Mining drills on display, University of Washington, after 1905
Signs read: (top to bottom) Modern Rock Drill "Jack Hammer", Diameter of hole 1 1/4 inch, speed 1600 blows per minute, drilling speed 8 in per minute, air pressure 80lbs per sq. inch, weight of drill 45lbs. Little Giant Rock Drill "Rand No 4", Later type of rock drill used in the...
| Format: | Other/Unknown Material |
|---|---|
| Language: | unknown |
| Published: |
1905
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| Subjects: | |
| Online Access: | http://cdm16786.contentdm.oclc.org:80/cdm/ref/collection/uwcampus/id/36698 |