472 Scientific Proceedings, Royal Dublin Society. 
to Professor Tyndall and the Irish Lights Commissioners. Under 
the Kitson system the petroleum is placed in a steel receiver 
capable of containing the quantity required for a light for a light- 
house or other place for the time for which the light is to be 
shown. Over the oil in the receiver, atmospheric air is com- 
pressed by an ordinary air pump to a pressure of say 501b. per 
square inch. This pressure remains practically constant ; a very 
few strokes of the piston of the pump on the occasion of each 
new charge of petroleum being sufficient to renew the necessary 
pressure. The petroleum under this pressure is forced through a 
soft brass tube, of very small bore, by which it is conveyed to the 
position in which the light is placed. Being heated at that point 
it is converted into combustible vapour or gas, and discharged 
through a needle-hole orifice. The quantity of petroleum thus 
heated is so exceedingly small that there is no possible danger of 
fire or explosion. The tube in which this heating takes place is 
only about 8 inches in length and { inch in diameter. 
To start the lamp the flame of a little methylated spirit is 
applied for two or three minutes to the heating tube, after which 
the heat is maintained by the light itself. The gas issuing 
from the needle-hole enters a wider tube of peculiar shape 
and dimensions, and in that tube it is mixed with air, forming 
a powerful Bunsen burner, which heats to splendid incandescence 
a mantle provided for the purpose. This mantle may be similar 
to the ordinary mantle with which we are so familiar, or may be 
one of stronger character and larger size. The intensity of the — 
light is not produced by the heat alone, as in the case of the 
ordinary incandescent burner, but also by the high pressure at 
which the petroleum gas is burned, coupled with the high 
illuminating power of that gas. 
The Kitson light, as first shown in this country, was not well 
adapted for lighthouse purposes, inasmuch as the apparatus con- 
nected with the conversion of the petroleum into a gaseous 
condition obstructed to a certain extent the passage of the light 
to the horizon. It was necessary to devise a means of placing 
this in a different position with respect to the burner, so that the 
light might be applicable to the ordinary dioptric apparatus of 
lighthouses. This alteration I have made, thus rendering the 
Kitson light suitable for general use in lighthouses. 
