When the inventor became convinced finally that 

 the maximum rather than the minimum of the 

 Ericsson's capability had been demonstrated, his 

 financial backers underwrote for the ship a new 

 caloric engine with smaller cylinders, to be operated 

 at higher pressure. When this new engine was tried 

 in New York Bay, with the ship performing beauti- 

 fully and with no outside observers on board, "at the 

 very moment of success — of brilliant success," " a 

 violent squall hit the ship. An open cargo door, 

 open for the discharge of rubbish, allowed her to fill 

 rapidly and she sank to the bottom. She was 

 quickly raised; but, in spite of its announced success, 

 the new engine was replaced by a steam engine. 

 No public explanation was given by Captain Ericsson 

 at this time for the abandonment of his caloric 

 engine. 



The caloric engine was claimed to be safer and 

 vastly more economical than a steam plant. It 

 was safer — there was no boiler to explode — but it is 

 doubtful whether the caloric engine was more 

 economical in pounds of fuel burned per horsepower 

 hour output. When the additional bulk of the 

 engine is considered, as compared to a steam power 

 plant, it becomes evident why Captain Ericsson 

 finally was forced to return to steam. If an air 

 engine operating at the low pressures then attainable 

 were made powerful enough to compete with a steam 

 engine, its bulk w^ould have exceeded the capacity of 

 the ship's hull. In a later patent, for an "improve- 

 ment in air-engines," Captain Ericsson referred to 

 the caloric engine of the Ericsson: "Experience has 

 demonstrated that the power of such engines will 

 always be found insufiicient for practical purposes." '* 



State of the Art 



In his 1824 essay on work and heat, Sadi Carnot 

 had observed that "in spite of the efi"orts of many 

 enterprising souls to improve heat engines, and in 

 spite of the satisfactory state to which engines have 

 been brought, their theory is but little understood, 



" William Church, Life of John Ericsson, New York, 1890' 

 vol. 1, p. 195. 



IS U.S. Patent 13348, July 31, 1855. For note on steam 

 engines in the Ericsson, see Mechanics' Magazine, London, 1855, 

 vol. 63, pp. 5-6. For outline of subsequent history of the ship, 

 which survived until 1892, see Erik Heyl, Early American 

 Steamers, 2 vols., Buffalo, 1956, vol. 2, pp. 79-80. For recent 

 work on air-engine development, see Philips Technical Review, 

 1947, vol. 9, pp. 97-104, 125-134. 



and attempts to improve them are still guided nearly 

 by chance." '^ 



The situation was not materially different in 1852, 

 although Carnot and his successors had developed the 

 principles that led eventually to coherent and demon- 

 strable statements of the laws of thermodynamics. 

 The men who actually designed and built engines 

 were not generally conversant with the latest findings 

 of scientists. If occasionally an engineer waded 

 through an English paper or the translation of a 

 French or German work, the implications of the new 

 ideas were seldom clear because the scientists them- 

 selves were groping for, but had not yet established, 

 an orderly theory of heat. 



Steam was the dominant inotive power, and, both 

 in power and in economy, steam engines were quite 

 highly developed. In size, few exceeded the 2,290 

 horsepower engine of the Collins liner Arctic that 

 consisted of two double-acting cylinders, each 8 feet 

 in diameter with a stroke of 10 feet.-" In economy, 

 none exceeded the stationary Cornish pumping 

 engines, which required about 2% pounds of coal 

 per horsepower hour output. 



In the 70 years since Watt's highly successful steam 

 engines had been introduced, numerous attempts had 

 been made to build a safer and more economical prime 

 mover that could be used in their place. ^' There were 

 two general lines of approach to the problem. The 

 first involved the employment of a working fluid other 

 than steam. The second aimed to conserve and 

 utilize heat by internal combustion — that is, by burn- 

 ing fuel in the working space of the engine. 



Alcohol, ether, and mercury — all of which have a 

 lower heat of vaporization (requiring less heat to 

 vaporize each pound of liquid) than water — were 

 tried in numerous engines. The inventors assumed 

 that the work done by each pound of vapor was the 

 same for all vapors; therefore, vapor that could be 

 generated with the least expenditure of heat would 

 be the most desirable. In 1824 Mechanics'' Magazine 



1' Sadi Carnot, Reflexions sur la Puissance Motrice de Feu, 

 Paris, 1824; reprinted in Annales de I'Ecole Mormale Superieure, ser. 

 2, 1872, vol. 1, p. 396. Also available in English translation by 

 R. H. Thurston as Reflections on the Motive Power of Heat, New 

 York, 1890. 



20 John H. Morrison, History of the American Steam Navy, 

 New York, 1903, p. 412. 



-1 An excellent summary of the history is George H. Babcock's 

 "Substitutes for Steam," Transactions of the American Society of 

 Mechanical Engineers, 1885-1886, vol. 7, pp. 680-741. 



PAPER 20 : JOHN ERICSSON AND THE AGE OF CALORIC 



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