Engine order telegraph
An engine order telegraph or E.O.T., also referred to as a Chadburn, is a communications device used on a ship (or submarine) for the pilot on the bridge to order engineers in the engine room to power the vessel at a certain desired speed. == Construction == In its original form, from the 19th century until about 1950, the device usually consisted of a round dial about 9 inches (230 mm) in diameter with a knob at the center attached to one or more handles, and an indicator pointer on the face of the dial.