The Wealden iron industry in the Weald was the site of the first blast furnace in Britain in 1491, and produced much of Britain's cast iron until the 1770s. Portsmouth Block Mills were the site of the world's first metal machine tools, built for the manufacture of wooden pulleys, invented by Henry Maudslay, and the site of the world's first industrial assembly line in 1803. South Foreland Lighthouse on 8 December 1858 was the world's first lighthouse with electric light, with the first type of industrial electrical generator made by Frederick Hale Holmes, from work he had carried out with Floris Nollet of Belgium, and 36 permanent magnets.