OIL WELLS OF TERRE HAUTE, INDIANA. 577 
in indigenous petroleum. I have, moreover, expressed the opinion 
that the overlying sandstones of Pennsylvania are also truly oleif- 
= erous. In a paper read to this Association last year, I showed 
that the Niagara limestone at Chicago holds imprisoned in its 
pores an enormous quantity of oil, and remarked that the reser- 
voirs which supply the wells in other districts are fissures along 
anticlinals, which fissures, though sometimes occurring in. strata 
above the oil-bearing horizon, in Ontario frequently occur in the 
` Corniferous limestone itself. Hence the view held by some that 
the source of the oil in that region is to be sought in.the a ing 
strata, is negatived. In Ontario, there intervenes between the 
Corniferous and Niagara formations the great eous. series 
known as the Onondaga or Salina formation. This, however, is 
together, and, according to f. Cox, where exposed at North 
Vernon, Indiana, are both Dein 
A well lately sunk at Terre Haute, Indiana, in search of fresh 
water has shown the existence of a productive source of oil in 
that region. It was carried nineteen hundred feet, and yields 
about two barrels of oil daily. A second well, a quarter of a 
mile east of north from the first, now gives a supply of twenty-five 
barrels of oil daily. After passing through one hundred and fifty 
feet of superficial sand and gravel, the boring was carried to a 
depth of sixteen hundred and twenty-five feet, where oil was 
struck. According to Prof. Cox, the strata passed through are as 
follows: Coal measures, seven hundred feet ; Carboniferous lime- 
stones with underlying sandstones and shales, seven hundred feet ; 
black pyroschists regarded as the equivalent of the Genessee 
slates, fifty feet. Beneath, at a depth of twenty-five feet in the 
underlying Corniferous limestone, the oil-vein was met with. The 
oil in the first well was found at the same horizon. A third well 
about a mile to the westward, was carried to two thousand feet, 
but only traces of oil were found. This locality, on the Wabash 
river is, according to Prof. Cox, on the line of a gentle anticlinal 
or uplift, which is traced a long distance to the west of south. 
This relation of productive oil-wells to such anticlinals was pointed 
out by Prof. Andrews and by myself in 1861. 
