Complex sentence: In 1904, Horstmann and his brothers founded Horstmann Gear to produce a variable speed gearbox he had invented for cars and motorcycles, which later became a general engineering company but specialising in gas street lighting controls, time switches, gauges, and latterly central heating controls.
Split into simpler sentences: In 1904, Horstmann and his brothers founded Horstmann Gear to produce a variable speed gearbox he had invented for cars and motorcycles. The firm later became a general engineering company and came to specialise in gas street lighting controls, time switches, gauges, and latterly central heating controls.