Experiments on Reduction by Furnace Gases directly applied . 154 To ISAAC LOWTHIAN BELL, Esq., President of the Iron and Steel Institute. MY DEAR BELL, In the hope of being useful to members of the Iron and Steel Institute, and others who do not read technical literature in foreign languages, this translation of M. Gruner's "Études sur les Hauts-Fourneaux" was undertaken. You have allowed me to dedicate the translation to you. No one having any knowledge of the subject will ask my reason for doing so. M. Gruner has methodically digested and arranged several important sections of your experiments and observations, and has thus rendered the results you have published more readily available to many who desire to inform themselves of the progress made in the application of exact science to blast furnace practice, and who lack the habits of study necessary for the full appreciation of your original work. The series of memoirs you have published in the Journal of the Iron and Steel Institute, on the chemical phenomena of iron-smelting-your careful diligence in the experimental verification of your observations in working furnaces, and your philosophical views in combining and reasoning upon them-have identified your name with the recent progress towards an exact theory of that wonderfully perfect apparatus, the Blast Furnace. You for the first time connected the Chemical and Calorific phenomena of the Blast Furnace together with such precision as permits us to calculate, with the certainty of a near approximation to the truth, the technical useful effect of any furnace, and the economical effect of furnaces working in any district for which the proportions of fuel, ores, and fluxes, and the temperature of the blast are known. The results of your observations, and the numerous facts elicited from many practical men in the "discussions" at the meetings of the Iron and Steel Institute, are indeed the groundwork of M. Gruner's "Studies," in which he establishes Analytical Formulas by which all the necessary calculations can be readily worked. The happy remembrances of thirty-three years' social intercourse and sympathy in the study of science applied to the arts, is an independent reason for my offering you this tribute of my friendship and esteem. Believe me to be, TOTTERIDGE, August, 1873.. Yours sincerely, LEWIS D. B. GORDON. TRANSLATOR'S PREFACE. THE Studies of Blast Furnace Phenomena by M. Gruner are not written in a style that "those who run may read;" but whoever will take the pains to read them will find his reward in a more exact appreciation of how the recent investigations of Mr. Bell and others into the chemical and calorific phenomena of the blast furnace may be practically applied to questions of blast furnace economy. For the last three years the question of the minimum cost, theoretically and practically, of producing a ton of pig-iron has chiefly occupied the attention of the meetings of "the Iron and Steel Institute," and has even been "discussed" at meetings of the Institutions of Civil and Mechanical Engineers. There is evidently no general answer to the question. Each particular case must be investigated for itself; and M. Gruner has so far generalized the results of experiment and observation hitherto recorded as to give formulas by which the chemical and physical elements of the question may be answered approximately a priori (see p. 122 et seq.) This answer may be made with sufficient accuracy for practical purposes by ascertaining merely the proportion of carbonic oxide to carbonic acid present in the ! escaping gases of any furnace of which we know the elements of its charges. The main point of novelty in the Studies, and what gives them their chief interest, is the precision given to this doctrine, first distinctly taught by Mr. Bell, that CO2 the ratio of in the escaping gases is the index of CO the working of the furnaces. The determination of an analytic process of calculation in place of a synthetic is of value for direct investigation of any case of blast furnace working that may present itself. Still, the other question debated, be it borne in mind, is the economy of fuel in furnaces, whether charged into the furnace and consumed there, or supplied from without as caloric in the heated blast. Again, it is only when furnaces are working with the same, or nearly the same, charges of ore, flux, and fuel, i. e., same quality of raw materials, and yielding the same quality of iron, that we can get comparative results of a reliable nature. Furnaces may be working in one district as well as in another, although using very different quantities of ore and fuel, and yielding very different quantities of iron, and showing very different profit and loss accounts. Pig-iron making, like other manufactures, must be looked at both from the purely technical and the economical point of view. There is a technical maximum of useful effect and an economical maximum of useful effect. The technical useful effect would be so much the greater as the yield of pig-iron from a given weight of carbon and ores of the poorer qualities is greater, |