A house-system control must say what changes. In Stelliums, Whole Sign houses remain the topical map: the complete Ascendant sign is the first place and the following signs become places two through twelve. Porphyry is an optional second layer for seeing position within quadrants established by the exact angles.
How the two layers are built
- Whole Sign places divide the zodiac into twelve complete signs beginning with the Ascendant sign.
- The Ascendant, Midheaven, Descendant, and Imum Coeli remain exact degree-sensitive angles.
- Porphyry trisects each ecliptic arc between adjacent angles, producing twelve generally unequal cusp intervals.
- Every planet retains both its Whole Sign place and, when calculated, its Porphyry quadrant house.
Governed worked example
Worked example: one planet, two structural records
In the Dallas 1990 frozen fixture, the Sun at 25°21′ Capricorn occupies the ninth Whole Sign place from Taurus rising. The Porphyry cusps place that same longitude in quadrant house ten. Stelliums therefore records WSH 9 and Porphyry 10 together: the ninth remains the topical place, while the Porphyry result can inform a separately governed angularity comparison.
Use the chart control
Open Chart display settings and enable Porphyry cusps. The dashed cusp layer is off by default so the Whole Sign wheel remains legible. The setting persists on the current device and changes only presentation; it does not recalculate or rewrite the saved nativity.