The Midlands Enlightenment therefore occupies a key cultural position linking the expansion of knowledge of the earlier Scientific Revolution with the economic expansion of the Industrial Revolution. 18th century Birmingham saw the widespread and systematic application of reason, experiment and scientific knowledge to manufacturing processes to an unprecedented degree, resulting in a series of technological and economic innovations that transformed the economic landscape of a wide variety of industries, laying many of the foundations for modern industrial society. In 1709 Abraham Darby I, who had trained as an apprentice in Birmingham and worked in Bristol for the Birmingham ironmonger Sampson Lloyd, moved to Coalbrookdale in Shropshire and established the first blast furnace to successfully smelt iron with coke. In 1732 Lewis Paul and John Wyatt invented roller spinning – the "one novel idea of the first importance" in the development of the mechanised cotton industry – and in 1741 they opened the world's first cotton mill in Birmingham's Upper Priory. In 1765 Matthew Boulton opened the Soho Manufactory, pioneering the combination and mechanisation of previously separate manufacturing activities under one roof through a system known as "rational manufacture". By the end of the decade this was the largest manufacturing unit in Europe with over 1,000 employees, and the foremost icon of the emerging factory system. John Roebuck's 1746 invention of the lead chamber process first enabled the large-scale manufacture of sulphuric acid, while James Keir pioneered the manufacture of alkali at his plant in Tipton; between them these two developments marked the birth of the modern chemical industry.