As a result many poultrymen who are making money with poultry use some such system as the open front house with various changes. They have found that fresh air is an absolute requirement to get the best results. But this matter brought out a few more interesting facts. It was found that dampness was a big drawback to egg production in cold weather. If the damp foul air, breathed out by the chickens, could not escape from the poultry building, the chickens did not have the health and vigor that they did in well ventilated houses. Consequently, the curtain helped considerably in allowing the fresh air to come in, and for the foul air to go out. The damp air, being heavily laden with moisture, settled to the bottom of the house, where the birds scratch, and unless the curtains extend fairly well down near the bottom of the house, the damp air has not a very good chance to escape, and consequently, there will be more or less moisture even with this type of house, if the damp air has no chance to escape. Another common fault with a great many poultry buildings is that they are drafty. The walls should all be air tight, except the south wall, or front, as has been mentioned. If there is a draft in the house the birds will contract a cold, and will take a prolonged vacation from their job of laying eggs. It is not uncommon to find a crack in the wall, just behind the perches of the house, and when we consider that in such houses the birds stay all night in a direct draft, it is little wonder that they appear so unhealthy. There are a few other common faults that we will consider before bringing this chapter to a close. It is often found that there are too many birds cramped into a small house. It is a good plan to allow at least four square feet of floor space for each bird that you winter. For instance, if we were planning on having one hundred birds this winter, we could have a house built twenty-five feet long, and sixteen feet deep. Multiplying these two figures, gives us four hundred square feet. Dividing this product by four, gives us allowance for one hundred birds. Then, lastly, the floor, itself. Too often the floor is cold. If a cement floor, we should cover it with about six or eight inches of good, clean, dry litter. Even if made of wood, a good substantial litter should be maintained. The best litter is probably of straw, but peat moss is fast gaining favor at present, where straw is not obtainable. With these few objections to guard against, let us next discuss just how we shall go about constructing a poultry house that will overcome the faults mentioned. CHAPTER X. HOUSING POULTRY FOR PROFIT.