FUEL 



501 



The calorific values of a selected variety of coals, as tried uader circumstances con- 

 sidered the most favourable for the development of heat, will be. found in the Table 

 at top of next page ; the result being given in a somewhat different form from tho 

 result in the preceding Tables. See COAL ; COKE. 



On Liquid Fuel. The proposal to substitute for the coal now used, as fuel in steam- 

 vessels some kind of liquid combustible, arose from the discovery of vast quantities of 

 petroleum in America; and it was that material which was in the first instance 

 recommended as the substitute for coal. A commission appointed in America to 

 investigate the subject reported that petroleum was beyond doubt more than twice as 

 effective as anthracite coal in the production of steam, and that steam could, by the 

 use of this material, be produced in less than half the usual time. 



It was an inference by no means unnatural that, if this were the case, and if coal 

 could be superseded by this material as the fuel of steam-vessels, a very great portion 

 of the space required in merchant steamers for the stowage of coal would be rendered 

 available for more profitable cargo ; that steam-packets might become independent of 

 coal depots at various points of their passage ; and that ships of war would be en- 

 abled to keep the sea for a very much longer time than they now do with coal. Any 

 prospect of jsuch advantages as these being attainable might reasonably have been 

 expected to justify a more thorough and searching investigation of this subject than it 

 has yet received in this country. 



