The American journal of science and arts . inthe specimens of parts of different plants in the shale, forming thesubstance of these fossils, is to me, I must confess, very difficult of Vegetation of the First Period of an Ancient World. 113 explanation. Some years ago a friend of mine found a kettle bot-tom at Old Kenton colliery, eighteen inches in diameter, coated withfine coal, the substance of which was entirely mineral carbon, orcharcoal, with a mixture of earthy matter and pyrites. A portionof this specimen is in the collection of the Geological Society. It is much to be regretted that h
The American journal of science and arts . inthe specimens of parts of different plants in the shale, forming thesubstance of these fossils, is to me, I must confess, very difficult of Vegetation of the First Period of an Ancient World. 113 explanation. Some years ago a friend of mine found a kettle bot-tom at Old Kenton colliery, eighteen inches in diameter, coated withfine coal, the substance of which was entirely mineral carbon, orcharcoal, with a mixture of earthy matter and pyrites. A portionof this specimen is in the collection of the Geological Society. It is much to be regretted that hitherto none of these interestingfossils have been followed into the strata. We do not know how farthey extend, or to what height they are standing. Again, in the coal districts of Scotland, amongst the troubles whichaffect the roofs of coal, there is one of a very singular form, knownby the name of pot bottom or, cauldron bottom, and are from the sizeof a foot to five feet in diameter. One of these is represented inthe annexed diagram :. a. Roof of Coal. Argil with sand. b. Pot or Cauldron bottom. c. Coal bituminous. d. Pavement of Coal. Fire Clay. In working the bed of coal, the miner generally knows that he isapproaching one of these, by the coal becoming twisted, and moredifficult to work, and this continues till this trouble in the roof is pass-ed. The general form is that represented in the figure, when, ofcourse, the mouth of the pot is always inverted. The sides of itare generally lined with coal from one-eight of an inch to an inch inthickness, and the pot or cavity is filled up with stone of the argilla-cious kind, or fire clay, having generally less mixture of sand thanis in the roof stone around. The under surface of the stone whichfills the pot is irregular and waving, not smooth like the roof adjoin-ing. Although the coal which lines the pot is connected with themain bed of coal, it is of a texture altogether different, having a brightappearance like jet, and brea
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Keywords: ., bo, bookcentury1800, bookpublishernewhavensconverse, bookyear1820
