Arc Transform Charts

The arc transform chart is simply an harmonic chart whose harmonic number is determined by the arc between the two selected planets or chart points, as follows:

1.Arc = Longitude of 2nd Planet - Longitude of 1st Planet

2.If Arc is -ve then change its sign to +ve

3.Harmonic = 360 / Arc

Note: If the Arc is less than about 1 second of arc, then the harmonic would be unacceptably high, resulting in an meaningless chart. Hence, to avoid problems in this case, the harmonic is set to 1.