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while weighing the same as the horse or the cow, will breathe 

 over 8,000 cu. ft. of air in the same length of time. 



Instead of ridding the body of the excreta of the kidneys in 

 liquid form as other farm animals do, the hen gives them off 

 as a white paste that is passed with the feces. All the water 

 that in other animals passes off in the urine must be largely 

 gotten rid of by the respiratory system. In order to do this 

 work, nature has given the hen not only a good pair of lungs, 

 but also a system of air sacks extending to all parts of the 

 body which are even connected with the cavities in the bones. 

 Unless there is fresh air to reach all parts of the body, the hen 

 will not do well. Unless there is a good ventilation to carry 

 off the moisture of respiration, the house is bound to be damp. 



The fact that the birds are kept in quite large flocks is an 

 added reason for thorough ventilation. King points out in his 

 Physics of Agriculture that the poisonous principle given off 

 by one individual is much more poisonous to another individual 

 who is compelled to breathe it than it is to the individual giving 

 it off. It is no uncommon thing to see a hundred hens on an 

 Iowa farm crowded into a little house with practically no 

 ventilation. No matter how well such hens are fed there will 

 be a lack of thrift if each hen is compelled to breathe the 

 poisonous gases given off by the rest of the flock. 



In order to secure good ventilation and at the same time 

 have absolute freedom from draughts, a house termed the 

 "open front" or "curtain front" house is built. See figures 

 3 and 6. This house is made absolutely tight on three sides 

 by the use of matched boards and prepared roofing. The 

 fourth side is equipped with cloth covered frames as in figure 

 6. These are opened in calm weather even though it is cold. 

 When it is stormy, they are lowered to keep out the rain and 

 snow. While a hen can roost in a tree in a high wind without 

 catching cold, the moment she is placed in a direct draught 

 inside of a house, she becomes sniffly. It takes only a short 

 time for a cold to progress into a well-developed case of roup. 

 Once established, roup is likely to go through the whole flock. 

 It is well to place cloth frames rather high so as to avoid hav- 

 ing the wind blow directly on the fowls when scratching on 

 the floor. A good wind break on the north and west sides often 

 makes it possible to leave the curtains open on quite stormy 

 days. 



SUNLIGHT. 



A third essential of a successful chicken house is plenty of 

 sunshine. It is in the spring that hens lay the most eggs. If 

 we are to secure winter eggs we must reproduce spring con- 

 ditions as far as possible. So far as the hen house is con- 

 cerned, nothing comes nearer to it than flooding the house with 



