188 POULTRY PRODUCTION 



wide, and sixteen feet high. It was provided with twelve 

 compartments, or incubators, each capable of holding 7500 

 eggs, making a total capacity of 90,000 eggs undergoing 

 incubation at one time." Heat is furnished by fires in grates 

 built in the rooms where the eggs are hatched. The proper 

 temperature is judged by the attendant by his sense of heat 

 and cold, and regulated by means of ventilators in the walls. 

 The eggs are tested for fertility on the tenth day with the 

 palm of the hand, or by placing against the face. Those 

 noticeably cold are regarded as infertile, and discarded. 

 The Egyptian ovens are public institutions and run on a toll 

 basis. From the fact that two chicks are usually expected 

 from three eggs, this method is evidently fairly satisfactory. 

 The theory has been advanced that because of continued 

 artificial incubation the fowls of Egypt have developed 

 the non-setting traits found in the Mediterranean breeds 

 today. 



The Chinese method, still in vogue, is equally primitive. 

 The ovens are much smaller, and made of wickerwork 

 plastered with mud. They are heated by fires in the same 

 compartment with the eggs. 



Various attempts have been made to perfect artificial 

 means of incubation during the last three or four centuries. 

 In 1750, Reaumur hatched chicks successfully by surrounding 

 a cask containing eggs with heating horse manure. 



In 1770 John Champion, of Berwick-upon-Tweed, England, 

 hatched eggs by passing flues carrying hot air through the 

 room in which the eggs were. In 1777 Bonneman, a French 

 physician, established hatching ovens in Nauterre, whereby 

 the heat was conducted from a fire to the eggs by the 

 circulation of hot water. 



The first American incubator was invented in 1844 and 

 patented in England under the title of Cantelo's Patent 

 Incubator. This was also a hot-water-heated machine, the 

 water being heated by a charcoal fire. The following year 

 a regulating device, whereby the temperature of the egg 

 chamber could be controlled, was invented by M. Vallee, 

 a poultryman, near Paris. It was not imtil about 1870, 

 however, that incubators began to engage serious attention 



