CARBONIFEROUS DISTRICT OF PICTOLf 333 



from 1-288, which is that of the best coal extracted, to 1-447, which 

 is that of the coarsest coal that has been worked. The mean specific 

 gravity of six samples, taken from the top, middle, and bottom of the 

 seam, in the central part of the mine, was 1-325, or exactly the same 

 with one of Professor Johnston's results. According to Professor 

 Johnston's trials, 1 pound of this coal is capable of converting 7-45 

 to 7-48 pounds of water into steam, or from the temperature of 212°, 

 8-41 to 8-48 pounds. This gives it a high place among bituminous 

 coals as a steam-producer. The worst defect of Pictou coal is, that it 

 contains a considerable quantity of light bulky ashes ; and this causes 

 it to be much less esteemed for domestic use than on other grounds it 

 deserves. It is very free from sulphur, burns long, with a great pro- 

 duction of heat, and remains alight when the fire becomes low much 

 longer than most other coals. 



The following assays show the composition of the coal from the 

 upper floor in different parts of the mine, and illustrate its gradual 

 deterioration at either extremity of the workings. 



100-000 100-000 100-0 



It will be observed that in all parts of the mine the lower coal is 

 inferior to that of the middle of the seam, and still more so to that of 

 the upper part above the "holing stone," or the "fall coal," as it is 

 termed by the miners. It will also be observed that all the coals in 

 the first column are inferior to those in the second, and that those in 



