502 Of Chimney Fireplaces. 



This must be done, first, by causing as many as pos- 

 sible of the rays, as they are sent off from the fire in 

 straight lines, to come directly into the room ; which can 

 only be effected by bringing the fire as far forward as 

 possible, and leaving the opening of the fireplace as 

 wide and as high as can be done without inconvenience ; 

 and secondly, by making the sides and back of the fire- 

 place of such form, and constructing them of such 

 materials, as to cause the direct rays from the fire, which 

 strike against them, to be sent into the room by reflection 

 in the greatest abundance. 



Now it will be found, upon examination, that the 

 best form for the vertical sides of a fireplace, or the 

 covings (as they are called), is that of an upright plane, 

 making an angle with the plane of the back of the fire- 

 place of about 135 degrees. According to the present 

 construction of chimneys, this angle is 90 degrees, or 

 forms a right angle ; but as in this case the two sides or 

 covings of the fireplace (A C, B D, Plate VIII., Fig. i) 

 are parallel to each other, it is evident that they are very 

 ill contrived for throwing into the room by reflection 

 the rays from the fire which fall on them. 



To have a clear and perfect idea of the alterations I 

 propose in the forms of fireplaces, the reader need only 

 observe, that, whereas the backs of fireplaces, as they 

 are now commonly constructed, are as wide as the open- 

 ing of the fireplace in front, and the sides of it are of 

 course perpendicular to it and parallel to each other, in 

 the fireplaces I recommend, the back (/' k, Plate IX., 

 Fig. 3) is only about one third of the width of the open- 

 ing of the fireplace in front (a b\ and consequently that 

 the two sides or covings of the fireplace (a i and b k\ 

 instead of being perpendicular to the back, are inclined 



