350 Means of increasing the Quantities of Heat 



by coal fires, a large proportion of wet clay is always 

 coarsely mixed with the coals before they are introduced 

 into the fireplace. If this practice had not been found 

 to be useful, it would certainly never have obtained gen- 

 erally, nor would it have been continued, as it has 

 been, for more than two hundred years. 



The combination of different substances, combus- 

 tible and incombustible, to form, artificially, various 

 kinds of cheap and pleasant fuel, particularly adapted 

 for the different processes in which the fuel is employed, 

 is a subject well worthy of the attention of enterprising 

 and ingenious men. How much excellent fuel, for 

 instance, might be made with proper additions and 

 proper management, of the mountains of refuse coal- 

 dust that lie useless at the mouths of coal-pits ; and 

 how much would it contribute to cleanliness and ele- 

 gance if the use of improved coke, or of hard and light 

 fire-balls, could be generally introduced in our houses 

 and kitchens, instead of crude, black, powdery, dirty 

 sea coal ! Of the great economy that would result from 

 such a change there cannot be the smallest doubt. 



It is a melancholy truth, but at the same time a most 

 indisputable fact, that, while the industry and ingenuity 

 of millions are employed, with unceasing activity, in 

 inventing, improving, and varying those superfluities 

 which wealth and luxury introduce into society, no 

 attention whatever is paid to the improvement of those 

 common necessaries of life on which the subsistence 

 of all, and the comforts and enjoyments of the great 

 majority of mankind, absolutely depend. 



Much will be done for the benefit of society, if means 

 can be devised to call the attention of the active and 

 benevolent to this long-neglected, but most interesting 

 subject. 



