SUCCESS IN POULTRY CULTURE 
soon as you can detect a coolness by plac- 
ing your hands on them. They should be 
turned twice each day. 
It is best to keep the incubator door 
closed unless the manufacturer’s instruc- 
tions are to keep it open during the time 
the eggs are being turned. The temper- 
ature of the machine should be maintained 
as near 103 degrees F. as possible. The 
bulb of the thermometer should always be 
on a level with the top of the eggs. | 
Some manufacturers recommend laying 
the thermometer on top of the eggs, but 
I never liked this plan very well, for the 
reason that sometimes the bulb will be 
lying on an egg with a live embryo, and 
sometimes on an infertile egg or on one 
which contains a dead embryo. If the 
thermometer bulb lies against an egg with 
a live embryo, the reading will be more 
than when it lies against an infertile egg 
or one containing a dead embryo, while 
the temperature in the incubator remains 
the same. The reason for such a result 
is that the egg with the live embryo gives 
off heat, while the infertile or dead egg 
does not. Such a result causes confusion 
and a tendency on the part of the operator 
46 
