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Title: Forges or the art of making iron – [1] First section
Original Title: Forges ou art du fer – [1] Première section
Volume and Page: Plates vol. 4 (1765)
Author: Unknown
Translator: Jeremy Platt [AusIMM, jeaplatt@bigpond.net.au]
Original Version (ARTFL): Link
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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. To use this work in a way not covered by the license, please see http://quod.lib.umich.edu/d/did/terms.html .

URL: http://hdl.handle.net/2027/spo.did2222.0001.452
Citation (MLA): "Forges or the art of making iron – [1] First section." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Jeremy Platt. Ann Arbor: Michigan Publishing, University of Michigan Library, 2010. Web. [fill in today's date in the form 18 Apr. 2009 and remove square brackets]. <http://hdl.handle.net/2027/spo.did2222.0001.452>. Trans. of "Forges ou art du fer – [1] Première section," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, vol. 4 (plates). Paris, 1765.
Citation (Chicago): "Forges or the art of making iron – [1] First section." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Jeremy Platt. Ann Arbor: Michigan Publishing, University of Michigan Library, 2010. http://hdl.handle.net/2027/spo.did2222.0001.452 (accessed [fill in today's date in the form April 18, 2009 and remove square brackets]). Originally published as "Forges ou art du fer – [1] Première section," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, vol. 4 (plates) (Paris, 1765).

The plate captions have been translated but not the legends. To volunteer to translate the legends, please contact diderot-info@umich.edu.

First Section. Exploitation of Mines and their Preparation.

Plate I: Forges, First Section, Ore Extraction from Underground Mine and Surface Mine


The first vignette represents a countryside in which several pits have been sunk to bring up the ore from underground, either lump ore or fine ore.

Figure 1 . A miner turns the crank of a winch m, n with a basket with a handle suspended on the rope; similar to that which the workman (Figure 2 ) is emptying on the pile of ore behind him; c, d, e, f are the four legs that support the winch; further away one can see the opening of another pit with a and b the supports of the winch.

Figure 2 . Worker, or assistant, who receives the basket full of ore when it reaches the level of the boards d, f ( Figure 1 which partly cover the pit) and empties it on the ore pile already dug from the mine, to then be transported to the furnace where it will be melted. Also in Figure 2 one can see the opening A of another well, above which is built a structure to prevent surface material from falling into the pit and filling it in; below this has been built a horse-driven machine driven for hauling the ore; D is a vertical winch on which the ropes are wrapped; the lower pivot of the axle of the winch is a bearing resting on a stone in the centre of the support and the upper pivot is held in a clamp fixed to the face of one of the cross bearers of the structure covering the pit. F F is a lever, at the end of which, F , is linked the harness to which the horse is attached; one can use several horses by multiplying the number of arms. B and C are two large pullies over which pass the ropes which wind and unwind alternatively on the winch D , to pull up the baskets filled with ore which are attached to them from the bottom of the mine - it is bucket B which is hoisting. H is the roof or cover of the structure. G is an extension of the cover over the pit to put the pullies and the ropes under cover. There is little justification for building such a structure and the machine inside it unless there is abundant mineral and the working of this can be carried out for some considerable length of time through the same shaft; these are the mines in rock with thick seams where one can run galleries in all directions, with the necessary pillars as shown in the vignette at the bottom of the sheet.

The second vignette shows a countryside and a mountain, in which one sees a rock mine, either on or near the surface.

Figures 3 and 4 show the workings of a mine in rock near the surface of the land, which differs from the other side of the vignette, Figures 5 and 6, where the workings are underground.

Figure 3 . Worker who is breaking up a lump of rock separated from the mass with a pick.

Figure 4 . Worker who is drilling a hole in the mass which will be charged with gunpowder to produce ore by breaking pieces of rock from the mass, which worker subsequently break up to facilitate transport; this worker uses, to drill the hole, a bar of round iron, the lower end of which was sharp and shaped in a diamond shape by triangular pieces which crossed at right angles like the hammer used by a sculptor and, by alternately raising and dropping this tool in the hole, which was started with a pick or other convenient tool; the worker takes care to turn this tool in his hands so that the points of the lower end strike in different positions; he also carefully pours water in the hole, not only to preserve the tool, but also to facilitate the removal and flushing of rock chips that he has crushed. When the hole is drilled to the required depth one charges the ore by introducing the required quantity of powder in a paper cartridge; One then places a rod of iron shown near c in the hole in the ore, making sure that the lower part of the iron rod penetrates the cartridge; one then fills the hole level with the surface with rammed tightly earth or with gypsum grout if one has it. Then the iron rod or needle is removed and replaced with powder, which acts as a primer, and the work is completed; it only remains to fire it using a slow match that allows the workers time to get away. f first face, e first bench, d second face, c second bench, b third face or bed of ore, a bottom of the mine.

One can see above the opening of a hole in the side of a mountain through which water from an underground mine may escape.

The other part of the vignette represents the workings of a mine in underground rock, the hill being shown as a cut-away to reveal the interior of the mountain.

Figure 5 . A miner who has broken a lump of rock and is breaking it with a heavy weight on the head of a corner which he has placed in a slot which he had made previously with a pick; it usually starts between the corner and the sides of the slot, with blocks of oak surrounding the corner to contain rebound chips. c block of rock broken away from the mass, d basket in which one puts the ore to take it out of the mining area, b wooden shovels for filling the baskets or wheelbarrows.

Figure 6 . A worker moving the ore using a wheelbarrow under the man-made tunnel, by which one can extract the ore; g, h, k are different galleries, some shored up, the others self-supporting, from which the ore has been extracted; e, f shaft or pit covered with boards resting on pits which were the entry to the mining area and by which the ore was extracted by the machine ( Figure 2 first vignette) that one sees represented in miniature on top of the mountain.

Plate II: Forges, First Section, Extraction and Shipping of Surface Bed Ore and River Ore


Plate III: Forges, First Section, Calcination of Ore in Fordenberg Ovens


This vignette shows two calcination ovens under one roof, of which one ( Figure 1 ) is empty as one can see through the door A ; the other oven, Figure 2 is charged and the door closed as will be described below.

These furnaces, square in plan, are internally 20 feet on each side and internally 16 feet on each side, the walls being 2 feet in thickness and 14 feet in height; in the middle of one of these faces is an opening or door built in 6 feet in height and 4 feet in width; it is through this opening that one removes the ore when it is calcined; but to charge this furnace one closes this door using 6 iron bars placed horizontally inside and held at equal distances by hooks of the same metal; it is against these bars that one places, on the inside, plates of fire resistant stone. One sees in B , Figure 2 the arrangement of this closure and, at the side of one of the furnaces, the stairs by which one ascends to the ground level at the top of the furnaces from which one services them.

Bottom of the Plate

Figure 3 . External elevation of one of the furnaces; B the door; 1, 2, 3, 4, 5, 6 the bars that support the stones forming the closure of the furnace.

Figure 4. Vertical cross-section of a charged furnace to allow one to see the different layers that compose the charge; A first layer which is coal and two and a half feet thick; B first bed of ore which is 4 feet thick, C second layer of coal which is one and a half feet thick, D second bed of ore which is two and a half feet thick, E third layer of coal only one foot thick, F third and final bed of ore 2 feet thick. The carbon is burnt in about fifteen days to calcine the ore which can be used as a measure of the ore needed to feed the furnace.

Figure 5 . Plan of one of two furnaces, A the door, b c the front wall, e d the opposite wall which leans against the earth.

Plate IV: Forges, First Section, Calcination of Ore


The vignette shows a slope on the edge of a forest into which is built a furnace of each type.

Figure 1 . A furnace built of masonry with cylindrical exterior and conical interior. Towards the base there is a door or opening through which one lights the fire. One charges the furnace in alternate layers of wood and ore; the lower layers are composed of the largest pieces of ore. The upper aperture of the oven is 9m feet in diameter reducing to 4 feet near the bottom and the oven is about 10 feet deep excluding the support wall which surrounds the upper aperture.

Figure 2 . At the bottom of the figure, a vertical cross-section of the furnace through the door and accompanying recess; A the recess, B the door, C lintel of the door, C D and E D interior walls of the inverted cone, D D support wall.

Figure 3 . Bird's-eye view of the same oven, B door side, DD support wall.

Figure 4 . Furnaces of the Foix region; they differ from the preceding in that their base is a square with each side has an inner length of 9 feet, the walls are 7 feet high, there is similarly a door at the base of a recess through which one lights the wood fire to calcine the ore; the wood and ore are arranged in alternate layers, the first layer is composed of coal and wood, upon which one places a layer of the largest ore; this layer is covered with a double layer of coal and wood upon which one places one of crushed ore and small pieces; the final layer has a convex upper surface and is much thicker than the first as can be seen in the following figure.

Figure 5 . Vertical cross-section of the furnace through the door and accompanying recess, A the recess, B the door, C the lintel of the door, C D and E D the walls of the furnace, F the first combustible layer made up of a layer of coal on top of which is a layer of wood, G a layer of ore composed of the biggest pieces, H the second combustible layer, made up of a layer of coal and of wood like the earlier one, I a layer of ore composed of smaller pieces and of which the upper surface is convex.

Figure 6. Plan view of the base of the furnace, A the recess, B the door

Plate V: Forges, First Section, Cleaning of Ore, Buddles


Plate VI: Forges, First Section, Robert's Buddle


Plate VII: Forges, First Section, Rinsing Vat and Sifting Trough


Plate VIII: Forges, First Section, Rinsing Vat and Sifting Trough


Plate IX: Forges, First Section, Pounding Mill


The vignette is of a stamp mill, built in the floor of a pond, from which it is separated only by the space necessary for its driving mechanism.

The stamp mill is made up of an impeller on a horizontal axle fitted with cams and a suitable number of stamps whose repeated falls pulverise the mineral needing this treatment. A the sluice gate for the wheel that one raises to allow water into the sluice, C the impeller of 8 feet diameter, which is made up of 16 vanes, each 15 inches wide and 10 inches long; the body of the wheel is made of two rows of strengthened curved beams to which are attached the supports of the vanes; the axle E F is about 12 feet long and 10 inches in diameter and is fitted with 15 cams arranged in a triple helix to lift each of the stamps three times in each revolution; C one of the lifters.

The frame of the stamp mill is composed of two strong twin upright beams I H , 7 or 8 feet long and 18 and 12 inches rectangular cross section; they are mounted vertically on a strong sole plate of about 9 feet in length and 18 to 20 inches square; this sole plate rests on and is notched into two tie beams at right angles, which are placed vertically below the upright beams, which are in turn held in position by four legs in compression and also by two laterals N fixed on the long side of the uprights and to the sole plate, and the two others, M , are fixed to the narrow faces of the uprights and the end of the tie beams on the downstream side.

Between the wide faces of the uprights, which are kept in place at the top by keyed braces K L , are placed five stamps which, allowing for the necessary clearance, occupy a space of 27 inches; each stamp being 5 inches square.

The stamps are each fitted with a lever at an appropriate height to match the cams on the axle and at their lower end with an iron plate as shown in the diagram at the bottom of the Sheet.

On the upstream side of the stamps is a space O where one places the ore that one wishes to crush. and higher up is the sluice gate B which supplies water to the stamp mill: the rear wall a b c has been cut away to allow one to see the interior of the space O and the ore that the flow of water carries under the stamps; the ore sufficiently reduced in size is carried by the current through a horizontal bar screen into the wash basin P where it is deposited and from where one eventually removes it, after letting the water out of the basin, to transport it later to the furnace.

Base of the Plate

Figure 1. General plan of the stamp mill, A sluice gate for the impeller, C D the impeller, E F the axle, G g the trunnions, B the sluice gate for the stamp mill, H I the twin uprights,, K k L l the keyed braces, N n the legs on the sole plate, M m the legs on the tie beams; 1, 2, 3, 4, 5 the stamps; 6, 7, 8, 9, 10 the cams, S trough by which the sufficiently pulverised ore flows, after crossing through the screen, into the wash basin P , T mould board area for draining the water from the wash basin.

Figure 2 . Cross section of the stamp mill from the downstream side or the screen. H I the twin upright beams, K k one of the two braces, N n the legs on the sole plate, Q q the sole plate, M m the legs on the tie beams, R r the ends of the tie beams, Y y spacer or guide for the lower ends of the stamps, V u the screen, X anvil or iron plate placed between the twin upright beams and recessed into the sole plate; it is onto this anvil that the stamps crush the ore; 1, 2, 3, 4, 5 the stamps.

Figure 3 . Enlarged development of several parts of the stamp and the rotating axle, N the axis of the axle, B a cam, C lifter, D key, which is itself keyed in place, E the fitting at the base of the stamp, F plan view of the sheath of the stamp, on which one sees the profile in 1, 2 , E e tail of the sheath of the stamp.

Figure 4. Some of the bars of the screen V u of the stamp mill and of the screen A H A of the sorting device shown in the preceding Sheet, a b half of one of these bars, they are square at both ends and triangular in the middle; the aspect facing the viewer in the diagram is that which faces downstream in the stamp mill, and downwards in the sorting device, so that the particles which are to be screened by this grille do not stick in it since the gap is wider on the exit side than on the entry side.

Plate X: Forges, First Section, Composed Pounding Mill