PETROLEUM. 
15 
The pipe-lines of the United States, comprising those of the sub- 
sidiary companies of the Standard Oil and a number of independent 
companies, aggregate thousands of miles in length and form a net- 
work spread over much of the country. 1 They consist of trunk lines, 
the longest of which connects Oklahoma with the Atlantic seaboard 
by way of Illinois, and gathering lines leading into the main chan- 
nels. The whole system is comparable to the arteries and veins of the 
human body. 
The pipes vary in diameter from 2 to 12 inches, but 6 to 10 inches 
represent the common sizes. The piping is made of iron plate and is 
ordinarily placed below the surface of the ground. At intervals of 
from 15 to 30 miles, according to the viscosity of the oil, are pumping 
stations, where powerful pumps seize the spent oil and force it for- 
ward with renewed vigor. In the case of heavy, viscous oils, such as 
those of California, it becomes necessary to heat the product at each 
pumping station to facilitate its progress. Unlike a railroad, the 
pipe-lines, in general, follow a direct course, uphill and down. 2 The 
pipe-line facilities of the country are ample to handle the normal dis- 
tribution of the current production. 3 
The significance of the pipe line in the development of the petro- 
leum industry has been great. It has made crude petroleum inde- 
pendent of the railroads 4 and through cheapness of operation has 
lowered the cost of petroleum products; it has freed the refineries 
from geographic allegiance to areas of production and permitted 
their establishment at strategic points in respect to consumption of 
products ; it has permitted and induced integration of activities, with 
marked advantage to the consuming public, but not unaccompanied 
by hardships and abuses falling upon small units of the industry 
1 The approximate mileage of the principal pipe lines of the United States is listed 
in Committee Print of Departmental Reports on H. R. 3232 and S. 2812, House Com- 
mittee on the Public Lands, 1918, and sums up to 28,995 miles. The total length of all 
the pipe-lines is much greater. 
2 An 8-inch pipe weighs 28 pounds per foot, and its cubic capacity is about 328 barrels 
of oil a mile. This means that millions of barrels of oil are required merely to keep 
the pipe-lines of the country active. The cost of an 8-inch pipe-line, on the basis of 
the costs of materials in California in 1914, is upwards of $20,000 a mile. (See Report 
of the Committee on Petroleum, California State Council of Defense, by Thelen, Black- 
welder, and Folsom, July 7, 1917, which represents a detailed and valuable study of the 
petroleum industry of California.) 
Pipe-lines are found in foreign oil regions as well as in the United States. In the 
Caucasus a line connects Baku with the Black Sea, 550 miles distant, passing through 
a rugged and broken mountainous district. At Tuxpam, one of the oil ports of Mexico, 
pipe-lines reach out under water for more than a mile, permitting ships at safe anchor- 
age to be loaded. 
3 The maximum daily capacity of the principal pipe-lines, as listed in Committee Print 
of Departmental Reports on H. R. 3232 and S. 2812, House Committee on the Public 
Lands, 1918, sums up to 1,908,750 barrels, over twice the daily production of the 
country. 
4 A very important feature under present conditions, bringing up an obvious com- 
parison with coal, which needs a like emancipation, at least in part. (See Bulletin 102 
of this series, parts 4 and 5.) 
