44 BULLETIN 102, VOL. 1, UNITED STATES NATIONAL MUSEUM. 



itself; and by stretching out to meet a growing area of exploitation 

 it has unified widely separated fields and enabled production to 

 grow to its present imposing size. The pipe line has woven the 

 scattered strands of adventurous exploration into a steady flow of 

 bulk raw material. (See fig. 5.) 



Some crude petroleum is transported in tank cars, but most of the 

 60,000 ^ tank cars in operation in this country are engaged in moving 

 petroleum products — gasoline, kerosene, and fuel oil chiefly. For 

 transportation by sea, steel tankers and towing barges, fitted with 



Pkoouct/oaj 



Pictorial Diagpam 



Crupe Oil Inpustry 



Fig. 5. — Diagram of the crude petroleum industry. From Report of the Com- 

 mittee ox Petroleum, California State Council of Defense. 



noncommunicating compartments, are employed for both crude pe- 

 troleum and its bulk products. The development of the tank steamer 

 has been an important factor in building up an important foreign 

 trade in petroleum products, is responsible for a considerable coast- 

 wise movement of crude and fuel oil,^ and has opened the oil fields 

 of Mexico to the United States and other markets. 



refining. 



Crude petroleum may be burned as fuel and nearly a fifth of the 

 domestic consumption is utilized in this way.^ But most of the petro- 

 leum is manufactured into a series of products which have wider 



1 Approximate number. 



2 The tanker is the only commercial rival to the pipe line ; movements of oil from the 

 Gulf to North Atlantic ports, therefore, normally go coastwise Instead of overland. 



3 A small proportion of the crude petroleum is used for dressing roads. 



