84 Sir H. Davy’s experiments and observations 
If of plain wire-gauze, the wire should not be less than 
of an inch in thickness, and from 28 to 30 both warp and 
woof. 
b. represents the second top which fits upon a. 
c. represents a cylinder of brass, in which the wire-gauze 
is fastened by a screw to prevent it from being separated 
from the lamp by any blow. c. is fitted into a female 
screw, which receives the male screw / 3 , of the lamp f. 
f. is the lamp furnished with its safe trimmer and safe feeder 
for oil. 
A. is the wire-gauze lamp put together with its strong 
wire supports, which may be three or four receiving the 
handle. 
J. is a small cage made of wire of platinum, of or of 
an inch in thickness, fastened to a wire for raising it above 
the wick, for giving light in inflammable media, containing 
too little air to be explosive. 
h. is a similar cage for placing in the bottom of the lamp, 
to prevent it from being smoked by the wick. 
C. is a lamp of which the cylinder is copper of ~ of an 
inch in thickness, perforated with longitudinal apertures of 
not more than the of an inch in length, and the ~ in 
breadth. In proportion as the copper is thicker, the apertures 
may be increased in size. This form of a lamp may be proper 
W’here such an instrument is only to be occasionally used, 
but for the general purposes of the collier, wire-gauze, from 
its flexibility, and the ease with which new cylinders are 
introduced, is much superior,* 
* In the first lamps which I made on this plan, more than twelve months ago, the : 
apertures were circular ; but in this case their diameters were required to be verv 
small, as the circular aperture is the most favourable to the transmission of flame. 
