60 



Professor W. A. Bone 



[Feb. 27, 



high rate of heat transmission, the boiler tubes after five months 

 continuous running day and night would show any signs of deterior- 

 ation. Consequently, one of the boiler tubes, selected by him, was 

 cut out and subjected to severe mechanical tests, similar tests being 

 simultaneously made with a new and unused boiler tube of same 

 dimensions. The results proved conclusively that the five months' 

 service had not in any way impaired the mechanical properties of the 

 boiler tubes, thus falsifying the confident predictions of several 

 critics that the tubes would be speedily burnt through : — 



The new tube was slightly thinner than the old one, and therefore 

 the betier comparison would be between the results obtained for the 

 specimens taken from the front and hack ends of the old tube, be- 

 cause, whereas the specimen from the front end had surrounded the 

 intensely heated "zone of combustion," that from the back end 

 had never been subjected to a higher temperature than that of the 

 water in the boiler (say 168° C. or 335° F.). The results of the 

 tests show practically no difference between the mechanical strengths 

 of the two specimens. Perhaps the best testimonial to the success 

 of this initial installation of a large boiler on the new principle 

 is the fact that the Skinningrove Iron Co. have put down a second 

 unit foi their new battery of coke ovens, which is now being started 

 up, and I expect, within a few weeks at most, to see the two boilers 

 working side by side. 



Within the last few months the firm of Krupps have put down a 

 boiler in connection with one of their coking plants in the Ruhr 

 district of Westphalia, from the plans of the Skinningrove plant. 

 This boiler has been running successfully since October last, and 

 about three weeks ago underwent its official steam trials, which were 

 carried out by the Bergbauliche Yerein. Pending the official 

 publication of the results in the German technical press, I am pre- 

 cluded from giving any details to-night, but an unofficial test on 

 October 30th, 1913, showed a total evaporation of C750 lb. of water 

 "from and at 212° Fahr." per hour, with ein efficiency ratio of 



