This was a device used in 19th century factories to indicate a workers quality of conduct. It was an early example of providing visible feedback to the worker. The grade was recorded each day in a Book of Character.

SILENT MONITOR: "The silent monitor was a coloured block with a different colour on each side."
Cite this page: N., Pam M.S., "SILENT MONITOR," in, April 13, 2013, (accessed September 16, 2021).