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THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[Skptember, 



descrv it. Great attention shouUl be paid to tliis point, in designing 

 circular porticoes, for, if the columns be scantily introduced, a doubt 

 is raised in the mind as to whether the portico is polygonal or circular; 

 and then the eye is distressed at the awkward appearance, portions of 

 the architrave assume, in overhanging between the intercolumnia- 

 tions. A portico formed of a double tier of columns, viz., one tier 

 above the other, produces by no means a happy cfFect, owing to its 

 somewhat ricketty appearance, columns forming but a poor foundation 

 to one another. Grouped columns, commonly called coupled coUnnns, 

 are wholly inadmissible in a portico. So licentious a system of com- 

 position but ill comports with the simple character of that feature, 

 which should display architecture in all her severity. There is then 

 no feature in his art, touching the effect of which a true architect 

 will feel more solicitous than that of the portico ; for well does he 

 know, that the few, but striking members, which unite in the formation 

 of a well designed portico, captivate the mind, whilst ravishing the 

 eye of the spectator ; just as in writing an elegant assemblage of words, 

 conveying a simple thought, arrests and charms the mind of the 

 reader. 



ON MALLEABLE IRON IN PERSIA. 



^n Jlccouiit of ili€ Iron Mines of Caradogh, near Tabreez in Pernio, 

 and of the hielhod tlicre practised of producing Malleable Iron by a 

 ningk process directly from the Ore. By James Robehtsox, Civil 

 and Mining Engineer, Slajor Persian Service, and late Director of 

 llie Shah's Ordnance IVorks, Persia ; Cor. MI. W.S., and Cor. F.A.S.S. 

 Read before the Royal Society of Edinburgh, March 2, 1810. 



The ancient Greeks have laid claim to the earliest discovery of the 

 method of manufacturing iron, but it will appear that the art was 

 known in Persia at least as early as among the Greeks. The method 

 of producing malleable-iron by a single process directly from the ore, 

 is not indeed quite unknown at the present day, but it is believed to 

 be altogether disused in Great Britain and throughout Europe ; but 

 there is no doubt that, in Britain, particularly at Castle Cough, Gla- 

 jnorganshire, and at Furness, near Ulverston, in Lancashire, as well as 

 elsewhere, malleable-iron must have been known long before the dis- 

 covery of cast-iron. In the ITtli century, malleable-iron appears to 

 have been made directly from the ore, in preference to the method 

 novp practised. In the Philosophical Transactions (for 1693, vol. xvii. 

 p. 695), there is the following short notice by Mr. Sturdy, of the me- 

 thod as then practised at Milthorpe-forge in Lancashire. " The forge 

 is like a common blacksmith's, with a hearth made of sow-iron, in 

 ■which they make a charcoal fire, and put in ore, first broken into pieces 

 like a pigeon's egg; it is melted by the blast, leaving the iron in a 

 lump, which is never in a perfect fusion; this is taken out and beaten 

 under great hammers, played with water, and, after several heatings 

 in the same furnace, it is brought into bars. They get about one hun- 

 dred weight of metal at one melting, being the produce of about three 

 times as much ore ; no limestone or any other flux is used." It has 

 been doubted by an intelligent author (Farey on the Steam Engine, p. 

 271), whether, by the process here described, the iron was really made 

 directly from the ore, or only from pig metal. The existence, how- 

 ever, of a similar process at the present day in Persia, evidently the 

 same which has been practised in that country from a very remote 

 period, will make it appear not the least improbable that iron may 

 have been thus produced from the rich hematite or fibrous red iron- 

 ore of Lancashire. 



The writer of this paper having resided for more than two years in 

 the neighbourhood of the Persian mines, and having been during that 

 time engaged in superintending the manufacture of cast-iron, trusts 

 that the following short account of the mines, and of the very primitive 

 process of the iron manufacture, which came constantly under his ob- 

 servation, may be found interesting, if it be not also of some practical 

 advantage, even where the manufacture is conducted with all the re- 

 finements of modem scientific improvements. 



We have no historical record from which to ascertain the period at 

 which the iron mines in the district of Caradogh were first wrought. 

 But there is every reason to suppose that they were resorted to from 

 the remotest antiquity. The district itself is very secluded, and is of 

 a wild, forbidding aspect; it has, without almost any interval, formed 

 part of the Medean, and latterly of the Persian empire ; and, under 

 the rule of native (irinces, has all along been free from the revolutions 

 which have so frequently convulsed Western Asia. The iron mines 

 themselves also bear evident marks of an^quity. They form large 

 quarry-like excavations, thickly surrounded by immense tumuli of iron- 

 sand and small pieces of ore, thrown out in the course of working 



Upon a rough calculation, founded on the size of the excavated hollow 

 which it exhibits, one only of the numerous iron mines which abound 

 in the district, was estimated by the writer of this notice to have now 

 afforded above 4,00U,UU0 cubic feet of iron-ore. Taking the specific 

 gravity of the ore at .'), a cubic foot would weigh about 3U'J lb., and 

 consequently seven cubic feet would weigh about a ton ; and -1,00! 1,000 

 cubic feet, the total quantity excavated from that mine, would weigh 

 57 1,-12S tons. Now, at the present day, '20UU horse loads is a full 

 allowance for the yearly quantity carried away, and as each horse 

 carries about 2 cwt., we have a total of 200 tons per annum as the ex- 

 ported produce at present. It may be reasonably assumed, tliat this 

 quantity has, upon an average, never been exceeded during the many 

 ages ill which the mines have been wrought. Indeed, this estimate 

 certainly exeeeds the actual average yearly produce ; for although a 

 considerable quantity of Russian iron is now imported, to supply the 

 increasing wants of the inhabitants, it cannot be imagined that, in 

 periods of their early history, the natives would require nearly so 

 much iron as they now do. Upon that assumption and without taking 

 into account the "other neighbouring mines, it would follow that 2857 

 years have passed since the soil was first removed from the surface of 

 the mine alluded to. Were the other neighbouring mines taken into 

 account, the antiquity of the whole would be proportionally increased. 

 The writer has not by any means stated these as calculations, or as at 

 all approximating to" accuracy, but still he thinks that, from such data, 

 fanciful as they may in some'raeasure appear, an estimate may legiti- 

 mately be formed on the very great antiquity of the Persian mines. 



The native smiths are dispersed in small hamlets, situated in the 

 woods which clothe the sides of the ravines, through which the moun- 

 tain torrents flow into the river Arras (the ancient Araxes). The iron 

 which is produced, although soft, is extremely tough. It is much 

 superior to the Russian iron, with which the greater part of Asia is 

 now supplied, and is manufactured chiefly into horse-shoes, and horse- 

 shoe nails, for which there is a great demand in Tabreez and the sur- 

 rounding districts, and among the Koords or Nomadic tribes wdio fre- 

 quent the mountain pastures in summer. The trade in it is shared 

 between the Mahomedans and the native Armenians ; and although 

 by no means extensive or deserving the name of the "Persian iron 

 trade," it gives employment to a considerable part of the population, 

 in quarrying the ore, burning the charcoal, and transporting these 

 articles to the forge. 



There are numerous mines in Caradogh, affording iron-ore of the 

 most valuable description, and of various kinds ; but those held in the 

 highest estimation are the Jewant, Koordkandy, and Marzooly ores. 



The Jewant mine is situated in an immense vein of red iron-ore. 

 This ore, on its fracture, often exhibits streaks of prismatic colours, 

 as if at one time it had been subjected to the action of lieat; quanti- 

 ties of iron-sand are dispersed in the interstices of the vein. 



The Koordkandy mine, situated on the summit of a very steep 

 mountain, produces rich magnetic iron-ore, from a vein of great di- 

 mensions. The Marzooly mine also affords excellent magnetic iron-ore 

 in great abundance. The vein in which the last is situated runs across 

 several hills, and is in most parts 100 feet in width. 



In working these mines, the richest pieces only of the ore are carried 

 away, the remainder is thrown aside. They are worked very irregu- 

 larly, and without concert, as there is no restriction imposed as to the 

 mode of mining by the Government. A few individuals sink a shaft 

 through the rubbish, and excavate as much as they require; another 

 party soon after arrive, and fill the first hollow up in the course of 

 sinking another shaft ; and in this way the rubbish is repeatedly turned 

 over, and gradually subsides and is consolidated into a mass as the ore 

 is removed from beneath, thus forming a serious o'ostacle to any one 

 who might attempt to work the vein in a more regular manner. The 

 ore is carried to the villages only during the summer, as the depth of 

 the snow in winter renders the mountain paths impiissable. It is 

 there retailed to the smiths, who purchase a horse-load of 2 cwt. for 

 about Is. sterling, or 10s. per ton. 



The ores above described, when smeUed singly, produce that kind 

 of iron which by English workmen is called hot-short, and by the Per- 

 sians salt-iron. The smiths, however, by means of a mixture, produce 

 iron of an excellent quality, which they term siceet-iron- The most 

 common mixture is two parts Jewant ore to one of Koordkandy, and 

 two parts of of Koordkandy to one of Marzooly. 



Materials for smelting the ore are found in an extensive natural 

 forest which occupies the natural parts of the district of Caradogh. 

 This forest covers the flat bottoms between the mountains, and spreads 

 to a considerable height up their sheltered sides, dwindling into dwarf 

 trees and bushes in the elevated and more exposed situations. It con- 

 sists chiefly of coppice oak, which springs from the roots of trees cut 

 and recut during a long succession of years. This jungle is partitioned 

 among the villages situated on its confines, tlie inhabitants of which 



