Page:Popular Science Monthly Volume 25.djvu/550

536 course, the wells become foul or leaky at times, and then resort is had to torpedoes of nitro-glycerine, which are sent down to the bottom of the "casing," and after them is sent an iron weight which secures the explosion. The rusting of the "casing" is the great enemy of the salt-worker; and, when his engine can not lift the mass of rusted iron, a "knife" cuts the rusted metal, and the engine tears it away piecemeal. But the salt-wells are exempt from any danger of taking fire; and it is never necessary, as in the case of oil-wells, to shoot off the "casing-head" with a cannon-ball.

After the brine has once reached the surface it is forced into large reservoirs, whence it is drawn off through "string" after "string" of "covers," until solar evaporation has left the coarser grades of salt. The "covers" or vats are usually sixteen by eighteen feet, and the product of each one per year is estimated at one hundred and fifty bushels; while the product at Syracuse is only about half that quantity. It is also claimed that the slope of the valley at Warsaw is peculiarly adapted to rapid evaporation by the sun. When the finer grades of salt are wanted, the brine is led from the reservoirs to an evaporating-pan, where a gentle heat is applied. Similar treatment in another pan completes the process, and the residuum of salt is raked upon a shelf at the side of the evaporator. After a slight draining it is taken to the bins, where a more thorough draining is allowed for a space of two or three weeks. The heat is applied to the evaporating-pans through steam-pipes, in the same manner that has been found most economical both at Saginaw and Syracuse. At Saginaw the fuel costs next to nothing, as it is the refuse of the lumber-mills; and the exhaust steam of the mills is also used for the pipes of the evaporating-pans. At Syracuse and at Warsaw the expense for fuel is greater, Warsaw using anthracite coal-dust, or "culm," at an expense of one dollar and sixty-five cents per ton. Whence, then, does Warsaw derive its hope for successful competition against Syracuse and Saginaw? The ever-ready answer is, that the strength of brine at Syracuse is sixty-six to one hundred at Warsaw—a difference that makes the cost of fuel twenty cents per barrel for Syracuse as against eight cents for Warsaw. In regard to the Saginaw brine, also, it is claimed that its residuum after evaporation is ninety-seven per cent of pure salt; while that of the Warsaw brine is one hundred—a difference which, if sustained, would amply cover the increased cost of fuel at Warsaw. The salt-men of Warsaw, too, have the greatest confidence that their borings for natural gas will result in giving them a fuel even cheaper than culm. The Warsaw men also declare that their own enterprises are on private land; and that they, therefore, have an advantage of the salt on the Syracuse reservations, every bushel of which must pay half a cent per bushel to the State. And they do not fail to call attention to the fact that the duty was one cent per bushel before the borings at Warsaw had proved a success. In short, they see no reason