120 



AIR-GAS IN THE COUNTRY HOUSE. 



which can be guaranteed to give a perfectly noiseless light under all natural working conditions. It is 

 necessary, for the sake of safety, to store the petrol outside the room containing the generating plant. 

 This need cause no inconvenience, as the petrol tank can be connected to the plant by means of a small 

 tube, through which the petrol flows automatically as required. The light obtainable for one penny 

 from air-gas ranges from forty to sixty candle-power for fifteen hours with petrol at one shilling per gallon. 

 It we base our calculations on the lower figure, and compare the cost with a forty candle-power burner 

 taking gas from a town supply at four shillings per thousand cubic feet, we find that it consumes two and 

 two-thirds cubic feet per hour, and in fifteen hours, therefore, forty cubic feet will have been used, costing 

 48d. -f- 1,000 x 40 == i-Q2d.,or very nearly twice as much as the air-gas. With petrol at more than a 

 shilling a gallon the comparison is less favourable. The amount of coal-gas used per annum for a house 

 such as shown in the plans would probably not be less than one hundred and fifty thousand cubic feet. 

 With gas at four shillings per thousand cubic feet this would amount to thirty pounds ; whereas, using 

 air-gas, the cost would be fifteen pounds thirteen shillings for the equivalent amount of light. Assuming 

 about five per cent, per annum on the capital cost of the installation to be put by for renewals and repairs 

 a liberal allowance we still have a net saving of over ten pounds in favour of air-gas. It is claimed 

 that the absence of colour in the light produced by means of air-gas makes it the nearest approach to day 

 light that we possess in any commercial system of artificial lighting. Its products of combustion do not 

 contain either sulphur or ammonia, and are therefore far less injurious than those of ordinary coal-gas ; 

 furthermore, it is non-explosive. It has, unquestionably, a great future for country-house lighting. 



MAURICE HIRD. 



BED RooMr ROOM 



145 FIRST FLOOR PLAN 



