38 



NATURE 



\_May 13, 18S0 



publishes. " In the softer qualities for plates, wire, &c., 

 it is at times astonishing what results are obtained. With 

 37 to 40 kilogrammes of actual breaking weight, as much 

 as 70 per cent., and in some cases even 75 per cent, of 

 contraction has been reached. At the same time this 

 ingot iron can take very high heats, forging and rolling 

 without a flaw. The production of this especial quality is 

 so simple, the cheapness of the raw material, the certainty 

 in working, its softness, and its ductility, all point to its 

 driving at no very distant date puddled iron plates out of 

 the market. For wire even of the smallest gauges it has 

 been declared better than that drawn from billets puddled 

 from charcoal pig." 



This is an extremely good result to have attained in the 

 short space of less than a year, and gives good ground 

 for the hope of further improvement in the future. The 

 manufacturers do not appear as yet to have quite succeeded 

 in producing a hard steel by this process. 



The remainder of Mr. Pink's paper contains an account 

 of very similar difficulties experienced and overcome to 

 those described by Messrs. Holland and Cooper. 



A paper of considerable practical interest was read by 

 Mr. Henry Simon, C.E., of Manchester," On an improved 

 System for the Utilisation of Bye-Products in the Manu- 

 facture of Coke." It is well known that in the manu- 

 facture of gas for lighting purposes the sale of the bye- 

 products, such as tar and ammoniacal liquor, which are 

 obtained during the distillation of the coal, is one of the 

 chief sources of profit. In the manufacture of coke it has 

 hitherto been the practice in this country to allow the tar 

 and ammoniacal liquor to run to waste. Such a course 

 not only causes waste, but increases the great nuisance of 

 coke ovens to the neighbourhood in which they are 

 planted. The extent of the waste may be inferred when 

 it is stated that at Manchester the gas-works obtain 

 Z%s. per ton for tar, and froin 20^-. to 25^-. per ton for their 

 ammoniacal liquor ; and it has been found at Besseges, in 

 France, where the bye-products are saved, that every ton 

 of coke obtained gives nearly 3 cuts, of ammoniacal 

 liquor, and 72i lbs. of tar, worth together, at Manchester 

 prices, about 4^-. bd. per ton of coke produced. 



In this country over 7,000,000 tons of coke a year are 

 produced for the manufacture of pig-iron alone, the value 

 of the bye-products of which is about 1,350,000/., a sum 

 which is annually lost to the nation. The demand for 

 the ammoniacal liquor, both for agricultural purposes and 

 for the manufacture of soda, is practically unlimited. As 

 an instance of the truth of this statement it may be 

 mentioned that one firm of soda-manufacturers, viz., 

 Messrs. Solway, have contracted for the whole production 

 of the Besseges Works, and transport it 300 miles by rail 

 to their factory near Nancy. 



By the new method of production nearly the whole of 

 the noxious effect of the ol 1 " beehive " coking ovens is 

 done away with. So great are these ill-effects that in the 

 words of the Royal Commission on no.xious vapours, 

 which sat in 1S77, " all vegetation near coke ovens, con- 

 ducted on the older methods, suffers severely. The 

 growth of trees is checked or destroyed, fences are killed, 

 crops of every description are injured, cattle suffer, and 

 upon inany occasions the effect of the vapours emitted by 

 coke ovens is terrible." In the counties of Durham and 

 Northumberland alone 6,000,000 tons of coal are annually 

 colced, and in the process give off 2,000,000 tons of 

 vapours, which consist in great part of the valuable tars 

 and nitrogenous compounds which might so easily be 

 saved. The quantity of sulphurous acids which escape 

 into the atmosphere every year in these districts is esti- 

 mated to be about 70,000 tons. 



In the process described by Mr. Simon "the coal is 

 rapidly carbonised by subjecting a comparatively thin 

 layer of it to a high temperature in a closed and retort- 

 like vessel, and whilst in the beehive ovens the volatile 

 products are burned inside, we burn them around the out- 



side of this retort-like vessel, and only after they are 

 deprived of the tar and ammoniacal liquor." Besides 

 saving these products, the heat of the hot gases is utilised 

 greatly for the production of steam. At Besseges about 

 45 pounds of water is evaporated into steam of \\ atmo- 

 spheres pressure per hour and per ton of coal coked ; and 

 it is said that under more favourable circumstances 59 

 pounds might be evaporated. The remainder of the 

 paper contains a technical description of the new appa- 

 ratus, the advantages of which are stated to be as 

 follows : — 



" I. Greater yield of coke by about 10 per cent. 



" 2. Greater purity of coke. 



" 3. A yield of about \s. worth of useful bye-products 

 per ton of coke. 



"4. An almost entire absence of smoke or noxious 

 vapours. 



" 5. In comparison with any other existing system of 

 coke ovens, equal facilities for utilising the heat, and a 

 reduced cost for repairs." 



Messrs. John Parry and Alexander Tucker read a joint 

 paper "On the Application of the Spectroscope to the 

 Analysis of Iron and Steel." They cominenced by 

 noticing that the analysis of iron and steel is usually 

 summed up in percentages of iron, manganese, carbon, 

 silicon, sulphur, and phosphorus, and perhaps copper, 

 nickel, and cobalt, and suggested that other elements 

 might also be at work, and that we ought not to remain 

 satisfied with percentages of the above substances till we 

 have proved the absence of others. It has, however, 

 been found extremely difficult to prove the absence of the 

 rarer elements, partly because the traces of these latter 

 are apt to accompany the large mass of iron throughout 

 the chemical processes. Under these circumstances it 

 was thought that the spectroscope, which has done so 

 much good work in other departments of chemistry, might 

 be usefully employe^. 



"Theoretically a well-focussed photographed spec- 

 trum of a steel should be an unerring index to its 

 composition ; this is partly true in practice, but it is not 

 in our experience absolutely so." ''We have found the 

 spectra of pure iron, Bessemer steel, tool steel, chrome 

 steel, Siemens' steel, and pig iron to be decidedly dif- 

 ferent, and the differences would be characteristic, but 

 they failed to show the presence of bodies which further 

 experiment proved to exist." "There are several reasons 

 why this should be the case. 



" I. The number of lines due to iron is so great (100- 

 130) that they overlap in the small spectra the lines due 

 to other bodies, and our apparatus does not readily allow 

 of images larger than one or two inches being taken. 



"2. The intensity of light due to the traces of bodies 

 may not be sufficient to record lines on the plate. 



" 3. Because of the variation in the volatility of the 

 elements, and therefore the necessity of variation in the 

 intensity of the spark." 



The authors therefore thought it important 'either to 

 separate the iron or considerably lower its percentage, and 

 the solution of this problem was their principal aim. The 

 results of their experiments have led them to believe that 

 as a rule the quantity of iron is much over-estimated. In 

 confirmation of this opinion they also quote the fact that 

 iron and steel are capable of absorbing twenty titnes their 

 volume of hydrogen, a quantity which is always omitted 

 in ordinary analysis, " which is probably due to the fact 

 that a steel saturated with hydrogen must be less liable to 

 oxidation in the heating furnace than one containing little 

 or none. In order to eliminate the iron a method of 

 digestion with various solvents was adopted. By this 

 process much larger quantities can be operated on at a 

 time than by the ordinary methods of precipitation. As 

 much as 7,000 grains of Bessemer steel were dissolved in 

 aqua regia. The solution was evaporated and heated in 

 a paraffin bath till the acids were driven off. Ammonia 



