152 



KNOWLEDGE 



[July 1, 1898. 



These tanks, of which over ten thousand are in use in the 

 States, usually have a capacity of eight thousand American 

 gallons. 



The introduction of pipe-lines — which are now laid from 

 all the important oilfields to the central refineries — con- 

 stitutes the greatest factor among the many innovations 

 which have, as a whole, led to the present cheap produc- 

 tion of petroleum in the States. Each well-owner, as his 

 oil is passed into the pipes, receives a certificate stating 

 that he is entitled to so much oil, and these certificates 

 are negotiable like bank-notes among those interested in 

 the trade. Of course, all the oil passes into the common 

 stock, so that no producer can obtain his own oil from the 

 refinery ; and for this reason any special oil, such as the 

 heavy and valuable oils of Franklin and Smith's Ferry, is 

 still conveyed in barrels. 



The use of pipe-lines was proposed in 18G0, but the first 

 successful line was laid in 18G5. Notwithstanding the 

 opposition of the teamsters, who had formerly enjoyei 

 the monopoly of the transport of petroleum, the laying of 

 these lines proceeded rapidly from the first, and it is said 

 that between twenty-five thousand and thirty thousand 

 miles of pipe-lines now exist in the States. 



Uil Keiinerv nx I'luladelpina. 



The main pipes are U3ually from four to six inches in 

 diameter, the small feeders which pass from them to the 

 wells being about two ioches. As the pipes are liable to 

 become choked by dirt or solid hydrocarbons, a small brush, 

 known as a "go devil," is occasionally passed through to 

 clear them. This brush, which travels along with the 

 oil as the latter is pumped through the pipes, is provided 

 with ball-and-socket joints, to facilitate its progress round 

 the bends ; and it is also fitted with vanes, which ensure 

 its rotation as it advances. 



The pumps now invariably ussd for these pipe-lines are 

 of the Worthington type, and work at a pressure which 

 sometimes rises as high as one thousand five hundred 

 pounds per square inch. The seven hundred and sixty 

 mile length of six-inch pipe extending along the New York 

 line is supplied by pumps of from six hundred to eight 

 hundred horse-power, and conveys about thirty thousand 

 gallons daily. There are eleven pumping stations, each 



containing two pumps. In one case a pair of these pumps 

 forces the oil through a distance of one hundred and ten 

 miles, but as a rule each pair serves about half that length. 

 Kerosene — the product of the distillation of crude 

 petroleum used as lamp oil— is mainly conveyed in tank 

 waggons or railway cars, tank barges, and tank steamers ; 

 but a small proportion is still sold in barrels, and, especially 

 in the Eastern markets, considerable quantities are disposed 

 of in tin "cases," each fitted with a screw cap and wire 

 handle, and holding about five American gallons. S3 

 great is the sale of these cases that as much as forty 

 thousand tons of tinplate is said to have been used in 

 their manufacture in one year. 



For ocean transport the oil is now usually conveyed in 

 tank steamers and sailing vessels, in which the whole hold 

 is formed in compartments or tanks to contain the oil. 

 In order to prevent injury to the vessels from the rolling 

 about of the oil in bad weather, the tanks are kept 

 absolutely fall, small auxiliary " expansion tanks ' being 

 fitted to them to receive any overflow when the oil expands 

 from rise of temperature, or to supply oil to the main 

 tanks when the bulk decreases. Practically the whole of 

 the ocean tratlie, both of kerosene, crude oil, and liquid 

 fuel, is now controlled by "these 

 vessels, although lubricating oil 

 and petroleum spirit, and other 

 of the lighter petroleum products, 

 are still conveyed in barrels. The 

 credit for the introduction of this 

 method of transport is due to 

 Mr. Ludwig Nobel, who, in 1878, 

 had two small tank steamers 

 constructed for use on the 

 Caspian. They were built at 

 Motala, in Sweden, in sections, 

 for conveyance to the Caspian, 

 where they are said to be still in 

 use. 



In the earlier days the escape 

 of gas and inflammable vapours 

 from the oil led to many disastrous 

 explosions, but the more efficient 

 methods of ventilation now in 

 vogue have minimized these dan- 

 gers. The tanks are also now 

 so arranged that they may be 

 thoroughly cleansed by workmen 

 and used for the conveyance of 

 ordinary cargo on the return 

 journey, and the most perishable 

 goods are so transported. 

 As the crude petroleum consists of a large number of 

 constituents in admixture, from dissolved gas and highly 

 volatile " petroleum spirits " to such solids as paratfin wax 

 and vaseline, it is resolved by distillation into the various 

 components used in commerce. For this purpose various 

 types of still have been devised, the Russians largely using 

 the " continuous " still, in which the crude oil is supplied 

 as fast as the distillate passes off; while, in the States, 

 large non-continuous stills, which are cooled down and 

 the residuum removed after each distillation, are princi- 

 pally in use. It is well known that, in distilling any such 

 mixture as petroleum, some of the constituents are decom- 

 posed into other bodies which are mainly more volatile 

 than the substance producing them. In what is known as 

 the " cracking process " this decomposition is accentuated 

 by allowing a portion of the distillate to condense on the 

 cooler upper part of the still, and run back upon the hotter 

 liquid at the bottom. This action is not allowed to take 



