Читать книгу Making Home Profitable - Kate V. Saint Maur - Страница 9

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There are a great many incubators on the market, some heated by hot air, others by hot water. If you select any one of the standard makes advertised you will get a good, practical hatcher. Printed instructions for setting up and running are sent out with every machine, but they don’t emphasise all the important points quite strongly enough for amateurs. Lots of people can’t drive a screw home accurately, and fail to realise that if the head is slightly to the right or left it throws the fixture which is being attached to the machine out of plumb, and a hair’s breadth makes a difference when such delicate appliances as thermostatic rods (the power which controls the heat), are concerned. A blunder supplies much knowledge. I should never have realised the necessity for absolute exactness if one of the screws used in attaching the lamp support to our second incubator had not gone slightly awry. It caused the chimney almost to touch one side of the socket into which it fits. That, in turn, drew the flame to one side, and caused it to smoke at night when turned up for extra heat. It was a very little blunder, apparently, but it almost spoiled the incubator, and quite spoiled the hatch.

To be sure that the incubator fixtures are plumb, use a spirit level, the only safe guide. After starting the machine, practise running it for a few days before putting in the eggs. When the heat reaches one hundred and two and one-half degrees, with the escape dial hanging the width of a match from the opening, put in the trays, which, being cold, will lower the heat, and should close the dial until the trays become warm, and the thermometer in the machine again registers one hundred and two and one-half, when the dial should once more be dangling the match width above the opening. Should the closing and opening not take place as the heat varies, the machine is not properly adjusted, and you must practise until it will bear the test before putting in the eggs.

The thermometers are supposed to have been tested before they are shipped, but it is well to buy an extra one and compare them; or get your doctor, who is sure to have an accurate thermometer, to do it for you. The egg tester comes with the incubator. It is a tin, funnel-like chimney that fits over the lamp, and has a projecting opening, bordered with black, before which to hold the eggs. The first test should be made on the seventh day; the second on the fifteenth day. Hold the egg, large end uppermost, in front of the opening. If it looks perfectly clear it is infertile and can be used to feed young chicks. If it shows a dark-red spot with spidery legs it is fertile, and must be returned to the incubator. Dead germs are rarely discernible at the first testing, except to the expert eye. By the fifteenth, the veriest amateur will be able to detect them.

Successful incubation depends principally on being able to maintain the amount of heat and moisture necessary at the different stages of development. A thermometer is furnished with most incubators, but as yet hygrometers are not, so it is advisable to buy one. For as they only cost $1.50 each, it would be pennywise and pound-foolish to do without one. Having these two little instruments to tell exactly the amount of heat and moisture present in the machine, simplifies the work wonderfully.

Personally, I like to have the thermometer register 102 degrees, and the hygrometer 75, when I first put the eggs in the incubator. The second week, the heat is increased to 102½, and the moisture lowered to 70 degrees. The third week, heat from 102½ to 103; moisture not over 45 until the nineteenth day, when the moisture is again increased to 55 or 60 degrees.

The reason for such fluctuation in the moisture may need some explanation. During the first stages of incubation it is necessary to prevent the escape of the water which is part of the egg, as it is needed to keep the albumen in the right condition for the development of the germ. After the tenth day, when the embryo is formed, the water should be gradually allowed to evaporate, so that the amount of air inside the shell increases, as it is needed to aid the circulation of the blood and permit the growth of the chick. Increasing the moisture again on the nineteenth day is simply done to soften the inside skin of the egg and make it easy for the chick to break through.

When extra moisture is to be supplied, place a pan of wet sand or a damp sponge in the bottom of the incubator. If the machine is standing in a very damp cellar, the difficulty is often to keep down the moisture rather than to increase it.

In this case, keep the trays out of the machine for a greater length of time when you turn the eggs each day, and open the ventilators. Probably the safest and simplest way to learn how to gauge this important point of moisture, is to set a hen at the same time that you start the incubator, and then compare the development of the air-cell in the egg every few days. If the development is too slow, open the ventilators at the side of the incubator wider, and air the eggs a little longer each day when you have the trays out to turn the eggs. Reverse affairs if the development is too quick. It is better to run the machine a degree or two above the given temperature than below it, especially during the last few days.

After the morning of the twentieth day don’t open the incubator until the hatch is over, or until late on the twenty-second day, and don’t get nervous if the temperature runs to one hundred and four or even to one hundred and five; it is caused by the animal heat of the chicks, and will do them no harm. Turning down the lamp slightly will of course reduce the heat; but be very careful not to let it run below one hundred and three during the last twenty-four hours. Low temperature prolongs the hatch, weakens the chickens and makes them susceptible to all sorts of ailments.

Individual outdoor brooders I think are the best, for in very cold weather they can stand in a light outhouse. I used to monopolise the summer kitchen from February to April, and then have them placed out in the orchard. Placing an outdoor brooder under cover is really only for the convenience of the attendant, for they are storm proof. If you commence with an incubator that holds one hundred and twenty to one hundred and sixty eggs you will require two brooders, and if in a cold or Northern locality, some small house which can be warmed during very cold weather, if you propose commencing to incubate in January. A brooder supposed to hold one hundred chickens will accommodate that number comfortably for about nine days, after which not more than fifty should be kept in it. Hence the necessity for two brooders. When the chicks are six weeks old in cold weather, and four weeks old in moderate weather, they can be removed to the small house (the temperature of which should be kept at sixty degrees during the night). Remember, incubation takes only twenty-one days, so you must allow at least three weeks to elapse before starting the incubator a second time.

Give the brooder a good coat of whitewash inside before using it. Cover the drum which furnishes the heat under the hover with two or three thicknesses of flannel, to make it soft for the little bodies to cuddle up against. Cover the floor of the hover compartment with a piece of old carpet or felt, and the outside compartment with sweepings from the haymow. Have the heat running steadily at ninety-five degrees for several hours before the chicks are to be put into it, and keep it at that heat the first seven or eight days. Then gradually let it fall to seventy-five degrees. Of course, I mean the heat under the hover. The rest of the brooder will be—and should be—several degrees lower.