Ventilators and Muslin Windows 119 



Little or no ventilation is needed at night during the 

 severest weather in the colder latitudes, but during 

 the day, when the fowls are more or less actively 

 engaged in scratching in the litter, the house should 

 be ventilated just as regularly as a sleeping apart- 

 ment should be aired when not occupied or when 

 the occupant is actively engaged in light manual 

 labor. Houses with single walls will become quite 

 frosty on the inside during the severest weather, 

 and this will cause more or less dampness whenever 

 the temperature is sufficiently high to thaw the 

 frost from the walls and roof. At this time ventila- 

 tion is most needed and may be supplied by placing 

 a ventilator in the highest part of the roof, which 

 will permit the heated air to escape. It is rarely 

 necessary to provide special means for cold air 

 to enter, as there is usually a sufficient number of 

 cracks about doors and windows to admit cold air 

 if means be provided for the lighter air to escape. 

 Fig. 41 illustrates the construction of a cheap and 

 effective ventilator. This may be readily closed 

 and opened by means of cords or chains as the 

 attendant passes through the house. 



Muslin windows have had and still have many 

 earnest advocates. As a means of ventilation with 

 minimum drafts they serve a most useful purpose. 

 They transmit light also, but, like many other 

 appliances, have some serious faults. Under some 

 conditions they soon become soiled and then are 



