This book was written to provide a short description of the atomic bomb project that would satisfy public curiosity without giving away any essential secrets. This edition has an intro by Philip Morrison, who worked on the project, and a nice supplementary essay by Smyth, which fills out the picture a bit.

This book is a MUST-HAVE for any historian or person with an interest in our nuclear heritage. This book, of which actually two versions were published ( the second after General Groves read the first version and blew a gasket) was written to establish a classification guide as to what was and was not public domain information at the time. As much of the initial work was done at colleges, there was considerable interest given to the project after the war, and this book was the 'official' response.
Easy to read, valuable reference.