The Doterd tragedy probably originated thus. Combustion may take place slowly that the rise temperature may only amount a few degrees, and such combustion may and probably does occur in all our coal-cellars.
I believe that in all cases where coal exposed the atmosphere, some degree oxidation, i,c, combustion, takes place. This conclusion was forced upon rather curiously and expensively. AVhen engaged in the distillation cannel, at Leeswood, Flintshire, I tested practically some cannel slack that was ofifered at a neighbouring colliery at eighteenpence per ton. The test was need a thesis statement best website to buy a research paper for research paper strictly practical one, the distillation a working sample a Upon the yield this I based a contract for a large quantity, online writing service which was delivered much faster than I could use and was therefore stacked for some time.
I then found that the yield inflammable hydrocarbon continuously diminished and at last became ruinously small, the slack at the bottom the heaps being Shortly after this the railway the colliery siding took fire under the rails.
It had online college writing help been ballasted with slack this oxidised, at first slowly, and became warmed this heat hastened the oxidation, which raised the temperature still higher, and need help writing a essay until red heat, smoke, and flame arose, rendering a reconstruction the siding If I right, all lose something when lay in a stock coals for the winter.
If the coal in large lumps the loss very small, practically unworthy notice, account the small surface exposed the air, and the ventilation between the lumps, whidi checks the rise temperature and consequent paper writing services best acceleration the combustion. But when small coal stacked in large quantity the loss may sufficient neutralise the economy buying at The liability such slow combustion varies with the quality the coaL Brassy coal, Le. coal which contains much that gold-like material that appears in scales and cubic crystals more addicted such wasteful and dangerous i want to buy a thesis proceeding than purer coaL This yellow metallic impurity iron pyrites, a compound instant essay writer sulphur and iron, which rapidly oxidises when exposed air and moisture, and becomes a compound sulphur, iron, and oxygen sulphate iroa The quantity oxygen thus taken large, and the bulk the compound increased sufficiently split the coal its swelling, and thus expose greater surface the air.
Then the sulphate oxidises still further, and red oxide iron formed. This a remarkably active oxygen-carrier.
It gives its oxygen very freely and liberally any neighbour thirsting for becomes reduced a lower oxide, which again takes more oxygen from the Some German chemists far as attribute the spontaneous combustion coal entirely this agent My experience contradicts this the cannel above named contains an unusually small quantity pyrites. Nevertheless, the experiments Richter and Haedicke show that the pyrites materially assists such combustion therefore, in selecting coal for steamships, this fact should considered, and highly sulphureous coal should altogether rejected, if used, should stowed with special care and APROPOS nothing, I propose make a note steel not discuss the vexed question What steel? and whether the modern product the Bessemer and Siemens-Martin furnaces, which contains but one quarter per cent, carbon or less, shall called steel or iron, but that curious and all-important phd thesis database property unquestionable steel, its temperability.
If a piece good old-fashioned Sheffield cast steel made redhot and then suddenly cooled quenching in water, becomes nearly as hard as diamond, and britde as almost useless.
If now heated again redness and slowly cooled, becomes almost as soft and tough as wrought iron. If the steel that has been hardened as above now moderately heated, partially softened or tempered, and this softening proportionate the temperature which raised, which temperature the workman measures the beautiful colouration its surface due the varying degrees oxidation. The discovery a substance which hard that can cut or otherwise shape almost every other substance the face the earthi and yet modified in hardness that may cut and sbape itself, one the most important ever made man. It ranis next the discovery the means kindling a fire. Steel composed iron and carbon but a true chemical compound, or merely a mixture? The elements chemical compounds are combined in definite invariable proportions in mixtures they are in any proportions. Chemical compounds differ greatly in their properties from those their elements. Mixtures usually have Steel anomalous in this respect It may contain any proportion carbon firom per cent as much as or per cent. and yet its hardening and tempering property not possessed either Whence comes this property, then ? I have ventured propound a theory own, that was fully detailed in the Metallurgical Review It based the fact that there exists a definite compound, consisting four equivalents iron one carbon. I obtained this compound in the form definite crystals.
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