3 o4 HISTORY OF f SCIENCE. 



cylinders bored with sufficient accuracy to prevent the steam from 

 escaping at the edge of the pistons. The amount of mechanical pre- 

 cision which is met with, even in the most ordinary machines and 

 scientific instruments of the present day, is more striking when con- 

 sidered in connection with the circumstance just mentioned. 



Not greater was the revolution in industry effected by the steam- 

 engine than that which has been brought about in the theoretic aspect 

 of science by the dynamical theory of heat, which about the same period 

 first took a definite form. Its inception must be associated with the 

 name of a man otherwise remarkable in several ways, and deserving 

 of mention in these pages if he had done nothing beyond founding 

 the Royal Institution of Great Britain. BENJAMIN THOMPSON was 

 born in 1 753, in a village of Massachusetts, U.S., called North Woburn. 

 His birthplace is but twelve miles distant from that of another Ben- 

 jamin, born half a century earlier, whose discoveries -will claim our 

 attention in the next chapter. From the age of thirteen to that of 

 eighteen Thompson acted as assistant in what our transatlantic cousins 

 call " dry goods stores." He then became successively a student of 

 medicine and a schoolmaster, and before he had reached twenty years 

 of age he had married, at a village then called Rumford but after- 

 wards named Concord, a widow v/ith ample means. It is doubtful 

 whether the marriage would have been a felicitous one, as his wife 

 was by many years his senior. A separation, however, soon took place, 

 on account of the disturbed condition of affairs brought about by the 

 struggle then impending between England and her great colony. 

 Thompson had been appointed major in a militia regiment, and he 

 fell under the suspicion of "being unfriendly to the cause of liberty." 

 In November, 1774, a mob assembled round his dwelling, and with 

 hootings and hisses demanded him to appear. He had, however, 

 secretly left Concord, and taken refuge at Boston. He was arrested, 

 and examined by the Revolutionary Committee on the charge already 

 named. Of this charge, however, he was fully acquitted, and set at 

 liberty. He now devoted himself to the study of military tactics for 

 a few months; but in the autumn of 1775 he was sent to England 

 with despatches from General Howe to the British Government. In 

 London he speedily ingratiated himself with the Secretary of State 

 for the Colonies, and in May, 1776, he was appointed to an under- 

 secretaryship. He had now finally quitted his native country, leaving 

 behind his wife, whom he never met again, and an infant daughter, 

 whom he saw only after twenty-two years had elapsed. In London 

 Thompson carried on many experiments on gunpowder, on one occa- 

 sion sailing with the fleet, to make himself acquainted with the firing 

 of heavy guns. In 1779 he was admitted Fellow of the Royal Society, 

 and having still retained his military commission, he was promoted to 

 the rank of colonel in the British army. In 1783 Thompson travelled 

 on the Continent, visiting among other places Vienna and Munich. 



