Resource Type

Eraser for Blackboards. (open access)

Eraser for Blackboards.

Patent for a new and improved blackboard eraser. This design "is composed of a block fashioned out of any suitable material—wood preferred— with a suitable handle, and provided with a base having a bed rounding in shape, provided with a rabbet following its edge, one side of which is beveled and the other plain, the two sides of said rabbet forming an obtuse angle about the entire perimeter of the said block" (lines 15-23).
Date: August 12, 1884
Creator: Kempen, Adolph H.
System: The Portal to Texas History
Electric Insulator. (open access)

Electric Insulator.

Patent for a new and improved electric insulator. This design "comprises a pair of fixed metal jaws or flanges having a common base of the same material integral therewith, and having between them a recess or groove for the reception of a wire, a key seat or slot passing through both jaws near their point of permanent union, and rounded off or made with a concave surface at its outer side, and a key or wedge convexly rounded on one side of its surface to correspond with said slot and adapted to be driven therein and to pass through both jaws and thereupon to hold the wire in said recess" (lines 27-38).
Date: August 12, 1890
Creator: Dunbar, John K.
System: The Portal to Texas History