340 THE POPULAR SCIENCE MONTHLY. 



These latter, however, are isolated cases, for we see that its economy 

 as a fuel gradually beat down prejudice and opposition, and the con- 

 sumption steadily increased ; but up to the beginning of the eighteenth 

 century the only purpose for which it was used was for the production 

 of heat in houses. It was now to enter upon its second grand phase of 

 usefulness — that for the generation oi force, as manifested through the 

 agency of the steam-engine, which was first used for mining pxu-poses. 

 By this application of steam not only was the mining of the coal made 

 cheaper, but the facilities for distributing it enlarged, and as engines 

 were improved from time to time, their number increased, because they 

 could be economically employed in a greater number of industries, and 

 therefore the demand for this class of fuel rapidly extended. 



About 1805 light established a new market and demand for the 

 black diamonds. For a hundred years or more there were various ex- 

 periments on the distillation of coal in order to produce tar and oils, 

 while the practical application of the in\asible gases that were set free 

 was not thought of till 1793, when WilUam Murdoch, engineer to Bol- 

 ton & Watt, employed coal-gas for lighting his house and offices, at 

 Redruth in Cornwall. The earliest application of this light, on a large 

 systematic scale, was in Manchester, where an apparatus for illuminat- 

 ing the cotton-mills of Messrs. Phillips & Lee was fitted up in 1804 and 

 1805, under the direction of Mr. Murdoch. This new invention rapidly 

 spread, and in 1807 public streets were thus lighted. During 1877 the 

 gas companies in New York City and the immediate vicinity alone re- 

 quired about 450,000 tons. 



At Coalbrook Dale, in England, between 1730 and 1735, Abraham 

 Darby made successful experiments in substituting coal for charcoal, in 

 the manufacture of iron, in the blast-furnace, and thus made the first 

 step in an industry that now requires millions of tons annually ; though 

 it was not till 1830 that this trade really began to assume the gigantic 

 proportions which it now has. At that date Neilson, in Scotland, ap- 

 plied the hot-blast to iron-furnaces, for the purpose of economizing fuel, 

 and succeeded so well that a ton of coal now reduces three times as 

 much iron as it did before. This, like all other inventions tending to 

 economy, increased the manufacture of iron, and consequently de- 

 manded more fuel, exactly as the merchant finds it to his advantage to 

 have quick sales and small profits. 



During the last twenty years chemistry has discovered many minor 

 but none the less striking applications of coal in utilizing the once 

 waste products of its distillation for gas. Among these may be cited 

 solid paraffin, which, when made into candles, equals in beauty those 

 of wax ; from its. analine are obtained many of the most exquisite 

 dyes, vs^hose shades and tints please the eye and gratify our tastes ; it 

 seems almost past belief that some of the delicate toilet perfumes come 

 from it, and that flavoring extracts to pander to our palates are dis- 

 tilled from the same black substance. 



