Lodes in the tertiary eruptions of Colorado
Possibilities of the Mother Lode in depth
Big wonder syndicate's Auriferous lodes
Air-transportation of gold dredges in new Guinea
Air-transportation of gold dredges in new Guinea
Air-transportation of gold dredges in new Guinea
Air-transportation of gold dredges in new Guinea
Saga of comstock lode, boom days in Virginia City
Tractors speed placer development in Alaska
Mining of Mercedes orebody, Macuchi, Ecuador, South America
X-Ray Image System for Nondestructive Testing of Solid Propellant Missile Case Walls and Weldments