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VII. On the Stratification of England; the intended 

 Thames Archways, &c. By John Farey, Esq, 



To Mr. Tilloch, 



SIR, 



/x regard for the interests of science has long occasioned 

 nie and others to regret, that a truly valuable and extensive 

 body of facts on the stratification of England, Wales, and 

 part of Scotland, the labour of 14 years or more, spent in 

 the most intense application to the subject by a gentleman of 

 Bath (Mr. JFilliam Smith, engineer, now resident in Buck-' 

 ingham street, Strand, London), should remain useless on 

 his hands, for want of sufficient public encouragement to 

 induce him to publish his Maps, Sections, Drawings and 

 Descriptions of extraneous Fossils and other particulars, most 

 of which are new, and appear quite essential to the placing 

 of the Geology of our own country, and perhaps of the whole 

 terraqueous Globe, among the accurate sciences. Mr, Smith 

 has traced the out-crop of a stratum of Chalk, that is, its 

 appearance on the surface of the land, or rather in the 

 hangings of certain ranges of our English hills for near 700 

 miles in length! The exact uniformity of appearances of 

 this out-crop in innumerable instances, corroborated by the 

 sinking of wells and other works of art upon or in this 

 stratum, in the greatest variety of situations, has fully 

 •warranted the conclusions ; that this immense mass of mat- 

 ter consists of a vast number of layers of chalk and siliceous 

 substances, the latter in almost every variety of form, from 

 that of solid black flint, to a white and fine sand or grit stone ; 

 the whole of which layers (except of flints) have in general 

 so much the appearance of chalk for 400 feet or more in 

 thickness, as hitherto to have passed under that denomina- 

 tion, and which it may perhaps be well still to retain as a 

 general name for th>s assemblage of strata. In like manner 

 the out-crop has been traced of an immense succession of 

 argillaceous, siliceous and ferruginous matters lying upon 

 the above chalk stratum, wherever the same is found to 

 have any regular strata upon it in England j which strata 



Mr. Smith 



