80 Dr Colquhoun on the Argillaceous Ore of Iron. 



very extensive ; for even a single blast-furnace consumes an 

 enormously large quantity of fuel, and would require there- 

 fore a considerable extent of forest-surface to maintain it in re- 

 gular action. Many attempts were made in England, as early 

 as the beginning of the seventeenth century, to substitute the 

 coke of pitcoal in the blast furnace for wood charcoal ; but 

 they all appear to have failed in succession, partly, no doubt, 

 owing to the strong prejudice which prevailed against the in- 

 troduction of a novel mode of manufacture, but in a much 

 greater measure from the very different management which it 

 demanded, and which at that period was necessarily very little 

 understood. The manifest importance, however, of render- 

 ing available to the purposes of the blast-furnace a material 

 which could be supplied to an almost unlimited extent, was a 

 sufficient stimulus to incite the iron manufacturer to persevere 

 in the investigation, in spite of the opposition of prejudice, and 

 even of the discouragement of practical difficulties. The pro- 

 perties of coke became by degrees more accurately known, and 

 the alterations which its use rendered necessary in the form, 

 and in the management of the blast-furnace, were thereby ap- 

 preciated. And to such perfection has the process of manu- 

 facturing iron by the coke cf pitcoal now been carried, that 

 this mineral has not only almost entirely superseded the em- 

 ployment of wood, but it has been the means of advancing the 

 manufacture itself in this country, to an extent which is un- 

 paralleled in the history of any other age or nation. It has 

 now been ascertained by long experience, that there is no other 

 fuel which is so well fitted, at once to supply the heat of the 

 furnace, and at the same time to endure the powerful blast 

 which is incessantly forced upon it. It may now be said to be 

 essential to our iron manufacture, which would indeed be al- 

 most annihilated, were the supply of it withdrawn. How 

 great a source of admiration and gratitude must it always be, 

 to regard the immense profusion in which this invaluable mine- 

 ral discloses itself, and the intimate connexion and neighbour- 

 hood which subsist between it, and the ore of iron. How im- 

 portant are its inexhaustible treasures to the country, which 

 must otherwise have been compelled either to relinquish the 

 manufacture of iron, or to lay under wood immense tracts of 



