Housing 131 



housing hens. This was the condition when the wind was 

 blowing and the curtains were down in front. This draught 

 could be easily seen by watching the dust and fine feathers 

 as they swept through the doors of the partitions. The 

 strangest part of the draught was that the air currents a few 

 inches inside this building would be moving in the opposite 

 direction from that in which the wind was blowing. The air 

 currents would move in opposite directions, although they 

 were only a few inches apart. Here again was a back- 

 draught. 



In order to find out more about back-draught and the 

 different movements of the air currents. I got a lot of small, 

 light feathers, attached them to fine threads and placed them 

 all around in the building. When the wind would be blowing 

 I could see exactly how the air currents would act. I soon 

 found out that the slightest breeze would create a back- 

 draught and that if I opened a large door at one end of the 

 building this back-draught would stop. But I was no better 

 off because I changed the back-draught into a forward 

 draught. 



I had cut holes in the roof, holes in the back, and I had 

 the building all patched up. My hens were all dying with 

 roup; nothing I did stopped the draught. But I saw that if 

 I left this place without learning how to stop the draught I 

 would be just as badly off at the next place I went to. I 

 might run into the same conditions, and while they might 

 not be so bad at some other place they might be bad enough. 



I had had roup at nearly every place I had been, and if I 

 left here I would probably never again have such an opportu- 

 nity to study. Here I had the wind every day, and I could 

 therefore make a new experiment every day. 



One day I closed the front of the building up as tight as I 

 possibly could and stopped the draught that had defied me 



