DURHAM AND NORTHUMBERLAND. 185

a tube hanging from the lantern to the groundcan ever be answerable.

This lamp was constructed of tin, beingabout twelve inches by eight square, and wassupplied with a bellows chamber at the topfor the purpose of accelerating the. draught ofair (see Plate VI. Figure 4). a the bellows;b the perforations for the air to pass out of thelamp, over which lies a small piece of woodhinged on with leather as a valve ; c the glass ;d the oil lamp; e a belt by which the lamp iscarried ; f the elastic tube. The lamp, whenlighted, is screwed in underneath at g. Ex-clusive of this invention being inadequate onaccount of the carbonic acid which occupiesthe floor, there did not appear any securityfrom an explosion within communicating withthe surrounding air. Experiments were triedby sending some gas provided for the purposeup the tube, which exploded violently, forcingthe sides and making the tin extremely hot;had it been surrounded by inflammable airthere is little doubt but a communicationwould have taken place through the perfora-tions in the bellows.