One of the easiest constructed forms of incubator for the artificial hatching of eggs consists simply of a cask well buried in a manure-heap. In the bottom of the cask place one or two sieves to hold the eggs, and make a door in the side for the removal of chickens, etc. A pane of glass may also be inserted either in the door or at any convenient point for viewing the interior. In the head, which should be removable, make an opening provided with a sliding cover, for regulating the size of the aperture, as may be necessary. Form a bed of fresh manure about 1 ft. thick (after bedding) and 6 ft. square. On this set the cask, and pack more manure around the latter until flush with the top. Now take off the head or cover and place a thermometer on one of the sieves. Replace the cover. The natural heat of the manure will warm the interior of the cask. When the temperature reaches 104° (seen by the thermometer), place the eggs on the sieves. The hatching process then begins, and lasts the usual time. Care should be taken to turn the eggs over once a day, and to allow them to cool slightly, thus imitating the natural habit of the hen when she leaves her nest in search of food. The temperature of the interior is kept uniform at 104° by removing manure from the side of the cask to lessen the heat, or by substituting manure fresh from the stables in place of the older material, in order to increase the warmth.

After the chickens have emerged from the shell, the interior of the cask should be carefully cleaned, and an artificial "mother" placed inside. This last consists of a loosely-fitting disk of wood, covered on its under side with sheepskin or a piece of buffalo-robe. Under it the chickens nestle. It may be supported from the head by a piece of cord, or by a rod held in clamps, so that its distance from the bottom of the cask may be adjusted to suit. The warmth necessary for the young chickens is maintained by the manure, so that the latter answers both for this purpose and for the hatching. The slide mentioned above, as located in the head of the cask, is intended for ventilating the interior.

This plan is now in practical operation on one of the largest poultry farms in the country and is evidently more simple than any other involving the use of special apparatus and gas or lamps for heating. A cylindrical vessel must be used-never a square one, since the chickens, in the latter case, will crowd into corners and smother each other. The number of eggs hatched depends upon the size of the cask or the number of casks used. As many as one thousand eggs have been thus incubated at a time. Any farmer having a manure-heap, however small, can easily test the plan, if only with a dozen eggs. The matter requiring the greatest care is to keep the temperature in the cask uniform, and to have the manure sheltered from rain, which would cool it.