Immense Cores Secured in Boring a 5 ½ -ft. Ventilation Shaft at Ely, Minn.
- Organization:
- The American Institute of Mining, Metallurgical, and Petroleum Engineers
- Pages:
- 1
- File Size:
- 148 KB
- Publication Date:
- Jan 1, 1938
Abstract
IN the September 1936 issue of MINING AND METALLURGY the pioneer work of boring a 5-ft. shaft to a depth of 1125 ft. at the Idaho Maryland mine in California was described. Later, a Bureau of Mines Information Circular (No. 6923) gave additional data. In re¬cent months still further progress has been made in this technique through the sinking of a 5 1/2-ft. shaft for Pickands, Mather & Co. at their Zenith mine, Ely, Minn. The present work was done with new carefully designed equipment and several experienced men so that progress, as shown below has been much better:
Citation
APA: (1938) Immense Cores Secured in Boring a 5 ½ -ft. Ventilation Shaft at Ely, Minn.
MLA: Immense Cores Secured in Boring a 5 ½ -ft. Ventilation Shaft at Ely, Minn.. The American Institute of Mining, Metallurgical, and Petroleum Engineers, 1938.