Products of mining and metallurgy.
CAST IRON WITHOUT RETOUCHING.
A cast iron gantry from the Tusey (Meuse) factory, run by Mr. Zégut, a former associate of Mr. Durenne, in Sommevoire, introduces us to the second of the rooms occupied by the metallurgical industry. A little further on, the same factory exhibits a whole collection of ornamental cast iron, equally remarkable as works of art and works of industry, by the beauty of the models and by the masterly difficulties overcome in their execution. Once reserved for the crudest uses, cast iron today shares with bronze the privilege of taking on the sacred form of goddesses; it is the bronze of the people, reserved for an immense future.
Bessemer and other steels.
After the portico of Tusey, we find on the right the steelworks of Imphy-Saint-Seurin, whose skilful director, Mr. Jackson, introduced and naturalized in France the Bessemer process for the manufacture of steel.
It is well known that the aim of this metallurgical method is to obtain molten steel directly by passing a current of air through the liquid iron. Bessemer's most important discovery was his recognition that the air current, far from cooling the molten metal as one might have thought, actually heats it up by burning the bodies in the cast iron that are more oxidizable than iron.
This new refining process therefore requires no consumption of coal; the metalloids contained in the cast iron are the real fuels which, by oxidising, produce the temperature useful for the operation.
When a cast iron contains the elements of steel, and when, in addition, the harmful bodies in it can be removed by the current of air without destroying the acieration, Bessemer steel is obtained immediately, by stopping the refining at the moment when the useless bodies have been oxidised.
However, in most cases, in order to produce pure steel and especially steel of a certain quality, it is in the interest of the company to completely eliminate all the metalloids that exist in the cast iron, to produce iron and even nitrogenous or burnt iron; the steel is then reconstituted by mixing the nitrogenous iron with a steel-bearing cast iron. In these circumstances, the manufacture of steel by the Bessemer method is marvellously simple: it all boils down to introducing into molten and completely refined iron, variable quantities of steel-bearing materials, which are found in a suitably chosen cast iron.
Such is the process in its entirety: a description of the apparatus cannot take place here; as for the products, Mr. Jackson's exhibition is almost exclusively composed of them.
Colonel Treuille de Beaulieu, reporting as a member of the international jury on the artillery pieces which appeared in London in 1862, said in his report: "If Mr. Bessemer succeeds in being able to melt large masses with regularity and without blowing, it is indisputable that he will have settled the question of steel as a cannon metal, for it is the increase in the cost price which is the difficulty to be overcome today. "
Judging by the steel ingot of 7295 kilograms that Mr. Jackson exhibited, and by the beautiful steel breaks that he showed us, it seems that the problem posed five years ago by the French jury's rapporteur has now been resolved. The exhibition of the Imphy-Saint-Seurin steelworks also has a very bellicose character. The steel cannons occupy the best places. One of them, an 8-piece, was tested at Ruelle. Next to it are cylindrical cannonballs, log-shaped projectiles, intended to act as pellets on the walls of ships; then, artillery axles. But war is not Mr. Jackson's only preoccupation; evidence of this are the straight and cranked locomotive axles, the beautiful planed grooved track crossings (Eastern Railway Company type), and.... and the cast steel rifle barrels.
Opposite this flashy crew is that of the steelworks and forges of Firminy (Loire), from which molten steel, refined steel and natural steel only come out in the form of springs, axle tyres, wheels, assemblies and forging parts. May the time come soon when steel will be used only for such purposes.
Alas! we have hardly taken a step forward, when in the middle of an admirable assortment of scythes and sickles, molten steel for taps, tools and dies, and cast steel parts worked by the Unieux steelworks, stands the inevitable molten steel cannon, and in the most apparent place, a whole collection of sabre blades arranged in the shape of a fan.
Let's move on. Here are the blast furnaces of Maubeuge (Nord). Thirty million kilograms of refining and casting iron, cast and wrought iron, merchant and special irons are produced every year. But what do we see there, right in the middle, on this shelf?... cylindrical-conical balls.
The blast furnaces and forges of Allevard (Isère) were not content to send us their products and, by means of relief models made to a suitable scale and pieces in various stages of completion, they wanted to introduce us to their method of manufacture. This is a happy thought that deserves public recognition. And may it find many imitators at the next exhibition! These models show us : 1° the production of cast iron by wood treatment of the spathic carbonate ores of Allevard; 2° the puddling for steel of spathic cast iron by means of wood gases; 3° the wrought ironing of raw steel done exclusively with a pestle hammer; 4° the setting to the profile and to the round by reheating of the wrought bars (these are the ordinary processes of rolling and bending); 5° the welding of the circles by means of three sets; 6° finally the setting to the diameter by means of circular rolling mills.
The Société des Haut Fourneaux et Forges de Denain et d'Anzin obviously could not send to the Champ de Mars the three-roller equipment by means of which it finishes profiled irons, rails and T-irons; but in the absence of the object itself, it shows us a huge drawing which represents it and whose view leaves nothing to be desired.
In the middle of the room, the Marquise factories have erected in the form of a monument some of those enormous cast-iron columns which, sunk into the bed of a river and filled with concrete, are used in a system now in favour to form the piers of bridges.
This process, proposed in 1845 by an inventive engineer, Mr. Trigier, was applied with great success, as no one is unaware, to the construction of the Kehl bridge on the Rhine, and more recently to the Argenteuil bridge on the Seine.
From this exhibition, we can bring together that of the Société des houillères de Commentry et de Montvicq and the foundries, forges and construction workshops of Fourchambault, Montluçon, Torteron and La Pique, which shows us the whole series of pipes supplied by it to the city of Paris, and deposited concentrically in order of size in a single column, and a section which only concerns the lower part of this column, shows the pipes which make it up, their diameter and their thickness. All have the same height: 4m100 and the same thickness: 25 millimetres; the diameter of the one which contains all the others is 1m,100.
On the latter are inscribed in white letters the names of the cities to which the company has supplied these pipes; the number is great. They go as far as Madrid, Reunion, and Guadeloupe.
This is not the only thing on display at the company's exhibition, the long description of which has been transcribed above. There is a specimen of the columns of the Palace whose wonders we detail; anchors, track changes, wheels and axles of wagons; even an artillery axle for a battery mount. A pair of wagon wheels bears the production number 79740. A double label, placed under a fishplate pad and under an angle pad, tells us that the factory has delivered 2143,000 pairs of the first model, for a track length of 6,500 kilometres, and only 32,400 pairs of the second model; the length of the track laid is still only 100 kilometres.
A word about the Commentry and Montvicq coal mines. The concession which they exploit is of 2180 hectares. The average thickness of the layer is, in Commentry, of 14 meters. The extraction followed the following progression: 1840, 14000 tons; 1850, 90000; 1855-56, 240,000; 1860-61, 370,000; 1865-66, 480,000 tons!
Everywhere the progression is the same, if not even faster. Coal consumption in England was 83 million tons in 1862; in 1864 it had risen to 93 million.
Assuming an annual increase of only 2,775,000 tonnes, Sir William Armstrong concludes that in a little over two centuries England will have exhausted all its known coal resources.
Some will be found elsewhere; so be it. The coal deposits of North America alone are eight times larger than those of the whole of Europe; I grant that. But the needs of industry grow with its progress, which is incessant; but industry takes root every day in regions where it was unknown. However large the deposits of coal, anthracite, lignite, etc. may be, the day will come when the last shovelful will be drawn from them. What will be done? I don't know, but I don't care. Not that I am indifferent to the fate of those who will come after us, but I have faith in the indefectibility of the general plan by virtue of which, an unknown number of millions of centuries ago, the supplies which constitute one of our present riches were formed. I believe that the power which, from the coal age, was preparing the progress which human industry was to make towards the end of the eighteenth century of the Christian era, I believe that Providence-to call it by the name which mankind gives it-has foreseen the case before us; That new resources, man helping himself, which is a necessary and sufficient condition for heaven to grant him, will reveal themselves in due course, and that at last mankind, which is only beginning to sort itself out, will not stop for the bourgeois reason that it has exhausted its supply of fuel.
The company of the foundries and forges of Terre noire, La Voulte and Besseges, produces annually: coal, 150,000 tons; iron ore, 160,000 tons; pig iron, 94,000 tons; cast iron, 7,500 tons; cast iron in pipes, 12,000 tons; iron, rails, sheets, etc., 50,000 tons; Bessemer steel, 50,000 tons. But what a poor figure the smelter and blacksmith would make at a World's Fair in 1867, who would have only rails, axles and gears to show! Also the company of the foundries and forges of Terre noire, etc., joined to these prosaic products a sufficient assortment of balls and cylindrical-conical bombs.
Montataire has magnificent sheets: a sheet 11 meters long, 1m, 10 wide, weighs 1197 kilograms; another, 8 meters long, 1 ",60 wide, weighs 1375JU1. A good example of their use is a roof of this kind with a span of 18",60 established in the Park itself in the middle of the avenue from the Palace to the Military School. Seamless wagon and locomotive tyres deserve a mention. One of them is 1.755 m in diameter. The same company has put under glass beautiful crystals of iron sulphate (green couperose), entirely free of alum.
The Audincourt forges also have beautiful sheets and, in addition, cylinders for sheet rolling mills, fluted cylinders for round and square irons and...solid ogival balls made of tempered cast iron.
Electroplating, as we all know, is the art of depositing on a metallic or metallized object, in coherent layers and moulded exactly on it, a metal extracted from the dissolution in which the object is immersed.
Depending on the conditions of the experiment, the precipitated metal either adheres intimately to the body on which it is applied, or is easily detached from it.
In the second case, the operation gives an exact mould of the part immersed in the bath; this is electroplating proper. In the first case, the product of the operation is the part itself coated with a more or less thick envelope of precipitated metal.
To this last category belong the:
Metal coatings on iron, cast iron and steel
Exhibited by the Company which exploits the processes recently invented by Mr. F. Weil. These processes allow the direct application of an adherent copper plating without the use of any of those coatings (minium paints, lead paints, etc.) which alter the details of the original execution.
Mr. F. Weil's processes have been described in the Annals of Chemistry and Physics. Let us limit ourselves to saying that the inventor uses baths formed of salts or metallic oxides held in alkaline, sodium or potassium dissolution, either (which is the most frequent case) by means of certain proportions of
of organic matter (tartaric acid, glycerine, albumin, etc.); or by the excess of the fixed alkali itself.
Metallic coatings are made with the help of these baths with or without the assistance and contact of zinc or metallic lead, sometimes at the ordinary temperature and sometimes at a higher temperature.
Not only are iron, cast iron and steel solidly copper-plated, but also, as visitors will see, the colours and tones of the metal coatings can be varied at will.
The products exhibited in this room by the Christofle et Cie factory belong to electroplating proper.
These are beautiful statues and admirable bas-reliefs, one of which is a large one representing the Assumption of the Virgin. It is well known that the factory in question applies electroplating especially to the reproduction of objets d'art and fine chiselling to the decoration of furniture, large statuary, engraving and the ornamentation of goldsmiths' objects. It is also well known that electroplating is only one of the branches of reproduction at the Christofle factory.
It employs 1500 people. The average wage for male and female workers is 4.50 francs a day, for women 2.50 francs. Seventy-five employees share 195,400 francs in wages. Every male and female worker, having worked ten years in the establishment, receives an endowment of 500 francs in non-transferable and unseizable savings bank notes. This endowment dates from 1851. Several beds were maintained by the factory in the asylums of Vincennes and Vézinet. They were intended for convalescent workers. They are helped during illness by a fund to which the establishment contributes the sum of 1500 francs, and which is fed by a contribution of 50 centimes per fortnight for men, 25 centimes for women, and by fines. This fund gives in case of illness: to married workers 3 francs per day, to unmarried workers 2 francs, to women workers 1.50 franc. It is with pleasure that we conclude this first glance at the products of mining and metallurgy with information of such a good example.
©L'Exposition Universelle de 1867 Illustrée