406 INDUSTRIAL INSTITUTIONS. 



are thus freed from the adherent syrup and left dry. Wet 

 clothes put into such a drum are made by its rotation to part 

 with nearly all their water, and come out merely damp. 

 And now, by the same method, the more liquid part of milk 

 is separated from the less liquid part the cream. 



In such cases the new process, which facilitates processes 

 previously used, is separate from them; but in other cases 

 the new process is so integrated with preceding processes as 

 to form a continuous process. Here, for instance, is an 

 appliance for raising to a high temperature a great body of 

 air passing through it. At one end is a steam-engine work 

 ing a force-pump which sends in this air, and at the other 

 end is a twyre or blower, which conducts the powerful stream 

 of hot air into a blast furnace : thus raising the intensity of 

 the smelting action above that produced by cold air, and 

 increasing the out-put of molten iron. And now there has 

 come a further stage. Instead of a separate and subsequent 

 process of puddling (changing cast-iron into wr ought-iron), 

 there has been made an arrangement such that the molten 

 iron flows from the blast-furnace direct into a puddling- 

 furnace, or a furnace which effects the like change; and so 

 there is saved all the coal previously expended in re-heating 

 pig-iron. Here then three sets of appliances are united into 

 one set. 



But advance in the cooperation of appliances is best seen 

 in the development of mechanism. At first &quot; the mechanical 

 powers,&quot; as they are called lever, inclined plane, wedge, 

 screw, wheel-and-axle, pulley were used only separately; 

 but in course of time there arose, by combinations of them, 

 what we distinguish as machines. For a machine say a 

 water-mill, a loom, a steam-engine, a printing press com 

 bines these various mechanical powers in special ways for 

 special purposes. Comparison of early machines with lato 

 machines shows that, by increases in complexity, they have 

 been adjusted to increasingly complex acts of production. 



A further stage, characteristic of modern days, is to be 



