PETROLEUM 377 



A considerable proportion of the oil finds its way into the tanks 

 at these stations by gravity and is forced to the large receiving 

 tanks at the main station by pumps, which are often driven by 

 natural gas engines, or it flows by gravity through suction 

 lines to pumps into pits and is then elevated to receiving tanks. 

 From the large receiving tanks the petroleum is forced into the 

 main lines at a pressure often of between 600 and 900 pounds 

 to the square inch. 



These massive pumps generally represent the highest 

 known mechanical efficiency, having triple expansion engines, 

 Corliss valves, condensers, air pumps, and efficient boilers. 

 They usually develop 300 to 400 horsepower and handle from 

 30,000 to 35,000 barrels in twenty four hours. The boilers 

 are economical and properly proportioned to this work, show- 

 ing a duty of 16 pounds of water evaporated at and above 212° 

 F. per pound of crude petroleum consumed as fuel. One 

 pound of good coal will evaporate 10 pounds of water, and 1 

 pound of natural gas (equal to 20 cubic feet) will evaporate 

 20 poimds of water under the same conditions. 



The main pumping plants are placed from 30 to 50 miles 

 apart, according to the elevation of summits that must be 

 overcome ; and by the addition of a parallel line, or loop lines, 

 for a portion of the way the distance can be increased so as to 

 reach localities convenient for fuel or water without greater 

 tax upon the pumps. 



There are probably 4,600 miles of main trunk line, from 

 4 to 8 inches in diameter, in the^'Appalachian and the Lima, 

 Indiana fields, reaching from northern Tennessee to Parkers- 

 burg, Cleveland, Buffalo, Franklin, Olean, and to the seaport 

 cities of New York, Philadelphia, and Baltimore. From the 

 Lima, Indiana field the main lines reach westward to Chicago, 

 Montpelier, Toledo, Lima, and eastward it connects with the 

 Appalachian system. 



Kansas has an extensive system of main lines and local 

 lines, reaching m several directions from Neodesha. In 

 California a mam line was recently completed, reaching from 

 Bakersfield to a refinery at Point Richmond, near San Fran- 

 cisco, and having a branch line to Coalinga. The length of 

 this main line is 278 miles, and it is connected near its starting 



