oil. The American crude oil is superior to that of Russia in the larger percentage of illuminant; but on the other hand the Russian oil excels in the greater quantity of its lubricant. PETROLEUM AS A FUEL. Petroleum as a fuel has not as yet taken the place of coal in the United States of America, and from the present outlook it seems that it will be a long time before the succession takes place, at least in those parts where coal is so abundant as in Pennsylvania. It requires one hundred and ninety-two gallons of petroleum to equal two thousand pounds of coal as a heat producer. With the present price of good steam coal in California the utilization of petroleum might prove an economy, and as the yield of the latter is becoming larger every day it is to be hoped that some one of our inventors may soon come forward with an appliance that will give more perfect combustion than anything we have now in use. The combustion at present is far from being satisfactory, the heat is irregular, and every absorbing material in and about the firerooms becomes saturated with the unconsumed volatilized oil; but petroleum has the advantage over coal in point of storage and the almost imperceptible percentage of ash. On the Caspian and Black Seas petroleum fuel has entirely superseded coal, for the simple reason that in these sections there is an almost fabulous production of the oil, while the use of coal necessitates an importation. For manufacturing purposes, in many instances where petroleum is used as a fuel, the articles are far superior to those made by the use of coal. The principal objection to former experiments made with the crude oil for steam purposes by the Central Pacific Railroad Company, was the vaporization and after-condensation, on the surroundings, of the unconsumed oil, and also the large amount of smoke and soot. This goes to prove that there was an imperfect combustion, due to the absence of heat and an insufficient supply of air; that is to say, the blast did not supply air in sufficient quantities to form a chemical unity with the carbon and hydrogen of the oil. The apparatus for supplying air and oil should be so constructed that the fuel and air would be so intimately mixed that the oxygen would unite with the carbon and hydrogen, the component parts of petroleum, and generate carbonic acid and water respectively. In Russia, after the lighter oils are driven off, the crude material is used for the purpose of generating steam in the locomotive boilers and on the steamers; and beside getting up steam in much less time than with other fuel, the combustion is perfect even to the absence of smoke and soot. The oil is fed into the tender from tanks, at the different stations, and thence through pipes into the furnaces, where it meets the steam jets. The tanks on the tenders are so elevated that the oil reaches the furnaces by gravitation through conductors so regulated that the oil is fed slowly and in small quantities. The following extract is taken from Executive Document, No. 131, House of Representatives, forty-ninth Congress, second session, from the reports of Lieutenant Wm. H. Schuetze, United States Navy, transmitted from the Department of State on the first of February, 1887, as follows: "Refuse petroleum has nearly supplanted wood as steamer fuel in all the Volga boats, estimated to be about two thousand in number." As far as any information could be gathered on the preparation of a new fuel, in Russia, the following would answer as a general description: To the boiling oil not less than one nor more than three per cent of common soap is added, and the ebullition continued until the soap is completely dissolved, which takes about half an hour, when the liquid suddenly turns into a waxy-like substance which hardens on cooling, and then the material can be pressed into bricks or any required form. It is difficult to kindle, but when once alight it gives off an intense heat, is slowly consumed without emitting any smoke, only leaving a percentage of ash in accordance with the amount of soda or potash contained in the soap used. It is further claimed that in comparison with anthracite coal, the latter is consumed in one third of the time, with one seventh of the heating power. Experiments are being made by some of the manufacturers of Springfield, Ohio, with crude petroleum as a fuel in the manufacture of malleable iron, with fair possibility of success. The Champion Electric Light Company, at the same place, claims twenty per cent saving over coal by the use of petroleum. Through the kindness of the Central Pacific Railroad Company, an examination into the methods of using petroleum as a fuel on their steamers was made, in company with Mr. Wm. McKenzie, Division Master Mechanic and Chief Engineer of Steamers, and much valuable information obtained, which is incorporated in this paper. After the lighter oils are driven off, the residual, which is obtained from the Pacific Coast Oil Company's refinery, is used for steam purposes on the five following steamers, viz.: The four first named use the oil regularly, but the Thoroughfare, being a freight boat, is only called into occasional use, therefore particular mention will only be made of those in constant service and the amount of material they consume per month of thirty-one days, and calculated in barrels of forty-two gallons each: Residual or heavy oils consumed in 31 days by steamer Julia.. 600 barrels. 1,750 barrels. 2,200 barrels. 1,450 barrels. The steamers Piedmont and Oakland, plying between San Francisco and Oakland, having the more powerful engines, and necessarily using a larger amount of fuel than the others, it would, perhaps, be better for the purposes of illustration to confine the description entirely to them. The Piedmont makes between San Francisco and Oakland, in one day, eighteen and one half round trips, and thirteen and one half on the following day, or, in forty-eight hours, a total of thirty-two round trips. The engineer, Mr. H. Hughes, states that in a day of eighteen and one half round trips there is consumed a little over three thousand three hundred gallons of oil, and that previously when coal was used it required about forty tons of the latter for two days, or thirty-two round trips. Therefore, in agreement with the statement of the engineer, there would be consumed for each round trip something over one hundred and seventy-eight gallons of oil, or the equivalent in coal of one and one quarter tons; or, to be a little more explicit, about one hundred and forty-two gallons of oil would equal for the purpose of creating steam power, one ton of Carbon Hill coal. On the Piedmont, as well as the Oakland, the feed tanks for supplying the furnaces are horizontal cylinders, and confined under the main deck, and each having a capacity for a two days' supply of oil. As they are not sufficiently elevated to furnish enough pressure for a proper feeding of the oil, small pumps are used for the purpose of raising the oil from the tanks to from ten to twelve feet above the level of the burners; the latter it reaches by gravitation. Each tank is supplied with pipes running from the top through the hull of the boat on either side for the purpose of carrying off any gas that may be generated by the oil. The engines are low pressure condensing engines running with thirty to thirty-five pounds of steam. Fresh water is used for the boilers and salt water for the condensers. The Piedmont has two large boilers, with two furnaces to each boiler and three burners to each furnace. At the burners the oil is atomized, or in other words, blown into the furnace as a fine spray, by a jet of dry steam which is fed by a red hot iron pipe passing through the furnace to the burners. The construction of the furnaces and burners may be more fully understood by an examination of the accompanying illustrations. Figure 1 is a vertical longitudinal section of one of the furnaces. Figure 2 is a vertical elevation of the fronts of the two furnaces belonging to one of the boilers, showing the positions of the oil and steam pipes, together with a horizontal view of the curved pipe E, in which the steam is superheated before it passes to the burners. Figure 3 shows the details of construction of one of the burners, and the mode of its connection with the oil and steam pipes which run horizontally across the top of the furnace door openings. Each burner A consists of two concentric tubes with a peculiar shaped mouthpiece. The inner tube, one fourth inch in diameter, is the transmitter of the superheated steam, and is surrounded by a second tube leaving an annular space one eighth inch wide between the two, which forms the conduit for the oil. The conduit does not open directly into the furnace, but instead, the inner tube is contracted to about one eighth of an inch near the mouthpiece by swedging, and just beyond the contraction it is pierced with numerous small holes through which the oil passes from the annular space to the inside of the inner tube, where it meets and unites with the superheated steam before reaching the mouth of the burner. The mouthpiece screws on to the outer tube, as shown in illustration A. Horizontally it is flattened and drawn out until the final opening through which the united steam and oil enter the furnace is a straight slit one and one half inches long and one sixteenth of an inch wide-flaring outwards at each end. The cocks or valves which regulate the supply of oil and steam to the burners are peculiar in construction. By reference to Figure 3 it will be seen that in each case the valve-stem projects a short distance beyond the valve-seat into the pipe leading to the burner; and this portion of the stem is ground to fit the pipe in which it slides so closely that even when the valve is raised a short distance from its seat, no oil nor steam could reach the burners were it not for the following device: In the cylindrical surface of this projecting portion of the valve-stem are placed several little channels parallel with its axis, and of different lengths, one of them reaching entirely up to the valve-seat, while the others are successively shorter. The result is, that when the valve is but a little raised from its seat, only a very small quantity of oil or steam can pass to the burner through the longest one of these little channels; but as the valve is opened further the |