HATCHING. 
ient, and is ible for a prod ing to Hatehing- 
cien responsi produce corresponding t 
one at Cairo, as_ being 
lock. It consists of two stories communicating with 
each other, and down the middle there is a passage, 
bably for the attendants,. Each side of the passage 
4s partitioned into 5, 6, or 8 chambers, or any other 
number, as no general rule seems to be preserved, and 
in a manner implanted in a hil- 
in these the eggs are deposited. At the outside of one 
angle of the building there is a furnace or fire-place, 
and this being filled with. a mixture of cow’s and ca- 
_mel’s dung, the ordinary fuel of that country, the heat 
is poms to both stories by means of flues during 3 or 
4 hours daily at different intervals ; but after 10 days fire 
_isno Easpalies, the oven being sufficiently heated. 
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 af- 
firm, 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, asecond tier of eggs co- 
vers the first. Mr Browne, if we rightly recollect, af- 
firms, that the eggs are deposited in such a manner as not 
to touch each other. All are turned twice 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 rejécted, and in four- 
teen days the whole are transferred to the upper story. 
“At length, on the twentieth and twenty-first day, exclu- 
sion takes place; and as the chickens can subsist two 
days without food, their owners have sufficient time to 
receive 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 Father 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 ae — a 
-cessary to encou and preserve such a branch o 
industry, a circle of cack villages must bring to 
* the mamal all the eggs belonging to that particular 
district. The inhabitants are liable to penalties if 
they dispose of them elsewhere ; and the proprietor of 
the mamal is also limited by certain restrictions. He 
is entitled to select those eggs which he deems suffi- 
VOL. X. PART II. 
651 
only two-thirds of the number. Thus the owner of 
eggs receives only 2000 chickens; but as unrea- 
sonable profits would sometimes be derived from the sur« 
plus, he is entitled to redeem the chickens at a certain 
price from the proprietor of the oven. Dr Graves, in 
@ paper in the Philosophical Transactions, says, that 
200 pounds of litter are daily required for heating 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 particu- 
lar ingenuity, Sudden alterations of weather may be de- 
structive of the progeny ; and an instance is given, where 
the oceurrence of a shower cooled the a 80 
much that 4000 chickens, nearly matured, perished in 
one oven, It is affirmed, that the inhabitants of a —_ 
called Bermé, situated on the Delta, are almost exclu- 
sively the of the process, which is transmitted 
from father to son, and preserved secret am them. 
At appointed times, they disperse themselves he 
out Egypt to take care of the ovens, 
The modern Chinese are well acquainted with the 
method of hatching. chickens by artificial heat. Mr 
Barrow. mentions, that even those families practise it 
who have a permanent abode on water. it 
the eggs in sand, at the bottom of wooden boxes, which 
are d on iron plates kept moderately warm. Thus, 
while a new brood is obtained, the old birds continue 
laying nearly without interruption, 
M. de Reaumur, an ingenious naturalist, devoted 
much time and attention to the subject of hatching 
eggs by artificial heat, which he seems to have heen 
desirous of introducing into France under the su- 
perintendence of a Bermean. He adopted different 
methods of accomplishing this, which are copiously 
detailed in a pete on the subject, that has been 
translated into several E m languages. Two plans 
were principally followed ; the first, which was analo- 
gous to that of the Egyptians, consisted in raising a 
superstructure above three bakers ovens, for contain- 
ing the e A small carriage on wheels, or rollers, 
was formed, in which were several drawers, or shelves, 
whereon the eggs were placed in successive rows, or 
strata, that is, one layer on each. The iage could 
be brought at pleasure on its wheels to any part of the 
surface, and the state of all the eggs could be ascertained 
on pulling out the shelves, or drawers, in which a ther- 
mometer Tikewise lay, for indicating the heat. By means 
of this simple apparatus, Reaumur succeeded perfectly 
in hatching chickens; and he acquaints us, that a 
nun, to whom he entrusted his first experiment, in the 
oven of a convent, obtained 20 from 100 eggs. He 
conceives, that a suitable oven, twelve feet square and 
four feet high, with a stove in the centre, could be erect- 
ed at little expence, which would necessarily be heated 
to 104°. Instead of thermometers, the temperature 
may be ascertained by melting a Bee of butter, as 
large as a walnut, with half as much tallow in a phial. 
When it flows like a thick syrup on inclining the phial, 
the proper heat is obtained. 
The second, though a less efficacious plan, ad 
by Reaumur, consisted in burying casks of eggs in a 
dunghill, the warmth of which might promote exclu- 
sion. Here, however, he was by uncommon 
difficulties ; and he acknowledges that, had the former 
expedient been first devised, he should never have re- 
sorted to the latter. His iments were originally 
made by depositing the ses simply in the dunghill in 
0 
