This branch of industry, though continued to the present day, as we shall have a future opportunity of illustrating, is not peculiar to Egypt. It was adopted at Naples in the fifteenth century, where there was a palace belonging to King Alphonso II. containing an oven that could hatch 1000 chickens. Francis 1. of France, is said to have made experiments on the same subject at his chateau of Mont Trichard, in the sixteenth century; and Thevenot, at a later period, affirms that one of the Grand Dukes of Tuscany, obtained an Egyptian to superintend his proceedings ; and also refers to the same process being adopted in Poland.
The art however seems to have been practised on the most extensive scale in Egypt, to which country we are constantly referred for details on the art of hatching birds by artificial heat. The Royal Academy of Sciences at Paris, indeed, esteemed this subject sufficiently interest ing for particular inquiry, and from the investigations which they made, as well as from the accounts of various travellers, we have obtained the following information.
A rectangular edifice of brick or clay, called a mama!, is constructed, half sunk in the earth. Niebuhr describes one at Cairo, as being in a manner implanted in a hillock. It consists of two stories communicating with each other, and down the middle there is a passage, probably for the attendants. Each side of the passage is partitioned into 5, 6, or 8 chambers, or any other number, as no general rule seems to be preserved, and in these the eggs are deposited. At the outside of one angle of the building Viere is a furnace or fire-place, and this being filled with a mixture of cow's and camel's dung, the ordinary fuel of that country, the heat is conveyed to both stories by means of flues during 3 or 4 hours daily, at different intervals ; but after ten days fire is no longer supplied, the oven being sufficiently heat ed. Lest the heat should be too great, ventilators are used; but those who conduct the process have no other rule, than to render the temperature equivalent to that of the baths of the country, and, if it is greater at first, they affirm, that it will occasion no injury. When the oven is converted to use, the floor of the compartments is covered with a mat, above which there is a bed of straw, and then a layer of eggs. Niebuhr says, a second tier of eggs covers the first. Air Browne, if we rightly recollect, affirms, that the eggs are deposited in such a manner as not to touch each other. All
are turned tigice each day, and four times during the night. Towards the eighth or tenth day, they are examined with a lamp, and those which appear unimpregnated are rejected, and in fourteen days the whole are transferred to the upper story. At length, on the twentieth and twenty-first day, ex clusion takes place; and as the chickens can subsist two days without food, their owners have sufficient time to re ceive them, or they are sold to others.
The number of mamals distributed throughout Egypt in the beginning of the last century was 386, according to Fa ther Sicard ; and the number of eggs hatched in each is said, by him and other travellers, to amount to 40,000, 50,000, or even 80,000 eggs, a fact almost incredible. But in the arrangements necessary to encourage and preserve such a branch of industry, a circle of several villages must bring to the mamal all the eggs belonging to that particular district. The inhabitants are liable to penalties if they dis pose of them elsewhere ; and the proprietor of the mamal is also limited by certain restrictions. He is entitled to se lect those eggs which he deems sufficient, and is responsi ble for a produce corresponding to only two-thirds of the number. Thus the owner of 3000 eggs receives only 2000 chickens ; but as unreasonable profits would sometimes be derived from the surplus, he is entitled to redeem the chickens at a certain price from the proprietor of the oven. Dr Graves, in a paper in the Philosophical Transactions, says, that 200 pounds of litter are daily required for healing the mamals ; and Pococke observes, that it is scarcely pos sible to enter them on account of the smoke.
The success of this process is supposed to result more from the nature of the climate in Egypt, where it is prac tised only during certain seasons, than from any particular ingenuity. Sudden alterations of weather may be destruc tive of the progeny ; and an instance is given, where the occurrence of a shower cooled the atmosphere so much that 4000 chickens, nearly matured, perished in one oven. It is affirmed, that the inhabitants of a village called Berme, situated on the Delta, are almost exclusively the mana gers of the process, which is transmitted from father to son, and preserved secret among them. At appointed times, they disperse themselves throughout Egypt, to take care of the ovens.