Figure 26.—Fireplaces originally intended for wood were frequently bricked up, and small cast-iron units of this type were built in, since the large openings required for wood were wasteful when coal was used. This was a very popular type of grate for hotel and private bedrooms about 1860 and can still be seen in old houses in coal regions. Note the plain and neat mantel of wide plank.
In general, the wider the opening the greater should be the depth. A shallow opening throws out relatively more heat than a deep one of the same width but accommodates smaller pieces of wood; thus it becomes a question of preference between a greater depth which permits the use of large logs that burn longer and a shallower depth ([fig. 28, A and B]) which takes smaller-sized wood but throws out more heat.
In small fireplaces a depth of 12 inches will permit good draft if the throat is constructed as explained above, but a minimum depth of 16 to 18 inches is advised to lessen the danger of brands falling out on the floor.
As a rule, fireplaces on the second floor are smaller than those on the first floor and it is well to follow this practice because the flue height is less for second floor fireplaces ([fig. 29]).
Unless a fireplace 6 feet wide is fully 28 inches deep, the logs will have to be split, and some advantage of the wide opening will be lost.
Screens of suitable design should be placed in front of all fireplaces ([fig. 30]).