First Diesel Engine

Diesel engine was invented by Dr.R.Diesel in year 1893. The heavy oil fuel was injected into the engine cylinder mixed with a jet of compressed air. This air-blast injection priciple id now seldom used today.
In the engine invented by Ackroyd Stuart,two years earlier than Dr.Diesel filed his first patent, the oil was injected into the cylinder without and compressed air, that is as a spray or mist of oil particles. A hot bulb or other external source of heat was used for ignition. This airless or solid injection priciple is now used on the majority of modern diesel engines.