Improvement in Double-Bitted Drills. (open access)

Improvement in Double-Bitted Drills.

Patent for "an easy mode of straightening wells while drilling them through rock or earth, and also for enlarging the same into a cistern when it is desired to keep on hand a large supply of water." (Lines 8-13) Includes instructions and illustrations.
Date: May 30, 1876
Creator: Yarbrough, William H.
System: The Portal to Texas History