 | Royal Geological Society of Cornwall - 1818 - 834 páginas
...down in a perpendicular through ii several strata, frequently terminates, and abuts " upon the solid surface of a stratum, where, " mining horizontally...surface of that " stratum, either north or south, at some dis" tance, the miners meet with another fissure, " running on the same point east and west."... | |
 | Royal Geological Society of Cornwall - 1822 - 506 páginas
...down in a perpendicular through " several strata, frequently terminates, and abuts " upon the solid surface of a stratum, where, " mining horizontally...surface of that " stratum, either north or south, at some dis" tance, the miners meet with another fissure, " running on the same point east and west."... | |
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So like" wise a fissure running, suppose east and west, " that passes down in a perpendicular through ii several strata, frequently terminates, and abuts " upon the solid surface of a stratum, where, " mining horizontally upon the surface of that " stratum,... 