[22] 100 Cubic inches of carburetted hydrogen from coal, require for burning 220 cubic inches of oxygen and produce 100 cubic inches of carbonic acid—100 cubic inches of the same gas obtained from wax, require for burning 280 cubic inches of oxygen and produce 137 cubic inches of carbonic acid—100 cubic inches of the same gas procured from lamp-oil, require 190 cubic inches of oxygen for burning, and produce 124 cubic inches of carbonic acid.
The following lines relating to the salubrity of the gas-light illumination are copied from Mr. Lee’s evidence in the House of Commons, when examined on that subject.
Question—“Is the health of your manufacturers at all affected by the use of gas?—Answer—Not in the least, or I would not have adopted it. I believe I explained to the Committee, that I used the gas-lights in my own house first.”
Q. “You have not seen the smallest alteration in the health of your workmen?—A. Not in the least, for had I seen it, it would have been a fatal objection to it.”
Q. “And you say the same in regard to the use of the gas-lights in your own family?—A. Certainly I do.”
As to the brilliancy of the flame, an appeal may be made to every one who has witnessed the gas-light illumination, whether it be not superior to the best wax candle-light, or the light of Argand’s lamps.
It may be described as a rich compact flame, burning with a white and agreeable light. It is also perfectly steady, when the flame is limited to a moderate size: in large masses, it is subject to that undulation which is common to it with all flames of certain dimensions, and is caused by the agitation of the surrounding atmosphere. The gas flame is entirely free from smell. The coal-gas itself certainly has a disagreeable foetid odour before it is burnt, so has the vapour of wax, oil, and tallow, as it comes from a lamp or candle newly blown out. This concession proves nothing against the flame of gas which is perfectly inodorous, a white handkerchief, passed repeatedly through it and applied to the nose, excites no odour.
Another peculiar advantage of the gas flame is, that it may be applied in any direction we please, as there is nothing to spill and the gas is propelled by a certain force which is always the same, it will burn equally well in an almost horizontal as in an upright position; and we can thus obviate two great objections to all our artificial lights, that their least luminous end is directed downwards where the light is generally most wanted, and that a shade is cast below by the stand or support of the combustible matter.
The size, shape and intensity of the gas-flame may be regulated by simply turning a stop-cock which supplies the gas to the burner. It may at command be made to burn with an intensity sufficient to illuminate every corner of a room, or so low and dim as barely to be perceived. It is unnecessary to point out how valuable such lights may be in nurseries, stables, warehouses, in the chambers of the sick, &c.
From the facility with which the gas-flame can be conveyed in any direction, from the diversified application, size and shape which the flame can be made to assume, there is no other kind of light so well calculated for being made the subject of splendid illuminations.
Where lustres are required in the middle of a room, the best mode of conducting the gas to the chandelier, is to pass the gas-pipe through the ceiling from the room above, immediately over the lustre. This can be easily done without injury to the apartment.
Where side-lights and chandeliers are required the tubes need never appear in sight, but may be concealed in the wall or floor of the house. When transparencies are wanted as decorations for halls, lobbies, &c. more than light, recesses may be filled with different coloured media, or paintings, and any intensity of light may be thrown on the object.