B I. A 



Tliis is replaced at lead every caft, and prevents tVie flame 

 and heated materials of the furnace from being blown 

 forward. 



/•/,;/? IX. jff. 4. is a ground plan of the arch pillars, 

 hearth, tuyeres, and vents of a Waft furnace. 



A, the hearth, or particular fpot where the fluid metal is 

 coUcfted. 



15, the dam-done. 



c, the fall, or opening, by which the metal is difcharged. 

 After the call it is filled with fand, which foon hardens and 

 prefents a very clofc texture to the fluid metal within. At 

 the following caft it is cut carefully down, till the bar pene- 

 trates to the quick. A circular incifion is then made, and 

 the metal flows out of tlie orifice in a coiuiefted round 

 llream, into the runner or channel made in the fand. 



dddcf, four vents or openings which communicate 

 with the falfe bottoms. Plate I. fg. 2. Thefe ferve to 

 convey the damp from the furnace bottom, and by being run 

 out into the external air, two in tlie front of the hearth, and 

 one at each tuyere, indicate by their temperature, and the 

 quantity of lleam or vapour which they emit, the real ftate 

 of the bottom below. 



l) 1>, the two pillars which fupport the front arch j 

 they, at the fame time, ferve as abutments to one leg 

 of each of the tuyere arches. The arch at the front is 15 feet 

 wide and 15 feet high, and inclines to the centre of the fur- 

 nace, in tlie fan^e manner as the fide walls of the pillars 

 approach. 



E, main or back pillar built entirely folid. 

 FF, vent holes (ix inches fquare, carried up from the foun- 

 dation, and brought forward to meet the open air every four 

 or five feet. 



G G G G G G, tops of the pillars covered with caft 

 iron plates, for receiving three large caft iron lintels, 10 feet 

 long, and 10 inches fquare. Thefe ferve to give folidity 

 to the arch, and fupport the lining and bodies of the 

 furnace. Fi^.S, 9, difi'erent forms of tuyere pipes. 

 lii.AS '■-Furnacf. — Hi/lory nf its Ong'in and Prngrefs. 

 In detailing the progrtfiivt hillory of the blaft furnaces, it 

 is necedarv to premife, that in tliis country it has undergone 

 a revolution, of which we meet with no fimilar inftance in 

 other countries. 



The mod natural and abimdant fuel which prefents itfelf 

 to mankind in their progrefs towards civilization, is that 

 fiu-nidied by the numerous and extenfive forells, which ge- 

 nerally occupy the furf;!ce of a wide and uncultivated coun- 

 try. Thefe, in the hidory of all nations, have been esrly 

 annoiiited to domedic ufes, and to the comfort of indivi- 

 duals. As a country became more populous, and the fpirit 

 of civilization increafcd, other advantages refulted from the 

 general ufe of wood as fuel. The amelioration of climate, 

 and the clearing of large trafts of land, inaking it fubfervi- 

 ent to the purpofes of agriculture, were not the fmallcft 

 benefits thus derived. As the progrefs of knowledge began 

 to devife and eftablifh regular manufadorics, to fupply the 

 wants of the thriving community, the fame fources of com- 

 butlion were opened to the manufacturer and the artizan. 

 Tiiefe, as they became fuccefsf\d, were only preludes to 

 other edablifhments more extenfive, more lucrative, and 

 entailing wants more difficult to lupply. Among others the 

 fmeiting of metals was no doubt ol early origin, and equally 

 dependent upon the woodland counties, in the immediate 

 neii;hbourho".d of the ores. In tliis clafs we can trace no 

 m^rtallurgical operation fo hodile to the exiftence of wood, 

 as an extenfive manufafture of iron. If this manufacture, 

 owing to the great and unexampled profperity of the coun- 

 try, iH place of remaining ftationary, or exhibiting fymptoras 



B L A 



of decline, arlfing from a want of confumptlon of the article, 

 has increafcd in capital, in extent, and riches beyond all pre- 

 cedent, wood, the bafc of the manipulation itfelf, depend- 

 ing only upon a dock rapidly declining, the exidence of 

 which was frequently incompatible with the views and in- 

 tered of the landed proprietor, mud foon have been annihi- 

 lated, and the art of making iron lod to the community. 



In this fingular fituation was Great Britain placed from 

 the reign of Charles II. to the middle of the lad cen- 

 tury. The increafing manufactures, commerce, and gene- 

 ral profperity of the country called loud for an additional 

 fupply of articles fabricated from iron, while wood, the 

 foundation of the whole art, was rapidly declining in point 

 of quantity, without the moll didant profpeft of ever being 

 again renewed. Pit coal had been long before the latter 

 period fuggeded as a fubditute, but prejudice, intereded 

 views of cdablifhed capitalids, and above all, a want of com- 

 mand of mechanical power, had prevented any fuccefsful 

 operation from being cdablifhed in this new department of 

 iron making. No founer, however, were thefe barriers to 

 improvement broken through, and a change of fuel in the 

 blad furnace found to be attended with profitable effefts, 

 than the languidiing date of the trade began to revive, and 

 improvements fucceeded each other, with a facility new and 

 adonidiiiig. In fift^' years the revolution was complete, 

 whether the confideratiou regards the incrcafe of the nianu- 

 faSure, the general ufe of pit coal in the blaft furnace, or 

 the almoft total annihilation of the charcoal mode of making 

 iron. 



It is uncertain at what period the manufaflure of iron 

 commenced in Britain. It is probable, that the working 

 of the tin mines of Cornwall, by the Phccnicians, would 

 iutrod.uGe into the country a clafs of men fl<illed in all the 

 then known metallic ores, capable of appreciating their true 

 value, by converting the riches of an unexplored country, 

 either to their own immediate neceffities, or to the conveni- 

 ences of the unflvilful inhabitants. The invailon of England 

 by the Danes, and their confequent edablifliment, wi old 

 mod likely add to the former dock of knowledge, in the 

 art of mining and fufing iron ores. Whatever truth there 

 may be in this conjefture, the faft ftands unquedioned, that 

 in feveral counties in England large heaps of Icoria are found, 

 with an accumulation of foil fufdcient to bear large trees. 

 Thefe have been from time immemorial called " Danes 

 cinders." So earlyas 1620, Dudley remarks, that large oaks 

 were then found in a ihite of decay upon the tops of fome 

 of thefe hills of fcoria. It is not, howe\er, probable, that 

 thefe cinders were the produft of the blad furnace. At a 

 period fo remote as that, wherein thefe htapsof fcoria mud 

 have been accumulated, the labours of the iron maker were 

 chiefly direftcd to the fabrication of fmall portions of malle- 

 able iron m foot llnjls and bloomer'ies . The art of moulding 

 and cading in iron was either totally unknown, or fo very 

 rude, as to excite no intered in favour of profecuting this 

 fine branch of art. If p'g or call iron was at all formed, it 

 was merely of the mod infufile nature, for being fpeedily 

 converted into malleable iron. It was not till long after- 

 wards, when improvements had taken place in the rude 

 machinery of the tjmes, and a divifion of labour feemed to 

 be produttive of many advantages, that dift"creiit furnaces 

 cxided : one for the making of pig iron, and another for 

 the converfion of it into malleable iron. This firll gave rife 

 to the blaft furnace, which, properly fpeakinjr, was an im- 

 provement refulting from the knowledge of the advantages 

 derived from a divifion of labour. After the appropriation 

 of the blaft furnace to the exclufive manufafturc of pig iron, 

 the manufaciurer would foon difcover, tliat the produdts of 



hi? 



