4;2^ Mr. John Taylor on the Dutij of 



vention of expansive working, why is high pressure steam used 

 in Cornwall ? explosions have been frequent enough* to deter 

 the miners from continuing the use of such a dangerous agent, 

 if they could carry on deep mining without its aid. 



The obvious intention of the communication at p. 324 is to 

 lead your readers to conclude that Mr. Woolf's patent was 

 for no invention at all, and that the system of working steam- 

 engines by high pressure steam acting expansively (which he 

 alone introduced into use) has had nothing to do with the 

 remarkable improvement of the performance of engines in 

 Cornwall, within the last seventeen years. 



The mention I made of Mr. Woolf's invention, arose inci- 

 dentally in answering the various questions put by the Com- 

 mittee. I cited Mr. Woolf as an example of the case that has 

 so often occurred, where an inventor who has rendered im- 

 portant service to the public, has derived no benefit from his 

 patent, because it expired before the invention came into use; 

 and I also cited Mr. Watt, as an example of the rare case of 

 an inventor who did derive an adequate recompense for his 

 public services, by the operation of an Act of Parliament,which 

 prolonged the term of his patent. 



If any member of the Committee had felt doubtful of the 

 accuracy of my statement, further questions would certainly 

 have been put, either to me or to others. I was fully prepared 

 to substantiate all I advanced ; and if you think it will prove 

 interesting to your readers, you can reprint from the evidence 

 reported by the Committee all that relates to Mr. Woolf, and 

 I will supply you with the explanation which I should have 

 given in support of my statement, if it had been called for. 



I am, Dear Sir, yours truly, 

 37, Howland-Street, Fitzroy-Square, JoHN FareY. 



May 10, 1830. 



[We shall gladly avail ourselves of Mr. Farey's offer of further informa- 

 tion on this important subject. It is due to the memory of our estimable 

 predecessor, Dr. Tilloch, to state that, so far as pecuniary means have con- 

 tributed to the completion of Mr. Woolf's invention, the public are in a 

 great measure indebted to him for it.] — Edit. ', 



LXI. On the Duty of Steam-Engines in Cornwall. By John 

 Taylor, Esq. F.R.S. Sfc. 

 To the Editors of the Philosophical Magazine and Annals. 

 Gentlemen, 



THE attention of the Admiralty has, it appears, lately been 

 drawn to the subject of the duty performed by the steam- 

 engines in Cornwall. This is said to have been done by Cap- 



* See Mr. John Taylor's paper on this subject in vol. i. of the present 

 series of the Philosophical Magazine, p. 12G, also p. 403. 



tain 



