34 On the Inland Navigation of 



Kilkenny coal of Ireland, burning without smoke. Its pro- 

 perties as a fuel are, however, various, according to the 

 situation and circumstances under which it is found. In 

 some places it is dry, and composed of carbon nearly pure, 

 the earthy matter amounting to little more than five per cent., 

 and there being no other impurity. In others it passes 

 towards the character of the adjacent carboniferous shale, and 

 then leaves much ashes after its combustion. In others, again, 

 it is saturated with water. This last variety burns much more 

 freely than any other, and, when dug from beneath water, or 

 from mines loaded with that liquid, it is found to assume a 

 resplendent pavonine hue. The flame that attends its com- 

 bustion is no doubt due to the decomposition of the water with 

 which it is charged, while that found in dry situations burns 

 away without emitting any gas heated so far as to become 

 luminous. In the one case, it forms a pleasant and bright fuel 

 for the open grate, while in the other it burns only in furnaces 

 possessing a great draught; but it then furnishes the most 

 durable and intense heat of any fossil substance. 



Many of the mines furnish specimens of fossil charcoal, in 

 •which the ligneous structure is as marked as in that recently 

 prepared from growing timber ; and thus is afforded another 

 link in the evidence, that all coal is of vegetable origin. In 

 the shale and sandstone that accompany the coal, great quan- 

 tities of vegetable impressions are also found. These appear 

 to be identical, in genera and species, with those which accom- 

 pany the bituminous coal of England. The shale that overlies 

 the coal has a very peculiar character, containing much car- 

 bon, but no bitumen, and may hence form a new mineralo- 

 gical species, carboniferous shale. 



This great coal field has not hitherto been traced into the 

 state of New York. Identity of geological position would, 

 however, warrant the belief, that its continuation, or a separate 

 but analogous formation, will be found on the western side of 

 the Catskill mountains ; and, in corroboration of this belief, 

 it may be stated, that the writer of this article found coal in 

 place, near the Little Falls of the Mohawk River, on the 

 western side of the mountain through which that stream forces 

 its way, and which is a continuation of the great Allegany ridge, 

 of which Moosick Mountains and the Catskills are parts. 



