CHAPTER V. 



ARTIFICIAL INCUBATION. 



SINCE the first edition of this workj a revo- 

 lution has taken place in the practice of 

 artificial incubation, so great that not one 

 machine then described now receives more than 

 historical mention in these pages. It is difficult 

 to understand the slow progress in the art made 

 during many years, or all the precise causes to 

 which the years of failure or uncertainty were 

 due, all the more when we remember that for at 

 least two thousand years artificial incubation 

 has been practised in both Egypt and China, 

 with the simplest appliances, but with unvary- 

 ing success. From a report by the American 

 Consul at Cairo, published in 1895, there 

 appears to have been a revival in Egypt of this 

 pursuit, which at one time had fallen to a 

 comparatively low ebb. He estimated at that 

 date the probable number of egg 

 Eee^ Ovens ovens as about 1 50, each of them 

 turning out on an average about 

 300,CX)0 chickens per season, hatched during 

 the months of February, March, and April : 

 some having less capacity, and others running 

 up to double the average number. They 

 are situated in villages which form centres 

 of agricultural districts, from which the eggs 

 are brought in, to be taken away again as 

 chickens at two days old. In some cases a 

 fee is paid for hatching, but as a rule the eggs 

 are bought outright for about sixteen shillings 

 per thousand, and sold independently as 

 newly hatched chicks for about si.x shillings 

 per hundred. 



The crude simplicity of these great incuba- 

 tors is striking. One of them will occupy 

 a ground plan of say 100 by 60 feet, and is 

 constructed massively of sun-dried brick and 

 clay. The end will be occupied by two or three 

 small halls or vestibule rooms, which guard 

 the temperature from the effects of opened 

 doors. From a second one of these, a small 

 door leads to a passage-way up the centre of 

 the building. From this central passage, small 

 entrances on each side lead to double-storeyed 

 circular rooms or vaults. These arc about six- 

 teen feet in diameter, the lower storey four 

 feet high, the upper one nearly double. Round 



the floor of each, ten inches or so from the wall, 

 runs a low wall or ridge about six inches high ; 

 in the trough between this and the wall portions 

 of fuel (composed of straw and dried dung) are 

 placed, and fires lighted, more or less in num- 

 ber as the heat requires increasing or lowering. 

 The operator stands in the centre, reaching the 

 upper storey through a hole in the centre of 

 its floor, and changes the position of the eggs, 

 which are laid on matting covered over with 

 bran, twice a day, from near the man-hole to the 

 circumference, or vice versd. Small apertures 

 at the top of each chamber let out the smoke 

 and superfluous heat. The eggs are tested much 

 as we do, at about the sixth and the tenth 

 day, and the newly hatched chicks are placed 

 till sold in a portion of the central passage, 

 which is rather cooler than the ovens, and serves 

 as a drying box. The apertures or entrances 

 to the ovens themselves, are closed and caulked 

 every time when the attendant withdraws. 



Thus simple is the Egyptian oven-incubator, 

 and so entirely is its management left to the 

 attendants. No copper tanks have they ; no 

 water-trays to temper the " hot dry air " ; no 

 thermometer do they know anything about ; but 

 they hatch chickens, and that without dreaming 

 of failure. On the other hand it is to be 

 remembered that the profession is hereditary, 

 handed down with its cherished secrets under 

 solemn oaths and initiatory rites from father 

 to son. We need not set much store by the 

 oaths ; but there is no doubt that experience 

 and heredity have developed an extraordinary 

 sense of touch, by which alone the operators 

 regulate the temperature, under constant per- 

 sonal observation, and after the first fortnight 

 know instantly whether an egg be alive. It 

 cannot fail to be noticed how their methods, 

 now that these are better known, run flatly 

 contrary to more than one principle which has 

 for years been assumed to be vital in artificial 

 incubation. 



Our historical notes must be very brief, and 

 confined to important points. All the earlier 

 attempts at artificial incubation were made in 

 France, whose monarch, Francis I., became 



