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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Feb. 17, 



Tlie best and cheapest solution of zinc is the sulphate, which may he safely 

 useJ lo coat articles of iron, the zinc having the greatest affinity for the 

 solvent of (he solution. One pound of dry crystallized sulphate of zinc, 

 to one gallon of water, forms a very good solution; very little intensity 

 of lattery is necessary, indeed, if the quaniilij he well balanced with the 

 surface of the articles in ihe solution, and the electricity has not too far 

 to travel, no intensity is required. The electro process therefore olTers a 

 cheap and eHectual mode of protecting iron frum oxiddtion, by coating it 

 with pure zinc. 



DIclalllc Cloth is another adaptation of this art, for which article we have 

 recently obtained patents, and which is valuable from its properties if resist- 

 ing the efl'ects of the almospl)ere, as well as being water and fire proof, besides 

 being so light that a surface of nine square feet may be made to weigh only 

 18 ounces. The mode of manufacturing is as follows:— On a surface of 

 copper, attach very evenly stout linen, cotton, or woollen cloth, and connect 

 it with the negative |iole of a galvanic battery, immerse it m a solution of 

 copper or other metal, connecting a piece of the same metal as that in 

 solution, with the positive pole : decomposition takes place, and endeavouring 

 to reach the copper plate, the metal insinuates itself into all tlje pores of the 

 cloth, forming a perfect metallic sheet. 



IMPROVEMENTS IN THE MANUFACTURE OF IRON. 



Patented by Thomas W. Booker, Esq., of Melin Griffith, near CardifT- 

 (From the Transactions of the Society of Arts.) 



The method usually, now and heretofore, adopted in the manufacture of 

 bar iron (where the dangerous, and, as the auihor thinks, reprehensible prac- 

 tice of puddling the crude or raw pig iron, without the intervention of the 

 refining process, is not adopted), is as follows : — The pig iron is thrown up 

 on what is called the milling finery, or run into the finery in a fluid state, 

 from the smelting or blast furnace, and after underguing the process of re- 

 fining, it is run out into cakes or moulds, and suffered to get cold ; it is then 

 broken up into lumps of a convenient size, and thrown into the. puddling re- 

 verberatury furnace, which is usually constructed with one door, and at 

 which only one man can work at a time. The author's improved method is 

 detailed in his specification, plan, and model, and its effect is this — a saving 

 of full 50 per cent, in fuel, and nearly 50 per cent, in metal, an immense 

 saving of labour, and a (greatly increased product of work in the puddling 

 furnace — the usual product of a puddling lurnace being from fourteen to 

 eighteen tons in a week, while the author's will as easily produce from forty 

 to fifty tons in a week. The author thus combines the processes of refining 

 wilh pudilling, and to show the importance of preserving, and the hazard of 

 dispensing wilh the refining process, he subjuins the results of analysis by 

 M. Berihier of three samples of cinder or scoria, in one of which the remark- 

 able fact of the presence of phosphoric acid shows how important this opera- 

 tion is to the purification of the iron : — 



Protoxide Pliosnhoric 



Silica. of Iron. Alumina. Acid. 



A Staff'ordshire sample.. 0-276 .... 0-612 .... 0040 .... 0-072 



A South Wales sample.. 0-368 .... 06-10 .... 0015 .... none 

 Ditto do. 0424 .... 0520 .... 0033 .... none 



The object of Mr. Booker's invention is to simplity and accelerate 

 the conversion of cast iron from its crude state into malleable or wrought 

 iron, for which purpose the refinery or furnace is adapted to the 

 various qualities or descriptions of cast or pig iron which it may be ne- 

 cessary to use, by surrounding or enclosing the hearth w-ith blocks of cast 

 iron, into and through which water is allowed to flow or not as may be ex- 

 pedient, and as is well understood in making refinery furnaces, the blast of 

 air being introduced through one, two, or more apertures or tuyres, as usual. 



The refinery isconnected with the reverberaiory or puddling furnace, which 

 is constructed ot the requisite form and dimensions. The bottom of the body 

 of the furnace, and the grate bars, and binding plates and bars, are formed of 

 iron ; the other parts of the furnace are constructed with firebricks, sand- 

 stone, or fire clay, as is well understood. In the neck, or near the flue of 

 the reverberatory furnace is an aperture through which the iron, when it has 

 become decarburetted or refined in the refinery, is introduced or run in a fluid 

 stale direct from Ihe refining hearth into the puddling or reverberatory fur- 

 nace. On each side of which reverberatory furnace a dour is constructed ; 

 the door in the one side being immediately opposite to the door in the other, 

 through which two doors the workmen perform tlie process of puddling in 

 the ordinary way in which puddling is done, when working only with one 

 door, which is the general practice. 



As RESPECTS THE Kefining. — Having thrown up the fuel, and having, by 

 the api.lication of fire and blast, procfuced the necessary heat, a charge of 

 nine cwt. or thereabouts of pig or cast iron, of the description generally used 

 for iorge purposes, is thrown on and melted down and decarburetted ot refined 



in the ordinary way ; and when the refining process is completed, the whole 

 charge of metal is run off in a fluid state direct into the reverberatory or 

 puddling furnace previously prepared to receive it, by having been already 

 heated to a proper degree of temperature, and by the bottom, sides, bridge, 

 and opening to the flue being protected in the ordinary way, by the work- 

 men having previously thrown in a sufficient quantity of limestone and iron 

 cinder, The metal having been introduced into the reverberatory or puddling 

 furnace in a fluid state, the workmen raise, apply, and regulate, and vary the 

 heat in the ordinary way, by feeding and moving the fire in the grate, and 

 raising or lowering the damper on the top of the stack or flue, as circum- 

 stances require, and as is well understood ; they at the same time stir and 

 agitate the iron with bars and puddles, while the escape of the oxide of carbon 

 in a gaseous shape takes place, and until the whole mass of iron agglutinates. 

 The workmen then divide it into lumps or balls of a convenient size, and draw 

 the charge from the furnace, passing the lumps to the squeezer, hammer, or 

 rolling cylinders, or such other contrivance or machinery as is used for 

 forging or compressing the iron. 



During the process of refining the iron, by the application of heat and _ 

 blast, in the open refining hearth, a considerable quantity of scoria or ■ 

 cinder is produced, which is tapped and run off as heretofore, as circum- ■ 

 stances require; but it is to be observed, that during the process wdiich the 

 iron undergoes in the reverberatory or puddling furnai e, the author does not 

 find that any cinder need be generated or produced, and cinders and lime- 

 stones are thrown in, as already described, for the protection of the various 

 parts of the furnace exposed to the action or agitation of the fluid metal, 

 but no cinder need be tapped or drawn off. 



Mr. Aikin's opinion.- The principal novelty in Mr. Booker's invention 

 consists in placing the refining and the puddling furnace so near each other 

 that the refined iron may be run in a liquid state into the puddling lurnace, J 

 instead of allowing it (as is usual) to cool and become solid when let out of ^ 

 the refinery, previous to its being transferred to the puddling furnace. The 

 beat lost by the iron is thus saved, as we 1 as the time required to bring the 

 solid refined iron to a state of fusion. Both the refining and puddling are 

 to be performed, according to Mr. Booker, in the usual way; it was there- 

 fore incumbent on him to show how it happens that while the common pro- 

 cess of puddling produces slag, his does not. 



Mr. Booker's statement that by his process a saving of full 50 per cent, in 

 fuel, and nearly 50 per cent, in metal, is eflected, appears to be an enormous 

 exaggeration ; the saving in the former being only (as far as appears) the 

 fuel required to melt the refined iron. In making iron of the best quality, 

 3174 cwt. of pig iron give 26"45 refined, which is reduced to 23 in the pud- 

 dling process. 8 74, therefore, is the loss which 3r74 pig suffers in becoming 

 puddled iron. Half this loss, namely, 4-37, will represent 50 per cent, of 

 saving, and this, added to 23, makes 27'3V, which is 0-92 more than the entire 

 quantity of refined iron. 



Berthier's analysis of two samples of scoriae from South Wales, and one 

 from Staffordshire, showing the presence of phosphoric acid in the former 

 and none in the latter, has no hearing on Mr. Bookei's statement, that in 

 the process of refining, the phosphoric acid is separated from the iron. 



If the quality ot the iron produced by Mr. Booker's process is not worse 

 than ihat of iron refined and puddled in the usual method, Mr. B."s process 

 deserves the approbation of the Society. But I would recommend that Sir 

 J. Guest, or some other pract cal iron master, should I'e consulicd. 



In answer to a communication from the Secretary, Mr. Booker writes; — 

 " I account for ' the production of slag in the common puddling furnace, 

 and its non-production in mine, as follows : — The common puddling furnace 

 is so constructed that the iron operated upon in it is exposed to a very rapid 

 draught or current of air, which rushes in at the grate at the back of the fur- 

 nace, and passes off through the body and into the flue and stack at the head 

 thereof. This draught is so great as to oxidize the iron, and transform a great 

 portion of it into slag or scoria during the process of puddling, which process, 

 moreover, is effected so slowly, that the charge of iron, consisting of from 3J 

 cwt. to 4J cwt. is exposed lo the heat and draughts in the puddling furnace 

 during the space of full an hour and a half. 



'- My puddling furnace is so constructed, that the draught or current of air 

 admitted at ihe grate is broken, and its oxidizing effects upon the surface of 

 the iron while fluid, and upon the fibrous particles as they cohere, after the 

 oxide of carbon has been expelled, are entirely neutralised. That pirtion> 

 therefore, of the charge which in the common puddling furnace is convertid 

 into slag or cinder, in mine is not wasted or oxidised, but remains, and is 

 converted into pure malleable iron. 



" 'The saving of fuel' is accounted for thus: — In the common puddling 

 furnace not more than 4S cwt. of metal is admitted at one time, and this in a 

 solid cold state. In mine, double Ihe quantity is admitted, and that in a 

 melted and fluid state. It is obvious that the time, fuel, and labour necessary 

 for melting the iron are saved, and that double the quantity of iron is con- 

 verted from a cast into a malleable state within halt the same space of time.', 



