chain from each side of a differential fixed to the chassis frame. Dennis Brothers developed and patented a reliable worm drive into a differential mounted on the back axle. Another feature of that period was spring drive, a torsional shock absorber mounted at the input end of the drive line. Commercial vehicles Commercial vehicle activity increased. Their first was a van for Harrods in London. Dennis made its first bus in 1903 and their first fire engine in 1908 — for Bradford Council Fire Department. The last car was made in 1913 after the Dennis brothers saw there was less competition in the commercial vehicle market. The rate of growth of the business may be gauged from the regular expansions on their new site at Woodbridge Hill on the outskirts of Guildford — in 1907, 1910, 1912 and 1913. In 1913 Dennis Brothers moved their main operations to a new much larger building of almost four acres on the twelve-acre site at Woodbridge leaving their purpose-built Onslow Street premises solely for repairs. In March 1913 the investing public learnt that Dennis Brothers was a manufacturer of motor-vans, motor-lorries, motor-fire-engines, motor-cars etc. The brothers' offer of shares to the public was substantially over-subscribed and Dennis Brothers Limited became a publicly listed company. Rising international tensions precipitated a major contract for supply of 1,000 3-ton "subsidy" lorries to private buyers on terms set by the War Office. Taking the subsidy obliged the buyer to release the vehicle to the War Office in time of war. Materials had been ordered but no subvention lorries completed when the situation changed. World War I After August 1914's outbreak of hostilities production was reduced to the subvention type 3-ton military lorries, now supplied directly to the War Office, and the Dennis turbine fire engine. The Ministry of Munitions took complete control of the whole business in 1915. New buildings were added to contain the manufacture of munitions. Between wars 1920s Following 1918's armistice there was a glut of war surplus vehicles and a consequent collapse in demand for new trucks. To try to compensate the Dennis product range was expanded into municipal vehicles — dustcarts (refuse collection), street cleaning vehicles, sewage tankers and pumps etc. Municipal vehicles do not suffer from the fluctuations of demand experienced by the overall economy. Buyers tend to replace them at fixed periods so there is an element of longer term