The efficiency of more fireplaces has been impaired by 

 making them too deep then by any other fault outside of 

 throat and flue construction (see No. 3 below). 



2. The head (and throat) should lie as far for- 

 ward as possible and the upper half of the back wall should 

 be inclined forward to meet the head. A curve for the in- 

 clined portion of the back wall (as in the Cuts) is pre- 

 ferable, but a straight line may be used. 



t- 



3. Maximum heat reflection into the roofl from 

 the fireplace side walls is obtained when the latter lie 

 at such an angle that, with the tongue of a carpenter's 

 square laid againct it at the floor line, the elbow being 

 at the back corner, the blade (or its line prolonged) will 

 pass just ahead of the jamb on the opposite side of the 

 arch. With side walls so designed, however, the maximum 

 possible depth is one-half the width, the side walls at this 

 depth meeting and leaving no width for the back wall. With 

 a deep fireplace, therefore, full carrying out of this 

 measure is not feasible. The principle should be borne 



in mind, however, and complied with as nearly as other nec- 

 essary considerations permit. 



Galvanized iron smoke pipe can be used above the 

 throat if desired, in place of a full masonry chimney at a 

 saving in cost. The ash chute is an optional addition. 

 If used, the emptying chamber at the bottom should be pro- 

 vided with an iron door (not shown in the Cut). 



In correcting defective fireplaces already built, 

 if the trouble is with the draft, first attention should 

 be given to the throat. This is commonly too wide, and 

 too far back. In the latter case its opening is usually 

 on a considerable slant so as to face the fireplace open- 

 ing instead of being horizontal. The trouble will often 

 be remedied by narrowing and leveling up the throat by 

 means of adding one or more courses or bricks at its back 

 edge. If trouble still persists, it is probably due to 

 too small a top flue opening. Most cases can be cured by 

 rebuilding, with the proper inside flare, the top 4 to 6 

 feet of the chimney, or that portion, say, above the roof. 

 If there is trouble with back draft this can be entirely 

 prevented by driving iron projections through into the 

 flue interior after the manner of the Maxim gun silencer* 



B.M. (1) 



