A GUIDE FOR KEEPERS OF POULTRY 219 
25 minutes. If quite cool shorten the time to 10 minutes. 
There is not much danger of destroying the vitality of 
eggs by cooling them except during the first 10 days, 
and not as much then as is generally supposed. 
Run the incubator for a day or two without eggs in it 
and get the regulator adjusted before putting the ma- 
chine to use. When it has been adjusted to 102° then 
put the eggs in. The temperature will fall immediately, 
as the cold eggs will cool the egg-chamber almost at 
once. Do not change the regulator because of this, but 
let the eggs warm gradually and the temperature will rise 
again to the proper point. 
Do not open the machine unless absolutely necessary, 
except when turning and cooling the eggs. Many 
hatches have been spoiled by opening an incubator to 
show friends how it worked. One would not expect a 
very good hatch from a hen that was constantly being 
taken off her nest. Do not turn the eggs until the third 
day nor after the 18th day. After the first shell is pipped 
close the egg-drawer and do not open it except for a 
very urgent reason until the chicks are all hatched. As 
soon as the chicks begin to break open the shells the 
moisture inside them escapes into the egg-chamber in 
the form of vapor, which often obscures the glass in 
front. This shows that the air inside is saturated with 
vapor and to open the machine at this time is to cause a 
sudden drop in the temperature which often chills a chick 
until it is unable to get out of the shell. 
Do not try to help a chick out of the shell. A chick 
that is not strong enough to get out of the shell without 
help is not worth saving. Sometimes when a very good 
hatch is coming off the chicks will gather at the glass in 
front and pile up, unless there is a nursery untlerneath 
