PETROLEUM. 



685 



has been opened and gradually declined in 

 production; yet, during that period, prices 

 have been for the most part much below that 

 figure. While it can not be disputed that the 

 present production is less than the consump- 

 tion, it is equally true that a permanent ad- 

 vance in price from present prices to one dollar 

 a barrel would lead to an abandonment of the 

 use of petroleum for many purposes, and, at 

 the same time, would stimulate production in 

 many localities where oil is known to exist 

 over a very wide area. 



Petroleum Products. The extent to which 

 substances manufactured from petroleum have 

 become necessities places them among the 

 most important products of modern technolo- 

 gy. First in importance among these products 

 is illuminating oil or kerosene, both in respect 

 to the vast bulk of the commodity and also the 

 large proportion of the human race dependent 

 upon it for artificial light. When compared 

 with the methods in use half a century ago, 

 illumination by means of this material has pro- 

 longed human life over half the habitable 

 globe, and it is the cheapest and most perfect 

 illuminating agent yet discovered. 



Next in importance in the list of products 

 are lubricating oils, which, when prepared of 

 various grades and qualities for different pur- 

 poses, have nearly superseded all other oils 

 devoted to similar uses. 



The lighter products begin with righolene, 

 which boils at 65 Fahr., and is the lightest 

 of all known fluids. This is prepared by con- 

 densing in a mixture of ice and salt that por- 

 tion of the distillate from petroleum that at 

 ordinary temperatures would be gaseous. It 

 evaporates so rapidly that it will reduce the 

 temperature to 19 Fahr. in twenty seconds. 

 It was originally prepared, and is still used for 

 producing local anaesthesia in surgical opera- 

 tions. A similar but not so volatile fluid has 

 been prepared in commercial quantities under 

 the name of cymogene. It has been used in 

 ice-machines to produce a very low tempera- 

 ture by its evaporation. The next least vola- 

 tile product is gasolene, the most volatile com- 

 mercial product of petroleum when no unusual 

 means are taken to condense the vapors. It 

 is used in automatic gas-machines to saturate 

 air with the volatile vapor, and, by thus car- 

 buretting the air, to produce an inflammable 

 gas. It has been found extremely useful for 

 this purpose, and is also used as a fuel in a so- 

 called "gasolene -stove" a very dangerous 

 utensil. A, B, and C naphthas are fluids of 

 different volatilities, taken off bet ween gasolene 

 and illuminating oil. They are used in mixing 

 paint, printing oil-cloths, dissolving resins, and 

 for other similar uses. Illuminating oils are 

 of different grades and qualities. Lubricating 

 oils are also of very various quality, from the 

 most delicate strained oils used on spindles to 

 heavy mixtures of residuum and crude oil 

 used on railroad axles. Filtered petroleum 

 residues, under the name of petroleum oint- 



ment, cosmoline, vaseline, etc., have been 

 widely introduced into medicine, having been 

 admitted to the United States Pharmacopoeia, 

 and very extensively used as a domestic reme- 

 dy. Lastly, the solid product of petroleum, 

 paraffine, has become of immense importance 

 in the art?, for candles, water-proofing cloth 

 and paper, insulating electrical conductors, and 

 many other uses. 



Technology. The general technology of pe- 

 troleum is simple in its details, and is adapted 

 to the handling of vast quantities of material 

 in the most rapid and economical manner. The 

 oil is received at the refineries from the wells 

 through one of the trunk-pipe lines, and is al- 

 lowed to settle in huge tanks, in order that the 

 small amount of water that invariably accom- 

 panies the oil, with any other impurities, may 

 be completely separated. From these storage- 

 tanks the oil is thrown by powerful steam- 

 pumps into the stills, at the rate of 2,000 to 

 8,000 barrels an hour. The stills are either 

 low, upright cylinders, heated by several fires 

 around their circumference, or plain cylinders 

 set horizontally in banks, similarly to steam- 

 boilers. The stills hold about 1,200 barrels 

 each. In the refineries recently constructed 

 they are not inclosed in a building, but are 

 entirely exposed to the atmosphere, excepting 

 a sheet-iron jacket, which prevents too great 

 radiation. The vapors from the stills are con- 

 ducted through a series of pipes immersed in 

 cold water, in which they are condensed. The 

 distillates at first are gaseous, but they gradu- 

 ally increase in density and pass through a 

 great variety of fluids, from cymogene to solid 

 paraffine. The fluids are separated and dis- 

 charged into different tanks by means of a 

 complicated system of stop-cocks. A system 

 of traps in these discharge-pipes also enables 

 the operator to send the gaseous distillates be- 

 neath the stills, where the fas may be con- 

 sumed as fuel. 



The crude naphtha is first run off, and in a 

 subsequent operation, often at another estab- 

 lishment, is by redistillation converted by 

 fractionation into gasolene and A, B, and C 

 naphthas. From crude naphtha the distillate 

 is run off until it becomes too dense for the 

 preparation of illuminating oil. This distillate 

 forms the "high-test " illuminating oil. having 

 a fire-test of 120 to 150 Fahr. The residue in 

 the still is then in a condition for "cracking." 

 This process consists of a slow distillation, dur- 

 ing which the vapors are constantly being con- 

 densed upon the upper portion of the still, from 

 which they flow or drop down upon the heated 

 oil. The oils are thus repeatedly heated to a 

 temperature above their boiling-points, pro- 

 ducing destructive distillation, and resulting in 

 the disengagement of a permanent gas, the depo- 

 sition of carbon in the still, and the production 

 of an oil of a specific gravity suitable for illumi- 

 nation. But this so-called ''cracked oil," is 

 not identical in quality or in composition with 

 the illuminating oil first distilled from the 



