The most notable feature of all these steamers is, that they are worked entirely with oil-fuel. Newcastle coal will soon cease to find a market on the Black Sea or the Mediterranean—it may even be driven out of the Red Sea, as the use of petroleum refuse in engines becomes better understood. Already it is the only fuel in use on the Caspian, either in the mercantile marine, in the Russian gunboat flotilla, or on the railways. Even in domestic stoves it is in favor throughout the Caucasus—all government offices in the neighborhood are thus heated—and the people are greatly encouraged in its use, with a view to saving the fast-decreasing forests of the Caucasus.
At present much oil refuse is poured into the sea as the only way to dispose of it, and yet its value as fuel is fully established; for whereas ordinary coal-burning steamers require to devote nearly half their carrying capacity to stowing fuel, those burning oil-refuse find that petroleum gives out twice as much heat as an equal weight of coal, so that they only require to carry half the quantity. The petroleum also requires far less constant attention from stokers than ordinary fuel. No stoking is required, no banking of fires—the whole thing is simple as a gas-stove, and one man can easily manage the simple apparatus composed of two tubes, through one of which trickles the petroleum, while through the other passes a jet of steam, which converts the oil into a spray so inflammable that it ignites, forming a great sheet of flame, which can be regulated at will—and thus steam is always ready at the exact pressure required, and labor and expense are reduced to the minimum. The advocates of coal declare that this fuel produces much heavy smoke and a tarry deposit, and also that it is liable to explosion. All this, however, depends on the refining, which will become more and more perfect as the value of each separate ingredient is more fully realized.
For instance, it is found that the dark waste fluid left after distillation contains four times as much gas as common coal. This has therefore been turned to account, and Messrs. Nöbel, having obtained a government monopoly in the lighting of the town for forty-nine years, have already established two thousand gas-lamps. They have also devised a new process for making candles of kerosene and solid oil for exportation. Soon they purpose turning their attention to the beautiful dyes to be obtained from the refuse tars, which they hope to turn to such good account that Baku shall be known throughout the world for the excellence and cheapness of its colors. Nöbel prophesies that it will become the world's emporium for cheap and beautiful paint in addition to all its other products.
