experience of one season with one of these ma- 

 chines (in California), and a season with three of 

 them (in Pennsylvania). 



" REGULATION." 



" This machine is regulated by the expansion ol 

 water. At one end of the tank, which contains thirty 

 gallons of water, is attached a regulating tube 

 some three or four inches in diameter. In this 

 tube is inserted a float made of thin brass foil, 

 weighing perhaps one ounce, but displacing water 

 to the amount of one and one-half pounds. 

 This float, with the expansive and contractile 

 force of thirty gallons of water behind it, 

 works with the regularity and precision of a 

 steam engine. [Regardless of what the heat 

 may be in the egg chamber, which must vary 

 according to the outside changes of temperature.'} 

 When the water expands it raises this float, which 

 forces up a small level bar to which is attached the 

 extinguishers on the lamps. When this float rises, 

 as it must do with the least expansion of water, the 

 heat is cut off on the lamps. [ The flame is lowered, 

 provided the lamp trip does not stick ; but if the 

 temperature of the room rises, you must be there to 

 add more water to make it lower the flame more 

 than usual, or to put out the light entirely. ] Should 

 the water cool and contract, the blaze is turned on 

 in full force. [If the room should become cold, the 

 operator must draw off some water , much or little, 

 according to circumstance s.~\ Now, as the tank is 

 the source of heat for the egg chamber, one can 

 readily see that it is impossible to injure the eggs by 

 94 



