112 



OF THE GENERATION AND 



[SECT. in. 



190. When any of these species of fuel is used for generating steam, there 

 must be a loss of effect equivalent to the quantity of vapour formed from the 

 hydrogen, and from the water in the fuel : one pound of hydrogen will form nine 

 pounds of steam, and in practice the loss of effect will be one-fifth of the power of 

 the hydrogen. This proportion being deducted from the whole effect, and also 

 1170 for each pound of water the fuel contained, we have the following table for 

 the power of the most important species of fuel. 4 



1 Murdoch, Phil. Trans. 1808. 2 Art. Gas Lights, Napier's Suppl. to Eucycl. Brit. 



3 Philosophical Magazine, vol. xvii. p. 312. 



* The latent heat of steam is 1000, (art. 82.) the temperature of low pressure steam is 220, and 



