306 THE SCIENTIFIC PAPERS OP 



the ore contained copper, the iron would contain it no doubt also ; 

 but in the particular instance referred to, the presence of copper 

 was accounted for by a previous charge which was made with ore 

 containing about a half per cent, of copper, and some of the 

 charge having remained attached to the sides of the furnace, it 

 worked into the succeeding charge. Some other speakers had 

 spoken with regard to the effect of copper on iron, and he could 

 fully confirm the observations made by Mr. Fothergill, that a very 

 small percentage of copper entirely prevented the iron from 

 coming together ; instead of forming balls, it remained separate, 

 and would not hold together. Dr. "Wright was the first speaker 

 to touch upon the fuel question, which question had been very 

 fully taken up by the President, and carried somewhat against the 

 conclusions arrived at by himself. Now, with regard to that 

 question, he wished to explain his views concisely, but more fully 

 than he had done in the paper. He must say that the furnace in 

 Birmingham was no criterion with regard to the economy of the 

 process, because that furnace was of comparatively small dimen- 

 sions, and was erected simply for the sake of experiments, the 

 object being to see the effect produced on the lining by different 

 treatment, and on the quality of the iron produced by various 

 mixtures and fluxes. Lately, he put in a lining which had not 

 been baked beforehand, and the result was that the balls would 

 not hang well together ; the bauxite came off in small filaments 

 from the lining, and acted, as he might say, like soap between the 

 nodules of iron, preventing their cohesion. That difficulty was 

 removed after exposing the lining to two days' intense heat, and 

 now the results were better, as might be seen by the two balls sent 

 up, which were then in the yard at the back of the building, and 

 had been produced in that little furnace. They were balls of 

 nearly 600 Ibs. each from charges of a thousand pounds ; one of 

 blackband and the other of Acadian ore. The normal way of 

 working the rotary furnace was as follows : The furnace was 

 charged with say a ton of pulverized ore, and the slow rotation 

 went on until the mass was heated through and through to full 

 redness. Then the carbon was introduced and mixed with the 

 charge in giving a rapid rotation to the apparatus. The conse- 

 quence was that reaction and fusion set in immediately, and it 

 was very important that at that point the action should be very 



