PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 427 



shale, and when fractured this oil comes through it at Oil Creek and 

 elsewhere throughout the United States. My objection to this tlieory is 

 that the coat is too short for the person it is intended to fit, as this shale 

 does not extend all over the United States. It is not found in Ohio nor in 

 Kentucky, Illinois and West Virginia. The Helderberg is from 40 to 200 

 feet thick; the Marcellus about 200 feet, and the Hamilton group is about 

 1,000 feet thick, and tliere are no bituminous shales in it. It is full of fos- 

 sils, and the sea must have been lull of animal life at that period when it 

 was formed. There are certain strata commencing with the Catskill moun- 

 tains, and which pass across the State of New York, containing the same 

 species of shell which can be detected at once. This is so clear that a man 

 might be let out of a balloon and he would immediately detect them at 

 sight. I have myself been astonished to discover them in places where I 

 would hardly expect to find then), sometimes 40 and 50 miles apart. The 

 oil lately discovered at Rushville and at Seneca lake, and along Mud creek 

 in Ontario county, are all of this group. They are undoubtedly of the 

 Hamilton group. The Hamilton group goes down as far as Schoharie 

 county and passes through about the centre of the inland lakes and through 

 Canada over to the edge of Lake Michigan. The wells of Canada are also 

 in the Hamilton or Marcellus group. Probably the well that has lately 

 been discovered, at Zanesville, Ohio, is of this group. The mountains at 

 Catskill are over 2,000 feet thick b^' actual measurement, and we are not 

 able to determine where the Hamilton group changes into the r.ext group 

 or the Portage. This is about 1,700 feet thick. Any one who has traveled 

 on the Buffalo and Erie railroad, and looked out while crossing the high 

 bridge at the clilfs and falls at Portage, on the Genesee river, has seen the 

 Portage group of rocks. This group has no great number of gas or oil 

 springs; but at Cuba there is an oil spring that has been known since the 

 earliest settlement of our countr}-. 



The Chemung group comes next in order. (Here the Dr. made a trans- 

 verse section on the blackboard, which represented the abrasion made by 

 the waters of Oil Creek flowing southward.) Now at Oil Creek they bore 

 400 or 500 feet, and strike the third series of sand stone, and that sand 

 stone must be near the junction of the Chemung and Portage groups. 

 Somewhere near the upper portion of the rock upon the Chemung, in the 

 State of Pennsylvania, comes in the Catskill group. This group of rocks 

 is 5,000 feet thick. Those who have travelled on tlie central railroad west 

 of Altoona by day, may have noticed the rocks turned up edgeways. 

 These are the Chemung and Catskill groups. We next, on the south of the 

 Appalachian mountains, come to the sub-carboniferous group, which is 

 3,300 feet thick, and on the top of this comes the true coal, 15,000 feet 

 thick. From the limestone to the top of the coal, every portion of it is 

 really a petroleum-bearing rock ; and I have no doubt but that throughout 

 the whole extent of the geological group alluded to oil will be found in 

 abundance, so that we can go to other places besides Oil Creek to buy oil 

 lands. At Oil Creek there have been some 2,000 vvells sunk, and the region 

 has been better developed than any other, and that is all the advantage 

 which it possesses. Suppose that the first well sunk there had been a 

 failure, no one would think of sinking another. 



