Mechanics. 359 



When we considered the utility of iron, its low price, and its 

 general distribution in the deposits of every age, we could 

 not but look upon it otherwise than as the great agent in 

 modern civilisation. Mr Budd then referred to his mode of 

 applying the gaseous escape, and said it was well known that 

 there were two descriptions of furnaces used for metallurgic 

 purposes. The one was the blast furnace, into which air was 

 injected by mechanical means at a great density, so as to 

 penetrate upwards of 40 feet of dense materials ; and the 

 other was the reverbatory furnace, where the fire was pro- 

 duced by means of the draft of a chimney stack. What he had 

 accomplished was by combining these two so that the gaseous 

 products of the furnace, instead of escaping through the tunnel 

 head, were drawn sideways by a high stack, and passing 

 through the stoves and boilers, leave behind the necessary tem- 

 perature of the blast and of the steam. In a blast furnace the 

 ores are smelted before the tuylres by the conversion of the 

 solid carbon into carbonic acid, which, passing up through 

 the middle region of the furnace into a bath of carbon, was 

 reconverted into carbonic oxide, capable of combining with a 

 farther dose of oxygen. It would be thus seen that the whole 

 of the carbon of the fuel should be present at the top of the 

 furnace in a gaseous form. When the British Association 

 met at Swansea, he had not used the gaseous escape at any 

 great distance from the furnace, his stoves and boilers being 

 very closely contiguous. Further experience, however, had 

 proved that by the aid of a stack at the end of the chain of 

 sufficient dimensions, the gaseous escape from the furnace 

 might be made to travel in the most tortuous directions, 

 descending to the stoves built for heating by the usual fire- 

 places, and traversing the boilers ; the only condition abso- 

 lutely necessary being that there should be an unbroken 

 communication with the high stack at the end, into which the 

 gaseous escape might at last pass, and by which it was drawn 

 forward, instead of passing off wastefuUy at the tunnel-head. 

 When, however, the draft was carried downward, and to long 

 distances, he had found it necessary to drop into the top of 

 the furnace a liopper or funnel, ma^le of sheet-iron, which 



