James Watt was born in Greenock, the son of an engraver. Encouraged by his father, he studied geometry and spent a year with a London instrument maker before going to work near Glasgow University. There he quickly impressed his clients, who included the chemist Joseph Black, with the quality of his workmanship. In 1764 while repairing a Newcomen engine, he realised it could be made more efficient if the steam was condensed outside the cylinder. The following year he went into partnership with Dr John Roebuck to build a more efficient steam engine. Their efforts were dogged by financial problems and technical difficulties and Watt was forced to undertake surveying work for canal companies.
In 1774 he was offered a partnership by Matthew Boulton, who had just built the imposing Soho Foundry near Birmingham. Watt left Scotland and within a year had perfected his improved stationary steam engine. These were quickly adopted for blowing iron furnaces and for draining mines, particularly Cornish tin mines. His next major innovation was the development in 1781 of the rotary engine which made it possible to drive forge hammers by steam. Orders for the new engine soon flowed in. Other improvements followed, including the centrifugal governor to regulate the speed of the engine three years later.
Much of his later life was taken up with defending the rights to his patents which effectively gave Boulton & Watt a monopoly of the market for driving engines for almost twenty years. His achievements were recognised by the University of Glasgow in 1806 when he was awarded the honorary degree of Doctor of Laws (LL.D). He is commemorated by a monument in Westminster Abbey as the handmaid of the industrial revolution.