Year: 1870

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oH the supply of air, the device was fol
lowed Of storing it below ground, where il
was supposed to be effectually isolated. The
extreme cold below ground, however, being
not below so the experiment proved .
failure. Next, ice-houses were built above
ground, the walls stuffed with some non.
conducting material, the ice covered with
straw or shayings, and the air excluded as
much as possible In this manner the ice
was kept with a greater degree of success
yet, immense compact bodies of it were re-
qulred In order to retain any through the
summer, and a. ccs ,eque gree expense
entailed. Still, az the method va the best
known, it was pursued for long period.
Finallyit was-most undoubtedly by chance
discovered, that in ofder to preserve ice
ef1ectually, i must be thoroughly ventilated,
and the explanation Of this apparently sin
gular but well established fact is as follows
The admission of fresh air to the body Of
the ice causes it to at least partly vaporize,
thereby consuming 1921 heat units, instead
Of 1875, wbick would be the case we're il
subjected to the mere melting process. In
consequence, the enveloping air is easily
cooled down to the temperature of the ice,
in which state it can have no further effect.
There is, Of course, degree beyond which
the supply Of fresh air becomes injurious.
Again, pure air about the ice prevents putri-
faction and rot in the organic substances
surrounding it, and thereby prevents the
evolution of heat, which would affect the
store of ice.


The practical rules to be observed, then,
in the harvesting, storing and preservation
of ice, may be briefly summed up as fol-
lows:


l. Secure the purest and most solid ice.
1t should, particularly, be free from organic
substances.


2. Get the ice when it is coolest. 1t is
decidedly beneficial to store it with tenn
perature considerably below the melting
point.


8. Put it up in a compact and solid
body, SO that the least amount Of surface
may be exposed to extraneous influence.


4. Do not directly surround nor cover it
with organic substances, such as straw,
shavings, and sav-dust.


5, Preserve considerable space about the
body Of ice, and ventilate the same that no
water should he allowed to stand around or
below it as a matter of course.


6. Keep the organic substance forming
the non-conducting material in the walls and
roof Of the ice-house dry, in order to prevent
any evolution Of heat from decay or rot.


A knowledge Of the fact that heated air
rises and the cold air remains on the loves.
place of a room, led to the expedient of
placing the ice over a room intended to be
cooled. But next arose the question re-
garding the most economical and efficient
method of transmitting the cooling effect of
the ice through the ceiling into the room be-
low. Wood was first used, but this allowed
little Of the GOODNESS Of the ice to be trans
mitted into the room below. Then the ice
was so packed as to have fues, with holes
through the ceiling, below them, where the
air coming in contact with the lee was coolen,
and this lowered the temperature Of the
room beneath By this arrangement, how
ever, the ice wasted rapidly, and the fiues
soon became SO large as to prove of no ben
eft just as the season when the cooling ef-
fects of the ice were most desirable Lastly
some one conceived the idea Of making the
ceiling Of iron, which would most directly
cool the uppermost air in the room and cause
it to descend, making room for other air to
be cooled and descend in like manner. These
ceilings were most eagerly taken hold Of and
praised as perfection. But their use has de-
velOped many great defects. The galvaniz-
ing scales off, allowing rapid corrosion of
the metal the seams become broken, allow
ing the water to run through; the room be-
low is not properly ventilated the condens-
ing Of the vapor in the room upon the sur
face Of the iron causes constant shower
besides, they are very expensive.