GEOLOGY. 295 



about the latter part of 1862. In this year another well the " Wood- 

 ford" was put down near, which tapped the same vein of oil, and 

 assisted in diminishing the How. The " BigPhillips" is now running at 

 the rate of 325 barn-Is per day. It is believed to be the only well 

 which began flowing without having been previously tubed. 



The " Woodford" well, alluded to above, was originally a 1,500 barrel 

 well. Its yield began to decrease in 1863, and finally eeased. Being 

 resuscitated, it is now pumping 50 barrels per day. 



The "Jones" well, put down in the latter part of 1862, within 30 feet 

 of the " Woodford," tapped the same vein, flowing 400 barrels per 

 day. Its How decreased gradually until the well had to be pumped. 

 It is now doing nothing. 



The " Noble " well struck oil in April 1863. Its maximum daily 

 yield was between 1,900 and 2, 000 barrels. It flowed six months with 

 uudiminished volume, when it began to decrease. It was flowing 

 until the 1st of February 1865 at the rate of 150 to 200 barrels per day, 

 when an accident stopped it. This well is said to have netted its 

 owners over $ 3,000,000. 



The " Empire" well was sunk in the fall of 1861, and began flow- 

 ing from 2,500 to 3,000 barrels per day. The flow continued, dimin- 

 ishing gradually for something over two years, when it stopped. The 

 well lay idle about a year. In the summer of 1864, an air pump was 

 applied, which caused the well to resume flowing lightly, live or six 

 barrels per day. The flow then slowly increased to 140 barrels. The 

 well is now yielding 110 barrels per day. 



Other wells have been partially resuscitated in like manner by the 

 use of an air pump. 



The average actual yield of oil in the Pennsylvania oil region is, of 

 course, greatly exaggerated in the estimates and imaginations of most 

 parties who have read of the subject, and heard it talked of in a general 

 way. It is presumed by those who have most closely watched the de- 

 velopment of the oil product from the first, that whereas the yield in 

 1862 was from 10,000 to 12,000 barrels per day, it is now (February, 

 1865,) not more than 6,000 barrels. It is probable that the former 

 yield even exceeded the amount named, as, during 1862, all the large 

 flowing wells then struck were prevented from running their full 

 quantity, owing to the merely nominal price of and demand for the 

 oil. Now, all the wells in the region arc permitted and aided to de- 

 liver to their utmost capacity. 



This decrease in the yield of a territory where, for more than four 

 years, the number of oil wells has been increasing, appears at the first 

 glance, quite inexplicable upon any other ground than that the supply 

 of oil is becoming exhausted. Some light, however, may be gained 

 on this subject from a brief review of the history of Pennsylvania oil 

 production from the commencement. 



The mining of petroleum began as a business in 1860, but did not 

 prove very successful until 1861. The first well was sunk in 1859, 

 near Titusville, Pa. It yielded some eight barrels per day. In the 

 summer of 1861, a number of flowing wells were opened at Oil Creek. 

 The consumption of the article was, however, very small, while the 

 production was suddenly increased from about 150 barrels daily in 

 February to some 2,500 barrels daily in August, and more than 6,000 



