On Double Refraction in Matter moving through the Aether. Offprint from: Philosophical Magazine, series 6, vol. 7, no. 40. THE BRACE EXPERIMENT

First edition, very rare offprint issue, of the 'Brace experiment' which attempted to detect the FitzGerald-Lorentz contraction of bodies in their direction of motion through the aether. "De Witt Bristol Brace (1859-1905), professor of physics and specialist in optics at the University of Nebraska, is best remembered for his experimental test of the Lorentz-Fitzgerald contraction hypothesis . . . In 1904 the opportunity arose for Brace to apply the extremely sensitive optical techniques he had developed to one of the crucial problems of his day. Two years earlier, Lord Rayleigh had proposed that the Lorentz-Fitzgerald contraction, if it existed, might produce an observable double refraction in a moving transparent medium. [Double refraction, also called birefringence, is an optical property in which a single ray of unpolarized light entering an anisotropic medium is split into two rays, each traveling in a different direction.] Rayleigh made experiments in which he failed to find the predicted effect, but his work was not quite accurate enough to be conclusive. Brace pointed this out and reconducted the investigation in his own laboratory, establishing beyond a doubt the absence of double refraction caused by movement of the refracting medium through the ether. This did not disprove the contraction hypothesis, but Brace at first believed that it did. Joseph Larmor showed that double refraction need not result from Lorentz contraction if matter is composed of electrically charged particles that contract in the same proportion as large bodies; he thus saved the Lorentz hypothesis and gave the electron its status as a fundamental particle of matter" (DSB). Brace "received his bachelor s degree from Boston University in 1881 and went on to graduate study at MIT and Johns Hopkins University. In 1883 his admiration for Kirchhoff and Helmholtz took him to Berlin, where he wrote a doctoral dissertation on magneto-optical effects. In 1888, shortly after his return to the US, Brace became professor of physics at the University of Nebraska, where he remained until his death" (DSB). No copies listed on ABPC/RBH. 8vo, pp. 317-329. Original pink wrappers.…