neck where it attached to the cylinder, a high degree of turbulence was set up as the ignited gases flashed through the neck into the cylinder, where combustion was completed. As the engine's load increased, so did the temperature of the bulb, causing the ignition period to advance; to counteract pre-ignition, water was dripped into the air intake. Hot bulb engines were produced until the late 1920s, often being called "semi-diesels", even though they were not as efficient as compression ignition engines. They had the advantage of comparative simplicity, since they did not require the air compressor used by early Diesel engines; fuel was injected mechanically (solid injection) near the start of the compression stroke, at a much lower pressure than that of Diesel engines. Oil-engined locomotive Richard Hornsby and Sons built the world's first oil-engined railway locomotive LACHESIS for the Royal Arsenal, Woolwich, England, in 1896. They also built the first compression-ignition powered automobile. Oil engines outside the UK Sweden Similar engines were built by Bolinder in Sweden and some of these still survive in canal boats. United States Hot bulb engines were built in the USA by the De La Vergne Company of New York City, later the New York Refrigerating Company – inventing the modern refrigerator in 1930, who purchased a licence in 1893. Akroyd engine and Diesel engine Both the Diesel engine, and the Akroyd engine run the same kind of fuel, petroleum oil, which has led to a dispute about whether or not the Diesel engine is based upon the Akroyd engine. The fact that the Diesel engine's operating principle differs from the operating principle Rudolf Diesel describes in his essay Theory and Construction of a Rational Heat Motor further contributed to this. The Akroyd engine was the first functional internal combustion engine that could use petroleum oil as fuel. It was operational in 1891, six years before the Diesel engine first ran. However, after the Diesel engine had proven successful, "Diesel engine" became the synonym for an engine that ran on any sort of petroleum oil. "Oil engines" that used the Akroyd operating principle were called "Semi-Diesel", and the name "Akroyd", which had been associated with oil engines, fell out of use. Therefore, Herbert Akroyd Stuart sought to replace the term Diesel engine with Akroyd engine in the early 20th century. Herbert Akroyd Stuart had two patents, No. 7146 Improvements in Engines Operated by