YENANGYOUNG. 



97 



tract (which, as we have seen, draw their oil nearly all from one and 

 the same bed, the 3rd oil-sand) into three classes : poor wells below 

 500 gallons a day, better ones yielding between 500 and 1,500 gallons 

 a day, and rich wells which yield more than 1,500 gallons a day. On 

 entering these observations on the map, plate XV, not much seemed 

 to be gained by this, rich and poor wells appeared to be distributed 

 in a most erratic way, only the well known fact that in the Yenan- 

 gyoung oil field a very rich and a very poor well may occur close 

 together appeared to receive further support. Note, for instance, 

 the case of wells No. 53 and No. 9, the former being a rich and 

 the latter a poor well, although their horizontal distance is barely 

 180 feet. But when the wells of each single class were connected 

 by lines, a most curious feature was almost at once noticed. The 

 lines connecting each class did not run straight or in a slightly 

 curved way, but they were arranged in a zig-zag course. The 

 following will demonstrate this ; wells Nos. 25, 27, 28, 26, 48, 55, 

 32, 35 are all rich wells, connecting these wells by an uninter- 

 rupted line, wells Nos. 25, 27, and 28 were situated on an almost 

 straight bearing; at No. 28 the line took a sharp turn inwards, 

 so to speak, and wells Nos. 28, 26 and 48 were again found to be 

 situated on an almost straight line, the above named five wells were 

 therefore situated on both sides of a very acute angle, at the apex 

 of which was well No. 28 ; proceeding further from No. 48 towards 

 Nos. 55, 32 and 35, these were again situated in an almost straight 

 line, meeting the line 28, 26, 48 at a very acute angle, but running 

 almost parallel to line 28, 27, 25. 



So far this may be accidental only, but, luckily enough, a few 

 more wells of the middle and poor class, proved almost to a 

 certainty, that the explanation of these lines must be something more 

 than a mere accident. On connecting the middle class wells Nos. 58, 

 30 and 31 by a line, it was found that they too were situated on a 

 rather acute angle, well No. 30 at its apex and wells Nos. 31 and 58 

 on its sides, and that line 58, 30 was almost parallel to line 25, 

 H ( 143 ) 



