AIR-GAS IX THI-: COl NTRV MOUSI-:. 



119 



144. -(&quot;.ROUND FI.noR IM.AX. 



most suitable for the system in question. Discrimination is very necessary at the present time, 

 when so many different [onus of generators are on the market, and the advice of a consulting 

 engineer is even more important in 1he case of an air-gas installation than in electric light 01 acetylene. 

 The cheap plant should he avoided, or the first ot will be supplemented by a considerable account for 

 renewals and repairs. The supply piping is tin- same as used for ordinary coal-gas. In houses pipe-i 

 for the latter, it is not usually needful to make any alterations, though when a weak mixture i&amp;gt; used it may 

 be necessary to increase the size of one or two main pipes in order to keep an even distribution of pressure 

 throughout the house. It is desirable to have the generating plant fixed in as central a position as possible. 

 because this tends to avoid great differences of pressure at the burners. The burners used with air-gas 

 vary according to the system. Each maker ol the apparatus supplies the burner which he considers 

 best suited to the strength of gas that his generator turns out. The differences consist mainly in using 

 a Bnnsen burner admitting a greater or less amount of air to the tlame, according to whethei the gas is 

 rich or poor in quality, or in cutting oft external air supply altogether and only using the air already mixed 

 in the gas lor purposes ol combustion, as is done in the case of very weak mixtures. 



ihe cost ol installation of an air-gas plant is, of course, the first consideration to anyone who may 

 be thinking ol adopting this form of lighting. The plans here reproduced are those of a country doctor s 

 house in which air-gas has been installed. The building itself, as will be seen from the plans, is a very fair 

 type of house costing from one thousand two hundred pounds to one thousand live hundred pounds. The 

 total cost of the 

 generating plant, 

 which is listed 

 as for forty to 

 fifty lights, 

 including pi p i. s 

 for t h r e e g a s 

 rings, two radi 

 ators, and thirty- 



u e points a .s 

 shown on the 

 plans, also tin- 

 cost of supply- 



1 ng thirty - two 

 burners, t h r e e 

 gas rings and 

 flexible tubing, 

 was seventy-six 

 pounds ten shil- 

 1 i n g s and six 

 pence. This price 

 i n c 1 u d e d all 

 erection work 

 connected with 

 the plant and 



supply pipes, and also the erection of the brackets, pendants, etc. The cost of the latter, all very simple 

 in design, was eleven pounds ten shillings. An electric switch for stopping the engine and a pneumatic 

 switch for operating the gas-tap at a distance were fixed in the doctor s bedroom at an extra cost of two 

 guineas. Two heating radiators were provided, one in the study and one in the drawing-room, at a cost 

 of eight pounds eight shillings. The grand total may be taken, therefoie, at one hundred pounds; but 

 the fact that the small sum of eleven pounds only was allowed for fittings must not be lost sight of. 



In a larger house, say, with three more bedrooms, making nine in all, correspondingly larger reception- 

 rooms and proportionately increased offices, it would be necessary to mstal a fifty to sixty light plant, and 

 the number of points would be increased to about forty. This would leave a fair margin of capacity on 

 the generating plant for radiators or future extensions. Such a plant, including the extra pipework and 

 fittings, fixed complete, would cost about twenty-two pounds more, providing that the fittings were of the 

 same simple character as in the house described. Three or four radiators of the size mentioned could be 

 put in if desired, and it may be noted in this connection that the smaller size radiators appear to be much 

 more efficient than the larger ones. Other accessories, such as gas fires, cooking itoves, laundry irons, 

 etc., are made for use with air-gas and do not differ much in design from those used with coal-gas. 



The last word has not yet been said in the matter of design of air-gas plant, and it is fairly obvious 

 that, with the number of plants being turned out and the keen competition between the makers, progress 

 is likely to be rapid and continuous in the near future. At present there appear to be few designs of fitting 



RADIATOR 



CAS RING 



3* 



