220 POULTRY FOR PROFIT 



which point the temperature is maintained through- 

 out the balance of the hatch. Readjustment of the 

 regulating device is frequently necessary when run- 

 ning a machine filled with strongly fertile eggs, as 

 there is always a tendency to a rise of temperature, 

 and this is considered a good sign. 



"The duck eggs are tested out after they have 

 been incubated about seventy hours and all the clear 

 eggs are sent to market. They are not in the least 

 injured for culinary purposes and will boil perfectly, 

 which is considered one of the best tests of a fresh 

 egg. In keeping qualities these tested out infertile 

 eggs are superior to all others, as they will keep in 

 perfect condition for months if kept in a cold dry 

 place. 



"A second test is always made on the tenth or 

 twelfth day and all eggs missed at first test, or those 

 in which the germs have died, are removed. A final 

 test is made on or about the twenty-fourth day. 

 Whenever a dead egg becomes putrid it is smelled 

 out and removed. These can often be detected by 

 color or marbled appearance of the shell. 



"The wire cloth of the egg trays is covered with 

 or replaced by burlap, which is less liable to injure 

 eggs and makes turning easier, as the eggs do not 

 roll about on it as they do on wire. Moisture is used 

 in the machines from the eighteenth day and is 

 considered a necessity in incubating duck eggs. The 

 usual method is to sprinkle the burlap and the eggs 

 thoroughly with water at about the temperature 

 of the eggs, the object being to saturate the air of 

 the egg chamber with moisture. 



On the twenty-sixth day the eggs and trays are 

 made quite wet with moderately warm water and 

 the machine closed to remain so till the hatch is over. 

 The ducklings are usually all out on the twenty- 



