426 wiiALE-i-isriEiiY. 



The economy of oil-gas for purpose"? of illumina- 

 tion, may be judged of from tlie following data : — 

 " One gallon of common whale-oil will produce 

 about 90 cube feet of gas *, and an argand burner 

 will require a cube foot and a,-half per hour to main- 

 tain a perfect light ; consequently, a gallon of oil, 

 made into gas, will afford such a light for sixty 

 hours ; and the expence, at a moderate price of oil, 

 will be, allowing for coals, labour, &c. not more for 

 one burner than three farthings per hour. 



" Such a burner will be equal, in intensity of 

 light, to two argand oil lamps, or to ten mould 

 candles. 



" The expence of argand oil lamps is usually ad- 

 mitted to be about lid. per hour each. 



" Suppose 10 mould candles to be burning, (at 

 4 to the lb. will he 21 lb. costing 2*. lie?.), one- tenth 

 part will be consumed in each hour, and the cost of 

 the light is then 3 id. per hour f." 



A^^itli wax-candles, reckoned at 4^. 6d. per lb. 

 the same quantity of light per hour would cost 14</. 



The following will therefore be the result : — 



* " Mr De Ville, of the Sti-and, who has made many nn- 

 portant experiments and observations on gas iUumination, with 

 a view of applying it to light houses^ is inclined to estimate the 

 average produce in gas, of a gallon of oil, at SO cubical feet." — 

 (Quarterly Jcurnal, vol. vii. p. iilG.) 



t Qura-tcrly Journal, vol. vii- p. ;U i. 



