932 IRON 



composition is a titantite of protoxide of iron and magnesia in variable proportions, 

 with peroxide of iron or magnetite ; its value as an iron ore depends upon the pre- 

 dominance of the latter components. Titaniferous ores, when not containing more 

 than 8 per cent, of titanium, may be treated advantageously, as they yield good iron 

 from the absence of sulphur and phosphorus ; but with larger proportion of titanium 

 they become too refractory, and require too much flux to be smelted alone, the propor- 

 tion of fuel required being greatly increased. 



History of Iron- Smelting. There is abundance of evidence that iron was well known 

 in the early ages, and was applied to various useful purposes. The earliest method of 

 working the furnace where ores were smelted seems to have been by exposing them to the 

 wind : the furnaces, perforated with holes, were built on eminences, and could only be 

 worked when there was a strong breeze ; the fire was regulated by opening and shutting 

 the apertures. Mungo Park gives, in his 'Travels in Africa,' the following interesting 

 account of an iron-smelting operation in Kamalia, at which he himself assisted : ' The 

 ironstone was broken into pieces the size of a hen's egg ; a bundle of dry wood was first 

 put into the furnace, and covered with a considerable quantity of charcoal ; over this 

 was laid a "stratum of ironstone, and then another of charcoal, and so on until the fur- 

 nace was quite full. The furnace was a circular tower of clay, about 10 feet in height 

 and 3 in diameter, surrounded in two places with withes, to prevent the clay from 

 cracking and falling to pieces by the violence of the heat. Bound the lower part, on a 

 level with the ground, but not so low as the bottom of the furnace, which was somewhat 

 concave, were made seven openings, into each of which were placed three tubes of clay, 

 and the openings again plastered up in such a manner that no air could enter the fur- 

 nace but through the tubes, by the opening and shutting of which the fire was regulated. 

 The fire was applied through one of the tubes, and blown for some time with bellows 

 made of goat's skin. The operation went on very slowly at first, and it was some hours 

 before the flame appeared above the furnace ; but after this it burnt with great violence 

 all the first night, and the people who attended put in at times more charcoal. On 

 the day following the fire was not so fierce, and on the second night some of the tubes 

 were withdrawn, and the air allowed to have free access to the furnace ; but the heat 

 was still very great, and a bluish flame rose some feet above the top of the furnace. 

 On the third day from the commencement of the operation all the tubes were taken 

 out, the ends of many of them being vitrified with the heat, but the metal was 

 not removed until some days afterwards, when the whole was perfectly cool ; part 

 of the furnace was then taken down, and the iron appeared in the form of a large 

 irregular mass, with pieces of charcoal adhering to it. It was sonorous, and when 

 any portion was broken off, the fracture exhibited a granulated appearance like broken 

 steel.' 



That the iron ores of Monmouthshire and Gloucestershire were extensively worked 

 by the Komans during the period of their reign in Britain is certain, from the immense 

 beds of iron cinders that have been discovered in the Forest of Dean ; it is probable 

 that Bath was the principal seat of their foundries; 'relics of their operations, in the 

 form of cinders and coins, have likewise been discovered in Yorkshire and in other 

 counties. During the reign of William the Conqueror, Gloucester was the city where 

 the trade of forging iron was chiefly carried on, the Forest of Dean supplying the 

 ores. It is uncertain when the art of casting wns first discovered ; cannon are 

 supposed to have been first used in England by Edward III., who used them in 

 his invasion of Scotland in 1327, at Cressy, and at the siege of Calais in 1346. 

 These cannons were not, however, cast, but were constructed on the same prin- 

 ciples as coopers construct their barrels ; a number of iron bars, fitting as close as 

 possible to each other, were arranged round a cylinder of wood, and were then bound 

 together by strong iron hoops ; the wood being driven out, there remained an iron 

 pipe which formed the barrel. This mode was superseded by casting the cannon of 

 bronze. 



During the 14th and 15th centuries, iron and steel were imported into this country 

 from Germany, Prussia, and other places, and also iron from Spain ; but as several 

 improvements in the manufacture has taken place in the course of this period in 

 England, laws were made towards the conclusion of the 15th century, prohibiting the 

 importation of any of the articles manufactured in this country in iron and steel. 

 During the reign of Elizabeth, the consumption of charcoal by the iron furnaces was 

 so great, that it was deemed necessary to enact laws to prohibit the erection of new 

 furnaces, and to prevent the felling of timber for fuel ; persons interested in the 

 manufacture of iron were consequently compelled to turn their attention to the finding 

 of some substitute for charcoal, and in the reign of James I. and Charles I. many 

 attempts were made to smelt iron with pit-coal, but without success ; the consequence 

 was the entire abandonment of iron-making in many pnrts of the couutry, and a great 



