Pomeroy's mining manual for prospectors, miners and schools :  Showing where and how to search for gold and silver mines, and to make tests / 
Ed. by Henry r. pomeroy 
 - 3 # ed, re-arrenged, rev. and enl. 
 - 119 páginas 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Prospección
<br/><br/><label>LC Class. No.: </label>TN271.G6  / P65 1881