330 ARTIFICIAL INCUBATION 
ing system m tne incubator cellar. The best plan is to cut in the 
wall single-sash windows, three by three feet, one for every thou- 
sand cubic feet of air space. These windows should be double, 
the outer sash hinged at the top, to be raised upward and outward, 
the inner sash hinged at the bottom and opening inward and down- 
ward. Neither sash should be open more than about 45 degrees, 
which will permit the air to circulate freely through the cellar, 
but not to blow directly upon the machines. A direct draught 
over them, especially during the high winds of early spring, is apt 
to make the lamps smoke, or to blow them out entirely. The use 
of double sash creates an air chamber which helps to keep the 
temperature and humidity even. It is well to have a vestibule 
with double swinging doors at the entrance of the building or 
cellar, to cut off drafts of outside air. 
Interior —A specially constructed incubator cellar should be 
plastered with cement, and have a concrete floor, raised a little 
in the centre so as to carry the water off to either side. This per- 
mits the thorough wetting of the floor, and also helps to maintain 
the right degree of humidity. A part of the incubator cellar should 
be partitioned off into a small room which can be easily darkened 
and used for testing. Here shelves should be built at a convenient 
height for holding testing lamps and egg traps, and a long table 
may be placed in the centre of the room for turning and cooling; 
the necessity of this depends somewhat upon the type of the 
incubator, for some are so constructed that the trays may be 
placed on top. It is desirable to have a shelf covered with tin or 
asbestos, preferably the former, for filling and trimming lamps, 
and over this other shelves for the storage of extra lamps, wicks, 
and other supplies. The safest way to handle the oil is to bring 
it in from the storage tank through a feed pipe, which does away 
with the necessity of carrying small oil cans around, and perhaps 
saturating parts with oil. There should be a closet or shelf for 
thermometers, hygrometers, and incubator records. Running 
water should be piped into the building, and a faucet conveniently 
located with hose attachment for sprinkling. 
The cost of such a building is an item, and it is best to figure 
this out from the capacity in dozens of eggs. Of course, the cost 
of a building specially designed will be greater than if a room is 
fitted up in a building meant for other purposes, but the advantages 
of the former will counterbalance the cost. An estimate, per 
dozen-egg capacity, will vary considerably, according to its type 
