A speedometer or a speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the 1900s, and as standard equipment from about 1910 onwards. Speedometers for other vehicles have specific names and use other means of sensing speed. For a boat, this is a pit log. For an aircraft, this is an airspeed indicator.
Charles Babbage is credited with creating an early type of a speedometer, which were usually fitted to locomotives.
The electric speedometer was invented by the Croatian Josip Belušić in 1888, and was originally called a velocimeter.