528 



METALS. 



at each operation. The waste amounts to about 37 

 per cent, based on a production of 90 tons of fine 

 iron. The consumption of fuel is from 22 to 24 

 cwt. (from 1,100 to 1,200 kilogrammes). The cost of 

 production, compared with that of the ordinary fur- 

 naces, shows in favor of the new system the economy 

 of at least 32s. (40 francs) per ton. The puddling 

 process of M. Pernot is now a thoroughly practical 

 one ; it is no longer an experiment ; it is a real mode 

 of manufacture by which can be obtained with cer- 

 tainty all the different products which are expected 

 from a puddling-furnace. The advantages of the 

 new system of furnace are the following : Increase 

 in product, as no doubt can be entertained that it 

 will soon double the production as obtained now 

 with a Siemens-Martin furnace ; decrease of nearly 

 one-half in the consumption of fuel ; decrease in the 

 same proportion of the working and general ex- 

 penses, etc. ; the repairs of arches and other parts 

 of the furnace are very easily and rapidly made ; 

 and, finally, this process can be applied as easily 

 by the small producer as by the large one, doing 

 away altogther with those gigantic machines which 

 characterize the Bessemer process. A small firm 

 may have its one furnace limited to the production 

 of its wants, andalarge company may p_ut up several 

 of them. Its first cost is very small ; it requires no 

 special workmen to attend to it; it keeps itself in 

 good order ; and, although no precise estimate of 

 the cost of its production has been made, it must be 

 comparatively very small. The operation is always 

 under cpntrol and easily altered in one way or other, 

 according to circumstances, which is in itself a real 

 advantage over the Bessemer process. The homo- 

 geneousness of the steel is insured in consequence 

 of the perfect stirring produced by the rotatory mo- 

 tion, which gives it a decided superiority over the 

 Martin process ; and stirring by hand is avoided, 

 and no wire or tools are to be taken into account. 

 The process can be applied to either small or large 

 iron-works. 



Effects of Cold on Iron and Steel. Iron 

 publishes an account of a long series of experi- 

 ments on this interesting question lately made 

 by Mr. J. P. Joule, with results which appear 

 to confirm those obtained by Spence some 

 years ago. The most striking of these experi- 

 ments are described as follows: 



1. A mixture of snow and sea-salt having been 

 placed upon a table, iron and steel wires were 

 stretched in such a manner that a portion of their 

 length was engaged in the freezing mixture, while 

 the rest was free from it ; in each case the wires ex- 

 perimented upon broke outside the cold mixture, the 

 temperature of which was 12 C. 



2. Twelve needles of good quality, about 3 inches 

 long, and jV inch in diameter, were fixed firmly by 

 their two ends at two inches distance from each 

 other; a wire was then fastened by one of its ends 

 to the middle of each needle, and attached at the 

 other end to a machine for measuring the power of 

 springs. The machine was then set in action until 

 each needle broke. Six of the needles taken at haz- 

 ard were tried at the temperature of +13 C., and 

 the six others in a freezing mixture, which reduced 

 their temperature to 11 11' 0. ; in the former case, 

 five of the needles broke with forces varying from 

 1.134 to 1.842 kilogrammes, the sixth bearing 1.701 

 without breaking ; in the latter case, five broke 

 under forces varying from 1.134 to 2.041 kilo- 



frammes, while the sixth bore a strain 1.701 without 

 _ reaking. The result is curious, the lowest break- 

 ing point being identical in the two cases, while the 

 highest occurred when cold was applied. Compar- 

 ing the totals, the averages are as follows : At ordi- 

 nary temperature, 1.637; at 11 11', 1.801 kilo- 

 grammes. M. Joule had previously tried the elasti- 



city of all the needles, and could find no difference 

 between them. 



3. It having been stated that the violent action to 

 which a railway-wheel tire is exposed resembled an 

 active power rather than mere pressure, and, further, 

 that cast-iron was supposed to be more affected by 

 cold than wrought-iron or steel, M. Joule made an 

 experiment of a different kind. He procured a num- 

 ber of cast-iron nails, 1J inch long, and about 4 inch 

 diameter in the middle, and having selected those 

 of which the weights were as nearly as possible the 

 same, he arranged each nail in such a way that a 

 cutting-hammer, weighing 5J Ibs., fell from a fixed 

 height on the middle of the nail, which was sup- 

 ported at each end. In order that the test should be 

 as sure as possible, the nails were taken at hazard, 

 and the trials with the cold nails alternated witli 

 those at the ordinary temperature. The nails were 

 chilled by being plunged in a freezing mixture, and 

 were struck with the hammer within five seconds of 

 being taken out. Twelve series of these nails were 

 experimented on, each series comprising sixteen 

 nails, those which were not broken being added to 

 the following lot. The results were as follows: 

 Three series were tried at the ordinary tempera- 

 ture, being +2 22' C., the cold being increased from 

 12 22' to 16 67', and the fall of the cutting-bit 

 from twenty to thirty inches, and only one of the 

 cold nails broken. In the fourth case, the tempera- 

 tures being the same, but the fall increased to thir- 

 ty-five inches, two cold and one of the other nails 

 were broken. In the fifth experiment, the fall being 

 increased to 39i inches, one of each eight nails was 

 broken. In the sixth, the cold was increased to 

 17 78', with the same ordinary temperature, and the 

 same fall of the cutter, and one of each eight again 

 broken. In the seventh, the fall was raised to near- 

 ly forty inches, when only one of the cold mails was 

 broken. In the next two experiments, the ordinary 

 temperature was 4" 40', and artificial cold, 16 67' ; 

 when, with a fall of fifty-nine inches, two cold and 

 one other nails were broken; and, with a fall of 

 seventy-five inches, three of each. Ten of the same 

 nails were then tried at the same temperatures, with 

 a fall of eighty-five inches, when two cold and one 

 other nails were broken. The six remaining nails 

 were then tried, three at the temperature of +4 44', 

 and three at 16 11', with a fall of ninety-eight 

 inches, two only of the cold nails and three of the 

 others being broken. Finally, an experiment was 

 tried with fresh nails, twelve of which had been 

 k5pt for four hours at a temperature of 16 11', 

 the ordinary temperature being +5, and the fall 

 seventy inches, the result being the breakage of 

 seven of the frozen and eight of the other nails. 

 Total broken twenty-two of the frozen nails and 

 nineteen of the others. 



Taking the whole of the above experiments into 

 consideration, M. Joule arrives at the conclusion 

 that frost or lowering of temperature does not ren- 

 der cast-iron, wrought-iron, or steel, more liable to 

 break, and that the accidents which happen on rail- 

 ways arise from the negligence of the companies in 

 not submitting their wheels, axles, and all the other 

 parts of their rolling-stock, to practical and sufficient 

 test before using them in the service of the line. 



Silicon in Pig-iron. In a paper on the con- 

 dition in which silicon exists in pig-iron, Mr. 

 C. Handfield Morton holds that this element is 

 chemically combined with the iron, and not, .is 

 claimed by many, in a state of mechanical ad- 

 mixture. The author states that he was in- 

 duced to make a few experiments upon this 

 subject, by noticing that silica was obtained in 

 the insoluble residue when pig-iron containing 

 a large quantity of silicon was dissolved by 

 dilute sulphuric acid, in vacua, instead of sili- 



