Mr. Bukewell’s Reply to Mr. Farey. 191 
of flowers, they must in this case describe the. colour of 
many by reference to that of others, which must be pre- 
sumed to be known. In this case, therefore, the nomencla- 
ture could only have reference to well known plants, and 
would be quite useless in countries where the said plants 
were not either indigenous or commonly cultivated. 
_ As all the numerous tints in nature may be said. to con- 
sist in the combinations and shades of the primitive colours $ 
that is, in the proportions of the various mixtures, and the 
intensity produced by the degree of light; the most ac- 
curate method would be to investigate these said propor~ 
tions, and make a nomenclature which should have re- 
ference to them: but as this would be a work of great la~ 
bour, it would be advisable if we could construct some 
more easy and familiar nomenclature. I merely suggest 
these hints at present, which I hope may be improved upon 
in future. 
Yours, &c, 
Clapton, June 30, 1813. THOMAS TORSTE a 
——» 
XXI. Mr. BaxeweEr in Reply to Mr, Farry, on the Great 
Derbyshire Fault. 
Yo Mr. Tilloch. 
Sir,—In the Philosophical Magazine forJuly 1812, some 
queries were addressed by me to Mr. John Farey, respecting 
what he has denominated the great Derbyshire Fault, re 
questing him to favour the public with some proofs of its 
existence. The Jast number of your Magazine contains a 
letter from Mr. I’. purporting to be a reply to mine, but 
omitting entirely the proofs which he was requested to pro- 
duce. I therefore take the liberty of refreshing his me- 
mory, with a second request to have a short and intelligible 
answer to these queries, as they regard: the determination of 
a most important question in the Geology of England. 
That your readers may have a more distinct view of the 
subject, [ shall briefly observe, that by the ** ereat Derby- 
shire fault” is meant a rent or fracture of the earth’s sure 
face, which has torn the island from Nottingham to near 
Macclesfield in Cheshire; and from thence in a line north 
wards into Yorkshire or Lancashire. According to Mr, 
Farey, the discoverer of this fault, the strata on the north 
side of it are elevated from a vast depth, and the strata on 
the south terminate against this rent or fault, or are cut off 
by it. To use a familiar illustration of faults given Py 
idd 
