The Auriferous Gravels of California. - This publication very rare and very hard to find was put out by John Hays Hammond, a legend and expert in his own right in the motherlode region of California. This publication was an excerpt in a publication report in the late 1800's that was not very well know. In the 80 pages the author describes the geology of their occurrence and the methods of their exploitation. Many diagrams and pictures make this one of the best forgotten publications of the Motherlode. Now back in Print by Sylvanite Publishing.