334 ARTIFICIAL INCUBATION 
mitting the action of the thermostat to the lamp; (c) arrangements 
for easy adjustment or regulation; (d) mechanism that will not 
get out of order with use. 
It is well to look into the mechanical construction of the 
machine if great and permanent efficiency is to be expected. A 
good incubator should be built of well-seasoned, kiln-dry lumber, 
and well put together, so that it will not swell or warp, or the joints 
come apart when subjected to heat, or rack and come apart when 
moved. It should be substantial, both in appearance and detailed 
construction. 
It should be of plain design, well finished, with several coats 
of varnish, making it as nearly waterproof as possible, so that 
the great humidity often present will not affect the wood. 
The past record of the machine should be investigated,—not 
only the advertisements, but also the practical results attained 
by those who have owned and used one. The reputation which a 
machine has made is usually its best recommendation and the 
safest one to rely upon. 
The machine bought should be of not less than one hundred 
eggs capacity or, better still, two or three hundred, since a small 
machine requires as much time and labor to operate it, and nearly 
as much fuel; it is also harder to keep it at a uniform temperature, 
because, owing to its small size, it is more easily influenced by 
changes in weather. In most cases the poultryman intends to 
increase the amount of hatching at some future time; the larger 
machine can be run at one-half capacity the first year or two, if 
desired, and the number of eggs increased when necessary without 
extra investment. 
Summary.—It is well to emphasize the fact that an incubator 
should never be placed in a damp, dark, musty cellar in a dwelling 
house, for proper conditions cannot be maintained nor can it 
be well ventilated. Nor should it be put in an upstairs room in a 
dwelling house, owing to the great variations in temperature day 
and night, and the certain increase in insurance rates. 
The room selected should be well ventilated, free from drafts, 
and of an even temperature day and night. The air should con- 
tain a moderate amount of moisture, and it should be possible to 
increase this humidity if desirable. The machine should be so 
set as to eliminate all danger of fire; the lamp box should be at 
least four or five feet from any combustible material, such as a 
wooden partition. It should be shielded from the direct rays of 
