YIELD OF WELLS. 187 



against 1S8S. The percentage of the middle class wells was as fol- 

 lows, iD 



1S8S 37°/o 



1891 45°/o 



1893 48°/, 



i895 46°/o 



Although we notice a certain increase since 1888, the percentage 

 has kept very steadily a little below one-half of the total for the last 

 four years. 



If we consider the wells of the first three classes together we notice 

 that not only do they form the vast majority of the productive wells, 

 but that their percentage keeps remarkably steady, being 82°/ , 8g°/ , 

 82°/ » S3°/ , in the years referred to. If we were to judge the prospects 

 of the oilfield from these wells it could not be asserted that they 

 were very promising ones, when the overwhelming majority of the 

 wells yields less than a barrel a day. 



Wells of the 4I/:, 5th and 6th class. — There is also an increase 

 in number since 1888, particularly noticeable in the wells of 

 the 4th class, which have exactly doubled, but on the whole their 

 percentage has not much changed, being in no case more than 18 °/ . 



We may therefore conclude that roughly 2 out of every 5 wells, 

 constructed according to the Burmese method, will yield less than 

 20 viss per day, 2 between 20 and 100 viss and only 1 more 

 than 100 viss. It therefore fully bears out the conclusions I arrived 

 at with regard to the production of the pit wells in my first paper. 



In my former papers I found it useful to give in a separate table 

 the total daily production of each class of wells. I think, however, 

 that such a table is superfluous, as it conveys no other ideas beyond 

 those already deduced from the number of the wells in each class. 

 Each class being established on the base of a certain fixed position, 

 it is clear that the aggregate production chiefly depends on the num- 

 ber of wells contained in each class, and if we were to multiply those 

 with the average for each class, we should arrive at a fairly correct idea 

 as to the daily production of each class, 



( 233 ) 



