Page:Popular Science Monthly Volume 10.djvu/502

486 with the red coloring-matter of the blood, which is more stable than that formed by carbonic anhydride, and cannot be readily decomposed by oxygen. According to Leblanc, one volume of it diffused through one hundred volumes of air totally unfits it to sustain life; and it appears that the lamentable accidents which too frequently occur from burning charcoal or coke, in braziers and chafing dishes, in close rooms, result from the poisonous effects of the small amount of carbonic oxide which is produced and escapes combustion, since the quantity of carbonic anhydride thus diffused through the air is not sufficient in many cases to account for the fatal result. The commissioners, therefore, do not consider the use of water-gas as safe as that of coal or naphtha gas, but they say that the addition to it of petroleum-gas greatly diminishes the danger. So far as they are aware, no accidents have occurred from its use in this country, although there have been several in Europe. The third objection, that the manufacture of water-gas is yet in its infancy, is to a certain extent true, as, although it has been in use in Utica, New York, where the works were recently burned, and is in use in one or two small places, as Poughkeepsie, New York, and the Manayunk District of Philadelphia, it has not been adopted by any of the large companies of Europe or America.

By a comparison of the results obtained by the leading companies in this country and Europe, some interesting facts are shown concerning the cost of production, which, in the United States, has been shrouded until now in mystery—the value of the different processes, the prices charged, etc. The accounts of the London companies, and of the companies of several other large European cities, are published, and therefore open to examination; but, with one or two exceptions, notably of the Philadelphia works, which are controlled by the city, this is not the case with American companies, which are, on the contrary, careful in guarding the secrets of their business. From most of them, certain items of information could be obtained by the commissioners only under the promise of secrecy. The prices charged consumers in Europe are generally much lower than those charged in this country, and it seems that, owing to cheaper labor and better prices obtained for the residuals (coke, tar, and ammoniacal liquor), the cost of manufacture is considerably less. The average price varies with companies and places, from $0,827 per 1,000 cubic feet at London to $1.51 at Paris. The lower price given, however, is charged by only one London company, the S. Metropolitan; the prices of the other companies are much higher, varying from $1.09 to $1,367. The lowest cost of production, 59 cents per 1,000 feet, is reached by the London company just named, and the highest, $1.21, by the Hamburg company. The high cost in Hamburg is to be partly accounted for by the fact that the price of labor is higher there than in any other European city. In 1875 the lowest price in any of the large cities