Speedometer

A digital, LCD speedometer in a Honda Insight

A speedometer or 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 early 20th century, and as standard equipment from about 1910 onwards.^[1] Other vehicles may use devices analogous to the speedometer with different means of sensing speed, eg. boats use a pit log, while aircraft use an airspeed indicator.

Charles Babbage is credited with creating an early type of a speedometer, which was usually fitted to locomotives.^[2]

The electric speedometer was invented by the Croat Josip Belušić^[3] in 1888 and was originally called a velocimeter.

^ Harris, William (10 July 2007). "How Speedometers Work". auto.howstuffworks.com. Retrieved 30 January 2015.
^ Lester, I.E. "Charles Babbage and the Difference Engine". NewMyths.com. Archived from the original on 3 August 2020. Retrieved 30 December 2022.
^ Sobey, Ed (2009). A Field Guide to Automotive Technology. Chicago Review Press. p. 78. ISBN 978-1-55652-812-5. Retrieved 30 January 2015.

[how-1] Harris, William (10 July 2007). "How Speedometers Work". auto.howstuffworks.com. Retrieved 30 January 2015.

[2] Lester, I.E. "Charles Babbage and the Difference Engine". NewMyths.com. Archived from the original on 3 August 2020. Retrieved 30 December 2022.

[3] Sobey, Ed (2009). A Field Guide to Automotive Technology. Chicago Review Press. p. 78. ISBN 978-1-55652-812-5. Retrieved 30 January 2015.

[1]

[2]

[3]