310 Royal Society, ; 
any others of the circumstances, I cannot see the ground 
of Mr. Taylor’s, arguments,. if such they can. be cailed, at 
page 130, to show the probability even, that I had mis- 
takenly confounded darge and small, in recalling bis atten- 
tion to the passage first alluded to; or.see, how the words 
‘upon a large scale,” as applied to an hydraulic engine, can 
be united to the height of the lift, to the neglect of time and 
quantity of water. I certainly could have had no view, as 
I had no motive, to disparage: Mr. Taylor’s invention, in 
correcting what [ thought, and still think, an erroneous 
general assertion, by stating what particulars my notes on 
Crash-purse Mine then furnished, as to what had there 
been done ; and [ beg now to supply the following, ob- 
tained, through the medium of a friend in London, from 
Philip Stevens who put up the Crash-purse engine for 
Mr. Trevithick. 
Length of the 15-inch pipe which conveys down the 
water of the Bradford river 44 yards; «diameter of the 
working cylinder 25. mehes, and Jength of stroke therein. 
105 feet: the above, by means of a beam 40 feet long, 
works three puinps, two of whose working barrels are 33 
inches diameter, and the other 103 inches diameter, which 
each separately lift 17 yards, ito the sough, six strokes in 
@ minute, of about seyen feet each. ue , 
I am, sir, 
Yours, &e. 
Westminster, April 16, 1811. JoHN Farey. 
LIV. Proceedings of Learned Societies. 
ROYAL SOCIETY. 
March 21 Mie Macartyny furnished a short paper on 
the stomachs of birds, in which he mentioned his discover- 
diy a new-organ in the mtestines of these animals, caleu- 
Jated to assist their digestive powers. 
March 28.-—A letter from Mr. John Farey, who has for 
a long time past been engaged in a mineralogical survey of 
Derbyshire and its environs, addressed to the President, was 
read, which, referring to a sketch map of “the district, ex- 
plains the situation of certain enormous fawlts that he had 
discovered, surrounding large tracts of country in Derby- 
shire,’ Nottinghamshire, Staffordshire, Cheshire, Lanea- 
shire, and Yorkshire, and within which the whole mass of 
strata (con aining coal scams over much of the surface) 
seem, @m a-comparison with those of the surrounding 
