TECHNOLOGY. 593 



effect of the gas will be to that of the coal from which it was 

 directly derived as 2.78 to 1; the great advantage in favor 

 of the gaseous fuel being due to the fact that this form of 

 fuel permits of a more perfect utilization of its theoretical 

 heating power in practice, while with coal the effective heat- 

 value is greatly lessened by elements of waste, which under 

 the conditions of practical use it is found impossible to ob- 

 viate. 



Regarding the practical value of the Strong gas for metal- 

 lurgical purposes, Dr. Moore's opinion is no less favorable. 

 It has a higher calorific value than the Siemens gas (which, 

 as incidentally remarked, contains by volume 69 per cent, 

 of nitrogen), and, aside from the question of economy, this 

 investigator affirms it to possess for use in metallurgy the 

 special advantages of affording a high and easily regulated 

 temperature, and a relatively small volume of products of 

 combustion compared with the heating effect it yields. " It 

 is, in fact," he affirms, "the most concentrated form of gase- 

 ous fuel hitherto attainable for this application." It may be 

 well to observe, regarding this highly important considera- 

 tion, that the conclusions of Dr. Moore respecting the com- 

 parative heating value of this form of gaseous fuel, favorable 

 as they are, would in general practice for miscellaneous uses 

 be much more so, inasmuch as his conclusions are based upon 

 the best standard of comparison available namely, the evap- 

 oration of water in average boiler practice. With regard to 

 this fact it must, however, be observed that in no department 

 of practice is coal used so economically as in steam-making ; 

 so that it is fair to presume that in domestic use and the in- 

 dustrial arts in general, aside from considerations of increased 

 convenience, uniformity of heating, and manageability, the 

 comparative economy of the gaseous fuel would be greater 

 than Dr. Moore has shown. 



When the possible future of gaseous fuel is considered in 

 connection with the slow progress that is being made tow- 

 ards the perfection of electric lighting for domestic purposes, 

 it seems more reasonable to anticipate the speedy extension 

 of existing gas-works to supply heating gas than to suppose 

 them to be in imminent danger of finding their occupation 

 gone, as many over-sanguine advocates of the electric light 

 do not hesitate to predict. 



