GAS. 



GAS-LIGHTING. 



377 



much cheaper relatively. Thus, for cooking, 

 they are quite economical. Even here they 

 are nearly as economical as coal-burning 

 inges, on account of their immediate lighting 

 ad extinguishing. No kindling-wood is re- 

 mired, and no fuel is used except what is re- 

 mired for the operations of cooking. 



Gas-Engines. A great deal of work has been 

 lone in this field by inventors, and a number 

 of engines are in the market. Their advan- 

 for small and intermittent power are 

 reat. They start at once into full action, are 

 imediately stopped, use no fuel except when 

 inning, and require no engineer. They are 

 mch more bulky for the same power than 

 d-engines, but tar excel the latter in econo- 

 ty. There is a certain amount of trouble in 

 irting them, but it is a minor disadvantage, 

 twenty cubic feet of gas per horse-power per 

 >ur is as low as the best of them can go. 

 icy have frequently been used for running 

 lynamos, but the electricians complain of their 

 rant of steadiness. 



Natural Gas. The use of gas from gas-wells 

 the petroleum-fields has grown into an in- 

 lustry of some importance. Several towns are 

 >w lighted with it, and it is used also for 

 >ves and fires. For many years it has been 

 used under the boilers at petroleum- wells, 

 many of which produce it. 

 Gas-Bnrners. The great improvement in this 

 egard refers to regenerative burners, which 

 be found described under their proper 

 leading. 



General Observations. For many years a fierce 

 rar has been waged between water-gas or 

 laphtha-gas and coal-gas. To-day, in spite of 

 its success, water-gas is still the subject of con- 

 troversy. It has certain objections. It con- 

 lins about one third of its volume of carbonic- 

 )xide gas, and this constituent "makes it un- 

 questionably more poisonous to those unfortu- 

 late enough to inhale it. Its higher specific 

 ravity, combined with its usually high illumi- 

 ing power, causes less of it to be consumed 

 pro rata. Where it- has been substituted for 

 ill-gas in entire districts, the gas delivered 

 las run down in quantity very seriously. It 

 light be supposed that this trouble was cura- 

 )le by making it of lowor illuminating power, 

 id increasing the pressure. But when of less 

 inn twenty candle-power the gas-flame is too 

 white and cold-looking, and to make it of good 

 appearance a high illuminating value must be 

 laintained. But where the quantity consumed 

 by the individual decreases, an inducement is 

 offered to others to burn it, and by giving 

 more light for the same money a healthful im- 

 petus is given toward an increase of consum- 

 ers. The use of uncarbureted gas for heating 

 purposes has been tried to a limited extent, 

 but the necessity of two sets of mains, one for 

 heating and one for illuminating gas, has op- 

 erated to prevent its introduction to any large 

 extent. It possesses about half the heating 

 power of illuminating gas, and, if an incandes- 



cent burner could be devised by which it could 

 be made light-producing, we might hope to 

 soon see its introduction on a large scale. Such 

 burners have been tried, but a successful and 

 practical one is yet to be invented. 



GAS-LIGHTING, REGENERATIVE SYSTEM OF. 

 Comparisons of the cost of gas and incandes- 

 cent electric lighting, and the forecasts of the 

 relative industrial position of these two modes 

 of illumination, have so far been based upon 

 the results at present obtained with the former 

 illuminant. While it has long been known 

 that the consumer realized but a portion of the 

 light which the gas was capable of giving when 

 burned under the best conditions that is, with 

 clean burners and proper pressure it has not 

 been supposed that results surpassing these 

 latter were practicable. Recent progress, how- 

 ever, in the construction of burners has shown 

 that gas-lighting has by no means reached its 

 limit, but thnt results are obtainable which are 

 much beyond anything that could have been 

 reasonably expected but a few years ago, and 

 which may enable gas to hold its own as an 

 illuminant against all comers. This progress 

 consists in applying to gas-lighting the regen- 

 erative principle, long and successfully adapted 

 to the industrial applications of fuel, chiefly in 

 metallurgical operations. The essential feature 

 of this system is, the utilizing the heat of the 

 escaping products of combustion which would 

 otherwise be wasted in raising the tempera- 

 ture of the air entering to support combustion, 

 as also that of the combustible. 



Whatever the system of illumination, the 

 light is always due to the incandescence of a 

 solid body. This solid body may be a fine wire 

 or filament of a suitable material, as in the 

 incandescent electric light, or a piece of lime 

 plunged into a non-luminous flame, as in the 

 lime-light, or may consist of innumerable fine 



articles of carbon distributed through the 

 arne. This latter is the condition realized in 

 all the luminous flames, whether of oils or gas. 

 Such a luminous flame consists of a body of 

 inflammable gases which are either non-lumi- 

 nous, as hydrogen or carbonic oxide, or which 

 are but feebly luminous, such as marsh-gas, 

 and a small percentage of heavy hydrocarbons 

 to which the luminosity is due. These latter 

 consist of hydrogen and carbon in chemical 

 union, the carbon of which is set free by the 

 heat of combustion. To these glowing parti- 

 cles of carbon, detained momentarily in the 

 envelope of burning gas, and excluded from 

 the air, the light of the flame is due. That the 

 light yielded may be the greatest possible, 

 these carbon-particles must be raised to the 

 highest attainable temperature. How impor- 

 tant this is, will be understood when it is re- 

 membered that the amount of light yielded by 

 any incandescent body increases much more 

 rapidly than the temperature as this latter is 

 raised. The precise relation between the light 

 and the temperature has not been determined, 

 and probably would not be found capable of 



