from The Century Dictionary.
- noun An instrument, or a system of mechanism, which carries, moves, or regulates the motion of a rule in a machine.
Sorry, no etymologies found.
Vail, in the practice of the first line, grew accustomed to sending messages by dipping the end of the wire in the mercury cup, -- the beginning of the present transmitting instrument, which is also his invention -- and Morse's "port-rule," types, and other complicated arrangements, went into the scrap-heap.
a series of types carried on a port-rule or composing-stick, which travelled at a uniform speed.