468 JtJiiriial of Af/riciiUurc. \'ictuiia. | 11 Ai(i., I!tl9. 



Egyptian Methods. 



The Egyptian system is also of great antiquity. Large rooms are 

 used with a passageway down the centre, and on the floor of the compart- 

 ments eggs are stacked in considerable heaps. Heat is supplied from 

 briquettes of pressed camel dung burning about 5 feet from the ground 

 071 shelves. The eggs are rolled by hand (a better system than that of 

 turning usually practised, even by experienced men), the men of one 

 district (Berea) being specially skilled in this work, and with such 

 keenly-developed, sensitive powers, that bad eggs can be at once 

 recognised by touch. The actual hatching percentage cannot be stated, 

 but it is known that it is not high. 



European Methods. 



The first incubator known in Western Europe was that shown in 

 1851 at the International Exhibition by Mens. Cautello. Its method 

 of construction was as follows: — A tank was filled with hot water, 

 and was fitted with india-rubber on the under surface of the bottom in 

 direct contact with the eggs. The sagging of the india-rubber pressing 

 on the eggs brought about a complete failure, and it was not until 1S78 

 That Monsieur Roullier-Amoult, principal of the French Department of 

 Agriculture Poultry Farm, at Gambais, introduced an effective machine. 

 The arrangement in this incubator was to put water in a tank and to 

 draw off a portion of it every few hours and in its place pour in a 

 similar quantity of boiling water. There was no lamp, nor regulator, 

 yet 66 per cent, was about an average hatch. Some machines of this 

 type are still in use. Five years later, Mr. Charles Hearson patented 

 the machine which bears his name, and for cooler latitudes, there is 

 probably still no better machine. Hearson added the lamp and capsule 

 for regulating the heat. 



There are now two main systems of incubation — {a) hot water 

 or tank machine type; and (&) hot air machine. In the hot 

 water type, the heat is supplied by radiation from the bottom of the 

 copper tank containing water heated by kerosene or gas. In the hot 

 air type, the heat supplied is a downward current of hot air, generally 

 obtained from kerosene or gas; although lately an excellent machine, 

 heated by radiation from electrically-heated resistance wire, has been 

 put on the market by a Victorian. This latest type, where electric 

 power is available at about 2d. per unit, is the cheapest as far as cost of 

 heating is concerned, and the initial cost of the machine is about the 

 same as most others. This and some other kinds have a " cut-off,'' 

 which reduces the cost of heating; other types merely allow the heat 

 to escape, but do not reduce the consumption of current. Preference 

 for any one type is a matter for the individual operator, who had 

 always better be master of one type than the slave of several; yet, far 

 too many breeders have a motley collection of all types and sizes. 



In warmer latitudes the objection to the tank machine is that it 

 cannot be easily cooled during the day time in a warm spell, nor quickly 

 heated on a cold night. For this reason, north of the Dividing Range, 

 the hot air type is generally preferred, though in the Gippsland and 

 Western Districts, with their cooler climates, the tank machine ii^ 

 excellent. 



There is little doubt that the mammoth type of incubator will 

 gradually supersede the small machines, on account of the greatly 



