Mineralogy and Geology. 111 
time for the November number, 0 Wwe now propose to fulfil the promise, 
so far ae space will perm 
Ass above, this Report pothe about 520 pages of letter-press, 
and is sic in large clear type, upon excellent paper, with well executed 
illustrations; and the whole is neatly and substantially bound in “eloth. 
Chapter I consists of remarks on the General Principles of geological 
science,—the physical features of the State, its nt geology, d&c. 
In Chapter II the Tertiary deposits and the Coal-measures are described 
and their relations to the other formations of the ah explained, by a 
clays, greenish sand, an bese he but a limited area in the southern part 
apparently of Eocene aes 
The Coal-measures being of great economical importance, are de- 
scribed at fe th, and numerous sections of their various beds are given, 
occupying near three-fourths of the entire area of the State. Them 
imum’ thickness of the whole series, exclusive of the Millstone grit, rt 
in the southern part of the State, about 900 feet, including six workable 
beds of coal, with an aggregate thickness of 30 feet. Going northward, 
the Coal-measures diminish in thickness, chiefly by the thinning out of 
lower beds, so that on the northern borders of the field, where the Mill- 
portance of this incthautlbls store of mineral wealth, ree of 
power and progress, to a state like ino, which also rom a ah extent 
of the most beautiful undulating prairie lands unsurpassed in productive- 
ness and easily brought under cultivation. 
In regard to petroleum in Illinois, the State Geologist remarks that it 
has been found in small quantities in two or three of the southern coun- 
ties; and that from the greater thickness, on the eastern borders 
e, of the rocks generally regarded as the source of the oil deposits 
in western Pennsylvania and eastern Ohio and Kentucky, it will be most 
apt to be found in paying quantities in the region of the Wabash val- 
ley. The eorrectness of this suggestion has been con! since the 
arte of the Report, by a valuable flowing well sunk at Terr re Haat, 
