Experimental
The Davison chart of two charts or births (Davison, 1977): a chart for the midpoint in time and the midpoint in space of the two births.
The conventions of a Davison chart here (the place's default, the house system, a known time only when both are known) may change in a minor release.
Optional
The Davison chart of two charts or births (Davison, 1977): a chart for the midpoint in time and the midpoint in space of the two births.
The conventions of a Davison chart here (the place's default, the house system, a known time only when both are known) may change in a minor release.