Mr Gordon’s Neio Portable Gas Lamp. S75 
mand of the flame is so complete, that it may be reduced to an 
almost imperceptible quantity. 
The forcing-pump by which Mr Gordon condenses the gas is 
nearly the same as that of the common condensing syringe, ha- 
ving a solid piston worked by a lever, with shears and a guide, 
to produce a vertical motion. As a considerable degree of heat 
is created during the condensation of the gas, the pump must be 
kept cool by surrounding it with a case filled with water, and 
changing the water as soon as it becomes heated. 
When it is required to fill a great number of lamps with con- 
densed gas, which will no doubt be the case, when it is sold to 
individuals from the reservoirs of Gas Light Companies, Mr 
Gordon recommends that the forcing-pump should be wrought 
by steam, or any other mechanical power, and that the gas 
should be condensed into a large reservoir, from which the lamps 
of numerous individuals may be filled at once with the conden- 
sed gas. A mercurial gage, similar to that used for ascertain- 
ing the force of condensed air, must be fixed to the large reser- 
voir, for the purpose of enabling any person to see the degree 
of condensation to which the gas has been brought. 
As we have had occasion to see Mr Gordon’s lamp put to the 
test of direct experiment, we feel ourselves entitled to speak 
with confidence of its excellence, and to recommend it as one of 
the greatest practical inventions which has for some time been 
presented to the public. Its application to the lighting of pri- 
vate and public carriages, as well as to coal mines, under the 
safeguard of Sir H. Davy’s invention, will be speedily put in 
practice ; and we hope the time is not very distant, when reser- 
voirs of condensed gas shall be established in every town and 
village of Great Britain, and when the lonely cottages of the 
poor shall be enlivened by this economical and chearful light. 
There is one application of the portable gas lamp to which we 
attach a very high value. By an extrem.e diminution of the 
aperture, the flame can be rendered so small (in which case it is 
reduced to a blue colour) as to give no perceptible light, and to 
occasion almost no consumption of gas. In this state the lamp 
may be used in bed-rooms, and the imperceptible flame may at 
any time be expanded into the most brilliant light, by turning 
the cock, by means of a metallic rod terminating near the bed. 
