1992.84

Bertha Shepard Slate

Cast aluminum slate, assembled from two pieces, a molded top and a flat bottom secured by 11 steel screws; top cast with pentagonal cells (432 total: 18 cells vertically by 24 cells horizontally) and three tray compartments at top to hold the type; "The Bertha Shepard Slate" cast above strage compartments; twelve (12) brass pentagonal type pieces, each with a bar on one side and two dots on the other.

ca. 1935

American Printing House for the Blind

Louisville, KY

APH Collection

Pentagonal arithmetic frames were originally developed at the Glasgow Asylum for the Blind around 1829. By turning the type in place, numbers 0-9 and operators were represented. APH began experimenting with different styles of arithmetic frames in the 1930s. In a letter to the head of the American Foundation for the Blind, Robert Irwin, APH President A.C. Ellis reported that he hoped to have a "small supply" of a pentagonal arithmetic frame available as early as January 1933. 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 which used type cast with raised numerals in the "Philadephia style." 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 Collection, 1992.84