APPLICATION OF THE GAS FROM COAL. ]01 



experiments were meiitioned in our Journal for June 1805> 

 is perfectly satisfactory with respect to the application of 

 coal gas as the material of furnishing light, and its compa- 

 rative cheapness and advantages, at least in a coal country : 

 but it must be obvious, that his calculations are by no means 

 adapted to London. 



Mr. Murdoch states the annual expense for lighting the Mr Murdoch's 



manufactory of Messrs. Philips and Lee at £6oo ; and ob- est""^\« ^'^^t 

 •^ '^ . ' applicable ta 



serves, that, to produce an equal light by candles would London. 



cost ^2000. The caunel coal employed however, as being 

 most profitable though sold at the highest price, costs there 

 only 22^. 6c?. per ton, and the coal for heating the retorts 

 only 10*. per ton. The coak produced there sells at 26s. 8d. 

 per ton. Now on inquiry at a very respectable coal mer- 

 chant's in London I find, that cannel coal sells here at ^4 

 per ton ; the coal for the furnaces may be averaged at 45*., 

 and the coak at 50*. It must be observed too, that the ap- 

 paratus being manufactured on the spot at Birmingham, it 

 of course was so much the less expensive. The statement 

 for the metropolis therefore would probably stand thus. 



Cost of 1 10 tons of cannel coal at £4 £440 Calculation for 



- ■ 40 tons of common coal at 45*. 90 the metropolis 



Interest of capital, and wear and tear of appara- for two hours: 



tus 650 



1180 

 Deduct for 70 tons of coak at 505. ] 75 



1005 

 Thus the expenditure would be £l005 to procure light 

 equal to that of as many candles as would come to £2000. 

 This is the calculation for light for two hours a dav. If we 

 take it for three hours a day, according to Mr. Murdoch's 

 second estimate, the calculation will be 



168 tons of cannel coal £672 or if extended 



60 tons of common coal I35 to three. 



Apparatus as before 650 



1457 

 Deduct for 105 tons of coak 263 



1194 

 or £1194 to procure the light of £3000 worth of candles. 



When 



