RANKIN'S DUCK BOOK 



as you can, as it will always cool your eggs perceptibly, and 

 more or less derange the temperature of your machine. This 

 is of course decidedly injurious and will more or less impair 

 the hatch. Now, this is a very important matter, and people 

 do not give it sufficient consideration. 



It is even advocated, by some incubator manufacturers, 

 that eggs should be cooled every day to 70 degrees, for the 

 simple reason that the old hen -does. They do not take into 

 consideration' that it is a necessity for the old hen, but may 

 not be for the embryo chick. When the hen leaves her eggs 

 to feed, and they become partially cold, when she recovers 

 them and brings those eggs in immediate contact with the 

 rapidly-pulsating arteries of her body, in fifteen minutes they 

 have acquired their normal heat. With the machine it will 

 require an hour or two. 



To meet this difficulty suitable instructions should be 

 given with and to suit different machines. Where the eggs 

 are turned automatically inside the machine, it is necessary 

 that they should be cooled at least once a day during the 

 last two weeks of the hatch. Taking the eggs out to turn 

 twice each day, cools them sufficiently during the winter 

 months ; in warm weather, leaving the outside and inside doors 

 open while turning cools them sufficiently. 



Some incubator manufacturers will tell you that thermal 

 changes, however great, will hot affect their machines. Their 

 patrons tell a different story. No machine was ever made, 

 or ever will be, that will run as well or give as good results 

 amid constant thermal changes as in an even temperature. 

 It is true that they reduce the heat, but it is by admitting 

 large draughts of air, running off the moisture and completely 

 destroying the humidity of atmosphere in their machines. 

 Then, how about those little ducklings which have been pipped 

 forty-eight hours? They can never get out unless you help 

 them. 



Suitable Buildings 



Many insurance companies object to incubators being 

 run in buildings covered by their policies, and will often 

 cancel them. This originated from the fact that so many 

 fire-traps, which were thrust upon the public in the shape of 

 incubators, had consumed the buildings in which they were 

 operated. The insurance companies were obliged in self- 

 defense to prohibit their use in insured buildings. But the 

 interdiction is usually removed upon the representation that 

 the machine is safe. Sometimes a slight premium is exacted. 

 In the event of insurance companies being obdurate, it is very 



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