On the Rhode -Island Coal. 229 



rated with a large proportion of carbon, either by fu- 

 sion or cementation, it naturally follows that this coal, 

 which consists principally of carbon, is as well calcu- 

 lated as possible, for the conversion of crude iron into 

 so useful an article. 



For the burning of lime, Rhode-Island coal will also 

 be found a useful substitute for wood. The steady 

 and uniform heat which it gives, renders it superior to 

 wood for this purpose, as, when properly applied, all 

 parts of the kiln will receive equal degrees of heat, and 

 the lime will, of course, be burnt equally, without sub- 

 jecting some parts of it to vitrification, while others are 

 not affected by the heat, which is often the case in the 

 general method of using wood for the purpose. 



In all those processes which require a slow and uni- 

 form degree of temperature, such as evaporation, this 

 species of coal is to be preferred, and I cannot, at pre- 

 sent, point out one to which it is more applicable, than 

 the manufacture of salt, an article of the first necessity, 

 and to which America will, at some future period, find 

 it necessary to pay more attention. 



For the supply of the steam engine, and, in general, 

 for every species of furnace but the reverbatory, this 

 coal is well qualified, provided the grates are so con- 

 structed as to give a sufficient draft of air, without 

 which it cannot be properly ignited. This, however, 

 with the knowledge which we possess here of the prin- 

 ciples of combustion, is a matter of little difficulty; 

 and the circumstance of its never caking, or adhering 



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