IO4 CALORIFIC POWER OF FUELS. 



Thus, the reaction with the water would be 



5 H 2 O + 3C = 2CO a + CO + loH ; 



carbonic acid being reduced to carbonic oxide in the final 

 reaction, as in the case with the air gasogene. 



Nine kilograms of aqueous vapor and 6 kilograms of 

 carbon produce I kilogram of hydrogen and 14 kilograms of 

 carbonic oxide, that is, a mixed gas is produced containing 

 about one half its volume of each gas. 



One cubic metre of hydrogen weighs 85.5 grams; one of 

 carbonic oxide, 1194 grams. Then the volumes occupied by 

 each gas would be 11.69 f r hydrogen and 11.13 f r car ~ 

 bonic oxide, or 51.23 per cent of hydrogen and 48.77 per 

 cent of carbonic oxide. 



From the foregoing account, it will be seen that the inter- 

 mittent flow is a cause of great loss of caloric in the working 

 of the water gasogene ; but when a gas is wanted solely for 

 heating at high temperatures, it may be obtained by a mixed 

 system working continuously. The gasogene is filled with 

 a mixture of air and steam, the air being employed in 

 the proper proportion to keep up the heat necessary, or, in 

 other words, to furnish by the combustion of part of the 

 carbon, the number of calories necessary to the gasifica- 

 tion of the other part. 



We have seen (page 103) that to gasify I kilogram of 

 carbon 2367 calories were needed. To maintain the heat 

 this quantity must be produced by the action of the air. 

 Mixed gases are poorer than water gas, as they contain more 

 nitrogen and carbonic oxide and less hydrogen. Theo- 

 retically, we should attain the result of furnishing the heat to 

 the gasogene necessary to maintain the temperature by sup- 

 plying the steam sufficiently superheated ; a gas very poor in 

 nitrogen would then be made. But the superheating of 

 steam causes new losses of heat. 



