440  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1904.        [bull.  260 
field  has  proved  commercially  profitable,  partly  on  account  of  the 
high  grade  of  the  oil,  in  part,  also,  on  account  of  the  long  life  of  the 
wells,  and  in  part  because  the  field  has  escaped  the  various  disad- 
vantages attending  a  boomed  field.  The  average  life  of  a  well  is 
not  far  from  five  years.  Many  wells  have  yielded  oil  for  from  ten 
to  twenty  years.  One  well  has  been  pumped  for  a  still  longer  time  I 
and  has  yielded  more  than  one  million  barrels  of  oil.  The  product 
is  for  the  most  part  refined  at  Florence. 
