¹ Temin, Peter, “Steam and Waterpower in the Early Nineteenth Century,” this JOURNAL, 26 (06 1966), p. 196.Google Scholar

² The last Cornish pumping engine survived until 1946, long after the commercial demise of the Watt and Newcomen engines, and in fact long beyond the commercial era of the high-pressure steam engine. Thus the modern conception of the Cornish pumping engine as a low-pressure engine developed. In Britain in the early decades of the nineteenth century, condensing Cornish engines operating at pressures near 40 pounds per square inch were thought of as high-pressure engines, but they were usually referred to (simply) as Cornish engines. The invention of the Cornish engine was widely attributed to Richard Trevithick. The confusion between the noncondensing high-pressure engine invented by Trevithick about 1803, which operated at pressures above 100 pounds per square inch, and the Comish engine whose development was begun by Trevithick and others about 1810 explains how “Trevithick's engine” could be widely adopted in Britain and yet almost all steam engines in Britain could be low-pressure by 1830.Google Scholar

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⁴ von Tunzelmann, , “Technological Diffusion During the Industrial Revolution: The Case of the Cornish Pumping Engine” in Hartwell, R.M., ed., The Industrial Revolution (Oxford, 1970).Google Scholar

⁵ Temin, “Steam and Waterpower,” p. 190.Google ScholarU.S. Congress, House, Report on the Steam Engines in the United States (H. Doc. No. 21, 25th Cong. 3rd session, Washington, D.C., 1838).Google Scholar

⁶ Pursell, Carroll W. Jr, Early Stationary Steam Engines in America (Washington, D.C.), 1969, pp. 63, 107.Google Scholar

⁷ Greville, and Bathe, Dorothy, Oliver Evans: A Chronicle of Early American Engineering (Philadelphia, 1935), pp. 271–72.Google Scholar

⁸ Pursell, Early Stationary Steam Engines in America, pp. 61–69.Google Scholar

⁹ Bathe, Oliver Evans, p. 128.Google Scholar

¹⁰ North, Douglass C., Growth and Welfare in the American Past (Englewood Cliffs, N.J., 1967), p. 111.Google Scholar

¹¹ Bathe, Oliver Evans, p. 160.Google Scholar

¹² Ibid., p. 210.

¹³ Ibid., p. 150.

¹⁴ Ibid., p. 223.

¹⁵ Farey, John, letter dated 02 24, 1883, Journal of the Franklin Insitute, XII, Series 2, No. 5 (11 1833), p. 352;Google ScholarGalloway, E., “On the Application of Steam, Expansively, in Cornish Steam Engines,” Journal of the Franklin Institute, XIL, Series 2, No. 4 (10 1833), p. 341;Google ScholarProfessor Thomson, “On the Dynamic Theory of Steam,” Edinburgh Philosophical Transactions (1850, 1851),Google Scholar reprinted in part in Journal of the Franklin Institute, XXXVI, Series 3 (November 1858), 304;Google ScholarEnys, , “Performance of Steam Engines in Cornwall,” Journal of the Franklin Institute, XIX, Series 2, No. 1 (01 1837), 60;Google ScholarPerkins, Jacob, “Observations on the Duty Performed by the Cornwall Steam Engine,” Journal of the Franklin Institute, XIX, Series 2, No. 5 (05 1837), 362. John Farey gives 19.8m as the “average performance of about 27 engines in Cornwall, taken during the whole of the years 1813 and 1814, when Mr. Watt's system was universally followed.” E. Galloway states: “Boulton and Watt's engines perform an average duty of raising 19,800,000 lbs. one foot high, with one bushel of coal.” Professor Thomson says: “The average performance of a number of Lancashire engines and boilers have been recently found to be such as to require 12 lbs. of Lancashire coal per horsepower per hour.…” Mr. Enys gives the duty of Watt engines as 19.5m in 1793, 17.5m in 1778, and 13.5m in 1812. Enys attributes the fall in efficiency after 1800 to the expiration of Watt's patent and the consequent cessation of duty-based payments to Watt. Perkins makes a distinction between two types of Watt engines: “a single stroke lowpressure engine with the flywheel will raise but 22 millions.”Google Scholar

¹⁶ Enys, “Performance of Steam Engines,” p. 60.Google Scholar

¹⁷ See footnote 15 above.Google Scholar

¹⁸ Bathe, Oliver Evans, p. 263.Google Scholar

¹⁹ Ibid., p. 226.

²⁰ There are numerous references to the effect that the large Cornish pumping engines could be operated at a duty of about 125m under test conditions, but average duty was never better than about 90m prior to 1834. Galloway, E., “On the Application of Steam, Expansively, in Cornish Steam Engines,” p. 273; Thomson, “On the Dynamic Theory of Steam,” p. 303. Thomson gives a ratio of 784 between experimental duty and average duty where the experimental duty was on the Fowery Consols Mine engine and the average duty was measured on the Taylors United Mine engine. Both figures were the highest ever reported.Google ScholarPerkins, “Observations,” p. 361, puts the matter in another light: “Having seen that a column of water might be expanded by the admission of a little air under the lower clack, I was induced to inquire, while in Cornwall, of an engineer, if he had ever known air to be admitted under the clack; after expressing surprise at my question he admitted that it was common, but that it was not acknowledged, since everyone wished to have it appear they had done as much duty as possible…although the circumstance of admitting air to mix with water seems to lessen the amount raised, yet this cannot, I think, be more than 15 to 20 percent and I fully believe 90m lbs. to have been raised one foot high by a bushel of coal.”Google Scholar

²¹ Homer, Sidney, A History of Interest Rates (New Brunswick, N. J., 1963), pp. 317–24.Google Scholar

²² Ibid., p. 318.

²³ Bathe, Oliver Evans, p. 263.Google Scholar

²⁴ “Steamboats on Western Waters,” Journal of the Franklin Institute, XXV, Series 3 (1853), 262.Google Scholar

²⁵ Bourne, John, A Treatise on the Steam Engine (London, 1847), p. 214.Google Scholar

²⁶ Bathe, Oliver Evans, p. 94. Evans gave a detailed estimate in 1804 for the cost of building a complete steam engine with a 6-inch bore by 18-inch stroke to run at 35 rpm with a steam cutoff at ⅓ stroke.Google Scholar

²⁷ Pursell, Early Stationary Steam Engines, p. 64.Google Scholar

²⁸ Bathe, Oliver Evans, p. 150; see also pp. 78, 132, 155, 185.Google Scholar

²⁹ Ibid., pp. 159, 187.