In the paper, “Transformations founded on the Twisted Cubic and its Chord System,” a series of space transformations was described, each of which had the property of transforming the chord system of one cubic into the chord system of the other. In the present paper it is shown that by the aid of a non-singular cubic surface the transformations of orders 1, 2, 3, 4, 5 may be derived directly without the intervention of a space transformation.

It will be found that these transformations form a group which is intimately associated with the 27 lines of the cubic.