REQUISITES OF A GOOD INCUBATOR. 267 



ebnited in the Book, where we read : "As a hen gather* 

 eth her chickens under her wings." The trouble has 

 been, lo these many years, that very little ingenuity has 

 been spent on contrivances for managing sitting hens, to 

 minimize the trouble they cause their keepers, while 

 inventive talent has compassed sea and land, earth and 

 air in perfecting, so far as possible, substitutes for them. 

 In constructing an incubator the sitting hen is always, 

 and properly, appealed to as a standard, and from her we 

 learn that, in addition to the purely mechanical requi- 

 site of a changing position of the eggs, the three chief 

 essentials of perfect hatching are heat, moisture, and a 

 supply of pure air. The eggs must be right, however, 

 in the first place, or the best incubator or mother hen in 

 the world cannot turn out strong, healthy chicks. In 

 the case of those hens which lay a great number of eggs, 

 as was pointed out by the writer in the American Agri- 

 culturist in 1870, those eggs laid near the close of the 

 laying term contain germs deficient in vitality. Mr. 

 J. L. Campbell, who is always worth listening to, says : 



" In a large flock of hens some of them are always right in the mid- 

 dle of a litter, and their eggs being in with the others will account 

 for the fact that some good, strong chicks can be hatched right 

 along all the time, and it is very well that this is so, but I shall 

 never kick again when my hens want to take a rest when I want 

 to hatch the eggs. In fact, I shall encourage them to do so whenever 

 the eggs begin to hatch poorly. Why. it looks very reasonable that 

 when a hen has laid a long time right along, day after day, something 

 must be getting scarce, because the supply has a limit. This is proved 

 by the fact that the hen finally has to stop. If ever I can get a flock of 

 hens to average 250 eggs in a year I shall be happy, but I have a good 

 bit to go yet to get there." 



The matter of well vitalized eggs at the start, when 

 using the incubator, and the importance of well-hatched 

 chicks at the outset when employing the brooder, all 

 operators are agreed upon. But there are many other 

 things concerning which there are interminable dis- 

 putes, notwithstanding a quarter of a century of experi- 

 ments. One book published by an expert who has 



