1 Note: the proposed paper will draw material from the last three chapters of a book project; the relevant chapters are included in this document. The role of British engineering skills in driving the diffusion of Newcomen engines, 1706-73 This paper will consider one of the key factors mentioned by the literature n shaping the trajectory of the diffusion process, the evolution of engineering skills.1 The paper is divided into three main sections. The first section will focus on the status of engineering skills during the early phase of their development through the 1730s when a major breakthrough took place with the construction of larger engines. The second section will examine the impact of the latter development in reducing fuel consumption and narrowing the gap with what was deemed to be “ideal” levels of fuel efficiency. The last section will focus on the process of learning-by-doing, a critical factor in driving improvements through the management of engines, and it will make some references on the regional asymmetries of such engineering skills. I The analysis of the revised Kanefsky database revealed two distinct phases in the diffusion of aggregate HP.2 Notwithstanding some healthy dose of caution raised by the econometric tests, the first structural break with the highest level of confidence takes place in 1746 followed by a second one in 1768. The timing of the structural breaks can be largely explained through the state of British engineering skills during this period. Skills relevant to the construction of the steam engine were virtually absent during the first dozen years or so (1706-18), while the aggregate diffusion line was barely distinguishable from the horizontal axis. Despite the fact that no every engineer involved is known, it is fairly clear that Newcomen himself was mainly responsible for the erection of the engine through 1715, i.e., through the time the syndicate took over and he became a mere member of it; Savery was involved in only a couple of instances. The first recorded appearance of the Parrots and Sparrow comes in 1715 but their contribution remained fairly small through the next three years and even more so in the case of a couple of additional engineers (e.g., Beighton). All in all, there were no much more than half dozen engineers 1 E.g., “The diffusion of the steam engine in eighteenth century Britain”; “The Early Diffusion of the Steam Engine.” 2 Kitsikopoulos, “The Diffusion of Newcomen Engines: A Reassessment,” Appendix IV. 2 that had the skills to erect the engine during these years. Concerns regarding the safety of the engine were also present. Writing in 1708, and presumably reflecting a more widespread perception, J. C. stated that colliery owners “are not many dare Venture of it”.3 However, since the burden of installations relied almost exclusively on Newcomen’s shoulders these fears were largely immaterial; even in their absence Newcomen could not have erected much more engines than he did. These problems were compounded by the inelastic supply of component parts, a fact which in itself reflects the lack of widespread engineering skills.4 Such skills gradually expanded from the late 1710s through 1745, right before the first structural break. The Parrots/Sparrow trio was dominant in this period, responsible for over a third (17) of the installations whose engineer is known, but they were joined by at least half a dozen other engineers (e.g., Hornblower, Potter, and Beech) in addition to the contributions of Newcomen, the syndicate, and those engines constructed by Coalbrookdale. But there were still major obstacles preventing the diffusion figures from becoming more robust. To begin with, setting up as an engine maker required a substantial sum of money. According to a mid- century account, it was a minimum of £500 and could not have been much lower earlier.5 In addition, long delays persisted in pulling together the resources necessary to install an engine. A Newcastle colliery had to wait for months to get timber to London and from thence to Newcastle, as well as coping with the delayed arrival of workmen and advisers; and, once resources were pulled together, considerable time would elapse before the engine was constructed, 20 weeks in the case of Edmonston colliery (1726). Personal communications were also painfully slow creating a breeding ground for friction and disputes. Weeks would go by trying to solicit responses from engine makers or in dealing with the 3 The compleat colier, p. 10. 4 As an illustration, an agreement was signed on November 10th, 1715 for the installation of an engine at Howgill colliery (Whitehaven) but the working of the engine was delayed until 1717. One of the problems was the delivery of parts. Whitehaven, not having much of direct trade with London or Bristol, the construction of the boiler and barrels was consigned to a William Nicholson, formerly a shipmaster and at that time the owner of a public house in Dublin. In another case recorded in 1718, Meres, the most active member of the patent syndicate, offered a prospective buyer a cast iron cylinder up to 24 inch diameter but noted that anything of a larger size would take six months to deliver. See Allen, “The 1715 and other Newcomen engines,” p. 245; idem, “Some early Newcomen engines,” p. 199. 5 Armytage, A social history of engineering, pp. 81-2, quote from the latter page; see also Lord, Capital and steam- power, p. 58. 3 proprietors of the patent.6 These problems, along with the slow growth of competent engineers, explain the lack of a structural break prior to the mid-1740s. The critical factor that led to the first structural break was mainly due to a key development in the field of engineering relating to the construction of larger steam engines leading to the potential of reducing their cost; this development went hand in hand with the growing experience in managing these engines through learning-by-doing. The former development will be looked at first. The very first cylinders, made by bell-founders, were characterized by high cost and faulty workmanship. In some cases the piston was very tight, in many others too loose causing condensation on top of the piston and thus the failure of the latter to travel the full distance at a considerable waste of steam. These technical flaws where bound to have the largest impact in places where fuel bills ran to high figures.7 Instead of addressing this and other mechanical and thermal inefficiencies, engineers sought to compensate by attempting to construct larger cylinders which, in theory at least, entailed the prospect of aggravating the problem. However, boring equipment fell short of the task with boring bars breaking in the effort to come up with larger cylinders. The pressures generated by this demand led the Coalbrookdale company to install in 1734 a mill with a larger boring bar. It seems to have been successful because a second one was ordered in 1745.8 This was a crucial development because it allowed the mean size of engines to jump from c. 10 hp through the 1730s to c. 25 hp thereafter. There is no question that the rise in the size of cylinders did not always lead to a proportional increase in the power of engines as Smeaton confirmed in 1769 by examining 15 engines in the Newcastle region and another 18 in Cornwall.9 However, it certainly offered the potential of reducing fuel consumption 6 Rolt, Thomas Newcomen, p. 83; Rowlands, “Stonier Parrott and the Newcomen engine”, pp. 57-8. 7 The engine at Wheal Rose (Cornwall) is said to have been so expensive to run by 1725 that the adventurers drove a mile-and-a-half adit in order to discontinue it despite the fact the mine was very rich; Rogers, The Newcomen engine, pp. 16, 18. This alarming attitude was echoed in the writings both of contemporaries and later historians: “The great expense of fuel was still a heavy tax upon the use of the engine, for every one of magnitude consumed £3000 worth of coal per annum; and as the mines were worked lower, and more power became requisite, the expense was frequently so great as to balance the profits of many mines. If therefore new improvements had not arisen, the use of the engine must soon have been limited to those works whose produce was so rich, or profits so great, as to enable them to bear this heavy expense of drainage”; Pole, A treatise on the Cornish pumping engine, p. 18. The same statement, almost verbatim, can be found In Pryce’s appendix to his Mineralogia Cornubiensis published in 1778; cited in The Notched Ingot, July 1966, p. 19. 8 Bourne, A treatise on the steam engine, p. 9; Rolt, Thomas Newcomen, pp. 121, 125; Stuart, Historical and descriptive anecdotes, p. 303. 9 One 60 inch cylinder engine developed more hp compared to five engines with larger cylinders. See Farey, A treatise on the steam engine, p. 234; Mott, “The Newcomen engine in the eighteenth century”, pp. 82-3. 4 per hp since, in theory, more powerful engines are more efficient. Smeaton compiled a table correlating engines of different hp with what their fuel consumption ought to have been. Based on it, for instance, an engine of 10 hp should have consumed c. 20-21 lbs of coal per hp/hour whereas the respective figure for a 25 hp engine should have been c. 16 lbs.10 That begs the question as to how the fuel consumption of actual engines compared to Smeaton’s ideal potential and how we can explain whatever pattern is discerned.