PROGRESSIVE POULTRY CULTURE 67 



Extinguish the flame of the incubator lamp an hour 

 or more before the eggs are to be placed in the machine. 

 Arrange the selected eggs on the trays and let them 

 stand in the incubator room long enough to gain its 

 temperature. Then slide the trays into place in the 

 incubator and light the lamp. It is well to begin incu- 

 bating in the morning so that the eggs and egg-chamber 

 will have time to warm up during the day and allow 

 of regulation before the operator retires for the night. 



Do not let the temperature on the level of the tops 

 of the eggs rise above 101 for several days and cer- 

 tainly not above 102 during the first week. The living 

 tissues of the embryo are delicate and the danger from 

 excessive heat in artificial incubating is very great. 



Ventilation of the egg-chamber may be restricted 

 the first few days, because only a slight amount of air is 

 required to supply oxygen for the small net-work of 

 blood-vessels within each live"egg. 



Now is the time to supply extra moisture by means 

 of water trays or wet sponges placed within the egg- 

 chamber if the air surrounding the eggs is at all dry. 

 If the machine is warmed by means of hot air moving 

 in a current through the egg-chamber it is possible to 

 increase its humidity by sprinkling the floor of the room 

 plentifully or frequently with water. The moisture 

 evaporates and is taken up by the air of the room and 

 some of this air after being heated by the incubator 

 lamp, passes into the egg-chamber. The moisture in 

 the air tends by its action on the shells of the eggs, to 

 decrease the size of the pores of the shells and thus 

 diminish the supply of air and therefore of oxygen 

 passing into the eggs. It is thus seen that the supply of 

 air may be reduced by restricting ventilation or by in- 

 creasing the humidity of the air in the chamber of the 

 incubator. 



Let the eggs remain on the trays without moving for 

 three full days. On the fourth day gently turn the eggs 

 by hand a little and reverse the trays. On the fifth day 

 the eggs may be rolled over and moved about to change 

 their positions on the trays besides reversing the trays 



