ARTIFICIAL INCUBATION. 6? 
turer, nor interested in the sale of incubators, I have no 
object in view other than a desire to correct some of the 
mistakes that have been made in the construction of in- 
cubators. The supposition that a constant stream of 
pure air must flow through an incubator is, in my 
opinion, an error. Not that there should not be plenty 
of pure air, but it should not pass through as a current. 
The hen on the nest airs the eggs, but she keeps the air 
still and motionless. The desire to regulate an incu- 
bator has caused incubators to be constructed that open 
and shut off the heat very easily; but an observer may 
notice that they will often open and close the valves 
every few minutes, thus causing the heat to change in 
as many times, and to allow of slow or fast currents 
according to the degree of frequency with which the 
valves open and shut. The best machines are those that 
slowly reach a point above or below the normal hatch- 
ing point. Too much air passes into the incubators 
and not enough in the brooders, as a rule. A little 
chick does not require so large a volume of air as is 
usually allowed, and a hundred of them together will 
not consume so much as a small quadruped. If the air 
is admitted below the eggs, there will always enough es- 
cape_to allow fresh air to enter for ventilation. We now 
hatch them, in our section, in incubators holding 400 
eggs each, by closing the drawer, allowing no mode of 
ventilation other than to keep three or four one-inch 
tubes open at the bottom of the incubator, and the 
chicks remain thus shut up for twenty-four hours at a 
time without inconvenience. In fact, by leaving them in 
the drawer they are thoroughly dry and prepared for the 
‘brooder when taken out. A regulator should be a very 
simple arrangement. Some of them are so delicate in 
construction as to do more injury than good, and it is 
often the case that the regulator instead of the incubator 
must be watched. The majority of persons put too 
