WATT. 395 



this letter to Dr. Priestley, and the reading of it, Mr. Watt 

 had addressed another letter to M. de Luc, dated 26th No- 

 vember, 1783,* with many further observations and reasonings, 

 but almost the whole of the original letter is preserved in this, 

 and is distinguished by inverted commas. One of the passages 

 thus marked is that which has the important conclusion above 

 mentioned ; and that letter is stated, in the subsequent one, 

 to have been communicated to several members of the Royal 

 Society at the time of its reaching Dr. Priestley, viz. April, 

 1783. 



In Mr. Cavendish's paper as at first read, no allusion is to 

 be found to Mr. Watt's theory ; but in an addition made in 

 Sir C. Blagden's own hand, after Mr. Watt's paper had been 



* The letter was addressed to M. J. A. de Luc, the well-known 

 Genevese philosopher, then a Fellow of the Royal Society, and 

 Reader to Queen Charlotte. He was the friend of Mr. Watt, who 

 did not then belong to the Society. M. de Luc, following the 

 motions of the Court, was not always in London, and seldom at- 

 tended the meetings of the Royal Society. He was not present 

 when Mr. Cavendish's paper of 15th January, 1784, was read ; but, 

 hearing of it from Dr. Blagden, he obtained a loan of it from Mr. 

 Cavendish, and writes to Mr. Watt on the 1st March following, to 

 apprise him of it, adding that he has perused it, and ^promising an 

 analysis. In the postscript he states, " In short, they expound and 

 prove your system, word for word, and say nothing of you." The 

 promised analysis is given in another letter of the 4th of the same 

 month. Mr. Watt replies on the 6th, with all the feelings which a 

 conviction he had been ill-treated was calculated to inspire, and 

 makes use of those vivid expressions which M. Arago has quoted ; 

 he states his intention of being in London in the ensuing week, and 

 his opinion, that the reading of his letter to the Royal Society will 

 be the proper step to be taken. He accordingly went there, waited 

 upon the President of the Royal Society, Sir Joseph Banks, was re- 

 ceived with all the courtesy and just feeling which distinguished 

 that most honourable man ; and it was settled that both the letter 

 to Dr. Priestley of 26th April, 1783, and that to M. de Luc of 26th 

 November, 1783, should be successively read. The former was 

 done on the 22d, and the latter on the 29th April, 1784. [NOTE; 

 BY MK. JAMES WATT.] 



