510 Of Chimney Fireplaces. 



and balanced, four inches is the best width that can be 

 given to the throat of a chimney ; and this, whether the 

 fireplace be destined to burn wood, coals, turf, or any 

 other fuel commonly used for heating rooms by an open 

 fire. 



In fireplaces destined for heating very large halls, and 

 where very great fires are kept up, the throat of the 

 chimney, may, if it should be thought necessary, be 

 made four inches and an half, or five inches wide ; but I 

 have frequently made fireplaces for halls, which have 

 answered perfectly well, where the throats of the chimneys 

 have not been wider than four inches. 



It may perhaps appear extraordinary, upon the first 

 view of the matter, that fireplaces of such different sizes 

 should all require the throat of the chimney to be of 

 the same width ; but when it is considered that the 

 capacity of the throat of a chimney does not depend on 

 its width alone, but on its width and length taken 

 together, and that in large fireplaces, the width of the 

 back, and consequently the length of the throat of the 

 chimney, is greater than in those which are smaller, this 

 difficulty vanishes. 



And this leads us to consider another important point 

 respecting open fireplaces, and that is, the width which 

 it will, in each case, be proper to give to the back. In 

 fireplaces as they are now commonly constructed, the 

 back is of equal width with the opening of the fireplace 

 in front ; but this construction is faulty on two accounts. 

 First, in a fireplace so constructed, the sides of the 

 fireplace or covings, as they are called are parallel to 

 each other, and consequently ill contrived to throw out 

 into the room the heat they receive from the fire in the 

 form of rays ; and secondly, the large open corners, 



