The Steam Engine Powers the Industrial Revolution
The Steam Engine Powers the Industrial Revolution
The invention of the steam engine in 1698 by Thomas Savery (1650?-1715) was among the most important steps toward the modern industrial age, in which machine power replaced human or animal muscle-power. Savery's 1698 patent of his steam engine—designed to help remove water that seeped into the bottom of coal mines—laid the foundation for a series of refinements and re-designs by Thomas Newcomen (1663-1729) and, most notably, James Watt (1736-1819) that resulted in the transformation not only of work, but also of the entire society for whose support that work was done. While any number of other inventions and devices played major parts in the march toward industrialization, it was the steam engine above all that established the place and importance of the machine in the modern world, and made possible the creation of the large factories that were among the most significant undertakings of industrial civilization.
By the late 1600s England had a fuel problem. Harsh winters and a growing population had resulted in the depletion of many of England's great forests, as trees were cut down and burned. What wood remained was more valuable as lumber than fuel. To solve the problem, England turned to its rich deposits of coal. Unfortunately, the mining of coal created its own set of problems, primarily the tendency of water to seep into the lowest reaches of coal mines, making it difficult if not impossible to extract the coal. Some attempts were made to remove the water by using hand-pumps to create vacuums in tubes: the water would then be sucked up the vacuum. Hand-pumping, however, was slow and ultimately ineffectual against the volume of water in the mineshafts.
Inventor and merchant Thomas Savery, of Devonshire, England, aware of experiments with steam and pressure, turned his technical abilities to the creation of a mechanical device for using those properties to raise water. Savery's device involved heating water in a boiler; the boiling water produced steam, which was routed through pipes to a receptacle, which was in turn connected to a suction pipe that extended down into the water to be raised. Once the receiving vessel was filled with steam, it was sprayed with cold water. The sudden cooling of the vessel quickly condensed the steam, creating a vacuum that resulted in a change in atmospheric pressure within the suction tube, forcing water up its length. Savery was granted a patent for the device in 1698.
Four years later he published a treatise describing his invention, The Miners Friend; Or, An Engine to Raise Water by Fire. His engines became known as Miners' Friends, although it is unclear whether any of them found actual use in coal mines.
There were some technical problems with the Miners' Friends, not least of which was the poor quality of metal fittings at the time. Because the device required control of internal pressure—technically, Savery's invention was an atmospheric engine rather than a true steam engine—it was vital that all of the pipes be tightly sealed. Such seals proved difficult to maintain, however, and Savery's devices suffered from constant failure of the pipe joints.
Another Devonshire inventor, blacksmith Thomas Newcomen, made refinements to Savery's device that turned it into a true steam engine. Where the Miners' Friend used an open fire, Newcomen's engine employed a sealed boiler. Above the boiler rested a piston cylinder; the piston was connected to a pump, whose weighted rod raised the piston to the top of the cylinder. With the piston at the top of the cylinder, the cylinder itself was filled with steam from the boiler. Cold water that was sprayed into the steam-filled cylinder condensed the steam, creating a vacuum, which drew the piston downward, completing the pump cycle. Each completed cycle raised the water in which the bottom of the pump rested. The first known working model of a Newcomen engine was deployed in 1712, although it is believed that many prototypes preceded it.
Newcomen's refinements greatly increased the effectiveness of the steam-driven water-lifting device, if not its efficiency. However, Newcomen's engine faced numerous legal problems as a result of Savery's patent and the belief that Newcomen infringed Savery's rights. After much negotiation Newcomen agreed to pay royalties to Savery and, later, to the syndicate that acquired Savery's patent after his death.
Efficiency issues were less easily resolved. While Newcomen's expertise as an ironworker contributed to improved joints and seals in the boiler and pipe system, there remained a severe flaw to his engine. Because the piston cylinder had to be cooled for every cycle and re-heated for each subsequent cycle, tremendous amounts of fuel were required simply to renew the steam. This mattered little at the coal mines, where there was, obviously, plenty of fuel. Indeed, for deeper mines, several Newcomen engines were used in sequence, raising water from one level to the next, each engine burning large amounts of coal to power each stroke of its pump. Elsewhere, though, the amount of fuel required became an obstacle to the engines' widespread use.
Newcomen engines did find wider use, however, with ongoing refinements and improvements, and the age of steam had truly begun. The full potential of steam, though, would await the attention of Scottish mechanical engineer James Watt.
Watt, an instrument maker, was asked in the 1750s to repair a Newcomen engine. Careful observation of the engine's workings inspired Watt. The inefficiencies were the result of combining the steam cycle and the condensing cycle in the same cylinder. Not only was the combination inefficient, it placed terrific and repetitive stress on the cylinder. During a Sunday stroll Watt had an insight: the condensation process should be separated from the piston cylinder. He quickly designed a new steam engine, one in which the steam, having done its work, was guided away from the first cylinder and into a second, whose sole purpose was to serve as a vessel for condensation. Watt built a prototype—which still exists—in 1765 and was granted a patent in 1769.
The benefits of Watt's insight were dramatic. Improvements in thermal efficiency—the hot cylinder could remain hot, the cold cylinder cold—resulted in a great increase in the steam engine's economy of operation: less fuel was needed to accomplish more work. Backed by wealthy English manufacturer Matthew Boulton (1728-1809), Watt created in 1775 the Soho Foundry in Birmingham, England. From this foundry Watt engines poured forth, as did ongoing improvements. Perhaps the most important improvement was Watt's 1782 introduction of the double-acting mechanism, which allowed the engine to drive both forward and backward piston strokes, essentially doubling its capacity for work. A further refinement adapted the steam engine for rotary motion—the engine could be used to power movement in any direction, making it ideal not only for up and down pumping actions but also for any repetitive cycle of movement. Soon, steam engines were driving cotton and wool mills and finding their way into other industries, notably the emerging transportation industry, which adapted steam engines for railroads and ships. Industry itself responded, finding ever newer and more ambitious uses for the now versatile engine.
Steam itself proved versatile under Watt's command of its properties. He heated his offices with steam. He devised instruments for measuring engine efficiency, and governors for controlling steam engines from improper or dangerous operation. Awareness of the potential dangers of steam engines, in fact, prompted one of Watt's few oversights: to the end of his life he remained opposed to the use of high-pressure steam, despite the dramatic increase in efficiency that higher pressure offered.
Nor were his inventions limited to the steam engine. As the success of his engine spread, so did the business demands Watt faced: deluged by paperwork, he invented a chemical process for copying documents, a process that remained in use until the arrival of the typewriter, long after Watt's death.
As the importance of the steam engine grew, Watt also applied himself—and his engineering skills—to documenting and measuring the engine's capacity for work. He created a unit of measurement based on comparing mechanical power with that of the previous universal power source, the horse. Watt's measurement unit, horsepower, equated the ability of a horse to lift 33,000 pounds (14,969 kg) 1 foot (.3 m) in 1 minute. Horsepower remains universally known as an index of mechanical energy.
But that was not Watt's only contribution to the language of energy measurement. When he died at the age 83 his refinement of the steam engine was already well on its way to transforming every aspect of human society. To this day his name is known not only as that of an engineer and inventor, but as perhaps the most common of all units of energy measurement: the watt.
The impact of the steam engine cannot be over-stated—it belongs with the printing press, electric power, telegraphy and the telephone, and lately, the computer, as inventions that have exerted a dramatic and far-ranging influence on civilization.
From its beginnings as a device intended to serve a specific purpose—lifting water—the steam engine itself rose to lift all of society into the industrial age. The Industrial Revolution itself—the transformation of economy from a local mill-and-shop foundation to one based on huge central factories and wide, rapid distribution of goods—rests on a cloud of steam.
Virtually every industry was affected and altered by the steam engine. The coal mines for which Savery's Miners' Friends were first developed became more and more important as a source of fuel for the rapidly increasing number of steam engines; in turn, the increased efficiencies of the engines enabled the mines to be sunk ever deeper without flooding. Mines for other minerals quickly followed the route of coal mines, deeper and deeper into the earth. Metallurgy itself responded to the demand for ever tighter and more durable seals: improvements in metal-working made larger boilers possible, and larger boilers were able to drive larger pistons, which in turn powered larger and more powerful machines.
Those machines made possible the cornerstone of industrial society, the factory. Huge, centralized manufacturing operations grew up around the relatively cheap and increasingly efficient mechanical energy provided by steam engines. The textile industry was among the first beneficiaries of steam power, as engines were applied to driving great looms, tended by dozens of workers, producing vast quantities of fabric.
The ability to adapt steam engines, by way of mechanical linkages, to rotary drives enabled the creation of steam-powered transportation. Rail lines crossed nations and soon, continents; steamships traveled the oceans far faster than could sailing ships. Some models of early automobiles were steam-powered. Much of the freight carried by rail and steamships was produced in steam-driven factories. Steam heat, used for centralized heating, became more common.
As the importance of the factory increased, cities themselves increased in size as the population was drawn to work in the factories.
Industrialization proved a double-edged sword. Some workers, artisans, and craftsmen, seeing machines displace their skills, responded by following the lead of Ned Ludd and sabotaged factories. Over the course of the nineteenth century, conditions in factories prompted calls for social reforms and concerns for workers' rights. The growth of industrialized civilization, powered by steam (and later, electricity and petroleum) could be seen in skies that themselves grew dark with smoke from burning coal.
For good and ill, though, the inventions of Savery, Newcomen, and Watt altered the course of world civilization, providing a cheap and efficient source of energy and power that was adapted, and continues to be used in various forms, to drive civilization's engines.
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Carnegie, Andrew. James Watt. New York: Doubleday, Page & Company, 1905.
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Savery, Thos. The Miners Friend; Or, An Engine To Raise Water by Fire, Described. London: S. Crouch, 1702.
Thurston, Robert. A History of the Growth of the Steam Engine. New York: D. Appleton and Company, 1878.