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THE PEOPLE'S PRACTICAL POULTRY BOOK. 



upper end of rod, N, is attached to an arm or lever, O, which is pivoted at 

 one end and swings freely at the other. P, represents a valve, which com- 

 municates with the incubating space, C, and is connected by wires, R, with 

 the free end of lever, O ; said wires are not rigidly connected with valve, P, 

 but have a sliding attachment. S, represents the lamp-burner, which is 

 provided with the tube, S, which is beveled off at one side, as shown. T, is 

 a guard or regulator, which is journaled on shaft, , beside the tube, S, and 

 when not in operation inclines from the same. The shaft, , is bent on the 

 outside of the burner into an elbow or crank, U, which is connected by the 

 spiral spring, V, to the lever, O. The operation of this invention is as 

 follows : The standard temperature for hatching eggs is about one hundred 

 and two degrees Fahrenheit, at which point this device is arranged to remain 

 inoperative ; but, 1 when the water' in tank, D, becomes heated above this 

 point, the expansion of the alcohol in tubes, K, causes the cork float or 

 piston, N, to elevate the rod, N, and lever, O, which latter being connected 

 to valve, P, by wire, R, and to regulator, I, by spring, V, opens valve, P, 

 and causes regulator, T, to close over the beveled side of tube, S, thereby 

 lowering the flame in proportion to the nearness it approaches the tube. 



FIGURE 3. FIGURE 4. 



When the valve, P, is opened, warm air rushes up through tube, W, and out 

 through said valve, thus coiling the space, C ; while the flame of the lamps, 

 being diminished, the temperature of the water in tank, D, will fall until the 

 medium of one hundred and two degrees is reached, when the alcohol in 

 tubes, K, will contract far enough to lower the lever, O, valve, P, and 

 regulator, I, to their former positions. X is a tube for drawing off the 

 water from the cold water tank, B ; Q is a slide, when the heat does not pass 

 off as rapidly as necessary through the valve P, to cool the incubator space 

 C, open the draw Q, and the cold air rushes in from below drawing out 

 the hot air above. It should always be borne in mind, however, that the 

 opposite end of the machine has a similar arrangement to that shown in 

 figure 1, with which one of the tubes, K, connects the whole operating in 

 connection. The wires, R, are not rigidly attached to valve P, as above 

 mentioned, but slide through a staple or orifice in the same, to the end that 



