82 
Farm PouUry. 
In the previous remarks I have not alluded to the employ- 
ment of incubators, which are now used to a very considerable 
extent by those who hatch large numbers of fowls. Whether 
incubators can be employed advantageously by the small farmer, 
d&pends altogether upon the number of chickens that he con- 
templates rearing. I do not tliink an incubator of less size 
than one containing fifty eggs is at all desirable, as the external 
surface in proportion to the bulk renders it less easy to keep up 
a regular temperature, and a small number of eggs can be as 
easily hatched under hens. The most successful incubator is 
that manufactured by Hearson, in which the supply of heat is 
instantly shut off when it exceeds or even reaches the desired 
temperature, which can be regulated to any required degree. I 
have tested this incubator for some years, and find that it 
hatches as large a proportion of eggs as the best hens. The 
eggs are placed in circumstances in wliich the natural condi- 
tions of hatching are most carefully reproduced. Moisture rises 
from below, the heat is given above, and the natural temperature 
cannot possibly be exceeded, however great the excess of heat 
from the lamp or gas employed in the machine. Incubators in 
which the heat depends on the supply of hot water once or twice 
a day are always altering their temperature, and are conse- 
quently unsuccessful. Others, in which the eggs are exposed to 
the fumes of hot air rising from the combustion of a lamp, are 
even less to be relied upon, as the eggs do not hatch well, unless 
the air in which they are contained is particularly pure. 
The impurity of the air is one of the chief causes why the 
eggs in an overcrowded or dirty fowl-house never hatch as well 
as those that are sat upon by the hens out in the open air, as 
under a hedge, or any other concealed situation. An incubator, 
therefore, should never be placed in a close-confined room, but 
in some compartment or shed where the atmosphere is particu- 
larly pure. The chicken breathes through the pores of the shell 
for many days before it escapes from the egg, and is particularly 
susceptible to the foul effects of an impure atmosphere in the 
early stages of existence. 
Whether or not an incubator can be used depends entirely 
on the requirements of the farmer, but should it be d(>termined 
to employ one, it is most desirable that an efficient instrument 
should be selected, as the use of cheaply constructed machines 
will only end in disappointment. 
W. B. Tegetmeier. 
