HUMIDITY AND COMFORT 



107 



layer of densely humid air around the crowd that results 

 from the moisture of the breath and the evaporation of 

 perspiration. Such rooms may often be rendered quite 

 comfortable by opening more windows or by starting an 

 electric fan, even when there is no way of lowering the 

 temperature of the atmosphere. 



In cold weather when the temperature of the body is 

 considerably higher than that of the surrounding atmos- 

 phere, moist air chills us. This is because moist air is a 

 better conductor of heat than dry air and readily absorbs 

 heat from the body. 



The air in most living rooms in winter is too dry. Since 

 the air in the room has been heated it is capable of holding 

 more moisture than the 

 outdoor air . Unless water 

 is supplied to it, its rela- 

 tive humidity is much 

 lower than that of the 

 air outside. In some 

 heated rooms in winter 

 the air is really drier 

 than the air over the 

 deserts. In this dry air 

 the perspiration evapo- 

 rates very rapidly and FIGURE 53. HOMEMADE HUMIDIFIEB 



makes us cold even 



though the temperature of the room is high. This hot, 

 dry air is injurious to the eyes, irritating to the nerves, 

 harmful to the membranes of the nose and throat, and con- 

 ducive to colds. Such air dries the moisture out of the glue 

 in the furniture, often warps woodwork, and tends to shrivel 

 up everything in the room. 



