PROCEEDINGS OF THE POLVTECHNIC ASSOCIATIOK. 585 



can be made here much cheaper than abroad, because we have 

 the Lehigh coal, which is especially adapted for its manufacture. 

 The Lackawanna will not answer the purpose, although it is bet- 

 ter adapted than the Lehigh for steam purposes. Thus there is 

 a distinction even among our difierent mineral coals, as to their 

 uses in the arts. Immense amounts are lost from our ignorance 

 of the art of adapting our fuel to our work. The necessity of 

 this adaptation will grow upon us as we advance. We consumed 

 over nine million tons of coal last year, and every year we are 

 progressing. Thus we are making room for a larger population 

 of well-fed, well-housed, well-taught men by the economy of fuel, 

 and the economy of the machinery driven by fuel. 



Mr. Churchill remarked that gaseous fuel is particularly appro- 

 priate when it is desired to apply all the heat at a particular 

 point. 



COMPRESSED AIR FOR PROPULSION. 



Mr. Wm. L. Haskins, of Williamsburgh : 



Mr. President — When railway transit is fast engrossing and 

 superceding all other means of inland conveyance, the best 

 method of facilitating that transit becomes an interesting object 

 of inquiry. When railway stocks, as a general thing, have ceased 

 to be remunerative, owing to the enormous amount of capital 

 employed in constructing, maintaining, and working roads in 

 common use, no little distrust must necessarily be felt in the per- 

 fection of the system on which both their structure and their 

 operation depend. 



Any improvements therefore, which, other things being equal, 

 shall possess the merit of economy and safety, is surely entitled 

 to consideration. 



The general importance is admitted and has been widely dis- 

 cussed of the need of some arrangement to reduce the weight of 

 locomotives, which destroy the tracks and bridges at a fearful 

 rate. A *' civil engineer " in the railway Review estimates that 

 the depreciation in the superstructure of railway in the United 

 States — mostly caused by the enormous weight of the locomotives 

 in use — is twenty-six millions of dollars per annum ! If this be 

 so, or if that depreciation amounts to half that sum, then a more 

 complete remedy for the evil than simply to reduce their weight — 

 saving only a percentage of that loss arising from it, while retain- 

 ing the enormous cost of providing and working them — would be 



