TESTING EGGS FOR INCUBATION 63 



The Incubator 



Cripples usually come from overheating the incubator, or from 

 irregularity of heat. Poor or insufficient ventilation will also cause 

 cripples. 



Now, what was the reason for these failures and what can others 

 learn from them? After a careful examination of the incubator, 

 which was a good one of the most approved make, I decided first 

 that the incubator did not stand perfectly level ; secondly, that the 

 thermometer was at fault. When the incubator is in the least de- 

 gree out of level, the heat will go to the highest side, leaving the 

 lowest possibly a degree or more too cold. The first thing to be 

 learned from this lady's failure is never to start the incubator with- 

 out being absolutely certain that it is perfectly level. The only 

 way to do this is to use a carpenter's spirit level. Put it on top of 

 the machine at each side and then crosswise, and be sure that the 

 bubble of air is at the proper spot. You may think that because it 

 stood level last year it is most likely to be all right this year. That 

 is leaving it to chance. One of the legs may have shrunk ever so 

 little from the dry weather or swollen from the dampness of the 

 room or the floor or ground may have changed ever so little at one 

 corner or side without it being perceptible to the eye. It is much 

 "better to be sure than sorry," so whether you are an expert or not, 

 do not commence this season to hatch without testing your ma- 

 chine with a spirit level. Do not trust to luck "pre-arrange" and 

 success will be yours. 



Test the Thermometer 



Do not start the incubator this season without testing also the 

 thermometer. Some friends of mine once bought a new incubator 

 of standard make. The thermometer was guaranteed correct ; two 

 years seasoned. They had just received from Canada twenty dol- 

 lars' worth of very choice eggs, and as they wanted to be sure of a 

 good hatch from those prize eggs, they bought this new incubator, 

 although they had a good one. Not an egg hatched ! They after- 

 wards discovered that the guaranteed thermometer was two de- 

 grees wrong. Do not trust to last year's testing. Thermometers 

 vary, and it takes at least two years to season them. 



It is not difficult to test a thermometer, but to do so you must 

 have one perfectly correct and accurate. This you can either bor- 

 row from the doctor or from your druggist, or you can take one 

 of your thermometers to the druggist and ask him to test it for you. 

 Then, having one that is accurate, take a bucket holding about two 

 quarts of water, put warm water heated to about 105 degrees into 

 the bucket, and put your thermometers into it with the bulbs all at 

 the same level. Keep the water well stirred, so the heat will be the 

 same all over. Hold the thermometers in it for fifteen minutes, then 

 read them and note the difference. If your thermometer is half a 

 degree too low, mark on the incubator, "Thermometer half degree 

 too low; run incubator half degree lower than directed," or oppo- 

 site if the thermometer reads too high. If you buy a new ther- 



