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prevent the explosion of the fire-damp, andwhich, by the nature of its apertures for giv-ing admittance and exit to the air, shouldbe rendered incapable of communicatingany explosion to the external air.

“ Having succeeded in the constructionof safe lanterns and lamps, equally portablewith common lanterns and lamps, whichafforded sufficient light, and which boremotion perfectly well, I submitted them in-dividually to practical tests, by throwinginto them explosive atmospheres of fire-damp and air. By the natural action of theflame drawing air through the air canals,from the explosive atmosphere, the lightwas uniformly extinguished; and when anexplosive mixture was forcibly pressed intothe body of the lamp, the explosion was al-ways stopped by the safety apertures, whichmay be said figuratively to act as a sort ofchemical fire sieves in separating flame fromair. But I was not contented with thesetrials, and I submitted the safe canals, tubes,and wire gauze fire sieves, to much moresevere tests : I made them the medium ofcommunication between a large glass vesselfilled with the strongest explosive mixture of

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