82 ILLINOIS STATE DAIKYSTEN’S ASSOCIATION. 
face of the earth, but in warming buildings and in cooling refrigerator rooms and ca 
If it were without the properties described, there would be neither need nor po^ 
bility of refrigeration, for organic life would perish from the earth. 
Air, on being warmed, say from 40 to 80 deg., expands and absorbs moisture if 
has access to water. When cooled by contact with a cold surface, it contracts and < 
posits its moisture, acting like a wet sponge when it is squeezed to a smaller compa 
It is not the heat of the stove which dries the wet towel; it is the absorption of i 
water by the expanded air. The frost does not come through or out of the stone wa 
the wall is cold enough to freeze the moisture condensed upon it from the air which 
cooled by it. With these principles understood we may examine intelligently t 
practical questions of refrigeration. 
Refrigerator warehouses may be divided into two classes, one in which the air 
the cooling room is cooled by a cold ceiling, which is itself cooled by ice resting on 
in the room or story above ; and another in which the air of the cooling room pas c 
through a body of ice and returns to the room. The former is best adapted to lar 
rooms having 1.000 or more square feet of door surface. The cold ceiling must be 
made as to carry oft' the water condensed upon it by cooling the air. For small co 
warehouses, I confess to a prejudice in favor of the method of passing the air throui 
ice or ducts leading through ice, as this process disposes of the question of moistm 
H hen the air of a closed room or car passes through a body of ice, it leaves it at s 
33 to 35 deg., having deposited its moisture on the ice, and become dry enough for mo 
if not all of the purposes for which refrigeration is used. And no more moisture can 
got out of it , except by cooling it lower than before or by chemical agencies. The squeezi 
sponge retains the water which remains in it until it is squeezed a second time hard 
than before. 
The room which is cooled by a cold current must not have any surfaces, accessib 
by the air, cold enough to condense moisture from the air of the room. I cannot 
course enter into details of construction. Builders of cold warehouses have diifere] 
models of accomplishing results, while working in harmony with the natural laws ; 
outlined herein, with more or less mechanical ingenuity and simplicity of constructic 
in details. 
Every proprietor of a creamery, if he cannot have a cold warehouse, should ha\ 
a cooling room, in which he can carry a carload, or at least his product between date 
of shipment. For this purpose, construct an ice box in one end of a closed room e^ 
tending from the ceiling of a room to within two or three feet of the floor, cased u 
tight all around, except an opening four or live inches wide, close up to the ceiling t 
let m the air of the room. The bottom of the box should be a strong gratiim whic 
holds up the ice and lets the cold air through freelv. Below this grate a tight" slopin 
dripping board, which carries the ice-water into a gutter which carries it out of th 
room. The lowest part of the dripping board may be live to ten inches below th 
grating, to allow free delivery of the cold air. A basement room is preferable as 
permits the easy charging of the ice-box through a trap door in the floor above j 
necessary to charge the ice-box from the cooling room, have a door in the side of th 
box for that purpose, which can be closed air tight. 
