Rensselaer Republican, Volume 19, Number 36, Rensselaer, Jasper County, 12 May 1887 — MECHANICAL. [ARTICLE]

MECHANICAL.

It is well known that by the ordinary method of heating and hammering only soft iron, steel, and a few other metals have been welded, bat by the use of electricity not only have cast iron, brdss, gun-metal, bronze, German silver, zinc, tin, lead, aDd many other metals been welded like to like, but it has been found in many cases verv easy to unite unlike metals. Small pieces, too, which were formerly difficult to weld on account of rapid cooling, are easily dealt with by the new process.— Blacksmith and Wheelright. In climates having a difference of 70 degrees in temperature between hot and cold seasons, a railroad track of 400 miles is 338 yards longer in summer than in winter. Of course, the length of the road remains the same, but expansion forces the lengths of metal closer together, making an aggregate closing up of space between the rails of nearly a yard in each mile. For this reason, it is impracticable to lay rails of more than thirty feet in length, unless some means shill be devised to produce a lapping-or splicing rail to make good the shrinking. It is now possible to construct a complete sewing-machine in one minute, or sixty in one hour; a reaper every fifteen minutes, or less; 300 watches a day, complete in all their appointments. More important than this, even, is the fact that it is possible to construct a locomotive in a day. From the plans of the draughtsman to the execution of them by the workmen, every wheel, lever, valve, and rod may be constructed from the metal to the engine intact. Every rivet may be driven in the boiler, every tube in the tube sheets, and, from the smokestack to the ashpan, a locomotive may be turned out in a working day, completely equipped, ready to do the work of 100 horses. A correspondent of the English Mechanic states that he has used the following composition, with completely satisfactory results, in the operation of cementing iron railing tops, iron gratings to stoves, etc., with such effectiveness, indeed, as to resist the blows of a sledge-hammer: Equal parts of sulphur and white lead are mixed with about a sixth of borax, the three being incorporated together in such a manner as to form a homogeneous mass. In the process of application the compound is first wet with a strong sulphuric acid, and a thin layer of it placed between the two pieces of iron, the latter being then pressed together. At the expiration of five days the work will be found perfectly dry, all traces of the cement having vanished; the iron presents the appearance of having been welded together, and great strength and durability are secured.

Each pound of coal per hour per horse power amounts in 300 10-liour days to 1.33928 gross tons of 2,240 pounds each, and in 300 24-hour days to 3.21428 gross tons. Each half-pound of coal per hour per horse-power is 8.60964 gross tons per year of 300 24hoiir days. Each quarter-pound of coal per horse-power is 0.23482 gross tons per year of 300 10-hour days, or 6.80357 gross tons per day of 300 24-hour days. Each eighth-pound of coal per hour per liorse-power is 0.16741 gross tons per year of 300 24-hour days. Thfe gross ton of 6.240 pounds of avoirdupois is given in these calculations. To reduce gross tons of 2,240 pounds to net tons of 2,000 pounds, multiply by 1.12 or divide by 0.8038, whichever is more convenient; and, conversely, to reduce net tons of 2,000 pounds to gross or legal tons of 2,240 pounds, divide by 1.12 or multiply by 0.8938, according to convenience.