as 
1872] 563 [Lesley. 
From the above table, it appears that all the oil-producing wells men- 
tioned in it get their supply from one stratum lying in an undisturbed 
and horizontal position, varying in their actual depths below a fixed 
datum level from 1,118 to 1,066 feet, a difference of only 40 feet. This 
difference is due to three causes, viz. :—1. The different depths in the 
sil-besring stratum penetrated by the bottom boring of the wells ; 
2. The slight inequalities in the upper surface of the stratum ; 3. And 
s, both from the northwest and 
chiefly, to a general slight dip of the ro 
from the southeast, in towards the centre line or axis of the trough or 
basin which here crosses the Allegheny River in its northeast-south west 
eourse ; and also to a still slighter and almost insensible decline of the 
axis of the basin itself southwestward. 
The table also confirms what was prover years ago, long before the fact 
was acknowledged by oil men, namely, that it makes no difference whethe 
a well is started in the valley bottom or on the hill tops, provided it goes 
down to the uniform and nearly horizontal oil-bearing sandrock. For 
some of these wells have their mouths at elevations more than 300 feet 
greater than others. Some on the river bank, and others high up at the 
heads of side ravines. The great No. 8 well was commeneed at an eleva- 
tion (379—96-—) 283 feet higher than those on the river bank whieh yield 
only from one to three barrels a day. 
The following table shows the thickness of the third sandroek where it 
was passed entirely through : 
No. 2.—No sandrock found and no oil. 
-Sandrock, 26 feet ; hard fine white sand. 
No. 5.—Sandrock, 27 feet ; fine pebbles. 
No. 6.—Sandroek, 16 feet ; with slate partings. 
No. 7.—Sandrock, 27 feet ; pebbles pretty coarse. 
No. 8.—Sandroek, very coarse and open. 
No, 9.—Sandroek, pebble very fine and close, very little gas. 
No. 10.—Sandrock, 10 feet; pebbles pretty fine, except in one thin 
streak. 
No. 11.—To sandrock, no oil, but great gas blow, doubtless from a 
fissure. 
No. 12.—Sandrock, 17 feet, all pebbles ; steady flow of oil. 
No. 13.—Sandrock, 18 feet ; coarse open pebbles; and a fair amount of 
yas. 
No. 14.—Sandrock, 18 feet ; large coarse pebbles ; fair amount of gas. 
Other noteworthy facts are as follows : 
No. 1 well, on the river bank, one half mile above the rolling mill, 
begun March, 1865, finished 1 866. 
No. 2 well, at the mouth of Cove Run, May, 1866—June, 1870. 
No. 8 well, on the river above the mill, commenced August, 1868— 
pumping in September, 1872, 1 barrel a day. 
No. 4 well, on the river above the mill, May, 1869—March, 1870. Cost 
£10,405. Record of: strata given below. 
——s 
Sa 
eee 
