In Fig. 128 is shown a simple form of this apparatus known as Corbett's incubator, which consists of a cylindrical wooden box, in which are placed two sieves containing the eggs. During the process of hatching, the box is buried to its upper edge in horse-manure, which must, however, be the product of grain-fed (not grass-fed) horses, and must not be over two months old. The ventilator shown at the top is opened to reduce the temperature as desired.
After the eggs are hatched the chicks are removed to what is termed the " artificial mother," shown in Fig. 129. This is a box exactly the same as the incubator, but provided with an horizontal disk, covered on the underside with a piece of sheep-skin from a long-wool sheep, and arranged to be moved up and down by a screw. The manure is heaped partly around the box, to provide the needed warmth; the door is let down for a pathway in and out for the chicks (see Fig. 129), and in this they are placed as soon as ready to be removed from the incubator. After having been fed a few times, the chicks will learn to Come out from beneath the wool to feed when the platform is tapped.