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arbitrarily placed, and not the point of an angle, which might distinguish homogeneous from welded masses.

3. As to resilience being the most important quality of steels, and for that reason the proper basis of classification, it is unnecessary to discuss this claim for resilience here. The question is whether the importance of a quality can make existence of that quality a definite basis of classification when it exists in both classes, gradually increasing in one and decreasing in the other, and being practically the same near the dividing line.

To sum up once more the answer to this and to all the cases of arbitrary classification : Exact definitions must be based on differences which always exist in every form and phase of the materials defined, and not on differences which, however great they may be in certain forms and phases of the materials, run together at one point, and there cease to be differences. If we divide steel from wroughtiron by an arbitrary line of percentage of any ingredient or of modification due to any ingredient, there must be some point at which the difference between steel and wrought-iron is infinitely small. If, however, we define steel as a compound made homogeneous by fusion, while wrought-iron, although the same in composition, is heterogeneous from welding, there is always, and at every grade of the respective materials, a large and radical difference. Casting fluid steel and welding pasty iron are always distinct in their characters and results; they do not at any point shade into each other. The latter classification is therefore exact and complete.

4. A very serious objection to the proposed division is, that it occurs at a point about midway in the range of structural steels. It would be less inconvenient, though not less unscientific, if it divided the general class of structural steels from the more ordinary grades of tool-steels. Of a pair of locomotive-tires, both made by the same process, out of the same materials, and containing as nearly as practicable 0.30 carbon, one might be steel and the other wroughtiron; or, a pair of locomotive-tires might both be steel, the one having been welded up from scrap, and the other drawn from a cast ingot; or, one end of the same ingot might be steel, and the other end wrought-iron, the first having been hardened, and the other annealed. The convenience of such a nomenclature is not obvious at first sight.

The author of the proposed definition we are criticising, has so vividly portrayed the disastrous confusion which would arise from changing a settled nomenclature that I can hardly do better than quote him in this connection. He says: “It is a complete change in the meaning of a word that is in every man's mouth-a change in which the intere-ts of the whole civilized world are affected, and in contemplating which, the convenience of all mankind is to be considered.. ... The natural conservatism of language would prolong this painful period of change, to a most unpleasant length. Moreover, the confusion would not end, till the change had been well established in the other languages of the civilized world. In meeting the word "steel,' in specifications, contracts, and indeed all literature, whether technical or not, whether English or foreign, it would be necessary to determine whether it had been written before or after the change had been affected."

In conclusion, it seems hardly necessary to again sum up what has been chiefly a reiteration, in different forms, of answers to criticisms on the present enlarged use of the term "steel," and of the one great objection to the nomenclatures, that they are fatally indefinite.

The names of new materials and processes, like the laws of trade, are not fixed by the arbitrary edicts of philosophers, but they are gradually developed, to meet the general convenience.

XVI.

THE MANUFACTURE OF IRON AND STEEL.

The following address was delivered by Mr. Holley at the opening of the Cleveland meeting, October, 1875, of the American Institute of Mining Engineers. As a specimen of comprehensive and acute criticism, it is not surpassed by any of his works. It recalls the trenchant comments which he visited in earlier days upon American railway practice. But the President of the Institute, speaking with the yet greater authority of a wide experience and a splendid fame, was far more certain of an appreciative hearing than had been the ambitious and comparatively unknown young engineer; and the tone of this address shows that he no longer needed to speak loudly in order to be heard. Mr. Holley entitled this address :

:

SOME PRESSING NEEDS OF OUR IRON AND STEEL

MANUFACTURES.

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In selecting for this occasion a subject necessarily connected with the iron and steel industries, I have thought that a review of these manufactures, with reference to some of their more pressing needs for improvement, will be more timely than a general or statistical paper. It is, I am aware, comparatively easy and positively useless, if not a little impertinent, for me to preach in general terms—to tell manufacturers that they should work more economically, and make better products, and utilize waste, and develop labor-saving machinery. I shall endeavor to confine my remarks to a few specific defects of practice and management, and to their equally specific and more or less developed remedies.

That serious defects exist; that they must be remedied; that the manufacture is indeed already on the verge of transition, will be generally admitted. But it cannot be revolutionized all at once, however desirable the technical results might be; for that would bankrupt the business at large. We cannot afford to pull down and rebuild all our blast-furnaces that do not make a ton of pig-iron with 25 cwt.of fuel; nor to replace all our hand-puddling furnaces with revolv

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ing ones, even if we could select the best revolver. Although the soft steels promise to supplant iron for most structural purposes, there is neither money nor present market to warrant all at once replacing our iron-works, or half of them, with steel-works.

Since, then, these manufactures can neither stand still nor be suddenly metamorphosed, their managers are saying to one another : “We must feel our way into larger development; we must work gradually into better practice; we must improve a little at a time.” All very true—but some of us have been saying it so long and so complacently, that it is rather acquiring the flavor of a pretext for doing next to nothing at all.

Whatever economies may be made by little improvements of old tools and processes, the grand results are to come from thorough and radical changes, not necessarily in all departments at once, but sweeping when they are introduced. Putting a slightly less wire-drawing cut-off upon an old steam-engine, promoting a little better combustion in a heating-furnace, empirically experimenting with refractory materials and purifying compounds, are all more or less useful, but the "survival of the fittest" is to be decided on larger issues than these.

Among the more important and decided improvements demanded in this critical situation of affairs, are the following:

I. Cheap Power.-The cost of coal to drive the machinery of an average American Bessemer plant, when applied through engines requiring, as they generally do, 5 or 6 pounds of it per hour for one horse-power, averages about $1.50 per ton of ingots. Engine-builders are ready to guarantee a duty of 21 pounds per hour per horsepower, and it is perfectly well known that a large number of engines, stationary and marine, are running at from 21 to 3 pounds. The saving of one-half the steam-coal in a Bessemer works would pay for a quarter of the total labor in the manufacture of ingots, or for all the refractory materials employed, or for all the royalties. In some works it would not be less than $50,000 per year.

The average cost of coal required to drive a rail and blooming mill is nearly $1.50 per ton of rails. Although mill-engines have the advantage over blowing-engines, of high speed, and are often of good type, yet it is probable that taking all our steel-rail mills together, a third of this cost could be readily saved, and this saving would be an aggregate of $175,000 per year.

The economies effected by better steam-engines are not exceptional -they are of every-day occurrence. They have revolutionized the

ocean-service and have completely changed the land-service, especially in New England, where fuel is dear. As one of many examples, I

* quote the Troy steel-rail mill-engine. This had a cylinder of 54 inches diameter by 3-foot stroke, and required the firing of 5 auxiliary boilers. A 44-inch Corliss cylinder was substituted, 9 per cent.

. of speed and 30 per cent. of work were added, and yet 3 boilers were thrown off, and the economy in fuel was about $25,000 per year.

It will not he questioned, I think, that regenerative furnaces will, gradually but inevitably, take the place of the ordinary heating, puddling and melting-furnaces, thus preventing the application of unspent furnace-heat to steam-generation. For this reason, economical boilers and engines are all the more important. When every rolling-mill and forge comes to burn coal for steam, the saving of a couple of pounds per hour per horse-power will be something enormous in the aggregate. Again, while many schemes for blast-furnace improvement are speculative, almost any expense to increase the economy of blowing-engines is warranted. Making uniform iron out of raw materials that cannot be uniform, requires reserve of power both in the temperature and the force and volume of blast. As coke and anthracite furnish barely gas enough under the best circumstances, combustion under boilers and the use of steam must be in the highest degree economical to meet the worst circumstances.

The blowing-engines of the country are usually very wasteful of steam, by reason of wire-drawing valve-gear, and especially of slow piston-speed. The latter is perhaps the greatest, and the least recognized, of all steam-engine defects. When steam enters the cylinder at say 75 pounds pressure and 320° temperature, a part of it is condensed into water before it can heat the walls of the cylinder to the same temperature. As the steam then expands from the point of cut-off down to the atmospheric pressure, its teni perature falls from 320° to 212°, and as it falls, this water is reëvaporated by the heat in the walls of the cylinder, thus cooling them down to 212°. The steam thus formed passes off with the exhaust into the atmosphere, and is lost. At the next stroke, steam at 320°, impinging against walls at 212°, is condensed, as before, and so this perpetual waste goes on. Now, we can conceive of a piston moving so fast that the walls of the cylinder would not have time to be measurably cooled ; and we can imagine a piston moving so slowly that nearly all the steam would be condensed. In practice, the indicator-card, which reveals the real work of the steam in the cylinder, shows a very

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