Signs.
From BiblePortal Wikipedia
Signs. [1]
1. The great bells at Canterbury in the 12th century; one took twenty-four and another thirty-two men to sound it.
2. A most intricate system of talking with the fingers, used by the Clugniacs to indicate their wants in hall.
3. Gerbert furnishes a minute account of a similar manual telegraph made use of by the precentor in a choir.
