I do not propose here to give my experience, together with the many experiments made during the last twenty years, but shall aim to give the reader simple instructions for hatching and growing ducks for market and selection of breeding stock. I would say here that the first thing for the operator to learn in turning the eggs is to do it carefully and well, without breaking or unnecessarily jarring them; and then, to do it as quickly as possible, especially if done in a cold atmosphere, so as not to derange the heat in the egg-chamber. The next thing is to maintain as even a temperature as possible during the hatch. I do not think that a variation of one degree is at all detrimental. But different people have different ideas of regularity. A man who did not have a first-class hatch, wrote me that he had kept the machine right to business, as it had run between 90 and 110 degrees during the entire hatch. Another man wrote that his machine had been as low as 100 degrees, and once up to 103 degrees, and wishing to know if I thought it would be fatal to his hatch.
There is no such thing as accuracy in the composition of some men, things are run "hap-hazard," failure and misfortune are always attributed to conditions, circumstances, or hard luck,—never to themselves,—and in case of a poor hatch, always the incubator. Instructions go for nothing with them. An enterprising incubator maker told me one day that he believed that the world was composed of cranks and fools (at least the poultry part of it). The one-half did not know anything, while the other half had all that was worth knowing and despised all instructions and common-sense.
In running your machine, the first step is to set it level and see that the glasses register alike in both ends of the machine. Next, procure good oil, 150 test (as poor oil will necessitate frequent trimming, besides crusting the wick). Do not use more flame than is necessary, as it will only be a waste of oil, and with some machines will increase the ventilation, and at the same time decrease the moisture. Be regular in both filling lamps and trimming them, as irregularity frequently involves forgetfulness, and that sometimes means disaster to the hatch. In trimming, it is well to turn on the same amount of flame in relighting your lamp as it had previously.
Figure 1.—Showing First Indication of Fertility.
In the Monarch Incubator this required amount can readily be seen at once by the action of the regulating bar. It informs the operator just when he has enough,—when too much and when too little. Keep both lamps and chimneys clean, and have stated periods for turning your eggs, which should be done twice each day. As I said before, an egg-tester is not required with duck eggs, as they are so transparent that the whole process can be plainly seen without in the flame of a common kerosene lamp. If a duck egg is carefully examined, after being subjected to a heat of 102 degrees for twenty-four hours, a small dark spot will be seen about the size of a large pin-head. This little spot, if the egg is gradually turned, will always float over the upper surface of the egg. This is the life germ, and the first indication of fertility in the egg, and is represented in Figure 1.
At the end of forty-eight hours this dark spot will have nearly doubled its size, and a faint haze will appear around its edges a shade darker than the surrounding contents of the egg. This haze is the first appearance of the blood veins radiating out from the germ.
Figure 2 shows how the egg appears at this stage with the air-cell slightly enlarged.