ARTIFICIAL INCUBATION. 1019 



(reduced from the size in ordinary machines,) traversed by the flue 

 L, W from the lamp T. The flue really returns through the tank, 

 so that the outlet W is on the same side as T. The cpncave egg- 

 tray B is supported in a drawer floored with open strips of wood K, 

 K. The concavity brings the outer eggs rather near the heat, and 

 obviates the necessity for moving the eggs about except in turning 

 them. Air enters, as in the machines previously described, through 

 the hole D in the bottom of the incubator, having to pass through 

 canvas soaking in the water-troughs C, C, whence it passes, impreg- 

 nated with moisture,, to the drawer, escaping by the ventilating 

 holes E, E. N is a thermometer. , ; 



The regulation is thus arranged: The lamp T has a vertical 

 flue, V, above it, as well as the heating flue L ; and if this be opened,, 

 all the heat escapes vertically instead of passing through the tank. 

 This flue V is closed by a flap-valve, F, at the end of the lever G. 

 Near the pivot of the lever at P is attached a stiff lifting-wire, pass- 

 ing through a tube, O, in the center of the tank ; and the bottom of 

 this wire rests on the capsule, which is simply laid on a small rigid 

 table at S, and as the capsule bulges it lifts P and F. Should the 

 machine be started thus, the heat would, rise to 98°, when the valve 

 would open. But the sliding weight H allows more pressure to be 

 put upon the capsule, thus raising the boiling-point. Thus the boil- 

 ing-point may be set anywhere from 98° to 107°, and the heat may 

 be kept regulated within about two . degrees. This regulatof. we 

 may remark, has been unusually successful in its operations. 



