“The gas prepared from oil is very superior in quality to that from coal; it cannot possibly contain sulphuretted hydrogen, or any extraneous substance; it gives a much brighter and denser flame; and it is also more effectual, i. e. a lesser quantity will supply the burner with fuel. These peculiarities are occasioned, in the first place, by the absence of sulphur from oil, and then by the gas containing more carbon in solution. As the proportion of light given out by the flame of a gaseous compound of carbon and hydrogen, is in common circumstances in proportion to the quantity of carbon present; it is evident that the gas which contains a greater proportion of olifiant gas, or supercarburetted hydrogen than coal gas, will yield a better and brighter light on combustion.”
“It is necessary, in consequence of the abundance of charcoal in solution, to supply the gas when burning with plenty of atmospheric air, for as there is more combustible matter in a certain volume of it, than in an equal volume of coal gas, it of necessity must have more oxigen for its consumption.[58] The consequence is, that less gas must be burnt in a flame of equal size, which will still possess superior brilliancy; that less is necessary for the same purpose of illumination; and that less heat will be occasioned. From five and a half to six cubical feet of coal gas are required to supply an Argand burner for an hour; two cubical feet to two and a half of that from oil, are abundantly sufficient for the same purpose.”
[58] Dr. W. Henry’s experiments gave the following result:—100 cubic inches of carburetted hydrogen from coal, require, for burning, 220 cubic inches of oxigen, and produce 100 cubic inches of carbonic acid—100 cubic inches of carburetted hydrogen gas procured from lamp oil, require 190 cubic inches of oxigen, and produce 124 cubic inches of carbonic acid,—100 cubic inches of carburetted hydrogen obtained from wax, require 280 cubic inches of oxigen, and produce 137 cubic inches of carbonic acid.
“One important advantage gained by the circumstance, that so small a quantity of this gas is necessary for burners is, that the gasometer required may be small in proportion. The gasometer is the most bulky part of a gas apparatus, and that least capable of concentration; and where-ever it is placed, it occupies room to the exclusion of every thing else. Some very ingenious attempts have been made to diminish its size and weight, as in the double gasometer,[59] and others, but without remarkable success. Here, however, where the room required to contain the gas is directly diminished, the object is so far obtained; and when that takes place to one half, or even one third, it is of very great importance. It in a great number of cases brings the size of the apparatus within what can be allowed in private houses; and in consequence of the rapidity with which the retort can be worked, the gasometer may again be reduced to a still smaller size.”
[59] This contrivance is more expensive and complicated than any of the gas holders of which a description has been given; nor is it safe, for if the slightest leak should happen in the interior vessel of the double gas holder, an explosive mixture would be formed, and dreadful consequences might follow; this can never be the case with any of the machines now in use.—Note of the Author.
“Another advantage gained by the small quantity of gas required for a flame, is the proportionate diminution of heat arising from the lights. The quantities of heat and light produced by the combustion of inflammable gases are by no means in the same constant relation to each other; one frequently increases, whilst the other diminishes; and this is eminently the case when coal gas and oil gas are burned against each other. The quantity of heat liberated is, speaking generally, as the quantity of gas consumed, and this is greatest with the coal gas; but the quantity of light is nearly as the quantity of carbon that is well burnt in the flame, and this is greatest in the oil gas.”
“The very compact state in which the apparatus necessary for the decomposition of oil can be placed, the slight degree of attention required, its certainty of action, its cleanliness, and the numerous applications which it admits of in the use of its furnace for other convenient or economical purposes, render it not only unobjectionable, but useful in manufactories and establishments; and these favourable circumstances are accompanied, not from any inferiority in the flame or increased expense, but by an improved state of the first, and saving in the latter.”
“Messrs. Taylor have shewn great ingenuity in the construction of their whole apparatus, but the washer and gasometer deserve particular notice for their remarkable simplicity also. In the washer, two planes are fixed in a box or cistern, in a direction not quite horizontal, but inclined a little in opposite directions; the planes are traversed nearly across by slips of wood or metal, fixed in an inclined position on the under surface, and which alternately touch one side of the cistern, leaving the other open and free. These planes being immersed in water, the gas is thrown in under the lowest ridge, and by its ascending power is made to traverse backward and forward along the ridges fixed on the planes, until it escapes at the highest part of the uppermost ridge. Thus, with a pressure of five or six inches of water only, it is made to pass through a distance of fourteen or sixteen feet under the surface of the fluid, and becomes well washed.”
“The smaller gasometers are made of thin plate iron, and being placed in a frame of light iron work, look more like ornamental stoves than the bulky appendages to a gas apparatus, which they supply. The larger ones are made very light, and when in pieces very portable, by being constructed of a frame of wood work, in the edges of which are deep narrow grooves; plates of iron fit into these grooves, which being caulked in and painted over, make a light and tight apparatus. These are easily put together in any place, and may therefore be introduced into a small apartment, or other confined space, where a gasometer already made up would not enter.”
For the following additional information on this subject, I am indebted to Messrs. J. and P. Taylor.