Historical information
This device, which consists of 2 slideable cork balls on nylon thread, is designed to gauge the height of liquid (hot or cold) in a receptacle such as a tumbler, jug, bowl without having to touch the liquid with the fingers. Print instructions are included with the instrument on how to operate the instrument, the instructions mention a braille copy is included, however this copy is missing.
Physical description
2 slideable cork balls on nylon thread with instruction leaflet, inside cardboard box
Inscriptions & markings
Royal National Institute for the Blind
Liquid dispenser
Catalogue no. 9290
