bulb engines in their Typ 1 motor plough, produced from 1912 to 1925. Munktells Mekaniska Verkstads AB, in Eskilstuna, Sweden, produced agricultural tractors with hot bulb engines from 1913 onwards. Heinrich Lanz AG, in Mannheim, Germany, started to use hot bulb engines in 1921, in the Lanz HL tractor. Other well known tractor manufacturers that used bulb engines were Bubba, Gambino, Landini and Orsi in Italy, HSCS in Hungary, SFV in France, and Ursus in Poland (who produced the Ursus C-45, a direct copy of the 1934 Lanz Bulldog D 9506, after World War II). At the start of the 20th century there were several hundred European manufacturers of hot bulb engines for marine use. In Sweden alone there were over 70 manufacturers, of which Bolinder is the best known; in the 1920s they had about 80% of the world market. The Norwegian Sabb was a very popular hot bulb engine for small fishing boats, and many of them are still in working order. In America, Standard, Weber, Reid, Stickney, Oil City, and Fairbanks Morse built hot bulb engines. A limitation of the design of the engine was that it could only run over quite a narrow (and low) speed band, typically 50 to 300 rpm. This made the hot bulb engine difficult to adapt to automotive uses, other than vehicles such as tractors, where speed was not a major requirement. This limitation was of little consequence for stationary applications, where the hot bulb engine was very popular. Owing to the lengthy pre-heating time, hot bulb engines only found favour with users who needed to run engines for long periods of time, where the pre-heating process only represented a small percentage of the overall running period. This included marine use — especially in fishing boats — and pumping or drainage duties. The hot bulb engine was invented at the same time that dynamos and electric light systems were perfected, and electricity generation was one of the hot bulb engine's main uses. The engine could achieve higher R.P.M. than a standard reciprocating steam engine, although high-speed steam engines were developed during the 1890s, and its low fuel and maintenance requirements, including the ability to be operated and maintained by only one person, made it ideal for small-scale power generation. Generator sets driven by hot bulb engines were installed in numerous large houses in Europe, especially in rural areas, as well as