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COAL MINES OP

forced the foul air to the upper part of therise, begins to compress it too much, whichcauses the fire-damp to force its way backthrough the waters; and, extraordinary as itmay appear, through the whole substance ofthe scaffolding. In one part of a mine whichDr. Clanny and myself descended, a bore hadbeen made through the scaffolding of threeinches in diameter, in order to liberate thegas below more freely ; and it is greatly to befeared, from past circumstances, that no modeof ventilation can be adopted which willsufficiently guarantee the security of the mineand the miner: for it is not a subject whichgives time for deliberation ; but if any thingoccurs to obstruct this ventilating medium,when an extensive eruption of gas breaks uponthe light, it communicates to all parts of themine around, and in one moment rears theterrific aspect of volcanic convulsion and death;or, as expressed by a little alteration of a pas-sage from Thomson:

Here terror holds his unrejoicing court,

And through this sombre hall the loud misruleOf driving thunder is for ever heard;

Here the grim tyrant meditates his wrath,

Here arms his fires with all subduing strength,

Bursts the strong hold which earth to nature gave,And rears a tomb where once a people lived.