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author of several excellent essays on stratification. To Mr. Farey I 
acknowledge considerable obligations for his exceedingly liberal and 
unreserved communications on subjects connected with these inquiries. 
According to the actual observations of Mr. Smith, as given by Mr. 
Farey, in his General View of the Agriculture and Minerals of Derby- 
shire, Vol. I. p. Ill, the following are the upper strata which have 
been discovered in this island, disposed in the order in which they occur. 
1. Sand. 
2. Clay, with septaria. 
3. Sand, with shells, varying in thickness, and in mixture with 
other substances. 
4. Soft chalk, with flinty nodules. 
5. Hard chalk. 
6. Chalk marl. 
7. Aylesbury limestone. 
8. Sand and clay strata, in one of which is a dark -coloured shelly 
limestone, called Sussex marble. 
9. Woburn sand, in which is a stratum of fuller’s earth. 
10. A thick clay, called the clunch clay. 
11. Bedford limestone. 
12. A thick clay. 
13. Rag-stone of Barnack, &c. 
14. Limestone and grey slate of Stunsfield, Colley Water, &c. 
15. Sand. 
16. Bath free-stone. 
17 . Sand and clays. 
18. Maid well limestone. 
19. Lias clay, containing the blue and white Lias limestone. 
20. Sand. 
21. Red marl. 
Beneath these follow the grit-stones and coal shales, and the alter- 
nating limestones and toadstones. Parts of these inferior strata appear 
