Fig. 4.—Testing an egg by the use of a metal-chimney tester which usually comes with an incubator or 
which can be purchased from poultry-supply houses. Such a tester can be readily fitted on an 
incubator lamp. 
and fourteenth days. The infertile eggs and those with dead germs 
should then be removed. White-shelled eggs can be tested on the 
fourth or fifth day, whereas the development in eggs having brown 
shells often can not be seen by the use of an ordinary egg tester until 
the seventh day. 
A satisfactory homemade egg tester or candler can be made with a 
shoe box or any other box that is large enough to hold a lamp. Cut a 
hole a little larger than the size of a quarter in the side of the box, 
so that when the lamp is placed inside the box the hole in the side 
will he opposite the flame. A hole should also he made in the 
top of the box large enough to prevent the top from catching 
fire from the heat of the lamp. If the chimney is long enough it 
should be allowed to extend through the top of the box, to allow the 
Incubation of Hens* Eggs. 7 
dead germs, leaving only 20 fertile eggs. These 20 eggs can then be 
put under two hens, and a new sitting placed under the third hen. 
METHOD OF TESTING EGGS. 
All members of the poultry clubs should be thoroughly familiar 
with the method of testing eggs. An egg, whether fertile or not, 
has a small grayish spot' known as the germinal spot, on the surface 
of the yolk. As soon as a fertile egg is placed under a hen or in an 
incubator the development of the germ begins. Test all eggs at 
least twice during the incubation period, preferably on the seventh 
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