334 THE SCIENTIFIC PAPERS OF 



paratively small consumption of coal. Inferior irons were often 

 puddled much more rapidly. 



Mr. Scatiergood said it was not white iron, but grey common 

 iron. 



Dr. Siemens, continuing, said that even then it depended very 

 much upon the constitution of that iron, upon the silicon it 

 contained, and the way in which carbon was combined with 

 iron ; but as regarded the time necessary to bring pig-metal to 

 nature, another observation which the same speaker made struck 

 him as being contrary to generally accepted views. Mr. Scattergood 

 said that less fettling was required than in the ordinary furnace, 

 because there was less surface, and he went on to say that if the 

 furnace could be constructed without any sides, no fettling would 

 be required. That perhaps was a slip only, because they all knew 

 without fettling they could not carry out the puddling process ; 

 they must have oxide of iron in order to oxidise the carbon and 

 silicon in the pig and bring it down to the condition of wrought 

 iron. He wished to make a few observations on the paper itself. 

 Mr. Smith very fairly stated that the furnace contained no 

 striking element of novelty. Of course the dandy was a well- 

 known thing ; it had often been tried in this country, and it had 

 never found favour with the men. On the Continent it was used 

 almost universally, and it produced no doubt very considerable 

 economy. Blast under the grate was used, moreover, to a very 

 large extent, and the points of novelty in the furnace before them 

 seemed to reduce themselves to the' round form of the puddling 

 chamber and the mode in which that chamber was cooled. Now, 

 with regard to the cooling of the chamber, he might observe that 

 he had once tried a similar arrangement without success. He had 

 placed under the puddling chamber an open vessel containing 

 water very similar to what had been shown, but he had had to 

 give it up very soon, because it was found that the vapour rising 

 from the water found its way through the joints into the puddling 

 chamber and affected the iron prejudicially. He should like to hear 

 Mr. Smith's observations on that point, and whether or not he 

 found any inconvenience on that score ; also with regard to the 

 inclined side of the puddling chamber, whether it had been found 

 that the side held the fettling as well as the vertical side, his 

 (Dr. Siemens's) own observation being that on the sloping side the 



