THE INCUBATION OF HENS' EGGS 203 



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 until about 1870, 

 however, that incubators began to engage serious attention 

 in this country, when a patent was awarded to one Jacob 

 Graves for an incubator and artificial mother, which was 

 followed by James Rankin, of southeastern Massachusetts, 

 with a machine that was guaranteed to hatch as many chicks 

 as could be done with hens. From that time the increase in 

 patents, ideas, and improvements have been enormous, but 

 it is only within the last twenty years that incubators have 

 been perfected in this country to such an extent as to be 

 practical successes. 



Value of the Incubator. — Generally speaking the most prof- 

 itable branch of poultry is the production of winter eggs, 

 which is very largely dependent u])on maturing the ])ullets 

 so that they will come into full laying before cold weather 

 sets in. To do this the time of hatching must not he 

 dependent upon seasonal conditions but under ])erfect con- 

 trol. The incubator is always in working order. 



