236 POULTRY PRODUCTION 



and affords openings for the chicks to pass in and out without 

 great loss of heat. 



The Cool-air Compartment. — In an outdoor brooder there 

 should be an exercising room in which the air is very much 

 cooler than under the hover. While a warm temperature 

 should always be available, a cool one is just as essential. 

 Without it the chicks cannot develop the power to maintain 

 the body temperature without the aid of artificial heat. Most 

 of their time from the beginning should be spent in a tem- 

 perature of at least 25° cooler than their body temperature. 

 After the first week it may well be even lower, providing the 

 higher temperature is available to warm the chicks whenever 

 they feel chilly. 



With indoor brooders of whatever type this cool compart- 

 ment will be the room of the building in which the brooder is 

 housed. One of the advantages of an indoor brooder is found 

 in the fact that this cool compartment will usually be very 

 much larger than is practicable in the ordinary outdoor 

 brooder, thus allowing the chicks more liberty and oppor- 

 tunity for exercise when bad weather does not permit their 

 going outside. 



The Ventilating System. — The ventilating system is gen- 

 erally very similar to that employed in the best types of 

 hot-air incubators. It consists of a fresh-air chamber sur- 

 rounding the direct heat fine, in which the flame is (see Fig. 

 117), and communicating with the air of the room. As the 

 air in this chamber is warmed by radiation from the direct 

 heat flue, it tends to rise and pass through a passage pro- 

 vided for the purpose, into, the hover chamber, displacing 

 the air under the hover, and drawing fresh air into the fresh- 

 air chamber of the heater. 



It is a fact worthy of notice that manufacturers of incu- 

 bators that are heated only by the introduction of fresh 

 warm air into the egg chamber, usually rely, in part at least, 

 upon passing the fumes from the direct heat flue through 

 a drum which heats the hover chamber by radiation. The 

 more complete the heating by radiation, the more restricted 

 will the operation of the ventilating system be. It remains 

 to be proved that the newly hatched chick is not in greater 



