On the Study of the Principles of Stratification. 127 
already known, but also to display the apparently hidden re- 
sources of other countries, and to furnish those data, which: the 
extended views of modern science have rendered necessary. , 
As the labour of gaining any new source of knowledge never 
fails to bring with it its own reward, by a proportional increase 
of the sources of pleasure, { hope an attempt to bring that of 
the prince iples of stratification imto more general notice, may not 
be without effect. It is a branch of knowledge, which, on ac- 
count of its useful nature, is perhaps better calculated to become 
popular, than any other. In proof of the truth of this remark 
it is only necessary to say, that it includes the principles of the 
important art of draining land;—that from it the probability of 
obtaining certain minerals in certain situations may be inferred 
from the nature of the superior strata, without the expensive 
process of boring ;—that it is calculated to check the delusive 
mining projects, which have ruined thousands, and at the same 
time to encourage those which are likely to be attended with 
success; that it also points out the best methods of working 
new mines, as well as the most effectual means of extending old 
ones, with security and profit. Iam, sir, yours, &c. &c. 
London, August 11, 1817. Tuomas 'TREDGOLD. 
P.S. Asthe recommendation of any particular branch of science 
may seem imperfect, without saying something on the means of 
obtaining it, I have subjoined the following list of works on the. 
subject of stratification. Perhaps some of your correspondents 
may think proper to extend it, with critical notices on the com- 
parative merits of the writers. 
Mr. Wm. Smith’s Mineralogical Map of England and Wales: 
and several numbers of the works he is now publishing, to 
explain it. ~ 
Mr. Farey’s Derbyshire Report. 
Mr. Bakewell’s Introduction to Geology, 2d edition. 
The articles ** Coal” and ‘¢ Stratification” in Dr. Rees’s New 
Cyclopzedia. 
Mr. Sowerby’s Mineral Conchology. 
Williams’s Natural History of the Pe Ge Kingdom,—And 
several valuable facts are collected, 
Mr. Whitehurst’s Inquiry into the Original State and Forma- 
tion of the Earth. 
Mr. W. Forster’s ‘Treatise on a Section of the Strata, New- 
eastle. 1809. 
The Transactions of the Geological Society. 
The 25th and following volumes of the Philosophical Maga- 
zine, &c, &c. and The Monthly Magazine. p ley we 
XXI. On 
