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Steam pump: 1698-1702

Thomas Savery has grown up in a mining district of Devon and knows the problem of flooded mines. In 1698 he obtains a patent for an engine to raise water 'by the Impellent Force of Fire'. It turns out to be the world's first practical steam engine. Designed purely as a pump, it has no piston but relies on the power of a vacuum.

A metal cylinder is filled with steam from a boiler. Cold water is poured over the outside, condensing the steam within and creating a vacuum which sucks water up through a pipe at the base. When the cylinder is full of water, the valve from below is closed. Steam is again introduced, forcing the water out of the cylinder through another valve. With the cylinder again full of steam, the process is repeated.

In 1702 Savery publishes a book about his invention, entitled The Miner's Friend. In it he describes how the idea came to him. One evening, after finishing his wine, he threw the empty bottle into the fire and prepared to wash his hands in a basin of water. Noticing steam coming out of the neck of the bottle, he plucked it from the fire and stuck it neck down in the basin. As the bottle cooled, it sucked up the water.

The story sounds improbable, and it may be Savery's way of trying to justify his patent - for the principles involved are already well known to contemporary scientists. What the pamphlet does show is that Savery intends to make money from his invention by supplying pumps to mines.

As it turns out, the maximum levels of pressure and vacuum achieved by Savery cannot lift water more than about twelve yards - too little for most mines.

Instead he finds his main customers among progressive country landowners, who are attracted by being at the cutting edge of technology. They use Savery's pumps to raise water for their houses and gardens.

Boiler, cylinder and piston: 1704-1712

Two Devon metalworkers - Thomas Newcomen, a Dartmouth blacksmith, and his assistant John Calley, a glassblower and plumber - are making good progress in some potentially very profitable experiments. They know the high cost of the horse-driven pumps which raise water from the copper and tin mines of Devon and Cornwall. So they are working on a steam pump.

Though probably unaware of this, they are combining two elements pioneered separately by Denis Papin and Thomas Savery - Papin's piston and Savery's separation of the boiler (providing the supply of steam) from the cylinder (where the steam does its work).

In Newcomen's engine the piston, emerging from the top of the cylinder, is attached by an iron chain to one end of a beam which seesaws on a central pivot. At the other end of the beam another chain leads down to the water-pumping mechanism.

Steam released from the boiler into the cylinder pushes up the piston. When the cylinder is full of steam, the same procedure follows as in Savery's engine. Cold water poured on the outside condenses the steam and creates the vacuum. But in this case, instead of directly sucking up water, the vacuum causes the piston to descend in the cylinder. The chain drags down one end of the beam, activating the pump at the other end.

As so often in the advance of science and technology, an accident provides Newcomen with the refinement which brings his pump up to an economic speed. A flaw develops in one of the seams of his cylinder. As a result some cold water, intended only to flow down the outside, gets into the cylinder when it is full of steam. It creates a vacuum so rapid and so powerful that it snaps the chain attaching the piston to the beam.

With this event another lasting feature of the steam engine is discovered. In all Newcomen's developed engines, which soon start work in England's mines, the steam is condensed by a jet of cold water injected into the cylinder.

The first of Newcomen's working engines is installed in 1712 at a colliery near Dudley Castle. It operates successfully here for some thirty years, as the first of many in the mining districts of Britain. Newcomen's machine undoubtedly infringes Savery's patent, for there is no denying that it works 'by the Impellent Force of Fire'. But Savery is having no great commercial success with his own machine. The two men come to an amicable arrangement, the details of which are not known.

Even with Newcomen's improvements, these machines are suitable only for the slow relentless work of pumping in the mines. Proof of the wider potential of the steam engine must await the inventive genius of James Watt.

A millennium clock: 1746

In 1746 a French clockmaker, Monsieur Passemont (his first name is not known), completes a clock which is almost certainly the first in the world to be able to take account of a new millennium. Its dials can reveal the date of the month in any year up to9999.

It is a longcase clock, in an ornate baroque casing which conceals a mechanism consisting of more than 1000 interconnecting wheels and cogs. Their related movements, as they turn at their different speeds with each swing of the pendulum, are designed to cope with the complexities of the Julian calendar. Thus, for example, one large brass wheel has the responsibility of inserting February 29 in each leap year.

This particular wheel takes four years to complete a single revolution. When it has come full circle, it pops in the extra day. (M. Passemont decides, however, not to grapple with Gregorian refinements; the absence of February 29 in 1700, 1800 and 1900 has had to be manually achieved.)

Louis XV buys the clock in 1749, three years after its completion. It is still ticking away two and a half centuries later in the palace of Versailles. The minutiae of daily time-keeping are also adjusted by hand (the clock loses a minute a month), but Monsieur Passemont's masterpiece requires no assistance in making a significant change in the first digit of its year display - from 1 to 2, at midnight on 31 December 1999.

Kay's flying shuttle: 1733

In 1733 John Kay, son of the owner of a Lancashire woollen factory, patents the first of the devices which revolutionize the textile industry. He has devised a method for the shuttle to be thrown mechanically back and forth across the loom. This greatly speeds up the previous hand process, and it halves the labour force. Where a broad-cloth loom previously required a weaver on each side, it can now be worked by a single operator.

Until this point the textile industry has required four spinners to service one weaver. Kay's innovation, in wide use by the 1750s, greatly increases this disparity. Either there must now be many more spinners, or spinning machines must achieve a similar increase in productivity.

James Watt and the condenser: 1764-1769

In 1764 a model of a Newcomen steam engine is brought for repair to the young James Watt, who is responsible for looking after the instruments in the physics department of the university of Glasgow. In restoring it to working order, he is astonished at how much steam it uses and wastes.

The reason, he realizes, is that the machine's single cylinder is required to perform two opposing functions. It must receive the incoming steam at maximum pressure to force the piston up (for which it needs to be as hot as possible), and it must then condense the steam to form a vacuum to pull the cylinder down (for which it needs to be as cool as possible).

The solution occurs to Watt when he is walking near Glasgow one Sunday in May 1765. The two functions could be separated by providing a chamber, outside the cylinder but connecting with it, in which a jet of cold water will condense the steam and cause the vacuum.

This chamber is the condenser, for which Watt registers a patent in 1769. The principle has remained an essential part of all subsequent steam engines. It is the first of three major improvements which Watt makes in the basic design of steam-driven machinery. The other two are the double-acting engine and the governor, developed in the 1780s.

Hargreaves' jenny and Crompton's mule: 1764-1779

An accident is said to have given a Lancashire spinner, James Hargreaves, the idea for the first mechanical improvement of the spinning process. In about 1764 he notices an overturned spinning wheel which continues to turn with the spindle vertical rather than horizontal. This gives him the idea that several spindles could be worked simultaneously from a wheel in this position.

He develops a version with eight spindles for use by his own family, thus immediately raising their output eight times. News of this causes jealous local spinners to invade his house and smash his machines.

Hargreaves moves to Nottingham, where he sets up a small cotton-mill using his invention. It acquires the name of spinning jenny, traditionally explained as being the name of the daughter who gave Hargreaves the idea when she knocked over her spinning wheel. He patents his device in 1770. By the time of his death, in 1778, the latest versions of his machine work eighty spindles each - and there are said 20,000 jennies in use in the cottages and small factories of Britain.

This is still an entirely hand-operated mechanism. The next essential development is the application of power. This is solved by Richard Arkwright, who takes out a patent for his machine in 1769.

Arkwright's innovation is in drawing out the cotton by means of rollers before it is twisted into yarn. He succeeds first with a machine worked by a horse, but two years later - in 1771 - he successfully applies water power, with the result that his invention becomes known as the water frame. It is in place just in time for an immense new expansion of the cotton industry after a high tax on pure-cotton fabrics (aimed at calicoes imported from India) is reduced in 1774.

Arkwright's machines are suitable for spinning the strong yarn required for the warp of the woven cloth. They are less good at the finer material needed for the weft. Yet conversely, Hargreaves' spinning jenny is only suitable for the weft.

The technologies of Arkwright and Hargreaves therefore complement each other for a few years until the merits of each are combined by Samuel Crompton, a worker in a Lancashire spinning mill. In doing so he takes the final step in the spinning technology of the early Industrial Revolution.

Crompton observes the tendency of the spinning jenny to break the yarn, and he resolves to improve this aspect of the process. He does so in a machine which he perfects in 1779.

Crompton's machine combines the principles of Hargreaves' jenny and of Arkwright's water frame. The name which it acquires - Crompton's mule - is a pun on that fact. As the offspring of a jenny (a female donkey) and of another creature, the new arrival is clearly a mule.

Crompton's machine is capable of spinning almost every kind of yarn at considerable speed. The flying shuttle in the 1750s put pressure on the spinners to catch up. Now the mule challenges the weavers. They respond in 1785 with the first water-driven power loom, invented by Edmund Cartwright after visiting Arkwright's mills at Cromford. With all this technology in place, the pressure is now on the suppliers of raw cotton in America.

Ironbridge: 1779

In the space of a few months in 1779 the world's first iron bridge, with a single span of over 100 feet, is erected for Abraham Darby (the third of that name) over the Severn just downstream from Coalbrookdale. Work has gone on for some time in building the foundations and casting the huge curving ribs. But in this new technology little time need be spent in assembling the parts - which amount, it is proudly announced, to 378 tons 10 cwt. of metal.

The lightness of the structure strikes all observers. An early visitor comments: 'though it seems like network wrought in iron, it will be uninjured for ages.' It is uninjured still. A great tradition, bringing marvels such as the Crystal Palace, begins in this industrial valley.

Machine tools, gun barrels and cylinders: 1774-1800

John Wilkinson, an ironmaster in Staffordshire and Shropshire, has been building up a lucrative arms trade. In 1774 he invents a machine, powered by a water wheel, which can drill with unprecedented accuracy through the length of a cast-iron cylinder to create the barrel of a cannon. It is a turning point in the development of machine tools.

James Watt realizes that Wilkinson's new machine is capable of the precision required for an efficient steam-engine cylinder. In 1775 Wilkinson delivers to Birmingham the first of the thousands of cylinders he will bore for the firm of Boulton and Watt. Boulton finds them 'almost without error; that of 50 inches diameter doth not err the thickness of an old shilling' in any part.

The Boulton and Watt engine delivered to Wilkinson in the following year is intended for a new purpose. Instead of the usual pumping of water, it is to undertake a more sophisticated role - working the bellows which pump air into one of Wilkinson's blast furnaces of molten iron.

The owners of the mills and mines of the young Industrial Revolution have many tasks to which a source of mechanical power, other than the traditional water of a mill race, could be usefully applied. They await with interest reports of this new type of engine. And the reports are good. By the time Watt's patent expires, in 1800, more than 500 Boulton and Watt engines have been installed around the country and abroad.

The increased efficiency of the new engines, compared with the previous Newcomen version, enables Boulton and Watt to charge by a novel and very profitable method. The machines are provided and installed free, and customers pay a royalty of one-third of the amount saved on fuel. One group of merchants interested in the Boulton and Watt machines, the London brewers, have no previous machine use for comparison. They present Watt with an interesting billing problem which results in the concept of Horsepower.

From 1783 the saving (and the royalty) is even greater, because in that year Watt puts on the market another major innovation - his double-acting engine.

Double-acting engine and governor: 1782-1787

Just as James Watt applied a rational approach to improve the efficiency of the steam engine with the condenser, so now he takes a logical step forward in a modification patented in 1782. His new improvement is the double-acting engine.

Watt observes that the steam is idle for half of each cycle. During the downward stroke, when the vacuum is exerting atmospheric force on the piston, the valve between boiler and cylinder is closed. Watt takes the simple step of diverting the steam during this part of the cycle to the upper part of the cylinder, where it joins with the atmospheric pressure in forcing the cylinder down - and thus doubles its effective action.

The most elegant contraption devised by Watt is in use from 1787. It is the governor - the first example of the type of controlling device required in industrial automation, and a feature of all steam engines since Watt's time.

Watt's governor consists of two arms, hinged on a central pivot and rotated by the action of the steam engine. Each arm has a heavy ball at the end. As the speed increases, centrifugal force moves the balls and the arms outwards. This action narrows the aperture of a valve controlling the flow of steam to the engine. As the power is slowly cut off, the speed of the engine reduces and the balls subside nearer to the central column - thus slightly opening the valve again in a permanent process of adjustment.

Cotton gin: 1793

The mechanization of spinning and weaving in England, between 1733 and 1785, greatly speeds up the industrial process and rapidly leads to a shortage of cotton. During most of the century the bulk of raw cotton arriving at Liverpool for the Lancashire mills is from India. The cotton grown in the southern states of America is commercially less viable because it is short-fibred.

The cotton fibres, which will be spun into cotton, have to be separated from the seeds which they protect and enmesh. This process, known as cotton picking, is done entirely by hand. The short fibres make it a slow and expensive task.

In 1793 Eli Whitney, a graduate of Yale, invents a machine which solves this problem. It consists of a hand-turned roller with projecting spikes. Each spike passes through a slot in a grid, wide enough to allow the spike to drag the cotton fibres through but too narrow for the cotton seeds to pass. They fall out into a separate container, while a revolving brush cleans the fibres, or lint, off the spikes.

Whitney's machine immediately trebles the speed at which cotton can be ginned, with major effects on the economy of the southern states of America. About forty times as much cotton (now established as 'king cotton') is produced in 1810 as in 1793. Vast new areas are taken in hand as plantations. The demand for slaves increases accordingly.

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