Rock Drill.
Description:
Patent for a new and improved rock drill. This design consists in "the combination, with the bit having the inclined cutting-edge extending diagonally from one end to the other and the curved recesses formed in the sides of the bit, of the passage-ways or grooves at either end of said cutting-edge opening into the said recesses" (lines 64-70).
Date:
December 28, 1886
Creator:
Rader, Powell
Partner:
UNT Libraries Government Documents Department