Mr. Farey’s Reply to Mr. Bakewell—Faulis in Derliys. 109 
ingstone), which after an uninterrupted range of basset 94 
Miles in length, I have traced to the zigzag fault at its two 
ends, and so of the 3d Coal-Shale and the 3d Grit Rock, 
after somewhat longer courses, in succession. And thus: 
Lain confident of being able, to fill up all the Coal series 
of Notts. Derby and York above the 4th Rock, and several 
Rocks and Coal-shales below it, terminating at each end, at 
the very Fault, which Mr. B. has chosen to attack (for 
let it be remembered, that my original Letter in your 
Magazine had no allusion. to Faults): but unless more 
general encouragement, in such a serious and public un- 
dertaking, presents itself, than heretofore, it must remain 
suspended at least, in favour of private Mineral Surveying, 
and business connected therewith, of which, fortunately, 
I have never been in want, any more than my Friend Mr. 
Smith, during the long period that his truly national under- 
taking, has from similar causes, been suspended, but which 
is now in train of almost immediate publication, as men 
tioned in my last. 
Mr. B. has chosen rather, to attempt to bring general 
opinion to bear upon my poor zigzag Fault, and besides 
this, at page 983, says more particularly, “‘In the above 
examination of the Derbyshire strata, Icannot learn that any 
trace of Mr. Farey’s fault called the zigzag fault, could 
be discovered ;”” alluding, as appears from the preceding 
page, to a ‘* perpendicular Section,’* or collection of 
Sinkings and Boreings, applied in succession, from the deep 
to the basset, which was begun several years ago by Mr, 
Theodore Silverwood, the very able Coal and Iron Agent, 
at Somercoats, Furnace, when it was under the direction of 
my scientific friend Mr. Mushet, whose Letter in your xlth 
vol. p.49, I am sorry that I have not yet had leisure to 
reply to, as it deserves. 
Mr. Silverwood’s general Sinking account, I have fre- 
quently seen, and have indeed a copy of it, as far as it had 
been completed each way from Somercoats, when last I 
was there, and it now appears, from a Letter of one of the 
proprietors to Mr, B. that Mr. S. is making progress with 
a vertical Section, of the Derbyshire strata, which is I hope 
* Such documents as these, exhibiting only the thickness of strata, which 
if taken oblique to the plane of the strata (as the boreings or sinkings hap- 
pen to be made) should be reduced to the perpendicular thicknesses, at the 
time of planning them in connection, I have usually denominated Sinking 
accounts, or Face-views, when they exhibit the faces of Quarries, Mines, &c: 
in order to distinguish them from vertical Sections, wherein the planes of 
strata are seen cut, and their tops and edges on the surface are exhibited, in 
wacceation, 
doing, 
