This is a brass nautical ship telegraph by the Chadburn's from Liverpool in England. Usually these are set on a vertical brass pedestal base as well. A telegraph, or E.O.T (Engine Order Telegraph) is used for the bridge captain to communicate the desired speed to the engine room. Chadburn's was established in 1872 and your telegraph dates to just about 1900. Not having the pedestal base with this does impact value. The estimate is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.