96 



Further experiments made at Milton Iron Works : — 



COLD BLAST. 



No. 13 — Bar of refined iron 2\ inches diameter, heated red and 

 hammered till cold, nicked ^ of an inch all round. One blow 

 broke it square off ; fracture quite crystalized. 



No. 14. — The same end of the last described bar, cold ham- 

 mered, nicked ^ deep, \ round. Two blows broke it square off ; 

 fracture quite crystalized. 



HOT BLAST. 



No. 15 — Bar of refined iron 21 inches diameter, heated red, and 

 treated precisely the same as the cold blast bar No. 13, nicked all 

 round 1 of an inch deep. Sixteen blows broke it ; the fracture full 

 of fibre. 



No. 16. — The same end of the last described bar, treated pre- 

 cisely the same as the cold blast bar No. 14, viz., nicked ^ of an 

 inch deep, l of an inch round. Nineteen blows broke it off; 

 fracture full of fibre. 



Note — The hammer used in these experiments weighed 24 lbs. 



Mr. Hartop requested permission to make one or two 

 observations, and said, that the paper was no answer whatever 

 to the one he had read six months ago, but instead of that, 

 was merely a statement of experiments on the bending and 

 breaking of iron after heating ; in fact, the paper had gone 

 into every position which it ought to have kept out of. 

 With respect to the specimens of cold blast iron from Mr; 

 Graham's, he would ask that gentleman's representative what 

 time the furnace at which they were made had been engaged 

 on the cold blast system, as it was a notorious fact that the 

 Milton iron works were not cold blast works. 



Mr. JuBB, of Mr. Graham's works, said, about three 

 months. 



Mr. Hartop would take three months. Now, all iron- 

 masters must know, that when furnaces were almost worked 

 out by making hot blast, they could not produce cold blast 

 iron from them worth having, if they wiere suddenly (or 



