Campanus

Meaning

Campanus divides the sky as it looks from the birthplace. Picture a great circle that rises from the east point of the horizon, passes straight overhead and comes down at the west point, then runs on below the earth: the prime vertical. Campanus cuts it into twelve equal arcs of 30°. Each house is the slice of sky between two of those marks, and its cusp is the degree of the zodiac that the slice’s edge crosses.

Precisely: through the north and south points of the horizon pass twelve great circles, like the segments of an orange, spaced 30° apart along the prime vertical. The horizon itself is one of them and gives the Ascendant and the Descendant; the meridian, which runs through the point overhead, gives the Midheaven and the IC. The others cross the ecliptic at the cusps of the 2nd, 3rd, 5th, 6th, 8th, 9th, 11th and 12th houses, and opposite cusps are 180° apart.

The idea is spatial, not temporal. Where Placidus asks how long a degree has been climbing, Campanus asks where it stands in the sky of the person born. It measures from the horizon of that place. It gives a natural picture of the houses as twelve regions of the local sky.

Its houses grow unequal faster than in any other system Ulune offers. At 45° of latitude they range from about 12° to 67° of the zodiac; at 60°, from about 4° to 118°, so one house can hold almost four signs. Inside the polar circles, the cusps can even run backwards round the zodiac. Close to the equator, by contrast, Campanus gives almost the same cusps as Placidus and Regiomontanus, and on the equator itself all three coincide.

In practice

• A minority choice today, kept by astrologers who like its picture of the houses as regions of the visible sky.
• Space-based reading. A planet’s Campanus house shows where it stood in the local sky, high or low, east or west, rather than how long ago it rose.
• Births far from the equator give very uneven Campanus houses; comparing with Porphyry or Equal houses helps to see what depends on the system.
• A sibling of Regiomontanus. Both use the same circles through the north and south points; they differ only in the circle they divide.

Origin and history

The system bears the name of Campanus of Novara, a 13th-century Italian mathematician and astronomer who served at the papal court. He is best known for his Latin edition of Euclid’s Elements, which became the standard one and was the first to be printed, in 1482. Historians such as John North have studied how the house division named after him was computed and used in medieval astronomy. It never became as common as Alcabitius’ or Regiomontanus’ systems, but it remained known, and modern software offers it as a standard option.

How Ulune calculates it

Choose Campanus in the birth form’s options. The Swiss Ephemeris computes the cusps with its code C. The Ascendant, the IC, the Descendant and the Midheaven are the cusps of the 1st, 4th, 7th and 10th houses.

Campanus is computed at every latitude, so Ulune never replaces it with Porphyry. Inside the polar circles, its cusps can come out of zodiac order. At some times of day there, the Swiss Ephemeris also puts its Midheaven opposite the point Equal or Porphyry houses would give. Ulune keeps both as the Swiss Ephemeris gives them, and reads the chart’s angles from them. In a composite chart in Campanus, the angles are the midpoint angles and the other cusps keep, inside each quadrant, the average of their places in the two charts.

Correspondences