METHODS OF HATCHING CHICKENS 307 



the different methods of furnishing heat to the eggs in the 

 two types of machines. 



The tank in the hot water machine adds to its cost. The 

 tank is also likely to get out of repair and leak after a few 

 seasons' use. The hot air type of machine is more generally 

 used, and on the whole is the more satisfactory. Whatever 

 may be the type of machine decided upon, however, one 

 that is well made should be chosen. 



Size of Machine. Machines vary in capacity from fifty 

 eggs to several thousand. Those of less than 100-egg capac- 

 ity have not proven as satisfactory as larger machines. A 

 machine of 125 to 150 capacity should give as good results 

 as larger machines. A machine of this capacity may be 

 used for any number of eggs less than that. It is a question 

 whether the machine would not hatch better if not crowded 

 to its full capacity. The size of machine to select should 

 be governed, first, by the number of chicks it is desired to 

 hatch, and, second, by the number of suitable fresh eggs 

 that may be secured. Where chicks are to be hatched for 

 fall and winter layers they should all be hatched at about 

 the same time, or within a period that will bring the pullets 

 to maturity at the proper time for laying. On this account 

 it will be better to confine the hatching to two runs of the 

 incubator. That would make a difference in about four 

 weeks in the ages of the two lots of pullets. A mistake is 

 made in hatching too early as well as in hatching too late 

 where good fall and winter layers are desired. If the pur- 

 pose is to produce about one hundred pullets for fall and 

 winter laying, two runs of a 150-egg machine will be neces- 

 sary. As to the egg supply, the fresher the eggs the better, 

 and an assured supply of eggs of good hatching quality is 

 necessary before purchasing the incubator. (See page 299.) 



Operating the Incubator. Space need not be taken 

 here with elaborate directions for running the machine. 



