George Ohm and James Watt

James Watt was born on 19 January, 1736 in Greenock, a seaport on the Firth of Clyde. His father was a shipwright, ship owner and contractor, while his mother, Agnes Muirhead, came from a distinguished family and was well educated. Both were Presbyterians and strong Covenanters. Watt attended school irregularly but instead he was mostly schooled at home by his mother. He exhibited great manual dexterity and an aptitude for mathematics, although Latin and Greek left him cold, and he absorbed the legends and lore of the Scottish people. When he was 18, his mother died and his father's health had begun to fail. Watt traveled to London to study instrument-making for a year, then returned to Scotland – to Glasgow – intent on setting up his own instrument-making business. However, because he had not served at least seven years as an apprentice, the Glasgow Guild of Hammermen (any artisans using hammers) blocked his application, despite there being no other mathematical instrument makers in Scotland. Watt was saved from this impasse by three professors of the University of Glasgow, who offered him the opportunity to set up a small workshop within the university. It was established in 1758 and one of the professors, the physicist and chemist Joseph Black, became Watt's friend. In 1764, Watt married his cousin Margaret Miller, with whom he had five children, two of whom lived to adulthood. She died in childbirth in 1772. In 1777 he married again, to Ann MacGregor, daughter of a Glasgow dye-maker, who survived him. She died in 1832. Watt had a brother by the name of John. He was shipwrecked when James was 17. Four years after opening his shop, Watt began to experiment with steam after his friend, Professor John Robison, called his attention to it. At this point Watt had still never seen an operating steam engine, but he tried constructing a model. It failed to work satisfactorily, but he continued his experiments and began to read everything about it he could. He...