102 CALORIFIC POWER OP FUELS. 



We have previously stated (page 97) that during the 

 combustion of carbon in a gasogene, there occurs a genera- 

 tion of nearly one third of the total heat were the fuel com- 

 pletely burnt. Besides this, the combustion produces a gas 

 containing about one third its weight of combustible gas and 

 two thirds inert gas (nitrogen), which is mixed with it. 



These are important causes of two sources of loss in 

 calories. In an air-gasogene one third of the calories is lost, 

 since the gaseous products give up most of their sensible heat 

 before being used. The 66 per cent of inert gas carries off 

 an enormous quantity of heat to the chimney, and thence to 

 the open air. It was with the idea of regaining or stopping 

 these losses, or at least a large portion of them, that water 

 gas originated. 



Aqueous vapor and carbon, when submitted to a high 

 temperature, produce carbonic oxide and hydrogen. Theo- 

 retically these are free from nitrogen ; but there is always 

 present a small percentage for various causes. In the air 

 gasogene 12 kilogram of carbon and 16 kilograms of oxy- 

 gen (atomic weights) unite to form 28 kilograms of carbonic 

 oxide. On the other hand, 12 kilograms of carbon and 18 

 kilograms of water form 28 kilograms of carbonic oxide and 

 2 kilograms of hydrogen. Then I kilogram of carbon fur- 

 nishes 2.5 kilograms of gas composed of carbonic oxide and 

 hydrogen. 



One kilogram of hydrogen has a caloric energy of 29042 

 calories.* These calories represent also the quantity of heat 

 necessary to decompose the water; in the case of the water 

 gas gasogene they are formed by the carbon burnt. The 12 

 kilograms of carbon will have to furnish, then, the calories 

 necessary to decompose 18 kilograms of water; that is, 



2 X 29042 58084 calories. 



* Water being considered as vapor. 



