2015 Reprint of 1923 Edition. Full facsimile of the original edition. Not reproduced with Optical Recognition Software. This collection of original papers on the special and general theories of relativity is an unabridged translation of the 4th edition of "Das Relativitatsprinzip," together with a revised edition of an additional paper by H. A. Lorentz. "The book constitutes an indispensable part of a library on relativity," "Nature." "It is really a thrill to read again the original papers by these giants," "School Science and Mathematics." "Warmly recommended," "Quarterly of Applied...