penny-farthing design in 1870. His company soon began producing these bicycles, and Coventry soon became the centre of the British bicycle industry. Further innovation came from Starley's nephew, John Kemp Starley, who developed the Rover safety bicycle, the first true modern bicycle with two equal-sized wheels and a chain drive in 1885. By the 1890s Coventry had the largest bicycle industry in the world, with numerous manufacturers, however bicycle manufacture went into steady decline from then on, and ended entirely in 1959, when the last bicycle manufacturer in the city relocated. By the late-1890s, bicycle manufacture began to evolve into motor manufacture. The first motor car was made in Coventry in 1897, by the Daimler Company. Before long Coventry became established as one of the major centres of the British motor industry. For most of the early-20th century, Coventry's economy boomed, in the 1930s, a decade otherwise known for its economic slump, Coventry was noted for its affluence; in 1937 Coventry topped a national purchasing power index, designed to calculate the purchasing power of the public. In the early-to-mid 20th century, a number of famous names in the British motor industry became established in Coventry, including Alvis, Armstrong Siddeley, Daimler, Humber, Jaguar, Riley, Rootes, Rover, Singer, Standard, Swift and Triumph . By the 1970s, most of these companies had been absorbed and rationalised into larger companies, such as British Leyland which subsequently collapsed. The research and design headquarters of Jaguar Cars is in the city at their Whitley plant and although vehicle assembly ceased at the Browns Lane plant in 2004, Jaguar's head office returned to the city in 2011, and is also sited in Whitley. Jaguar is owned by the Indian company, Tata Motors. With many of the city's older properties becoming increasingly unfit for habitation, the first council houses were let to their tenants in 1917. With Coventry's industrial base continuing to soar after the end of the Great War a year later, numerous private and council housing developments took place across the city in the 1920s and 1930s. The development of a southern by-pass around the city, starting in the 1930s and being completed in 1940, helped deliver more urban areas to the city on previously rural land. In the 1910s plans were created to redevelop Coventry's narrow streets and by the 1930s the plans were put into action with Coventry's medieval street of Butcher Row being