TYPES OF INCUBATORS 333 



The type selected will depend largely upon the number of eggs 

 to be hatched, the mammoth incubator being best adapted to large 

 poultry plants, or community centres where there is a demand for 

 custom-hatched and day-old chicks. It is being used to some 

 extent on large broiler plants, and more and more in commercial 

 hatching; but its popularity is only of recent origin. In custom 

 hatching a compartment or a number of compartments are rented 

 at so much per hatch, the person who hires the compartment 

 supplying the eggs and taking the chicks, and the operator fur- 

 nishing the heat and doing the work connected with running the 



Z>e^er weight, to balance 

 C Connecting rod and thumb nut 

 & ewr- arm. 



.eonp damper which controls the 

 "heat entering and leexvrna 

 the heater flue 



FIG. 159. A complete self-regulating device for incubatora heated by lamps. 



machine. The chief advantages of this are its large capacity and 

 small cost for labor and fuel. 



Profitable hatching by artificial incubation depends upon 

 securing a good incubator in a good location. Some of the points 

 to consider in selecting an incubator are: 



The machine should be best adapted in size to the conditions, 

 the mammoth incubator where thousands of chicks are to be 

 hatched within a short time, the individual lamp machine for 

 much smaller numbers on small poultry plants or farms. 



The simplicity of the machine should always be taken into 

 account. The more mechanism there is, the greater the danger 

 of mistakes in management; the more parts there are to get 

 out of order and work poorly, the less satisfactory the machine 

 will be. 



Since the effectiveness of the machine depends in great measure 

 upon the maintenance of a uniform temperature of desired degree, 

 the regulating apparatus should be carefully examined (Fig. 159). 

 This apparatus should combine four requisites: (a) A sensitive 

 well-built thermostat; (6) a simple but certain method of trans- 



