3. A mechanical attachment to the steering wheel, which, in the absence of a tiller, shows the position of the helm. A compass in the cabin of a vessel, usually placed where the captain can see it at all hours, and thus inform himself of the vessel's course.
4. (Science: machinery) A machine or contrivance for indicating or recording something, particularly for keeping a check upon employees, as factory hands, watchmen, drivers, check takers, and the like, by revealing to their employers what they have done or omitted.
5. (Science: zoology) The tattler. See Tattler.