Control of Temperature. 347 



better than solid masonry but are not as warm as those well 

 constructed of all wood and good building paper. 



An unplastered brick wall, or a brick wall plastered with 

 coarse lime mortar only, is one of the poorest which can be 

 used either to retain or exclude heat. Its pores are so open 

 that the smallest wind pressure or wind suction causes a 

 ready flow of air through every portion of the wall, 

 changing the air of the room quickly. 



For cheese curing rooms, where the temperature is to be 

 held down by means of cold air ducts, masonry walls, even 

 when made air tight, are not suitable because they are such 

 good conductors of heat and so massive that they tend to 

 maintain a uniform temperature in summer somewhat 

 higher than the mean of the air outside. 



426. Hollow Masonry Walls When stone or brick walls 

 are made hollow they become much warmer in winter and 

 cooler in summer than when built solid because the air is a 

 much poorer conductor of heat. The thickness of the air 

 space is not important and one-half an inch thick is prac- 

 tically as serviceable as one of 6 inches. 



Where basement or semi-basement, curing rooms for 

 cheese are constructed the upper four feet of the wall 

 should be made with a dead air space to prevent the heat of 

 the warm soil as readily reaching the interior. So, too, in 

 the case of dwelling houses in cold climates, whether they 

 have cellars under them or not, it is important to make the 

 upper 3 or 4 feet of the wall hollow for the reason that the 

 cellar will be warmer and hence the floors under the living 

 rooms above. 



427. Brick Veneered Walls. Where brick are cheap and 

 lumber high, walls made of 2x4 studding sheeted inside 

 and outside with matched fencing and then veneered with 

 brick make a very durable and warm building. The brick 

 will not decay and the expense of nails and frequent paint- 

 ing are avoided. 



It does not do to depend upon the brick for warmth, how- 



