102 REPORT — 1844. 



correct that the heating power of any description of fuel be a proportional of 

 the quantity of carbon it contains ; it then follows that the anthracite must 

 be greatly superior to the bituminous qualities, which yield little more than 

 one-half the quantity. Considerable difficulty is however encountered in the 

 combustion of the anthracite coal, as intense heat is not only an element, 

 but time, and a large quantity of oxygen are absolutely necessary to volatilize 

 its products. It has been known to pass twice through an iron smelting 

 furnace, and subjected for upwards of forty hours to the temperature of 

 melting iron, without being affected beyond theexteriorsurface, having been 

 calcined to a depth of not more than three-fourths of an inch. Such however 

 is the obduracy of its character, that intense heat makes little or no impres- 

 sion upon it. To burn anthracite coal effectually, and to extract the whole 

 of its volatile products, it must be broken into small pieces and thrown upon 

 a furnace having a large supply of oxygen passing continually through it. 



In the combustion of bituminous coal the operation is totally different, 

 being partly friable, and splitting into fragments as the gases are evolved ; 

 hence arises the superior value of that description of fuel in almost every 

 branch of the industrial arts. 



The Newcastle, and the best qualities of the Durham coal, are exceptions 

 to most others of the bituminous kind ; ttiey contain a much greater quan- 

 tity of carbon, and are thus better fitted for the furnace. From some accu- 

 rate experiments by Mr. Richardson they are found to contain — 



Carbon 8.5*613-n 



Hydrogen 5205 I Specific gravity 



Azote and oxygen . . 7-226 f 1-278. 



Ashes 1-956 J 



100- 

 The Lancashire coals approach nearer to the Newcastle and Durham than 

 most others ; and, taking the mean of some recent experiments, they con- 

 tain, — 



Carbon 82-95 



Hydrogen 5*86 



Azote and oxygen 7*93 



Ashes 3-26 



100- 

 The specific gravity of the Lancashire coal is rather more than that of the 

 Newcastle coal, but in other respects their constituents are much alike, with 

 the exception of a greater proportion of ashes in the former than is found m 

 the finer qualities of the latter. r r i i » 



Dr. Kane, in his recent work on the ' Industrial Resources of Ireland 

 (already alluded to), has given some valuable information on the properties 

 of the Irish anthracites and other coals found in different districts of the 

 country. He also ascertained the value of the different beds of lignite which 

 retained their original structure of wood, which burned with a brilliant light, 

 and left a black dense charcoal. 



The constituents of two specimens analysed by Dr. Kane, gave, — 



I. 11. 



Volatile matter 57*70 5370 



Pure charcoal 33-66 30-09 j 



Ashes 8-64 16-21 ] 



100- 100- 



From the above it would appear that the ceconomic value of lignite is about- 



