This is a technique largely employed in horary and known to have been used by Ptolemy. In this, closer examination of any area of the chart is undertaken by redefining all the houses from a specific house cusp. For example, if someone asks about the affairs of a brother, the 3rd house of their chart is used as the 1st house for the brother, so that the radical (i.e., original) 4th house is used as his 2nd house, the radical 5th is used as his 3rd, and so on. In this case, the 5th house becomes referred to as the ‘turned’ or ‘derived’ 3rd house of the brother.