London, Faber, 1935. First edition, first impression. Hardback. A very good copy. A rare sf involving a scientist, two women who are in love with him (standard), X-rays, literal guinea pigs and thought projection. Uncommon. Jacket has a large tear to the upper corner, some sunning to the spine, a little edge wear, some bumping to the tips and a little dusting. [10360, Hyraxia Books].