The Pumping Engine

[Part of a series: The Age of Steam]

In the early years of the eighteenth century, Thomas Newcomen devised the first practical engine for pumping water out of a mine. His engine condensed steam to generate power from the weight of the air, relying on the new scientific knowledge developed by Torricelli, Pascal, von Guericke, and others, in the previous century. The science of pressure thus came full circle – questions opened by mining pumps, when closed, had helped to develop a better one. We will see this interplay between practical mechanics and philosophical inquiry recur in this story.

But the streams of thought that led from Torricelli to Newcomen were meandering ones. The injection of hot steam from an external boiler to move a piston was by no means an obvious way to exploit the weight of the air. Inventors first tried a more direct approach – burning fuel within the piston itself.

The Gunpowder Engine

in 1661, von Guericke produced the first reverse suction pump, lifting weight with a piston by drawing the air out from under it with a suction pump. This was a fine demonstration of the weight of the air, but hardly a practical device, since it just turned one form of mechanical work (to pump out the air) into another, at a loss.

It was natural for inventors of the age to turn first to gunpowder, the most powerful source of energy known at the time, as a more effective way of evacuating the cylinder. A few pounds of gunpowder could drive a cannonball with enough force to crack a stone wall, stave in the oaken sides of a ship, or rip a column of men asunder. If that energy could be tamed and put to a more gradual kind of work, it could provide a new alternative to the watermill and windmill. Indeed, Christian Huygens, the most zealous proponent of the gunpowder engine, believed it could do far more.

Huygens spent most of his life in the Hague, and became a fellow of the Royal Society, across the channel in England. But in 1666 he was lured to Paris by an offer of a position at France’s Academy of Sciences. Unlike its English counterpart, which was a private association of gentlemen that was merely chartered and authorized by the crown, the French Academy was an arm of the state, funded and organized by Louis XIV’s chief minister, Jean-Baptiste Colbert. Huygens proposed to him an extensive research program, including study of the vacuum, steam, and wind power, and “the power of gunpowder of which a small portion is enclosed in a very thick iron or copper case.”[2]

In a manuscript written in 1673, he argued that this new machine (of which he had, by this time, developed a prototype) would bring about a revolution in the use of a substance hitherto limited to violent uses:

…not only can it serve all purposes to which weight is applied but also in most cases when man or animal power is needed, such that it could be applied to raise great stones for a building, to erect obelisks, to raise water for fountains or to work mills to grind grain, when there is not sufficient space or facilities to use horses. And this motor has the advantage that it requires no expenditure or maintenance when it is not in use. …[It] permits the discovery of new kinds of vehicles on land and water. And although it may sound contradictory it seems not impossible to devise some vehicle to move through the air…[3]

Huygens was one of the greatest minds of the seventeenth century. He wrote on mathematics, optics, mechanics, and astronomy, and invented the most accurate timepiece of the age, the pendulum clock. His gunpowder engine, however, despite his effusive endorsements, cannot be counted among his great successes. It consisted of a piston nested inside a metal cylinder, with two circular openings near the top fitted with a kind of one-way valve, and another opening in the bottom for attaching a dish with the powder charge. When the charge was ignited, it would drive the cylinder up with the force of the expanding gasses, which would then escape through the one-way valves (Huygens used wet leather sleeves) exposed at the top of the stroke. Much of the air having been expelled, the pressure inside the chamber fell well below that of the atmosphere, which pushed the cylinder back to the bottom again.

Setting aside the problem of automating the replacement and ignition of the powder after each stroke, this machine was simply not efficient enough to justify its use in any practical setting. Gunpowder was far from a cheap fuel source (in late-seventeenth-century England, two pounds of it cost about as much as an average day’s wage[4]) but the biggest problem was that it evacuated only a portion of the gases in the cylinder, inducing a relatively weak push from the air, and reaching equilibrium after only a few strokes. It did not take long for others to realize, though, that the condensation of steam could serve the same function more effectively, and any fuel (the cheaper the better), could be burned to make it.

Steam Power

The fact that steam could generate motion was known since ancient times. Heron of Alexandria, philosopher, mathematician, and teacher, and the last great intellect to emerge in Ptolemaic Egypt before its decline under Roman rule – the same Heron who had described the force pump – also described an engine operated by steam. It consisted of a covered cauldron, with two pipes leading out of its cover into the sides of a hollow metal sphere, so arranged so that it could spin on the axis of those pipes. Two more pipes, each bent at a right angle in opposite directions, protruded from the top and bottom of the sphere. When the cauldron, filled with water, was heated from below, steam flowed into the ball and blasted out of the bent pipes, causing the sphere to spin.

Some have called this the first known steam engine, but the machine operated on the same physical principle as many modern lawn sprinklers. If one imagines trying to power a gristmill with a sprinkler, it will give some an idea of the practical value of Heron’s engine as a form of steam power. Though Heron doesn’t elaborate on the function of his contraption, it seems likely that it served as a novelty for delighting visitors or a prop for philosophical demonstrations.

Of more practical value was the aeolipile[5], “ball of Aeolous,” the god of wind, described by that other great mechanician of the classical world, Vitruvius. Also known as a sufflator, it had a simpler design than Heron’s engine, consisting of a metal container with a single small opening. When filled with water and heated, it would emit a jet of steam. This blast could be used to increase the heat of a fire, much like a bellows, and after the recirculation of Vitruvius’ writings by the Renaissance humanists, aeolipiles proliferated across Europe. They appeared in a variety of ornate designs (often in the shape of a human head with steam blowing from the mouth), evidently used as both courtly display objects and practical devices for alchemists and glassmakers.

Both Heron’s engine and the aeolipile treated steam power as a kind of wind, but the new science of pressure in the seventeenth century drew new attention to the potential of steam, as a fluid that could shrink and expand. In 1683, English baronet Samuel Morland wrote a treatise in which he noted that steam would occupy a space 2,000 times as large as the equivalent liquid water, and that such steam “being controlled according to the laws of statics, and by science reduced to the measure of weight and balance, it bears its burden peaceably, like good horses, and thus may be of great use to mankind, especially for the raising of water.”[6] It was in this light that Huygens’ erstwhile assistant at the Royal Academy, Denis Papin, began, many years later, to rethink his former mentor’s gunpowder engine.

Papin, eighteen years Huygens’ junior, had trained as a medical doctor before taking the position as his assistant in 1673. But as a Huguenot, he felt that he could not get a fair shake in the oppressively Catholic monarchy of Louis XIV, so in 1675 he emigrated to London, where he became active in the Royal Societ and served for some time as an assistant to the foremost researcher on air and the vacuum in England, Robert Boyle. In 1687 he took up an academic post in the German town of Marburg, in the Landgraviate of Hesse-Kassel, which had a community of Huguenot exiles.

The Landgrave wanted Papin’s assistance in building advanced waterworks for his province, and by 1690 Papin had developed a model steam engine for this purpose, with a 2.5 inch diameter cylinder.^[7] He began by trying to build an improved a gunpowder engine, but had as little luck with it as he and Huygens had had in the 1670s. It seems likely that he derived the idea of substituting steam for gunpowder from his own invention of 1679, the steam digester, the ancestor of our modern pressure cookers which included a safety lever that was driven up by the force of high-pressure steam.[8] The Papin engine consisted of a cylinder with a small amount of water in the bottom and the usual piston. When sufficiently heated, the water would turn to steam and drive the piston up the cylinder, where a catch held it in place until the steam condensed, at which point the catch was released and the force of the air would push the piston down again. He hoped to use a single fire to heat multiple cylinders attached to the same driveshaft, heating one to the boiling point and then moving to another to allow that one to cool, and thus producing a continuous motion.[9]

But this engine, along with Papin’s several other inventions for the Landgrave – a blowing machine, a steam boat, a steam cannon – never went beyond the prototype stage, and Papin felt himself increasingly beset by enemies in Marburg. After an accident with his steam cannon in 1707 wounded several notables, he decided to be quit of the place. After an unpleasant voyage in which his prototype steamship was confiscated and destroyed by boatmen jealous of their guild privileges, he washed up again in London. His former patron Boyle having died many years since, Papin fell into destitution and died himself sometime after January 1712, when the last written evidence of his life was recorded.[10]

There are other traces of thinking about steam engines in the historical record around this time, but Papin’s is the first known to have actually been built (if only in miniature, prototype form), and to have behind it a substantial backer (in the form of the Landgrave). Why, then, did Papin go on to destitution instead of fame and fortune? By using his digester as a model, Papin had wedded himself to high-pressure steam to drive the upstroke of the piston, constraining the force of which taxed the skills of seventeenth century metal-working. It is likely that this prevented his from successfully scaling up his model engine. Moreover, his engine was simple to a fault – by boiling water in place in the cylinder itself, he tied himself to a constant cycle of cooling and boiling water which was both time consuming and wasteful of fuel. By the time of his death, however, two Englishmen, each taking very different tacks, had superseded Papin’s work, producing the first steam-driven machinery to see practical use.

Newcomen

In 1698, an English military engineer from a Devon mercantile family named Thomas Savery patented his “Miner’s Friend,” the first serious attempt we know of to try to exploit the fluidity of steam to commercial ends. However, what he built was not strictly speaking an engine at all, but a steam-driven pump. It filled a chamber with steam from a separate boiler, then doused the outside with water to condense it. The resulting vacuum pulled water up a descending pipe into the chamber. Like any suction pump, this drawing action could lift water only about thirty feet, so it relied on the next burst of incoming high-pressure steam to drive the water the rest of the way to the surface through a vertical standpipe. This meant it suffered from the same limitations as the force pump – it had to be placed down insidea mine to pump effectively, and its pumping height was limited by the metallurgical capabilities of the day to build vessels and pipes that could withstand the required pressure. Several Savery engines are known to have burst at the seams, sometimes with fatal consequences.

Savery’s design found various uses as a source of water pressure – for aristocratic gardens, for example – and other inventors continued to refine the design for decades. But, despite the sobriquet with which Savery had christened it, the inability of the “Miner’s Friend” to lift water to any great height without threat of explosion prevented it from becoming the basis for a popular piece of mining equipment.

Meanwhile, another Thomas had been hard at work on his own engine design. Thomas Newcomen like Savery, was a Devon man, who worked as an ironmonger and blacksmith, supplying mining tools, among other things. Whether he knew of Savery’s steam pump before beginning his own his unknown; they certainly had opportunities to cross paths in Devon. In any case the engine he developed proved to be of a very different design, and can have owed little to Savery other than the idea of using steam as a fluid to produce mechanical force. Unfortunately for Newcomen, Savery had secured a broad patent, giving him exclusive rights to “make, imitate, use or exercise any vessells or engines for raiseing [sic] water or occasioning motion to any sort of mill works by the impellent force of fire,” a fact that would force Newcomen into a subordinate partnership with Savery and his heirs, regardless of the provenance of his ideas.[11]

Newcomen’s fully-realized design (built in collaboration with assistant John Calley, variously identified as glazier and a plumber) contained two key advances. First, it used only condensation to generate power, and so required no troublesome high-pressure steam. In this he recurred to Guericke’s original concept of a suction pump in reverse. The piston attached to one end of a heavy, wooden rocker beam, with the other attached to the pumping equipment. When steam inside the cylinder was condensed, and the weight of the air depressed the piston, it lifted the other end of the beam, working the pump. The injection of fresh, low-pressure steam did not push the piston up, but it did equalize the pressure above and below it, allowing the weight of the beam to lift itself back to its original position.

Second, it achieved that condensation by injecting cool water into the cylinder, which produced a much more rapid and powerful stroke than pouring it over the outside as in Savery’s design. Newcomen apparently stumbled on this approach by accident, when water intended to cool the outside of the cylinder leaked through a hole into its interior.

But beyond these general improvements, in every specific of his design Newcomen demonstrated a mechanical genius far beyond that of his predecessors. After years of experimentation, he had managed to make his engine entirely self-acting – all the valves that controlled the admittance and expelling of steam were controlled by pegs on a rod moved by the action of the engine itself.[12] What of the supply of cold water needed to quench the steam? That was accounted for too, with a small auxiliary pump that drew water out of the sump where it drained after leaving the cylinder up to a tank above the engine, where it could descend by gravity to be used again.

Clacking and wheezing, lurching through its stilted motions time and again as long as it was supplied with a steady diet of steam, Newcomen’s engine was the closest thing to an artificial life form yet invented by man. One poet compared the boiler to a panting “iron womb.”[13] Another, Erasmus Darwin (grandfather to Charles) compared the engine to a nodding giant:

Bade with cold streams the quick expansion stop,

And sunk the immense of vapor to a drop.

Press'd by the ponderous air the Piston falls

Resistless, sliding through it's iron walls;

Quick moves the balanced beam, of giant-birth,

Wields his large limbs, and nodding shakes the earth.[14]

The exact nature of the pump driven by the early Newcomen engines is unclear, all the descriptions available having focused on the engine itself rather than the machinery at its business end. But one could surmise that it might have been a series of suction pumps (all of whose pistons the engine’s beam could have lifted simultaneously), or some sort of bucket elevator, from which the beam disengaged on each downstroke and re-engaged on each upstroke.

The first well-attested installation of one of Newcomen’s engine is at a coal mine in the periphery of Birmingham in 1712, though Newcomen had surely been developing the engine for many years prior to that. He may have erected earlier models above the tin mines of Cornwall, just to the west of his native Devon.[15] By the time Savery’s patent expired (at last) in 1733, 100 Newcomen engines had been constructed in England alone, with several others in Belgium, France, Germany, and elsewhere in Europe. Newcomen himself had died in 1729.[16] In 1753, the first steam engine arrived in the Americas. It was assembled at the Schulyer Copper Mine in New Jersey, from parts manufactured in Cornwall.

Though he did not suffer and die in penury like his predecessor Papin, Newcomen did not find fame and honor as a great inventor. In Newcomen’s time, the very concept of the great inventor had yet to be fully invented. A mechanically-minded fellow with a bright new idea was more likely to be regarded as a kook than a genius. But one must also remember that Newcomen’s engine remained almost exclusively a piece of mining equipment. The unidirectional power stroke made it hard to use the Newcomen engine for anything else. Though very useful to miners in need of a way to clear their ever-deeper excavations of water, it was not obviously transformative of society in the way we might imagine “the steam engine” to be. It is thanks to both the luck of being born later and the skill and knowledge to devise a more generally applicable engine that the name of James Watt is much better remembered than that of Thomas Newcomen.

Some did try to use Newcomen’s engine as a more general replacement for mill-driven machinery of the sort most often powered by water. Attempts to attach the engine to a flywheel that would then drive machinery continuously did not fare well. More successful was the simple expedient of using a steam engine to pump water uphill and then letting it descend again to drive a waterwheel. The best-known example of this is the mill for making copper pins at Warmley near Bristol, where, Arthur Young wrote in 1771, “[a]ll the machines and wheels are set in motion by water; for raising which, there is a prodigious fire engine, which raises, as it is said, 3000 hogsheads every minute.”[17] Such a process could make economic sense only where natural water power was scarce and cheap fuel was abundant.  Which brings us to coal. Before we continue the story of the steam engine per se, we must tell the story of the fuel that would power it for centuries to come.

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[2] Quoted in Friedrich Klemm, A History of Western Technology (Cambridge, Mass: MIT Press, 1964), 212.

[3] Quoted in Klemm, 213-215.

[4] Gunpowder prices: https://www.gutenberg.org/files/54411/54411-h/54411-h.htm#Page_184 (~11 pennies/pound 1695); Wages: https://www.jstor.org/stable/pdf/1819834.pdf (~20 pennies/day 1683-1692)

[5] In a bit of terminological confusion, Heron’s engine is often also called an aeolipile. However I reserve the term for the more common object. See W. L. Hildburgh, “Aeolipiles as Fire-blowers,” Archaeologia 94 (1951), 27-55.

[6] Samuel Morland, “The Principles of the New Force of Fire” (1683).

[7] The biographical details of Papin’s life comes from David C. A. Agnew, Protestant Exiles from France, Chiefly in the Reign of Louis XIV, Volume 1 (1886), 151-153.

[8] [Reference to 2004 article on Papin and Hero]

[9]Alfred Auguste Ernouf, Denis Papin, Sa Vie et Son Oeuvre (1874), 76-68.

[10] Ernouf, 131-33,

[11] Quoted in James Greener, “Newcomen and his Great Work,” The Journal of the Trevithick Society (2015), 67.

[12] The invention of the equipment required for the machine to operate autonomously is sometimes attributed to a boy hired to operate the machine who had tired of having to work the valves himself. It is more likely that he made a small improvement to already extant self-acting machinery. See Greener, 95-96. The confusion ultimately is unresolvable, since there is no contemporary documentation of the process of development of the engine.

[13] John Dalton, “A Descriptive Poem: Addressed to Two Ladies,Aat Their Return From Viewing the Mines Near Whitehaven.”

[14] Erasmus Darwin, Economy of Vegetation, Canto I: lines 254 – 263.

[15] The argument that there were precursor Newcomen engines in Cornwall is the focus of Greener, “Newcomen and his Great Work.”

[16] Richard L. Hills, Power from Steam: A History of the Stationary Steam Engine (Cambridge: Cambridge University Press, 1989), 30.

[17] Arthur Young, A Six Weeks Tour through the South Counties of England and Wales (1771), 184-185.