The Londoner cannot keep the small and loose order of the grammar of good English; the Genoese conjugates his patois verbs, with subjunctives and all things of that handsome kind, lacked by the English of Universities.
"Essays"
Alice Meynell
We have seen, indeed, that if B and D are harmonic conjugates with respect to A and C, then the point-row described by B is projective to the point-row described by D, and that A and C are self-corresponding points.
"An Elementary Course in Synthetic Projective Geometry"
Lehmer, Derrick Norman
It is not difficult to see that the double-points in the involution are harmonic conjugates with respect to corresponding points in the involution.
"An Elementary Course in Synthetic Projective Geometry"
Lehmer, Derrick Norman