58 POULTRY FOR PROFIT 



soaking through into the nest. On such trifling mat- 

 ters as this does the success of a hatch depend. 



Test the Thermometer 



The incubator thermometer should be tested at 

 the beginning of every season. Any druggist will 

 test the thermometer for you, or you can do it your- 

 self by obtaining a physician's clinical thermometer, 

 which is known to be correct, and placing the bulbs 

 of both thermometers in water which has been 

 warmed to 100 degrees. The difference should be 

 carefully noted and allowed for in reading the in- 

 cubator thermometer. 



It is also a good plan to test the temperature of 

 the egg chamber by placing several thermometers 

 in different positions on the tray. If the tempera- 

 ture in one part of the egg chamber is lower than 

 in other places, this indicates that that side of the 

 tray is lower and needs to be raised. 



The Moisture Problem 



Many incubators require additional moisture at 

 hatching time, but this is a matter that should not 

 be meddled with until you are perfectly sure that 

 yours is this sort of machine. It is a problem the 

 best operator understands but partially, and there 

 is almost as much danger of drowning the chicks 

 by giving too much moisture as of their failing to 

 get out of the shell for lack of it. If the air is too 

 dry the moisture in the egg will evaporate too 

 rapidly. If the air is too moist it will evaporate too 

 slowly. There you are, between Scylla and Charyb- 

 dis, for no one has yet devised a way of finding 

 out certainly whether the vapor pressure, which is 

 practically the same as humidity, is just right or 

 not. When it has been proved, by previous hatches, 



