A GUIDE FOR KEEPERS OF POULTRY 217 
impair the vitality of the stock to such an extent that the 
eggs will not give good results in the incubator or under 
a hen. Eggs only a few days old are much to be pre- 
ferred to those more than 10 days old, as they deteriorate 
very rapidly after the first week.” 
INCUBATORS, HOW TO OPERATE.—Manufac- 
turers of incubators always send with every machine 
they sell full directions as to operating them. These 
directions apply only to the machine with which they 
belong, and should be closely followed, as the manufac- 
turer naturally knows more about his machine than any 
one else. Some machines have a ventilating system 
which allows air to circulate more freely than others, 
and such machines evaporate more moisture than those 
not so freely ventilated. Other peculiarities of structure 
require different treatment and all these are important 
to success; the operator should therefore observe direc- 
tions. The beginner who thinks he knows better than 
the manufacturer how an incubator should be operated 
is very likely to fail. There are a few points on which 
manufacturers do not agree, and this is our excuse for 
securing the opinion of Mr. Nix on the factors that make 
for success. 
The best place to operate an incubator is in a dry, 
well-ventilated cellar. A cellar in which an incubator 
is being operated should be free from any odors of de- 
caying vegetables, should have a free circulation of air 
and should not vary widely in temperature throughout 
the dav. Such a cellar makes the operating of an incuba- 
tor a very simple matter. The next best place is a room 
in the house which has windows in the north only, so 
the sun will not shine into it at any time in the day 
during the weeks that hatching is going on. Should such 
