Curll.] 431 f j„„. 19, 



"VVilliout doubt, the general reader will be much confused in attempting 

 to trace the oil sands in their proper order through the mass of records here 

 given. No ellort has ])een uiade to harmonize the apparent discrepancies 

 made by drillers in numbering the Saiulrocks. The records have l^een 

 copied from the originals just as they were received, only making them to 

 conform to the general plan adopted in the publication of the whole mass 

 of records, good, bad and indifferent, which we have on hand. It will be 

 a work for future study to select those which are reliable and to arrange 

 and classify them in an intelligible manner. We hope that the publica- 

 tion of these records as they are given to us by men who claim to under- 

 stand the order and arrangement of the oil rocks, will satisfy them that they 

 are not working understandingly, and show them the necessity of a closer 

 examination of the measures drilled through and a more careful numbering 

 and measurement of the Sandrocks. 



Mr. Nettleton's levels, as mentioned in his report, were all based on his 

 Ennis Ilill datum. In 1874 we established the height of this Hill, by levels 

 connecting with the railways at Tidioute, Tionesta and Rouseville, as 

 1713 feet above tide.* We now add 7 feet to reduce this to ocean level, f 

 making it 1720 feet above the ocean. The elevations of the following wells 

 have all been adjusted to this standard. 



All the wells not otherwise noted are located in Venango Count5% 



Some of the records here given from Enterprise and the Columbia Hirm 

 on Oil Creek have been published in a previous issue. It will be noted 

 that these differ fr<jm the former quite materially — a circumstance which 

 shows how unreliable, for close study, the best of records are, even when 

 obtained from the well owners and superintendents themselves. 



To make sure always that the well record sent in should be the par- 

 ticular one required Mr. Netlleton adopted the plan of numbering the 

 wells in his field book as he leveled to them. He also carried with him a 

 paint-pot and brush and marked the same number used in his note book 

 l)lainly on the samson-post. This is the '• engineer's number" referred to 

 in the blanks. When the well owner returned the record he gave, in ad- 

 dition to the name of the well, the number on the samson-post, and thus 

 there could be no mistake made in adjusting the levels to the record. 

 These numbers are given in the following pages at the end of the name of 

 tlie well, in brackets, thus : Ennis Well (1), Harmonial Well No. 1 (53), 

 &c., &c. 



•At Schuylkill bridijre, Philadelphia, Pennsylvania Uallroad datum. 

 + In Raritan Bay, C'oa.st Survey datum. 



