ILLUMINATION. 
8l 
can hardly look down the microscope tube without 
damage to the eyes, unless much of the light is cut off 
by coloured glasses; and we are able to get the small 
point of incandescence, with the good quality of the 
mixing jet, by the following device, still having quite as 
much power of light as is needed for any ordinary 
purpose. 
A mixing jet is procured, having the nipple consider¬ 
ably smaller than usual, and the hydrogen tube of this 
is connected with the house gas, while oxygen from a 
cylinder is conveyed to the oxygen tube of the jet. 
The only point requiring attention is that the tubes be 
not allowed to become stopped by dirt of any kind ; if 
such a stoppage were to occur there might be danger 
of oxygen being forced into the gas supply of the house. 
We have used this arrangement constantly for years, 
and have never had the semblance of a mishap. Gas 
cylinders should always be fitted with some kind of 
“regulator,” for regulating the pressure and amount 
of gas in the jet; no regulator is better than Beard’s 
patent, and another finds much favour—the regulator 
of the Brin’s Oxygen Co. It is also a great convenience 
to have on the cylinder a “ pressure gauge ” ; by means 
of this we can tell how much gas is in the cylinder at 
any time. All these fittings for the lime-light are well 
known, and can be procured from almost any optician. 
The following device will not only save much gas, but 
enable the worker to get a much more equable illumin¬ 
ating power from the lime-light than he would get by 
the ordinary method of turning up the jet-taps each 
