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XXIX. Short Notices of Geological Ohservations made in the 

 Slimmer of IS\4, in the South oj" Yorkshire, and in North 

 Wales, and of some Inferences iherefrom, as to the Structure 

 of England and IVales. By John Farey, Sen. 



To Mr, Tilloch. 



Sir, — Jl or several months past it has been my intention to send 

 you during ilie present winter, an account, considerably in de- 

 tail, of my Observations on the Strata during the last Summer, 

 and of certain new Geological inferences which they seem to 

 warrant, as far at least as the structure of England and Wales 

 is concerned : but seeing reason now to fear, that Time will not 

 permit the sending all the details intended, I must beg your in- 

 sertion of a shorter Notice on the subject. 



\\'hen I began, several years ago, to apply the Smitliian prin- 

 ciples of Stratification to practice, in the minute investigation of 

 the Strata of particular Estates and their vicinities, and, with 

 less minuteness, to much larger Districts, I fell in some instances 

 into the error, to which observers of Nature have ever been 

 liable, of concluding too soon, that I had become acquainted' 

 with all the leading characters of the Strata which I had investi- 

 gated locallv: — when for instance, I had traced my 1st, 2d, and 

 Srd Gritstone Rocks of Derbyshire, for more than 25 Miles, from 

 Dutfield northward, witii but slight variations in their thicknesses 

 or characters, as single Rocks, and had traced the Limestone- 

 shale belDvv and the 4th Grit, above these Rocks, still fuither 

 northward, beyond Woodhead and Penistone, without material 

 variations in their characters, I too hastily concluded (when about 

 to finish mv observations beyond Derbyshire on that side, in 

 ISOi)) from observations at a few points, as to some other points, 

 in the ranges of these three iiilermcdiate Rocks and their Coal- 

 shales in this part of ^'orkshire. 



To some errors which were, in conse{|uencc hereof, printed in 

 my Derbyshire Report, other more material ones having !)eeii 

 added, by Persons v.ho attempted to follow up the investigations 

 1 had Ijcguii, and disappointment following, in some trials that 

 ^vere made in search of Limestone, in Udeu Vale, 1 was sent for 

 la<t Summer, to complete my observations in this corner of 

 Yorkshire, to the left of the old Road from Sheffield to Peni- 

 stone. By this means 1 discovered the source of my former 

 mistakes, in the new and unexpected characters which the 1st, 

 2d, and Ihd Rock.s, and other intervening strata, exhibit, in these 

 parts of their Ranges. Instead of the same entire thickness of 

 these Rocks continuing, as above mentioned, each one was here 

 found much thicker, ,sc|)arated into two dibtinct Rocks, by bind 



Vol. i:.. No. 203. March IS 15. L or 



