MABERY. — COMPOSITION OF PETROLEUM. 



297 



clogging the wells by loose material, " shooting " the wells after boring 

 is not practised. The flow from the wells is irregular ; frequently it 

 will amount to 300 barrels a day for a week, and then stop, and the oil 

 must be pumped. 



The oil territory in Japan includes the following fields : — Amaze, 

 Nagaoka, Niitsu, and Hiyama. The different sections of the oil terri- 

 tory may be classified as follows: — 



Amaze 

 Amaze I ^liyagawa \ green oil 



Gendogi 

 Hirei 

 Kitatani 

 Katsudo 

 Koguchi 

 Kusodsu 

 Hiyama { Hiyama 



Nagaoka 



Niitsu 



dark oil 



} dark green oil 



The Amaze field is the oldest ; the Hiyama field has been most re- 

 cently developed; both these oils contain paraffiue. 



The crude oils from the different fields differ essentially in their prop- 

 erties, as shown by the different specific gravity, the different percentages 



