Of Chimney Fireplaces. 489 



stantly cold ; which must always be the case where, in 

 consequence of a strong current up the chimney, streams 

 of cold air are continually coming in through all the 

 crevices of the doors and windows, and flowing into the 

 fireplace. 



But although rooms furnished with fireplaces con- 

 structed upon the principles here recommended, may be 

 easily and most effectually ventilated (and this is cer- 

 tainly a circumstance in favour of the proposed im- 

 provements), yet such total ventilations will very sel- 

 dom, if ever, be necessary. As long as any fire is kept 

 up in the room, there is so considerable a current of air 

 up the chimney, notwithstanding all the reduction that 

 can be made in the size of its throat, that the continual 

 change of air in the room which this current occasions 

 will, generally, be found to be quite sufficient for keep- 

 ing the air in the room sweet and wholesome ; and, in- 

 deed, in rooms in which there is no open fireplace, and 

 consequently no current of air from the room setting 

 up the chimney, which is the case in Germany and all 

 the northern parts of Europe, where rooms are heated 

 by stoves, whose fireplaces, opening without, are not sup- 

 plied with the air necessary for the combustion of 

 the fuel from the room ; and although in most of the 

 rooms abroad, which are so heated, the windows and 

 doors are double, and both are closed in the most exact 

 manner possible, by slips of paper pasted over the crevi- 

 ces, or by slips of list or fur, yet when these rooms are 

 tolerably large, and when they are not very much crowded 

 by company, nor filled with a great many burning lamps 

 or candles, the air in them is seldom so much injured 

 as to become oppressive or unwholesome, and those 

 who' inhabit them show by their ruddy countenances, as 



