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Rotary Boring-Drill.
Patent for an improved rotary boring drill of the roller type for use in digging wells or mines in earth or rock. These improvements are primarily a means for housing the cutters of a drill in a removable housing that can be quickly removed but also firmly secured against accidental removal during operation.
Date:
December 31, 1918
Creator:
Hughes, Howard R.
System:
The Portal to Texas History