2001.211.43

Hoff Aid

Stamped steel slate has one line of 30 cells; bright steel rod with spiral groove at 1/4 inch intervals; movable die-box fitted with six inverted, conically shaped caps the size of the braille dots on the dark steel base; paper holder fits into the left side of the slate; stylus is used on the die-box to depress the caps to form braille dots; stamped on base, "AMERICAN PRINTING HOUSE FOR THE BLIND/LOUISVILLE, KY".

H-0.875 W-9.25 D-2.125 inches

ca. 1960

American Printing House for the Blind

Louisville, KY

The Hoff Aid was an upward-writing slate designed primarily for use in making mathematical calculations on paper. It permitted examination of the brailled characters without having to remove the paper from the slate. Paul Hoff, a teacher at the Minnesota Braille and Sight Saving School, filed a patent application for his aid in 1946, seeing it as a compromise between the light weight and portability of a pocket slate, and the right-to-left upward writing capability of the braillewriter. It was introduced in the APH catalog in 1955, primarily as a mathematics tool, and discontinued in 1973 after a total production of 538 units. In the end it was determined to be too expensive ($22.50 in 1963) when compared to a slate, and too slow when compared to other math tools such an an abacus. Item is part of a slate collection that belonged to David Ronecker (1918-2001). He was blind since birth, attended the Missouri School for the Blind, worked in
Texas as a medical technician for the armed forces, and was an avid collector of slates. He was the uncle of Charles Zinser, who acquired the slate collection after Ronecker's death.

Museum Purchase, 2001.211