On the Origin of the Blast Furnace. 407 



enveloped in the slags, specimens of iron in a malleable state 

 tliough rarely, more frequently rough nodules of large-grained 

 steel, resembling blistered steel, and others of a more dense 

 fracture, but of a similar quality. The more fusible reguh of 

 white mottled and gray iron are found in great abundance, all 

 of them possessing forms and appearances of fusion more or 

 less perfect, according to the quantities of carbon with which 

 they are luiited ; and it is but justice to the memory of the 

 Hither of this art to add, that the specimens of gray cast iron 

 are more abundant than those of the other sorts. 



Tliis furnace seems to have been erected upon the spoils of 

 former ages of iron-making, and probably the situation was in 

 the first instance determined by the numerous bloomeries that 

 existed in the neighbourhood; the scoria of which has in after 

 ages been worked to so much advantage in the blast furnace ; 

 and though, as a blastfurnace, possessed of no great antiquity, 

 yet, as the site of the ancient bloomery, entitled to be consi- 

 ilered as the remains of an extensi^■e manufactory of iron in 

 ages more remote. 



Upon the whole, several circumstances incline me to the 

 opinion, that the blast furnace must have been known in some 

 of the then iron-making districts of England, before it was in- 

 troduced into Dean Forest. I saw an account some years 

 ago, to which I cannot now refer, that in the reign of Queen 

 Elizabeth, cannon and mortars of various sizes, and in con- 

 siderable quantities, were made of cast iron, and exported from 

 England to the continent ; which could hardly have been the 

 case, had the invention of the blast furnace, with all its imper- 

 I'ections upon its head, taken place about the beginning of that 

 leign. The oldest casting I have met with in Dean Forest is 

 dated 1620. 



The great infusibility and difficulty attending the manage- 

 inent of calcareous ores, such as those belonging to Dean 

 I'orest, is another circumstance that inclines me to think that 

 the art ol" making pig-iron did not originate in tliat quarter; 

 and probably did not succeed entirely till the practice of in- 

 creasing their fusibility by the addition of the bloomery cinder 

 became known and established. These conjectures are con- 

 firmed by reference to a paper in my possession, professing 

 to be an account of all the blast furnaces in EnglantI previous 

 to the n)anufacture of pig-iron from pit coal ; probably about 

 the year 1720 or 1730: in which, however, the blast furnace of 

 Tintcrn Abbey is omitted, and possibly others. At that pe- 

 riod there were in all England 59 furnaces, making annually 

 17, .'''.'JO tons, or little more than five tons of pig-iron a week 

 for each fiuiiace. This paper I shall subjoin in detail : ami 



juy 



