DURHAM AND NORTHUMBERLAND. 51

In the case of this explosion, as in manyother instances, all precautions proved unavail-ing and ineffectual, for want of an insulatedlight. The fire-damp rushed on the candles,ignited, and in a few minutes tore the mineto pieces, by which eight of the workmenwere killed, and two severely wounded.

It must here be remarked in corroborationof the evidence that, notwithstanding the ut-most perfection of the ventilating system (atpresent attained), no security can be permanentif the possibility of communicating ignition

to the carbureted hydrogen gas exists ; for, inthis instance, not only the proper avenues tothe workings, but the current of ventilation,were obstructed by means of a sinking in ofpart of the mine.

This by the miners is denominated a creep,*

(and upwards) lighter than atmospheric air, and ascendsto the roof of the mine, having the purer air between itand the choak-damp. But although they rise and fall ac-cording to their specific tendencies, it does not follow thatthey remain unmixed, but it is most probable that theyare liable to mutual penetrations, which are produced in agreater degree when worked upon by an active agency,and, we may naturally suppose, are lessened in the absenceof an evolutionary power.

* When working one of the seams in the HarringtonPit, a creep of this kind occurred, which, caused a rentE 2