INCUBATION 255 



choice of an incubator. Some operators can get good results from 

 any machine, others cannot successfully run at the same time 

 machines requiring different adjustments. 



With rare exceptions new incubators of all makes will hatch 

 fairly well if given sufficient attention, but the cheaper machines 

 usually require much closer watching than the higher-priced ones, 

 and at best are short-lived. It is generally advisable for a beginner 

 to select an incubator popular in his neighborhood, because then he 

 may profit more by the experience and suggestions of other oper- 

 ators. Hot-air machines are now commonly preferred for indi- 

 vidual incubators of ordinary capacity. In the so-called mammoth 

 incubator, consisting of a series of egg chambers on the same 

 heating system, hot-water heaters are necessarily used. These 

 mammoth incubators have the advantages of being more econom- 

 ical of fuel, requiring less labor to care for heaters and causing 

 less risk of fire, but the regulation of temperature throughout the 

 series has not yet ^ been brought sufficiently under automatic con- 

 trol to satisfy most operators. 



Manufacturers' directions for operating incubators. The direc- 

 tions furnished with an incubator should be followed at first and 

 until the operator has a well-defined purpose in departing from 

 them. These instructions are not exactly adapted to every situa- 

 tion, but afford the best starting point for the operator in deter- 

 mining the mode of operation best adapted to his locality. While 

 incubators are in the main similar, most of them have some 

 minor differences which may affect the mode of operation, and 

 it is presumed that the manufacturer's instructions cover these 

 points. The manufacturer's instructions usually presuppose cer- 

 tain general conditions. They are based on the assumption that 

 the incubator will be operated in a dry, well-ventilated cellar 

 or room. Such instructions are manifestly inaccurate for an in- 

 cubator placed in a damp cellar, — where the circulation of air 

 is slow though perhaps sufficient to provide oxygen as fast as 

 needed, — and also inaccurate for machines in an extremely dry 

 location. A machine which requires no moisture under average 

 conditions may require moisture in a dry place, and in a damp 

 location may need more ventilation. A machine which requires 



'■ 1911. 



