THEIR ECONOMIC IMPORTANCE. 173 



other articles of utility and ornament : from its shales we 

 extract alum, copperas, sulphur, and paraffin oils ; its lime- 

 stones are employed in architecture, agriculture, iron-smelt- 

 ing, bleaching, tanning, and numerous other arts, at the 

 same time that they furnish many of our most decorative 

 marbles, and are often the repositories of lead, zinc, anti- 

 mony, and silver : from its ironstones we extract much of 

 that metal without which all our implements would have 

 been comparatively rude and inefficient, and the machinery 

 of our factories, our steamboats, our railroads, and telegraphs 

 impossible ; while with its various coals we heat our dwell- 

 ings, cook our food, light our streets and apartments, and 

 raise that steam-power by which human industry is increased 

 ten-thousand-fold, time and space abridged, and the differ- 

 ent nationalities of the earth brought into more intimate 

 union and brotherhood. 



And yet, important as these substances are, they are far 

 from having attained their limit either in the amounts an- 

 nually raised or in the purposes to which they can be 

 applied. One has only to cast his eye back on the state of 

 our coal-fields some thirty or forty years ago, as compared 

 with what they are now, to be at once convinced of the 

 progress that has been made, as well as of the progress that 

 is still attainable. At that time, fire-clay was raised only 

 from a few open workings, and had little or no value; 

 alum-shale was mined only at a single work; blackband 

 ironstone was rejected; bituminous shales were utterly 

 worthless ; the ordinary coals had for the most part merely 

 a local sale (for there were no railroads), and brought less 

 than half their present prices ; cannel coal was seldom 

 raised, and was scarcely saleable even at a fifth of its pre- 

 sent cost (for gas-works had not then come into operation) ; 

 and the whole amount of coal raised in Great Britain did 

 not much exceed 30,000,000 tons, while now it has reached 



