L. Gruner (1808-1883)
1883 Obituary [1]
M. LOUIS GRUNER was born in Switzerland in 1808, and died March 26, 1883, in the 76th year of his age. M. Gruner was one of the first students of the Polytechnic School in Paris, which he entered in 1828. After studying there for two years, M. Gruner proceeded to Germany, where he devoted himself for eighteen months to the practical acquisition of mining knowledge. He subsequently became Professor of Mining Engineering at the School of Mines in St. Etienne, which position he held from 1835 to 1847. In the latter year he was called to be chief engineer of the district of Poitiers, where he devoted special attention to the coal basins of the department of the Creuse, making them the subject of a special work which appeared in 1868. During his residence in Poitiers, M. Gruner was largely employed in exploring the mineral resources of that district, and among his other works, he attempted a classification of the rocks and veins of the central plateau—a subject of which he treated more recently before the Geological Society of Lyons in 1856, and before the Geological Society of France in 1865.
In 1852 M. Gruner was called to occupy the position of Director of the School of Mines at St. Etienne. In 1858 he left St. Etienne to assume the Metallurgical Chair at the Ecole des Mines in Paris, where he was also Inspector. In 1872 he left the Ecole des Mines to become President of the Conseil General du Corps des Mines, which high position he continued to hold until the time of his decease.
M. Gruner has been one of the most prolific of French writers on mining and metallurgy, and at one time or another he has dealt with every one of the many aspects that these wide-reaching subjects embrace. His first published memoirs are notes on his travels in Germany in 1831, which appeared in the Annales des Mines in 1834 and 1835. In the same publication he published papers on mining and cognate subjects during the ten years ending with 1846. In 1841 he published an important work on the geology of the Department of the Loire, and this was followed in 1844 by a second work on the coal basin of the same Department. Papers on the latter subject were published by M. Gruner from year to year, as new beds of coal were discovered or opened out, and in 1852 the collected series of papers was issued under the title, "Description and Classification of the Coals of the Basin of the Loire." The amount of labour involved in this work was very considerable, as it gave the chemical composition, &c. of eighty-six varieties of coal in the St. Etienne and Rive-de-Gier basins, under the four heads of:
- 1. Houilles Anthraciteuses (anthracite coal.)
- 2. Houilles Grasses a court flamme (coking coal.)
- 3. Houilles Grasses ordinaire (manufacturing coal.)
- 4. Houilles Grasses a longue flamme (gas coal.)
In 1854 and 1855 M. Gruner added the composition, &c. of seventeen new varieties of coal in the Loire basin, as well as the anthracites of the Roannais, and the coals of the basin of the Creuse; while about the same time, or subsequently, he examined and reported upon the coals of Besseges and Graissessac, and the lignites and bituminous schists of Nucetto in Italy, Thonon in Savoy, and Lirida and Carthagena in Spain. More recently, when MM. Scheurer-Kestner and Ch. Meunier had determined directly the calorific power of certain fuels, M. Gruner, in a further memoir, showed that the heat of coals of all kinds increased and decreased in proportion to the quantity of pure coke left after the fuel had been submitted to heating in closed vessels, and determined the proportions of fixed carbon in the five leading varieties of coal—a system of classification which has subsequently been adopted as official in France.
The subject of the preparation of fuel of different kinds has been treated by M. Gruner in a paper on the "Agglomeration of Combustible Minerals;" while the carbonisation of fuel has been made the subject of several memoirs, the most notable being one on "The Carbonisation of Wood and the Preparation of Red Charcoal by the Italian Method;" and another on "The Relative Merits of Different Systems of Ovens employed for the Carbonisation of Coal."
There is probably no department of the iron manufacture to the literature of which M. Gruner has not made contributions more or less valuable. The Annales des Mines bear testimony to his unceasing activity in this direction. Two of his memoirs in that publication refer to a series of calorimetric observations which he made to determine the heat possessed by metallurgical products at the moment of their fusion as well as when they left the furnace; and in this way he has been able to formulate certain valuable data relating to the difference between the heat developed and the heat actually utilised in various furnaces under different conditions. In 1860 he prepared for the use of students at the Ecole des Mines some tables showing the forms and dimensions of blast furnaces at many of the leading works in France, and other countries as well, with the data thereupon founded respecting the relation which should exist between the different parts of a furnace, and between the interior capacity and the weight of the materials forming the charge, which was subsequently republished in the first volume of his well-known Traite de Metallurgie. These questions have also been dealt with in two separate memoirs, which he published while he held the Metallurgical Chair at the Ecole des Mines—the one being entitled Notes sur les Fours a Cuve a Section Rectangulaire, Ovate, ou Cerculaire; and the other Etudes sur les HautsFourneaux. The subject of the hot-blast has been considered by M. Gruner in a memoir published in the second volume of the Annales des Mines for 1872, as well as in his more elaborate Traile de Metallurgie; while in his Etat Present de la Metallurgie du Fer en Angleterre, published in 1862, he drew the attention of Continental metallurgists to the importance of a suitable charging apparatus for blast furnaces.
So far as the chemical phenomena of iron smelting are concerned, M. Gruner has published three memoirs—the first entitled, Dedoublement da l'Oxyde de Carbone; the second, Etudes sur les Hauts-Fourneaux; and the third, Notice sur du Carbone Floconneux, in which this subject has been considered. The first of these three papers was presented to the Academy in 1871, when MM. Boussingault, Balard, Fremy, and H. Saint-Claire-Deville spoke of it as " containing a great number of facts of the highest importance for the study of the properties of carbonic oxide, and its action on iron and oxides of iron, for the theory of the manufacture of iron and of the cementation process;" and they recommended that the Academy should publish it in the Recueil des Savants Strangers, which was done. The Notice sour l'Origine du Carbone Floconneux was read at the Lyons meeting of the French Association for the Advancement of Science in 1873; and it established by direct experiment, the fact that carbonic oxide became decomposed in all parts, relatively cold, of the blast furnace, and that the amorphous carbon which was deposited in the blast furnace had the same composition as that obtained in the laboratory by the prolonged action of carbonic oxide on iron ore, at a temperature of 300° to 400° C.
The Bessemer process received early and constant consideration at the hands of M. Gruner. In a paper published in 1857 he showed that Mr. Bessemer's expectation of being able to use the commoner varieties of iron could not be realised, because in a vessel with an argillaceous lining the slags were always too siliceous. This subject was more fully treated in a second memoir, published in 1860, and in the well-known work which, in 1862, he published conjointly with M. Lan.
Several papers have been published by M. Gruner in which the physical and chemical characteristics of steel have been considered. In one of these § the author showed that steel occupied an intermediate place between soft puddled iron and pig; that the defects of certain varieties of steel were due to the presence of foreign substances, which affected equally the tenacity of puddled and pig iron; that steel is only one of a series which begins with the most impure pig, and ends with the softer iron; that steel and pig iron, when tempered, contain carbon in the combined state; that both give up a part of their carbon in the form of graphite when they are submitted to gradual cooling; and that the hardness of steel increases with its content of carbon, and its unworkableness with the content of foreign substances. In the same work the author described the various methods of steel manufacture both ancient and modern.
In 1868 and 1869 M. Gruner devoted much time to a study of the Heaton process, - first at the Langley Mill Works near Nottingham, and afterwards in small experimental works established at La Villette, Paris. The result of M. Gruner's observations were made known to the world in two pamphlets, which are sufficiently well known in the metallurgical world.
The various processes that have been suggested or put in practice for the manufacture of steel direct from the ore - including those of Siemens, Martin, Chenot, Ponsard, and Ellershausen - have been critically examined by M. Gruner, who has also in another memoir dealt with the effect of tungsten and titanium on the hardness and tenacity of steel. Among other subjects which have been taken up by M. Gruner, mention can only be made of his examination of the minerals of lead and cobalt of the Val d'Anniviers (Switzerland); of the minerals of lead.. in the Alps of Lombardy, and in the Cevennes (France); his elaborate analysis of copper pyrites from the Valais (Switzerland), the Loire, the Haute-Loire, and the Drome; his criticism on the wet process of treating poor copper pyrites, as tried in Hungary by Professor Bechi of Florence; and his elaborate essay on "The Present State of the Metallurgy of Lead."
In 1836 he published a memoir "Sur le Traitement des Minerals Auro-Argentiferes de la Basse Hongrie;" in 1834, along with MM. Foy and Harle, a notice on the amalgamation of auriferous minerals by the Tyrolean method; in 1839, a note on experiments with Mensuil safety-lamps; in 1859, on the washing of minerals; in 1851, a report on the employment of salt in agriculture; and in 1873, a report on the mining and metallurgical productions shown at the Vienna Exhibition.
M. Gruner was made an honorary member of the Institute in 1875, and took part in the discussions at the Paris meeting in 1878.