The theory of the imaginary in geometry : together with the trigonometry of the imaginary / by J. L. S. Hatton. Hatton, J. L. S. (John Leigh Smeathman), 1865-1933. Geometry, Projective. Numbers, Complex. QA471 .H35 516 HAT Includes index. Cambridge : The University press, 1920. 1920. 1920 Text vi, 215 p. : eng