The Thirteen Books of Euclid’ s Elements. Translated from the Text of Heiberg, with Introduction and Commentary, by Sir T. L. Heath, K.C.B., D.Sc, Sometime Fellow of Trinity College, Cambridge. Vol. I. Introduction and Books i.&ii. Pp. x + 424. Vol.11. Bks. iii.-ix.; pp. 436. Vol. III. Books x.-xiii., and Appendix; pp. 554. (Cambridge: University Press). £2 2s. net.