The Day the Universe Changed - James Burke [93]
In 1782 an ironmaster called Henry Cort contacted Watt with what he called his ‘grand secret’. This technique for producing iron demanded blasts of air, which Watt’s engine could produce by driving bellows, and considerable hammering power, again provided by Watt. The system was designed to make much more iron by heating it in a reverberatory furnace until the slag floated to the top of the molten metal. At this point the slag was usually separated out. Cort left it in the mixture and increased the temperature. The molten metal was then left to cool for a short time and put under the forge hammer still red-hot, until the slag was hammered out. It was then put through rollers - still almost at welding heat - and the rest of the slag rolled out. The technique produced fifteen times more iron than could be made by conventional methods. The iron was more malleable than cast iron due to the de-carburising effect of the air as the iron was stirred in the furnace, a process called ‘puddling’.
Cort’s wrought iron could be rolled off at the rate of fifteen tons in twelve hours. The effect of the new iron production on architecture, tunnel and viaduct construction, engineering and machines themselves was enormous. Now machines could be made of metal more cheaply than of wood.
A new machine had by this time entered service in the textile industry. It was the Crompton ‘mule’, designed by Samuel Crompton, a Bolton weaver, and so called because it was a crossbreed of the spinning jenny of Hargreaves and the water-frame spinner made by Arkwright. The first mule was in production by 1779. It combined the rollers of the water-frame with the moving carriage of the jenny. The great advantage of the mule was that the relationship between the speed of the rollers and the movement of the carriage could be altered, permitting various types of yarn to be spun.
A painting of the first iron bridge in history, fittingly built at Coalbrookdale. By 1780 it was already a tourist attraction, as can be seen by the elegance of the visitors in the boat mid-stream, who are having the bridge described to them.
Other machines were developed to handle almost every part of the process of making cotton. The cotton industry may be said to have made the Industrial Revolution the great force for change that it was. The industry was centred initially in Lancashire because of the African and transatlantic trade through Liverpool and because the area had not been unionised by the guilds, so there were few restrictive practices. The late seventeenth-century legislation setting up apprenticeship systems had not applied in Lancashire.
The cotton industry itself was a new phenomenon, so there were no prejudices and practices to stifle innovation. Rising imports of cheap cotton from America and the West Indies and the use of the new machinery increased production phenomenally. In 1781 Britain imported just over five million tons of raw cotton; eight years later the total had multiplied over six times. As production went up, the price went down and demand became overwhelming. The weavers were so rich that those in Bolton wore their hats with the new Bank of England five pound notes stuck in the bands.
In the last eight years of the century the price of muslin dropped by two-thirds. The market stimulated the construction of even more machinery, some of it now power-driven, as in the new factory opened in 1801 at Pollockshaws near Glasgow, which had two hundred looms. The cotton industry also stimulated innovation in other trades, with mechanical printing of cloth in 1783 and new methods of bleaching and new dyes in 1790.
The new steam engines needed coal for fuel. Transportation and coal mining improved to meet the demand. The coal was used to make more iron to meet the needs of transportation and machinery. As more iron was produced, more engines and machines were made, and production went up, increasing demand for the raw materials and their transportation. And