234 A LAMP FOR WORKING IN A NARROW EXCAVATION. 
SAFETY METHOD OF LIGHTING COAL-MINES. BY DAVID BOOTH, ESQ. 
The above engraving represents a vertical 
section of a coal-mine, with its down-cast 
and upcast shafts. 
Within the downcast-shaft is fixed the 
feeding-main, which is a pipe leading from 
the surface to the bottom of the pit, and 
thence proceeding under and along the pave- 
ment to any distance, and in any direction 
that may be requisite : its progress is here 
marked by the letters AAA, &c. This 
pipe (having another inserted) is for the 
purpose of carrying atmospheric air and gas 
to the several burners « « «, &c. 
B B B B B is the evacuating-main for con- 
veying the products of the combustion, which 
pass along until they reach the upcast-shaft, 
when they ascend to the mouth of the pit 
(and higher if necessary), where they are 
dispersed in the atmosphere. This main is 
carried along the roof of the pit, as high as 
it will allow. 
The supply of air and gas to the burners 
may easily be regulated by stop-cocks, and 
the lighting of the lamps may be accomplish- 
ed, without exposure, by means of one or 
other of the various modes of producing in- 
stantaneous light called Lucifers, Eupyrions, 
&c., acted upon by a wire passing through 
an air-tight aperture. Each lamp may be 
separately extinguished and unscrewed from 
the mains, so as to be cleansed when neces- 
sary, while the others are left burning. 
For working in narrow excavations, a 
moveable lamp may be supplied with air from 
the nearest part of the feeding-main, by 
means of a flexible tube (similar to that of a 
beer-engine) furnished with screws and stop- 
cocks, so as to be lengthened by additional 
pieces, or shifted to other stations at plea- 
sure. From the required length and flexi- 
bility of this air-tube, it might be difficult 
to insert a gas-pipe and probably oil only 
could be burnt. This distance, too, to 
which the lamp would, in some cases, need 
to be carried, might render it impracticable 
to convey the produce of the combustion 
to the evacuating main ; but, nevertheless, 
it is presumed that the lamp might be made 
perfectly safe inthe first place, by having 
the chimney of sufficient length to prevent 
the possible egress of the flame; and, se- 
condly, providing that the heated vapour, 
before mingling with the atmosphere of 
the mine, should have to pass through 
small holes, similar to those in the rose 
of a watering-pot, and which holes might 
be lengthened into tubes, or even passed 
through water if found necessary. The in- 
flammable gas of mines, if it enter the Davy- 
lamp, must be carried along with the cur- 
rent that supplies the flame, and would not 
readily pass into this insulated lamp, the 
current of which would always press out- 
wards. 
The proposer is aware that the preceding 
is merely a sketch of a general principle, 
which will require to be modified according 
to particular circumstances. He acknow- 
ledges, too, that, in many cases, its adoption 
would lead to much expense ; but, as a 
counterpart to this, may be placed the annual 
saving, from premature destruction, of a 
great number of valuable human lives. 
David Booth. 
Charlotte -street, Bloomsbury, Feb. 8, 1836. 
{Mechanics' Magazine. 
