Housing 137 



and out through the inlet that the chicks used, thus creating 

 a very bad draught. 



I now saw why the chicks had the roup. But if the chicks 

 had the roup, why had not the other chicks that were in the 

 same room a short time before gotten it? 



To get at the answer to this question was a puzzle, but I 

 remembered that the trade winds which blow only in certain 

 months of the year had just begun, and they had not been 

 blowing during the time the first chicks were in the house. 

 Consequently there was no draught in this house when the 

 first lot of chicks was in it, but by the time the second lot 

 was put in the wind had begun. With the wind came the 

 draught, and with the draught came the roup. 



I regarded this as one of the best experiences I had ever 

 had, because I was a long time in finding the trouble, and if 

 I had not been positive that draught was the cause of roup 

 and stuck to that believe I never should have found the 

 real cause. 



In my roup-proof house the wind is broken 24 feet up in 

 front of the roosting hens and 16 feet in front of the house 

 proper. The roof of the lattice yard and part of sides of 

 the lattice yard, which allowed the air to circulate freely, 

 prevented the air from forming a pressure which would 

 resist the incoming air and forcing it back, creating a back- 

 draught, because the air inside the lattice yard would move 

 freely in every direction exactly like the outside air. 



This is the secret of abundant ventilation without draught. 

 The pure, fresh air is thus allowed to drift slowly around the 

 hens, absolutely without draught of any kind, as the lattice 

 breaking up the wind prevents it from sweeping forward 

 and creating a forward-draught. 



Abundant ventilation without draught is identical with 

 nature's outside conditions, in which roup is seldom known. 



