American Incubators. 187 



The oldest of these is Halsted's " Centennial,'" now im- 

 proved and called Xew Centexxial.* 



The construction of this is certainly very simple, as it has 

 neither clock-work, electricity, weights, pulleys, gear or 

 ratchet wheels, provided the four "thermostatic bars so 

 pivoted aud linked together that they multiply power and 

 motion," do not make a complication. 



The machine consists of a small water heater, which warms 

 the water in a tank placed over the egg-chamber. The source 

 of heat may be either kerosene oil or gas. The eggs, placed 

 in trays, are warmed by radiation on the upper surface only. 

 Under the trays are shallow pans of water six to ten degrees 

 cooler than the eggs, the aim being to imitate the conditions 

 which are observed when hens make their nests on the 

 ground. The air in the egg-chamber is also moistened by 

 water from troughs suspended above the eggs. Ventilation is 

 provided through tubes which introduce a constant flow of 

 fresh air close under the tank, thus warming it before it 

 comes in contact with the eggs. The impure air is taken out 

 from the bottom. All the eggs are turned at one time by 

 means of an ingenious construction of the bottom of the egg- 

 tray. A set of thermostatic bars above the eggs raise and 

 lower the flame of the lamp or gas burner, and thus adapt the 

 heat given out to the changes of temperature in the room, 

 and hold the heat of the machine close to the desired point by 

 a constant and not by a fitful or alternating action. There is 

 a chamber under the egg-trays which is warmed by the tube 

 which returns the water from the tank to the heater outside, 

 which is used as a " Nursery " for the chicks. 



The machine is well made, neatly finished, easily managed, 

 and gives satisfaction. The inventor has long been before the 

 public as a maker of incubators, and this combines features 

 which have proved their usefulness in his other machines. 

 — , 



*Made by A. M. Halsted, Eye, N. T. 



