A speedometer is a gauge that measures and displays the instantaneous speed

Speed

In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...

 of a land vehicle. Now universally fitted to motor vehicle

Motor vehicle

A motor vehicle or road vehicle is a self-propelled wheeled vehicle that does not operate on rails, such as trains or trolleys. The vehicle propulsion is provided by an engine or motor, usually by an internal combustion engine, or an electric motor, or some combination of the two, such as hybrid...

s, 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

Airspeed indicator

The airspeed indicator or airspeed gauge is an instrument used in an aircraft to display the craft's airspeed, typically in knots, to the pilot.- Use :...

.

The speedometer was invented by the Croatia

Croatia

Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

n Josip Belušić

Josip Belušic

Josip Belušić was a Croatian inventor.In 1888 Josip Belušić invented and designed the first electric speedometer. Belušić was born in the region of Labin in Istria, and was a professor in Koper. This invention was patented in Austria-Hungary under the name of "velocimeter."...

in 1888, and was originally called a velocimeter.
The eddy current

Eddy current

Eddy currents are electric currents induced in conductors when a conductor is exposed to a changing magnetic field; due to relative motion of the field source and conductor or due to variations of the field with time. This can cause a circulating flow of electrons, or current, within the body of...

 speedometer has been used for over a century and is still in widespread use.