1 02 INCUBATION 



correct ia stirred about in warm water until the degree 

 of heat is 105 F. or a little higher. Other thermometers 

 are then held in the same hand with the one known to 

 be correct and all are stirred about in the water so that 

 the reading of all may be taken under like conditions. 

 Any instruments that fail to mark the temperature cor- 

 rectly are rejected. It is best to test all thermometers 

 in use at least once a season. 



The printed directions that come with each incubator, 

 giving instructions for its operation, also tell where 

 the thermometer is to be placed in the machine, and to 

 secure the best results such directions should be fol- 

 lowed to the letter. The thermometer is usually placed 

 in or near the center of the egg tray. 



Temperature and Moisture. An expert who has had 

 more practical experience with the use of incubators 

 than any other man has said: "Briefly stated, all that 

 is required to hatch eggs artificially is a temperature 

 of 100.5 F. at the center of the eggs, which is 101 F. to 

 103 F. by contact; at the same time, the eggs should 

 be immersed in still air containing moisture of a relative 

 humidity of from 45 to 70 per cent., this moisture to be 

 changed sufficiently often to carry off the waste gases 

 eliminated by the eggs. Any excess of ventilation be- 

 yond this is deleterious." 



Professor Lamson, of the Connecticut State Agricul- 

 tural College, has said that the chief factors in the arti- 

 ficial incubation of good fertile eggs are "temperature, 

 turning the eggs, moisture, and ventilation." The mean- 

 ing of this would be that when eggs are hatched in the 

 incubator, the temperature as usually taken by a ther- 

 mometer should range from 101 F. to 103 F. and that 

 when a thermometer is used that would indicate the 

 temperature at the center of the egg the temperature of 

 that position should be 100.5 F. The thermometer used 

 for taking this particular test is known as the "In-Ova 

 Thermometer." This is a thermometer the bulb of which 

 is inside a celluloid egg, the bulb resting in the center 

 of the egg. When such a thermometer is used it indi- 



