Passing to manufactures,we find here the all-prominent fact to be the substitution of the factory for the domestic system,the consequence of the mechanical discoveries of the time.Four great inventions altered the character of the cotton manufacture;the spinning-jenny,patented by Hargreaves in 1770;the waterframe,invented by Arkwright the year before;Crompton's mule introduced in 1779,and the self-acting mule,first invented by Kelly in 1792,but not brought into use till Roberts improved it in 1825.None of these by themselves would have revolutionised the industry.But in 1769-the year in which Napoleon and Wellington were born-James Watt took out his patent for the steam-engine.Sixteen years later it was applied to the cotton manufacture.In 1785Boulton and Watt made an engine for a cotton-mill at Papplewick in Notts,and in the same year Arkwright's patent expired.These two facts taken together mark the introduction of the factory system.But the most famous invention of all,and the most fatal to domestic industry,the power-loom,though also patented by Cartwright in 1785,did not come into use for several years,and till the power-loom was introduced the workman was hardly injured.At first,in fact,machinery raised the wages of spinners and weavers owing to the great prosperity it brought to the trade.In fifteen years the cotton trade trebled itself;from 1788to 1803has been called its 'golden age".for,before the power-loom but after the introduction of the mule and other mechanical improvements by which for the first time yarn sufficiently fine for muslin and a variety of other fabrics was spun,the demand became such that 'old barns,cart-houses,out-buildings of all deions were repaired,windows broke through the old blank walls,and all fitted up for loom-shops;new weavers'cottages with loom-shops arose in every direction,every family bringing home weekly from 40to 12O shillings per week.'At a later date,the condition of the workman was very different.Meanwhile,the iron industry had been equally revolutionised by the invention of smelting by pit-coal brought into use between 1740and 1750,and by the application in 1788of the steam-engine to blast furnaces.In the eight years which followed this later date,the amount of iron manufactured nearly doubled itself.