Trolly Wheel and Harp. (open access)

Trolly Wheel and Harp.

Patent for trolley wheels, where "the transmission of the current through the wheel to the harp is maintained at the maximum and the necessary wear of the relatively movable parts reduced to a minimum" (lines 11-15).
Date: May 7, 1912
Creator: Neighbour, William W.
System: The Portal to Texas History