Hidden Treasure: The Story of a Chore Boy Who Made the Old Farm Pay

by John Thomas Simpson

"I already know how to regulate the temperature, and turn and cool the eggs."

"Do you know how to test them?" asked Bob, "to tell which eggs are fertile?"

"Yes," replied Edith, "that's easily done. You can use a candle and an old shoe box by removing one end and cutting a hole a little larger than the size of a quarter in the bottom of the box, located so that when it sets over the kerosene lamp, the hole in the bottom will be opposite the flame. Of course, you'll have to cut another hole in the box, so that the heat will escape, and the eggs are tested with the large ends up. This is done so the size of the air cell may be seen, as well as the condition of the embryo."

"How do you tell when an egg is fertile?" asked Bob.

"That's easy," said Edith. "The infertile eggs, when held before the small hole when the lamp is lighted inside the box, will look perfectly clear, same as a fresh one, while the fertile ones will show a small dark spot, which is known as the embryo. Of course, you have to learn to tell whether the embryo is living or dead, but that's easy to learn."

"I think I could take care of an incubator all right," she continued. "The first thing you do is to see if it is running steadily at the desired temperature before filling it with eggs; then you must fill the whole tray at one time and not add fresh eggs to a tray after it's once started. The eggs must be turned twice daily after the second and until the nineteenth day. The eggs must also be cooled once daily from the seventh to the nineteenth day, depending on the weather."

"Do you fix the lamps first, Edith, or turn the eggs?" asked Bob.

"Oh, you must turn the eggs before you fix the lamps," she replied, "and, of course, the machine must be cared for at regular hours, just the same as your dairy cows, and the lamp and the wick must be kept clean at all times—otherwise you would not get a uniform heat."

"When do you test the eggs?" asked Bob.

"On the seventh and fourteenth days; after the eighteenth day you must not open the machine until the chicks are hatched."