The theory of perspective demonstrated : in a method entirely new. By which the several planes, lines, and points, used in this art, are shewn by moveable schemes, in the true positions in which they are to be considered. Invented, and now published for the use of the Royal Academy at Woolwich. By John Lodge Cowley. - Cowley, John Lodge, (printed for T. Payne; J. Dodsley; J. Millan; B. White; Webley; T. Longman; R. Horsfield; S. Hooper; and J. Bennet,, 1766)