How to Turn Eggs.
At the end of forty-eight hours they may be turned. This should be done by gathering up the eggs at the end of egg-tray and placing them upon the eggs in centre of the tray, rolling the centre ones back to the end of the tray. The tray should be reversed, and the same thing done to the other end. It is not necessary that the eggs should be completely reversed,—simply change the position, rolling over one-half or one-third.
The egg-trays should always be turned end for end, and changed from end to centre of machine. This is necessary in case there should not be a uniform heat in egg-chamber, as it will equalize matters, and, in a measure, obviate the difficulty. Now, all this, though it takes some time to describe it, can be done very quickly, requiring only a few moments for each machine. I usually allow about ten minutes for each 1,000 eggs, though it can be done much quicker if one is in a hurry. I am often requested by people to put in patent automatic egg-turning trays in my machines, it would so simplify matters. I reply:
"So it would; and when you can produce a machine with a perfect uniformity of heat in the egg-chamber, I should be most happy to use an automatic tray, but I have never yet seen that machine." In our own double-cased Monarch, in cold weather, there is at least one degree difference between the end and centre of egg-tray. In single-cased machines this difference must be largely increased, and in automatic trays the eggs must necessarily remain where they are placed through the entire hatch. Now, under these conditions, if the heat is right in the centre of trays it must be all wrong in the ends. The hatch will be protracted long after the proper time, and if those on the ends of trays come out at all it will be forty-eight hours behind time and with weakened constitutions, keeping one in constant stir with their sickly plaints. It is needless to say that there is a great mortality among birds of that description, and at the end of ten days they are usually among the things that were.
Hatching the Eggs.
The next thing is testing the eggs. This matter is essential as well as economical, with both hens and incubators. I once knew a man who ran a six hundred-egg machine for three weeks on one fertile egg. The other 599 proved infertile, and he did not know it until they refused to hatch at the end of three weeks—a great waste of oil, but a greater waste of time,—three whole weeks in the best part of the season. Another man kept forty hens sitting three weeks with an average of one fertile egg to each bird, when three of them could have done all the hatching just as well, and then, at the end of four days, could have had the rest put upon better eggs.
A great waste of hen power, you will say, with time lost, together with forty dozen eggs, which would have been just as good for table use had they been tested out in four days. It often happens in the winter, when eggs are apt to be infertile, that, after testing the contents of four trays, they can be contained in three, when the other can be filled with fresh eggs. Here is where the advantage of adjustable trays comes in. Often the operator running a large machine has not eggs enough to fill it without a part of the eggs becoming very old, and also losing ten or twelve days of valuable time; with the adjustable tray, eggs can be introduced at any time, and the same heat preserved on all. I usually test duck eggs at the end of the third day. The fertile germ is then plainly visible, and the eggs can be passed before the light, several at a time.
The novice had better postpone the operation till the fourth day, when he, too, will have no trouble in detecting the germ. The same rule will hold good with all white eggs, but dark-brown eggs should not be tested till the sixth or seventh day. This can be done much sooner, but a large machine full cannot be tested in a minute, and the eggs should be far enough advanced so that the operator can take two or three in his hand at once, and passing them before the flame, readily detect the germ. I never use a tester for duck eggs, as a simple flame is sufficient, the egg being translucent.
During the first stages of incubation the germ is very distinct, even at the third day. The clear eggs are reserved for family use or disposed of to bakers. An expert cannot distinguish them from a fresh-laid egg, either in taste or appearance. There is usually a small percentage of the eggs that are slightly fertilized, in which the germ will die during the second or third day. These can be readily detected at the end of the fifth day, and should be taken from the machine, and reserved as food for the young ducklings. Another and potent reason why all infertile eggs, and those with dead chicks in them, should be taken out of the machine, is that after the circulation begins in the egg, especially during the last part of the hatch, the temperature of a live egg is several degrees higher than that of a dead one. The one radiates heat, the other absorbs it; so that if the operator is running his machine 102 degrees, with his glass on a dead egg, he may be all unconsciously running it at 104 or 105 degrees on a live one.
I had a letter from a man some time ago stating that his thermometers were developing strange freaks,—that though they registered the same while in water, at 103 degrees, when lying on the eggs a few inches from each other in the machine, they were several degrees apart, and wishing to know by which he should run, the higher or lower. I wrote him that his glasses were all right, and that he was the one at fault, and had he followed instructions and tested his eggs he would have had no such trouble. He wrote that as his machine was not quite full, and as he had plenty of room, he neglected to test them, thinking it would make no difference.