1 8 Of the Management of Fire 



the rooms, the lamps, the various utensils and machines 

 made use of in the different manufactories, all the dif- 

 ferent economical arrangements and contrivances for 

 facilitating the operations of useful industry, were so 

 many models expressly made for imitation. 



But in the arrangements relative to the economy of 

 fuel, besides a view to immediate public utility, another 

 motive, not much less powerful, contributed to induce 

 me to pay all possible attention to the subject; namely, 

 a desire to acquire a more thorough knowledge relative 

 to the nature of heat and of the laws of its operations ; 

 and with this view several parts were added to the 

 machinery, which I suspected at the time to be too 

 complicated to be really useful in common practice. 



The steam, for instance, which arose from the boil- 

 ing liquids, instead of being suffered to escape into the 

 atmosphere, was carried up by tubes into a room imme- 

 diately over the kitchen, where it was made to pass 

 through a spiral worm placed in a large cask full of 

 cold water, and condensed, giving out its heat to the 

 water in the .cask ; which water thus warmed, without 

 any new expense of fuel, was made use of next day, 

 instead of cold water, for filling the boilers. That this 

 water, so warmed, might not be cooled during the 

 night, the cask that contained it was put into another 

 cask still larger; and the space between the two casks 

 was rilled with wool. The cooling of the steam, in its 

 passage from the boiler to the cask where it was con- 

 densed, was prevented by warm coverings of sheep- 

 skins with the wool on them, by which the tubes of 

 communication, which were of tin, were defended from 

 the cold air of the atmosphere. 



By this contrivance, the heat, which would otherwise 



