Throwback Thursday Object: An Arithmetic Slate
Our object this week is an arithmetic slate from the 1930s. This is a prototype, the final version was cast in aluminum and featured pentagonal holes. Pentagonal arithmetic frames were originally developed at the Glasgow Asylum for the Blind in Scotland around 1829. By turning a metal peg in place, numbers 0-9 and operators were represented. APH began experimenting with different styles of arithmetic frames in the 1930s. The frames first entered the catalog in 1935. By 1937, however, the pentagonal frame was no longer in the catalog, in favor of a gridded frame, often called a “Texas Slate,” which used metal type cast with raised numerals. A year later, APH introduced its version of the Taylor arithmetic slate, which used octagonal holes, but was similar in concept to the pentagonal design. APH called its pentagonal slate, the “Bertha Shephard Slate,” but I don’t know who Miss Shephard was.
Micheal A. Hudson
American Printing House for the Blind