1839.] On the Egyptian system of Artificial Hatching. 45 



very little care. They take them up in handsful and throw them 

 below. Here they remain till the subsequent day, on which they 

 are draw out to the corridor, where they pass some hours ; sometimes 

 one whole day. After this they are carried in covered baskets to par- 

 ticular houses, as will be explained, where they begin to eat ground 

 corn or hard eggs. During the day they are exposed to the sun ; be- 

 fore sunset they are carried to a room to be sheltered from the cold. 

 The Arabs never help the chicken in breaking the egg-shell. 



During the hatching at which I was present, the natural tempera- 

 ture in the shade varied from 13° to 16° ; the day on which the chick- 

 ens were bom it was 16°, and the thermometer exposed to the sun 

 about midday marked 29°. On the subsequent day, under the same 

 circumstances, it rose to 33^°. The weather was always perfectly 

 fair excepting the fifteenth day, on which a little rain fell during the 

 night. All the apertures were on that occasion well shut up, and the 

 dampness produced no bad effects. 



I have always placed the thermometer in the upper stove (n. fig. 3) 

 in which the fire existed. That which served me for these observa- 

 tions compared with others of Reaumur's, was found to be rather lower 

 than these. 



The oven in which I studied this description, began its labours on 

 the 2d of February last. Generally they begin fifteen or twenty days 

 later. The hatching season closes in the month of June at the latest. 



In the midst of summer the sun is more powerful, and the eggs 

 more abundant and cheap. Why, then sfrould this operation be prac- 

 tised in the spring ? 



To give a satisfactory answer to this objection, there must be 

 facts of which I am not possessed, never having had either opportu- 

 nity or time to set one of the ovens in operation during the hot 

 season. However I am fully convinced in my own mind that 

 spring is the season best calculated for this operation in Egypt, 

 according to the present mode of working ; for the first inventors of 

 these ovens would not have fixed upon this season but through expe- 

 rience, having no doubt made repeated trials. 



Where facts are wanting, conjectures founded on observations 

 and reason, may frequently in a great measure supply the deficiency ; 

 I shall therefore state what I conceive to be the reasons for giving 

 spring the preference to summer in the lighting of the ovens. 



1. During the spring months a hot southerly wind prevails, which 

 ceases at the commencement of summer, yielding to a strong, cold, 

 northerly one ; this fills the whole atmosphere with dust and fine 

 sand, of which there is such abundance in Egypt ; it is therefore im- 



