EXPERIMENT STATION BULLETINS. 251 



is 7 feet high to permit this arrangement of windows, while the back 

 of the house is only high enough to work in conveniently. The shed 

 roof would be 9 feet 8 inches high to the top of the plate or 2 feet 8 

 inches higher than the combination roof. The gable roof in the back 

 would be 7 feet high, while 4 feet 8 inches is as high as necessary, caus- 

 ing a waste of material in the back of the house. It is apparent that for 

 these specific conditions the combination roof has the advantage over the 

 other two types commonly used in poultry houses. 



VENTILATION. 



The most important essential in a poultry house is an efficient system 

 of ventilation, affording an abundance of fresh air without drafts. 

 Fresh air insures dryness in the poultry house. A damp cold atmos- 

 phere is much more disastrous than a dry extremely low temperature. 



Ventilation may be secured by patent ventilators, straw lofts, muslin 

 curtains, and open fronts. Patent ventilators are seldom used on ac- 

 count of the cost of construction, and the unsatisfactory manner in 

 which they operate in the low types of building. 



The straw loft is made by leaving spaces of one-inch or more between 

 the ceiling boards which are covered with a foot or so of loose straw. 

 Both ends of the loft should have openings, the one on the windward 

 side being kept closed during cold weather while the other should re- 

 main open. This method of ventilation has a double advantage in that 

 it not only affords an abundance of fresh air, but the straw takes up 

 the moisture readily, thus rendering the house dry and producing a satis- 

 factory system of ventilation. In addition the house with a straw loft 

 is very desirable during hot weather the temperature being influenced 

 less by the heat from the sun. 



Muslin is being used, in part, in place of glass windows to secure fresh 

 air and is exceedingly popular because of its economical features. 

 Houses with one square foot of muslin and one square foot of glass to 

 every eighteen square feet of floor space are common, the amount vary- 

 ing from one foot of muslin to twenty feet of floor space in a house 

 ten feet wide to one foot of muslin to ten square feet of floor space, 

 in a house twenty feet wide. Some poultrymen are building houses 

 with all the windows covered with muslin and where this is done double 

 the amount of muslin previously mentioned should be used. A com- 

 bination of glass and muslin is preferred and is satisfactory if properly 

 used. The house should be aired out each day more than the muslin 

 permits, for as soon as the cloth becomes damp it will not allow the 

 air to pass back and forth thus rendering the ventilation imperfect. 

 Should the walls and ceiling become damp insufficient ventilation is 

 being used or the house is not sufficiently aired out during the day. 

 Any odors in the house indicate deficient ventilation and more fresh 

 air should be admitted. Fresh air is essential to insure a healthy flock, 

 but in supplying it one must not overlook the danger of drafts. Drafts 

 can be avoided by placing all openings on the south side of the house 

 and also by placing the muslin frames at such a height that when open 

 the air will circulate over the birds on the floor. Frames can be hinged 



