588 DOMESTIC ANIMALS, DAIRYING, ETC. 



sloping one way, best adapted to the narrow house facing the south. 

 A roof of this kind with the high side to the south sends all the 

 water to the rear, is simple to construct and will not absorb as much 

 heat as the combination or gable roof, upon a portion of which the 

 sun's rays strike more directly. The shed roof should not be used on 

 houses over fourteen feet wide as the length of span will permit 

 sagging and in order to secure a sufficient pitch to the roof the front 

 would need to be excessively high thus causing greater cost of con- 

 struction. 



Another type of roof frequently used is the gable form which 

 does away with the long span, thus being adapted for use on wider 

 buildings. In addition it affords a greater pitch which is desirable in 

 the use of shingles. The objections to its use are that it is necessary 

 to have the back side of the house as high as the front, thus causing 

 a waste of material upon the back, ends and partitions. 



The combination roof is in reality a roof combining the features 

 of the shed and gable roof having unequal spans, the shorter usually 

 being about one-third the length of the longer. This roof has the 

 advantage of both types in that it can be used on a house wider than 

 the shed roof type, affording a steeper pitch with less cost for siding. 

 In addition the back side of the building is no higher than with the 

 shed roof thus making it much more economical to construct than 

 the gable roof. It should be remembered that as long as the pitch of 

 the roof remains unchanged the material used for all three styles of 

 roofs is exactly the same and the saving in material occurs in the 

 sides, ends and partitions. Bearing this in mind an examination of 

 the figure herein will show the desirable features of this type of roof 

 as compared to the shed or gable when used on a house sixteen feet 

 wide and having one foot rise to every three feet horizontal run. The 

 dotted line shows the average angle of the sun's rays for Dec. 21 at 

 the latitude of about 44 which indicates the necessity of placing the 

 windows 6 feet 6 inches high in order for the sunlight to reach the 

 far side of the house within. The front of the house 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, causing 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 houses. 

 A damp cold atmosphere is much more disastrous than a dry ex- 

 tremely low temperature. 



Ventilation may be secured by patent ventilators, straw lofts, 

 muslin curtains, and open fronts. Patent ventilators are seldom 

 used on account of the cost of construction and the unsatisfactory 

 manner in which they operate in the low types of building. 



