274 THE LIFE OF A BIRD. 



leave it to eat or drink, or to take exercise, and 

 will then return to it of their own accord. 



As the chickens become older they no longer 

 require the fostering warmth of the artificial 

 mother, and are then turned out, if the weather is 

 genial, into the poultry-yard. At night their 

 wants are cared for still ; and at Chiswick there is 

 a long low building called the roosting house, fitted 

 up for their accommodation. This building is 

 warmed by hot water pipes, which maintain it at 

 an equable temperature, and also obviate the 

 dangers arising from damp or exposed roosting 

 places. 



It will be observed, that it has been the aim of 

 every arrangement in this ingenious and success- 

 ful system of artificial incubation, to imitate, as far 

 as with wood and metal it is possible so to do, 

 the circumstances under which chickens are reared 

 by their natural parent. The rule taken has been, 

 that we must not try to improve upon the opera- 

 tions of nature, but follow implicitly in her steps 

 in all our attempts to imitate her wonderful 

 operations ; and the result appears to have demon- 

 strated its wisdom. The leading feature of the 

 whole is the application of warmth to that part of 



