190 History of Inland Transport 



of Dean, while the Severn provided water-power and inland 

 navigation. The industry was also carried on in Staffordshire ; 

 and here, in the reign of James I., some important experi- 

 ments were made in the direction of using coal instead of 

 wood in the manufacture of iron ; but this idea was not fully 

 developed until Abraham Darby had shown, in 1735, how 

 coke, in combination with a powerful blast, could be sub- 

 stituted for wood. What is regarded as the real turning- 

 point in the iron industry followed in 1760, when Dr Roebuck 

 built, at the Carron works, his new type of blast furnace, in 

 which coke was to be used. 



An impetus was thus given to the industry, and an impetus 

 it certainly needed, inasmuch as the production of iron in 

 the United Kingdom had sunk in 1740 to 17,350 tons. Then, 

 in 1783, Henry Cort, of Gosport, patented his process for 

 converting pig-iron into malleable iron through the operation 

 of " puddling " in a common air-furnace consuming coal, and 

 in 1784 he patented a further process for turning malleable 

 iron into bars by means of rollers instead of forge hammers. 



These further inventions were of much service ; but the 

 greatest advance of all followed on the application of steam 

 to iron-making, as one of the many results of James Watt's 

 achievements. Steam enabled the manufacturers to get a 

 far more powerful blast in the new furnaces, at a consump- 

 tion of about one-third less of coal, than had been possible 

 in the process of smelting carried on with the help of water- 

 power. The use, also, of coal instead of timber for fuel, 

 and of steam-power in place of water-power, made the iron- 

 masters independent both of the forests and of the rivers of 

 southern England, and led to the further expansion of the 

 iron industry being transferred to such districts as Stafford- 

 shire, the north-east coast, Scotland and South Wales, where 

 the now all-important coal could be obtained no less readily 

 than the iron-ore. 



So the migration of some of the greatest of our national 

 industries from south to north, begun by the streams on 

 Yorkshire hills, was completed by the steam-engine of James 

 Watt. 



The effect on the iron industry itself of the improvements 

 in manufacturel^was prodigious. The 1 7, 3 5 o^" tons of iron 

 which^were alone produced in 1740 came from 59 furnaces, 



