 | John Parkhurst - 1807 - 890 páginas
...that have in them many of these cracks, that are so small that they are scarcely discernible. These are indeed the natural conveyances of water, and when once they are opened, it runs incessantly. I have observed such an irruption of water in vast quantity out of stone, that, exempting... | |
 | 1851 - 496 páginas
...stone, and that have in them many cracks, which are so small that they are scarcely discernible. These are, indeed, the natural conveyances of water ; and when once they are opened, it runs incessantly." " In one district of the Cornish mines, there is a series of adits branching off from... | |
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... are so small that they are scarcely discernible. These are indeed the natural conveyances of water, and when once they are opened, it runs incessantly. 