1866.1 229 [Lesley. 



It will be seen by comparing the above section with that of the 

 Sligo Salt Well, furnished by Mr. W. W. Lyon (April 7th, 1865, 

 page 63 above), that the opinion I expressed then was correct, viz. : 

 that the reason of the non-productiveness of the Sligo Well, and of 

 the Clarion River region generally, was merely due to the fact that 

 the Sligo Well, although 992 feet deep, really has penetrated the 

 Brady's Bend strata only 800 feet, and therefore has stopped short 

 of the third and chief oil horizon of Venango County by nearly 300 

 feet. I believe that, were the Sligo Well to go down this additional 

 distance, it would yield the same petroleum and in the same quanti- 

 ties that the Brady's Bend Well is said to yield. 



I cannot say that any accurate identification of corresponding strata 

 in the two wells has been made out. The record of the Sligo Well 

 is from the report of the well master, who describes the look of his 

 borings as they are brought up in the sand pump. The record of the 

 Brady's Bend Well is from the dried sands and powder and fragments 

 of borings preserved in bottles. To obtain a fair comparison and 

 identification, there is but one way, viz.: to bray the borings in a 

 mortar and ram them into a glass tube ; giving to each kind of bor- 

 ings as many tenths of inches of glass tube as the borer found feet of 

 the rock ; and wiping out the tube after every fresh charge, so as to 

 keep the inner surface transparent. If this be done carefully, and 

 the charges are well rammed down to the exact depth (marked by an 

 ink line on a longitudinal strip of paper pasted on the outside of the 

 tube), two tubes can be laid side by side, and any real identifiability be 

 instantly detected. There is no reason why every well-house should 

 not keep one or more such permanent records of its well. Some of 

 the tubes might be half-inch, for dried and powdered borings, to show 

 the color, and others inch tubes, for the fresh wet borings, to show the 



