1854.] 



ON AN IBIPROVEMENT IN THE MxVNUFACTURE OP IRON AND STEEL. 



105 



I propose in this brief memoir to demonstrate the possibility 

 of an industrial revolution in the United States with regard to 

 tlie manufacture of cast iron, iron, and steel. 



A few historical considerations must first be presented. It 

 is universally known that iron was at first manufactured exclu- 

 sively by means of charcoal with apparatus of small dimensions. 

 This method precluded the preparation of large quantities, and 

 it became quite insufficient when the introduction of steam- 

 engines gave to industry so much wider a field. The immense 

 importance of coal began to be recognised, and iron was manu- 

 factured bj^ its means, according to new methods, which fa- 

 voured its more rapid production in greater quantities. 



A rivalry thus commenced between coal foundries and those 

 kept up by wood, in which the latter were evidently to be 

 overcome. The nations possessing great coal districts, parti- 

 cularly Great Britain, became the producers of iron for all the 

 rest. 



In these circumstances, if suddenly there should be dis- 

 covered a new means of making iron with wood as rapidly and 

 as economically as it is done at present with coal ; if, besides, 

 the iron thus prepared should offer in qualitji very great ad- 

 vantages in comparison with that made with coal ; is it not 

 natural to suppose that the consumers who are only attracted 

 by the cheapness of English iron, would cease to employ it ? 

 Even admitting that under certain circumstances this iron 

 would be dearer, they could more advantageously use it for 

 those purposes for which iron of the fijst quality is indispen- 

 sable, such as the manufacture of steel. 



The country best situated for the success of this industrial 

 revolution is undoubtedly the United States of America. For 

 example, wood is found there in great quantities, and may in 

 some places be obtained at a very low price : on the other 

 hand, the beds of mineral iron are very numerous ; modes of 

 transport, always important in the working of iron, exist in 

 great numbers. Here we find all the conditions necessary to 

 success ; it temains only to establish with certainty the advan- 

 tage of this new method of manufacturing iron, and to explain 

 its high importance. 



1st. Wood is not charged with those mineral substances 

 which injure at once the calorific efiect and the quality of the 

 metals fabricated by it. Coal contains often ten per cent, of 

 matters either useless or injurious. Wood, on the contrary, 

 contains hardly one-half per cent, of mineral substances, which 

 besides are never injurious. All wood has great chemical 

 uniformity, while coals differ much from each other, which 

 involves the disagreeable necessity of ranging the methods of 

 employing them. It is well known to metallurgists that wood 

 should not be employed as a combustible without previous pre- 

 paration, on account of the large proportion of water which it 

 contains. 



For many years the most various experiments have been 

 made to prepare the wood before using it as a combustible. 

 The method to which we would now call attention has been 

 used for a short time in Styria and Carinthia, which consists in 

 taking from the wood only the water, and stopping the distilla- 

 tion as soon as the substances which begin to escape contain 

 carbon. Two methods have been used to effect this conversion 

 of wood into Ugncux (lignum). 



1st. The gases coming from the fire-place are brought into 

 immediate contact with the wood ; thus the wood is raised to a 

 temperature above 100' Oentigradc, which fih'oui-s still more 



the vaporisation by the tendency the gases themselves have to 

 be saturated with vapour.''' 



In the second method, only the heat radiating from the 

 gases in the fire-place is employed. These gases are not brought 

 into immediate contact with the wood, but are conducted In 

 pipes of cast or sheet iron, around which the wood is piled. 



This second method affords by far the most satisfactory re- 

 sults, being the more economical, and avoiding the disadvantage 

 which sometimes attends the first, of making the ligneux 

 pyrophoric, and thereby liable to spontaneous combustion on 

 exposure to the air. 



It is important to render the second method still more per- 

 fect. The following means might be advantageously employed : 

 — The combustion of the wood employed effects the conversion 

 into ligneux, which is thus raised to a temperature of 150° 

 Centigrade. All the water contained in this wood escapes in 

 vapour; but the heat contained in this vapour and in the 

 ligneux should be made useful, as well as the latent heat con- 

 tained in the vapour. For this three successive chambers will 

 be necessary. The wood loaded on waggons, passes in succes- 

 sion from one chamber to another. In the first chamber the 

 wood will begin to be heated and to dry by means of the latent 

 heat of the vapour, disengaged in the second, and condensed 

 in the third ; and also, by means of the latent heat of the air, 

 cooled in the third, and brought back to the first. It is in the 

 second chamber that the entire conversion of the wood into 

 ligneux takes place; the ligneux will pass into the third cham- 

 ber to cool ; the heated air will be conducted to the first cham- 

 ber to heat another load of wood ; the vapour which is found 

 there, and which comes overheated from the second chamber, 

 vrill be condensed, and thus will give more heat to the first 

 chamber, with which it communicates by pipes. 



In following the preceding method, it is possible to change 

 10 parts of wood (standing for 1-00 o? ligneux, 0-40 of water) 

 into ligneux, by means of one part of wood employed as A 

 combustible. 



There is another method more economical which might be 

 employed to convert the wood into ligneux. It consists in 

 utilising the wasted flame of the metallurgic apparatus, after 

 ha\'ing of course previously used it for other purposes ; for 

 example, heating the cauldrons ; because on ceding from the 

 apparatus the gas is of too high a temperature fof the operation 

 in question, and is still sufficiently hot after having been em- 

 ployed for the previous processes. But this method, by which 

 economy is carried to the utmost extent, though very suitable 

 in France or Germany, does not seem necessary in America, on 

 account of the cheapness of the vegetable combustible. 



Thus far we have only explained, and very briefly, the first 

 part of the new method of manufacturing iron. We now come 

 to the second part, which is t\io jiuddling process ■vi\t\iligneux. 

 The puddling, it is well known, is effected by burning in a 

 rcvcrberatory furnace the combustible gases which come from 

 a lateral fire-place. The important part of the operation is to 

 conduct into the furnace a suflicient quantity of air to produce 

 a total combustion of the gaseous subst.anccs. Generally too 

 much air is admitted, which has the disadvantage of uselessly 

 absorbing the heat. Mineral combustibles are much better 



* It is unnecessary in this memoir to describe cither the chamber in 

 which this process takes place, or the requisite apparatus and details 

 of the different processes. 



