85 
on the combustion of gaseous mixtures. 
D. is a lamp fitted with a tin-plate mirror of half the 
circumference of the cylinder, and reaching as high as the 
single top, which may be used in strong currents of fire- 
damp to prevent the heat from rising too high. 
All these forms of the wire-gauze lamp are equally safe. 
In the twilled-gauze lamp less fire-damp is burnt, and the 
radiating and cooling surface is greater, and it is therefore 
fitted for very explosive mixtures, or for explosive currents. 
The wire-gauze lamp with a double cylinder, or with a 
reflector, answers the same purpose. 
The general principle is, that the cylinder should in no 
case be suffered to be heated above dull redness ; and this is 
always effected by increasing the cooling surfaces, or by 
diminishing the circulation of the air. 
I cannot conclude this notice respecting the safe-lamp, 
without stating, that in the practical application of my views 
I have received the most enlightened and liberal assistance 
from the Rev. John Hodgson and Mr. Buddle, who have 
been the first persons to put my principles to the test of 
actual experiment in the mines, and to confide their safety to. 
those new resources of chemistry. 
