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To produce 27 millions of chickens without artificial heat, at least two millions of productive hens would be required in the space of four months!
The artificial mode of hatching does not oppose any obstacle to the natural one, since a hen born by means of the oven, or under the wings of the mother, at every season of the year can as well in Egypt as in any other country cover and hatch its own eggs.
One great inconvenience has been attributed to this method-it is said that the fowl degenerates, and consequently its egg.
This opinion originated in observing that the fowl of Egypt is generally smaller than that of Europe. The fact is true ; but I can by no means agree that it is the consequence of artificial hatching. It is to be considered, 1st, That in Egypt several animals are of smaller size than those of other countries. 2d, That the artificial hatching consisting only in applying to the egg the same degree of heat that it might receive under the hen, without changing any of the natural operations, the number of days which it employs in vivifying it, &e. there is no plausible reasons to suppose that the chicken does not under this process attain its natural size, 3d, That there is in some parts of Upper Egypt a large kind of fowl called bigany or dinderany, and its eggs placed in the oven produce fowls equal in size to the mother. 4th, and to me the most convincing argument of all-if the action of fire could so reduce the fruit of the egg during its development, other circumstances being the same, the same cause must continue to operate every year, and small as this annual diminution may be considered in the number of ages that this method has been practised, (we find artificial egg hatching mentioned by Herodotus,) the fowl of Egypt ought to be reduced by this time to the size of a fly at least. Lastly, even admitting the hypothesis of degeneration, we must admit that the decrement has operated in a very slow and imperceptible manner. This diminution being so inconsiderable, can by no means neutralize the beneficial results of artificial hatching.
The economy and benefit that this method is capable of diffusing among those who practise it being sufficiently demonstrated, I will proceed to give a circumstantial narrative of all the steps of the operation, as I have seen it practised in the ovens established in Ghisa, a suburb of Cairo, situated upon the right shore of the Nile.
The building is composed of a corridor with vaulted roof 40 feet long and 5 broad (A B C D, fig. lst) The vaulted roof has five small apertures to give light. In the centre, to the right hand, there is a door of 31 feet high and 2 broad (E, fig. lst); this leads to another corridor (F G H I, fig. lst) 48 feet long by 5 broad, also with vaulted 41 roof, in the centre of which there are three apertures (J K L, fig. 2nd) of nine inches in diameter, to give light from above; to the right and left hand of the corridor there are five divisions or cells of two stoves. Each inferior room or stove has aperture of 14 feet square I, fig. 2nd). The superior room has another aperture above of two feet five inches in height, and one foot nine inches broad (N, fig. 3rd); it has also an aperture of one foot square in the wall of the right hand, and another of equal size in the left, which I have seen constantly stopped up with tow (d, fig. 4th). The walls of the said upper stove begin rectangular from the ground, finish in a vault of 6 feet high (0, figs. 3rd and 4th), with a hole in the top of nine inches diameter (P, figs. 3rd and 4th). The ground of this room is nine feet long and eight broad (X Z V U, fig. 5th) and has in its breadth, that is to say in the same direction with the corridor, two grooves (QQ, RR, fig. 5th.) of nine inches broad and two deep, and in the centre an aperture almost round of two feet in diameter (S, fig. 5th). The first room entering to the right hand is destined to keep a fire always kindled; it has only one stove, and its door is larger than the others (T, fig. 2nd). The first room to the left hand has no hole in the ground of the upper stove, but only a fissure of two feet, which separates the ground from the interior of the wall, to which it is notwithstanding united by several iron bars in the form of an oblique grate, (b, fig. 6th.) In this cell the materials destined for combustion are thrown through the hole in the top. They pass through the grate as through a sieve, and are taken away by the inferior aperture to be transported to the opposite cell which contains the magazine of fire.
There are, lastly, to the left hand of the exterior corridor two rooms 15 feet square, with vaulted roofs of 12 feet high, with an aperture in the top ; they are intended for the preparation of eggs, as well as a place for chickens recently born, &c. (f and g, fig. lst).
The material for constructing the oven, is the same employed generally in Egypt for the houses of the peasants; that is to say, mud mixed with straw. The vaults are constructed with burnt bricks. The ground which divides the cell in two stoves is sustained upon two trunks of palm trees parallel to the corridor, and a bed of branches of the same tree supported by the said trunks. Upon this entablature is spread the mud which forms the ground whereon the fire is placed.
A little straw or tow is prepared on the ground of the inferior room ; upon it a mat is placed, and upon the mat 6000 eggs,
which are not more than twenty-one days old, taken from a hen-yard in which there is a cock.
For combustibles the dry dung of animals is used, which the Arabs reduce to small pieces with their hands; this material they call (dims). In the first room to the right hand two pyramids of burning dims are formed, covered with common earth. The dims must take fire slowly, without making a flame. It is taken up with a fire shovel, put on to a plate of baked earth, and afterwards placed in the grooves (Q Q, RR, fig. 5th) which have been first half-filled with cold dims. Again a little dims is placed upon the burning portion, and upon the whole a little earth is strewed. The burning dims which is taken from the magazine is continually replaced with an equal quantity of cold material.
On the morning of the day destined to begin the operation the fire is placed in the cell to warm it, and at sunset the 6000 eggs are disposed in the manner explained. The fire is renewed three times a day-at dawn, at midday, and at sunset; there is however no very religious exactitude observed in this. If the fire put on in the evening is yet alive at the dawn of the subsequent day, it is left, and is not renewed till midday. In one instance, which I saw, being ready about 12 o'clock to put on the fresh fire, a quarrel happened, and it was not put on till 3 o'clock. At sunset it was not renewed, and this dims lasted till the dawn of the subsequent day.
When the new fire is put on, the door of the superior stove is left open, also the hole of the vault, and if the fire is too strong, even the small door of the inferior stove. The aperture in the ground of the superior stove is always covered, as well as the two apertures in the walls to the right and left hand. When the heat begins to mitigate and the smoke to disappear, all the small doors of the inferior stove are stopped up, afterwards the hole at the top of the vault, and lastly the door of the superior stove, which is not generally stopped. The doors of all these apertures are merely handsful of tow for each. When the fire is recent, and the heat at its greatest strength, the thermometer marks 33° or 34° of Reaumur. When the fire is extinct, and before it is renewed, the heat is 30° sometimes as low as 29o.* Six or
seven times every twenty-four hours the operation that I am going to describe is practised.
A man entirely naked enters by the door (N, fig. 2nd); he either carries a light in his hand or he opens the hole of the vault to procure light; he opens also the round hole in the centre of the ground, and comes down through it to the inferior stove. He carries all the eggs placed on the side V fig. 7th to the side U; and those of the side U to the side V. The eggs placed under the central hole are found sensibly colder than those placed at V and U, and these latter not so warm as those of the sides X and Z. Generally they are heaped toward the corners. This operation is very necessary not only to apply the heat to all the points of the egg, but to apply it in the same proportion to all the eggs, so that development may not be effected sooner in one than in another. This removing of the eggs is performed during the day, and several times during the night. Thus the affair proceeds till the 7th day. On this day, as on the 8th, the whole of the groove before the door R R, fig. 5th, is not filled with fire, but only 2 or 2 feet near the entrance. By these means the heat is diminished gradually; and during these two days the thermometer at its greatest height marks only 32° or 31° of Reaumur. After the 8th day fire is no longer placed in the room. We should naturally expect that the cell unprovided with fire would return to the natural temperature of the surrounding air, but it is not so. We have already said that in the oven there are eight cells destined to the process of hatching. Three or four days after that on which the eggs have been put in the first room, they are placed in the second, and so on successively. The consequence is, that though one or two cells may be without fire, the others contain it; besides which fire is always burning in the chambers wherein the fuel is prepared, the door of which is never stopped, while its temperature ranges from 36° to 38°. All these fires produce a degree of heat which diffuses itself through the whole building, and maintains even in those rooms which are without fires a temperature varying from 27° to 27%On the 14th day another operation is performed. Half the eggs are left in the inferior room (fig. 8th) and the other half are brought to the upper one upon a circular bed of tow (fig. 9th); in this way they continue wrapping them up two or three times a day, but without bringing down those from above, or carrying up those from below. To this operation of dividing the eggs they do not attach much importance. During my observations of the operation, this division was not executed till the 16th day, because they had no tow ready to prepare the circular bed with. When the eggs are divided, the man does not enter again through the
door of the superior stove, but through that of the inferior one, arranging the eggs below ; afterwards standing up he pushes his head and arms through the hole of the roof, and arranges those above.
The eggs which have not been in the oven eight days they call suo (el tari) the fresh. I have eaten some of them after two or three days baking, and they were good. Towards the sixth or seventh day, they look at them before a light. If the egg appears opaque and obscure, it is inferred that the operation will succeed; on the contrary, if it is transparent and white, they conclude that the chicken will not be formed. The people who keep the oven eat these eggs or sell them. They have the appearance and taste of boiled eggs. Those which go on without fire after the eighth day they call celo (meláh) the good. Lastly, those which have continued more than twelve days in the cells they call lymall (el mésku) which has taken ; or that wherein the chicken is already formed. The cells where eggs are divided half below and half above, as they are placed after the fourteenth day, have their doors constantly stopped with great care. During the last days of the process the hole of the top of the vault is not only stopped with tow, but with a great deal of earth upon the tow. Four or five days before the end of the operation, the door in the upper stove being open, as well as the hole of the vault, the thermometer indicates 26°, the hole being stopped 271, and the door being stopped 27°. Two days before the birth of the chicken, being all well stopped, the temperature reached to 28°, and the day before to 281. At the moment that the chickens are coming to life the heat is 28°; and in the inferior stove, in which there are about a thousand recently born, 30°; an augmentation which proceeds no doubt from the animal heat of the young birds, since there is no fire in the room, nor has there been any in it for thirteen days.
It is also curious to observe that the temperature varied during the last few days; this probably is the effect of the animal heat which begins to develope itself in the inside of the eggs.
If we reconsider all the facts I have detailed, we shall see that the hatching of which we are speaking, consists only in applying to the egg equally and regularly during twenty-one complete days, a degree of heat which beginning with 33 or 34 of Reaumur, falls to 27}° or 27°, and rises again to 28° or 29° with the help of the animal caloric, produced by nature in the process of hatching.
As soon as the chickens are born, the egg-shells are thrown away. The eggs of the inferior stove are carried to the upper, and the chicken to the inferior, which is reserved for them. These are treated with