1866. | Geology. 535 - 
sumption of coal reached the portentous figure of nearly one 
hundred millions of tons. I have simply endeavoured in this 
communication to indicate to the public that they are not to believe 
in the almost boundless range of our coal fields which some persons 
would assign to them.” 
From Mr. Hedley’s communication “On the Sinking of 
Annesley Colliery,” about eleven miles from Nottingham, it 
appears that the shaft is at present 200 yards deep; that the 
formations through which it passes are New Red Sandstone, 68 
feet; Permian, about 150 feet; below which are the usual alter- 
nations of sandstones, shales, thin coals, and fire clays of the Coal 
measures, which dip due east, about 1 in 36, conformably with the 
Permian beds; that when about six feet above it, water burst up 
from the Magnesian limestone in such abundance that the three 
pumps which were constantly employed discharged 1,500 gallons 
per minute; and that as the sinking progressed it was necessary to 
line the shafts with cast-iron tubing to the depth of 98 yards, 
below which ordinary brickwork sufficed. The author regarded 
this sinking as affording conclusive proof of the practicability of 
sinking through the water-bearing strata which cover a large area 
of Coal measures in the eastern part of Nottinghamshire. 
Professor Hitchcock, of Lafayette College, United States of 
America, stated, in his paper “On the Geological Distribution of 
Petroleum m North America,” that the petroleum produce of the 
United States increased from 24 millions of gallons in 1862, to 
upwards of 91 millions in 1865; the value of the latter quantity 
being about four million pounds sterling. Petroleum sometimes 
occurs in synclinal basins, in cavities and fissures in the strata 
which may or may not le in synclinal basins, in long lines of 
faults, and beneath anticlmal arches. Great wells involve three* 
essentials :—Plenty of bituminous matter in the petroleum forma- 
tion, from which an abundant supply may be drawn; cavities and 
crevices formed by the unequal elevation of the strata; an imper- 
vious cover, like the roof of an anticlinal, to have prevented the 
escape of the petroleum gas in past ages. In the American con- 
tinent, an area several hundred thousand square miles in extent is 
underlaid by oleiferous formations, which are known to have a 
vertical range from the Pliocene, through the Cretaceous, Triassic, 
Carboniferous, and Devonian, to the Upper and Lower Silurian. 
The quantity and quality of the petroleum is proportional to the 
depth to which the wells descend. The lightest oils come from the 
greatest depths. In conclusion, the author asked, and commended 
to the attention of the Association, the question, which he confessed 
himself unable to answer, “ How was the petroleum formed ?” 
Kindred to the foregoing was Professor Ansted’s paper “ On 
