384 



SCIENCE. 



[N. S. Vol. ni. No. 63. 



illuminating power and requires to be en- 

 riched by passing petroleum oil into the re- 

 torts during the manufacture, and it is only 

 when water gas has already been brought 

 up to a certain candle power that acetylene 

 gas can be mixed with it without losing its 

 effectiveness as an illuminant ; so that it 

 cannot be used as a substitute for petroleum 

 to enrich crude water gas. 



There is no apparent reason a priori why 

 an admixture of a combustible gas should 

 deprive acetylene of its illuminating power, 

 and it is interesting to examine separately 

 the effect of each one of the constituents of 

 water gas to see which one has this prop- 

 erty. 



Brooklinegas, besides 16% of illuminants 

 derived from oil, contains equal quantities 

 (about 26%) of hydrogen, marsh gas and 

 carbonic oxide. If each one of these is 

 burnt separately with acetylene it appears 

 immediately that it is the carbonic oxide 

 which renders the acetylene flame non-lu- 

 minous. Ammonia also has a singular effect 

 upon common gas and upon acetylene, 

 nearly destroying the lighting power and 

 giving a beautiful faint purple flame with 

 curious marked fringes, but ordinarily only 

 traces of ammonia are contained in gas. 

 Nitrogen has much less effect than am- 

 monia or carbonic oxide in destroying the 

 illuminating power of acetylene. 



The preceding statements tend to show 

 that a summary of the qualities of acetylene 

 gas, as compared with common gas, must 

 comprise other data beside the measures of 

 candle power, and I have endeavored to 

 point out some of the peculiar properties of 

 the new light which are advantageous. 

 The price and the taste of the consumers 

 must decide the question of competition. 



The gas of small towns is usually poorer 

 in quality and higher in price than in large 

 towns, and perhaps the opportunities for the 

 introduction of acetylene are greatest in 

 this direction. Consumers may be willing 



to pay $15 per thousand for acetylene gas 

 where they paj^ $1.50 for 16-candle water 

 gas or coal gas. 



I should expect to see it first introduced 

 to replace the very expensive oil gas used 

 in railroad carriages, and also for special 

 purposes where great brilliancy and concen- 

 tration are required, like the head lights of 

 locomotives. For such purposes the Wels- 

 bach light cannot be used, because it is de- 

 stroyed by jarring. The adherence of the 

 flame to the burner is an advantage for rail- 

 road use, making the flame hard to blow 

 out. For shop-window illumination the 

 Welsbach light, which is very much cheaper 

 than gas burnt in any other way, seems to 

 be beyond the reach of competition ; and 

 the Auer burner, which is similar, is now 

 used for street lighting in Paris, and these 

 incandescent lights work well wherever the 

 light is not shaken, and where the disagree- 

 able green tint is not an objection. 



For country houses acetylene light seems 

 well fitted and might replace the very bad 

 illumination of gasolene light. 



Much skill and special knowledge are re- 

 quired to run gas works, while the making 

 of acetylene from the carbide or its distribu- 

 tion as a Uquid is so simple that acetylene 

 stations could be established in many vil- 

 lages too small to make gas works pay. 

 Moreover the winter consumption of gas is 

 two or three times that of the summer, when 

 the gas plant lies idle in part. AVith acety- 

 lene there is an advantage in this direction, 

 because the value of the plant would be 

 much less. 



The whiteness of acetylene light renders 

 it useful for displaying or sorting colors, and 

 some experiments made with Mr. C. R. 

 Walker show that, for photographic pur- 

 poses, when equal quantities of acetylene 

 light and of water-gas light, measured by 

 candle power, are compared, the acetylene 

 light has two and one-half times the actinic 

 value of the other. 



