276 



SCIENCE-GOSSIP. 



direct into the water connected with the gasometer ; 

 (2) where the carbide is held in a basket, or cage 

 attached inside the gasometer, rising and falling 

 with it, being dipped in the water as it descends, 

 and when the gasometer ascends, being suspended 

 until the gas is used before again dipping ; (3) 

 where the water is dropped upon the dry carbide, 

 and the resulting gas conveyed to the gasometer. 



Practice has shown that No. 1 system is the 

 most desirable, and probably the safest. In 

 each instance the supply of water to the carbide, 

 or carbide to the water, as the case may be, 

 is automatic, and dependent upon the gas being 

 removed for consumption. The danger of No. 3 

 system is twofold. First, in case of failure of 

 the automatic cutting off of the water supply, 

 the whole of the gas is generated from the carbide, 

 which would usually be more than the gasometer 

 would hold, and either create an escape of gas or 

 undue compression. Another objection is the 

 generation of heat, which might possibly lead to 

 complications, as acetylene gas under the action of 

 heat very rapidly resolves itself into various con- 

 stituents forming organic compounds. It is hardly 

 probable that the caloric evolved would be suffi- 

 cient to ignite the gas in the generator. Objection 

 to No. 2 system arises from the fact that gas 

 continues to be evolved from the dampness of its 

 surroundings, after the gasometer has been filled 

 up to its full pressure. The advantage of No. 1 

 system consists in the absence of heat, the auto- 

 matic supply of carbide being only sufficient to 

 give off the exact amount of gas to suit the 

 capacity of the generator. Further, by the first 

 system generators may be constructed to go on 

 working automatically for months at a time, which 

 could hardly be the case with safety with either 

 of the other plans. 



These generators may be made in any size, to 

 supply a single burner or a large city ; one great 

 advantage being that whatever number of lights 

 are required that sized genera-tor only need be 

 obtained. 



It will thus be seen that every installation of 

 acetylene gas can be absolutely self-contained 

 and independent of all street mains and the 

 expensive establishment of large gasworks. This 

 will doubtless be the feature which will most 

 commend the general use of acetylene gas. 

 If, however, the light be required by a 

 Rural District Council for village lighting the 

 gas may be generated at a central station, 

 circulated by mains and charged for by meter. 

 Or, if preferred, separate lights can be given to 

 every house, each residence having its own gene- 

 rator and being supplied with its own carbide. 

 This applies also to the street-lamps, which can 

 be made self-contained in every instance and to 

 work for any reasonable period without attention. 



The great advantage of these generators is that 

 they require no skilled manipulation, a domestic 

 servant being able, without any special training, 

 to attend to one for an ordinary house. Before 

 long the carbide will be placed on the market, so 

 that it will become a recognized item at our 

 grocers' or oilmen's shops. For those houses 

 which are already supplied with gas-fittings all 

 that is necessary will be to disconnect the coal-gas 

 and place in a convenient site in the garden, yard 

 or area, a comparatively inconspicuous box con- 

 taining the generator, to which the house gas 

 piping will be attached. These boxes may be 

 made ornamental. The acetylene gas burners 

 differ from ordinary coal-gas burners in being 

 supplied with far smaller orifices ; the candle- 

 power of acetylene gas, when both are used 

 through an ordinary gas burner, having been 

 found to be about twenty times greater than coal- 

 gas. Of course country houses and others that 

 are not supplied with gas fittings will require 

 those made for acetylene, which are much lighter 

 and less obtrusive than for coal-gas. 



The present stage of the acetylene gas industry, 

 which may be considered quite in its infancy in 

 this country, is hardly the proper time to estimate 

 the ultimate price at which it will be supplied to 

 the public. It may be roughly stated, however, 

 that generators, excluding the cost of housefitting, 

 will shortly be obtainable at an initial cost of 

 something like seven shillings and sixpence to ten 

 shillings per burner capacity. They will doubtless 

 be supplied on the hire system, as at the present 

 time are gas-meters and cooking-stoves. These, 

 generators being made of galvanized iron, will last 

 for many years without requiring repair. 



The carbide will doubtless reach a much lower 

 price than at present sold, as competitive manufac- 

 ture advances. Even now, at a cost of eighteen 

 pence, an amount of acetylene gas can be made 

 which equals in illuminating power 1,000 cubic 

 feet of coal-gas. The latter, under the most 

 favourable circumstances seldom reaches so low 

 a price, and in a large number of cases it ranges 

 from four shillings and sixpence to ten shillings 

 per 1,000 cubic feet. 



In intensity and brilliance as an illuminant there 

 is no doubt that with the aid of properly con- 

 structed burners acetylene gas takes the first 

 rank. So bright is it, indeed, that a small flame, 

 such as might be used for domestic purposes, 

 when held in front of an electric glow lamp during 

 incandescence will cast a shadow not only of the 

 globe but also of the filament through which the 

 electric current is passing. Another feature of the 

 acetylene flame is the almost entire absence of 

 any blue or non-illuminating centre so conspicuous 

 in coal-gas jets. Its great intensity renders un- 

 necessary for ordinary purposes the application of 



