ARTIFICIAL HATCHING. 61 



changes should not be made with young things of any kind. 

 Those once accustomed to drink must suffer by deprivation ; 

 and if any change is made, it should be very gradually, and 

 not carried to the extreme. The very worst effects of all 

 are produced by allowing young birds to drink to repletion 

 after prolonged thirst. But it has been noticed that 

 chickens reared on the dry system are much less prone to 

 this in after life. 



At the age of four months any surplus chickens, if of the 

 larger breeds, should be grown enough for the table ; and if 

 they have been well fed, and come of good stock, they will 

 be. For home use we say, let them be eaten as they are 

 they will be quite fat enough. Fattening is also a rather 

 delicate process, success in which it takes some experience 

 to acquire, and which must be treated in a separate 

 chapter. 



CHAPTER IV. 



ARTIFICIAL HATCHING AND REARING. 



To give a history of even the principal attempts that 

 have been made to hatch chickens by heat artificially 

 applied would far exceed our limits, and would be of no 

 practical use. More or less elaborate machines have been 

 constructed by Cantelo, Minasi, Vallee, Carbonnier, and 

 others in France ; and by Brindley, Schroder, and others in 

 England. We refer here merely to the old school. All 

 were costly machines, and all were more or less successful in 

 hatching with skilled management, but none were generally 

 successful. We believe M. Vallee to have been the first to 

 employ a self-acting valve to regulate the temperature ; and 

 Mr. Schroder was, we believe, the first to provide free 

 ventilation from the centre of the egg-drawer, and, above 

 all, a cold-water tank under the eggs to provide a moist 



