Economics and Trade • Movers and Shakers: A Discussion about Industry and Power
Watt was born on January 19, 1736 in Greenock, Scotland as the fourth of five children, three of whom died in infancy. His mother, Agnes Muirhead, was descended from a well-known Scottish clan dating back to the 11th century. His father, James Watt Sr., was a carpenter, instrument maker, and merchant. Watt had health problems throughout his childhood and early adult years. Because of his health, Watt was initially taught at home rather than at school. When he did go to school, the only subject that interested him was mathematics, probably because both his grandfather and uncle were mathematicians. He spent most of his teenage years working in his father's shop, learning metalworking, woodworking, and instrument making. Watt's mother died when he was 17, and he decided it was time to strike out on his own.
Introduction to the Steam Engine
After learning to make instruments during a short apprenticeship in London, Watt moved to Glasgow, Scotland to pursue a career as an instrument maker. However, the craft guilds would not let him work unless he finished his apprenticeship, which would take another six years. Finally, friends found him a position as an instrument maker for the University of Glasgow, which was exempt from guild restrictions. While at the university, he made friends with faculty members John Robison and Joseph Black, who introduced him to the technology of steam engines and helped him with scientific issues through much of his career.
On July 16, 1764, Watt married his cousin, Margaret Miller, and the couple subsequently had two children, including a son, James Watt III. Unfortunately, Margaret died in 1774. Watt then married Ann McGregor in 1776, and they eventually had an additional two children, Gregory and Jessy. Neither lived beyond early adulthood.
In order to understand Watt's contributions to the scientific community, it is necessary to know what a steam engine is. A steam engine boils water to make steam; injects the steam into a cylinder to move a piston back and forth; and connects the piston to another machine that needs power, like a pump, a textile machine, a mill, or a conveyor belt. The components of the engine are a boiler; a cylinder containing the piston; a condenser to turn the steam back into water; and levers, wheels, and beams to connect the piston to the machinery. In early steam engines, the piston was moved by condensing the steam directly in the cylinder to create a vacuum that pulled the piston down. In modern ones, high-pressure steam is alternately injected into each side of the piston in the cylinder, which produces more power without having to create a vacuum in the cylinder or provide a condenser. Watt was the link between the early and the modern engines.
The first steam engines were not designed by Watt but by Thomas Savery late in the 17th century, and they were improved on by Thomas Newcomen early in the 18th century. They were used for pumping water out of coal mines and proved to be awkward and unreliable machines. They did, however, demonstrate the potential of steam as a source of power.
Revolutionizing the Steam Engine
Watt made his first improvement to the steam engine in 1765, while working at the University of Glasgow. Using the Newcomen engine as a model, he removed the condensing step from the cylinder with the piston and put the condenser in a separate chamber, which made the steam engine much more powerful and reliable. Another of his inventions alternately injected steam into each side of the piston so that it was powered in both directions and almost doubled the power produced. Those two developments revolutionized the steam engine.
In 1766, Watt resigned from the university and started an engineering company to concentrate on research for the steam engine. In 1769, he filed a patent on the separate condenser and brought in a partner, John Roebuck, to manufacture the condensers and other products he invented. During that period, Watt invented other ways to improve the steam engine's efficiency, including a governor to control the engine's speed, an indicator to show the steam pressure, and novel ways to convert the motion of the piston to drive different types of machines.
Initially the business did very well, but by 1774, technical and financial problems caused Roebuck to lose interest. One of the investors in the company, Matthew Boulton, bought out Roebuck's share of the partnership, and Watt moved to Birmingham, England, where Boulton was located, in 1775. They built a new factory in the Soho district to build steam engines. The resulting company, called the Boulton & Watt Company, became an immensely successful business that manufactured steam engines to provide power for such industries as textiles, manufacturing, and mining. During the next 25 years, the partners sold over 500 engines.
Watt and Boulton's partnership lasted until 1800, when they transferred their shares of the business to their sons, James and Matthew respectively, and both of the older men retired. Although Watt did not invent nor manufacture steam engines for such movable uses as locomotives, the technology he developed for his stationary engines was crucial to the 19th-century development of steam engines for tractors, trains, and ships.
The First Modern Engineer
Watt spent the rest of his life doing research on various inventions. In addition to steam engines, he developed several novel mechanical concepts that led later generations of physicists to whole new fields of theoretical mechanics. He was also a civil engineer and surveyor of canal routes, and he modified a telescope to measure distances to nearby objects (that instrument is now called a transit and is still used by surveyors). He was an excellent chemical engineer, as well, and he developed processes to bleach and dye textiles and to produce alkali and other chemicals in commercial quantities. Furthermore, he invented a letter-copying machine, a drawing machine that added perspective to drawings, and an instrument that measured acidity in liquids. In many ways, Watt was the first to adapt scientific principles to solve engineering problems—basically, the first modern engineer.
In 1785, Watt was elected to Britain's prestigious Royal Society of London, an organization dedicated to scientific inquiry. In 1806, he was awarded an honorary doctorate from the University of Glasgow. The British government also offered him the title of baronet, but he graciously declined. Watt died on August 25, 1819 in Heathfield, England. In later years, a unit of electrical power was named the "watt" in his honor.
Briggs, Asa, James Watt and the History of Steam Power, 1949; Briggs, Asa. The Power of Steam: An Illustrated History of the World's Steam Age. Chicago: University of Chicago Press, 1983; Von Tunzelmann, G. N., Steam Power and British Industrialization to 1860, 1978.
Dubrulle, Elizabeth. "James Watt." World History: The Modern Era, ABC-CLIO, 2019, worldhistory.abc-clio.com/Search/Display/316180. Accessed 15 Oct. 2019.
Entry ID: 2169905