As all the existing streets were already built up, new houses were built on the remaining open spaces as well as on gardens and land at the rear of existing properties, and others were built outside the area of the old city. Over a period of 30 years, the number of houses in Coventry almost doubled from 2,930 in 1801, to 5,865 in 1831. In 1842 an Act of Parliament took away Coventry's county status and re-defined its boundaries as a city, but in recognition of its need to expand the revised boundaries enclosed 1,486 acres (6.01 km2), a considerably larger area than that of the old walled city. During the next 50 years, there were another two boundary extensions which absorbed further outlying districts, increasing the enclosed area to 4,417 acres (16.78 km2) in 1899. 20th century Industrial developments The city continued to produce ribbons, woven labels and other small textile items, and 1904 heralded the opening of Courtaulds' first silk works at Foleshill in Coventry. The company was the first to produce nylon yarn in Britain in 1941. The first British motor car was made in Coventry in 1897 by The Daimler Motor Company Limited, and a growing number of other small motor manufacturers began to appear. The progress of this new industry was slow at first, but within 10 years the motor trade was employing some 10,000 people, and by the 1930s bicycle making had largely been replaced by motor manufacture which grew to employ 38,000 people by 1939. Coventry had become a centre of the British motor industry; Jaguar, Rover and Rootes being just three of many famous British manufacturers to be based in the area. The cycle and motor manufacturing industries brought into existence a wide variety of subsidiary trades. Most notably these were general engineering, metal casting, drop forging, chain-making and the manufacture of instruments and gauges, machine tools, and all types of electrical equipment. The manufacture of aircraft, aero engines and related equipment also took place in Coventry as early as 1916, and during World War II the aircraft industry dwarfed all other local industries. With the outbreak of war many of the motor firms switched to aircraft work, and the whole of Coventry's industrial skills and resources turned to war production of one sort or another. Changing character Construction of a new Council House to take on the administration duties performed by