle. Derived by Johannes Muller.

•Topocentric - Based on the rotation of the horizon line, cutting the ecliptic at equal spaces in equal time. Recently derived (c 1961) by Vendel Polich and Anthony Page.

•Equal - Equal system with the 1st house cusp set to the Ascendant. First described by Ptolemy in his book Tetrabiblos.

•Aries - Equal system with 1st house cusp set to 0° Aries

•Solar Sign - Equal system with 1st house cusp set to 0° of the Sun’s sign

•"Planet" on 1st - Equal systems with 1st house cusp set to that planet’s longitude

•Vertex on 7th - Equal system with 1st house cusp set opposite to the Vertex

•MC on 10th - Equal system with 10th house cusp set to the Midheaven’s longitude

•Whole Signs - Equal system with 1st house cusp set to 0° of the Ascendant’s sign

•Hindu Bhava - Based on the Porphyry system, but with the cusps shifted to the midpoints of the Porphyry houses, so that the Ascendant falls in the middle of the first house.

•Alcabitius - Time based system, based on the trisection of the diurnal arc of the ascendant traveling towards the Midheaven.

•ASC in 1st - Equal system with center of 1st house set to the Ascendant.

•Whole Signs (Fortune) - Equal system with 1st house cusp set to 0° of the Part of Fortune's sign.

Whichever house system you highlight in the list will become the new default house system.