120 
AMERICAN AGRICULTURIST. 
schooi.ey’s patent preservatory. 
Some Interesting Facts concerning 
Cooling and Drying Rooms. 
Above we have made an engraving of an ar¬ 
rangement for using ice, involving the application 
of principles which it will be interesting to exa¬ 
mine, whether the reader be at present so situated 
as to make any practical use of them or not. 
Our illustration represents one-half of a building, 
supposed to be divided through the middle, from 
the ridge-pole to the ground, in order to better 
show the interior arrangements. This structure 
may be a large one, twenty or thirty feet each 
way, or only a small room of but a few feet in 
size. 
The side walls, w, w , and the lower and upper 
floors,/ and u, are made double, being filled in 
with saw-dust. The upper floor, however, con¬ 
sists of a single layer of boards, nailed upon the 
under side of the joists, with the saw-dust piled 
on loosely, a foot or more in thickness. Above 
this is an open space or garret, under the rafters 
or roof, with holes in each gable-end to admit 
a free circulation of air. The main room is di¬ 
vided into two compartments—the fruit-room 
and ice-room—by the partition d. The partition 
d , unites with the walls on both front and rear, 
but a small opening of a few inches is left both 
above and below it—that is between the whole 
length of the lower and upper edges and the floor 
and the ceiling. The ice, as represented, is piled 
up in a compact mass in the right division, and 
covered in the usual manner with straw, A 
small vacant space, v, is left between the ice and 
the division wall, though this is not necessary 
unless the entire body of ice is so compact and 
frozen together as to prevent the air from circu¬ 
lating through it. The floor under the ice de¬ 
scends to the right from /, so as to carry any 
waste water out at o. There is an ingenious 
arrangement in the waste-pipe to prevent the ac¬ 
cess of air or vermin. It will readily be seen 
that before the water rises high enough to over¬ 
flow the right projection, or gate, the upper or left- 
hand gate dips down into it, so that the opening is 
always closed with water. 
Let us now examine what will be the effect of 
the ice upon the air in the adjacent room. It is 
well known that air when becoming warmer rises 
upwai 1, because it is more expanded and conse¬ 
quent 1 y lighter, while colder air sinks downward. 
In a stove-pipe or chimney it is the heating and 
expanding of the air that causes it to rise, pro¬ 
ducing the draft. The same thing takes place in a 
room. Raise the lower sash of a window a little and 
also depress the tipper sash A lighted candle, or 
a bit of cotton on the end of a string, held near 
the upper opening, will show that a current of 
lighter, warm air is rising and passing out at that 
point; while at the lower opening, at the bottom 
of the window, a current of heavier, cold air is 
flowing in to take the place of that ascending. 
This current will be kept up steadily, so long as 
the room is warmer than the atmosphere without. 
The same thing will be seen by experimenting 
with the cracks under and over a door connect¬ 
ing a warm and a cold room. The slightest differ¬ 
ence in temperature of the two rooms will pro¬ 
duce a very sensible draft. If we darken the 
room, and admit a few rays of sunlight at some 
point, and then stir up a little dust from the car¬ 
pet or floor, we can trace the course of the air as 
it descends from the lower part of the window, 
flows along the floor, and becoming warmed, rises 
in currents, and passes back along the upper sur¬ 
face, returning outward through the upper open¬ 
ing. We may here add, that the most effectual 
way to ventilate a room is to thus open a window 
a little both at the top and bottom. It may be 
further stated, that winds are produced in like 
manner. From some cause, the air in one place 
becomes warm, and rises upward, and cold air 
from an adjacent locality, settles or rushes in to 
occupy its place. This is followed by air still more 
distant, so that the simple heating of the air at 
one point may set the atmosphere in motion for 
hundreds of miles, thus producing a wind current. 
The gentle western breezes of the morning, al¬ 
ways experienced When there are no other dis¬ 
turbing causes, are accounted for by the fact, that 
the sun at the eastward is heating the air, and 
causing it to rise, and the air further west is mov¬ 
ing forward to occupy its place. 
Butto return to our engraving. The air around 
and among the ice will always be kept cool. It 
will consequently settle downward and flow along 
under the division wall, d, and into the lower part 
of the fruit-room. At the same time, the warmer 
air will flow into the ice-room through the open¬ 
ing over the division wall. The arrows show the 
direction of the currents of air. This motion 
will always be kept up so long as the air in the 
fruit-room is in the slightest degree warmer than 
that in the ice room. We see, then, that by 
such an arrangement the-fruit room is practically 
kept nearly as cool as if actually filled with ice. 
There is another important end secured by this 
arrangement, viz., that the air in the fruit-room 
is kept very dry or free from moisture. The air 
always contains more or less invisible water 
floating in it. The amount of water in the air 
depends upon its temperature. Thus : at zero a 
cubic foot of air contains only about one-sixth 
part of a grain of water (.18), and we speak of it 
as a cold dry atmosphere. At the freezing point’ 
32°, a cubic foot of air contains about 2£ grains 
of water (2.35); at 40°, about 3 grains ; at 50°, 
4£ grains ; at 60°, 5 4-5 grains ; at 70°, 8 grains : 
at 80°, 10J grains ; at 90°, 14,2-5 grains. At 100°, 
a cubic foot of air contains over 19 grains of wa¬ 
ter, or more than 8 times as much as at the ice, 
or freezing point, or 106 times as much as air at 
zero. When a cold current of air comes in con 
tact with a warmer one to cool it, the warmer 
air gives up a portion of its water which descends 
to the earth, the myriads of little particles uniting 
together into visible rain drops which fall down 
to the ground. So when the air is cooled by con¬ 
tact with the colder earth at night, it gives up 
some of its water in the form of dew. In like 
manner the surface of a tumbler cooled by ice 
water within, in turn cools the air around it, and 
the air no longer having so great a capacity for 
water gives it up to be deposited upon the sur¬ 
face of the glass. So the windows, being cooled 
from without, lower the temperature of the air in 
contact with them and thus withdraw the mois¬ 
ture, which trickles down upon the glass. 
Just in this way our ice-room operates. The 
warmer air of the fruit-room takes up moisture 
from the articles there; but when it passes over 
to the ice, being there cooled it gives up a portion 
of this moisture to the ice, flows back below in a 
drier condition, to take up more moisture as it is 
warmed again. This change goes on unceasingly. 
We see, then, that our engraving furnishes an in¬ 
structive study. To make the description com¬ 
plete we will alude to one or two things more. 
At e is seen the entrance to the store room, in 
which may be kept all kinds of food, vegetables, 
fruit, &c. Should the air need changing at any 
time, to get rid of odors, it is done thus : Just un¬ 
der the ceiling is seen a flat slide. Moving this 
to the left, two holes through it will be brought 
under the two ventilators, one leading into the 
open air above, the other into the garret. When 
this is done, the fresh air from the garret will set¬ 
tle into the ice-room, while the warm air in the 
fruit room will ascend through the larger ventilla- 
tor and pass off. In this way the whole air in 
both rooms will soon become exchanged for a 
new supply. 
There are a great variety of arrangements 
which can be made on the principle here illustrat¬ 
ed. For example, suppose the ice-room were a 
hundred feet distant, with only an open tube 
leading to the top of it from the top of the 
fruit-room, and another tube connecting the bot¬ 
tom of the two rooms ; it is evident that the 
same change of air would take place, viz., a cur¬ 
rent of warm air to the ice room through the up¬ 
per tube, and a current of cold air from the ice 
room through the lower tube. Any room in a house 
may thus be cooled, and dried also, by connecting 
it with even a distant ice-house. A chamber 
may be cooled and dried, by connecting its upper 
surface with the top, and its lower surface with 
the bottom of an ice-room or even a cool cellar. 
In short, any room in a house may be cooled and 
dried by an ice-room placed anywhere within reach 
of it, simply by connecting their upper and lower 
surfaces by capacious air passages. 
It is hardly necessary for us to dilate upon the 
many advantages of a Preservatory on the plan 
illustrated above. Its usefulness for hotels, eating- 
houses, for keeping fruits fresh, especially for 
dairy operations, can, we think, scarcely be ovei 
estimated. 
---- 
Always to indulge our appetites is to extinguish 
them. Abstain that von may enjoy 
