ARTIFICIAL INCUBATION". 67 



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 



