Carbon monoxide does not usually exist to such an extent in the natural gas produced in West Virginia or Pennsylvania as is found elsewhere. Analysis shows its presence in the natural gas produced in the Lima-Indiana field to the average extent of about one-half of 1 per cent, and to the average extent of 1 per cent in the natural gas produced in Kansas. Formaldehyde is in some cases formed upon putting the cold surface of a teapot in contact with the gas flame of a stove, or when the flame impinges on the cold sheets of a steam boiler. Its presence in small quantities is made known by its pungent and irritating effect upon the nostrils and throat. The effect is danger ous, yet there are no cases known in which death has resulted from this gas thus generated.
Illuminating The illuminating properties of natural gas vary in different lo calities, because of the difference in the per centage of the heavier hydrocarbon, ethane (GEL). All the natural gas found adjacent to petroleum fields has a larger proportion of ethane than the gas farther removed, and there fore the candle power is considered greater. Ordinary natural gas, if consumed with a com mon tip at the rate of 7 or 8 cubic feet per hour, will yield about 6 or 7 candle power. In an ordinary Argand burner with chimney, it will give about 12 candle power in consuming 5 to 6 cubic feet per hour. When natural gas is consumed in contact with a mantle of alkaline earth (thoria, etc.), the result is the cheapest and best illuminant known.
Calorific The calorific or fuel value of natural gas varies in different locali ties, as the amounts of carbon' and hydrogen vary. Those natural gases which contain the highest percentage of carbon give the best re sults. The standard used in measuring fuel values is called the British thermal unit, writ ten B. T. U., and is the amount of heat neces sary to raise the temperature of one pound of pure water 1° F. at or near 39° F., which is the temperature of the maximum density of water. As tested by this standard various sam ples of natural gas showed heat values ranging from 740 to 1,312 B. T. U. per cubic foot. The quantity of air necessary for the perfect combustion of natural gas varies from 10.4 to 10.8 parts of air to 1 part of natural gas. A number of tests have fully demonstrated that when ordinary care is taken in burning natural gas under boilers in actual service, 1 cubic foot of natural gas will do work equivalent to the evaporation of 1 pound of water from and at 212 F. Since 20 cubic feet of ordinary natural gas weigh 1 pound, 1 pound of natural gas will evaporate 20 pounds of water, while, under similar conditions, 1 pound of petroleum will evaporate only 16 pounds of water, and 1 pound of good coal will evaporate but 10 pounds of water; therefore 10 cubic feet of natural gas or one-half a pound is equal to one pound of good coal. In fact in a number of tests with a Klein or a Kirkwood burner, .87 cubic foot of natural gas has evaporated 1 pound of water from and at 212° F., which will
make 17,400 cubic feet equal to one ton of good coal. The actual heating effect of natural gas as a fuel approaches much nearer the theoretical result than can be attained with coal. The price paid by the domestic consumer for natural gas varies in localities, ranging from 13 to 27 cents per 1,000 cubic feet. The consumers near the supply pay less than those farther off. Manufacturers pay less, ranging from 6 to 18 cents per 1,000 cubic feet. About 20,000 cubic feet of natural gas will equal one ton of good bituminous or anthracite coal. If we assume the average price to the domestic consumer to be 22 cents per 1,000, then $4.40 worth of gas will produce the same heating effect as one ton of good coal delivered in the bins — to which must be added the expense of shoveling it into the furnace and the removal of the ashes, as well as the inconvenience of the necessary dust and dirt which invariably accompanies a coal fire.
The Natural Gas Natural gas, as applied to the internal combustion engine, has caused a complete revolution in the methods of securing power throughout the gas belt. It has in nearly all instances superseded any other source of power in pumping petroleum wells, In some instances this has been done by substi tuting a gas cylinder for the steam cylinder, using the same engine bed. The economy in the use of natural gas and the dispensing with the costly and troublesome boiler, with its con stant attendant, has brought it into great favor for all sources of power, from a 1 horse-power up to 1,500 horse-power engine.
The following table gives the equivalents of natural gas and coal for both the gas and steam engine per indicated horse power per hour: Natural gas is used in domestic service principally as a source of heat and light. It is employed extensively in industrial estab lishments for many purposes, notably in the generation of steam; in the manufacture of glass; puddling of iron ; in roasting ores; in heating furnaces, for lacquering and japanning, annealing and reheating, case hardening, tool tempering, preheating castings in oxyacetylene welding; and for heating china kilns, water stills, fire expanders, etc.; and in the manufac ture of steel and pottery; it is also utilized as a source of power in the gas engine, used in drilling and operating oil and gas wells and in pumping oil, and as a general source of power for all purposes. The heat value stored in natural gas is greater than that caused by any artificial combination of carbon and hydro gen, and it is a perfect fuel as it issues from its original rock-sealed reservoirs. No prepara tion is necessary for its combustion and no residue is left. It is not affected by ordinary temperature and it is easily distributed by pipes to points of consumption. It a most economical source of light and power, and an ideal household fuel. Carbon black (q.v.) is the only commercial article that is made directly from natural gas.