AND ON PREVENTING ITS EXPLOSION. 57 



December 1815,) that the lamps burn with more brightness 

 near the floor than near the roof of the mine ; the lamp, there- 

 fore, with the tube, will be adapted to such situations, or at 

 least the circumstance of the air being brought from the floor 

 will counterbalance any obstacle from its being inclosed, and 

 will allow it to burn as well as an exposed lamp would. In the 

 Scotch coal-mines in general, the system of ventilation appears 

 to be even less perfect than it is in the mines in the north of 

 England, probably from the same necessity not having existed^ 

 for rendering it equally perfect, as the production of fire-damp 

 is so much less abundant. The circulation of the air in them 

 is often so languid, that a method of lighting by a close lamp 

 would perhaps be attended with difficulty, at least if it were 

 necessary to place the lamp in such situations, which, however, 

 the contrivance of employing a lantern with a lens, in some 

 measure would obviate. The English mines present the com- 

 bination of a more perfect ventilation with the constant pro- 

 duction of enormous quantities of fire-damp ; the object, there- 

 fore, is to guard against explosions from the accidental accu- 

 mulation of the gas, while, at the same time, the general plan 

 of ventilation admits of this being more easily carried into ef- 

 fect. A singular method, which shews both the imperfect 

 ventilation, and the moderate extent within which the gas is 

 generated in the Scotch mines, has been practised, — that of fi- 

 ring the quantity accumulated at a stated period, — in some 

 mines daily. A miner enters the mine with a lamp inclosed 

 in a lantern ; he advances as far as is proper, holding it as low 

 as possible, and lying down on the ground, or sometimes even 

 in a trench dug in the ground 3 he removes the lamp from the 

 lantern, and raising it, or advancing it towards the closed ex- 

 tremity of the working, where the gas is collected, fires it. Mr 

 Scott, in the communication referred to, proposes a plan of 

 Vol. VIII. P. I.. H firin^ 



