domestic illumination, heating and cooking. Many people experimented with coal distillation to produce a flammable gas, including Jean Tardin (1618), Clayton (1684) Jean-Pierre Minckelers, Leuven (1785) and Pickel (D)(1786). William Murdoch was successful. He joined Boulton and Watt, at the Soho manufactory in Birmingham in 1777, and in 1792 he built a retort to heat coal to produce the gas that illuminated his home and office in Redruth. His system lacked a storage method until James Watt Junior adapted a Lavoisier gazomètre for this purpose. A gasometer was incorporated into the first small gasworks built for the Soho manufactory in 1798. William Murdoch and his pupil Samuel Clegg went on to install retorts in individual factories and other workplaces. The earliest was in 1805, at Lee & Phillips, Salford Twist Mill, where eight gas holders were installed. This was shortly followed by one in Sowerby Bridge, constructed by Clegg for Henry Lodge. The first independent commercial gas works were built by the Gas Light and Coke Company in Great Peter Street, Westminster, in 1812, with wooden pipes laid to gas lights on Westminster Bridge on New Year's Eve in 1813. Public gas lights were seen as a means to reduce crime and until the 1840s they were regulated by police authorities. Because of safety concerns expressed by the Royal Society, the size of gas holders was limited to and they were enclosed in gasometer houses. In fact any small leak from an enclosed gas holder created a potentially explosive build-up of air and gas within the enclosing house, presenting a far greater danger than the original leak did; putting houses around gas holders was discontinued in the UK. In the United States, however, where gas needed to be protected from much more extreme weather, gasometer houses continued to be built and were architecturally decorative. The telescopic gas holder was first invented in 1824. The cup and dip (grip) seal was patented by Hutchinson in 1833, and the first working example was built in Leeds. Gas holders were then built all around the UK in great numbers starting in the 1850s. The first were the two-lift column-supported type; later they could have four lifts, being frame-guided, and they could be retrofitted with an additional flying lift. The large gas holders at Kings Cross, London, were built in the 1860s. William Gadd of Gadd & Mason in Manchester invented the spirally guided