CHAPTER XIX. 
NATURAL INCUBATION AND BROODING. 
Two distinct methods of incubating the eggs of the domestic 
fowl are in use on different types of poultry plants,—one, commonly 
called the natural method, in which the hen herself generates the 
heat necessary for incubation; the other, commonly called arti- 
ficial incubation, in which heat is supplied in some manner other 
than by the hen. In the artificial way heat is generated by the 
combustion of some fuel, the hen as a mother being left out of 
consideration entirely. Each of these methods has advantages and 
disadvantages, and each is adapted to certain types of poultry hus- 
bandry. The advantages and disadvantages of each are here given. 
Advantages of Natural Incubation.—(1) It is more economical, 
where a small number of eggs are to be hatched and where first 
cost only is considered. The installation of a medium-sized incu- 
bator costs from fifteen to twenty-five dollars, whereas the same 
number of eggs can be hatched under hens with but little initial 
expense. (2) Chicks brooded by the hen appear to have as much 
or more stamina, and are subject to fewer diseases, than those 
artificially bred; it is doubtful, however, if there is as much differ- 
ence in this respect as is generally supposed. (3) A great many 
progressive poultrymen, hatching relatively large numbers, con- 
tinue to use the hen exclusively, for they consider that the progeny 
are of superior quality. 
The disadvantages of the natural incubation are numerous, and 
all are well grounded and self-evident. (1) It is not always possible 
to have a supply of sitting hens on hand. If a large hatch is desired 
early in the spring, it is practically impossible to depend with any 
degree of certainty upon the hen, since the natural period of broodi- 
ness does not usually begin until well along in the spring. It 
would have been impossible to develop the broiler industry, as it 
has been developed, by the natural method, for there are few, if 
any, sitting hens on the average plant during the fall and winter. 
(2) There is invariably the danger and liability of the hens leaving 
the nest at any time they see fit. They may, as far as outward 
appearances go, be exceptionally good sitters when selected, and 
may sit on the eggs for a time; but the period of broodiness may 
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