CHAPTER FOUR

AN IN —TECHNOLOGY, ORGANISATION AND MARKETS, 1760–1870

Baltic iron had come to dominate the British market because of the incapacity of Britain’s own forge sector. British lacked the energy resources to keep pace with the heightening demand for mal- leable iron on their domestic market. Some ironmasters sought to over- come this de ciency by organisational means. They hoped to raid the abundant energy reserves of British North America by transferring the preliminary stages of the production chain to the colonies. An Atlantic iron trade, with smelting out-sourced to the -rich plantations, would be a reproof to the ‘Ignorance & wrong reasonings’ of those Swedish ministers who maintained ‘that England can not be without their Iron’.1 That hope was, as we have seen, thwarted. The alternative to organisational re-jigging was technological transfor- mation. there was, as every textbook on British economic history makes clear. Smelting with and the development of coal- red re ning methods, most notably Henry Cort’s technique, freed the British iron industry from its dependence upon vegetable fuel in spectacular fashion. Yet technological change could not be conjured up at will. The development of effective coal-based tech- nologies was a drawn-out, tortuous business. Some elements of the ‘coal technology package’ were present by the rst decade of the eighteenth century, but it was not until the 1790s that the iron industry turned fully to a mineral fuel platform. Indeed, it was not until the Napoleonic era that the combination of coke smelting, puddling furnaces, rolling mills, and steam power became the industry standard. Because of this, Baltic iron remained fundamental to the British economy in the early stages of . Baltic iron, it should be recalled, did not reach its peak on the British market until 1793. It was only in the years after 1800, when tariff barriers against foreign iron were ratcheted up, that the fate of Russian and Swedish iron was sealed.

1 TNA: PRO CO 388/34, Edward Finch to Lord Harrington, 22 April 1735. an industrial revolution in iron 251

The introduction of coal technology in Britain

The revolutionizing of the British iron industry is conventionally dated to 1709, when Abraham Darby mastered smelting with coke. It was indeed a signal event. But that is not to say that mineral fuel had no earlier role. Far from it. Pit coal had in ltrated some parts of the pro- duction process almost as soon as the indirect process ( plus forge) was introduced to the British Isles. Coal could not be used in a nery hearth because sulphurous impurities in the fuel would be imparted to the iron as it lique ed, but pit coal could be used in the chafery without too adverse an effect. Here, the blooms of re ned metal were merely being raised to a red heat before being drawn out under the forge hammer into bars. No chemical transformation was involved and so the risk of contamination was far lower. There is evidence of coal being used in this way from the second half of the sixteenth century.2 By the eighteenth century ‘Mill-bar’, the type of brittle bar destined to be slit into nail rods, was routinely drawn out in a coal- red chafery; it was only the tough ‘Merchant-Bar’ that had to be ‘drawn out with a Charcoal Fire only’.3 Furthermore, mineral coal could be used quite safely to reheat iron in rolling and slitting mills, and was so from the very introduction of that technology into the British Isles. In the course of the seventeenth century mineral coal insinuated its way into every part of the production chain for which it was eligible. But the reduction of iron from its ore remained proof against it. All attempts to use mineral coal in a blast furnace ended in failure. It was not until Darby tried subjecting coal to a prior air-free combustion, one that yielded coke, that a satisfactory could be coaxed from the furnace. The breakthrough at Coalbrookdale in 1709 was a landmark in the history of humankind. Even so, coke-smelted pig was not an exact sub- stitute for its charcoal-smelted equivalent. Coke pig had a high silcon content. This had its advantages: silicon-heavy pig iron was especially uid in its molten condition, and therefore well suited to the production of castings. Yet there were countervailing disadvantages. Coalbrookdale

2 Richard S. Smith, ‘Sir Francis Willoughby’s ironworks, 1570–1610’, Renaissance and Modern Studies, XI (1967), 90–140; A.C. Jones and C.J. Harrison, ‘The Cannock Chase ironworks, 1590’, English History Review, XCIII (1978), 795–810. 3 The state of the trade and manufactory of iron in Great-Britain considered (1750), p. 4.