PART X.
Gas Metre, or Self-acting Guage, which measures and registers, in the absence of the observer, the quantity of Gas produced in a given time, from any given quantity of coal, or consumed during a given period, by any number of burners or lamps.
For the invention of this machine we are indebted to the ingenuity and talents of Mr. Clegg, and undoubtedly, of all the improvements with which the new art of procuring light has been recently enriched, there is none which has been attended with results more beneficial to the interest both of the manufacturer and consumer of coal gas.
In this machine we see combined a standard or check on the conduct of the workmen, which enables the manufacturer of coal gas to assure himself of obtaining at all times the greatest possible produce from his establishment; a measure by which he can deal the gas out to his customers in whatever quantities they may require it, and an index which registers the exact quantities furnished, and thus serves as an infallible account of debtor and creditor between the seller and purchaser of gas.
This machine, therefore, performs at once all the duties of an overseer, meter, and book-keeper, and performs them all so much more effectually, that its operation is not dependant on matters so uncertain as the care or integrity of servants, but on unerring principles which are fixed and incapable of any hidden misapplication.
The view in which this machine naturally demands our particular attention is that in which as a standard of the work which ought to be performed, it enables the manufacturer to make sure of obtaining the greatest possible produce from his establishment.
The gas metre serves this purpose in the first place by enabling the proprietors of gas works to know what is the utmost possible quantity of gas which can economically be obtained from any given portion of coal, with a given portion of fuel, in any given time.
It is necessary, in every gas light establishment, in order to know whether as much gas is obtained as might and ought to be produced, that it be previously ascertained by a series of experiments how much gas the species of coal used at the works is capable, on an average, of producing, and such data it is obvious, can only be obtained by means of an apparatus, which, like this gas metre, shall take measure of the quantities of gas supplied by the manufactory at all times, and under all circumstances.
It may, perhaps, be imagined, that assays sufficient for that purpose might be made by means of a few retorts, or small experimental apparatus, or by noting down the quantity of gas produced at the works during the time the valves which convey the gas into the street mains are shut, and during which time the capacity of the gas holders may afford a rule for ascertaining the quantity produced. But nothing can be further from the truth; assays of this description to be practically useful and to serve as a basis for the operations of a large establishment, must be made on a scale of magnitude and be continued for a considerable period of time as well as under every variety of circumstances.