172 POULTRY BREEDING AND MANAGEMENT 



warm months. As the winter departs and the warm spring 

 days come, the hen is at her best, her comb is the reddest. 

 Nor does it mean that warmth is inimical to egg produc- 

 tion. In the writer's experiments at the Utah Station a 

 little artificial heat increased the egg yield (Bulletin 102), 

 but it was apparently at the expense of vigor, for the 

 fowls in the cold house weighed heavier than those in the 

 warm house at the end of the winter. A proper system 

 of artificial heat may stimulate egg production, but an 

 economical, and safe system has not yet been found. 



THE MISSOURI POULTRY STATION HOUSE 

 Ventilation is secured by slatted shutter and by opening windows. 



A warmly built house cannot be made warm and com- 

 fortable without artificial heat in cold weather. Let us 

 see. To make it warm the practice has been to double 

 board it. It is tight boarded on each side of the studding, 

 and under the boards there is building paper to make it air- 

 tight. Then glass windows are put in to give light and 

 sunshine, and there must be double windows also. If the 

 hens are to have fresh air there must be openings in the 

 walls to let in fresh air and when fresh air is let in cold 

 air comes in. A double wall of that kind, even without 

 the ventilation, will not keep out the cold. It will keep 

 it out a little longer than single walls; the changes in the 



