Of Chimney Fireplaces. 567 



arise from doors and windows being fitted to their 

 frames with so much nicety as not to give a sufficient 

 passage to air from without to get into the room to 

 supply the current up the chimney, which must always 

 exist when a fire is burning in the room, I embrace this 

 opportunity of mentioning a contrivance for remedying 

 this defect, which I am persuaded would not only be 

 found most effectual for that purpose, but would at the 

 same time contribute very essentially to rendering dwell- 

 ing-houses more salubrious and more comfortable, by 

 facilitating the means of warming them more equally 

 and ventilating them more easily and more effectually. 



In building a house, an air-canal^ about twelve or 

 fifteen inches square, in the clear, and open at both 

 ends, may be constructed in or near the centre of each 

 stack of chimneys; and two branches from this air- 

 canal, both furnished with registers, may open into each 

 of the adjoining rooms, one of these branches opening 

 into the fireplace, just under the grate, and the other 

 over the fireplace, and near the top of the room, or just 

 under the ceiling. Each of these branches should be 

 about four inches square, in the clear ; and to prevent 

 the uncouth appearance of the open mouth of that which 

 opens into the room over the fireplace, it may be masked 

 by a medallion, a picture, or any other piece of orna- 

 mental furniture proper for that use, placed before it at 

 the distance of one or two inches from the side or wall 

 of the room. 



The bottom of this air-tube should reach to the 

 ground, where it should communicate freely with the 

 open air of the atmosphere; but it should not rise quite 

 so high as the chimneys (or canals for carrying off the 

 smoke) are carried up, but should end (by lateral open- 



