True first edition of this seminal report, predating the edition published for public consumption by Princeton University. This was George M. Murphy's copy, with his ink name on the front wrapper, dated 24 September 1945; Murphy was the Associate Director of the Manhattan Project. He has also signed the title-page, as also have project participants W. F. Libby (who one the Nobel Prize for Chemistry in 1960 for his method to use Carbon 14 for age determination in archeology, geology, geophysics and other branches of science), R. H. Crist, F. B. Brown, George Scatchard, Francis Miller, Bruce Miller, and Graham Cook. H.D. Smyth was Chairman of the Department of Physics at Princeton University and Consultant to Manhattan District of U.S. Corps of Engineers. Also included is another copy, in yellowish cream wrappers (which are possibly later), unsigned.