Polytechnic Association. 855 



I would here remark that the air-blast, as found in the ordinary 

 machine shops of our country, is sufficient, if properly applied, in the 

 production of steel and malleable iron from cast-iron according to this 

 process. 



This process is equally effective, applied to the process of puddling. 

 The cast-iron can be reduced to pure malleable iron by simply con- 

 tinuing the process to the requisite extent. 



The President — One peculiarity of this process is that you can 

 graduate the amount of air so as to produce pure steel or any gradation. 

 Bessemer has to use about twenty pounds pressure to the square inch 

 in his blast. The result is that the air passes up through in channels, 

 and only a very small part of the oxygen is utilized. In this pro- 

 cess nearly all the oxygen is utilized. Another peculiarity is that 

 this apparatus can be applied readily to any ordinary furnace. Its 

 utility, however, can only be ascertained by many experiments. 



Mr. J. B. Root — What will be the additional expense of the 

 casting ? 



Dr. Blanchard — Merely the loss of two and one-half per cent of 

 carbon. 



The President — The oxygen of the air unites not only with the 

 carbon, but with the iron ; and there is the great point to be settled 

 with regard to the economy of this process : how much iron is burned 

 up and reduced to oxide % In the Bessemer process, about ten per 

 cent of the iron is supposed to be consumed. 



Dr. Blanchard further stated that the air-blast has a pressure of four 

 pounds to the square inch, and is heated to about 600 degrees. He 

 proposed hereafter to try the effect of chlorine gas in the blast, to 

 eliminate the phosphorus. 



The Improvement of the Steam-engine and the Education of 



Engineers. 

 By Prof. R. H. Thurston. 



Having rapidly sketched the history of the steam-engine, and of 

 some of its most important applications, we may now take up the 

 question : "What is the problem, stated precisely and in its most general 

 form, that engineers have been here attempting to solve ? 



After stating the problem, we will examine the record with a view 

 to determine what direction the path of improvement has taken 

 hitherto ; and, so far as we may judge the future by the past, by infer- 

 ence, to ascertain what' appears to be the proper course for the present 

 and for the immediate future. 



