981 



IRON MANUFACTURE AND TRADE. 



IRON MANUFACTURE AND TRADE. 



f!83 



iron from the slag of their old charcoal smelt-works, in a furnace sug- 

 gested by Sefstrom in 1821. At Liege slag is mixed with-the poorer 

 ores, and smelted. The Silesian slag has been utilised since 1855, by 

 mixing it with a certain per-centage of argillaceous schist and limestone. 

 The same thing is done in Austria. The slag of the Dean Forest Works 

 used to be made into a peculiar kind of black bottles at Bristol. 

 Numerous processes have been patented in England within the last 

 few years for rendering the slag useful, generally by mixing it with 

 lime or limestone. Dr. Percy has recently observed : " An immense 

 quantity of iron slag, far richer than many iron ores, is annually 

 thrown away. It may be that the presence of phosphorus in sensible 

 quantity is one of the causes which prevent the re-smelting of this slag 

 with advantage. This fact has not yet sufficiently attracted the atten- 

 tion of those engaged in the manufacture of iron. The discovery of a 

 method of extracting economically good iron from these rich slags 

 would be of great advantage to the country, and could not fail amply 

 to reward its author." Among the term million ton of slag supposed 

 to be annually produced in this country, many specimens are very 

 beautiful when cast into moulds, looking like marble and serpentine 

 when polished. Hence (have arisen certain plans of utilisation, irre- 

 spective of the re-smelting for the sake of the metal. But there are 

 drawbacks. If exposed to the air, the -slag becomes oxidised and 

 rusted ; if not well annealed, it becomes friable ; if in every way well 

 prepared, it takes BO much labour and fuel to work it that it ceases to 

 be a commercially profitable material. 



The third subject, the utilisation of waste heat, was taken up a few 

 years ago by the Ebbw Vale Iron Company of South Wales. After a 

 furnace hag performed the work for which it is intended, various gases 

 escape with the smoke, at the upper orifice ; and these gases carry 

 with them a large amount of valuable heat. If the heat could be 

 abstracted and usefully applied, without lessening the power of the 

 furnace, an economical benefit would result. The above-named com- 

 pany had eleven blast-furnaces, five engines to produce the blast, and 

 twenty-five boilers to supply the engines with steam. The greater 

 number of these boilers were wholly heated by the waste heat from 

 the blast-furnaces ; and various ovens and stoves in the works were 

 heated by similar means. The heated gases were arrested near the top 

 of the furnace, carried out by a horizontal tube, mixed with atmo- 

 spheric air admitted in thin sheets or layers, and ignited by a small 

 fire. It formed a true gas-light; and this gasUight heated a large flue, 

 which was surrounded by a boiler containing water ; and thus was a 

 supply of steam obtained. These operations at Ebbw Vale depended 

 on the combustion of the furnace gases ; and the Ystalyfera Works 

 modified the process by mixing the gases more thoroughly with atmo- 

 spheric air. At the iron-works generally, however, it is considered that 

 there are disadvantages which counterbalance the supposed saving; and 

 neither plan has yet been very extensively acted on. 



Iron Trade. The expansion of the iron trade is one of the most 

 remarkable things in the history of our national industry. When 

 charcoal was used for fuel ; when there were no steam-engines to force 

 in a blast ; when the air employed for the blast was cold ; and when there 

 were neither rolling-mills nor shingling-hammers, a large production 

 was impossible. Nor was there such a demand as would make even 

 an approach to th.it which now exists ; for iron bridges, iron ships, iron 

 houses, iron roads, iron pontoons, iron cables, iron articles from ' Great 

 Easterns' down to shirt-buttons are things of the present. It is 

 supposed that in 1740, the produce of iron in Great Britain was about 

 17,000 tons. In 1750, a bill was brought into parliament, in the 

 interest of iron-purchasers, for the importation of iron from the Ame- 

 rican colonies. This was opposed by the tannert, on grounds not very 

 easy to guess d priori, but curiously illustrative of the spirit of protec- 

 tion. If, it was argued, colonial iron be admitted, English iron masters 

 would be undersold ; if so, some would be ruined and others would leave 

 the trade ; if so, many of the furnaces and forges would be put out of 

 blast ; if so, less wood would be used for fuel ; if so, there would be 

 less oak -bark in the market ; and if so, the tanners might suffer from a 

 deficiency of tan-material. Later in the century, however, when im- 

 provements and new appliances were numerous, it mattered little 

 whether colonial iron was imported or not; seeing that the home 

 produce would supply all demands. By 1788, the produce reached 

 68,000 tons; the weekly produce from the blast-furnaces averaged 

 about 20 tons each. By 1796, the produce was 125,000 tons, and the 

 weekly average per furnace 27 tons (taking the celebrated Dowlais 

 worts as an exemplar). Approximate estimates made at different 

 tunes, set down the quantities of pig-iron made at 250,000 tons in 1806, 

 400,000 tons in 1820, and 690,000 tons in 1827; the average produce 

 per furnace being raised in those same years to about 42, 62, and 70 

 tons per week, partly by the adoption of larger dimensions in the 

 furnaces themselves, and partly by improved processes. 



The introduction of the hot blast by Mr. Neilson in 1829 was 

 shortly followed by a very remarkable extension of the manufacture. 

 , r,<lure of 1838 was about 1,000,000 tons, and the weekly average 

 per furnace about 85 tons. The year 1839 was the first for which any 

 trustworthy statistics were obtained, the estimates fur previous years 

 having been little more than guesses. Mr. Mushet, for that year, set 

 d'.wn the number of blast-furnaces at 430, of which 377 were at work, 

 producing about 1,250,00(1 tons in all. Of the furnaces in blast, 135 

 > in Wales, 188 in England, and 64 in Scotland ; Wales had the 



largest yield per furnace, but England the largest total yield. Soon 

 after this period the Scotch manufacturers made such an enormous 

 extension of the trade, that they quite glutted the market. The large 

 profits led to the building of new furnaces ; the discovery of blackband 

 in the Airdrie district increased the available store of cheap raw 

 material ; the hot-blast effected a saving in the coking of the fuel ; 

 and the Scotch banking system led to the advance of capital almost to a 

 reckless extent. Hence the produce of pig-iron in Scotland, which had 

 been only 37,000 tons in 1830, rose to 197,000 tons in 1839, and 

 276,000 in 1843. It was especially in 1841 that the Scotch makers 

 glutted the market, at a time when the demand was not brisk ; Stafford- 

 shire and South Wales suffered severely, for they could not manu- 

 facture at a profit, at the prices established by the Airdrie masters. 

 The railway mania of 1844-5, however, revived the trade ; the com- 

 panies not only took all fhe railway-bars available, but called for so 

 enormous a quantity that new furnaces were needed to supply it. In 

 1845. Scotland alone made 470,000 tons of iron, of which no less than 

 234,000 were shipped at the Clyde for England and elsewhere ; in 1846 

 these numbers rose to 522,000 and 277,000 .tons .respectively. Advan- 

 cing to the year of the Great Exhibition, we find that Scotland produced 

 in 1851 the vast quantity of 803,000 tons; which was increased to 

 840,000 in 1853. It had by this time been discoTered that Scotland 

 could make raw or pig-iron at a cost only a little exceeding 21. per 

 ton ; from 1848- to 1853, the market price varied from 21. to SI. ; 

 many of the furnaces being thrown out of blast in the season when 

 the market price only reached, or barely reached, the cost of produc- 

 tion. Bar-iron fluctuated much more considerably ; for it differs more 

 in quality, and has had a larger amount of labour bestowed upon it, 

 than pig or crude iron ; it was sometimes as low as 51. per ton, some- 

 times as high as 101. Mr. Braithwaite Poole gave an estimate of the 

 iron produce of 1852, for the whole kingdom ; from which it appears 

 that there were 497 furnaces in blast, 158 out of blast, and nearly 

 2,700,000 tons of iron produced of which England produced 1,190,000, 

 Scotland, 775,000, and Wales 716,000. The authority for this estimate 

 was, however, not given ; and so far as Scotland is concerned, it falls short 

 of one given by Mr. Scrivenor. ' 



The most trustworthy statistics of the iron trade of Great Britain, 

 and the latest available in date, are probably those of Mr. Truran, 

 published in his volume on the ' Iron Manufacture.' This engineer 

 was manager of Guest's vast establishment at Dowlais, and afterwards 

 of Crawshay's at Hirwain ; and consequently had the best means of 

 acquiring a practical knowledge of the whole subject. His figures 

 refer to 1855. He gives the name of every iron-work in Great Britain ; 

 the number of blast-furnaces at each ; the weekly power of production 

 at each furnace; and the aggregate power of produce in the year. 

 Avoiding all the minute detail, some of the more geneftl results may 

 be given here, dividing the island into districts for facility of com- 

 parison : 



District. 

 South Wales . 

 South Wales (anthracite) 

 North Wales . 

 Dean Forest . . 

 Lancashire (charcoal) 

 South Staffordshire . 

 North Staffordshire , 

 Derbyshire . 

 Shropshire . 

 South and West Yorkshire 

 North Yorkshire and Durham 

 Scotland . 



These figures present much which is worthy of notice. The total 

 producing power in 1855 was about 4,400,000 tons, made in 746 blast 

 furnaces at 227 iron works ; presenting an average weekly producing 

 power of 113 tons per furnace. The shares of produce were, in round 

 numbers, England 2,080,000; Wales 1,240,000; Scotland 1,080,000. 

 In the South Wales district, the great Dowlais Works alone figure for 

 18 blast furnaces and a produce of 108,000 tons. The South Stafford- 

 shire district hail numerous works, but none very large, the highest 

 comprising five furnaces; the weekly yield varied from 80 to 150 tons 

 per furnace. The Scotch works comprised many of large extent, such 

 as the Gartsherrie with 16 furnaces, and the Dundyvan and Monkland 

 with 9 each ; the produce was very high, for none of the furnaces 

 figured for less per week than 120 tons, and the average rose to 145. 

 The most surprising advance, between 1839 and 1855, had been made 

 in the Tees district, or Durham and North Yorkshire, owing to the 

 discovery of ironstone in the Cleveland hills. This district had only 

 5 furnaces, of 50 tons weekly yield each, in 1839 ; whereas it had 79 

 furnaces, of 132 tons yield, in 1856. The largest or most powerful 

 furnaces were in Monmouthshire (belonging to the so-called South 

 Wales iron district), where some of them had a yield of more than 

 200 tons per week. 



Mr. Truran was careful to state that the above were the producing 

 poweri of all our iron works, if all the furnaces had been in full blast 

 throughout the whole year. But this is never the case ; there aro 

 always many furnaces out of blast, and many periods of slackened 



