YENANGYOUNG. 121 



decline noticed in the 328 wells, they would show a loss of 23,184 

 viss per mensem ; the total decrease of the production originating 

 from the exhaustion of the petroliferous sand would therefore amount 

 to 113,712 viss per mensem, or everything remaining the same the 

 average monthly production in 1895 would have amounted to 629,446 

 viss, instead of 788,297 viss. 



Instead of the production having fallen off, it has actually risen to 

 the extent of 45,139 viss per mensem, as against the preceding year, 

 while the productive wells have increased to the number of 107 as 

 compared with 1893. The question may therefore be raised whether 

 the production of these 107 new wells is sufficient to balance the es- 

 timated loss in the production of the 406 older wells and to account 

 for the increase ; in order to answer this satisfactorily I have made 

 the most careful enquiries about the production of these 107 new 

 wells which amounted to 6,423 viss per day or 192,690 viss per 

 mensem, or 33,837 viss per mensem above the required amount. 

 We see therefore that not only do the new wells fulfil the required 

 conditions, but they actually supply somewhat more than required, 

 from which we may naturally infer that the aggregate production of 

 the 412 old wells is a little smaller than has been calculated. 



We may therefore consider it as proved that notwithstanding 

 the increased depths of the wells, the production has declined, 

 a phenomenon which may be considered as the surest indication of 

 the exhaustion of the bed exploited by these wells. 



I think that the above conclusion bears out my statements made 

 in 1891, namely, that the bed of petroliferous sand which sup- 

 plies six-tenths of the production begins to show signs of exhaustion, 

 I purposely refrained from taking the state of wells in 1888 into 

 consideration, because I am unable to identify the individual wells of 

 that year with those considered above, but I firmly believe that they 

 would prove the same condition. 



It is quite possible that when boring deeper fresh parts of the third 

 oil bearing sand will be opened out, but as I have pointed out above, 



( '67 ) 



