tiMssmc cAiOHJc iHcmt 





Figure 4. — Two-cylinder stationary test engine built before tiie engine for tlie 

 Ericsson was started. Eacli vvorlcing cylinder was 6 feet in diameter. The 

 length of stroke was 2 feet. (From Applelons' Mechanics^ Magazine and Engineers' 

 Journal, February 1853, vol. 3, pi. 2.) 



Performance Figures 



Captain Ericsson never chose to subject his caloric 

 engine to examination by a competent observer and 

 he published no performance figures that exhibited 

 evidence of their having been determined by an 

 actual test of the engine. 



When critics began to analyze the performance of 

 the engine, using such data as they could find, and 

 to publish their results, Ericsson was quick to question 

 the motives, experience, ability, and conclusions of 

 each writer, but he was not willing to give actual 

 performance figures. Inadvertently, he gave a few 

 data in his replies to his "detractors," and some indi- 

 cation of his understanding of thermodynamic prin- 

 ciples was thus supplied. 



Captain Ericsson particularly objected to the mathe- 

 matical approach of Maj. John G. Barnard, which had 

 been published serially.^" Barnard — an Aimy en- 

 gineer who had graduated from West Point in 1833 

 at the age of 1 8, ranking second in a class of 43 — made 

 a series of elaborate calculations; but even allowing 

 for faulty data, his results were frequently in error. 



^^ Appletons' Alechanics' Adagazine and Engineejs' Journal, 1853, 

 vol. 3, pp. 82-86, 152-158, 217-221. 



He became so involved in details that he was unable 

 to sustain a convincing argument. However, he was 

 well aware of the mechanical equivalent of heat, and 

 stated clearly its application to the regenerative feature 

 of the caloric engine. Captain Ericsson characterized 

 Major Barnard's calculations as "symbolical mystifi- 

 cation, the horror of all practical men — a mystification 

 which smatterers invariably inflict on them," and 

 proceeded to show, by diagrams and arithmetic, that 

 the "theoretical power of the engine was 1313 

 horses."^' 



Major Barnard had concluded that the indicated 

 horsepower of the caloric engine was 262.^- Captain 

 Ericsson, during his press conference in the Ericsson, 

 had said it was 600. The Scientific American arrived 

 at the preposterously precise figure of 244.572 horse- 

 power. Various other calculations ranged from 1 1 6 to 

 316 horsepower.^' 



31 Ibid., pp. 121-122. 



32 Ibid., p. 218. 



33 Scientific American, 1853, vol. 8, p. 149; Mechanics' Magazine, 

 London, 1853, vol. 58, p. 170 [208 hp.]; American Journal of 

 Science and Arts, 1853, ser. 2, vol. 15, p. 405 [316 hp.]; Proceedings 

 of the American Academy of Arts and Sciences, 1852—1857, vol. 3, 

 p. 29 [116 hp.]; Minutes of Proceedings of Institution of Civil Engi- 

 neers, 1853, vol. 12, pp. 331, 348 [208 and 226 hp.]. 



PAPER 20: JOHN ERICSSON AND THE AGE OF CALORIC 

 560619—60 2 



49 



