110 Defence of M. De Pronyfrom 



There is therefore nothing deleterious in the usual practice of 

 adulterating this commodity of the tahle. The fraud only tends 

 to deteriorate the quality and flavour of the genuine article it- 

 self. 



XIV. Defence of M. de Prony/?077i the Aspersions contained 

 in Memoir of Mr. Watt. By Air. John Farey. 



To Mr. TillocL 



Sir, — X HE memoirs of the late James Watt, Esq. which you 

 have printed in your last volimie, are highly interesting, and the 

 writer has done no more than justice to the inventive genius of 

 that great man in the account of the origin of the improved steam- 

 engine. 



This memoir charges M. de Prony with committing a flagrant 

 act of injustice in his History of the improved Steam-engine, in 

 tvt/o volumes in quarto. It is stated that M. de Prony there 

 gives the invention of the improved steam-engine to Messrs. 

 Perriers, never once mentioning the name of Mr. Watt. 



It would indeed have been a most flagrant act of injustice if 

 Mr. Prony had done so, and in that case 1 would willingly have 

 left that gentleman to encounter all the odium which the author 

 of the memoir throw:, upon him ; but M. de Prony does state 

 Mr. Watt to be the inventor, and that the improved engine was 

 brought from England by Mr. Ferrier ; which is the fact. As 

 only a few of your readers can have an opportunity of examining 

 M. de Prony's book, and as all must concur in reprobating his 

 conduct, whilst this allegation stands uncontroverted ; it will be 

 only justice in you to print the following extracts from the work 

 in qiies'cion. 



It is entitled Nouvelle Architecture Hydraidiqae, par M. de 

 Prony , Ingenieur des Pants et Chausses, in two volumes quarto, 

 printed at Paris; the first volume in 1790, and the second in 

 1796. 



In the preface to volume I. p. xii. is a Report on the first 

 volume of this work to the Academy Royal in 1798. The re- 

 porter says, " Le dernier chapitre contient I'histoire et Fusage 

 des machines a fm depuis le Marquis de Worcester, jusqu'aux 

 dernieres decouvertes faites par MM. Watt et Bolton, et dont la 

 machine a double injection vient d'etre apportee en France, et 

 presentee a I'Academie par M. de Betancourt." 



Mr. Pronv begins his account of steam-engines at page 563, 

 vol. I. His historj of the successive English inventions by the Mar- 

 quis of Worcester, Captain Savcry, Newcomen, and Cawley, is 



very 



