1 Matching Results
Results open in a new window/tab.
Results:
1 - 1 of
1
Attachment for Rotaries.
Patent for rotary well-drilling machinery where the "ring or bushing to rotate independently of the table and the present invention is directed to means for accomplishing the rotating effect." (line 24-27)
Date:
July 20, 1920
Creator:
Johnston, Horace G.
System:
The Portal to Texas History