478 



NATURE 



{Sept. 12, 1889 



many years the beneficial effect produced by manganese on steel 

 had been well known, and it occurred to R. Y . Mushet, son of 

 David Mushet, one of, if not the earliest scientific metallurgist in 

 the United Kingdom, to try its influence in the converter on iron 

 made from the haematite iron of the west of England which con- 

 tained from o '05 to OT per cent, of phosphorus. This addition, 

 apparently by its removing occluded or combined oxygen in the 

 molten iron, afforded the necessary relief, and the operation 

 being one of extreme simplicity enables steel or wrought iron to 

 be produced at a greatly reduced cost. To such an extent has 

 this been carried, that ore is brought by sea over a distance of 

 1000 miles to Middlesbrough, and from it steel rails are made 

 more cheaply than a greatly inferior article of iron can be pro- 

 duced from the abundant and economically wrought bed of iron- 

 stone found within a couple of miles of that town. As an example 

 of the facility of conversion may be adduced the fact that the 

 molten metal is brought direct from the blast furnace, turned 

 into steel or ingot iron as the case may be, and the heat evolved 

 by the operation is sufficient to enable the product in many cases, 

 without further use of fuel, to be taken direct to the mill and 

 rolled into a finished bar. 



We have just seen that O'l per cent., or thereabouts, of 

 phosphorus renders steel or ingot iron valueless ; in like manner 

 very insignificant variations in the quantities of carbon or silicon 

 materially affect their quality. Now the blow, as it is termed, 

 in a Bessemer converter may be accomplished in from twelve to 

 fifteen minutes. It is clear, therefore, the opportunity of ascer- 

 taining the precise quality of the steel is one of very short 

 duration. It is, I think, not disputed that a product can be 

 obtained by this process possessed of very high, if indeed not 

 of the highest excellence ; but it is also pretended that the 

 quality is not sufficiently uniform for certain purposes. The 

 ordinary reverberatory furnace is incapable of affording the 

 necessary temperature for melting steel or wrought iron, but 

 by employing the fuel in a gaseous state, and by heating the 

 air and gas before they are brought together, as is done in the 

 valuable furnace suggested by the Messrs. Siemens, the heat is 

 so intensified that wrought iron in it is rapidly fused. Steel is 

 nov7 largely made in such furnaces, either by mixing wrought and 

 cast iron, as proposed by M. Pierre Martin, or by means of cast 

 iron alone, when the carbon is removed by the addition of 

 iron ore and some limestone, in which case, by the agency of 

 the ore, the metalloids are oxidized and removed from the bath 

 of iron. Some hours being required for this, sufficient oppor- 

 tunity is afforded for ascertaining the progress of the operation. 



The cause of the iron in the Siemens furnace as well as in the 

 Bessemer converter retaining its associated phosphorus, in time 

 began to attract the attention of chemists. In each case the 

 expulsion of the metalloids is effected by oxidation. The carbon 

 is gasified, and the silicium on being acidified is absorbed, and 

 forms a slag containing usually ^40 to 50 per cent, of silicic 

 acid. In the presence of such an excess of this substance, any 

 phosphoric acid, if formed, could not be absorbed by the slag. 

 It was the late M. Griiner, of Paris, who, in 1867, first pointed 

 out this fact, and he it was who first recommended the use of 

 lime in order to render the slag basic instead of acid. Further, 

 in order to avoid the presence of silica, he recommended at the 

 same time that the converter should be lined with lime instead 

 of with fire-clay. 



The same subject engaged my own attention, when guided 

 by the fact that, as oxide of iron in the puddling furnace 

 was capable of acidifying and removing a large quantity 

 of the phosphorus as iron phosphate, it might be possible by 

 keeping the temperature of the metal below that required for 

 the process of puddling to make this removal more complete. 

 The result of these experiments was communicated to the Iron 

 and Steel Institute in March 1877, when it was shown that pig- 

 iron containing 1 75 per cent, of P could in a few minutes have 

 this reduced to o"2 per cent. 



The rapid destruction of the ordinary Bessemer converter led 

 Mr. G. I. Snelus to consider the practicability of using a lime 

 lining, and on experimenting with this on a working scale he 

 confirmed the opinions previously enunciated by Griiner, by 

 observing that the presence of lime had removed a considerable 

 quantity of the phosphorus. These discoveries constitute the 

 foundation of the very important basic process of Messrs. Thomas 

 and Gilchrist, which consists in adding lime to the molten steel 

 in a converter constructed on the principle described by Mr. 

 Snelus. Considerable difficulty had, however, been expsrienced 

 by this metallurgist in the attachment of the lime lining to the 



walls of the converter. This important question was solved by 

 Mr. Edw. Riley by exposing dolomite to a very high tempera- 

 ture in order to prevent further shrinking, and then grinding 

 and mixing the powder with coal tar. This formed a species of 

 cement which is applied to the sides and bottom of the con- 

 verter in the form of bricks or as cement. 



The acidification and subsequent transference to the sl^ of 

 the phosphorus by the basic treatment has led to its application 

 to agriculture. For this purpose the slag is ground to a fine 

 powder, and sprinkled over the land without any further 

 preparation. By this operation an indispensable element of 

 animal life is derived from the remains of living creatures 

 which, ages ago, found a grave in the feiruginous mud destined 

 to become the great Cleveland bed of ironstone. 



Before closing this portion of my official duty, I cannot refrain 

 from tendering to chemists an assurance of the great advantage 

 the manufacturers of iron feel they have derived from the lessons- 

 taught them by chemical science. I am the more anxious to do 

 this because we, among others, have been reminded that we are 

 losing the supremacy among industrial nations we once enjoyed 

 for want of that knowledge of chemistry which is more assidu- 

 ously cultivated abroad than it is in our own country. I am 

 not prepared to deny that the opportunities for acquiring a 

 scientific education are less generally spread here than is the 

 case in France, Germany, or Belgium, but for this the nation, 

 and not the iron trade in particular, is responsible. It must also 

 be admitted that as manufacturers we no longer stand so far 

 above other lands as we formerly did. In this result any 

 differences of education are in no way concerned, for if I were 

 to classify the nationalities of the various inventions enumerated 

 in the course of my remarks, the fears of those who are alarmed 

 at the appearance of a Belgian girder or a German steam-engine 

 on our shores would, I think, be allayed. Perhaps I might be 

 allowed to offer a very few words on the technical side of this im- 

 portant question of education. Much I shall not be able to say,, 

 because I have not yet been able to learn the precise position 

 the subject occupies in the minds of its most earnest advocates. 

 If it means, as is sometimes alleged, a system by which, along 

 with scientific instruction, manual dexterity in the use of tools, 

 or a practical knowledge of various manufacturing processes has 

 to be acquired, I confess I am not sanguine as to the results. 

 Certain I am that if foreign workmen are more skilful in their 

 trades, which, as a rule, I doubt, and which in the iron trade I 

 deny, this superiority is not due to scientific training in the 

 manner proposed, for in this they possess, so far as I have seen, no 

 advantage over our own workmen. My objection to the whole 

 system is the impossibility of anything approaching a general 

 application being practicable. I have not a word to say against 

 the rudiments of science being taught wherever this is possible. 

 The knowledge so obtained may often give the future workman 

 a more intelligent interest in his employment than he at present 

 possesses ; but I think they who expect much good to attend 

 such a thin veneer of chemistry or physics do not take sufficient 

 account of the extent of the knowledge already possessed by more 

 highly educated men who are now directing the great workshops 

 of the world. It is by extending and enlarging this that sub- 

 stantial aid has to be afforded to industry and science, and not 

 by teaching a mere smattering in our primary or any other 

 schools. In the case of young people who from necessity must 

 leave the school-room at an early age, my own leaning is 

 towards the present system, with the addition of drawing and 

 some natural science. By it certain important lessons are taught, 

 which, if not followed under the discipline of the schoolmaster, 

 run some risk of being entirely neglected. After this, prob- 

 ably, the playground will be found more useful and much 

 more popular with school-boys than trying to learn a trade by 

 means of tools which, before he has to use them in earnest, may 

 be thrown into the scrap heap. 



As a national question the attention of the Government, 

 Imperial or municipal, ought to be directed to the import- 

 ance of establishing in all great manufacturing centres insti- 

 tutions resembling that of the Physical College of this city. 

 These should consist of appropriate and even handsome build- 

 ings, properly furnished with all the instruments and appliances 

 required for teaching the sciences in their practical bearings on 

 industrial pursuits. In Newcastle, as well as in other places, 

 this has been done on a fairly ample scale, and the advantages 

 the College of Science in this city are capable of affording are 

 offered on such terms that no one can plead expense being a 

 barrier to mental improvement. 



