270 



SOME NEW MODES OF LIGHTING. 



As compared with petroleum incandescent lighting, the benzine 

 system is more expensive and less suitable for brilliant illumination, 

 such as is required in streets, railway stations, and factories, but on 

 account of its greater convenience and cleanliness is perhaps better 

 suited to lighting of dwellings, heating, and cooking pur])Oses. 



Alcohol may also be employed for incandescent lighting, either 

 alone or in a mixture, and may be distributed under feeble pressure; 

 but at present the use of alcohol for this purpose does not appear to 

 be practically successful. In 1002 it Avas stated that alcohol lamps 

 of from 60 to 800 candlepower burned from 10 to 16 grams per candle- 

 power hour, while lamps of from 100 to 1.000 candlepower employ- 

 ing mixtures of alcohol and hydrocarbons in equal ratio consumed 5 to 

 10 grams of alcohol per candlepower hour. To make alcohol lighting 

 commercially successful it is necessary to find a solid or liquid hydro- 

 carbon soluble in alcohol and very cheap, Avhich will give rise to 

 enhanced heating effect with diminished cost. 



A new incandescent petroleum lamp has ap- 

 peared which consumes a mixture in equal parts 

 of the vapors of water and petroleum. Headers 

 may recall descriptions of an ingenious little 

 water vapor blow torch. The new Altmann 

 burner is evidently based on the same idea, but 

 is more compact, for it combines the reservoirs 

 of water and oil and requires no wick like Mer- 

 cier's blow torch. In the Altmann burner com- 

 l)lete combustion of the hydrocarbon is effected 

 in presence of the water vapor, and the flame, 

 in absence of the incandescent mantle, is blue 

 like that of the Bunsen gas bvirner. A vertical 

 section of the lamp is shown in fig. 2. In the 

 reservoir, which is divided in two sections, is the w^ater "W and the pe- 

 troleum P. The two liquids pass by separate channels e to the vapor- 

 izing tubes d d. By means of a small auxiliary lamp placed centrally 

 at /, the gas tubes are heated to the temperature required to vaporize 

 the liquids, thus producing a mixture of gases in the chamber r, heated 

 both by the radiation of the incandescent mantle and by the little 

 burner /. This auxiliary burner is fed with coml^ustible liquid con- 

 tained at P near the foot of the lamp. On leaving the chamber <?, the 

 mixed vapor traverse a tube h to a burner analogous to those employed 

 for incandescent lighting w^ith ordinary illuminating gas. In the 

 models now in use the intensity of illumination ranges from 80 to 100 

 candlepower. The consumption of joetroleum is about a liter (one- 

 fourth of a gallon) in twenty-four hours, so that the cost is about 

 0.002 cent per candlepower hour. A heater is constructed by the 

 same company which also appears to be very economical. 



Fig. 2.— The Altmann 

 lamp (croiss section). 



