ON CONSUMPTION OF FUEL AND PREVENTION OP SMOKE. 103 



two-thirds of an average quality of good coal ; and comparing these with 

 other results obtained from similar lignites, two-thirds may fairly be taken 

 as the calorific value of this description of fuel. Dr. Kane further examined 

 a great variety of turf, and amongst others those prepared by Mr. C. W. 

 Williams from the bogs of Cappage, Kilbeggan, Kilbaken, &c. ; the elemen- 

 tary products of which are, according to Dr. Kane, as follows : — 

 Cappage. 



Carbon 51*05 



Hydrogen. . . . 6'85 



Oxygen 39-55 



Ashes ^2-55 



100- 



100- 



100- 



It will be unnecessary to exemplify a greater variety of fuels, such as the 

 different kinds of wood used in America, Russia, and different parts of the 

 continent. In this country timber is seldom if ever used ; and taking the 

 comparative merits of the fuels already enumerated, it will be found (in as- 

 suming the quality of carbon contained in each as the measure of their re- 

 spective values) that the Welsh furnace coal and the Newcastle and Lanca- 

 shire coals stand pre-eminent in the order of their heating powers, either as 

 regards their application to the furnace or to the ordinary purposes of domestic 

 life. 



The American anthracites, which in some cases contain upwards of 90 

 per cent, of carbon, are extensively used in that country; and assuming the 

 mean 91*4 of Professor Johnston's experiments to be correct, and calling it at 

 1000, we then have an approximate value of the different fuels experimented 

 upon, and in general use in this country. 



Table of Comparative Results, showing the calorific and ceconomic Value 

 of different kinds of Fuel. 



In the above table the oeconomic value is assumed to be a proportional of the 

 quantity of carbon contained respectively in each sort of coal, and provided 

 the lignites and turfs are excepted, the others may safely be taken as nearly 

 the correct value of the principal mineral fuels of the kingdom. 



II. The relative Proportions of the Furnaces, and the Forms of Boilers. 

 On this part of the subject there are several points worthy of attention ; 

 namely, the proportions of the furnaces of stationary boilers of different con- 

 structions, the dimensions and position of those with exterior and interior 



