A go-kart, also written as go-cart (often referred to as simply a kart), is a type of sports car, close wheeled car, open-wheel car or quadracycle. Go-karts come in all shapes and forms, from non-motorised models to high-performance racing karts. Karting is a type of racing in which a compact four-wheel unit called a go-kart is used. In the beginning, Art Ingels invented the first go-kart in Los Angeles in 1956. Etymology The exact origin of the term is unclear. One of the first appearances of the term is an 1885 painting by the Scottish artist Hugh Cameron RSA: "The Go-Cart". It is also unclear why the "C" was later changed to a "K". Non-motorised Gravity racers, in North America usually referred to as Soap Box Derby carts, are the simplest type of go-karts. They are propelled by gravity. Go-karts without motors (quadracycles) may also be propelled by bicycle pedals. Motorised Engines Traditionally, small two-stroke and four-stroke internal combustion engines are used in motorised go-kart racing. Power is transmitted from the engine to the rear axle by way of a chain (some rentals use a belt). Four-stroke engines can be standard air-cooled industrial based engines, sometimes with small modifications, developing from about . Briggs & Stratton, Tecumseh (company closed in 2008), Kohler, Robin, and Honda are manufacturers of such engines. They are adequate for racing and fun kart applications. There are also more powerful two-stroke engines available from manufacturers like Yamaha, KTM, Biland, or Aixro (Wankel engine) offering from . They run at up to 11,000 rpm, and are manufactured specifically for karting. PRD makes the PRD Fireball, a two-stroke engine delivering at 15,580 rpm. Electric go-karts are available, requiring only that the batteries of the karts be plugged into an array of chargers after each tun. Since they are pollution-free and emit no smoke, the racetracks can be indoors in controlled environments. Electric karts powered by lead-acid batteries can run a maximum of 20–30 minutes before the performance is affected, while those powered by lithium batteries may last up to 2 hours on a single charge. Some karts have been fitted with hydrogen fuel cells. High-performance electric go-karts for amusement parks and indoor tracks may have external electronic controls in the event of an accident or other hazards, in which the track attendant or the race referee can remotely slow down or stop all vehicles on the track via