James Watt

James Watt (1736–1819) was a Scottish inventor and mechanical engineer whose improvements to the steam engine contributed substantially to the Industrial Revolution.[1][5] Although Watt invented and improved a number of industrial technologies, he is best remembered for his improvements to the steam engine.[1]

Early Life and Education

James Watt was born in Greenock on the River Clyde. His father was a wealthy shipbuilder and shipowner and his mother also came from a privileged background.[11] Watt's father, the treasurer and magistrate of Greenock, ran a successful ship- and house-building business.[1] Watt's paternal grandfather, Thomas Watt (1642–1734) was an import to Crawfordsdyke near Greenock in its early days, coming from Aberdeenshire and carrying skills as a teacher of mathematics, or "professor" of the subject as he was sometimes styled.[16]

James was not a healthy child and most of his schooling was undertaken at home by his mother.[11] A delicate child, Watt was taught for a time at home by his mother; later, in grammar school, he learned Latin, Greek, and mathematics.[1] For the most part he was educated by his parents at home. His father taught him writing and arithmetic, and his mother taught him reading.[13]

Of much more interest to James was his father's store, where the boy had his own tools and forge (furnace to shape metals), and where he skillfully made models of the ship's gear that surrounded him.[13] The source for an important part of his education was his father's workshops, where, with his own tools, bench, and forge, he made models (e.g., of cranes and barrel organs) and grew familiar with ships' instruments.[1]

It was not until he went to the Grammar School at the age of 13 that his mathematical ability became obvious. In the evenings he worked in his father's Greenock workshop making models and repairing nautical instruments.[14]

Professional Development and Training

Deciding at age 17 to be a mathematical-instrument maker, Watt first went to Glasgow, where one of his mother's relatives taught at the university, and then, in 1755, to London, where he found a master to train him.[1] In 1755 Watt went to London to serve his apprenticeship as an instrument maker. He spent a year working for John Morgan, mastering in 12 months the craft which normally required three or four years training.[14]

Although his health broke down within a year, he had learned enough in that time "to work as well as most journeymen." Returning to Glasgow, he opened a shop in 1757 at the university and made mathematical instruments (e.g., quadrants, compasses, scales).[1] A Professor at Glasgow University, Joseph Black, arranged instead for Watt to set up his workshop within the university, which he did in 1757.[11]

Key Influences and Mentors

He met many scientists and became a friend of British chemist and physicist Joseph Black, who developed the concept of Latent heat.[1] While there he attended the lectures of Joseph Black, who was developing his theory of Latent heat, and he also became well acquainted with John Robison, a brilliant young chemist.[2] One of his University friends was Professor Black, who had discovered Latent heat previously and had been lecturing on it without Watt's knowledge. They shared many interesting conversations after Watt told Professor Black of his "discovery".[6]

Shortly afterward he met British physician, chemist, and inventor John Roebuck, the founder of the Carron Works, who urged him to make an engine. He entered into partnership with him in 1768, after having made a small test engine with the help of loans from Joseph Black.[1]

Steam Engine Innovation

Watt's work with the steam engine began in 1764, when he was requested to repair a Newcomen steam engine used at the university. Designed by English engineer Thomas Newcomen in the early 18th century, the engine was incredibly inefficient.[5] In 1764 Watt observed a flaw in the Newcomen steam engine: it wasted a lot of steam. Watt deduced that the waste resulted from the steam engine's single-cylinder design.[1]

In May 1765, after wrestling with the problem of improving it, he suddenly came upon a solution—the separate condenser, his first and greatest invention.[1] Watt had realized that the loss of Latent heat (the heat involved in changing the state of a substance—e.g., solid or liquid) was the worst defect of the Newcomen engine and that therefore condensation must be effected in a chamber distinct from the cylinder but connected to it.[1]

Created by Watt during the 18th century, this engine addressed the inefficiencies of its predecessors by employing a "separate condenser," which conserved steam and reduced fuel consumption by approximately 75%.[2] Watt patented the device in 1769.[1]

Partnership with Matthew Boulton

After Roebuck went bankrupt in 1772, English manufacturer and engineer Matthew Boulton, the manufacturer of the Soho Works in Birmingham, took over a share in Watt's patent. Bored with surveying and with Scotland, Watt immigrated to Birmingham in 1774.[1] After Watt's patent was extended by an act of Parliament, he and Boulton in 1775 began a partnership that lasted 25 years. Boulton's financial support made possible rapid progress with the engine.[1]

In the next year, the first two Watt engines were installed, and many more would follow. Business improved significantly when Watt invented a rotary motion steam engine in 1781 that could be used for a wider variety of applications and a double-acting engine, which featured pistons that pulled as well as pushed.[5]

Additional Inventions and Innovations

To describe the efficiency of his engines, James Watt coined the term 'horsepower'. This allowed the output of steam engines to be measured and compared with the power output of draft horses.[3] James Watt's contribution to industry efficiency was commemorated by naming the watt (W) for him. The watt is the unit of power in the International System of Units (SI) equal to one joule of work performed per second.[1]

Watt's micrometer, designed between 1770 and 1771, was what we would now call a 'rangefinder'. It was used for measuring distances, and was essential for his canal surveying work. Adapted from a telescope, with adjustable cross-hairs in the eye-piece, it was particularly useful for measuring distances between hills or across water.[3]

Around 1766, James Watt devised a portable version. The device was mounted on three legs, and consisted of a box which opened out to form a flat surface, with an adjustable arm holding an eye-piece. Jointed parallel rulers mounted beneath the board held both a brass point and a pencil, used to trace and sketch the object to be reproduced.[3]

Personal Life

In 1764 he married his cousin Margaret Miller, who, before she died nine years later, bore him six children.[1] His wife died in childbirth in 1772. In 1777, he was remarried to Ann Macgregor, daughter of a Glasgow dye-maker.[17] Ann MacGregor was the daughter of a dye maker in Glasgow. They had two children: Janet, who died at 15, and Gregory, who lived to become a geologist.[23]

Drawings and paintings of Watt show a tall, handsome man, rather Jeffersonian in appearance, who wore his hair well over his ears, as was the style. Along with his prominent forehead and thoughtful expression, most portraits show a slight stoop to the shoulders and generally suggest a delicate constitution.[7]

Later Years and Retirement

In 1800, Watt's patent expired, and he turned his share of the business over to his son James. The inventor then retired, quite wealthy, to Heathfield Hall, a home he had built near Birmingham, where he continued to work on mechanical inventions.[7] In 1790, James Watt built a mansion known as Heathfield Hall.[23] He retired ten years later and lived a life of leisure. He often travelled to visit family and friends with his wife.[23]

He had developed many warm friendships, as well as a gentle personality characterized by modesty, wide-ranging interests, and a sense of humor.[7] Despite his groundbreaking work in steam engine technology, Watt also had a passion for botanical studies and was a skilled gardener in his spare time. Watt had a great sense of humor and was known for his witty remarks and clever observations, which endeared him to many of his contemporaries.[17]

Legacy and Impact

His improvements to the steam engine were a significant factor in the Industrial Revolution, and when the Watt engine was paired with Thomas Edison's electrical generator in the late 19th century, the generation of electricity on a large scale was possible for the first time.[5] What's more, Watt's steam engine opened up an entirely new field of application: it enabled the steam engine to be used to operate rotary machines in factories such as cotton mills. Unsurprisingly, demand for Watt's steam engine was high, and it was quickly adopted across multiple industries.[1]

In addition he was made a fellow of the Royal Society of Edinburgh and of the Royal Society of London; and he was made one of a small number of foreign associates of the French Academy of Sciences. There are statues of him at Westminster Abbey; in Birmingham; and at his birthplace in Greenock.[11]

The location of James Watt's birth in Greenock is commemorated by a statue close to his birthplace. Several locations and street names in Greenock recall him, most notably the Watt Memorial Library, which was begun in 1816 with Watt's donation of scientific books, and developed as part of the Watt Institution by his son.[21]

James Watt lived to the ripe old age of 83. He died at his home on August 25, 1819. His remains are inside the expanded church of St. Mary's in Handsworth.[23] Watt was buried in the grounds of St. Mary's Church, Handsworth, in Birmingham. Later expansion of the church, over his grave, means that his tomb is now buried inside the church.[21]