Thus, the one interested in getting a start in poultry has an option on either of these three ways. The local circumstances of the purchaser will largely determine which method will be the best. But which ever method is used, let me caution you that too much care can not be given in finding a source that is perfectly honorable in their business dealings, as there has been in the past a considerable amount of unfair dealing on the part of some dealers in the poultry business, but I am glad to say that these people are fast being weeded out, and the tendency is now for honest, upright dealings in all three branches of the industry, as the dishonest people have found that their methods forced them out of the business. Not everybody will be independent of the incubator, however, so we will next discuss something in regard to the commercial incubator, also including and comparing the natural incubation of the egg. CHAPTER IV. INCUBATION In order to get a better idea of artificial incubation, let us first examine a few facts concerning the way in which the hen hatches her eggs in the natural process. The fertile egg is hatched when the egg is subjected to a heat over 100 degrees, F., for a period of about twenty-one days. The mother hen, by setting on the eggs for this period, will bring off her hatch on the twenty-first day, if she has been given ordinary care. Let us see what are the principles involved in this natural incubation, that we may the better understand the artificial method of incubation. When the hen first becomes broody, and wants to sit, she might try to “steal her nest.” This is another way of saying that she will try to locate some secluded spot, and after she has succeeded in laying a dozen or fifteen eggs, she will then spend nearly her entire time on the nest, until she proudly marches back to her old haunts with a small clutch of chickens. It is a natural instinct of most hens to become broody in the spring of the year, to reproduce their kind. A constant desire to sit on the nest is a sure sign of broodiness. When one has the eggs to put under the hen to hatch, it is best first to try to secure a general purpose bird for this method, as they have been found the best, for reasons previously stated.