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Practical cold storage ; the theory, desi
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PRACTICAL
COLD STORAGE
THE THEORY, DESIGN AND CONSTRUCTION OF BUILDINGS AND APi>ARATUS
FOR THE PRESERVATION OF PERISHABLE PRODUCTS, APPROVED
METHODS OF APPLYING REFRIGERATION , AND THE
CARE AND HANDLING OF EGGS, FRUIT,
DAIRY PRODUCTS, ETC.
BY
MADISON COOPER
refbigeb.ating engineer and architect
Author of "Eggs in Cold Storage," "ich Cold Storage," etc.
Second Edition
PUBLISHERS:
NICKERSON & COLLINS CO.
CHICAGO
1914
COPYRIGHT, 1904, 1905 AND 1914
By Nickerson & Collins Co.
ALL RIGHTS RESERVED
PRESS OF
ICE AND REFRIGERATION
CHICAGO
TO MY FATHER
As a tribute to his matchless enterprise
and genius for practical aud 'scientific
research, and in acknowledgment oj
valuable assistance rendered, this work
is affectionately inscribed.
The a uthor
PREFACE TO FIRST EDITION.
The difficulties encountered in preparing a 'book on so
broad a subject as practical cold storage have been so great as
at times to discourage the author from continuing. He
has endeavored to collect the greater part of his own writ-
ings and at the same time has compiled from all available
sources. The present book has the many shortcomings usu-
ally found in every pioneer work, and there are many gaps in
the chain of information given for the reason that detailed
knowledge has in many cases been unobtainable. A large
portion of the general mntter which has a])peared on tho
subject of cold storage is of little or no value as a part of a
book on this subject, for the reason that it contains many repe-
titions and contradictions, and for the most part has been writ-
ten by persons not familiar with refrigeration either from a
practical or scientific standpoint. The matter and information
which appeared prior to about 1895 is mostly valueless in the
light of present information, as the earlier articles were gener-
ally incomplete and in part erroneous.
The immense amount of labor involved in digging through
the great piles of chaff to find the few grains of wheat has
been out of all proportion to the actual results obtained. Re-
liable scientific data and the records of tests have in many
cases been difficult or impossible to obtain. Comparatively lit-
tle along this line is in existence and some of it is jealously
guarded by its possessors. Practical information on the hand-
ling, packing and storing of perishable products is obtainable
only in a small way for the reason that comparatively few op-
erators of cold storage houses have made any record of results
and can put their experience in tangible form for the use of
others. The author be.gs to acknowledge the assistance of his
many friends among the engineers and cold storage men. It
6 PRACTICAL COLD STORAGE
has been his aim to give due credit where any considerable
amount of matter has been furnished by others, but some of
the matter contained herein has been secured from sources
the origin of which has been lost and not traceable, and if
due credit is not given it is from no wrong intent on the part
of the author.
This book is intended to cover the field of applied re-
frigeration with the exception of ice making, ice machines, and
the technical and theoretical side of the mechanical production
of refrigeration. These important matters are fully treated by
several valuable and comprehensive works. The reader is re-
ferred to these books for the data, theory and information nec-
essary to a full understanding of the principles of thermo-
dynamics and refrigerating machine construction and opera-
tion.
There is much regarding the use of ice, both natural and
artificial, as a practical refrigerant, even on a large scale,
which has not heretofore been fully described. The possibili-
ties of successful refrigeration by means of ice have not been
carefully studied and given due consideration. If rightly ap-
plied, ice, either natural or manufactured, in combination with
salt, will produce any results in the preservation of perishable
products, which may be produced by any means of cooling;
limited, of course, by the range of temperature which can be
obtained. The importance and extent of this branch of the re-
frigerating industry has not been appreciated by those who
have given their time to the study of refrigeration. The de-
velopment of the mechanical systems of refrigeration came at
a time when the use of ice as a refrigerant had not been re-
duced to a scientific basis, consequently our best talent was di-
rected toward the perfecting and introducing of the ice ma-
chine. Nevertheless, there are many successful ice cold storage
houses who are doing fully as perfect work as the best machine
refrigerated houses. The value of products which are daily
refrigerated by ice for preservation, exceeds by far those re-
frigerated by mechanical means. This statement is best appre-
ciated when we consider that a large part of the output of the
hundreds of ice factories is used in small refrigerators for the
PREFACE TO FIRST EDITION 7
temporary safe keeping of fruit, vegetables, meats, dairy prod-
ucts, etc.; that the immense natural ice crop annually har-
vested is consumed in the same way ; that an important portion
of the eggs, butter, cheese, fruit, etc., are stored in warehouses
cooled by ice, or ice and salt, and that perishable goods during
transportation are kept cool by ice almost exclusively. From
these facts it is evident that a description of the manner of se-
curing and storing the natural ice crop and the best methods
of utilizing ice, either natural or artificial, for cooling or freez-
ing purposes, must be of considerable value to the users of re-
frigeration generally.
An important branch of cold storage design, and in fact
all work in refrigeration, is the design and construction of
walls which form insulation against heat, and built of such
materials as may be had at a moderate cost. The chapter on
insulation has aimed to give the results of the best information
at present obtainable on this subject, both in the United States
and in foreign countries.
The chapters on the practical operating of cold storage
houses and the care and handling of goods for storage have
been written largely from the author's practical experience,
supplemented by information obtained from others. The busi-
ness of cold storage has now assumed so vast a proportion and
such a great variety of goods are now placed in refrigerated
rooms for preservation, that no one person could possibly cover
so vast a field. The author, therefore, acknowledges his in-
debtedness to many who have made a specialty and have had
much experience with the various goods. General directions
are given for the handling of a cold storage house without ref-
erence to any particular product, and if these are followed un-
derstandingly and care and judgment used, the cold storage
manager may avoid many of the errors common to those new
to the business. It must be remembered that a good house
poorly handled cannot compete with an inferior house well
handled. At least one-half is in the management and too
much care cannot be exercised in looking after the details of
a refrigerating installation, not only for the purpose of secur-
8 PRACTICAL COLD STORAGE
ing economy in operation of same, but also to insure the keep-
ing of the stored goods in the best condition.
By far the major portion of what is printed in this book
is from the original writings of the author ; a portion of which
has appeared in the columns of Ice and Refrigeration; The Ice
Trade Journal, etc., as articles under the titles of "Eggs in Cold
Storage," "Ice Cold Storage," etc. It was because of the suc-
cess of the articles on "Eggs in Cold Storage," which were
subsequently printed in pamphlet form, and the complimentary
reception of same, which encouraged the author to undertake
the present work. It is now submitted to the trade with a full
appreciation of its imperfections and incompleteness. As far
as possible these will be remedied in future editions. It is the
earnest request of the author that those who find errors or omis-
sions or can suggest in any way improvements, correspond
with the author to the end that "Practical Cold Storage" may
be made as complete and accurate as possible.
Any information which will further the interests of the
business, will in turn benefit all who are engaged therein. For
any one to believe that he is the possessor of secret informa-
tion which is vital to his success over competitors, is in a great
majority of cases the extreme of absurdity. Much of the
matter appearing in this publication has at some time been
considered as trade secrets. The false and narrow-minded
position taken by some in connection with this matter is well
illustrated by certain remarks made to the author in regard
to the publication of this book. The following is a sample:
"Now that you have this information accumulated, why not
keep it for your own use instead of giving it away?" It is quite
true that the author has expended in time, effort and money
in connection with the preparation of the matter contained
in this book, much more than he can be remunerated for in
its sale. It is, however, here given for what it is worth and
with the hope that it may be of substantial benefit to many
readers.
It might not be out of place to call the reader's attention
to the fact that, in practically all the original matter by the
author contained in this book, reasons are given for statements
PREFACE TO FIRST EDITION 9
made so far as practicable. This enables tbe new beginner or
student to study intelligently the natural laws which govern
the principles of refrigeration. Comment and criticism has
been freely bestowed without fear or favor on the various
ideas, systems and methods which do not meet the approval
of the author. Matter which has been compiled or extracted
from other sources has in some cases been changed or modified
to suit the individual ideas of the author. Should the advo-
cates of anything here criticised feel that they have not had a
fair presentation the author will be glad to take the matter
up and discuss the points involved.
While this work is in some respects imperfect and there
is no doubt room for the addition of much information, reli-
able data, and the results of extended observations and tests,
there has not heretofore been anything like as complete a
presentation of the entire subject ; and in consideration of this
fact the reader is requested to be lenient in his criticism. If
any errors or lack of details are noted, the author would be
pleased to acknowledge same and will endeavor to explain
the points at fault. No other object has been in mind in pre-
paring this book than a furtherance of scientific knowledge
on the subject of refrigeration as applied to the preservation
of perishable products, and' the great assistance rendered by
those who have assisted is hereby acknowledged. The combi-
nation and comparison of information is beneficial, and if
those who have further data or records of tests will only put
them before others in their line of business, no loss will be sus-
tained by the indvidual giving the information, while much
general good will result.
PREFACE TO SECOND EDITION.
Since the appearance of the first edition of this book com-
paratively few improvements and changes have been made in
practical applications of refrigeration, and development has
been largely along the lines of perfecting and improving
methods and systems already introduced. Many new applica-
tions of refrigeration have been found, and it has been demon-
strated that the use of refrigeration for preventing destructive
deterioration of perishable goods, so-called, as well as the con-
trolling of chemical and other processes by supplying the low
temperatures often needed, is even at the present time in its
infancy. We may look to the future for a much wider applica-
tion of refrigeration for many purposes, some, doubtless, at
present not thought of. The chief use of refrigeration at the
present time is in the preservation of perishable food products,
but many other applications are being brought to light from
year to year, among the most recent of which may be mentioned
the following:
Curing tobacco, tempering watch springs, in the manu-
facture of rubber, drugs, syrup, soap, ink, paint, vinegar, isin-
glass, etc., in oil refineries, sugar refineries, chemical works,
mercerizing works, photo material factories, in the manufacture
of explosives, plows and other agricultural implements, optical
instruments, electrical machinery, etc., in welding processes,
for retarding growth of plants and vegetables, in laboratory
work, hospital practice, shaft sinking and tunneling, for testing
automobile parts, batteries, insulating material, paving ma-
terial, etc.
■ The cooling of inhabited spaces, which means living and
work rooms, during the heated term, is an application of re-
10
PREFACE TO SECOND EDITION 11
frigeration which has been much talked about, but with which
comparatively little has been done. Most people prefer to "swel-
ter" rather than provide a comfortable working temperature in
warm weather. Even those who can well afford conveniences
and comforts of any kind do not take much interest in this
proposition, and very little progress has been made during past
years in this direction. Some few theatres, hotel rooms, public
halls, etc., have been cooled, but only experimentally as it were,
and in a clumsy and cheap sort of way.
Madison Cooper.
Calcium, N. Y., October 1st, 1914.
INTRODUCTION.
There is no authentic history of the use of refrigeration
as applied to what is now popularly called "cold storage," and
it is only williin the paht thirty or forty years that the practical
usefulness of refrigerated storage has been appreciated by the
world at large. In the year 1626 Lord Bacon is said to have
taken a chill from the stuffing of a chicken with snow, in order
to preserve it, which resulted in his death. It would seem that
the death of so eminent a person from such a cause should have
attracted attention to the possibilities of applied refrigeration,
but either the poor success of the experiment, or the fatal re-
sult to its originator seems to have had a deterrent effect on fur-
ther investigation along this line at that period.
It is doubtful whether any scientific demonstration or com-
mercial enterprise of recent years has been of greater moment
to the human race than the science of refrigeration and its
practical application in the modern cold storage industry.
When scientific inquiry had proven the efficacy of low tempera-
tures in preventing decay and had demonstrated the possibility
of obtaining and maintaining low temperatures at will, the
cold storage business of today was but the natural evolution re-
sulting from such demonstration. When it became apparent
that profit was obtainable by placing perishable goods in cold
storage during a period of glut or surplus and disposing of them
at some subsequent period of comparative scarcity or increased
demand, the building of cold storage houses and the perfection
of machinery or apparatus for their economical operation be-
came the inevitable result. The pioneers in the cold storage
business were speculators of the extreme kind, but this cannot
be said of those in the business today. Where in the early days
12
INTRODUCTION 13
the cold storage operator owned the goods he stored almost en-
tirely, and his customers were uncertain, now the goods placed
in cold storage are almost wholly owned by dealers, and are
held for the supplying of their regular trade.
Refrigeration has four chief uses in the economy of nature
and in commerce :
1. — To prevent premature decay of perishable products.
2. — To lengthen the period of consumption and thus greatly in-
crease production.
3. — To enable the owner to market his products as needed.
4. — To make possible transportation in good condition from point
of production to point of consumption, irrespective of distance.
First: Without refrigeration there woud be much actual
waste from decomposition before it would be possible to place
perishable food products at the disposal of the consumers. The
immense fruit trade of the Pacific coast would never have been
developed without the assistance of refrigeration, nor could the
surplus meat products of the southern hemisphere have been
brought half way around the globe to relieve the shortage in
thickly settled England without its aid. Without the aid of
refrigeration to create a constant market, the production of
meats, of eggs, of fruits and other food products would be great-
ly curtailed.
Second: In many classes of produce the ordinary season
of consumption was formerly limited to the immediate period
of production, or but briefly beyond. Now nearly all fruits may
be purchased at any season of the year and dairy and other
products are for sale in good condition and at reasonable prices
the year around.
Third: Instead of being obliged to sell perishable goods,
when produced or purchased, at any price obtainable, the owner
can now put away in cold storage a portion or all of his
products to await a suitable time for selling. This not only
results in a better average price to the producer, but places
perishable food stuffs at the command of the consumer at a
reasonable price at all times and greatly extends the period of
profitable trading in such products.
Fourth: The certainty and perfection with which food
products may be conveyed from the place of production to the
14 PRACTICAL COLD STORAGE
large centers of population where they are to be consumed is one
of the triumphs of refrigeration ; yet the refrigerator car service
is only in its infancy so far as perfection of results is concerned.
It is safe to say that our immense Pacific coast fruit trade could
not exist without it. The over sea carriage of products has also
been developed along with the development of refrigeration
as applied to this work.
Cold storage is a benefit to all mankind in that it allows of
a greater variety of food during all seasons of the year. Health
and longevity are promoted by the free consumption of fruits,
and the placing of fresh fruits at the disposal of even the poorest
of our citizens during every month in the year will certainly re-
sult in a wholesale benefit to mankind, so far-reaching in its
effects as to be incalculable.
Physicians and scientists who have investigated the subject
unite in praising the modern practice of refrigeration as applied
to the preservation of food products and in arresting decay in all
articles of value liable to injury by exposure to high or normal
temperatures. A prominent English physcian* in an address
before the Sanitary Institute at their Congress in Birmingham
in 1898, after describing at length the various methods, namely :
Drying, smoking, salting, sugar and vinegar, exclusion of air
(canning), antiseptics, chemicals, etc., in use as food preserva-
tives has this to say of refrigeration :
This brings us then to the last of the modern methods of food pres-
ervation on the large as well as on the small scale, and as it is the last,
so itis the best. The fishmonger avails himself of it in his ice well and
on hisstall. It is by its agency that all the perishable food on our great
liners is preserved during even prolonged voyages, and it is used in the
great food depots of many of our large towns. In this town tons of
perishable foods are continually preserved by its action, and where such
stores do not exist they ought to be provided. In this way all perishable
articles can be kept until such times as they shall be required for sale and
distribution.
Formerly the methods of producing cold were complicated and dear,
and had many drawbacks, but these have been overcome. * * * Cold
acts not by killing the organisms that effect decomposition, but only by
inhibiting their action; in which respect it differs from heat and certain
chemical antiseptics, such as chlorine, for instance.
Among the advantages of preservation by refrigeration may be men-
tioned : —
1— It has been proved the most effective as a preservative, surpassing
in efficiency, salting, boric compounds, or any other practical method.
*Alfred Hill, M. D., F. R. S., Edin. F. I. C. Medical Officer of Health
and Public Analyst to the City of Birmingham, Eng.
INTRODUCTION IS
2 — It adds nothing and subtracts nothing from the article preserved,
not even the water, and in no material sense alters its quality.
3 — ^It causes no change of appearance or taste, but leaves the meat
or other substance substantially in its original condition, while it renders
it neither less nutritious nor less digestible, which cannot be said of some
other methods in colmmon use.
My contention is that all additions to food whose influence on health
is doubtful ought- to be prohibited and their use supplemented by refriger-
ation.
Strong language like this coming from such an eminent
authority not only vouches for the usefulness of refrigeration,
but also for the perfection of its results, and to a thinking per-
son offers an assurance that an industry established on so broad
a basis must present an ever widening field of usefulness. New
products are constantly being added to those which are placed
in cold storage for safe keeping or preservation, and it seems
not a wild prediction to say that at some time in the future the
great majority of our food products and other perishable goods
will be handled in and sold from refrigerated rooms.
Considering the importance the cold storage industry has
already attained, its rapid growth and future outlook, the
amount of accurate information available to those engaged in
the business seems very meager. The difficulties to be overcome,
the skill required, and the importance of a well designed struc-
ture are not usually explained by those interested in promoting
new enterprises in this line, and consequently not appreciated by
those making the investment. Financial disaster has overtaken
many large companies who have erected costly refrigerating
warehouses; those which have succeeded have in many cases
been forced to install new systems, make expensive changes,
and make a thorough study of the products handled. The ex-
perience of nearly all has been emphasized at times by heavy
losses paid in claims made by customers for damage to goods
while in storage, or the necessity of running a large house while
doing a very small business. Those about to become interested
in business may find food for thought in the above, and the
history of a dozen houses, in different localities, will furnish
valuable information for would-be investors.
The scarcity of knowledge on the subject in hand, while
being partly the result of the partially developed state of the
art until very recently, is also very largely owing to narrow-
16 PRACTICAL COLD STORAGE
mindedness on the part of some of the older members of the
craft who have largely obtained their skill by experience and
study, some of them having expended large sums on experi-
mental work. The same experiments have perhaps been made
before, and are of necessity to be made again by others, simply
because the first experimenter would not give other people the
benefit of his experience. It seems that at the present stage in
the development of refrigeration the improvements to be made
during the next thirty years will be of very much less im-
portance than those made during the last thirty years; trade
secrets, so jealously guarded by some, must disappear, as they
have in other branches of engineering. Storage men have been
obliged to work out their own salvation in solving problems,
sometimes, however, sending their most difficult points to be an-
swered through the columns of the trade journals, and, per-
haps, comparing ideas with those of their personal friends in
the same line of business. It is to be observed that the mosti
progressive and up-to-date manufacturing concerns give their
contemporaries every opportunity to observe their methods,
and are very willing and anxious to talk over matters pertain-
ing to their work from an unselfish standpoint. So, too, the
successful cold storage manager will be sure to make "visitors
welcome."
In anything which appears in this book, it is not the
author's intention to convey the idea that any mere theoretical
knowledge which can be acquired by reading and study, or
even by an exchange of ideas in conversation, can take the place
of practical observation in actual house management ; but there
are applications of well known laws which are not generally
understood by storage men and their progress is handicapped
from lack of this theoretical knowledge. The two following
illustrations, bearing on temperature and ventilation, are among
the common errors made in practice, yet easily understood when
studied and tested: Some storage houses formerly held their
egg rooms at 33° F., fearing any nearer approach to the freez-
ing point of water (32° F.), thinking the eggs would freeze. A
simple experiment would settle this point, giving the exact freez-
ing temperature, as well as the effect of any low temperature
INTRODUCTION 17
on the egg tissues. Eggs will not freeze at 28° F. Again, oth-
ers have thought to ventilate by opening doors during warm
weather. It never happens that storage rooms can be benefited
by this treatment at any time during the summer months, and
only occasionally during the spring and fall. The dew point
of outside air is rarely below 45° F. during summer, and when
cooled to the temperature of an egg room, moisture will be
deposited on the goods in storage, causing a growth of mildew.
The question of the proper temperature at which to carry
goods is of the first importance. Correct temperatures alone,
however, will not produce successful results, any more than a
good air circulation or correct ventilation would give good results
with a wrong temperature. The common impression of cold
storage is what the name implies — simply a building in which
the rooms may be cooled to a low degree as compared with the
outside air. Even those who manufacture and install refrigerat-
ing machinery and apparatus often show either gross careless-
ness or ignorance of the requirements of a house which will
produce successful results. After a careful examination of some
of the recently constructed houses supposed to be strictly modern
and up-to-date, the author has the impression that the designers
regarded temperature as the only requisite for perfect work.
Some of the rooms in these new houses are simply insulated and
fitted with brine or ammonia pipes, the proper location of same
having received no attention whatever, being placed, in most
cases, in convenient proximity to the pipe main, and in one or
two instances, the top pipe of the cooling coils was fully two
feet from the ceiling. The necessity for providing for air cir-
culation seemed not worthy of consideration, to say nothing of
the lack of anything like an efficient ventilating system for the
furnishing of fresh air. These things are mentioned here for
the purpose of cautioning against a superficial study of cold
storage problems. It is advisable for everyone interested to un-
derstand the underlying laws which govern the results to be
obtained. Eead carefully the chapters on "Air Circulation,"
"Humidity" and "Ventilation."
Cold storage, if the right system is installed and properly
handled, will produce some remarkable results in the preserva-
18 PRACTICAL COLD STORAGE
tion of perishable products. It must not be expected, however,
that the quaUty and condition of the goods are improved by
storage. Cold storage does not insure against a certain amount
of natural deterioration. Goods for cold storage must be in
prime condition and selected by an experienced person if it is
expected to carry them to the limit of their possible life. A
cold storage house successfully operated and managed will sup-
ply a uniform temperature at the proper degree throughout the
storage season. It will regulate the humidity at the proper
point and will supply fresh air properly treated to force out the
accumulated gases. The storing of ilnsuitable, imperfect and
inferior goods has led to much misunderstanding and some
litigation between the man who stores the goods and the ware-
house man. Both should, if possible, be familiar with the con-
dition of the goods they are handling; the different stages of
ripeness, quality and liability to deterioration. Cold storage
cannot improve the physical condition of perishable goods and
is in no way responsible for damage or decay which may arise
from improper picking, grading, packing or handling before
placing in the storage house. If these things are properly under-
stood by all concerned much misunderstanding will be avoided,
and greater satisfaction and profit will result to all concerned.
CHAPTEE I.
HISTORICAL.
THE DEVELOPMENT OP COLD STORAGE.
Mother earth as a source of available refrigeration, is with-
out doubt a pioneer. In the Temperate Zone at a depth of a
few feet below the surface, a fairly uniform temperature is to
be obtained at all seasons of about 50° to 60° F. In some
places a much lower temperature is obtained. The same prin-
ciple is true in any climate, the earth acting as an equalizer
between extremes of temperature, if such exist- Caves in the
rock, of natural formation, are in existence, in which ice re-
mains the year around, and many caves are used for the
keeping of perishable goods. The even temperature, dryness
and purity of the atmosphere to be met with in some caves
are quite remarkable, owing no doubt to the absorptive and
purifying qualities of the rock and earth, as well as to the
low temperature obtainable.
CBLLAKS.
Cellars are practically artificial caves and if well and prop-
erly built are equally good for the purpose of retarding de-
composition in perishable goods. A journey through the
Western states reveals many farmers who are the possessors
of "root-cellars," (usually detached from any other structure,)
and considered a first necessity of successful farming, the new
settler building his cellar at the same time as his log house.
A root-cellar is used partly as a protection against frost, but
it also enables the owner to keep his vegetables in fair con-
dition during the warm weather of the spring and summer
months. The use of cellars for long keeping of dairy products
is familiar to all. Many of us can recollect how our mothers
19
20 PRACTICAL COLD STORAGE
put down butter in June and kept it until the next winter,
and perhaps it will be claimed by some, that the butter was
as good in January as when it was put down. It was not as
good, far from it- If you think it was, try the experiment to-
day and you will see how it will taste and how much it will
sell for in January, in competition with the same butter
stored in a modern freezer. The butter made years ago was
no better either. No better butter was ever made than we
are producing to-day. In short, cellars were considered good
because they had no competition — they were the best before
the advent of the improved means of cooling. Cellars are still
of value for the temporary safe keeping of goods from day to
day, or for the storage of goods requiring only a comparatively
high temperature, but with a good ice refrigerator in the
house, the chief duty of a cellar, nowadays, is to contain the
furnace, and as a storage for coal and other non-perishable
household necessities. To be sure cellars have their place as
frost-proof storage in winter, but we are discussing the cool-
ing problem here.
ICE.
The use of ice as a refrigerant during the summer months
is a comparatively modern innovation, and not until the nine-
teenth century did the ice trade reach anything like system-
atic development. The possibility of securing a quantity of
ice during cold weather and keeping it for use during the
heated term seems not to have occurred to the people of revo-
lutionary times. About 1805 the first large ice house for the
storage of natural ice was built, and with a constantly increas-
ing growth, the business rose to immense proportions in 1860
to 1870- The amount harvested is now much larger than at
that time and constantly increasing, but the business is now
divided between natural ice and that made by mechanical
means.
The first attempt at utilizing ice for cold storage pur-
poses was either by placing the goods to be preserved directly
on the ice or by packing ice around the goods. These meth-
ods are in use at present as for instance in the shipping of
poultry, fish and oysters, and the placing of fruit and vege-
HISTORICAL 21
tables on ice for preservation and to improve their palatability-
The first form of ice refrigerator proper consisted merely of
a box with ice in one end and the perishable goods in the
other. This form of cooler is illustrated in the old style ice
chests, Ti^hich are now mostly superseded by the better form of
house refrigerator with ice near the top and storage space
below. On a larger scale small rooms were built within and
surrounded by the ice in an ice house. These rooms were
of poor design and did not do good work, largely the result
of no circulation of air within the room. The principle of
air circulation was recognized later, and by placing the ice
over the space to be cooled, a long step , in the right direc-
tion was taken. By this method the air was induced to cir-
culate over the ice and down into the storage room. During
warm weather a good circulation of air in contact with the ice
purifies the air and produces a uniformly low temperature.
Many houses on this system are still in existence, although
rapidly being superseded by improved forms.
About the time when the overhead ice cold storage houses
were being installed freely, mechanical refrigeration came into
the field. Mechanical refrigeration in which the storage room?
are cooled by frozen surfaces, usually in the form of brine
or ammonia pipes, was much superior to ice refrigeration, in
that the temperature could be controlled more readily and
held at any point desired and that a drier atmosphere was
produced. Ice and mechanical refrigeration will be discussed
fully in treating of construction and in discussing the value
of different systems for different purposes. It may be re-
marked in passing that ice is at present and will probably al-
ways remain a most useful and correct medium of refrigera-
tion, especially for the smaller rooms and, under some con-
ditions, large ones as well. The invention and introduction of
the Cooper brine system using ice and salt for cooling marked
an important step in ice refrigeration- This system is de-
scribed in the chapter on "Refrigeration from Ice."
MACHINEEY.
The first method of mechanical refrigeration to come into
general use, and one which is still largely in use on ocean
22 PRACTICAL COLD STORAGE
going steam vessels, was by means of the compressed air ma-
chines. These operate by compressing atmospheric air to a
high tension, cooling it, and expanding it. These machines
are very uneconomical in that the compressed gas is not
liquefied. Present practice in compression machines mostly
employs either ammonia gas or carbon dioxide gas, both of
which may be liquefied by pressures and temperatures readily
obtainable. Other gases are in use also, but ammonia is the
favorite as it liquefies more easily. The apparatus known
as the absorption ammonia system is really a chemical rather
than a mechanical process, but is usually classed along with
the mechanical systems. In this system, the ammonia gas
is driven off from aqua ammonia under pressure, by heating;
the gas is liquefied by cooling, and the refrigerating effect ob-
tained by expanding the liquid ammonia thus obtained through
nipes surrounded by the medium to be cooled. This system
ir, quite largely in use and preferred by many to the com-
pression system, although the latter is used in a large majority
of plants.
CHAPTER II
ORGANIZING AND STARTING A COLD STORE.
POSSIBILITIES OV THE BUSINESS.
As a means of preserving perishable food products, and
in some cases other goods, from decay or deterioration, refrig-
eration has come into use with a rapidity that has surprised its
most sanguine advocates. The author has been identified with
the produce and refrigerating industries for nearly thirty years,
and during the last half of this period has sometimes feared
that the cold storage business was likely to be overdone. At
present there seems no immediate prospect of such a condition,
and it is probable that some years will elapse before there will
be more cold storage space than goods to fill it. This seems
the more probable when we consider the diversified products
which are now stored in refrigerated rooms for preservation.
Furs, as an illustration, are now placed in cold storage to pre-
vent damage from moths, and to preserve the texture of the
skins, and the best furriers report the results as greatly super-
ior to the old method of treatment. Not only are the ravages
of the moths prevented, but the furs come out of cold storage
actually improved in appearance. Dried fruits are now perfectly
kept during the warm months by placing in cold storage.
Nuts are kept in the best possible condition by storing in
cold rooms. Potatoes and cabbage are carried through the
winter and turned out in a condition not thought possible years
ago. These are only a few of the products comparatively new
to cold storage. Each year finds something new in cold storage
for safe keeping, and new uses are being found for refrigera-
tion continually. There seems no limit to the possibilities of
the business. It is certainly only a matter of time when the
bulk of perishable products will be handled in and sold from
23
24 PRACTICAL COLD STORAGE
cold storage, and kept under refrigeration from the time
produced.
By far the greater number of the cold storage plants of
small or medium capacity are buUt and operated by the
producers of or dealers in perishable goods as an aid to their
business. In fact, refrigeration is no longer considered only
as a help, it is a necessity, and the perishable goods operator
without suitable cold storage facilities is decidedly at a disad-
vantage as compared with his competitor who has. This chap-
ter is not written for the man who has use for cold storage in
the form of a private plant, but more for those inexperienced,
or who might wish to become interested in a larger plant for
general use.
The starting and building up of a commercial cold stor-
age business requires all the business sagacity and ability
usually necessary to success in any other line, and in addition
there are some special qualifications which it may be worth
while to consider. The formation of a company, the selec-
tion of a system of refrigeration, and the proper construc-
tion of the cold storage building are merely preliminary to
the actual hard work and care necessary to success, and the
cold storage business may develop into more of an undertaking
than the average person has any idea of. Even after some
investigation the business points are not always as plain as they
should be. After the house is built biisiness must be obtained,
and satisfactory results given to customers or the venture
will prove a failure. A cold storage should not be built,
equipped and operated by a person with no knowledge of the
perishable goods business, thinking that the business will come
naturally. Cold storage is generally only an auxiliary of the
perishable goods trade and must be considered as such.
There are many cold storage men now operating houses
who complain of poor business, and think there is no demand
for cold storage in their locality, when the simple truth is
that they have not the proper facilities for the preservation
of the goods they try to handle. They turn out musty eggs,
strong butter and rotten apples, and consequently their cus-
tomers only use the storage when they are compelled to, Cases
ORGANIZING AND STARTING A COLD STORE 25
may be cited where a properly-equipped house has been started
in competition with the kind above described, and obtained
a profitable business from the start. In progressive times like
the present, when competition is sharp, it is poor business
policy, if not positively suicidal, to go into business with any-
thing except the best facilities. If you are going into the
cold storage business, build a good house, and equip it with
modern apparatus from designs by a practical and experienced
man. A cheap house should not be considered.
An enterprising and self-reliant man is usually at the
head of a new cold storage enterprise. It requires both these
qualifications to establish a house where apparently little de-
mand exists for such a concern, and generally this is about the
situation where there is no cold storage house. There cannot,
of course, be business done in the cold storage line where no
cold storage house exists; but an intelligent canvass of the
situation should indicate the probability or not of business
following the erection of a house. If the situation shows fair
prospects there can be no failure if the enterprise is handled
with the same care and ability necessary for success in other
lines of business. Gold storage houses have been constructed
with small apparent demand for the space, but after being in
business for a year or two to prove an ability to carry goods
well, the house has done a good business. In not a single
instance known to the author has a well-built, properly-
equipped and carefullj'^-operated cold storage house been a
source of loss to its owners. In determining the advisability
of erecting a house, it is well to have enough business assured,
if possible, to pay operating expenses. If this much can be
had the first season, the success of the business is no longer
in doubt, and the house will generally pay nicely the second
or third year. Should the owners be in the produce business,
and buy and store enough goods to pay the operating expenses,
they can demonstrate the success of the house the first year
or two on their own account, and in future seasons obtain
outside business very easily. Of course many houses are run
for private use only, and the suggestions above do not apply
to such cases. It i,s trvi? that there have been a good many
26 PRACTICAL COLD STORAGE
failures in the cold storage business, but they are invariably
the result of a poor house or poor handling, with the result-
ing heavy claims for damage to goods in storage, or of over-
capitalization and mismanagement.
PKOBABLE CAPACITY REQUIRED.
It is difficult to determine what capacity plant to put up
in a place of given size, but usually a smaller capacity than
50,000 cu. ft. should not be figured as a commercial enter-
prise, and a capacity of from 75,000 to 100,000 cu. ft. can be
built and equipped so much cheaper in proportion that gen-
erally speaking a capacity of 50,000 cu. ft. is almost too small
for economical construction and operation. It is quite often
the case that the capacity of a cold storage plant is figured
much too small, and it is seldom that the capacity is figured
too large, and as a cold storage plant is not readily susceptible
of increase of capacity it is advisable to build reasonably large
to start with, allowing somewhat for natural growth of busi-
ness. It is almost always the case that as soon as a cold
storage house is built and demonstrates its ability to carry
goods successfully, business develops which was not thought
of before. The putting up of a cold storage practically creates
to some extent a demand for refrigerated space and business
for such a plant.
Very little reliable information can be obtained by those
who contemplate the erection of a cold storage house, from
people already in the business; especially if in the immediate
vicinity of the proposed house. This is because those in the
business already, regard the building of a new plant as more
or less direct competition, and are quite liable to be biased
in their Aaews of the cold storage business in general, and of
the proposed plant in particular. There is one thing which
may be put down as unnecessary, that is the putting up of
a small, cheap house as a trial, expecting, if it pays, to put
up a larger and a better one. A small, cheap house, while
not certain to be a failure, is more than likely to be so, and
consequently the larger and better house is never built, and
another is added to the ranks of those who think cold storage
ORGANIZING AND STARTING A COLD STORE 27
of no value, and a failure in a business way. Build well, if
at all — it is not necessary to experiment, as this has been
done repeatedly already, and, the results from a well-built
cold storage house are to be depended upon. The population
of a town or city does not always indicate its ability to support
a cold storage warehouse. A large residential population has
very little need for such an establishment, while a compara-
tively small wholesale center at once makes a demand for
storage for perishable goods. A large town, located in a rich
producing district, generally gives a good opening for the
upbuilding of a business, particularly where the chief articles
of production are eggs, butter, cheese or fruits.
COST OF PLANT.
The cost of a first class and fully equipped cold storage
building is somewhat startling to many people who contem-
plate embarking in the business and who have their ideas of
cost based on buildings of ordinary construction. The cost of
a cold storage plant is two or three times as much as that of
a non-refrigerated building of the same size. The shell of
a cold storage plant is only a portion of the total cost, and
seldom or never exceeds half the cost. In many cases it is
only one-third the cost of the finished plant. This varies with
the character of the structure, class of insulation, and type of
refrigerating equipment. It may be stated as positive that
there is no such thing as a cheap cold storage house which
will at the same time do good work. Because of the cost of
internal arrangements and equipment, a cold storage cannot
be compared with any other kind of a building, and the rea-
son why people are surprised at the cost is because they make
comparisons with buildings of ordinary construction. Prob-
ably two out of three persons who investigate with the idea
of building are deterred because of the expense running higher
than anticipated. The reader, who has preconceived ideas
on the cost of a properly-equipped plant, may safely prepare
for a shock should he wish to obtain estimates.
The cost of a first class cold storage plant of 50,000 cubic
feet capacity, allowing some space for receiving, shipping.
28 PRACTICAL COLD STORAGE
storage of empty packages, office, etc., will be from $20,000
to $30,000. The sum of $20,000 will in some localities be
sufficient to build such a plant of frame construction, properly
insulated and equipped in a first class manner, and $25,000
to $30,000 T^'ill build a substantial brick building carefully
insulated and equipped after modern methods. These esti-
mates are approximate only, but are as near as estimates can
be made without making accurate figures as applied to a par-
ticular locality. A plant double this capacity can probably be
built at a cost of from $35,000 to $50,000. The cost is very
much less in proportion as the capacity is increased. Of
course the cost of such a plant depends on how much space is
required outside of the cold storage rooms, into how many
rooms the plant is divided, and the amount of freezer space
needed. If any considerable part of the plant is required
for low temperature or freezer storage it increases the cost
considerably.
The above estimates are based, as stated, on first class
construction and are estimated on average conditions. The
Cooper brine system, using ice and salt for cooling, can usu-
ally be installed at a lower cost in small capacity than me-
chanical refrigeration if the brine circulating system is ap-
plied. In larger plants there is very little difference between
the cost of equipping with the Cooper brine system and me-
chanical refrigeration. It may be stated very definitely in
this connection that the best cold storage results require brine
circulation in connection with the mechanical systems of re-
frigeration, and direct expansion piping should not be used
for what are known as high temperature rooms at a tempera-
ture of 30 degrees F. and above. Direct expansion may be in-
stalled at lower cost, but it is not desirable, for reasons which
are explained elsewhere.
It should be noted further that means of cooling are not
the only requirement of a cold storage plant. The Cooper
systems of air circulation and ventilation and the chloride
of calcium process are applicable to any means of cooling,
and these systems have proven their effectiveness wherever in-
.«tnlled, This suggestion is offered for the reason that in esti-
ORGANIZING AND STARTING A COLD STORE 29
mating costs of cold storage plants, the cost of buildings, in-
sulation of the rooms and the means of cooling are not the
only costs. The Cooper systems referred to add comparative-
ly little to the total cost of the plant, but yet they do add
something. However, as they are applicable to any method
of cooling, they should not be considered, when comparing the
cost of the Cooper brine system, using ice and salt for cooling,
with the mechanical systems of refrigeration.
An extract from the 1911 report of John A. Ruddick,
Dairy and Cold Storage Commissioner of Canada, is interest-
ing because he gives some figures on cost of cold storage
houses, and further as showing what these houses are insu-
lated with. From the table which follows it may be noted that
mill shavings are used exclusively in three houses, and used
in combination with other materials in three other houses;
and that cork is used exclusively in five different houses ; Lith
in one ; and hair felt in combination with shavings in two.
"Many inquiries are received at this office from those who desire
to know the probable cost of a cold storage warehouse of given ca-
pacity. There are so many factors that have an influence in fixing
the cost of a cold storage warehouse, such as the. class of building, the
character of the insulation, the proportion of high and low tempera-
ture space, the size of the warehouse, etc., that it is impossible to give
any but an approximate answer to such questions.
"The cost, with some particulars of the construction, and the
size in cubic feet, of some of the warehouses which have been sub-
sidized under the Cold Storage Act, is given below to afford some
information on this subject. All names and location of the ware-
houses are indicated by numbers only. The class of construction
for the buildings, apart from the insulation, is represented by letters
thus:
"A — ^Wooden building.
"B — Brick or concrete walls, 'mill construction floors.'
"C — Reinforced concrete.
"D — Brick, stone or concrete, ordinary floors.
"It will be observed that there is considerable difference in the
cost of the warehouses in this list on a cubic foot basis. The differ-
ence is owing to the fact that some of them are wholly equipped for
a very low temperature for fish freezing, while others have a large
proportion of space intended for fruit or egg storage at non-freezing
temperatures. The difference between the total space and the refriger-
ated space is represented by engine rooms, corridors, packing floors,
etc
J. A. RUDDICK,
Dairy and Cold Storage Commissioner."
30
PRACTICAL COLD STORAGE
Class of
Size of
Building
Building
Cubic
feet
IB
974,622
2D
372,000
3A
142,218
4C
744,488
5D
71,520
6B
202,262
7A
100,000
8D
220,000
9A
108,040
lOB
356,400
IIB
270,000
12D
200,000
Insulation
Refriger-
ated
space
Cork
Hair felt and shavings.
Shavings
Cork
Cork
Lith
Shavings
Shavings
Cork and shavings
Cork
Cork
Hair felt and shavings
I-
Cubic
feet
700,224
105,000
37,960
346,538
37,161
64,000
50,000
33,600
59,940
225,000
111,050
131,510
Cost
Exclusive
of Site
Dollars
167,000.00
31,019.62
27,386.69
160,500.00
23,577.00
65,000.00
18,682.00
20,000.00
57;500,00
158,043.00
60,000.00
49,000.00
COST OF COLD STORAGE HOUSES FOE APPLES.
Many figures have been given as representing the cost
of cold storage houses for apples, per barrel of capacity.
These range from $2 per barrel for plants of 250,000
cubic feet, or with a capacity of 25,000 barrels as a minimum
cost, up as high as perhaps $4 to $5 per barrel in a plant with
a capacity of 500 to 1,000 barrels. It must be noted that
there is nothing exact about these figures, as so much depends
on cost of materials in different localities and type of build-
ing, but any estimates or figures are far better as a guide than
none at all. The author believes it possible to build a 250,000
cubic foot cold storage plant for apples for $50,000, but this
certainly would not be reinforced concrete nor would it be
brick and heavy mill construction, nor any type of slow burn-
ing construction. It would mean an economically built build-
ing of frame and on a favorable building site, but there are
many localities where a plant of the capacity stated could not
possibly be built on a basis of $2 per barrel capacity. In other
words, local conditions and everything else must be favorable
in order to make it possible to build at this cost.
An important point influencing cost is the variety of
apples stored. If summer and fall varieties are stored in large
quantities requiring heavy cooling duty during the warm spells
in late summer and fall, a much larger and more expensive re-
frigerating equipment is necessary, whereas if mostly winter
ORGANIZING AND STARTING A COLD STORE 31
varieties are stored, which go into the house during cool or
cold weather when little refrigeration is needed to bring them
down to carrying temperature, a comparatively light refriger-
ating equipment can be installed at proportionately lower cost.
Still another important factor is the arrangement of the
building. If built on three or four floors, and few partitions
are needed, (suppose, for instance, each floor is one big room),
the cost of building is very much less. If the plant is built all
on one or two floors requiring large superficial area, and di-
vided into a large number of small rooms, the cost is greatly
increased.
The amount of space needed for receiving, shipping,
office, coopering, storage of empty packages, etc., in some
cases is equal to the cold storage capacity, and this means in-
creased cost per barrel of storage capacity. If it were possible
to build a cold storage plant with nothing but cold storage and
with no other space for other purposes, it may readily be seen
that the cost would be much reduced.
It is probable that among the houses now actually in serv-
ice there are few if any which could now be built at a cost
of $2 per barrel of capacity. The larger ones would mostly
cost from $2.50 to $3.50 per barrel, and some of the smaller
ones from $3.50 to $5.00 per barrel.
CLASS OF GOODS PLACED IN COLD STORAGE.
The product which may be depended upon to furnish the
largest portion of the business to a newly-established cold stor-
age depends on the location. Some houses are built solely for
cheese, others for eggs, and others only for apples; but gener-
ally speaking, eggs form the largest and best paying product
which is handled in cold storage. Eggs are probably the most
difficult of all products to successfully carry for a period of
six or eight months. If they are stored in too dry an atmos-
phere thev drv out or shrinlc, and in this condition decay more
quickly, "if the air is too moist the eggs will mold and become
musty." There is more danger of having a room too moist than
too dry, and the damage resulting from too moist a room is
also much greater. The best temperature for eggs is 29° to
30° F., and thev are carried at this temperature by the best
32 PRACTICAL COLD STORAGE
houses. A forced circulation of air is beneficial, and the mois-
ture in the air should be regulated to the proper degree. For
testing the air moisture of a cold storage room an instrument
called the sling psychrometer is used. The subject of humid-
ity is rather complicated, and the reader is referred to chap-
ter on '"'Humidity," and "Eggs in Cold Storage," for a more
comprehensive treatment of this subject.
Butter is probably second in importance to eggs, and all
cold storage houses have rooms fitted especially for this pro-
duct. The correct temperature for carrying butter has not
been definitely settled by a majority agreeing on some one tem-
perature, and at present butter is held in cold storage at tem-
peratures ranging from below zero to 25° F. The most com-
mon temperature now is between 10° and 15° F., and the
author believes this to be low enough. Many practical men in-
sist that zero is better, and some houses are carrying it at this
temperature. Still others are holding temperatures for but-
ter at from zero to 10° F. Butter storage room should be kept
dry enough to prevent the formation of mold, and generally
no attention is paid to the matter of humidity ; the room being
amply dry, nothing further is thought of it. If butter rooms
are too dry, as they frequently are, it leads to a bad drying
out of the packages, and of the surface of the butter as well,
causing it to get "air-struck" or "strong" and shrink in
weight. Butter, in order to keep well in cold storage, must
be protected from contact with the air. Much has been said
about freezing butter, but the butter fat practically has no
freezing point, and it simply gets harder and harder the lower
the temperature; so the idea that butter freezes at a tempera-
ture just under 32° F. is entirely erroneous. (See chapter on
"Butter in Cold Storage" for more complete information.)
Cheese is not ordinarily considered so difficult a product
as butter and eggs to refrigerate successfully, but this idea
comes largely from the fact that cheese has only within the
past fifteen years been well handled in cold storage, and the
possibilities of refrigeration for this purpose have not been
fully understood. Cheese will not spoil if stored in cellars or
basements; nevertheless a properly-equipped cold storage room
ORGANIZING AND STARTING A COLD STORE 33
will quickly pay for itself in the improved results obtainable.
Cheese should be carried at about the same degree of humid-
ity as eggs, and at a temperature ranging from 38° down to
30° F. It is very common practice now to place cheese in
cold storage when only eight or ten days old. At this age it is
not properly cured, and should' not be placed in a lower tem-
perature than 38° F. The temperature may be gradually low-
ered after a month or two, and at an age of three or four months
the temperature of the. room should reach 30° F., but should
not go any lower. If the temperature is carried much below
30° F. for any length of time it will injure the texture of the
cheese, and even at 30° F. some claim that it makes the cheese
"short" or brittle in texture. Cheese will freeze so as to be un-
fit for market at about 20° to '25° F. The reason why cheese
should not be placed in too low a temperature while new, is
that it may not ripen or "cure up" properly, and is liable to
develop a bitter flavor. It must be remembered in consider-
ing this subject that cheese is of many different kinds and
widely varying quality. What is said above refers to an aver-
age make of American cheddar cheese. (For further informa-
tion on the cold curing of cheese see chapter entitled "Cheese
in Cold Storage.")
Apples are stored in large quantities during the fall and
winter months. The quality of the fruit should be- prime, and
not too fully matured. It is customary to place apples in egg
rooms as fast as eggs can be removed in the fall, and no bad
effect will result. Apples and eggs should not, of course, be
placed in the same room together, but when a room is emptied
of eggs it is customary to fill it with apples. After the apples
go out and before again filling with eggs, the room should be
thoroughly whitewashed. (See chapter oh "Keeping Cold
Stores Clean.") There are many different varieties of apples,
and some of them require special treatment in cold storage,
but the generally accepted temperature for apples for long-
period storage is 30° or 31° F. Some apple men prefer high-
er temperatures, and get good results, but the lower tempera-
tures are the favorite. Apples should not be quickly cooled
when' placed in cold storage. If a week or two is consumed in
34 PRACTICAL COLD STORAGE
reducing them to the correct temperature so much the better.
(See chapter entitled "Apples in Cold Storage.")
Oranges are very successfully cold-stored at temperatures
of from 32° to 35° F. Lemons are very sensitive to cold,
and may be seriously damaged if the temperature approaches
near the freezing point. Fifty degrees is thought best for lem-
ons. Lemons and oranges must be stored separately and iso-
lated from products like eggs and butter. It is best not to
handle these in the same building unless through a separate
outside entrance, as much damage results to eggs and butter
if flavored with the odor of citrus fruits. Some prominent
cold storage houses have been veij heavy losers from being
obliged to pay for damage from this cause.
Dried fruit and nuts, flour, and other goods known as
grocers' sundries, are now a large item for cold storage in
some wholesale centers. This business comes largely from the
wholesale grocers and commission men. These goods are
stored at a temperature of 35° to 45° F. The storage of furs,
woolens, etc., is an important and lucrative business in many
cities, and where the volume of business is sufficient a room
may be set aside for the purpose, and made to pay well. Any
temperature below 40° F. is all that is necessary for this class
of goods. Potatoes may be kept in cold storage at a tempera-
ture of 34° F., and carried until spring in prime condition.
Potatoes freeze easily, and are entirely ruined when frozen, so
the temperature must never touch the freezing point. Cabbage
may be carried some time in a green condition, at a tempera-
ture of 31° F. Freezing will not damage cabbage materially
if the frost is drawn out slowly. The freezing and storage of
poultry is a remunerative business, and much poultry is han-
dled through cold storage. The freezing may be accomplished
at 12° to 15° F. with good results if stock is freshly killed and
in small packages. For temporary holding without freezing a
temperature of 30° F. is best. Poultry can only be held a few
weeks at this temperature, a month to six weeks being the ex-
treme limit. Beer and meat are handled by some houses. Beer
should be held at 35° to 38° F., and meat at 30° to
38° F., depending on length of time it is to be carried.
ORGANIZING AND STARTING A COLD STORE 35
KATES FOE COLD STORAGE.
The rates to be obtained for storing different products
vary with the locality, competition, etc., but the following will
serve as a guide. These rates are mostly higher than average
rates on carload lots, but will serve as a guide to those not
familiar with local rates. Each locality has its own rates to
some extent:
Per Season Season
Month. Rate. Ends.
Eggs, per 30 doz. case f .12% $ .50 January 1
Butter, per 100 lbs 20 .75 January 1
Cheese, per 100 lbs .■ 15 .60 January 1
Apples, per barrel 12 .50 May 1
Lemons, per box 08 .35 July 1
Oranges, per box 07 .30 July 1
Dried Fruit, per 100 lbs 07 .30 November 1
Nuts, per 100 lbs 08 .35 November!
Furs, Coats, etc 2.00 January 1
Potatoes, per 100 lbs 08 .30 April 1
Cabbage, per ton 1.50 4.00 April 1
Poultry freezing, per cwt 25 1.00 April 1
Beer, space rented at 15c. per cubic foot per year.
Meat, per 100 lbs., 15c per month.
EARNINGS OP COLD STORES.
To show the prospective earnings of a small house we will
take one of 50,000 cu. ft. capacity operated on the Cooper
system, and assume that we secure the first year half its ca-
pacity, or twenty cars of eggs. Twenty cars of eggs equal 8,000
cases. If we secure a season rate on all, at the carload-rate of
40 cents, this will give us a gross income of $3,200. Operating
costs are difficult to obtain even with the simple ice and salt
system owing to widely varying circumstances under which
plants operate. An estimated cost of the ammonia or other
mechanical systems is out of the question as the item of at-
tendance alone is never uniform.
The operating expenses of a house of 50,000 cu. ft. of
space conservatively figured will be in northern localities
where natural ice may be secured cheaply and assuming that
the plant is equipped with the Cooper brine system, using ice
and salt for cooling, and operated the entire year, about as
follows:
36 PRACTICAL COLD STORAGE
700 tons of ice at 50c per ton $350.00
80 tons of salt at $5.50 per ton 440.00
6 tons of chloride of calcium, $15 per ton 90.00
Power for lee crushing and elevating, operating fans
for air circulation and ventilation, and for driving
freight elevator, average $25 per month 300.00
Labor, 6 hrs. per day for 200 days at 20c 240.00
$1,420.00
The item of labor above does not include labor of han-
dling goods in and out of the house, but is based only on the
labor required for charging priraarj^ tanks of the Cooper brine,
system with ice and salt, looking after temperatures and run-
ning the house. In many places ice may be had for less than
50 cents per ton. In other places these costs average higher,
but the above is conservative, and will apply to average cases.
From these figures it is seen that with our house half full
of goods, the business would pay a fair profit above actual ex-
penses. It may be well to note here that it costs practically
as much to operate a cold storage house half filled with goods
as it would if completely filled. The only difference is a small
labor item of the handling, and the cost of cooling the extra
quantity of goods in the first place to the temperature of the
room, both very small items. The moral of this is that the
cold storage manager should aim to have his house filled every
year. If apples are to be had as the eggs go out in the fall,
the income for the year is materially increased with little cost,
as apples require only a small amount of refrigeration during
the cool weather of fall and winter.
ADVICE TO THOSE Ngw to THE BUSINESS.
A few words of advice to prospective investors regarding
the danger of experimenting in cold storage construction. It
is dangerous from the fact that a failure means the damage of
a very valuable product, and a consequent heavy money loss.
The most absurdly foolish schemes have been tried by men
with no practical or scientific information, and the result has
been what any thorough-going cold storage man could fore-
see— either fiat failure or no tangible results from the experi-
ments tried. Sometimes it occurs that the would-be cold storage
man thinks to save architect's and engineer's fees by planning
ORGANIZING AND STARTING A COLD STORE
37
his^ own building, or by taking some of the plans and ideas
which appear from time to time in the agricultural or trade
papers, and working them over to suit his case. It is the
author's positive opinion that four times as much money is
wasted in this T\'ay as there is saved. No two houses properly
use the same construction and arrangement, and each case re-
quires special study by the designer in order to do it justice,
and he is a poor engineer indeed who cannot save twice his
fees to his client. The above advice is given with an intimate
knowledge of the subject, as the author has spent much money
on experiments and tests of various kinds, and never expects
to be properly reimbursed for the time and effort expended.
All lines of industry are more and more specialized, and the
planning and equipping of a cold storage house is just as much
a special business as the buying and selling of produce.
As has already been pointed out, the results possible to
attain by the use of ice are equally as good, within certain lim-
its, as may be obtained by employing the ammonia or me-
chanical system. The ice and salt system has the advantage
of being cheaper to install, cheaper to operate, and a better
control of temperature is possible. These are all very good
reasons why the ice and salt system should be adopted where
ice is a sure crop, and can be put in the house at a moderate
price. There is absolutely no question about the results ob-
tained from storing goods in such a house, well-built and prop-
erly managed. The most perfect results possible in refriger-
ation may be obtained, and at a small cost as compared with
the mechanical systems. Where manufactured ice is in use
the small cold storage house, butcher, produce dealer, or any
other business requiring refrigeration in comparatively small
amounts, can in many cases obtain the best results at a lower
cost by the use of ice and salt than by the installing of a small
machine. Besides this they are absolutely safe against a
breakdown.
The question is often asked, "How long will a cold stor-
age house and its equipment of piping and iron work remani
in good operating condition?" No positive answer can be
made, as a great deal depends on the building and the ap-
38 PRACTICAL COLD STORAGE
paratus, and the way it is handled and cared for. The aver-
age life of a cold storage building and the insulation should
not be essentially different from that of an ordinary building
of the same construction, and this means that it will last in-
definitely. The equipment, with ordinary repairs, would do
good service for from fifteen to twenty-five years, probably long-
er under favorable conditions. An ice storage room will re-
main in good condition for from fifteen to twenty-five years,
and it is probable that it would be serviceable for the purpose
for a much longer time.
CHAPTER III.
SYSTEMS OF REFRIGERATION.
INTRODUCTION.
In the first chapter under "Historical" a brief review
was given of the introduction and development of various
cooling methods for the preservation of perishable goods. It
is not the intention in this chapter to give much more than
the principles on which the various systems operate. The uses
of caves and cellars for cold storage are so crude and unsat-
isfactory that they are hardly worth considering except from
an historical standpoint. The various methods of cooling
by means of ice may be found in the chapters on "Iceboxes
audReMgeratorg^" "Refrigeration for Retailers" and "Re-
frigeration from Ice," and the reader is referred to these chap-
ters for more complete details. Mechanical refrigeration has
been explained so fully in the "Compend of Mechanical Re-
figeration," "Machinery for Refrigeration," &c., that the fol-
lowing outline is only intended to serve in explaining the gen-
eral principles of the various systems of mechanical refrigera-
tion. ■
COLD AIB SYSTEM.
The cold air refrigerating machines operate on the prin-
ciple that a compression of air generates heat, and its expan-
sion afterwards absorbs heat or produces cold. The air is
first compressed in an especially built pump or compressor,
and the heat produced is removed by applying water for cool-
ing. The refrigeration resulting from the expansion of air
from the expansion cylinder is utilized for cooling purposes.
Mechanical work and heat are convertible, and this law is
utilized in the cold air refrigerating machine. It is necessary
39
40 PRACTICAL COLD STORAGE
for the air when expanding to work against a piston in order
to exhaust the stored heat of the compressed air. This leaves
the expanding air in condition to do useful refrigerating work.
There are two systems of cold air machines; one being
known as the open cold air system and the other the closed
system. In the open system fresh air is taken in with each
stroke of the compressor pump, and the air, after expanding,
is discharged to the atmosphere. In the closed type of machine
the same air is used over and over again.
The first cold air machine to be constructed in the United
States was utilized for ice making, and was built by Dr. Gorrie
in Florida about the year 1850. The heat of compression
was removed by a spray of water introduced into the compres-
sion cylinder, and by expanding the cooled air a second spray
of water was turned into ice.
Undoubtedly the largest number of cold air machines
in use are of the Bell-Coleman make, which machine is of
the Windhausen type; the Bell-Coleman machine being of
improved design and construction. The Allen dense-air ma-
chine has been largely used in the United States, while in
England the Linde Co. and the Haslams' have furnished a
largo number of installations.
Practically as well as in theory the cold air refrigerating
machine requires more power than those machines which uti-
lize a liquefiable gas in the cycle of operation. This means that
large compression and expansion cylinders with the accom-
panying increased friction, as well as moisture in the air, &c-,
all operate to reduce the efficiency of the cold air machine.
Improvements, however, have been made recently, and it is
probable that a useful place will always be found for the cold
air machine. On shipboard especially this system of refrig-
eration has been found very satisfactory for several reasons.
It is much safer to operate, and the question of economy does
not seriously enter the problem in connection with refrigera-
tion or ice making on ocean-going vessels.
CARBON DIOXIDE SYSTEM.
This system is identical in principle with the ammonia com-
pression system described further on. Carbon dioxide is a
SYSTEMS OF REFRIGERATION 41
gas which is liquefiable at certain temperatures and pressures.
A much higher pressure is required than with the ammonia
system, .and the system has not found favor for this reason,
as the loss from clearance and friction is considerable and the
system, speaking generally, is not as efficient as the ammonia
system. There is, however, a great advantage in the carbon
dioxide system from the fact that the gas is non-poisonous,
and considerable quantities may be liberated in a closed space
without danger to life or health. This qualification makes
the system of distinct advantage in many places, especially
in the confined areas of ships and for certain uses on land
as well.
COMPRESSION AMMONIA SYSTEM.
Substances which are gases at ordinary temperatures may
be changed to liquids at low temperatures and comparatively
high pressures. Ammonia is such a substance and is in most
common use for cold storage and ice making purposes. The
gas is compressed by means of a power driven machine of
suitable design and , cooled by .flowing water over coils of
pipe containing the compressed gas. This reduces it to a
liquid form. In changing a gas to a liquid much heat is
given up which is extracted by the cooling water.
To obtain refrigeration the liquid is expanded to a gas
again during which process heat is absorbed or cold generated.
The expansion, controlled by means of a valve, is through a
•suitable system of pipe coils usually. The evaporation or ex-
pansion of the liquid into the form of a gas cools the pipes,
and this in turn "cools the surrounding medium, either air, brine
or water, or whatever it may be. Ammonia piping placed in a
cold storage room absorbs heat which means cooling, and
ordinarily frost collects on the outside of the coils. Theoretical-
ly the same amount of heat is absorbed from the surround-
ing mediums during ,proceK.« of expansion as has been pre-
viously given up by the ammonia during process of compres-
sion and cooling. The ammonia is thus used in a continuous
cycle, being returned periodically from a gas to a liquid state
rind vice versa.
42 PRACTICAL COLD STORAGE
While this system is very simple in general scheme, yet
the necessary parts of the apparatus are quite complicated and
various auxiliary machinery is necessary besides the compres-
sor and condenser. It is, however, much more simple than
the absorption ammonia system, which is about to be described,
and for this reason, doubtless, it has come into more general usef
ABSOKPTION AMMONIA SYSTEM.
The absorption ammonia system has an entirely different
cycle of operation than the compression system. While the
gas used is the same, yet it is used in a different way, and
while the absorption system is generally classed as mechanical
refrigeration, yet the process is more chemical or physical
than it is mechanical. In the compression system the ammonia
gas is known as anhydrous ammonia, and in the absorption
system, the anhydrous ammonia is absorbed in water at the
commencement of the cycle. The mixture of ammonia and
water, known as aqua-ammonia is heated in a suitable still or
generator, which evaporates or drives off the anhydrous am-
monia, and the processes of condensation and expansion are
just the same as they are in the ammonia compression system
as already described. After expansion through a suitable sys-
tem of coils and after doing the work of refrigerating or ice
making, the ammonia gas (anhydrous ammonia) is absorbed
back into the water again in a suitable tank or vessel known
as the absorber.
There are four distinct stages in the process of refrigera-
tion with the absorption system as .follows: First, Genera-
tion of the gas or vapor; Second, Condensation of the gas;
Third, Evaporation or expansion of the condensed gas from a
liquid to a gas again ; and Fourth, Absorption of the gas into
water. As in the compression system there are some rather
complicated parts and apparatus necessary to control all of
these processes, and as the cycle is somewhat intricate rather
closer attention is required and a better understanding of the
underlying laws than is required in connection with the opera-
tion of the ammonia compression system.
SYSTEMS OF REFRIGERATION 43
It may be suggested in passing that the ammonia absorp-
tion system is especially adapted to situations where rather
low temperatures are required and where condensing water of
not above 60° F. is available. The efficiency and capacity of
the absorption system does not fall off as rapidly when lower
temperatures are required, as does the compression system.
CHAPTER IV.
GEOMETRY OF COLD STORAGE HOUSES.
BEST PROPORTIONS FOR COLD STOKES.
An important factor in the cost of constructing and cost
of refrigerating cold storage rooms, as independent rooms, or
as a complete warehouse, is the relation of dimensions (length,
breadth and height) to area of outside exposure. This point
is often lost sight of in the design of refrigerated structures,
and the desire to gain all the space possible on main floor some-
times leads to some very absurd arrangements from a theoreti-
cal, practical or business standpoint. The installing of first-
class elevator facilities in a cold storage warehouse is very im-
portant and with a fairly high rate of speed and a commodious
car, space on the floors above is practically as valuable as
space on the ground floor. The idea that storage rooms should
be low, say 7 feet to 9 feet, has often been carried to an un-
warranted extreme. It is where rooms are to be used for tem-
porary purposes only that it is desirable to have the rooms
low to avoid unnecessary labor in handling the goods. Rooms
for long period storage purposes as a general rule should be
made from 10 feet to 12 feet in height; not only as a matter
of economy of space and cost of construction, but the circula-
tion of air in the room is much more perfect. This is especial-
ly true of direct piped rooms. The importance of this subject
has been so often overlooked in the construction of cold stores
that it ha.s been thought advisable to direct attention to it
here. The relation of the cubical contents of a building to
its outside exposure or superficial area is readily appreciated
by noting a few figures, as follows :
Take three rooms or buildings of equal storage capacity,
with cubical contents of 1,000 cubic feet, and whose three di-
GEOMETRY OF COLD STORAGE HOUSES
4S
mensions vary. The cube with length, breadth and height
each 10 feet (see Fig. 1) has an outside exposure of 600 sq. ft.
Fig. 1. — BxLxH equals 1,000 cubic feet.
10x10 equals 100; 100x6 equals 600 sq. ft.
Ratio of cubical contents to outside
exposure 1,000 to 600.
Comparing with another rectangular space of equal ca-
pacity— whose breadth is 1.0 feet, height 7 feet 6 inches and
length 13 feet 4 inches. (See Fig. 2.)
Fig. 2. — BxLxH equals 1,000 cu. ft.
10'xl3'4"x2 equals 266 2-3 sq. ft.
lO'x 7'4"x2 equals 150 sq. ft.
7'6"xl3'4"x2 equals 200 sq. ft.
Total 616 2-3 sq. ft.
Ratio of cubical contents to out-
side exposure 1,000 to 616 2-3.
46
PRACTICAL COLD STORAGE
It will be noted that the change of dimension in this case
is but slight from the cube, so the increase of outside exposure
is only 2.77 per cent.
Taking another and more pronounced departure from
the cube and still retaining the capacity of 1,000 cubic feet,
where the breadth is 6 feet 8 inches, length 25 feet and height
6 feet (see Fig 3) .
Fig. 3.-
-BxLxH equals 1,000 cu. ft.
6'0"x25'0"x2 equals 300 sq. ft.
6'8"x25'0"x2 equals 333 sq. ft.
6'8"x 6'0"x2 equals 80 sq. ft.
Total 713 sq. ft.
Ratio of cubical contents to outside
exposure, 1,000 to 713.
To sum up the comparison of the cube with the other two
rectangular rooms or buildings would be as follows :
Cubical con-
tents in cubic
feet.
Superficial area
or outside ex-
posure in
square feet.
Percentage of
Increase over
cube.
Fig. 1
Pig. 2
Pig. 3
1000
1000
1000
600
616 2-3
713
2.77
18.83
The result is important in view of the fact that the loss
of refrigeration from heat leakage through the walls is on the
GEOMETRY OF COLD STORAGE HOUSES 47
average probably three-fourths of the total amount necessary
to supply and maintain temperature in cold storage rooms.
The amount of heat leakage will be directly proportion?il to
the exposed outside surface or superficial area of the room or
house. The cost of insulation, which is usually figured by the
square foot of wall surface, is also increased proportionately,
and the cost of building is also greater. The cost of insulation
and cost of cooling to make good the heat leakage will be 18.83
per cent greater if the room or building is built as in Fig. 3,
than if built in the form of a cube, as in Fig. 1. Therefore,
in the design of cold storage rooms or buildings, the nearer
a cube may be approximated, the cheaper the first cost and
■ cost of operation, other things being equal.
This must not be carried to an extreme which will make
the conduct of the business laborious or expensive. Some
classes of trade require much floor space and little height,
while others may use a high room. For a business where
many goods are handled in and out, daily, ground floor space
is extremely valuable. In extreme cases it may be necessary,
on account of expense and time consumed in handling, to ar-
range all storage rooms on the ground floor. To do this the
advantages obtained must more than offset the increased cost
of construction and operation. For a business where goods
are mostly in for long-term storage a house of several floors is
practically as convenient, costs less, is cheaper to operate and
requires less ground space.
By the use of labor saving devices described elsewhere,
such as the gravity carriers combined with elevating appar-
atus and spiral lowering parts properly arranged, there is no
need of figuring to have all handling and storage space on one
or even two floors. As an instance, may be cited the pre-cool-
ing of oranges. The fruit is in storage for a matter of two
to four days only, and the basement makes a most valuable
location for the cold rooms. Main floor space for the grading
and packing is necessary to secure air and light for the work-
ers. The fruit is lowered into the cooling rooms by a spiral
conveyor and raised by an endless chain elevator.
CHAPTER V.
INSULATION.
GENERAL CONSIDERATION.
The original matter comprising this chapter was pre-
pared nearly eight years ago, and contained practically all
of the scientific and practical information available on the
subject up to that time. Since then comparatively little has
been added to the general subject except by those who have
been interested in making or selling special insulating ma-
terials, and by far the larger number of articles and papers
which have been written on the subject have been by people
who were thus interested rather than by engineers who should
be able to gauge such matters from a disinterested standpoint.
The educational influence, therefore, of the current literature
on the subject of insulation tends to induce people to buy ma-
terials which are marketed in especially prepared forms ready
for applying. It is the purpose in this chapter to present in
a fair and unbiased manner the merits of different insulating
materials and discuss ways and means of applying them re-
gardless of outside influences or personal opinion. The au-
thor has had to do A\'ith the planning of many refrigerating
installations during the past twenty-five years, and he believes
that there has been no other influence in his recommenda-
tions than strictly merit, and it should be possible to say this
of every legitimate engineer who expects to retain the respect
and confidence of his clients.
Insulation as applied to the purposes of cold storage con-
struction is the providing of a suitable wall to prevent the
penetration of an unreasonable amount of heat, and perhaps
also to prevent the penetration of cold during extreme win-
ter weather. It is not possible to prevent the loss of refrigera-
tion (the inflow of heat) or the coming in of cold (the out-
INSULATION 49
flow of heat) entirely, no matter how perfect an insulation is
used; and the commercial aspect of the problem must be consid-
ered. It cannot possibh^ be profitable to provide an expensive
insulation to save losses which will not pay interest on the in-
creased investment. The selection of a suitable insulating ma-
terial and its correct application is consequently of the utmost
importance in the design of cold storage and refrigerating
plants. It should be stated here that the illustrations contained
in this chapter are not all by the author, nor does he in every
case recommend the construction shown without qualification.
The details shown are intended to set forth representative
forms of insulation as generally used. The insulating values
of different materials as shown by tests have to a great extent
been accepted from the figures made by those who have tested
the material in question, and the accuracy of these figures is
not vouched for by the author. The apparatus used in mak-
ing the tests is rather thoroughly described in detail, and suf-
ficiently accurate information given so that it will be possible
for the reader to make tests on his own account if desired.
The great variety of materials and combinations of ma-
terials which have been and are still used as cold storage in-
sulation is accounted for largely by the fact that up to within
comparatively recent years no proven standards of efficiency
were available. The person having a given work in charge
used his own ideas, and in most cases this resulted in poor
insulation from an efficiency standpoint. There was alto-
gether too much guesswork, individual ideas and popular
prejudice. Some people would be satisfied with a very small
quantity of the cheapest kind of material put up in any kind
of a way, not appreciating the fact that insxilation is the vital
feature of a successful and economically operated plant. Others
used plenty of material, but not knoAving how to apply it
properly much money and labor was wasted. As illustrating
this idea the author has had occasion to remove as many as
eight thicknesses of dressed and m-atched lumber composing
the outer insulated walls of a cold storage building; each thick-
ness of lumber separated from the others by a one inch
furring strip and a layer of paper. Thus fully double the
so PRACTICAL COLD STORAGE
quantity of lumber necessary was used. By a little skillful
design a better insulation could be put up for half the cost.
As illustrating the other extreme a case is recalled where the
only insulation consisted of a four inch air space formed be-
tween the outer boarding and the inner boarding on the studs
of the building with an added two inch air space on the inside.
The insulation thus consisted of two air spaces, one of four
inches and another of two inches with three thicknesses of
lumber and three thicknesses of paper. These two cases illus-
trate the great divergence of opinion as to what cold storage
insulation should consist of. We know at this time that air
spaces are fully understood to be out-of-date as insulation.
There has, however, been much intelligent pioneer work
done in the designing and testing of insulation and in the selec-
tion of suitable materials. This work has at times been handi-
capped and difficult owing to inaccurate representations and
claims made by manufacturers and salesmen of various special
insulating materials, and the laboratory tests of the non-con-
ducting properties of various substances have been distorted in
some cases to suit one particular material. The tests, while
perhaps correct, were often misleading to the customer so
far as enabling him to form a correct impression of the real
insulating value of the materials in question is concerned.
Another influence which has been at work has also delayed
progress in developing of good cold storage insulation. The
manufacturers of refrigerating machinery have usually de-
voted space in their catalogues to approved insulations, but
they have seldom secured the services of skilled engineers in
the design of same or suggested advanced or progressive ideas
on the subject. The details of insulation which they recom-
mended were as a rule entirely insufficient for economical
operation, and they were satisfied to sell a larger refrigerating
machine, as it was found easier to do this than to convince the
customer that he should invest more money in better insula-
tion. Besides, a bigger machine meant a bigger sale. It is
a pleasure to say, however, that more judgment and fairness
is now being used, and as knowledge spreads, we may look for
better and more economically insulated cold stores in- future.
INSULATION 51
THEORY OF HEAT.
Heat vitally concerns all cold storage and refrigerating
problems, as it is the elimination of heat and the preventing
of its entrance that makes refrigeration necessary. A brief
outline of the theory of heat will be useful to a better under-
standing of the laws underlying the design and construction of
insulation.
Heat is a form of activity or energy and does not possess
substance. The sun is the one source of heat from which other
sources are fed by direct radiation. The heat of the earth,
chemical combination, electricity, friction, etc., are only mani-
festations, but are regarded as the lesser sources of heat. Heat
tends towards equilibrium ; thus a cold body is warmed by
one of a higher temperature. If the temperature of the air
is warmer on one side of a wall than on the other, heat flows
through until temperatures are equalized. It is not possible
to prevent this, but there is a vast difference in the heat re-
tarding value of various materials which may be used to form
an insulated wall.
The transmission of heat is effected in three different
ways : first, by radiation ; second, by convection ; and third, by
conduction. Radiation is the direct passage of heat through
the air from one body to another without perceptibly heat-
ing the air, and is manifested to the senses by the heat which
is felt when standing by an open fire. By radiation, heat is
thrown off in every possible direction from every point of a
hot body. In an inclosed air space with different tempera-
tures as shown in Fig. 1, the radiant heat would pass from
the high to the low temperature side directly across the space
indicated by arrows. The scientific definition of radiant heat
is that it is in the nature of a wave motion communicated
through an exceedingly subtle ether, which is supposed to
pervade all space, and that it is obedient to the laws of refrac-
tion, reflection, polarization, etc., the same as light.
Convection of heat is the transfer from one place to
another by the bodily moving of the heated substance, such as
when air," water or any other gas or fluid comes in contact
with a heated surface; the particles touching the heated sur-
52
PRACTICAL COLD STORAGE
face become warm and lighter., therefore ascending and giving
place to the colder and heavier particles below. This action is
illustrated by the heating of rooms with stoves; the air as
warmed rises to the top of the room and its place is taken by
the colder air from below. The principle of convection, or cir-
culation as it is generally understood, is shown by Figs. 2 and
3, where the air in the inclosed space with one side warmer
IH51DE
CO°f
OUTRIDE
WALL
^o°f:
IN5IDE
WALl
kSOTT
Vall
3oT
MMS^I,
^^^1
Outride
Wall
fi Outside
Wall
10° r
PIGS. 1, 2 AND 3— ILLUSTRATING WAYS OF HEAT TRANSMISSION.
than the other, being heated on that side, becomes lighter by
expansion and rises; as it gets to the top of the confined space,
it passes over to and down the cold side where it gives up
heat; as it is cooled, it contracts and becomes heavier; it then
sinks and returns to its original place. This circulation will
INSULATION S3
continue indefinitely or until the temperatures on both sides of
the space are equalized. Fig. 3 illustrates this principle when
a wall is subdivided into a number of such spaces, and the
circulation becomes more complicated and retarded, passing
less heat for the same thickness of wall in a unit of time
than a single space, as illustrated in Fig. 2.
Conduction is a term applied to heat flowing from a
warmer to a colder part of a body, or if a solid substance ig
placed in contact with a body having a higher temperature,
the particles of the substance nearest are warmed, and they in
turn give up a portion of the heat received, to particles next
to them and so on from particle to particle until the whole
substance is heated; this is accomplished without any sensible
motion. A more familiar example of conduction is putting
one end of an iron poker in the fire; after a time, the other
end will become heated and apparent to the sense of feeling.
As heat then is not a substance but a vibration of the
molecules that compose a body, and as the rapidity of these
vibrations is the cause of the difference of temperature, it
is really improper to speak of heat and cold as such ; but it is
convenient to use these old familiar terms in describing the
phenomena, just as it is said that the sun rises and sets, where
it is in fact the earth that moves.
Theoretically, all bodies and substances transfer heat by
radiation, convection and conduction at the same time, and
this is called complicated transfers of heat. Scientists state
that bodies at high temperatures will lose more heat by radia-
tion than by convection and conduction, and that heat radiated
by a coal fire is estimated to be about one-half of the total heat
generated. At lower temperatures, such as is dealt with in
refrigerating work, transmission of heat by radiation is very
small, and practically, convection and conduction only need
be considered in cold storage construction.
UNITS OF HEAT.
"Heat is measured quantitatively by the heat unit, which
also varies in different places like other standards. The unit
used in the United States and England is the British Thermal
Unit (abbreviated B. T. U.), and represents the amount of
54 PRACTICAL COLD STORAGE
heat required to raise the temperature of one pound of water
1° F. The French unit is the Calorie, and is the quantity of
heat required to raise the temperature of one kilogram of
water from 0° to 1° Celsius.
"Some writers define the B. T. unit as the heat required
to raise the temperature of one pound of water from 32° to
33°. Others make this temperature from 60° to 61°, and still
others define it as the amount of heat required to raise 1/180
pound of water from the freezing to the boiling point. The
last two definitions give nearly the same result, and may be
considered practically identical."*
The unit of heat transmission or insulating value is the
number of B. T. U.'s that will pass through one square foot of
a substance per hour, per degree difference in temperature
between the two sides of the substance. Some engineers prefer
(in refrigerating work) to use a time unit of one day (24
hours) instead of one hour in their values. This is perhaps
more comprehensive, as refrigerating capacity is usually
figured per day, and it also is an advantage in that the values
are more likely to be expressed in whole numbers and less in
decimals.
CONDUCTORS OP HEAT.
Many laboratory experiments conducted by noted phy-
sicists during the past century have given us tables of heat
conducting properties of the metal, mineral, liquid and vege-
table substances; these tables vary from one another, depend-
ing upon the methods used and the nature of the experiments.
These experiments demonstrate that the metals are the best
conductors of heat; that the vegetable and animal substances
are the poorest conductors of heat, and that between these
the minerals and liquids are all arranged in varying degrees
of heat conductivity.
Laboratory tests of the heat conductivity of materials
cannot be absolutely relied upon when these materials are to
be used for cold storage insulation. These tests are usually
* Dr. J. B. Siebel, "Compend of Mechanical Refrigeration."
INSULATION S5
made under high temperature conditions and relatively low
humidity, such as steam pipe covering. Such conditions do'
not obtain in cold storage work where the lower temperatures
and relatively higher humidities are the conditions. Numer-
ous articles and papers have been written for the trade per-
iodicals and read before various associations on the subject of
insulation. Some of these articles are very theoretical and are
based altogether too much on laboratory test tables of heat
conductors, which make them almost useless for practical
application in cold storage construction.
The following table of the relative heat conductivity of
a number of substances is taken from Sir William Thomp-
TABLE OF RELATIVE HEAT CONDUCTIVITY.
Article on "Heat" In Encyclopedia Britannlca.
Copper 455.
Iron 80.
Sandstone 5.34
Stone 2.95
Traprock 2.075
Sand 1-31
Water 1-
Oak (across fiber) 295
Walnut (along fiber) 24
Fir (along fiber) 235
Walnut (across fiber) 145
Fir (across fiber) 13
Hemp cloth (new) 072
Wool (carded) 061
Hemp cloth (old) 0595
Writing paper (white) 0595
Cotton wool 0555
Eiderdown 054
Gray paper (unsized) 047
^jj. 0295
Cork' '.'.'.'.' 0145
Note- The figure for air has been fixed by J. Clark Maxwell's
brilliant investigations. He gives its conductivity at 1/20,000 that of
copper as 1/3,360 that of iron, a determination reached by mathemati-
cal deductions from the kinetic theory of gases.
son's article on "Heat" in the Encyclopaedia Britannica, re-
duced to a unit of conductivity of one for water; this includes
authorities that he regarded as reliable on that subject. Part
of this table was taken from experiments made by Peclet, whose
table is also given in B. T. units.
In recent years many tests of composite insulations put
together just as they would be erected in a cold storage house
56 PRACTICAL COLD STORAGE
wall have been conducted and tables compiled therefrom by
experimenters who have made the subject of insulation a study,
and who have had much practical experience in its applica-
tion in their capacity as designing architects and engineers.
These tests show in many cases a wide variation in results,
owing no doubt to the fact that the tests have been made
under widely varying conditions and methods and also to the
changeable factor of human error or personal equation in the
observation of the tests. The work of these experimenters
shows much painstaking care, and much good has resulted
in raising the standard of the construction of scientific and
practical cold storage insulation.
As to quantitative or rate of transmission, the following
table from experiments made by M. Peclet* gives the amount
TABLE OP POOR HEAT CONDUCTORS.
By M. Pficlet.
Units of heat
transmitted.
Gray marble, fine grained 28.
White marble, coarse grained 22.5
Limestone, fine grained 14.8
Limestone, coarse grained 10.5
Glass 6.
Brick .....5.6
Terra cotta 4.8
Plaster of paris 3.6
Sand 2.2
Oak, across the grain 1.7
Fir, across the grain 0.75
Fir, along the grain 1.4
Walnut, across the grain 0.83
Walnut, along the grain 1^4
Guttapercha l'37
India-rubber l]3g
Brick dust, sifted l!33
Powdered coke l!3
Iron filings ][[ {26
Cork ;;; i;i5
Powdered chalk gg
Powdered wood charcoal ] Iss
Straw, chopped !!!!..!]! 56
Powdered coal, sifted .54
Wood ashes '5
Canvas, new '41
Calico, new .....'. 40
Writing paper ...........'. .Zi
Cotton, raw or woven . . ' 32
Eiderdown ..............." '31
Blotting paper ...........' .26
•PSclet's "Traite de la Chaleur," IV Ed., Tome 1, Pgs. 542 to 555.
INSULATION 57
of heat in B. T. units transmitted per square foot per hour,
through various substances one inch in thickness. He terms
these poor conductors (to distinguish them from the metals).
The results of these experiments are considered quite reliable,
as they are used extensively by heating engineers of Europe
in their calculations for the heating of buildings. The ex-
periments were made by heating one side of the substances
with hot water, and cooling the other side with cold water,
the difference between the temperature of the two sides" being
1° F.
In the latter part of the eighteenth century, Count Rum-
ford, who did much work in the experimental study of heat,
maintained that liquids had no conducting power at all, but
gained heat by convection only. This was afterward found
to be incorrect, as shown in the above table, and shows in fact
that water stands next to the mineral substances in conduc-
tivity.
In an article written by Prof. John M. Ordway,* on "Non-
conductors of Heat," which treats of insulation tests conducted
on steam pipes, he subjoins the following table of non-conduc-
tivity of various substances. The figures in the last column
are for covering, one inch thick, with a difference of 100° F.
on each side of the covering. In most of the tests a stream of
water at about 176° F. was kept running through the heater.
In some cases the source of heat was steam at 310° F. as
stated.
A careful study of these tables shows that still air is one
of the poorest conductors of heat available for practical pur-
poses. The distinction between confined air and still air, and
the greater conducting qualities of the former has not been gen-
erally understood, and it is perhaps on this account that air
space construction has been used so much for cold storage
insulation. Note what Dr. Hampson, an English authority,
has to say on air spaces. The conclusions reached by him have
also been demonstrated by the author and other experimenters
in this country, and the result is the present tendency to use
materials which will subdivide the air into an infinite number
' *lce and Refrigeralion, October, 1891, Page 21«.
58
PRACTICAL COLD STORAGE
NON-CONDUCTORS OF HEAT.
Net cubic
of solid
Non-conductors one inch thick. matter In
Still air
Confined air
Confined air=310''
Wool— 310°
Absorbent cotton
Raw cotton
Raw cotton
Live-geese featliers=310°
Llve-geese featliers=310°
Cat-tail seeds and hairs
Scoured hair, not felted
Hair felt . . ;
Lampblack=310°
Cork, ground
Cork, solid
Cork charcoal=310°
White-pine charcoal=310°
Rice-chaff
Cypress (Taxodium) shavings
Cypress (Taxodium) sawdust
Cypress (Taxodium) board
Cypress (Taxodium) cross-section
Yellow poplar (Liriodendron) sawdust. .
Yellow poplar (Liriodendron) board
Yellow poplar (Liriodendron) cross-sec.
"Tunera" wood, board
Slag wool (Mineral wool)
Carbonate of magnesium
Calcined magnesia=310°
"Magnesia covering," light
"Magnesia covering," heavy
Fossil meal=310°
Zinc white=310°
Ground chalk=310°
Asbestos in still air
Asbestos in movable air
Asbestos in movable air=310°
Dry plaster of paris=310°
Plumbago in still air
Plumbago in movable air;=310°
Coarse sand=310°
Water, still
Starch jelly, very firm, "
Gum-Arabic, mucilage, "
Solution sugar, 70 per cent, "
Glycerin, "
Castor oil, "
Cotton-seed oil, "
Lard oil, "
Aniline, "
Mineral sperm oil, ' "
Oil of Turpentine, "
n. Heat units trans-
mltted per sq. ft.
100
per hour
43
108
203
4.3
36
2.8
36
2
44
1
48
5
41
2
50
2.1
50
9.6
52
8.5
56
B.6
41
45 '
49
5.3
50
11.9
58
14.6
78
7
60
20.1
84
31.3
83
31.8
145
16.2
75
36.4
76
30.4
141
79.4
156
5.7
50
6
50
2.3
52
8.5
58
13.6
78
6
60
8.8
72
25.3
80
3
56
3.6
99
8.1
210
36.8
131
30.6
134
26.1
296
52.0
264
335
. . . *
345
290
251
197
. . . .
136
129
125
. . . .
122
115
95
INSULATION 59
of spaces. As insulators against heat Dr. Hampson, in a series
of lectures at University College, Liverpool, England, sums
the various substances up as follows:
Conduction and convection areTjest prevented by a totally empty
space intervening between the external objects and the internal cold
objects — in other words, by having a vacuum between two air-tight
walls. Radiation can be to a great extent prevented by having a bright
metallic surface between the inside and outside. The efficiency of this
combination was shown in one of the silvered vacuum vessels designed
by Professor Dewar, which contained liquid air which had been made
half a week before. Where such an arrangement was impossible, the
best thing to do was to fill the insulating space as far as -possible with
the substance that had the smallest capacity for conducting heat. Iron
has about one-seventh the conducting power of copper, wood or other
organic substances still less, ice has only about one two-hundredth, and
air not more than a twenty-thousandth part of the conducting capacity
of copper. Air, therefore, is the best insulating substance available;
but its value depends upon its stillness, for if free to move in spaces
of considerable size, it will be in constant circulation, convection cur-
rents carrying in heat from the warmer outside walls to the colder
Inside walls of the insulating spaces. These spaces should therefore
be very shallow, so that the viscosity of the air, which is very small,
will be able to prevent it from moving. It is their possession of a
large proportion of air, prevented by septa or filaments from moving,
that determines the excellence of the usual insulating materials, such
as eider down, wool, feathers, hair, chaff, cork, slag-wool, asbestos,
charcoal, wood, sawdust, etc.
A VACUUM THE POOREST CONDUCTOR.
Physicists seem to have proved that a vacuum (familiarly
illustrated in the thermos, or vacuum bottle) is a poorer
conductor of heat than air, and a reference is made to it by
Dr. Hampson, as noted above. This was discussed by Dr. H.
W. Wiley in an address before the American Warehousemen's
Association convention at Washington, D. C, December, 1903,
and as it is interesting in connection with the subject it is
quoted in part as follows:*
There is one practical suggestion which these theories present,
namely, that a vacuum is by far the best protection against radiation
that has ever yet been discovered. Sawdust, shavings, cork, cloth,
wood and many other substances have been extensively used to pro-
tect cold spaces against radiation, but none of these have anything
like the obdurating properties of a vacuum. Liquid air and even
liquid hydrogen contained in a vacuum receiver, that is a receiver
surrounded by a vacuum, retain their liquid state for hours and even
days. There is, of course, a loss by radiation and evaporation from
the exposed surface, because pressure dare not be used in confining
these bodies, but this loss is comparatively slow. The vacuum be-
comes an almost perfect protector against heat. If, therefore, the
refrigerating rooms which you use could be surrounded with a vacuum
'Reported In /e» and Refrigtratiott, January, 1904. pare IS.
60 PRACTICAL COLD STORAGE
space, it would most certainly reduce very largely the expense of main-
taining the low temperature. There are, of course, practical objections
to the use of a vacuum for this purpose of a very serious character.
The two chief objections would be the difficulty of maintaining an air-
tight space so that there would be no leakage into the vacuum and
the enormous pressure upon the walls of the vacuous space pro-
duced by the atmosphere itself. It is easy to construct a steam boiler
which will bear a pressure of from 400 to 600 pounds to the square
inch, and it ought not to be difficult to construct a vacuous space
around a refrigerating room which would resist a pressure of 15
pounds to the square inch. The expenditure and the energy required
to evacuate this space and keep it practically free from air would, In
my opinion, be profitably expended, providing the two conditions of
imperviousness and pressure could be regulated. The idea is at least
worthy of experimental trial and it is hoped that some of you will
submit it to a practical test.
Mr. James Wills of New York once made a practical
trial of a vacuum as insulation for brine piping with good
results, but it has not been learned that the experiment has
met with sufficient success to warrant its adoption on later
work which was constructed under that gentleman's super-
vision.
Harold B. Wood in a paper on Ice Storage House Con-
struction,, suggests the construction of ice storage walla con-
sisting of two six inch solid concrete walls with a six inch space
between them, this space to be maintained as a vacuum. This
suggestion was not made with a view of its immediate adoption,
but as a food for thought as representing the possibilities at
some time in the future. Vacuum insulation is possible but
not at all practicable at the present time.
VARIATION OF HEAT TRANSMISSION.
M. Peclet proved experimentally that the rate of trans-
mission of heat was directly proportional to the difference of
temperature on each side of a substance, and was inversely
proportional to the thickness. That is; if a substance one
inch thick transmitted say, one B. T. U., the same substance
two inches thick would transmit one-half B. T. U. under
game conditions.
The results of later experiments, on poor conductors and
on those used in combination (such as used in the construction
of cold storage warehouses) show, however, that these con-
clusions are in doubt. John E. Starr, in an article* on results
INSULATION 61
of tests, conducted by himself, states: "It is a well known
fact that the amount of heat transferred per degree of differ-
ence increases somewhat with each degree of increase of differ-
ence of temperature." This same experimenter illustrates this
principle graphically by a diagram of testsf showing ice melt-
age in ordinary domestic refrigerators at various differences of
temperature between inside and outside. If the transmission
had been directly proportional, the plotted curve on the dia-
gram would have been a straight line.
This increase of transmission per degree of difference as
the difference increases is also shown by a chart published
in Ice and Cold Storage (British), March, 1901 (see Fig. 4,
page 48), of results of tests with eight different constructions
of the same thickness. It is a matter of regret that the methods
of testing were not described in this case so that we could
judge of their reliability. Eeferring to the chart it will be
found that the line plotted for the rate of transmission of each
material is a curve, having a range of temperature difference
of 80° F. Calculating down to per-degree difference at each
end of the chart and dividing the result by the range of
difference (80° F.) shows co-efficients of increase, varying
from 25 to 50 per cent.
The author, in conducting a series of tests in 1900 and
1901 (which will be described further on), obtained results
that tended to prove the correctness of the observations cited
above. This co-efficient of increase varies for different sub-
stances and combinations of materials, and to determine these
co-efficients accurately would be a difficult task indeed. From
the above facts it is obvious that the co-efficients of heat trans-
mission obtained by tests of substances which were made under
a temperature difference of only one degree, are too small for
practical application, and they should be increased about 50%
when used for designing cold storage insulation. This is of
increasing importance when we consider that the tendency
of modern cold storage practice is toward maintaining lower
temperatures, often resulting in a difference of temperature
of from 70° to 90° F. between inside and outside of walls. This
•"Non-conductors of Heat," in Ice and Refrigeration, July, 1891, page 37.
t "The Cost and Value of Low Temperatures," in Ice and Refrigeration.
September, 1S91.
PRACTICAL COLD STORAGE
INSULATION
63
is comparatively a high range of temperature and the condi-
tions to this extent are similar to heating work.
That transmission of heat through any substance is not
inversely proportional to the thickness seems evident by an
examination of the following table converted from the metric
system by Chas. F. Hauss, Antwerp, Belgium. This writer
states* that this table is used by Adolph Block of Hamburg,
one of Germany's most reliable engineers:
TABLE OF CO-EFFICIENTS OF TRANSMISSION IN B. T. U. PER
SQ. FT. OF SURFACE PER HOUR.
Cooling
Surfaces
Thick-
ness
of Walla
Difference in Temperature— Fahrenheit
1° 1 5° 1 10° 1 -15° 1 20° 1 25° 1 30° I 35° 1 40° 1 45° 1 50° 1 .';.';° 1 «no i »«
dolid
Bricl
Walls
4Ji'
10'
15'
20»
25'
30'
35'
0.4S
0.34
0.2e
0.22
O.IS
0.16
0.13
2.4(
1.7(
1.3(
I.IC
0.9C
0.8C
0.6;
) 4.8(
) 3.4(
2.6(
2.2(
1.8(
1.6(
1.3C
) 7.21
) 5.K
) 3.9C
3.3G
2.70
2.40
1.95
9.6C
6.4C
5.2C
4.40
3.60
3.20
2.60
12.0C
8.5C
6.5C
5.50
4.50
4.00
3,25
14.4(
10.2C
7.8C
6.6C
5.4C
4.80
3.90
16.8(
11.9(
9.1(
7.7(
6.3C
5.6C
4.5.1
)19.2C
13.60
10.40
8.80
7.20
6.40
5,20
21.50 24.0C
15.30 I7.0C
11.65 13.00
10.00 11. OO
8.10 9.0C
7.20 8.00
5.85 6.50
26.5C
18.70
14.30
12.00
9.90
8.80
7 15
28.80 31.20
20.40 22.00
15.60 16.90
13.20 14.30
10.80 11.70
9.60 10.40
7.80 8.45
7.20 7.80
6.60 7.15
33.60
23.80
18.20
15.40
12.60
11.20
9,10
8.40
7 70
40'
U.12
O.bl
1.21
1.8U
2.40
3.01
3.6(
4.20
48(
5.40 6.00
660
45'
U.U
O.bi
111)
1.65
2.20
2.76
3.30
3.85
4.41
4.95 5.50
6 05
Solid
Sandstone
12'
0.45
2.2S
4.5G
6.75
9.0(
11.25
13.50
15.75
ixno
20,25 22.50
24.75
31.50
29.30
24.50
22.40
20.30
18.20
16.80
15 40
18'
20'
0.39
0.35
1.96
1.75
3.90
3.50
6.85
5.25
V.80
7.00
9.75
8.75
11.70
10.50
13.65
12.2')
15.60
14 00
17.95 19.50
15.65 17.50
21.45
19 ^S
23.40 25.25
21 00 22 75
24'
U.J2
l.bO
3.20
4.80
6.40
8.01
9.61
n.2(
12.Rf
14.40 16.00
17.60
19 20 20 80
For Lime-
28'
32'
0.29
0.26
1 45
1.30
2.90
2.60
4.36
3.90
5.80
5.20
V.24
6.50
8.V0
7.80
10.15
9.10
11.60
10.20
13.05 14.50
11.65 13.00
15.95
14 30
17.40 18.85
stone add
36'
0.24
1.20
2.40
3.B0
4.80
6.O0
7.2i:
«.4f
9«1
10.40 12.00
13.20
14 40 15 fiO
10 per cent.
40'
0.22
1.10
2.20
3.30
4.40
6.50
6.60
7.7t
8.80
10.00 11.00
isno
13 20 14 39
44'
0.2U
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00 10.00
11 00
12.00 13 00
48"
0.19
[0.95
J. 90
2.8o
3.80
4.Vo
5.70
6.65
7.60
8.551 9.50
10.4,')
11.40 12.35
13.30
Solid Plaster 1 -'-21'
0.6013.00
6.00
9.00
12.00 15.00118.00
2100
24 00
27.00130.00
3? 00
WOO
39 00
42 00
Paititio:;3 Z '-3i'
0.48|2.40
4.80
7.20
9.60 12.001 14.40
16.80
19.20
21.50l24.00
24.00
28.80
31.20
,13.60
Floors
Joists with
double 'floors
Stone floor on
0.07
0.35
0.70
1.05
1.40
1.75
2.10
2.45
2.80
3.15
3.50
3.85
4.20
4.55
4.90
arches
Flanks laid on
1.20
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
earth
0.16
0.80
1.60
2.40
3.20
4.00
4.80
5.60
6.40
7.20
800
8,80
9 60
1040
11.20
Planks laid on
asphalt
0.20
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
1000
lino
1200
13 00
14.00
.\rch with air
space
0.09
0.45
0.90
1.35
1.80
2.25
2.70
3.15
3.60
4.ft')
4„50
4 95
5 40
5 8,")
6.30
Stones laid on
eartii
0.08 0.401
0.80
1.20
1.60
2.00
2.40
2.80
3.20
3.60
4.00
4.40
4.80
5.20
5.60
Ceilings Joist with
single floors
5.10 0.50
1.00
1.50 2.00
2.50
3.00
3.50
4.IHI
4,50
5 (10
5,50
fi.nn
a an
7.00
Arches with
I air spaces
).14 0.70
1.40
2.10 2.80
3.50
4.20
4.90
5.60
6,30
7.00
7.70
8.40
9.10
9.80
Windows! Single
.00 5.00
.0.00
15.00 20.00
25.00,30.00
35.00
40.00
15.00
50.00 55,00 60.001
65.00 70.00
1 Double
3.46 2.30
4.60
7.05 9.20
11.50'l3.80
16.10
18.40
20.70
23.00 25.30 27.60|
30.00 32.20
SkylightslSingle 1
.06 5.30 10.60
5.90 21.20 26.50|31.80|37.00|
12.40|47.70|53.00|58.30 63.60169.00174.20
jDouble IC
.48 2.40 4.80
7.20 9.60 12.00|l4-.40|l6.80l
9.20|21.60|24.00|26.50 28.80|31.20|33.60
Doors
|0.40|2.00| 4.001 6,001 8.00|10.00|12.00|14.00|16.00|18.00|20.00|22.00|24.00|26.00|28.00
Dif. in Temperature 1. 1° I 5° I 10° | 15° | 20° | 25° | 30° I 35° | 40°| 45° | 50° | 55° | 60° I 65° I 70°
•Paper read before American Society of Heating and Ventilating
Engineers, New York, January. 1904.
64 PRACTICAL COLD STORAGE
This table is of limited value for cold storage work, but
serves to show the great variation in results obtained by differ-
ent experimenters. Tt will be noted that this table is based on
M. Peclet's first proposition, viz: That the rate of transmission
is proportional to the difference of temperature on each side of
the substance.
The fact that the transmission of heat through any sub-
stance is not inversely proportional to the thickness is also
shown by the following tables after Box,* where N is the
value in P>. T. U. transmitted per square foot for a difference
of 1° F. between temperatures each side of wall in 24 hours.
% brick 4% inches thick N. equals 5.5 B. T. Units
1
1%
2
3
4
9 " " " " 4.5
14 " " " " 3.6
18 " " " " 3.0
27 " " " " 2.6
36 " " " " 2.2
Stone walls 6 inches thick N. equals 6.2 B. T. U.
5.5
12
18
24
30
36
5.0
4.5
4.3
4.1
HEAT TRANSMISSION THROUGH "WALLS.
The following formula for calculating the amount of heat
that will pass through a wall of a certain area is by Dr. Siebel.*
If the number of square feet contained in a wall, ceiling,
floor or window be f, the number of units of refrigeration, R,
that must be supplied in 24 hours to offset the radiation of such
wall, ceiling or floor may be found after the formula:
R=fn (t— tj B. T. units,
fn (t— tj
or, expressed in tons of refrigeration : E^= tons.
284,000
In these formulae t and t^ are the temperatures on each
side of the wall, and n the number of B. T. units of heat
transmitted per square foot of such surface for a difference of
1° F. between temperatures on each side of wall in twenty-
♦From "Compend of Mechanical Refrigeration," Page 181.
INSULATION 65
four hours. The factor n varies with the construction of
the wall, ceiling or floor from 1 to 5. For single windows
the factor n may be taken at 12 and for double windows at
7. (Box.) For different materials one foot thick we find the
following values for n :
Pinewood 2.0 B. T. TJ.
Mineral Wool 1.6
Granulated Cork 1.3
Wood Ashes 1.0
Sawdust 1.1
Charcoal, powdered 1.3
Cotton 0.7
Soft Paper Felt 0.5
If a wall is constructed of different materials having differ-
ent known values for n, viz, n^, n^, n^, etc., and the respec-
tive thickness in feet d^, dj, d,„ the value, n, for such a com-
pound wall may be found after the formula of Wolpert, viz:
I
n =■
d.
d.
ds
—
+
—
+
—
Hi
n^
ns
The value of n may be obtained from any of the fore-
going tables that are based on the transmission per hour by
multiplying bj'^ 24, the number of hours in a day, and where
the values given are for materials one inch in thickness, n
and d should be in inches.
INSULATIOiSr OF COLD STORAGE WAREHOUSES.
The function of a cold store is to maintain temperatures
suitable for the storage of perishable materials. This generally
means that the cold storage rooms are held at a temperature
below that of the surrounding air, but it may be also that the
cold rooms are useful to keep out frost, such for instance as
apple storage in winter. In the first case heat flows into the
rooms, and refrigeration must be supplied to absorb it. In
the second case it may be necessary to supply heat to prevent
dangerous low temperature in the storage rooms. As ordin-
arily built the walls of a building do not offer sufficient resist-
ance to the passage of heat, and therefore in cold storage con-
66 PRACTICAL COLD STORAGE
struction additional materials are used, and these are called
"Insulation," as distinguished from the structural walls of the
building.
A perfect insulation is impossible. No matter of what
materials or how thick the walls are made, a certain amount
of heat will pass through them, and this must be taken up by
the refrigerating medium. If it were possible to stop all heat
transmission through walls, doors, etc., no refrigeration would
be necessary after the goods in storage had been cooled down
to the required temperature. On the contrary, it is a well
established fact that one-half to seven-eighths of the refrigera-
tion applied to cold storage rooms is expended in removing
the heat transmitted through the walls of the building, de-
pending of course upon the amount of goods stored and the
frequency with which they are handled in and out.
The great importance of proper and efficient insulation
is evident when it is considered that all the heat passing
through it must be taken up by the refrigerating apparatus,
which, in the case of poor insulation, will need to be from
25% to 50% larger than if the insulation were first-class.
This larger apparatus means a greater first investment than if
a smaller apparatus could have been used, and this difference
might better have been invested on the insulation. The addi-
tional operating expense of the larger apparatus would be con-
tinuous from year to year and would amount to many times
as much as it would if first-class insulation had been con-
structed in the first place. The investment put into good
insulation has to be made but once, while with poor insulation
the loss of refrigeration through removing the greater heat
leakage makes a continual heavy expense. Insulation should
be considered in the light of a permanent investment, same
as buildings and equipment, the returns of which should be
based on the savings effected by the lower operating cost. It
is a great deal cheaper to prevent heat from entering a build-
ing by providing efficient insulation than to remove it bv
means of refrigeration.
PRACTICAL FEATURES CONSIDERED.
It is agreed that air spaces are the basis of insulation.
It ia also agreed that the large air spaces such as are formed
INSULATION 67
by the ordinary studding of a frame building or such as have
been built up by means of several thicknesses of paper separated
by furring strips, are inefficient and not worth their cost. It is
also now agreed among the best posted engineers, and especially
FIG. 5 — SHOWING ICE FORMATION BETWEEN INSULATION NOT
PROPERLY AIR-PROOFED.
those who have had a hand in tests and experiments on the vari-
ous type.s, that insulation should consist of some light and por-
ous material which holds within itself minute cells or small
spaces of air. Cork is one of the best materials for insulating
68 PRACTICAL COLD STORAGE
purposes on account of its fine texture and its waterproof quali-
ties, and its property of non-capillarity.
The illustration (Fig. 5) shows clearly what happens
when insulation is not properly air-proofed. The insulation
in this case was formed by paper air spaces one inch apart,
and was on the walls of a fish freezer held at 10° to 15°
above zero. These paper air spaces, as shown, are frozen full
of ice. The paper used was gray rosin sized, which is not air
and moisture proof and which is not now much used for modern
insulation.
It was early discovered in connection with the storage
of natural ice, which was the real beginning of the cold storage
and refrigerating industry, that sawdust was a very efficient
protection against heat, and it is still being used for this
purpose. Up to comparatively recent times practically all of
the natural ice storage houses were either insulated in the
walls, or the ice was covered with sawdust to protect it from
the heat. Sawdust may be obtained almost anywhere, and
as a cheap material which could be readily obtained it doubts
less had a useful place in the early days of ice storage.
At the present time mill or planer shavings are being sub-
stituted to a great extent. Mill shavings have the advantage
over sawdust in being obtainable in a fairly dry condition.
Sawdust, with the exception of that obtained from box fac-
tories, etc., is generally from green lumber and most always
damp or wet. It also moulds readily and thus has the ele-
ments of decay in it before it is ever placed in the building.
On the contrary, mill shavings as now generally handled in
bales, are nearly always obtainable in a thoroughly dry condi-
tion, being baled promptly from the planers and stored under
cover. The shavings also come from the outside of the lum-
ber and are thus from the dryest part of it, and in many cases
the lumber planed is dry. Shavings in bales weighing about
80 to 100 lbs. are easily handled and can be shipped to some
considerable distance at low freight rate, and have come into
use as an insulating material not only in connection with
natural ice, but in some of the very best cold storage plants.
INSULATION 69
There are, of course, many other materials used for the
fiUmg of spaces besides sawdust and mill shavings, and among
them may be cited such materials as mineral wool, cottonseed
hulls, chaff, leaves, cut straw, crushed coke, locomotive breeze,
cinders, ashes, etc., and the permanency and efficiency of any
COUV
ROOM
30
w///i'/,'flif
FIG 6-
-SHOWING ORDINARY SPACE BETWEEN STUDS OF A FRAME
BUILDING.
of these materials which are used for filling spaces depends
on a principle which is comparatively little understood and
which it is here attempted to make plain.
Referring to Fig 6 which may represent the ordinary
space between the studs of a frame building, note that the
interior wall, or what would be the inside of a cold storage
70 PRACTICAL COLD STORAGE
room, is exposed to a temperature of 30° F., while the outer
wall which might represent the outside of the building is ex-
posed to the atmosphere at a temperature of say 80° F. Heat
is conducted from the outer or 80° wall to the inner or 30°
wall, as we have already seen, by three means :
First — Conduction.
Second — Radiation.
Third — Convection.
First — Conduction is of small consequence in a wall of
this kind except through the solid studs of the building, as
there are so many different pieces or particles of the sawdust
or shavings, etc., that the route of travel for the heat would
be extremely tortuous and long and very little heat would
pass from the outer wall to the cold wall by this means.
Second — As radiation is the direct travel of heat from
one surface to another without interference from any solid
being interposed, we may assume that the amount of heat
transferred by radiation from the warm wall to the cold wall
is practically negligible.
Third — This leaves us only convection, which in plain
language means circulation, and we can reduce it to a still
plainer term by calling it air circulation, and the illustration
shows the path of circulation, conveying the heat from the
warm wall to the cold wall.
As above stated, the circulation of air in a filled space
such as we are considering is nowhere near as rapid as it
would be were the space open without anything in it, but the
circulation is there just as surely, and as applied to the prin-
ciple we are considering is fully as destructive as though it
were more rapid.
Assume further that the space we are considering is
contained between a layer of boarding on the outer or warm
wall and on the inner or cold wall, and that these layers are
composed of rough lumber, which necessarily would mean
that there would be cracks or openings between the
boards through which the air might pass. It will
readily be seen, then, that air would penetrate near the top of
the wall, circulate to the inner or cold side of the wall, down
INSULATION 71
the cold side, and eventually gravitate out at the bottom as
shown by the solid line arrows. There would, of course, be
also some circulation (convection) within the space between
the studding independent of this in and out circulation re-
ferred to, and this is shown by the broken line arrows. In
addition there will be some circulation into the cold room at
the top and out of the cold room at the bottom as shown by the
small broken line arrows.
Now, what is the result of this? Take a warm day in the
summer with high humidity and with air flowing in through
the filling material and coming in contact with the cold side
of the wall. There is a condensation which will cause a wetting
of the inner boards, the inner edge of the studs, and a wetting
of that portion of the filling materials (sawdust or shavings,
etc.) which lies nearest the inner boards. There is no possible
guesswork about this. It has been demonstrated in a very
large number of cases. This wetting, of course, is not present
at all seasons of the year, but only during warm weather. In
cold weather the filling material would naturally dry out,
and this doubles the damage. Alternate wetting and drying
will in a very few years cause a rotting and detonation of
the filling material and the frame and sheathing of the build-
ing. Of course, not many cases would be as extreme as this,
and in most cases paper would be used, but some of the paper
is of such a character that it allows the passage of air with its
contained moisture, and the result while not perhaps as destruc-
tive, is nevertheless endugh to be serious and damaging.
Numerous cases have come to the attention of the author
where the ceiling boards on the upper floor of a cold storage
plant have become wet and saturated with moisture, and some
of these cases have been so aggravated that the nails have pulled
out of the joists and allowed boards to fall from ceiling. Other
cases may be cited where the same result has occurred because
of the circulation of air through a brick wall and in between
the joists. The necessity for a perfect air seal especially on
the outer surface of an insulated wall is unquestioned, but this
fact is not as well appreciated by the trade in general as it
should be. Where these bad effects occur those who come in
72
PRACTICAL COLD STORAGE
contact with the results are likely to condemn the material
used, and it is this unfair condemnation of useful materials to
■which it is desired to call attention at this point.
The results of the use of falling materials as outlined, in
the hands of inexperienced or incompetent people who do
:^^^w^^^^^^^^?^^■^^
1
PIG. 7— SHOWING WALL, INSULATED WITH SHAVINGS.
not understand the underlying laws governing the design of
insulation and the practical features thereof, has to an ex-
tent, brought such a useful and valuable insulating material
as mill shavings into undeserved disgrace. Other materials
like mineral wool, sawdust and granulated cork have similarly
INSULATION 72
been discredited, and the author has personally seen some ma-
terials, removed from cold storage construction which might
lead a person not well versed in the subject to condemn these
materials for insulating purposes. It is really not the material
that are at fault, but the manner in which they are used.
We will refer to another sketch (Fig. 7) showing a wall
insulated with Mhat we have called a "filling material" such as
granulated cork, sawdust, mill shavings, mineral wool, etc.
Instead of the studding being boarded on the exterior and
interior with rough boards and protected perhaps with a poor
quality of porous paper, this time we use a layer of surfaced
boards, then special insulating paper which is perfectly air-
tight and water-proof, and then matched boards; thus
having the paper tightly clamped between two smooth boards,
making practically a perfectly sealed surface both on the
outer and on the inner surface of the insulated wall. Please
note details of construction. In such a wall there can be no cir-
culation of air through the outer boards nor through the inner
boards. The circulation or convection as shown by the arrows
is confined entirely to the space within the air-tight surfaces
resulting from the use of insulating paper on the outer and
inner sides of the wall as stated. Thus there is no penetration
of warm, moisture-laden air and no rotting, as there would be
if the space between the studs were not made air-tight.
The author has in his experience seen some very extra-
ordinary conditions and some very bad conditions too. These
bad conditions embrace practically every known material
which is used for insulation, and to make it more emphatic il
should be repeated that it is not in most cases the fault of the
material, but the method of application. Any insulating ma-
terial to be durable and permanent mxist be sealed from air
and moisture and this includes cork as well as other material.
Cork, while being non-capillary ■ to an extent, is such to an
extent only, and if exposed to moisture conditions will rot out
and deteriorate. Mineral wool will not rot, but will lose
its insulating value to some extent if damp, and the support-
ing studs and boards will soon rot if dampness occur in the
manner explained. Other materials deteriorate and decay if
74
PRACTICAL COLD STORAGE
exposed to dampness. Air tight protection to the insulating
substance is the key to permanent insulation regardless of
the particular kind of material used.
Any material used as cold storage insulation must be
protected from penetration of air. This statement may be
laid down as the underlying principle of all insulation, and
there is positively no exception. While it is claimed that cork-
board is non-capillary and will not absorb moisture, this is only
true to a certain extent, and corkboard or cork in any form
will rot out just as certainly as will sawdust if exposed to the
same conditions, and it will rot out just as quickly, too.
The illustration (Fig. 8) explains the action of moisture
in connection with shavings when they are not properly pro-
tected from air and moisture contact. The sketch represents
"" Qor\AmT\»aS.lor\ or Tnoi^-lurC er\ ho»ri,s
«n4. rai^in^ vf ])»«r^« and joiilc,
PIG. 8— SHOWING ACTION OF MOISTURE ON BOARDS AND JOISTS.
the ceiling joists of a cold storage room. The joists are boarded
on the bottom edge with double boards with paper between,
and the joists are filled in between with shavings as shown.
The top edge of the joists are exposed and the shavings are
not protected on top by paper or other covering material.
The temperature of the room below being say at 30° F. and
the temperature of the air above it at 80° F. ; the air in cir-
culating into the shavings would carry with it moisture which
would be condensed on the boards and bottom edge of the
joists during extremely warm weather; and then again dur-
ing cold weather this moisture would evaporate or dry out.
This being repeated for several years results in a rotting of
the boards and the lower edge of the joists to an extent which
\vill cause the nails to pull out and the boards to fall off, and
INSULATION 75
this has actually occurred. The condensation could have been
entirely prevented by covering the shavings with water-proof
paper and boarding, the same as applied to the lower edge of
the joists. Ijeakage of moisture through the ceiling of cold
storage rooms is quite common in some of the older plants, and
this has been attributed to leakage of the roof in many cases, as
the condensation may be so great as to actually cause a
dripping.
An attempt has been made to explain why cold storage
insulation may become deteriorated after a time and why it
is necessary to understand the natural laws governing, to be
able to properly design insulation. There is no material in
use which is exempt from deterioration unless properly pro-
tected, and even though the material be to an extent non-capil-
lary, such as cork, yet the deterioration will be just as certain
as though the material were greatly absorptive like hair felt
or mill shavings. All insulation should be protected from
air circulation and air contact not only on the face of the wall
toward the refrigerated room, but just as carefully protected
on the exterior face of the wall toward the outside air; in
fact the protection of the exterior face of the wall is more
important than on the inner face of the wall.
Another element in cold storage practice that demands the
construction of first-class insulation is that goods should be
carried at a uniform temperature throughout every part of
the room. With poor insulation this is not possible, no matter
how large the cooling apparatus may be, as the parts of rooms
nearest the outside walls will be higher in temperature than
those nearest the cooling surfaces. This condition often re-
sults in a part of the goods being carried at a higher tempera-
ture than they should be, on account of danger of freezing
those that are nearest to cooling surfaces.
The value of the insulating materials depends upon their
efficiency in preventing the transmission of heat from the out-
side to the inside of the building. A study of the heat con-
ducting properties of the various materials and substances as
shown by tables here given leads to the conclusion that with
but few exceptions we must turn to the vegetable and animal
76 PRACTICAL COLD STORAGE
substances for this efficiency. In selecting materials of this
class for practical insulation, we are limited by many re-
quirements besides non-conductivity of heat. These are enu-
merated below in the order of their importance, viz:
1. It should be odorless, so as not to taint the perishable goods
stored.
2. It should have the minimum capacity for moisture, and in case
it should become damp, It should not rot or ferment.
3. It should be vermin proof, and give no inducement for rats
or mice to nest within it.
4. It should not be liable to inherent disintegration or spontane-
ous combustion.
5. It should be of light weight, not so much on account of light-
ness itself, because buildings are usually built sufficiently heavy where
they are to be used for warehouse purposes, but because the lighter
materials are usually better non-conductors of heat.
6. If used as a filler, it should be elastic so that when it is once
packed firmly, it will not settle further and leave open spaces which
will be almost impossible to find and costly to repair.
7. It should be reasonably cheap and economical of labor so as
not to be prohibitive for general use.
8. It should lend itself to practical application in general work.
In addition to the above requirements, water or moisture
proof qualities are desirable and in certain classes of struc-
tures fireproof qualities are needed. The best natural non-
conductors of heat are neither fireproof nor waterproof, and
therefore these qualities must be secured by proper design and
application, as has already been pointed out. A consideration
of the various materials commonly used and illustrations of
the application of same will therefore be in order.
MATERIALS.
From the tables already given, it will be noted that still
or perfectly motionless air is one of the best insulators against
heat. But to keep it motionless it is necessary to confine it in
very small spaces to prevent circulation and convection of heat.
This is best accomplished by properly constructing spaces and
filling them with some sort of material in bulk. The value
of these fillers depends upon the number of minute spaces into
which they divide the air. Their value follows closely upon
their specific gravity; that is, the lighter the material, the
better insulation it is, owing to the microscopically confined
air in the cells or structure of the material itself. Again, the
value of these fillers depends upon the density to which they
INSULATION 77
are packed; it has been found that if they are packed too
loosely they will permit air circulation, and if packed too
closely, the conduction of heat will increase. With nearly all
the materials at present in use, the best results seem to be ob-
tained when packed to a density of from eight to ten pounds
per cubic foot. Starr gives a specific gravity of about .160
as being the lowest density to which a material should be
packed. This corresponds to about ten pounds per cubic foot,
which is, in the experience of the author, heavier than such
materials as straw, wood shavings or cork shavings can be
packed in actual practice. In using fillers in walls, atten-
tion should be given as to whether or not the materials of
which they are composed are in their natural state good or poor
conductors of heat. Mineral wool, for instance, is made from
furnace slag or rock which are considered comparatively good
conductors. Tf materials of this nature are packed very tightly,
their value as insulators is greatly lessened. Materials which
in a raw state are poor conductors, such as straw, sawdust, wood
shavings or cork may be packed very tightly without decreas-
ing their insulating value. In fact, the insulating value of
such materials is generally increased by close packing.
STEAW, CHAFF, ETC.
Such materials as chopped straw and hay, dried grass
and leaves, chaff and hulls of the various grains have all
been used as fillers, as described above, and under certain
conditions they are fairly efficient as non-conductors of heat.
They are frequently abundant and cheap, but as the proper
protection of same from access of air and moisture is not
well understood, they are seldom used at the present time. In
country locations and on the farm they are often used to
considerable advantage as a packing material for temporary
ice houses, fruit houses, etc., their availability, far from manu-
facturing centers, making them naturally fit for such purposes.
As the scientific design of cold storage insulation becomes bet-
ter known these common materials will no doubt come into
more general use as their efficiency and low cost entitle them.
78 PRACTICAL COLD STORAGE
SAWDUST.
Sawdust as an insulating material practically belongs with
those noted above, but it is used to such a large extent for
various purposes connected with refrigeration that it deserves
separate mention. There seems to be no preference for the
sawdust of any particular wood, as they are all about the
same in insulating value. This value is very high when the
sawdust is dry and clean, but if damp, it will rot, ferment and
heat, and in this state will disintegrate and settle down, leaving
spaces at top for leakage of heat. The most undesirable
feature developed by the use of sawdust when damp, is the
liability of a moldy or musty condition of the rooms, and
this may aflfect the goods in storage. Nearly all sawdust avail-
able is from green lumber, and this is very undesirable for
insulating purposes. As already pointed out, if sawdust is
thoroughly dry and kept so by proper air and moisture-proof-
ing methods, it will make good and efficient insulation for
many years. The use of green or damp sawdust in contact
with lumber or woodwork should not be permitted under any
circumstances.
There has long prevailed an idea that sawdust or similar
materials would harbor rats and mice, and that this made
such materials undesirable as insulation. As a matter of ac-
tual fact none of the common insulating materials, not even
mineral wool, is exempt from this criticism; but there is little
likelihood of trouble from this cause if the building is well
built and the houses kept in good repair. In all the author's
long experience, rats or mice have never been a serious bother.
If they get in they usually quickly succumb to the cold and
cleanliness of premises.
The most useful application of sawdust is for packing
ice in houses storing natural ice, where it is open to the
action of the air at all times and renewed each year, or as it
rots out, and for this purpose green or damp sawdust is nearly
as useful as if dry. However, with the growing tendency
to store ice under refrigeration there will be less demand for
sawdust for this purpose.
INSULATION
SHAVINGS.
79
Shavings or chips from the planing mill have largely
superseded sawdust as a common material for insulation, as
they are free from many of the objections that have proved
most undesirable in the use of sawdust. Shavings are speci-
fied by the author in the composite insulations designed by
him, and he believes that when they are properly used and
protected from air and moisture there can be no objection made
to them. But they should not be used in large bulk (nor
should any filler for that matter), but rather in combination
with several other materials, as illustrated further on. Shav-
ings will not rot, ferment or settle down under similar condi-
tions as rapidly as will sawdust, because the fibrous structure
FIG. 9— BALE OP SHAVINGS.
of the wood has not been destroyed. Shavings are elastic and
clean to handle, and if properly packed (about 8 to 9 pounds
to the cubic foot) will remain in position for an indefinite
period. They should be delivered to the building reason-
ably dry and clean, but if there is some mixture of dry saw-
dust, this is not objectionable.
Many firms, particularly in the eastern and part of the
middle western states, make a practice of putting up shavings
in bales. This is a great advantage, both for shipping and
handling, as it permits of their use at points distant from
their manufacture. They are put up in compressed bales
weighing 80 to 120 pounds, ten and fifteen cubic feet per bale.
PRACTICAL COLD STORAGE
80
(after shaking out, and when repacked in the insulated wall)
and as supplied have the appearance shown in Fig. 9. The
demand for shavings for fuel and other purposes makes them
extremely hard to obtain in some localities during the fall
and winter, and this difficulty will no doubt increase with
time, as the settled portions of our country are being rapidly
denuded of forests. The shavings of the soft woods are pre-
ferable, as they are less brittle and lighter than those from
the hard woods. It is also preferable to use shavings from
some odorless wood, such as spruce, hemlock, whitewood, etc.
If shavings come to hand which are damp or have been
wet, they may be dried in a short time by spreading out under
cover in a warm dry room. If they have begun to mold or
ferment they should not be used.
MINERAL Vi'OOL.
A material which is much used is commonly known as
mineral avooI, granite rock wool, rock cotton or rock cork in
this country, and as silicate cotton in England. Mineral wool
is usually made from the slag of blast furnaces, with lime-
stone added; and the rook wool or rock cotton, from granite
and limestone. The principles involved in manufacture are
the same in either case and the process is comparatively sim-
ple. The rock is first crushed, then mixed with coke and
fed into furnaces, where it is fused at a high temperature, about
3,000° F. The molten slag or lava is then run out at the
bottom of the furnace through a high pressure steam blast
which blows it into fleece or wool, much resembling sheep's
wool, except that the fibers are brittle. These fibers are very
fine, and interlace each other in every direction, forming in-
numerable minute air spaces. In common slag wool about
92% of the mass consists of air spaces and in the best rock
wool the proportion is about 96% when it is very lightly
packed. It will be seen that for this reason it is a very good
insulator, regardless of the fact that it is made from a material
having a comparatively high conductivity. Used as an insula-
tor, it should be free from "shot" and all other solid pieces, as
much as possible. It has the qualities of being fairly vermin
INSULATION
81
and fire proof and is not liable to decay, but if it is packed
too tightly in the walls, its brittleiiess will cause it to break up,
which decreases its insulating value. It should not be paclced
closer than about twelve pounds to the cubic foot. Mineral
wool will absorb moisture quite freely, if not properly moisture-
proofed, and it is stated by some authorities that if it be-
comes wet and then freezes, the water that has penetrated the
air cells between the fibers, will expand and break the struc-
ture of the material into a granulated mass, which will settle
or pack down, and in this state it is a poor insulator. One of
the chief objections to mineral wool as a filler is its difficulty
in handling, as the fibers wall prick the skin and in a very
short time will cause the hands to become sore, but the most
important objection is the minute particles of wool floating
through the air as it is handled, making it bad for the eyes
f/////////////////////////////////////////////C-^^^^^^^^ COATINQ
_J;j5»VJATERPR00r PAPER
__^__ ^S^-7&INCH D.tM BOAERS
MINERAL. WOOU 5LAB2f , ^
FIG Ul— MINERAL WOOL SLAB AND ONE METHOD OF
APPLICATION.
and injurious to breathe. It is for this reason that workmen
dislike to handle it, and this dislike indirectly causes the
work to be slighted and poor insulation may result. Owing
to its nature, mineral wool or any of its manufactured
products are very desirable as a retardant to rats and mice,
and it is valuable to use in protecting other materials from
their ravages. Two inches of this material on the exterior of
an insulated wall makes it reasonably mouse and rat proof.
82 PRACTICAL COLD STORAGE
MANUFACTURED FORMS OF MINERAL WOOL.
There has been, in the past few years, a tendency to manu-
facture insulating material that would be portable, easily han-
dled and put in place, not liable to settle, etc. This has
been accomplished by making the material into compressed
slabs or sheets to a density and stiffness sufficient to be easily
handled, sawed and fitted same as if it were lumber. Slabs
made of mineral wool are thus manufactured by several differ-
ent firms in this country, and have the appearance shown in
Fig. 10. These slabs are usually made in standard sizes of
18x48 inches and 36x48 inches and from one to three inches
in thickness, the manufacturers being willing to cut these'
slabs to any size smaller than this, if specified. These slabs
are a great improvement over mineral wool in bulk form, as
they can be adapted to modern construction where it is the
purpose to stratify or laminate the materials to form a com-
posite insulation, as such is now considered the most efficient
in retarding heat transmission. Mineral wool in this form
may also be properly protected from moisture and finished
with cement for inside lining of rooms if desired.
Many methods of applying this "felt" or mineral wool
slab have been devised by the manufacturers, but these are
more or less impracticable on account of the assumption that
these slabs are sufficiently strong to hold nails and support
the construction; and the fact that these boards are not air
or moisture proof is overlooked and therefore the construc-
tion must make good these necessary requirements. Fig. 10
shows a method used by the author in applying this material.
It will be noticed that the slabs are not necessary to the solidity
of the construction, but they are placed between battens or
furring and lightly tacked in place ; waterproof paper is placed
on each side and between each slab, thus preventing any
leakage of air or moisture through the wall. Fig. 11 (see
following page) shows a method, recommended by the manu-
facturer, of applying mineral wool slabs to brick or stone
walls in the construction of fireproof insulation. The wall is
first coated with waterproof cement put on hot, or Portland
cement, into which the slabs or sheets of insulating material
INSULATION
83
are set. Two or more courses of two or three inch slabs may be
used, with the cement between. After setting tlie slabs, an-
other coating of waterproof cement is applied and the surface
plastered with Portland cement troweled down to a smooth
.surface.
Another application of mineral wool to cold storage in-
sulation is to pack it into rectangular galvanized iron cans of
suitable size and thickness with soldered joints, and build
these cans into the wall of the building. In one such applica-
FIG. 11— METHOD FOR APPLYING MINERAL WOOL SLABS.
tion, consisting of a twelve inch wall of salt-glazed terra cotta
blocks, a four inch and an eight inch, with five inch mineral
wool filled cans inside, and finished with a three inch terra
cotta wall, all the members were set in Portland cement and
the wall plastered with the same material. This construction
would certainly be permanent, but the insulating efficiency
could not be high. Two separate layers of the galvanized cans
separated by an air space would increase the efficiency greatly.
84 PRACTICAL COLD STORAGE
CIIAKCOAL.
Charcoal is described as a more or less impure form of
carbon obtained from various vegetable and animal materials
by their partial combustion out of contact with air. That most
in general use is obtained from wood and is a hard and
brittle black substance which in a granulated or flaked form is
used to a large extent in England and in Europe for
insulation. It is used as a filler and applied in the same
manner as sawdust, mineral wool or shavings. Charcoal has
not been used to any considerable extent in this country for
insulation, except for the ordinary family refrigerator. Its
use is not to be commended; and on account of its black,
dusty nature, it is very dirty, to say the least. The abundance
of many other materials at hand, equally efficient, does not
warrant giving it even a trial. ,
CORK.
Granulated cork is considered one of the most efficient
and high-grade fillers for insulating purposes that we have
available, and it is odorless, clean, elastic, durable and does
not absorb moisture readily, but like all other fillers, is sub-
ject to attack by rats and mice, unless properly protected. Cork
is the bark of a particular tree growing on the coasts of North-
ern Africa and Southern Europe. Spain furnishes by far
the greater portion of that imported into this country. This
bark is deprived of its non-elastic and impure parts, after which
it is cut up into proper sizes for commercial use. The granu-
lated cork is the waste product in the manufacture of stoppers,
handles, etc. When filling spaces with cork, it should be
rammed in tightly, so as to reduce the size of the air spaces
between the particles, and to prevent future settling. Granu-
lated cork mixed with hot pitch or asphalt has been used and
is considered by the author to be a good insulator around
brine mains where they pass through masonry walls or are
laid under ground. With this material, molds or forms are
placed around pipes and the mixture poured in hot, thus
completely surrounding the pipes and making a permanent
covering.
INSULATION 85
Cork has also been made up into compressed sheets, bricks,
etc., of various sizes. The appearance of the sheets is shown
in Fig. 12. They are usually made 12x36 inches in size and
vary from one inch to three inches in thickness. These sheet.-
are made by compressing the granulated material or shavings of
cork in iron molds and baking in a temperature of about 500°
F. This is done without the addition of any cement or bind-
FIG. 12— SHEET CORK INSULATION WITH CEuIENT PLASTER
FINISH.
ing material, but the j^rocess liquefies the natural gum of the
cork sufficiently to bind the granules into a solid mass. In
some processes a cementing material is used, making what
are termed imi^regnated cork sheets. These boards are more
or less porous, and therefore to a^^ply them practically the
author has used them in constructions similar to mineral woi'l
slabs as shown in Fig. 11, set between furring strips and witli
waterproof paper between each layer of sheet cork.
86
PRACTICAL COLD STORAGE
The manufacturers evidently recognized the difficulty of
applying the sheets (otherwise than shown in Fig. 11) without
nailing through them. This was impracticable because the sheets
lack sufficient strength to hold nails and nails are also objec-
tionable on account of tearing the paper and cork. Conse-
quently the two inch and three inch thicknesses of sheet cork
can now be obtained with inserted nailing strips of wood, as
shown in Fig. 13. This is unquestionably a good improve-
ment, as it gives a more solid construction for nailing, and
does away with furring strips to some extent. Eeferring
again to Fig. 13, the author would consider it impracticable
Inserted spruce nailing strip.
Brick wall.
Pitch, paint or parafiine.
Nonpareil sheet corlt.
Nonpareil slieet cork.
< Paper, it' inside finish is wood.
} Pamt, if inside finish is^cemeut.
Spruce sheatliing or ceme'nt
FIG. 13 — SHEET CORK WITH INSERTED NAILING STRIPS OF WOOD.
and difficult to fasten the first sheet to the brick wall as shown.
A better method would be to set horizontal nailing strips of
wood in the brick wall every sixth or seventh course, or nail
horizontal furring strips to the inside of the wall, set 18-inch
centers and set the sheets vertically with joints lapped over
the furring strips, as shown in Fig. 14.
Another method of erecting cork sheets, which possesses
several advantages, is to cement them solidly to brick or tile
walls in a bed of Portland cement. A single course of the
cork sheets either two or three inches thick is used, or a double
course with cement between, as shown in Fig. 12, according to
INSULATION
87
the severity of the conditions. The interior finish may be
either matched boards, which are nailed to the inserted wood
strips in the corlt sheets above referred to, as shown in Fig.
13, or a fireproof cement finish of either Portland cement or
White Marble (Magnesian) cement may be applied directly
to the exposed surface of the cork sheets, as shown in Fig. 12.
This method gives an efficient insulation which is both water-
proof and fireproof and is being uspd at present more largely
than any other with very satisfactory results.
As above stated compressed cork is made in shape and
size resembling brick, which, for partitions and inside walls,
WATERPROOF COATING
•COMPRESSED CORK
■AIR. SPACE
■:r::^^=-WATERPRO0r PAPER
___ - % INCH D.f n BOARDS
FIG. 14— COOPER'S METHOD OP APPLYING SHEET CORK.
are laid up in the same manner as brick with liquid or asphalt
cement as a binder for the joints. Cork bricks are also made
that are impregnated with hot asphalt or pitch so as to sur-
round each particle, the purpose being to produce an article
that should be water-proof. This treatment would without
doubt decrease the insulating value of the cork bricks and its
purpose is therefore questionable.
Cork sheets or blocks set in and plastered with Portland
cement, are being successfully used in constructing partitions
without other supporting means or the regular structural mem-
bers. The life of such partitions is necessarily the life of the
88 PRACTICAL COLD STORAGE
cork, and therefore extreme care must be used in water-proof-
ing. Caution is urged against depending too much on the
waterproof and non-capillary qualities of cork. It must be
properly protected from air and moisture by a permanent tight
covering of some kind. The cement plaster cannot be de-
pended upon for this puri^ose unless coated with neat cement
put on with a brush, and great care used in the work.
IIAIK FELT.
Ilair felt material has very appropriately )jeen termed
"Natui'e's Insulation,'" as there is no question but that nature
FIG. 15 — HAIR FELT.
created hair for the chief purpose of protecting animal life from
the changes of temperature. It is one of the most indestructi-
ble materials with which we have to deal, and when properly
applied it is one of the best in.sulators available. Cattle hair
as it comes from the tanners is thoroughly washed and air
dried, put through pickers and blowers until all dirt, etc., is
removed and the hair thoroughly deodorized. It is then put
through felting machines where it is formed into sheets of
one-quarter of an inch to two inches in thickness, put up in
rolls Iwenty-foiu' inches to seventy-two inches wide and fifty
feet lung. This felt has the aj^pearance shown in Fig. 15. In
specifying this material the author requires it to be furnished
INSULATION
89
in narrow widths (preferably 24 inches) and applied between
furring strips and paper set vertically as indicated in Figure
16. The sheets should run from floor to ceiling continuously
and may be held in place by nails driven into side of furring
strips at an angle and then bent in as shown in Fig. 16. No
nails should be driven directly through the hair felt and
papers, as that destroys the air and waterproof qualities to
that extent and thereby decreases the value of the insulation.
In applying the sheets of hair felt to the ceiling, it has a
tendency to sag. This can be avoided by nailing temporary
cross cleats to the furring strips every five or six feet, as the
sheets of felt are put into place, and these can be removed as
the inside wood finish is put on. The use of twine as shown
W///////////////////////////////////A
VJATERPROOr PAPER.'
FIG. 16— METHOD OF APPLYING HAIR FELT.
in the sketch has proved practicable in many cases. A little
practice and patience is needed. If the hair felt is ordered
the proper width for use, there will be very little cutting to
be done except to cut off the lengths as needed. The best
method of cutting hair felt is with a long bladed sharp knife
or chisel guided along a straight edge held down firmly ; some
workman with accurate aim can do a fair job with a sharp
hand axe.
Besides being used as it comes from the manufacturer,
hair felt is put up in many ways, by applying paper, etc., to
the surface. In some situations this would be very desirable.
QUILT INSULATORS.
Those insulating materials known as "quilts" are in the
nature of a felt held in place between two papers and stitched
together, and are usually made in one-quarter and one-half
90 PRACTICAL COLD STORAGE
inch thicknesses, thirty-six inches wide, put up in rolls of
from 100 to 500 square feet. These quilts were originally
designed and manufactured for deafening purposes, viz.: to
absorb and dissipate the sound penetrating through floors and
partitions in dwellings, etc., where with proper construction
they serve both as deafeners and insulators.
There are various filling materials used for making up these
quilts, such as hair felt, mineral wool, flax fibre and eel-grass,
all of which are very durable, each possessing qualities that
recommend them for use. The nature of the hair felt and
mineral wool has already been touched upon. The so-called
flax fibre, recently introduced, is made from flax straw, that
has been crushed, picked and deodorized, and the sap or gum
FIG. 17— CABOT'S INSULATING QUILT.
removed, leaving a light fibrous material that if properly
protected makes a good insulator. Eel-grass is used in "Cabot's
Quilt" exclusively and has been on the market for a number of
years as a deafening material. The quilt has the appearance
shown in Fig. 17. This eel-grass, or sea weed, as it is often
called, is a long, grass-like material of great durability.* It
has great resistance to fire, and owing to the large percentage
of iodine (common to all sea-plants) which it contains, it is
repellant to rats and mice.
For the application of these quilts to cold storage and re-
frigerator car construction, they have been made in thicknesses
up to one-half inch, and waterproof papers have been placed
on one or both sides of the quilt instead of the common build-
*"A sample of eel-grass, 250 years old and in a perfect state of
preservation, may be seen at Mr. Cabot's office." — F. E. Kidder in "Build-
ing Construction."
INSULATION 91
ing papers. Some makers have coated one side of the quilt
with a waterproof asphalt coating, this to be turned toward
the damp side of the wall. These improvements have enhanced
the value of these quilts for insulating purposes and they
compare very favorably with other materials for practical use.
The common method of applying is to place a layer of
quilt between two sheathings of flooring and nail through it,
METHOD OP APPLYING CABOT QUIDT.
and then apply more sheathings and quilt as shown in Fig.
18. While fair results can be obtained by this construction, it
is somewhat impracticable on account of the elastic nature
of the quilt, and is also wasteful of lumber. A better method
of applying these quilts and saving lumber and increasing the
insulating value would be as recommended by tlie author and
92
PRACTICAL COLD STORAGE
shown in Fig. 19, on following page. In case it is desired
to omit the shavings, the wall may be furred with %-inch
strips and the quilt then applied, as shown, to the number of
thicknesses desired.
INSULATING PAPEKS.
As we have already seen, those materials having any con-
siderable insulating value, are extremely porous, and therefore
FIG.
ANOTHER METHOD OP APPLYING CABOT QUILT.
air under even a light pressure will flow through them quite
easily. To prevent this flow of air and the penetration of mois-
ture is absolutely necessary, otherwise the insulation will be-
come damp, and in time, regardless of materials used, almost
worthless on account of deterioration and decay. It is the
general practice to use air-tight and waterproof papers on each
side of the insulating materials for the purpose of preventing
this flow of air and moisture through the walls.
INSULATION 93
There has been a widespread impression that papers pos-
sess a high insulating value, and consequently many expensive
and complicated insulations have been constructed, using pa-
per as the chief material. It is now generally recognized by
refrigerating engineers that the chief value of paper in an
insulated wall is in its resistance to the passage of moisture
and air through the walls. Its use also tends to make an insu-
lated wall more composite without increasing its thickness, as
it changes the density of the insulation and thereby retards
the transmission of heat. Besides the requirements of being
air and water proof, papers must be odorless, have strength
and durability, and should not be brittle and liable to crack in
low temperatures, as this makes them difficult to handle and
results in leaky insulation.
There are a great many insulating papers on the market,
some of which are reliable and durable, but all so-called rosin-
sized, oiled and tar coated or tar saturated papers should be
avoided on account of their odor, and the rosin-sized papers
also avoided on account of the positive certainty of disintegra-
tion, because they carry their own destructive elements. It is
also advisable to avoid all so-called "coated" papers, that are
coated on both sides and have a light-colored center, as they
will disintegrate sooner or later, if unfavorable conditions arise.
Papers should be selected that have been saturated and thor-
oughly impregnated with pure asphalt or similar material or
have a center layer of asphalt, as thus they are practically in-
destructible when used for cold storage insulation; these qual-
ities, combined with the requirements above stated, make them
superior to all others for insulating purposes. These high'
grade papers are more expensive in first cost, but their dur-
ability makes them cheaper in the end. As the cost of using
good papers is usually less than 5 per cent of the total cost of
the insulation, and waterproof and air tight paper is the vital
feature of good insulation, it is poor economy to select an in-
ferior grade. Insulating papers are usually manufactured
thirty-six inches wide and come in rolls of 500 or 1,000 square
feet.
The papers should be applied with the greatest care in
lapping around corners, etc., all joints should be lapped at
94 PRACTICAL COLD STORAGE
least two inches and under severe conditions these joints should
be cemented. It should be kept in mind that the proper ap-
plication of the papers is one of the most important parts of
the insulating -work, because, as already noted, the insulation
must be air and water proof to remain efficient for any length
of time. If the workmanship is poor, the advantages of using
first-class papers are neutralized.
WOOD FOR INSULATION.
"Wood has, of course, played as important a part in con-
structing insulation, as it has in general building operations,
because of the ease with which it can be procured and worked,
together with its strength, lightness and durability. In ad-
dition to its general use for framing and floor construction in
brick warehouses (except in thoroughly fireproof structures),
it is used for forming the air spaces or filled spaces and inside
finish of the insulated rooms. Wood has been regarded as a
good insulator and this belief has, in many cases, tended to its
excessive use in constructing insulations, such as, for instance,
the use of from six to ten thicknesses of boards in one wall.
Considering the greater insulating values of filling materials
over solid wood, it is the general opinion of most refrigerating
engineers that many thicknesses of boards built up with air
spaces in such a manner, is not only extremely expensive, but it
is not efficient as insulation in proportion to the cost and space
occupied. One of the chief requirements in the use of wood,
already stated as essential to other insulating materials, is that
it should be odorless. This applies particularly to the inside
sheathing and finish of cold storage rooms used for sensitive
goods such as eggs. This requirement restricts the kind of
woods available to a very few, of which spruce, hemlock, bass-
wood and whitewood are the most desirable. Spruce is to be
preferred on account of being easier to work and not so liable
to have loose knots and shakes as hemlock, but it cannot be
easily obtained at reasonable prices in large quantities except
in the eastern states and the far west. Hemlock is abundant in
all the northern, middle and eastern states and Canada, where
it is used extensively in all building operations, but it is cross-
INSULATION 95
grained, rough and splintery, and liable to split when nails
are driven into it. It is claimed that owing to its splintery-
nature, hemlock is practically mice and rat proof. White pine
may sometimes be used, when the other kinds are not avail-
able, but it should be as free as possible from pitch and thor-
oughly seasoned. For a warehouse in Butte, Mont., designed
by the author, it was necessary to use tamarack for the inside
finish as the only native wood available that did not have a
stronge odor, and its use in this case was very satisfactory.
Where it is necessary to use a wood that may have a slight
odor, it should be given one or two coats of properly prepared
whitewash or other deodorizer as soon as the walls are finished.
Directions for making and applying whitewash may be found
elsewhere in this book.
That lumber should be thoroughly dry to get the best re-
sults in efficiency and durability of the insulation it is almost
unnecessary to state. If the lumber is even partially green,
it carries a considerable amount of moisture with it into the in-
sulation, causing more or less injury, and the use of under-
seasoned lumber should therefore be properly guarded against.
In erecting insulation during cold weather it is very necessary
to keep fires going so as to have all materials as dry as possible.
This is often neglected to the great detriment of the work.
All boards for sheathing should preferably be dressed and
matched, as it gives more air-tight and stronger work, and par-
ticularly for inside finish, as it has a much better appearance.
Rough boarding or surfaced boards may often be used for the
interior of the insulated walls where the joints are properly
protected, and rough boarding has often been used for inside
finish solely for the purpose of giving a rough surface for
whitewashing, as it is claimed that whitewash will peel or flake
off of a wall of dressed lumber. This is, however, not consid-
ered a valid reason by the author, as whitewash properly pre-
pared will not peel oft\ (See chapter on "Keeping Cold Stores
Clean.")
NAILS.
The use of any particular kind of nail may, on first
thought, seem to be of little importance, but when we consider
96 PRACTICAL COLD STORAGE
that the efficiency of the completed work depends upon every
detail of construction and that nails are good conductors of
heat, there is no question that the kind of nails and the manner
of their use is of some importance, The author usually speci-
fies that "cement coated wire box nails" be used. These nails
have a smaller diameter than the ordinary wire nails, but the
cement coating gives them greater holding power. This fact
permits the use of a smaller size nail for the same class of work,
for instance: Where 8d and lOd common nails are used for
sheathing. 6d and 8d cement coated may be used for the same
work. It is therefore evident that using cement-coated nails
not only reduces the heat transmission on account of their
smaller diameter, but also on account of being able to use nails
one-half inch shorter, as indicated above. The cement coating
also protects the nails to some extent from rusting.
COMPOSITE INSULATION.
Strictly speaking, all constructions are composite (except
solid wood or masonry construction), as they are necessarily
made up of materials having different densities and different
values as insulators. An English authority divided insulated
walls into two classes, which he calls the "forced" and "op-
tional" insulation. The former is of course the masonry or
frame wall of the building proper, and the latter the "lining"
or material added as insulation. Where the building is a frame
structure, the whole wall may be termed optional insulation,
because the space between the studding of walls may be insu-
lated with any filling material desired.
As already stated, even if the insulating value of one
inch or one foot in thickness of this or that material be known,
it gives no practical basis on which to design insulations, ex-
cept as a guide as to what materials may be practically used.
To calculate the value of composite insulations by the use of
formulae is extremely inaccurate, as account should be taken
of the papers used which have more or less value and the divi-
sion of the material into spaces by the paper acts to largely in-
crease the in.sulating value. It is for the purpose of determin-
ing the value of composite insulations that various testing ap-
INSULATION 97
paratus have been designed by different experimenters. It
may not be out of place to describe these briefly, so as to be
able to judge the reliability of the results obtained in the dif-
ferent cases.
INSULATION TESTERS.
The most common and inexpensive apparatus used is a
box constructed of the material that is to be tested and pro-
vided inside with a water-tight tin box having a drain pipe
with a trap connected at the bottom, similar to that shown in
Fig. 20. Top of box is provided with a removable tight cover.
This complete box is then placed in a room where a constant
temperature is maintained and a known quantity of ice is
FIG. 20— INSULATION TESTING APPARATUS.
placed inside the box. At stated intervals the ice meltage can
be determined by weighing the water coming from the ice
through the drain pipe in bottom. To get comparative re-
sults boxes of various materials, but of the same size and
thickness, can be fitted up, and all tested under the same con-
ditions. The quantities of ice melted in each case can be
compared and the relative efficiency of each material judged.
To determine the rate of heat transmission in B. T. Units
for this kind of tester, it will be necessary to consider time,
difference of temperature, square feet of surface in box and
9g PRACTICAL COLD STORAGE
quantity of ice melted. This can be illustrated by an imagin-
ary test case as follows: Take a tester two foot cube inside
measurements with walls four inches thick, the inside and out-
side temperatures being respectively 32° F. and 70° F. (assum-
ing the inside temperature to be the same as the ice) and the
meltage of ice per day (24 hours) is 50 pounds, we then have:
Inside surface 24 sq. ft.
Outside surface 42.6 sq. ft.
2)66.6
Mean surface between inside and outside of box 33.3 sq. ft.
Difference of temperature between inside and outside of box.. 38° P.
Ice melted per day (24 bours) 50 lbs.
342x50 equals B. T. U. transmitted per day =7100
tnoo
B. T. XJ. transmitted per sq. ft. per day \ = 213.2
(33.3
{213 2
38x24"
Testers similar to the one above described with changes
in details, spaces provided for thermometers, etc., have been
designed with the purpose of getting more accurate results, if
possible. Riege and Parker* designed and used a tester which
they described as follows:
In testing the value of insulating walls or partitions there should
be some means of determining accurately the rate of flow of the heat
through the wall or partition. This can be done with accuracy in sev-
eral different ways, though in the following test the apparatus used
consisted essentially of a wooden box, a tin box, thermometers, and
a pail to catch the drip from the ice, the agent used in cooling. The
boxes were respectively forty-four inches and twenty-five inches cube
on the inside, the tin box containing the ice to be melted. The wooden
box was made of %-inch white pine, tongue-and-groove boards, nine
inches wide, and really was a double box, the boards of the inner one
running at right angles to those of the outer in order to make the box
as air-tight as possible. The lid of the box, which was twelve Inches
deep on the inside, had a 12-inch band aroUnd the edge where the lid
rested on the box, and to make the joinings of the two as air-tight as
possible, the edge was lined with felt. Both the lid and the box were
then lined with what is known as builder's paper or "sheathing," which
secured a still better protection against outside changes of tempera-
ture. The tin box rested on a couple of wooden horses, twelve inches
high, so that when placed in position, there was a space of twelve
Inches all around the tin to the sheathing. From the bottom of the
tin box led a tube which passed into an inch pipe, this latter pipe
extending through the wooden box, and the lower end being immersed
in a can of water, prevented any outside air from entering either box.
All fittings were air-tight. Thermometer tubes were let in from the
*Icc and Refrigeration, January, 1895.
INSULATION 99
four sides to within six inches of the tin box, as well as a long tube
from the wooden box cover through the tin box cover to within a
couple of inches of the ice.
Before starting a test the ice was allowed to melt until the drip
from the can showed a regular flow, thereby allowing the true weight
of ice melted during the test to be determined. During a test tem-
peratures were noted on all four sides of the wooden box, also within
six inches of the tin box, and also inside the latter, the readings being
taken half hourly and the weight of ice melted hourly. When the
thermometer tubes were not in use, they were closed with corks. Com-
parison tests were made of each substance, each test lasting from
six to twenty-four hours. Tests were made of air, shavings and cork,
first at ordinary temperature and later with a steam coil an inch
above the wooden box to represent the effect, when steam was cir-
culated, of the sun on the roof of a storage house.
A later improvement on the above described tester, which
is used by some experimenters to-day, where simplicity and
cost must be considered, is to construct it similar to a domestic
refrigerator and about the same size, with an ice bunker and
air ducts installed so as to get a uniform circulation and tem-
perature inside. Small windows with three or more thicknesses
of glass are placed in sides of testers to read the thermometers
which are hung inside. The heat transmission is calculated in
the same manner as described for small tester above.
The comparative results that can be obtained with the '
above described testers are quite accurate when the different
materials tested are of the same thickness in each case. But
in comparing different thicknesses of material, there is a
chance for great error unless the inside dimensions of tester
are changed so as to give the same proportionate" mean sur-
face. This fact is readily seen if the tester shown in Fig. 20
is taken and the walls made eight inches thick instead of four
inches. The mean surface of the tester in that case would be
45.3 square feet, as against 33.3 square feet in the first case.
This difference in mean surface would favor the thicker insu-
lation when calculated in B. T. U.
John E. Starr, in an article on "Non-conductors of
Heat,"* describes the testing apparatus he designed and used
at that time, which was quite complicated as compared with
those above described, but was no doubt intended for greater
ranges of temperature than could be obtained with them. He
describes his tester as follows:
The writer, in investigating the value of insulating construction,
has used a rather simple but effective apparatus for accurately meas-
*Ice and Refrigeration, July, 1891.
100 PRACTICAL COLD STORAGE
urlng the flow of heat. He has a box carefully constructed and thor-
oughly insulated on the top, bottom and two sides. The two ends
remaining (exposing an area of something over four square feet) were
used as the test ends, and the various styles of construction to be
tested were built in these ends. In this way two tests could be made
at the same time. Directly against these two ends were placed water
reservoirs of thin galvanized iron of the same superficial area as the
test ends, that is to say, something over four feet square. These
reservoirs were about one inch wide and each held from twenty-five
to twenty-seven pounds of water. Outside of these reservoirs was an-
other very thicli insulation against the outer air, all except a small
opening in the middle of the top for thermometer readings. A steam
coil was placed inside of the box, and connected at its inlet with a
steam boiler and at its outlet with a steam trap. By regulating the
steam pressure the interior of the box can be kept at any desired
temperature; and the construction is such that any heat that finds
its way into the water must come through the insulation to be tested,
and that all the heat that comes through the insulation must find
its way into the water, as the water exactly covers the insulation. The
tests, therefore, can be made quantitative, as well as qualitative, by
observing the rise of temperature of the water, and tailing into ac-
count its weight. Readings are taken at regular periods of the tem-
perature inside the box, and of the water in each cap, or reservoir,
and of the surrounding atmosphere. The water caps, however, are
so thoroughly insulated from the surrounding atmosphere that unless
the temperature of the water in the caps rises to a very high degree,
and unless the test is of very long duration, only a small amount of
heat escapes from the water and passes into the air. The value of the
insulation surrounding the caps being known, however, a correction
can be made, if necessary, for such escape of heat from the water.
What is probably the most valuable and scientifically ac-
curate testing apparatus in use was constructed by the Non-
pareil Cork Manufacturing Company at their factory at Bridge-
port, Conn. A description of this apparatus was published in
Ice and Refrigeration, June, 1899, and is reproduced here as
follows :
Their apparatus consists of an insulated room, 12x10x8 feet, the
temperature of which can be held at any point desired from zero
Fahrenheit up, by means of a W. M. Wood compression machine
operating with direct expansion. A uniform temperature through-
out the room is secured by forced circulation, an electric fan being
used to drive the air up over the expansion coils which are inclosed
at one end of the room. The air passes out and down through a
false ceiling having graduated perforations arranged to allow a uni-
form amount of cold air to fall in .all parts of the room. This is the
method employed in various refrigerating plants with entire success,
by Mr. John E. Starr. In the center of the room is an insulated box,
3x3x6 feet inside measurement, having one side removable. It con-
tains an electric heating coil and a small electric fan arranged to give
a circulation of air and insure uniform temperature in all parts of the
box. Standard thermometers, both mercurial and recording air pres-
sure, reading 1/10° F., are placed so as to give the temperature of the
refrigerated room and the heated box, the readings being taken out- •
side the room. This obviates any necessity of the operator enter-
ing the refrigerated chamber while the test is being made. The
INSULATION 101
Weston standard ammeter and voltmeter measure the electricity sup-
plied in the fans and heating coil, and a suitable rheostat regulates
the amount of the current.
The method of determining the heat conductivity of any
insulating construction is as follows:
The temperature of the room and box are respectively lowered
and raised until they conform to the conditions under which the pro-
posed insulation will be used. Then the amount of heat or electricity
supplied to the box Is gradually diminished by means of the rheo-
stat, until the point is reached where the temperature in the box re-
mains constant. It is evident that at this point the radiation must
exactly equal the amount of heat supplied, or there would be a rise
or fall in temperature, as the case might be. After the supply and
radiation have been maintained constant for two hours, readings are
taken every five minutes for three hours more. If they do not vary
more than 1/10 of 1° F., they are considered practically exact. The
average is taken as the permanent radiation of the box under the
given conditions. The box contains 100 square feet of surface, meas-
ured at the center of insulation, consequently 1/100 of the total radi-
ation is the rate per square foot. This rate being obtained, the re-
movable side of the box is replaced with a side constructed of the
insulation whose value is desired. The test is then repeated, and
the total heat loss from the changed box will be greater or less, as
the case may be. The removable side contains twenty square feet
surface, therefore eighty square feet of the box remain unchanged,
and the radiation through this must be the same as before. This
amount is at once determined from the previous tests, and the differ-
ence between the total heat loss from the box in its changed condi-
tion, and this amount must give the radiation through the twenty
square feet, comprising the new side which has been put in. One-
twentieth of this amount is of necessity the rate per square foot, and
this divided by the difference in temperature between the room and
box, will give the exact radiation per square foot of surface per de-
gree of difference in temperature.
A testing apparatus which has been used by the author
is based on the same principles as that above described, but
somewhat smaller in size and of simpler construction. The
tester was built with one side removable and arranged so that
any kind of insulating material could be tested in same. This
tester was placed in a cold storage room where a temperature of
15° F. could be obtained and which was equipped with an air
circulating system. The inside of the tester was heated by
eight incandescent electric lamps, each controlled by a but-
ton switch from the outside. The temperatures inside of the
tester were observed by means of a specially made long-stem
thermometer projecting through top of tester and read from
the outside. The thermometer was graduated to read to 1/5 of
a degree. The apparatus is shown in Fig. 21.
The incandescent lamps used were 110 and 52 volts of
16 c.p. on a 52-volt circuit. These would give approximately
102
PRACTICAL COLD STORAGE
50 B. T. units and 200 B. T. units respectively per hour, but
they were accurately calibrated by a water calorimeter test. This
consisted of an insulated tank, capable of holding twenty-five
or more pounds of water, which was allowed to stand in a con-
THERMOMETER
Rn-10VABLE COVER
WITH INSULATION
TO BE TESTED
BUTTON SWITCH
FIG. 21.— COOPER'S INSULATION TESTING APPARATUS,
stant temperature until the temperatures of the water and tank
were equal. Under such conditions each lamp was put in a
water-proof socket and tested separately by immersing in the
water and noting time taken to raise twenty-five pounds of
INSULATION 103
water 1° F. In this way the B. T. units of each lamp per
hour were obtained, and with each lamp controlled separately,
the temperatures in tester were controlled at will up to 150°
F. Owing to the fact that the life of incandescent lamps is
limited, they will, after a certain time, decrease in power. This
made it necessary to retest them periodically. The author be-
lieves that the results obtained with the above apparatus are as
accurate as those that have been obtained by other experi-
menters.
INSULATING VALUES OF COMPOSITE STRUCTURES.
The results obtained by the different experimenters have
been illustrated and published in various trade papers, pamph-
lets and catalogues. The author has assembled and illustrated
these results .in the following figures as accurately as informa-
tion permits. Figs. 22 and 23 give the result of tests made by
John E. Starr (some of which were made for the Nonpareil
Cork Mfg. Co.), at different times and for different purposes.
Most of these were presented by him in a paper read before
the eleventh annual convention of the American Warehouse-
men's Association in October, 1901.*
Figs. 24 and 25 give the results of other tests made by the
Nonpareil Cork Manufacturing Company with their elaborate
testing apparatus, described above, comparing their material,
for the most part, with the wood board and air space construc-
tion.
Fig. 26 is a reproduction from an article in Ice and Re-
frigeration, September, 1896, on "Cold Storage Buildings."
The drawings are there credited to the Fred W. Wolf Company,
who give the heat transmission as having been determined
from practical experience, but do not describe how or by whom
these tests were made.
Fig. 27 gives the result of tests made by the author with
the testing apparatus above described as designed by him.
These show the tests on a variety of materials and were not
made in the interests of any of them in particular, but were
made chiefly to determine the value of air space construction
as compared with filled spaces and sheet material.
•Reported in Ice and Refrigeration, November, 1901.
104 PRACTICAL COLD STORAGE
The above described tests are all based upon the amount
of heat transmitted per square foot, per degree of difference be-
tween inside and outside temperatures, per day (24 hours).
Figs. 28 and 29 are reproductions from drawings made
by George PI. Stoddard and accompanying his paper on "In-
sulation," which was read before the eleventh annual conven-
tion of the American Warehousemen's Association.* The na-
ture and form of testing apparatus which was used to obtain the
results shown in these drawings were not given by him in his
paper. In explanation of these drawings we quote in part
from his paper as follows:
It maj' be of interest to consider how the transmission of heat
takes place through an outside wall, such as is often used for a cold
storage warehouse. Fig. 28 shows a section of such a wall. Starting
from the outside, it is made up as follows: 24 inches of brick, 2-inch
air space, two %-inoh matched spruce sheathing with paper between,
then twelve inches of spruce mill shavings, then two %-inch spruce
sheathing, with paper between. We will assume a temperature of
92° P. for the air and objects outside, and a temperature of 32° F. for
the air and objects inside of the warehouse. Heat is transmitted
through this compound wall as follows: To the outer surface of the
brick by radiation and contact of air, through the brick by conduc-
tion, across the air spaces by radiation and contact of air, through
the inner wall of sheathing and shavings by conduction, and from the
inner surface of the wall by radiation and contact of air.
Knowing that the rate of transmission must be the same to and
through and from the wall, it is of interest to note the temperatures
of the different faces of the wall, and see how they vary from the
outside temperature of 92°, to the inside temperature of 32°. There is
only the difference between 92° and 90.7° between the outer air and
the outer surface of the wall, then the temperature drops to 81.8° at
the inner surface of the brick, to 80.1° at the other side of the air
space, to 76° at the inner surface of the outer double sheathing, to
37.4° after passing the shavings, to 33.3° at the inner surface of the
inner sheathing, and then to the temperature of 32° in the room.
In Pig. 29 are shown curves representing the rate of transmis-
sion through walls similar to that which we have just considered,
with the brick wall varying from eight to twenty-eight inches in thick-
ness, combined with inner walls having the shavings from two to
twelve inches thick. The vertical distances in all of the similar dia-
grams represent the B. T. TJ. transmitted per square foot per hour
per 1° P. difference in temperature between the inside and outside
of the wall, and also the equivalent pounds of ice melted per square
foot per twenty-four hours for a difference of a little over 59° P.
Pig. 30 shows a similar curve for a partition of typical construc-
tion (see Fig. 31), with the thickness of shavings varying from two
to twenty-four inches.
In Fig. 31 are shown partitions made up of sheathing and with one,
two, three and four air spaces, and also one made up of sheathing and
paper with nine air spaces, and the rate of transmissipn of heat
♦Published In Ice and Refrigeration, November, 1901
-i-J
_^-^^lHCH PIHE BOARD
f, ImCH LAMP BUCK,
*■ *^;^% IHCH OAK,
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5.70
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PIG. 22.— B. T. U. TRANSMITTED PER SQ. FT. FEB DAY PER
DEGREE OF DIFFERENCE OP TEMPERATURE.— STARR'S TEST.
106
PRACTICAL COLD STORAGE
B.T. U.
,-7felNCH BOARD
-- 1 IMCH MIHERAL WOOL
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76 INCH BOARD
4.60
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PR.V135.
Same Slightly
^MoisT 1.60.
SAMEthMPZiO.
■15-
6 PATENTED 31L1CATED ^TRAWBOARD
AIR. CELL riNISHED INSIDE
~~f&i
INCH BOARD
—PATENTED CEMENT
^z.4a
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• W.P PAPER.
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76 INCH BOARD
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FIG. 23. — B. T. U. TRANSMITTED PER SQ. FT. PER DAY, PER
DEGREE OF DIFFERENCE OP TEMPERATURE. — STARR'S TEST.
-3-
, ^-%1NCH D.»M. SPRUCE
-— W.F.FAFER.
^-vC~'1'n.p.s.coek
\--W.P.PAFEE
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— -W.PPAPER,
2 IMCH H.P5. CORK.
C"~-W.f; PAPER.
^.%1MCH D.tI-T.SFEUCE
_ --^INCH DtM 5PR0CE
«a '."" " "^ PAPCE
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fo INCH Cwn SPRUCE
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^^. % INCH MM. SPRUCE
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, "-IINCH AIRSPACE
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_^.--76INCH DtM.SPRUCE
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■3.10
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ino
^^ --76 IHCH D,+M. SPRUCE
W.PPAPER
Z.IMCH PUMI3T0NE
^^W.R PAPER
^^TfeiHCH dtm spruce
PIG. 24. — B. T. U. TRANSMITTED PER SQ. FT. PER
DEGREE OF DIPPERBNCB OF TEMPERATURE.
NONPAREIL CORK MPG. CO.
I Dry 3.4
I Moist 5.9
DAT, PER
108
PRACTICAL COLD STORAGE
B.T.U.
NQ
^JfemCH DiM.sreucE
S- W.P.PAPER.
'':^ — ^^llNCH M.BSCORK
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^ —% INCH DtM. SPRUCE
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t.to
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^ /a INCH DtM SPRUCE
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-^ INCH D+n SPRUCE
1.9
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FIG. 25. — B. T. U. TRANSMITTED PER SQ. FT. PER DAY,
DEGREE OF DIFFERENCE OF TEMPERATURE.—
NONPAREIL CORK MFG. CO.
PER
B. T. U.
g^^fekajgg^^^-l
JCRATCHEO KOUUOW TILI
'SPACE riLUCD WITH
MIMEBAL. WOOL
™,--l"3eBATCHED HOLLOW T
^.CEMEUT PLASTttt
H^__DoueLe apAcc hollow t
ARCHES
I CCnCKTPLAaTEB
Tloor. Construction -riECPRoor
— l"AIR5PASe
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4'3PACE riLLCO WITH
MlHEBALWODL
■— rAlll3PA«C
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ll
J I
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IV e'3T tf03 ■ I6"0.C .
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■WATERPttOOr mpCR
4'3PACC nmEPWITH
" "IfiCRAl. WOOL
1 or Wall
1.74
B0ARI>3
PAPCPS
t: SPACES TILLED
VIM
-l^'pLANk. rLOORINq
^WATrRPROOf PAPERS
NCH BOARP3
■ PACE riLLED WITH
MINERAL WOOL
w WATERPBOOr PAPER.
IMCH BOARDS
4] BEDDEf IH DRV
(DERr-ILLINq 11'MIQM
]^Z
TLOOR- C0N5TRVCTI0N
FIG. 26. — B. T. U. TRANSMITTED PER. SQ. FT. PER DAY, PER
DEGREE OP DIFFERENCE OF TEMPERATURE.—
FRED W. WOLF CO. TEST.
>TO.
J % IMCh QtM. doaum
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~- -WP. PAPER-
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■WF. PAPER.
■% rMCH DrM. BOARDS
— /BlNCHPtMBOARPS
^-^—W.P PAPER.
■*--- (IMCH AlRr SPACE
aia-O "-W.P PAP^R.
~~"%rMCHD.tM B0ARP3
•4.01
'7.n
9.12.
FIG. 27.-B. T. U. TRANSMITTED PER SQ. FT. PER DAT PER
DEGREE OF DIFFERENCE OF TEMPERATURE.— COOPER'S TEST,
INSULATION
111
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112
PRACTICAL COLD STORAGE
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TNCHES or 5HAVING6 "a"
FIG. 29.— STODDARD'S DIAGRAM SHOWING RATE OF HEAT TRANS-
MISSION THROUGH A WALL.
FIG. 29a.— STODDARD'S DIAGRAM
ABOVE WALL
-a'SPRUCESHEATHINO-
SHOWING CONSTRUCTION OF
INSULATION
113
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114
PRACTICAL COLD STORAGE
B.T.U=.I402
ICE -1.402
B.T.U.^.095S)
ICE =.0.959
B.TU-.07Z3
ICE --0.7Z3
B.T.U.=.076
ice: = 0.76
BJ.U.-. 05 87
iCL.= 0.587
FIG. 31.-
-PARTITION OF SHKATHING AND AIR SPACES SHOWING
RATE OF HEAT TRANSMISSION. — STODDARD.
INSULATION
115
HAIR FELT
GRANULATED CORK
MILL SHAVINGS
SHEATHING .*' AIR SPACES
-%"SPRUCE SHEATHINO
BT.U. .0+83
ICE - .483
?S SPRUCE SHEATHms ■
FIG. 32. — RELATIVE THICKNESS OF PARTITIONS PACKED WITH
VARIOUS INSULATING MATERIALS.
116 PRATICAL COLD STORAGE
through such Insulation is given in B. T. U. and ice melted. In Pig.
32 is given the actual thickness of different partitions packed with
various insulating materials of such a thickness that all of the com-
plete partitions shall be of the same insulating value. There is also
shown one made up of sheathing with air spaces. Prom this is seen
how much more space is taken up by one form of insulation than
by another.
An examination of Pigs. 31 and 32 will show the comparatively
small value of air spaces for the purpose of insulation, and it may be
stated, that, for this purpose, a wide air Space has no greater value
than a narrow one, and that any space over one-half inch in width,
if it can be kept dry, will be of greater value if filled with an insu-
lating material as good as mill shavings, than if left as an air space.
AIK SPACES.
It is evident from the results shown with the various
constructions, that those built up out of wood boarding and
air spaces, or air spaces formed with battens and paper make
the poorest showing when the space occupied and cost in la-
bor is taken into consideration. The author considered the
one-half inch air spaces formed by battens and paper as shown
in his tests to be efficient until practical experience and the
tests conducted by him proved otherwise. The workmanship
in building such spaces is usually poor, as unusual care, not
appreciated by the average workman, must be taken so as not
to puncture them when under construction. Air space con-
struction is difficult to erect so as to be air and moisture proof.
Another extensive use of air spaces has been between the
brick wall and the insulation, as shown in Figs. 29 and 33.
The alleged purpose of its use in this position has been, first,
proof against moisture entering the insulation; second, for
the insulating value it may have. With the growing disbelief
in the use of air space construction, this second purpose can
be considered of little value. The prevention of moisture en-
tering the insulation from brick walls by the use of air spaces
is only partially true, as may be readily understood. The mois-
ture will enter the air space and will eventually affect the in-
sulation more or less. There are sometimes local conditions
that would warrant the use of an air space between the brick
wall and insulation, but in the opinion of the author, such de-
sign should be avoided wherever possible by waterproofing the
brick wall and placing the insulation against the waterproof-
ing. This method saves both space and material for the same
POR CEIUNG OF
COLO STORAGE ROOMiS
AND ICE HOUSE.
FOR WALL OF
^?THlot%''T'^±G ^Q*ftoir'^''*"*'°°'* ^^ COBKAS SHOWN I COLD STORAGE ROOM
— ■■ ' '■ ■ •- -*-"°^ < AND tCE HOUSE
2"TMICK. OF T.-4 Gi BdARM ■"'' *"^^ "^^E OFBRICK,
PAPER BETWECM
FOR INTERM£DrATE FLOORS.
,s*th1ckneag£s of t. a g. boards
" " papeh betwebn
Vmineral wool cr cork
2^THICK. OF T. d G. BOARDS
" '* PAPER BETWEEN
MINERAL WOOL OR CORK
FOR PARTITION WALLS.
s'tHICKNEGS^S op T. a 0. BOARDS
•s* •' m - ■ -. paper betweek
9''air space pilled as shown
■2'THICK. of T- * G- BOARDS
»* •■ " " - <pAPER aerwEEN
a'AIR SP'CE FILLED AS SHOWN
a'THioc. OF r. « c. boards
a" " •' " PAPER BETWEEN,
MtNERAL WOOL OR CORK
FOR GROUND FLOORS.
a'xMICK. OF T. A G. BOARDS
3" II >' . . PAPER BETWEEN
i'AIR SPACE
2'thICK, of T. a C. BOARDS
a* •' " PAPER BETWEEN
'MINERAL WOOL OH CORK
J SHELVING
a'sTUDOlNQ
•AIR SPACE INSULATION.— PRICK CO.
118
PRACTICAL COLD STORAGE
vJATEOenoor PApcb."
.rHAinreLTiCOBKOK
'PLAN or IN3ULAT10N-
FIG. 34.— COOPER'S DESIGN FOR INSULATED CONSTRUCTION.
INSULATION 119
insulating efficiency obtained. The question of the amount
of space occupied by the insulation is of importance, as it
represents a certain money value, both in first cost and as stor-
age space, and it should be the designer's aim, within practical
limits, to use the best insulation and that requiring the least
space.
TYPES OF INSULATION.
Fig. 34 illustrates a construction used to a great extent
by the author in his cold storage work. The inside of the
masonry walls are waterproofed and the filled space of from
six to ten inches is placed against it, then the sheathing, sheet
material and papers are placed inside, next to the storage
rooms. With a ten-inch filled space and four-inch sheathing
and sheet material as shown, a total of fourteen inches, we
have an insulation for a storage temperature of 30° F., and
the basement with a total of fifteen inches, for a temperature
of from 20° to 25° F. For sharp freezing purposes there
should be an eight inch and a six inch filled space and an ad-
ditional thickness or two of sheet material.
Figure 35 illustrates the construction and insulation of
a frame -building suitable for a temperature of 30° F. The
space bet\'\'een the studs should be sub-divided, as shown in
Fig. 35a. This lessens the liability of settling of the filler and
the penetration of moisture. The use of wide filled spaces
such as shown in Fig. 28 is not considered good practice, as
heat passes through a construction of uniform density more
rapidly than through one made up of successive layers of dif-
ferent densities, therefore the thickness of the wall in the
former case will be greater than that in the latter to obtain
the same insulating value. This is evident by referring to
Figs. 28 and 34, the former with twelve-inch brick wall, air
space and twelve-inch shavings, as shown, a total of thirty
inches in thickness, transmitting % B. T. U. per square foot
per degree difference between inside and outside temperature.
The latter, with twelve-inch brick wall, eight-inch shavings and
five inches of sheathing, sheet material and paper, as shown,
totals twenty-five inches in thickness, will transmit same
120
PRACTICAL COLD STORAGE
,*r -v^^ ■Kj"''' xi '■".■ r^ /%-'
J.i'^5HAVlNQS
=~7a INCH D.«M. BOARDS ^ I//'/
__x"mimeral wool BLOCK^ ,'//
CORK OR HAIR. FELT L'
•^V/ATERPROOr PAPER '
-YasuRr boards
__ZVlo'5TUD3-riLLED
"with 5HAVINC33
I 7&INCH mn. BOARDS
/ Z."rilMERAL WOOL BLOCk
/ jT CORK OR HAIR TELT
/ //' r -WATERPROOF PAPERS
III ffi //a INCH SURF. BOARDS
/// /' //t'I'-LED WITH SHAVING
' • 'ii//
FIG. 35.-
-SECTION SHOWING INSULATION FOR A FRAME
BUILDING.
INSULATION 121
amount of heat. Here is a saving of five inches in storage
space which will earn the difference in cost between the two
constructions in a short time. Dividing the shavings space
into two separate spaces is advisable to increase insulating effi-
ciency.
INTERNAL CONDENSATION.
Another feature in the construction shown in Fig. 34 of
equal importance to the space saved, is durability. This is
accomplished by placing the indestructible materials, such
as water-proof paper, and mineral wool block, sheet cork or
hair felt in successive layers on the side next to the storage
room where the conditions are most severe. These severe con-
ditions are caused by a tendency of the enmeshed air in all in-
sulating materials to condense the moisture held in suspen-
sion when subjected to low temperatures. This moisture will
impair the durability of some materials, such as sawdust, shav-
ings, etc. That such condensation does take place within the
insulation, near the low temperature side, was demonstrated to
the author in the tests made by him. Between each test the
removable cover was unscrewed from the tester, which' was lo-
cated in the cold storage room, and taken into a room having
an ordinary temperature, where the material in the cover was
changed for the next test. The enmeshed air in the material
put into the tester, was of an ordinary temperature and held a
certain proportion of moisture in suspension, and when the
material was reduced to the low temperature in the cold stor-
age room, this moisture would condense on the cold side of the
layer confined by the waterproof paper. In some cases where
the room temperatures were very low the condensed moisture
would freeze on the cold side. These conditions obtained, de-
pending on the dryness of the material when it was put into
the tester, but would show more or less moisture in almost
every case. The moisture condensed would be greatest in the
layer nearest the cold side of the partition and would gradu-
ally diminish in each layer toward the high temperature side,
where it would be perfectly dry. This was not moisture that
had been carried into the insulation by the leakage of air, but
was the condensation of the moisture held in suspension by the
122
PRACTICAL COLD STORAGE
air enmeshed in the material. Air space construction showed
the greatest condensation, wide filled spaces came next and the
high grade of sheet materials, divided by waterproof paper
showed the least. From the above it is evident that high-
grade materials should be used next to the storage rooms, as
they will not deteriorate as rapidly wjth the presence of mois-
ture. This construction also protects the loose filler in the
filled space, which is removed further from the inside wall,
therefore making its duty less severe as regards the action of
moisture. This construction is shown in Fig. 34 as used by
FIG. 35a.— PLAN OF SUBDIVISION OF SPACES AS SHOWN IN FIG. 31.
the author. It is also evident from the above described action
of moisture in the insulation, that the importance of using dry
materials cannot be urged too strongly.
PRACTICAL POINTS.
Where the storage space occupies two or more stories, it
has frequently been the practice to insulate the intermediate
floors out to the masonry walls and then erect the wall insula-
tion independently for each story, as. shown in Fig. 33. This
is a questionable practice, as it increases the number of joints in
the con.struction and consequently the chance of air leakage
into the rooms. Cases illustrating the damage from air leakage
^ INSULATION 123
between joints and above ceiling or beneath floors of storage
rooms come to the author's attention frequently. The last one
was so pronounced a case that the entire ceiling of an upper
room became so rotten in a few years' time that it practically
fell, making the entire renewal necessary. The damage was
caused by leakage of air, and consequent deposit of moisture
on the cold ceiling. Where the building is a fireproof struc-
ture with steel beams and masonry floors, it cannot of course
be insulated otherwise than by treating each floor indepen-
dently, or in a similar way to that shown in Fig. 42.
A better method than that shown in Fig. 33, would be to
make the wall insulation continuous from floor of lower story
to ceiling of upper story, as shown in Fig. 34. Where the ends
of joists bear into the wall, the insulation should be scribed
and closely fitted around each joist. This is easily done where
the construction is properly designed to allow a wide spacing
of the joists. Insulation constructed in this way decreases the
chances of leakage to the minimum.
Referring again to Fig. 33, it will be noticed that the
spaces between joists are but partially filled with the filling
material, leaving an empty space in each case. This would
have been of greater insulating value if packed full to the top.
The spaces betM'een the lower floor joists should first have
been lined with waterproof paper before the filler was put in,
as shown in Fig. 35, to prevent the penetration of air and
moisture.
TANK INSULATION.
The insulation detail for a steel ice freezing tank, as
shown in Fig. 36, is of the general form used by most design-
ers.- Attention is here again called to the use of high-grade in-
sulators at what will be the coldest point of the insulation for
reasons already discussed. In the light of our present informa-
tion, the use of a 2-inch or 4-inch air space next to the steel
tank would be considered a waste of space. This would much
better be filled with granulated cork and hot pitch or asphalt,
as shown in detail, as this would prevent the condensation of
moisture and protect the steel tank from corrosion. The space
under bottom of tank should first be filled level with top of
124
PRACTICAL COLD STORAGE
floor cleats and then the tank set in place, after which the
space around sides can be poured full from the top. A fre-
quently neglected detail is covering the top edge of tank insu-
lation with galvanized iroii or other waterproof material, as
shown in Fig. 36. This detail should not be overlooked or
slighted, as the unavoidable spilling of water and dripping of
brine in connection with ice making will eventually damage
the insulation.
FIKEPEOOP INSULATION.
The tendency of modern building construction, especial-
ly in our large cities, is toward the solution of the problem of
fireproofing, so as to decrease the danger and risk of fire. It is
V.+'^TUDS -iVCEN.-
tspace tilled with pitch-
7'6incm d.*m-b0ard3.^^
4 inch filled 3pace^
3"hair felt, cork OR^
mineral wool block*"
waterproof paper. -^
FIG. 36.— INSULATION OF BRINE TANKS.
natural that this same problem should confront the cold stor-
age man, but the difficulties of providing insulation that would
be fireproof, and remain at the same time insulation in fact,
is a problem not easily solved.
In the article on "Insulation for Cold Storage," read be-
fore the eleventh annual convention of the American "Ware-
housemen's Association, Starr stated regarding fireproof in-
sulation, as follows:
I cannot refrain from alluding to the subject of fireproof insula-
tion, more in the hope of drawing out information than adding to it.
INSULATION 125
Steel frame work has in the past been a considerable bugbear to cold
storage men, but the time is already at hand when the problem of en-
tirely fireproof construction, both as to building and insulation, must
be solved. As to the insulation end of the problem, the difficulty is
not so much with the question of obtaining a fireproof filling material,
but to find a substitute for wood, to hold the material in position.
Cementing insulating material in the shape of blocks has been experi-
mented with, but If the cementation is enough to give sufficient rug-
gedness to the block the insulation qualities are, as a rule, impaired,
and the cost as well as the space occupied by the insulation is in-
creased.
If a semi-fireproof insulation that might be classed as fire-retard-
ant construction is permissible, the problem is somewhat simpler, as
several materials are at hand that can be classed as retardants, such
as compressed cork, hair felt, silicated paper, air spaces, etc., but if
the whole structure, studs, filling material and wearing face, are to
be fireproof, we are practically restricted to mineral wool, mica and
calcined pumice for filling material; and for retaining and wearing
wall, to brick or some of the various cement fireproof boards on the
market. The use of the latter would seem somewhat experimental,
and the question of fireproof studs for supporting them, so far as I
know, has not been answered.
As nearly all building materials available that can be
called fireproof are poor insulators against heat, it is evident
that the walls must be extremely thick to have the same insu-
lating value or the machinery must take up the extra heat
transmitted through them. The former course, with the pres-
ent method of constructing fireproofing, is almost prohibitive
on account of first cost and the space occupied; the second
course necessitates a continuous heavy operating expense. The
advisability of fireproof insulation, especially in small houses,
is questionable, as the items of interest on investment, space
lost, and increased operating expenses will oftentimes equal the
difference in insurance rates obtained between a fireproof and
a well designed "mill construction" warehouse.
It is the observation of the author that the greatest num-
ber of fires occuring in cold storage warehouses originate out-
side of the storage rooms, except in occasional instances where
it is caused by defective electric wiring. Therefore, if the cold
storage portion were surrounded and divided by fire walls,
openings properly protected and the electic wiring installed ac-
cording to approved methods, it would seem that the fire risk
was cut down to a minimum, as the nature of the machinery
and the goods usually stored are not of an inflammable charac-
ter. This point must, however, be appreciated by the fire un-
derwriters to make it of any value to the storage man in the
126 PRACTICAL COLD STORAGE
way of lower rates. That they will appreciate it in the near
future there is no doubt, and then the requirements of fire-
proof insulation will seem unnecessary, except perhaps in the
large warehouses in the large cities.
Cold storage warehouses have been erected on the lines in-
dicated above with ''mill construction" and wood insulation
and have obtained a very low insurance rate, considering the
general attitude of the fire underwriters toward the cold stor-
age warehouse business.
The necessity of fireproof insulation is felt in storage
vaults for furs and fabrics, and justly so, as these articles are
usually of great value and oftentimes could not be replaced
if lost or damaged. This class of storage will permit a great-
er operating expense to offset the poorer insulating value of the
fireproof insulation. Figs. 37 and 38 are details of the wall
and ceiling insulation in the storage vaults of the Lincoln
Safe Deposit Company, New York. The plaster blocks were
fastened to tbe brick walls, every alternate block in every al-
ternate row with iron anchors. The ceiling blocks Avere sup-
ported by tee irons, which in turn were suspended from the
brick arches, as shown. These plaster blocks usually consist
of plaster-of-paris and some binding material, such as manila
fibre or common straw, and in the event of a severe fire they
would probably fail and allow the filling material to fall out.
The failure of plaster blocks was fully demonstrated by the
Baltimore fire, where, in every case noted, partitions erected
of them were completely destroyed. The company above
named, in making later extensions to their plant, used cork
blocks applied directly to the brick wall and plastered inside,
as shown in Fig. 13.
Constructions such as shown in the two upper details of
Fig. 26 are strictly fireproof and may be used where the tem-
perature difference between the inside and outside would not
be more than 25° to 30° F.
Figs. 39, 40 and 41 are reproduced from illustrations de-
signed by Alfred Siebert.* These constructions were intended
for bre-\very refrigeration where the temperatures required are
•In "American Handy-Book of the Brewing, Malting and Auxiliary
Trades."
INSULATION
127
comparatively high, as their heat traiismission would be pro-
hibitive for cold storage work. The difference of detail betAveen
Figs. 35 and 36 is in the method of bonding the tiles to the
main wall ; in the former case, some of the tiles are laid head-
,..v/.r -BOATED WITH PITCH
;^^j— 4' or MINERAL WOOL
M\~~'^^ PLASTER. BLOCK
"■''■■^' -ADAMANT PLASTER.
FIG. 37.
i
-DETAIL OF WALL INSULATION.
a-tSsga^Mt-i?.-
COATED /
WITH PITCH
2.'! PLASTER. BLOCKc/ ^
Ceiling-
adamant PLA3TER.'
FIG. 38.— DETAIL OF CEILING INSULATION.
ers with one end secured in the brick wall and in the latter
case iron anchors are used.
If a fireproof building is to be insulated where a slow
burning or fire retardant material can be used, a construction
as shown in Fig. 42 is the most practical and with the proper
.■-heet or block material would be almost thoroughly fireproof.
128 PRACTICAL COLD STORAGE
Such insulation can be finished inside with cement or plaster,
as shown.
The inside finish on the walls of the rooms is of some im-
portance as a fire retardant. With the use of hard oils, var-
nishes,' shellacs, etc., the spread of a fire would be rapid, as
these materials are very inflammable, but with the use of prepa-
rations such as cold water paint or whitewash, the spread of
fire would be retarded, as these mixtures are not inflammable,
and would give some protection to the woodwork on that ac-
count.
BRINE PIPE INSULATION.
The importance of thoroughly protecting the pipes that
carry the cooling agent to the various parts of the storage
building is as great as insulating the rooms. On account of
the low temperature of these pipe surfaces, they condense much
moisture, and if the covering is poor and not well protected
on the outside from air leakage, a dripping and soggy condi-
tion is sure to follow each time the cooling agent is shut off.
If this condition is once obtained the value of the covering is
permanently impaired.
There are some pipe coverings on the market, especially
suitable for brine piping, made of cork or mineral wool in
block form in the same manner as already described for wall
insulation, and are made sectional to fit any size pipe or fit-
ting, having the appearance shown in Fig. 43. Some of these
sectional coverings are provided with canvas cemented to the
sections with ample lap at the joints, and these laps are ce-
mented together as the sections are put in place. Directions
for putting on are usually sent with the material by the manu-
facturers. Hair felt is also a good material to use if properly
applied, as indicated in Fig. 44, and can be handled very well,
if cut in lengths of five or six feet, wrapped around the pipe,
and thoroughly wired with galvanized or copper wire. If a
second layer is to be put on, waterproof paper should be put be-
tween the two layers and wired on, and the second layer then
applied in the same manner as above. The outside layer
should have waterproof paper wired on and then covered with
strip canvas, binding it on spirally with a good lap at the
129
Piaster
FIG. 39. — SIEBERT'S BREWERY INSULATED CONSTRUCTION.
joints. The canvas must be bound on tightly. The covering
should then have at least two coats of a good elastic waterproof
paint.
It is of primary importance that the pipes should be dry
FIG. 40. — SIEBERT'S BREWERY INSULATED CONSTRUCTION.
and should be given a coat of paint before covering is put on.
The author recommends that the layers of covering should be
thin, not more than one inch in thickness, and that at least
two thicknesses be used, having waterproof paper between each
fJoles^-por pouring in pi'toh
Asphalt
FIG. 41.— SIEBERT'S BREWERY INSULATED CONSTRUCTION.
layer with cemented joints, so as to insure the air-tightness
of the covering.
For brine mains laid under ground, through brick walls
or up through partitions, a covering of granulated cork mixed
130
PRACTICAL COLD STORAGE
Intermediate rLoou
I'CEMENT rLOOP,
I ^WPCOATINQ
--1%"FLANKL
r-WP PAPER.
X'CORK. HAIR PELT OR
OUT31DE WALLi
BASEriEIiT rt-OOE.
PIG. 42.— INSULATION OF FIRE PROOF STRUCTURES.
INSULATION 131
with hot pitch or asphalt is best, as described under cork ma-
terials. This method was used by the Quincy Market Cold
Storage Company of Boston, Mass., in running a street pipe
line from one of their buildings to the other. The pipes were
laid in creosoted plank boxes of proper size to permit sufficient
space around them, and the mixture of cork and pitch was
then poured in.
Fig. 45 illustrates a form of tunnel for underground brine
pipes that has been used by the author. In this case, as shown,
the tunnel was constructed of brick, waterproofed both inside
and outside and the top constructed so as to be removable in
FIG. 43. — CORK BRINE PIPE INSULATION.
case of necessity. The brine mains inside were covered in the
usual way, leaving an unfilled space around them in the tun-
nel.
WATER AND DAMP PROOFING.
The results of the penetration of moisture into the in-
sulation has already been discussed under the various sub-
heads; and the functions of waterproof paper in the interior
of the insulation to stop this moisture, should by this time be
pretty well understood. But the penetration of moisture
through the masonry walls to the insulation must be prevented
by special treatment.
The tendency of masonry to absorb moisture is fully recog-
nized and provided for in the building trades. It frequently
happens in heavy and driving rain storms, of some duration,
that the water will be driven through a 9-inch and even
through a 13-inch brick wall. This is counteracted in gen-
eral building operations, if it is desired to plaster on the in-
132
PRACTICAL COLD STORAGE
side of the wall, by constructing a 2-inch air space in the ma-
sonry wall. This space will prevent the passage of moisture
sufficiently so as not to damage the plaster. A second method
is to line the inside of a solid masonry wall with hollow brick
or porous terra-cotta blocks. The third and most common
method is to form an air space on the inside of the wall by
vertical furring, and the lath and plaster is then put on. All
of these methods have been used in cold storage warehouse
construction, especially the last, as has been shown by the illus-
trations given.
Basement walls are usually coated on the outside with
cement and pitch or asphalt to prevent the moisture in the
— WATEEPROOr PAINT
ON PIPE
— llNCH HAIR. FELT
-VJATERPEOOr PAPER.
— IINCH HAlIirELT
-WATERPROOr PAPER
__CANVASjCOATED WITH
WATERPROOr PAINT
FIG. 44— HAIR FELT BRINE PIPE COVERING.
soil from penetrating to the inside. If the soil is very wet and
there is danger of the water level reaching above basement
floor at some periods of the year, as is often the case in some
localities, there should be a dampproof course extended under
basement floor, through the masonry walls and up on the oui
side of them to grade. This work belongs to building con-
struction rather than to our present subject and it is therefore
unnecessary to treat of it in detail. The position of this damp
course is indicated in Fig. 34.
The common method of protecting the insulation from
the moisture in the masonry walls is to coat the walls on the
INSULATION
133
inside with various preparations, such as paraffin, pitch, as-
phalt, etc. These are usually put on hot in a liquid state. No
preparation having a strong penetrating odor, such as coal
tar, should be used, as it is liable to taint the goods in storage.
Pitch, if properly put on, makes a fair coating, but on ac-
count of its quick hardening and brittleness, it is very difficult
to apply in cold or even cool weather, and when cooling it will
contract and fine cracks will appear running in every direc-
/COATED WITH HOT PITCH^-.^
FIG. 45. — TUNNEL, INSULATED CONSTRUCTION.
tion. To avoid this, the roofing men will mix coal tar with it
to give elasticity, but it is then, of course, unfit for the inside
walls of cold storage rooms on account of the odor, as stated.
The best material for coating inside walls is pure asphalt,
and it is specified almost exclusively by the author for this
purpose. This material is odorless after it is applied, the odor
given off when subjected to heat is not penetrating and quickly
disappears. Unlike coal tar or pitch, which are products of
distillation from gas works, pure asphalt is a natural mineral
bitumen, and although it is similar in appearance to pitch,
it is not so dense or brittle and it has sufficient elasticity so
that it will not crack when cooling. Besides the commercial
134 PRACTICAL COLD STORAGE
paving asphalts which are very impure, there are also refined
asphalts on the market which are claimed to be over 90 per
cent pure. These are the product of distillation from the oil
wells of Texas and California, and because they contairi a
higher percentage of bitumen are more elastic than the paving
asphalts. Asphalt is difficult to apply to cold storage walls on
account of quick hardening, but not so much so as pitch. The
chief difficulty, especially in small cities, is to obtain a pure
asphalt and also to get workmen who have had experience in
applying it. The local roofing men have little or no need of
pure asphalt, as the common material for fiat roofs in this
country is pitch and coal tar, and consequently they do not
carry asphalt in stock. In fact, many of them are under the
impression that asphalt, pitch and coal tar are the same thing
and will sometimes attempt to use the latter materials when
asphalt is specified.
The commercial paving asphalt comes as a solid cake in
barrels weighing from 500 to 550 pounds and containing,
when melted to a liquid, about fifty gallons. The refined as-
phalts come also in 250-pound barrels, containing twenty-five
gallons. -Asphalt is melted in large kettles, such as used by
roofers, without the addition of any oils or coal tar. Care
should be taken not to boil the asphalt, as its natural oils are
thereby evaporated, and when cooled down it will become more
brittle. The hot asphalt should be applied to the surfaces with
string mops to get the best results, the process is slow and
tedious on account of the heavy consistency and its quick
cooling. The surface should afterward be examined and all
holes and crevices pointed up with asphalt. If the walls are
dry and the weather warm, a gallon of asphalt will cover
about thirty square feet of ordinary brick surface; in cold
weather a gallon will cover about twenty square feet, or 6,000
or 4,000 square feet per ton, respectively. Where the walls
are very rough or constructed of rubble masonry the asphalt
coating will not cover much more than 3,000 square feet per
ton. The surfaces that are to be coated must be free from frost
or ice, and should be thoroughly dry to obtain the best results.
While a good coating of asphalt on inside of wall will
prevent moisture from reaching the insulation, it does not
INSULATION 135
waterproof the brick wall itself. Brickwork full of moisture
IS a much poorer insulator than when dry, and as we should
get the greatest insulating value possible' out of the construc-
tion, it is evident that the outside of the walls should also be
waterproofed. There are a great many preparations on the
market that are being used for waterproofing external walls
with more or less success, but as they will all oxidize and dls^
integrate in time, the coating has to be renewed at intervals
to prevent the absorption of moisture. The coating may re-
ceive proper attention when applied for the first time, just
after the building is erected, but it is A'ery likely that neces-
sary future coatings will be neglected or forgotten; on this
account it is not safe to rely upon the outside coating only,
the inside walls should also be waterproofed as indicated above.
Boiled linseed oil is often used on external walls with very
good results. If three coats are first given, one coat applied
every three to five years thereafter will be sufficient. The oil
does not change the color of ordinary brickwork to any ex-
tent, but tends to give it a darker and richer appearance.
White or red lead, ground in boiled linseed oil, is more
durable than the oil alone, but it entirely changes the appear-
ance of the building and in most cases would not.be permissible
on that account. New work should not be painted until the
walls have been finished two or three months, and at least three
coats should be given the first time. The above two prepara-
tions are probably as good, if not better, than any of the pat-
ented preparations on the market.
Cabot's Brick Preservative, made in Boston, Mass., has
been used in general building operations as a- waterproofing
quite extensively, and, it is claimed, with good success. This,
preparation is made both colorless and with a red color so as
to be adaptable to any color of brick, and it is applied with
a brush in the same way as oil, no heat being necessary.
Mr. Stoddard, in his paper on "Insulation," previously
referred to, describes in detail tests on the waterproofing of
brick, using various preparations and materials. These tests
are about as complete as anything that has been attempted in
this line, and being pertinent to the subject, are given in full,
as follows:
136 PRACTICAL COLD STORAGE
During the summer of 1899 a large variety of paints, oils, var-
nishes, cements and so-called waterproof coatings were tested for a
cold storage company in the hope of Hnding some coating that would
make waterproof and airproof the brick walls of its warehouses. The
tests were made with quarter bricks with good, fair surfaces, free
from large holes, and, as nearly as possible, like those used in the ex-
terior walls. Quarter bricks were used instead of whole bricks, so
that sensitive balances could be used for the different weighings. All
weighings were made to within one-thousandth of a gram. The re-
sults of the more satisfactory tests are tabulated below, and besides
these, many other tests were made, but they were either unsatis-
factory or the materials tested of no value for the desired use. The
quarter bricks to be tested were immersed in water of a temperature
of about 70°, the brick being placed on its side, with one inch of
water over it. Weighings were made as follows:
Of the brick before coating.
Of the brick after coating.
Of the brick after immersion 24 hours.
Of the brick after immersion 48 hours.
Of the brick after immersion 72 hours.
Of the brick after immersion 96 hours.
Of the brick after immersion 120 hours.
At the end of each twenty-four-hour period the quarter bricks
were taken from the water, the outer surfaces carefully dried by
cloth and blotting paper, and then the bricks were immediately
weighed before any evaporation could take place from the pores
of the brick. This was repeated in most of the tests until the bricks
had been immersed for a period of 120 hours. After this continued
immersion the bricks were taken from the water and their surfaces
examined in order to see what change, if any, had taken place in
the coating. In some cases the coating had softened, in some shriv-
eled, and in one case the coating, naphtha and a paraflBne-like sub-
stance, which before immersion was evidently well into the pores
of the brick, had gradually worked out into the water.
The nature of the substances tested varied greatly. Some were In
the nature of paints and varnishes, and were retained mostly upon
the surfaces of the bricks. To this class belonged the materials
used in tests marked A, B, D, G, L, O, P and Q. Other substances
were more in the nature of a paste or coating applied upon the sur-
face of the bricks. In this class may be included the substances used
in tests marked C, I, K, N, R, S, T and U. Another class of sub-
stances was supposed to soak into the bricks, and by filling the pores
exclude moisture. To this class belonged the substances used in tests
E, F and J. Other coatings consisted of two substances, which,
when combined, were supposed to form an Insoluble compound or
compounds which would fill up the pores of the brick. The tests of
this class are marked H, M and V.
Some substances which were submitted for test could be applied
to the bricks only by soaking, and so were not available. Some
bricks offered for test were soaked full of the so-called waterproof-
ing, and of course would not absorb water or anything else while
in that condition, as the pores of the brick were already filled. Many
resins, gums and oils were tested, but were of no practical use.
Pitch, asphaltum, etc., were objectionable, because of their odor
and color. The results of the tests giving the most favorable re-
sults are as shown in following tables:
In regard to the result of the tests it is worthy of remark that
some of the substances that have been considered as among the best
waterproof materials proved to be either of little value or very in-
ferior to some of the other substances.
INSULATION
TESTS OF WATERPROOFING BRICK.
137
1
2
3
4
5
6
7
8
9
10
U
12
WEIGHT — CRAMS
INCREASE IN WEIGHT BY
ABSORPTION OF WATER
COMPARED TO
BARE BRICK
e
'■-.
a
CO
a;
a
0
si
2
3
0
X
9
0
X
00
ui
3
0
N
2
0
X
si
s
0
X
0
M
6
6
c
A
B
C
D
E
F
G
H
I
J
K
L
M
N
0
P
s
T
U
v
630.32
556.71
578.43
527.80
616.10
633.80
584.40
499.52
504.12
666.94
607.29
519.68
652,50
510.20
570.87
496.20
502.87
639.10
571.11
581.92
537.70
637.60
706.87
588.92
551 .00
523.40
670.07
610.90
527.34
692.99
529.10
.586.20
503.00
515.12
543.60
602.20
606.31
581.16
621.85
8.78
14.40
3.49
9.90
21.50
73.07
4.52
51.48
19.28
3.13
3.61
7.69
40.49
18.90
15.33
6.80
12.25
1.39
2.59
0.60
1.88
3.49
11.53
0.77
10.31
3.82
0.47
0.59
1.48
6.21
3.70
2.69
1.37
2.44
0.30
1.39
1.15
1.00
2.10
4.75
4.88
7.30
3.73
20.33
7.00
3.76
24.78
23.10
26.98
24.85
29.08
3.72
3.10
2.35
6.46
21.15
"2;i8'
"5.55
12.13
7.48
9.70
6.33
21.13
8.60
5.78
'Km
'da'.70
5.00
5.55
4.69
9.69
29.60
1.10
2.16
3.25
2.88
7.15
12.83
9.68
11.30
'ii'.hi'
9.30
'27!i6'
23.80
28.00
28.75
31.28
6.15
7.35
8.07
12,69
31.02
"2!49'
3.49
4.00
'ii'is'
13.30
12.12
23.13
'i2!68'
'28!7i'
"i'.is
9.20
10.21
15.64
1.50
2.89
5.13
5.10
9.99
14.13
14.38
15.32
15.63
'2i:S3'
21.72
28.24
23.72
28.70
28.72
32.03
1.63
3 11
1.14
2.84
5.11
13 75
3.23
13.36
6.93
3.94
4.19
5.66
10.53
8.35
7.71
7.16
8.85
0.24
0.52
0.89
0.97
1.62
2.23
2.41)
3.07
3.10
3.47
3.59
4.18
4.33
4.65
5.03
5.79
0.37
•1.32
*1.53
*1.68
*2.69
32.15
*5.17
w
X
Y
' Bare
' Brick' '
■489.64'
'2i;26'
■39:69
'39!69'
'42:43'
'ii'.m
* Compared lo coaled brick. 1 gram equals 15.43 grains; 28.35 grams equals 1 ounce avoirdupois.
KEY TO TESTS OF W.ATERPROOFING BRICK.
A.
B.-
C-
D.
E.-
F.-
G.
H,
I.-
J.-
K.
L.-
M
N.-
O.
P.
Q.
R.
S.-
T.
V.
KEY TO TESTS OP WATERPROOFING BRICK.
-Bay State air and waterproofing 3 coats.
•Red mineral paint, ground in oil 2 coats.
Spar varnisli with plaster of paris 2 coats.
-Spar varnisli | ^°^^^-
-New "Vork sample, No. 2 01 5'
•New York sample. No. 1 Soaked.
-Shellac ■*• ''oat.
.—Portland cement, i coat; soap and alum, 3 coats.. 4 coats.
-White enamel paint | coats.
-Paraffine in naphtha ° coats.
—Hot paraffine ^ ooa,ts.
—Water paint ■ • ** <=°^^®-
— Portland cement mixed with Ca CI2, 1 coat.
Water glass, 3 coats 4 coats.
—Portland cement ^ ''O^J^-
-Black varnish. No. 2 « coats.
Spar varnish I l°f-
-Black varnish, No. 1 ^ coats.
-Waterproofing, No. 1.
•Waterproofing, No. 4. Similar to "R."
-Waterproofing, No. 3. Similar to "R."
-Waterproofing, No. 2. Similar to ' R.
138 PRACTICAL COLD STORAGE
v.— Bi-chromate potash and glue— exposed to sunlight.
The Sylvester process, H, soap and alum, proved to be of little
value, even when applied to a surface made as smooth as possible
with Portland cement. This process was also tried without the ce-
ment, hut was even less effective. Hot paraffine has often been used
to waterproof walls; but, under the conditions of these tests, it proved
to be very far from waterproof. Portland cement is another sub-
stance which did not prove to be as good as its reputation.
Of all the materials tested, those used in tests A, B, C and D ren-
dered brick, to which they were applied, more nearly waterproof.
Spar varnish, used in tests C and D, was very good under test; but
it is a very expensive material, and will withstand exposure to the
weather only for a rather limited time.
The material used in B was a common mineral paint ground in oil.
It was very good under test; but the best authorities on paint pre-
dicted for it a very short life in actual use, as it would disinte-
grate after a short time by the oxidation of the oil.
The substance used in test A not only proved to be the best
waterproofing substances of any tested, but it seems to have all the
qualities necessary for the coating of the outside of brick walls. It is
moderate in price, and is easily and quickly applied, being put on with
a brush the same as a varnish or paint. When applied to a brick wall,
it forms a glossy, hard, transparent coating, and, instead of defacing
the wall, it greatly improves its appearance, making the common
brick look like enamel or glazed brick. The substance is a specially
prepared and highly oxidized oil that has been and is used in the best
varnishes. As it is thoroughly oxidized in its preparation, exposure to
air should affect it but little, and it should not need to be renewed for
many years. The brick walls of a number of large warehouses were
coated with this substance one and two years ago, and the coating is
apparently as good as when first applied. One gallon will cover from
eighty to 100 square feet of surface with three coats, the first coat
taking considerable oil, but each successive coat taking less. A brick
wall should be as dry and warm as possible when the coating is
applied. It should not be applied to a, damp wall just laid, or when the
outside temperature is below 40° P. This oxidized oil is known com-
mercially as "Bay State Air and Waterproofing."
If the coatings of this substance continue to wear as well in the
future as they have in the past two years, the substance will prove
of the greatest value for airproofing and waterproofing the brick
walls of cold storage warehouses. Any eflScient waterproofing that can
be applied to the outside surface of a cold storage warehouse is of
the greatest Importance, as there is where the entrance of moisture
would best be stopped; but this outside coating should not be de-
pended upon alone to prevent the entrance of moisture into the ware-
house, and there should always be inner layers of some air-tight mate-
rial, like an air-tight paper, wi,th the joints cemented.
If we make use of a durable insulating material of good eflSciency.
apply it carefully and of a proper thickness, and make it air tight
and moisture proof, we have done all that is practical to well insulate
a cold storage warehouse.
A better method than using preparations will, in the
opinion of the author, be used in the future for waterproofing
external walls. This is to face them with glazed brick or
salt-glazed terra-cotta blocks, laid with thin joints of rich ce-
ment mortar. The glazing is absolutely waterproof and would
INSULATION 139
last for an indefinite time, but the present cost of glazed brick
would make their use almost prohibitive, as they cost from
$80.00 to $100.00 per thousand. Glazed terra-cotta on tile
in the form of hollow building blocks can now be obtained,
and are used as a facing for outside walls in the same manner
as pressed brick. In this position these blocks, if properly laid,
will practically prevent the absorption of moisture, and
would cost about the same, laid in the wall, as selected common
brick.
COST.
There are very little reliable data available on the cost
of constructing insulation. This is owing mostly to the fact
that this kind of construction is comparatively new in the
building trades, and is usually done by the cold storage men
with day labor. As a rule no separate accounts of costs are
kept, as it is not apparent to the owners what future service
such information would yield — they do not expect to build
any more cold storage houses. There is also the variable fac-
tors of labor and material which may affect each locality dif-
ferently, often to the extent of 50 per cent difference in cost.
This is of course true of all building operations, but especial-
ly so of constructing insulation, as the work is new and un-
familiar to workmen generally. All these conditions make it
difficult to determine the cost of any particular insulation,
without knowing exactly the conditions of each individual
case.
The advantages of sufficient and properly constructed in-
sulation will usually appeal to the prospective cold storage man
until the question of cost is brought up. It is a mistaken idea
in general that when the building proper is finished, the great-
er part of the investment necessary for a complete cold stor-
age house is expended. The construction of a cold storage
house may be divided into three general operations; first, con-
struction of the building proper ; second, insulation ; third, ma-
chinery or cooling apparatus. The additional cost of the in-
sulation may generally be taken as one-half to two-thirds the
cost of the building proper.
140 PRACTICAL COLD STORAGE
Generally speaking, the cost of insulation, erected in
place, for temperatures of 30° F. down to 0° F., will be from
about 25 cents up to 50 cents per square foot, in proportion to
the above temperatures. The Nonpareil Cork Manufacturing
Company gives the cost of the construction, shown as style No.
20 in Fig. 21, as about 22 cents per square foot ; that shown as
style No. 13 in Fig. 21 as about 38 cents per square foot, and
that shown as style No. 16 in Fig. 21, as about 48 cents per
square foot. A construction shown in Fig. 24, with air space
next to the brick wall, four %-inch boards and twelve inches
of shavings, will cost from 20 to 25 cents per square foot. A
construction shown in Fig. 30, with eight inches of shavings
and two inches of hair felt, sheet cork or mineral wool blocks,
may be constructed for 25 to 30 cents per square foot. This
construction is suitable for temperatures of from 30° to 35°
F. This construction shown in the lower part of Fig. 30,
which is suitable for a temperature of 20° to 25° F., may be
constructed for 28 to 32 cents per square foot. A construction
of the same character suitable for temperatures of from 5° to
10° I\ may be built for about 40 cents per square foot. Re-
ferring to the five constructions shown in Fig 28, giving the
same insulating value for various thicknesses of different ma-
terials, and comparing the hair felt with the air space and
wood board construction, there is a total thickness of eight
inches with the hair felt partition, and a total thickness of
thirteen inches with the board and air spaces; giving a dif-
ference of five inches in thickness with the same insulating
value. The hair felt construction would cost from 35 to 40
cents per square foot, and the board and air space construction
would cost 30 to 35 cents.
The waterproofing of the brick walls has been included
in the estimates given above. The cost of waterproofing with
hot asphalt, when that product can be obtained at $40.00 per
ton, will be about 2% cents per square foot. Waterproof and
odorless papers cost from $2.50 to $5.00 per roll (1,000 square
feet), depending on the thickness and quality.
The insulating material in the form of blocks or sheets,
such as mineral wool block, sheet cork and hair felt, varies
in cost from four to six cents per square foot per one inch
INSULATION 141
thick. This does not inchide freight, which would increase
the cost, depending on the locality. Mineral wool is sold by
the pound or ton and can be obtained at from $25.00 to $30.00
per ton.
The cost of planer mill shavings is variable, depending
upon the proximity to the mills, season of the year, etc. In
some cases known to the author they have been obtained for
the mere trouble of hauling them away, but in most cases
they are sold, either by the load or by th^p bale. The cost per
bale of 80 or 100 pounds varies from 15 to 25 cents.
SUPBKINTENDENCE.
On account of the special character of cold storage insula-
tion, the work should be carefully and frequently inspected
to see that the materials are of the quality specified and that
the work is executed according to details. The construction of
insulation requires more care in the way of tight joints and
first-class workmanship throughout, than is usually obtained in
ordinary buildings. The labor required is mostly such as be-
longs to carpenters, and as they are accustomed to do work
along certain lines common in ordinary building operations,
it is sometimes difficult to train them into the high class
work necessary for cold storage insulation. It must be con-
stantly kept in mind that the insulation must be air and water
proof. The materials and the combination in which they are
used, no matter how excellent they may be, are much decreased
in insulating value if these points are neglected. The ma-
terials, as they arrive at the work, should be inspected to de-
termine if they are dry, and they should be kept under cover
until used, to prevent them from becoming wet or damp. Plan-
ing mill shavings are sometimes damp when they arrive at
the work and the bales should be loosened up and spread out
in the building to allow them to air dry. The materials should
be delivered sufficiently in advance to admit of proper inspec-
tion and of being replaced with new material, if found un-
satisfactory.
The superintendent should see that all filling materials,
such as granulated cork, mineral wool, shavings, etc., are prop-
142 PRACTICAL COLD STORAGE
erly packed into the spaces to about the proper density. (See
Materials.) The prevention of the future settling of the filler
is mainly a question of personal care in seeing that it is prop-
erly packed, and all corners and tops of filled spaces, which
are difficult to pack, will need particular attention. The water-
proof papers, as already stated, are used to prevent the pas-
sage of air and moisture and their application, therefore, is of
prime importance. All joints should be lapped two or more
inches, and each course of papers should be lapped around cor-
ners and angles of rooms. In case the paper should be torn
by the workmen, it should be replaced or another sheet should
be placed over it. All sheathing and matched boards should
be free from large or loose knots, should be fitted up close in all
corners and angles, and nailed at bearings only. No nails
should be driven through boards and paper, and project into
the filled spaces or into the sheet material. As a proper fin-
ish for the inside corners and angles of rooms and around door
jambs, the author recommends and uses %-inch or %-inch
quarter-round mouldings as giving air-tight, neat-appearing
and serviceable finish.
CHAPTER VI.
DOORS AND WINDOWS.
It was for many years the custom to build the doors re-
quired for cold storage rooms directly "on the job" where
used, applying such hardware as was available. Some of the
doors resulting from this practice were very poor and seldom
if ever could a passable job be obtained. At present no one
thinks of building cold storage doors on the job as these may
be obtained from manufacturers who make a specialty of this
class of work. The home-made door if it fits when new will
seldom remain tight for any length of time. Ordinarily they
are made with a long bevel fitted to a corresponding bevel of
the frame, and the least swelling or settling will result in
difficult operation and air leakage. Sometimes packing of
canvas or other material is applied to the bevel, but it is al-
most impossible to make a tight fit in this manner. Nearly
all doors made on the job sooner or later stick in the frame and
refuse to open without many persuasive kicks and surges — we
all know how it is.
The special cold storage and freezer doors made by firms
who make a specialty of this line shut tightly with small pres-
sure, forming a practically perfect air seal, and open readily
when the handle is grasped. The time saved in opening and
shutting these doors will soon pay for the additional cost over
the home-made article. The prices for these doors are reason-
able considering the excellent workmanship, insulation and
material used. Any insulation may be had by specifying it
when ordering. The author recommends these special cold
storage doors to those who desire first class work. If it is nec-
essary, owing to remoteness from transportation, or other rea-
son, to build the doors "on the job" the chief aim should be
143
144 PRACTICAL COLD STORAGE
to build them tight at one or two points all around, and not on
a long bevel. Sometimes a gasket or packing may be used be-
tween door and frame to make a better seal.
rt is very generally known by those who are familiar
with cold storage work that windows are a bad proposition
from an insulation, mechanical or a practical standpoint. The
increased fire exposure is of some consequence, too, and with
the low cost of electric light, windows should not be thought
of for cold storage work. Barring the small amount of heat
given off, the incandescent electric lamp is an ideal device
for lighting cold storage rooms, as the air is not vitiated as
when using gas, kerosene or candles. Nevertheless, there are
many situations where windows are very desirable in connec-
tion with refrigerating work. Artificial light is often difficult
to locate properly and in connection with ice storage rooms,
where more or less moisture is nearly always present and arti-
ficial light therefore troublesome, natural light through win-
dows is greatly to be preferred.
In considering methods of construction for windows in
connection with cold storage work, the setting of the sash in
the frames is one of the most important and at the same time
difficult parts of the problem, and we might as well forget all
about trying to make windows removable in any way if used
in connection with cold storage work. It is practically out of
the question for the reason that they must be fitted tightly and
set so as to be air-tight. The frames in which the sash set
must be of heavier and more substantial material than ordi-
nary. Where ordinarily a 2-inch frame is used, 3-inch is bet-
ter for cold storage work, and it should be preferably of hard
wood, or nothing less substantial than hard pine. Frames
must be planed on both sides so as to make it possible to
make an air-tight joint by fitting insulating paper tightly. The
frame must positively be set in the wall before the insulation
is put in place, and it must be wide enough to allow the insu-
lating material, whatever it may be, to be fitted tightly around
it when the insulation is being placed. If wide planks are
not available, the frames should be made of plank grooved to
receive a spline or tongue, making a comparatively tight joint
DOORS AND WINDOWS. 145
and substantial work. Wherever joints are made in the frames
they should be thoroughly coated with thick lead and oil.
The sash to be used should be what is known as double-
glazed. Sash of ordinary thickness may be used but they are
made so as to receive glass on both sides, leaving an air space
of about one-half to three-quarters of an inch between the two
glass. The glass should, of course, he set in lead and oil and
carefully puttied in so as to form ai^ air-tight joint. In fit-
ting the sash into frames care should be taken that they fit
reasonably tight and they should be set in fresh lead and oil
paint, and stops driven up tightly so as to form an air-tight
job.
FIG. 1 — AN APPROVED METHOD OP CONSTRUCTION AND
SETTING OP COLD STORAGE WIND'OW.
If careful and experienced workmen are employed in the
construction and setting of the frames and in the setting of
the sash in the frames as above directed, and if the insulation
is carefully fitted around the frame, a job which is not quite
nearly impervious to air, but which is absolutely air tight may
be obtained, and one of the most important objections to win-
dows as used in cold storage rooms is thereby eliminated. An-
other most important objection is the loss of refrigeration on
account of heat transmission through the glass, and through
the air spaces formed thereby. This objection can be partial-
ly eliminated by using a suffici'ent number of sash. No less
than four double-glazed sash should be used for temperatures
146 PRACTICAL COLD STORAGE
of about 30° F., and five or six in the better class of worlc or
for lower temperatures. Use as large panes of glass as is
practicable, to avoid the shadow and obstruction of light
caused by a multiplicity of muntins. It is not practicable to
put in sufficient sash to make the insulation equal to that of
the balance of a well insulated wall, but if the above directions
are carefully followed and a sufficient number of sash used,
the loss of refrigeration through the comparatively small area
of the windows ordinarily used may be reduced to a small
amount. The isometric drawing herewith shows a detail of
construction and relation of parts to each other.
What is said above in reference to the setting of windows
in cold storage rooms applies, of course, equally well to the
setting of windows in cold storage doors, which is often a very
desirable thing to do. If the door opens, however, from a re-
frigerated corridor or air-lock into the cold storage room
proper, a large number of sash or thicknesses of glass are not
necessary, and two sash or four glass will usually be ample.
If windows are wanted which may be opened they should
be ordered from the makers of cold storage doors described
above. A window for cold storage purposes, which will open,
is practically a door with glass in it and is made in essentially
the same way.
CHAPTER VII.
AIR CIRCULATION.
IMPORTANCE 03? PROPER AIR CIRCULATION.
A circulation of air is necessary to produce the best pos-
sible conditions in a cold storage room, and this necessity is
now realized by the most progressive people engaged in the
business. Considerable controversy has taken place between
those who advocate the cooling of rooms by piping placed di-
rectly in the room, and those who have adopted some form of
fan or forced circulation in which the pipes are placed in a
coil room or entirely outside the storage room, and the air dis-
tributed through the room by means of air ducts. The peo-
ple who have been the longest in the business do not like to
believe that any improvement can be made on placing the
pipes in the room, and insist that they can turn out as good
stock as their more progressive competitors who use some form
of forced circulation. To substantiate this argument, they re-
fer to So-and-so who tried fans and had to put pipes in
the rooms to hold his temperature, and claim that the results
from the forced circulation system are no better than from the
old methods of gravity air circulation. This argument is not
sound, and it is proposed in this chapter to show clearly why
a circulation of air is necessary, and also why a positive circu-
lation, by means of fans, with a proper system of air distri-
bution, is better than direct piped rooms, or any circulating
system which depends on a difference of temperature in the
air in different parts of the room for its operation.
Notwithstanding the attention which this subject has at-
tracted, and the resulting discussion, there is yet much which
is but imperfectly understood, such as the confusing of the
terms, "air circulation" and "ventilation." The two are as
147
148 PRACTICAL COLD STORAGE
distinct as can be, and it should be borne in mind to begin
with that ventilation is what the name implies — the intro-
ducing of fresh air from an outside source for the purpose
of purifying the room. Circulation refers only to the move-
ment of air within the room, and in no case should the term,
"ventilation," be applied to this subject in connection with re-
frigeration. Ventilation is mentioned only in explaining the
difference between the two, and is not under consideration here,
but is taken up in a separate chapter. Our present subject for
discussion is air circulation in refrigerated rooms — the same
air over and over — and has no connection with the supply-
ing of outside air. To the end that the misunderstood features
of the subject may be cleared up somewhat, the history and un-
derlying principles of refrigeration and air cooling will be tak-
en up, to show as clearly as possible the gradual development
of the industry leading to the systems and methods of cooling
now in use. The advantages of a forced circulation of air in
cold storage rooms will be so plainly demonstrated that any
thinking man must acknowledge them.
HISTORICAL.
The most primitive form of cold storage consists in em-
ploying the comparatively low temperature to be obtained in
cellars or caves for the keeping of products subject to rapid de-
composition. In this way they are protected from the extreme
heat of summer, and to this extent preserved by a natural
source of refrigeration. In this crude form of cold storage, air
circulation was unknown, and if any existed it was by accident.
Articles placed in a cellar or cave are cooled by radiation or
conduction from the earth altogether, and not by a circula-
tion of air. After caves and cellars, natural ice was employed
for cooling purposes, and came quickly into general use, for
the reason that lower temperatures and a dryer air were to be
obtained. For cooling purposes, ice was first stored in under-
ground pits dug in the earth, with the idea that the melting
of the ice M'ould be retarded. Goods for preservation were
placed on or within the mass of ice. This was an improve-
ment over the use of cellars in the matter of temperature only.
Even after the ice house was placed above ground and provided
AIR CIRCULATION
149
with insulated walls, the favorite method was to build a room
within the ice house, and surrounded on three sides by the ice,
for the storage of goods to be preserved. Circulation of conse-
quence did not exist, and goods placed therein quickly deter-
iorated, caused by a growth of mold and a musty condition
of the air, induced by a very moist atmosphere.
A bit of personal experience will serve to illustrate some
of the early phases of ice cold storage. About the year 1875
ICE. tlOUSE.
FIG. 1.— DIAGRAM IMPROPERLY CONSTRUCTED ICE COLD STORE.
the author's father constructed a large ice house adjoining a
cheese factory and creamery. In one corner of the ice house,
and opening into the creamery, was built a fair sized room for
the storage of butter. The ice was placed on top of this room
and also against two of its sides. Openings were provided at the
top for the cold air from the ice house to come into the room,
ISO
PRACTICAL COLD STORAGE
but no circulation of consequence took place, because the laws
governing air circulation were not given proper attention. A
large part of the cooling in the room was by direct conduction
through its walls. The room carried fairly cold, at about 37°
F. A large block of fine creamery butter was stored in the
room for about three months. When removed, the tubs were
very moldy, and the butter as well ; the butter, even during the
short time stored, being decidedly injured in flavor. This
room was very damp, the ceiling and walls showing very wet,
and moldy to some extent. In the light of present experi-
ence, this method of storing butter seems absurd, and it is men-
tioned simply to illustrate how a lack of circulation and some
V/////////////////////////////////////^^^^^
FIG. 2.— PULL ICE RACK WITH GOOD AIR CIRCULATION.
means of absorbing the moisture will cause bad symptoms
in a cold storage room in a comparatively short time. Fig. 1
illustrates the construction of this room, in the corner of the
ice house. It will be noted that no flues were provided to con-
duct the warm air to the top of the ice house, and the cold air
toward the bottom of the storage room. Openings from the
ice chamber only were provided, and this will not promote a
circulation of air except under accidental conditions.
iShortly after the above related experience, a large room in
the basement of the stone store building was fitted up for the
storage of cheese. This was built on the side icing plan, the
ice being placed in a rack or crib along one side of the room.
AIR CIRCULATION
151
which was about twenty-five feet wide. The room was insu-
lated by studding and sheathing against the walls, and filling
behind with sawdust. It was surprising to see the ice disap-
pear, and the temperature could not be held below an average
of 45° F. This room was superior in one respect, however,
to the butter storage room just described. It had a fairly
strong circulation of air as long as the ice rack was kept full,
and cheese came out in fair condition, though moldy, after
a three or four months' carry. A serious drawback to the suc-
cessful working of the room was that when the ice was partly
melted in the ice rack, the top of the room would become much
warmer than near the floor. This was especially noticeable
COLO ^Tf^fTTfT OrWR.
in cif^cuLRTion f
r///////////////M/////y////////////^^^^^
PIG. 3._SHOWING SLUGGISH AIR CIRCULATION.
during warm weather. When the ice rack was full this con-
dition was greatly improved, but when the ice was much re-
duced, the air at the top of the room became warm and- dead.
Fig. 2 illustrates a full ice rack and a comparatively perfect
circulation of air to the top of the room. Fig. 3 shows a slug-
gish circulation, with a dead stratum of warm air at the top of
the room, resulting from the small quantity, and location of
ice in the rack.
As a natural improvement on the side icing plan men-
tioned above a structure two stories high was constructed, with
ice at the top and storage space below. The ordinary domestic
refrigerators are mostly built on about this plan, and this,
idea has been developed to the fullest possible extent. Many'
152
PRACTICAL COLD STORAGE
patents have been granted to inventors for improvements in
details of construction and the promoting and control of cir-
culation in cold storage rooms with overhead ice. Fig. 4 shows
why overhead ice produces a good circulation, if properly de-
signed, with up and down flues. Prominent among the old
PIG. 4.— OVERHEAD ICE WITH GOOD AIR CIRCULATION.
overhead ice systems are the Jackson, Stevens, McCray, Dex-
ter, Nyce and Fisher. These systems, as compared with any
method of end or side icing, are markedly superior, and many
of these old houses are still in service. Any system using na-
tural ice only as a cooling agent is now considered obsolete,
AIR CIRCULATION 153
when compared with the present day methods of air cooling
by means of chilled pipe surfaces in the form of brine or am-
monia piping, but in the early days of cold storage these old
systems were very satisfactory. Circulation of air may be
mentioned as the keynote of whatever success was attained
by the overhead ice systems. So much for the value of a cir-
culation of air in any room cooled by ice. It has been proved
in practice that a circulation of air is necessary in such a room.
It is equally true of a room cooled by metal surfaces through
which a refrigerant at a low temperature circulates.
CIRCULATION PURIFIES THE AIR.
A penetrating and fairly strong circulation of air is ab-
solutely necessary in cold storage rooms because it is a part
of the process which purifies the air. Nearly all goods which
are ordinarily placed in cold storage for the purpose of retard-
ing decomposition give off moisture. Along with the moisture
given off are impurities in the form of finely divided decom-
posed matter from the surface of the goods. Gases resulting
from surface decomposition, and the ripening of the goods in
some cases, are also present. Besides the moisture given off by
the goods, other moisture is continually finding its way into cold
storage rooms by the opening of the doors, leakage through the
insulation, and from the lungs of persons present in the rooms,
all of which contains a greater or less percentage of impurities.
These last sources are small in comparison with the amount of
moisture and impurities given off by the stored goods, but,
nevertheless, are quite large in some cases, and worth consid-
ering. To prove beyond a question that goods give off large
quantities of moisture and impurities, it may be well to consid-
er what would be the result should the moisture and impur-
ities be allowed to accumulate in the storage room. Let us as-
sume an absolutely tight room, cooled from an outside source
without exposed pipe surfaces or other means of taking up the
moisture and impurities which are contained in the air of the
room, say a room within another room, the outside room be-
ing cooled, and taking up all heat from the inside room. An
experiment conducted by the author, described in chapter on
154 PRACTICAL COLD STORAGE
"Eggs in Cold Storage," under the heading of "Packages," il-
lustrates fully the necessity of taking up moisture as given
off by the stored goods. These experiments demonstrate con-
clusively what would result if goods were placed in a refriger-
ated room which did not contain means for absorbing the
moisture and impurities that are given off by the stored goods.
It is imperative that the moisture be continually removed from
a cold storage room containing moisture-giving goods.
The relation between moisture and impurities in cold
storage rooms is very close, as these elements are united to a
large extent. It is a well known fact that water has a great
affinity for impurities of various kinds. The same is true
of water in the form of vapor or moisture in the air of cold
storage rooms, which has a great attraction for the gases and
impurities which are given off by the stored goods. In fact,
it is probable that the greater part of the impurities never part
company with the moisture when they are both exhaled by the
goods. It is, then, easy to understand that a room which has
means of absorbing moisture also has means of purifying the
air, and that the air is purified to a large extent in proportion
to the thoroughness with which it is circulated and brought
in contact with the means for absorbing moisture. It must
not, however, be understood that the air of a cold storage room
is absolutely purified by having the moisture removed. There
are gases which have little or no affinity for moisture which
cannot be disposed of in this way. Fresh air must be supplied
to maintain perfect conditions in cold storage rooms where
goods are stored for long periods. (See chapter on "Ventila-
tion.") If a cold storage were perfectly purified by the remov-
al of moisture there would be no odors of consequence present
in such a room. How many cold storage rooms has the reader
ever seen that were free from noticeable odors?
Probably the worst form of impurity which is met with
in cold storage rooms is the germs which produce a growth of
fungus, or mold. These germs are no doubt present in the
atmospheric air everywhere. Their presence is manifested only
under certain favorable conditions of moisture and tempera-
ture. Conditions of excessive moisture in the presence of de-
AIR CIRCULATION ISS
caying animal or vegetable matter, together with a moderate
degree of heat, are favorable for a very rapid growth of fun-
gus. It is a well known fact that in the dry mountain dis-
tricts of California or Colorado freshly killed meat may be
hung in the open air without decomposition. The air con-
tains so little moisture that the germs will not propagate. Fresh
meat exposed in the same way in the moist, tropical climate
of Florida or Cuba would be quickly decomposed so as to be
unfit for food. Germs of mold and decay flourish in a warm,
moist atmosphere, but quickly succumb where it is dry and
cool. As the moisture is absorbed and removed from the
air of a cold storage room, with it are largely removed the
germs and other impurities. Low temperature pipe surfaces
freeze the moisture from the air, and in this way a large por-
tion of the impurities is disposed of. It may already have oc-
curred to the reader to ask what all this has to do with air
circulation in cold storage rooms. We have discovered that
a room may be cooled from an outside source and still be an
unfit place for goods when no means of taking up the moisture
are present. Even should the pipes be placed directly in the
room, the results would be bad unless there is a circulation
of air. A circulation of air is absolutely essential to a perfect
cold storage room, because the air must be continually moving
in contact with the pipe surfaces or other means of absorb-
ing moisture. The question of what means are the best for
removing the moisture from a storage room is not under dis-
cussion. Our problem is to ascertain the best means for cir-
culating the air in contact with the means for absorbing the
moisture.
METHODS or PIPING THAT HINDER CIRCULATION.
When mechanical refrigeration first came into the field,
the arrangement of cooling surfaces and a provision for air
circulation was neglected about as it was by the pioneers in
natural ice refrigeration. The cooling pipes were placed almost
anywhere, regardless of the laws of gravity which control air
circulation. At first the ceiling of the room was a favorite
place for locating the coils of pipe for cooling the room. The
156
PRACTICAL COLD STORAGE
ceiling was utilized because thus the pipes were out of the
way in piling up goods, and also on the theory that "cold
would naturally drop." Cold, or, more accurately speaking, cold
air, will naturally drop, but placing the pipes on the ceiling of
a room will not assist the circulation ; it will, in fact, produce
practically no circulation at all if the whole ceiling of the
room is covered with pipes uniformly. Ceiling pipes have
generally been abandoned for the more rational method of
placing the pipes on the side walls of the room. Fig. 5 shows
ceiling piping, and should make plain why no circulation is
created when the pipes cover nearly the whole top of the room.
v////////////m///////////m
f
■/////////////////////////////////////,
;l
!
i
^ r
^(W^
.,v.-c,t5tt^
Xr
J
0TOF(n(\E: F(00^{
\
V.
W//////////////////////////////y
W/
PIG. 5.— SHOWING CEILING PIPE WITH IMPERFECT AIR
CIRCULATION.
The left half of the diagram shows the pipes covering the entire
ceiling, the right half in two sections. Note the arrows show-
ing the resulting circulation in each case. As is well known,
cold air is heavier than warm air and, if free to move, the
cold air will seek a lower level than the warm air. This move-
ment of the cold air downward and the warm air upward is
what is known as gravity air circulation. A slight difference
in the temperature will cause a circulation of air if the warm
and cold air are separated from each other and not allowed
to mix, which would cause counter-currents and retard the
AIR CIRCULATION 157
circulation. In a cold storage room, the air in contact with
the cooling coils, as it is cooled, flows downward toward the
floor by reason of its greater specific gravity. The compara-
tively warm air above is drawn down to the pipes, where it is
in turn cooled, and the flow is continuous. If the entire ceiling
is covered with pipes, what results? The air in contact with
I
i I 1 I, / I'-
FIG. 6. — SHOWING SIDE WALL PIPING.
FIG. 7.— AIR CIRCULATION WITH DIRECT PIPING.
the pipes cannot fall because it cannot be replaced by warm
air from above. The result is that practically no circulation
of air takes place in such a room. A slight local circulation
in the vicinity of the pipes is all that results, except under un-
usual or accidental conditions. The goods are cooled for the
most part by direct conduction and radiation; the top tier of
goods would be cooled directly from the pipes and each tier
158 PRACTICAL COLD STORAGE
under successively from its neighbor above in the same manner.
Goods are cooled by radiation by the passage of heat from the
goods directly to some colder object Avithout the heat being
conveyed by the movement of the air, as it should be, and as
it is where a good circulation is present in the room. In a
room in which the goods are cooled by radiation mostly, the
moisture instead of being deposited entirely on the cooling
pipes, as it should be, is also likely to be deposited on the walls
or ceiling of the room, or on the goods themselves. The result of
such a condition may be serious. This cooling by radiation,
as compared with cooling by a circulation of air, may seem
like a very finely spun theory to some, but let the skeptic
watch his house for a demonstration. Is there any practical
cold storage man now in the business who has not noticed an
accumulation of frost or moisture on goods if they were piled
too near to the exposed cooling pipes? What causes this re-
sult? Radiation — nothing else.
METHODS OV ASSISTING GRAVITY CIRCULATION.
The bad effects of radiation cannot be altogether overcome
by placing the pipes on the sides of the room, but it is counter-
acted to some extent by the resulting circulation of air. Fig.
6 shows side wall piping and the resulting circulation, which
is confined largely to a small space near the coils. The arrows
show approximately the path of circulation. If the room is
wide, no circulation at all will take place near the center. In
some cases pipes have been carelessly placed two or three feet
down from the ceiling, as shown in the illustration. This
results in the air of the room becoming stratified — a warm
layer of air in the top of the room resting on a cold layer
beneath. Figs. 2 and 3 illustrate this clearly. This may be
operative to such an extent as to cause a difference in tempera-
ture between floor and ceiling as great as 10° F. A case
has come to the author's notice with exactly these conditions.
Another bad arrangement of side wall piping was that of a
room more than fifty feet square piped completely around on
the side walls from floor to ceiling, with the exception of the
doors. No circulation could penetrate to the center of such
a room, and conditions were very poor, in consequence.
AIR CIRCULATION 159
The placing of a screen in front of the side wall piping,
hung well up toward the ceiling of the room, as illustrated in
Fig. 7, marks the first scientific step toward a betterment of
air circulation in a room with direct piping. It prevents the
action of radiation, and assists the volume, velocity and area
of circulation, but does not well take care of the center of the
room, although the increased velocity forces the air to cover
a greater area and flow to a greater distance from the coils.
The screen or apron should be of wood or any moderately good
non-conductor. By separating the warm from the cold cur-
rents of air, the velocity is increased on the same principle
that a fire burning in a flue creates a greater draft than when
burning in the open air. Radiation is prevented in the same
PIG. 8.— SAME AS PIG. 7 WITH FALSE CEILING.
way that a fire screen protects one from a too hot fire in a
grate, only the radiation, as already explained, is in a reverse
direction.
In Fig. 8 the same arrangement of apron is shown as in
Fig. 7, but added thereto is the false ceiling extending oul
toward the center of the room. This addition to the per-
pendicular apron causes the air, after circulating over the coils,
to spread out more toward the center of the room and cover the
cross-sectional area much more uniformly. While it decreases
the velocity proportionately, it is considered a superior arrange-
ment to the perpendicular apron alone, placed in front of the
coil. The false ceiling should have a slant of about one foot
160
PRACTICAL COLD STORAGE
in twenty, and the opening on the outer edge near center of
room need not be over four or five inches in depth in most
cases. Without the false ceiling some space must be left for
a circulation of air at the top of the room; with it, the goods
may be piled close up to the false ceiling, so no space of con-
sequence is wasted in using it.
The arrangement shown in Fig. 9 was first originated by
Mr. C. M. Gay, and was described in the August, 1897, issue of
Ice and B.efrigeration. Barring the space occupied, it is by
far the best arrangement of room piping now in use. The fol-
lowing is quoted from Mr. Gay's description : "Upper pipes of
box coils should be about ten inches below ceiling of the room,
to prevent sweating. (Sweating in such a case is caused by
m//////////////yy//////^^^^
V
/
^
%y///////////////////////////////////////////////y///^^^^
PIG. 9. — MR. GAY'S ARRANGEMENT OF ROOM PIPING.
radiation, as already explained.) When brine or ammonia
is turned into these pipes the cold air around the pipes seeks
an outlet downward, and passes between the false partition
and the side wall of the room, thus displacing or pushing along
the air in center of room, the cold air naturally seeking the
lowest point and the warm air the highest point, each by
reason of its relative gravity. Thus, as the cold air falls from
the cooling surfaces it is replaced by the warm air from highest
point in center of room. This secures a natural circulation
and a dry room, there being no counter-currents nor tendency
to precipitate moisture on walls or ceiling." Mr. Gay's re-
marks regarding his system apply with still greater force to
AIR CIRCULATION 161
the St. Clair system, and to a greater or lesser extent to any
system which provides for a removal of the cooling pipes from
the room.
The St. Clair system, illustrated in Fig. 10, is sometimes
called the pipe loft system, because the cooling coils are placed
above the storage room in a pipe loft or coil room. This is a
favorite arrangement where an overhead ice cold storage house
IS remodeled and equipped with the mechanical system. In
this case the pipes are placed in a portion of the old ice room,
and perhaps the old air ducts used for air circulation. If the
'^///////////////////////////////////////////////////////^^^^^
FIG. 10. — THE ST. CLAIR PIPE LOFT SYSTEM.
storage house consists of several floors of storage the pipe loft
may be placed at the top and the rooms below all cooled from
one pipe loft, but a much better method is to have an inde-
pendent coil room for each room, and circulate the air through
separate air ducts. This prevents contamination from foreign
odors when different products are stored in different rooms.
The circulation is more vigorous and effective with the St.
Clair system than with any pipe-in-the-room system, depend-
ing on the law that the higher the column of air the stronger
the draft, in the same manner that a tall chimney gives a
162 PRACTICAL COLD STORAGE
stronger draft than a short one. The effect of this is to produce
a good circulation of air with a comparatively small variation
of temperature. The St. Clair system is also better because by
suitable trap doors on the air ducts, the pipes may be shut off
from the room, when the temperature is such outside as not
to require the circulating of the refrigerant. The necessity of
keeping the air of a storage room from contact with the frosted
pipes when the refrigerant is shut off will be considered in
connection with the forced or fan circulation system, to be
described further on.
ARGUMENTS FOR IMPROVED SYSTEMS OF AIR CIRCULATION.
We have seen how rooms for the storage of perishable
products are cooled by natural or gravity circulation or by
direct radiation. Reasons have been given why each succeed-
ing method was superior to the former one. It is very easy
to see that where a room is cooled by direct piping, or by any
system of gravity air circulation, the goods within such a
room cannot all be exposed to the same conditions. Goods
piled at the floor and near coils where the air circulates direct
from coils are certainly exposed to a much colder air and
stronger circulation than those farthest from coils and near
the ceiling of room. Gravity air circulation, as its name in-
dicates, depends on a difference in weight, and therefore a
difference in temperature of the air in different parts of the
room, for its existence, and there must, therefore, be varying
temperatures in different parts of the rooms. The difference in
temperature will range generally from 2° to 5° F., with the
best arrangements here described. The greater the difference
the stronger the circulation, usually. With a difference in the
temperature of the air in different parts of the room goes a
variation of other conditions; especially as to dryness and
purity of the air.
Many cold storage warehouses, equipped in many differ-
ent ways, even some of them cooled by natural ice, are pro-
ducing results satisfactory to their owners; to use a familiar
phrase, "are having good results." This is not at all surpris-
ing, when it is considered that a result which is satisfactory to
AIR CIRCULATION 163
one man would not be satisfactory to another; but it is very
confusing to an interested person who undertakes to investigate
the various cold storage houses of his acquaintance, with a
view to ascertaining which system is best suited to his needs.
The variety of opinion expressed depends largely on the
individual prejudice of the person giving the opinion. The
investigator, if not fairly well posted on the subject himself,
usually is so confused that he takes the advice of his most in-
timate acquaintance, and adopts some old time system which
has been found reliable. This means, in a majority of cases,
that he is adopting some out-of-date ideas for a new house,
which should embody all the latest improvements. Should the
investigator be a fair minded man and well informed on the
subject, new improvements, with logic and practical results
behind them, are adopted, after due consideration. Eesults
are, of course, the final test, but it is very necessary that a per-
son should have actual and not fancied results, and unless
new ideas for improvement are investigated and adopted, cold
storage men will get "behind the procession," the same as in
other mechanical and scientific lines. When a new system
or device can show results equal to or better than the older
ones, costs no more to install and operate, and, further, is
based on scientific principles and common sense, that system
is the one to adopt. It will surely demonstrate its superiority
in the long run. There are many in the business who still
think that direct expansion piping placed directly in the
room is the acme of perfection and cannot be improved upon.
Argument for improved systems in such a case is useless.
A comparison of the methods of heating our best public
buildings in former years, with those in use at the present
time will show us the past and present, or rather the past and
future of cooling the best cold storage houses. In years gone
by, the best and most costly structures were heated directly
by stoves, later by hot-air furnaces, and lastly by the indirect
or fan system. A stove for heating a room may be compared
with direct piping for the cooling of a storage room. We all
know the disadvantages of a stove for house heating— too
much direct radiation, and a poor distribution of heat. The
164 PRACTICAL COLD STORAGE
same may be said of a room cooled by direct piping, only it is
the refrigeration that is poorly distributed. Cooling a room by
the pipe loft system is about the same as heating a room with
a furnace, with the disadvantages common to both. The
advantages of handling the air of a cold storage room by means
of a fan are likewise comparable with the advantages to be
had from a well designed forced system of heating. The best
heating work is now done by means of fans, and the best cold
storage work of the future will be done by means of fans. To
prove the advantages of the fan system of heating, it is not
necessary that people should suffocate and die in a building
heated by stoves or furnaces; neither is the fact that goods do
not completely spoil or decay rapidly in a room cooled by di-
rect piping any evidence that the fan or forced circulation
system is not superior by far to the pipe-in-the-room or any
gravity method. Unquestionably the fan system of heating
gives a control of temperature, humidity and purity of air,
not obtained in any other way. The forced circulation system
of cooling also gives a control of temperature, humidity and
purity of air in a cold storage room, not to be had otherwise.
PROS AND CONS OF rORCEP) CIRCULATION.
The chief, and in fact the only objection known to have
been urged against forced circulation for cold storage rooms
is a fancied notion that it will lead to a greater drying out
or shrinkage in weight of goods which are placed in storage
for preservation than if a system of gravity air circulation or
pipes in the rooms were used. The author has searched long
and faithfully for the origin of this old tradition, but has never
been able to discover that it was founded on fact. At least
none of the most modern houses employing the fan system,
so far as known, have ever had complaints from excessive
evaporation. The worst shrunken goods which ever came to
the author's notice were some eggs from a house cooled by
direct expansion piping placed directly in the room. It is
probable that the claim that goods evaporate or lose weight
more in a room cooled by the fan system is wholly a matter of
theory, based, no doubt, on the assumption that the air is cir-
AIR CIRCULATION 165
culated at a much higher velocitj'-. It is well known that a
movement of the air aids evaporation. Every intelligent house-
wife knows that linen hung in the open air to dry will be
freed of moisture quicker when a moderately strong breeze
is blowing than when the air is still. The same principle ap-
plies to the goods stored in a refrigerated room, but evapora-
tion from the goods in storage is dependent not only on the
movement of air in the room, but on the humidity or dryness
as well. If the humidity is properly regulated no harm will
result from a very thorough circulation of air, even at a brisk
speed. It may have happened in the early days of fan cir-
culation, that the air was rapidly circulated with little or
no distribution, and the goods exposed directly to the blast of
air where it was blown into the room were excessively evap-
orated; but in the numerous houses designed by the author,
and using one or the other of the two systems of air cir-
culation described further on, no such trouble has been experi-
enced. If the humidity of the air is at the correct point, and
the circulation of air well distributed throughout the room,
and not too strong, no excessive or damaging evaporation will
occur, and where trouble from this cause has been experienced
it will be found in every case that no systematic control of
humidity has been attempted. It is as easy to control humid-
ity as it is to control temperature, if proper means are pro-
vided, and we go about it in the right way. Absorbents and
ventilation are both useful for this purpose, but this feature
of cold storage is not under consideration here, and is treated
on elsewhere under the proper heading.
With a positive and well distributed circulation of air,
a storage room may be maintained at a humidity which would
be dangerous if only a sluggish gravity circulation of air
were in operation. A brisk movement of air in all parts of
the room quickly removes the moisture and impurities from
the vicinity of the goods, and carries them to the cooling coils,
where they are, for the most part, condensed or frozen on the
pipe surfaces. This should explain how goods may be carried
in good condition and with very little shrinkage in a room
where a well designed system of forced circulation is employed.
166 PRACTICAL COLD STORAGE
Three of the houses designed by the author are used exclusively
for the storage of cheese. It is well known that cheese loses
weight very rapidly in cold storage, and the problem hereto-
fore has been to carry the cheese reasonably free from mold,
and with as little evaporation as possible. Cheese has been
stored in the houses referred to for three months, with very
little mold, and with no shrinkage from marked weights, and
the proprietors assert that there is less shrinkage, even on
"long-carry" goods, than there was with the overhead ice
system which they formerly had in service. This is a suffi-
cient proof of the value of forced circulation for the cold
storage of cheese. The same applies equally to other classes
of goods. With a room equipped with any of the gravity
systems of air circulation, already described, the circulation of
air cannot be regulated, because it depends on the temperature
of the refrigerant (generally brine or ammonia) circulating
through the pipe coils. As the temperature of the refrigerant
is regulated to suit outside weather conditions (lower in warm
weather, and higher in cold weather), the velocity of air cir-
culation is not constant, being least in the cold weather of
fall and winter, when most needed. With a good system of
forced circulation installed, the chief problem of the cold
storage man is to employ a proper degree of humidity. (See
chapter on "Humidity.") Our discussion now brings us to a
consideration of the various methods of mechanical air circu-
lation in use. The weak as well as the strong points of the
various systems which have been put in operation will be con-
sidered, regardless of where or by whom originated.
UNDESIRABLE FORCED CIRCULATION.
The simplest, and probably the most unscientific, form
of mechanical air circulation in cold storage rooms is the
small electric fan. These fans are usually of the four or six-
bladed disk type, of from twelve to eighteen inches in diameter,
attached directly to the shaft of a % or % -horse power electric
motor. The electric current for operating is usually obtained
from the socket for an incandescent electric lamp. Electric
fans are usually placed on the floor in the end of an alleyway,
AIR CIRCULATION 167
or in an opening in the piled goods, and are used for creat-
ing a flow of air from one extremity of the room toward the
other. If the circulation is strong enough, these fans tend to
create a uniform temperature in the room; but, as the air
from the fan will follow a path of least resistance, the circu-
lation resulting from their use is largely confined to the alley-
ways and openings in the piles of stored goods — it does not
penetrate through and behind the goods where it would be
most useful. The use of this type of fan in cold storage rooms
is of doubtful utility, and is liable at times to lead to a positive
harm by causing a condensation of moisture on the goods in
storage, as a result of the warm upper stratum of air coming
in contact with the cold goods near the floor of the room. In
some cases electric fans have been used to propel the air from
the cooling pipes, for which purpose they are placed in an
opening in a screen or mantle covering the pipes, forcing the
cooled air outwardly into the room. This is a first step toward
scientific forced circulation, and is useful as far as it goes. In
many cases the electric fan is useful only as a "talking point,"
as it is likely to impress a person, who is not familiar with
cold storage work, with the cooling power of the refrigerat-
ing apparatus, to stand for a few seconds in the breeze created
by one of these high-speed fans. Their use has been adopted
to an extent not at all warranted by the results to be obtained,
and they will no doubt be gradually discontinued as the
fallacy of the idea becomes apparent. Those who use electric
fans as above described, by so doing admit the superiority of
forced circulation over the gravity system, and also admit that
their rooms are in bad condition, and that some mechanical
means of agitating or circulating the air is necessary. Instead
of such a poor makeshift it seems that they will eventually
come to the idea of installing a scientific system of forced
circulation.
Having proved a circulation necessary, it is evident that
a method which will cause the circulation to be continuous,
and at the same velocity, regardless of outside weather condi-
tions, etc., must be better than depending on natural circula-
tion, which varies greatly with the varying conditions and
168 PRACTICAL COLD STORAGE
appliances which produce circulation as we have already seen.
It follows further, then, that the system which will produce a
circulation which is continuous, and at the same velocity, and
besides is uniformly distributed to all parts of the room, must
be the most nearly perfect way of handling the air for cold
storage rooms. Any of the methods of gravity air circulation
in which the pipes are placed in the room or otherwise, as
shown in Figs. 5 to 10, are dependent on the outside weather
conditions, temperature of room, temperature of refrigerant in
pipes, length of time goods have been in storage, etc., for
their operation. A continuous and uniform air circulation
//|vy/////////////////////////////////^^^^^
PIG. 11.— PRIMITIVE FORM OF FORCED CIRCULATION.
can only be obtained by the adoption of some mechanical
means, and is usually secured by the use of a fan of some
kind.
VARIOUS FORMS OF FORCED CIRCULATION.
So far as known to the writer, the systems of forced
circulation here described include all of the recognized equip-
ments which have been installed in one or more prominent
houses. The patent records show a large number of crude
developments which have in most instances been abandoned
without having been put into practical use. A system which
has been installed in several large houses in the United States,
AIR CIRCULATION 169
and to some extent abroad, is what may be termed a primitive
form of forced circulation. This term fully expresses just
what the system is, as no method could be applied in a more
crude way. It consists simply in placing the refrigerating
pipes outside the storage room, and using a fan to propel the
air to and from the room. Fig. 11 shows a floor plan of a room
so equipped. The air is forced into the room at each end,
and the return air to coil room drawn out in the center as
shown. Cold air in this connection is spoken of as being
the air from coil room to storage room, and T^arm air is men-
tioned as the air from storage room to coil room. These
terms are used relatively only, and will be employed in the
descriptions contained in this article. It should be understood
that in actual practice the difference in temperature between
the incoming and outgoing air is very small. In a well de-
signed system this need not be over two or three degrees at
the most. The cold air inlets at ends of room are in some
cases placed near the floor and in others near the ceiling,
but further than this no distribution of air is attempted other
than that resulting from the location of the inlet and outlet.
Sometimes the ducts are arranged to force the air into the
room at the center, and the return air to the coil room is
taken out at the ends, or the cold air is allowed to flow from
the several openings in a duct running across the center of
the room, but no adequate distribution results from this
method.
Employing the forced circulation system in this way is
very much like the indirect systems of steam heating as at first
installed. It is noticeable now that the best steam heating
work provides a thorough distribution of the heated air
throughout the apartments through a great many small open-
ings rather than forcing a large volume of air into the room
at one or two places. It needs no argument or demonstration
to show that a room heated or cooled by air forced in at one
or two openings must have varying degrees of temperature,
humidity and circulation depending on the remoteness or
proximity to the direct flow of air from inlet to outlet, for
the reason that the air from inlet always seeks the most direct
170
PRACTICAL COLD STORAGE
path to the outlet and moves through the area of least re-
sistance, usually through the center alley of room. This is a
positive fact and not a theory. The author once visited a large
room of the kind above described, and despite the manager's
statement that he had tested in every known way and found
conditions absolutely uniform, the author for himself saw a
temperature variation of two degrees, and this between two
thermometers hung in the center alley of room at the same
height from floor, and without any extraordinary conditions
to cause such a variation. As a matter of fact the real differ-
ence in temperature in this room between the coldest and
//m//////m///////////////////////////u^^^
'mM7777MII7mm7m7777777777m7n7m/mmm77IJW777777777777777m//>
FIG. 12.— A SYSTEM OP FORCED AIR CIRCULATION.
warmest point could not have been less than five or six degrees.
The longitudinal section of a room shown in Fig. 12
illustrates a system of forced air circulation which has been
installed to a moderate extent, but has not become as well
established as the one first described. A false ceiling is pro-
vided for distributing the cold air from cooling coils at the
top of the room, but as with the system just described, no
collecting ducts are provided for the purpose of uniformly
removing the air from the room. The air from coil room
comes into the room through narrow, slit-like openings in the
false ceiling, and is returned to the cooling coils through and
AIR CIRCULATION
171
by the disk fan located in the partition between coil room
and storage room. It would seem that this is working counter
to the natural laws of gravitation, although it may be looked al
in another light also. It is often remarked that "cold will natur-
ally drop," but this should not confuse us when studying the
means for promoting circulation. If the cold air is admitted to
the room at the top, it will of course fall to the floor if allowed to
do so ; but why admit the cold air at the top of the room if it
is wanted at the floor? In a room fitted with direct piping
the cold air does not drop through the goods in storage, but
down over the cooling coils, and rises through the goods in
ym//////mm////////;///////f///////m
FIG. 13.— COLLECTING AND DISTRIBUTING AIR DUCTS.
storage as it is warmed. It would seem, then, that any method
of distributing the cold air at the top of the room is wrong in
principle, especially as no means of uniformly drawing ofl"
the air at the bottom of the room is provided. When warm
goods are placed in a room equipped in this way, the moisture
given off as the goods are cooled must be very liable to collect
on the cold false ceiling. To provide uniform temperatures
and humidity with this system it is necessary to provide a
strong blast of air, which is to be avoided, as goods directly in
front of the fan may be exposed to too great a drying influence.
172
PRACTICAL COLD STORAGE
The arrangment of collecting and distributing air ducts
shown in the cross section of room, Fig. 13, has been installed
in a number of houses in America, and, like some of the
others, depends on the "cold will naturally drop" theory for
its operation. The arrow shows the natural tendency of the
air circulation from the cold air ducts on the sides of the room
to the warm air collecting duct in the center. In some cases
the cold air is distributed in the center and collected at the
sides of the room, and where the room is narrow only two
ducts are used, as in Fig. 14, a cold air distributing duct on
one side of the room and a warm air collecting duct on the
opposite side. In every case the ducts are placed at the
I
i
COLO -Ria OUCT
V
/
Q
^ 0 I
I
FIG. 14.— SMALL ROOM WITH TWO DUCTS.
ceiling, on the theory that the air from cold air duct will drop
and distribute itself along the floor before being drawn back
to the coil room through the return duct. The openings pro-
vided in the air ducts of this system are usually square open-
ings, fitted with sliding gates to regulate the flow of air into
the room and its return to cooler. These gates are placed
five or six feet apart, consequently a good distribution of air
is not provided, and goods exposed to the rapid flow of air
directly in front of the openings will get a much greater
volume of circulation than is to be found in any other part
of the room. When a room of this kind is filled with goods.
AIR CIRCULATION
173
preventing the air from falling from the cold air duct to the
floor, no circulation of consequence will be obtained near the
floor, for the reason that air will travel through path of least
resistance, almost directly from feeder duct to return duct,
about as shown by the arrows.
A method somewhat similar to the one just described is
that in which the cold air distributing ducts are placed at the
floor and the warm air return duct is placed at the ceiling,
as represented by the cross sections of rooms. Figs. 15 and 16,
In narrow rooms only one distributing duct is used, as shown
in Fig. 16. In wider rooms two distributing ducts on opposite
'Mm/i/i/////////////////////////m///f////////////M
V/ \v Jol / \ n^rrxjnn fi^m DUCT ^^-""''''^ y/.
') -.
filR DUCT
y /
w////7////////////////////////////////w///////^^^^^
FIG. 15.— ARRANGEMENT OF "WARM AND COLD AIR DUCTS.
sides of the room at the floor are used, and one collecting duct
at ceiling in center of room. This arrangement has the merit
of operating according to the laws of gravity, but still lacks
the thorough distribution of cold air and collection of warm
air, as shown in the system described further on. It is, how-
ever, considerable of an improvement on any of the preceding
methods, and the author has demonstrated in actual service
that it will produce fairly uniform circulation and tempera-
tures with a comparatively gentle flow of air. This system is
to be recommended for goods which do not give off much mois-
174
PRACTICAL COLD STORAGE
ture. It is preferable to use numerous small holes rather than
a few large openings in the supply and return ducts.
COOPER SYSTEMS OF AIR CIRCULATION.
The system shown in the cross section of room (Fig. 17)
was developed by the author after some experiment and has
since been improved by two successive steps, the details of
which will be described. It was the old trouble of sluggish
circulation, especially during the fall and winter, which im-
pelled the author to experiment for its betterment. As an im-
provement over the small electric fan already mentioned, an
m//mm//////////f//n/i////////////mmm^
yy .---^ aUCT Innm^mm^/^
I /
X/C0U3 RfR aUCT '/jl
'''/^////}///////////////////W//M////////////////y
FIG. 16.— ARRANGEMENT OP WARM AND COLD AIR DUCTS.
exhaust fan was fitted up to take air from the cooling apparatus
and deliver it to the rear end of the room through a perforated
duct. The air was allowed to find its way back to the coils as
best it could.
This method was applied to a long narrow room, and
certainly was a decided improvement over the sluggish natural
circulation which it superseded. Following this, the perforated
false ceiling was applied, with distributing cold air ducts on
the walls, as shown in Fig. 17. The cold air from coil room
was forced into the side ducts and flowed into the room through
a great number of small holes in the top, bottom and sides
of the cold air ducts. The warm air from the room flowed up-
AIR CIRCULATION 175
ward through the small perforations in the false ceiling and
through the space between the ceiling of the room and false
ceiling and thence to the coil room, where the air was cooled,
and caused to repeat the same circuit continuously. The first
apparatus was clumsy and the proportions of the various parts
not correct, but the efficacy of a forced circulation of air, and
a thorough distribution and collection of the incoming and
outgoing air of a cold storage room so plainly proven, that a
further development of the idea was undertaken.
It was demonstrated by above described experiments that
a comparatively small amount of air, well distributed and
PIG. 17._COOPBR'S FIRST SYSTEM OF AIR CIRCULATION.
uniformly drawn off at the top of the room after flowing
upward through the goods in storage, would produce very
uniform conditions throughout the entire area of the room.
Following up this information, the apparatus was reduced to
a more practical form by substituting one broad duct near
the floor, as in Fig. 18, for distributing the cold air, in place
of the two distributing ducts as used in the apparatus shown
in Fig. 17. The top duct of the two did not accomplish any
result of consequence, and was considered objectionable, as the
air passing from this duct to the false ceiling did not percolate
throuo-h the goods to any considerable extent, and resulted.
176
PRACTICAL COLD STORAGE
practically, in a loss of the work done by the air flowing from
the top duct. Two ducts also made the apparatus more compli-
cated. Using the broad single distributing duct near the
floor in combination with the false ceiling resulted in a very
penetrating and uniform circulation of air, and in practical
service it has been found to produce superior results. No
practical objections have been urged against it. As shown by
the arrows, the air is caused to cover very uniformly the
entire cross-sectional area of the room. This was accomplished
by perforating the distributing ducts with small holes, and
so proportioning them that a larger part of the flow of air is
i///m///;/////////////m//////m//m//M^^^
Fffi-SZ CE.ll.lf1G - PZRfORfrTEO
FIG. 18.— COOPER'S IMPROVED SYSTEM OF AIR CIRCULATION.
from the bottom of the ducts. The ducts are also perforated
to some extent on sides and top. By piling the goods a few
inches off the floor the air from bottom of ducts flows under
the goods and out to center of room. This action is also
assisted by having the greater number of the perforations in
false ceiling in the middle third or quarter of the room, so as
to draw the air out from sides of room. As indicated by the
arrows, the air moves up from the distributing duct, is drawn
AIR CIRCULATION
177
into space above false ceiling, and returned to coil room to
be cooled.
The system described in the foregoing paragraph is nearly
theoretically perfect so far as a uniform circulation of air is
concerned, and a more thorough method than any of its prede-
cessors, but it still remained to design the perforated false floor
and false ceiling combination (Fig. 19) to produce a system
which cannot be improved upon theoretically. Not only is the
system theoretically perfect, but its practical application is so
simple as to be unobjectionable. As shown clearly by the
sketch, the flow of air is directly upward from floor to ceiling,
I
/ I 1
I I ! I I ! I , ' 1
M ! f t 1 . ' I f ' ,
I I I ' I f I r i
I ' •''' ^"^^^ FLOOR ■.^\ II
pOLO filff DUCT
I
PIG. 19. — COOPER'S LATEST IMPROVED SYSTEM OF AIR
CIRCULATION.
consequently all goods piled in such a room are exposed to
exactly the same conditions as to circulation, temperature,
humidity and purity of the air. In a room equipped with this
system, with the parts correctly proportioned, it is entirely
safe to pile goods closely, only allowing a fraction of an inch
between the packages and at sides of room and placing thii.
strips beneath the goods to allow air to flow from perforations
in false floor. Where, in rooms fitted with direct piping and
some of the fan systems as well, a large space must be left
at floor and ceiling for a circulation of air, with this system
178 PRACTICAL COLD STORAGE
goods may be piled close up to ceiling leaving only half an
inch for the air to flow into perforations in false ceilings. As
the space occupied in height by false floor and the space under-
neath is, in most cases, only one and three-fourths inches and
that occupied by false ceiling oqly one and one-fourth inches,
it is apparent that much space will be saved by using this sys-
tem. After a room is filled with goods and cooled down to the
correct carrying temperature, no difference in temperature can
be noticed in different parts of the room. No blast of air can be
felt in any place, a gentle flow from perforations only is no-
ticeable, therefore no particular place has more circulation
than another to cause a drying out of the goods. The advan-
tages of this system over any of the others may be summed
up as follows:
1. A more equal distribution of air, especially when the
room is filled with goods. Goods in center of room are ex-
posed to the same temperature, circulation, etc., as those at
sides.
2. Saving in space, as it allows the room to be filled full
of goods without leaving large spaces at top and bottom for a
circulation of air.
3. Where the air is so perfectly distributed and col-
lected it is not necessary to circulate such a large volume,
saving in power and lessening the liability of evaporation of
goods. ■ R ^"!^'^
The objections against this system which have been offered
are of no practical consequence. The first one usually men-
tioned by an inquirer is that the space under false floor is
likely to collect litter and become foul. The author admits
that this apparent objection for some time kept him from in-
troducing this system to practical service, but when once tried,
this was found of no consequence, as the false floor is made in
sections, easily handled, and it is as easy to raise these ;md
sweep underneath as to remove the 2x4s or 4x4s generally used
to pile goods on. Another objection is the supposedly high
initial expense. A contract was awarded for the construction
of this system for a fair sized house, in which the cost for air
circulating system, including fans and motors, did not exceed
AIR CIRCULATION 179
$20 per 1,000 cubic feet. It will be seen that the cost is of
very small importance as compared with the practical results
obtained and the saving in space effected. Those who are
skeptical about the advantages of forced circulation, and of
this system in particular, are invited to visit some of the plants
designed by the author.
The objections against forced circulation are largely fanci-
ful and are not substantiated when investigated. The idea that
goods dry out or evaporate rapidly in a room so equipped, has
never been even suggested by the author's experience, and this
objection may be dropped without further comment, as this
ground has been thrashed over before. It is thought by many
that a forced circulation system is unnecessary, expensive to
install and costly to keep in operation. It may be admitted
that forced circulation is unnecessary in the same sense that
refrigeration was unnecessary fifty years ago. People are get-
ting along without it because they do not know or under-
stand its advantages. Many other applications of machinery
are not absolutely necessary, but are used for the improved
results obtained. If properly designed, the cost of equipping a
house with an improved system of forced circulation need not
be much greater than with direct piped rooms, for the reason,
mainly, that only half or two-thirds as much piping is needed,
and because of the saving in main pipes by locating the cool-
ing coils centrally and blowing the air to and from the room
with a fan. As to cost of power for operating, this is very
small, if using the fans specially designed by the author for
this purpose. (Fans for use with air circulating systems
should be of special construction. This is considered under
the chapter on "Ventilation.") It is customary to install a
half horse power motor for handling the air in a room of
15,000 cubic feet. The actual power necessary is from one-
quarter to three-eighths of a horse power. As an offset to the
cost of operating the fan, may be placed the great saving in
space gained by the use of the fan system. In no case is this
less than 5 per cent of the space refrigerated, and sometimes
will amount to over 10 per cent. Even if all the objections
urged against the system were true, this alone is enough to
180 PRACTICAL COLD STORAGE
compensate and more besides. When from 5 to 10 per cent
may be added to the earning capacity of a storage house
without additional cost of operation it means a big increase
in the net profit of the business.
Not the least of the advantages of the forced circulation
system is, that during cold weather when the ammonia or
brine is shut off from circulating through the pipes, their
frosted surfaces are not exposed in the storage room. It is
comparatively easy to clean the pipes, as they are more acces-
sible than they are in any of the direct piping systems. A still
greater advantage may be gained by using a process invented
by the author, which consists in placing chloride of calcium
above the pipes, so that the brine resulting from a union of
the moisture in the air with the calcium will drip down over
the pipes. (See chapter on "Uses of Chloride of Calcium.")
This prevents the formation of frost on the pipes at all times,
and during cold weather, when the refrigerant i& shut off, by
keeping up the supply of calcium, the moisture and purity of
the air are under perfect control.
That the tendency is toward the adoption of forced circu-
lation for the best new work cannot be doubted, even by those
who do not advocate these systems. It cannot be expected that
they will come into use all at once,'but the author feels justified
in predicting that ultimately more than half the high grade
installations will be done under these systems. The present
opposition comes largely from the "old line" people in the
business who do not like to see changes and improvements
made on methods with which they have "had good results"
for so many years.
CHAPTER VIII.
VENTILATION.
NECESSITY l^OR VENTILATION OF COLD STORES.
In discussing humidity and circulation, it has been ex-
plained how a large portion of the gases of decomposition and
impurities of various kinds, which are incident to the presence
of perishable products in cold storage, are carried by the
moisture existing in the air, and that when this moisture
is frozen on the cooling pipes, or absorbed by chemicals, the
foul matter is largely rendered harmless. It may now be
noted further that even with a good circulation and ample
moisture-absorbing capacity, there will still be some impuri-
ties and gases, detrimental to the welfare of the stored goods,
which have little or no affinity for the water vapor in the air,
and consequently accumulate in the storage room. Ventila-
tion is necessary to rid a refrigerator room of these perma-
nent gases.
The subject of ventilation for cold rooms has been very
much talked of, but there is really little known about it, so
far as any practical information is concerned. Some of the
more progressive cold storage managers have given some at-
tention to this part of the business, but many of the largest
and best known houses do not ventilate their rooms at all,
except perhaps during the winter or spring, when rooms are
aired out for the purpose of whitewashing. In some cases the
change of air incident to opening and closing of doors, when
goods are placed in storage or removed therefrom, is relied on
to supply ventilation. This is quite inefficient, because goods
are mostly stored during two or three months, and removed
from storage likewise, leaving several months when no fresh air
of consequence can penetrate to the room, except as the doors
181
182 PRACTICAL COLD STORAGE
may be opened for the purpose of taking the temperature of
the room. Furthermore, this kind of ventilation during the
warm weather of summer and during a large part of the
spring and autumn months is worse than no ventilation at all.
Some storage men even take so radical a position on this matter
of opening doors during warm weather, as to insist that the
door shall not be opened for the purpose of reading
the thermometer. A double window is placed in the door
of each room, with the thermometer hanging so that it
can be read from the outside without opening the
door. While the author has not practiced this method,
it seems to be a good idea, and it is certainly pre-
ferable to ventilating the room through doors which open to
the outside air. When doors into rooms open into a corridor,
the evil is partly prevented, but opening the door or window of
a storage room directly to the outside air when the tempera-
ture outside is materially higher will always result in more
or less bad effect on the goods, because of the water vapor in
the warmer incoming air being condensed on the stored goods.
Another source of ventilation similar in its results to the
opening of a door or window is that resulting from the leakage
of air directly into the storage room, through the pores and
crevices in the walls, around the doors and windows, etc. —
leakage of air literally — air that gets in when everything is
supposed to be closed. The amount is usually imperceptible,
but is enough in some houses to be a serious detriment to the
quality of work done. In small houses with large outside ex-
posure and poor insulation this air leakage is considerable,
but in the big refrigerators of several hundred thousand cubic
feet capacity, and with thorough insulation, it is reduced to
practically nothing. The loss of refrigeration caused by air
leakage, while of some importance, is of small moment beside
the bad effects resulting from the moisture and impurities
brought in by the warm air from the outside. The value of
prime, tight insulation, as a conserver of refrigeration, aside
from a matter of keeping out the warm, moist air, is discussed
in the chapter on "Insulation," but a word about windows and
doors is properly in line with the present discussion.
VENTILATION 183
"WINDOWS AND DOOES.
Rather than consider what might be a good way of plac-
ing windows in a cold storage building, their use should be
discouraged. Even with four or five separate glass, divided by
air spaces and with all joints set in white lead, the loss of re-
frigeration is large. It is also very difficult to fit insulation
around the window frame so as to make a good job; and even
if a passable job were practicable, the expense of putting in
windows is sufficient to condemn their use. The increased fire
exposure is of some consequence, too, and with the low cost of
electric light, windows should not be thought of for cold stor-
age work. Barring the small amount of heat given off, the in-
candescent electric lamp is an ideal device for lighting cold
storage rooms, as the air is not vitiated by gases and odors as
is the case when using gas, kerosene or candles.
Doors which will shut tight, forming a nearly perfect air
seal, with a small amount of pressure, have long been wanted
for cold storage rooms. Most of the ordinary bevel doors,
either with or without packing on the bevel, will not shut
even approximately tight; and in operation nine out of every
ten stick and refuse to open except after many persuasive
kicks and surges — we all know how it is. The special cold
storage doors on the market, the author believes to be far above
anything else in this line, and does not hesitate to recommend
them to those wanting a door which will prevent air leakage.
The prices are very reasonable, considering the excellent ma-
terial and fine work put into their construction. The slight
additional cost over the common door will be quickly saved,
by reason of their quick action — opening quickly when the
fastener is worked. If a door is built on the job, the chief idea
to be considered in its construction, is to build a door which
is tight at one point all around. It is absolutely impossible
to make a door fit on a long bevel, but the effort is very fre-
quently made. (See chapter on Doors and "Windows.)
AIR LEAKAGE.
Having presented the subject of air leakage, we may as
well ask how it is caused and why it must be guarded against.
184 PRACTICAL COLD STORAGE
It is amenable to the same law as gravity air circulation, which
was explained quite thoroughly in the first part of the chapter
on "Air Circulation." When the outside air is very much
warmer than that of the storage room, the air in the storage
room produces a pressure on the floor and lower part of the
room, by reason of its greater weight, and consequently it seeks
to escape there. If there are openings near the floor where the
air can flow out, and others at the ceiling or upper part of the
room, the air will flow in at the top and out at the bottom
of the room. Reverse the conditions of temperature, and the
direction of flow of air is also reversed. That is, when the air
outside is colder than the air of the room, the cold air will flow
into the room at the bottom and the comparatively warm air of
the room out at the top. This action is nicely illustrated by
noting the air currents in a door which is opened into a cold
room when the temperature is very warm outside. The warm
air rushes in at the top of door and the cold air of room out
at the bottom. In cold weather the direction of air flow will
be reversed.
Perfect inclosing walls for a cold storage room would be
perfectly air tight, as they would be if lined with sheet metal,
with soldered joints. The interior conditions would then be
under more perfect control. It is hardly necessary to do this
(although it has been done in cases of some old time houses) ,
as a practically tight job may be had by using the right ma-
terials, well put on. Air leakage may not be exactly ventila-
tion, but it is a kind of ventilation which has given the author
some trouble in the past, and does still, consequently the diffi-
culties of operating a house with defective insulation and large
outside exposure, and still turning out first-class goods are very
thoroughly appreciated.
PKACTICES TO AVOID.
Methods of ventilation which are permissible when ap-
plied to the work of supplying fresh air to ordinary structures
are generally dangerous when used to ventilate cold storage
rooms. The problem in ventilating non-insulated structures
is merely the supplying of fresh air from the outside without
VENTILATION 185
causing a marked change in the temperature, and without
creating strong drafts. Air for the ventilation of refrigerator
rooms, during warm weather, must be of very nearly the same
temperature and relative humidity as the air of the room to be
ventilated, and free from the germs which hasten decay and
cause a growth of fungus on the products in storage. If a
door or window of a storage room is opened directly to the out-
side atmosphere, there will be little or no circulation of air in-
to and out of the room when the temperature outside and in
is about the same, unless the wind should be favorable. As
we cannot ventilate in this way when the air outside is colder
than the storage room, on account of freezing the goods, and
the introduction of fresh air, which is warmer than the stor-
age room, is not permissible, for reasons already given, the
matter reduces itself to not ventilating at all during warm
weather (which most houses practice) or of properly cooling
and purifying the air before forcing it into the storage room.
It will bear repeating that it is positively bad practice to al-
low air from the outside to get into a cold storage room dur-
ing the summer months, also during a large portion of the
spring and fall months, unless cooled and purified first. The
fact that we cannot see the moisture deposited in the form of
beads of water, or floating in the air in the form of fog or
mist, does not indicate that it is not present. The sling psy-
chrometer, described in discussing humidity, will give an ac-
curate indication of the result of this unscientific method of
ventilating.
MEANS FOR AIR HANDLING.
Any natural means of handling air or ventilation is in-
accurate and inoperative, or it may be positively harmful, ex-
cept under favorable conditions. If depending on natural
gravity for ventilation it will be guesswork, to a greater or less
extent, because depending on conditions which vary with the
season, temperature, direction and force of the wind, etc. The
late Robert Briggs,* an authority On ventilation, makes a con-
cise statement of the advantages of using fans for ventilation,
' •Proceedings Am. Soc. Civil Engineers, May, 1881,
186 PRACTICAL COLD STORAGE
in his "notes on Ventilating and Heating." He says: "It
Avill not be attempted at this time to argue fully the advantages
of the method of supplying air for ventilation by impulse
through mechanical means — ^the superiority of forced ventila-
tion, as it is called. This mooted question will be found to
have been discussed, argued and combated on all sides in nu-
merous publications, but the conclusion of all is, that if air is
wanted in any particular place, at any particular time, it must
be put there, not allowed to go. Other methods will give re-
sults at certain times or seasons, or under certain conditions.
One method will work perfectly with certain differences of in-
ternal and external temperature, while another method suc-
ceeds only when other differences exist,. * * * No other method
than that of impelling air by direct means, with a fan, is
equally independent of accidental natural conditions, equally
efficient for a desired result, or equally controllable to- suit
the demands of those who are ventilating."
PLENUM vs. EXHA.UST METHODS OP VENTILATING.
There are two general methods, with some modifications,
for handling air for ventilation: The plenum or pressure
method, in which the fresh air is forced into the room ; and the
vacuum or exhaust method, in which the foul air is drawn
out. The exhaust method is to be avoided for ventilating cold
storage rooms, for reasons which we shall see presently. With
this method, sometimes the exhaust steam from an engine is
utilized to induce a draft of air upward from storage room,
by heating the air in a stack or ventilation flue connected at
its lower end with the room to be ventilated. In some cases
no provision is made for an inflow of fresh air, in which case
it will seep in at every crack, crevice and pore (by reason of
the partial vacuum created by exhausting the foul air) , bring-
ing a load of moisture and germs of disintegration into the
storage room. This exhaust steam method is no different in
its result than if a fan were placed so as to draw the air out of
the storage room under conditions which are otherwise the
same as described in connection with the exhaust steam
method. Should we provide an inlet for fresh air, through
VENTILATION 187
proper absorbents, the same law would be operative, only to a
lesser degree, as a partial vacuum must in any case be created
before the air from outside would flow into the room, tending
to the dangerous air leakage already fully discussed.
The plenum or pressure method is by far the best for our
purpose. The air should be forced into the room by a fan,
after first properly cooling, drying and purifying it. An out^
let for the escape of the foul gases which it is desired to be rid
of should be provided near the floor, as these gases, by reason
of their greater gravity, tend to accumulate in the lower part
of the room. It will be observed that forcing the fresh air
in creates a pressure inside the room, and if there is any air
leakage, it will be outwardly from the room — exactly the way
we want it to go. Having brought our subject to the point
where it is found that the best way to ventilate is by the use
of fans forcing the air into the storage room, we will deter-
mine what type of fan is best adapted to our needs. What is
said of fans for ventilation is equally true if they are to be
used for forced air circulation, described in chapter on "Air
Circulation."
PANS FOR VENTILATION.
It is admitted by a majority of experts on air moving ma-
chinery that the disk or propeller wheel type of fan, through
which the air moves parallel to the axis of fan, is not efficient
or desirable for work where the air has to travel through a
series of tortuous air ducts, as in the forced air circulation sys-
tem for cold storage work, or for ventilation purposes where
there is some resistance. Where any resistance of importance
is encountered, the disk fan must be driven at a high rate of
speed, and at an immense loss of power, to compel it to deliver
its full quota of air. Another disadvantage of the disk type is
the difficulty of belting to the shaft, or of getting power to the
fan in any form, if it is inclosed entirely in an air duct. The
disk type will therefore be dismissed, and the well known cen-
trifugal, or peripheral discharge fan taken up.
This type of fan draws the air in at its center parallel
to the shaft, and delivers it at right angles to the shaft at
the periphery or rim of the fan wheel, the law governing its
188 PRACTICAL COLD STORAGE
action being the well understood centrifugal force, which is
commonly illustrated when we see the mud fly from a buggy
wheel, or the water off a grindstone. The advantage of these
fans over the disk type is that the centrifugal action set up by
the rotary motion of the fan is utilized to give velocity to the
air in its passage over the fan blades. In the selection of a
fan for the purpose of forced circulation in the storage room,
or for forcing in fresh air for ventilation, it should be noted
that a large, slow running fan wheel is very much more eco-
nomical of power than a small fan running at a high rate of
speed, both doing the same amount of work. The loss of re-
frigeration, too, in a rapidly moving fan, is of consequence, be-
cause the air is warmed by impact with the blades. The pro-
portion of power saved by the use of a large fan running at a
slow rate of speed rather than a small fan running at a high
rate of speed, both delivering the same amount of air, is al-
most phenomenal, and does not seem at all reasonable at first
view. The volume of air delivered by a fan varies very near-
ly as the speed, while the power required varies about as the
cube of the speed. That is, doubling the speed doubles the vol-
ume of air, while the power required is increased eight times.
We will take a specific case. A 45-inch fan wheel, revolving
at a speed of 200 revolutions per minute, delivers, say, 5,000
cubic feet of air per minute, and requires but one-quarter of a
horse power to operate it. If the speed is increased to 400
revolutions, the volume of air delivered will be only about
10,000 cubic feet, while the power required to drive it will be
raised to two horse power. These figures are theoretical, but
within certain limits are approxiniated in practice.
Tor use in cold storage work the objection common to
nearly all the air moving machinery found listed by the manu-
facturers is the seemingly unnecessary amount of metal used
in its construction. The heavy weight of the fan wheels, and
the large diameter of shaft necessitated by such weight, causes
much friction on the journals, so that when running at the
slow speeds desirable for cold storage work, more power is re-
quired to overcome the mechanical friction than is actually
required to move the air.
VENTILATION 189
No doubt the high speeds necessary for some work have
obliged the manufacturers to make their fans amply strong
for the highest speeds, consequently they are not economical
for the slower speeds. It would not be appropriate for a per-
son to fan himself with a dinner plate — it would do the work,
but would not be economical of power.
Having been unable to find a fan wheel well suited to the
requirements of cold storage duty, the author has designed and
constructed a line of fan wheels especially for slow speeds,
which are amply strong and capable of moderately high
speeds, when necessary, but are very much lighter than most
fans on the market, and consume proportionately less power
in mechanical friction.
TREATING AIR FOR VENTILATION.
So far we have found out what kind of ventilation is not
desirable, and have an inkling of what kind would be desir-
able. The question before us now is to properly treat the air
before introducing it into the storage room, so that it may be
fresh — i. e., pure oxygen and nitrogen, without excessive mois-
ture,* and free from the impurities and germs which may con-
taminate the product which is being refrigerated.
The free outside air during warm weather, especially in
the vicinity of our large cities, contains, among many others,
germg which produce the parasitic plant growth which is
called mildew or mold. The exhalation from the lungs of the
many animals and men who inhabit our cities, and the evap-
oration from the dust, dirt and decaying matter of various
kinds peculiar to the street, render the air a receptacle and con-
veyor for impurities and germs of many species. The species
of germs which concern us are active in proportion to the
temperature and humidity of the air. In a warm atmosphere
which contains much moisture they take root and grow rap-
idly, throwing off more germs of their kind, which impreg-
nate the air in an increasing ratio as the humidity and tem-
perature are increased. The humidity of the outside air is
not necessarily increased with the temperature, but it is al-
ways increased to some extent, and as the temperature of the
190 PRACTICAL COLD STORAGE
outside air rises we must necessarily be more and more careful
how we treat and handle the air which we are to use for the
ventilation of refrigerated rooms.
It is readily understood why it is necessary to cool the air
before introducing it into the storage room to at least as low a
temperature as that of the room to be ventilated, and some
cold storage managers have ventilated on this basis, thinking
that this was all that was necessary for successful ventilation.
Air cooled only to the temperature of the storage room will be
saturated with moisture at that temperature, and will be in
condition to develop mold rapidly. An improvement on this
manner of handling is to cool the air to be used for ventilation
to a few degrees (say five or six) below the temperature of
the storage room. The air will then be rendered as dry as that
of the storage room. This is a good method of ventilation,
and one which the author has practiced, but it is open to criti-
cism, because of the fact that the air is not purified fully at
the same time it is cooled and dried. If the air is first cooled
to several degrees below the temperature of the room to be
ventilated it will be of benefit to the room, if not overdone,
but in results will not be equal to a system to be described
and illustrated further on in this chapter.
Several houses known to the author ventilate by letting
the warm outside air in at a point near to the ceiling, directly
over the cooling coils, expecting that the air will be properly
cooled and dried before it flows into the room itself. The same
objections are applicable to this system as are applicable to
any plan of ventilating where the air is cooled only to the tem-
perature of the room to be ventilated, because the air will be
at the saturation point, and will therefore raise the humidity of
the room, as well as introduce a quantity of germs and im-
purities.
SIMPLE AIR COOLER FOR VENTILATING.
If we ventilate by simply cooling the air, the simplest
and most effective method, as shown in Fig. 1, is to take the
air from as high and sheltered a place as is accessible about the
building; draw it down over frozen surfaces in the form of
VENTILATION 191
brine or ammonia pipes, which may be arranged anywhere
along the wall of a room, outside of the storage entirely if
more convenient. An exhaust fan takes the air from the coils
AMMONIA
COIL.
STEftM
Coiu
FIG. 1.— BRINE OR AMMONIA COOLER.
in the ventilating flue and forces it into the room to be venti-
lated, allowing it to escape in the neighborhood of the cooling
coils, where it will mix with the air circulation, and flow into
192
PRACTICAL COLD STORAGE
VENTILATION 193
the room through the regular channel. It is necessary to pro-
vide an outlet for the escape of foul air whenever fresh air is
forced into the room. This outlet should be near the floor,
and of about the same area as the inlet pipe. A steam coil
may be provided beneath the cooling coil in ventilating flue,
as shown in the sketch for the purpose of melting the frost
off the pipes. The casing around the cooling coil should, of
course, be insulated moderately, as well as the pipe leading
from it to the storage room, wherever exposed to the warm out-
side air. The size of apparatus necessary for this purpose need
not be large as the quantity of air which is generally required
for the ventilation of storage rooms is quite small, compara-
tively.
"Americus"* mentions a method of washing air for ven-
tilation, which seems to have advantages. The idea is to draw
or force air through a body of water or brine by immersing
the intake pipe so that the air will bubble up through the
liquid. This seems quite simple, but when it comes to forcing
air through a liquid with a fan it is not so simple, as nothing
short of an air pump will drive air through a pipe submerged
as above described, unless the opening from pipe is placed
quite near the surface of the liquid; in which case the bene-
fit to the air is very small. Experiments conducted by the au-
thor along this line were considered failures.
COOPEE SYSTEM FOE "WAEM M'EATHEE VENTILATION.
Shown in Fig. 2 is what appears as a rather complicated
apparatus, but on investigation it proves to be quite simple.
There are three parts to this apparatus, as follows:
Pifgt. — The air-washing tank, in which the air flows up-
ward against a rain of water from a perforated diaphragm
above, as clearly shown in the sketch. This not only cools
the air to the temperature of the water, say 55° or 60° F., but
it also takes out a large portion of the impurities of various
kinds. From the washing tank the air is passed on, in a com-
paratively pure and cool state, to be still further cooled.
Second. — The cooling tank, in winch the air is cooled to
several degrees lower temperature than that of the storage
*In Ice and Refrigeration, July, 1898.
194 PRACTICAL COLD STORAGE
room. This removes the moisture which holds in suspension
the few impurities which may have passed the washing tank,
the moisture being deposited on the frozen surfaces within the
cooler.
Third. — The drying box, into which the air from the cool-
er is passed, and which contains chloride of calcium. This
chemical is a well known absorber of moisture, what is techni-
cally known as a deliquescent substance. If moisture of any
account passes the cooler it is surely stopped in the dryer,
which "makes assurance doubly sure," so far as delivering a
pure dry air is concerned. It would be a hardy germ, indeed,
that would not succumb to the washing, cooling and drying
processes of this system of ventilation, which is as thorough
as it well may be theoretically, and practically is very effec-
tive.
FREQUENCY AND AMOUNT OF VENTILATION.
The volume of air necessary for ventilating a given size
of storage room can only be estimated, and probably no two
storage men will agree as to what is a correct quantity. Some
say that the introduction of a volume of air equal to that of
the room to be ventilated should take place each day; others
twice each day; some even take so radical a view of it as to
say the oftener the better if the air is properly dried and
cooled. This is of course true enough, but foul gases which
can be gotten rid of by ventilation accumulate but slowly in a
storage room, and it is probable that the introduction of a vol-
ume of fresh air, properly treated, equaling that of the stor-
age room, twice each week will be ample for the purpose of
keeping the room in good condition, and in most cases once
each week may do nearly as well. There is much to be devel-
oped yet in the direction of ventilation of refrigerated rooms,
more particularly in the way of some method of knowing
when a room requires ventilating. Perhaps some bright chem-
ist will in time make investigations and ascertain what the
gases are which we must dispose of, and indicate some simple
method of determining their presence, and in what propor-
tion.
VENTILATION 19S
All that has been said about ventilation so far applies
only to the ventilation of cold storage rooms when the air
without is warmer than the air of the storage room. We will
now give our attention to another kind of ventilation that is
applicable when the air without is at about the same tempera-
ture as the storage room, or at some degree lower. This will
be designated as cold weather ventilation, as this term seems
to express its function perfectly.
COLD WEATHER VENTILATION.
It has long been a well understood fact that products held
at about 30° F. or higher are more liable to be injured in
cold storage during the cool or cold weather of fall and winter
than during a long carry through the heated term. Much
has been said and written about why the old style overhead
ice cold storages give such poor results during fall and winter,
the reason assigned being lack of circulation, as the meltage
of ice ceases when the cool weather comes. This is true; fur-
ther, the large body of ice becomes an evaporating surface, and
the dirt and impurities which are found in all natural ice,
to a greater or less extent, have accumulated on the top of
this ice, and the evaporation which takes place carries gases
from this miscellaneous matter into the air of the storage
room, with consequent bad results. In some houses this may
be avoided by closing the trap doors covering circulation flues,
but it is seldom done, and in many houses it is impossible.
Now are we who cool our storage rooms with brine or
ammonia pipes very much better off in this one respect than
those who have these much despised overhead ice cold stor-
ages? Our rooms are cooled by frozen surfaces, on which ac-
cumulates the evaporation from the goods in store, which, as
we have already plainly seen, contains much foul matter and
impurities. Precisely as in the ice cold storages, the cooling
surfaces, which absorb moisture during warm weather, become
evaporating surfaces, and give back to the air of the room a
considerable portion of the various impurities and germs
which have been accumulated during the warm weather of
summer. To make this point more plain it may be considered
196 PRACTICAL COLD STORAGE
thus: During the period when the outside air is considerably
warmer than the air of the storage room it is necessary to keep
some refrigerant at work cooling the air within. This is usu-
ally done by circulating brine or ammonia through pipes and
the air of the room is circulated in contact with the pipes.
When the outside temperature is high, more of the refrigerant
must be circulated, or its temperature must be lowered; as the
weather turns cooler in the fall, less refrigerant, or the same
amount at a higher temperature, must be circulated, and when
the air without reaches the temperature of the room, the circu-
lation of refrigerant must be discontinued altogether. When
this is done the moisture on the cooling pipes begins to evapor-
ate. This evaporation added to that which is given off by the
goods themselves soon causes the air to be saturated with very
impure and poisonous vapors which cause the goods to deter-
iorate very rapidly.
DISPOSAL OF MOISTURE.
The influence which the temperature of the refrigerant
flowing in the cooling pipes has on the condition of a stor-
age room may be better understood by taking a specific case:
A room with a temperature of 33° F. and a humidity of 70 per
cent has a dew point (temperature at which the air precipi-
tates moisture) of 25° F. Therefore any cold surface (as a
pipe surface), having a temperature of 25° F. or lower, will
attract moisture when exposed to the air of the room. If the
pipe surfaces are heavily coated with frost, as they usually
are as cold weather approaches, the frost acts as an insulator,
and the refrigerant flowing in pipes must be at a considerably
lower temperature than the air of the room, or no moisture
is attracted. We have all noted how the accumulation of mois-
ture on pipe coils is slower and slower as the thickness in-
creases, until finally a limit is reached where no more frost
will form ; yet owing to the largely increased surface the room
can be kept at its normal temperature. If pipes are badly
loaded with frost, sometimes no absorption of moisture will
take place when the refrigerant flowing in the coils is 10° or
15° below the temperature of the room. The surface exposed
VENTILATION 197
to the air of the room, whether in the form of frost or other-
wise, must be at or below the temperature of the dew. point,
or no moisture will be absorbed. The value of suitable mois-
ture-absorbing surfaces as the cool weather of fall and winter
approaches cannot be overestimated, as many have found to
their sorrow that two weeks stay in cold storage under bad
conditions in cold weather will do more harm to eggs in par-
ticular than four months during hot weather.
The remedy for this trouble is found in keeping the air
of the room from coming in contact with the poisonous frost
which has been accumulated on the pipes during their period
of duty during warm weather ; or what is still a better way is
not to allow the frost to accumulate on the pipes at all, by us-
ing a device, described elsewhere under head of "Absorbents."
How to keep the air from contact with the frost on pipes is not
an easy matter, and in case of piping suspended directly in
the room it is an impossibility.
"With a system of screens arranged around coils, as de-
scribed in the first part of the chapter on "Air Circulation,"
trap doors may be very easily fitted to the openings and the
air circulation shut off in this way; but the simplest and best
way is to equip the rooms with forced circulation, and locate
the pipes outside of the room entirely. Then it is only a mat-
ter of shutting off the circulation over coils, or allowing it to
continue through a by-pass, or if the process described in the
chapter on "Uses of Chloride of Calcium" is used, the circu-
lation may be allowed to continue over coils. It seems quite
clear, from what has been written, why a storage room gets
foul quickly during cool weather, and also that the bad con-
ditions may be bettered by cold weather ventilation. The harm
resulting from the foul evaporation from frost on cooling pipes
may be obviated by not allowing contact between it and the air
of room, but the evaporation from the products themselves
must be taken up by other means when cooling surfaces are no
longer operative.
HINTS ON COLD WEATHER VENTILATION.
By carefully observing conditions a storage room may
nearly always be kept in prime condition during cold weather
198 PRACTICAL COLD STORAGE
by no other means than the introduction of fresh outside air
at as frequent inters'als as right conditions of temperature and
humidity will permit. It is quite safe to force in plenty of
air which has about the same temperature and humidity as
the room to be ventilated. There are few impurities in the
clear, crisp air of a bright fall day, and many such are avail-
able for our purpose in the latitude of Minnesota and New
York, and a somewhat smaller number, perhaps, in the lati-
tude of Iowa or Ohio. It is only a matter of handling the free
air of heaven understandingly. One's impressions, however,
will hardly do in judging what air is good to use for ventila-
ting purposes. If you have a bright, clear day, or, what is
still better, a clear cold night, which has the appearance of
being what you want, get out your sling psychrometer and
set all guesswork aside. It is frequently possible to fill your
storage rooms with fine, pure air at a temperature about the
same as that of the room, as early as the latter part of October,
if you are watching for the opportunity. Provide a good big
fan wheel, which will handle a large volume of air in a short
time, and when conditions are right blow your rooms full of it.
Repeat this whenever the weather conditions will permit.
"We may now consider cold weather ventilation under an-
other condition, viz.: When it is colder outside than inside
the storage room. "Whenever the outside air is 8° or 10° be-
low that of the storage room it is always perfectly safe to in-
troduce it into the storage room, after it has been first warmed
to the temperature of the room to be ventilated. That is, it
is safe so far as introducing moisture or impurities is con--
cerned. If we should ventilate in this w^ay continuously our
humidity would be lowered to a point where the goods might
suffer from evaporation. It is necessary, therefore, that obser-
vation of the humidity of the room so ventilated be taken, so
that this kind of ventilation may not be overdone.
The method of getting air into the rooms under these
last two systems of ventilation is of no special moment, ex-
cept that it be under control, and we have already noted that
the only good way of handling air was by the use of fans,
preferably large and of light weight, and running at a slow
VENTILATION 199
speed. Where the forced circulation is installed, it is some-
times practicable to so connect the fans used for this purpose,
that cold weather ventilation may be handled by them; but
a separate fan is much better and while it seems more com-
plicated it is really simpler to operate, because handled inde-
pendently. When using an independent fan or when using
the forced circulation fan for ventilating, the fresh air mixes
with the circulation and is well distributed by it to various parts
of the room.
The ventilation of cold storage rooms is not a matter
which can be safely left to such help as may be at hand, and
if good results are to be secured "the boss" should see to it
himself. Cold weather ventilation, especially, must be han-
dled carefully and scientifically or trouble may result instead
of benefit. No absolute rules can be given for handling ven-
tilation because of widely varying conditions, but if what has
been written is read and studied carefully the subject can be
taken up intelligently and followed out to its legitimate con-
clusion.
CHAPTER IX.
HUMIDITY.
IMPORTANCE OF ASCERTAINING HUMIDITY IN COLD STORES.
Up to about the year 1898 the subject of humidity of
cold storage rooms was given very little or no attention by
cold storage operators, and no successful means of testing hu-
midity had been found for the requirements of refrigerated
rooms. About the year above referred to the author secured
a sling psj'chrometer, such as is used at stations of the United
States Weather Bureau, and made- some tests. This instru-
ment is now in general use for the purpose, and is well adapted
for obtaining the humidity of cold storage rooms. More at-
tention has been given to the subject each year, and as it
costs practically nothing and requires very little time, all
houses should make tests to know how they stand in this im-
portant respect.
The humidity of a cold storage room under ordinary con-
ditions depends on the season to a moderate extent, and the
condition of the room, as regards ventilation, in some cases.
In late fall or winter, especially, if air is taken directly into
the room from the outside, the humidity will be low. As cool
weather approaches, the tendency is for the humidity to rise,
and unless kept down by ventilation or by the use of absorb-
ents, serious consequences are sure to follow.
To enable us to thoroughly understand the meaning of
relative humidity, as it is called, we will study a few extracts
from "Instructions to Voluntary Observers."* Humidity is
considered on a decimal scale, with 100 the saturation point of
the air, at which it will hold no more water vapor and 0 the
point at which air contains no moisture whatever. The vari-
•Issued by the United States Weather Bureau, Washington, D. C.
200
HUMIDITY 201
ous percentages between these points is a degree of humidity
relative to these two extremes, or relative humidity. The
quotations below are not contained in the recent issue of in-
structions, but are from the issue of 1892, which is now super-
ceded by that of 1897.
WATEE VAPOR IN AIR.
The air contains vapor of water, transparent and colorless like
its other gaseous components. It only hecomes visible on condens-
ing to fog or cloud, which is only water in a fine state of division.
The amount Is very variable at different times, even in the vicinity of
the ocean. The amount of moisture that can exist as vapor in the
air depends on the temperature. There is a certain pressure of va-
por, corresponding to every temperature, which cannot be exceeded;
beyond this there is condensation. This temperature is called the
temperature of saturation for the pressure. When the temperature
of the air diminishes until the saturation temperature for the va-
por contained is reached, any further fall causes a condensation of
moisture. The temperature at which this occurs is called the dew
point temperature of the air at that time. The less the quantity of
moisture the air contains, the lower will be the temperature of the
dew point. For different saturation temperatures, the weight of va-
por, in grains, contained In a cubic foot of air Is as follows:
Temperature VT'eight in a
of Saturation, Cubic Foot, Grains.
Degrees F. . __
0 0.56
10 0.87
20 1.32
30 1.96
40 2.85
50 4.08
60 5.74
70 7.98
80 10.93
90 14.79
100 19.77
The air is never perfectly saturated, not even when rain is fall-
ing; neither is it ever perfectly dry at any place. Relative humid-
ity expresses relative amount of moisture in the air only as long as
the temperature of the air remains constant. For this reason relative
humidity is an imperfect datum. At a low temperature even a high
relative humidity represents a very small amount of vapor actually in
the air, while a low relative humidity at a high temperature repre-
sents a great deal.
The most important law relating to above concise state-
ments, and one which, if carefully noted and apphed, will
make all work in humidity easily understood, is best expressed
thus: The capacity of air for moisture is increased with its
temperature. Strictly speaking, air has no capacity for mois-
202 PRACTICAL COLD STORAGE
ture, the water vapor being simply diffused through the air
after the nature of a mechanical mixture. For all practical
purposes, we may regard it as being absorbed by the air, and it
is usually so treated.
At a temperature of 40° F., air will hold in suspension
more water vapor than at any lower temperature (see table) ;
and when the difference is as much as 10° F., the difference in
the amount of moisture the air will hold is very considerable.
To illustrate: Air which is saturated with moisture at 30° F.,
when raised in temperature to 40° F., then holds but 68 per
cent of its total capacity.
INSTRUMENTS FOE DETERMINING HUMIDITY.
There are two kinds of instruments in use for determin-
ing humidity-hygrometers and psychrometers. The hygrometer
depends on the expansion and contraction of some substance,
as a human hair, in the presence of more or less moisture in
the air. The hair used is fastened at one end, the other end
passing around a pulley, to which is fastened a pointer, which
moves over a graduated arc as the hair changes its length
The scale reads from 0 to 100. The chief advantage of these
instruments is that results are obtained at once, the reading
corresponding to the percentage of saturation or relative hu-
midity; but these instruments are affected by changes of tem-
perature, and shocks or vibration materially affect the reading.
Further, they are more expensive in first cost, and not so
convenient to use, as they must hang for some time in the
room to be tested, while with the sling psychrometer, described
in another paragraph, an observer can pass from room to room,
getting observations in less than two minutes in each room,
needing but one instrument and making all observations at
practically the same time.
A psychrometer is simply two thermometers mounted on
a frame; the bulb of one being covered with muslin so as to
retain a film of water surrounding it. The working of this
instrument depends on a law which may be roughly expressed,
as "evaporation carries off heat." The evaporation of water
from the bulb incased in muslin, known as the wet bulb, cools
HUMIDITY 203
it somewhat, depending on how dry the air surrounding it
may be. The difference between the reading of the wet bulb
thermometer and the reading of the dry bulb thermometer,
when compared with reference to a prepared table, gives the
relative humidity of the air at the time of making the observa-
tion. Psychrometers are of two kinds, stationary and sling.
The stationary psychrometer is essentially like the sling
psychrometer, both depending on the same principle. The
sling instrument is more compact and provided with a handle
for whirling, while the stationary instrument is intended to
be fastened against the wall, or on a post, the musKn covering
the wet bulb being connected by a porous wick with a reservoir
of water, to keep the supply of water continuous. This is
essential, as it takes some little time to obtain a correct reading
with this pattern of instrument. For this reason it is open
to the same objections as the hygrometer. Also, after short
use the muslin covering the wet bulb, and the wick feeding
water to it, become clogged with solid matter and fungous
growth affecting its accuracy. At any temperature below 32°
F. this instrument is useless, as the water will freeze in the
wick supplying the muslin on the wet bulb, and the muslin
becomes dry in consequence.
For practical, accurate and quick results at any tempera-
ture there is no instrument so reliable and convenient as the
sling psychrometer, preferably of the pattern known as Prof.
Marvin's improved psychrometer, shown in Fig. 1. This is
a standard Weather Bureau instrument, and when used in con-
nection with the tables of humidity published by the bureau,
any needed results may be obtained with a fair degree of
accuracy. The sling psychrometer, as illustrated, consists of a
pair of thermometers mounted on an aluminum plate, one
higher than the other, the lower having its bulb covered with
a small sack of muslin. At the top, the frame or plate sup-
porting the thermometers is provided with a handle for whirl-
ing, this handle being connected by links to the plate, and
provided with a swivel to allow of a smooth rotary motion.
The bulb of the lower thermometer is wet at the time of mak-
ing an observation, the muslin serving to retain a film of
204
PRACTICAL COLD STORAGE
water, surrounding and in contact with
what is known as the wet bulb of the
psychrometer. The muslin should be
renewed from time to time, as the meshes
between the threads will gradually fill
with solid matter left by the evaporation
of the water and the natural accumula-
tion of dust from the air. The muslin
in this condition will neither absorb nor
evaporate the water readily.
HOVy TO USE THE SLING PSYCHROMETER.
To make an observation dip the mus-
lin-covered bulb in a small cup or other wide-
mouthed receptacle containing water. Whirl the
thermometer for ten or fifteen seconds, then dip the
wet bulb of the psychrometer into the water again.
Whirl again for ten or fifteen seconds, stop and read
quickly, reading the wet bulb first. Repeat once or
twice, noting the reading each time. When two suc-
cessive readings of the wet bulb agree very nearly,
the lowest point has been reached. Dip the wet bulb
only after the first whirling, as this is done only to
make sure that the muslin is thoroughly saturated
with water. If the water used is of nearly the same
temperature as the room, correct readings are sooner
obtained. If the psychrometer and water are at a
much higher temperature than the air of the room,
it will take a proportionately longer time to reach
a correct reading, but the accuracy will not be im-
paired, if sufficient time is allowed for the mercury
to settle. It is very important that the muslin-cov-
ered bulb should not become dry in the least; it
should be saturated with water during the full time
of observation. There will be no difficulty in get-
ting accurate readings down to 29° F., as indicated
FIG. 1.— by the dry bulb. At about this temperature, and
PSTCHRO- with the wet bulb at about 27° F., ice will form on
the wet bulb and cause the psychrometer to become
>f
HUMIDITY 20S
somewhat erratic in its behavior. Readings below 30° F. are,
therefore, very difficult to obtain, and it is only after repeated
trials that results may be obtained in some cases. By dipping
the instrument in water at a temperature near the freezing
point and then rapidly whirHng it results may usually be ob-
tained. A stationary hygrometer is entirely inoperative at any
temperature below 32° F., as the water in the fountain and wick
will freeze solid. The sling psychrometer, according to Prof.
Marvin, its originator, is supposed to be as accurate when the
wet bulb is covered with ice as when covered with water, but
this is not borne out by the author's personal experience. There
is something to be desired in the way of further information
on this point.
It is difficult to describe the proper movements for whirl-
ing the sling psychrometer, a little practice being the best
instructor. The handle is held in a horizontal position, the
frame mounting the thermometers revolving around the pivot,
after the manner of the weapon with which David slew Goliath,
and from which our moisture-tester gets the easy part of its
name. A high rate of speed is unnecessary, a natural, easy
motion of the forearm or wrist being all that is required. When
stopping the psychrometer the arm should follow the ther-
mometer from the highest point of the circle of rotation,
whereby the radius of the path of the psychrometer is in-
creased, and the momentum overcome. The stopping can be
accomplished in a single revolution, after a little practice.
The psychrometer will come to rest very nicely by simply
allowing the arm to stand still, but the final revolution will
be quite irregular and jerky.
In making observations in a storage room, the psychro-
meter should be held as far from the body as convenient, and
toward the direction from which the circulation comes — the
observer standing to the leeward as it were. In some cases
it is necessary, or advisable, to step slowly back and forth a
few steps, and the observer should turn his head from the
direction of the psychrometer so that his breath will not affect
the reading. In reading a thermometer, read as quickly as
possible, and do not allow the breath to strike the bulb. It is
206
PRACTICAL COLD STORAGE
a common practice with the author to hold his breath while
reading a thermometer. It is unnecessary to caution against
allowing the psychrometer to strike any object while whirling.
In case it should, the observer will have $5 worth of experience,
but no psychrometer.
The following short table needs no explanation further
than has been already given. It will cover most cases in cold
storage observations. It was not intended for cold storage
TABLE OF RELATIVE HUMIDITY, PER CENT.
t-l
H
Q
Difference between dry and wet thermometers (t—
t').
1^
0°.5
1°.0
1».5
2''.0
2°. 5
3°.0
3°.5
4''.0
4°.S
S'.O
s°.s
e'.o
a
25
94
87
81
74
68
62
56
50
44
38
32
26
25
26
94
88
81
75
69
63
57
51
45
40
34
28
26
27
94
88
82
76
70
64
59
53
47
42
36
30
27
28
94
88
82
76
71
65
60
54
49
43
38
33
28
29
94
89
83
77
72
66
61
56
50
45
40
35
29
30
94
89
84
78
73
67
62
57
52
47
41
36
30
31
95
89
84
79
74
68
63
58
53
48
43
38
31
32
95
90
84
79
74
69
64
59
54
50
45
40
32
33
95
90
85
80
75
70
65
60
56
51
47
42
33
34
95
91
86
81
75
72
67
62
57
53
48
44
34
35
95
91
86
82
76
73
69
65
59
54
50
45
35
36
96
91
86
82
77
73
70
66
61
56
51
47
36
37
96
91
87
82
78
74
70
66
62
57
52
48
37
38
96
92
87
83
79
75
71
67
63
58
54
50
38
39
96
92
88
83
79
75
72
68
63
59
55
52
39
40
96
92
88
84
80
76
72
68
64
60
56
53
40
41
96
92
88
84
80
76
72
69
65
61
57
54
41
42
96
92
88
84
81
77
73
69
65
62
58
55
42
43
96
92
88
85
81
77
74
70
66
63
59
56
43
44
96
92
88
85
81
78
74
70
67
63
•60
57
44
45
96
92
89
85
82
78
75
71
67
64
61
58
45
46
96
93
89
85
82
79
75
72
68
65
61
58
46
47
96
93
89
86
83
79
76
72
69
66
62
59
47
48
96
93
89
86
83
79
76
73
69
66
63
60
48
49
97
93
90
86
83
80
76
73
70
67
63
60
49
work, being a part of the regular humidity tables published by
the Weather Bureau. The full set of tables can be had by
addressing the chief of the Weather Bureau, Department of
Agriculture, Washington, D. C. They are published in
HUMIDITY 207
pamphlet form, along with tahles giving dew point tempera-
tures. Observers must work out the small fractions for them-
selves, if they think necessary, but results within the limits
covered by the table are near enough for practical purposes.
It is of no use to test for moisture unless having the
means to control it, any more than a thermometer would be
of use unless the means of regulating temperature were at
hand. Humidity can be controlled by ventilation, already
discussed, and the use of absorbents, which are considered in
the following chapter.
CHAPTER X.
ABSORBENTS.
USE OF ABSORBENTS IN COLD STORAGE.
The use of absorbents in cold storage rooms has been
common since the industry was in its infancy; their use
originating, no doubt, from an appreciation of the fact that
the air of a storage room quickly became too moist and impure
to do the work of preservation perfectly. When absorbents
and ventilation are applied to refrigerated rooms they prac-
tically have one duty in common — that of purifying the air.
Ventilation purifies by furnishing pure air which displaces
the foul air; absorbents by attracting the moisture, and with
it the impurities of the storage room. But while ventilation
is largely for the purpose of forcing out the permanent gases
or impurities which have little affinity for moisture, absorbents
are for the purpose of taking up the moisture and the germs
and impurities which are absorbed by it.
Active absorbents can be made to perform duty in absorb-
ing the moisture which is usually condensed on the cooling
coils, as illustrated in one style of the antiquated overhead
ice cold storages, called Prof.. Nyce's system. In this system
the ice is supported above a water-tight sheet iron floor which
forms the ceiling of the storage room, the air of the room
being cooled merely by contact with this cold metal surface,
which is cooled by the ice above. The moisture given off
by the goods in storage, and that resulting from air leakage
was taken up by an absorbent, chloride of calcium being the
chemical mostly in use for this purpose. It was applied by
suspending it in pans at the ceiling of the room, or in some
cases on the floor under the goods. Prof. Nyce's system gave
good results years ago in competition with the Jackson, Dexter,
208
ABSORBENTS 209
McCray, Stevens, etc., systems of overhead ice cold storage; and
which low temperatures, and the improved systems of air
circulation now in use have rendered obsolete to a greater or
less extent. Mention is made of this system not as recom-
mending it, but to show the possibilities of absorbents in
drying and purifying storage rooms.
LIME.
The two chemical absorbents in general use for taking
up moisture and the impurities from cold storage rooms are
chloride of calcium and lime (either unslaked or air-slaked, or
in the form of whitewash). (See chapter on "Keeping Cold
Stores Clean.") Occasionally waste bittern from salt works
is used, but the active principle of bittern is chloride of cal-
cium. Ordinary quicklime has the property of absorbing
moisture and impure gases from the air, and is used in very
much the same way as chloride of calcium ; that is, it is placed
around the room on trays or pans. Lime, however, has very
little capacity for moisture as compared with chloride of
calcium, and when exposed to the air it will simply air-slake,
which means that it will absorb moisture enough from the air
to disintegrate into the form of a powder. Lime in this form
is known as air-slaked lime, and is used to a large extent in
storage rooms. Air-slaked lime as it comes from the lime house
will absorb very little moisture, but it gives off minute particles
of lime which have a good effect in preventing the growth
of fungus, which we have already fully discussed. Air-slaked
lime is usually applied by spreading on the floor of the room,
between the 2x4s (which are used at the bottom of each pile
of goods) , to the depth of an inch or more. This must neces-
sarily be done when the goods are piled, and consequently
its efficiency is very low when the cool weather of fall comes.
This defect has been overcome by scattering fresh air-slaked
lime through the rooms so as to create a cloud of lime dust,
but this is objected to because it musses up the packages. A
better way of using lime is in the lump form (quicklime)
which can be placed around the top of the room in trays or
pans and renewed from time to time through the season.
210 PRACTICAL COLD STORAGE
CHLORIDE OP CALCIUM.
Chloride of calcium is the most vigorous absorbent (or
drier, as it is called) which we are discussing. It is the same
salt of the metal calcium as common salt (chloride of sodium)
is of the metal sodium. Both have a strong affinity for water,
but chloride of calcium is much the more energetic of the
two. Where, in moist air, common salt simply attracts enough
moisture to become damp, chloride of calcium will absorb
enough water to lose its solid form entirely, uniting with the
moisture of the air to form a solution or brine. The strong
affinity of this salt for water has been utilized for the purpose
of drying and purifying refrigerated rooms, and in this capa-
city has been a general favorite for years. The most primitive
method of applying it is to place it in a simple iron pan,
allowing the brine to run off into a pail as fast as formed. A
better way is to support the calcium on a screen of galvanized
wire, with a galvanized pan below for catching the brine.
This allows of a free circulation of air around the calcium.
This apparatus should be suspended near the ceiling of the
room, one end slightly higher, to allow the brine to run off
into a galvanized iron pail, supported at the low end of the
pan. Galvanized iron is specified because black iron rusts
badly when exposed to the air. (In the chapter on "Uses of
Chloride of Calcium" a complete description of the uses of this
material and illustrations of methods of applying are given.)
Do not in any method of using chloride of calcium evap-
orate the water from the brine and use the salt over again.
The impurities will stay in the salt to a large extent, which is
quite harmful, and the calcium has at least lost its value as
a purifier, to a large extent. The quantity of calcium neces-
sary depends on the conditions under which it is to be used,
but in any case it is safe to use much more than the author saw
in use in one eastern house. A room about 30x50 and about
fourteen feet high had the refrigerant shut off, and the room
was in rather bad condition as to moisture, etc. In each end
of the room a pail was placed, on which rested a wire screen,
with perhaps ten or fifteen pounds of chloride of calcium on it.
ABSORBENTS 211
Electric fans were playing on the calcium, which was doing its
best, but it seemed "like trying to dip the sea dry with a clam
shell." This room should have had at least two drums (about
1,200 pounds) at work in it to do it justice.
CHAPTER XI.
USES OF CHLORIDE OF CALCIUM.
CALCIUM CHLORIDE AS AN ABSORBENT.
Chloride of calcium is a substance which is known in
chemistry as a deliquescent salt, which term means that it
will become liquid by the absorption of moisture from the air.
It is obtained as a by-product in the preparation of ammonia
from ammonium chloride and lime; in the preparation of
potassium chlorate from calcium chlorate and potassium
chloride; in the ammonia-soda or Solvay process, and in the
manufacture of carbon dioxide or carbonic acid gas. The
greater portion of the commercial product comes from the
waste bittern from the salt works, and the Solvay process for
the manufacture of soda.
The capacity of chloride of calcium for water depends
largely on the temperature at which the solution from which it
is prepared is evaporated, and to the presence of a greater or
less percentage of impurities (chloride of magnesium, chloride
of sodium, gypsum, sulphates, etc.), some of which possess
comparatively little or no value as absorbents. Commercial
chloride of calcium, as generally prepared, holds about 25
per cent of water, and it will absorb in addition to this, when
exposed under average conditions in cold storage rooms, some-
where from one-half to nearly its own weight of water, de-
pending on humidity of the air, temperature, method of apply-
ing, etc. It is the most active moisture absorber, or drier — as
it is sometimes called — in common use, and because of its
low price ($10 to $15 per ton), it has come into general use
for many purposes. In general character, common salt (chlor-
ide of sodium) and chloride of calcium are similar, both hav-
ing strong affinity for moisture.
212
USES OF CHLORIDE OF CALCIUM
213
It is a well known fact that cold storage rooms are
purified to a large extent by extracting the water vapor which
is held in suspension by the air contained in the rooms. The
water vapor contains a greater part of the foul gases, germs
of decay, etc., which are given off by the goods, or introduced
into the rooms by admitting impure moist air from the out-
side. The water vapor laden with these impurities is dis-
posed of in mechanically refrigerated cold storage rooms by
being frozen on the cooling pipes. Because of the strong
FIG. 1.— CALCIUM SUPPORTED NEAR CEILING.
affinity of chloride of calcium for moisture, it can be utilized
to accomplish the same duty in moisture absorbing and puri-
fication which can be accomplished by the refrigerating pipes.
It has been in use for years for this purpose; the natural ice
cold storage houses having used it largely before the advent
of the refrigerating machine. When used in a room cooled
by air circulated directly from the ice, it is of very little service
except during very cold weather, because such a room is held
214
PRACTICAL COLD STORAGE
at a positive humidity by the air circulating continually in
contact with the moist surface of the melting ice.
The possibilities in the use of chloride of calcium for mois-
ture aborbing are well illustrated in the system of overhead
ice cold storage originated by Professor Nyce. (See chapter
on "Absorbents.")
The success of this system depends on chloride of calcium
as its only agent for moisture absorbing and purification, and
proves conclusively its value for the purpose, and those who
FIG.. 2.— METHOD OF CONSTRUCTION OF CALCIUM PANS.
are operating mechanically refrigerated houses can take some
ideas from this old system which will assist them through the
cold weather of fall and winter, when they are obliged to dis-
continue the flow of refrigerant through the cooling pipes.
When this becomes necessary, the frost on pipes must be
promptly cleaned off (which is at times impossible, owing to
the stock of stored goods in the room), or the frost will throw
USES OF CHLORIDE OF CALCIUM 215
off water vapor which is laden with impurities which have been
absorbed from the air of the room. The result is easy to fore-
see. The air becomes moist and foul, and goods stored in
such an atmosphere deteriorate very rapidly. The remedy for
such a state of things is to expose to the air of the storage
rooms a large quantity of chloride of calcium; or, what is
better still, this condition can be made impossible by prevent-
ing the formation of frost on pipes by the application of chlor-
ide of calcium by a process invented by the author, which will
be described further on.
DEVICES FOE APPLICATION.
The methods of applying chloride of calcium to the work
of moisture absorbing are numerous, but the devices illus-
trated and described here have been found to do well and will
fit almost any case that may come up. Fig. 1 is a cheap,
simple way of supporting the calcium near the ceiling of
room. It is best to support the calcium near the ceiling, as
the space is less valuable and the moistest air is to be found
there. The pan or trough of galvanized iron, shown in the
sketch, should be inclined toward the outlet, so that the liquid
calcium will flow off into a receptacle as fast as formed. The
pan is usually suspended over the alley-way between goods, so
that it may readily be refilled as required. These pans may
be of any size and shape desired, corresponding to the space
which they will occupy, but in placing them in the room
plenty of space should be left on the sides for the free access
of air. The pan shown in Fig. 2 is an improvement on the
first, in that the calcium is supported on a wire screen, several
inches above the pan below, allowing a free flow of air around
the calcium, exposing a greater siirface to the action of the air.
The liquid dripping from above covers the pan beneath with
a film of brine, and the air in contact with this brine will
give up its moisture to some extent, resulting in a more dilute
brine and, consequently, greater economy in the consumption
of the calcium. In other words, a pound of the calcium used
in the device shown in Fig. 2 will absorb more moisture than
the same quantity used in the device illustrated in Fig. 1,
216
PRACTICAL COLD STORAGE
The general explanation of proper method of using, given in
connection with Fig. 1, is equally applicable to Fig. 2. These
pans should be constructed of galvanized iron throughout,
as they are exposed intermittently to the action of the chloride
and the dry air outside when they are out of service; and,
j£ri\h^^-K^
^
rM^MAjf^f^
ylORlP
FIG. 3.— ARRANGEMENT FOR DRYING THE AIR IN ROOMS BY
USING CHLORIDE OP CALCIUM.
as the calcium will keep them moist a long time, the action
of the air in connection with this moisture will cause them
to rust badly. Any iron surface continually covered with cal-
cium brine will rust very little — no more, probably not as
USES OF CHLORIDE OF CALCIUM 217
much, as it would if exposed to the atmosphere under ordinary
conditions.
The device shown in Fig. 3 is a more positive and power-
ful arrangement for drying the air of storage rooms than either
of the two described. The chloride is placed in a tank or box
on wire screen shelves, as shown, and the air forced or drawn
through the box by an exhaust fan, which may be placed on
the inlet or outlet end, as may be most convenient. The moist
air should be taken from the top of the room to be dried, and
conducted to the bottom of box, the dry air to be taken out of
the top of box and discharged at the opposite end of the
room. In this way the moist air comes first in contact with
the liquid calcium, or brine, which lies at the bottom of the
box. As the drip from the top shelves drops from one shelf
to another, always in contact with the air moving upward, it
becomes more and more dilute. It will be seen, therefore, that
the air which is moistest comes first in contact with the dilute
brine at bottom of tank, and last with the dryest calcium at
the top of box. This results in a greater economy in the use
of calcium, and gives a more perfect drying effect. The de-
vices shown in Figs. 1 and 2 are much slower in their action,
because depending on the ordinary air circulation in the room
to bring the 'air containing the mixture in contact with the
calcium.
COOPER CHLORIDE OF CALCIUM PROCESS.
A better method of utilizing chloride of calcium than
those described has been designed and thoroughly tested by the
author. Claims fully covering this process have been allowed
by the patent office at Washington, and it has been put in
service in a large number of refrigerating plants. In this
system the calcium is made to perform two distinct duties, that
of keeping the pipes free of frost during warm weather, and
during cold weather, that of maintaining the air of the storage
room at the correct degree of humidity, at the same time main-
taining it in a pure state. The process is applicable to any of
the mechanical systems of refrigeration wherein a refrigerant
is circulated through coils of pipe, or to any system where
218 PRACTICAL COLD STORAGE
the rooms are cooled by refrigerated metal surfaces. A smaller
amount of surface is required to do a given refrigerating duty
when the pipes are clean than when the frost is allowed to
accumulate on the pipes, and the economy of a device which
will keep the refrigerating pipes free of frost at all times will
be appreciated by any person familiar with the business, as it
is well known that frosted pipes are insulated partly, the degree
to which they are insulated depending on the thickness of the
coat. We have Mr. E. T. Skinkle's ("The Boy") opinion that
this is probably about as the square of the thickness of the
frost. Mr. John Levey states: "Perhaps the best system of
using chloride of calcitim for reducing humidity is one de-
signed by Madison Cooper, in which the calcium is placed in
perforated troughs over the cooling pipes in such a manner
that the brine formed by absorbing moisture will trickle down
over the coils and cut off the frost. This not only reduces
the humidity of the air but increases the efficiency of the
coils from 15 to 25 per cent., and will result either in a lower
temperature in the rooms or a slowing down of the brine
pump to maintain the same temperature." The author's
process consists simply in placing a quantity of chloride of
calcium in proximity to the refrigerating surfaces, so that the
brine resulting from a union of the moisture in the air with
the calcium will drip over the refrigerating pipes. After pass-
ing down over the pipes, the brine falls onto a water tight floor,
which is provided with drip connections to the sewer, or the
brine may be collected and used as a circulating medium in
the system. This effectually and continually disposes of the
brine which contains the moisture and impurities from the air
of the storage room, therefore contamination from this source
is impossible. The apparatus illustrated in Fig. 4 is a simple
and effective manner of applying the calcium, although it can
be applied in any other manner to produce the desired result;
as in case of ceiling coils the calcium may be placed directly
on the pipe. The film of brine, covering the pipes, which is
produced in this way, practically prevents the formation of
frost, and the cooling surfaces of the pipes are, therefore, main-
tained at their maximum efficiency at all times. The eco-
USES OF CHLORIDE OF CALCIUM 219
nomical advantages of this process are great, the cost of install-
ing the apparatus very small, and the expense for calcium not
large.
The disadvantages of the system are very few, if any.
The chief one which has been suggested so far is that the
chloride of calcium brine trickling over the pipe surfaces
would cause the pipes to rust. Kather than rust the pipes, the
brine has a cleaning and protective effect, and coils which
Chloride or C^Lciur
|S^ (5| P
PIG. 4. — COOPER'S CHLORIDE OP CALCIUM PROCESS.
have been equipped with this process show freer of rust after
being in service for a few weeks than when first fitted up. It
is generally conceded by those who have observed carefully
that the most favorable condition for rusting of iron is alter-
nately wetting and drying in the presence of a free circula-
tion of air. When the pipes are coated with a film of brine,
no corroding action of consequence will take place, because
the air cannot have free access to the surface of the pipes.
220 PRACTICAL COLD STORAGE
The expense for chloride of calcium has also been cited as
an objection to the process. When it is considered that it is
only necessary to supply about the same weight of the salt as
of the frost to be kept off the pipes, it will be seen that expense
for this salt is of very small importance. The estimated
weight of frost which will accumulate on the pipes during
the season in a room of 20,000 cubic feet is about 2,000
pounds. The amount will vary greatly with the season of the
year, product stored, and whether room is opened often or not,
but above figures will cover average conditions. The cost of
calcium as compared with the economy which results from
maintaining clean pipes at all times is of small moment,
amounting to only a very small percentage of the saving
affected by maintaining the refrigerating surfaces at their
maximum efficiency at all times.
To show the possibilities of this process, combined with the
system of forced air circulation designed by the author and
fully described in the chapter on "Air Circulation," the fol-
lowing is quoted from a letter received from a gentleman using
these , systems. He says:
A remarkable thing is the small amount of cooling surface re-
quired. I put eleven coils, sixteen and one-half feet long, fourteen
pipes to the coil, in the coil room, and I am indeed surprised to find
that with this system I only need one of these coils, containing 231
feet of 1-inch pipe, brine entering at 14° F. from our ice tank.
This statement refers to the cooling of a room of about
20,000 cubic feet capacity to a temperature of 33° F. This
means that a lineal foot of 1-inch pipe is cooling about eighty-
five cubic feet of space, with brine at an initial temperature of
14° F.
Naturalh"^, this process, like all others, would have some
limitation as to its application; and this limitation is found
when a temperature of about 10° F. is reached. It has been
used successfully in a room where the temperature was car-
ried at 10° to 12° F., but when tested in a freezer at a tem-
perature of 8° F. the action of the calcium was very slow and
the process partly inoperative. At a temperature of 30° F. the
action is rapid, and no difficulty was experienced in keeping
a coil of sixteen 1-inch brine pipes, one above another, prac-
tically free of frost.
USES OF CHLORIDE OF CALCIUM 221
In case of slow action of the calcium in cutting frost
off pipes when it has already formed, or in low temperature
freezers, the action may be hastened by pouring strong chloride
of calcium brine over the lumps of calcium in the gutter and
allowing it to drip down over the pipes. This starts the ac-
tion and this may be repeated at intervals if necessary.
Brine circulating pipes can also be kept free from frost
by coating them on the outside with a very strong solution of
chloride of calcium using a brush dipped in brine for the
purpose; the moisture precipitated on them will not freeze
and form frost, but will be absorbed by the calcium and drip
off the pipes.
This can be done even after the pipes are coated with
frost and the frost will soon be absorbed and leave the pipes
bare. It is best, however , to coat the pipes with calcium
before starting to cool the room, then apply the brine during
the season as often as necessary to keep them clean. This
plan is especially adapted to small rooms where the coils are
placed over water-tight floors or pans to catch the drip.
PREPARING AND HANDLING.
The preparation of chloride of calcium for use is attended
with some very disagreeable features, unless a person has had
experience and knows the nature of the material to be handled.
Some of those who have used calcium have been discouraged
from using it again by the hard labor required to put it in
shape, and the wetting of floors it causes when carelessly
handled. It is also very destructive to leather shoes, and for
this reason rubber overshoes or rubber boots should be used
when handling this material. For the benefit of those who
have never handled this salt, and for those who have experi-
enced difficulty in its preparation, the following directions are
given, which if adhered to, will make the preparing of calcium
for use as simple a matter as any of the routine work about a
cold storage warehouse.
Chloride of calcium in the commercial form comes from
the manufacturers in the form of a solid cake, encased in an
air tight sheet iron jacket. These jackets are known as drums.
222 PRACTICAL COLD STORAGE
They are simply ordinary black sheet iron of a very light
gauge, and are of no value, and when removed from the cal-
cium may as well be thrown away at once. The drums of cal-
cium weigh about 600 to 700 pounds each, and, though heavy,
are easily rolled or trucked, and require very Uttle space for
storage.
For use, the calcium needs to be broken into lumps,
ranging in size from ten pounds downward. This is for con-
venience in handling and for the purpose of exposing a fair
amount of surface to the action of the air. For breaking the
calcium select a clear floor space, where nothing can be in-
jured by the moisture, which soon collects on the small pieces
which are scattered in breaking. Pound the drum with a
FIG. 5.— BREAKING UP DRUM OF CALCIUM.
sledge hammer, using strong, vigorous blows, working around
the drum and do not strike twice in the same place (see Fig.
5), as this tends to pulverize the calcium too much for easy
handling and for air drying purposes, though for brine mak-
ing the finer the calcium is broken the better. After pound-
ing the drum outside thoroughly, stand it on end and take
off the top of the drum by prying it out with an old ax or
chisel. It is then an easy matter to cut down the side with
an ax, when the sheet iron jacket may be easily removed. Any
large pieces needing further breaking may be reduced in size
without much trouble by striking on the flat side. It is a very
simple and easy matter to break the calcium in this way. An
active man will prepare and place a drum in an hour or so.
USES OF CHLORIDE OF CALCIUM 223
The calcium begins absorbing moisture from the air very
quickly, especially in warm, humid weather, and for this
reason when a drum is once broken into, it should be dis-
posed of as quickly as possible. The small pieces which fly
about when the cake is being broken should be swept up
promptly to prevent making a muss; some dry sawdust, scat-
tered over the place where the cake was broken, will be found
useful in taking up the moisture which accumulates. As
before stated, chloride of calcium is of a similar character to
common salt, and aside from the disagreeable property of
making everything damp with which it comes in contact, and
keeping it so for some time, is entirely harmless.
CIJLOBIDE OF CALCIUM BEINE.
A non-congealable liquid is used in- refrigeration as a
secondary or circulating medium for absorbing the cooling
effect of an expanding gas, and applying it directly to the
work to be done. This non-congealable liquid has been in the
past usually a solution of common salt in water; but of late
chloride of calcium has come into use quite generally for this
purpose. Probably the chief reason why it has not come into
general use before to the entire exclusion of common salt
brine, are : " That it is, or has been, much more expensive in
first cost; that it is more difficult to prepare and handle the
solution, and also that it cannot be obtained everywhere like
common salt. Chloride of calcium possesses positive advan-
tages over common salt for brine making. It is now used by
many of the leading engineers in the business, and where once
adopted, has not, in a single instance known to the writer,
been discarded for common salt. As the use of the so-called
brine coolers have made the brine circulating system more
desirable, and the brine system is now in favor for most
purposes, the proper understanding of chloride of calcium
and its use should be a part of the information possessed by
every engineer connected with the business.
Those who have written on the subject of refrigerating
machinery and refrigeration, have had very little to say re-
garding the merits of the two different salts for brine pur-
224
PRACTICAL COLD STORAGE
poses. Most of the information formerly available relates to
common salt brine, which is a sort of tacit recommendation
for its use; but brine and brine making in a general way
have until recently been given very little attention by writers
on refrigeration. In connection with some investigations bear-
ing on the process for preventing frost on refrigerating pipes
already described, the author has collected all the available in-
formation on the general subject of chloride of calcium, and
all facts obtainable show that calcium brine has important
advantages over that made from common salt.
The manufacturers or venders of chloride of calcium claim
that it is a better conveyor of refrigeration and that "it does
FIG. 6. — PIPE USED FOR POUR TEARS WITH CALCIUM CHLORIDE.
not eat up the pipes like salt." These claims are, roughly speak-
ing, true, and if the reasons why had been given, the claims
would have more weight with engineers. The author's reason
why chloride of calcium brine will not rust refrigerating pipes
has already been given in connection with the explanation
why calcium brine trickling over the pipes in the frost pre-
venting process will not rust the pipes. Probably ordinary
salt brine will not corrode the pipes very much more on the
inside, but wherever it has access to the exterior of the pipes
in contact with air, as from a leaky joint, the corrosion and
deterioration are much more rapid than where calcium brine
is used. It is probable that the impurities encountered in
USES OF CHLORIDE OF CALCIUM
225
common salt are responsible to a great extent for the peculiar
rotting action which it has in some cases on cast or wrought
iron or steel. Calcium also contains damaging impurities at
times. Figs. 6, 7 and 8 illustrate the "pitting" or corrosion of
pipe when using salt brine, and freedom from same when
chloride of calcium brine is employed. The surfaces of pipes
moistened by common salt brine, are, owing to varying condi-
tions causing a tendency to dry at one season of the year and
become moist at another, subject to the action so favorable for
the corrosion of the metal. Calcium brine will not, under
any conditions to be met with in cold storage rooms, give up
enough water to lose its liquid form, so will not allow of a dry-
ing out on the pipes except after a considerable length of time
has elapsed.
Without the aid of chloride of calcium the present perfect
types of brine coolers would not have been possible. Now the
» ''5 ' 4'
PIG 7.— INTERIOR OF A UNION USED IN SALT BRINE FOR THREE
YEARS,
brine cooler is recognized as a feature of nearly all up-to-date
cold storage plants, and in many ice factories the brine for
freezing is cooled in a brine cooler. The saving of space, low
cost, and perfection of interchange of temperature between the
ammonia and the brine, makes the brine cooler an ideal device.
Operating engineers appreciate the saving to them in care of
226 PRACTICAL COLD STORAGE
looking after a large number of expansion valves scattered
throughout the plant.
Obviously calcium brine has a great advantage over com-
mon salt brine at temperatures below zero F. Common salt
brine at its maximum density will freeze at about 7° below
zero F., while calcium brine can be made which will not
freeze at 50° below zero F. It will be seen that where a tem-
perature of zero F. or lower is required in cold storage rooms
with brine circulation, calcium brine only can be used. For
a given minimum brine temperature a less dense brine of
calcium can be used than of common salt, giving more con-
ducting power per pound. The advantages of this are that
a given weight of calcium brine can be made to convey more
FIG. 8.— PIPE USED FOR FIVE YEARS Vt^ITH SALT BRINE.
units of refrigeration than the same weight of salt brine
saving in the weight and amount of brine to be circulated.
Chloride of calcium brine has the advantage of not bein"
liable to deposit crystals in the pipes should the temperature
drop below normal, and there is practically no danger of
freezing if reasonable care is used in its preparation. Ref-
erence to the subjoined table shows that calcium brine has an
ultimate freezing point of about 54° below zero F. with a 30
per cent solution. A 25 per cent solution is all that is re-
quired in almost any work, and for most purjioses a 20 per cent
solution is amply dense. For ice making, where a brine tem-
USES OF CHLORIDE OF CALCIUM
227
PROPERTreS OF SOLUTION OF CHLORIDE OF CALCIUM.
BRINE.)
(CALCIUM
Cfa
6 .
<U
S
(■;
fc
3 S
t->.3
.a
--3
.5"
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3
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V flj
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Ob
0
•9 s 0
11.0
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£0
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m
1
a
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<
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'5
s.
Pressures
4
8
I
1.007
I
--31.10
— -5
46
•996
2
1. 015
2
--30.38
— -9
45
.988
12
3
1.024
3
--29.48
— 1.4
44
.980
i6
4
1.032
4
--28.58
— 1.9
43
•972
22
5-5
1. 041
5
- -27.68
— 2.4
41-5
•964
26
«-5
1.049
6
--26.60
— 3-0
39-5
.960
32
8
1.058
7
--25-52
-3-6
38
-936
36
9
1.067
8
--24.26
— 4-3
37
-925
40
10
1.076
9
--22.8
— 5-1
35-5
.gii
"^
11
1.085
10
--21.3
34
.896
48
12
1.094
11
--19.7
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32-5
.890
52
13
1. 103
12
--18.1
— 7-7
30.5
.884
^^
14-5
1. 112
13
-16.3
-8.7
28
.876
62
15-5
1. 121
14
--14-3
-9-8
26
.868
68
17
I.I3I
15
+12.2
—11.0
23-5
.860
72
18
1.140
16
--10.0
— 12.2
21.5
•854
76
19
1-150
17
--7-5
-13-6
20
•849
80
20
1-159
18
--4.6
—15-2.
18
•844
84
21
1.169
ig
-1- 1-7
—16.8
15
•839
88
22 '
1. 179
20
— 1.4
—18.6
12.5
.834
92
23
1.189
21
— 4-9
—20.5
10.5
.825
96
24
1.199
22
— 8.6
—22.6
8
.817
100
25
1.209
23
-11.6
—24.8
6.
.808
104
26
1.219
24
-17. 1
—27-3
4
-799
108
27
1.229
25
—21.8
—29.9
1-5
Vacuum.
•790
112
28
1.240
26
—27.0
—32.8
I
.778
116
29
1.250
27
—32.6
—35-9
5'
•769
120
30
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28
-39-2
-39-6
8.5
•757
31
1.272
29
-46.3
-43-5
12
32
1.283
30
-54-4
—48.0
15'
33
1.294
31
-52-5
—46.9
10
34
1-305
32
-39-2
—39-6
4
35
1. 316
33 ■
—25.2
-31-8
1-5
35-5
1-327
34 -
- 9-7
— 23.2
36.5
1-338
35 ■
- 2.8
— 16.2
37-5 1-349
36 -
--I4-3
-9.8
Note. — The -|- sign denotes ' temperature ' above zero, ths
temperature helow zero.
— sign,
perature of 10° to 20° F. is carried in the tank, a brine rang-
ing from 12 to 18 per cent is all that is required. The brine
must of course, be strong enough to prevent ice forming on the
228 PRACTICAL COLD STORAGE
expansion coils, so that the temperature of the expanding
ammonia must largely regulate the density of the brine. It
will be noted from the table that a very strong solution of
chloride of calcium has a much higher freezing point than
a more dilute brine. A brine containing too much calcium
is therefore to be guarded against. The most common test for
brine is the salometer, a hydrometer scaled from zero of pure
water to 100 per cent or more, which is about the point of a
saturated solution of common salt brine. A Baume hydro-
meter scale can also be used for ascertaining percentage of
calcium. The per cent of calcium given in the table represents
the total per cent, and as the commercial fused chloride of
calcium already contains about 25 per cent of water, more
of this article will be required for a given quantity of water
than is stated in the table. The small sub-table of approxi-
mate practical proportions of the commercial calcium and
water, for brine of a required test, will be found useful in
the making of brine. (See page 230) .
The preparation of brine, using chloride of calcium, is a
simple matter but somewhat slower than where common salt
is used, owing to the much smaller surface exposed to the
action of the water. It is difficult to break calcium by hand
into small grains like salt, therefore it dissolves comparatively
slowly. The simplest way is to put the correct proportion of
calcium and water in a barrel or barrels, and stir slowly with
a piece of gas pipe to facilitate solution. Another method is
to put the correct quantity of calcium and water in the brine
tank, and start the pumps running. The circulation of water
in contact with the crushed calcium is what is neces-
sary. Others use a steam pipe lead directly into the
brine tank or other receptacle. This is perhaps the more
rapid way, but it is not desirable, from the fact that the solu-
tion may not be at the correct degree when completed, be-
cause of the indefinite amount of steam necessary to effect a
solution. It is best to have the solution amply strong at first,
as it can be readily reduced by adding water in sufficient
quantity. If the live steam method is used, a good proportion
to put into the brine receptacle is six pounds of the calcium
USES OF CHLORIDE OF CALCIUM
229
to each gallon of water, or a drum to each 100 gallons. This
will make a very strong brine which can be diluted as required.
In testing brine it is necessary to have the solution at a tem-
FIG. 9.— HYDROMETER IN GLASS JAR.
perature of 60° F., as any variation from this temperature
will cause error in the test. The brine is easily warmed or
230
PRACTICAL COLD STORAGE
cooled to the correct degree. A glass hydrometer jar (see
Fig. 9) is useful, as supplying a convenient tall vessel, and
the scale on the hydrometer can be read more accurately than
with a piece of gas pipe with a cap on one end, which some
use.
The following table is the one referred to above for the
making of calcium brine and will be found of practical value :
PRACTICAL TABLE FOE MAKING CALCIUM BRINE.
Pounds Chlo-
ride of Calcium
Degrees
Freezing
(Commercial
BaumS,
Point,
fused) to one
60° P.
Degrees F.
gallon of water
2V2
80
20
4
3
88
22
— 2
3%
96
24
— 9
4
104
26
—17
4%
112
28
—27
5
120
30
—39
5%
...
32
—54
A part of the preceding tables and some of the informa-
tion contained therein has been kindly supplied by the manu-
facturers of chloride of calcium, and while the tables have
been proved inaccurate, they will answer for practical purposes.
CHAPTER XII.
ESTIMATING REFRIGERATING DUTY.
FACTOKS TO BE CONSIDEEED.
A query which comes up constantly in cold storage prac-
tice is the amount of refrigeration required for any given pur-
pose. One of the first questions asked by a prospective pur-
chaser of a refrigerating apparatus is "How much will it cost
to run it?" Such a question is not possible of accurate answer
without knowing the conditions, and the conditions are in
many cases difficult to determine. We will attempt to outline
the facts and information needed before calculations are pos-
sible which will give the figures so often called for by the above
question. Usually no calculations are made in handling the
problem, but what is known as "rule of thumb" method is
used, commonly so many linear feet of pipe for so many cu-
bic feet of space.
The sources of heat to be taken care of in connection with
the refrigeration of cold storage rooms may be roughly con-
sidered as follows:
First — Conduction through the walls containing the re-
frigerated space.
Second — Introduction of heat by means of goods or warm
air.
Third — Generation of heat within the refrigerated space.
It is obvious, from a consideration of these conditions,
that the volume or cubic capacity of the refrigerated space has
no direct bearing on the problem except perhaps to limit the
possible requirements; hence the common question as to the
cost of operating a given capacity is entirely "beside the
mark."
231
232 PRACTICAL COLD STORAGE
Necessarily there must be some unknown quantities to
deal with like opening of doors, workmen employed in the
rooms, etc., but we may calculate the greatest number of known
quantities obtainable and assume or estimate on the unknown
quantities. The refrigerating duty may be considered under
the following heads, although they combine partially in mak-
ing the necessary calculations :
First — Temperature to be maintained in the room.
Second — Temperature of the outside air.
Third — Exposed insulated surface of the room.
Fourth — Character and thickness of insulation employed.
Fifth — Quantity, temperature and kind of goods placed
in the room per day.
Sixth — Number of lights and workmen employed and
time.
Seventh- — Frequency of opening of doors and time stand-
ing open.
As this is a practical and not a scientific discussion we will
try to eliminate the unimportant and arrive at approximate
results, which as a matter of fact, is all that is possible in
advance of actual performance. Workmen in the room are to
be reckoned with sufficiently to place the goods in storage and
remove them therefrom, and this factor may be covered by
allowing a small percentage, say 3 per cent to 5 per cent to the
duty of cooling or freezing the product stored. About 1,000
B. T. U.'s per hour per person may be allowed. The burning of
lights is also another necessary factor, and practically keeps
pace with the time of workmen in the room. Modern electric
lights make very little heat, and the heat evolved by lights
may be omitted or estimated along with the heat from work-
men. About 160 B. T. U.'s for a 50 watt p. lamp per hour
may be allowed. The generation of heat within the space to
be cooled from fermentation of goods may be mentioned, but
cannot be specifically discussed as very little is known with
reference to this factor as applied to the different goods which
are commonly held in cold storage. If electric motors are used
for driving fans or pumps it may be considered that all the
electrical energy put into the motors is turned into heat and if
ESTIMATING REFRIGERATING DUTY 233
the motor is located within the refrigerated space this is some-
times worth considering. One electrical watt-hour may be al-
lowed as equal to about 3.2 B. T. U.'s.
The opening of doors is, in some cases, a very serious
thing, especially if the room is a retail cooler and has no ves-
tibule between it and the outer air. Also carelessness on the
part of workmen in leaving doors open is well known, and as
may be readily appreciated, even a rough assumption of an al-
lowance for this factor is almost out of the question.
This brings us then to the five factors which may be handled
with some degree of accuracy : Superficial area ; outside tempera-
ture ; room temperature ; insulation and goods stored. The differ-
ence between outside temperature and inside temperature and
the square feet of surface exposed taken with the conductivity of
the insulation really make one factor, which may be accurately
calculated by taking the average. Say, for instance, the day
temperature is 85° F. and the night temperature 55° F. Then
assume the inside temperature averages during the twenty-
four hours 35° F., and you have a difference between outside
and inside temperature of 35° F. Suppose now we assume
that the insulation is equal to 15 inches of mill shavings with
double boards and paper on each side. Stoddard gives this a
value of .03 B. T. U.'s or three one-hundredths of a B. T. U.
per hour per degree difference, or applied to our problem 1.05
B. T. U.'s. Call it 1 B. T. U. This would mean that one
pound of ice would take care of 142 square feet of surface un-
der the above set of conditions ; and applying this to a room say
20x30x12, which has 2,400 sq. ft. outside exposure, and divid-
ing by 142 gives about 17, the pounds of ice required to take
up the heat coming through the insulation per hour. Mul-
tiply by 24, and we get about 400, the number of pounds of
ice required per day. This is, of course, a very small amount
for the size of the room, but it is not often that as efficient
insulation is used, although it should be. The holding of tem-
perature then with good insulation is a very small matter
were it not for the other factors.
This brings us to the cooling or freezing of the goods,
which is by far the most important factor in many cases. In
234 PRACTICAL COLD STORAGE
determining refrigerating capacity required or amount of re-
frigerating or pipe surface necessary to do the work, the cool-
ing or freezing service to be handled must be considered as the
most important thing. Service means the use to which the
room is to be applied. If, for instance, the room is used for
the storage of eggs, which mostly go into storage in April dur-
ing cool weather, the refrigeration required will be to take
up the heat which comes through the insulated walls. On the
other hand, if the room is to be used for the cooling of freshly
killed poultry or freshly killed meat, then the heat which finds
its way through the insulation is of minor importance, and
the cooling of the product is of greatest importance.
If the weight of the goods to be cooled is known it is a
comparatively easy matter to ascertain accurately the amount
of refrigeration required for cooling, and in doing this we
must know the so-called specific heat of the goods to be cooled.
SPECIIflC HEAT.
Different products or substances of equal weight require
different amounts of heat to raise them to a given tempera-
ture. Water requires the most heat of any and is, therefore,
used as the unit of measurement. The figure which is used to
express the heat required to raise the temperature of any giv-
en kind of materia] 1 degree as compared with the amount of
heat required to raise an equal weight of water 1 degree, is
called the specific heat of that particular material. For in-
stance, eggs and poultry have a specific heat of .80. This
would mean that one unit of heat being required to raise 1
pound of water 1 degree, only eight-tenths of a unit would be
required to raise 1 pound of eggs or poultry. What is said as
applied to raising the temperature applies also to the lowering
of the temperature, and the following table covers some of the
goods which are carried in cold storage .
The last column showing latent heat of freezing refers to
the comparative effort required to freeze the various products,
based on the latent heat of freezing water into ice, which equals
142 heat units. It will be noted that the latent heat of freez-
ing the different substances is almost in direct proportion to
ESTIMATING REFRIGERATING DUTY
235
the amount of water contained in them, as compared with the
solids. Another point which will be noted is that fat meat re-
quires much less refrigerating effort than lean meat, for the
reason that it contains much less water.
Products
Specific
Specific
heat
heat
"Water
Solids.
above
below
Per cent.
Per cent.
freezing.
freezing.
B. T. U.'s
B. T. U.'s
per lb.
per lb.
72.00
28.00
0.77
0.41
51.00
49.00
0.60
0.34
63.00
37.00
0.70
0.39
39.00
61.00
0.51
0.30
70.00
30.00
0.76
0.40
74.00
26.00
0.80
0.42
91.00
9.00
0.93
0.48
59.25
40.75
0.68
0.38
87.50
12.50
0.90
0.47
80.J8
19.62
0.84
0.44
78.00
22.00
0.82
0.43
73.70
26.30
0.80
0.42
Latent
heat of
freezing.
B. T. U.'s
per lb.
Lean beef
Fat beef
Veal
Fat pork
Eggs
Potatoes
Cabbage .
Cream . . .
Milk
Oysters . .
Fish
Poultry . .
102
72
90
65
100
105
129
84
124
114
111
LATENT HEAT OF FREEZING.
The refrigeration required to reduce the temperature of a
given product through any specified range is practically con-
stant, but varies widely for different products as the above ta-
ble indicates. If the cooling process is not carried below the
actual freezing point of the product the amount of refrigera-
tion may be found by multiplying the specific heat of that
product by the number of degrees through which the product
is to be cooled. If the goods are actually to be frozen the
amount of refrigeration must be increased by the latent heat
of freezing, and if the product after freezing is to be lowered in
temperature still further the refrigeration required must be
still further increased by the specific heat of the product be-
low the freezing point multiplied by the number of degrees
through which it is cooled below freezing.
As an example we might consider 10,000 pounds of fresh-
ly killed poultry to be cooled through a range of 68° F. By
referring to the table it will be found that the specific heat of
poultry above freezing would be 0.80, and, therefore, the heat
to be extracted would be represented as follows:
0.80x10,000x68=544,000.
236 PRACTICAL COLD STORAGE
544,000 divided by 142 (number of B. T. U.'s per pound
of refrigeration) gives us the cooling equal to 3,830 lbs. about.
If the poultry is frozen the additional refrigeration will be as
follows :
10,000x105 (latent heat of poultry when freezing) =
1,050,000 B. T. U.'s which, divided by 142 gives 7,394 lbs.,
and if additional cooling to say 0° F. is required, the addition-
al refrigeration would be as follows :
10,000x0.42x32=about 134,400 B. T. U.'s or 946 pounds.
The total refrigeration duty required to cool the 10,000
pounds of poultry through a range of 68° F. freezing it at 32°
F., and then chilling it to 0° F. would be as follows:
3,830+7,394+946=12,170 lbs., which divided by 2,000
(number of pounds in a ton) gives us somewhat over 6 tons
of refrigeration required for the total work.
It should be noted in this connection that the poultry is
figured to be frozen at 32° F. whereas the actual freezing point
of poultry would be somewhat lower than this and, therefore,
the calculation is not absolutely correct, but near enough for
practical purposes.
ROUGH ESTIMATES FOR CUBIC SPACE.
As suggested at the beginning of this discussion estimates
based on cubic capacity are necessarily pure "rule-of-thumb"
estimates, but they are, of course useful as a guide, and the fol-
lowing figures are given as a rough approximation of the
quantity of refrigeration needed for cold storage houses of
varying capacity:
For storage houses of 1,000,000 cubic feet or over from
20 to 30 B. T. U.'s per cubic foot per day.
Storage houses of from 250,000 to 1,000,000 cubic feet,
25 to 40 B. T. U.'s per cubic foot per day.
Storage houses of from 50,000 cubic feet to 250,000, 35
to 50 B. T. U.'s per cubic foot per day.
Storage houses of from 15,000 to 50,000 cubic feet per
day, 40 to 75 B. T. U.'s per cubic foot per day.
Cooling boxes or rooms of from 1,000 to 10,000 cubic
feet, 60 to 100 B. T. U.'s per cubic foot per day.
ESTIMATING REFRIGERATING DUTY 237
Refrigerators or coolers of less than 1,000 cubic feet, from
100 to 500 B. T. U.'s per day.
Rooms which are used for chilling or cooling of such
goods as meats, etc., should have an allowance of 50 to 100
per cent additional, and for the actual freezing of goods the
amount should be multiplied by two or three.
To find the refrigeration required for a building of aver-
age insulation under average conditions an approximate
method may be used, by multiplying the exposed surface by a
factor which depends upon the temperature at which the build-
ing is to be carried and upon its size. Temperatures ranging
from zero to 32° F., for surfaces of less than 5,000 square feet
it may vary from 2.00 to .20. For buildings having from 5,000
to 20,000 sq. ft. of surface the factor of 1.5 to .15 may be used,
and for surfaces of buildings from 20,000 sq. ft. upward from
1.2 to .12 respectively. These figures, it must be noted, are
for average insulation. Good insulation should not require
more than one-half the above figures. Average insulation is al-
together too poor in quality or not enough of it in thickness,
but insulation has been discussed elsewhere.
It is customary to allow in packing house work one ton
of refrigeration for the cooling of ten 750 pound cattle, or
thirty-five 350 pound hogs, and a rough estimate for small
plants is a ton of refrigeration for from five to seven beeves
and the same amount for from fifteen to twenty-five hogs. An-
other rough estimate is a ton of refrigeration for from 3,000
to 5,000 pounds of meat to be cooled. It must be noted in
this connection, however, that all these rough estimates give
a large surplus of capacity on account of small plants, and
the actual requirements are very much less.
For average conditions and with fair insulation and for
plants of 25 to 50 tons and larger for general cold storage
warehouses one ton of refrigeration in 24 hours will maintain
the following capacities and temperatures :
12,000 cu. ft. of general storage space at 32°-35°F. temperature.
sioOO cu. ft. of egg storage space at 28°-30°F. temperature.
5,000 cu. ft. of butter storage space at 10°-14°F. temperature.
3,000 cu. ft. of game and poultry storage space at 10''-18°F. tem-
perature.
2,000 cu. ft. of game and pultry storage space at Q°F. temp.
238 PRACTICAL COLD STORAGE
Modern Refrigerating Machinery states that:
"In breweries one ton of refrigeration will maintain 8,000
cu. ft. of general storage space at 30° to 36° ¥., or will cool
40 barrels of beer-wort from 70° to 40° F.
In abattoirs and packing houses one ton of refrigeration
will maintain
10,000 cu. ft. of curing space at 35°-40°P.
3,000 cu. ft. of freezing space at 20°P.
1,500 cu. ft. of freezing space at 0°F.
If the number of animals is known, independent of the
heat losses through walls and exposed surfaces, one ton of re-
frigeration is required to properly chill
7-10 beeves, each weighing about 700 lbs., and surrounding space.
20-25 hogs, each weighing about 250 lbs., and surrounding space.
50-60 calves, each weighing about 90 lbs., and surrounding space.
70-75 sheep, each weighing about 75 lbs., and surrounding space,
CHAPTER XIII.
EGGS.
IMPORTANT FACTORS TO BE CONSIDERED.
Eggs are the most important goods now taken care of
by cold storage methods, both as regards aggregate value and
benefits to the community. They are also among the most
difficult products to successfully refrigerate. In 1898 the au-
thor estimated the total value of eggs under refrigeration for
safe keeping at about $20,000,000 annually for the United
States alone. Statistics show that the consumption of eggs
doubles every five to ten years. Therefore the value of eggs
annually cold stored in the United States at this time (1913)
cannot be very far from $70,000,000. Appreciating the im-
portance of the industry and the lack of accurate information
available, the author, some years ago, in the interest of a bet-
ter understanding and dissemination of knowledge on the cold
storage of eggs, communicated with quite a large number of
individuals and companies, requesting that they give full an-
swers to a printed list of questions sent them. The result was
most gratifying; nearly one-half of those written to acknowl-
edged receipt of the inquiry, and more than one-half of this
number gave fairly complete replies to the questions sub-
mitted. Considering the fact that the inquiries were regarded
by some as being of a rather personal nature, the proportion
of managers sending replies in full was large. Several gentle-
men were frank enough to say that personal considerations
prevented them from giving any information; others gave
guarded or partial replies. In the main, however, storage men
have shown themselves willing to give information and ex-
change ideas.
The list of inquiries sent out covers the subject quite thor-
oughly, and divides it into six different parts, namely, tempera-
239
240 PRACTICAL COLD STORAGE
ture, humidity, air circulation, ventilation, absorbents and
packages, with three separate questions relating to each. To
the data furnished by others is added information from the
author's experience and practice with such explanation of un-
derlying laws as may seem necessary to a clear understand-
ing of the principles of successful egg refrigeration. It is
hoped that those who are new to the business may obtain valu-
able information from these collected data, and that those
with experience may derive some benefit in the way of a re-
view, and possibly pick up some new ideas as well.
TEMPERATURE.
Questions regarding the correct temperature of egg rooms
have been asked repeatedly of storage men who have been in
the business long enough to be looked to for advice, the same
person, perhaps, giving a different answer from time to time,
as his ideas change. There is no temperature on which a large
majority of persons can agree as being right, and as giving su-
perior results to any other. The claims made by the advo-
cates of different temperatures will be considered, to determine,
if possible, what degree is giving the best results in actual
practice.
The three questions relating to temperatures were writ-
ten to draw out opinion as to the right temperature, the low-
est safe temperature, and what deleterious effect, if any, the
egg sustained at low temperatures, which did not actually
congeal the egg meat. The three temperature queries
were:
First. — At what temperature do you hold your rooms for
long period egg storage?
Second. — What temperature do you regard as the low-
est limit at which eggs may be safely stored?
Third. — What effect have you noticed on eggs held at a
lower temperature?
All the replies received contained answers relative to tem-
perature, and by a very small majority 32° F. is the favorite
temperature for long period egg storage. Some few, 33° F.
and 34° F., with a few scattering ones up to 40° F. Under
EGGS
241
the freezing point, none recommended a temperature lower
than 28° F,, and for a very obvious reason, this being near
to the actual freezing temperatrue of the albumen of a fresh
egg. A jery respectable minority say a temperature ranging
from 30° F. to 31° F. is giving them prime results; and sev-
eral recommend 30° F. straight, and say they should go no
lower. In recent years there has been a decided tendency
among storage men to get the temperature down near the safety
limit, but many houses are so poorly equipped that they are
unable to maintain a uniformly low temperature below 33°
F., without danger of freezing eggs where they are exposed
C
'^ ^
«^f*^--
^
*I«M
t>
!||lMn
[
•
T
1
1 '
^J;_
\:-
FIG. 1. — VIEW IN EGG ROOM SHOWING METHOD OF PILING THE
EGGS. NOTE PERFORATED FLOOR AND CEILING.
to the flow of cold air from coils. A house must be nicely
equipped to maintain low temperatures with safety. More
houses would use temperatures under 32° F. were they able
to without danger to the eggs. A very successful eastern house
issued a pamphlet in 1892. At that time they maintained a
temperature of from 32° to 34° F. in their rooms. In sending
out this little book during the winter of 1897-98 a postscript
was added, as follows : "This pamphlet was published in 1892,
when our plant was started. Since that time all first class
cold storage houses have lowered their temperatures mater-
ially." No better illustration than this can be cited to show
242
PRACTICAL COLD STORAGE
the tendency of the times. These people now use a tempera-
ture of 30= F. for eggs.
Most of the replies received contained answers to the sec-
ond question, and the greater portion state this as being about
2° F. lower than that recommended for long period storage
It is presumed that these two degrees are allowed as leewa>,
or margin of safety, for temperature fluctuations. Some state
that eggs cannot be safely held below 32° F., but give no rea-
son why, while two or three say a temperature of 27° F. will
do no harm to eggs in cases. One reply states that eggs held in
FIG. 2. — EGG ROOM — FALSE FLOOR AND FALSE CEILING SYSTEM
OF COOLING.
cut straw at 25° F. for three months showed no bad symptoms.
It has never been made clear how the package can be any
protection against temperature, when the temperature has been
continuously maintained for a length of time sufficient to al-
low the heat to escape; and eggs will positively freeze at 25° F.,
as proven by experiments mentioned in another paragraph.
The answers to the third question were few in number,
but cover a wide range. The scarcity of data on this point in-
dicates that few have experimented with eggs at temperatures
ranging from 25° F. to 30° F. Some say: "dark spot, de-
EGGS 243
noting germ killed"; others, "white gets thin"; others, "eggs
will decay more quickly"; or, "they will not 'stand up' as long
when removed from storage." It is also claimed that "yolk
is hardened or 'cooked' when temperature goes below 32° F."
Some answers state a liability of freezing if eggs are held in
storage at a temperature below 32° F. for any length of time.
As far as possible, we will dig out reasons for the claims
made by advocates of both high and low temperatures, both
having equal consideration. Taking 29° F. or 30° F. and
38°F. or 40° F., as representing the lowest and highest of
general practice, we will see what is claimed by each; and
also the faults of the other fellow's way of doing it, as they see
it. Those who are holding their egg rooms at 40° F. say it is
economical, that the eggs will keep well, that the consistency
of the egg meat is more nearly like that of a fresh egg after
being in storage six months, than if held at a lower tempera-
ture. As against a low temperature they say: A temperature
of 30° F. is expensive to maintain; the yolk of the egg be-
comes hard and the white thin, after being in store for a
long hold; and that when the eggs are taken from storage in
warm weather it will require a longer time to get through
the sweat than if held in storage at a somewhat higher tem-
perature, resulting in more harm to the eggs. Some claim
that the keeping qualities are impaired by holding at a tem-
perature as low as 30° F., and others note a dark spot, or clot,
which forms in the vicinity of the germ, when eggs are held
below 33° F. Against this formidable array of claims, the
low temperature men have some equally strong ones, although
fewer in number. They say: "There is very much less mil-
dew, or must, at 30° F. than at temperatures above 32° F. ;
the amount of shrinkage or evaporation from the egg is less;
an egg can be held sweet and reasonably full at this tempera-
ture from six to eight months." This last claim is a broad
one, and comparatively few houses are turning out eggs an-
swering to this description.
The following, relating to high temperatures, is quoted
from a letter written by one of the best posted men in the
business, who has spent much money and time on experi-
244 PRACTICAL COLD STORAGE
ments, and studied the question for years. He says : "A tem-
perature of 40° F. is very good for three months' holding,
but if they run over that, it is more than likely the eggs will
commence to cover with a white film, which grows the longer
they stand, and finally makes a musty egg." This gentleman
advocates a temperature of 30° F. for long period holding. It
should be noted that the high temperature men ignore entirely
the effect of high temperatures on the growth of this fungus,
spoken of as a white film. The worst thing about most storage
eggs is the taste caused by this growth (usually called mildew
or mold), which results in what is commonly called a musty
egg. To enable us to understand the validity of these claims
made by the 30° F. people, it will be necessary for us to as-
certain the conditions which are favorable, and also the con-
ditions which are unfavorable for the propagation of this
growth of fungus, which has given storage men so much
trouble, ever since cold storage was first used for the preserva-
tion of eggs.
Heat and moisture are the two conditions leading to its
rank growth, and the opposite — dryness and cold — will retard
or stop the growth entirely. In moist, tropical countries many
species of this parasite grow, while in the cold, dry regions
of the north its existence is limited to a single variety. The
causes leading to a growth of the fungus on the outside of an
egg are not far to seek. It feeds on the moisture and pro-
ducts of decomposition which are being constantly given off by
an egg, from the time it is first dropped until its disintegration,
unless immersed in a liquid, or otherwise sealed from con-
tact with the air. This evaporation not only takes moisture
from the egg, but carries with it the putrid elements from the
egg tissue, resulting from a partial decomposition of the outer
surface of the egg meat. Conditions of excessive moisture and
the presence of decaying animal or vegetable matter, together
with a moderate degree of heat, are essential to the formation
of fungus of the species which are found growing on eggs in
cold storage. As the heat and moisture are increased, the
growth of fungus will be proportionate. Furthermore, we all
understand that heat hastens decomposition, and the partial
EGGS 245
decomposition of an egg results in a growth of the fungus, as
before explained, when conditions of temperature and hu-
midity are favorable. If the temperature is low, this growth
is slow; for instance, if eggs are held at a temperature of 30°
F. in an atmosphere of given humidity, the growth of fungus
is less rapid than if held at any temperature higher, with the
same per cent of humidity. As our subject merges into hu-
midity here, the reader is referred to what is said in regard
to this under the head of "Humidity."
Returning to the objections iirged against low tempera-
tures, we will see what damage is claimed from the use of a
temperature of 29° to 80° F. The objections are: Liability
of freezing ; germ is killed ; white becomes thin ; yolk is hard-
ened, and eggs will not keep as long when removed from stor-
age. Some interesting results are obtained from experiments
made by the author. Half-rotten or "sour" eggs freeze at
temperatures just a trifle under 32°. Fresh eggs freeze at 26°
to 27° F. In testing eggs which had been held in storage for
several months, it was noted that the freezing point had been
reduced from 1° to 2° F. An egg which is leaky will freeze
at 2° to 3° higher temperature than one which is sound, prob-
ably owing to the evaporation from the uncovered albumen re-
sulting in a lower temperature. The freezing point of eggs,
as above, is understood as being the degree at which they be-
gin to form ice crystals inside. Of the replies received touch-
ing on the freezing point of eggs, nearly all agree with above
experiments. The "dead germ" theory the author has never
been able to locate in fact, having never seen anything of the
kind in eggs held as low as 28° to 29° F. for several weeks'
time; nor in eggs held at 30° F., or a trifle under, through
the season. As only two or three mention having noted this
result, it would seem that some local conditions, and not low
temperature, were responsible.
The matter of the white becoming thin when eggs are
held at low temperatures has some bearing; in fact, any egg
held at a cold storage temperature for a long carry will show
this fault, to a certain extent, especially if cooled quickly when
stored, or warmed suddenly when removed from storage. It
246 PRACTICAL COLD STORAGE
is the author's opinion that a difference of 4° to 6° F. in
carrying temperature will not be noticeable in its effect on
the albumen of an egg; and as to the effect of a low tempera-
ture on the egg yolk, it has been demostrated that any tempera-
ture, which will not actually congeal the albumen, will not
harm the yolk of an egg. There is a slight tendency, in this
case, to a similar effect to that produced by a low temperature
on cheese; that is, causes it to become "short" or crumbly.
In regard to a low temperature egg not keeping as long
when removed from storage, it has been the experience of the
author that no difference was noted between the eggs put out
from storage and the current receipts of fresh eggs, so far
as any complaint or objection was concerned, the eggs being
shipped in all directions, in all weathers and subject to many
different conditions. A test was also made, by placing three
dozen of eggs, which had been carried in storage at a tempera-
ture of 28° to 30° F. for five months, in a case along with
three dozen fresh eggs. After three weeks no pronounced
change was noted in either, both showing considerable evap-
oration as a result of exposure to the dry fall atmosphere. They
were exposed to the temperature of the receiving room, fluctu-
ating from 50° F. to 80° F. The eggs from storage went
through a "sweat," while the fresh were not subjected to any
such trial. As most eggs are consumed inside of three weeks
after being removed from storage, this would seem like a good
practical test of the vitality of a low temperature egg. A
mere matter of economy between holding a room at 40° F.
and from 29° to 30° F., while readily appreciated and ad-
mitted, seems of very small importance, when a positive ad-
vantage can be obtained by carrying eggs at the lower tem-
perature; and a difference of from 4° to 5° F. would be scarce-
ly worth considering.
An advantage of low temperature, not yet mentioned, is
the increased stiffness, or thickness, of the white of the egg
while in storage, holding the yolk in more perfect suspen-
sion. When eggs are held at a temperature of 36° F., or
above, for any period longer than four months, the yolk has
a decided tendency to rise and stick to the shell, causing rot-
EGGS 247
ten eggs, known as "spots." It is usually understood that
the yolk settles ; but, being of a fatty composition, it is lighter
than the albumen, and rises instead. If the albumen is main-
tained in a heavy consistency, the yolk is retarded from rising,
and held in a more central position. It was long a practice
with storage men to turn eggs at least once during the sea-
son, to prevent the above trouble, and some recommend it
even now ; but the practice has been generally abandoned with
the advent of low temperatures for egg storing.
It should be noted that what is said above applies to con-
ditions as they were some twelve or fifteen years ago, but the
same general ideas prevail at this time with reference to the
storage of eggs. Fifteen years ago or more the author was the
first to advocate a storage temperature of 30° F. for eggs. Now
very few eggs are stored at a temperature above 31° F., and
the most of the big city houses carry them at temperatures
ranging from 28° F. to 30° F. The author recommends 29°
F. as being the best temperature everything considered for
general long period egg storage purposes; 28° F., is perfectly
safe if using an improved system like the Cooper false floor
and false ceiling system, described in the chapter on "Air
Circulation," but it is not safe with direct piped rooms, as
eggs may freeze near the cooling pipes, whereas the tempera-
ture will be considerably higher in the center of the room near
the ceiling. Eggs will not freeze at 28° F., but they will
freeze at 27° F. and possibly at 271/2° F. If, therefore, the egg
room does not go below 28° F. it may be relied upon that
good, sound eggs will not freeze.
When eggs are put in cold storage they should not be
cooled rapidly. The effect on the egg tissues is bad — they
should have time to rearrange themselves to the changed tem-
perature. This is especially true where eggs are placed in
storage in extreme warm weather. Sudden warming is also
detrimental to the welfare of an egg, for a similar reason to
above. The most noticeable effect of either is a thinned albu-
men. Tf this process of cooling and warming could be ac-
complished slowly (which is not always practicable commer-
248 PRACTICAL COLD STORAGE
cially), a well kept storage egg would come out of storage
with nearly the same vitality it had when fresh.
HUMIDITY.
Information on the subject of humidity, as applied to
the cold storage of eggs, is very meager. Not more than a
dozen of the replies received in answer to the list of inquiries
sent out contained information on the three queries under the
head of humidity. Considering the amount of talk we have
all heard, with dry air as a subject, this scarcity of knowledge
is rather surprising. Those who have had experience with cold
storage work and the products handled are well aware that an
essential for good results in egg refrigeration is a dry atmos-
phere in the egg room ; but just how dry, very few are able to
give even an approximate estimate. Very likely if a cold
storage man is asked in regard to it, he will reply that an
egg room should be "neither too moist nor too dry." What
this "happy medium" is, that will not shrink or evaporate
the eggs badly, and yet keep down the growth of fungus to
a minimum, is what all are striving for, and very few have
the means of knowing when this point is reached. A few
years ago a prominent commission man, in conversation with
the author, speaking of storage eggs, said: "You storage men
are between the devil and the deep sea. You always shrink
'em or stink 'em"; meaning that eggs which were held long
m storage would show either a considerable evaporation or a
radical "musty" flavor. To some extent this is true, but with
a penetrating circulation, careful ventilation and a judicious
use of absorbents (all of which are considered under their
proper heads) eggs can be, and are, turned out of storage
without this strong, foreign flavor, and with little evaporation
or shrinkage.
The questions relating to humidity were written with a
full understanding of the scarcity of information on the sub-
ject, and were designed to locate, if possible, those who were
making tests of air moisture, and get opinions on the correct
humidity for a given temperature. The following are the
queries :
EGGS 249
First.— What tests, if any, have you made of the dryness
or humidity of your egg rooms?
Second. — What per cent of air moisture do you find gives
the best results at the temperature you use?
I'hird. — What instrument do you use for testing air mois-
ture?
The first and third questions are practically the same, the
latter being written simply to make the query plainer and
indicate whether an instrument or some other test was used
for determining air moisture. Four houses reporting were
using the dry and wet bulb thermometers; the others were
using hygrometers of French or German make.
The answers to the second question varied greatly; some
also giving actual testing humidity of their rooms and their
opinion of a correct degree as well. From 70 to 80 per cent
of humidity is the test of nearly all reporting, and of the
rooms tested by the author, nearly all show a similar humidity,
with one occasionally going as high as 85 per cent, and some
as low as 65 per cent. Two answers recommended a humidity
of 65 per cent, and one a humidity of 60 per cent, with a tem-
perature of 30° to 32° F. Others hold that their testing hu-
midity of 70 to 80 per cent is correct.
Under the head of "Temperature," it is stated that: "If
eggs are held at a temperature of 30° F. in an atmosphere of
a given humidity, the growth of fungus is less rapid than if
held at any temperature higher with the same per cent of hu-
midity." By referring to the table on page 168 we see that a
cubic foot of air, when saturated at a temperature of 40° F.,
contains 2.85 grains of water vapor, while at 30° F. it con-
tains but 1.96 grains, or only about two thirds as much as at
40° F.
The same hold true with any relative humidity, the same
as when the air is saturated. Take, for instance, air at a tem-
perature of 40° F., with a humidity of 75 per cent, then a cu-
bic foot of air holds 2.14 grains of water vapor per cubic foot;
and at a temperature of 30° F., with the same relative humid-
ity, it would hold but 1.47 grains. This great difference in
the amount of moisture contained in the air at different tem-
250 PRACTICAL COLD STORAGE
peratures, and still having the same relative humidity, has as
radical an effect on the growth of fungus as does the difference
in temperature. This is no mere theory, as the writer has
demonstrated it, to his own satisfaction, at least, during several
seasons' observation. If it is hoped to keep down the growth
of fungus in a temperature of 40° F. by maintaining an at-
mosphere with a lower relative humidity, the result is a badly
evaporated egg, which loses its vitality and value very rapidly
when held in storage for a term exceeding three or four
months; the white becomes thin and watery, with a strong
tendency to develop "spot" rotten eggs. As the fullness or
absence of evaporation is of only secondary consideration to
their sweetness, when eggs are tested by buyers, it is necessary
to prevent this trouble if the eggs turned out from storage are
to be considered first-class.
From the foregoing it seems clear that to turn out sweet
eggs at a temperature of 40° F. it is necessary to maintain a
lower relative humidity than at any temperature lower, and
the result cannot fail to be as described. The author has al-
ready given a summary of the replies to the questions relat-
ing to humidity, which are few in number, and not very
complete. A little is better than nothing, however, and by
comparing his own data with the results obtained by others,
and paying careful attention to their opinions, the following
table of correct humidity for a given temperature in egg rooms
has been compiled. There are no data on the subject in
RELATIVE HUMIDITY FOE A GIVEN TEMPERATURE IN EGG ROOMS.
Temperature Relative Humidity
In Degrees F. Per Cent.
28 85
29 83
30 80
31 79
32 75
33 74
34 70
35 68
36 66
37 64
38 61
39 59
40 56
EGGS 251
print, so far as known, and no claim for absolute accuracy is
made in presenting this first effort in that direction, but as
the figures are taken from actual results, no great mistake can
be made by depending on them. The percentages of humidity
given are modified, to some extent, by the intensity and dis-
tribution of the air circulation employed .
CIRCULATION.
A thorough and penetrating circulation of air must be
maintained in a cold storage room for eggs if good results are
to be insured, and the importance of this condition is quite
generally appreciated. It is also a fact that a strong, search-
ing circulation will do much to counteract defects in a cooling
apparatus, or wrong conditions in the egg room in some other
particular.
The reason why a thorough and well distributed circula-
tion of air in an egg room will give superior results over a slug-
gish or partial circulation may not be readily apparent. A
circulation of air is of benefit in combination with moisture
absorbing capacity in the form of frozen surfaces or deliques-
cent chemicals. Stirring up the air merely, as with an elec-
tric motor fan, without provision for extracting the moisture,
is of doubtful utility, and may, in some instances, prove posi-
tively detrimental, as it is liable to cause condensation of
moisture on the goods, or walls of storage room, instead of its
correct resting place — the cooling coils and absorbents. Let us
see how the circulation of air in a storage room operates to
benefit its condition.
Under head of "Temperature," we have seen that the
evaporation from an egg contains the putrid elements result-
ing from a partial decomposition of the egg tissues, and that
the air of a storage room carries them in suspension. It is
probable that these foul elements are partly in the form of
gases absorbed in the moisture thrown off from the egg; and
if, therefore, this moisture is promptly frozen on the cooling
pipes, or taken up by absorbents, the poisonous gases and pro-
ducts of decomposition are very largely rendered harmless.
This is also true of the germs which produce mold and hasten
decay, which are ever present in the atmosphere of a storage
252 PRACTICAL COLD STORAGE
room, being carried to a considerable extent by the water
vapor in the air, along with the foul matter of various kinds
referred to. If the vapor laden air surrounding an egg is not
removed and fresh air supplied in its place, the air in the im-
mediate vicinity of the egg becomes partly charged with ele-
ments which will produce a growth of fungus on its exterior,
afifecting and flavoring the interior — the flavor varying in in-
tensity, depending on how thoroughly impregnated with fun-
gus-producing vapor the air in which the egg is kept may
be. In short, then, circulation is of value because it assists in
purifying the air. It should be kept up so that the air may be
constantly undergoing a purifying process to free it from the
effluvium which is always being thrown off by the eggs, even at
very low temperatures.
The questions bearing upon circulation contained in the
list of inquiries sent out by the author are as follows ;
First. — In piping your rooms what provision was made
for air circulation?
Second. — What difference in temperature do you notice in
dififerent parts of the. same room?
Third. — Do you use a fan or any kind of mechanical de-
vice for maintaining a circulation of air in the rooms?
More answers were received on this subject than on the
subject of humidity, but not exceeding one-third contained
practical replies to all three inquiries. Several of the answers
confounded circulation with ventilation, as before alluded to.
The flrst question, in particular, was badly neglected, indicat-
ing, no doubt, that no provision was made for circulation in
a majority of cases. The common device in use for causing air
to circulate more rapidly over the cooling coils, when they
are placed directly in the room, is some form of screen, man-
tle, apron, false ceiling or partition. Many of these have been
put up after the house has been in operation for some time,
and are very crude afFairs, applied in all conceivable combina-
tions with the pipe coils. In some cases canvas curtains, or a
thin wooden screen, have been suspended under ceiling coils
with a slant to cause the cold air to flow off to one side, and
with surprising improvement to the room, considering the
EGGS 253
simplicity of the device. Forced circulation with a complete
system of distributing air-ducts is coming into general use, as
the merits of this way of producing circulation are better un-
derstood and appreciated.
The second question was answered more generally, but
that some of the answers were mere guesses, or statements
made without testing, is very evident, as they state that no
difference was noticed in different parts of the same room.
With open piping or gravity air circulation, this is an im-
possibility— it is only possible with a perfectly designed forced
circulation system. In contrast to this claim some answers
state a difference in temperature of as high as 4° to 5° F.,
but most answers show a difference of 1° to 2° F.; a few of
%° to 1° F. ; and, still others, as before stated, none at all. A
marked variation of temperature in different parts of a room,
while in most cases caused by defective circulation, is due some-
times partly to location of room as to outside exposure, prox-
imity to freezing rooms, character of the insulating walls,
etc. An egg room placed over a low temperature freezing
room will show more variation between floor and ceiling than
when located over another egg room, conditions being other-
wise the same. Where this arrangement occurs, and the egg
rooms are operated on a natural gravity air circulation system,
eggs may be frozen near the floor, when a thermometer hang-
ing at the height of a person's eyes would read 30° F. or
above. Even with the very best insulation, the result of this
very common arrangement is a defective circulation and
more or less variation in temperature between floor and ceil-
ing.
In reply to the third question, about a dozen state that
they are using some form of mechanical forced circulation.
The advantages of this method are discussed quite fully else-
where in this book. About double this number are using the
small electric fans. These also have been treated in the dis-
cussion of mechanical air circulation in another chapter.
As air circulation is a somewhat neglected subject, and
'comparatively few have experimented enough to have posi-
tive opinions, based upon practical experience, regarding the
254 PRACTICAL COLD STORAGE
merits of different devices and methods, some of the more
prominent and successful ones are illustrated and discussed
elsewhere in this book. (See chapter on "Air Circulation.")
VENTILATION.
The introduction of a large volume of fresh air is not
essential for the purpose of purifying rooms in which eggs are
stored, because the accumulation of permanent gases in an
egg room is quite slow, comparatively (as in rooms where
well ripened fruit is stored) ; but a small supply of fresh air
continuously, or at regular intervals, is of much benefit.
The questions referring to ventilation contained in the
letter of inquiry sent out by the author are as follows :
First. — What plan do you pursue in ventilating egg
rooms?
Second. — Under what circumstances and how often do
you ventilate?
Third. — How often do you consider it advisable to make
a complete change of air?
Outside of a bare dozen, the replies on this much-talked-of
subject were of no value whatever for our purpose. Most of
those answering do not ventilate; many others get their ven-
tilation through the opening of doors; some ventilate through
an elevator shaft, by opening doors at top and bottom, etc.
Only three or four were properly cooling and drying the air
before introducing it into the egg rooms. One successful stor-
age manager says that : "It is trouble enough to take microbes,
bacteria, moisture, etc., out of one batch of air" (meaning the
air in his rooms at the beginning of the season) , without add-
ing to his troubles by sending in more air loaded down with
the same mischief makers. As pointed out in the chapter on
"Ventilation," unless the air to be used for purifying the
rooms is itself first cooled and purified, this man's idea is per-
fectly correct. Ventilated egg rooms will, however, turn out
eggs which are in every way better than from rooms not ven-
tilated, other conditions being equal. Eggs from ventilated
rooms are clearer and stronger bodied (albumen thicker) than
from non-ventilated rooms.
EGGS 255
No accurate data have yet been established regarding the
volume of fresh air which is advisable to use for ventilating
egg rooms, but it is a simple and inexpensive matter to supply
enough, and too much cannot be used if it is first properly
dried and purified and brought to about the same temperature
as that of the storage room. Ordinarily it is unnecessary to
ventilate egg rooms until filled with goods and closed for the
season. After a short time (two to four weeks) begin ventilat-
ing, as the accumulation of gases commences at once as soon
as the rooms are permanently filled and closed. Ventilate in
small quantities and for several hours at a time once or twice
a week, rather than iri large quantities less often.
For a discussion of the principles involved and mechanical
details of this subject see chapter on "Ventilation."
ABSORBENTS.
The letter of inquiry sent out by the author contained
three questions referring to absorbents, written with an idea
of ascertaining the coating used for the walls of a storage to
the greatest extent; what absorbent was the favorite, and in
what manner applied. The questions are as follows:
First. — Do you use an absorbent or purifier in your egg
rooms?
Second. — In what way do you use or apply them?
Third.— Do you paint or whitewash? What kind and
how often applied?
The most common wall coating in use for egg rooms is
plain, every-day whitewash, in various proportions of lime and
salt. Several recommend one part of lime and one of salt.
This makes a very good whitewash, giving a firm, hard sur-
face, but unless some method of blowing warm, dry air through
the rooms is feasible, it will dry very slowly, which is likely
to cause it to have a mottled appearance instead of the. pure
white which gives a storage room such an attractive appear-
ance. A better proportion for ordinary cold storage work is
three parts of lime and one of salt. This mixture^ will dry
faster, and will give a white surface which will not easily rub or
flalce off. There are many formulas for good whitewash, some
256 PRACTICAL COLD STORAGE
of them so complicated as to be impracticable ; but plain lime
and salt, with perhaps the addition of a little Portland cement,
will be good enough for our purpose. See chapter on "Keeping
Cold Stores Clean" for details of whitewash making, etc.;
also chapter on "Uses of Chloride of Calcium" for applica-
tion of his material, also chapter on "Absorbents."
STORAGE PACKAGES.
Eggs are continually giving off moisture from the time
they are first dropped by the hen until they disintegrate,
unless sealed from contact with the air, and we can therefore
never hope to keep them in cold storage for several months
without their losing some weight by evaporation. To prove
that eggs must evaporate, the following experiment was tried
by the author in his early experience : An ordinary 30-dozen
egg case was lined with tin, with all joints carefully soldered.
The eggs were then placed in the fillers in the tin lined case in
the usual way. and an air-tight tin cover soldered on, forming
a hermetically sealed package. After about sixty days' stay
in an ordinary refrigerator the tins were unsoldered. The
result noted was peculiar and startling. The inside of the
tins was dripping wet, and very foul smelling, and the eggs
were all rotten. This same experiment was tried by a friend,
working independently and without knowledge of the author's
experiment. He used an ordinary fruit jar, with screw top
fitting onto a rubber ring. His results were similar. In addi-
tion this gentleman packed some eggs in flour in a fruit jar,
otherwise under the same conditions as the other experiment.
The eggs packed in this way were all found to be in good
condition when the jar was opened, as the moist evaporation
from the eggs had been taken up by the flour. These experi-
ments prove beyond a doubt that an egg must evaporate con-
tinually, and they prove, further that the eggs must be sur-
rounded by some medium which will absorb this evaporation.
In the chapter on "Air Circulation" it is explained how
the air is best circulated so as to remove the moisture and
impure gases from the vicinity of the goods. This must be
done, otherwise the fillers and package containing the eggs
EGGS 257
would shortly be in as bad condition as the fillers in the experi-
ment just mentioned. The theory and explanation of the other
conditions in the storage room necessary for successful egg
refrigeration have also been taken up under the various heads.
We will now look into the requirements of the package con-
taining the eggs while in cold storage.
The questions contained in the letter of inquiry relating
to the egg package are as follows:
First. — AVhat egg package have you found to turn out
the sweetest eggs?
Second. — Have you used any kind of ventilated egg case,
and with what results?
Third. — Have you ever used open trays or racks, and with
what results?
As many different people have experimented with different
packages, hoping to get something which would turn out per-
fectly sweet eggs, with little evaporation, the replies received
to the questions relating to packages are interesting, and many
contained information valuable as data. The favorite package
is the ordinary 30-dozen egg case, made of whitewood, using
medium weight hard calendared fillers. The term whitewood
is usually meant to include either poplar, cottonwood or bass-
wood, but two or three other varieties of wood, not so well
known, are designated as whitewood. Basswood is by some not
placed in the whitewood list, but the best authority known to
the author says that basswood is as properly a whitewood as
poplar or southern whitewood. Poplar and cottonwood are
most in use for storage purposes, and many insist that bass-
wood is objectionable because of its liability to ferment or
sour and cause tainted or musty eggs. All kinds of cases have
been in storage in the house operated by the author, and if
all were thoroughly dry, no difference could be noted in the
carrying qualities of the different kinds of whitewood, and the
preference has been for well seasoned basswood cases. It may
be that basswood is more likely to sour and affect the eggs than
poplar or cottonM'Ood,: but it is always advisable to get stock
for egg cases in the fall and have them nailed up during the
winter allowing two or three m:onths for the cases to season
258 PRACTICAL COLD STORAGE
and dry out before the opening of the egg storing term. Some
have dry kilns for cases, but a naturally seasoned case is to be
preferred, as then it has a chance to deodorize as well as dry
out. In some localities other woods are used for egg cases.
Ash, maple, hemlock and spruce have been used for storage
cases, generally because they are cheaper than whitewood in
that locality. Any strong scented wood like pine will not do
because of the flavor imparted to the eggs.
The pasteboard frames and the horizontal dividing or
separating pasteboard pieces which form for each egg an in-
dividual cell in the case are usxially spoken of as fillers. For
years only one grade of these was made — those of ordinary
strawboard. When moistened by the evaporation from the
eggs this material has a peculiar rank odor, which was taken
up to some extent by the eggs if they were allowed to remain
in the fillers for several months. Much of the flavor resulting
from a growth of fungus has been laid to the fillers, and much
of the flavor resulting from flUers has been laid to a growth of
fungus or must, but there is no question about strawboard fillers
not being a perfect material for cold storage use. Many kinds of
fillers have been tried, and many ideas suggested for the im-
provement of cold storage eggs. A whitewood pulp filler made
its appearance some years ago, but did not come into general
use. After being in, storage a few months, it absorbed moisture
to such an extent as to become very soft, and they were
objectionable on this account. A good manila odorless is
now on the market which is giving good satisfaction where
tried. Ordinary strawboard fillers have been coated with vari-
ous preparations, shellac, paraffine, whitewash, etc. Any sub-
stance in the- nature of waterproofing might better be left off
for the reason, as we have seen, that eggs must evaporate, and
a waterproof filler would hold the moisture and not allow it
to escape into the air of the room. It is essential to the well
being of an egg that it should evaporate, as proven by the ex-
periments in hermetically sealing, before described. Many
have gone to the expense of transferring the eggs into dry
fillers in the middle of the season. One season of this was
enough for the author. A better way is to decrease the hu-
EGGS 259
midity of the room as the fillers become more and more loaded
with moisture. The humidity may be decreased by the use of
absorbents or by ventilation, as already discussed in their prop-
er places. Fillers made of thin wood have been used in years
gone by with fair success, but their manufacture has now
been entirely discontinued. They were made of maple, shaved
very thin, and were a prime filler so far as odor was concerned,
but in cold storage the frames warp badly, and the time and
eggs wasted in getting the eggs out of the fillers was a serious
item against their use. As a shipping filler they were also a
failure because of the excessive breakage. Some years ago
an eastern company began the manufacture of what is known
as the odorless fillers. These fillers are light brown or buff
in color, and from the best information the author can obtain,
are composed largely of scrap paper stock, with some long fibre
like manila added for strength. In the manufacture the
stock is treated to a thorough washing and deodorizing process,
and the result is a filler with very little odor. Eggs put up
in these so-called odorless fillers and subjected to the same
conditions as a similar grade of eggs packed in common straw-
board fillers have come out of cold storage in better condition
in a good many cases. A ventilated filler made by a well known
creamery supply house, has been suggested as an ideal filler
for cold storage, but they are so poor mechanically that they
are not to be thought of. The material cut away to form the
air circulation space weakens the structure of the filler to such
an extent as to make it dangerous as a shipping filler. What-
ever filler is used, it should fit the cases, not crowding in, nor
still so loose as to shake. If this point is looked after much
breakage and consequent poor results from storage in the cold
room may be avoided.
Many styles of ventilated egg cases have been placed on
the market in years past, but very few or none survive the
test of time. A ventilated case, made by having the sides cut
an inch narrower than the ends, has come into use, especially
in one large eastern city. Making the sides narrower forms a
space of half an inch on both sides of case at top and bottom,
for the ready access of air to the interior of the case. This case
260 PRACTICAL COLD STORAGE
is of very simple construction, and efficient in allowing a free
circulation of air into the case. Others, however, prefer a
case with sides in two pieces, claiming that the cracks will
allow enough air circulation. Still others prefer the shaved or
veneered cases with solid sides and bottom, claiming that this
kind of a case will prevent excessive evaporation from the eggs.
As pointed out elsewhere, humidity and circulation have much
to do with the evaporation from eggs; in fact, are of much
more importance than the package, although the package
necessarily has much to do with it. A tight package will allow
of less evaporation than an open one. In a very dry room with
a vigorous circulation a moderately tight package is the thing,
but in a comparatively moist room with poor circulation the
more open the package the better.
An appreciation of the poor circulation and damp air of
the overhead ice systems has caused many of their operators to
resort to the use of open trays or racks for the storage of eggs.
Very palatable eggs have been turned out in this way, but
the use of trays in any ammonia or brine cooled room would
lead to very excessive shrinkage of the eggs and consequent
heavy loss in candling. On a commercial scale, too, the stor-
ing of eggs in trays is hardly practicable, as it increases the
risk of breakage immensely, and the eggs must be transferred
from the cases when received at the storage house, and back
into cases again when shipped, involving much labor, and
perhaps loss of valuable time at some stages of the market. In
any but a very moist room, eggs stored in open trays, in bulk,
will lose much from evaporation, and the loss will be propor-
tinately higher than on an equal grade of eggs stored in or-
dinary cases and fillers. The advantage of trays, if any, for
some houses, is that contamination from fillers is avoided,
and about 40 per cent more eggs can be stored in a given
space. The eggs are, however, more liable to must as a re-
sult of moisture condensing on their surface with change of
temperature, or on the introduction of warm goods into the
storage room.
The material used for forming a cushion in the case on
top and bottom of the fillers to protect the eggs from contact
EGGS 261
with the case, and so that they will carry in shipping, is gener-
ally either excelsior, which is finely shaved wood, usually bass-
wood, or the chips made in the manufacture of corks, known
as cork shavings. The big cold storages have in the past recom-
mended cork in preference to the best excelsior. Here again
comes a question of dryness. If the excelsior has been in stock
for a year and stored in a dry place it is to be preferred to
cork shavings, otherwise cork is the best, because we know cork
is always dry. Cork makes a very poor cushion as compared
to excelsior; it is liable to shift in the case, leaving one side
without protection. As a matter of cost, too, cork is much
more expensive than excelsior. If people want cork in their
cases they can have it by paying the price, but dry, seasoned,
fine basswood excelsior is better, for reasons stated. The best
houses are now recommending dry excelsior in place of cork
on account of the excessive breakage when a cushion of cork
is used.
Eggs have been packed in oats for years, but the practice
has gradually fallen off, as eggs stored in cases from the best
cold storage houses have been improved in quality from year
to year. Oats, if dry, will absorb moisture from the eggs quite
rapidly, and are objectionable on this account. If the oats
are not dry the germs of mold are developed rapidly, and as
the moisture is given off by the eggs the mold will grow,
causing the eggs to become "musty." Therefore the main
difficulty in using oats as packing for eggs in cold storage is
to have them at the correct degree of dryness. It is almost
impossible to have them in the same condition at all times.
Oats have also been used in cases inside the fillers; that is, the
layers of eggs are first put into the filler ; then the oats are sifted
into the spaces around the eggs flush with the top of the filler.
This is repeated through the whole case; all the space in the
case not occupied by the eggs being filled with oats, excepting
the small space taken by the fillers themselves, the object being,
of course, to prevent the "filler taste."
At intervals we read of some method of preserving eggs,
which is said to be sure to supersede ordinary cold storage
for the good keeping of eggs. A scheme was tried on a large
262 PRACTICAL COLD STORAGE
scale somewhere across the water, in which the eggs were sus-
pended in racks in a cold room — the racks being turned at
regular intervals by automatic machinery to keep the eggs from
spoiling; that is, to keep the yolk from attaching to the shell.
A low temperature will prevent this, as pointed out in this
chapter under the head of "Temperature," and why a man
should waste good energy inventing such a machine is pass-
ing all comprehension. The quantity of various chemical
preparations manufactured and sold for egg pickling or pre-
serving is even now quite large, but the high class stock now
turned out by the best equipped cold storage houses has made
any other method of preserving eggs at the present day almost
entirely obsolete.
HINTS.
There is a long string of "don'ts" in regard to packing,
handling and storing eggs which might be put down, but the
author will be content with a few of the simpler and most
useful ones. To start with, don't store very dirty, stained,
cracked, small or bad appearing eggs of any description. Have
your grade as uniform as possible. The culled eggs will usually
bring within two cents of the market price, and it pays better
to let them go at a loss rather than try to store them. Don't
use fillers and cases the second time; they are more likely to
cause musty eggs than the new ones. Don't ship eggs in cold
cars or place eggs which are intended for storing in ice boxes.
In shipping eggs from the producing section to the storage
house in refrigerator cars, no ice should be put in the bunkers,
because if the eggs are cooled down and arrive at their destina-
tion during warm or humid weather they will collect moisture
or "sweat," and an incipient growth of mold will result. Don't
use heavy strawboard fillers for storing eggs. If "the best
way to improve on a good thing is to have more of it," then
the best way to improve on a poor thing is to have less of it;
and if strawboard fillers are objectionable, then the thinner
they are the better, because less of the material is present to
flavor the eggs. Further, the thin board fillers are more por-
ous, and allow of a freer circulation of air around the eggs.
EGGS 263
The grade known as "medium" fillers are best for cold stor-
age purposes. As already stated, odorless fillers are better
than any strawboard fillers. Don't use freshly cut excelsior.
It should be stored in a dry place at least six months. Use
no other kind but basswood or whitewood. Don't store your
cases, fillers or excelsior in a basement or any damp place.
Don't run warm goods into a room containing goods already
cooled when it can be avoided. For this reason very large
FIG. 3. — VIEW IN EGG TESTING ROOM.
rooms are not to be desired. A small room may be quickly
filled with goods and closed until goods begin to go out in the
fall. If a large room is used it may require several weeks to
fill completely, during which time the fluctuation of tempera-
ture is at times excessive, causing condensation on the goods,
which will propagate must quickly.
To illustrate : We will suppose the egg room partly filled
with goods cooled to a temperature of 30° F. Several cars of
eggs at a temperature of, say, 70° F. are run into the same
264
PRACTICAL COLD STORAGE
room. The new arrivals, in cooling to the low temperature,
give off large quantities of vapor from cases, fillers and the
eggs themselves, the vapor condensing, of course, on any ob-
ject in the room which is below the dew point of the air from
which the warm goods came. This may seem like a finely spun
theory, but the author has had some experience which amply
justifies this explanation. That the moist vapor given off by
the warm goods does not show in the form of beads of water,
or fog, or steam, is no proof that it does not exist. If the ex-
tremes of temperature are as great as 25° F. condensation will
occur on nine days in ten during the egg storing season. The
goods already in storage are raised in temperature materially
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FIG. 4.— PLAN OP EGG TESTING BOOTH,
by placing in warm goods, which is harmful to some degree.
The logical deduction from above seems to indicate that warm
goods should not be placed in a room with goods which have
been reduced to the carrying temperature. A separate room
should be provided for this purpose near the receiving room
in which the goods coming in warm may be cooled to very
nearly the temperature of permanent storage room. This is a
refinement which small houses cannot afford, and which most
of the larger ones do not have.
EGGS
265
carefully from time to time through the season and compare
quality with those from other houses.
It should be positively understood that merely theoretical
knowledge on this subject is of only limited assistance; and
those who undertake new work are advised to put a man in
charge who has had experience with the product which it is
proposed to handle in storage, as well as acquaintance with
the mechanical details of the plant.
CONSTRUCTION OF EGG CANDETNG ROOM.
The construction of rooms to be used for the testing or
candling of eggs has not reached a stage where it may be
stated that there is any design which might be called standard
or that is generally approved by the trade. Nearly every pro-
PIG. 5._SECTION OF EGG TESTING BOOTH.
prietor has his individual ideas on this subject, and, therefore,
nearly every different plant is fitted up in a different way. The
266
PRACTICAL COLD STORAGE
booth system, which consists of individual stalls or separate
small rooms for each person, is coming into general favor. The
advantage of this system is that each person works by him-
self, and, therefore, better work is possible, and each operator
must stand on his own individual merits. In other words, the
system allows of a closer inspection and a closer systematizing
of the important operation of candling eggs.
The number of booths necessary depends upon the volume
of business to be handled and any number of booths may be
arranged in a large room, which may be called the "Candling
Eoom." (See Fig. 10.) Candling is simply a misnomer in this
^ H0W5 l^fjiam.
Candler m»^'
FIG. 6.— DETAIL OF CANDLER.
connection and originated from the fact that a candle was or-
iginally used for testing eggs. Very few candles are now in
use for this purpose and the electric light is in general favor.
The construction of the booth is subject to some modifica-
tions; the one shown in accompanying view, plan, section and
elevation, also detail of candling box or candler (see Figs. 3,
4, 5, 6 and 7), has been proved by practical service to be eco-
nomical of space and, withal, convenient. As shown, sufficient
shelf room is provided for fillers above a plank table on which
rest cases which contain the eggs to be tested and for the dif-
EGGS
267
ferent grades into which the eggs are classed. With the size
booth shown, sufficient room is provided for five cases on the
table. ^ The booth may be constructed of a single thickness of
boarding on three sides and top, the fourth side being closed by
a curtain of heavy, dark colored denim, or any suitable mate-
rial. This curtain should be hung on a wire or rod with rings
so as to slide easily, and it may or may not be divided in the
center. In Fig. 3, which is reproduced from a photograph, is
shown the booth system in service. The white candling boxes
FIG. 7. — FRONT ELEVATION OF EGG TESTING BOOTH.
show plainly in the center of the booths. Cork shavings used
as a cushion at top and bottom of egg cases are shown in the
box between booths. The barrels are intended to receive the
litter of various kinds, such as old newspapers, which accom-
pany country packed eggs. The pail for rots is shown above
the barrel.
The candling box or candler which contains the electric
light or lamp may be constructed of ordinary egg case material
one-quarter of an inch thick. One-half -inch quarter round is
268
PRACTICAL COLD STORAGE
nailed into three corners of this box, inside, to strengthen it.
The fourth corner is pierced with two holes placed close together,
as shown in the detail. The holes should be one and one-quarter
inches in diameter. The bottom of the candler is left open so
that light from the electric lamp may be thrown into the cases
on the table below. The top of the candler may be partly
closed by a piece of cardboard, or otherwise, in case too much
light is reflected to the ceiling so as to make the candling room
too light for close candling. The circulation of air, however,
through the candling box should not be entirely shut off, for the
reason that it will cause rapid destruction of the electric lamps
by overheating. u . !
FIG.
-EGG CANDLING .SCENE, MAIN RECEIVING ROOM FLOOR.
Sometimes the candler or candling box is made of tin or
sheet metal about four inches in diameter and six to ten inches
in height. In one or both .sides of this cylinder a single oblong
or oval hole is provided about one and one-fourth inches in its
shortest dimension and about one and one-half to two inches
in its greatest dimension, or separate holes may be provided as
suggested in connection with the box above described. Very
EGGS 269
good candlers or egg testers as they are sometimes called are
to be had on the market ready made and usable either with
electric light, kerosene lamp or candle.
The details of candler or tester are subject to many modi-
fications to suit individual ideas. The question of candling two
eggs at once or singly has been much discussed among profes-
sional egg candlers. Many prefer the candler with two holes,
and still others insist that one hole is sufficient. The author
has personally used the booth and candler described and be-
lieves it to be equal to anything which has come to his knowl-
edge. All dimensions are given on the diagrams so that the
construction of the booth sj^stem as above described will be
simple for those who desire to test the practicability of the
scheme as applied to their local requirements.
The room in which the booths are arranged, or what may
be called the candling room proper (see Fig. 10), should be of
FIG. 9.— REFRIGERATED EGG CANDLING ROOM.
sufficient size to accommodate the handling of goods in and
out of the room and allow space for empty cases, fillers, etc.,
and it should also be large enough to provide storage space for
one or two days' packing. The room should be insulated in
any fairly substantial manner, and means for maintaining same
at about 55° to 60° F. in warm weather should be provided.
In other words, we should provide a cold storage room for
candling eggs. Eggs coming in from the country during warm
270
PRACTICAL COLD STORAGE
weather may be placed at once in this room and should be re-
duced to a temperature of about 55° to 60° F. before being
candled.
FIG. 10.— PLAN OP CANDLING ROOM.
EGGS 271
It is fully understood among practical egg shippers that
when eggs come in from the country in hot weather they often
appear to be in very much worse condition than they really are.
After being cooled to about 60° F. the eggs may be candled and
judged for their actual quality. A refrigerated candling room
is also a great benefit in stopping further immediate deteriora-
tion when the eggs come in heated. The more progressive
modern egg houses which are being erected at the present time,
where cold storage is an adjunct, have refrigerated candling
room facilities. The value of these arrangements will be at
once appreciated by those who have had experience in candling
eggs during the heated term.
The candling room may be refrigerated in any suitable
way, but a fan system of air circulation is generally preferred
about on the lines shown in plan of candling room. In this
way the cold air from coils is distributed along the floor on the
opposite side of the room from the operators and the warm air
is taken out over their heads, above the booths. It is advisable
to provide openings in the top of the booth for a circulation of
air; these openings to have hinged doors so as to regulate the
circulation.
The cooling pipes may be placed in a box or bunker near
ceiling of the room and a drip pan provided underneath. This
will avoid all dripping or spattering on the goods or cases, and,
by distributing and drawing off the air as suggested, uniform
temperatures are obtained and strong drafts are prevented. If
the room is reasonably high, fairly good results may be obtained
by placing the cooling pipes on the side walls near the ceiling
and providing drip gutters beneath, or the room may be cooled
by natural ice by proper arrangement of openings from the
source of ice supply. If the refrigerated candling room is once
put in service for use during hot weather, its advantages will
be so apparent that the operator will wonder how he was ever
able to get along without it.
FREEZING EGGS IN BULK.
For ordinary commercial purposes eggs which are to be
frozen in bulk, in the form of egg meat, after having been re-
272 PRACTICAL COLD STORAGE
moved from the shell, are best handled in a hermetically sealed
package. Tin is better than glass or crockery, as the liability
of breakage in handling is less, less danger of bursting in freez-
ing, less space required in storage and less weight to handle.
The only weak point of the tin package is its liability to rust if
a cheap grade of tin is used, especially when the white and yolk
are frozen separately. The white may be discolored by the rustr
ing of the tin. This may be reduced to a minimum by using a
good grade of tin.
Some of the large packers pump the air out of the package
before soldering, with the object in view of preventing contam-
ination by the impure imprisoned air. Good results niay be
had, however, by soldering tight after the egg meat is frozen
solid, as the small amount of air trapped in the tins contains
little moisture and impurities, and is partly sterilized by ex-
posure to the low temperature of the freezing room. Soldering
or otherwise sealing the package is not absolutely necessary for
successful results, but it makes a more practical package to
handle, and prevents evaporation from the surface of the egg-
meat, which evaporation makes a leathery "skin," which may
necessarily be a waste. The author is one of the pioneers in
successful egg freezing, and the standard package at first in
use was the ordinary lard can holding about twenty-five pounds.
These cans were provided with slip covers with no pretense
of making them air tight, and very successful results were
obtained. It is advisable, however, to protect the surface of
the egg meat in some way.
A very good package is what is known as the Record
package or butter tub, and consists of an inner tin package
and an outer thin wood shell with an air space between the
two. These packages are fitted with covers which are pretty
nearly air-tight when carefully closed.
To prevent the yolks from becoming solid as if cooked,
which prevents their proper melting or dissolving when thawed,
they must be effectually broken, and thoroughly mixed with
the white. This is sometimes done by placing the egg meat
in a churn and churning vigorously for a few minutes, but
this has the disadvantage of not surely breaking all the yolks,
EGGS
273
or if they are broken, the mass may become frothy from the
beating up of the whites. The method used by the author
was to dump the eggs after removing from the shell on a wire
screen of about % or % inch mesh, and scrape the yolks
through with a wooden paddle or scraper. The screen should
be of tinned or galvanized wire, and should be arranged in the
bottom of a basin about four inches deep. This screen bottom
basin should be fitted to a pail or utensil of convenient size. The
pail may be provided with a spout about V-/2 inches in diameter
to facilitate pouring into ,the permanent storing packages.
Before pouring the egg meat into the permanent storing pack-
FIG. 11.— EGG-BREAKING OUTFIT.
(A tin pan, 10 by 10 by 2 inches, having a tin-bound wire screen,
J^-lnch mesh, fitting: firmly over the top. In the middle, at opposite
sides, are uprights 3 inches high, each having a slot into which is slipped a
piece of tinned boiler steel. The slot binds at the bottom to hold the
steel strip firm. It is sharpened on its upper edge. This knife gives a
clean crack in the egg shell and can readily be replaced after a bad egg.
The sherbet cups are of smooth glass. They withstand steam sterilization.
A larger container than a sherbet cup can not safely be used. Neither can
an opaque vessel be used. Glass is necessary for good grading.)
age, stir thoroughly from the bottom, as the yolk has a tendency
to remain on top, being lighter than the white. Forcing
through the screen will break every yolk without fail, and if
274 PRACTICAL COLD STORAGE
stirred carefully, the white and yolk will be mixed together,
and when thawed no lumpiness or specks will be present.
The United States Department of Agriculture, Bureau
of Chemistry, represented by Dr. Mary E. Pennington, has
issued a bulletin with suggestions on the preparation of frozen
eggs. A suitable apparatus for egg breaking and separation
which is recommended is shown in the illustration.
A refrigerated breaking room is also recommended, held
at a temperature of not higher than 65° F. This room should
be free from foreign odors and have plenty of light and be
supplied with fresh air. It is also suggested that all utensils
and apparatus in the room be of metal or other material per-
mitting an easy cleaning and sterilization, and that eggs as
soon as broken should be promptly placed in the freezer.
In freezing, fill the package only about two-thirds full at
first. When frozen solid there will be some expansion of the
egg meat, causing it to bulge or hump up in the center. After
freezing solid two-thirds full, complete filling, and when all
frozen there will be very little hump in the center of the pack-
age. Do not fill the package completely, but leave from ^
to 1 inch at the top, depending on the size of package. When
the filled package is frozen solid, solder on the cover if the
package is to be hermetically sealed, or if an ordinary package
is used, without sealing, proceed as follows: If the eggs are
separated (yolk and white to be frozen separately), reserve
some of the white to apply to the tops of cans after freezing.
Pour on about half an inch of the white on the yellow, and
allow to freeze, then put parchment paper circles on the top of
both white and yolk, pasting or sticking it down carefully with
the egg white. The effect of this treatment is to make the
top of the package fairly air-tight and protect the egg meat
from the air, and the half inch of white on top of yolk will
prevent the leathery "skin" already referred to. Some packers
reserve a little of the white to cover eggs, frozen yolks and
whites together. A parchment circle stuck on top of package
with a little of the white, will prevent largely the formation
of the leathery "skin," which is caused by the drying out of
the surface of the egg meat. After the tins are filled, frozen
EGGS 275
and capped as above, the slip covers are put on, and they are
stacked up in the permanent storage room. Sometimes the
tin cans are placed in wood crates to facilitate handling, but
more space is required in storage.
In freezing the white and yolk separately, which is very
desirable for the better class of trade, it is advisable to keep
the white and yolk about even in quantity and this may be
done if the people who do the work are skillful, and the eggs
are of good quality. In fact, the white will naturally run a
little ahead of the yolk. It is better that the yolk have a little
of the white mixed with it, as it is easier to thaw out smooth
without lumps. It is better to keep whites and yolks of even
quantity, as then it is easier to sell an equal amount of each.
The white should not be sold separately except at a much
higher price.
The author has demonstrated by actual trial that a tem-
perature of 20° F. is best for freezing and storing egg meat in
bulk. It has been recommended that eggs be frozen at 18° F.
or 20° F. and stored at a somewhat higher temperature, say
25° to 28° F. It has also been recommended that zero or
thereabouts was better than any of the higher temperatures.
At temperatures of 25° F. and above, the white of the egg
softens and becomes gummy, and deteriorates rapidly in quality.
The damage is especially noticeable when white and yolk are
frozen separately. When frozen at 10° F. and lower a greater
expansion of the egg meat takes place, and when thawed it is
watery, and not as useful for all purposes as the stock frozen
at somewhat higher temperature. One of the best bakers in
Boston informed the author that he could use the separated
eggs frozen and held at about 20° F. for any purpose for which
a perfectly fresh egg was adapted. In putting up eggs for
freezing they should be placed in a cold room (not necessarily
a freezing room) immediately when removed from the shell,
as fermentation begins soon in warm weather, and loss of
quality results. If the eggs are broken out of the shell at the
storage house, remove them to the freezing room every hour.
If they are made ready at a distance, provide a refrigerated
room for temporary cooling, and see that all broken stock is in
276 PRACTICAL COLD STORAGE
the freezer every night. If the frozen stock is thawed by
setting in a tank of cold water, better results are to be had than
when allowed to thaw in a warm room. The egg meat should
be used up at once when thawed, as fermentation commences
soon, and the stock soon becomes useless.
In estimating quantity of frozen or bulk eggs they are
sometimes figured on a basis of ninety eggs to the gallon and
at the rate of one and one-fourth pounds to the dozen, but
this, of course, is only for estimating purposes as there is a
considerable variation in different sizes of eggs and at different
seasons of the year.
CHAPTER XIV.
BUTTER
TEMPERATUEE.
In the early days of butter refrigeration it was thought
that temperatures of from 35° to 40° F., such as might be had
by cooling with ice only, were sufficiently low. These tem-
peratures kept the butter in a reasonably solid state, and for
a storage period of two or three months gave good results in
preserving the flavor and preventing deterioration. The ten-
dency has been steadily toward lower temperatures until now
zero and below is thought by many to be most suitable for
butter storage. This is by no means a general impression,
and the majority of produce men still believe that any tem-
perature below 20° F. is sufficiently low for ordinary com-
mercial results. It may be stated that the average of opinions
on the subject at this time favors 12° to 15° F., and as there are
only a few results of accurate tests available at this time to prove
anj' particular temperature as best for varying conditions and
purposes, the present status of the matter is presented in some
detail for the consideration of the reader. The author has
maintained for some time that any temperature below 15° F.
was low enough for periods of three to six months, which covers
the average time for which three-fourths of the butter is cold
stored. If the butter is stored in suitable packages, and is
well made to begin with, no important good can be accom-
plished by storing at lower temperatures. On the other hand
if the butter is in packages not suitable, of inferior packing
and grade, and it is desired to store for long periods, or it
becomes necessary to carry from one year to another, tempera-
tures of from 10° above zero to below zero Fahrenheit may
produce improved results. It is certain that 20° F. (above
277
278 PRACTICAL COLD STORAGE
zero) and perhaps somewhat lower will retain the desirable
butter flavors better than from 35° to 40° F., so it appears
reasonable that 10° F. above zero will retain flavors better than
20° F. or thereabouts. For a number of years the author has
recommended a temperature of from 10° to 14° F. for butter
storage, and sees no reason at this time to change.
FREEZING BUTTER.
We hear nowadays about freezing butter for holding in
storage. This commonly refers to any temperature below the
freezing point of water (32° F.). Some houses have recom-
mended and practiced "freezing" the butter at zero or there-
abouts for a few days, and then storing permanently in a tem-
perature of from 10° to 20° F. above zero. Butter does not
freeze in the ordinarily accepted sense of the term. It is of an
oily nature, and simply gets harder and harder as the tempera-
ture is reduced. The freezing point of butter, if it may be so
called, is from 92° F. to 96° F. as determined by test. (See
"Specific Heat of Butter" further on.) The freezing point of a
substance, as ordinarily understood, means the temperature at
which it changes from a liquid to a solid, and butter therefore
freezes at many degrees above the freezing point of water. The
talk about rupture of fat globules in butter by freezing, there-
fore, is not well applied. Butter does not freeze at any cold
storage temperature, but simply becomes harder and denser as
the temperature is reduced. Tt will, however, probably be ulti-
mately shown by repeated tests that storing butter at an
extremely low temperature will cause a "shortness" or rup-
ture of the grain, but this theory is advanced by the author on
his own responsibility.
PROTECTION FROM THE AIR.
The successful holding of butter in cold storage depends
as largely on the protecting of the product from air contact
as in maintaining a low temperature in the storage room. Pos-
sibly with extreme low temperatures of zero or thereabouts, pro-
tection from the air will be of less consequence, but this point
cannot at present be overlooked if best results are desired.
BUTTER 279
Butter being composed largely of an oil or fat, is susceptible of
becoming rancid or "air-struck" when exposed to the air for a
considerable time ; the higher the temperature the quicker the
butter becomes rancid. It is reasonable to suppose, therefore,
that the lower the temperature the longer butter may be held in
contact with the air without becoming rancid. In other words
as the temperature of a butter storage room is held lower, the
less the necessity of care in protecting the butter from the air of
storage room, but it is in any case desirable that the package
should be as air-tight as possible. It cannot be known at time
of storing how long the butter will be held, and the nearer
air-tight a package is, the longer will it keep the butter in
good flavor and condition. Butter packed under direction of
the United States Government for export and use in warm
climates is put up in hermetically sealed cans, and some of our
"boys in blue" bear witness to the palatability of same, even
when carried under insufficient and inferior methods of re-
frigeration. Another means of canning is the method formerly
in use for packing butter for shipment to California. The
butter was made up in rolls and packed in tight casks which
were afterwards headed up and all spaces between rolls and at
sides and ends of casks were filled with brine or "pickle" as
it is called. As the refrigerating means were formerly inade-
quate, this method was necessary in order that the butter
might be carried through to destination in palatable condition.
Firkins (kegs holding about 100 lbs. of butter) were much
in use at one time, especially for shipment to foreign countries.
These wooden packages were thoroughly soaked with brine,
packed solid and nearly full. The head was put in and when
the butter was cooled, the space resulting from shrinkage of
the butter was filled with pickle composed of salt, saltpetre,
and sugar. Attempts have also been made to cover the butter
in ordinary tubs with brine pickle after the tubs were placed
in storage, in order to protect the butter from the air, but the
muss and slop resulting made this scheme impracticable. These
methods of packing butter are mentioned as representative of
the former practices in use to prevent the butter becoming
air-struck and rancid. At this time very little butter is stored
280 PRACTICAL COLD STORAGE
under any of these methods, owing to the expense of packing
and impracticability of the packages for the retailer. Butter
stored immersed in pickle also has a soaked appearance, where
it comes in contact with the pickle, which is objectionable.
BUTTEK FLAVOK AND AKOMA.
It was at one time thought that flavor and aroma of butter
were due to the food upon which cattle were fed. During the
"full grass" months of May, June and July, this was especially
noticeable, and at this time cows give milk which makes a fine
quality of butter. The bacteriologist has changed our ideas on
this matter, and by the use of a "culture," nearly as fine an
aroma and flavor may be produced in midwinter as on full
grass. By pasteurization and ripening the cream by the use
of a culture of suitable bacteria, fine flavored butter may be
made at all seasons of the year. One of the chief object'
accomplished in cold storing butter is to retain the flavors and
aroma which are produced by the ripening or souring bacteria
of milk and cream. Loss of these is prima facie evidence that
butter is no longer fresh. Low temperature and protection
from the air will accomplish the desired results.
PREPARING BUTTER FOR COLD STORAGE.
Butter intended for cold storage purposes should have the
buttermilk thoroughly removed by washing and working mod-
erately in water. The working should not be carried too far so
as to spoil the grain of the butter, but as much of the butter-
milk as practicable should be worked out and a moderate
amount of pure water and salt incorporated in its place. The
butter should be well salted so that the water content shall be
in the form of strong brine. Butter containing a large portion
of moisture keeps best in cold storage. Butter made by the
old deep setting process or by raising the cream by setting in
cold water, keeps much better than the best separator butter.
No doubt some will be somewhat surprised to learn this. The
reason is that more of the casein is left in the butter by the
centrifugal separator and this causes a fermentation which
deteriorates the butter more rapidly. The author has seen two
BUTTER 281
lots of butter placed in cold storage at the same time and stored
m the same room— one lot was fancy separator creamery butter
worth at that time about 18c per lb. ; the other lot was a second
grade gathered-cream creamery, worth 14c per lb. When
removed from storage four or five months later the 14c butter
sold the best on the open market. The gathered-cream butter,
as most of my readers are aware, is made from cream skimmed
by the farmer and collected and churned at a creamery, and
the cream in this case was secured by setting or gravity as it
is sometimes called. The resulting product is always inferior
in flavor when first made. The case above is mentioned to
show the comparative keeping quality of centrifugal separator
and .gravity raised cream butter when placed in cold storage.
Other things being equal, butter from gravity cream is better
than separator butter.
PROCESS BUTTER.
"Process" or renovated butter, which is made from a mis-
cellaneous lot of dairy butter melted, purified, regranulated and
flavored by the use of a bacteria culture, has comparatively poor
keeping qualities in cold storage and therefore very little is
stored. The most common way is for the process operator to
store the original package or by repacking into barrels. If
barrels are used they should be soaked well with brine and then
lined with parchment paper before packing in the butter. Don't
store rancid butter for processing — select only that which is
fresh and reasonably sweet. Butter which is slightly sour from
presence of buttermilk is not as good for cold storage, but in
processing this largely disappears, and butter which is sour
-from this cause may be stored to advantage if fresh. In fact,
it is difficult to get the medium grade dairy butter which is
largely used for processing, during the months of June and
July, which does not have more or less this sour character.
The chief point of importance to guard against in selecting
butter to be cold stored for future processing is rancidity. Butter
which has once become even slightly rancid will deteriorate
more rapidly in cold storage and is unfit for making anything
but low grades of process butter. Store in the original package
282 PRACTICAL COLD STORAGE
if possible, providing it is in good condition, as repacking
breaks the grain and injures the keeping quality. If it is
necessary to repack, pack solidly without leaving air holes.
USE OF JAKS FOR BUTTER STORAGE.
For a limited local trade a good grade of dairy butter in
small jars is very desirable. Select good flavored, even colored
butter for storage, and turn everything else into "packing
stock" or low grades. Remove all miscellaneous cloth and
paper coverings, replacing by cloth or parchment paper circles
or caps and spread on evenly a fine grade of dairy salt to a
thickness of one-eighth of an inch, or sufficient to cover the
surface of the butter thoroughly. Over this tie a cover of
light colored manila wrapping paper, and you have a package
which is practically air tight. It is also in good shape for
sale when removed from storage. The jars may be piled one
upon another to a height of three or four feet. Racks are
best for piling jar butter with shelves at intervals of three or
four feet. In piling in an ordinary room without racks, there
is great danger of a collapse of piles of jars and the result may
be imagined. .lars are undesirable for shipping, hard to
handle, and liable to be broken, but they make a fine package
for cold storage, and are desirable for retailing. For storage
in a small way, for local consumption use jars.
STORING BUTTER IN TUBS.
Tubs of various sizes larger at the top are the standard
butter packages, and by far the greater portion of the butter
made in the United States is handled in tubs containing about
sixty pounds. The best material for tubs is white ash, but some
markets, notably Boston, prefer tubs made from white spruce.
The covers of tubs should be of the same material as the staves
and bottom, or of some sweet hard wood. The soft woods, par-
ticularly pine, may impart a foreign flavor to the butter. The
following directions for soaking tubs and preparing them for
packing are given by P. M. Paulson :*
In packing butter It is first necessary to properly prepare the
package; this I do by soaking the tub and then placing in a tank of
•In New York Produce Review.
BUTTER 283
brine so that the tubs are held completely in the brine for about 12
to 14 hours. The liners I also place in brine for about the same length
of time. When butter is worked sufficiently and ready for packing,
I line the tubs. If I am alone to pack, I line five or six tubs at a time;
if my helper has time to help me, we line enough tubs to hold what
butter we have in a working. The liners we place in smoothly In
the tubs in a way so that the top edge of the liner can be turned
down over the edge of the tub about i^ inch. Next I put the bottom
circle in position. If I am packing alone, I take five or six pounds
of butter (not more) and put in each tub that I have lined; I then
press it firmly together with the packer, seeing that there are no
holes left in the butter and also that it is pressed firmly against the
edge of the tub. I repeat this operation until tub is filled and enough
more so that there is from one to two pounds on top. When this has
been pressed firmly down, I take a string, wet it, and cut the butter
off level with the tub; next I take the paper lining and turn it back
over the edge of the tub and on to the butter, neatly and with care,
. being careful . not to tear the paper, and smooth it down. Then I
place the cloth circle on the tub; this should be large enough to reach
to the outside edge of the tub. Then I take a little water with my
hand and moisten the cloth, next sprinkle a little salt on, and rub it
lightly with my hand, so that it is even all over. In placing the cover
on, care must be taken to get it on properly; if it don't go on easily
I place my knee on the cover and tap the edge lightly with a hammer
until I get the cover on; it is better to hammer on the edge of the
cover than to hit the staves on the tub, as it keeps the butter in
better shape. In placing the tins, I place the first one on over the
end of the cover rim; this will prevent the rim from tearing off if it
should by accident get caught; the second tin I place directly across
from the first one, the third and fourth at equal distance between first
and second. I always try to place the tins so that they will reach
down into the top hoop on the tub; last I drive a %d. nail in the
lower end of tin; the end on the cover I have always found does very
well with one nail. I always use a tin that has one nail in each end;
they are the most convenient to use. Wire tub fasteners should not
be used, the trade does not like them. Before I place butter in re-
frigerator I always see that the tubs are perfectly clean.
The liners mentioned by Mr. Paulson are of parchment
paper and come ready cut to proper size for tub used. A pint
of brine in the bottom of the tub when starting to pack, is
desirable,, as it fills all cavities and the pores of the wood. In
packing keep the butter pressed down in the center first and
then at the sides so as not to leave openings in the butter which
may later become air spaces by evaporation of the brine and
cause the butter to sooner become "air-struck."
OLEOMARGARINE AND BUTTERINE IN STORAGE.
Oleomargarine and butterine are of a similar nature and
resemble butter, but are much more easily preservable by re-
frigeration, and may be kept for long periods in fine condition.
The reason is that they contain very little casein or other sub-
284 PRACTICAL COLD STORAGE
stance liable to fermentation and decay, being composed almost
wholly of fats and oils which do not spoil quickly, even at ordi-
nary temperatures. A temperature somewhat higher than that
recommended for butter is generally used for butterine and
oleomargarine. Temperatures of from 20° to 30° F., are in
common use for the storage of these products.
LADLE BUTTEE.
"Ladle" butter is butter reworked, resalted and repacked,
so as to put it in marketable condition and give it a uniform
grade. Much of this is butter of good quality, but lacking in
uniformity of color, salt, and package. The ladler takes the
miscellaneous "farmers," "dairy," "store" or "packing stock"
butter, and by rehandling turns out a butter which is improved
commercially to an extent which has in the past made the
business profitable. The ladler makes his profit in intelligent
grading and in the increase of weight by resalting, washing,
and reworking. "Ladling" has now been largely superseded
by "processing." Very little ladle butter is placed in cold
storage at the present time. Those who have had experience,
know that "ladles" do not keep well in cold storage. The
reworking incorporates thoroughly throughout the mass any
rancidity or bad flavor present in any part of the butter, and
the result is that after standing a comparatively short time
"ladles" are off flavored and take on a "ladley" taste and odor,
even when carried in low temperatures. As in processing,
butter intended for ladling is cold stored as original butter and
rehandled as wanted by the trade. Directions given for the
handling of original butter apply equally when used for proc-
essing or ladling.
CREAMERY BUTTER.
Creamery butter is so well known as not to need much de-
scription. At the present time nearly all creamery butter is
made from cream which is separated from the milk by a centri-
fugal machine known to the trade as a separator. Separator
butter has poorer keeping qualities than butter made from
cream raised by setting the milk in cold water or what is called
the gravity process, for reasons already stated, but for the ordi-
BUTTER 285
nary commercial storage term of three to six months, keeps well
enough for practical purposes when held at temperatures of
10° to 14° F. The sixty-pound tub is the package generally
used, particulaily by the retailer, but much butter after having
been stored in large tubs is tempered to soften it slightly and
then repacked into smaller packages; the one pound print,
wrapped in parafifine or parchment paper being a favorite,
Butter which is to be "printed" before sale should be stored in
as large, air-tight and well soaked or impervious packages as
possible. Some dealers use firkins or butter carriers holding
100 to 200 pounds. Do not try to store butter in prints for
any length of time as the grain is somewhat broken in printing
and its keeping qualities therefore impaired. For the same
reason do not store in small packages which are not impervious
to air and moisture. The directions for packing previously
given apply especially to creamery butter. In some cases a
covering of paste salt (salt which is ground fine) is used. This
is mixed with water and is put on as a paste, which hardens
on drying, forming an air tight crust over the top of the
butter. The butter cannot well be examined without mussing
or destroying this paste salt covering, and it is not used to
any extent except for cold storage purposes. The Australian
butter box, a rectangular and nearly cubical package, holding
about 60 lbs., is coming into quite general use. Butter from
these boxes cuts up with little waste when printed in one pound
bricks, and the shape of the package makes it very economical
of storage space.
FISHY FLAVOR IN BUTTER.
The development of a peculiar flavor in butter which is
stored under refrigeration has long been under discussion and
for a time the cold storage house was blamed for this trouble.
Afterwards the trouble was attributed to the use of inferior
salt containing lime. More recent investigations prove beyond
a question that neither cold storage nor impure salt is the chief
cause of fishy flavor in butter.
A circular by L. A. Rogers, Chief of the Dairy Division,
Department of Agriculture, Washington, D. C, goes to show
286 PRACTICAL COLD STORAGE
that fishy flavor is most often caused by the development of
a certain acid produced in the ripening of cream. It is also
suggested that other causes might produce fishy flavor and
that butter sometimes described as fishy was merely oily
flavored, or otherwise off in flavor, the flshy flavor being a
peculiar oily taste suggesting salted fish.
During the past three years the Dairy Division has made
a large number of lots of experimental butter and in no case
has fishy flavor developed. The reason ascribed is that all'
the butter has been made from pasteurized cream without
ripening in the regular way, and by the addition of a so-called
starter or bacteria for the development of flavor. The subse-
quent ripening of the pasteurized sweet cream treated with
starter improves the flavor of fresh butter without adding
acid in sufficient quantity to cause fishy flavor. The pasteur-
izing of cream which has already soured in the ordinary way
will not prevent the development of fishy flavor in butter stored
for long periods under refrigeration.
It is suggested in addition to the findings of the Dairy
Division as above, that fishj^ flavor in butter is a comparatively
recent trouble and it has developed only since the centrifugal
separator has come into general use. It is suggested that the
fishy flavor referred to is caused by a fermentation caused
largely by the presence of an excess of the curd or cheese ele-
ments in the butter made from separator cream. Butter made
from cream raised in the old fashioned way contains very little
of the cheese element.
MOLD IN BUTTER PACKAGES.
Mold in butter packages has given much trouble, both in
cold storage and' in the regular cooling rooms when held for
temporary storage. This may be caused by improper soaking
of the tubs or a badly constructed refrigerator or cooling room
at the creamery, or the empty tubs may have been stored in a
damp place such as a cellar or basement at the creamery. A
growth of mold once started is quite likely to continue to grow
and may in a short time affect and flavor the butter. A growth
of mold may be prevented by storing the empty packages in
BUTTER 287
a dry place; providing a good refrigerator with suitable air
circulation at the creamery; and by care and attention in
packing the butter, as already outlined. Instead of using water
for soaking the tubs, use brine. Water promotes mold — brine
destroys it. Salt is cheap. Use it in connection with your
butter packages, and mold will not trouble you. Use parch-
ment paper liners and use brine for moistening at time of pacb
ing. See chapter on "Creamery and Dairy Refrigeration" for
information regarding suitable facilities for cooling rooms, etc.,
in connection with creameries.
SPECIFIC HEAT OF BUTTER.
The following regarding the specific heat of butter* by
G. H. King, Agricultural Phji-sicist, University of Wisconsin, is
reproduced here for the valuable scientific information it
contains :
It would be a very difficult, if not an impossible, task to deter-
mine the true specific heat of the butter fat of commerce, making cor-
rections for the elements of latent heat, for the reason that butter
is so complex a product, and the butter fat itself varies so much in
composition with the season and with the stage of the lactation period,
and even with the individuality of the animal producing the butter.
I have made an approximate determination of the specific heat of
butter fat between 100° C. and 0° C, and find it to be .5494.
This result was obtained by taking ordinary butter, melting it and
boiling until all water was driven off, and skimming to remove solids
not fat, and then filtering hot.
There was then placed into a pocket in a block of ice 200 grams
of the clear butter fat at a temperature of 100° C, and brought quickly
to 0° C, when the butter fat and ice melted were weighed. Calculat-
ing the specific heat from the amount of ice melted, the result found
was .5494.
Butter fat, leaving the other ingredients out of consideration, is
largely a solution of tripalmitin and tristearin in triolein, or, in com-
mercial language, butter fat is a solution of palmitin and stearin
in olein. But in addition to these three fats there are also found
varying amounts of five others, viz., butyrin, myristin, caproin, caprylin
and caprin.
The pure triolein, or olein of vegetable fats and oils, becomes
solid only at a temperature as low as 21° F. The tripalmitin, or
palmitin of vegetable and animal fats, occurs in three isometric or
allotropic forms, with melting points as high as 115°, 142° and 144°
P., respectively, while the tristearin, or animal and vegetable stearin,
also occurs in three forms, which remain solid, when pure, until a
temperature of 124°, 148° and 157° F., respectively, is reached.
The temperature at which butter becomes solid, or semi-solid,
varies with the relative amounts of the three chief fats which happen
to be present in the sample. It is stated that ordinarily butter be-
•From Ice and Refrigeration, June, 1901, page 278.
288 PRACTICAL COLD STORAGE
comes fluid or melts at between 92° and 96° F., which should be un-
derstood that below these temperatures the olein is no longer able to
hold all of the palmltln and stearin in solution. Pure lard melts at
78° to 87° F., and its composition is given as 62 per cent olein and 38
per cent of palmatin and stearin. Butter fat, in the spring, from fresh
cows on green grass has a composition near 50 per cent of olein, 30
per cent of stearin and 20 per cent of palmitin; but later in the period
of lactation, and in the fall when the feeds are drier, its composition
may change to 30 per cent olein, BO per cent stearin and 20 per cent
palmitin.
It seems likely from these observations that the amount of heat
necessary to be applied to butter, in raising it from freezing to its melt-
ing point, and to be withdrawn from it in cooling it from its melting
point down to freezing, will not be very far from the amount which
would be required to make a corresponding change in temperature
of water, pound for pound.
HUMIDITY, CIRCULATION, VENTILATION.
Humidity, air circulation and ventilation have been given
comparatively little attention as applied to the storage of butter.
At the low temperatures at which butter is generally stored the
air contains so little moisture as to be amply dry to prevent
mold, and nothing further is thought of it. In fact, most
butter storage rooms are dryer than necessary, and it is difficult
to prevent the butter drying out from this cause. It is only
necessary to have a butter room dry enough to prevent mold
on packages, as the goods are supposed to be sealed from air
contact. What this humidity should be there are no records
to show, but moisture does not trouble the general run of
storage rooms for butter. A circulation of air in butter storage
rooms is of no great consequence, as sufficient air circulation for
purification of the air is usually present. Most butter storage
rooms are equipped with direct piping, but some are provided
with air circulation by means of fans, when a quicker cooling
is possible. Ventilation of butter storage rooms is advisable
at regular intervals, using the apparatus described in the
chapter on "Ventilation." Gases from the oxidizing of butter
fat and odors from the wooden packages accumulate in the
storage room unless disposed of by ventilation.
CHAPTER XV.
THE DESIRABILITY OF COLD STORAGE FOR CHEESE.
The cold storage of cheese on an extensive scale is of com-
paratively recent date. Formerly it was considered sufficient
to store cheese in an ordinary cellar or basement room, perhaps
cooled by ice bunkers, but about thirty years ago cheese were
first placed in cold storage, both with the old overhead ice
method of cooling and the first ammonia refrigerated houses.
The author remembers distinctly when as a boy he visited the
old St. John's Park Depot in New York, which was then cooled
with one of the first ammonia systems to be put in commercial
cold storage service and was used quite largely for cheese storing.
The success of the early experiments in keeping cheese in cold
storage was such as to extend the practice, and at the present time
practically all cheese which are to be held for consumption at
some future time are placed in cold storage for preservation.
In fact the advantages of low temperature have been so thor-
oughly appreciated that it has led the various experiment sta-
tions to conduct some very extensive experiments in what is
called "the cold curing of cheese."
As a matter of fact, cheese "ripen," "cure" or mature at
any low temperature at which they may be safely stored. Cheese
is one of the products that improve with age. It is not at its
best when first made ; in fact it is unpalatable and unhealthful
when new or "green." It requires "curing" in order to make
it a suitable article for 'food. Under ordinary conditions the
curing process goes on regardless of temperature, but the action
is much slower as the temperature is lower. The results of ex-
periments which are here given prove conclusively that a much
better quality of matured cheese results when the cheese are
289
290 PRACTICAL COLD STORAGE
placed in cold storage soon after being made. It seems that the
low temperature prevents the development of bad flavors and
deleterious gases which injure the flavor and texture of the
cheese, while at the same time it allows the rennet which is
used in the manufacture of cheese to fulfill its mission of curing
or developing. The experiments which are described in detail
further on need no additional explanation.
The result of these experiments seem to prove the advisa-
bility of establishing centralizing stations, which are in reality
cold storage plants, for the receiving of cheese when first made.
A plant of this character may be built at any convenient rail-
road point and the cheese from a number of different factories
hauled thereto at frequent and regular intervals. They are
then placed under suitable temperature, and other conditions,
and are ready for immediate shipment at any time. The ad-
vantage of this method over the old factory system of allowing
the cheese to remain on the curing room shelves for a time is
that the flavor is improved, shrinkage reduced to a minmum
and the cheese are protected from exposure to hot weather,
which is one of the worst things that the cheese manufacturer
has to contend with. Appreciating this difficulty, the sub-earth
duct system has been adopted by some of the more progressive
factories. This is simply an air duct running underneath the
ground through which circulates air which is introduced into
the curing room. In passing below the surface of the earth,
the temperature of the air 'is reduced to 60° to 65° F. and the
temperature of the curing room is therefore modified during
extremely warm weather. It was found that this system in
many cases had the disadvantage of causing cheese to mold
badly and no doubt it will be abandoned in favor of the cold
storage or cold curing method. There is an advantage in hav-
ing cheese brought to a central cold storage or curing station
in that it is easier for buyers to inspect and brings the cheese
all into a market center as it were. There is no reason why
they should be out of possession of the salesman any more with
this system than they would under the old method. Co-opera-
tion and consolidation will enable cheese manufacturers to real-
ize much better prices for their product, owiiig to improved
CHEESE 291
quality, if they will but adopt the cold storage system instead of
the old-time curing room method. A large part of the expense
of a central cold storage station would be paid by the saving
effected at the factory in not being obliged to provide for shelves
and curing room space.
The best refrigerating system for use in connection with
cold curing will depend upon the section where located and local
conditions to a large extent. In cooling with air circulating in
direct contact with ice, a temperature below 40° F. cannot be
depended upon and as experiments demonstrate that cheese
stored at a temperature of 30° to 35° F. are of a better flavor
and texture, it is evident that some system which will produce a
lower temperature would be advisable. In addition, the humid-
ity of a room cooled directly from the ice is very high (in other
words, very moist) . It has been demonstrated that the relative
humidity of such a room when used for the cold curing of
cheese would be at times somewhat above 90 per cent. These
conditions are very favorable for the growth of mold. The
.direct ice system therefore is not advisable for the reason that
sufficiently low temperatures and regulation of humidity can-
not be obtained. The Cooper brine system, cooling with ice
and salt, described elsewhere in this book, is recommended as a
system which will control temperatures, and in connection with
the Cooper chloride of calcium process, also described elsewhere,
the humidity of the room may be regulated to any desired de-
gree. In situations where natural ice cannot be obtained cheap-
ly, the use of refrigerating machinery is advisable and the tem-
perature and humidity can thereby be controlled in the same
way as with the Cooper brine system.
THE COLD CUEING OF CHEESE.*
The prevalent opinion among cheese dealers has always
been that low temperatures, varying from 35° to 50° F., or
thereabouts, resulted in the production of an inferior quality of
cheese, in comparison with that from 60° to 70° F. No care-
•frvtrapt^i from Bulletin No. 49, Bureau of Animal Industry, U. S.
i^,.n?ntlivine results of experiments conducted under the directions
^f^Hen??B^Alvo^rd Chief of Dairy Division. More detailed information
may be obtained by consulting same.
292 PRACTICAL COLD STORAGE
fully controlled experiments bearing on this problem have been
recorded earlier than those undertaken by Babcock and Russell
at the Wisconsin Agricultural Experiment Station, and de-
scribed in the fourteenth (1897) annual report of that station.
The results of those tests showed that cheese placed at refrig-
erator temperatures (45° to 50° F.), directly from the press,
was of superior quality as to flavor and also as to texture, and
that such cheese was wholly free from any bitter or other unde-
sirable taints.
In connection with their studies on the influence which
galactase and rennet extract exert on the progress of cheese
ripening, the same investigators later employed still lower tem-
peratures 25° to 30° F.). Cheese were kept at these exces-
sively low curing temperatures for a period of eighteen months.
The quality of these cheese, cured as they were below the freez-
ing point throughout their whole history, was exceptionally
fine, and emphasized still more than the previous experiments
did the fact that the ripening of cheese can go on at much
lower temperatures than has heretofore been considered pos-
sible.
These results led to an extended series of experiments, in
which cheese made on a commercial scale was cured at a range
of temperature from below freezing (15° F.) to 60° F. — a
point which common practice has now accepted as the best ob-
tainable temperature that can be secured without the use of arti-
ficial refrigeration.*
In these experiments (consisting of five series made at in-
tervals throughout a period of two years) 138 cheeses were used
for which 30,000 pounds of milk were required. These experi-
ments were upon a scale which represented commercial condi-
tions, and therefore obviated the objection which is often urged
in commercial practice against the application of results derived
simply from laboratory experiments.
The Ontario Agricultural College began experiments on
the cold curing of cheese in April, 1901. As a result of these
tests the conclusion was drawn that the cheese cured at low tem-
•No doubt the term " artificial refrigeration" as here used means cool-
ing by any means other than natural earth or air temperature, and not
the general accepted meaning, viz., refrigerating machinery.
CHEESE 293
peratures (37.8° F.) was much superior to that cured in ordi-
nary curing rooms (average temperature during season 63.8°
F.). Mr. R. M. Ballantyne, a prominent cheese expert, said
of this cheese that "they (the merchants) universally expressed
surprise at the condition of the cheese that was put into cold stor-
age at the earliest period (that is, directly from the press), as
they expected to find the cheese still curdy and probably with a
bitter flavor."* If this experiment is borne out by other ex-
perts, it would appear as if the best way to handle hot-weather
cheese would be to ship it to the cold storage directly after mak-
ing, and this would certainly mean a great revolution to the
trade.
A considerable number of experiments have also been made
at other stations (Dominion government tests and New York
State and Iowa experiment stations), where somewhat lower
temperatures were used than those which are normally em-
ployed for ripening. The results obtained all show an improve-
ment in quality that becomes more marked as the temperature
is reduced.
In order that a much larger experiment might be insti-
tuted, covering the different types of cheese as represented by
eastern as well as western manufacture, Drs. Babcock and Rus-
sell, of the Wisconsin Station, presented this matter for consid-
eration to the Dairy Division of the Bureau of Animal Industry.
As a result of this proposal the oflicers of the New York Agri-
cultural Experiment Station were also consulted and plans per-
fected for the co-operative experiments conducted simultaneous-
ly in Wisconsin and New York.f It should be noted that it
was so late in the season of 1902 when the arrangements for
this work were completed that it was impossible to obtain favor-
able conditions in all respects.
In addition to the influence which a range in temperature
exerts on the quality of cheese, as determined by flavor and tex-
ture scores, instructions were also issued to secure data regard-
ing the loss in weight which the different lots of cheese suffered
•Bulletin No. 121, Ontario Agricultural College, June, 1902.
tThe eastern experiments are not given here as the results differ in
detail onlyrgeiieral conclusions being the same in both series of ex-
periments.
294 PRACTICAL COLD STORAGE
at the different temperatures. The commercial quality of the
product was to be determined by a jury of experts who were
thoroughly in touch with the demands of the market. Al-
though the effect of coating cheese with paraffin soon after
being taken from the hoop was not at first proposed as a part of
this work, it was finally included.
The reasons for selecting 40°, 50°, and 60° F. as the tem-
peratures to be used in these experiments are fully given on a
later page. It may be assumed that the advantages of a cool
and even temperature in curing Cheddar cheese have been al-
ready established in preference to a warm temperature or to
very variable conditions which frequently include periods above
70° F. and sometimes much higher. As already stated, 60° F.
or thereabouts is regarded as the lowest temperature practicable
without artificial refrigeration ; this may therefore be taken as
fairly representative of what may be called a "cool" tempera-
ture for curing cheese. And rooms held at 40° and 50° F.
were selected as representative of a "cold" temperature for cur-
ing, or comparatively so. Tt is thus hoped to emphasize by
these experiments the distinction between cool curing and cold
curing.
The cheese for these experiments were purchased by the
United States Department of Agriculture, which also paid all
expenses of transportation and storage and for the experts who
made the periodical examinations. The two experiment sta-
tions selected the cheese, arranged all details of storage and ex-
amination, supervised the work throughout, performed the
chemical and other incidental scientific work, kept the records,
and reported results.
Each of the reports, prepared by the two experiment sta-
tions participating in this work, treats the same general subject
and similar lines of experiment and observation from its own
point of view. The reports therefore differ in many respects,
and yet they may be easily compared upon all essential points.
Both support the same general conclusions as to the advantages '
of curing cheese at low temperatures, summarized as follows :
1- — The loss of moisture is less at low temperatures, and
therefore there is more cheese to sell.
CHEESE 29S
2. — The commercial quality of cheese cured at low temper-
atures is better, resulting in giving cheese a higher market value.
3. — Cheese can be held a long time at low temperatures
without impairment of quality.
4. — By utilizing the combination of paraffining cheese and
curing it at low temperatures the greatest economy is effected.
THE WESTERN EXPERIMENTS.*
For the purposes of this experiment Chicago would natur-
ally have been chosen as a curing station, but it was found dif-
ficult to make arrangements for the range of temperatures de-
sired. Suitable arrangements, however, were made at the cold-
storage warehouse of the Roach & Seeber Co., Waterloo, Wis.,
where rooms were fitted up and the desired temperatures secured.
As Wisconsin is the leading cheese-producing state of the
west, the bulk of the product selected for experiment was of
the type of cheese manufactured in this state. In order, how-
ever, to cover more thoroughly the cheese-producing territory
of the west samples were also secured from a number of the
neighboring states. In this way all types of American cheese
were obtained, ranging from the firm, typical Cheddar
suitable for export, to the soft, open-bodied, moist cheese, in-
tended for early consumption. For convenience we may group
these various lots of cheese under three different types, as fol-
lows :
I. — Close-bodied, firm, long-keeping type, suitable for ex-
port trade (typical Cheddar) .
II. — Sweet-cured type.
III. — Soft, open-bodied, quick-curing type, suitable for
early consumption.
Type I represents the class of cheese that is especially man-
ufactured in Wisconsin, while, as a rule, type III represents
the kind of cheese that is chiefly made in Michigan. The rep-
resentatives of the sweet-curd type were taken from Iowa and
Illinois, although this class is made to some extent in all sec-
tions.
♦Conducted by S. M. Babcock and H. L. Russell, assisted by U. S. Baer,
all of the Wisconsin Agricultural Experiment Station.
296 PRACTICAL COLD STORAGE
In having the cheese made at these various factories direc-
tions were given for the use of a uniform amount of rennet and
salt. Color was left optional for each maker to follow his cus-
tomary practice. The use of 3j4 ounces of Hansen's rennet
extract and 21/2 pounds of salt per 1,000 pounds of milk was
recommended in each case with the exception of the smaller
cheese (dairies and 10-pound prints), which were salted at the
rate of 2% pounds per 1,000 pounds of milk. The cheese was
made from September 26 to October 4. The condition of the
milk was influenced in several instances by the fact that severe
frosts had occurred in some sections, which injured the quality
of the product. This was particularly true in the case of the
Alma, cheese, which was in consequence somewhat tainted. The
milk from which the Iowa cheese was made was also reported as
of inferior quality. The I\Iichigan goods were too high in acid,
and were cooked low, making a soft cheese which was quick-
curing and which kept poorly.
Where it was necessary to secure cheese from such a wide
range of territory it was manifestly impossible to expect that the
curing could be carried out as satisfactorily as if it had been
done at or near the factories. The varying period of transit to
which the cheese was subjected with no especial temperature
control, affected, of course, the initial stages of curing, but the
conditions of the experiment prevented the carrying out of im-
mediate installation of the cheese in the cold curing rooms, es-
pecially in the case of those made outside of Wisconsin, although
the shipments were made in October, when the temperature
range was moderate.
TEMl'BKATUEES XT WHICH THE CHEESE WAS CURED.
The cheese was weighed and put in the respective rooms as
soon as received at Waterloo. It was stored in boxes during
the curing, as is the custom in the handling of cold-storage
goods. The temperatures at which it was desired to hold the
cheese for curing were 40°, 50°, and 60° F. These points
were selected for the following reasons : In our previous experi-
ments we had found that the character of the cheese cured at
the lower temperatures (40° and 50°) was much better than
CHEESE 297
that produced at 60° F. Perhaps it would have been better
for the purpose of the experiment if the cold-cured cheese could
have been compared with the same make of cheese cured under
the widely variable conditions which prevail in most factories,
where often the maximum temperature is in the neighborhood
of 80° F. and the fluctuation is 20° or more ; but we have made
this comparison with the very best conditions that obtain in fac-
tories provided with subearth ducts and other means of tempera-
ture control. In such cases a temperature of 60° F. can be
maintained with a fair degree of constancy. The experiments,
therefore, compare the cold-curing process with that of the best
prevailing conditions.
The temperatures actually maintained varied only slightly
from the chosen points, and in the two colder rooms were re-
markably uniform. The 60° room was subject to somewhat
wider fluctuations, but was much more uniform than is obtained
in summer where no artificial refrigeration is practiced.
DETAILS OF SCORING THE CHEESE.
It would have been advisable to have the cheese examined
a considerable number of times by the commercial judges, but
it was impossible to carry out this test so frequently. The tests
were therefore arranged to come at those periods which would
give the judges the most accurate idea of the character of the
cheese held at the different temperatures.
As a jury of commercial experts, representing the differ-
ent markets, the following gentlemen were selected: C. A.
White, of Fond du Lac, resident representative in Wisconsin
of a leading dairy produce house of New York; T. B. Millar, of
London, Ontario, a cheese expert and large buyer for the export
trade, and John Kirkpatrick, a member of a leading produce
firm of Chicago.
For the jury trials representative cheese were taken from
storage and shipped by refrigerator service to Chicago, where
they were submitted to a thorough examination by the commer-
cial judges. The first of these commercial scorings was made
when it was found that the 60° product was ready for market.
This test was made on January 6, 1903. Another test was made
on March 23, when the cheese was about 7 months old.
298 PRACTICAL COLD STORAGE
It might at first thought seem preferable to have had the
cheese sold in the open market and thus secured a strict com-
mercial valuation on the product,, but, as everyone knows, a con-
siderable variation in quality may exist without an appreciable
difTerence being made in the market price. Then, too, the in-
evitable fluctuations in the market price would render compari-
sons at different periods untrustworthy. To obviate these diffi-
culties the cheese was scored on the basis of a standard price
(13 cents). The fact that but few of the cheese reached this
standard should not be interpreted as indicating a poorer qual-
ity than the average market product, for the cheese was ad-
judged by the jury to be superior in quality ; but the price was
in part determined by the market appearance of the goods,
which was somewhat inferior because of the fact that they had
been box-cured and had received practically no care in curing,
as the curing station was located at a distance from Madison.
The scores of the commercial jury were supplemented by a
series of scores made by Mr. Baer which covered the entire his-
tory of the cheese from the time it was received until its final
disposition. In this study it was possible to follow more closely
the course of the ripening.
SHRIXKAGE OF CHEESE IN WEIGHT WHEN CURED AT DIFFERENT
TEMPERATURES.
The losses in weight which cheese undergoes in the curing
process is a matter of such practical importance that it is ad-
visable when possible to accumulate data relating to it. This is
all the more important in this connection because no studies
have yet been reported on cold-cured cheese, and it was therefore
deemed advisable to keep a record of the losses in weight so
that the shrinkage at these lower temperatures might be com-
pared with those which normally obtain at the best temperatures
now employed. The average shrinkage under existing curing
conditions in the majority of factories results in a loss of 5 to 7
per cent for the first thirty days, with a gradually diminishing
rate for longer curing periods. This results in a heavy tax to
the producer, and any factor which reduces these losses increases
thereby the total receipts from the milk produced.
CHEESE 299
There are a number of factors which modify the rate at
which a cheese loses its water content during the course of ripen-
ing. The following factors are known to exert a more or less
marked influence, although it is impossible to arrange them in
order of their relative importance, as they are always inter-
dependent :
1- — Temperature of curing room.
2. — Relative humidity of air in curing room.
3. — Size and form of cheese.
4. — Moisture content of the cheese.
5. — Protection to external surface of the cheese.
The influence of temperature is closely connected with the
relative humidity of the curing room ; but, in addition to the
effect which the higher temperatures exert on this factor, it
should be observed that water evaporates more rapidly at a high
than at a low temperature, even though the relative humidity
remains the same. The more potent influence of temperature
is, however, the effect which varying degrees of heat exert on
the relative humidity of the atmosphere. A fall of 20° F. from
ordinary air temperatures practically doubles the relative hu-
midity, provided the point of saturation is not passed. As the
average relative humidity of the air is generally over 50 per
cent, it therefore follows, in cold-curing rooms supplied with
outside air, the temperature of which is from 30° to 40° F.
higher in summer than the inside temperatures, that the -air of
these rooms is practically saturated, thus greatly reducing the
loss of moisture from the cheese.*
So far as the cheese itself is concerned, the moisture of the
room may be materially altered by the way in which the cheese
is handled during the curing process. If the cheese is shelf-
cured, as is the custom in most factories, the surrounding air
more nearly approximates the average relative humidity of the
entire room than is the case where the goods are box-cured. In
•Conclusions so positive as these are not warranted. Temperature and
humidity are not necessarily closely related. Water evaporates more
rapidly at high temperature because the capacity of air for moisture is
increased with its temperature, but it does not necessarily follow that the
humidity is increased as the temperature is reduced, and a room in which
the air is nearly saturated with moisture seldom exists. If it did it would
be a bad place to store cheese because mold would grow rapidly. See
chapter on "Humidity."
300 PRACTICAL COLD STORAGE
the latter case the air is more nearly saturated, as is shown by
the greater liability to mold and rind-rot.
This point is well shown in a series of observations on the
relative humidity of the air in a box containing a cheese placed
directly therein from the press.
A factor which is frequently overlooked is the varying
moisture content of the cheese. The more moisture there is
left in the cheese the more rapid the evaporation. The varying
moisture content of different types of cheese is determined by
the temperature at which the curds are cooked, the time of ex-
posure, and the acidity of the curd. A cheese in which the
acidity is developed is materially drier than a sweet-curd cheese.
Salt also has a tendency to diminish the water content. In the
foregoing cases the cause of this diminution in moisture is due
to the shrinking of the curd particles under the influence of
these factors. An increase in fat lessens the drying of the curd.
Much loss of moisture can also be prevented by coating the
cheese with paraffin, a practice which is now coming into very
general use for the prevention of mold and to lessen shrinkage
in weight.
EXPEEIMENTS IN SHRINKAGE OF COLD-CURED CHEESE.
In these experiments the first careful weighings were made
when the cheese was received at the cold-storage plant in Water-
loo. The cheese was shipped from the factories directly after it
was removed from the press, but was in every case several days
upon the road. In no instance was the interval between making
and installing in cold-curing rooms less than five days, and it
ranged from this up to seventeen days with one lot from Michi-
gan, which was delayed in transit. During this period, which
was in early October, the cheese was subjected to varying condi-
tions of temperature and exposure. In a few cases boxes were
broken, and in other instances the cheese was delayed at points
of transfer. It was impossible to obviate these difficulties, as
the cheese was purchased at distant points in order to secure
representation from a wide range of territory and from different
types of cheese. This variation in initial drying changed, of
course, the rate of loss when cheese was placed in cold-curing
CHEESE 301
rooms, so that this factor must be taken into consideration in
studying the data presented below.
The losses reported here cover those only which took place
in the cheese after it had reached the cold-curing rooms, but
careful records have been kept for the entire curing period ; and
these data, we believe, are of sufficient importance to warrant
full consideration in this connection.
DETAILS OP WEIGHING.
The cheese was all weighed on counter scales, weighing ac-
curately to fractions of an ounce. In order to check the ac-
curacy of the weights, each cheese was weighed separately and
the weight recorded; then the whole lot was weighed collec-
tively. As these weights agreed within a few ounces, they
show the accuracy of the weighings. For practical purposes
it is desirable to know the losses which occur for stated periods.
It was, however, impracticable for all of the cheese to be weighed
at exactly the same intervals, as it was put in storage at differ-
ent dates, but it was designed to secure at least three weighings
for the first month of storage, two weighings for the second,
and at. about monthly intervals thereafter. If these data are
charted, it is possible to deduce an estimated loss for any stated
period, and in doing so we have selected the following intervals
as being those concerning which data would be most frequently
desired. For this purpose ten, twenty, thirty, sixty, ninety,
etc., days have been selected.
CONDITIONS UNDER WHICH THE CHEESE WAS STORED.
In this work the attempt was made to hold the cheese at
40°, 50°, and 60° F. The actual temperatures secured aver-
aged 36.8°, 46.9°, and 58.5° F. The variation in temperature
in the two lower rooms was practically negligible, as it was only
2° to 2%°. The tempreature of the 60° room oscillated some-
what more (4° F.), but was very much more uniform than
ordinary factory curing rooms.
Hygrometric data were not secured during the whole
period, as it was at first thought that a saturated atmosphere
would prevail where the cheese was box-cured, but during the
302 PRACTICAL COLD STORAGE
course of the experiments it was noted that the 50° cheese was
not molding as much as was that at 40° to 60°. This fact
could onh' be explained bj^ the assumption that a less humid
atmosphere was present in the case of the 50° room.*
DISCUSSION OF RESULTS.
As there are several factors which affect the rate of shrink-
age which the cheese suffers in curing, it will be desirable to
discuss the data collected under several heads. The conditions
of the experiment were such as to temperature that an espe-
cially favorable opportunity was had for the study of the in-
fluence which this factor exerts on the cheese. It is, of course,
necessary in a study of this sort to have the cheese uniform in
size. The moisture contents of the cheese cannot, of course, be
made alike, but in this study the cheese of the same type have
been grouped together — that is, as firm Cheddars suitable for
export, and softer, moister cheese intended for home trade.
INFLUENCE OF TEMPEKATUTvE ON SHRINKAGE.
To study the rate of loss of Cheddar cheese when kept at
different temperatures, 129 flats were selected from nine differ-
ent lots of cheese made by six different makers. These were
exposed at three different temperatures, which averaged, re-
spectively, 36.8°, 46.9°, and 58.5° F. The results obtained
were calculated upon the number of cheese which were sub-
jected to stated weighings. During the experiments much more
data were collected on the lower temperatures than on the 60°
lot. This was regarded necessary, as up to this time we have no
published data on cheese cured at so low a temperature.
For purposes of convenience the different lots of cheese
were divided into three types, depending upon their character.
I. — Firm-bodied cheese (export type), of Wisconsin.
IT. — Sweet-curd type, as represented by the Iowa and Illi-
nois makes.
III. — A very moist, soft type, suitable for home trade
(Michigan).
The general conclusions arrived at were :
•See previous remarks on temperature and relative humidity.
CHEESE 303
1. — The losses sustained by the diflferent lots were very
much less at 40° F. than at either of the other two temperatures.
For a ninety-day period the losses of the 40° cheese ranged from
1 to 1.4 per cent, while the 50° and 60° product shrunk from
3.4 to 4.5 per cent for the same time. In other words, by the
use of the lower temperature for curing practically two-thirds
of the losses which occurred at the temperatures of 50° and
60° F. were prevented. If these results are compared with what
happens under ordinary factory conditions, -the loss at these low
temperatures for a period of ninety days (the minimum curing
period recommended) will not be more than one-fourth of that
which obtains under average factory conditions when the cheese
are held for a period of about twenty days. The saving for any
such factory making 500 pounds of cheese daily would amount
to at least 15 pounds ©f cheese (or $1.50) per day as an average
for the season, and considerably more than this for cheese made
during hot weather. This saving in itself would go far toward
meeting the extra expense of lower temperature curing, even if
the product were no better than that cured at higher temper:
tures.
2. — The differences between the cheese cured at 50° and
60° F. are not so marked as between 50° and 40° F. It is
quite probable, as before mentioned, that the 50° room was
somewhat drier than the 60° (as shown by the lessened mold
growth), and hence the rate of loss was abnormally increased
in this room.*
3. — If the firm Wisconsin type is compared with the softer
variety, as shown in types II and III, it appears that the losses
are considerably less, especially at the higher temperatures, al-
though this difference is not so observable at 40° F.
4. — The data referred to above showed a marked saving in
losses where the cheese was cold cured, but in these experiments
it must be remembered that the cheese was subjected to higher
temperatures during transit, and hence dried out somewhat
more than would have occurred if put in storage as soon as re-
*The reason why evaporation is less at the lower temperatures Is not
necesJarlly' owing t? higher relative humidity but to the lesser capacity
of the air for moisture at low temperatures, and the fact that mold natur-
ally g-rows much more slowly at low temperatures.
304 PRACTICAL COLD STORAGE
moved from the press ; also, that this cheese was box-cured, and
therefore under conditions which prevented rapid evaporation.
Under other conditions the losses would have been greater than
represented here, and the difference in the rate of loss between
the different lots wider than reported above. This would still
further increase the saving.
It must be remembered that the entire loss in weight dur-
ing the curing of cheese is not due to evaporation. A cheese
in curing is constantly breathing out carbon dioxide the same as
any living organism, due to the development of microorgan-
isms (bacterial growth within the cheese as well as molds on sur-
face). Aside from these biological factors, it has been shown
by Van Slyke and Hart* that profound proteolytic decomposi-
tions also give rise to an appreciable amount of COj. With
cheese at 60° F., in which external mold growth was suppressed,
they found a loss of approximately one-fourth of 1 per cent
in ninety days. In our cold-cured cheese, copious mold de-
velopment occurred, and hence the losses of carbon from the
cheese due to this growth would be considerably greater than if
no such growth occurred. With the nearly uniform rate of
shrinkage shown in these cold-cured cheese, regardless of size,
it is quite problematical M^hether this loss in weight may not be
chiefly due to the operation of the foregoing factors. If this
is so, we may consider such losses as absolutely unavoidable un-
der normal conditions, for the action of microorganisms which
can not be suppressed will inevitably result in the production
of some volatile products.!
At the temperatures of 50° and 60° F., where the relative
humidity was below saturation, the factor of evaporation is ap-
parent and is inversely related to the size of the cheese. From
a practical point of view, it is worth noting that the losses in
both sizes of cheese cured at 60° F. are approximately 50 per
cent more than they are in the cheese ripened at 50° F.
♦Bulletin No. 231, New York State Agricultural Experiment Station
p. 36.
tThis interesting deduction is supported by the tests by the author
and others on the keening of eggs in sealed packages. See chapter on
"BgES in Cold Storage."
CHEESE 305
INFLUENCE OF PAKAFPINING CHEESE ON SHRINKAGE
DURING CURING.
Within the last few years the custom of coating the cheese
with an impervious layer has been suggested, with the object
mainly of preventing the development of mold. For this pur-
pose paraffin has been found to be the most suitable agent. The
application of such a layer to the cheese not only prevents the
growth of mold spores by excluding the air, but materially re-
tards the rate at which the cheese loses its moisture. Paraffined
cheese then dries out much more slowly than the untreated
product, and the application of this method is of particular ser-
vice in the handling of the smaller types of cheese, which have
a relatively larger superficial area exposed to the air.
In the paraffined cheese at 40° F. the losses were reduced
practically to a minimum, as was also the case with the unparaf-
fined at this temperature. As evaporation would certainly be
lessened in the paraffined lot, the uniformity of loss between
these and the unparaffined still further substantiates the view
advanced earlier, that these losses are not so much due to shrink-
age from evaporation as they are to metabolic activities of or-
ganisms and possibly chemical transformations within the
cheese.
EFFECT OF TEMPERATURE ON QUALITY OF CHEESE.
Originally it was planned to have the cheese judged by
commercial experts, but it was found impossible to arrange for a
sufficiently large number of such tests to closely follow the pro-
gressive changes which occurred in the course of the ripening
of the cheese. Hence, in addition to the examinations made by
the jury of commercial experts, the cheese was carefully scored
at Waterloo by Mr. Baer at frequent intervals.
COURSE OF RIPENING IN TYPE I.
Type I was represented by four different lots of Wisconsin
cheese. All of them were well-cooked, firm-bodied, slow-ripen-
ing cheese that may be regarded as typical Cheddars. In one
case the milk from which the cheese was made was evidently
tainted, as the cheese was slightly off at the outset.
306 PRACTICAL COLD STORAGE
The results of these periodical scores by Mr. Baer show that
good cheese was produced at all temperatures in the first three
lots. Naturally that cured at 60° F. developed more rapidly
than the goods cured at lower temperatures, but it should be
noticed that even at this temperature some of the firm-textured
FIG. I.— THREE CHEESE .SECTIONS — TYPE J
Cheese at top cured at 40°, in middle at .50°, and at bottom at 60°.
cheese went off in five months. At 50° and 40° F. the cheese
was about six weeks to two months behind the 60° in develop-
ment, but in time it reached as high as the 60° lot, and generally
of a better quality, and kept this maximum condition much
CHEESE
longer than the 60°. This enhanced keeping quality
pronounced at 40° than at 50° F.
307
was more
In the lot made from tainted milk the imperfect condition
PIG. 2.— TWO VERTICAL CHEESE SECTIONS — TYPE I.
Cheese cured at 40° on left and cheese cured at 60° on right.
308
PRACTICAL COLD STORAGE
was pronounced at all temperatures, but was more prominent
at 60° than below.
In studying the scores by Mr. Baer, it is possible to combine
the numerical scores of the four different lots of Wisconsin
cheese belonging to the same type and so obtain a set of aver-
.3
'<■
'' i"
FIG. 3. — TWO CHEESE SECTIONS — TYPE II.
Cheese cured at 40° on top, cheese cured at 60° on bottom.
ages, as to flavor, texture, and price, which indicate clearly
the progress of the curing of these various lots at the different
temperatures.
CHEESE 309
The variation in flavor observed at the different tempera-
tures is more marked than any other characteristic. It appears
that at the higher temperatures the flavor is more developed dur-
ing the earlier ripening stages, but as the cheese increases in age
the quality of the flavor at the higher temperatures deteriorates
more rapidly than in the cold-cured goods. At the end of five
months the 40° wa.s still improving, and even at this time was
higher than at any period with the 50° and 60°. At the end of
eight months the cold-cured cheese was still of excellent quality,
and showed no signs of deterioration.
The texture of the cheese followed quite closely a develop-
ment similar to that noted above. In the earlier stages the 60°
had the highe.st score, but it reached its maximum in three
months, while the 50° and 40° continued to improve up to the
end of the test, and was higher in the 40° at this time than at
any time in the 60°.
The beneficial effect of cold-curing on this firm type of
cheese is strikingly apparent from the above data. Not only
was this cold-cured cheese free from any bitterness or taint inci-
dent to the curing process, but it was much improved in
texture, as is evident from Fig. 1, which shows the appearance
of cheese made from the same vat, but cured at approximately
40°, 50°, and 60° F. When the cheese is cold cured the body
is much closer, as the curd particles are subject to more pro-
nounced shrinkage at higher temperatures, which causes the
formation of these irregular, ragged cracks. This is perhaps
rendered more obvious in cheese cured at 40° and 60° F.. as
shown in Figs. 2 and 3. "When it is remembered that the results
ordinarily obtained in factory curing are not anything like as
satisfactory as those shown in the cheese cured at 60° F., the
improvement in quality, as shown by the texture of the cheese
cured by the cold-curing process over that now in vogue, is
emphazised still more.
The 50° cheese stands intermediate between the distinct-
ively cold-cured product and that obtained under best present
conditions without artificial refrigeration. Emphasis has al-
ready been laid upon the fact that a considerable improvement
in quality is to be expected where a slight diminution in tem-
310 PRACTICAL COLD STORAGE
perature is secured over that foimd in the best type of factory
curing now in vogue. This system of "cool-curing" — that is,
the use of a temperature from 52° to 58° F., as recently advo-
cated by the Canadian authorities* — stands midway between the
cold-curing process and the sj^stem now most frequently in use.
The benefits to be gained by this system are evident from the
Canadian experiments, in which 480 pairs of cheese were cured,
one of each lot being kept at 52° to 58° F., while the other was
ripened in an ordinary curing room (61° to 70°). Quoting
Mr. Ruddick's paper, he says that "in every case the cool-cured
(cheese) has been pronounced the best in quality."
From the experiments detailed above it appears that further
improvement in quality is possible if the curing temperature is
still further reduced (40° to 50° F.). It must be remembered
in this comparison that the highest temperature we employed is
much lower than the average factory curing room. The differ-
ence in quality between cold-cured and ordinary-cured cheese
would be much greater than that represented in this work.
The cheese of this type at 60° F. ripened rapidly and
showed an excellent quality in all lots but one, which was
tainted from the beginning, but they all passed their prime
in three months and showed marked deterioration by the end
of five months.
With this type of cheese it must be remembered that the
quality of the flavor produced at low temperatures is quite
different from that found at 60° F. Cold-cured cheese possesses
a very mild but perfectly clean flavor, together with a solid,
waxy texture.
COURSE OF RIPENING IN TYPE II.
The cheese in Type II is not so uniform in its make-up as
that of Type I, but it represents that type of American product
in which less acid is developed than is found in the normal
Cheddar cheese. This cheese is more open in texture and con-
tains a considerable number of mechanical and small Swiss
holes, as shown in Fig. 3. The cheese was somewhat low in
•J. A. Ruddick in paper presented at the Ontario Dairymen's Associa-
tion. January, 1903.
CHEESE 311
flavor, due in all probability to the milk and method of manu-
facture, and not to the curing, as this defect was quite as appar-
ent at the lower temperatures as at 60° F.
The Iowa cheese was found to be of only fair quality,
but at all ages was better at 40° F. than at other temperatures,
although the difference is considerably less than it was with
the firmer Wisconsin type of cheese.
The Illinois cheese was quite similar to the Iowa lot, but
the texture of this cheese at 60° F. was considerably more
impaired than that obtained at the lower temperatures.
COURSE OF RIPENING IN TYPE III.
Type III represents the softer make of cheese intended for
home trade, and one which cures more quickly, and therefore
does not keep as long as the firmer Cheddar type. This type is
represented by four different lots of Michigan cheese made at
the same factory. They were not of standard quality, but were
too acid. The first three lots were materially delayed in transit
and consequently had undergone considerable change before
being cold-cured. From the detailed data it is evident that lot
four was the best, and in this lot the 40° and 50° were both
better than the 60°.
In this case the flavor of the four lots was poor, only once
exceeding 40 points. While the 60° scored higher at one
time than the cheese at the other two temperatures, the 40°
cheese at five months equaled the flavor of the higher tempera-
ture cheese at this time.
The difference in price of this cheese at three montlis was
inconsequential, and from this date the cheese at all tempera-
tures fell off rapidly in value.
All four lots of these Michigan goods were more or less
delayed in transit, although lot four was no more so than some
of the cheese in the other types. But with this moist, quick-
curing cheese it was much more susceptible to temperature in-
fluences, and hence was materially impaired before being put
in storage. This condition, taken in connection with the in-
ferior make (high acid), renders this part of the experiment
unsatisfactory.
312 PRACTICAL COLD STORAGE
In the first test the jury consisted of Messrs. White, Millar,
and Kirkpatrick. In the second test, made when the cheese
was five months old, one of the judges (Kirkpatrick) was
unfortunately unable to assist. It is therefore impossible to
compare with each other the average scores secured in these
two tests, as the judgment of the different members of the jury
naturally is not uniform. In comparing, therefore, the course
of ripening in the three and five months' tests, it will be neces-
sary to correct the averages given by eliminating the score of
the judge who was absent in the second test.
For purposes of study, however, the two tests can be con-
sidered independently and the influence of the different tem-
peratures on the character of the cheese determined.
RESULTS OF 'FIRST .JURY TRIAL.
When the cheese had been cured for three months, the
sample cheese which had been tested previously at monthly
intervals by Mr. Baer, was shipped by refrigerator service to
Chicago and submitted to the jury for examination.
Type I. In the four lots of cheese which comprised this
group the 50° product was higher in flavor twice, the 40° once,
and once the 40° and 50° were alike. In no case, even at
this age, when the 60° cheese was at its best (as shown by the
serial examinations made by Mr. Baer), did this cheese reach
as fine a flavor as at the lower temperatures.
In texture the 40° lot was ahead twice, once the 50° and
60° were alike, and once the 60° was the highest.
As to price, in no case did the 60° equal the value set upon
the cheese cured at the lower temperatures, although the differ-
ence given by the judges was slight. It must be remembered
that the price assigned by the commercial jury was influenced
materially by the fact that there is considerable difference in
quality, even among the best types of cheese, without a cor-
responding difference in price. In the majority of cases, when
the cheese scored within one or two points of perfect, the price
was cut from a quarter to a half cent below the market stand-
ard (13 cents), simply because the appearance of the cheese
on the surface (mold, etc.) warranted this reduction from a
CHEESE 313
purely commercial point of view. The judges were free to
admit that intrinsically the cold-cured cheese was of much bet-
ter quality than is usually obtained in the market. This cheese
was box-cured and received no especial care throughout the
experiment; consequently the exterior appearance of the same
had been impaired. With proper control this condition could
have been entirely obviated, as we have been able to show
repeatedly where cheese was cold-cured under our direct super-
vision.
Type II. In this type, in which less acid was developed,
little or no difference was observed in the Iowa goods; but in
the Illinois cheese the 40° product had a better flavor and
texture than the cheese cured at 50° or 60° F. Fig. 4 shows
the appearance of the Illinois cheese cured at the three tempera-
tures when three months old.
Type III. This type is represented by four different lots
from the same factory. All of the lots were highly acid and
were of somewhat inferior make. Then, too, the earlier lots
were delayed in transit from the factory to the curing station,
so that the results of the experiment should not be considered
as necessarily typical of the cold-curing process. In this group
of four tests the 50° goods were ahead twice on flavor, the 60°
orce, and once the 40° and 60° were alike. In texture the 50°
was the highest three times out of four.
GENERAL SUMMARY OF THE FIRST (tHRBE MONTHS) TEST.
The cheese was examined at this date by the commercial
judges, as it was thought that the highest temperature cheese
(60°) had reached its maximum condition. It was naturally
expected that the 60° product at this time would rank higher
in quality than the cold-cured goods.
From this it appears that the 50° cheese was superior in
flavor and texture, not only on the basis of the total scores,
but also as to the number of times they ranked highest or equal
to the cheese cured at either of the other temperatures. This
test was made before the 40° goods were marketable, but even at
this time this cheese compared favorably with the 60° prod-
uct.
314
PRACTICAL COLD STORAGE
RESULTS OP SECOND JURY TRIAL.
The second commercial scoring was made at the end of
five months, at which time it was thought that the cold-cured
goods could best be judged from a market point of view. The
results of this scoring follow :
FIG. 4. — THREE CHEESE SECTIONS — ILLIXOTS CHEESE
Cheese at top cured at 40°, in middle at .50°, and at Ijottora at 60°.
Type I. In the four lots tested of this firm-bodied cheese,
the 40° was highest in flavor three times and the 60° once.
Averaging the total scores shows that the 40° cheese scored
2,8 points higher than the 60°, and even the 50° was 1.6
points above the cheese held at what has been considered ideal
curing conditions.
CHEESE 315
In texture the 40° was highest twice, while in the other
cases the scores were equal. Numerically, the average texture of
the 40° was nearly a point above the 60°. At this age the
60° goods began to show signs of deterioration, while the cold-
cured goods kept much better.
Type II. In this test one lot of the 60° goods (Iowa)
was mislaid in transit, and hence was not tested, but in this
case the 40° was 2 points above the 50° in flavor, and 1 point
on texture. In the Illinois cheese but little difference was ob-
served.
Type III. In this softer cheese, twice the 40° scored high-
est in flavor, the 50° and 60° once each. On texture the
40° scored highest twice, the 50° once, and the 50° and
60° tied once.
GENERAL SUMMARY OP SECOND (fIVE MONTHS) TEST.
In this test the average score, as well as the number of
times any lot has scored the highest, shows that the 40° cheese
was superior to those at either of the other temperatures, while
at this age the 60° cheese showed that it had passed its prime.
COMPARISON OF THE FIRST AND SECOND JURY TRIALS AS INDI-
CATING THE KEEPING QUALITY OF THE CHEESE.
It is important to compare the scores of the commercial
judges made at the first and second jury trials, as in this way
it is possible to study the keeping quality of the cheese cured at
different temperatures. Unfortunately one of the judges couK'
not be present at the second test. Therefore the judgment of
the other two has been used in comparing the data of the two
tests.
Type I. With reference to flavor, type I showed its better
keeping qualities, inasmuch as it held its own at 40° F., while
at 50° F. the cheese had deteriorated 2 points and at 60° F
2.9 points. The texture improved at all temperatures as the
age increased, but was much more pronounced (oyer a point)
at 40° than at 50° or 60° F. This improvement in flavor and
texture is also reflected in the enhancement in commercial
value. The 40° gained 0.2 cent per pound in three to five
316 PRACTICAL COLD STORAGE
months, while the 50° fell off 0.1 cent and the 60° 0.2 cent per
pound. Thus in all ways the advantage of cold curing is evi-
dent on this firm, solid type of the Wisconsin cheese.
Type II. In this type, in which less acid was developed
than in the typical Cheddar type, the deterioration in flavor
was less at 40° F. than at either 50° or 60° F. In texture,
however, all scored lower at five months, the data showing a
wider difference at 40° F. than at the other two temperatures.
In price, however, the cheese was considered to he worth 0.2
cent per pound more at 40°, while the 60° cheese had depreci-
ated 0.7 cent.
Type III. In the softer Michigan make, in which more
rapid deterioration would be expected, the falling off in flavor
was 2 points at 60° F. as against 1.1 points at 40° F. In tex-
ture the 40° improved 0.4 point, while the other two depreci-
ated 0.8 and 0.3 point, respectively. In price, all these goods
were of less value at flve months than at three, but they had de-
preciated 0.5 cent at 60° and only 0.1 at 40° F.
Summarizing the above, there can be no question but that
the keeping quality of all of these various types of American
cheese is improved by curing them at these lower temperatures.
This is more evident with the firm, solid Wisconsin type of
Cheddar than with the softer, quick-curing goods; but even
these can be held with less deterioration at these temperatures
than is possible under present curing conditions.
SUMMARY OF EFFECT OF TEMPERATURE ON QUALITY.
As the three different types of cheese represented in these
experiments varied so muxjh in character, it will be fairer to
state the conclusions with relation to each separately. The score.?
on these lots of cheese were made separately by our own cheese
expert throughout the whole curing period, and also at stated
intervals by the commercial judges.
Type I. At 60° F. flavor developed more rapidly than at
lower temperatures, but the maximum score at this temperature,
as indicated by Baer, was equaled or exceeded by the maximum
score at 50° or 40° F. In the scoring made by the commercial
jury the 50° averaged 0.6 point higher than the 60°, when
cheese was three months old. When five months old, the 40°
CHEESE 317
was 2.8 points higher than the 60°, and the 50° 1.6 points
higher.
In texture the course of development was quite the same,
the judges scoring the 50° ahead at three months, but at five
months the 40° averaged nearly a point higher than the 60°.
Type II. In this low-acid cheese the course for ripening
followed the same rule as in the above type, although this
cheese was inferior in quality to the preceding type.
Type III. The results on this quick-curing type of cheese
were affected by the delay in transit, which permitted of a
considerable degree of ripening before the cheese was put in
the curing rooms. In this type of cheese the improvement was
less marked, but when the enhanced keeping quality is con-
sidered, the cold-curing process was found to be advantageous
even under these advanced conditions.
INFLUENCE OP PARAEEINING ON QUALITY OE CHEESE.
With the use of lower temperatures for curing, a higher
degree of saturation of the atmosphere is always found, which
greatly promotes the development of mold, and this growth
injures the salability, though not the quality, of the cheese,
and hence many attempts have been made to overcome the
difficulty.*
The most efficient method yet proposed is to coat the sur-
face of the cheese, with an impervious layer, which, by exclud-
ing oxygen, prevents development of molds. For this purpose
the cheese are immersed in a bath of melted paraffin, which,
upon cooling, adheres closely to the surface. While this effec-
tually accomplishes the desired end, it is a question of import-
ance whether the quality of the cheese so treated is affected
prejudicially or not. It is possible to conceive that the reten-
tion of all volatile decomposition products within the cheese
might injure the flavor of the product.
In these cheese-curing experiments it was thought advisa-
ble to institute a series of trials to determine what influence
paraffining had on the quality, as shown by the flavor and
•The statement that the lower the temperature the higher the relative
humidity cannot be allowed to stand in the light of present information.
Further, mold is checked by the lower temperature. See chapter on
"Humidity."
318 PRACTICAL COLD STORAGE
texture scores. For this purpose the cheese which was used
in the experiments on shrinkage (La Crosse lot) was scored
by Mr. Baer, and was also submitted to the experts for scoring
at the regular periods.
It is evident that the difference between the same lot of
cheese when paraffined or unparaffined is very slight. If the
course of curing is considered, as is shown by the scores of Mr.
Baer, which were taken when the cheese was one, two, three
and five months old, it is apparent that the application of par-
affin has not injured either the flavor or the texture of the
cheese. It will be further noted that in the "daisies" the un-
paraffined cheese was, with one exception (60°), better at the
beginning; but throughout the remainder of the curing and to
the end of the experiment the paraffined improved much more
rapidly, and without exception was as good or better than the
unparaffined.
With the prints the difference in scores was practically
negligible.
This same cheese was scored by the commercial experts
when it was three and five months old, and it should be noted
that the opinions of these experts coincided quitely closely with
those of Mr. Baer.
It would be unsafe from these limited experiments to draw
any general conclusions, but so far as they go these trials show
that no injurious effect was observed on either the flavor or
(he texture of the paraffined cheese.
GENERAL SUMMARY.
The purpose of the experiments detailed above was to test
the value of low temperatures for the curing of cheese made
under widely different but commercial conditions. To accom-
plish this purpose, it was deemed advisable to purchase the
product from a wide range of territory. This condition ren-
dered it impossible to install the cheese in the curing rooms
immediately after it was taken from the press, and hence the
full effect of the process is not so evident as would have been
the case if the cheese had not had any preliminary curing.
Naturally a comparison of the cold-curing process would
be made with the conditions most frequently found in fac-
CHEESE 319
lories, but in these studies the low temperature cured product
has been compared with cheese ripened at about 60° F. — a tem-
perature which has hitherto been considered as the best for the
ripening of Cheddar cheese.
EFFECT ON SHRINKAGE.
When cheese is cold-cured, the losses due to shrinkage in
vveight are greatly reduced over what occurs under ordinary
factory conditions.
1. — Influence of temperature. — Cheese cured at 40° F. de-
creased in weight in ninety days from 1 to 1.4 per cent, while
that cured at 50° and 60° F. lost fully three times as much.
This saving would be still further increased if comparison were
made between the results of cold curing and existing factory
conditions. Under prevailing factory practice cheese is sold
at a much earlier date than is advisable with cold-cured goods,
but the loss under present conditions, for even as brief a cur-
ing period as twenty days, is fully four times as great as has
occurred in these experiments in a ninety-day period (the mini-
mum curing period recommended) under cold-curing condi-
tions (40° F.). This saving in a factory making 500 pounds
of cheese daily would average not less than 15 pounds of cheese
per day for the entire season, or considerably more than this if
only summer-made cheese were cold cured.*
2. — Influence of type of cheese. — In these experiments dif-
ferent types of cheese were used, ranging from the firm, typical
Cheddar to the soft, moist, quick-curing cheese made for the
home trade. The losses with the firmer type were considerably
reduced in comparison with the other, but the conditions to
which the softer types of cheese were subjected were not as
favorable (because of initial delays) , and hence the losses with
these types can not be relied upon with such definiteness. As
this cheese was exceedingly moist, the total losses from the
press were undoubtedly greater than here reported.
*It seems to the author that undue stress is being- laid on the great
benefit to be derived from a saving in evaporation or shrinkage in weight.
If this loss is saved to the manufacturer the retailer or consumer is the
sufferer, because moisture has no value as food, and the loss of moisture is
practically all that evaporation means. More importance should be given
to the Improved quality, because the saving in weight comes out of the
retailer or consumer.
320 PRACTICAL COLD STORAGE
3. — Influence of size of cheese. — The size of package ex-
erts a marked effect on the rates of loss. At ordinary tempera-
tures, the smaller the cheese the more rapidly it drys out. This
difference in loss diminishes as the temperature is lowered, and
in our experiments at 40° F. was practically independent of the
size. This condition, however, was undoubtedly attributable
to the relative humidity of the curing room, which at 40° F.
was 100 per cent.
4. — Influence of paraffin. — By coating the cheese with
melted paraffin the losses at 60° were reduced more than one-
half; at 50° the saving was somewhat less, and at 40° the
losses observed on the paraffined cheese of both sizes used were
slightly in excess of those noted on the uncoated cheese.*
5. — As some loss occurs even in a saturated atmosphere,
where evaporation is presumed not to take place, it implies that
the shrinkage in weight of cheese under these conditions is not
wholly due to dessication, but is possibly affected by the produc-
tion of volatile products that are formed by processes inherent
in the curing of cheese.
EFFECT ON QUALITY.
6. — The three types of cheese before referred to can scarce-
ly be compared closely with each other, as they were so differ-
ent in their make-up and subject to somewhat different condi
tions during transit. By far the most satisfactory portion of the
experiment is that which relates to Type I, in which the best
quality of cheese was represented. With these firm, typical
Cheddars the influence of temperature on curing could best be
studied. This cheese was also placed in storage nearer the
press than any of the other types, and hence the test as to the ef-
fect of the curing temperature was more satisfactory. In this
type the 60° cheese was of excellent quality and naturally de-
veloped faster than the cold-cured goods, but in time it was
surpassed by the cheese at the lower temperatures (50° and
40°), and, when the keeping quality of the latter was taken in-
•Ketallers of cheese in England have in some cases made strong objec-
tion to the paraffining of cheese for the reason that they suffer much
greater loss from shrinkage when cutting up the cheese for retailing.
From these experiments it seems that the cold-curing of cheese has much
more to do with preventing loss of weight than paraffining.
CHEESE 321
to consideration, it was found to be superior in every way to
that cured at 60° F. Even when the condition of the milk
was not entirely perfect, the quality of the cold-cured cheese was
better, although the original taint was not removed.
"With the sweet-curd (type II) and the soft home-trade
cheese (type III) the effect of the disturbing influences pre-
viously noted rendered it impossible to obtain as satisfactory
results, but, even under these adverse conditions, the 40° and
50° cheese generally ranked better than the 60°, and, when
keeping quality was taken into consideration, was materially
better.
This same cheese was also scored independently by com-
mercial experts when three and five months old. The results
obtained conform very closely to those mentioned above, and
indicate the superiority of the cold-cured product (either at 50°
or 40°) in comparison with the cheese cured at 60° F. This
improvement in quality reflects itself also in the commercial
values which were placed upon the cheese cured at different
temperatures, both by our own expert and also by the commer-
cial judges.
In this low-temperature-cured cheese the flavor was re-
markably mild but clean, and was free from all trace of bitter-
ness or other taint. The texture was fine and silky and the
body close.
7. — Keeping quality. — The keeping quality of the cold-
cured cheese far excels that of the cheese ripened at higher tem-
peratures. The better types of cheese cured at 40° F. were
at the end of eight months still in their prime, while the 60°
cheese had long since greatly deteriorated.
g_ — Effect of paraffining on quality. — Portions of two lots
of cheese were paraffined as they came from the press, but were
otherwise handled the same as the unparaffined cheese. The
results obtained showed that paraffining did not prejudicially
affect their quality at any temperature. As paraffining great-
ly reduced the shrinkage, the beneficial effect of the system is
obvious. The rapid introduction of the method in commercial
practice further attests its value.
322 PRACTICAL COLD STORAGE
9. — The production of a thoroughly broken-down Ched-
dar cheese of mild, delicate flavor and perfect texture meets a
demand which is impossible to satisfy with cheese cured at
high temperatures. Without any question, if the general
market can be suppHed with this mild, well-ripened cheese,
consumption will be greatly stimulated, not only by increasing
the amount used by present consumers, but by largely extend-
ing the use of this valuable and nutritious article of food.
10. — The improvement in quality of cold-cured cheese,
the enhanced keeping quality, and the material saving in
shrinkage due to lessened evaporation are sufficient to war-
rant a considerable expenditure on the part of cheese pro-
ducers in installing cold-curing stations.
The principle of increasing cost of equipment to lessen
cost of production or augment gross earnings is recognized as
a sound financial method by all large enterprises, and, while
the expense involved is considerably more than is incurred
under existing conditions, yet the advantages enumerated more
than compensate for such expense where carried out under
proper conditions.
11. — This system is particularly applicable where the
product of a number of factories can be handled at one point,
and such consolidated curing stations must be established be-
fore the cold-curing process can be economically introduced.
Such stations are now successfully used in a number of local-
ities. The greatest advantage will undoubtedly accrue from the
use ' of this system of curing with summer-made cheese, but
the process is equally applicable to cheese made at any season of
the year.
author's concluding remarks.
The foregoing report of the result of experiments by the
Wisconsin Station demonstrates fully the desirability of low
temperatures for cheese storing, and for the curing of cheese by
placing -it in a low temperature as soon as manufactured. The
experiments do not, however, include temperatures of from
30° to 32° F., which are now considered best for long period
storage of cheese. It is desirable that the best temperatures for
CHEESE 323
the most successful storing of cheese should be determined and
additional experiments should be made for this purpose. It is
also practicable to extend the experiments so as to include
foreign makes as well as the various types of American cheese.
The cheese business is now practically all handled through
cold storage, and temperatures ranging from 30° to 40° F. are
in use. The use of cold storage for the curing of cheese is,
therefore, not in an experimental stage, and it is to be regretted
that the experiments of the Department of Agriculture did not
include temperatures of 30° F. and 35° F. as representing the
commercial practice of the times, and a still lower range to de-
termine the possibilities in this direction.
The initial quality of cheese has much to do with what is
best for it in the way of temperature while curing or cold stor-
ing, but nothing positive may be said on this point at the
present time, as no results of experiments are at hand as a
guide. The author recommends that a good average clean-
flavored make of American cheese be first placed in a tempera-
ture of about 40° F. After being in storage for a month or
two reduce the temperature gradually so that at the end of two
or three months the temperature reaches 30° F., which is rec-
ommended for a permanent storage temperature. This tem-
perature is somewhat lower than is generally considered best,
but if handled as suggested better results may be had than at
any higher temperature.
CHAPTER XVI.
CREAMERY AND DAIRY REFRIGERATION.
NECESSITY FOR REFEIGERATION.
It has been estimated that the total amount of butter pro
duced in the United States is about 2,000,000,000 pounds each
year. It is probable that the amount is in excess of this, rather
than less. The consumption of butter is rapidly increasing and
the average quality of same is likewise being improved, but it
is probable that not more than one-half of the butter made
reaches the consumer in prime condition. The most impor-
tant reason for this is, no doubt, that refrigeration is not en^-
ployed to a sufficient extent, or where employed, not intelli-
gently or scientifically applied.
Though nowadays not of the same importance to the dairy
as it was before the centrifugal creamers were invented, yet in
our climate ice or refrigerating machinery is indispensable to
the production of fine butter. To fully control the process, the
butter maker must be able to heat and cool the cream at will,
and the butter often requires a cooling which cannot be effected
without ice or a refrigerating machine. Every creamery and
dairy not provided with a machine should, therefore, have an
ice house, and a refrigerator or cooling room should always be
constructed.
Refrigeration is absolutely necessary to the proper manu-
facture of butter, and is likewise necessary to the proper keep-
ing or preserving of same after it is made. Refrigeration is
applied in the manufacture of butter to the manipulation and
proper tempering of the raw materials and the keeping of the
butter when made at a low temperature to prevent deteriora-
tion. Considering the great importance of refrigeration as
applied to creamery products, comparatively little attention has
324
CREAMERY AND DAIRY REFRIGERATION 325
been given to this branch of the business. It is not meant by
this that those who are operating creameries have not given
careful thought to this matter, but that the refrigerating engi-
neers and the makers of refrigerating machinery have not stud-
ied its application to creamery and dairy service as fully as
they might.
As in all other branches of the refrigeration of perishable
food products, the United States is in advance of other coun-
tries in the preservation, by cold, of milk, butter and cheese.
Until a comparatively recent day, however, the most ■ pro-
gressive of the dairy companies often cooled their cans of milk
by immersing them in a bath of cracked ice. This process
was not only cumbersome, in that it necessitated the repeated
handling of the heavy cans, but the cans themselves were thus
injured. The ice and water were scattered over the premises,
which rendered cleanliness very difficult. A dairy establish-
ment refrigerated artificially presents a neater appearance. The
milk as it is brought in from the country is first tested for
quality. It is then placed in a large tank, from which it passes
through three sets of fine strainers, which remove all small par-
ticles of dirt or dust that may have gotten into the cans. It then
passes through a series of pipes, which are submerged in a large
brine tank. The tank contains the ammonia expansion coils,
by which the brine is kept at the required temperature. After
passing through these coils, the milk is drawn off into cans,
which, in turn, are stored in a large refrigerator, kept at a tem-
perature of about 35°.
Denmark and Sweden, in Europe, have made the greatest
advance in the refrigeration of the products of the dairy, ma-
chinery being extensively employed for that purpose. The
creameries and butter factories of Belgium and Holland are
also becoming more modern in this respect year by year. A
late innovation in the dairy industry in northern Germany
and Denmark is the process of freezing milk into blocks, and
shipping it abroad as milk ice, mostly to England. The re-
quired machinery agitates the milk during the freezing process,
so that when ready for the market the substance of the froze'n
milk is uniform throughout.
326 PRACTICAL COLD STORAGE
The pasteurization of the milk, which is now becoming
quite general in the larger creameries in this country, as it is
in European countries, notably Denmark and Belgium, calls
for additional demands on refrigerating apparatus, as it is
found essential to reduce the temperature after pasteurization
as rapidly as possible. •
ICE VERSUS KEFKIGEEATING MACHINE.
There is at the present time considerable controversy be-
tween those who advocate the use of ice for creamery or dairy
refrigeration and those who recommend refrigerating machin-
ery. There should be no quarrel between these two different
methods, as each one has its proper sphere, and there are cases
where the selection of either one or the other would be a matter
largely of individual opinion. Where natural ice can be stored
cheaply at, say, a cost of $1.00 a ton or less, and where the
quantity of milk to be handled would not exceed 10,000 or
15,000 pounds per day, the use of natural ice is usually to be
preferred to installing refrigerating machinery. On the other
hand, where the quantity of milk to be handled is large and
ice is comparatively expensive, a refrigerating machine can
profitably be employed.
The advantages and disadvantages of the mechanical sys-
tems over ice have been quite fully investigated by Prof. Oscar.
Erf, late of the College of Agriculture, University of Illinois.
His deductions, however, were based on conditions which do
not apply in states of about the same latitude as New York,
Michigan, Wisconsin and Minnesota, and even south of these
latitudes there are places where natural ice can be housed at
much less cost than 90 cents per ton, which he has taken as a
basis. His investigation seems to have been conducted from
an intelligent and fair-minded standpoint, and his results are
useful to creamery men, if proper allowances are made for the
difference in latitude and other working conditions. Prof. Erf
gives his results in detail, but we will only consider his sum-
mary of the disadvantages of mechanical refrigeration, as
follows:*
*From Ice and Refrigeration, June, 1902.
CREAMERY AND DAIRY REFRIGERATION 327
1. — Large capital invested.
2. — Necessitates daily or continual operation, unless provided
with large storage tanks.
3. — Operating expenses for labor, coal, oil, ammonia and repairs.
4. — Excessive dryness in such refrigerators, often causing a great
shrinkage in the products.
5. — Great risks for accidents that might happen, such as breakage
on machines and the delay of repairs.
6. — Expense of pumping water for condensing ammonia.
The advantages offsetting these disadvantages by using machin-
ery for refrigeration, as compared with the use of natural ice:
1. — No risks to run in securing cold whenever needed.
2. — Practically no variation in cost of producing cold from year
to year.
3. — ^The refrigerator is under better control.
4. — Any temperature may be practically obtained above zero.
S. — Atmosphere is dryer in refrigerator; hence butter is less sus-
ceptible to mold.
6. — Less disagreeable labor, such as the handling of ice.
7. — Cold room can be kept cleaner.
8. — Does away with the impurities imbedded in river and pond ice.
9.^ — Provides for a more perfect method of cream ripening, which
results in a better product.
10. — Secures economy of space in the cool room, which lessens
the radiating surface for same amount of refrigeration.
The disadvantages as set forth are sufficiently plain to all
who have had experience with refrigerating machinery. The
advantages which are cited are more or less true, especially as
applied to the ordinary application of ice as generally used in
creameries. Should the Cooper brine system be used, as de-
scribed further on, there would be :
1. — Absolutely no risk to run in securing cold whenever needed.
2. — Any temperature may be practically obtained down to 15° F.
3.^The refrigeration would be under fully as good control and
a more uniform temperature could be obtained than by the use of
refrigerating machinery.
4. — The moisture in the atmosphere of the cold room could be
carried at any temperature desired and under as good control as
with the mechanical system. , , .
S. — ^The amount of disagreeable labor required, should an ice
crusher and ice elevator be used, would be very small indeed.
6.— The cold room can be kept as clean as with any system. _
7. — Impurities in the ice would have no influence on the air of
the room for the reason that the air does not come in contact with
the ice.
8. — As perfect results can be had in the ripening of cream.
9. — The economy of space in the cold room would be as great as
with any system.
In other words, the Cooper brine system will produce any
results which can be had with refrigerating machinery down
to a temperature of 10°, or even 5° F., and besides this, it is
absolutely sure against a breakdo-^n.
328
PRACTICAL COLD STORAGE
THE CREAMERY REFRIGERATOR.
A cooling room for maintaining the butter at a low tem-
perature after being made, is admitted to be absolutely neces-
sary in every creamery, and it cannot be dispensed with, except
in cases where butter is loaded into a refrigerator car each day.
Even then the butter will handle much better and arrive on the
market in much better condition if it is hardened so that it
is
^^
SPACE I EETUEEH
)( 3T\ID5 FIL )||lED WITH j|;
DRAIM- — ®
COOLIMG ROOM
^///////////////////^^^^^
SPACE i BETWEEH X STVDS FIL
^S^^SS^S^»^m-h1■>■>»^^>^>».■;^'l1>.\^^■>^^^1>i■^.^'ly
Vled with y c
^Msss^^^ss'>sSssv.^';^■^sss&<.v»'>ssssss^s^SSvv^
FIG. 1— PLAN SMALL COOLING ROOM.
will carry without shaking or slopping in the tub, to say noth-
ing of the advantages of always having it at a low temperature
until consumed. Butter is practically at its best when first
made, and the nearer it can be retained in this condition until
consumed, the better satisfaction it will give the customer and
the greater will be the ultimate gain to the creamery man.
When butter is to be shipped frequently, a small cooling room,
CREAMERY AND DAIRY REFRIGERATION
constructed with ice chambers above the storage room,
tially as outlilned in Figs. 1 and 2, should be built in
creamery not provided with mechanical refrigeration.
329
essen-
every
It is
PIG. 2— SECTION SMALL COOLING ROOM.
much better to place the ice over the room than it is to put the
ice in a rack at one end or one side of the room. A lower tem-
330 PRACTICAL COLD STORAGE
perature will be obtained and a dryer atmosphere will result,
owing to the circulation of air, as indicated by the arrows. A
room of this kind should be well built, and a few dollars extra
spent in the insulation of same will be saved in a short time
in the saving in the quantity of ice required. The temperature
to be obtained in the room also depends on good insulation.
If the insulation is thorough, a temperature of 36° to 40° F.
may be depended upon. Of course, at the time when warm
butter is placed in the room, the temperature will naturally rise
to quite an extent. The construction of a room of this kind
can be adapted to suit local conditions and the nature of the
materials which can be most readily obtained. The detailed
description which follows, of a room constructed on the pla&i
as laid down in the preceding paragraphs, will be of consider-
able value and interest to owners of creameries.
The floor joists, ceiling joists and side wall studding'should
all be filled with mill shavings, sawdust, tan bark, cut straw or
any similar material. This material, however, must be dry and
protected on the outside and inside by the best grades of insulat-
ing paper (not the ordinary rosin sized or common building
papers) . Care should be taken that in all corners the paper is
thoroughly lapped to make an absolutely air-tight surface, so as
to prevent a circulation of outside air into the space which is
filled with the insulating or packing material. It is best to
double-board the outside of the room and put the insulating
paper between. On the inside of the studding and on the top
of the floor joists and on the bottom of the ceiling joists use
matched boarding. Covering this interior surface should be
placed a much better grade of insulating material than the
filling between studs and joists. This may be of hair felt, sheet
cork, granulated cork, rock fiber felt, mineral wool, Cabot quilt,
or any of the best grades of insulating materials. If there is
any liability of trouble from rats or mice, they can be kept
out of a room of this kind by using an inch or two of rock fiber
felt or mineral wool on the outside of all walls. Rats or mice
cannot work in either of these materials. The rock fiber felt
spoken of is practically a mineral wool made up in the form
of sheets or boards. The materials indicated may be used to
CREAMERY AND DAIRY REFRIGERATION 331
a thickness of 2, 3 or 4 inches, depending upon the amount of
money the owner is willing to spend and cost of refrigeration.
These various materials must, of course, be put on between
battens or cleats of sufficient thickness to flush up even with
the layers of insulating material. If hair felt, sheet cork or
rock fiber felt is used, the different thicknesses should be sepa-
rated by a good grade of insulating paper. The interior of the
room should be lined with matched stuff, preferably of poplar,
spruce or hemlock. (The chapter on "Insulation" may be of
interest in this connection.) If it is desired to wash out a re-
frigerating or cooling room of this kind from time to time, the
interior finish may be of shellac or hard oil, preferably shellac,
or, the inside surface may be coated with whitewash, which
may be renewed from time to time. (See chapter on "Keep-
ing Cold Stores Clean.") The joists for supporting the ice
should be of fairly strong material, depending on the size of
the room and should be pitched slightly toward the drain end
of the ice floor. The joists for supporting the ice are not car-
ried into the insulation, but rest on ribbands of 2x4s spiked
onto the outside of the insulation. A batten should be set in
the insulation for receiving these ribbands. The pan or floor
under the ice consists simply of two thicknesses of dressed and
matched stuff with a covering or lining of No. 20 galvanized
iron. A loose rack of wood should be placed on this iron floor
to prevent its wearing or getting punctured in handling the ice
thereon. The galvanized iron should be turned up on the
sides 4 to 6 inches. The circulation of air is provided for by
placing a tight board screen on one side of the ice space which
is carried up to near the ceiling. The other or opposite side
of the ice space has cleats or slats which keep the ice in place
and allow a circulation of air. This screen and the slats men-
tioned are, of course, fastened to 2x4s or to 2x6s, which form
the open spaces for the circulation of air on the two sides of
the ice chamber. The screen and cleats should be beveled on
the top and bottom so that any dripping will be on the gal-
vanized iron pan and not into the air flues and then down into
the room. These various parts are illustrated in Fig. 2, but
are not shown in detail. For filling ice into the ice chamber,
332 PRACTICAL COLD STORAGE
a door may be provided at any point, but should not be on the
side where the air flows down from the ice room to the storage
room or up from the storage room into the ice chamber. This
ice door may be at the top, and the room can be filled from
the floor above if convenient. Both the ice door and the door
for entering the room are preferably one of the special doors
which are on the market and which cost but very little more
than the home-made door, and are superior in every way.
The above cooling room is intended to be filled from an
independent ice house, which should be located as near the
cooling room as convenient.
COMBINATION ICE HOUSE AND REFRIGERATOR.
The following description,* by W. G. Newton, will be of
interest :
The ice house is in the opposite end of the building from the
boiler room and the ice is put right in on the ground floor and the
refrigerator is built next to it and holes cut through next to the floor
for the cold air to enter and same at top for warm air to go out. The
ceiling over the ice needs to be from four to six feet higher than it
is in the refrigerator, then if the outlets for the warm air are right up
close to the ceiling (not having so much as a piece of molding be-
tween the top of the hole in the side and the ceiling overhead), the
dampness will all go off with the warm air up over the ice, leaving
your refrigerator dry and sweet.
As to the expense of building, it is not much, as a room 20x20
or 20x30 feet at most will hold ice enough to cool most of the cream-
ery refrigerators if they have some ice stored elsewhere for other
uses. All that is necessary is to have the walls of the ice house
properly insulated with sawdust and air spaces and then the yearly
renewal of sawdust in which to pack the ice is saved.
Not only creameries, but several large meat markets here have
this kind of an ice house and refrigerator combined, and they are
giving the best of satisfaction. There is a patent on them. The days
of building refrigerators vifith ice overhead have gone by in this sec-
tion of the country.
This appears like a fine arrangement to save labor and pro-
duce the lowest possible temperature with ice. The ice room
must be as well finished and insulated as the refrigerator and
no sawdust or packing material used on the ice. It would be
advisable to build the ice room more than four to six feet higher
than the refrigerator, and ten or fifteen feet would be better.
An ice room of say 20x30x20 feet dimensions should be suf-
ficient for an ordinary creamery, but this depends on what is to
*From New York Produce Review,
CREAMERY AND DAIRY REFRIGERATION 333
be done with the milk. The storage of ice in a building, as is
well known, tends to cause it to decay and deteriorate rapidly,
and this is the only real objection to the plan, as the ice room
would be in bad condition long before the refrigerator. A well-
built house on a stone or brick foundation would be almost a
necessity for the purpose.
In practice, in some exterme cases, it has been found advis-
able to fill into the ice house as many pounds of ice as there
are pounds of milk to be treated, or to harvest 100 cubic feet of
ice for each cow furnishing milk to the dairy or creamery.
Less than one-half this quantity may be ample in many cases,
so much depends on the treatment to which the milk and
manufactured product is subjected. Where pasteurization is
practiced, much more ice is required, especially where no well
water is available. During the winter, ice or snow may be used,
which is simply hauled together in a heap near the creamery,
so that no ice is taken from the ice house until April or May.
Where separators are used, no ice is needed for raising the
cream, but the latter needs cooling either as it runs from the
separator or after the ripening, before churning.
Ice is also needed in the hot summer months to cool the
butter before or between the workings, and for keeping it firm
in texture before it is shipped, so that it may leave in the very
best condition for standing exposure to heat while in transit to
its destination. Butter in prints is sometimes shipped in cases
with an ice box filled with crushed ice in the center.
The amount of ice required for these various purposes
varies according to local conditions, and cannot be definitely
stated, though it may be calculated approximately. The chap-
ters on "Harvesting, Handling and Storing Ice" and "Ice
Houses" give methods of handling ice and details for construc-
tion of ice houses of various capacities.
TRANSPORTATION OP MILK AND CREAM.
In the transportation of milk and cream, baggage cars,
refrigerator cars, and cars especially constructed for the pur-
pose are employed. The railroads adopt the style of car best
suited to their individual requirements. In the case of light
334 PRACTICAL COLD STORAGE
shipments and short hauls, superannuated baggage cars appear
to meet every requirement and are generally moved in con-
junction with local passenger trains. In the case of long hauls,
however, refrigerator or special milk cars are used. These
cars are plentifully supplied with ice during the warm summer
months and, in extremely cold weather, are often steam-heated
to prevent the milk from freezing. Cleaning generally takes
place after each run, the cars being either swept or washed by
means of a hose. Trains making long hauls are usually com-
posed entirely of refrigerator or special milk cars and are oper-
ated on about passenger schedule time, the actual running time
being as fast as fifty miles an hour. The capacity of a large
milk car is 325 ten-gallon cans.
Nearly all railroads which handle a large milk traffic have
well-built covered receiving and shipping stations along their
lines, nearly all of them with an ice house connected in which
natural ice in sufficient quantity is stored during the winter.
Shipping stations are equipped with large cooling vats in
which cans of milk are placed immediately after being deliv-
ered by the farmers. These vats are ffiled with water and ice,
the milk is stirred and cooled down to 40° F. within forty min-
utes from the time it is received, and kept in ice water until the
train arrives, when it is loaded direct from the vats into a refrig-
erator car.
COOPER BEINE SYSTEM.
The application of the Cooper brine system to the refriger-
ation of a creamery cooling room and freezing room is shown
in Mgs. 3 and 4. They also show the arrangement of ice
crushing and ice handling apparatus, which will deliver crushed
ice to any convenient point in the creamery workroom for the
cooling of cream, butter, shipping, or other purposes. Fig. 3
shows the plan view of one end of the creamery with ice house^
adjoining. The refrigerated space in the creamery consists
of a cooling room with a capacity of about one carload. The
butter freezing room has a somewhat larger capacity. The rela-
tive size of these rooms can, of course, be changed to suit any
conditions. The cooling room and freezing room are both
entered from the vestibule and not from the workroom. This
CREAMERY AND DAIRY REFRIGERATION
335
prevents the access of warm air into the rooms, which is very
important, especially in the freezing room. If it is desired, the
cream cooling vats may be placed in a cooling room of this
kind, but as planned, it is intended that the cream should be
cooled with crushed ice or cold well water. There are a num-
ber of different ideas on arrangements of this kind, but with the
apparatus shown any arrangement can be provided to suit the
ideas of the owner or local requirements.
The Cooper brine system, patented by the author, which
referigerates the cooling room and freezing room, is described
fully in the chapter on "Eefrigeration from Ice."
PIG. 3 — PLAN COOPER BRINE SYSTEM FOR CREAMERY.
ICE HANDLING MACHINERY.
The ice crusher and ice elevator which are clearly shown
in Fig. 4 are quite simple in their operation, and as labor sav-
ing machines are the best form of apparatus which has been
applied to the handling of ice. It only requires that the ice
be broken into irregular pieces of 20 to 30 pounds or there-
abouts, and fed into the ice crusher. The crusher breaks the
ice into small pieces the size of hens' eggs or smaller, and it
336
PRACTICAL COLD STORAGE
drops into the bucket elevator where it is raised to a point suf-
ficiently high to allow of its being spouted to a convenient point
in the creamery and to the flexible spout which is used to feed
ice into the tanks containing primary coils of the gravity brine
system. Four or five tons of ice may be handled with an appa-
ratus of this kind in half an hour. As recommended in con-
nection with the "Model Creamery Ice House" described in the
chapter on "Ice Houses," the ice should not be covered with
CREAMERY AND DAIRY REFRIGERATION 337
sawdust or packing material of any kind, and where the ice is
clean in the ice house, the labor of handling same to the
crusher and delivering to any convenient point in the creamery
is very little as compared with the old-fashioned method. This
outfit and apparatus is not recommended for the average small
creamery, but where several tons of ice are to be handled each
day, or where it is desired to store a certain portion of the prod-
uct of the creamery and carry it for several months, as good
results may be obtained with the Cooper brine system as with
a refrigerating machine. The expense of installing, while it is
considerably more than any of the old-style refrigerators, is
less than for a good refrigerating machine.
COOLING OF MILK AND CREAM.*
The following is a portion of an address by Loudon M.
Douglas, read before the Cold Storage and Ice Association at
Islington, England:
The main object in view in cooling fresh milk for immediate
consumption is to arrest the development of the spores which pro-
duce bacteria, and which, in their turn, destroy the milk — that is to
say, the milk becomes sour. It will be understood, however, that the
bacteria referred to are those which are always found in the milk
produced, even under proper hygienic conditions. Heat is the essen-
tial condition for their development, and, in the absence of that con-
dition, they will remain inactive. Of pathogenic bacteria we need
not speak here.
Properly speaking, under good hygienic conditions, it should only
be necessary to cool the milk before sending it out, and this is prac-
ticed by some retailers. It may, however, be considered an advantage
to previously pasteurize the milk at a high temperature, and then
cool it down. It is not easy to say which way is the better. In any
case both methods are in use.
In cooling town's milk direct from a temperature of, say, 68° to
38° F., all that is necessary is a small refrigerating machine connected
to a circular cooler. The cold brine from the machine is circulated
through the flutings of the cooler and the milk run over. When it
reaches the bottom and escapes, the temperature will be about 38° F.,
the balance of the heat units having been absorbed by the brine. But
by means of a similar small machine a very large cooling effect may
be produced by having a large insulated store tank fitted with agitat-
ing gear and filled with either water or non-freezable brine.
It is obvious that, by working the small machine for a length-
ened number of hours upon this store, the heat will be extracted and
utilized to cool in turn a very large quantity of milk in a short time,
a quantity quite beyond the power of a small machine to deal with di-
rectly. Thus, by intelligent working a small machine costing a com-
paratively small sum can be made to perform a large amount of work.
* Extracted from Ice and Refrigeration, June, 1904.
338 PRACTICAL COLD STORAGE
In the case where milk is previously pasteurized the procedure
is different, and can not be better demonstrated than by referring to
a large dairy where the work is carried out. The dairy in question
handles 1,000 gallons of fresh milk per day, all of which is distributed
either directly to consumers or to shops for such distribution, and, in
considering the question of refrigeration, it was stipulated that the
cooling of the quantity named should be performed in one hour, and
that there should also be provision made for cooling a churn store,
a cream store, and a butter store of certain dimensions. Now, the
machine necessary to cool the 1,000 gallons from 68° to 45° F. in one
hour, equal to the elimination of 230,000 B.T.U., would be a very
large one, whereas the B.T.U. to be eliminated from the accessory
stores would be comparatively few. Obviously, therefore, if a large
machine had been installed it would have been much of its time idle.
The problem, therefore, was to find a machine which would perform
the whole work during working hours. This was done by providing
storage tanks for 1,000 gallons of brine, and the heat is extracted
from this during a series of hours. Obviously all this brine when
cooled down is available, and it is only necessary to run it through
a large capillary cooler while the milk to be cooled is run over the
outside. The heat of the milk is transferred to the brine, and thus
the cooling is accomplished with great rapidity. The pasteurized miH
is first of all cooled with ordinary water from the town's supply tc
68° F., and from that temperature is lowered through 23° to 45° F.
The machine used is capable of eliminating 45,000 B.T.U.s per hour.
But the total number of B.T.U.s to be elimated are altogether 355,000,
taking into account the accessory work to be done; thus, if 355,000
is divided by the output of the machine, viz., 45,000, you get the num-
ber of hours' work necessary, viz., eight, or an ordinary working day.
There is a margin of 5,000 B.T.U.s allowed for contingencies.
The creamery system has now become well established through-
out Europe, and feeding stations to main creameries are recognized
as essential to economical working. The process which is usually
carried out in these places is as follows:
The milk is brought by the farmers to the creamery, sampled,
weighed, pasteurized, and separated. When the cream leaves the
separator it may be at a temperature of from 170° to 180° F., and is
therefore immediately run over a circular capill'ary cooler, through
which water is circulated, and reduced to about 65° F. It is then
run over another cooler, through which brine is circulated, and cooled
to about 45° F., being caught in churns, and in this state taken to
the main creamery to be ripened and made into butter. The separated
milk is treated in very much the same way. A large surface water
cooler reduces the temperature to 68° F., and the milk is then run
over a small cooler and reduced to 48° F., at which temperature it
is returned to the farmer.
Some actual tests of a machine (at Ballinorig) might be appro-
priately recorded here:
1. — 100 gallons of brine were cooled from 40° F. to 27° F. in one
hour (condensing water 57° F.), or equal to the elimination of 13,000
B.T.U. per hour.
2. — 100 gallons of brine were cooled from 27° F. to 17° F. in one
hour (cooling water, 58° F.) =10,000 B.T.U. per hour.
3. — IGO gallons of brine were cooled from 45° F. to 31° F. in one
hour (cooling water, 57° F.) =14,000 B.T.U. per hour.
These tests bring out very strongly the fact that at comparatively
high temperatures cooling is effected at a much more rapid rate than
at the lower range of temperatures, and the amount of energy con-
CREAMERY AND DAIRY REFRIGERATION 339
sumed is greater at lower or ice-making temperatures than at the
higher, and this must be borne in mind in specifying the duty of the
machine. The machine in question is one of the very smallest made,
but the same result is obta;ined with machines of all sizes.
Perhaps the greatest interest is attached to the application of
refrigeration to a central or main creamery, for in such a place all
the important applications can be put into effect. These may be
classified thus: A, cooling cream from separator; B, cooling sep-
arated milk; C, cooling ripened cream; D, cooling water for washing
butter; E, cooling a butter store.
As in the auxiliary creamery, the cream is first of all cooled with
water to about 68° F., so in the main dairy. The cream is brought
down to a temperature of 48° F. by passing it over a circular capillary
cooler, and is then run into the ripening vats. Here the process of
ripening rapidly increases the temperature again, and in about eigh-
teen or twenty hours it is at about 65° F. At such a temperature it
would be ruinous to churn, inasmuch as the texture of the butter
would be oily and bad, and there would also be an excessive loss of
butter fat in the 'buttermilk. The perfect churning temperature (in
summer) may be anything between 48° and 52° F., and to attain
this it is obvious that the temperature of the cream must be lowered
some 13° to 17° F. The most economical arrangement by which this
can be accomplished is by having the cream-ripening vats sufficiently
high up in the creamery to enable the cream to i-un over a capillary
cooler, then flow into the churn. Such an arrangement is simple and
works well. By proper and in'telligent adjustment of the appliances,
the cream can be reduced in temperature to 48° F. precisely, if
wanted.
_ Separated milk in the main creamery is treated in the same way
as in the auxiliary, viz., first of all passed over a large circular cooler,
in which water takes up the heat from the milk. It is then passed
over a small cooler in which brine is the cooling medium, and de-
livered to the farmer at 48° _F.
Cold water in a creamery is very desirable. The average tempera-
ture of well water in the British Isles is 52° F., but that is not con-
sidered to be low enough for washing purposes; besides, if it were,
well water is not always available. Hence, provision has to be made
for cooling water to a very low temperature. This is done in a
separate tank, usually placed in a sufficiently elevated position to
command the 'butter worker and churn. An insulated tank of, say,
one to 500 gallons capacity, is fixed on the wall with brackets, or on
a platform, and in this is fixed a direct expansion or brine coil con-
nected to the machine. The cooling is more quickly produced if a
small agitator is placed in the tank, as by that means the water is
more quickly brought in contact with the cooling surface. Water at
from 45° to 58° F. seems to be generally preferred.
John A. Ruddick, Dairy and Cold Storage Commissioner
of Canada, in a paper presented at the Chicago meeting of the
American Society of Refrigerating Engineers has the following
to say about
THE REFKIGEEATION OF MILK.
Housewives and dairymaids have, from time immemorial, em-
ployed a measure of refrigeration for milk when they placed it in
various receptacles, in cool cellars, for the purpose of securing a
340 PRACTICAL COLD STORAGE
maximum amount of cream or to keep it sweet as long as possible.
It is only within recent years that actual refrigeration has been used
in the preservation and handling of milk. Absolutely pure milk, that
is, milk free from germs of fermentation, or as it exists in the cow's
udder, will keep indefinitely at any temperature if protected from
infection, but if any of the members of this society were brought up
on farms, as your humble servant was, they will know how imprac-
ticable it is to procure milk without more or less, generally more,
impurities finding entrance into it. If the multiplication of these
germs which are thus introduced is not checked in some manner
most profound changes soon take place in the milk.
I should be the last person to decry the efforts which are being
made all over Christendom to obtain cleaner and more sanitary milk,
because I know the need thereof, but I would emphasize the im-
portance of cooling in that connection, because I believe it to be
probably the most potent factor in preserving milk in a sweet and
wholesome condition, and one that has not been given the prom-
inence which it deserves. The process of pasteurization, very often
looked upon as a heating process, is half refrigeration, because the
heating without immediate and rapid cooling would, in most cases,
be worse than useless. Refrigeration will not remove impurities from
the milk, but it does have the effect of checking the multiplication
of bacteria. It is of the utmost importance that the cooling of milk
should be proceeded with as quickly as possible after it is drawn
from the cow. Milk which is cooled immediately, say to 60° F., will
keep longer and be in better condition than if it is allowed to remain
at a temperature of 70 to 80 degrees for several hours and then after-
wards cooled to 40. I use these figures more to illustrate my mean-
ing than to record actual experience. The refrigerating engineer
who is called upon to design or erect a milk-cooling plant should
provide for quick cooling with as little exposure to the air as possible.
Some years ago an attempt was made to ship milk long dis-
tances in a frozen condition. Milk was sent from Scandinavia to
Great Britain, covering a journey of two or three days and it was
predicted that it would be possible to ship it by this method across
the Atlantic. The scheme has apparently not been commercially suc-
cessful, because we have heard nothing about it of late years. One
of the objections to the freezing of milk is the formation of fliocculent
particles of albumen or casein compounds which are not readily dis-
solved when the milk is thawed. It also has the effect of collecting
the fat globules into small lumps of fat.
It may be said, therefore, that for practical purposes a temperature
of 40° F. or under is low enough for the preservation of milk, and
that its preservation can only be a matter of days under ordinary
commercial conditions.
CHAPTER XVII.
APPLES.
INTRODUCTION.
Cold storage in its present partly improved state is for the
most part a growth of the past quarter century, and it is sus-
ceptible of much more development. The first so-called cold
storage was by means of ice placed within the space to be
cooled, which is very primitive and inferior. In what follows
in this chapter, it must be understood that improved methods
of storage by refrigeration are referred to, wherein temperature,
and conditions of humidity, air circulation, .and ventilation
are under control.
If it had been predicted in 1880 that in 1910 practically
all apples wanted for consumption during winter and spring
would be stored immediately after picking in artificially re-
frigerated rooms or what is popularly known as cold storage,
the prognosticator would doubtless have been called vision-
ary. Even as late as 1890 comparatively few apples were stored
under refrigeration. At that time it was thought (erroneously,
as will be demonstrated farther on) that apples were such a low
priced product that they could not afford payment of cold stor-
age charges, and therefore, the greater bulk of the crop was
stored in basements, cellars or frost-proof storage of some kind.
Such structures may be partially cooled by letting in outside
air whenever natural temperatures are suitable, but a control of
temperature in this way is only partial.
The value of cold storage as compared with cellar or frost-
proof storage has been demonstrated by some experiments con-
ducted at the cold storage plant of the Michigan Agri-
cultural College. The building originally had some rooms
cooled with ice, and later some of these rooms were remodeled
341
342 PRACTICAL COLD STORAGE
and cooled by Cooper brine system and chloride of calcium pro-
cess. A part of the basement was without refrigeration, and left
so especially to test the value of cold storage for apples, as com-
pared with frost-proof or cellar storage. The following gives
essentially the results of the experiments.
The average temperature of the cold storage room, Septem-
ber to May, was nearly 35° F. ; that of the cellar 42°. By
January 6, 100 per cent of the Kieffer pears in the cellar had
rotted ; during the same time three per cent rotted in the cold
storage room. By May 22, 100 per cent of Baldwin apples
stored in the cellar rotted as compared with two per cent in
the storage room. Between the same dates, the results on Spys
were twenty-one per cent for the storage and 100 for the cel-
lar; on Baldwins, thirteen in storage, 100 in cellar. These
figures not only show the advantage of a cold storage over a
cellar, but they show what influence a small margin of 7° F.
has on the keeping of apples.
At the present time the apple storage business is almost
wholly conducted in comparatively large warehouses. For the
most part these are located in big cities, and the apples are
shipped to them during the picking season ; but there are also
many large cold storage houses in the apple growing sections
run by firms or individuals ; only a few of them are owned and
operated by co-operative fruit growers' organizations. For vari-
ous reasons, some of which are discussed further on in this
chapter, the natural development of the storage of apples in
artificially cooled structures is in the direction of storage by the
producer. By this is meant that the producer will in future
largely store his own products, either as an individual in his own
house, or as a member of a fruit growers' or fruit shippers' or-
ganization. This is the present tendency of the business, and
in future it will doubtless be mostly handled in that way, in
preference to storing in the big city houses, where the most of
the business is now done. The apple grower, therefore, will do
well to keep posted on the situation, and study the various
means of refrigeration, with an idea of selecting the system
best adapted to his circumstances and location, when the time
comes for him to install his own cold storage plant.
APPLES 343
At the present time most apple growers have all their
money invested in planting and have not the surplus money to
put into a cold storage plant. Even co-operative concerns are
difficult to promote, as no one grower will invest more than a
small amount. As the business becomes older and growers ac-
cumulate a surplus they will, doubtless, put in plants of their
own to a large extent. This problem is more fully discussed
further on in this chapter.
HISTORICAL.
To Professor Benjamin M. Nyce (sometimes styled Rev-
erend) is due the credit of giving the first impetus to commer-
cial apple storage. Prof. Nyce was known as a preacher, teacher
and chemist, and his home was in Decatur county, Indiana. In
1856, being in poor health, he was advised by his physicians to
eat plenty of fruit during the entire year. At that time this
seemed impossible, as cold storage was unknown in its present
form and perfection, but Prof. Nyce, being a man of resource,
undertook to improve on the then common method of storage,
which we now call direct ice cooling, and which is discussed at
some length in the chapter on "Refrigeration from Ice." The
limitations of direct ice cooling were fully understood by Prof.
Nyce, and he thought it possible to develop a cold storage system
in which the humidity of the air could be controlled. Tempera-
ture he did not attempt to control any further than to get the
lowest temperature which ice melting naturally would give him.
Humidity he controlled by placing in the room lumps of chlor-
ide of calcium for taking up surplus air moisture and the mois-
ture resulting from the emanation or evaporation from the fruit
in storage. This system was patented in 1858, and is described
in some detail in the chapter above referred to.
After considerable experimental work and not a little
loss of money and damage to goods in storage, it was demon-
strated that apples must be stored by themselves, as should
other products. By using a tremendous thickness of insulation
(two to three feet) temperatures as low as 34° F. were obtained
with this system. Houses were built at Cleveland, Ohio,* In-
•This house was visited by the author during the winter of 1912-191J
and it was still in operation for the storage of apples.
344 PRACTICAL COLD STORAGE
dianapolis, Ind., Covington, Ky., and other points. It is stated
that the house at Covington made a profit of $16,000 on apples
sold in May and June, 1866, and that 4,000 bushels stored in
the Cleveland house in 1870 yielded a profit of $7,200. Pub-
lication of these enormous profits was followed by active de-
mand for the right to build under the Nyce patent, and quite
a number of houses were constructed, mostly by the inventor,
as he would not sell the right to use his patents. In this way
he suffered financial loss, and as other and improved methods
came into use the Nyce System soon fell into neglect. The re-
sults obtainable with this system under favorable conditions
were so good that it led to all sorts of unreasonable claims, and
much radical and flimsy construction was indulged in, doubtless
with the idea that the wonderful system, as it was considered,
would do almost anything. We can, however, without ques-
tion give Prof. Nyce due credit for being the pioneer in the
successful cold storage of apples, and, as a man of enterprise,
scientific attainments and ability, he is entitled to much credit.
The utilization of a freezing mixture consisting of ice and
salt was employed as early as 1865, and this development of
cold storage has had an important influence even on present
methods. As at first employed ice and salt was placed in V-
shaped galvanized iron tanks suspended from the ceiling and
filled from above, and in some cases the walls of the room were
covered with fiat tanks in a similar manner. Temperatures low
enough to freeze large quantities of poultry, game, etc., were
secured, and prior to the introduction of mechanical refrigera-
tion quite a number of plants were equipped in this way. For
a time this scheme was carefully guarded as a secret, but it
soon became known and was utilized in quite a number of
places, and assisted in the general development of the business.
The ice and salt method of cooling is at present in use in a
large number of houses, and will doubtless continue for many
years to come, as it is a very simple and efficient method, and
as applied with the Cooper brine system, described elsewhere
in this book, results are obtainable which are not in any way
inferior to those obtained by mechanical refrigeration.
Mechanical refrigeration was introduced in this country
between 1860 and 1865, but it was fully ten years later or
APPLES 345
after 1875, before modern systems of cold storage by this means
were introduced and some years later before these were put on
a practical basis. The principles of mechanical refrigeration,
as at present applied, are discussed in one of the opening chap-
ters of this book. It may be said that the greater part of the
apple storage business now is done in houses wherein tempera-
tures are maintained by artificial means.
COLD STORAGE AND COMMERCIAL APPLE GROWING.
The growing of fruit, and especially apples, as a business
distinct from general farm operations, has made striking prog-
ress during the past half century. Early in the nineteenth cen-
tury commercial orcharding was unknown, and the growing of
apples and other fruits was conducted in a small way about the
farm home for family use, or possible for sale in nearby cities
or towns. As the cities have grown and the country developed,
and transportation facilities have been extended and improved,
fruit growing has assumed a commercial aspect. During the
past twenty years especially, apple growing has developed into
one of the leading agricultural industries.
The free use of fruit as a staple article of food, and here
we may remark again, apples especially, has been accompanied
by a higher standard of living, and doubtless the future will
see less flesh foods eaten and more vegetable foods. By the use
of improved cold storage the natural apple consuming season is
extended to late winter and early spring, and the crop, instead
of being thrown on the market mostly at picking time, is in
demand during a period twice as long as formerly. This means
a greatly increased average price to the producer, and a lower
average price to the consumer, for the reason that waste is
largely eliminated. These great advantages are all creditable
to modern cold storage. With modern refrigerated transporta-
tion, commercial orcharding in the Mississippi Valley and in
the North Pacific Coast region has developed largely, and the
product of these regions is now a regular factor in the Eastern
market. Where formerly the orchards of Michigan and west-
ern New York were ample to supply the demand in the large
eastern cities like New York, Boston, and Philadelphia, now
346 PRACTICAL COLD STORAGE
the crop of the "Western apple grower is in demand as well as
the product from the increased orchards in Michigan and in
New York. Cold storage and refrigerated transportation have
not heen merely an assistance in this development, but an ab-
solute necessity.
With the developing markets and larger demand and with
the improvement of distribution from large wholesale centers,
has come the possibility of control of markets by distributors
and buyers. Nearly every year complaints are heard that apple
buyers create their own market-prices. Cold storage in the
producing sections, so that growers may hold their own crops,
will doubtless solve the problem. Whether these houses should
be constructed and operated by individual growers, or on a co-
operative basis as a community proposition, is a matter which
cannot be determined except by a canvass of the local situation
and conditions.
There seems to be no question but that certain abuses in
the buying and selling of apples have been practiced, and the
growers have been placed under great disadvantage in many
cases. A community or co-operative or an individual cold
storage plant may be the solution of the problem, and there is
no question but what this would be the correct thing for those
who have money to hold their crops and market them them-
selves. Tf a community could be induced to combine and put
up a plant and employ an experienced salesman to market
their goods they would doubtless find it most profitable indeed.
This means quite a heavy investment in a plant and necessarily
considerable of an extra investment tied up in storage, but
doubtless local banks could easily take care of this latter prob-
lem by using warehouse receipts issued on goods in storage as
collateral for the basis of short time loans.
The practice is to stamp goods as received with a lot num-
ber, using a rubber stamp. One or more of these lot numbers
may be combined in a warehouse receipt, but it is customary
to issue warehouse receipts on a carload so as to facilitate ihe
business of taking up warehouse receipts and shipping in round
lots. However, large dealers sometimes take out warehouse re-
ceipts on 500 barrels to 1,000 barrels. It may be noted in this
APPLES 347
connection that it is necessary in order to issue warehouse re-
ceipts that the apples be packed in a uniform and permanent
package. Open barrels, crates or boxes would hardly be per-
missible, and certainly apples stored in bulk would never do
at all.
By handling the business on the basis of warehouse re-
ceipts a large amount of money is not necessary, as it is cus-
tomary for banks to advance about three-quarters the value of
goods when placed in storage, taking the warehouse receipt,
which is endorsed over to the bank as security. The putting up
of a cold storage plant necessarily means somewhat of an in-
vestment, and some figures have been given on the cost of a
cold storage plant per barrel. These range from $1.00 per bar-
rel up to $3.00 per barrel. The cost depends entirely on the
following :
First: Type of building; whether frame, brick, stone,
concrete, etc.
Second : Location ; whether in the South, where the pick-
ing season is comparatively warm, or whether in the North,
where the picking season is comparatively cold. Where the
fruit goes into storage at high teniperature a much heavier
equipment is necessary.
Third : Whether the plant will be used for summer stor-
age of other goods, such as eggs, butter, cheese, etc. A much
heavier and more expensive insulation and a much heavier re-
frigerating equipment is necessary if this is to be done.
Fourth : System of refrigeration. Where natural ice may
be stored at reasonable cost the Cooper brine system using ice
and salt for cooling is best adapted. In certain southern loca-
tions the mechanical or chemical systems are necessary, and
these are much more expensive.
Fifth : Variety of apples to be stored. If the main crop
consists of winter apples coming in at a comparatively late date
only a small amount of refrigeration is needed to cool the fruit
as received, whereas if the bulk of the crop consists of summer
or fall varieties much more refrigeration is needed and a much
heavier refrigerating equipment is required for this reason.
348 PRACTICAL COLD STORAGE
Sixth: Size and capacity of cold storage plant. Neces-
sarily if the plant is a small one the cost per barrel is much
higher than in a large plant. For instance, a small plant in
service in New York State with a capacity of 500 barrels actual-
ly cost about $2,000, which is about $4.00 per barrel. A cold
storage plant with a capacity of 10,000 to 20,000 barrels would,
of course, cost very much less in proportion, as the cost of build-
ing and the cost of insulating would be less, for the outside ex-
posure is less and cubic capacity very much greater in propor-
tion to the material required for construction.
So far as the building itself is concerned this may be of
cheap frame construction and cheaply insulated in many lo-
calities. In the North, insulation which would answer for a
frost-proof building would also ordinarily answer for a cold
storage building for the storage of winter varieties of apples
largely. In some cases larger packing space is required. It is
often necessary to store a large number of empty packages and,
therefore, as much space or possibly more may be required in
connection with a cold storage building which is not under re-
frigeration, as is actually employed for cold storage purposes.
These things are of course subject to local influences and re-
quirements. It may be stated roughly that a plant of even
very large capacity and where very little space is required for
handling purposes, storage of empty packages, etc., cannot cer-
tainly be built for $1.00 per barrel of storage capacity. This
figure might have been correct some years ago, but with ad-
vancing cost of materials and labor it is doubtful if a suitably
equipped cold storage plant of any capacity could be built today
at a less cost than $1 .50 per barrel. It may be estimated roughly
that a cold storage plant of from 5,000 to 10,000 barrels would
cost in the neighborhood of $2.25 to $3.00 per barrel of cold
storage capacity, and a plant of from 10,000 to 20,000 barrrels
would cost from $1.50 to $2.25 per barrel of cold storage ca-
pacity. Necessarily these figures are only estimates, and local
conditions might make the cost greater, but it is improbable
that a plant could be built for less, although perhaps in some
places, as in Virginia, with comparatively cheap lumber and
labor, these costs might be reduced somewhat. The only way
APPLES 349
to get an accurate cost is to take a given locality with its mate-
rial and labor costs and the requirements as to size and shape
of the building and make an estimate based thereon.
The question of whether individual plants are best or larger
houses located at some central point where it might be on the
railroad, is open for discussion, but the personal preference of
the author would be for individual plants. In most cases it is
difficult to get the best and most influential growers into a co-
operative concern, but it is sometimes possible to get practically
all interested to combine to the extent of forming a selling or-
ganization. If each large grower had his own cold storage house
his fruit could be picked and packed under the best conditions
and circumstances. It is even possible to pick hurriedly, put-
ting the apples in barrels without heading up permanently, and
then sorting and regrading at leisure, thus getting a very careful
grading. This is not possible where fruit is delivered to a cen-
tral or community storehouse. Picking time is always a rush
time and it is of great importance that the work be carried for-
■ward quickly and grading and packing must necessarily be
done hurriedly under these conditions, especially if the grower
does his own grading and packing. This is one of the most
important reasons why each individual apple grower should
have his own cold storage plant, and by those who are now
handling orchards as a commercial undertaking this fact will
be understood at once.
It may readily be seen from the figures given above that
with two or three favorable seasons a grower could pay for a
cold storage plant out of profits which could reasonably be ex-
pected. The fruit business, like other lines, necessarily has its
"off years," but these are compensated for by extra good years,
so that we may consider that it would be possible to pay the
entire cost of a cold storage plant out of the profits of three to
five average years. It is, of course, assumed that largo growers
will, to an extent, interest themselves in markets and work up
a trade or brand by careful and conscientious packing and not
put their brand on any fruit which is inferior. One such grower
in the State of New York is known to the author who has made
enough profit to pay for his cold storage plant in three years'
operation.
3S0 PRACTICAL COLD STORAGE
ADVANTAGES OF LOCAL COLD STORE.
J. W. Wellington, in "Purdue Agriculturist," bearing on
the suggestion that growers own their own cold storage houses,
suggests the following :
Cold storage has a direct bearing on the marketing of fruits.
Apples put into cold storage will keep long beyond their natural sea-
son and the commission men make the most of the fact. They buy
fruit at moderate prices and hold until the prices advance. It is specu-
lation, but at the same time, a form which rarely fails. With an apple
like our friend, the Grimes, cold storage is necessary and consequently
a large part of the Grimes raised in Indiana do go into storage to be
sold later at much increased prices. The probability is this — when
Indiana becomes the fruit state, that it surely will in a very few
years, — the fruit growers will own, co-operatively, their own storage
houses and thus secure what is of right their own.
The Year Book of the Department of Agriculture for 1903
contains the following comments with relation to the subject as
discussed above :
"In handling the apple for cold storage the ideal is reached
when the fruit can be taken directly from the tree to the ware-
house. So far as the fruit is concerned, a similar condition is
approached when it is shipped to a distant warehouse in re-
frigerator cars, or the ideal is attained in those sections or sea-
sons in which the picking and handling of the crop occur in
cool weather. It may not be practicable for the apple dealer
who is located in a distant city to store his fruit in warehouses
situated near the orchards, nor is the local warehouse advisable
in sections where there are inadequate facilities for transporting
the fruit to distant markets during the winter. As a general
rule, it is to the mutual interest of the owner and the ware-
houseman that the fruit be stored where it can be watched
throughout the season by the owner, as the warehouseman is re-
sponsible only for the proper management of the building and
its contents, and not for the ultimate condition of the fruit."
The local cold storage warehouse is especially favorable to
the apple grower who stores his own fruit and who is not located
near a large city warehouse. It is also adapted to apple dealers
in cities who have permanent representatives near the orchards.
In those sections in which the fruit is likely to ripen in warm
weather, like the warmer apple regions of the Mississippi and the
Allegheny Mountain districts, the grower is frequently forced
APPLES 351
to sell his apples in the local market or to a dealer at a low price.
If the weather is unusually warm the fruit is likely to arrive in
the markets in bad condition, and the apple trade soon becomes
demoralized. On the other hand, if the fruit is shipped to a dis-
tant storage house and the packing, shipping or handling is de-
layed, its storage quality has been seriously impaired before it
reaches the warehouse.
A system of warehouses located in the orchards and man-
aged by growers, or operated by companies in nearby towns,
would reduce some of the difficulties with which the growers in
the warmer apple belts have to contend, and would thereby give
greater stability to the industry in those sections. There can be
no question, from the standpoint of the keeping of the fruit, of
the advantage of a warehouse located near the orchard, but its
usefulness to the business as a whole depends not on the keeping
quality of the fruit alone, but on the larger question of its adap-
tability to the present requirements of the apple trade.
Experiments by the Michigan Agricultural College, re-
ferred to in the introduction to this chapter, have demonstrated
that the maturity of fruit and time elapsing from picking until
stored, determines largely the possible life of apples in storage.
In these experiments it was demonstrated that only 21 per cent
of Spys stored immediately after picldng rotted, as compared
with 49 per cent left in a barn ten days before storing. In Spys
fully matured and well colored, but perfectly firm, 18 per cent
rotted up to May 22d, as contrasted with 62 per cent taken
from the same trees two weeks later.
UNITED STATES GOVERNMENT EXPERIMENTS.
The following is largely extracted from Bulletin No. 48,
Bureau of Plant Industry, U. S. Department of Agriculture, by
G. Harold Powell, Assistant Pomologist in Charge of Field In-
vestigation, and S. H. Fulton, Assistant in Pomology :
THE FUNCTION OP THE COLD STORAGE WAREHOUSE.
There is a good deal of misapprehension as to the function
of the cold storage house in the preservation of fruits. This
condition leads to frequent misunderstandings between the ware-
352 PRACTICAL COLD STORAGE
houseman and the fruit storer, though they might he avoided
and the condition of the fruit storage business improved if
there was a clearer definition of the influence on fruit preserva-
tion of cultural conditions, of the commercial methods of han-
dling, and of the methods of storage.
A fruit is a living organism in which the life processes go
forward more slowly in low temperatures, but do not cease even
in the lowest temperatures in which the fruit may be safely
stored. When the fruit naturally reaches the end of its life it
dies from old age. Tt may be killed prematurely by rots, usually
caused by fungi which lodge on the fruit before it is packed, or
sometimes afterwards. The cold storage house is designed to
arrest the ripening processes in a temperature that will not in-
jure the fruit in other respects and thereby prolong its life
history. It is designed also to retard the development of the
diseases with which the fruit is afflicted, but it cannot prevent
the slow growth of some of them. It follows that the behavior
of different apples or lots of apples in a storage room is largely
dependent on their condition when they enter the room. If
they are in a dissimilar condition of ripeness, or have been
grown or handled differently, or vary in other respects, these
differences may be expected to appear as the fruit ripens slowly
in the low temperature. If the fruit is already overripe, the low
temperature cannot prevent its deterioration sooner than would
be the case with apples of the same variety tliac M'ere in a less
mature condition. If the fruit has been bruised, or is covered
with rot spores, the low temperature may retard, but cannot pre-
vent its premature decay. If there are inherent differences in
the apples due to the character of the soil, the altitude, and to
incidental features of orchard management, or variations due
to the methods of picking, packing, and shipping, the low tem-
perature must not be expected to obliterate them, but rather to
retard while not preventing their normal development.
In general it is the function of the cold storage warehouse
to furnish a uniform temperature of the desired degree of cold
through its compartments during the storage season.*
*The experiments so far conducted cover only the influence of tem-
perature in cold storage. Much has yet to be done in determining the best
methods of refrigerating which control air circulation, ventilation and
humidity. More is promised along these lines.
APPLES 353
The warehouse is expected to be managed in other respects
so that the deterioration of the fruit or any other injury may
not be reasonably attributed to a poorly constructed and in-
stalled plant, or to its negligent or improper management. The
warehouseman does not insure the fruit against natural de-
terioration ; he holds it in storage as a trustee, and in that rela-
tion is bound to use only that degree of care and diligence in
the management of the warehouse that a man of ordinary care
and prudence would exercise under the circumstances in pro-
tecting the goods if they were his private property.
If the temperature of the storage rooms fluctuates unduly
from the point to be maintained and causes the fruit to freeze
to its injury, or to ripen with abnormal rapidity, or if the man-
agement of the rooms or the handling of the fruit in other re-
spects can be shown to have been faulty or negligent, the ware-
house has failed to perform its proper function.
OtJTLINE OP EXPERIMENTS IN APPLE STORAGE.
An outline of the apple storage experiments of the United
States Department of Agriculture is presented here. The fol-
lowing problems were under investigation during two apple
seasons :
1.- — -A comparative test of the keeping quality of a large
number of varieties grown in different regions and of the same
varieties grown under different conditions and in different lo-
calities.
The fruit was stored in closed oO-pound boxes in a tempera-
ture of 31° to 32° F. One-half of the fruit in each box was
wrapped in paper.
2. — A determination of the influence of v&rious commer-
cial methods of apple handling on the keeping quality of the
most important varieties in the leading apple-growing regib'ii's
of the eastern United States.
Each variety was piciked at two different degrees of ma-
turity: First, when nearly grown but only half to two-thirds
colored, but about the time when apples are usually picked;
second, when the fruit was fully grown and more highly col-
ored, but still hard. In each picking the fruit was separated
3S4 PRACTICAL COLD STORAGE
into two lots, representing the average of the lightest and of
the darkest colored or most mature specimens.
Part of the fruit of each series was sent to storage as soon
as picked. A duplicate lot was held two weeks in the orchard
or in a building, either in piles or protected in packages, before
it was sent to storage.
Comparative tests were made to determine the efficiency of
different kinds of fruit wrappers on the keeping of the fruit,
and observations on the behavior of the fruit in closed and ven-
tilated packages were recorded.
3. — A determination of the influence of various cultural
and other conditions of growth on the keeping quality of the
fruit.
Comparison was made with the same variety from heavy
clay and from sandy soils, from sod, and from cultivated land,
from young, rapidly growing trees, and from older trees with
more steady habits.
4. — A determination of the behavior of the fruit under the
conditions outlined in temperatures of 31° to 32° F., and in
34° to 36° F.
5.- — A determination of the behavior of the fruit when re-
moved from storage, and of its value to the consumer.
The fruit used in the investigations was taken from cen-
tral and eastern Kansas, southwestern and central Missouri,
.southern and central Illinois, western Michigan, northeastern
West Virginia, northern and western Virginia, western North
Carolina, central Delaware, southern Maine, central Massachu-
setts, and from eastern, central, and western New York. A de-
.scription of each orchard accompanies the data included in the
account of the variety test.
It was necessary to duplicate the work in different parts of
the country, as the climatic and other conditions and the varie-
ties differ in each section. The work must be repeated for sev-
eral successive seasons before gener^ conclusions can safely be
drawn from it, as the climatic conditions differ each year and
thereby affect the results.
FACTOKS INFLUENCING THE KEEPING QUALITY OF APPLES.
In recent years there has been a tendency to pick the apple
crop relatively earlier in the season than formerly. It is quite
APPLES 355
generally supposed that the longest keeping apples are not fully
developed in size or maturity and that the most highly colored
fruit is less able to endure the abuses that arise in picking,
packing, and shipping.
Aside from these general impressions, several important
economic factors have influenced "the picking time. A large
proportion of the apple crop is purchased in the orchard by the
barrel or by the entire orchard by a comparatively few apple
merchants. The fruit may be picked and barreled either by
the grower or by the purchaser, but with the growing scarcity
of farm hands and other labor it has become necessary to
begin picking relatively earlier in the autumn to secure the
crop before the fall storms or winter months set in.
The general increase in freight traffic during the past few
years has overtaxed the carrying capacity of the railroads as
well as their terminal facilities for freight handling, and has
influenced the apple dealers to extend the picking and shipping
season over the longest possible time, in order to avoid con-
gestion and consequent delays in shipping and in unloading
the fruit. The facilities at the warehouses are often inadequate
for the quick handling of the fruit from the cars when it is re-
ceived in unusually large quantities, and this condition has
also favored a longer shipping season.
In localities where the entire crop is sometimes ruined by
the bitter rot after the fruit is half grown the picking of the
apples is often begun early in the season in order to secure the
largest amount of perfect fruit.
It is not generally the case, however, that the immature
and partly colored fruit has the best keeping quality. On the
other hand, an apple that is not overgrown and which has
attained full growth and high color, like the lower specimen of
York Imperial in Fig. 1, but is still hard and firm when picked,
equals the less mature fruit (upper specimen. Fig. 1) in keeping
quality and often surpasses it. The mature fruit is superior in
flavor and texture; it is more attractive to the purchaser, and
therefore of greater money value. It retains its plumpness
longer and is less subject to apple scald. If, however, the fruit
is not picked until overripe, it is already near the end of its
356 PRACTICAL COLD STORAGE
life history, and will deteriorate rapidly unless stored soon after
picking in a low temperature.
In the experiments with the Tompkins King and the Sut-
ton apples grown in New York on rapidly growing young trees
producing unusually large apples, the fruit that was three-
fourths colored kept longer than the fully colored apples from
the same trees. Dark red Tompkins King showed 28 per cent
of physiological decay in February following the storage. Light,
half red Tompkins King from the same trees, picked at the same
time, showed 10 per cent of physiological decay in February fol-
lowing the storage. Fig. 2 shows Tompkins King in February
at two degrees of maturity in September, 1902, from young,
rapidly growing trees. The upper specimen represents fruit
that was highly colored but firm when picked ; the lower speci-
men shows fruit one-half to two-thirds colored. The less mature
fruit kept in good condition a month longer than the highly
colored apple. These apples were overgrown — a condition likely
to occur on young trees. Whether the same conditions hold
true of other varieties that are overgrown has not been deter-
mined.
From older trees, apples that are fully grown, highly col-
ored, and firm when picked have kept as well in all cases (and
better in many, as shown in Fig. 1) than immature and under-
colored fruit.
A considerable number of later varieties may be picked
when they are beginning to mellow, and will keep for months
in prime condition provided they are handled with great care
and quickly stored after picking in a temperature of 31° to 32°
F. Fruit in this ripe state cannot be left in the orchard or in
warm freight cars, or in any other condition that will cause it
to ripen after picking, without seriously injuring its value. In
this ripe condition it should be stored in boxes, and a fruit wrap-
per will still further protect it.
Apples that are to be stored in a local cold storage house
to be distributed to the large markets in cooler weather may be
picked much later than fruit requiring ten days or more in
transit, but the use of the refrigerator car makes late picking
possible where the fruit must be in transit for a considerable
APPLES
357
FIG. 1 — SCALD ON YORK IMPERIAL, APPLES.
358 PRACTICAL COLD STORAGK
time in warm weather in reaching a 'distant storage house.
While it is not the purpose of this publication to discuss
cultural practices in the orchard, some suggestions in relation to
the methods of securing more mature and more highly colored
' fruit may not be without value to the fruit grower.
A large proportion of the poorly colored fruit from old or-
chards is caused by dense-headed trees and close planting,
which prevent the free a,ccess of air and sunlight and delay the
maturity of the fruit in the fall. The fundamental corrective
in such cases lies in judicious pruning, by which means the
fruit may be exposed to the sunlight.
In other cases the poor color may be due to a combination
of heavy soil, tillage, frequent turning in of nitrogenous cover-
crops, spraying, and neglect in pruning. These conditions stim-
ulate the trees to active growth, the foliage increases in health,
size, and quantity, and, as the water-holding capacity of the soil
is enlarged by the incorporation of the cover-crops and is re-
tained by the tillage, the trees grow late in the fall and the
fruit does not properly color before the picking season arrives.
It is often possible to overcome the difficulty by severely pruning
the top to let in more air and light. If this treatment does not
prove efficient, the cover-crops may be withheld, when the fruit
will usually mature earlier in the fall, unless the season is wet.
As an additional treatment where necessary, the growth of the
orchard may be still further checked by seeding it down until
the desired condition is attained.
It is not possible to secure a uniform degree of maturity
and size when all the apples on a tree are picked at one time,
as fruit in different stages of growth is mixed together on the
iame tree. The apples differ in size and maturity in relation to
their position, the upper outer branches producing the large,
highly colored and early ripening fruit, while the apples on the
side branches and the shaded interior branches ripen later.
Greater uniformity in these respects is approached by proper
pruning and by other cultural methods, but the greatest uni-
formity can be attained when, like the peach or the pear, the
apple tree is picked over several times, taking the fruit in each
picking that approaches the desired standard of size and ma-
turity.
FIG.
-TOMPKINS KING APPLES. OVERGROWN ON YOUNG TREES
360 PRACTICAL COLD STORAGE
Summer apples, like the Yellow Transparent, Astrachan,
and Williams, are usually picked in this manner," and fall va-
rieties, like Twenty Ounce, Oldenburg, and Wealthy, are some-
times treated similarly. In recent years a few growers of winter
apples have adopted the plan for the late varieties, with the re-
sult that the size, color, and ripeness of a larger proportion of
the fruit are more uniform. This method of picking is not
usually adapted to the apple merchant who buys the crop of a
large number of orchards, and who can not always secure effi-
cient or abundant labor, but for the specialist who is working
for the finest trade and who has a storage house nearby or a
convenient refrigerator car service to a distant storage house,
the plan has much to commend it.
INFLUENCE OF DELAYING THE STORAGE OF THE FRUIT.
The removal of an apple from the tree hastens its ripening.
As soon as the growth is stopped by picking, the fruit matures
more rapidly than it does when growing on the tree and matur-
ing at the same time. The rapidity of ripening increases as the
temperature rises, and it is checked by a low temperature. It
appears to vary with the degree of maturity at which the fruit
is picked, the less mature apples seeming to reach the end of
their life as quickly as or even sooner than the more mature
fruit. It varies with the conditions of growth, the abnornially
large fruit from young trees or fruit which has been overgrown
from other causes, ripening and deteriorating very rapidly. It
differs with the nature of the variety, those sorts with a short
life history, like the summer and fall varieties, or like the early
winter apples, such as Rhode Island Greening, Yellow Bell-
flower, or Grimes Golden, progressing more rapidly than the
long-keeping varieties like Roxbury, Swaar, or Baldwin.
Any condition in the management of the fruit that causes
it to ripen after it is picked brings it just so much nearer the
end of its life, whether it is stored in common storage or in cold
storage, while treatment that checks the ripening to the greatest
possible degree prolong.?. it.
The keeping quality of a great deal of fruit is seriously in-
jured by delays between the orchard and the storage house.
APPLES 361
This is especially true in hot weather and in fruit that conies
from sections where the autumn months are usually hot. If
the apples are exposed to the sun in piles in the orchard, or are
kept in closed buildings where the hot, humid air can not
easily be removed from the pile, if transportation is delayed
because cars for shipment can not be secured promptly, or if
the fruit is detained in transit or at the terminal point in
tight cars which soon become charged with hot, moist air, the
ripening progresses rapidly and the apples may already be
near the point of deterioration or may even have commenced
to deteriorate from scald, or mellowness, or decay when the
storage house is reached.
On the contrary, the weather may be cool during a similar
period of delay and no serious injury result to the keeping qual-
ity, or the ripening may be checked in hot weather by shipping
the fruit in refrigerator cars to a distant storage house.
The fungous diseases of the fruit, such as the apple scab
(Fusi-cladiuw. dendriticum) (Wallr.) (Fckl.) and the pink
mold (GephalotheciuTn roseum Cda.) which grows upon the
scab, the blue mold (Penicillium, glaucum Link) which causes
the common, soft, brown lot, the black rot (Sphaeropsis malor-
um Pk.) and the bitter rot (Glaeosporium fructigenum Berk.),
develop very fast if the fruit becomes heated after picking. The
conditions already enumerated which cause the fruit to ripen
quickly during the delay between the orchard and the storage
house are also most favorable to the development of fruit
diseases. It is therefore of the greatest importance that the
fruit be stored immediately after picking, if the weather is
warm, in order to insure it against the unusual development of
the fungous rots.
In the fall of 1901, when the weather in western New
York was cool, there was no apparent injury from delaying
storage of a large number of varieties two weeks and then
shipping the fruit to Bufifalo, the transit occupying from one
to three days. There was also no apparent injury to the fruit
from Virginia treated in a similar manner, but in southwestern
Missouri, where it was warmer, the apples delayed two weeks
before storing were seriously injured in their commercial keep-
ing qualities.
362 PRACTICAL COLD STORAGE
The results accomplished during 1902 have been of the
most instructive character. During the latter half of Septem-
ber the temperature in eastern New York averaged about 62°
F., with a humidity of 84°. During the first half of October
the average temperature v.'as 53° F. and the humidity 80°.
Rhode Island Greening, Tompkins King, and Sutton ap-
ples picked September 15, 1902, and stored within three days,
were firm till tlie following March, with no rot or scald, but
fruit from the same trees not stored till two weeks after pick-
ing was badly scalded or decayed by the 1st of January. None
of the immediate-stored fruit was scalded or decayed by the
1st of February, but the delayed Sutton and Rhode Island
Greening apples were soft and mealy, and one-third were
scalded at that time, while nearly 40 per cent of the delayed
Tompkins King were soft and worthless. The commercial
value of these varieties was injured from 40 to 70 per cent by
the delay in storage.
Apples of these varieties picked from the same trees on
October 5, 1902, and stored immediately, and also some stored
two weeks later, were less injured by the delay, as the tempera-
ture and humidity were not sufficiently high to cause rapid
ripening or the development of the fruit rots.
From the standpoint of the orchardist or apple dealer who
can not secure quick transportation to the large storage cen-
ters, or who can not obtain refrigerator cars, or who is geo-
graphically situated where the weather is usually warm in
apple-picking time, the local storage plant in which the fruit
can be stored at once and distributed in cool weather offers im-
portant advantages. The importance of this phase of the fruit-
storage business and its relation to the fruit-growing industry
are emphasized as the apple business enlarges.
INFLUENCE Ol' STORAGE TEMPERATURE.
The investigations indicate that the ripening processes are
delayed more in a temperature of 31° to 32° F. than in 35°
to 36° F. The apple keeps longer in the lower temperature,
it scalds less, the fruit rots and molds are retarded to a greater
extent, while the quality, aroma, flavor, and other character-
APPLES 363
istics of the fruit are fully as good, and when removed from
storage it remains in good condition for a longer period.
The impression is quite general that fall varieties and the
tender early winter sorts, like Fameuse, Wealthy, and Grimes,
are injured in some way by the low temperature, but the in-
vestigations of the Department of Agriculture indicate that
these varieties behave more satisfactorily in every respect when
stored at 31° to 32° F.
If the fruit is intended for storage for a short time only,
and it is desired to have it ripen before removing it from the
storage house, then a higher temperature may be desirable to
hasten the maturity.
The influence of the temperature on the ripening processes
appears to depend on the condition of the fruit. Baldwin,
Esopus Spitzenburg, Roxbury, Jonathan, Lady Sweet, and
other long-keeping eastern-grown varieties have been held in
prime commercial condition throughout the storage season in
a temperature of 35° F., when carefully picked and handled
and stored soon after picking; but when the fruit was care-
lessly handled or the storage was delayed in hot weather, then
a temperature of 31° to 32° F. was required to retard the ripen-
ing.
It might be safe to use a temperature of 34° to 35° F. in a
storage house located near the orchard, in which the fruit may
be stored immediately after harvesting, but for general com-
mercial apple handling, a temperature as low as 32° F. is
needed to overcome the abuses that usually arise in picking,
packing and shipping.
Apples are sometimes frozen in the storage rooms owing
to a considerable drop in. the temperature or to a poor dis-
tribution of the cold air. If the fruit compartment adjoins a
freezer room and the insulation is poor, the fruit may be frozen
in packages piled close to the freezer wall. Apples placed near
the refrigerating pipes or near the cold-air duct where it enters
the room may be injured by freezing if the plant is improperly
installed or managed: or if the piping or air circulation is
faulty, the temperature at the bottom may be lower than that
at the top of the room.
364 PRACTICAL COLD STORAGE
No definite investigations have been made by the Depart-
ment of Agriculture as to the effect of temperatures lower than
31° F. The exact freezing point of apples has not been deter-
mined, but it is below this point. It may possibly vary with
the composition or condition of the variety. Under the most
favorable conditions, apples are sometimes commercially stored
at 30° F.* without injury, but 31° F. should be considered a
critical temperature below which it is unsafe to store this fruit,
except in houses that are properly constructed and in which
the temperature is maintained uniform in all parts of the
rooms.
The frosting of the fruit does not necessarily injure it.
When the apple freezes, the water in the cells is withdrawn
and frozen in the intercellular spaces, and if it thaws slowly
and the freezing has not been too severe, the cells may regain
the water without injury and resume their living function. If
the thawing is rapid, the cells may not reabsorb the water with
sufficient rapidity, and in this case it remains in the inter-
cellular spaces and is lost by evaporation. In addition, the
tissues next to the area of greatest freezing may be forced apart
bj'^ the formation of ice crystals in the intercellular spaces.
If the freezing is so severe as to withdraw too much of
the cell water, the cells may not be able to absorb it and will
be killed in the same manner as if dried out in any other way.
Occasionally the freezing is so rapid that besides the withdrawal
of water the cell contents are disorganized or possibly frozen
outright ; at any rate, the cell may be directly killed by a sud-
den change of temperature. It is probable that varieties may
differ as to the degree of freezing they will stand without in-
jury, and further, that the same sort may vary in this respect
when grown under different conditions or subjected to differ-
ent treatment.
•The author's personal experience is that a temperature of 30° P. is
better than any degree above that, and 29° F. is practicable and advisable
for long-period storing of the better keeping varieties. To safely store
at 29° to 30° F. it is necessary that a thorough forced circulation of air be
employed (see chapter on "Air Circulation"), and in cooling the fruit down
to the final carrying temperature, the refrigeration must not be applied
too suddenly. If, say, the fruit has a temperaure of 60° or 70° F. when
placed In storage, a period of two or three weeks should be. consumed In
reducing to 29° or 30° P. This applies to the better keeping kinds only.
Softer varieties must be cooled quickly, as their life is shorter, and too
much deterioration will take place during cooling process if handled as
suggested above. — Author.
APPLES
365
The most characteristic results of injurious freezing are a
translucent appearance of the skin of the fruit, a water-logged
and springy or spongy condition of the flesh, a forcing apart of
the tissues, and a brownish discoloration of the flesh. The brown-
ing may result from any cause which results in the death of the
cells and is not necessarily characteristic of freezing. It often
happens that the skin of the fruit retains its normal bright-
ness after the interior has discolored.
In the practical handling of frozen stock, the tempera-
ture should be raised very slowly until the frost is withdrawn.
If possible, the fruit should not be moved until it is defrosted,
as it discolors quickly wherever a slight bruise occurs, or even
where the skin is lightly rubbed. With these precautions ob-
served it is often possible to defrost stock that is quite firmly
frozen without apparent injury to it.
INFLUENCE OF A FRUIT WRAPPER.
In the storage investigations under discussion a compari-
son has been made between wrapped and unwrapped stock on
FIG.
-APPLES UNWRAPPED AND IN TISSUE, PARCHMENT,
WAX WRAPPERS.
AND
the keeping quality of the fruit, and the efficiency of dift'erent
kinds of paper for wrappers — tissue, parchment, waxed or paraf-
fin, and unprinted news — has been tested. A box of un-
wrapped fruit with packages of fruit wrapped with the kinds
of paper mentioned in order above, is shown in Fig. 3.
366
PRACTICAL COLD STORAGE
It has been found that the wrapper may influence the keep-
ing quaUty in several different ways. It extends the life of the
fruit beyond its normal period by retarding the ripening pro-
cesses. The influence of the wrapper in this regard is apparent
especially at the end of the normal storage season of the naked
fruit when the flesh begins to grow mealy from overripeness.
At this time the wrapped apples may be firm and remain in
prime condition for several weeks or even months. The wrap-
per is especially useful in extending the season of early winter
sorts, or in making the long-keeping varieties available for use
over a still longer period of time.
The wrapper may be useful in preventing the transfer of
rot from one apple to another. If the fungous is capable of
growing in the storage temperature, it is not likely that the
wrapper retards its growth, but when the spores develop they
are confined within the wrapper and their dissemination is
difficult or impossible.
The importance of a wrapper in protecting the fruit from
decay and in extending its season may be better appreciated by
reference to the following table :
AMOUNT OP DECAYED FRUIT APRIL 29 IN BUSHEL, PACKAGES
Variety.
Baker
Dickenson .. .
Mcintosh .. . .
Mcintosh
(second lot) .
News
paper
wrapped.
Un-
wrapped.
Per cent.
Per cent.
3.7
6.4
7.7
27.2
43.0
15.0
19.7
32.0
Variety.
Northern
Spy ...
Wagener
Wealthy
News
paper
wrapped.
Per cent.
5.6
38.0
42.0
Un-
wrapped.
Per cent.
52.0
63.0
60.0
The wrapper protects the apple against bruising and the
discoloration that may result from improper packing or rough
handling; it checks transpiration, and by the preservation of
the attractive appearance and firmness of the fruit adds to its
commercial value.
No important difference was noticeable in the efficiency
of the different wrappers, except that a mold developed freely
APPLES 367
on the parchment paper in a temperature of 36° F. This mold
grew only to a slight extent in 32° F.
A double wrapper is more efficient in retarding ripening
and transpiration than a single wrapper. A good combination
consists in a porous news paper next to the fruit, with an im-
pervious wax or paraffin wrapper on the outside. The wrap-
pers vary in cost from 20 cents per thousand for news paper,
9x12 inches, to 70 cents per thousand for the better grades of
paraffin.
INFLUENCE 01' CULTURAL CONDITIONS.
Preliminary studies have been made on the influence of
cultural and other conditions surrounding the growing fruit
on its storage quality. Considerable data along this line will
be brought out in the comparison of the same variety grown
in different sections. It has been observed that the Tompkins
King, Hubbardston, and Sutton apples from rank-growing
young trees ripen faster than smaller fruit from older slower-
growing trees, and therefore reach the end of their life history
sooner. From older trees these varieties have kept well till
the middle of April, while from young trees the commercial
storage limit is sometimes three months shorter.
It has been noticed that Rhode Island Greeidng apples
from old trees remain hard longer than the same variety from
young trees, but the' greener condition of the fruit from the
older trees when picked at the same time made it more suscepti-
ble to scald. Rhode Island Greenings from Mr. Grant G.
Hitchings, South Onondaga, N. Y., showed 50 per cent of
scald from young trees on April 28, 1903, and 82 per cent in
smaller, greener fruit from older trees.
Rhode Island Oreening, Mann, and Baldwin apples grown
on sandy land ripened more rapidly than similar fruit from
clay land, where all of the other conditions of growth were
similar. Fig. 4 shows the average condition of Baldwin apples
on April 28, 1903, grown on sandy and clay soil in the orchard
of Mr. W. T. Mann, Barker, Niagara County, N. Y., and
stored in a temperature of 82° F. The 'upper apple was grown
on clay ; the lower, on sandy soil.
368
PRACTICAL COLD STORAGE
FIG. 4.— BALDWIN APPLES FROM CLAY AND SANDY SOIL.
APPLES 369
This fruit was picked in October, 1902, and was stored
soon after picking. The fruit from the heavy clay soil was
generally smaller and was much less highly colored. Both lots
kept well throughout the storage season. The fruit from the
sandy land was riper at the end of the storage season, better in
qiiality, and worth more to the dealer and to the consumer.
The subject will require critical study over a period of
years before it will be possible to fully understand the influ-
ence of various cultural, climatic, and other conditions of
growth on the life processes in the fruit.
INFLUENCE OP THE TYPE OP PACKAGE.
The principal storage packages for apples are barrels of
about 3 bushels capacity and boxes holding 40 to 50 pounds.
The larger the bulk of fruit and the more it is protected from
the air the longer it retains the heat after entering the storage
room. If the fruit is hot and the variety a quick-ripening sort,
it may continue to ripen considerably in the center of the
package before the fruit cools in that position. The long-
keeping varieties that are harvested and shipped in cooler
weather are less likely to show the effect of the type of the
package. The smaller package therefore presents distinct ad-
vantages for the early, quick-ripening varieties and is most
useful in the hottest weather, as the fruit cools down quickly
throughout the package and its ripening proceeds uniformly.
There is a wide difference of opinion concerning the com-
parative value of ventilated and closed packages for apple stor-
age. The chief advantage of the ventilated package appears to
lie in the greater rapidity with which its contents cool off, and
its value in this respect depends on the amount of ventilation in
the package. The contents of an ordinary ventilated apple
barrel do not cool much more quickly than the contents of a
closed barrel, and the value of the ventilated barrel for the
purpose for which it is designed is somewhat doubtful.
Apples in a ventilated package are likely to shrivel if the
fruit is stored for any length of time. In the ordinary ven-
tilated apple barrel the exposure is not sufficient to affect the
fruit to any extent, but in boxes in which there is much ex-
370
PRACTICAL COLD STORAGE
posure the fruit may be corky or spongy in texture if held
until spring.
The size of the package may have an important influence
on the length of the storage season. Its influence in this respect
is especially marked when the fruit begins to mellow in tex-
ture. Barrel stock in this condition needs to be sold to prevent
the bruising of the fruit from its own weight, but apples
equally ripe may be carried in boxes safely sometimes for sev-
eral weeks longer.
BEHAVIOR OF THE FEUIT WHEN REMOVED FROM STORAGE.
There is a general impression that cold-storage apples de-
teriorate quickly after removal from the warehouse. This
opinion is founded on the experience of the fruit handler and
the consumer, but the impression »is not generally applicable
to all storage apples. In fact, it is probable that storage apple?
do not deteriorate more quickly than other apples that are
equally ripe and are held in the same outside temperature. If
the fruit is overripe when taken from storage — and a good
deal of stock is stored until it reaches this condition — it natur-
ally breaks down quickly; but firm stock may be held for
weeks and even months after it has been in storage.*
The rapidity of deterioration depends also on the tempera-
ture into which the fruit is removed. The following table shows
AMOUNT OF DECAY AFTER REMOVAL FROM STORAGE
DIFFERENT TEMPERATURES.
TO
Date re-
moved from
storage
(1903).
Date in-
spected.
Per cent rot
Variety.
44 °F.
48°F.
61°P.
67°F.
Baldwin
Jan. 29
Jan. 29
Feb. 10
Feb. 13
Feb. 16
Feb. 20
Mar. 3
Mar. 7
Mar. 24
Apr. 6
0
0
0
0
0
5
5
20
36
0
0
0
0
4
10
15
0
3
12
21
23
3
10
14
24
28
•This is confirmed by the author's experience, and applies not only to
apples, but also to other goods which are cold stored. — Author.
APPLES 371
the amount of decay in Baldwin apples from the same barrel
after removal and pubjection to different temperatures :
Late in the spring the fruit is far advanced in its life and
the weather is becoming warmer. All apples similarly ripe,
whether in cold storage or not, break down more quickly at
this time than in the winter.
In commercial practice the dealer often holds the apples
for a rise in price, and finally removes them from the ware-
house, not because the market has improved, but for the rea-
son that he finds that a longer storage would result in serious
deterioration from fruit rots and overripeness. When a con-
siderable amount of stock is decayed on removal from the
warehouse the evidence is conclusive that the apples should
have been sold earlier in the season. In the purchase of cold-
storage stock the consumer will have little cause to complain of
the rapid deterioration of the fruit if he exercises good judg-
ment in the selection of apples that are still sound and firm.
THE IMPORTANCE OF GOOD FRUIT.
Apples do not improve in grade in cold storage. In han-
dling a crop too much care can not be given to grading the fruit
properly before it enters the storage house. The contents of
many packages are injured by the spread of disease from a few
imperfect apples. Rots enter the fruit most easily wherever
the skin is bruised or broken, and in the early stages of the
rot development it is common to see the diseases manifesting
themselves around worm holes or bruises occasioned by rough
handling, from nails that protrude through the barrels, or from
other causes.
When the crop is light it may pay to store apples that
are not of the first grade, but such fruit should be rigidly
eliminated from the best stock and stored where it can be
removed earlier in the season than the better qualities.
The attractiveness and the value of the best fruit is often
injured by careless handling. A bruised spot dies and discolors.
Finger marks made by pickers, graders, and packers, and in-
juries from the shifting of the fruit in transit or from rough
handling, become more apparent as the season advances. In
372
PRACTICAL COLD STORAGE
fact, all of the investigations of the Department of Agricul-
ture emphasize the fundamental importance of well-grown,
carefully handled fruit in successful storage operations.
FIG. 6.— WELL PACKED BSOPUS
SPITZBNBUEG APPLES.
PIG. 6.— "SLACK" PACKED
NORTHERN SPY APPLES.
Fig. 5 shows a well packed barrel of Esopus Spitzenburg
apples removed from storage in March, 1903. The fruit was
properly packed in the orchard and repacking was not needed
when the fruit was sold.
Fig. 6 shows a "slack" packed barrel of Northern Spy
apples removed from storage in March, 1903. The fruit was
not packed firmly in the orchard. It settled in the barrel,
leaving it "slack" when removed from storage. Barrels in this
condition need to be repacked. The fruit is easily bruised
and it deteriorates more quickly in the storage house and
after removal when it is loosely packed.
APPLE SCALD.
When some varieties of apples reach a certain degree of
ripeness the part of the fruit grown in the shade often turns
brown, not unlike the color of a baked apple. This difficulty
does not extend deep into the flesh, but it detracts from the
appearance of the fruit and reduces its commercial value. This
trouble is commonly called "apple scald." It may appear in
fruit held in common or in cold storage.
APPLES 373
The exact nature of scald is not well understood, though
apple men have many theories by which its appearance is
popularly explained. The most common theory gives rise to
the name of scald — that is, the brown, cooked appearance is
thought to be due to the overheating of the fruit when it is
stored, or to a temperature too low for the variety, or to pick-
ing the fruit when too ripe; and other matters relating to the
growth and handling of the fruit are thought to develop it.
As the scald is an important commercial problem it has
been considered from several standpoints in the fruit-storage
investigations of the Department. The nature of the scald,
the influence of the degree of maturity of the fruit when picked,
of commercial method of handling, of fruit wrappers, of dififer-
ent temperatures, and of cultural conditions on its develop-
ments are among the problems investigated.
Apple scald is not a contagious disease. According to Dr.
A. F. AVoods, Pathologist and Physiologist of the Department
of Agriculture, it is a physiological disturbance not connected
in any way with the action of parasitic or saprophytic organ-
isms such as molds or bacteria. Briefly, it is the mixing of the
cell contents or premature death of the cells and their brown-
ing by oxidation through the influence of the normal oxidizing
ferments of the cell. There are many conditions which in-
fluence the development of this trouble. It appears to be
closely connected with the changes that occur in ripening after
the fruit is picked, and is most injurious in its effects as the
fruit approaches the end of its life. Several of the factors that
influence it will be discussed. Fig. 7 shows the scald on a
Rhode Island Greening apple. The cross section shows that
the scald is a surface trouble and does not extend into the
flesh.
The scald always appears first on the green or less mature
side of an apple, and if the fruit is only partly ripe it may
spread entirely over it; but the portions grown in the shade
and undercolored are first and most seriously affected. The
upper specimen in Fig. 1 shows the distribution of scald on
an immature York Imperial apple in March, 1903. The apples
that are more mature and more highly colored when picked are
374
PRACTICAL COLD STORAGE
'V
FIG. 7.— SCALD ON RHODE ISLAND GREENING APPLE.
APPLES
375
less susceptible to injury, and the side grown in the sunlight
may remain entirely free from it. The lower specimen in
Fig. 1 (picked from the same tree at the time, October, 1902,
when the upper specimen was picked) shows a well-colored
York Imperial apple and its freedom from the scald is notice-
able. A wall only is shown on the right-hand side of the apple,
where the color is not as dark as elsewhere.
When the apple crop is picked before it is mature the
fruit is more susceptible to scald than it would have been later
in the season. The relative susceptibility of immature and more
mature apples is brought out in the table following. The
fruit was picked two weeks apart. At the first picking the
apples were partly colored, or in the condition in which a large
proportion of the commercial apple crop is harvested. At the
second picking the fruit was more mature, with better color,
but still hard. The differences in ripeness are fairly repre-
sented in the fruit in Figs. 1 and 2. The percentages do not
represent the relative susceptibility of the different varieties to
scald, as the fruit was grown in different States and the obser-
vations were made at different times. The percentages show
the average amounts of scald in fruit stored at temperatures
of 31° to 32° F. and 34° or 36° F.
SCALD ON MATURE AND IMMATURE APPLES.
Variety.
Baldwin
Ben Davis
Do
Rhode Island "Greening".
Winesap
Yellow Newtown
York Imperial
Average
Locality grown.
New York .
Illinois'
Virginia . . .
New York. .
Illinois
Virginia . . ,
....do
Mature
well
colored.
Per cent.
3.1
2.6
13.1
25.4
0.2
2.3
2.0
6.9
Immature,
partly
colored.
Per cent.
29.2
15.8
41.6
43.4
31.8
9.4
18.2
27.0
In the practical handling of orchards the fundamental
corrective of scald lies in practicing those cultural and bar-
376 PRACTICAL COLD STORAGE
vesting methods that develop maturity and a highly colored
fruit. These methods have already been briefly discussed. The
picking of the fruit when too green, dense-headed trees that
shut out the sunlight, heavy soil, a location or season that cause
the fruit to mature later than usual and makes it still green at
picking time — these are among the conditions that make it
particularly susceptible to the development of the scald.
After the fruit is harvested its susceptibility increases as
its ripening progresses. Early in the storage season the scald
may not appear, but later the same variety may have developed
enough to injure its commercial value. The amount of scald
at different periods of the season on the same lot of Baldwin
apples stored at 32° F. is brought out in the following state-
ment:
AMOUNT OF SCALD AT DIFFERENT PERIODS OF STORAGE SEASON.
Per cent.
January 29, 1903 0
February 21, 1903 0
March 20, 1903 20
April 21, 1903 23
It should be the aim of the apple storer to remove the
fruit from storage before a variety normally begins to scald,
and to hold until late in the season only those sorts that do
not scald.
INFLUENCE OF TEMPERATURE ON SCALD.
The temperature that checks the ripening to the greatest
degree also retards the appearance of the scald. In some of the
apple-growing sections it is quite generally believed that bad
scalding varieties should be stored in a temperature of 36° to
38° F., and that a temperature as low as 32° F. hastens its
development. The investigations of the Department have
shown that this impression is not well founded, but on the
contrary they indicate that the scald develops more freely in
the higher temperature. To illustrate, one lot of York Imperial
apples, a variety which is greatly affected by scald, had devel-
oped 16.9 per cent of this trouble by January 22, 1902, in a
temperature of 86° F., while a similar lot stored in a tempera-
ture of 32° F. developed only 3.4 per cent. One lot of Rhode
Island Greening apples by February 3, 1903, had developed 21
APPLES
Z11
per cent in 32° F., while a similar lot, in 36° F., showed 55
per cent. In the case of the Sutton apple, investigation showed
25 per cent of scald in apples stored at 32°, and 42 per cent
where the temperature was kept at 36°.
If the fruit is stored as soon as it is picked, or is shipped
in refrigerator cars or in cool weather, and if it has been han-
dled in the most careful manner, the ripening may not proceed
much more rapidly and the scald may not develop more freely
in the higher than in the lower storage temperature.
When the fruit is removed from the storage house the
scald sometimes develops rapidly. Its appearance at this time
seems to depend on at least two important conditions — ^the
ripeness of the fruit and the temperature into which it is taken.
Late in the storage season the scald is most severe ; first, because
the fruit is more mature, and, second, for the reason that the
warm weather prevailing at that season develops it quickly.*
The development of the scald also seems to be influenced
by the amount of humidity in the air. So long as the fruit
remains cold and condenses the moisture of the atmosphere
upon it the scald is retarded more than in a dry air of the same
temperature.
The accompanying table shows the rapidity with which
the scald may develop on Baldwin apples when portions of
the same barrel are removed to different temperatures. There
was no increase in the amount of scald in any of the lots after
nine days.
,
Date re-
moved from
storage.
Date In-
spected.
Per cent of scald.
Variety.
44" F.
48° F.
61» F.
67" F.
1903
1903
Baldwin .
Jan. 29
Jan. 29
0
0
0
0
do
.... do ....
Feb. 3
0
6
21
22
do
...'. do .. ..
Feb. 4
Feb. 6
4
4
11
25
21
40
37
do
.... do ....
63
do
.... do ....
Feb. 7
4
25
41
63
•It Is suggested that scald develops much more rapidly In case the
fruit Is allowed to rise In temperature suddenly. When removed from
storage, apples, as well as other goods, should not be exposed at once
to comparatively high temperatures. — ^Author.
378
PRACTICAL COLD STORAGE
SCALD DEVELOPED IN DIFFERENT TEMPERATITRES WHEN APPLES
WERE REMOVED FROM STORAGE.
The upper specimen in Fig. 8 shows the average condition
of a lot of Wagener apples in March, 1903, having been picked
FIG.
-WAGENER APPLE— SCALD DEVELOPED AFTER REMOVAL
FROM STORAGE.
APPLES 379
in October, 1902, and stored at a temperature of 32° F. There
was no scald on the apples when removed. Forty-eight hours
later, after the fruit had been in a temperature of 70° F., the
light-colored portion of the apples was badly scalded, as shown
in the lower apple. Late in the storage season the fruit is more
susceptible to scald, and a high temperature when the fruit is
removed from the storage house may develop it quickly.
It should be the aim of the fruit storer not only to remove
the fruit before the scald normally appears, but to hold the ap-
ples after removal in the lowest possible temperature to pre-
vent its rapid development.
INFLUENCE ON SCALD OF DELAYING THE STORAGE OF THE FRUIT
AFTER IT IS PICKED.
The ripening of the fruit between the time of picking
and its storage increases its susceptibility to scald.
When the picking and shipping seasons are cool and dry it
may be possible to delay the storage of the fruit for some time
without injury so far as the predisposition of scald is concerned.
En the investigations of 1901-2 in western New York there was
no apparent injury from delaying the storage, but the weather
conditions at this period were ideal for apple handling.
The scald develops seriously when the storage of the fruit
is delayed in hot weather. Detentions in the orchard, in tran-
sit in closed cars, in unloading at the terminal, or in the ware-
house cause the fruit to ripen quickly and favor the rapid
growth of the fruit rots, as they bring the fruit much nearer
the end of its life before it enters the storage room. Under these
circumstances the fruit may scald badly, mellow early in the
season, and rot, and no storage treatment can correct the abuses
to which it has been subjected.
The following table brings out the injury that may be
caused by delaying the storage of the fruit in hot weather. The
mean average temperature between September 15 and 30, 1902,
was about 62° F. and the mean average humidity about 84°.
Fruit picked from the same trees on October 4, 1902, and stored
two weeks later, when the temperature was about 53° F. and
the humidity about 80°, was not injured by the delay. The
380
PRACTICAL COLD STORAGE
apples referred to were grown in eastern New York and stored
in Boston, and these records were taken the following February.
SCALD ON IMMEDIATE- AND DELAYED-STOEBD APPLES IN
FBERUAEY, 1903.
Variety.
Rhode Island Green-
ing
Sutton
Tompkins King . . .
Picked
Sept. 12,
1902, stored
Sept. 15.
Per cent.
0
0
0
Picked
Sept. 15,
stored
Sept. 30.
Per cent.
38
33
15
Picked
Oct. 4,
stored
Oct. 9.
Per cent.
(No record)
0
0
Picked
Oct. 5,
stored
Oct. 19.
Per cent.
(No record)
0
0
INFLUENCE OF & FRUIT WRAPPER ON SCALD.
The influence of the various fruit wrappers mentioned has
been studied in connection with the scald. Sometimes the
wrappers retard it to a slight degree, but often the trouble is
as severe or more severe in the wrapped fruit. Whenever the
wrapper has been effective in retarding the scald the wax or
paraffin paper was most useful.
The following table gives a comparison between wrapped
and unwrapped fruit, and emphasizes the fact that for com-
mercial purposes the wrapper should not be looked upon as an
effective means of preventing the trouble. The records of each
variety are based on 8 to 32 bushels of fruit, one-half of which
was wrapped.
SCALD ON WRAPPED AND UNWRAPPED FRUIT.
Variety.
Locality.
Wrapped.
Unwrapped.
Baldwin
New York
Illinois
Per cent.
12.4
5.8
27.1
47.8
22.9
32.3
30.0
17.9
9.6
Per cent.
19.9
2.8
Do
Virginia
28.7
Illinois
40.3
Mlnkler
do
20.1
Rhode Island "Greening".
New York
Virginia
37.6
47.0
Do
Illinois
10.2
Virginia
12.9
APPLES 381
VARIETIES MOST SUSCEPTIBLE TO SCALD.
All varieties are not equally susceptible to scald, and there
appears to be a wide difference in the amount developed in the
same variety grown in different parts of the country. While the
light-colored portion of an apple is more susceptible than the
more highly-colored part, it does not follow that green or yellow
varities are more susceptible than red ones. Of the important
commercial sorts used in the investigations of the Department
of Agriculture, the varieties named in the subjoined list have
proved susceptible. The season when the scald is most likely
to appear is given with each kind, though there may be a wide
variation from year to year. The time of the appearance of
the scald is influenced to an important degree by the method
of handling the fruit and by its degree of ripeness.
Arctic, serious midwinter Smith, Cider, serious, early
Arkansas often serious, after winter.
midwinter. Stayman Winesap, some-
Baldwin, often serious, late in times serious, midwinter.
season. Wagener, serious, midwinter.
Ben Davis, often serious, late White Doctor, serious, mid-
in season. winter.
Gilpin, often serious, late in White Pippin, slight, late In
season. season.
Green Newtown, slight, late Willow, slight, late in season.
in season. Winesap, often serious, late
Grimes, serious, early winter. in season.
Huntsman, serious, midwiu- Yellow Newtown, slight, late
ter. in season.
Lankford, serious, midwinter. York Imperial, serious, mid-
Nero, serious, midwinter. winter.
Paragon, sometimes serious, York Stripe, slight, late in
midwinter. season.
Ralls, slight, midwinter.
Rhode Island Greening, se-
rious, midwinter.
COMPARISON OF VARIETIES IN COLD STORAGE.
A large number of varieties of apples grown under various
conditions were under observation by the Department of Agri-
culture. It was the purpose of the investigation to determine
the keeping quality of the varieties during the commercial
apple-storage season, which usually terminates May 1, or shortly
afterwards. It was not attempted to carry the varieties longer
than the apple-storage season, though many of them when
382 PRACTICAL COLD STORAGE
finally taken from the storage house were in prime condition
and would have kept well for a longer period. ,
There is a wide difference in the keeping quality of the
same variety when it is grown in different parts of the country.
There is a striking variation also in the behavior of the same
variety when it is grown in the same locality under different
cultural conditions and in different seasons. There may be a
permanent difference in the keeping quality of the apples of
one region when compared with those of another, but it is not
safe to draw general conclusions in this regard until the varieties
of each have been under observation during several seasons and
have been grown under different cultural conditions. No at-
tempt was made in the investigations to draw comparisons be-
tween the keeping quality of the same sort from different
places. The behavior of each lot is given in commercial terms
rather than in detailed notes, so that the grower or apple han-
dler may know something of the storage value of a variety
under the conditions in which it has been observed by the
Department of Agriculture. The fruit was stored in bushel
boxes in a temperature of 30° to 32° F.
STIMMAEY OF U. S. GOVERNMENT EXPERIMENTS.
An apple usually should be fully grown and highly col-
ored when picked, to give it the best keeping and commercial
qualities. When harvested in that condition it is less liable to
scald, of better quality, more attractive in appearance, and is
worth more money than when it is picked in greener condition.
An exception to the statement appears to exist in the case
of certain varieties when borne on rapidly growing young trees.
Such fruit is likely to be overgrown, and under these conditions
the apples may need picking before they reach their highest
color and full development.
Uniform color may be secured by pruning to let the sun-
light into the tree, by cultural conditions that check the growth
of the tree early in the fall, and by picking over the trees sev-
eral times, taking the apples in each picking that have attained
the desired degree of color and size.
APPLES 383
Apples should be stored as quickly as possible after
picking. The fruit ripens rapidly after it is picked, especially
if the weather is hot. The ripening which takes place be-
tween the time of picking and storage shortens the life of the
fruit in the storage house. The fruit rots multiply rapidly if
storage is delayed and the fruit becomes heated. If the
weather is cool enough to prevent after-ripening, a delay in
the storage of the fruit may not be injurious to its keeping
quality.
A temperature of 31° to 32° F. retards the ripening pro-
cesses more than a higher temperature. This temperature fa-
vors the fruit in other respects.
A fruit wrapper retards the ripening of the fruit; it pre-
serves its bright color, checks transpiration and lessens wilting,
protects the apple from bruising, and prevents the spread of
fungous spores from decayed to perfect fruit. In commercial
practice the use of the wrapper may be advisable on the finest
grades of fruit that are placed on the market in small pack-
ages.
Apples that are to be stored for any length of time
should be placed in closed packages. Fruit in ventilated pack-
ages is likely to be injured by wilting. Delicate fruit and
fruit on which the ripening processes need to be quickly
checked should be stored in the smallest practicable commer-
cial package. The fruit cools more rapidly in small packages.
Apples should be in a firm condition when taken from
storage, and kept in a low temperature after removal. A high
temperature hastens decomposition and develops scald.
The best fruit keeps best in storage. When the crop is
light it may pay to store fruit of inferior grade, but in this case
the grades should be established when the fruit is picked. The
bruising of the fruit leads to premature decay.
The scald is probably caused by a ferment or enzyme
which works most rapidly in a high temperature. Fruit picked
before it is mature is more susceptible than highly colored, well-
developed fruit.
After the fruit is picked its susceptibility to scald increases
as the ripening progresses.
384 PRACTICAL COLD STORAGE
The ripening that takes place between the picking of the
fruit and its storage makes it more susceptible to scald, and de-
lay in storing the fruit in hot weather is particularly injurious.
The fruit scalds least in a low temperature. On re-
moval from storage late in the season the scald develops quick-
ly, especially when the temperature is high.
It does not appear practicable to treat the fruit with gases
or other substances to prevent the scald.
From the practical standpoint the scald may be prevented
to the greatest extent by producing highly colored, well-devel-
■ oped fruit, by .storing it as soon as it is picked in a temperature
of 31° to 32° F., by removing it from storage while it is still
free from scald, and by holding it after removal in the coolest
possible temperature.
A variety may differ in its keeping quality when grown
in different parts of the country. It may vary when grown in
the same locality under different cultural conditions. The
character of the soil, the age of the trees, the care of the
orchard — all of these factors modify the growth of the tree and
fruit and may affect the keeping quality of the apples. The
character of the season also modifies the keeping power of the
fruit.
COMMERCIAL RESULTS FROM THE COLD STORING OF APPLES.
The following outline of various experiments and experi-
mental results in addition to the work of the U. S. Department
of Agriculture is of interest as bearing on the actual results al-
ready obtained in the storage and transportation of apples.
Many of these tests or experiments have been conducted with
extreme care and by men of scientific training and attainment.
A word of caution, however, must be suggested. Experiments
must not be taken too literally. The results apply only to the
specific fruit and conditions under which the tests were made.
The quality of any variety of apples is extremely variable one
season with another, and depends also on the soil on which
grown and the climatic conditions. These details must be kept
in mind always in considering the practical and scientific as-
pect of any set or series of experiments, or practical results.
APPLES 385
CANADIAN GOV'ERNMENT EXPERIMENTS.
A report by John A. Ruddick, Dairy and Cold Storage
Commissioner of Canada, printed as Bulletin No. 24, and
headed "Some Trial Shipments of Cold Storage Apples," gives
some very interesting and explicit results secured from the
shipment of apples from various Canadian territory to Scot-
land. The experiments M^ere undertaken to demonstrate the
great advantage of cold storage over frost-proof storage, and
the educational value of these shipping experiments are most
important. The following extracts from Mr. Ruddick's Bul-
letin No. 24 will prove of general interest :
"The apples used for the experiment were the ordinary
commercial packs of different growers, as represented by The
Oshawa Fruit Growers, Limited, and The Sparta Co-operative
Fruit Growers' Association.
In presenting the results of these trials we have taken each
shipment separately, showing the net returns against the total
cost, including freight and storage charges and the expenses of
members of the staff in looking after the packing and ship-
ment. These costs are necessarily much higher than they
would be in a regular commercial transaction, where careful
records and notes are not necessary.
It was thought advisable to have one carload of apples
held in an ordinary frost- proof storage for the sake of compari-
son. These apples were from the same orchards and packed by
the same persons as the apples stored at Montreal and St. John.
With the exception of lots 1 and 2, the apples were car-
ried in cold storage across the Atlantic, and the two Calgary
lots were shipped in refrigerator cars. All the apples carried
in cold storage were held at a temperature of 32 to 34 degrees
during the whole storage period.
Lot 1. — ^Apples in barrels stored at Oshawa, Ont., in frost-proot
warehouse.
Picked— October 25-30.
Packed— November 22-23.
Stored— November 22-23.
Shipped from Oshawa — February 24.
Shipped from St. John — March 2.
386
PRACTICAL COLD STORAGE
COST.
No. Brls.
Variety.
Pur-
chase
price.
Amount.
Cost of
Repacking
before
Shipment.
Total
Cost.
26
$3.75
2.75
3.25
2.50
$97.50
55.00
84.50
50.00
$1.70
1.30
1.70
1.30
6.00
$99.20
20
56.30
26
20
No. 1 Baldwin
No. 2 Baldwin
86.20
51.30
92
$287.00
$293.00
Sold by Simons, Jacobs & Co., Glasgow, March 15, 1910.
ex. ss. Cassandra from St. John, N. B.
PROCEEDS. .
No.
Brls.
Variety.
Average
Price
Sold for.
Gross
Proceeds.
Total
Charges.
Net
Proceeds.
Net loss
per BrI.
24
19
24
20
No. 1 Spy
No. 2 Spy
No. 1 Baldwin . . . .
No. 2 Baldwin
$
3.67
3.40
4.39
3.77
$
88.11
64.60
105.36
75.42
34.08
26.79
35.04
28.40
$
54.03
37.81
70.32
47.02
0.92
0.61
0.21
87
5 us
92
ed in repacking.
$333.49
$124.31
$209.18
A thermograph was placed in the warehouse along with
the apples and a continuous record of temperature was ob-
tained. For the first 12 days the temperature was between 40
and 42 degrees. During the following month it averaged about
.35 degrees and from that time until the apples were shipped, it
varied only between .32 and 34 degrees. The temperature in
the car from Oshawa to St. John held steadily at 32 degrees.
These apples were repacked before shipping, the shrinkage
being 5 barrels in 92. They were sold at the same time as lot
2, but under separate marks. Although no charge for storage
is included in the total cost of this lot, the net loss was greater
than in any other lot of the same apples. This was partly due
to the loss and expense in repacking and partly to a poor mar-
ket, but if these apples had been held longer before sale, the loss
would in all probability have been greater.
APPLES
387
Our cargo inspector at Glasgow, Mr. Jas. Findlay, report-
ing on this lot, stated: "This mark, while in very fair order
as a whole, were mostly slight 'shakes' and the fruit was rather
ripe and inclined to give way." He also mentions that the
Baldwins showed considerable scald.
Lot 2. — ^Apples in barrels stored at St. John, N. B., in cold storage.
Picked (Baldwins)— October 25-30.
Picked (Spies) — November 1-5.
Packed (Spies) — November 2-5.
Packed (Baldwins) — November 6-9.
Stored at St. John — November 15.
Shipped to Glasgow — March 2.
COST.
No. Brls.
Variety.
Purchase
Price.
Amount.
Cost of
opening,
examin'g
and
tighten'g
brls.
before
shipment.
Storage
charges.
Total
cost.
45
40
40
30
No. 1 Spy
Nw. 2 Spy
No. 1 Baldwin.
No. 2 Baldwin.
3.75
2.76
3.25
2.50
168.76
110.00
130.00
75.00
$
2.92
2.60
2.60
1.95
11.25
10.00
10.00
7.50
182.92
122.60
142.60
84.46
156
483.75
10.07
38.76
532.67
Sold by Simons, Jacobs &, Co., Glasgow, March 15, 1910,
ex ss. Cassandra from St. John, N. B.
PROCEEDS.
No. Brls.
Variety.
Average
Price
Sold for.
Gross
Proceeds.
Total
Charges.
Net
Proceeds.
Net loss
per Brl.
44
40
40
30
No. 1 Spy
No. 2 Spy. ...
No. 1 Baldwin
No. 2 Baldwin
ed in plugging
1.67
3.60
4.66
3.90
barrels
201.08
144.00
186.40
117.00
64.68
66.80
68.46
42.90
136.40
87.20
127.96
74.10
1.03
0.88
0.36
0.34
164
1 US
156 ■
648.48
,222.83
426.65
NOTE. — The freight from Oshawa to Glasgow via St. John, N. B.,
worked out at $1.02 per barrel and the broker's charges for insurance,
landing, delivering, etc., at 21 cents per barrel. The usual 6 per cent
commission was charged.
388 PRACTICAL COLD STORAGE
This lot was from the same orchards as lot 1. It in-
cluded two mai'ks, "A" and "B." The A's were carefully
packed, to avoid, if possible, the necessity of repacking. The
packing of the B's was in accordance with the usual practice
and was intended to be temporary, with a view to repacking.
The condition of both marks was found to be so good on
March 1st that it was decided to ship them as they were, after
"plugging" the slack barrels. Only one barrel was used to
plug 154. It was thought that the damage from repacking
the B's would amount to more than the possible unevenness
of the original temporary pack. It will be observed that this
shows a better return than lot 1, after charging the cold storage
expenses.
It should be remembered that lot 1 and lot 2 were packed
alike, that lot 1 was repacked before shipment, with a shrink-
age of 5 barrels in 92, and that lot 2 (in cold storage) was not
repacked, one barrel in 155 being used for plugging.
Lots 1 and 2 were carried as ordinary cargo across the
Atlantic at a temperature of about 40 degrees.
Mr. rindley reported as follows concerning lot 2 : —
"The apples in above steamer shipped by the Department
of Agriculture, branded 'Oshawa Fruit Growers' Association.'
I found on arrival to be in the following condition : —
"Spy No. 1 and 2 gi-ade, countermarked 'A,' were in good
sound condition, almost free from bruise spots. I saw several
of the bottoms of barrels of No. I's and they all were very
sound; Ihe color was good, the size even, and they were gener-
ally choice. The Baldwins No. 1 and 2 of this mark were also
in good condition, free from scald, and of good color and even
size.
"Spy No. 1 and 2 countermarked 'B' were also in good
condition, but fruit not so even, large and smaller apples be-
ing mixed. A trace of bruising was just showing on odd ap-
ples throughout the barrels, and coloring was not so even or
good. Baldwins No. 1 and 2 were in good condition, an odd
apple here and there showing 'brown' in the barrels ; otherwise,
fruit was clean and of very fair color generally."
APPLES
SALE OF LOTS 1 AND 2 COMPARED
389
Lot 1
Tnt 5
Frost Proof Storage.
Cold Storage
Variety
Difference per Brl.
in favor of
Net
Loss
Per
Grade.
Storage
Period.
Temperature.
Loss
Per
Storage
Period.
Temp.
Cold st'r'ge
after pay- Frost
Brl.
Brl.
ing storage proof
charge of, st'r'ge
25c per bl.
i
deg.
t
$
t
Spy No. 1
Nov. 22
1909
About 40 deg.
first fortnight;
1.73
Nov. 18
1909
32
1.03
.70
" "2
to
about 34 deg.
2nd fortnight
.92
to
.88
.04
Baldwin No. 1
Feb. 24
and about 35
deg. for bal-
.61
Mch. 2
"
.36
.25
" 2
1910.
ance of period.
.21
1910
'*
.34
.13
In summarizing the results, Commissioner Ruddick states
the later-picked apples had, of course, the better color and ap-
pearance and kept slightly better. The advantages of quick
cold storing after picking were obvious, and this is the great-
est lesson to be drawn from the trials. Cold stores should be as
near as possible to the place of production, and the fruit should
go direct from the orchard to the cold store as soon as possible.
If packing is carefully done, repacking is not necessary in cold-
stored apples. This means a big saving in expenses and in
waste. The season for Greenings can be extended safely several
weeks if the apples are well matured on the trees and placed in
storage without delay.
In conclusion the report says :
"It is very frequently asserted that apples deteriorate
quickly after being removed from cold storage. It would seem
to depend entirely on the stage which the ripening process
had reached. Apples ripen slowly in cold storage. If they axe
held until the limit is' nearly reached, they naturally deterior-
ate quickly when removed, but no more quickly than they
would if the same stage had been reached in ordinary storage
at any temperature. * * * *
NOTE. — The apples ex Oshawa frost-proof storage were shipped on
February 24th, and during the six days the oar was in transit to St. John
the temperature In the car remained steadily at 32 degrees.
390 PRACTICAL COLD STORAGE
'•'There is evidence in the results of these trials which
would go to show that apples which are cold-stored promptly
after picking and held at 32-34 degrees for, say five months,
then removed to a high temperature for one month, will
be in better condition at the end of the sixth month than if
they had been exposed to the same high temperature for the
first month and then placed in cold storage for the rest of the
period. Or, in other words, exposure to a high temperature
just after picking, when the life processes are active in the ap-
ple, will cause more injury than the same exposure at a later
stage."
APPLE COLD STORAGE EXPERIMENT RESULTS BY THE NEW
HAMPSHIRE EXPERIMENT STATION.
The following is interesting information as bearing on the
handling of apples commercially, by shipping them to the
big city houses, paying storage, commission, etc. :
On November 20th, 1899, a number of barrels of apples
were shipped to one of the Boston cold storage houses. Be-
ginning with February two barrels were taken out each month
until July and examined. The fruit did not receive any ex-
tra care and was representative of apples as ordinarily pur-
chased at that time of year on the open market. It was found
that the apples could not safely be allowed to remain after
April 1st, as they decayed rapidly after that date. The prices
at time of shipment ranged between $1.25 and $2.00 and on
April 1st they brought $3.50 to $4.25.
On Oct. 27th, 1900, a second shipment of apples was sent
to cold storage with the following results. Price when put in
storage, $1.25. On April 23rd ten barrels sold for $34.00 Ex-
pense, carting, 50c., commission, 8 per cent, $2.72. Net pro-
ceeds, $30.78 or $3.08 per barrel. Freight and cold storage
charges must be deducted from this amount. The storage
rates were 10c. per barrel per month, or for the season ending
May 1st, 35 to 50 cents, according to the number of barrels.
The freight charges can easily be found out according to the
location of the individual.
The greatest care in handling and placing the fruit im-
APPLES 391
mediately into cold storage pays for the extra trouble. One
must understand that cold storage will simply retard and not
prevent entirely the spread of decay. If the fruit is in prime
keeping condition on entering, it is likely to come out in pro-
portionately as good condition.
Where apples were placed in brine and cold air storage,
the cold air gave the best results.
From an examination of the prices paid in the fall and
those paid on April 1st for the past six years, the results show
that there has been a sufficient increase to warrant the extra
expense of storage in every case and on the average the prac-
tice has resulted in good profit.
ME. roe's WISCONSIN EXPERIMENT.
J. P. Roe, in Farm Press, reports some experience with
the storage of apples grown in Wisconsin. He says that the
winter apple for long keeping which is adapted to the north-
west is yet to be discovered. Of the fall varieties that succeeded
in cold storage he reports that the Wealthy, the Mcintosh Red,
the Faraeuse or Snow, and a Russian variety known as the Red
Annis, give most satisfactory results. Of the summer varie-
ties the Dutchess of Oldenburg and Yellow Transparent are
successful. The Yellow Transparent is ordinarily considered
a very soft variety, and not suitable for cold storing, but in
Wisconsin this variety is much firmer and a much better keep-
er than when grown further south. Mr. Roe, however, re-
ports some discoloration in the storage of Yellow Transpar-
ents. He reports that for general commercial purposes a red
apple is preferable to white, as it is not only more salable, but
more durable under cold storage treatment, and the results of
a bruise not so conspicuous.
Mr. Roe suggests that if fruit growers are inclined on ac-
count of an unusual state of the market to experiment with ap-
ples in cold storage, they should go slowly, and only try a
few barrels. He reports having stored 50 barrels of Longfields,
and that they proved a total loss. As the author has suggested
elsewhere in this chapter, the result of a single experiment must
not be taken as final, nor as positive data on which to base fu-
392 PRACTICAL COLD STORAGE
tnre action. Repeated experiments under different conditions
are necessary in order to be even an approximate guide.
MFv. yOUNCxEES' NEBRASKA EXPERIMENTS.
Some interesting facts on the cold storage of apples are
gathered from the report of Mr. Youngers "of the Nebraska
Horticultural societjr, who collected and stored 180 barrels of
apples, representing 34 varieties, the fall previous to the Co-
lumbian exposition. The following markings were made on
a scale of 10 points for a perfect condition, or as nearly so as
apples could be at that time of year. These markings were
made at the time the apples were taken from cold storage.
June 15 July 14 Aug. 2 Sept. 2 Oct. 2 Nov. 1
Ben Davis 10 10 10 10 10 10
Winesap 10 10 10 10 10 10
Genet 10 10 10 10 10 10
W. W. Pearmain 10 7 6 6 4 3
Limhertwig 10 10 10 10 10 10
Allen's Choice 10 10 10 10 9 8
Willow Twig 10 10 10 10 10 10
Sweet Russet 10 10 9 9 8 8
Little Red Romanite... 10 10 10 10 10 10
Lansingburg 10 10 10 10 10 10
Mcintosh Red 9 9 9 9 9 9
Sairnip : 9 9 9 9 7 3
Dominic 9 8 8 8 7 6
Prrn- Pf:niiy 8 8 8 7 6 5
Iowa Blush 8 8 8 8 7 5
The following varieties retained all of their good qual-
ities up to the time of their last marking, Nov. 1 : Ben Davis,
Winesap, Genet, Limhertwig, Willow Twig, Little Red Ro-
manite and Lansingburg.
The other varieties which were stored, but which in the
percentages showing their condition at the time it was desired
to use them, fell below the lowest percentage named in the
li.=t given were as follows: Jonathan, G. G. Pippin, Missouri
Pijjpin, Northern Spy, Wallbridge, Yellow Bellflower, Eicke,
Price's Sweet, Sheriff, Snow, Fulton, Minkler, English Golden
Russet, Roman Stem, Ortley, Milam, Talman Sweet, Perry
Russet, Wagener.
All of this fruit was gathered and placed in cold storage
during the fall of 1807, most of it during the month of Oc-
tober. Each apple was wrapped first in a sheet of waxed pa-
APPLES 393
per, using 9 by 12 inch sheets for small apples and 12 by 12
inch sheets for large ones. Then another covering of common
newspaper was added and the apples carefully packed in bar-
rels, filling them up so as to require considerable pressure to
. get the heads in. They were stored in a cold storage room in
South Omaha, and the temperature did not vary over one
degree from 36 degrees from the time they were placed in stor-
age until they were removed.
TIME LIMIT FOE APPLE COLD STORAGE.
The extreme practical limit of time possible to carry ap-
ples in cold storage has been demonstrated in numerous cases.
Ben Davis, for instance, an apple which is known as a remark-
able keeper and of poor quality, has been stored for two years
in cold storage without decay. The apples were, of course,
shrunken or shriveled and discolored, but were sound. Rus-
sets have also been carried over from one season to another in
an experimental way. These are mere experiments, and apples
are not handled on a commercial scale for storage longer than
eight or nine months.
When the fruits of spring and summer ripen, apples of the
previous season's growth properly go out of the market. They
should be considered primarily a fruit for winter's use. Some
few fancy varieties or apples of exceptionally good quality are
carried over through the spring and into summer mainly for
fruit stand and other special trade.
An experiment or practical demonstration was tried in a
Buffalo, New York, cold storage house, to demonstrate the time
limit of apple storage. It was believed that an apple had a
maximum life period beyond which it would succumb to age,
whether in or out of storage, and that while cold storage would
prolong its life, it could not preserve the fruit beyond a cer-
tain limit of time.
The apples used in the test at Buffalo were of several va-
rieties, including Tallman Sweets, Northern Spys, Smith's Ci-
der, Spitzenbergs, Tompkins County Kings, Culverts and the
like. Some of these were distinctively what are called soft or
fall apples and not expected to keep very long even in cold
storage.
394 PRACTICAL COLD STORAGE
The apples were placed in the cold storage warehouse Oc-
tober 4 and 6, 1904, They were taken out during the first
week in January, 1906. On opening the boxes in which they
had been placed the apples in appearance were found to be all
right and in an excellent state of preservation, but some of the
varieties lacked flavor, either their own distinctive flavor or any
good apple flavor, while others were quite as good as those har-
vested in the autumn of 1905. They had stood the test for
15 months and looked as though many of them could have
lasted another six months.
The above is a good example of so-called experiments by
the average warehouseman. It is very difficult for the aver-
age person to judge accurately the question of quality. He is too
prone to say that a thing is good or bad, and let that settle it.
In the above case, for instance, it is stated that, while some
of the apples lacked any distinctive apple flavor whatever, yet
others were as good flfteen months after storage as the freshly
picked apples, or the crop from a year later. The impossibility
of any such result need not be questioned. Apples after stor-
ing for a year or more would certainly be very much inferior,
regardless of how they were kept, and no apples are stored com-
mercially for this length of time.
PACKAGES SUITABLE FOR COLD STORAGE.
A package suitable as a container of apples for cold storage
need not necessarily be such as would be convenient for hand-
ling. But, practically, it is essential that the packages used for
cold storage be such as can be used successfully as a shipping
and handling package. By years of trial and demonstration,
two kinds of packages have proved commercially successful
both for storing and for handling, viz. : The three-bushel barrel
and the somewhat more modern one-bushel box.
Much comment, unfavorable to the barrel, has been in-
dulged in by those who think they know what package is most
suitable for apples. The box has been lauded as the best pack-
age, and this, doubtless, has been owing to the fact that west-
ern growers, especially in the North Pacific territory, have used
the box exclusively, and have shipped East large quantities of
APPLES 395
very finely colored and finely selected apples. The use of boxeis
will not give the fruit a fine appearance, if it is not inherently
of excellent quality. The box is a desirable package for many
purposes, but has no great advantage over the barrel as a pack-
age for the retailer. Practically it is just as easy to sell a
three-bushel barrel as it is one-third the quantity in a bushel
box. The average consumer has no place to keep even as
small a quantity as one bushel of apples, and he buys in a quan-
tity not exceeding one peck and even by the quart or pound.
The three bushel barrel is a package which will remain
with us for many years to come, and it should not be con-
demned nor blamed for those things for which it is not re-
sponsible. The fact that those who pack apples, "face" both
ends of the barrel with large and fine appearing fruit, is a
standing joke, and the old familiar barrel has probably from
this reason as much as any, been condemned. The barrel is
by no means responsible for the deceit and dishonesty of fruit
packers. The great advantage of the barrel over any rectan-
gular package is that its shape makes it very strong, and it
thus protects the apples from damage by bruising while being
handled. Another great advantage of the barrel is that it is
tight, or reasonably so, to an extent which protects the fruit
from a direct contact and circulation of the air. This is a big
advantage, not only while in cold storage, but while being
handled out of storage. The advantage of protecting apples
from air in cold storage is mentioned more fully on another
page.
The box has none of these advantages. The apples as
packed in the box cause the box to spread, and when being
trucked or handled the sides are easily dented or sprung, and
thus the fruit is more or less damaged. The spreading of the
sides and top and bottom of the box, open cracks at the cor-
ners, which allow the air to circulate more or less freely in
contact with the fruit. This is, of course, offset to some extent
by lining with paper, and in case of fancy fruit, where each in-
dividual apple is wrapped, as is discussed under the head
"Double Wrapping for Apples." The chief advantage of tl^e
box is that it shows up the fruit to better advantage; that the
396 PRACTICAL COLD STORAGE
package is more portable or easier handled and that it takes
very much less space in handling and storage. The saving in
space by using a rectangular package is well understood by
cold storage warehousemen, and the bushel box for apples as
compared with the three bushel barrel, makes a saving of about
50 to 75 per cent. This, of course, in cold storage where space
is valuable, is very important.
As a suggestion, the author ventures to offer the follow-
ing: It is possible to put up a fine grade of apples in some
sort of cartons, holding perhaps one dozen or two dozen ap-
ples, depending on size, and having these cartons, preferably
of paper or cardboard, of some unit size, so they will fit into a
rectangular wooden box ; possibly a bushel box might be made
to serve in this connection. It is, of course, thoroughly ap-
preciated that this plan would make it difficult to show or ex-
amine the fruit to advantage, but doubtless the cartons could be
so arranged that the covers could be opened easily. The great
advantage of some unit package of this kind is that the original
package as packed by the fruit grower or by the original packer,
would go to the consumer without rehandling, and the scheme
has the further great advantage that the cartons suggested would
be easily portable, and would make a nice package which the
retailer could deliver to the consumer. Fruit growers who. de-
sire to work up a fancy private trade direct to the consumer
would find some package of this kind a most valuable factor.
Portable packages, and packages which will protect the goods
are of great assistance as a selling factor in any line of busi-
ness. The selling of goods in bulk is being more and more done
away with, and doubtless this will apply to apples as well as to
other lines of goods.
BOX AND BAEKEL COMPARED.
Prof. S. W. Fletcher, director of Virginia Agricultural
Experiment Station, discusses the merits of the box and barrel
as follows*:
1. Quantity of fruit — It is probably true that the box is
a more convenient quantity of fruit for the "ultimate consum-
*Prom paper presented before the American Pomological Society.
APPLES 397
er," who has recently received so much attention by tariff
makers, than the barrel. Over 30 per cent of our population
now live in cities, and the percentage of city dwellers is in-
creasing with each census. A majority of the city and town
people, constituting the main market for fruits, have no cool
cellar in which fruit can be stored. Their storage facilities are
limited to the refrigerator. They wish to buy only such a
quantity of fruit as will keep, at the ordinary temperature of
the house, while it is being used. Under such conditions the
box is a more convenient package than the barrel. A large
basket of the Climax type, holding about a peck, would be more
convenient still, especially for summer and autumn apples.
On the other hand, there is a large demand for apples in
bigger bulk, — not only because of the custom of years, but al-
so for the winter supply of those who have a cool cellar, and for
export. Certain varieties carry better across the water in bar-
rels, than in boxes, because the latter packages permit the en-
trance of salt air.
2. Cost of package — On the Pacific Coast, apple boxes cost
from six cents to nine cents, knocked down. As three boxes can
be packed out of one barrel, at that price the boxes are cheaper
than the barrel. In the East we pay from eleven cents to
twenty-one cents per box. In Virginia, boxes cost ten cents to
twelve cents; in Minneapolis, Minn., fourteen cents; while Mr.
Robert Brodie of Montreal states that his boxes cost twenty-
one cents. The price of barrels in the East ranges from
thirty cents to forty-five cents, with an average of about
thirty-five cents. Bought knocked down in carload lots, they
have cost certain growers twenty-eight cents to twenty-nine
cents. The inferior quality of some eastern-made boxes, as
noted previously, should also be considered. The compara-
tive cost of barrels and boxes is a local problem, and each grow-
er will have to get estimates.
3, Grading and packing — The fundamental difference
between the two types of packages is here: The box encour-
ages, and almost enforces, honest and uniform grading, while
the barrel permits carelessness in this respect. The cost of
packing is also an item. "Where a very large quantity of fruit
398 PRACTICAL COLD STORAGE
is packed by specially trained men, it costs little if any more
for labor to pack in boxes than in barrels. But the small
grower, and especially one who has been accustomed to the
barrel pack, will find that it costs from one-third to one-half
more to pack in boxes than in barrels. It should be noted, al-
so, that very small, or otherwise inferior fruit seldom if ever
yields as high returns in the box pack as in the barrel pack.
Only the large sizes go well in boxes. It is a question for each
grower to decide, whether he can get more by sorting out his
fancy and No. 1 stock for boxing, and selling the smaller fruit
in barrels, than to sell all in barrels as No. I's.
Another point to be considered is the shape of the fruit.
It is almost imperative that box fruit should be quite regular
in shape. Lop-sided and misshapen fruit, like the York, es-
pecially from young trees, would not pack well in boxes.
The most important point under this heading, however,
is that no one has ever succeeded with the box pack using com-
mon stock. Only fancy and No. 1 fruit of the best quality has
paid in boxes. By intensive methods, and especially by thin-
ning the young fruit on the trees, many of the best western
growers have been able to produce fruit, ninety-five per cent of
which is fancy. Practically all of the Hood River fruit is box
fruit. I doubt if, on an average, thirty per cent of the apple
crop of Virginia, or Ontario, or any other part of the East,
is box or fancy fruit. This point must be kept emphatically
in mind when the suggestion is made that the box should be-
come the exclusive apple package of the East, as it is now in
the "West.
4. Quality of fruit. — Of far less importance than the
grade of the fruit in th3 package, in respect to the question
before us, is its quality. It is a fact, however, that the box
fruit that has commanded the highest prices is mostly of va-
rieties of high quality, — Winesap, Spitzenberg, Newtown. But
other varieties, even some of very indifferent quality, have
been sold in the box package to great advantage, showing that
the style of package and the grade of fruit, rather than its
flavor, are the deciding factors. However, the general experi-
ence has been that the better the quality of the fruit, the
APPLES 399
more apt it is to pay in the box pack. If varieties of inferior
quality pay in the box pack, it is because the style of package
and the grading outweigh the deficiency in quality.
Experience with the box package in the East. — Having
in mind the essential difference between the box and the barrel
trade, it does not seem strange that most of the attempts to
use the box in the East have not resulted satisfactorily. It is
probably near the truth to say that eight out of every ten
trials of the apple box in the East have been unsuccessful. A
notable example is an experiment by the Field Pomologist of
the U. S. Department of Agriculture, Mr. W. A. Taylor, several
years ago. He sent abroad during two seasons eight carloads of
carefully graded box Baldwin, York, and Newtown, but with
indifferent results as compared with barrels. There are many
possible reasons for these failures.
1. Custom. — Custom is hard to change, — and the box
package is an innovation in the East. As a rule, eastern buy-
ers and grocers do not look with favor upon the box, partly
because the profits in repacking and selling a barrel of
indifferently packed apples are apt to be greater than in han-
dling three well packed boxes. If the producer could deal with
the consumer, it would be different ; there is no doubt but that
a majority of the consumers would prefer the box, or a smaller
package, if the fruit did not cost much more.
2. The market. — A good deal depends upon what a certain
market prefers, in the matter of fruit packages, as well as in
fruit varieties. "West of the Mississippi there is special necessity
for caution in this respect. Some buyers want their fruit in
boxes, and others prefer barrels, according to the market they
expect to reach. The grower who ships should be equally wise.
3. Poor packing and grading. — More failures arise from
this cause than from any other. The art of packing boxes is
not acquired in an hour. It is work for specially trained men,
not for the average farm help. In this respect it differs ma-
terially from barrel packing, which may be quite well done
by ordinary help. Moreover, the habits of several generations
of men who have packed in barrels, using "facers" and "fill-
ers," have descended to the fruit growers of today; and many
400 PRACTICAL COLD STORAGE
of them find it extremely difficult to keep the smaller, poor-
ly colored, or slightly imperfect specimens from gravitating
to the bottom of the box. It will take a generation or two,
perhaps to breed out that habit. The western man deserves no
credit for being more honest in this respect, for, as has been
pointed out, honest}' was not merely the best policy for him,
but the only policy that would pay freight rates.
General conclusions. — The drift is all towards the smaller
package. This is in keeping with the trend or the times with
respect to other commodities. There is no doubt but that the
box package, or at least the smaller type of package, will
some time entirely supplant the barrel. The smaller package
will not necessarily be made of wood. We can expect the
wooden package to be replaced, eventually, by paper, cellulose,
or some other cheap material. Even now some very substan-
tial paper boxes are on the market. AVhen speaking of the box
type of package, therefore, we refer to the size and shape of
package, rather than to the material.
But while the box type of package is the ideal towards
which we are rapidly working, it by no means follows that
every Eastern fruit grower should begin packing in boxes at-
once. He should begin only when he is ready; and nine-
tenths of the growers are not ready. To be ready for box pack-
ing means that the grower can get good boxes about as cheap as
barrels, bushel for bushel; that he is able to grow a crop of
fruit, preferably of high quality varieties, at least ninety per
cent of which is fancy pr No. 1; that he is able to command
skillful and experienced packers ; that he is able to put a large
quantity of box fruit on the market, not one year only, but
year after year, so as to win a reputation for the brand; and
that he ships his fruit to markets that are already familiar with
the box pack and take kindly to it. At the present time not
one apple grower oiit of ten, east of the Mississippi, is able to
meet these conditions.
With respect to the market, the fruit grower must recog-
nize the different demands of two entirely different types of
markets. One of these, the common or general market, will
pay a fair price for good or common stock. The other, the
APPLES 401
special or fancy market, Mali pay a fancy price for fancy stock.
At the present time the box package supplies the special or
fancy market almost exclusively, while the barrel package sup-
plies both, but more especially the common or general mar-
ket. These two classes of markets will always exist, or as long
as some people are more successful in accumulating money than
others. It goes without saying that the demand for cheap or
common fruit, at a fair price, will continue to be very much
greater than the demand for fancy fruit at a high price; be-
cause there are many more people who are in moderate circum-
stances than there are people who are able to pay fancy prices for
fruit. The proportion of fruit growers who are able to grow
fancy fruit is as small as the proportion of consumers who are
able to pay fancy prices. Location, soil, and the varieties best
adapted thereto may make it more profitable to grow staple
varieties for the common market. This cheap fruit — the main
supply of the great middle class of people — will be marketed in
barrels to best advantage for many years to come.
The successful marketing of apples in boxes depends so
much upon skillful grading and packing and upon the pos-
session of a large quantity of fruit so packed, that it seems likely
that very little impetus v>'ill be given to box packing in the
East except through co-operative shipping associations. Here
and there an exceptional grower may tind it profitable to pack
his fancy grade of certain varieties in boxes; but it does not
seem probable that box packing will make much headway in
the East except through the co-operative shipping association,
with its trained business manager and its crews of trained
packers.
These conclusions indicate that the eastern fruit grower
should be a conservative on the subject of the box apple package.
The drift is towards the smaller package — but, at the present
time and for many years to come, apple growers who are so
situated that they must produce apples for the general or com-
mon markets — which means a majority of the growers — will
find the barrel more profitable. With the advent of co-operative
shipping associations, the box package will become more and
more common in the East, and eventually even for the com-
mon grades of fruit.
402 PRACTICAL COLD STORAGE
DOUBLE WRAPPING FOR APPLES BEHAVIOR OF DIFFERENT
VARIETIES.
A striking example of the possibilities of cold storage in
the preservation of apples was furnished by the work of the Ne-
braska State Horticultural Society at the Transmississippi ex-
position of 1898, reported by V. A. Clark. The fruit was gath-
ered and put in cold storage during the fall of 1897, most of it
during the month of October, though some not until December.
Each apple was wrapped first in a sheet of waxed paper, using
9 by 12 inch sheets for small apples and 12 by 12 inch sheets
for large ones. Then another covering of common news-
paper was added. This double wrapping made practically an
air-tight cell for each apple, thus preventing any spread of
decay. The fruit was then carefully packed in barrels, fill-
ing them up so as to require considerable pressure to get the
heads in. The temperature of the room in which they were
stored did not vary over one degree from 36 degrees from the
time they were placed in it until they were removed. A num-
ber of varieties were still in good condition Nov. 1 of the fol-
lowing year.
To determine how such double wrapping lengthens the
period of keeping a few barrels of unwrapped Ben Davis and
Winesap apples were placed in the same storage room at the
same time and received exactly the same treatment as the others.
Seventy per cent of them were decayed when taken out June 1.
Those remaining in firm condition were so badly discolored
and had lost flavor to such an extent as to render them wholly
unfit for either show or market. A few of the same varieties
were also wrapped in newspaper only. Of these about 30 per
cent were in very poor condition June 1. The fruit which went
into cold storage in 1897 was taken out at intervals during
the summer and fall of 1898 and at that time was examined
and each variety received a mark, according to the condition in
which it was found.
One of the most interesting parts of the report of these
experiments is the account of the behavior of the different va-
rieties in cold storage. Some retained all their good qualities
up to the close of the exposition, Nov. 1, 1898. These were
APPLES 403
Ben Davis, Winesap, Ralls Genet, Limbertwig, Willow Twig,
Gilpin and Lansingburg. Although the Salome lost a little in
quality, it kept well in storage and on the table. Fruit taken
from storage June 1 retained color and firmness for nearly five
weeks. Some retained a good outward appearance, but lost
in some other quality, as, for instance, the Iowa Blush, the
skin of which became so bitter as to render the fruit unfit
for use.
On the other hand, some varieties retained their eating
qualities, but lost in outward appearance. Such was the Milam,
which kept well, but lost in color. There were also numerous
other kinds of deterioration. Minkler lost flavor and began to
decay, the English Golden Russet and Fulton shriveled, the
Roman Stem became mealy and lost flavor. Sheriff and Wal-
bridge discolored so badly as to render them unfit for show or
market and they deteriorated rapidly; Fameuse retained color,
but many burst and after a few days became mealy, and the
Yellow Bellflower went down suddenly.
Moreover, the behavior of varieties having a certain char-
acteristic in common was not always the same in respect to it.
The Missouri Pippin, a dark apple, faded in storage, but the
Walbridge and Sheriff, also dark apples, came out almost black.
Nor did the lighter colored apples fade more than the dark red
ones, for Grimes Golden and Yellow Bellflower, both yellow
apples, held their color unchanged, while Missouri Pippin, a
dark red apple, as has been said, faded.
Too much reliance must not be placed on the results of
storing different varieties. So much depends on the condi-
tion of the fruit when stored, the soil on which it is grown, and
the local characteristics of the variety. It is reported, for in-
stance, that Fameuse retained color, but fhat many of them
burst and after a few days became mealy. That might be
characteristic of Nebraska Fameuse, but certainly not be char-
acteristic of northern New York and New England and Can-
ada Fameuse. The above tests are valuable only as they re-
late specifically to the apples grown in Nebraska and the cul-
tural conditions prevailing.
404 PRACTICAL COLD STORAGE
Another caution is that the results from storing double
wrapped fruit must not bo taken too literally. The exact kind
of paper used, and the exact character of the barrels used, and
the system of refrigeration employed in cold storing have not
been given in detail, and all these have an important bear-
ing on the fitial result. An absolutely air-tight covering for
the fruit, or an air-tight barrel or package would be fatal to
its keeping qualities, and although doubtless many feel that
wrapping fruit in waxed paper encases it in an air-tight en-
velope, this is not by any means the case. Waxed paper, in
fact, is quite porous so far as penetration or flow of gas or
air through it is concerned.
PILING Bx\REELS OF APPLES.
Owing to the comparatively heavy weight of a barrel of
apples and its somewhat awkward shape, the proper handling
and stowing of same in cold storage rooms is difficult and where
the rooms are high it is a very laborious task to get the top
tiers of apples into place. Figure 9 shows a method which has
been worked ovit in practice, and which has proved to be en-
tirely satisfactory as well as simple and inexpensive.
The device used consists of a tackle consisting of two single
block? as shown. The rope is fastened to the upper block,
then run through the lower block, and then through the up-
per block, and thence to the hands of the operator. The low-
er block is attached to what is known as a barrel clamp, con-
sisting of two flat hooks for engaging the chimes of a barrel,
which are fastened to a chain, the center of which is fastened
to the lower block as shown in the cut. The upper block is
fastened to a piece of 2-inch pipe supported iii any convenient
way over the central piling alley. The pipe may be supported
by hooks from the ceiling or by blocks of wood from the ceiling
against a post. In any case the piping is removable. The up-
per tackle block is fastened to the pipe only by a loop of rope,
which can be slid along on the pipe to the different piles, and
untied completely for removal to another support.
With this device a biirrel can be raised by one man, as
shown, to a position where it can be rolled back to a location on
APPLES
405
any tier as the apples are built up ; 2 x 4's are laid on the floor,
one at each end of the barrel directly underneath the head of
the barrel, so that no weight comes on the sides or bilge of the
barrel. Other 2 x 4's are placed on each tier of barrels up to
the 3d, or 4th, or 5th, or possibly the 6th tier according to
height of the room. Above that the barrels are piled without
2 X 4's, each one being placed in the notch or space between
the two barrels of the tier below as shown in the illustration.
It is not advisable to pile in this way more than four tiers in
height.
PIG. 9 — PILING AND LIFTING APPLES.
While one man can hoist a barrel in this way, where rapid
work is wanted, it has been found expedient to have two men on
the rope and one on the pile. This apparatus has been found
entirely practicable in service, and considering the small ex-
pense and ease of application it should work out wherever there
are many barrels to pile, either of apples or of any other similar
goods.
Apples have been piled in this way in a room 20 feet in
height, and we see no reason why they could not be piled in a
room higher than this. Of course, there is some danger in
handling apples on high piles, as a weak barrel in the bottom
406 PRACTICAL COLD STORAGE
may cause trouble. However, by arranging to have the grain
of the wood in the heads of the barrels come vertical as much as
possible, and by alternating from one side to the other so that
the vertical grain would be first on one side of the pile and then
on the other, it would seem that with good substantial piling
strips, possibly pieces which were 2% inches or three inches
thick and 4 inches or 5 inches wide, that apples could be piled
to a height of 30 feet if required.
HANDLING APPLES IN BARRELS AI-TEE COLD STORING.
The question often comes up as to whether it is detri-
mental to apples to handle them from one storage room into
another after they have been in storage for some months. It
is occasionally desirable to do this so as to concentrate the lots
remaining on hand into one room or into less space than they
would occupy when scattered about the house. It is also some-
times desirable to move apples from the public cold storage
into private storage at the end of the storage season.
As a general statement it is damaging to apples to move
them after they have been in storage for several months or
more. The damage comes from the fact that after being
stored, apples become" slack" in the barrels on account of
natural shrinkage, and may be badly bruised in handling.
Further than this, if the apples are affected with rot to any
extent, handling the barrels in "slack" condition, smears the
good apples from the decayed ones. In any case, apples after
being in storage for four or five months are pretty well ma-
tured, and it is damaging to handle them to any extent. If
they are of extra good stock and reasonably tight in the bar-
rels, and not affected with rot, they can be moved if carefully
handled. Under these conditions, they should not be rolled
on the bilge or sides of the barrels, but should be rolled on the
chime, or handled carefully on trucks without allowing them
to drop or be jarred in any way.
PACKING APPLES.
We are indebted to John A. Ruddick, Cold Storage and
Dairy Commissioner of Canada, for the following on packing
apples in barrels and boxes :
APPLES
407
The barrel in common use in Ontario is made of 30-inch
staves, that in use in Nova Scotia of 28-inch staves. The dimen-
sions are: Between heads, 27% inches; head diameter, 17
inches; middle diameter, 19 J^ inches. The specifications for
a good apple barrel call for a sound stave, 9/16-inch jointing.
PIG. 10— SCRBW^ PRESS FRAME.
FIG. 11 — IRON CIRCLE PRESS HEAD.
cut five to two inches, and averaging four inches in width at
the bilge. The head to be not less than % inch in thickness,
dressed, and to have eight hoops.
When packing the apples in barrels each apple is laid
with the stem end down, the stem having been previously cut
408 PRACTICAL COLD STORAGE
off with a stemmer. Upon no consideration should a very
large or very small apple be used to finish up in the center of
the face. If the apples are colored, the second layer should be
placed so that the color of the apples will show though between
the apples for the first layer. After this second layer is laid
the apples may be turned in from the round-bottom baskets in
which the graded apples have been placed. Never use any de-
vice that will require the apples to fall any distance into their
place on the grading table or in the barrel. The presumption
is that the grading has been done off the: grading table, and
that fruit of a perfectly uniform grade is put in each bar-
rel.
Heads cut from heavy paper or light pulp board are very
desirable on both ends of the barrel. The patent corrugated
heads cannot be recommended. It is doubtful, too, whether
there is any advantage in using fancy paper heads.
The pressure will depend somewhat upon the variety. The
Spy must be pressed very moderately ; the Eussets, on the con-
trary, will stand much heavier pressure. If packed for stor-
age, the pressure need not be as heavy as when packed for ex-
port. Slackness in barrels is as often caused by over-pressing as
by under-pressing. Over-pressing will break or bruise the skin,
inducing decay.
The most efficient and handy form of barrel press is the
screw press frame, shown in Fig. 10. To make the pressure
equal, an iron circle press head is used, as shown in Fig. 11.
The bars A and B are made with an arch and with a shoulder
to fit against the iron circle, 0. The circle should be fourteen
inches in diameter and made of quarter-inch bar iron.
BARRELS VERSUS BOXES.
The question of boxes versus barrels has been discussed in
eastern Canada for a number of years. The British Columbia
fruit growers use no barrels. A careful analysis of the condi-
tions in eastern Canada would seem to show that neither pack-
age possesses all the virtues. The following facts are well es-
tablished.
1. — The highest priced apples are shipped in boxes.
APPLES 409
2. — The box is the only practical package in which an
apple can be transported with any reasonable degree of econ-
omy in a fit condition for the highest dessert trade.
3. — Only the best grade of apples will pay in boxes.
For the last four or five years a few Canadian shippers have
each year experimented with boxes. In only one or two cases
have they pronounced it a success. A fairly close inquiry into
the conditions under which these experiments were carried
on shows that the business was not handled in the best way.
Nearly all who experimented with boxes did so with unskilled
packers. In many cases the boxes were faced and then the ap-
ples were simply rolled in on top of this face, after the man-
ner of barrel packing, and finished in every respect like bar-
rel packing, with no attempt at arranging the apples in tiers.
Of course, nothing but failure could be expected from such a
style of packing.
The size of the Canadian apple box is 10x11x20 inches,
inside measurement. This is obligatory for the export trade.
It is recommended that the box should be made with the fol-
lowing specifications: The end pieces not less than % inch
nor more than % inch thick; the sides not less than % inch,
the top and bottom Y^ inch thick. These dimensions cannot
be changed to any great extent. Dovetailed boxes are not a
success with fruit.
Whether the apples should be wrapped or not depends
somewhat upon the variety and the grade of fruit. Wrapping
has several advantages: 1, it serves as a cushion in the case of
delicate fruit; 2, it prevents rot and fungus diseases from
spreading from specimen to specimen; 3, it maintains a more
even temperature in the fruit, and 4, it has a somewhat more
finished appearance when exposed for sale.
Wrapping has also some disadvantages: 1, it adds to the
cost of packing, and 2, it prevents rapid cooling in cases where
the fruit is not cool at the time of packing.
Lining papers for the boxes are not often used. At the
Ontario Horticultural Exhibition for 1906 not more than
twenty-five per cent of the boxes shown for prizes were lined.
The practice, however, is to be commended. It costs but a
trifle and adds greatly to the appearance.
410 PRACTICAL COLD STORAGE
When packing apples in boxes, packing tables are abso-
lutely essential. These should be of two sorts, as it is impos-
sible to get packing and grading done at the same table eco-
nomically. When the apples are brought to the packing house
the first operation is grading them into Fancy, No. 1, No. 2 and
Culls, which may be done by help that knows nothing about
the practical part of box packing. The grading is best done on
tables lined with canvas or burlap.
PIG. 12— PACKING BENCH FOR BOX APPLES.
The basis of rapid box packing is good, even grading.
The packer should have before him an even run in point of
size, without which it will be impossible for him to do rapid
work, or, indeed, do good work. The really skillful packer
will take the very slightly smaller apples and use these at the
ends of the boxes, the larger always going toward the middle
of the box. But this difference in the size of the end and the
middle apples is so slight that only the practiced eye of the
packer would detect it. The skillful packer will also take ad-
APPLES 411
vantage of the slight inequalities in shape. If the packer
finds that there is a slight slackness in a row of apples which
he is packing across the box, he can usually make this perfect-
ly tight by simply turning the specimens one way or the other.
Of course, the opposite fault of being somewhat too crowded
can be remedied by the same process. It is, perhaps, not equal-
ly important to grade to color, yet this adds greatly to the ap-
pearance of the finished box. If, then, the packer has the
choice, he will put the lighter-colored apples in one box and
the highly-colored apples in another. Both boxes may sell
equally well, but neither would have sold so well had the apples
been mixed in color in each box.
After the packing is completed the cover of the box must
be carefully nailed in position. The lining papers are folded
neatly at the edge of the top of the box, to allow for the swell,
and will then overlap slightly at the center. The staff of the
Fruit Division of Canada have been using a bench, illustrated in
Fig. 12. This is the style, with some modifications, in general
use on the Pacific Coast, and can readily be made by any one
handy with tools. The box is set between, and is held firmly
by, the clamps shown.
PACKING IN TIERS.
The simplest method of packing boxes is nothing more
than the barrel pack practised with boxes. It is needless to
say that such a method of packing a box will result in abso-
lute failure. The number of apples in a box can be deter-
mined almost instantly by the style of pack, of which there
may be a large variety. Some practiced packers claim to dis-
tinguish as many as sixty different styles of pack. Familiarity
with half a dozen, however, will enable an intelligent person to
pack successfully all common varieties. In a general way the
size of the apples is indicated by the number of tiers or layers
in the box. The box is supposed to be open so that it is eleven
inches wide and ten inches deep. If, then, three layers or tiers
of apples will fill the box properly, that sized apple is spoken
of as a 3-tier apple. In the same way, if five layers or tiers fill
the box, the size is said to be 5-tier. The 3-tier apples would
412
PRACTICAL COLD STORAGE
be the largest that would be packed, such as the Alexander
or overgrown specimens of the King and Spy. These may be
so large that only forty-five will go in a box. It is possible to
get a 3-tier apple with sixty-three in a box. In the same way,
a 4-tier apple usually contains ninety-six specimens, but it
may contain as high as 112.
If the apples of one layer are placed in the spaces be-
tween the apples of the one below, there would be, say, four
First and Third Layers.
Second and Fourth Layers.
FIG. 13-
-SHOWING DIAGONAL 2-2 PACK,
96 APPLES.
3% TIERS, 4 LAYERS,
layers of apples intermediate in size between those that would
fill the box in three layers or in four layers if packed directly
over each other or straight pack. Such intermediate size
would be styled a 3i^-tier size. Similarly, the intermediate
size between a straight 4-tier and a straight 5-tier would be
spoken of as a 4% -tier. From the smallest Fameuse that should
be packed, to the largest Kings or Alexanders, there are be-
APPLES
413
tween thirty-five and forty different sizes, each of which re-
quires a different style of pack. These different styles of pack-
ing are really only modifications of two general types. The
first is called the "Straight" pack, where every apple but those
in the first layer is directly over another. The second is called
the "Diagonal" pack, in which no apple is directly over any
other which it touches. Usually the apples in the alternate lay-
ers are directly over each other, but never in the contiguous
layers.
7
First and Third Layers.
FIG. 14-
Second and Fourth Layers.
-DIAGONAL 2-2 PACK, 3% TIERS, 4 LAYERS, 88 APPLES
Both straight and diagonal packs may be modified in a
number of ways. A modification of the diagonal pack in com-
mon use is called the "Offset." Place three apples touching
each other, but leaving a space about the width of half an apple
between one side of the box and the last apple. The next row
of three would be placed so as to leave the space on the oppo-
site side. A very useful diagonal pack is made by placing three
414
PRACTICAL COLD STORAGE
apples in the first row, one in each corner and one in the middle.
The second would then be made with two apples, the third
with three-, and so on, until the tier is completed. The second
layer would be commenced with two apples and alternated
with three, as in the first layer. The first and third and fifth
layers, and second and fourth would be the same, and directly
over each other. By commencing this pack with two apples,
instead of three, the box will contain two apples less. With
larger apples, the 2-2 pack is used. This is begun by placing
an apple in one corner of the box and then dividing the re-
maining space evenly with another apple. Into these spaces
Second and Fourth Layers.
FIG. 15— SHOWING A 3-2 PACK, 4% TIERS, 5 LAYERS, 188 APPLES.
IF LAYERS ARE REVERSED THERE WILL BE 187 APPLES.
are pressed two apples forming the next row. This is con-
tinued until the box is filled. Four layers will fill the box, the
first being directly over the third, and the second over the
fourth.
The art of packing can only be learned by packing. It
APPLES
415
requires a deft, hand and a trained eye, so that slight differences
may be recognized and utilized to fill the box and so tightly
packed that the box may be put on end with the lid off and yet
no apples fall out.
The accompanying illustrations will give a very good
idea of the method of packing apples in boxes and of the
appearance when packed.
Fig. 18 shows several different styles of pack. The up-
per left hand box has five rows, straight pack, for part of the
face layer, and' four for the remainder. This device is quite
unnecessary and seriously mars the look of the pack. The
PIG. 16— HOW TO START A 2-2
DIAGONAL, PACK.
FIG. 17— HOW TO START A 3-2
DIAGONAL, PACK.
middle box of the upper row is an "offset" pack, not desirable
if any other can be used. When opened on the side the spaces
are prominent. The upper right hand box is a 3j4-tier, 2-2
pack. The left hand box of the middle row is a slight modifica-
tion of the same pack for larger apples, there being only
eighty-eight instead of ninety-six in the box.
Fig. 19 shows four boxes of Alexanders. The upper right
hand box is a straight 3-tier, containing forty-five apples, but'
shows the defect of having one row smaller than the rest. The
416
PRACTICAL COLD STORAGE
right hand lo^Yer box is a 3-tier with sixty-three apples. The
left hand upper box is a 3-tier with fifty-seven, but defective
in grading. The lower left hand box is a very even pack, larger
than 3-tier, containing forty-one apples.
FIG. IS— SHOWING VARIOUS STYLES OP PACKING.
It will be noted that the left hand box has twenty apples
in each layer, while the next has eighteen.
APPLES
417
Fig. 20 shows how wrapped apples will accommodate them-
selves somewhat more easily than unwrapped to the different
styles of pack, owing to the elasticity of the paper covering.
FIG. 19— SHOWING DIFFERENT STYLES OP PACKING ALEXANDERS
PIG. 20 — SHOWING WRAPPED APPLES IN BOXES.
THE SWELL IN BOX PACKING.
Fig. 21 illustrates a very neat pack for a conical apple,
like certain types of Northern Spy and Ben Davis.
Eastern packers have been so long accustomed to the
barrel, a rigid package, that it is difficult for them to con-
ceive that the essential difference between box packing and
418
PRACTICAL COLD STORAGE
barrel packing lies in the fact that the box is an elastic pack-
age. The secret of rapid and good packing is largely in a
recognition of the elasticity of the top and bottom, and, to a
very slight extent, of the sides of the box. It is understood,
of course, that the box remains always the same dimensions,
but the apples to be packed are constantly varying in size, and
yet the experienced packer has no difficulty in securing an
arrangement of the tiers, so that after a certain number of
tiers are placed in the box, the box is properly filled without
the aid of any extraneous packing material, such as paper
shavings, excelsior or pulp pads.
Nevertheless, even the most skillful packer requires for
the best packing slight difference in the size and shape of the
FIG. 21— NEAT PACK FOR CONICAL APPLES.
individual apples, differences so slight that they would escape
the attention of all but the practiced eye. Small as the differ-
ences may be between the specimens of any particular pack-
age, this difference in size and shape is very important, and is
taken advantage of by the packer to secure the swell in the
center of the top and bottom.
This swell serves two purposes. It enables the packer to
find a place for the apples slightly larger or smaller than the
main run in one or both diameters. There is a careful grading
as to size by the eye, so that the smaller specimens are placed
at both ends on each tier and the slightly larger one toward
the center. This must be done by selecting the proper shaped
APPLES 419
fruit, because it is not desirable to break the plan of any par-
ticular tier; that is, if the packing is begun with the apple
stems down, it is desirable that the whole tier should be packed
stems down. In that case the flatter apples would be placed
near the ends of the box, while the apples that were equal in
transverse diameter, but not longer through the axis, would
be placed toward the middle. Where this is done consistently,
it will be found that when the box is packed ready for covering,
the apples at the ends of the box project half an inch or more
above the box, while at the middle they would rise about an
inch and a half above the sides of the box. This selection and
placing of the apples becomes, in the skillful packer, automatic,
and he scarcely feels that he is making the selection, so rapidly
is it done. Yet if a selection of this sort is not made, there is
no possibility of securing a box that will not go slack.
^TSNTILATION.
There are necessarily conflicting opinions among authori-
ties as to the best way to keep apples, and especially so as to
the kind of package, and whether the package should be
ventilated or not. Some seem to think that a package with a
free circulation of air is necessary, but the majority of experi-
enced fruit packers and fruit storers contend, and their con-
tention is backed by experience, that apples in common with
some other goods must be protected from the air of the storage
room. It has been demonstrated by long experience that a
package like the ordinary apple barrel, which, while being
tight, is really of porous wood, and allows just enough pene-
tration of air and escape of gas from the fruit, gives the best
results in cold storage. The fruit must not be tightly sealed, or
there will be an accumulation of gas and moisture, which will
very quickly rot the apples. Should anyone doubt this state-
ment, it would be very easy to make an experiment by putting
apples away in a tightly sealed tin package with a soldered
top, which will not allow penetration of air nor the escape of
gases and moisture from the interior. Place this receptacle
in cold storage for two months, and then cut it open and ex-
amine the interior. The necessity for ventilation will be at
420 PRACTICAL COLD STORAGE
once apparent. The exact quantity of ventilation is, of course,
impossible to determine accurately, but as before stated, the or-
dinary apple barrel thoroughly dry before placing in storage,
allows just about the right ventilation. It is common practice
among growers who have their own storage facilities at the
orchard, to store apples in barrels without heading up the
barrels. They are placed on end with the top uncovered. This
is permissible only for a few weeks at most and even for that
short period the open end should be protected by paper or by
the cover laid on loose.
The necessity for ventilation has been thoroughly dem-
onstrated by Professor Fred W. Morse, of the New Hampshire
Experiment Station in a bulletin which he is pleased to call
"The Respiration of Apples and Its Eelation to Their Keep-
ing Quality." "We extract below some of the main points
demonstrated :
RESPIRATION OF FRUITS.
"The respiration of animals is a well known action and
the necessity for it in the living creature is fully appreciated.
The fact that plants and parts of plants must also breathe is
not so commonly understood. Yet all living cells, whether a
part of animal matter or vegetable matter, must have oxygen
to keep them alive and they give up carbon dioxide and water
as a result of the action of the oxygen on some of their
contents. Parts of plants when cut off from the main stem
do not die at once, and must continue to breathe. This is
true, whether the severed part is a leafy branch, a fruit or a
root; but some parts live much longer after removal than
others, and the apple continues to breathe for many weeks
after it has been picked from the tree.
Respiration, whether in animals or in plants, causes a
destruction of matter in the cells much like the destruction
of wood in a stove, and the rate at which this destruction goes
on can be measured by determining the amount of carbonic
acid that is breathed out in a given length of time.
In animals, under usual conditions, the food which they
eat makes good the losses produced by respiration. An animal,
APPLES 421
however, may live without food for some time, during which
period it still breathes in oxygen and breathes out carbonic
acid and water, but it steadily loses weight and grows thin in
flesh because there is a steady destruction of cell material with
no food to replace it.
Fruit, after having been picked from the tree, is in the
condition of the starving animal. Its cells still keep up respira-
tion with nothing in the way of food to make good the losses
produced by the action. Since apples and other fruits have
no body heat to maintain, the breathing process is not so active
as in animals, and they may last months after being picked
from the tree. Yet there is a steady, continuous loss in
weight as the weeks go by, although the fruit is sound and
firm.
For example, fruit put in cold storage Nov. 13 and
weighed at intervals of two months had lost as follows :
January 2, 0.33 per cent. March 5, 2.34 per cent.
May 6, 3.60 per cent. July 1, 4.71 per cent.
That the shrinkage in weight is due to respiration and
not to simple drying out of the water is shown by the practic-
ally constant percentages of water and dry matter, since if
the solid material was not destroyed it should gradually in-
crease in proportion while the water would decrease. Results
proving this point are here given.
A lot of Baldwin apples were set aside in October and a
few of them analyzed at intervals.
October 24, water, 85.45
October 31, water, 85.41
November 21, water, 85.23
November 29, water, 85.02
iJecember 27, water, 85.5B
April 20, water, 86.19
dry matter, 14.55.
dry matter, 14.59.
dry matter, 14.77.
dry matter, 14.98.
dry matter, 14.44.
dry matter, 13.81.
Respiration is partly a chemical reaction and in apples,
like most chemical reactions in the laboratory, it grows more
rapid as the fruit becomes warmer, and is slowed down when
the fruit is cooled. If two sets of experiments were carried out
as described in a previous paragraph, one set in a refrigerator,
and the other in a warm room, it would be easily seen at the
end of four or five days that the warm room had caused the
larger amount of respiration. Since no exact figures had been
422 PRACTICAL COLD STORAGK
obtained showing just how rapidly an apple was changed in
composition when stored at an ice cold temperature compared
with another apple at 45 degrees and another at summer tem-
perature, it seemed possible to measure the rate by determining
the amount of carbonic acid given off by the fruit at different
temperatures. The carbonic acid would not show the kind of
changes taking place within the cells of the apple; but it
would be a measure of the rate at which those changes were
progressing since the formation of the carbonic acid must be
one of the reactions concerned in them.
It was seen on comparing the average rates of exhalation
of carbonic acid at the different temperatures, that in passing
from melting ice (32°) to cellar temperatures (45° to 50°)
the rate nearly triples, and in passing from the medium tem-
perature to summer temperatures the rate doubles.
Since the breathing out of carbonic acid is an indication
of the rate of chemical change within the fruit, it follows that
changes of composition must take place from four to six times
as fast at summer temperatures as in cold storage and from
two to three times as fast in cool cellars as in cold storage.
These increases in rate are in agreement with the laws
of chemical action, as the speed of such reaction is found to
double and sometimes to triple when the temperature is raised
18 degrees Fahrenheit (10 degrees Centigrade).
There is a practical application of this law to be made to
the care of fruit, especially at apple picking time.
It is frequently the case that warm days with temperatures
of 70 degrees occur in October and sometimes continue for a
considerable period. Fancy apples intended for long keep-
ing in cold storage should be cooled as soon as possible and
kept cold. The breathing process is at the expense of cell
contents and must weaken the keeping qualities as it goes on.
And this destructive action is from four to six times as fast
out of cold storage as inside it.
Another fact in connection with the respiration is im-
portant. It is not stopped in cold storage, but simply slowed.
Apples cannot be kept indefinitely but keep about twice as
long in cold storage as in a cool cellar.
APPLES 423
author's suggestions in CONNECTION" WITH APPLE STORAGE.
In conclusion the author wishes to offer suggestions and
an outline of information in connection with picking of fruit
at the correct maturity; the proper packing of the fruit in
suitable packages ; and sundry suggestions with reference to the
handling of fruit before placing in storage, while in storage,
and when removed therefrom. Hints as to suitable systems
of refrigeration and illustrations of a practical nature will also
prove of service to those who are interested in operating cold
storage houses.
As a general statement, apples for cold storage should be
carefully selected or graded. At the same time it is possible
to store them for short periods of one to three months without
the necessity for careful grading. This is desirable and neces-
sary sometimes to tide over a temporary surplus of fruit at
picking time. It is also common practice with some fruit
growers, who have their own cold storage, to put the apples
in barrels as picked, hurry them into cold storage, and then
take their time about grading, and this work is done without
removing them from the cold storage room. The great ad-
vantage of this method is the ability to pick the apples very
rapidly, and thus save time during the picking period, which
is an extremely "rushed" time with apple growers. It also
enables the growers to pick the apples at the proper stage of
maturity, which is most important. As has been stated else-
where, if apples are placed in barrels without being headed
the open ends of the barrels should be protected in some way,
if no more than with ordinary building paper. This protects
the apples from a drying out or evaporation, which is fully
discussed elsewhere in this chapter.
To develop flavor to the greatest extent possible it is neces-
sary that apples be picked on a dry day, and when the sun is
shining brightly, and after the dew has disappeared in the
morning. Sun on the apples is beneficial while they are hanging
on the trees, but after they are picked they should not again be
exposed to direct sunshine. The common practice of putting
apples in piles in the orchard causes a vast damage each year,
which is far greater than is supposed. If apples are picked and
424 PRACTICAL COLD STORAGE
placed in cold storage the same day, they will ripen slowly
and come out of storage at the proper period in much better
condition for use than they were when picked from the trees
in the fall. They will be better because they have slowly rip-
ened, and the flavor has been retained and developed to its
niUest extent.
Whether it is most desirable to grade in the orchard as
many do, or store the apples without grading as above suggested,
can only be determined by the individual grower, but if the
crop is of considerable magnitude it is suggested that with the
cold storage house in close proximity to the orchard, the prompt
storage without taking the time to grade and pack carefully,
is doubtless the best and most practicable method commercially.
Of course, if the apples are graded at the time they are picked,
the work is completed once for all, but on the other hand, the
apples after remaining for several months in cold storage al-
ways show some defective ones, and it is necessary to rehandle
and repack in many cases. It would seem, therefore, that
quick and rapid work at picking time, and a leisurely and
careful grading prior to shipment and while still in cold stor-
age, would be a most desirable method. It is, of course, not
suggested that apples should be handled and graded after they
have been long in cold storage, but if the grading is done within
two or three months from the time the apples are stored, the
better keeping or winter varieties can be handled without any
damage. The softer or short keeping varieties cannot, of course,
be handled in this way to the same advantage, and in fact, the
softer cannot be stored for long periods under any circum-
stances.
CHAPTER XVIII.
PEARS AND PEACHES.*
INFLUENCE OF COLD STOKAGE ON THE PEAK INDUSTRY.
Before the advent of the cold storage business the supply
of summer pears frequently exceeded the demand. This con-
dition of the markets, which were demoralized in hot, humid
seasons, pertained especially to the early varieties, like the
Bartlett, which ripen in hot weather and need to be sold in a
short time to prevent heavy losses from rapid decay. The in-
troduction of the refrigerator car and of the cold storage ware-
house, together with the rapid growth of the canning industry,
has done much to improve the pear situation by artificially
establishing a well regulated and more uniform supply of
fruit throughout a longer period of time. The pear acreage
of the country has more than doubled within a decade, and is
enlarging the relative importance of cold storage to the pear-
growing business, though a large part of the increase especially
in California, along the Atlantic coast from New Jersey south-
ward, in Texas, and in the central west, is primarily related to
the canning industry.
Pear storage has developed most largely in the east. In
New York and Jersey City from 60,000 to 100,000 bushels of
summer pears, 30,000 to 60,000 bushels of later varieties, and
many cars of California pears are stored amiually. In Boston,
since 1895 there have been stored each year from 5,000' to
15,000 bushels of early pears, principally Bartlett, and from
7,000 to 20,000 bushels of later varieties, such as Anjou, Bosc,
Angouleme (Duchess), Seckel and Sheldon. In Buffalo
•Extracts from Bulletin No. 40, Bureau of Plant Industry, United
States Department of Agriculture, by G. Harold Powell, Assistant Pom-
ologrlst in charge of Field Investigations, and S. H. Fulton, Assistant in
Pomology.
425
426 PRACTICAL COLD STORAGE
10,000 bushels are sometimes stored in a single season, and in
Philadelphia from 30,000 to 35,000 bushels. While there are
no accurate statistics available and the quantity fluctuates from
year to year, it is probable that as many as 300,000 bushels
are stored in a single year throughout the country at large.
There are many practical difficulties in pear storage. The
early-ripening varieties which mature in hot weather, like the
Bartlett, often "slump" before they reach the storage house, or
are in soft condition, especially if they have been delayed in
ordinary freight cars in transit. They may afterwards decay
badly in storage, break down quickly on removal, or lose their
delicate flavor and aroma. When stored in a large package
like the barrel, the fmit, especially of the early varieties, often
softens in the center of the package, while the outside layers
remain firm and green. Frequently no two shipments from
the same orchard act alike, even when stored in adjoining pack-
ages in the same room, and the warehouseman and the owner,
not always knowing the history of the fruit, are at a loss to
understand the difficulty. It has been the aim in the fruit-
storage investigations of the Department of Agriculture to
determine as far as possible the reasons for some of these stor-
age troubles, and to point out the relation of the results to a
more rational storage business.
OUTLINE OP EXPERIMENTS IN PEAR STORAGE.
The investigations in pear storage were of a preliminary
nature only. The experiments undertaken have been planned
with a view to determining the influence in the storage room
of various temperatures, of the character of the storage package,
of a fruit wrapper, of the degree of maturity of the fruit when
picked, and of other factors in relation to the ripening processes
in the storage house, and also to ascertain the behavior of the
fruit and its value to the consumer when placed on the market.
The Bartlett and Kieffer pears principally were used in
the experiments, but several other kinds were under limited
observation. The Bartlett represents the delicate-fleshed, tender
pears, ripening in hot weather, which are withdrawn from
storage before the weather becomes cool. The Kieffer, on the
PEARS AND PEACHES 427
other hand, is a coarse, hard pear, ripening later in the fall in
cooler weather, and in which the normal ripening processes are
slower. It is a longer keeper, and like other fall varieties is
withdrawn in cool weather.
The Bartlett experiments extended through the season of
1902. The fruit was grown by Mr. F. L. Bradley, Barker,
N. Y., in a twelve-year-old orchard on a sandy loam, with a
clay subsoil. The orchard is a half mile from Lake Ontario
and is 50 feet above the level of the lake. The fruit, which
was full grown, but green, was picked early in September, and
was packed in tight and ventilated barrels, in 40-pound closed
boxes, and in slat bushel crates. Part of the fruit in each lot
was wrapped in unprinted news paper, and an equal amount
was left unwrapped. Part was forwarded at once by trolley line
to the warehouse of the Buffalo Cold Storage Company at
Buffalo, N. Y., nnd a similar quantity was held four days
before being stored. The fruit reached the storage house
within ten hours after leaving the orchard.*
The Kieffer experiments have extended over two years. In
1901 the fruit was grown by Mr. M. B. Waite, Woodwardsville,
Md., in a Norfolk sandy soil, on rapidly growing five-year-old
trees, from which the fruit was large, coarse, and of poor qual-
ity. It was stored in the cold storage department of the Center
Market at Washington, D. C. In 1902 the fruit with which
the experiments were made was grown by Mr. S. H. Derby,
"Woodside, Del., on heavy-bearing ten-year-old trees on sandy
soil with a clay subsoil. The fruit was smaller, of finer tex-
ture, and of somewhat better quality than that used the previ-
ous year. It was stored in the cold storage department of the
Reading Terminal Market in Philadelphia, Pa.
The Kieffers were picked at three degrees of maturity:
First, when two thirds grown, or before the fruit is usually
picked; second, ten days later, or about the time that Kieffers
are commonly picked, and third, ten days later, when the fruit
was fully grown and still green, but showing a yellowish tinge
around the calyx. In each picking, part of the fruit was
•BarUett pears should be picked when the seeds begin to turn brown.
This is a sure sign of proper maturity and may be relied upon. — Author.
428 PRACTICAL COLD STORAGE
shipped to storage and was placed in rooms with a temperature
of 36° and 32° F. within forty-eight hours. Equal quantities
stored in each temperature were wrapped in parchment paper,
in unprinted news paper, and were left unwrapped. A dupli-
cate lot of fruit remained in a common storage house ten days
in open boxes, when it was packed in a similar manner and
sent to storage. This fruit colored considerably during the
interval, but was still hard and apparently in good physical
condition on entering the storage house. The pears were stored
in 40-pound closed boxes and in five-eighths bushel peach
baskets. One hundred and fifty bushels were used in the
experiments.
INFLUENCE OF THE DEGREE OF MATURITY ON KEEPING QUALITY.
The experiments with the Kieffer pear show that under
conditions similar to those in Delaware and eastern Maryland
this variety may safely be picked from the same orchard dur-
ing a period of at least three weeks, or when from two-thirds
grown to full size, and that the fruit in all cases may be stored
successfully until the holidays, or much longer if there is
still a demand for it. It is absolutely essential that the fruit
be handled with the greatest care, that it be sent at once to
storage after picking, that it be packed carefully to prevent
bruising (preferably in small packages, like a bushel box),
and that it be stored in a temperature not above 32° F. if it is
desired to hold it for any length of time. If stored by the
middle of October, the fruit, by the latter part of December,
will take on a rich, yellow color when kept in a temperature
of 32° F., and earlier if a higher temperature is used. The
fruit may be withdrawn during the holidays, and will stand
up, i. e., continue in good condition, for ten days or longer
if the weather is cool, and will retain its normal quality
if the rooms have been properly managed. While the later
picked fully grown pears keep well, they are already inferior in
quality at the picking time, as the flesh around the center is
filled with woody cells, making it of less value either for eating
in a fresh state or for culinary purposes. These coarse cells in
the Kieffer and some other late varieties do not develop in the
PEARS AND PEACHES 429
early picked fruit to so large an extent. Pears of all kinds need
to be picked before they reach maturity and to be ripened in
a cool temperature if the best texture and flavor are to be de-
veloped. It is a matter of practical judgment to determine the
proper picking season, but for cold storage or other purposes
the stem should at least cleave easily from the tree before the
fruit is ready to pick. Many trees bear fruit differing widely
in the degree of maturity at the same time, and in such cases
uniformity in the crop can be attained only when the orchard
is picked several times, the properly mature specimens being se-
lected in each successive picking. This practice not only se-
cures more uniformity in ripeness, but the fruit is more even
and the average size is larger than when all the pears are
picked at the same time.
INFLUENCE Of DELAYED STORAGE ON KEEPING QUALITY.
Pears ripen much more rapidly after they are picked than
they do in a similar temperature while hanging on the tree.
The rapidity of ripening varies with the character of the
variety, the maturity of the fruit when picked, the temperature
in which it is placed, and the conditions under which it has
been grown. If the fruit is left in the orchard in warm weather
in piles or in packages, if it is delayed in hot cars or on a
railroad siding in transit, or if it is put in packq,ges which retain
the heat for a long time, it continues to ripen and is consider-
ably nearer the end of its life history when it reaches the
storage house than would otherwise be the case. The influence
of delay in reaching the storage house will therefore vary with
the season, with the variety, and with the conditions surround-
ing the fruit at this time. A delay of a few days with a quick-
ripening Bartlett in sultry August weather might cause the
fruit to soften or even decay before it reached the storage house,
though a similar delay in clear, cooler weather would be less
hurtful. A delay of a like period in storing the slower ripen-
ing Kieffer would be less injurious in cool October weather,
though the Kieffer pear, especially from young, trees, can some-
times be ruined commercially by not storing it at once after
picking.
430
PRACTICAL COLD STORAGE
PIG. 1 — KIEFFBR PEARS IN MARCH — REDTTCED ONE-PIPTH.
PEARS AND PEACHES 431
From the experiments with the Bartlett and the Kieffer
pears, from which these general introductory remarks are de-
duced, it was found that the Bartlett, if properly packed, kept
in prime condition in cold storage for six weeks, provided it
was stored within forty-eight hours after picking in a tempera-
ture of 32° F. ; but that if the fruit did not reach the storage
room until four days after it was picked there was a loss of 20
to 30 per cent from softening and decay under exactly similar
storage conditions.*
The Kieffers stored within forty-eight hours in a tempera-
ture of 32° F. have kept in perfect condition until late winter,
although there is little commercial demand for them after the
Holidays. The fruit grown by Mr. Waite on young trees in
1901, which was still hard and greenish-yellow when stored
ten days after picking, began to discolor and soften at the core
in a few days after entering the storage room, though the out-
side of the pears appeared perfectly normal. After forty to
fifty days the flesh was nearly all discolored and softened, and
the skin had turned brown. The fruit from the older trees on
the Derby farm in 1902, which was smaller and finer in tex-
ture, appeared to ripen as much as the Waite pears during the
ten days' delay. This fruit, however, did not discolor at the
core and decay from the inside outward, but continued to ripen
and soften in the storage house and was injured at least 50
per cent in its commercial value by the delay. Fig. 1 shows
the condition of the Kieffer pears stored in a temperature of
32° F. as soon as picked and withdrawn in March. Under
these conditions the fruit kept well until late in the spring.
Fig. 2 shows the condition of fruit picked at the same time and
stored in the same temperature ten days after picking, when
withdrawn in January. The delay in storage caused the fruit
to decay from the core outward.
Fig. 3 shows the influence of immediate and delayed stor-
age on Maryland Kieffer pears. The fruit in the box at the
right represents the average condition of pears picked October
•Bartlett pears have been successfully stored, at the orchard where
grown, in a Cooper brine system plant for periods of from six to ten
weeks and even longer, and have been held for the Christmas trade. —
Author.
FIG. 2— KIBFFER PEARS IN JANUARY — REDUCED ONE-FIFTH.
PEARS AND PEACHES 433
21, stored October 22, and withdrawn March 3. Storage tem-
perature 32° F. The fruit was wrapped in parchment paper.
It was in prime commercial condition when withdrawn from
storage. The fruit in the box at the left represents the average
condition of pears picked from the same trees at the same time.
It was stored in the same temperature ten days later and with-
drawn March 3. All of the fruit had decayed.
The results of the experiments point out clearly the injury
that may occur by delaying the storage of the fruit after it is
picked, and emphasize the importance of a quick transfer from
the orchard to the storage house. If cars are not available for
transportation and the fruit can not be kept in a cool place, it is
safer on the trees so far as its ultimate keeping is concerned.
It is advisable to forward to storage the delicate quick-ripening
varieties, like the Bartlett, in refrigerator cars. The common
closed freight car in warm weather soon becomes a sweat box
and ripens the fruit with unusual rapidity. The results show
clearly that the storage house may be responsible in no way
for the entire deterioration or even for a large part of the
deterioration that may take place while the fruit is in storage,
and that the different behavior of two lots from the same
orchard may often be due to the conditions that exist during
the period that elapsed between the time of picking and of
storage.
INFLUENCE OF DIFFERENT TEMPEEATUEES ON KEEPING QUALITY.
There is no uniformity in practice in the temperatures in
which pears are stored. Formerly a temperature of 36° to 40°
F. was considered most desirable, as a lower temperature was
supposed to discolor the flesh and to injure the quality of the
fruit. The pears were also believed to deteriorate much more
rapidly when removed to a warmer air. In recent years a num-
ber of storage houses have carried the fruit at the standard apple
temperatures, i. e., from 30° to 32° F. Large quantities of
Bartlett, Angouleme, and Kieffer pears have been stored in
32° and 36° F. in the experiments of the Department. The
fruit of all varieties has kept longer in the lower temperature
and the flesh has retained its commercial qualities longer after
434
PRACTICAL COLD STORAGE
removal from the storage house. Bartlett pears were in prime
commercial condition four to five weeks longer, Angouleme two
months longer, and Kieffer three months longer in a tempera-
ture of 32° F. Figs. 1 and 5 show the condition of Kieffer
pears in March, 1902, in 32° and 36° F., the two lots having
received similar treatment in all respects except in storage
temperatures. The fruit held at 36° F. did not keep well after
December 1.
Fig. 4 also shows the influence of 36° and 32° F. storage
FIG. 3.— WRAPPED KIEFFER PEARS. REMOVED FROM STORAGE
(32° P.) MARCH 3.
temperature on the keeping of Kieffer pears. The fruit in both
packages was picked October 21, and stored October 22. The
package at the left represents the average condition of the fruit
when withdrawn March 3 from a temperature of 36° F. All
of the pears were soft and discolored, and some of them decayed.
The fruit in the package at the right, kept in a temperature of
32° F., with bright yellow, firm, and in prime commercial con-
dition.
In the higher temperature the fruit ripens more rapidly,
which may be an advantage when it is desirable to color the
PEARS AND PEACHES
435
fruit before it leaves storage; but the fruit in that condition is
nearer the end of its life history and breaks down more quickly
on removal to a warm atmosphere.
There is a much wider variation in the behavior of pears
that have been delayed in storage or that are overripe when they
enter the storage room at 32° and 36° F. than in pears stored
at once in these temperatures. In the higher temperature the
fruit that has been improperly handled ripens and deteriorates
more quickh'. The lower temperature not only keeias the fruit
longer when it is stored at once, but it is even more essential in
preventing rapid deterioration in fruit that has been improperly
handled.
FIG 4 — WRAPPED KIEFFER PEARS. REMOVED FROM STORAGE
(36° AND 32° F.) MARCH 3.
INFLUENCE OF THE TYPE OF PACKAGE ON THE KEEPING
QUALITY OF THE PEAK.
Pears are commercially stored in closed barrels, in ven-
tilated barrels, in tight boxes holding a bushel or less, and in
various kinds of ventilated crates. The character of the pack-
age exerts an important influence on the ripening of the
436 PRACTICAL COLD STORAGE
fruit and on its behavior in other respects, both before it enters
the storage house and after it is stored, though this fact is not
generally recognized by fruit handlers or by warehousemen.
The influence of the package on the ripening processes appears
to be related primarily to the ease with which the heat is radi-
ated from its contents. The greater the bulk of fruit within
a package and the more the air of the storage room is excluded
from it the longer the heat is retained. Quick-ripening fruits,
like the Bartlett pear, that enter the storage room in a hot
condition in large, closed packages, may continue to ripen
considerably before the fruit cools down, and the ripening
will be most pronounced in the center of the package, where
the heat is retained longest. The influence of the package,
therefore, will be most marked at the time during which the
fruit is exposed to the hottest weather and on those fruits that
ripen most quickly.
In the experiments of the Department of Agriculture the
Bartlett pears were stored in tight and in ventilated barrels, in
closed 40-pound boxes, and in slat bushel crates. After three
weeks in the storage house the fruit that was stored in barrels
soon after picking in a temperature of 32° F. was yellow in the
center of the package, while the outside layers were firm and
green. Fig. 6 shows the average condition of the fruit in
these two positions one week after storing. The upper speci-
men shows the condition of the fruit in center of a barrel. In
this position the fruit cools more slowly than that near the
staves or ends and it therefore ripens considerably before the
temperature is reduced. The lower specimen shows the condi-
tion of the pears at top and bottom and next to the staves
of the same barrel. In these positions the fruit cools quickly
and the ripening processes are retarded. For quick ripening
fruits that are handled in hot weather small packages are pref-
erable. After five weeks in storage the fruit in the center of
the barrel was soft and of no commercial value, while the out-
side layers were still in good condition. The difference was
still greater in a temperature of 36° F., and was more marked
in both temperatures in fruit that was delayed in reaching the
storage house.
PEARS AND PEACHES
437
FIG. 5-KIEFP"BR PEARS IN MARCH— REDUCED ONE-FIFTH.
438 PRACTICAL COLD STORAGE
In both the closed 40-pound boxes and the slat crates
the fruit was even greener in average condition than the
outside layers in the barrels, and it was uniformly firm through-
out the entire package.
There was apparently no difiference between the fruit in
the commercial ventilated pear barrel and the common tight
pear barrel.
"With the Kieffer, which enters the storage room in a
cooler condition and which ripens more slowly, a comparison
has been made (in 1902) between the closed 40-pound box and
the barrel, and while the difference has been less marked the
fruit has kept distinctly better in the smaller package. The
fruit in barrels was the property of Mr. M. B. Waite, and was
under observation by the Department through his courtesy.
There is a wide difference of opinion concerning the value
of ventilated in comparison with tight packages for storage pur-
poses. No dogmatic statements can be made that will not be
subject to many exceptions. The chief advantage of a ven-
tilated package for storage appears to lie in the greater rapidity
with which the fruit cools, and the quickness with which this
result is attained depends upon the temperature of the fruit,
its bulk, the temperature of the room, and the openness of the
package. The open-slat bushel crate, often used for storing
Bartlett pears, with which rapid cooling is of fundamental im-
portance, may be of much less value in storing later fruits that
are cooler and which ripen more slowly, and it may be of even
less importance in Bartletts in cool seasons.
The ordinary ventilated pear barrel does not appear to
have sufficient ventilation to cool the large bulk of fruit quickly.
The open package has several disadvantages. If the fruit
is to remain in storage for any length of time its exposure to
the air will be followed by wilting, which, in fruits held until
late winter or spring, may cause serious commercial injury.
The ventilated package, especially if made of slats, needs to
be handled with the utmost care to prevent the discoloration of
the fruit due to bruising where it comes in contact with the
edges of the slats.
PIG 6 BARTLETT PEARS AFTER ONE WEEK IN STORAGB-
REDUCED ONE-FIFTH.
440
PRACTICAL COLD STORAGE
There was little difference in the behavior of the BartlcUs
in the closed 40-pound boxes and the slat crates at the end of
five weeks, and it would appear that a package of this size,
even though closed, radiates the heat with sufRcient rapidity
to quickly check the ripening. Therefore the grower who uses
the 40-pound or the bushel pear box for commercial purposes
can store the fruit safely in this package, but if the barrel is
used as the selling package, and the weather is hot, it is a
better plan to store the fruit in smaller packages, from which it
may be repacked in barrels at the end of the storage season.
While this practice is followed in several storage houses, it is
FIG.
-kie:ffer pears from cold storage on .January 20,
unwrapped.
not to be encouraged, as the rehandling of the fruit is a dis-
advantage. Rather the use of the pear box should be encour-
aged as a more desirable package, both for storage and for
commercial purposes.
The fruit package question, as it relates to the storage
house, may be summed up by stating that fruits like the
Bartlett pear and others that ripen quickly and in hot weather
may be expected 10 give best results when stored in small pack-
PEARS AND PEACHES
441
ages. If the storage season does not extend beyond early win-
ter, an open package may be of additional value, though not
necessary if the package is small. But fruits like the winter
apples and late pears, which ripen in the fall in cool weather
FIG. 8 — KIEPFBR PEARS PROM COLD STORAGE ON JANUARY 20.
and remain in storage for a long period, should be stored
in closed packages to prevent wilting. In such cases the dis-
advantages of a large package, like a barrel, are not likely to be
serious.
442 PRACTICAL COLD STORAGE
INFLUENCE OF A WEAPPER ON KEEPING QUALITY.
The life of a fruit in cold storage is prolonged by the use
of a fruit wrapper, and the advantage of the wrapper is more
marked as the season progresses. In Figs. 7 and 8 are shown
the average quantity of sound specimens of Kieffer pears in
unprinted news paper and in parchment wrappers in compari-
son with the quantity of commercial unwrapped pears in boxes
in January, the fruit having been picked October 21 and
placed in storage on the following day in a temperature of
32° F. Nearly 50 per cent of the unwrapped fruit (see Fig.
7) had decayed at that time, while that in unprinted news-
paper and in parchment wrappers (see Fig. 8) kept in perfect
condition. Early in the season the influence of the wrapper
is not so important, but if the fruit is to be stored until late
spring the wrapper keeps the fruit firmer and brighter. It
prevents the spread of fungus spores from one fruit to another
and thereby reduces the amount of decay. It checks the ac-
cumulation of mold on the stem and calyx in long-term storage
fruits, and in light colored fruits it prevents bruising and the
discoloration that usually follows.
Careful comparisons were made of the efiiciency of tissue,
parchment, unprinted news paper, and waxed papers, and but
little practical difference was observed, except that a large
amount of mold had developed on the parchment wrappers in
a temperature of 36° F. A double wrapper proved more
efficient for long keeping than a single one, and a satisfactory
combination consists of an absorbent, unprinted news paper
next to the fruit, with a more impervious paraffin wrapper out-
side.
The chief advantage of the wrapper for the Bartlett pear,
which is usually stored for a short time only, lies in the
mechanical protection to the fruit rather thap in its efficiency
in prolonging its season. Its use for this purpose is advisable
if the fruit is of superior grade and designed for a first-class
trade. For the late varieties the wrapper presents the same
advantages, and has an additional value in increasing the
commercial life of the fruit. It is especially efficient, if the
package is not tight, in lessening the wilting.
PEARS AND PEACHES 443
INFLUENCE OF COLD STORAGE ON THE FLAVOR AND AROMA OF
THE FRUIT.
There is a general impression that cold storage injures the
delicate aroma and characteristic flavors of fruits. In this
publication the most general statements only can be made con-
cerning itj as the subject is of a most complicated nature, not
well understood, and involving a consideration of the biological
and chemical processes within the fruit and of their relation
to the changes in or to the development of the aromatic oils,
ethers, acids, or other products which give the fruit its in-
dividuality of flavor.
It is not true that all cold storage fruits are poor in qualitj'.
On the contrary, if the storage house is properly managed the
most delicate aromas and flavors of many fruits are developed
and retained for a long time. The quality of the late fall and
winter apples ripened in the cold storage house is equal to that
of the same varieties ripened out of storage, and the late pears
usually surpass in quality the same varieties ripened in com-
mon storage.
The summer fruits, like the peach, the Bartlett pear, and
the early apples, lose their quality very easily, and in an im-
properly managed storage house may have their flavors wholly
destroyed. Even in a room in which the air is kept pure the
flavor of the peach seems to be lost after two weeks or more,
while the fruit it still firm, much as the violet and some other
flowers exhale most of their aromatic properties before they
begin to wilt.
It is probable that much of the loss in quality may be at-
tributed to overmaturity, brought about by holding the fruit
in storage beyond its maximum time ; but it should be remem-
bered that the same change takes place in fruits that are not
ripened in cold storage, the aroma and fine flavor often disap-
pearing before the fruit begins to deteriorate materially in tex-
ture or appearance.
On the other hand, it is certain that the quality of stored
fruits may be injuriously affected by improper handling or by
the faulty management of the storage rooms. Respiration goes
444 PRACTICAL COLD STORAGE
on rapidly when the fruit is warm. If placed in an improperly
ventilated storage room, in which odors are arising from other
products stored in the same compartment or in the same cycle
of refrigeration, the warm fruit may absorb these gases and
become tainted by them, while the same fruit, if cool when it
enters the storage room, will breathe much less actively, and
there will be less danger of injury to the quality, even though
the air is not perfectly sweet. The atmosphere of the rooms, in
which citrus fruits or vegetables of various kinds — such as cab-
bage, onions, and celery — are stored, is often charged with the
odors arising from these products, if the ventilation is not thor-
ough. In small houses, in which a single room cannot be used
for each product, fruits are often stored together during the
summer months, and at this period the storage air is in greater
danger of vitiatioji, since it is more difficult to provide proper
ventilation.
The summer fruits, therefore, being generally hot when
placed in the storage room, are in condition to absorb the odors
which are likely to affect the rooms during the warm season, and
as the biological and chemical processes are normally more
active in the case of such fruit than in fruits maturing later, the
flavors deteriorate more quickly, even in well-ventilated rooms.
The fruits that are picked in cool weather and enter the storage
rooms in a cooler and less active condition are not in the same
danger of contamination.
From the practical standpoint it may be pointed out that
summer fruits should be stored in rooms in which the air is
sweet and pure. They should not be stored with products which
exhale strong aromas, and the danger of contamination is less-
ened if the fruit can be cooled down in a pure room before it is
placed with other products in the permanent compartment pro-
vided for it. For the same reason the winter fruits should be
stored in rooms in which the air is kept pure, and preferably in
compartments assigned to a single fruit.
The experiment furnished no evidence that the quality de-
teriorates more rapidly as the temperature is lowered. On the
contrary, all of the experience so far indicates that the delicate
flavors of the pear, apple, and peach are retained longer in a
PEARS AND PEACHES 445
temperature that approaches the freezing point than in any
higher temperature.
BEHAVIOR or THE FRUIT WHEN REMOVED PROM STORAGE.
There is a general impression that cold storage fruit de-
teriorates quickly after removal from the warehouse. This
opinion is based on the experience of the fruit handler and the
consumer, and in many cases is well founded, but this rule is not
applicable to all fruits in all seasons. The rapidity of deteriora-
tion depends principally on the nature of the fruit, on its degree
of maturity when it leaves the warehouse, and on the temper-
ature into which it is taken. A Bartlett pear, which normally
ripens quickly, will ripen and break down in a few days after
removal. If ripe or overmature when removed, it will decay
much more quickly, and in either condition its deterioration
win be hastened if the weather is unusually hot and humid. In
the practical management of this variety it is fundamentally
important that it be taken from storage while it is still firm
and that it be kept as cool as possible after withdrawal. It is
probably true that all fruits from storage that are handled in
hot weather will deteriorate quickly, but it appears to be equally
true that similar fruits that have not been in storage break
down with nearly the same rapidity, if they are equally ripe.
The late pears, which ripen more slowly, if withdrawn in cool
weather will remain firm for weeks when held in a cool room
after withdrawal. If overripe they break down much sooner,
and a hot room hastens decay in either case. The same princi-
ples hold equally true with apples. The winter varieties, if
firm, may be taken to a cool room and will remain in good con-
dition for weeks and often for months and will at the same
time retain their most delicate and palatable qualities, but in
the spring, when the fruit is more mature and the weather
warmer, they naturally break down very much more rapidly.
In commercial practice fruits of all kinds are often left in
the storage house until they are overripe. The dealer holds
the fruit for a rise in price, but sometimes removes it, not
because the price is satisfactory, but because a longer storage
would result in serious deterioration. If considerable of the
446 PRACTICAL COLD STORAGE
fruit is decayed when withdrawn, the evidence is conclusive that
it has been stored too long. Fruit in this condition normally
decays in a short time, but the root of the trouble lies not in
the storage treatment, but rather in not having offered it for
sale while it was still firm. In the purchase of cold storage fruit,
if the consumer will exercise good judgment in the selection
of sound stock that is neither fully mature nor overripe, he will
have little cause to complain of its rapid deterioration.
SUMMAEY.
A cold storage warehouse is expected to furnish a uniform
temperature in all parts of the storage compartments through-
out the season, and to be managed in other respects so that an
unusual loss in the quality, color, or texture of the fruit may
not reasonably be attributed to improper handling or neglect.
An unusual loss in storage fruit may be caused by improper
maturity, by delaying the storage after picking, by storing in an
improper temperature, or by the use of an unsuitable package.
The keeping quality is influenced by the various conditions in
which the fruit is grown.
Pears should be picked before they are mature, either for
storage or for other purposes. The fruit should attain nearly
full size, and the stem should cleave easily from the tree when
picked.
The fruit should be stored at the earliest possible time after
picking. A delay in storage may cause the fruit to ripen or to
decay in the storage house. The effect of the delay is most
serious in hot weather and with varieties that ripen quickly.
(See Figs. 1, 2 and 3.)
The fruit should be stored in a temperature of about 32°
F., unless the dealer desires to ripen the fruit slowly in storage,
when a temperature of 36° or 40° F., or even higher, may be ad-
visable. The fruit keeps longest and retains its color a^d flavor
better in the low temperature. It also stands up longer when
removed.* (See Figs. 2, 4 and 5.)
The fruit should be stored in a package from which the
heat will be quickly radiated. This is especially necessary in
•30°P. Is even better for pears If the fruit Is In prime condition when
stored, and It Is desired to hold It to the extreme limit of Its life. — ^Author.
PEARS AND PEACHES 447
hot weather and with quick-ripening varieties like the Bartlett
pear. For the late pears that are harvested and stored in cool
weather it is not so important. Bartletts may ripen in the center
of a barrel before the fruit is cooled down. A box holding not
more than 50 pounds is a desirable storage package, and it is not
necessary to have it ventilated. The chief value of a ventilated
package lies in the rapidity with which the contents are cooled,
but long exposure to the air of the storage room causes the fruit
to wilt. (See Fig. 6.)
Ventilation is essential for large packages, especially if the
fruit is hot when stored and ripens quickly.
A wrapper prolongs the life of the fruit. It protects it
from bruising, lessens the wilting and decay, and keeps it bright
in color. A double wrapper is more efficient than a single one,
and a good combination consists of absorptive unprinted news
paper next to the fruit, with a more impervious paraffin wrap-
per outside. (See Figs. 7 and 8.)
The quality of a pear normally deteriorates as it passes
maturity, whether the fruit is in storage or not, or it is never
fully developed if the fruit is ripened on the tree. The quality
of the quick-ripening summer varieties deteriorates more rap-
idly than that of the later kinds. Much of the loss in quality in
the storage of pears may be attributed to their overripeness.
The quality is also injured by impure air in the storage rooms,
and the warm summer pears will absorb more of the odors than
the late winter varieties. The fruit will absorb less if cool when
it enters the storage room. The air of the storage room should
be kept sweet by proper ventilation.*
The rapidity with which the fruit breaks down after re-
moval depends on the nature of the variety, the degree of ma-
turity when withdrawn, and the temperature into which it is
taken. Summer varieties break down normally more quickly
than later kinds. The more mature the fruit when withdrawn
the quicker deterioration begins, and a high temperature hast-
ens deterioration. If taken from the storage house in a firm
condition to a cool temperature, the fruit will stand up as long
•See chaptfer on Ventilation for suitable means of supplying fresh air
and forcing out the accumulating gases arising from pears when in cold
storage.
448 PRACTICAL COLD STORAGE
as other pears in a similar degree of maturity that have not been
in storage.
It pays to store the best grades of fruit only. Fruit that is
imperfect or bruised, or that has been handled badly in any
respect, does not keep well.
INFLUENCE OF COLD STORAGE ON THE PEACH INDUSTRY.
Cold storage has not materially influenced the develop-
ment of the American peach business, and it is not likely to do
so to any extent in the future. In the early days of peach
growing the industry was localized in sections like the Chesa-
peake peninsula. New Jersey, and Michigan. The use of the
fruit in considerable quantities was then limited to a few nearby
markets and to a short time in July, August and September.
Now peach growing is rapidly extending to all parts of the
country where the climatic conditions and the facilities for
transportation are favorable. The refrigerator-car service has
brought the peach belts and the distant markets close together,
and whenever the crop is general the New York or the Chicago
trade may be supplied almost continuously from May till late
October with fruit from Florida, Texas, Georgia, the Chesa-
peake peninsula. New Jersey, the Ozark mountain region,
Michigan, New England, California, West Virginia, western
Maryland, and other peach-growing sections.
The chief value of cold storage to the peach industry will
probably lie in the temporary storage of the fruit during an
overstocked market, when, however, there is a reasonable pros-
pect of a better market within two or three weeks. It might be
useful also in filling the gaps between the crops of different
regions, especially when there are local failures which prevent a
continuous supply. It is not now profitable to store the fruit for
nny length of time, nor under any circumstances unless the
(onditions of the fruit and the storage conditions are most
f avorable. The life processes in the peach and the weather con-
d'itions in which it is handled make it even more critical as a
storage product than the delicate Bartlett pear. In normal
ri pening it passes from maturity to decay in a few hours in hot,
humid weather. The aroma and flavor are most delicate in
PEARS AND PEACHES
449
character and are easily injured or lost, and the influence of
any mismanagement of the fruit in the orchard, in transit, or
in the storage house is quickly detected by the consumer.
PRACTICAL DIFFICULTIES IN PEACH STORAGE.
Under the most favorable conditions known at present,
peach storage is a hazardous business. Before the fruit is taken
from the storage house the flesh often turns brown in color,
while the skin remains bright and normal. If the flesh is
PIG. 9.— PEACHES IN COLD STORAGE ROOM.
natural in color and texture it frequently discolors within a
day or two after removal. There is a rapid deterioration in the
quality of stored peaches when the fruit is held for any length
of time, the delicate aroma and flavor giving way to an insipid
or even bitter taste. Sometimes the flesh dries out, or under
other conditions it may become "pasty." Dealers in storage
peaches frequently sell them in a bright, firm condition, and
shortly afterwards the purchasers complain of the dark and
worthless quality of the flesh. It has often been noticed that
fruit in the various packages in the same room does not keep
450 PRACTICAL COLD STORAGE
equally well, some of it ripening and even softening while the
fruit in other packages is still firm. In fact, the difficulties are
so numerous that few houses attempt to store the fruit.
It has been the aim in the cold storage investigations of
the Department of Agriculture to determine, as far as possible,
the cause of the peach-storage troubles and to indicate the con-
ditions under which the business may be more successfully
developed.
OUTLINE OF EXPERIMENTS IN PEACH STORAGE.
The investigations were conducted in the cold-storage de-
partment of the Reading Terminal Market in Philadelphia, Pa.,
with Elberta peaches from the Hale Orchard Company, Fort
Valley, Ga., and in the warehouse of the Hartford Cold Storage
Company, Hartford, Conn., with Elberta and several ■ other
varieties grown by J. H. Hale at South Glastonbury, Conn.
In Georgia the fruit was packed in the Georgia peach car-
riers, left unwrapped, and divided into two lots, one represent-
ing fruit that was nearly full grown, well colored, and hard;
the other, highly colored fruit, closely approaching but not yet
mellow. Three duplicate shipments were forwarded at different
times in the two bottom layers of refrigerator cars, and in
each shipment part of the fruit was placed in the car within
three or four hours after it was picked, and an equal quantity
delayed in a packing shed for ten to fifteen hours during the
day before it was loaded. Equal quantities of each series were
stored in temperatures of 32°, 36°, and 40° F. The transfer
from the refrigerator car to the storage house was made by
wagon at night, the interval between the car and storage vary-
ing from two to five hours.
In Connecticut the fruit represented two degrees of matu-
rity, similar to the Georgia shipments, except that the most ma-
ture fruit was mellow when stored. This fruit was grown at
an elevation of 450 feet on trees six years old. It was medium
in size, firm, highly colored, and of excellent shipping quality.
Equal quantities were wrapped in California fruit paper and
left unwrapped, and packed in the Connecticut half-bushel bas-
ket, in Georgia carriers, and in flat, 20-pound boxes, holding
PEARS AND PEACHES 451
two layers of fruit. The peaches were forwarded by trolley to
the storage house, which was reached in two hours after the
fruit left the packing shed. Duplicate lots of all the series were
stored in temperatures of 32°, 36°, and 40° F.
GENERAL STATEMENT OF RESULTS.
The general outcome of the experiments, both with the
Georgia and the Connecticut fruit, is similar and may be
summed up as follows :
The fruit that was highly colored and firm when it entered
the storage house kept in prime commercial condition for two
to three weeks in a temperature of 32° F. The quality was
retained and the fruit stood up two or three days after removal
from the storage house, the length of its durability depending
on the condition of the weather when it was removed. After
three weeks in storage the quality of the fruit deteriorated,
though the peaches continued firm and bright in appearance for
a month and retained the normal color of the flesh two or three
days after removal. If the fruit was mellow when it entered
the storage house it deteriorated more quickly, both while in
storage and after withdrawal. If unripe it shriveled consider-
ably.
In a temperature of 40° F. the ripening processes pro-
gressed rapidly, and the flesh began to turn brown in color
after a week or ten days in storage. The fruit also deteriorated
much more quickly after removal, as it was already nearer the
end of its life history. It began to lose in quality at the end of a
week.
In a temperature of 36° F. the fruit ripened more rapidly
than in 32°, and more slowly than in 40° F. It reached its
profitable commercial limit in ten days to two weeks, when
the quality began to deteriorate, and after this period the flesh
began to discolor.
Fig. 10 shows average condition of Georgia Elberta peaches
two weeks in storage after forty-eight hours withdrawal to a
warm room. The upper specimen represents the average condi-
tion of fruit stored in a temperature of 36° F. The lower speci-
men represents the average condition of the fruit stored in
452
PRACTICAL COLD STORAGE
32° F. The lower temperature gave better results in every
respect.
The fruit kept well in all of the packages in a temperature
of 32° F. for about two weeks, after which that in the open bas-
PIG. 10— ELBERTA PEACHES, STORED FOR TWO WEEKS AT 36° F.
AND 32° F.
PEARS AND PEACHES 453
kets and in the Georgia carriers began to show wilting. In the
20-pound boxes, in which the circulation of air is restricted,
the fruit remained firm throughout the storage season.
It is necessary that the fruit be packed firmly to prevent
bruising, in transit, but if the peaches pressed against each
other unduly it was found that the compressed parts of the flesh
discolored after a week in storage. A wrapper proved a great
protection against this trouble, especially in the baskets of the
Georgia peach carrier, and in all of the packages the wrapped
fruit retained its firmness and brightness for a longer time than
that left without wrappers.
The fruit should be removed from storage while it is still
firm and bright. The peach normally deteriorates quickly after
it reaches maturity, and the rapidity of deterioration is influ-
enced by the nature of the variety, by the degree of ripeness
when removed, and by the temperature into which it is taken.
A quick ripening sort, like Champion, is more active biolog-
ically and chemically than the Elberta variety, and the warmer
the temperature in which either is placed the sooner decomposi-
tion is accomplished. It is advisable, therefore, to remove the
fruit while firm and keep it in the coolest possible temperature.
The peaches in. the top of a refrigerator car that has been
several days in transit in hot weather are sometimes overripe
and need to be sold as soon as the market is reached, while at
the same time the fruit in the bottom layers may still be firm.
The rapidity with which the fruit cools down in the car depends
on the care with which the car is iced, and on the temperature at
which the fruit enters the car. Fruit that is loaded in the mid-
dle of a hot day and that has been picked in a heated condition
may be 20 or more degrees warmer than fruit picked and loaded
in the cool of the morning. Such warm fruit ripens much more
rapidly, consumes more ice in cooling down, and takes longer
to reach a low temperature. When the temperature in the top
of the car is higher than that of the lower part the ripening of
the upper layers of fruit will be hastened. If the fruit is des-
tined for cold storage, these upper layers, if more mature, should
be piled separately, and sold as soon as their condition warrants
it. Under these conditions, if the fruit from this position is
454 PRACTICAL COLD STORAGE
mixed in with the rest of the load it may begin to deteriorate be-
fore the remainder of the fruit shows mellowing.
The general principles outlined in former pages for the
handling of the Bartlett pear apply to the storage of the peach,
except that the latter fruit is more delicate and the ripening
processes are even more rapid. Every condition, therefore, sur-
rounding the peach in the orchard, in transit, in the storage
house, and at withdrawal must be most favorable. The fruit
must be well-grown and well-colored but firm when picked. The
packing must be done with care to prevent bruising. If the
fruit is to be transported in refrigerator cars, it should be loaded
soon after picking, and preferably before it loses the cool night
temperature. The peaches should be transferred from the cars
to the storage house, or from the orchard to the storage house
if the latter is near the orchard, in the quickest possible time.
The air of the storage room should be kept sweet and pure.
The fruit should always be removed to the coolest possible
temperature, usually at the end of two weeks, while it is still
firm, and it should be placed in the consumer's hands at once.
If the fruit is overripe when picked, or becomes mellow
from unfavorable handling before it enters the storage house,
it is already in a critical condition and may be expected to de-
teriorate quickly.
If the conditions outlined are observed in the handling
of the peach, it is possible to store it temporarily with favorable
results.
CHAPTER XIX.
COLD STORAGE FOR FRUIT GROWERS*
ADVANTAGES OF LOCAL COLD STORAGE.
The experiments conducted by the United States Depart-
ment of Agriculture (described in other chapters) to determine
the best methods of handling and storing fruits have resulted
in securing information of much value. Information before
well known to the author and others connected with the
industry has been verified by the experiments and put in the
form of plain statements of facts. It has been fully demon-
strated that better results are secured by the placing of fruit in
storage promptly when picked, and that fruit, especially apples,
should remain on the trees until well colored and fairly ripened
before picking for storage. These facts argue strongly in favor
of the fruit grower operating his own cold storage. Prof. G.
Harold Powell, who had the experiments in charge, says :
The local warehouse is ideal for quick storage and for the grower
who is competent to handle his own crop. Capital has developed
the warehouse business in the large cities, as it is more convenient to
distribute the fruit from them and more economical to maintain a
plant where a general storage business can be operated. But as the
importance of quick storage at harvest time is more generally appre-
ciated, it will probably lead to a greater development and concentra-
tion of local storage houses and to a greater use and improvement of
the refrigerator car service. * ♦ • I believe that one of the devel-
opments that will take place in the future is the building of ware-
houses in the apple producing regions, and the distribution of the prod-
uct from these warehouses in cooler weather.
The part in italics is used by the author to emphasize the
point under consideration, viz. : That best results and greatest
profits to the grower can only be secured by placing the fruit in
cold storage as soon as removed from the trees. This does
not necessarily mean that the grower must have a cold storage
•Extracted from a series of articles written for Green's Fruit
Grower by the author.
4S5
4S6 PRACTICAL COLD STORAGE
house on his premises, although in many cases this is the best
and most practical plan ; but the cold storage house should be
easily accessible in order to secure the best results. Many fruit
growers are at present so situated that their fruit is packed in
barrels and shipped by refrigerator car to the nearest storage
point, requiring only two or three days in transit. Even this
short time causes deterioration of some of the softer varieties
of fruit, as the warm fruit going to the car cooled with ice only
will not in all probability become cooled below 45° or 50° F.
With a local cold storage the fruit requiring quick work may be
cooled down rapidly to a temperature of 30° F., thus improving
its keeping qualities, and shipped out later in the season when
outside temperatures are lower. Many times refrigerator cars
are not available and the damage is then much greater.
As an instance of one of the benefits to be derived from
home cold storage may be cited the barrel situation during
some years. It is often impossible to obtain barrels in sufficient
quantity to take care of the crop at harvest time, and it is rea-
sonable to say that many thousands of dollars have been lost
to the grower from this reason on account of deterioration of
quality of fruit while lying in the orchards waiting for barrels.
In many cases total losses have occurred. Apples may be suc-
cessfully stored without barrels; and boxes and crates are regu-
larly used for this purpose. They may also be stored in bulk,
but this is not as good. A grower provided with suitable cold
storage facilities does not have to wait for barrels.
Apples to stand shipment long distances before placing in
storage must be picked while still somewhat immature. The
bothersome apple scald is increased by too early picking, as
it has been shown by the experiments and by practice that ma-
ture, well colored fruit does not scald to any extent. On this
score Professor Powell states: "The experiments indicate that
sc far as maturity is concerned, the ideal keeping apple is one
that is fully grown, highly colored, but still hard and firm when
picked. Apples that are to be stored in a local cold storage house
to be distributed to the markets in cooler weather may be picked
much later than fruits requiring ten days or more in transit.
* * * Therefore, to sum up in a general way, the results of
COLD STORAGE FOR FRUIT GROWERS 457
the experiments which have been made seem to indicate that the
ideal fruit for storage purposes is that which is taken from the
tree to the warehouse in the quickest possible time, in order to
prevent the fruit from consuming a large proportion of its own
life history during the delay that may take place."
COMMERCIAL ASPECT OF THE PROBLEM.
These are some of the benefits of home or local cold storage.
Many instances could be cited where large profits have been
made by placing fruit in cold storage for a time and selling
when the market was comparatively bare, but these seasons are
exceptions, and in going into a cold storage proposition, the
grower should not expect more than a reasonable profit, amount-
ing to interest and a fair remuneration for the risk assumed. One
season with another, a good profit is certain if the business is as
well handled as it should be, and none but a careful person of
methodical habits will succeed in the operation of a cold storage
plant. In the future the grower with modern cold storage fa-
cilities will have the advantage over his less progressive neighbor
from the fact that his losses will be less and he will be able to
place in the hands of the consumer a better preserved and more
attractive grade of fruit.
The question may arise as to the probable result of the
erection of a much larger number of cold storage houses than
are now in use throughout the section of the country where com-
mercial orcharding is largely practiced, and also the probable
result of the great increase of acreage of fruit bearing trees. The
application of cold storage is still in its infancy. It cannot be
said that its use so far has been in any way detrimental to the
development of the industry, on the contrary, it has been a
great benefit, as fruit growers well know. If the development of
cold storage has been beneficial in the past, why should not
further development be beneficial? It may be true that the
profits will not be as great in the future with more storage
houses in use, but the profits will be more certain and regular.
The old cry of overproduction has been raised in connection
with fruit growing and storing, but with the country only half
populated, growing fast, and with developing tastes and rapid
458 PRACTICAL COLD STORAGE
improvements in transportation, overproduction is impossible. If
there has at times been a temporary overproduction in the past,
it has not been due to a surplus, but to lack of facilities in dis-
tributing and transportation. Commercial orcharding is rap-
idly expanding and cold storage will be necessary as an aux-
iliary. There can be no disastrous glut of the market when
cold storage will absorb the surplus at harvest time and dis-
tribute it as needed by refrigerated transportation to the mar-
kets of the world. With developing civilization and a better
understanding of the beneficial results of a fruit diet, stimu-
lated by a rapid increase in the price of meats, the use of fruits
as food will surely multiply many times. It is doubtful if the
present enormous planting of fruit trees will cause any over-
production. Nearly every one can remember when the cold
storage of apples was almost unknown — they were stored in
basements, cellars or "fruit houses" without refrigeration. Prob-
ably a few are still doing this, but it is safe to say that not
more than 20 or 25 per cent of the fruit is so stored for tem-
porary purposes, and storage of this 20 or 25 per cent would
save money in improving the quality of the fruit by employing
artificial refrigeration. Owing to the considerable investment
necessary it is improbable that the construction of cold storage
plants will ever be on a scale large enough to cause an over-
supply of cold storage space, and the time will shortly arrive
vrhen practically all perishable goods will be handled in and
sold from cold storage. Those who first provide themselves with
cold storage will be the ones to be benefited most largely
thereby.
DESIGNS FOE SMALL COLD STORES.
The absolute necessity of cold storage at or near the orchard
in order to secure the most perfect results seems unquestionable.
What then should a modern cold storage plant consist of? The
answer depends largely upon climatic conditions and extent and
character of the crop to be handled. We will here consider only
the needs of the comparatively small grower who will store say
from 200 to 2,000 barrels. The use of natural ice for cold stor-
ing of fruit dates back thirty years or more. As has been
previously pointed out, and as generally understood among the
COLD STORAGE FOR FRUIT GROWERS 459
trade, the natural ice systems with which we are all more or less
familiar have not been generally successful for the purpose.
The chief objections to these methods were found to be lack of
control as to temperature and too much moisture in the air of
the rooms. The lowest dependable temperature during warm
weather was about 38° to 40° F., oftentimes higher. The
moisture in the air was excessive at times, especially during cold
weather when the temperature was lowest in the storage room.
FIG. 1— VIEW OP HOUSE FOR FRUIT GROWERS. PLAN No. 1
At the present time a temperature of 30° F. is considered best
for apple storage, and any apparatus which cannot produce this
temperature cannot be considered for practical purposes as a
modern system. Humidity also should be under control. It is
for this reason that the ice systems have gone into disuse, and
the ammonia or mechanical systems are understood to be the
best. The advantages of simplicity and low operating cost
when using ice for cooling, combined with the positive control
of temperature and moisture obtainable with the ammonia or
460
PRACTICAL COLD STORAGE
mechanical system, are all embodied in the Cooper brine sys-
tem, described in another chapter. This system has none of
the disadvantages of complicated machinery, requiring skilled
labor, as is necessary with the mechanical or chemical systems.
The buildings here illustrated are planned to meet the
needs of those who have a crop large enough to make storing
profitable. It is not recommended that a cold storage plant of
less capacity than 200 to 300 barrels be built, except under spe-
I
FIG. 2— FLOOR PLAN, HOUSE FOR FRUIT GROWERS, PLAN No. 1.
cial local conditions which might warrant a smaller capacity.
The cost of constructing a very small house is greater in pro-
portion as will be seen by the subjoined estimates. The cost of
operating is also greater in proportion and the time and care
necessary to make a success of a very small plant will operate a
much larger one equally well. The relative cost of a plant of
600 barrels capacity and one of 1,500 barrels capacJtj' are here
figured with some degree of accuracy for average conditions.
The operating cost would be in about the same proportion. The
cost of building and operating a house of say 300 barrels would
COLD STORAGE FOR FRUIT GROWERS
461
be more than half as much as the house here described for 600
barrels. It will be apparent that an extremely small house is
not profitable under average conditions.
Plan No. 1, which is illustrated by perspective, plan and
sectional views (see Figs. 1, 2, 3 and 4), is suitable for a
capacity of from 200 to 1,000 barrels of apples or other fruit,
without change in arrangement of rooms and general plan
of building. The cold storage space consists of a large room
PIG. 3 — SECTION A-B OP PLAN No. 1, HOUSE POR FRUIT GROWERS.
12 feet in height, which may easily be maintained at a temper-
ature of 30° F. during the warmest midsummer weather, and a
smaller room, or cooling room, shown in Fig. 2, 8 feet in height,
which is used for bringing down the temperature of the fruit
partly before placing in the large storage room. Access to the
storage room is only had through the cooling room, preventing
at all times the inflow of warm air. This cooling room is most
462
PRACTICAL COLD STORAGE
useful during comparatively warm weather, for instance, while
storing the summer or winter varieties of fruit, or for cooling
and storing Bartlett pears or similar fruit which require quick
cooling. By placing the fruit over night in the cooling room a
considerable part of the heat may be removed and then, when
removed to the storage room, no marked change of temperature
in the large room will take place. The cooling room has pipe
PIG. 4— SECTION C-D OP PLAN No. 1, HOUSE FOR FRUIT GROWERS
coils of sufficient capacity to carry a uniform temperature of
30° F. during the cold weather of fall and winter and this room
may be used for permanent storage of the late winter varieties
which are not placed in storage as a rule until cold weather in
the fall. The cooling room is entered from a packing or receiv-
ing room, as it is generally called. The packing room may be
made larger if desired, or it may be omitted if cold storage is to
be built adjacent to a fruit packing shed already in use. The
COLD STORAGE FOR FRUIT GROWERS
463
packing room is provided with a chimney, so that a fire may
be built in extremely cold weather if necessary to prevent low
temperature in the storage room and cooling room, or when it is
desired to work in packing room in winter. From the packing
room, stairs lead up to lofts above. These lofts are useful for
the storage of empty packages, etc. The ice room adjoins both
the packing and storage rooms. There are no openings from
FIG. 5— VIEW OP HOUSE FOR FRUIT GROWERS, PLAN No. 2.
the ice room to any part of the building except to tank house
for the purpose of raising ice to tanks.
Plan No. 2 (illustrated in Figs. 5, 6, 7 and 8) is in most
respects like plan No. 1, but is adapted to larger houses. Plan
No. 2 may be readily built ranging in capacity from 1,000 to
2,000 barrels. The estimate is based on a capacity of 1,500 bar-
rels. The ice room is placed at one end of the house in this case
and the storage room between the ice room on one side and pack-
ing and cooling rooms on the other. The storage, cooling and
packing rooms bear the same relation to each other and are of
the same height and similarly equipped as in plan No. 1.
It should be understood that both these plans include about
464
PRACTICAL COLD STORAGE
as much space in the packing room and lofts as is contained in
the storage rooms equipped with the cooling apparatus. In
case it is desired to dispense with this storage space for empty
packages, etc., as would be the case when the cold storage was
built against a barn or fruit house already existing, a consider-
FIG. 6— FliOOR PLAN, HOUSE FOR FRUIT GROWERS, PLAN No. 2.
able saving could be had by some slight changes in plans. If a
sidehill location is available, a two-story building is more
economical to build, and cheaper to refrigerate, and the access
by team to the two different floor levels is a great convenience
and saving in the handling of goods for packing and storage.
Such a plant which has been built and operated is illustrated
COLD STORAGE FOR FRUIT GROWERS
465
further on in this chapter. Old buildings may be remodeled in
most cases to good advantage and a handsome saving thereby
effected.
The estimates here given are for good, though plain con-
struction, and cold storage houses built in this way will do good
services for many years. The estimated cost of constructing and
insulating a cold storage house of 600 barrels capacity on plan
No. 1 is $1,365. The cost of refrigerating equipment, consist-
ing of piping, galvanized iron work, etc., $650, making a total
•STOFtAqc Room
'.^'^fy.'-'/lHSIS^'ii:^^''- ""1""
^ R3
FIG. 7— SECTION A-B OP PLAN No. 2, HOUSE FOR FRUIT GROVSTBRS.
of $2,015. Plan No. 2 is estimated at $2,545 for building and
$1,075 for equipment, total $3,620. These figures are based on
average costs and conditions, and will of course vary somewhat
in different sections. Country locations are usually much
cheaper to build in than cities, but this is not always true.
The ice room in this style cold storage house is merely a
storage place for ice, and there are no openings from the ice into
the storage part of the building. The ice room is to be filled in
466
PRACTICAL COLD STORAGE
winter, and will hold sufficient ice not only for the operation
of the cold storage plant for an entire season, but for any ordin-
ary farm or family uses as well. No packing material of any
sort is used on or around the ice. The floor, sides and ceiling
of ice room are well insulated with mill shavings or some similar
material. This saves considerable unpleasant labor in taking
FIG. 8.— SECTION C-D OF PLAN 2, HOUSE FOR FRUIT GROWERS.
out ice, and the ice will keep as well or better than it will in
the old style way of covering with sawdust or other material.
The ice is also clean and ready for use when taken out. Ice
is filled into the ice room through an ice door extending from
floor to ceiling, consisting of inner and outer sections which
are filled between with shavings or other material
after filling the room with ice. Ice for use in the primary tank
of the Cooper brine system is first broken or pulverized in the
ice room and then raised by a rope through a trap door to
the tank house. The operation of this system which cools the
room is based on well known natural laws that heat expands and
COLD STORAGE FOR FRUIT GROWERS
467
cold contracts. (For description see chapter on "Refrigeration
from Ice.")
A MODEL SMALL FRUIT STORE.
The plant of George Smith, South Eiver, N. J., illustrates
a desirable type of sidehill construction. The view shown in
Fig. 9 is what might be called the front of the building. The
photograph was taken while snow partly covered the ground,
and before the plant was entirely completed ready for business.
FIG.
-GEORGE SMITH'S FRUIT STORAGE HOUSE,
SOUTH RIVER, N. J.
The door and platform shown give access to the receiving room
on the second floor of the building. (See plan and sections for
the arrangement of rooms.) The convenience of handling fruit
in on the second floor is made possible by the fact that the plant
i? built on a side hill, and one end of the building is excavated
partially into the hill. This arrangement may also be seen in
the view showing the rear of the building with ice pond.
The building is 65x40 feet with 20 feet locust posts set on a
concrete wall 14 inches in width and three feet in depth. On
468
PRACTICAL COLD STORAGE
the front of the building this concrete wall is carried up to the
top (if the second floor, forming a retaining wall for the earth
FIG. 10— niVER VIEW— ICE POND IN FOREGROUND.
^\\\"^^^:^^y^^;:y^:^:^^^
>^-.v\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\-g
Stori le Rbom''a,
los R.oor
-^^\\\\\i^^^^x\\\\^WN\\\\%^^
1
FIG. 11— FIRST FLOOR PLAN.
COLD STORAGE FOR FRUIT GROWERS
469
or grading which gives team access to the receiving room. This
retaining wall also results in giving access to the shipping room
on the main floor, as may be seen in plans and sections. The
ice pond, shown in rear view of building is flooded only in win-
ter, and when the ice is being housed it is floated right to the
gig or elevator, where it is hoisted into the building by a horse.
After the ice harvest is over the water is let off and the pond
affords good pasture during the summer months.
As the fruit comes from the orchards it is taken in on the
second floor into the receiving room, where it is sorted and
4//////i/f///)/>///)J^//f'ff>Jf"*t^*^7777r^
PIG. 12— LONGITUDINAL, SECTION.
packed, and then lowered to the shipping room from where
it is placed in the cooling room. This room is 26x15 feet, and
is useful for partially cooling the fruit before it is placed in the
storage rooms proper. The cooling room is chilled to a moder-
ately low temperature by the melted ice and salt. Ice is hoisted
from the ice room by means of a hand hoisting drum. A rope
from this drum runs through pulleys to a car and ice bucket.
After the ice is crushed in the ice room, it is drawn up to the
470
PRACTICAL COLD STORAGE
track and is easily pushed along, so as to dump directly into the
primary tanks. The ice is broken by hand and shovelled into
the bucket.
The ice room has a capacity of about 500 tons, but this
quantity is not needed for the two rooms equipped. Five
FIG. 13— TRANSVERSE SECTION.
hundred tons would more than operate the complete plant with
four rooms equipped for refrigeration for an entire year.
A COUNTRY ESTATE FRUIT STORAGE.
The extensive and beautiful country estate of E. C. Con-
verse of New York, located at Greenwich, Conn., is provided
with a modern and practical cold storage plant, designed by the
author. No great amount of money has been expended on
ornamentation, and the plant, while of fine appearance, is
strictly businesslike.
Fig. 14 shows the east or approach view, and gives a very
good idea of the exterior appearance. The building is 48x99 feet,
and consists of two floors of cold storage and a roomy attic or
third floor. The exterior of the building is of rustic stone.
The roof is of slate and the building is, therefore, practically
COLD STORAGE FOR FRUIT GROWERS
471
fireproof from the exterior. A large loading and sorting plat-
form of concrete occupies the south end and a part of the west
side. This platform is equipped with a pipe frame on which a
canvas awning may be hung to furnish shade or to protect from
storm.
As -n-ill be seen by the basement and first floor plan the
south end of the building on both floors forms a receiving,
packing or shipping room and a power freight elevator and a
FIG. l-l-
-CONTERS F.\RJI. GREEXWTCH, CONN.-
AND FRUIT PACKING PLANT.
-COLD STORAGE
stairway gives access to both floor and the attic. On the first
floor this space is used as a packing room and the same is true
of the basement, although as originally planned the basement
was intended as a fire engine house on account of the location
of the cold storage plant which is near the northeast corner of
the property. The attic is used for the storage of empty barrels,
boxes, etc., which are used in connection with the business and
the rear of the attic over ice room contains a water tank from
which water is drawn for mixing spray material, etc.
472
PRACTICAL COLD STORAGE
The cold storage plant consists of five separate rooms, the
total capacity, exclusive of ice room mentioned later, being
about 5,000 barrels. The two rooms in the basement are called
frost-proof rooms for the reason that they are equipped with a
comparatively light refrigerating apparatus for maintaining
temperature only during cold weather. The three rooms on the
first floor are all heavily piped for maintaining temperatures
during summer if necessary. The ice room is also equipped
•M//////////////////////M
rraai ^nDf I^Dm ^THiW.t' Frasl 'Pr(M>r ItAom U J&« 1%flOl
" " ..a'ili ■ ■ I ■
M — ■■m^A..^AmmMMMmy}:^mmmmmmm
\
T~!f:
FIG. 15 — BASEMENT PLAN.
with refrigerating pipes on the ceiling as it is anticipated that
this room will be used for the cold storage of apples as the
orchards come more fully into bearing and a new ice room will
be constructed at the north end of the building. A very clear
idea of the appearance of the inside of the cold rooms may be
secured from the two illustrations, one showing barrels of apples
in storage and the other boxes of apples in storage.
The longitudinal and transverse sections show the primary
tanks of the Cooper brine system, the ventilating fan, power
shaft, ice elevator tower, ice spout, etc. The ventilating fan is
arranged to draw air from outside during cool or cold weather
either for ventilating the rooms and to force out the accumu-
lated gas from the stored product, or for cooling the rooms as
required. It is also arranged to force air over a heater for
COLD STORAGE FOR FRUIT GROWERS
473
warming the rooms if necessary in an extremely cold time, or
when whitewashing the rooms at the beginning of a season's
business.
It may be explained in connection with the barrels stand-
ing on end that they are not headed up and contain apples
direct from the orchards, placed quickly in storage without
sorting, and that they will be sorted and repacked as required
for shipment. This accounts for their storage on end rather
FIG. 16— FIRST FLOOR PLAN.
than being stored on the side as is customary. The apples in
boxes are likewise hurried from the orchards to the cold storage
room and no attempt made to sort them, except to leave the
culls, if any, in the orchard.
The plant was designed for the storage of apples, peaches
and grapes and, as reported by Mr. Geo. A. Drew, superintend-
ent, it fills the requirements admirably. A temperature of 32°
F. is maintained for apples and grapes, and peaches are stored
at about 40° F. Peaches have kept in first class condition for
at least three weeks, and there seems to be no reason why with
careful handling and a. little more experience they cannot be
stored for a much longer period. Prompt cooling of the fruit
when picked is secured by the location of the cold storage plant
474
PRACTICAL COLD STORAGE
within a few minutes drive of the orchard. This question of
location cannot be too strongly emphasized in connection with
cold storage plants designed principally for the storage of fruit.
Conyers Farm is located eight miles from Greenwich, the near-
est railroad station, and the advantage of storing fruit on the
farm at the orchards is very great. Prompt storage at picking
and without the waste of time necessary for sorting will be one
of the prime essentials for the successful handling of fruit in
future.
PIG. 17 — LONGITUDINAL SECTION.
SUGGESTIONS APPLYING TO LARGER PLANTS.
For cold storage houses of a capacity greater than about
2,000 to 5,000 barrels of fruit, the complete Cooper systems are
installed. In addition to the brine system and chloride of
calcium process, they include the forced air circulating and
ventilating systems, viz., an improved method of circulating the
air of the storage over the secondary coils in the storage rooms,
and a system for ventilating cold storage rooms by the forcing
in of air which has been thoroughly purified, dried, and brought
COLD STORAGE FOR FRUIT GROWERS
475
to about the temperature of the storage room. These air cir-
culating and ventilating systems are necessary in larger houses
where the arrangement is more complicated and the rooms are
larger and the natural circulation of the cooled air is not uni-
form in all parts of the rooms; thus making advisable the use
of a forced air circulation induced by a power driven fan. On
account of requiring continuous power, the air circulating sys-
tem has not been applied to the small houses here described.
FIG. 18— TRANSVERSE SECTION.
In places where ice may not be had at low cost, and where
the capacity is comparatively large, say, 40,000 barrels or more,
a machine system of refrigeration is advisable. A skilled
engineer should be employed by the year to operate the plant
and maintain it in efficient condition.
ADDITIONAL ESTIMATES OF COST.
It is difficult to give accurate figures on the total cost of a
cold storage plant as this necessarily involves a great variety
of conditions. A plant of one or two cars capacity would mean
one which might be used by a small fruit grower, but which
would not be adequate for a comparatively large one. A plant
476
PRACTICAL COLD STORAGE
of 5,000 rabic feet which would probably store about four car-
loads of fruit can be built at a cost of about $2,000. This would
include plenty of space for packing room, storage of empty
packages, ice storage room, etc. A plant of this capacity could
be built without allowing much space for these purposes at a cost
of probably $1,200 to $1,500. A plant of one to two carloads
if all in one room, with perhaps a vestibule refrigerated by drips
from primary tank, could be built at a cost of from $700 to
$1,000 complete. It is hardly possible that a smaller plant
than this could be made profitable. However, an 8xl0-foot
room, 7 feet high could be built at a cost of $350 to $500 com-
FIG. 19-
-ArPLE STORAGE ROOM SHOWING BOXES USED FOR
STORAGE.
plete, and the equipment for the Cooper brine system and the
chloride of calcium process could be furnished for $175 f. o. b.
cars factory. This would also include complete plans for the
construction and insulation of the room. If a room of this
capacity were to be built of other dimensions with plans made
especially and the equipment built especially the cost would be
$25 to $50 more.
REMOVING FKUIT FEOM STORAGE. SUGGESTIONS FOR CORRECT
TREATMENT.
When removing pei'ishable goods from cold storage a cer-
tain amount of care is essential. The plan of artificially drying
COLD STORAGE FOR FRUIT GROWERS
477
air to prevent moisture on the goods is entirely correct theoreti-
cally, but practically it can not be made operative. It is
hard enough, for instance, to get people to take their goods out
of storage two or three days in advance of actual requirement,
to say nothing about putting them through a complicated
warming up or de-frosting process.
The very best suggestion the author has in connection
with this matter is to simply take the goods out of storage; lay
down a tarpaulin or canvas or wagon cover on the floor; pile
your goods on it; and then cover the goods tightly with the
FIG. 20 — APPLE STORAGE ROOM, SHOWING BARRELS ON ENDS
NOT HEADED.
tarpaulin or canvas. A tarpaulin is pretty nearly air-tight, and
this scheme will protect the goods from direct air contact while
they are warming up, and will prevent sweating. This process
takes several days depending on the weather, and if a free
circulation of air is present they will naturally warm up much
quicker.
Not only does the above scheme accomplish the desired re-
sult, but it brings the temiierature of the fruit or other goods
up gradually and thus prevents deterioration which may occur
478 PRACTICAL COLD STORAGE
if the scheme of exposing them to artificially dried air and cir-
culating the air over the fruit were adopted. For the wel-
fare of perishable goods it is best not only to cool them rather
slowly when placed in cold storage, but to warm them rather
slowly when taken out of cold storage, and of course, the con-
densation or "sweating" must necessarily be prevented if best
results are desired. Commercially, even the scheme of covering
with tarpaulin is almost out of the question, as people cannot or
will not take the' necessary time and the exact requirements, or
supply needed, is not known from day to day. Goods intended
for cold storage should be packed in a package which will pro-
tect its contents fairly well from a circulation or direct con-
tact with the outside air and this will to a large extent prevent
the trouble experienced from condensation if the package is
not opened until the goods have warmed up to the tempera-
ture of the surrounding air. The "sweat" is not at all nec-
essary.
CHAPTER XX.
STORING CIDER UNDER REFRIGERATION.
ELIMINATING CHEMICAL PRESERVATIVE.
This is a new subject to most people, and even those who
have been in the apple growing and cider making business for
some years have had no experience and know little about the
keeping of cider by means of cold storage. It is safe to say
that the consumption of apple cider could be increased to
many times what it is now, if sweet cider without marked
fermentation could be had by the consumer for any consider-
able period of time. As the business is now handled there is
a big surplus of cider during the fall, and the only cider
available during the winter or spring is that which is bottled
or preserved in some artificial manner. The most of the
ciders on the market are treated with some preservative chemi-
cal which make them more or less unwholesome. Other
methods consist of sterilizing by partially boiling, and then
bottling. This latter method means an inferior quality of
cider so far as palatability is concerned.
With the enormous plantings of apple orchards which
are now going forward it would seem that after a few years
the production of apples will be so large that growers will find
it necessary to secure every possible outlet for the fruit, and for
the manufactured products of same, such as cider. Those who
are interested in orcharding should bear in mind the possi-
bilities of the development of a fancy cider trade. The pre-
liminary results reported below can doubtless be improved
upon, and it would seem that with suitable cold storage facili-
ties at or near the orchards, an almost unlimited market for
a well prepared and properly clarified cider could be developed.
Apple growers understand fully the difficulties of keeping cider
479
480 PRACTICAL COLD STORAGE
for any length of time without resorting to chemicals. Good
cold storage facilities where the temperature can be held under
positive control are absolutely essential to the successful storage
of cider in its natural state.
The U. S. Department of Agriculture, Bureau of Chem-
istry, has issued a circular by H. C. Gore on the cold storage
of apple cider from which we extract the information which
follows. The information given in this circular is thoroughly
practical and the experiments, while admittedly preliminary,
are doubtless very thorough, and it is probable that further
experimentation will bring to light comparatively few addi-
tional facts, except possibly the adaptability of different var-
ieties of apples for cider making purposes.
FRUIT USED FOR THE EXPERIMENT.
The apples used by the Government in the experiments
referred to were of the grade commercially known as "Sec-
onds." As it was not practical to begin the experiments when
the fruit was received, the apples were stored at a temperature
of 32° F. when received in Washington. Considerable decay
occurred during cold storage in case of the Tolman (Tolman
Sweet), Winesap, Yellow Newtown (Newtown Pippin), Ralls
(Geniton) and Gilpins. As the apples were not of first grade
this was to be expected, but very little decay was found among
the Baldwins, Golden Russet, Roxbury Russet and Kentucky
Red.
As the fruit was not ground for cider as soon as received,
Mr. Gore suggests that the sugar content of the apples was
probably higher than it would have been had this been done,
and that this is particularly true of the three late winter varie-
ties, Baldwins, Golden Russet and Roxbury Russet, on account
of the fact that most fall and winter apples contain starch at
picking time which disappears rather rapidly in common
storage, and comparatively slowly in cold storage. On the
other hand, the acid content would have been much higher had
the apples been ground promptly when received, because the
acid disappears rapidly during cold storage. These facts have
been demonstrated by repeated experiments.
STORING CIDER UNDER REFRIGERATION 481
PREPARATION AND HANDLING OF CIDER.
Not less than an entire barrel of apples was used in the
experiments, and from that up to six barrels in case of the
Baldwins. All rot was removed from each lot of apples be-
fore grinding, and Mr. Gore states that the method of pre-
paring the juice closely approximated standard commercial
practice. It may be noted in this connection, however, that
it is not customary to remove rot from apples before grind-
ing for cider, except in preparation of extremely high grade
goods. The fact that all rot was removed in these experiments
may doubtless account for the fact that fermentation did not
occur quickly. Those who wish to experiment in connection
with the cold storage of apple cider should note this fact and
be very careful not to grind apples which are found slightly
decayed.
For the government experiments the fruit was ground
in a rotary apple grater or grinder of the usual type and
pressed by powerful hand power presses ; racks and press cloths
were used, following the usual American method. The racks
were 36 inches square, and each cheese or pomace was 32
inches square and about three inches thick, representing the
pulp from a barrel of apples. As a cold storage package five
gallon kegs were used as containers for the juice from eight
varieties, and a 50 gallon barrel for the juice from the Baldwin
apples. Containers were sterilized by steaming and then
rinsing with cold clear water immediately before using. After
the kegs were filled they were placed out of doors over night
at a temperature of about 32° F. or in the cold storage room
at the same temperature; thus cooling the cider rapidly.
After the casks had been placed in their final position in
the cold storage house, a three-eighths inch hole was bored in
the head of each, to serve as a vent in case of gas forming,
and through which samples could be taken at any time. The
holes were temporarily blocked with cotton to keep out foreign
matter, and the plugs were removed only when drawing sam-
ples, which were taken frequently during the first week of
storage and somewhat less often thereafter.
482 PRACTICAL COLD STORAGE
DISCUSSION.
The striking fact brought out in experiments was that
cider was kept in cold storage from 36 to 83 days, and an
average of 61 days, before beginning to ferment noticeably.
We may note in this connection what has already been sug-
gested, that all decay was removed from the apples before
grinding, and this probably accounts for the comparatively
long period before fermentation commenced. The average for
the Tolman, Winesap, Yellow Newtown, Ealls, Gilpin and
Baldwin was 50 days. These varieties represent the usual type
of American cider apples more fully than do the Russets and
Kentucky Reds. From 90 to 125 days were required before
the ciders had fermented too far to be called sweet, or an
average of 107 days for all varieties, and 99 days for the six
varieties just mentioned. No deterioration in flavor of the
cider was noticed during cold storage, except in case of the
Tolman, which can hardly be considered a cider apple. Al-
though some of the ciders were frozen while in cold storage,
yet no perceptible injury in flavor resulted. Not only was the
characteristic flavor of the apple varieties maintained, but
actual improvement was noted, due to the presence and re-
tention by the. low temperature of carbon dioxid or carbonic
acid gas. The Baldwin, Golden Russet, Roxbury Russet and
Kentucky Red gave the highest grade of ciders. The rate of
fermentation increased rapidly in all instances after about
fifty days, but the changes in this respect were far slower than
those occurring in common storage without refrigeration.
SUMMARY.
A brief summary of the results of the experiments may
be stated as follows:
(1) Ciders prepai-ed from apples free from decay chilled
rapidly to the freezing point immediately after pressing, and
then held in cold storage at 0° C. (32° F.) remained without
noticeable fermentation for a period of from 36 to 57 days,
an average of 50 days for the Tolman, Winesap, Yellow New-
town, Ralls, Gilpin and Baldwin varieties and of 83 days in
STORING CIDER UNDER REFRIGERATION 483
the case of the Golden Russet, Roxbury Russet and Kentucky
Red.
(2) These ciders were held for a period of from 90 to
119 days, an average of 99 days for the first six varieties and
of 125 days for the last three, before they fermented sufficiently
to be considered as becoming "hard" or "sour."
(3) The ciders were found to have suffered no deteriora-
tion (with the exception of the Tolman), but rather had be-
come more palatable during storage.
CLARIFYING OF THE JUICE.
While nothing is said in this bulletin about the clarify-
ing of the apple Juice preparatory to storing, this subject is
treated in Bulletin No. 118 by H. 0. Gore, Bureau of Chem-
istry, U. S. Department of Agriculture, and Mr. Gore has
given the details very fully indeed: Fresh apple juice con-
tains a large quantity of solid matter which partially settles
on standing. This solid matter or "pomace" as it is known,
contains dirt particles or foreign matter and starch grains, as
well as fragments of the apples, and albuminous matter. The
albuminous matter composes the greater part of the sediment
and is very objectionable, as its presence detracts from the
appearance of the finished juice, and it contains the elements
which quickly cause fermentation.
The removal of the materials which form sediment are,
therefore, of the utmost importance in the preparation of a
marketable product, and a product which can be successfully
cold stored without sterilizing or without treating with chemical
preservatives. The sediment may be removed by filtration or
by allowing it to settle. It may also be clarified by passing it
through a centrifugal separator. Filtration is expensive and
slow and out of the question commercially. Allowing the
sediment to precipitate by gravity is also slow and imperfect.
The best method is by the use of a centrifugal cream separator,
and repeated trials have shown that a cream separator will
successfully clarify the juice, leaving only traces of sediment
in the product. The suspended matter in the juice collects
in the bowl of the separator, while the clear juice flows out
484 PRACTICAL COLD STORAGE
through the milk and cream openings. After operating the
machine for a time the foreign matter and sediment will be
found tightly packed in the bowl of the centrifugal machine.
A little experience will indicate just how long the separator
can be operated before it is necessary to stop and clean out
the sediment.
With reasonably clear juice, clarified quickly after press-
ing, it is doubtless possible to cold store apple cider for several
months, if not for periods of very nearly a year. The extreme
limit has not been determined, but it is doubtless upward of
six months.
CHAPTER XXI.
NURSERY STOCK*
WINTER STORING OF NURSERY STOCK.
It may be stated at the outset that this chapter is written
with regard to northern conditions, especially such as would
be the average north of the Ohio River. In applying the
suggestions and information given to other conditions further
south due allowance should be made for variation of winter
climate.
It is within recent years that the digging of trees from
nursery row in the fall and storing during the winter for
spring shipment has come to be an established feature of the
nursery business. This subject was brought to the author's
attention by a discussion between nurserymen of the advisa-
bility of the method. In this discussion the term "cold stor-
age" was used in reference to the cellars or sheds in use for
the purpose. Having a great interest in cold storage matters,
the author determined to get the best information obtainable
from those actually using the storage method. Letters of in-
quiry were therefore sent out to representative nurserymen.
That nurserymen are in the main progressive and liberal
minded is evident from the interest shown and the careful
replies received. This chapter, therefore, gives no mere theory
or opinion by the author, but information carefully gleaned
from those actually engaged in the business and put in shape
by one who has had a long experience with the cold storage of
perishable products.
From the information obtained, it is beyond doubt a fact
that a large majority of nurserymen are using retarding houses
or frost-proof winter storage facilities of one kind or another.
♦Originally published in The National Nurseryman, by the Author.
485
486 PRACTICAL COLD STORAGE
A few are using artificial cooling, but as a general proposi-
tion, this is not as yet fully appreciated. In time, no doubt,
this feature will also come to be permanent, not only for main-
taining regular temperatures during winter, but should .there
be an overstock of certain varieties in the spring, it would
result in a great saving to store the surplus over until the next
shipping season. Artificial cooling is another step in advance
of frost-proof storage in the same sense that fall digging and
frost-proof storage is a step in advance of the old method of
digging at shipping time in the spring. It is natural that
every planter should want his trees immediately as soon as
the frost is out of the ground. The result is that they all
want their stock at the same time. As a consequence, nursery-
men who do any considerable amount of business and have no
storage facilities have more than they can attend to in the
spring. Even with this almost impossible problem to solve,
there are many who are not converted to the storage method,
so a few words regarding its advantages and alleged disadvan-
tages will be timely. The advantages may be stated as follows:
1. — Protection from Loss: — Every few years thousands of dol-
lars' worth of trees and vines are killed during a severe
spell of extremely low temperature during the winter at a
time when the ground is nearly bare of snow. It is also
believed that nursery stock is in better condition to thrive
when dug in the fall and stored in an even temperature
approximating the freezing point than if allowed to stand
in the nursery subject to wide fluctuations of temperature
which will cause injury to a greater or less extent, depend-
ing upon severity of the winter and snow protection
afforded.
2. — Prompt Shipment: — If no storage is provided digging
must be done in the spring after frost is out of the ground.
Frost is not generally out of the ground in northern
regions, until April 1, sometimes later. This means that
a large part of the trees are not finally planted until May
1 to June 1, and perhaps not until the leaves have started.
Trees set under those conditions do not thrive as well and
many die.
NURSERY STOCK 487
3. — Saving in Labor: — The shipping season is so short that if
trees were all dug and shipped after frost is out of the
ground the necessity of having a large and well trained
force to get the shipments out promptly would be very
expensive. With storage facilities, stock can be graded at
convenience, counted and put in bundles ready for pack-
ing by cheap help during the winter. Trees may be dug
in the fall at a much lower cost than in the spring, owing
to more abundant available labor and dryer working con-
ditions. Less hands are required as the labor is more
evenly distributed.
4. — Theoretically Correct : — Trees dug late in the fall are dor-
mant from natural causes and will stand handling, ship-
ping and planting much better than trees dug after frost
is out of the ground in the spring. After frost is out, sap
starts and the tree is mpre liable to be damaged by rough
usage and replanting. A dormant tree held at about the
freezing point will retain its vitality almost indefinitely.
The disadvantages or bad effects of winter storage as
claimed by those who oppose the method, are that trees dry
out and mold when stored and that when finally set the
percentage of trees which die is greater. It is also claimed
that among the stock which survives, the growth is retarded
and the trees handicapped by at least a year's growth as com-
pared with freshly dug trees. Plenty of evidence is obtainable
from disinterested parties that these efifects result in some
cases. These bad effects are, however, not from defects in
the method, but from careless or unskillful handling, or lack
of suitable storage facilities. Farther on we will take up the
construction of suitable buildings. It is notable that the
advocates of freshly dug trees are almost wholly of the "old
line" element who stick to old customs, because some few
failures have resulted from the winter storage method. This
method, which has barely passed the experimental stage, can
not but record some failures on account of improper applica-
tion.
Nurserymen who practice the selling of freshly dug trees
are handicapped in the handling of their business, and the
488 PRACTICAL COLD STORAGE
increasing of same to any considerable proportions is practic-
ally impossible. In extensive enterprises, where the sales lists
reach thousands of people, and where the distribution is made
throughout a number of states possessing a variety of soil and
climate conditions, the distribution must extend over a very
considerable period of time, much greater than is allowed by
the normal behavior of the plant; therefore, artificial means
must be resorted to in order to hold the nursery stock in
suitable condition for shipment, to provide for this wide dis-
tribution. From the preponderance of evidence in favor of
winter storing, it seems that this will be universal in due time.
We have then to consider the most approved methods now
in use and suggestions for possible improvements.
COMMON METHODS OF WINTER STORING.
Some of the nurserymen who do not advocate winter stor-
age, admit the need of something better than spring digging
by "heeling in" or "trenching" their trees for the winter in
a protected place which will drain naturally. They admit
that this allows of possible damage to the tops of the trees in
severe weather, but it saves time and wet digging in the
spring. As an improvement over this it is only another step
towards the solution of our problem to put a shed over these
heeled-in trees to protect the tops from low temperature dur-
ing severe weather. This is a common method and was, until
quite recently, practiced by some very large nurserymen. A
frost-proof cellar or shed is provided in which the trees are
heeled-in in the fall, so as to have them ready for spring ship-
ment. The storage shed is kept at the freezing point or some-
what above, so that sorting, grading and packing may go on
independent of weather conditions outside, enabling ship-
ments to be made as early as desirable in the spring. Much
storage space is needed with this method and under such con-
ditions the trees may dry out or shrivel, but the heeling-in in
storage method has the advantage of being more independent
of temperature changes than where the stock is piled up with
roots exposed. A change of temperature is largely what causes
the drying out of trees, owing to the change of humidity with
the changing temperature.
NURSERY STOCK 489
Most of the winter storage structures in service are built
partly below the surface, but many of the largest are wholly
above the ground. Nearly all are insulated by building air
spaces into the walls or by a filling of shavings, sawdust or
similar non-conducting materials. It is the idea in building
partly below ground to secure the protection afforded by the
earth. It is a well known fact that at a depth of a few feet
below the surface of the earth a nearly stationary temperature
of about 55° F. may be obtained winter and summer. This
will prevent freezing in winter if the cellar is rightly built, but
it will likewise cause a marked rise in temperature whenever a
winter thaw occurs and it becomes necessary to close the build-
ing tightly. The heat of the earth will then work up into the
storage room and a temperature of 40° F. to 50° F. may
result. Another disadvantage of the cellar is that when the
first trees are stored during the fall, the surface of the earth is
quite warm, and it is very difficult to keep the temperature
of the cellar low enough. Ventilators, windows and doors are
opened on a cold day or night, and in this way the tempera-
ture is, after considerable delay, finally reduced to the desired
point. A warm spell alternating with cold weather in the fall
after storing commences will cause a great deal of damage
by causing the temperature of the cellar to vary greatly. A
variation of temperature and consequent variation of humidity
will not only cause a drying out or shriveling of the trees,
but may cause a growth of mold or mildew. A building wholly
above ground has many of the disadvantages above mentioned,
and also the disadvantage of lack of protection during ex-
tremely cold weather. There are, however, advantages in
above-ground construction, in that, if the building is built of
frame, it will not rot out as quickly, and it may be cooled more
readily in the fall, and it is not affected so much by heat
from the earth. It is stated by many nurserymen that tem-
peratures are very difficult to maintain in any of the ordinary
sheds or cellars in use, especially during the storage season in
the fall and during the shipping season in the spring. Winter
storage for nursery stock should be so arranged that when
490 PRACTICAL COLD STORAGE
natural temperature is suitable, air may be taken from the
outside and forced into the room for refrigerating, and when
natural temperatures are not suitable, as during a warm spell
in fall or spring, or during a winter thaw, artificial refrigera-
tion may be applied. Moisture brought in with stock, — especi-
ally if the fall has been a wet and warm one, — might cause
mold. A proper cooling and temperature regulating system
would prevent this.
DAMAGE FROM TEMPEKATURE CHANGES.
From the data at hand, it seems clear that practically all
of the damage to nursery stock experienced in winter storing
in cellars or sheds as ordinarily practiced, comes from changes
of temperature, and a generally too high temperature, which
cannot by present methods be avoided. It has been noted that
trees dug late in the fall and placed in storage after the tem-
perature of storage room has been reduced to about the freez-
ing point have carried through in better condition than those
dug at an earlier date and placed in storage while the tempera-
ture of the room was still comparatively high. This may be
partly because the wood is more dormant, but is probably
largely because it is easier after about November 15 to
keep down the temperature of the storage room. A high
temperature and frequent changes of temperature will cause
stock to dry out and shrivel. This is especially true of vegeta-
tion of quick growth, such as peach trees. To prevent this
drying out, a spraying with water is often resorted to, but this
again leads to mold or mildew if the temperature is high and
not very carefully handled. One nurseryman states: "When
stock is put in late in October and November, it needs no
wetting at all, but stays damp all winter and spring;" another
says: "In our own case, we find on account of the ups and
downs of temperature, we must sprinkle with water more or
less, but we believe that with a fixed temperature that did
not vary to any great extent, the water could be omitted." No
better argument could be made for low and uniform tempera-
tures. There is no question at all that trees may be dug any
time after October 1, or after the tree is dormant from natural
NURSERY STOCK 491
causes, placed in a temperature of from 28° to 30° F., held
steadily until spring, and come out in better condition for
planting than stock allowed to remain in the nursery all
winter and dug at the shipping time. Humidity must be
attended to, but this is very easy to regulate at the low tempera-
tures mentioned. As to temperatures at which trees should be
held there seems to be a wide difference of opinion ; no doubt
this opinion is largely influenced by the temperatures it is
possible for each individual nurseryman to maintain in his
storage cellar. Nearly all admit the difficulty of keeping
uniform temperatures, and opinions as to correct temperatures
vary from 30° to 50° F. No doubt 30° F. will produce better
results than any of the higher temperatures. It has been
demonstrated in the history of preserving perishable products
by refrigeration that the lower the temperature at which any
particular product may be carried without damage from such
low temperature, the better and longer it may be kept in cold
storage. Certainly a temperature of 30° F. cannot injure
nursery stock if it is able to withstand severe winter weather
with any degree of safety. It seems reasonable, therefore, that
this is a suitable temperature to maintain.
HUMIDITY AND TEMPERATURE.
At a temperature of 30° F. the air contains very little
moisture, and in fact it cannot hold much, so the possibility
of drying out nursery stock is much less when stored in a
temperature of 30° F. than at from 40° to 50° F., which
many recommend. The capacity of air for moisture is a
direct property of its temperature — the higher the temperature,
the more moisture air will take up and hold. At 30° F. air
will hold less moisture than at any higher temperature. Air
which is saturated with all the moisture it will hold at 30°
F. contains 1.96 grains per cubic foot. At a temperature of
40° F. ; 2.85 grains per cubic foot. This shows the rapid
increase in capacity for moisture as the temperature of the
air is increased. Suppose we are holding our storage room
for nursery stock at 30° F. and a warm spell of weather comes,
one which obliges us to close tightly all openings leading to
492 PRACTICAL COLD STORAGE
the outside air. After a few days the temperature goes up to
40° F. What is the result? The air, say, was at the 84 per
cent relative humidity at 30° F. When the temperature has
increased to 40° F., the relative humidity will be 56 per
cent. What does this mean? Simply that the air has be-
come comparatively very dry and that moisture-containing
products like trees will dry out very quickly. This case is
stated to show the operation of this simple natural law in
connection with the winter storage of nursery stock. Possibly
these exact conditions might not occur in practice, but they
would be approximated. The great importance of maintaining
uniform temperature and humidity is plainly illustrated, and
the cause of the drying out of trees by fluctuating tempera-
tures is readily seen.
To overcome the difficulties of winter storing as above
outlined artificial refrigeration should be applied when neces-
sary to maintain sufficiently low temperatures. By the term
artificial refrigeration it should not be understood that a com-
plicated ice machine system is necessary. The term is used to
express cooling effects other than those produced by outside
atmospheric conditions. Such a refrigerating equipment is
embodied in the Cooper brine system described in chapter on
"Refrigeration from Ice."
IMPROVED BUILDINGS AND APPARATUS.
The accompanying illustrations show a combination winter
and summer storage building constructed wholly above ground.
The storage space is divided by a partition into two rooms, one
small room 30x50 feet, and one larger room 50x80 feet. These
rooms are both cooled from one battery of pipe coils, but the
air ducts are provided with gates so that the entire refrigerating
effort may be applied to the smaller room. The refrigerating
equipment is of sufficient capacity to maintain a temperature
of 30° F. in the small room during midsummer, and to main-
tain the same temperature in both rooms during comparatively
cold weather, say from November 1 to May 1. Both rooms
may be used for winter storage, and during the summer the
large room may be shut off and only the small room used. If
NURSERY STOCK
493
494
PRACTICAL COLD STORAGE
it is not desired to store nursery stock during the summer,
other goods may be taken for storage if they are to be had, or
the plant may be shut down during the summer. No expense
whatever is necessary when the plant is not in operation. The
main part of the storage- building, 50x110 feet, is essentially
like many storage cellars or houses now in use, consisting of
as plain and as cheap a building as can be built, and roughly
insulated. At one end of the storage building is the ice room.
w//MM/M/////////y/////////////////////////My/^^^^
Ice Room
POWER. shaft-
Ventilating ^
Room
^/^^//mw.^i!^^m<%^.!%y/J
y/////////////////////////////M
FIG. 3.— PLAN OP VENTILATING ROOM ABOVE COIL ROOM.
which also contains the complete refrigerating and mechanical
equipment. The ice room is 50x25 feet on the ground, 30
feet high inside and will hold about 750 tons of ice, which is
more than sufficient to maintain the temperature as above
stated during the year. The room containing the secondary
coils of the Cooper brine system is located on the ground.
Above this room is located the tanks containing the primary
coils and the ventilating room containing the heater for use
during extremely cold weather and at such times as it is
NURSERY STOCK
49S
necessary to warm or dry the storage rooms. The gasoline
engine or other power used for driving the fan for circulating
the air through the storage room and for ventilating, is also
located in the room above the tank and ventilating room, where
access is had to top of tank for filling with ice. On this floor
is also provided storage bins for salt. In houses the size of the
one here illustrated, or larger, an ice crushing machine and
FIG. 4.— CROSS SECTION AT B-F OF FIG. 2.
FIG. 5.— CROSS SECTION AT C-D OF FIG. 2.
ice elevator as shown is desirable, especially as the power is
at hand for operating the same. In smaller plants this may
be dispensed with.
The operation of the plant is as follows: Ice is fed to the
ice crusher, which reduces it to about the size of hen's eggs;
from the crusher the ice drops into a bucket elevator, which
lifts it up above the tank containing the primary coils and
496 PRACTICAL COLD STORAGE
drops it into the tank through a flexible spout. It will be
noted that very little labor is necessary with this arrange-
ment. As the ice falls into the tank a small amount of salt
is sprinkled in. This produces a low temperature in the tank,
which cools the chloride of calcium brine in the primary coils
and causes a circulation as already described. The actual cool-
ing of the storage rooms is accomplished by drawing the air
in through small ducts on the sides of the rooms by means of
the fan and causing it to pass over the secondary coils of the
Cooper brine system in coil room, where it is cooled; then
forcing it from fan into large duct in center, where it is evenly
distributed to the rooms. When necessary to heat the storage
rooms, the return air to coil room is caused to circulate over
the large, jacketed heater in ventilating room, or fresh air for
ventilation may be drawn over heater for ventilating and heat-
ing at the same time. When weather conditions are right, a
large volume of air from the outside may be forced into the
storage rooms for the purpose of cooling the rooms. Many
times greater cooling results may be secured in this way
than by the opening of doors and windows, and the cold air
is evenly distributed to the rooms so that no freezing or harm
can result, as is possible to goods stored near open windows
or doors on frosty nights.
The estimated cost of complete apparatus, aside from the
buildings, for a house the size shown, completely erected in
place, is from $2,500.00 to $2,800.00.
The plant described will maintain uniformly low tempera-
tures at about the freezing point in the entire building dur-
ing the cold weather when most of the nurserymen's products
are stored, and in one-fourth of the house during the summer.
The initial cost of the apparatus is not excessive, the cost of
operation almost nominal and the results to be obtained posi-
tive. Only a moderate amount of refrigeration is required
in storing nursery products, but when required, it is very
important, and the cost is so small that it will soon pay for
itself in saving of loss and perfection of results possible to
obtain. In many cases the nurseryman is a fruit grower as
well, and cold storage would be a good auxiliary to add for
NURSERY STOCK 497
the purpose of taking care of the softer fruits temporarily and
the hardy fruits for a longer term of storage.
This description of a suitable plant for nurserymen is de-
signed for northern locations where the nursery business has
had greatest development. In the south or extreme west
the mechanical systems of refrigeration would be best adapted ;
or in a large plant in the north. The other features of the
plant would remain the same so far as construction, air circu-
lation, etc., is concerned.
NOTES.
Some suggestions are here added from the Florists Ex-
change, as follows:
Everyone who has handled the Japanese Snowball in Spring knows
how quickly its huds swell when Winter ends, and how necessary it is
to get it planted the very first thing. It must be classed with the
Larch for early planting and shipping, for, unlike some shrubs of
early sprouting nature, it does not take kindly to being planted when
in leaf, or when near this condition. Because of this, plants of it
should be dug in Autumn and placed in cold storage for Spring use.
If no building suitable is available — it should be one kept at about
the freezing point — the plants should be buried under ground out-
doors until Spring opens, selecting a sloping bank for the purpose, or
at least a place where water drains away freely.
All early starting trees and shrubs should be treated in this way.
The Larch, already mentioned, for one, the Weeping Willow for
another, bush Honeysuckles, Spiraea sorbifolia, and several other
kinds that will come to mind as well.
Many nurserymen have cold storage houses already in which to
store, in Autumn, stock required for localities earlier than where they
are, and it works also to the advantage of buyers in colder States as
well, for when in the cold storehouse the plants can be kept in good
condition almost indefinitely, so that both early and late customers
may be supplied.
Florists have found benefit from having shrubs in flower at a
later date than usual with the varieties, and retarded plants such as
those held back in storage houses are very useful. It is quite com-
mon to treat Hydrangea paniculata grandiflora in this way, deferring
its planting until late May, or any time desired, which brings it in
flower long after the natural crop is over; and this course could be
adopted with any and all shrubs useful in the same way as the Hy-
drangea named. It is in favor of the latter shrub that it is aided by
pruning it back when planting it, with the object of making It thrive
even if the weather should be hot and dry, a pruning that the Snow-
ball and other shrubs that flower from their last season's growth
could not receive.
CHAPTER XXII.
POTATOES.
METHODS OF PRESEEVATION.
Indications lead to the conclusion that potatoes will fol-
low the history of cheese and apples in methods of preserva-
tion. In the early days of the cheese business, even after
cold storage was available, much cheese was stored in cellars
or basement storage or in ordinary ice refrigerators of large
capacity. Now, practically all cheese made reposes for a time
at least in cold storage. Apples were formerly mostly stored
in "common storage" or "frost-proof" storage, but now the
bulk of the crop not sold promptly for consumption is placed
immediately in cold storage. Likewise, potatoes in their early
history were, and we might say still are, stored in the cool
temperature of a basement or a cellar rather than in artificially
cooled space. In recent years, however, quite a large quantity
of seed potatoes have been cold stored and this has demon-
strated possibilities of successful storage which were not known
under the old methods, and will doubtless lead to a general
use of cold storage for keeping eating potatoes as well as those
used for' seed.
SEED POTATOES FOE BAELY CEOP PLANTING.
The business of growing early potatoes in the South for
Northern market is now an important one and the storage of
seed potatoes gives a good income to -a number of cold storage
houses. In many parts of the South the practice is to raise
two crops of potatoes per year on the same ground, the second
planting being in June and .Tuly, promptly on harvesting of
the first crop. It has been found that the first crop of potatoes
cannot be used as seed for the second crop, because it is too
498
POTATOES 499
slow in sprouting, and the second crop tubers have also proved
to be unsatisfactory for second planting for reasons not stated.
The best results have been obtained by shipping in North-
ern grown potatoes and placing them in cold storage until
wanted. A temperature of 38° F. to 40° F. has been em-
ployed, but it is believed that lower temperature would give
still better results, as will be suggested further on.
Around Louisville, Ky., the business is handled somewhat
differently than described above. Here second crop potato
growing does not mean two crops of potatoes on the same land,
but a crop of potatoes follow a crop of cabbage, cauliflowers,
etc. Seed from the so-called second crop for the following
year's use is put into cold storage, and planted from July
20 to August 15. Late varieties are planted first, and the
crop is mostly marketed for eating in February, March, April
and May. They are still unsprouted as late as May and in
perfect market condition. Early varieties are planted later,
and the vines are usually killed by frost about Oct. 1st to
15th, and while somewhat immature, are in good condition
for planting after lying dormant for four or five months.
Excellent results are reported from this practice. It is not
possible to use first crop potatoes from further south for the
same year's second crop planting at Louisville for the reason
that they have not lain dormant long enough and sprout
slowly or rot in the ground. Cold storage seed will come up
in a week or less if the ground is moist and warm.
Many Northern growers secure second crop seed from the
South, and place it in cold storage for early planting. While
the second crop potatoes are somewhat green and immature,
yet this does not in any way affect them for quick growing;
it seems in fact to assist prompt sprouting and vigorous grow-
ing when planted.
It is of the utmost importance that potatoes to be used for
seed must remain dormant for a period of four months or more.
"riTTING" FOR STORAGE.
Some of the above remarks apply to the securing of suit-
able tubers for storage. One of the chief points is that the seed
500 PRACTICAL COLD STORAGE
be placed promptly in the cold room. It has been demonstrated
that steady temperature, with steady humidity has much to
do with the vitality of the tubers for growth when taken out of
storage. A potato which has sprouted and dried out to the
extent of perhaps one-quarter or one-third its weight, certainly
cannot push the new growth like a firm, plump potato which
has not started growth.
The "fitting" of the tubers for cold storage is important.
Good farmers know that potatoes must not be placed at once
in the cellar when dug. There are two reasons for this. The
cellar will be dryer and lower in temperature later in the
season, and the potatoes must be allowed to dry and ripen up
and lose their surplus moisture before storing. It is cus-
tomary to allow the tubers to lay on the ground only long
enough to dry so that the soil will not adhere and then haul
them to cover where they are spread out and covered with bags
to protect from the light and allowed to dry and ripen. From
one to three weeks are commonly allowed for this. If, however,
potatoes are not harvested till late autumn and are fairly well
matured and allowed to dry off thoroughly in the field before
being picked up, they may safely be hauled direct to the cold
storage room, where they may be stored in open boxes or
crates or barrels without heading up for a few weeks and then
placed in the permanent storage package. Potatoes should, for
best keeping qualities, be fairly ripe when harvested. Potatoes
which "skin slip" will turn black and do not keep well, and
have a bad appearance when exposed for sale.
The necessary "fitting" of potatoes for storage depends
on conditions of soil when tubers are dug, degree of maturity,
and to some extent the character of the soil. Some years dur-
ing the harvesting season the soil is quite dry, and potatoes
dug under these conditions need very little "fitting." Other
years with the soil filled with water, the tubers may need two
weeks or more of exposure to air currents before placing in
cold storage packages.
PACKAGE.
All sorts of packages are used for shipping potatoes, boxes,
barrels, crates and bags, and the favorite method of shipping
POTATOES 501
full carloads is to handle in bulk as this is cheaper and a
heavier load may be placed in the car, which is an advantage
in extremely cold weather. Crates are used largely as a har-
vesting package as they are convenient, and allow of a circula-
tion of air, and the soil adhering readily drops off. Crates
may be used for storage for a few weeks only, but for perma-
nent storage boxes or barrels, or some tight wooden package
should be used. Bags or sacks should not be used as a storage
package except for short periods, as they lead to too great a
bulk being stored together, and besides the tubers may be
bruised or even crushed. By building racks or shelves at
intervals of about three feet in height potatoes may be stored in
bulk for several months at a high relative humidity with
fair success. The practice cannot be recommended, but where
suitable packages are not available it is permissible. Boxes
and barrels are about equally good as a storage package, but
preference is given in the storage of potatoes to the old reliable
barrel as it is in the storage of apples. Barrels make a strong
package which will stand rough handling and which is just
about air-tight enough to give the needed ventilation and
properly protect its contents. Storing in bulk is permissible
for short carry only and cannot be approved for any period
of longer than two months.
Whatever packages are used for cold storage purposes,
whether boxes or barrels, these may be used over again year
after year if local conditions make it advisable. If, for in-
stance, the cold storage house is near the place where the
tubers are grown, the storage package may be taken to the
fields and filled there. In shipping it is often found more
convenient to ship in sacks or in bulk than in barrels or boxes,
and for this reason the suggestion to use the wooden package
for storage purposes only, is a practical one.
One very important point must be borne in mind if
storing in a room where daylight is admitted: Potatoes will
become "sun struck" and turn black if exposed to daylight
for any considerable length of time. A package, therefore,
which will protect the tubers from the light is absolutely essen-
tial.
502 PRACTICAL. COLD STORAGE
TEMPERATURE.
While the correct temperature cannot be stated with
accuracy in the absence of definite data and the result of
experiment, 33° F. to 35° F. has been mentioned by those
best posted and with the most experience in the business. At
the same time the tendency in the storage of many products is
downward in temperature, and we doubt not but what potatoes
will in time be carried at 32° F. or even 30° F. and possibly
lower.
It is said that if subjected to too low a temperature for
considerable periods, say a month or more, potatoes gradually
become sweet to the taste when cooked. Chemists explain
this as being due to an enzymic action, whereby the starch,
of which a potato largely consists, is converted into sugar.
This action is going on in the tubers even at the low tem-
perature of cold storage, and it seems that the lessened respira-
tion or evaporation of moisture from the tubers more than
keeps space with the enzymic action. That is, lowering the
temperature reduces the respiration, while the enzymic action
is only slightly lessened. At ordinary temperatures the two
actions equalize each other to an extent that the sugar is
completely oxygenized. The sweetness of flesh caused by low
temperatures disappears when the tubers are again subjected
to ordinary temperatures. If potatoes were intended for seed
purposes this sweetness would be of no consequence.
The lowest temperature which potatoes will withstand
without damage has not been determined with any degree
of accuracy, but it has been reported that tubers stored in a
basement room with an earth floor, during severe winter
weather have successfully stood a temperature of 28° F. to
30° F. During a considerable portion of the winter the walls
were covered with frost. It would seem, therefore, that the idea
that potatoes would freeze and be completely ruined at a tem-
perature of 32° F. is incorrect. It is, however, well known
that if potatoes do freeze they are useless for any purpose, and
doubtless it is this serious result when frozen that has caused
people to believe that they freeze at about 82° F.
POTATOES 503
When potatoes are first placed in cold storage it may be
advisable to carry a temperature of 40° F. or 45° F. and
gradually bring it down to the temperature at which it is
finally desired to carry the tubers, and a few weeks at the
higher temperature might prove beneficial.
HUMIDITY.
No experimental data is available on the subject of hu-
midity for potato storage, but it is well known that the stor-
age room should not be too dry. It is, in fact, generally con-
sidered that the more moist a room can be carried within rea-
sonable limits, the better will the tubers keep. It is, of course,
possible to have the air so moist that it will cause mould, but
in cold storage this is hardly probable. The influence of a
greater or smaller quantity of goods in the cold storage room
where potatoes are stored would be important, but if the goods
were boxed or barreled, this would not have so much effect.
A cold storage room, to get the best results, should be filled as
full as possible. A room with few goods in it ordinarily means
a comparatively dry room, and this does not give best results.
A humidity of from 85° to 90° is suggested as correct for a
potato storage room with a temperature at from 33° F. to 35° F.
The use of chloride of calcium in a potato storage room is
essential if a heavy quantity of goods is stored in bulk. If
the room should be too damp or the goods carried for long
periods, a small amount of chloride of calcium exposed to the
air of the room would be beneficial, as it would tend to check
a growth of mould and keep the air pure as well as regulate
humidity.
MISCELLANEOUS.
E. H. Grubb, of Carbondale, Colo., states that while pros-
pecting in the early days, he met a prospector who directed him
to some potatoes which he had stored two years before in an
old tunnel at an altitude of 12,000 feet. The potatoes, Mr.
Grubb states, were found in perfect condition, being the same
as when dug. The tunnel had a circulation of air in it and
a temperature of about 40° F. Making due allowance for
the well-known preservative effect of Colorado mountain air,
504 PRACTICAL COLD STORAGE
it would seem that if the potatoes kept without rotting for as
long a period as two years, it was quite remarkable, and as
there must have been considerable change of temperature at
different seasons of the year, the long keeping possibilities of
potatoes were by this circumstance fully demonstrated. This
might argue against cold storage rather than for it, but it is
probable that the potatoes were not in the perfect condition
stated, and while they doubtless looked very good to a hungry
prospector, would hardly class as marketable.
It is reported that potatoes shipped in refrigerator cars
which are heavily iced, will not be as apt to freeze in very
cold weather as they would if the car were not iced. There
can be no scientific explanation of such a claim, and the only
practical reason is that with the ice bunkers filled with a
heavy weight of ice, there is a little more balance on the tem-
perature and a larger body or mass to be cooled before the
potatoes in the car will freeze. However, if the ice bunkers
are water-tight and water from the melting ice is allowed to
stand in them, as some of the cars are arranged, this would be
a very good reason why potatoes would not freeze as quickly
as they would without any ice or water in the bunkers. The
water in the bunkers would freeze before the temperature of
the car would be reduced much below the freezing point, and
thus the potatoes kept from freezing.
There is another old fashioned idea that potatoes will not
freeze in hauling as long as they are kept in motion. It is,
of course, a well known fact that any liquid or solid body will
not freeze as hard if kept in motion, but it will freeze just
as surely in motion as it will at rest and somewhat more
quickly. The scientific explanation is that ice crystals form
more quickly in liquids or bodies at rest than they will if
agitated. The difference in freezing point, however, would
be but slight, and this old fashioned idea is, therefore, largely
erroneous.
CHAPTER XXIII.
GRAPES.
LONG STORAGE OF GRAPES.
Comparatively little has actually been done in the success-
ful cold storage of grapes for long periods. There is, however,
some activity in this direction, and it seems that the large grow-
ers who produce grapes on a commercial scale, are experiment-
ing along this line. It has been found practicable to carry some
varieties until February, when small fruits are comparatively
scarce and prices high. The favorite winter keeping varieties are
the Catawbas and the Vergennes. The Concord and other sim-
ilar varieties do not seem to do as well in storage owing to the
fact that they loosen from the stems and decay starts at that
point.
For long period storage, grapes are removed from the
vines when barely matured, and placed in shallow boxes in the
packing house for a few days, until the stems have wilted and
the natural evaporation or sweating has taken place. They are
then packed in baskets lined with paraffine paper which is
carefully folded over the top so as to make a fairly air-tight
package. The fruit is carefully selected and carefully handled
from the vineyard to the packing house, and carefully handled
when placed in the baskets. It is not pressed or crushed into
the baskets as is sometimes done where grapes are packed for
prompt consumption. The baskets are only Jarred gently to
settle the grapes firmly into position.
"When picked and packed in this way the length of time
which grapes can be stored is quite remarkable. The writer
has long appreciated the possibilities in this line, but growers
have been so conservative in taking hold of the proposition, and
unwilling to put any money into a suitable cold storage plant,
505
S06 PRACTICAL COLD STORAGE
that the development of the cold storage of grapes has been
extremely slow. Of course the amount of business which can
be handled in this way is small as compared with the total
volume, as only certain varieties and only the best selected stock
should be stored; but where the best quality grapes can be
grown and where a suitable cold storage house is , available, a
handsome additional profit should accrue to the grower by
handling as above suggested.
EXPERIMENT OF AGRICULTURAL DEPARTMENT.
The Bureau of Plant Industry, U. S. Department of Agri-
culture, has made some experiments in grape storage and ship-
ping of which the following is a brief summary :
"The importations of fresh grapes from Spain during the
present season (1912) amount to nearly 900,000 barrels which
have sold at wholesale prices ranging from $2.50 to $7.00 per
barrel, or from 5 to 15 cents per pound, the bulk selling at
the lower price. Under ordinary conditions, most of the Cali-
fornia table grapes must be marketed within a period of a little
over two months and the early attempts to hold them in stor-
age for the holiday markets did not prove entirely successful.
"The Bureau investigations have shown the importance of
handling grapes with care to insure their being packed in sound
condition. It has also been found that it is impossible to hold
the varieties of grapes that are commercially grown in Califor-
nia any appreciable length of time without a filler of some kind.
The Spanish grapes are packed with a filler of ground cork. As
this material is both scarce and expensive in California, special
efforts were made to obtain a satisfactory substitute. Many dif-
ferent materials were tested but only one has thus far proved
wholly satisfactory. This is redwood sawdust, which is a waste
product of the California sawmills. Much to the surprise and
gratification of the Department investigators this material has
proven even superior in many ways to the ground cork. It is
found that the grapes hold longer and in better condition when
packed with the redwood sawdust. Great pains have been taken
to corroborate the results and the data have been consistent
throughout. It was necessary to learn how to prepare the saw-
dust in order to have the grapes remain in attractive and salable
GRAPES 507
condition. The sawdust must be perfectly dry and the finer
particles must be removed.
"A number of varieties have been under investigation, and
naturally their behavior under storage conditions has been
different. Of the varieties grown in commercial quantities, Red
Emperor, Malaga and Flame Tokay have been found to hold
best in storage. The lengths of time which these varieties may
be held vary from sixty to seventy days for the Flame Tokay
and Malaga, and from ninety to one hundred and ten days for
the Emperor.
"In the commercial test of the application of this work
during the past storage season the grapes were packed in drums
holding about twenty-seven pounds, and the work of packing
and shipping was done largely under the supervision of one of
the bureau representatives. The drums were forwarded from
California to Chicago and New York under refrigeration where
they were held at a temperature of 32 degrees in cold storage.
The Emperors proved to be the best for storage purposes and
formed the bulk of the grapes sold for the Christmas trade. The
best grapes of Flame Tokay may be held until Christmas, but
the ordinary run of this variety will not hold in first-class con-
dition beyond December 1. The Malaga varies considerably in
its behavior in storage, depending upon the conditions under
which it is produced. Some lots of this variety have been held
in first-class condition until January 1 in past years, while
others are not safe beyond December 1.
"The value of this work to the grape industry of California
is apparent when the full significance of the extension of the
marketing season is appreciated. The production of table
grapes in California is increasing and unless some way can be
found either to broaden the area over which the fruit may be
distributed, or to lengthen the marketing season, the industry
■will be face to face with a serious problem of over-production.
When it is considered that this country uses large quantities of
imported grapes, the demonstration of the possibility of replac-
ing the foreign product by one home grown, is worthy of the
most strenuous effort.
508 PRACTICAL COLD STORAGE
"The possibilities of packing California grapes with the
redwood sawdust filler for export are also recognized and efforts
are being made to extend the marketing area by this means.
A small test shipment of California Tokay Grapes shipped to
England was made during the past season and the fruit arrived
in excellent condition. The sawdust pack in drums is well
adapted to ocean transportation, because the necessarily rather
rough handling in loading and handling aboard does not affect
the grapes when packed in this way, while the ordinary open
crates are too weak to withstand rough handling, and in ad-
dition the grapes deteriorate during a long trip unless a filler is
used."
More recent reports are that grapes have been stored in
October and carried as late as January 17th, or a period of
three months. It is presumed that this is about the commercial
limit of the cold storage of grapes, as they are rather delicate
and not naturally substantial enough to handle or cold store
for any great length of time. It is to be regretted that in
reporting these experiments more information has not been
given as to temperature at which they were carried and some
discussion given on the subject of humidity, conditions of
storage, etc.
Some recent experiments conducted by the U. S. Depart-
ment of Agriculture in California in the shipment and storage
of grapes from the Fresno District indicate that the Emperor
and Almeria varieties of grapes may be packed in redwood
sawdust, stored at a temperature of 32° F., shipped to Eastern
markets and stored for a period of five to six months in sound
and useful condition. Muscatel grapes have been cold stored
for four months successfully as reported by W. E. Alexander
of Escondido, Calif. It seems that this method of packing
and storage is likely to develop into an important industry.
CHAPTER XXIV.
THE PRE-COOLING OF FRUIT.
OUTLINE.
The term "pre-cooling" as applied to fruit means the pro-
cess of rapidly and permanently reducing the temperature of
the fruit immediately after picking and before it is put into
cold storage proper or loaded into cars for transportation. Fruit
when removed from the tree immediately becomes a substance
without life, and the processes of decay are at once started and
continue more or less rapidly during the natural history of
the fruit, depending upon the temperature. With the softer
fruits, especially as represented by peaches, which form an im-
portant article of commerce, it is of the utmost importance that
the heat be taken out of the fruit promptly when picked in or-
der to transport it for several days to market in prime condi-
tion. Cooling is accomplished in various ways, which will be
described further on in this chapter either by mechanical re-
frigerating methods or by the use of ice or ice and salt. Pre-
cooling is necessary mostly because the so-called refrigerator
cars which are largely in use are not equipped with sufficient
cooling capacity to take the heat out of the goods after load-
ing into the cars.
ADVANTAGES OE PRE-COOLING.
It has been demonstrated by actual tests by the representa-
tives of the U. S. Department of Agriculture that warm fruit
loaded into a refrigerator car required from three to four days
to reach a temperature of 45° F., and even then the fruit in
the car was not uniformly cooled, that in the top of the car
being from 10° to 25° higher in temperature than that lo-
cated at the floor and near the ice bunkers. During this period
of three or four days the high temperature of the fruit and
the moisture and gases in the car result in conditions which
S09
510 PRACTICAL COLD STORAGE
promote decay and rapid deterioration. Fruit slightly blem-
ished or injured in picking under these conditions will on its
arrival in the market show up in poor condition and be un-
salable at the highest market price. It is claimed that a loss
of two million dollars has resulted to the citrus fruit growers
of the Pacific Coast in one season through failure to properly
cool and transport their product to the ultimate consuming
market. This is the shipper's viewpoint. From the view-
point of the transportation companies they are interested
in pre-cooling from the fact that an ordinary refrigerator car
as generally loaded will transport only about 400 boxes of
oranges, whereas the same car loaded with fruit properly
pre-cooled may hold from 550 to 600 boxes. More will be
said on this score in connection with suggestions for shipping
oranges which have been pre-cooled before shipment.
Prior to the year 1905 the peach growers of Georgia and
California were unable to ship ripe peaches in refrigerator cars
to distant markets without incurring heavy losses because of
over ripening and decay during transit. The same trouble was
experienced more or less with California oranges and grapes,
and other products of lesser importance have come in for their
share of losses and unsatisfactory results. Pre-cooling where
properly applied will result in saving a greater part of the
losses which have heretofore been encountered, but necssarily
pre-cooling will not take the place of care and common sense
and experience and skill in the handling of any perishable prod-
uct. Pre-cooling is only one of the steps necessary to attain
an approximately perfect result in giving the ultimate con-
sumer a first class quality of fruit. What is said above should
not be construed as meaning that pre-cooling facilities are now
available to fruit shippers where needed. Such is far from the
case, and as a matter of fact pre-cooling is only just beginning,
and probably not one-tenth of the fruit shipped to market is
subject to adequate pre-cooling conditions.
METHODS OP PKE-COOLING.
There are two general methods of pre-cooling in use :
First — The car pre-cooling method, and
Second — The warehouse pre-cooHng method.
THE PRE-COOLING OF FRUIT Sll
Pre-cooling fruit in cars after loading has been advocated
and put forward by the transportation companies to a con-
siderable extent, and they have erected some very large and ex-
pensive pre-cooling plants for this purpose. No doubt they
have been influenced in this by the control which this would
give them of the business as well as the revenue which would
result. It is the positive opinion of the author, however, that
this method is not theoretically correct, nor is it practically ef-
ficient, nor is it likely to come into general use. The disad-
vantages of this method are so great as compared with the
warehouse method of cooling that it will doubtless fall into dis-
use, and those plants which have already been erected for this
purpose will probably be put to other uses.
CAK PRE-COOLING.
Car pre-cooling is accomplished by setting the cars loaded
with fruit on a side-track adjacent to the cooling plant. Cold
air ducts or chutes are attached to the trap doors through which
ice is loaded into the ice bunker, and in some cases the cold air
ducts are attached to the doors of the car. Suitable cold air
and return warm ducts are provided. A fan circulates the cold
air at a low temperature rapidly through the ducts which re-
sults in circulation of the air through the car removing the
heat to a coil room or bunker room containing refrigerating
pipe coils where the heat is absorbed, and the air after being
cooled is again sent on its mission of cooling. This results in
a very constant cooling or chilling, but it may be said that the
fruit is not uniformly cooled throughout the car by this method,
as it is not possible with ordinary waste of loading to secure a
uniform flow of air throughout the body of goods in the car.
Some very remarkable quick cooling results have been obtained
by this method of cooling, the temperature being reduced from
that of the ordinary outside air, say 80° to 90° F. down to
35° or 40° F. in from one to three hours. Very rapid cooling is
absolutely necessary with this method, for the reason that it
is not permissible for obvious practical reasons to have loaded
cars standing on sidetrack for any considerable length of time.
A rapid cooling or chilling of fruit is positively detrimental to
512 PRACTICAL COLD STORAGE
its quality, and it is one of the reasons why car cooling can-
not produce as perfect results as may be had with warehouse
cooling. Added to this the lack of uniformity in cooling as
above suggested, and added still again to this the fact that the
cars may stand on the siding for some hours waiting their turn
at the pre-cooling plant, it may be seen that the car cooling,
practically, is a very difficult thing to work out, to say nothing
of the inferior cooling results secured.
A car pre-cooling plant must be equipped relatively with
a very large refrigerating capacity in order to accomplish the
very rapid cooling required on account of the limited time
available. This means a very high first cost for a plant of
this type, and the construction of numerous plants at points
where but few cars are to be cooled is impracticable for this
reason. The relative high cost of the machinery required and
the short time each day that this machinery can be used from
a commercial standpoint makes the car pre-cooling plant a
difficult problem. If, as has already been established at sev-
eral places, it is attempted to concentrate the car cooling plants
at chief shipping points, the delay and additional cost of switch-
ing cars to such plants, is a further disadvantage. There
are other practical objections to car cooling also, and the dif-
ficulty of attaching the removable ducts to the cars without
much loss of refrigeration due to leakage of cold air, has not
been overcome.
■WAREHOUSE PEE-COOLING.
Pre-cooling rooms arranged for this purpose need not be
essential] j'^ different than regular cold storage rooms except that
it is desirable to take the heat out of the fruit as rapidly as prac-
tical, and therefore, a larger refrigerating capacity is necessary
and a fan system of air circulation desirable although not ab-
solutelj' necessary. In warehouse pre-cooling the time ele-
ment is not so important, and the fruit may be advantageous-
ly kept in storage under refrigeration for several days if nec-
essary. Three days or 72 hours is considered correct by this
method for citrus fruits and the longer keeping varieties and
24 to 48 hours for peaches and softer fruits. A reasonable
THE PRE-COOLING OF FRUIT 513
length of time should be taken for pre-cooling because a sud-
den cooling or chilling of warm fruit means a rapid change in
its cell structure and this hastens deterioration. Therefore, the
longer period practically that is consumed in fruit pre-cooling,
the better the results to be expected. In warehouse cooling the
air need not be as cold nor circulated as rapidly as in the car
method. The room may be better insulated and better con-
structed, and there will be very much less loss of refrigeration,
and the cooling is accomplished at much lower cost. The
warehouse type of plant is the only one practicable for the
shipper who desires to pre-cool his own fruit, or for fruit as-
sociations who desire to put up their own plant for this pur-
pose.
Another advantage of the warehouse method of pre-cool-
ing is the possibility of loading a much greater quantity of
fruit into a car of a certain given capacity. With the car cool-
ing method the fruit must be piled open so as to allow a free
circulation of air throughout, whereas with the warehouse
method wherein the fruit is cooled before loading, it is not
neces&ary to leave any space whatever between the packages of
fruit in the car, and this results in increasing the capacity of
each car by 25 per cent to 50 per cent as has already been sug-
gested.
POSSIBILITIES OF FRUIT PRE-COOLING,
Aside from the advantage of pre-cooling fruit to prevent
deterioration and to have it arrive on the market in the best
possible condition there are some practical advantages which are
not yet generally understood.
It has apparently been assumed that pre-cooled fruit after
loading into refrigerator cars, must necessarily be iced in transit
to maintain temperatures in the cars and deliver the fruit in
prime condition at destination. This assumption is based on
the use of the average refrigerator cars now in service. If suit-
ably insulated cars were provided, no ice bunkers or other
means of refrigerating would be necessary for a ten days' trip
in the warmest weather. By suitable insulation is meant in-
sulation equivalent to what is now used in our best cold storage
houses.
514 PRACTICAL COLD STORAGE
Assuming a suitably insulated car, and that it will be
loaded full of fruit, the more the better for our purpose. If
the fruit is cooled before shipping, to 32° F. and the doors and
ventilators tightly closed, this car will arrive at its destination
during average summer weather at a temperature of from 45'
F. to 50° F. This would be a very suitable temperature for
unloading the fruit into the average temperature to be en-
countered during the spring or summer season. Of course, in
shipping during the winter when low temperatures are likely
to be encountered in transit or when unloading, it would be
better to pre-cool the fruit to only 35° F. or 38° F. These
statements are approximate, and are based on theoretically cor-
rect figures and can be depended upon in practice.
To insure best results under the above suggested method,
not only should the fruit be loaded tightly into the car with-
out air spaces between or around the fruit, but it should be
protected on top if much space is left between the fruit and
the top of the car, by means of thick, heavy paper spread across
the car and secured by battens. If the car is loaded nearly to
the ceiling this need not be done. Of course, it is unnecessary
to state that if the car is loaded during warm weather, it
should be blown out for an hour or so with cold air before
loading fruit into it, and a suitable loading vestibule reaching to
the sides of the car to not only protect the fruit while loading,
but to keep the car cold, would be desirable.
It must be understood that this applies to fruit which is
pre-cooled before loading and which is loaded into an insulated
car, which is suitably insulated equal to the best modern cold
storage insulation. Under this method of handling the ventila-
tor of the car should not be opened at any time while en route
to destination. It is assumed that at least 600 boxes of oranges
would be loaded into one car.
It will be readily appreciated that the above suggested
scheme opens up some possibilities in fruit shipping which were
not dreamed of up to very recent date. It would seem that
icing by the railroads with their arbitrary and outrageous
charges therefor would be entirely eliminated from the ship-
ping of fruit for long distances in future. The plan proposed
THE PRE-COOLING OF FRUIT 515
of pre-cooling and carrying through to destination without
icing or without supplying refrigeration will not only be a
great saving to the shipper in loss of fruit by damage while in
transit, but it will also be a big saving to the railroads on ac-
count of not being obliged to haul ice or other means of cool-
ing, and lose time by the stopping of trains at intervals for re-
icing. The entire proposition looks so simple and sensible that
there can be no real argument against it except preconceived
ideas and former practice. It will be interesting to see who will
be first to adopt and work out this suggestion.
Pre-cooling has already become a very important feature
of fruit production and marketing, but the developments are
unimportant as compared with what they will be in future
years. The general process has been thoroughly demonstrated
and is by the best informed and best qualified judges of the
situation, admitted to be a necessity for proper marketing.
Adequate facilities will doubtless be provided after a time, but
this will be when those who are most vitally interested, the
growers and shippers, are thoroughly convinced that it will
be profitable, and when they are better able financially to pro-
vide their own pre-cooling facilities. It will not do at all to
depend on the transportation companies for means for doing
this work. They are chiefly interested in getting their pay for
transportation, and as long as they can get this with present
facilities and equipment, it is not at all likely that they will
see fit to improve them materially. What is said here applies
particularly to refrigerator cars and their construction which
we will now consider separately.
KEFEIGERATOR CARS.
The refrigerator car service of this country is deficient
and unsatisfactory, and this fact will doubtless be admitted by
those who really know and at the same time are disinterested.
While the average refrigerator car is certainly better than a
box car for shipping perishable goods, it is far from satisfactory
and far from being as perfect as it might be, and the cars now
in use fall far short of what they should be considering the
length of time through which they have been developing.
516 PRACTICAL COLD STORAGE
If reasons are sought for the present inferior refrigerator
car service, the answer bj'^ those in control of the business is
that they are handicapped by present types of construction and
former practice and by the necessity of keeping down the cost,
as well as by the contracted area or space available. These
reasons are plausible and to some extent reasonable, and they
are based on facts, but the reasons are nothing more than
reasons, and they may all be overcome. It is, of course, neces-
sary to keep withia the natural practical limits of car dimen-
sions, but these are not all arbitrary within reason. Present
construction and former practice except as it applies to methods
of icing, loading, etc., need not stand in the way of radical
changes if they are found to be improvements. Keeping the
cost down is all right enough from a business standpoint,, bui
if great benefits are to be derived from improved construction
with increased cost, the first cost of a refrigerator car need not
stand in the way of improvements.
There are, as the author sees it, two chief reasons which
are not mentioned above, and .which probably have more bear-
ing on the present inferior refrigerator car construction and
service, practically considered, than the ones given:
First : The refrigerator car service is mostly in the hands
of two or three strong companies. Improved devices suggested
by outsiders must first be approved by those in authority; and
this means the approval by persons generally with limited ex-
perience in refrigeration and with no scientific training. Add
to this the possibility that railroad officials and their friends are
interested in the building of refrigerator cars now in use, and
a good reason for lack of progress is plain.
Second : The refrigerator car lines are in business to make
money. If they can get as much for the use of a poorly in-
sulated car of inferior construction as for a first class car, why
should they provide something better? It would be an awful
thing if they should spend $200 or $400 more in building
and insulating a more perfect car. The shippers pay the bill
for icing, and why should the cost of cooling interest them?
And if the fruit partly spoils or deteriorates as it frequently
does, it is the shippers' loss, not the car lines'.
THE PRE-COOLING OF FRUIT 517
There are, of course, other things to be considered like
lack of proper skill and knowledge of what constitutes suitable
insulation for a given work, but the above may be considered as
chief. Considering the fact that shippers the country over
have been paying a price high enough for the best of equipment
and service, the first cost of a refrigerator car should be of
secondary importance. Surely there is no excuse for economy
to the extent of a few hundred dollars on each car, when a
positive saving in operating cost to much more than pay big
interest on the investment, may be shown, to say nothing of
the saving in damage to goods in transit.
We now get back to pre-cooling. As has been already
suggested above, pre-cooled oranges (pre-cooled during a period
of two or three days in the packing house and not for as many
hours at the railroad car-cooling plant) are now being shipped
without icing during the cool weather of March and April in
the inferior refrigerator cars now provided. If suitably in-
sulated cars were obtainable, oranges properly pre-cooled could
be shipped from California to New York in any weather with-
out icing, and would arrive in really better condition than
when shipped with ice in the regular way, and there would not
be any necessity for icing anywhere if the car insulation were
as good as the average cold storage warehouse. The insulation
of the present refrigerator car is only an excuse for insulation,
as it is not more than one-quarter to one-third the insulation
considered correct for a modern cold storage plant of small
capacity.
It will be claimed that additional insulation means the
loss of so much space, as well as increasing the weight to be
hauled. This will be such a small fraction of the possible
saving resulting from loading 25% to 50% more fruit into a car
when the fruit is properly pre-cooled, that it needs no answer.
The National League of Commission Merchants assembled
in convention early in the year 1913 offered resolutions con-
demning the present equipment of the private refrigerator car
lines as inadequate and obsolete, and suggesting that this
feature of the transportation business be put under the juris-
diction of the Interstate Commerce Commission. They also
518 PRACTICAL COLD STORAGE
passed resolutions favoring the building of pre-cooling plants
at shipping centers. This fact is mentioned to show that re-
frigerator cars and pre-cooling are closely allied, and a reprfi-
sentative body of produce dealers like the National League of
Commission Merchants may be considered qualified to pass
on the results which have been secured in fruit transportation
and shipping.
Criticism is perhaps unfair without suggestions for im-
provement, and the author, therefore, offers the following sug-
gestions for improving the insulation of refrigerator cars. It
is not practicable to offer suggestions for improved refrigeration
as this involves complicated mechanical details, but improved
insulation is such a crying need that it is very easy indeed to
suggest improvements along this line.
It may be interesting to note that the present average
insulation of a refrigerator car consists of not more than one
to two inches in thickness of insulating material, and not that
much where the framework of the car interferes. There are,
of course, some air spaces, but air spaces are obsolete as insula-
tion, as is now well known by competent refrigerating engin-
eers. The suggestion, therefore, is made that the insulation be
increased to at least six inches of some of the better insulating
materials like hair felt, or sheet cork, and that the frame of
the car itself be filled with some material like mill shavings or
granulated cork. This material must, of course, be properly
protected from access and penetration of air and moisture, and
this may be easily accomplished by using the best grades of
insulating paper.
The question at once comes up as to what additional sum
of money this would mean in increased cost of a car, and
roughly speaking, assuming the exposed surface of an ordinary
refrigerator car at 1500 square feet, the extra expense of suitable
insulation over what is now being used would be in the neigh-
borhood of $400 per car. Ample insulation in a refrigerator
car is especially necessary on account of the large outside ex-
posure compared with the cubic capacity, also because the car
is exposed to the direct rays of the sun.
THE PRE-COOLING OF FRUIT 519
If the refrigerator car service were handled as most other
businesses are necessarily handled, and those who own and
operate the refrigerator cars were obliged to pay for the icing
of same out of their own pockets, the cost of increased insula-
tion would be paid in a year or two in the actual saving in ice
consumption to say nothing about the great saving from de-
terioration of the perishable goods which are transported in
the car. Those who are responsible for the building and operat-
ing of refrigerator cars must be induced by peaceable means,
if possible, or by compulsion if more reasonable methods fail,
to provide adequately insulated cars for both summer and
winter service.
What constitutes adequate insulation is necessarily sub-
ject to a difference of opinion, but this can all be figured out
in dollars and cents when it is reduced to the actual loss from
ice melting, and if something may be allowed for unnecessary
loss from damage to perishable goods shipped, the showing is
in favor of a heavy insulation on refrigerator cars instead of
the present flimsy and inadequate quantity which is provided
as a mere excuse and called suitable insulation. The refriger-
ator car service up to the present time is almost as bad an
abuse and an imposition on the shippers of perishable goods
as the express abuse has been on the shippers heretofore.
SUGGESTIONS ON SHIPPING ORANGES WHEN THOROUGHLY PRE-
COOLED IN PACKING HOUSE.
During March pre-cool to 36 or 38 degrees only.
After March, pre-cool to 32 degrees. Do not use ice in the
ice bunkers of refrigerator cars.
Load tightly in the car and load as heavy as the rules of
the railroad, or circumstances, will permit. It should not be
necessary to leave more than a foot of space above boxes at the
top of the car.
Put paper on top tier of fruit if not loading up to capacity.
Run the paper crosswise, lapping about 6" to 12" and fasten
with lath on both sides. Use as wide paper as obtainable to
avoid multiplicity of joints.
Paper as tightly as convenient the openings from the body
of the car to the ice bunkers. This is to be done, of course,
520 PRACTICAL COLD STORAGE
only when the shipments are not iced either before shipment
or in transit. Use a heavy and rather porous paper rather than
the glazed insulating paper.
Protect fruit fully from contact with air while moving
from cooling rooms to the car. Extreme care is especially
needed at the car door. If a suitable canvas vestibule is pro-
vided, the car may be too dark to work in and an extension
electric light may be used.
It may be possible to cool the car partly in warm weather
before loading fruit into it, by attaching suitable cold air
spouts for an hour or two, much as is done at the railroad pre-
cooling plants.
The idea in not cooling to 32 degrees in March is to, pro-
vide some resistance to frost, if below freezing temperatures
are encountered in transit. Also from the fact that higher
temperatures will answer as well during cool weather.
It seems that we are not near the car capacity with even
as many as 600 boxes. If so, we are limited only by the
number of boxes possible to load into the car. There may,
however, be some business reason for not loading a larger
number of boxes than at present.
By papering the openings from the car to the ice bunkers
and loading heavily, a mass of cold fruit is obtained which will
aid much in carrying the low temperature for several days.
Note that these suggestions apply only to pre-cooled fruit,
which is not to be iced in the car either at time of shipping or
in transit.
CAK COOLING METHOD ILLUSTRATED.
The plan and section shown herewith represent on a small
scale the principle of the car method of pre-cooling. The
essential parts of such a plant consist of the primary means of
cooling located in coil room or bunker room; a fan for cir-
culating the air over the primary means of cooling, and suit-
able discharge and return ducts for conveying the air to and
from the car to be cooled. In the plant here illustrated flexible
detachable ducts are arranged so as to be attached to the trap
doors of the ice bunker of the ordinary refrigerator car. This
cooling plant was designed by the author and has been sub-
THE PRE-COOLING OF FRUIT
521
jected to a satisfactory test, and the following description gives
the result of same:
"The car is so connected up to the cooling room that the
air goes in at one end, through the ice bunker door and out at
the opposite end, then back through the room to be re-cooled.
In this method the fruit is given air at a temperature of ten
or fifteen degrees colder than the temperature of the car and
within an hour the temperature of the air going into the car
is reduced to about 35° F. During the next hour the tempera-
ture of the air is reduced to 32° F. The cooler and fan are
of sufficient caj^acity to bring the temperature of the car down
to 32° in from three to six hours, according to the pack of
the fruit and the temperature in the beginning.
'"The efficiency of this system of pre-cooling was tested
bv the Northern Pacific Railwav Co.. who had one of their
PIG. 1— FRUIT PACKING HOUSE .\ND PRE-COOLING PLANT,
UPl-AND HEIGHTS ORANGE ASSO., UPLAND, CAL.
most modern insulated I'efrigerator cars loaded with pears and
placed on track in the state of Washington for pre-cooling. A
cold blast was forced through this car for twelve hours until
the temperature of the air in and out showed the same, 34° F. ;
then the ice bunkers were thoroughly filled, all doors and
openings to the car were locked and the keys turned over to an
attendant who accompanied the car to Minneapolis to see that
522
PRACTICAL COLD STORAGE
no changes were made enroute. At Minneapolis the ice bunk-
ers were well filled, temperature at the top and bottom of the
fruit at the middle of the car still remained 34°, and the fruit
was in prime condition. The car was forwarded to Chicago,
where the same conditions were observed as to ice, temperature
and condition of fruit. From here it was continued to New
I
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FIG. 2— PLAN OF BASEMENT.
York city, where an inspection showed one ice bunker half full
of ice, one two-thirds full and the temperature of fruit at the
top warmed up to 36°, while the temperature on the floor
still remained 34° and the fruit in prime condition. By this
pre-cooling process peaches have reached Texas and Philadel-
phia in first class condition."
THE PRE-COOLING OF FRUIT
S23
WAREHOUSE METHOD OF PRE-COOLING.
The pre-cooling plant or apparatus of the Upland Heights
Orange Association shown in the accompanying illustrations
is located in the basement of the building entirely below
the platform level, and a very good idea of the arrangement
of the pre-cooling rooms is shown in the basement plan. The
transverse and longitudinal sections also show the relation of
the pre-cooling plant to the packing room on the main floor
of the building.
To those who have never visited a fruit i^acking plant,
the complicated machinery used for handling, grading, sort-
ing, packing, storage and loading of frviit into cars is some-
PIG. 3— VIEW IN PACKING ROOM, UPLAND PLANT.
thing of a novelty, not to say a revelation of the possibilities of
automatic machinery. A bird's eye view of the graders, as they
are called, is shown in the view of the interior. These con-
sist of belts which carry the fruit along until it drops into the
receptacle arranged for its particular size. Before passing to
the graders, the fruit is delivered onto traveling belts where
it is sorted by experts. From the graders where the fruit is
524
PRACTICAL COLD STORAGE
graded into sizes, it is taken by the packers, wrapped with paper
and packed into boxes. After having covers nailed on, the
fruit is placed on a conveyor which delivers it down to the
pre-cooling rooms in the basement. The fruit enters through
the corridor, and may be delivered to any one of the four
pre-cooling rooms. Each room has a capacity of three car-
loads, and this represents the daily pre-cooling capacity of
the plant. For instance: Room No. 1 may be loaded with
fruit today; room No. 2 tomorrow; and room No. 3 the third
day. While room No. 1 is being discharged on the fourth
day, room No. 4 is being loaded; so that allowing three days
FIG. 4 — TRANSVERSE SECTION.
for pre-cooling and with four rooms, one extra room is given
for the loading and unloading of fruit. After being pre-
cooled, the fruit can pass out through the corridor, and by
means of endless chain conveyors and elevators is delivered
directly up to the car platform shown in the exterior view,
where it is loaded directly into a refrigerator car without ex-
posure to warm air.
The pre-cooling apparatus and system consists of: first,
the ice room; and second, the coil room, both shown in the
basement plan. The ice room is to be kept filled with ice which
is delivered in cars as required. Air from the ice room is, by
means of a fan and suitable air ducts and gates delivered to
THE PRE-COOLING OF FRUIT
525
any one or more of the four pre-cooling rooms and for any
period required. The air from the ice room is used for cooling
for a period of from one to two days and the temperature of
the fruit brought down to about 40° to 45° F. After bringing
the fruit down to this temperature by means of air from the
ice room, again by a fan and suitable arrangement of air
ducts and gates, air is used from the coil room until the tem-
perature is brought down to the desired point for shipment,
about 32° to 35° F. The length of time required depends
necessarily on temperature of fruit when stored and
quantity of fruit under pre-cooling at one time. When
cooling three cars per day it has been found that
FIG. 5 — LONGITUDINAL, SECTION.
in about forty-eight hours air from the ice room will reduce
the temperature of the fruit to 45° F., and that in about
twenty-four hours air from the coil room will still further re-
duce the temperature of the fruit to 35° F.
When ice is delivered from the cars it is loaded into the
ice room by means of a lowering rig. Located in the ice room
is the ice crusher. This is arranged to deliver ice to an endless
chain bucket elevator, which in turn delivers it to a spiral
conveyor, which is shown in the transverse section. From the
spiral conveyor by means of a flexible spout the ice is delivered
irectly to the primary tanks of the Cooper brine system.
526
PRACTICAL COLD STORAGE
The pre-cooling plant is equipped with the complete
Cooper Sj'stems with the exception of the ventilating system.
Each one of the four rooms is equipped with the false floor
and false ceiling system of air circulation. The coil room con-
tains the secondary coils and these coils are equipped with the
Cooper calcium jjrocess for preventing frost on the cooling pipes
and purifying and drying the air of the room.
PLANT OF POMONA VALLEY ICE CO.
In and near Pomona, which is one of the great centers of
the orange industry, a number of the Orange Growers' Associa-
FIG. e — PRE-COOLING AND COLD STORAGE PLANT, POMONA VAL-
LEY ICE CO., POMONA, CAL. WAGON APPROACH AND
RECEIVING PLATFORM.
Mountains a mile higli may be seen dimly to tlie left.
tions saw the advantage of pre-cooling their fruit before loading
it into the cars, and the further advantage of being able to
hold in cold storage for a time, some of their fruit instead of
shipping it all as fast as packed. In this way a considerable
business was offered to the Pomona A^alley Ice Company, which
has a well equipped ice factory at this point. For a time the
THE PRE-COOLING OF FRUIT
527
oranges sent to this concern for pre-cooling or storage were
handled in one section of their ice storage rooms, but as that
space was needed for the storage of ice, the company decided
about a year ago to erect a pre-cooling and cold storage house
especially designed for the handling of oranges.
Views of this plant are shown herewith. The building
is approximately 60x90 feet, with a basement and two floors
above ground. Commodious hallways cross through the build-
ing from the wagon platform to the railroad side of the build-
FIG. 7 — BASEMENT PLAN.
ing, and on either side of this hallway, in the basement, are
two storage rooms, each of a capacity of from five to seven car-
loads, according to the height to which the boxes are piled.
The same arrangement of rooms occurs on the first floor. On
one side of the hallway on the second floor are two more stor-
age rooms, and on the other side next to the factory are four
528
PRACTICAL COLD STORAGE
coil rooms. The general arrangement of plant is shown by
the plans and sections.
As will be seen in the accompanying view, each coil is
made of a continuous bent pipe. The Cooper forced air circu-
lating system is used, air being driven by a special fan located
in each coil room through air-ducts leading to the various stor-
age rooms. In one of the accompanying views these air-ducts
can be seen, also the perforations in the false floor through
which the air is admitted to the storage rooms. One can
FIG. 8— POMONA VALLEY ICE CO. PRE-COOLING PLANT.
Railroad side showing platform on which ice is brought from ice storage
to the left and loaded into the bunkers of refrigerator cars.
also see in this same picture, the corresponding openings in
the false ceiling through which the air is returned to the
coil rooms to be again chilled after it has been somewhat
warmed by doing its work of refrigeration. No difficulty is
found in maintaining any desired temperature. There is a
surprisingly small difference in temperature between the coil
rooms and the storage rooms, and even when it is found de-
sirable to not operate the refrigerating machinery for some
hours, practically no rise of temperature occurs in the storage
rooms containing fruit which has been thoroughly cooled.
This arrangement of combined ice making and pre-cooling
THE PRE-COOLING OF FRUIT
529
seems to be a mutually advantageous scheme for an ice plant
located in a fruit growing district, and for growers located
near such a plant. It makes business for the one and furnishes
very desirable facilities for the other, and at storage rates which
the experienced manager of a refrigerating plant can readily
understand are less than could be obtained by a fruit shipping
concern which operates its plant only for pre-cooling and is
therefore able to use its full capacity during only a compara-
tively small portion of each year.
FIG. 9 — VIEW' IN ORANGE PRE-COOLING AND STORAGE ROOM.
Equipped wUh the Cooper False Floor and False Celling System of Air
Circulation.
SOME FIGURES ON FRUIT PRE-COOLING.
Facts and figures are always interesting even though they
may be fragmentary and somewhat incomplete, and as a gen-
eral thing facts and figures cannot be made to cover all cases.
The following, however, will be of some general assistance :
SHIPPING ORANGES WITHOUT ICING.
As applied to the California orange shipping service it has
been already suggested in this chapter that oranges might be
shipped after being properly pre-cooled, in a suitably insulated
car for several days without the necessity of re-icing, and a
530
PRACTICAL COLD STORAGE
few figures covering the possibilities of this subject will, there-
fore, prove useful. Assuming a car of 600 boxes of oranges
weighing 70 pounds each, to be loaded into a refrigerator car
with insulation equivalent to what might be called first class
cold storage insulation, and such as the author has commonly
designed for cold storage work, the cooling results could be ex-
llaillraakcl aiellng
FIG. 10 — FIRST FLOOR PLAN.
pected if the fruit were cooled to 32° F. before loading it into the
car, and the car chilled by blowing it out with cold air before the
fruit was loaded, and assuming that the car in transit would be
exposed during a period of eight days to an average temperature
of between 80° F. and 85° F.; the oranges under these condi-
tions would arrive at their destination at a temperature of about
THE PRE-COOLING OF FRUIT 531
50° F. In other words the stored up refrigeration in the 42,000
pounds of oranges cooled to 32° F. would be sufficient to carry
the refrigeration for eight days with a final temperature on
the fruit of 50° F., if the car were exposed to an average tem-
perature of 80° to 85° F. while in transit. It would be better
for the oranges to arrive on the market at a temperature of
50° F. than 32° F., and they would be in better condition for
unloading and exposure to a comparatively high temperature.
These figures are approximate, but they are sufficiently accurate
to show the possibilities of fruit pre-cooling and transijortation
if suitably insulated cars are provided. In other words re-
FIG 11 — VIEW IN COIL ROOJI SHOWTNO FROSTED AJTMONIA COILS.
SECOND FLOOR PLAN.
frigerator cars would not be necessary, but only insulated cars
providing the insulation were of sufficient value and equal to
the author's standard cold storage insulation.
QUANTITY OF ICE REQUIRED FOR PRE-COOLING.
The cost of pre-cooling may be figured on a basis of ice
costs, and the following figures will prove useful in this con-
nection :
Taking gross weight of the average orange box, (85
pounds) and 448 boxes to the car, this Avould give us 38,080
pounds. The specific heat of oranges is .92, and the tons of
532
PRACTICAL COLD STORAGE
refrigeration required for cooling a car would be computed as
follows :
38080X.92X36''
z= 4.44 tons
284,000
In the above 36° represents the range of temperature, or
say from 70° F. down to 34° F. The product of the numbei
of pounds multiplied by the specific heat, multiplied by tem-
perature range, and divided by 284,000 (the number of heat
units representing a ton of ice melting) gives the number of
FIG. 12— SECOND FLOOR PLAN.
tons of refrigeration required to do the work of cooling; or
4.44 tons. This is doubtless not exact, as the estimated gross
weight of a box of oranges is taken, and the specific heat of
the wood in the box is not exactly the same as the fruit itself.
The figures, however, are near enough for any practical pur-
pose. It must be understood, however, that this does not repre-
sent accurately the amount of ice required to do the entire
THE PRE-COOLING OF FRUIT
533
cooling, for the reason that no heat leakage through the in-
sulated walls of the cooling room is represented in the above
calculation, and as this would be a variable quantity depending
on outside temperature, insulation, etc., it may be neglected.
PRE-COOI,ING GRA.PES.
Assuming a carload of 24,000 pounds of grapes is to be
cooled from 85° F. to 35° F. or through a range of 50° F.
This will mean approximately that a pound of ice will cool
nearly three pounds of fruit, and it will, therefore, take about
four tons of ice to cool a car of grapes. If the ice costs $4.00
FIG. 13 — LONGITUDINAL SECTION.
per ton it would require $16 worth of ice to do the actual cool-
ing of grapes. To this would need to be added about 25% for
heat leakage and other losses, and on this basis about $20
would be the cost of pre-cooling a carload of grapes through
the range of temperature indicated. In many places ice may
be had at a much lower cost than this, especially in natural ice
territories, and in other places the ice costs may be higher.
SOME ADDITIONAL COOLING COSTS.
At Pomona, California the Fruit Growers' Exchange
formerly secured their refrigeration from the local ice plant
S34
PRACTICAL COLD STORAGE
and paid for same on a basis of four cents per box. They
also figured that it cost them $2.00 per car to place the fruit in
the rooms and remove it to the car on gravity carriers. They
paid from $3.00 to $3.25 per ton for ice in the bunkers of the
car, and their total pre-cooling and pre-icing charge was figured
at about $32.50 per car, allowing for interest, depreciation and
taxes. This plant handled between 400 and 500 carloads per
year, and their rooms had a total capacity of about 42 cars of
fruit. These rooms were cooled by a fan system of air circula-
tion from a bunker room with direct expansion ammonia pip-
ing, and the total cost of cooling rooms and plant represented
an investment of between $25,000 and $30,000.
t. J i. i
FIG. 14— TRANSVERSE SECTION.
At East Highlands, California, the Fruit Association has
a cold storage and ice making plant complete. There are six
rooms with a combined storage capacity of about 24 carloads,
with five carloads per day capacity for pre-cooling. About 48
hours is consumed in reducing the temperature of the fruit to
33° F. The method of cooling is gravity air circulation, with
the refrigerating pipes located above the fruit room. The total
cost of this plant was about $50,000.
At the plant of the Upland Heights Orange Association,
described in preceding pages about 150 carloads of fruit are
THE PRE-COOLING OF FRUIT
535
handled per year, and there are four cold storage rooms with a
combined capacity of about 12 carloads, and the plant has a
cooling capacity of about three cars per day. The ice required
for pre-cooling and pre-icing costs about $3.75 per ton freight
paid to Upland. The total cost of this plant including equip-
ment and insulation of the rooms, but not including any part
of the building cost was about $11,000. G. Harold Powell,
^^^
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. £-,
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n
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FIG. 15 — VIEW IN CORRIDOR IN BASEMENT.
In the background, spiral of incoming gravity conveyor is shown and
sections of roller conveyor leading to outgoing elevator.
the well known fruit expert, has the following comments on
this system : "The advantage of this system lies in the fact that
the shipper is relieved of the management and maintenance of
a complicated refrigerating plant. It is easily operated. The
depreciation is comparatively small. The practicability of the
536 PRACTICAL COLD STORAGE
system depends on the prices at which the shipper can pur-
chase the ice. It may cost more per ton for the ice for this
type of plant than the cost of ice manufactured at the shippers'
mechanical ice plant. The operating expense and the main-
tenance of the gravity brine system will be less and he will
have to balance one against the other in considering the com-
parative merits of the two systems."
THE KAPIMTY OF COOLING FRUIT.
To those interested in pre-cooling of fruit we commend a
careful perusal of what G. Harold Powell has to say on the
above subject. Mr. Powell has, doubtless, had more experience
in fruit pre-cooling and shipping than any other living person,
and what he says may be considered authoritative.
"The rapidity of cooling the fruit depends primarily on
the difference between the temperature of the cold air and the
temperature of the fruit ; secondly, it depends on the method of
circulating the air over the fruit. Low temperature and rapid
circulation means quick cooling, but there is a limit in both
temperature and rapidity of circulation beyond which it is
not safe or economical to go. This is still in the experimental
stage. As a general principle, the air should be as cold as the
fruit will stand without injury. When the fruit is warm the
temperature of the air may be below the freezing point with-
out danger to the fruit. How low it is safe to run the tempera-
ture under these circumstances is still in the experimental
stage. When low temperatures are used, it is necessary to
provide heavier refrigerating machinery and better insulation
to insure against an excessive loss of refrigeration through the
walls of the building. To cool the fruit uniformly in all parts
of a package requires 24 hours or more of time. Quicker re-
frigeration by extremely low temperature subjects the exposed
fruit to the danger of freezing. It results in the uneven cool-
ing of the fruit in the packages and in the different parts of the
room and is expensive on account of the comparatively large
loss of refrigeration through the walls of the chill room during
the cooling of the fruit."
THE PRE-COOLING OF FRUIT 537
AMOUNT OF KEFRIGERATION REQUIRED TO PRE-COOL ORANGES.
Mr. Powell is again quoted as follows :
"The amount of refrigeration required to cool a carload
of fruit to a desired temperature depends on the initial tem-
perature of the fruit; the temperature to which it is to be
reduced, and the insulation of the plant. To reduce the tem-
perature of the fruit and the package alone will require an
amount of refrigeration as set forth in the following table :
Tons of Refrigeration
Required to Cool Oranges.
Range of Cooling 448 Boxes
100 to 35 degrees 5.94 tons
90 to 35 degrees 5.03 tons
80 to 35 degrees 4.11 tons
80 to 35 degrees 4.11 tons
70 to 35 degrees 3.20 tons
The figures above represent the actual amount of melt-
ing ice required to reduce the temperature of the fruit and
packages. To these figures should be added at least one-half
more refrigeration, depending on the insulation and construc-
tion of the plant. It is probably safe to estimate that it would
require six tons of ice or refrigeration to reduce a carload of
448 boxes from 80° F. to 35° F. To this must be added
about 6^/2 tons for the initial icing of the car, making thereby
a total of about 13 tons of ice required to cool a carload of fruit
over the range of temperature specified and to fill the bunkers
of the car."
CHAPTER XXV.
SHIPPING PERISHABLE PRODUCTS.*
PROTECTION FROM INJURIOUS TEMPERATURES.
The information following is largely a compilation of the
opinions of farmers, merchants and shippers in all parts of the
country, which were received in reply to a circular letter sent
out by the United States Weather Bureau. The principal
kinds of goods which are considered perishable, and for which
protection from excessive heat or cold is necessary are: All
fruits and vegetables, milk, dairy products, fresh meats, poul-
try, game, fish, oysters, clams, canned fruits and vegetables,
and most bottled goods. In the transportation of perishable
freight there are three primal objects to be attained :
1. — The protection of the shipment from frost or excess-
ive cold.
2. — The protection of the same from excessive heat.
3. — The circulation of air through the car, so as to carry
off the gases generated by some classes of this freight.!
The degree of cold to which perishable goods may be sub-
jected without injury varies greatly with different commodi-
ties, and depends somewhat on the time the shipment will be
on the road, its condition when shipped, whether it is kept
continually in motion, and also on whether it is unloaded im-
mediately upon arrival at its destination, or allowed to stand
some time. The direction of shipment, whether toward a cold
area or away from it, should also be considered.
•Abstracted from Farmers' Bulletin No. 125, United States Department
of Agriculture.
tWhat is meant, doubtless, is ventilation or the allowing of outside
air to circulate through the car by opening vents or ice bunker covers.
This is desirable where the fruit is loaded In a heated condition, but not
at all necessary when fruit is properly pre-cooled as it should be, — ^Author.
538
SHIPPING PERISHABLE PRODUCTS 539
CARS, APPLIANCES AND METHODS OP SHIPPING.
Precautions taken in shipping to protect from cold are
packing in paper, straw or sawdust, boxing, barreling with
paper lining, shipping in paper lined cars, refrigerator cars,
and cars heated by steam, stoves and salamanders.
Shippers and agents concur in the statement that danger
in transportation by freezing can be practically eliminated by
the shipment of produce by modern methods; the lined car
suffices in spring and autumn, and usually during winter, while
in extremely cold weather specially built cars are used.
In ordinary freight cars perishable goods can be shipped
with safety with the outside temperature at 20° F., and in re-
frigerator cars at 10°. In the latter these goods may be safely
shipped with an outside temperature of from zero to 10° be-
low, if the car is first heated, and at the end of the journey the
goods are immediately taken into a warm place without being
carted any great distance.*
To protect goods shipped in an ordinary car, the sides of
the car should be protected by heavy paper tacked to the wall,
and by the addition of an inner board wall, a few inches dis-
tant from the outer one. A car thus equipped and packed with
produce, surrounded by stra,w, will retain sufficient heat to
prevent injury for twenty-four hours, the average air tempera-
ture inside the car being at least twelve degrees higher than
the outside air. Cars are sometimes warmed by steam from the
locomotive when in motion, and by stoves when steam is not
available. Cars, after being loaded, are carefully inspected
as to temperature within ; their destination is considered ; and,
if the weather is exceedingly cold, or is liable to be, the car
is often accompanied by an attendant ; otherwise it is inspected
* Any statement cannot be as positive as this and be accurate when
applied to so varying a subject as shipping of perishable goods. The
protection of food products in shipment during extremely cold weather
depends on several things with a great variation of conditions. Fully as
much depends on the temperature of the goods themselves as on the
temperature of the car and the use of insulating substances for packing
th« goods or the use of an insulated oar. Take as an example the
shipping of eggs: If loaded into a good refrigerator car at a temperature
of 30° P. (as when loading from the cold storage room) no amount of
protection or the use of an extra well insulated car will prevent freezing
if on the road for several days' with an outside temperature below zero.
On the other hand, if started at a temperature of from 45° to 50° P. a
moderate protection will suffice, and the regular refrigerator car will take
them through safely.' — Author.
540 PRACTICAL COLD STORAGE
from time to time on the road. Lined cars — that is, cars lined
with tongued and grooved boards on the sides and ends — are
considered the best for shipping potatoes, as they can be heated
by an ordinary stove and will stand a temperature, outside, of
20° below zero, when a man is in charge to keep up the fires.*
REFEIGEEATOR CAKS.
The better class of refrigerator cars will carry all perish-
able goods safely through temperature as low as 20° below
zero, provided they are not subjected to such temperature long-
er than three or four days at a time; but with the ordinary
refrigerator cars a temperature of zero is considered danger-
ous, especially if the goods they contain be of the most per-
ishable kind.
In winter time refrigerator cars are used without ice in
forwarding goods from the Pacific coast; in passing through
cold belts or stretches of the country the hatches are closed,
and the cars being lined and with padded doors, the ship-
ment is protected against the outside temperature; in passing
through warmer climates the ventilators are opened in or-
der to preventing the perishable goods from heating and de-
caying.
It is stated, however, that for the shipment of fruit the or-
dinary refrigerator car is not entirely satisfactory, and that
there is a strong demand for a better refrigerator car than can
now be obtained, t
A car is wanted that will carry oranges, bananas, etc.,
without danger of chill through the coldest climates of the
country, as the delays in housing are injurious to the keeping
•The most approved arrangrement In a potato shipping car Is a false
floor and a partial false ceiling to allow of a circulation of air. The stove
Is placed In the center and the warm air ascends to the celling where It
passes along to the ends of the oar, descending and returning under the
false floor to the stove In center of car. — Author.
tThe author knows this to be a fact. The refrigerator cars now in
use have been designed for the most part by men of no modern scientific or
mechanical knowledge; they are inferior In many ways and present great
opportunity for Improvement. They have, for the most part, less than half
the Insulation needed, and even less than half the insulation which would
be used in a stationary cold storage room of similar size. Owing to the
nature of the companies controlling the refrigerator car business, the
practical engineer has little opportunity of introducing improved methods
In the construction of refrigerator cars. — ^Author.
SHIPPING PERISHABLE PRODUCTS S41
qualities of the fruit, and the dealer is also kept out of the
use of his goods.
The following is a descriptin of a much used patent re-
frigerator car:
"The car is double lined and has at each end of the interior
four galvanized iron cylinders, reaching from the floor to near
the top. Ice is broken to pieces about the size of the fist, and
the cylinders filled with this ice and salt, the whole being
tamped down hard. It is claimed that cars iced in this man-
ner do not need re-icing in crossing the continent, as other
styles of cars do. The car is iced in winter in the same man-
ner as in summer, as such icing prevents freezing."*
The car that has the most floor space and will hold the
greatest quantity of ice is preferred by most shippers.
Mistakes are often made in building fires in round-
houses where cars of produce are stored, unnecessarily heating
it, a uniform temperature, just above the danger point, being
the most favorable.
VENTILATED CARS.
In 1895 an experiment for testing the advantages of dif-
ferent modes of ventilation during the shipment of fruit was
made under the direction of the Eiverside Fruit Exchange, of
Riverside, Cal. Five cars loaded with oranges were shipped a
distance requiring a seven days' run. Four refrigerator cars
and one ventilated or fruit car were used. Two of the refrig-
erator cars had the ventilators closed from 4 a. m. till 8 p. m.
each day, and open the remainder of the time. The other two
and the fruit car had ventilators open during the entire trip.
Observations were made of the outside and inside temperatures
at 4 and 9 a. m. and 3 and 8 p. m. In the first two cars the
inside temperature ranged from 46° and 42° F. minimum to
56° and 58° F. maximum, respectively; in the second two,
from 48° and 44° F. minimum, to 58° and 62° F. maxi-
mum, respectively; and in the fruit car from 42° minimum
to 68° maximum. The outside temperatures ranged from eight
*An absurd statement. Icing and salting will not prevent freezing,
and there is no use in icing during cold leather. If tanks could be filled
with water, freezing of goods in the car would be, in some cases, pre-
vented.— Author.
542 PRACTICAL COLD STORAGE
degrees lower to nineteen degrees higher than the inside. It
was found that the temperature varied less in the refrigerator
cars than in the fruit cars, owing to the fact that they were
better insulated. It was also found that the fruit in the cars
which had the ventilators closed during the day arrived in
much better condition than that in the cars which had the
ventilators open.
OUTSIDE AND INSIDE TEMPERATURES.
The relation between the outside air temperature and the
temperature within the car varies largely, depending on the
kind of car, whether an ordinary freight or refrigerator car,
whether lined or not, whether standing still or in motion ; and
also on the weather, whether windy or calm, warm or cold. In
an ordinary freight car the difference ranges from two to fif-
teen degrees, and in a refrigerator car from fifteen to thirty de-
grees. If the latter be provided with heating apparatus, the
temperature in winter can be kept at any required degree.
From six observations taken at intervals of ten minutes,
it was found that on a warm day, when the mean of the six
readings outside was 68°, it was 66° F. on the inside of an
ordinary freight car, and 63° F. inside of an uniced refriger-
ator car. On a cold day the mean of six observations was 38°
F. outside and 35° F. inside of an ordinary car, and 36° F.
inside of a refrigerator car; the cars were stationary.
Freight from the Pacific coast to the Mississippi valley,
or to the Atlantic coast, has to pass through several varieties
of climate at any time of the year, so that at one time the
temperature inside the car will be materially above the out-
side temperature, while perhaps a few hours later it will be
below.
Products sent loose in a car are packed in straw on all
sides, particular attention being paid to the packing around
doors, and to see that the car is full. Manure is largely used to
protect perishable goods, the bottom of the car being thick-
ly covered with it, and in some cases it is put on top of the
goods.*
•No sane man would use manure In a car with perishable food
products unless the^ were In some sealed package like cans or bottles.
In any case straw, or better still, mill shavings are better than manure
for any purpose of this kind. — ^Author.
SHIPPING PERISHABLE PRODUCTS 543
The temperature of the produce when put into the car is
quite a factor to he observed. If it has been exposed to a
low temperature for a considerable time before, it is in a
poor condition to withstand cold, and the length of time so
exposed should be talcen into account. It is also claimed
that a carload of produce, like potatoes will stand a lower
temperature when the car is in motion than when at rest.*
Goods at a temperature of 50° to 60" F., packed in a re-
frigerator car, closed, have been exposed to temperatures 10°
to 20° below zero for four and five days without injury.
FKESH MEATS.
In shipping fresh meats the almost universal practice is
to ship in refrigerator cars where the temperature can be
maintained at any desired degree, a temperature from 36° to
40° being considered, the best.
Beef. — Fresh beef for shipping should be chilled to a
temperature of 36° F., although under favorable conditions it
wUl arrive in a good state if chilled to only 40° F. The cars
should be at the same temperature as the chill room, and it
is considered very important to have an even temperature from
the time the beef is taken from the chill room until its ar-
rival at its destination.
In shipping long distances in summer, it is necessary to
re-ice the cars, the frequency depending on the prevailing
temperature, so that no fixed rule can be given. In winter
the temperature is kept up to 36° F. by means of stoves or oil
lamps.
If refrigerator cars are not used, the meat should he
wrapped in burlaps, and the carcasses hung so as not to touch
each other. With an outside air temperature of 50° F., or
below, in dry weather, meat that has been thoroughly cooled
will keep a week if shipped in an ordinary box car.
Pork. — Pork is injured more quickly by high temperature
than other meats, and greater care should be taken with it in
storing and shipping. Sudden changes in temperature of
•One of the old popular ideas without material foundation. Men
and animals will withstand low temperature best when in motion, but
this does not apply to perishable goods. — ^Author.
544 PRACTICAL COLD STORAGE
from 10° to 20° F. are very injurious to fresh meats, and
should be provided against when possible.
Poultry. — Poultry, if shipped at a temperature of 50° F.
or higher, should be packed in ice and burlaps; and if under
50° F., in dry weather, no extra precautions are needed. In
shipping live poultry the coops are frequently overcrowded,
resulting in the death or great deterioration of many of the
fowls.
DAIRY PRODUCTS AND EGGS.
Milk. — Milk for shipping requires great care to prevent
souring; it should be reduced after drawing to a temperature
of 40° F., which extracts the animal heat. It should never
be frozen, as it becomes watery and inferior in quality when
thawed out.
Eggs. — Eggs are packed in crates with separate pasteboard
divisions, with a layer of excelsior top and bottom. Pickled
eggs are injured by cold sooner than fresh ones.
A prominent wholesale dealer in butter, eggs, and cheese
at Chicago, says:
Eggs in storage and transportation cannot stand a lower tem-
perature than 28° F.; if packed well in cases and loaded in a refrig-
erator car they usually come through in good condition at from 5° to
10° helow zero, and at 10° above zero in common cars, if not exposed
more than forty-eight hours.
Butter and Cheese. — A wholesale butter and cheese firm
of Chicago writes as follows:
Butter is probably unaffected by extreme cold. We have never
experienced any damage by butter being too cold; in fact, in carrying it
in cold storage, it is carried at from zero to 10° above; but extremely
warm weather is very injurious and damages the article to a consid-
erable extent. To preserve butter it should be kept as cold as possible,
as we state above, all the way from 32° above down to zero. It all
depends upon what the facilities are for carrying the same. Of course,
when we place it in cold storage the temperature we would require
would be zero to 10° above, and, of course, that temperature we can-
not have in handling It when we come to sell it out in our store, but
we take great care not to take out of storage any more than can be
readily sold. In regard to cheese, extreme cold and extreme heat are
both injurious to same. For instance, extreme heat will cause cheese
to swell and ferment [Not if the cheese is well made. Extreme heat
injures cheese by starting the butter fat, which causes the cheese to
become dry and crumbly.], while extreme cold will freeze it; the curd
becomes dry and like sawdust, and it will never again be firm and
stick together, but will crumble. It takes quite a temperature to
freeze cheese, say 10° above for one or two days out on the road would
freeze It. It is very slow in freezing and very slow in thawing out.
A skim-milk cheese will freeze quicker than a full cream cheese.
SHIPPING PERISHABLE PRODUCTS 545
FISH AND OYSTERS.
Fish. — Fish are shipped by express and also by freight.
When shipped by express they are packed in barrels with ice.
When shipped by freight they are packed in casks holding 600
pounds each, or in boxes on wheels, holding about 1,000 pounds
each. When shipped in carload lots they are packed in bins
built in the car and thoroughly iced. The amount of ice sup-
plied should equal one-half the weight of the fish. Fish keep
best when the temperature of the box in which they are stored
is about that of melting ice. Under favorable conditions fish
remain sound and marketable for thirty days after being
caught and packed in ice. The entrails of fish should be re-
moved before shipping, as they are the parts that most readily
decay, and taint the flesh of the fish. This is especially nec-
essary in shipping long distances.
Oysters.— Shucked oysters, shipped in their own liquor
in tight barrels, will not spoil if frozen while in transit. Thick
or fat clams or oysters will not freeze as readily as lean ones,
as the latter contain much more water. Oysters will not freeze
as readily as clams. It is safer when oysters or clams in the
shell are frozen to thaw them out gradually in the original
package in a cool place.
In freezing weather oysters and clams, in the shell, are
shipped in tight barrels lined with paper.
FRUITS.
It is important to note that in shipping fruits, etc., many
of the precautions taken in packing to keep out the cold will
also keep in the heat, and there is really more danger in some
instances from heating by process of decomposition than from
cold. All fresh fruit tends to generate heat by this process. A
carload of fresh fi-uit approaching ripeness, closed up tight
in an uniced refrigerator car, with a temperature above 50°
F., will in twenty-four hours generate heat enough to injure it,
and in two or three days to as thoroughly cook it as if it had
been subjected to steam heat.*
•This heating action is of small moment if the fruit is cooled before
placing in the car to a temperature of 40° F. or lower. — Author.
546 PRACTICAL COLD STORAGE
Suitable refrigerator transportation must, therefore, pro-
vide for the heat generated within, as well as the outside heat.
The perfection of refrigeration for fruit is not necessarily a
low, but a uniform temperature; a temperature from 40° to
50° F. will keep fruit for twenty or thirty days, if carefully
handled. Strawberries have been transported from Florida to
Chicago, tranferred to cold storage rooms, and remained in
perfect condition for four weeks after being picked.*
Fruit intended for immediate loading in cars should be
gathered in the coolest hours of the day, and that which has
been subjected to a high temperature before being shipped
should be cooled immediately after being loaded. Ordinary re-
frigeration vnll not cool a load of hot fruit within twenty-four
hours, and dviring that time it will deteriorate in quality very
much. It should be cooled in four or five hours in order to
prevent fermentation. It is stated that the more intelligent
of the large shippers of fruit in the south have about concluded
that it is impracticable with any car now in use to load fruit,
especially peaches and cantaloupes, direct from the orchard
into the car with assurance of safety. In deference to this
opinion one southern railroad has announced its intention of
establishing at the largest shipping points along its lines, cool-
ing rooms for the purpose of putting the fruit in satisfactory
condition for transportation before being loaded.
Shipments of tropical fruits in ordinary freight cars can-
not be safely made when the temperature is below 30° F.,
except in cases where the distance is so short as not to expose
them for a longer period than twelve hours, and even then
they must be carefully packed in straw or hay. The hardier
Northern fruits and vegetables can be safely shipped in a
temperature of about 25° F., but the same protective measures
must be employed as m the case of tropical fruits when lower
temperatures prevail. Long exposure to temperature of 20°
F. is considered dangerous to their safety. Foods preserved
in cans or glass should not be shipped any distance when the
temperature is below the freezing point.
•An uncommon or trial shipment. These results cannot be duDli-
oated on a commercial scale. — Author. uupn
SHIPPING PERISHABLE PRODUCTS S47
Oranges and Lemons. — Oranges shipped from Florida to
points as far north as Minnesota are started in ventilator cars,
which are changed at Nashville to air-tight refrigerator cars,
the ventilators of which are kept open, provided the tempera-
ture remains above 32° F., until arrival at St. Louis, from
which point the ventilators are closed and the cars made air
tight. Lemons and oranges are packed in crates. Each layer
of crates in the car is covered by and rests upon straw, usu-
ally bulkheadeu back from the door and car full. Oranges
loaded in ventilated or common cars should be transferred to
refrigerator cars when the temperature reaches 10° above zero;
in transit, with a falling temperature, the ventilators should
be closed when the thermometer reaches 20° F., and with a ris-
ing temperature the ventilators should be opened when it
reaches 28° F. For lemons, the minimum is 35° F. for
opening and closing the ventilators, and for bananas 45° F.
for opening or closing. Some shippers say that ventilators on
cars containing bananas, lemons and other delicate fruits
should be closed at a temperature of 40° F.
Bananas. — Jn shipphig carloads of bananas a man is usu-
ally sent in charge to open and close the ventilators. Bananas
should be put in a paper bag and a heavy canvas bag, and
then covered with salt hay, unless put in automatic heaters,
when the fruit is packed only in salt hay. Bananas are par-
ticularly susceptible to injury by cold, and require great care.
If exposed to temperatures as low as 55° F. they almost invari-
ably chill, turn black and fail to ripen. Cars containing them
are sometimes, in extremely cold weather, protected by throw-
ing a stream of water on them, which, freezing, forms a com-
plete coating of ice. The method adopted by some firms, of
shipping this fruit in winter, is to heat refrigerator cars to
about 90° F. by oil stoves, remove the stoves and load the
fruit quickly, put the stoves back and heat up to 85° or 90°
F., then remove the stoves again, close the car tight, and start
it on its way. Bananas shipped in this manner are held to be
safe for forty-eight to sixty hours, even though the tempera-
ture goes to zero.
S48 PRACTICAL COLD STORAGE
Quinces, apples and pears are packed in barrels, each
layer of barrels covered with and resting on straw.*
VEGETABLES.
Potatoes are packed in straw, bulkheaded back, the center
of the car left empty, and the car filled as high as the double
lining. When the temperature is 12° F. or more below freez-
ing, the rule is to line the barrels with thick paper, and at
extremely low temperatures, as a matter of extra precaution,
the barrels are covered over the outside with the same kind of
paper.
In shipping early vegetables to a northern market from
the South, for distances requiring more than forty-eight
hours to cover, openwork baskets, slatted boxes, or barrels with
openings cut in them should be used to allow a circulation of
air.
As a rule, truckers will not haul vegetables to the cars
for shipment when the temperature reaches 20° F. or lower,
and in no case when it is near 32° F. if raining or snow-
ing, f
trSE OF WEATHER REPOETS.
In connection with the shipment of food products liable
to injury by heat or cold, much benefit may be derived from an
intelligent use of the information contained in the daily
weather reports and forecasts published by the Weather Bu-
reau, which show the temperature conditions prevailing over
the whole country at the time of the observations, the highest
and lowest temperatures that have occurred during the past
twenty-four hours, and the probable conditions that will pre-
vail during the next twenty-four or thirty-six hours. These re-
•Straw is reaUy only necessary on the bottom, top, sides and ends
of car; no useful result is obtained by packing straw between barrels —
Author.
tA point in connection with the transportation of perishable soods
not touched on is the importance of not overloading refrigerator cars with
fruit or other goods of like nature unless pre-cooled before loading fsee
chapter on Pre-Coolmg). The warm air from goods will accumulate in
the upper part of the car, and no refrigerator car now in service so far as
known to the author has a circulation of air sufficiently perfect to s-ivp
even approximately uniform temperatures. It is generally necessary to
leave at least a foot or eighteen inches space at top and space betwp«ii
packages for- air circulation. California fruit shippers fully aDoreciatp
this and always tack strips of wood between packages, which holds thn
packages In place and allows of good air circulation. — Author
SHIPPING PERISHABLE PRODUCTS 549
ports and forecasts are received at nearly every Weather Bu-
reau office, of whicli there is one or more in nearly every
State and Territory, and published on maps and bulletins,
which are posted in conspicuous places in the city where the
office is located, and mailed to surrounding towns. The re-
ports, or a synopsis of them, are also generally published in
the daily papers.
Fuller information than is obtainable from either of these
sources may be had at the Weather Bureau office itself, from
the observer in charge, or, where none of these means is avail-
able, arrangements may be made with the observer to sup-
ply special information by mail, telephone or telegraph. In
the large cities of the country, dealers in perishable goods are
guided in their transactions very largely by the information
thus obtained. The temperature of the region to which ship-
ments are to be made is carefully watched, and the shipments
expedited or delayed, according as the conditions are favorable
or unfavorable. Shipments on the road are protected from
injury by telegraphic instructions as to the necessary precau-
tions to be taken. As shipments in ordinary box cars, or as
freight, are less expensive than in refrigerator cars or by ex-
press, advantage is taken of a favorable spell of weather to
use the former methods.
Information as to the altitude of the regions traversed
by the shipping routes, such as may be obtained from the con-
tour maps published by the United States Geological Survey,
the location and capacity of the roundhouses along the routes,
and the points on the railroads where transportation is liable
to blockage by snowdrifts, in connection with that given by
the daily weather maps, will prove of value to the shipper in
the supervision of his consignment.
In shipping early vegetables North from Southern ports
the weather reports are utilized to determine whether to use
water or railroad transportation, the former being the cheaper.
Dealers in certain kinds of produce, by careful attention to
the daily weather reports and the weekly crop bulletins, keep
themselves informed as to the sections where conditions most
favorable for large crops have prevailed, and are thus enabled
5S0 PRACTICAL COLD STORAGE
to judge of the probable supply and to know where to pur-
chase to advantage.
As illustrations of the manner in which advantageous use
may be made of the weather reports, suppose a merchant in
Ohio has an order in January for a load of apples or potatoes
to be shipped to St. Paul ; when his shipment is ready he may
ascertain by personal inquiry at the Weather Bureau office, or
by a study of Ihe published reports and forecasts, the prob-
able temperature conditions between Ohio and Minnesota for
the period that the shipment is likely to be on the road, and
regulate the same accordingly. If neither of these means of
information is accessible to him, he may telegraph the ob-
server at the nearest Weather Bureau office, Cincinnati, Co-
lumbus, Cleveland, Sandusky, or Toledo, as the case may be,
requesting the information, or he may arrange beforehand
with the observer to be informed by telegraph when the con-
ditions are favorable for making the shipment, the cost of all
telegrams, of course, to be borne by himself. While the con-
signment is on the road he should still keep himself informed
as to the temperature conditions of the region through which
it passes, and if injuriously low temperatures are likely to oc-
cur, may telegraph to have it housed or otherwise protected un-
til the conditions are again favorable. By the use of similar
means, a packei* having a large number of hogs to slaughter
may ascertain in advance when temperatures favorable for
that purpose are likely to prevail in his locality; or a South-
ern merchant having a consignment of tropical fruit on the
road to the North may insure its protection from injuriously
high or low temperatures by telegraphic instructions as to the
opening or closing of ventilators, or the use of ice or artificial
heat.
During the season when cold waves are liable to occur,'
a careful watch of the reports and forecasts will often enable
dealers and others to protect from injury large quantities of
produce in storage. Instances are numerous where the use of
such information has resulted in large pecuniary benefit.
SHIPPING PERISHABLE PRODUCTS
SSI
During the severe cold wave of January 1 to 5, 1896>
which overspread nearly the entire United States east of the
worth of property was saved from destruction by the warnings
of the Weather Bureau, which were sent out in advance of the
wave.
TEMPERATURE TABLE.
In the following table are given the highest and lowest
temperatures which perishable goods of various kinds will stand
without injury, whether packed in ordinary packages, stored
in freight cars or placed in regular refrigerator cars.*
LOW^BST ANC HIGHEST TEMPERATURES TO WHICH PERISHABLE
GOODS MAT BE SUBJECTED VSTITHOUT INJURY.
(The — sign denotes temperature below zero Fahrenheit.)
Perishable Goods.
Lowest Outside
Temperature.
a*-
as
tsao
£]P.g
-Oft
> ■
o o
5°
How Packed.
Ale, ginger
Apples, in barrels
Apples, loose . . .
Apricots, baskets
Aqua ammonia, barrels
Asparagus ....
Bananas
Beans, snap . .
Bear
Beef extract .
Beer or ale^
Beets
Bluing
Cabbage, early or late
Cantaloupes
Carrots
Catsup
Cauliflower
Celery
°
O
30
20
20
10
28
15
35
24
30
20
28
22
50
32
32
26
Zero
—20
25
15
32
2t)
26
20
:30
20
25
20
32
25
30
25
25
15
22
15
10
Zero
—10
—10
75
—10
75
10
70
—10
70
90
65
65
—10
Zero
75
70
—10
Zero
75
10
80
20
-10
70
65
CoTered with straw.
Packed in straw.
In boxes covered withmoss.
In boxes with straw.
In barrels or crates.
Shipped loose.
In manure and shavings.
In crates.
Barrels or crates.
In barrels with straw.
Packed in crates.
♦The temperatures given seem to the author to be too arbitrary and
in some cases incorrect, but are useful as a guide. There are many things
to be considered In fixing the lowest and highest safe temperatures for
perishable goods, chief of which are: First. — Initial temperature of goods
when loaded Into car. Second. — Temperature to which exposed en route.
Third. — Time on the road. Other conditions, like ripeness of fruit and
variety, have much to do with the temperature it will withstand without
Injury. — ^Author.
552
PRACTICAL COLD STORAGE
LOWEST AND HIGHEST TEMPERATURES TO "WHICH PERISHABLE
GOODS MAT BE SUBJECTED WITHOUT INJURY— CONTINUED.
(The — sign denotes temperature below zero Fahrenheit.)
Perishable Goods.
Lowest Outside
Temperature.
pi=
a h
lt<
How Packed.
Cheese
Cider
Clam broth and juice..
Clams in shell
Cocoanuts
Crabs
Cranberries
Cucumbers
Cymlings, or squashes.
Deer
Drugs (non-alcoholic) . .
Eggs, bar'led or crated
Endive
Extracts (flavoring) . . .
Pish
Fish, canned
Flowers
Grapes
Grapefruit
Groceries, liquid
Ink
Kale
Leek
Lemons
Lettuce
Lobsters
Mandarins
Medicines, patent
Milk
Mucilage
Mustard, French
Okra
Olives, in bulk
Olives, in glass
Onions
Oranges
Oysters, in shell
Oysters, shucked
Parsley
Parsnips
Partridges
Paste
Pears
30
22
30
20
30
10
28
32
32
Zero
32
30
10
20
10
18
35
34
32
32
20
15
28
32
26
25
32
32
32
25
26
25
28
25
20
28
20
30
32
32
10
32
32
25
18
20
10
20
Zero
20
20
22
—20
28
20
Zero
15
Zero
15
20
20
20
20
15
Zero
20
20
15
20
20
28
28
15
20
20
25
20
10
20
10
20
20
20
Zero
25
20
10
—10
—10
—10
Zero
Zero
Zero
—10
Zero
10
10
Zero
65
75
65
Zero
Zero
80
70
Zero
65
—10
—10
Zero
Zero
Zero
—10
65
65
io
75
70
Zero
Zero
75
Zero
Zero
75
Zero
—10
75
Zero
Zero
80
80
65
70
75
70
65
In barrels.
In barrels or crates.
In baskets and barrels.
In boxes with moss.
In crates.
Shipped loose.
In boxes or crates.
In barrels always iced.
Packed in moss.
Packed in cork.
In boxes or crates.
In boxes.
In boxes or crates.
Do.
In boxes.
In sawdust.
In baskets or boxes.
In barrels.
In barrels or crates.
In baskets, bar'ls or crates
In barrels.
Do.
In baskets.
In baskets or barrels.
In bunches in boxes.
In barrels.
80
SHIPPING PERISHABLE PRODUCTS
SS3
LOWEST AND HIGHEST TEMPERATURES TO WHICH PERISHABLE
GOODS MAY BE SUBJECTED WITHOUT INJURY— CONCLUDED.
(The — sign denotes temperature below zero Fahrenheit.)
Lowest Outside
Temperature.
Perishable Goods.
Peaches, fresh, baskets
Peaches, canned
Peas
Pickles, In bulk
Pickles, In glass
Pineapples
Plums
Potatoes, Irish
Potatoes, sweet
Preserves
Radishes
Rice
Shrubs, roses or trees.
Spinach
Strawberries
Tangerines
Tea plants
Thyme
Tomatoes, fresh
Tomatoes, canned
Turnips, late
Vinegar, barrels
Watermelons
Waters, mineral
Wines, light
Wild boar
Wild turkey
Yeast
m >»
Si?
wo ci
bo
Cd-4->
'j2 bo
■a.™
S.'^it!'?
_SO
■g (1) J)
(H O t(
M fW
3m
32
20
32
22
20
32
35
33
35
20
20
20
35
15
33
25
28
20
33
28
15
22
20
28
22
Zero
Zero
28
20
15
20
18
16
25
32
25
28
10
15
10
10
15
25
15
20
10
28
25
Zero
18
10
25
15
—20
—20
25
10
Zero
—16
—10
Zero
Zero
10
10
—10
—10
—10
Zero
10
—5
—10
Zero
Zero
Zero
80
'so
75
65
70
95
90
90
75
85
How Packed.
In baskets or barrels.
In barrels.
In barrels or crates.
In boxes with paper.
In barrels or baskets.
Do.
In baskets.
In barrels and sacks,
in canvas or sacking.
In barrels or crates.
In boxes.
In boxes.
In small baskets.
In boxes.
In barrels.
In barrels or in bulk.
Shipped loose.
Do.
SHIPPING BEEF AND MUTTON.
The following description regarding the practice of hand-
ling and shipping beef and mutton from Argentina to Eng-
land offers some useful and practical suggestions:
The cattle and sheep are killed as near their own pastures
as possible and the carcasses (unless the atmospheric conditions
are favorable for natural precooling) pass at once to the refrig-
erating chambers where they are frozen at a temperature be-
tween 5 and 10 degrees F. The hard frozen carcasses are held
at a temperature of about 15 degrees from the time they are
554 PRACTICAL COLD STORAGE
frozen in the various works in the antipodes, and in the Ar-
geiitine, until they are thawed out for the consumer in Great
Britain.
Chilled beef, large quantities of which are sent to Great
Britain, principally from the United States and the Argentine,
needs to be handled in a totally different manner. In the
case of hard frozen meat, the proposition from a refrigerating
point of view, after once the meat is thoroughly frozen, is
comparatively simple. Within certain limits, any temperature
well below the freezmg point of meat, will maintain it in per-
fect condition for lengthly periods; and although 15 degrees
r. has been mentioned as a suitable temperature, a range of
temperature, say between 10 degrees F. and 18 or 20 degrees F.,
makes but little difference to its keeping qualities. "With chilled
meat, however, it is quite another story, and for long storage
the temperature has 10 be maintained with as little range as
possible, a variation of even 1 degree having some influence
upon its keeping qualities. The freezing point of beef, that is
the temperature at which the liquids are completely changed to
solids, is between 28 and 29 degrees F. It has been found that
a temperature slightly above this, say 30 degrees F. or there-
abouts, is the best and most satisfactory for the storage and
carriage of chilled beef. This temperature must be maintained
as steadily and with as little variation as possible, and even
with such precautions the length of time during which chilled
beef can be held in perfect condition is only about six weeks.
ON lCIl>rG POULTRY.
Relative to the poor condition in which iced poultry some-
times reaches the market, the New York Produce Review pub-
lishes the following:
At this season of year dressed poultry dealers experience much
trouble, owing to the fact that stock arrives out of condition and
large amounts of money are lost because of the low and unprofitable
prices realized for this poor conditioned poultry.
During cold weather shippers send their dressed poultry dry-
packed, but as soon as the weather becomes warm the poultry is
iced and there seems to be great difficulty at times in getting the
iced poultry through in fine condition. The stock will arrive with ice
almost melted off, and often entirely gone, and the poultry more or
less out of condition. There seems to be more poultry spoiled in
transit during this season of year than at any other time, the quantity
SHIPPING PERISHABLE PRODUCTS SS5
even exceeding the amount damaged during the very warm weather,
and the natural inference is that the fault lies with the shipper and
Is largely due to carelessness.
It is always difficult to get the animal heat entirely out of the
poultry, as well as other meat, and it is thought that much of the
stock which arrives out of condition has not been thoroughly cooled
before icing, the comparatively cool weather doubtless causing pack-
ers to give this important matter less attention than they should.
But the main trouble is the lack of ice used by shippers.
During really hot weather the shipper ices the stock thoroughly,
and it usually comes through all right, but while weather is cool,
as in the Fall, shippers use less ice to carry the stock, and while it
reaches here in good shape if weather keeps cool, every warm spell,
or, in fact, every warm day that appears rapidly melts the Ice, and
the poultry is ruined before it reaches the market, so far as top mar-
ket prices are concerned, as it has to be forced off to cheap trade
for what it will bring.
It is certainly penny wise and pound foolish policy for shippers
to try and save a little on their ice accounts at the expense of their
poultry. The loss incurred every few shipments by having their stock
arrive out of condition is much greater than the cost of a little more
ice with each shipment, and it is hoped that some effort will be made
by shippers to remedy this long-time evil, which is a drain on the
larger and regular shippers as much, if not more, than on the smaller
shippers. With little care this loss could be avoided by operators and
it would be a great saving to the shipper and receiver of both annoy-
ance and money.
DRESSED POULTRY IN TRANSIT.
The following interesting suggestions by George B. Horr
is taken from The Butchers' Advocate:
The development of the system of refrigeration has demonstrated
that proper packing of poultry for shipment is very essential to insure
its arrival at destination in good condition. To accomplish this suffi-
cient ice must be used in packing to last while the poultry is in transit.
Most shippers pack their poultry in alternate layers of crushed Ice and
poultry, placing a large cake of ice on top and covering all with
burlap. Usually from 175 to 200 pounds of poultry are packed in an
ordinary sugar barrel, using about the same quantity of crushed ice.
Some shippers take the precaution of lining the barrels with brown
or parchment paper covering the top cake of ice in the same manner
before putting on the burlap. The quantity of ice required in propor-
tion to the quantity of poultry in each barrel depends upon local con-
ditions— that is, it would not be necessary for a shipper located in
Illinois and desiring to ship to New York to use as great a quantity
of ice in packing as a shipper in Kansas. With the ordinary treatment
which is furnished by the various refrigerator transportation com-
panies the temperature of a refrigerator car ranges from 35 to 45
degrees when crushed ice and salt is used, the temperature depending
on the construction and condition of the car. It follows that there
must be some melting of ice in the barrels of poultry, making it nec-
essary to use a greater quantity of ice in packing, according to the
distance poultry is to be shipped, and for this reason, also, the main-
tenance of time schedules is of great importance.
A considerable quantity of dressed poultry is forwarded in what
are termed "pick-up" cars and poultry packed for shipment in such
556 PRACTICAL COLD STORAGE
cars requires a greater quantity of ice than wtien shipped in through
cars. A pick-up car is one scheduled to pick up small shipments of
hutter, eggs and poultry at designated local stations between terminal
points.
The method of shipping dry packed has come into use largely
during the past few years until now more poultry is shipped dry-
packed than scalded, but the prompt removal of the animal heat from
the dry-packed poultry requires a plant specially equipped for the
purpose and calls for a larger investment of capital than the other
method. The removal of the animal heat from dry-packed poultry is
accomplished by placing the poultry on racks in a cooling room, whose
temperature is held at thirty-two to thirty-five degrees. The poultry
remains in this room from twenty-four to forty-eight hours. Some
shippers reduce to a minimum the chance of forwarding poultry not
thoroughly cooled by using a thermometer, as previously described,
except that the temperature of dry-packed poultry must be reduced
to forty degrees. After the animal heat is removed the poultry is
wrapped in parchment paper, either by wrapping each bird separately
or by lining the boxes and placing paper between the layers of birds.
When the packing is so completed the lot of poultry is held in a cold
room having a temperature of thirty-two to thirty-five degrees until
oar is ready for loading.
In the case of pick-up cars which are sometimes iced and started
from small stations it is not always practicable to use crushed ice and
salt. In such cases cake ice without salt is used, the car being iced
a longer time before loading and at the first re-icing station the re-
maining ice is broken up and crushed ice and salt added. Most of
the large railway systems between the Mississippi Valley and the
Atlantic seaboard are well equipped for re-icing cars, this being
done practically every twenty-four hours while cars are in transit.
The method of re-icing is first thoroughly to tamp down the ice re-
maining in the tanks and then fill the tanks with crushed ice and salt.
Drip pipes and traps are also examined and cleared of any refuse.
The way bill or card on the car indicates contents and also stations
where it is to be re-iced. The system is so well safeguarded that it
is almost impossible for a car to pass a re-icing station without re-
ceiving proper attention. These stations are so constructed that a
train-load of refrigerator cars can be re-iced in from thirty to sixty
minutes.
Since the perfection of the system of cold storage and the con-
struction of cold storage houses at large centers, a much greater quan-
tity of frozen poultry has been transported. The greater part of this
is handled in refrigerator cars iced in the same manner as for dry-
packed poultry. A small portion is transported in un-iced cars, plenty
of straw being used around doors and other openings, the theory
being that as the poultry is frozen it will remain in that condition if
so packed that the outside air cannot reach it.
Regarding the packing of poultry for shipment Dr. Pen-
nington says:
For long hauls, that is, for 5 days or over, the bird should be
packed at a temperature not to exceed 32 degrees F. How much
lower the temperature can be depends entirely on the sort of refrig-
erator car that is to be used. The great majority of the refrigerator
cars in service do not maintain a temperature of less than 40 degrees
F. in the middle of the car at the top of a three to four foot load.
The temperature at the bunker ends of this car, refrigerated with
SKIPPING PERISHABLE PRODUCTS 557
a mixture of ice and salt, may go to 10 degrees P. and hard freeze
the poultry at the bunker end on the floor of the car.
REGARDING EGGS.
The effect of good handling and refrigeration on the output of
southern eggs has been even more marlied than the effect on poul-
try. Tennessee and Kentucky ship eggs north during the winter
months when the supply from other sections has almost ceased. When
warm weather comes the eggs in the past have gone still further
south, where standards in eggs are not so high, or into the fertilizer
pile. Last summer a few shippers, provided with artificial chilling
facilities, shipped eggs north for a long part of the summer, and found
it profitable. They combined a campaign for careful, quick handling
and maintained low temperatures as soon as possible after laying.
They found that once thoroughly heated, so that the processes which
make for incubation had begun, or in the infertile egg, the deteriora-
tive course induced by heat, refrigeration cannot check nor even
greatly slow such changes. Hence, eggs which had been subjected
to unfavorable conditions would change en route, even though refrig-
erated, to such an extent that the packer would not recognize them
when they reached their market. If, however, they were well chilled
when fresh, deterioration during an average haul under refrigeration
was almost a negligible quantity, commercially speaking.
All of our experimental shipments of eggs have confirmed and
emphasized our observations on the results obtained by the industry.
We find that such factors as dirty shells, wet nest, damp cellars, etc.,
etc., cannot be overcome by refrigeration, and that the egg must go to
the cooler in good condition whether it be for prompt marketing or
for long storage, if the maximum benefit of the low temperature is
to be secured.— Dr. Mary E. Pennington.
LOADING CARS.
Concerning this subject M. C. Spatz, Linfield, Pa., in the
Egg Reporter ottered the following pertinent suggestions :
Begin in one corner of the car.
Set case lengthwise, and tightly against end and side of the car.
End case, set on floor, tightly against first case and against end of car.
Continue this layer entirely across car, seven or eight cases as
the space may allow.
Now follow with second layer and set cases exactly same way as
first layer, so that one case sets squarely upon the other.
Continue these layers until high enough to accommodate the num-
ber of cases to be loaded evenly over entire car. .
This will nearly always leave some space open on opposite side
of car from which we started.
Now the second row: Begin on opposite side of car from the one
we started with first row. . , ^ ^. r,^,
Pile same way as first row, not forgettmg to load tightly. This
will leave an equal space open on opposite side of car from which we
found such space in first row. .,, ^ ,
Third row: Begin on same side of car as we did with first row, so
that the space left open will be found on same side again as of first
row
Continue this method until within 3 or 4 feet of 'middle of car.
Now measure carefully with some cases the space not occupied and
558 PRACTICAL COLD STORAGE
find how to arrange the balance of cases, so as to fiU out this centre
of car tightly. Sometimes it is necessary to put three cases cross-
wise in car, but avoid putting cases crosswise if possible.
One good way is to start all the rows for which space is yet left
at one time, on one side of the car, and thus finish a space only one
case wide at a time, being particular to push all cases of all rows
tightly towards one end of the car.
Now, there may be a few inches of space left between the last
started row, and the one already piled all the way across.
Therefore push the second width of cases in the newly started
rows all tightly towards the opposite of the car from which you pushed
the first width.
Place the third width of cases same as first width, the fourth
same as second, etc.
My experience in loading and unloading during the past nine
years is that not once has a car of eggs loaded in the above described
manner been found in bad condition at destination.
It is, however, very seldom that a car from the west comes loaded
in this manner.
It is a mistake to leave an open space between every case of the
fioor layer, so as to let the cold from ice chambers, pass under goods.
These floor layer cases will generally be squeezed apart, thus
damaging both cases and eggs, making unnecessary expenses and
much trouble to all concerned.
MIXED OAKS.
Cars containing both butter and eggs should be loaded with the
butter in the ends, for the following reasons:
1st. Butter tubs do not pack tightly and thus leave space for
the cold air from ice chambers to pass through to the eggs.
2nd. Many cars have improperly constructed ice chambers and
thus water is splashed against the goods. This will not injure butter
as it would eggs.
If both butter and eggs are properly loaded, I do not see why
there is any more danger of damage to goods from bumping of cars
than if butter is placed in middle.
Before a car of eggs is started to be loaded, the ice chambers
should be carefully examined. Dirt in drip pan should be removed,
and drip pipes cleaned.
This may often avoid much annoyance and expense to shippers,
receivers and the railroad companies.
When using ice in cars, eggs should be placed on flat solid floor
racks, that are about 2 or 3 inches high.
The round or oval strips nailed to the floor in some cars are no
good and permit injury to the bottom layer of cases. They are not
a preventative of water getting into the eggs.
CHAPTER XXVI.
FURS AND FABRICS.
A DEVELOPING BEANCH OF THE COLD STORAGE INDUSTRY.
The use of refrigeration for the protection of furs, fur
and woolen garments, rugs, carpets, trophies, fine furniture,
etc., against the ravages of moths or carpet beetles is compara-
tively recent, and prior to the year 1895 no business of con-
sequence was done in this line. Now many of the larger house-
hold goods warehouses, and most of the regular cold storage
houses, have rooms devoted to this purpose, and numerous large
concerns, both in America and Europe, are operating refrigerat-
ing equipments exclusively for the preservation of furs and
fabrics. The large department stores are rapidly being
equipped with cold storage facilities to care for their furs,
woolens, etc., during the heated term.
The use of cold storage for this line of goods is not as
yet fully developed. The prejudice of furriers has been largely
responsible, and when the cold storage manager first endeavors
to obtain business in this line, he usually has a struggle with
the furrier. The time honored method of caring for furs, etc.,
during the heated term, has been to periodically beat, brush,
comb or treat them with various chemicals or liquids for the
purpose of destroying or preventing the hatching of the egg
which produces the larvae of the destructive miller and beetle.
These pests are very generally known as moths. The care of
furs during the hot weather of summer has been one of the
sources of the furrier's income during his dull season. Natur-
ally, therefore, he looks upon any new method of protecting
furs with suspicion and in an unfriendly light. In nearly
every instance where the author has obtained the experience of
warehousemen on this subject, the same conditions prevail.
559
560
PRACTICAL COLD STORAGE
In some instances where cold storage is largely in use for
fur storage, it has been introduced by the cold storage ware-
houseman interesting a prominent local furrier, and making
concessions which would attract his business. This furnishes
PIG. 1.— COLD STORAGE ROOM FOR RUGS AND CARPETS.
a good reference. After acciuiring such a customer, business
may be solicited by distributing attractive descriptive advertis-
ing matter from house to house. A number of warehousemen
known to the author have secured their business almost wholly
by advertising directly and without the help of local furriers.
It is only a c^uestion of time when the prejudice of furriers will
be overcome, and they will become the heaviest customers of
FURS AND FABRICS
561
the cold storage house ; but, for the present, their preconceived
ideas and fancied financial interests make them the competitors,
in some cases, of the cold storage house.
FIG.
2.— COLD STORAGE ROOM FOR FABRICS AND TROPHIES,
SHOWING CODDING PIPES.
FUR STORAGE PROFITABLE.
The storage of furs and fabrics pays better per cubic foot
than any other class of goods, and cold storage houses located
in or near the residence portion of cities, in latitudes where
furs are worn, should make an effort to obtain this business.
The detail of looking after it is considerable, but it works in
nicely with other business. So far the business has been largely
developed by the household goods warehousemen, and at pres-
ent the largest and most successful businesses in this line are
conducted by such houses, chieflj' because these already have
562
PRACTICAL COLD STORAGE
a clientage from whom to draw business, and are equipped
with facihties for collecting and delivering goods. To the
warehouseman who handles both household goods in dry
storage and perishable goods in cold storage, the setting aside
of a room for the purpose is a comparatively inexpensive experi-
ment, and it is likely to result in a good business. The largest
and most successful houses handling these goods have fire-
PIG. 3.— COLD STORAGE ROOM FOR RUGS.
l^roof bi;ilding«. The large value stored in a small sjiace makes
the fireproof building especially desirable for this class of
goods.
TEMPERATURE.
The correct temperature for a fur and fabric room has not
been accurately determined as yet. Rooms are in operation
ranging in temperature from 15° to 40° F. It has been demon-
strated that a temperature of 40° F. will prevent the operation
of damaging larva3, but does not destroy them as shown by
Dr. Read's experiments described at the end of this chapter.
FURS AND FABRICS 563
A safe working temperature for the cold room would be any-
where between 25° and 35° F., and it is believed that the
latter temperature is amply low, if continuously maintained.
Raw silk has been placed in cold storage for other reasons
than to prevent the working of damaging moth. When stored
at ordinary temperatures a loss of weight and lustre results,
caused by the evaporation of the natural moisture and volatile
matter contained in the silk. A teiBperature below 30° F.
prevents the evaporation and maintains the lustre. Inferior
grades are especially liable to damage when exposed on the
FIG. 4. — COLD STORAGE ROOM FOR RUGS AND CARPETS.
shelves for a time and cold storage is necessary to a successful
holding.
HUMIDITY. .
Furs and fabrics should not be stored in a room with
goods giving off moisture, as at times the moisture in such a
room may be excessive and harm result. A room containing
nothing but furs will be comparatively dry, because furs do
not give off moisture, and the only source from which moisture
may be added to the air of the room is by air leakage, opening
564
PRACTICAL COLD STORAGE
doors, and the exhalation from persons working in the room.
A well insulated fur room, protected by a properly designed
air lock or corridor, is so dry that the pipes rarely show white,
the coating of frost is so very light. It has been advanced as a
theory that a very low temperature, like say zero or 10° above,
would be detrimental to the skins or leather of furs, causing
them to dry out. Evaporation is caused by a low relative hu-
midity, entirely independent of temperature, so this theory
is not tenable. fiSce chapter on "Humidity.") The average
FIG. 5. — COLD STORAGE ROOM FOR GARMENTS.
humidity during winter, when furs are in use, is much lower
in most localities where furs are worn than that of a cold stor-
age room under ordinary conditions. No very accurate data
are at hand regarding the humidity at which fur rooms should
be carried, but it is no doubt lower than for goods which throw
off moisture ; that is, the room should be dryer. It may happen
that furs removed from a refrigerated room and taken into
a comparatively warm atmosphere will show dampness on
their outer surfaces. This is not from any fault of the storage
room, but because the moisture is condensed from the warm air
FURS AND FABRICS
S6S
upon the cold surface of the goods. This may be avoided by
packing the goods inside the cold storage room in tight paper
boxes or bags before delivery, so that the goods will be warmed
slowly and condensation prevented. If furs and fabrics are
kept in a room by themselves, no harm will result from the
moisture, unless conditions are radically wrong. If, when
removed from storage, goods show a condensation of moisture,
they should be thoroughly aired until dry before delivering,
by placing where a gentle current of air will flow over them, as
customers may think the moisture was caused by some defect
in the system' of cold storage.
/M///////////////////////////m^^^
/
i
fm^///////////////////////m////y///^^^
FIG. 6. — AUTHOR'S DIAGRAM, SHOWING DUCTS FOR AIR CIRCU-
LATION IN FUR COLD STORAGE ROOMS.
AIK CIRCULATION.
The forced air circulation system is particularly applicable
to the storage of furs and fabrics, and it is recommended, not
especially as a matter of purifying the rooms or producing
greatly improved conditions, but as a means of avoiding the use
of cooling pipes, placed directly in the rooms. Pipe coils on
the walls or ceiling of a room may drip at times and cause a
spattering of water, which will damage the goods. Space
will also be saved, which is an important item, especially in
expensive fireproof warehouses. The accompanying illustra-
tions of rooms used for fur storage show clearly the large space
566
PRACTICAL COLD STORAGE
occupied bj' piping. It is not only the loss of space actually
occupied by the pipes, but also that the goods must be stored
at a safe distance from them. Thoroughly distributed circu-
lation of air is not essential when using the forced circulation
system for furs; all that is necessary is a distribution of air
which will produce uniform temperatures. A cross-section of
the ducts arranged in a fur room designed by the author is
shown in diagram. The perforations in these ducts are on the
sides of the flow and return ducts. No marked difference in
temperature can be noted in different parts of the room when
the fan is kept in continuous operation. This arrangement of
~^""vri^
FIG. 7. — FUR STORAGE ROOM — COOLED BY FAN SYSTEM OF AIR
CIRCULATION — NO PIPES IN ROOM. — FRANKLIN REFRIG-
ERATING COMPANY, SARANAC LAKE, N. Y.
air distribution is not recommended for any goods which
throw off moisture, but is sufficient for furs and fabrics. The
first rooms to be used exclusively for the storage of furs and
fabrics were equipped with brine piping directly in the room,
and such an arrangement is still largely in use, but the forced
circulation or indirect system outlined above is rapidly coming
into use.
In connection with the fan or forced circulation of air
for fur storage rooms, fireproof shutters or dampers held open
by fusible links, should be povided in the main air ducts. A
FURS AND FABRICS
567
very disastrous fire occurred iu New Yoric, where it was thought
that the damage was much augmented by the fact that the fan
system was in use. This particular house, after the fire, substi-
tuted direct brine piping, and also subdivided their space. In
a comparatively large plant several smaller rooms are in any
case much more desirable than one or two large rooms.
VENTILATION.
The ventilation of fur rooms may be easily accomplished;
and while not absolutely necessary to the welfare of the goods,
FIG. 8. — COLD STORAGE ROOM FOR FURS, SHOWING PIPING
ON SIDE WALLS.
it is much better to have a nice sweet smelling room to show
prospective customers than one which has the lifeless and
impure atmcsphere encountered in some fur rooms. The warm
weather ventilating system invented by the author for use in
summer is desirable at frequent intervals. (See chapter on
"Ventilation.") At one of the cold storage plants designed by
the author a quantity of clothing containing moth halls was
^68
jfKACTICAL COLD STORAGE
received, and the fact was not discovered until the room was
well scented. A few hours' operation of the •\varm weather
ventilating system was sufficient to sweeten the air of the room
perfectly. The rooms may be blown out and thoroughly
ventilated by forcing in fresh cold air from the outside by
using the cold weather ventilator in winter.
EDUCATION OF CUSTOMERS.
One of the first difficulties of the cold storage manager is
to educate his customers to do away entirely with the use of
FIG. 9.— COLD STORAGE ROOM FOR GARMENTS, SHOWING PIPING.
moth balls, camphor balls, tar camphor, carbolic camphor,
powders, tar paper or any of the ill smelling trash of various
kinds which has for years been used to keep out the damaging
moths. Some warehousemen have also been troubled by the
stable odor from robes and coachmen's garments. Goods re-
ceived containing these objectionable odors should be carefully
aired for some days before placing in the cold storage room.
FURS AND FABRICS
569
If the odors cannot be eradicated, the goods must be isolated
in a room hj themselves, or rejected for storage and returned
to the owners. It should be the warehouseman's study to re-
turn goods in as good or better condition than when received.
To this end, all objectionable goods must be excluded from
the storage rooms.
For his own protection the warehouseman will note con-
dition of all goods when received for storage. The unreason-
FIG. 10.— COLD STORAGE ROOJI FOR CARPETS, SHOWING PIPING.
able or dishonest customer is always with us, and he may
expect his furs back in prime condition when they were really
damaged at the time they were delivered to the storage house.
The services of an expert furrier are provided in some cases,
and where the volume of business is sufficient, one may be
regularly employed. Any bright young man may be trained
to inspect furs on arrival at the storage house. Any blemishes
or imperfections should be noted on the receipt given to the
customer. All furs should be carefully beaten, dusted and
570 PRACTICAL COLD STORAGE
aired before placing in the refrigerated rooms, and properly
placed or stored to keep them in the best possible condition.
HANDLING AND STORAGE.
Trophies like stuffed animals, heads, skins, etc., are best
hung or laid on racks. The best method of storing coats,
cloaks, etc., is to hang them on forms or shoulder stretchers
to preserve the shape and hang of the garment. If any metal
hooks with shoulders are used they should be wrapped with
tissue paper to prevent discoloring light colored furs or gar-
ments. The forms are suspended from racks, and the whole
covered by a piece of heavy unbleached sheeting. This arrange-
ment is plainly shown in the accompanying view of a cold stor-
age room (Fig. 8). The illustrations (Figs. 1 to 10) also show
the method of storing fur rugs, stuffed heads, carpets, trunks,
etc. In some cases each individual garment is encased in a
separate cloth cover. Separate closets are sometimes provided
for the use of single individuals, furriers and large customers,
or for the storage of especially valuable garments, the keys to
which may be carried by the customer. Such closets are usually
made of slat or open wire work, to allow of a free circulation
of air.
SUGGESTIONS FOK ADVERTISING MATTER.
A few of the advantages of refrigeration for the protec-
tion of furs and fabrics are here concisely stated for the benefit
of those preparing printed matter for distribution :
POLIO —20—
Cold is Instrumental In the production of furs, and it is as neces-
sary to their preservation.
Cold develops and enriches the fur when on the animal's back
and preserves Its color and gloss when manufactured into useful cov-
erings. Cold storing is like putting the fur back into Its native
element.
Cold prolongs the life of the fur by retaining the natural oils,
which are evaporated by the hot, dry air of summer.
Not only is the appearance of the fur improved, but the flexibility
and softness of the leather which supports it are retained.
Carpets, rugs and other woolens lose color and life in the hot sum-
mer air. A cold atmosphere revives the colors and rejuvenates the
fiber.
The wear and tear on furs, carpets and rugs by excessive heating
is entirely eliminated.
FURS AND FABRICS S71
Garments stored on forms in refrigerated rooms are ready for
immediate use; in fact, can be removed from cold storage, worn for a
single night, and returned.
Curtains or draperies may be suspended from racks, avoiding
damage from folds.
Furriers who have used the system heartily indorse it.
Obnoxious odors from use of moth preventives are avoided.
Cold storage rooms are dust proof.
Cold storage gives absolute security against moth.
RATES FOR STORAGE.
The usual storage rates for fur and fabric cold storage
are given below. The prices are in some cases less, in fact,
sometimes only one-half those given. Each warehouseman
must be governed by local conditions and competition, and
in most cases the charges made by the furrier under the old
method must be approximately met. A furrier's charges nearly
always include a guarantee against fire and moth.
SEASON RATES ON EURS.
Muffs $0.75 to $1.00
Boas, caps or gloves 75 to 1.00
Collarettes j 1.00 to 1.50
Capes not exceeding 20 in. in length 1.00 to 1.50
Capes or sacques not exceeding 24 in. in length 1.00 to 1.50
Capes or sacques not exceeding 28 in. in length 1.50 to 2.00
Capes or sacques not exceeding 36 in. in length 2.00 to 2.50
Garments, such as dolmans, long sacques, etc 1.50 to 2.50
Overcoats, etc., not exceeding 40 in. in length 1.50 to 2.50
Garments exceeding 40 in. in length 2.00 to 3.00
Lap robes 1.50 to 2.50
Rugs, according to size 1.00 and up
Stuffed animals, birds, mounted heads, etc 1.00 and up
Monthly rate, one-third of season rates.
Season, nine months.
SEASON RATES ON WOOLENS, ETC.
Woolen garments stored in same manner as fur garments, two-
thirds of fur rates.
Blankets, clothing or other garments stored in trunks or boxes,
rate of seven cents per cubic foot per month, or fifty cents per cubic
foot per season of nine months.
Carpets and rugs not in boxes or trunks, four cents per cubic foot
per month.
Suits and dress suits, f 1.50 per season.
Furniture, forty cents to sixty cents per cubic foot per season.
Monthly rate, one-third of season rate. Season, nine months.
Some warehouses make the season only six months, but
the usual season is nine months, and in most cases is figured
to end January 1. Goods carried beyond January 1 are
572 PRACTICAL COLD STORAGE
usually charged for at a short season (i. e., January 1 to April
1) rate, at one-third the long season rate. It is customary for
warehousemen to malce a rate which insures against fire, moth
and theft, although this is by no means a universal rule. When
so done the usual rate is 1 per cent per season on valuation,
insurance rate to govern to some extent.
■WAREHOUSE RECEIPTS.
The form of warehouse receipt here shown has been found
in practice to answer the purpose for furs, etc., very well, but
is subject to many limitations and modifications. The words
"Not negotiable" should be printed or stamped across the face
of the receipt. It need not necessarily take this form, but
should include the items mentioned and should read somewhat
as follows:
TWENTY-FOUR HOURS' NOTICE REQUIRED FOR WITHDRAWALS.
NEW YORK STORAGE COMPANY.
COLD STORAGE DEPARTMENT.
New York
RECEIVED
191. . . as per Schedule below, contents of
packages unknown. To be stored in Gold Storage.
Lot No For the account of
for which the sum of % per month $
is to be paid, from the date hereof until January First, 191
The responsibility of this Company for any piece or package
or the contents thereof, stored in this department, is limited to the sum
of one hundred dollars, unless the value thereof is made known at
the time of storing and receipted for in the schedule, and an addi-
tional charge be paid for a higher valuation.
On consideration of the above sum, the said New York Storage
Company agrees to protect the said articles from loss or damage by
moths, fire and theft to the extent of such valuation.
Should these goods be withdrawn before the expiration of the
above term of storage, no portion of the charge shall be remitted, and
if continued longer, it shall be deemed a renewal under the same
conditions, for which a like rate shall be chargeable.
The said goods are hereby valued for the purpose of insurance,
at the sum specified in the schedule.
When the property covered by this receipt is withdrawn, this re-
ceipt should be surrendered to the Company.
A written order should be given when others are to have access
or when goods are to be removed.
No person is authorized to make any other agreement or con-
dition on behalf of this Company.
Supt.
FURS AND FABRICS 573
DK. read's experiments.
This chapter would not be complete without the addition
of an extract from the article on the "Cold Storage for Fabrics,"
by Dr. Albert M. Read, of the American Security and Trust
Co., Washington, D. C, published in full in the June, 1897,
issue of Ice and 'Refrigeration. Dr. Read has taken up the
subject and handled it in a masterly and exhaustive way.
Credit is also due to Walter C. Reid, of the Lincoln Safe Deposit
Co., New York, and Albert S. Brinkerhoff, of the Utica Cold
Storage and Warehouse Co., Utica, N. Y., for assistance in
securing much of tbe information contained in the foregoing.
Following is a portion of Dr. Read's article, referred to:
COLD STORAGE FOR FABRICS.
In order to conduct our business intelligently, it became neces-
sary to ascertain the effect of low temperatures upon the moth and
beetle in the various forms of egg, larvae and perfected insect. We,
therefore, had a small room fitted with brine pipes, divided into sev-
eral sections by stop-cocks, so that the temperature could be con-
trolled to within about 5°, and began operation at from 20° to 25° F.
When we thought we had exhausted the subject at these tempera-
tures, we took the next in order, from 25° to 30° P, and progressed
in this manner upward until the temperatures of from 50° to 55° P.
were reached. Each of these tests necessarily consumed considerable
time, the series having occupied the full period of two years. Early
in the first year, however, we learned that the line of safety lay
somewhat higher than the freezing point (32°), and our plant was
run for the balance of the season at that temperature.
The Egg. — It is probable that the egg of the moth and beetle re-
quires a temperature somewhat higher than 55° P. for hatching. I
say probably, because, owing to the difficulty of obtaining the eggs,
the experiments on them have not been sufliciently numerous to allow
of positive conclusions, although those that have been made point
strongly to the possibility stated.
The Larvae. — The larval condition is the one in which all the
damage to fabric is done by the insects in question. In passing from
the egg through this condition to the perfected insect, the fiber of the
wool, fur, etc., is eaten by the larvae of both the moth and the beetle
for the grease and animal juices in it, these constituting the princi-
pal source of food, and the larva of the moth for material out of which
to spin the web that constitutes a large proportion of the cocoon used
for its protection. In the larval state it was found that any tempera-
ture lower than 45° P. was sufficient to keep the insect from doing
damage to fabric, although all that temperature, and at a temperature
as low as 42° P., there was slow and sluggish movement of the animal.
At temperatures below 40° P. movement was suspended, and the larva
became dormant. At temperatures above 45° P. the movements of
the larva became active, and it began to work upon the fabric, the
amount of this work and the quickness of movement increasing with
each degree of temperature up to 55° P., when the normal condition
of activity appeared to be reached.
574 PRACTICAL COLD STORAGE
The Perfected Insect. — The miller and heetle, when subjected to
temperatures below 32° F., were soon killed, as they were also after a
longer time at all temperatures between that and 40° F. At tempera-
tures between 32° and 40° P., however, when the insects were placed
in the center of a roll of heavy woolen rugs, they appeared to enjoy
an immunity from death for several weeks, although during this
period they were entirely dormant.
It will be seen from the above that the investigations made have
quite conclusively proven that cold storage rooms for the preservation
of furs and fabrics from the ravages of moth and beetle may be kept
at a temperature as high as 40° F. with perfect safety, so far as these
insects are concerned. There may, in some plants, however, be trou-
ble from the drip from the cooling pipes of the storage room at this
temperature, which will, of course, be very objectionable, and should
be obviated by a slight lowering of the temperature of the room.
We have run our rooms at temperatures varying from 35° to 40° F.
without trouble in this regard.
In the course of the investigation some matters of interest in
connection with the effect of cold upon these insects came to my
notice. As these may prove of value in the future, I will state them
in a few words. It was found that the larvae of both the moth and the
beetle had the power of resisting temperatures as low as 18° F. for
a long period without apparent harm, and that they came out of the
dormant condition superinduced by the low temperature in the same
physical condition as when they entered it, and apparently took up
their natural avocation at the precise point where it was interrupted.
When these larvae were alternately exposed to low and higher de-
grees of temperature, so that they passed from the dormant to the
active condition and back again several times in succession, their
power of resistance was considerably lessened, and they died much
sooner than when kept dormant in a low temperature continuously.
This would indicate that a winter, during which short periods of cold
are followed by similar periods of warm weather, would be followed
by a summer of decreased insect life.
CHAPTER XXVII.
WILD FERNS.
The storage of wild ferns has developed into an important
feature of cold storage industry in parts of New England,
and doubtless there will be some demand elsewhere for space
for their proper handling. Comparatively little is accurately
known about suitable packages, handling and storage.
USES AND MARKET.
Ferns are in great demand by florists during winter, and
the holiday season in particular, as a background or "back-
ing" for cut flowers. The greater part of ferns so used are
picked in the mountainous parts of New England, the Berk-
shire Hills of Western Massachusetts being especially produc-
tive, with Hinsdale the chief center. They are stored during
the entire year and shipped out on orders to practically all
parts of the country. New York city is a great consumer, but
other Eastern cities also use large quantities, and they are
shipped in large lots to Chicago and even the far west.
STORAGE METHODS OLD AND NEW.
In the early history of the fern shipping business it waa
customary to store them in barns, in beds about 10x4x1 ft.,
covering them with moss. Others were stored in cellars, sprink-
ling with water from time to time to prevent drying out, but
owing to uncertain temperature, and various other conditions
not under control, considerable loss resulted from wilting and
rotting. It was found that as business increased picking must
be commenced earlier in the fall, when the weather is too warm
to keep the ferns properly, and cold storage was then resorted
to. Cold storage has proved to be the salvation of the busi-
ness on a large scale. At first undertaken in a small. and ex-
575
576 PRACTICAL COLD STORAGE
perimental way, the results were so much of an improvement
that now the business is wholly handled through cold storage.
Under the right handling, packing and temperature, the ferns
come out of storage with the fresh, green appearance which
makes them so attractive when used by the florists in combina-
tion with cut flowers.
PICKING TIME AND DETAILS.
Exact data are not now obtainable as to the best time of
picking, but it is generally understood among the pickers that
the work should not begin until the first frost, and the picking,
therefore, takes place mostly during September and October.
Picking begins about June 20th, but not for storage. It
seems that the ferns are toughened by the cool nights of fall,
which probably act to lower the moisture content or dry them
to some extent. Anyway, it is well understood that the pick-
ing for storage should not begin until the first frost, and
experience has demonstrated that ferns picked before are not
properly matured for storage and shipping purposes. The
picking is done mostly by women, children and old men, and
as the work is done during a time of the year when rural occu-
pations are least pressing, the work is very acceptable and
forms an important industry and source of income in some
sections. One and one-quarter to two cents per bunch of
twenty-five is paid according to variety, care in picking and
quality, and even at this seemingly low rate some of the most
expert pickers earn as high as $7 per day.
PACKING, SORTING, ETC.
The wild ferns usually collected are commonly divided
into two grades or varieties, "dagger" and "fancy" ferns. The
"dagger" variety is the more hardy and easier to pick, and
less loss is usual in storing. The leaves are of waxy appear-
ance and coarser than the "fancy" ferns. As the name in-
dicates, "fancy" ferns are very delicate of leaf and finer in
every way and easily damaged in picking and handling. The
greatest care and skill is necessary in preparing the bunches
or bundles. Not all the ferns are marketable, by any means.
WILD FERNS 577
and the careleiss picker is penalized. Buyers located at the rail-
road station receive the ferns from the pickers, and if neces-
sary carefully sort them. Bunches of 25 are standard, and
the ferns must be carefully arranged so as to lay flat, to avoid
crushing or bruising. None broken or decayed or badly dis-
colored are packed for shipment. As a storage package a
wooden box is used (mostly second-hand shoe boxes), and
the ferns are packed in layers with moss on top, bottom and
sides, about 5,000 to 10,000 to the box. The object is to pack
in such a way as to retain the moisture and exclude the air.
TEMPERATURE AND COLD STORAGE TREATMENT.
A close determination of the most suitable temperature has
not been made, but it is more than probable that what is
wanted is a temperature which will freeze the moisture in the
packing material and still leave the ferns unfrozen. Satisfac-
tory results have been obtained at 30° F., but a temperature
of 25° F. to 28° F. is suggested as more suitable, and experi-
mental work along this line is recommended. Ferns picked in
August and early September should not be stored at as low
a temperature as those picked later. If the ordinary frosts
up to say October 15th in the Berkshire Hills will not damage
the ferns, it would seem that 25° F. in cold storage should not,
but still in the presence of moisture soaked packing material
the effect may be different. The moss used in packing is
pretty well soaked, and 28° F. to 30° F. will, of course, freeze
the packing material and leave the ferns unfrozen.
It is absolutely essential to best results that ferns after
picking should be promptly sorted and packed and placed in
cold storage. If they are shipped and on the road for several
days, heating is likely to result and ruin the ferns. If placed
in cold storage the same day, so much the better, but in cool
weather a day or two may elapse without damage.
If shipment by rail to a cold storage house is necessary,
by all means use refrigerator cars. Far better results may be
had, however, by cold storing where picked, or sufficiently near,
that the ferns packed one day may be in storage the next. A
cool or cold room for sorting and packing is almost a necessity,
578 PRACTICAL COLD STORAGE
and this may best be obtained in connection with a cold storage
plant.
In piling the boxes in cold storage it is advisable to pro-
vide a two-inch air circulating space on top, bottom and sides
of the box, so as to allow a quick cooling and freezing. After
a week in storage thej' may be piled more tightly, keeping
them from side walls and floor at least two inches.
Eesults from cold storing have been reported as very ir-
regular, and, as stated at the beginning of this chapter, the
accurate information available is small. It would seem that
the irregular results must be due to the condition of the ferns
when picked, or the exposure to varying conditions before
storing, as it is comparatively easy now to hold uniform tem-
peratures in cold storage. The lack of uniformly successful
results cannot be blamed to cold storage, but rather to lack
of uniformity in the product stored, probably too early pick-
ing or too late picking, or too careless or unintelligent hand-
ling before storing.
CHAPTER XXVIIl.
LILY OF THE VALLEY BULBS.
COLD STORAGE BULBS PRODUCE BEST RESULTS.
Lily of the Valley is one of the most important objects of
culture among florists, and cold storage is now recognized as
an absolute necessity in connection therewith. During the
winter season the announcements of wholesalers may be seen
in the florists' papers, advertising "Cold Storage Valley." Thus
do the florists acknowledge their dependence on cold stor-
age for bulbs, or "pips," as they ai'e called, of high quality
and with good vitality for developing the desired bloom. The
advantage of stock from cold storage is that it may be brought
into bloom in three to four weeks without the application of
a high degree of heat or "forcing," as it is called. This has
two advantages: First, less bench room or space required in
the greenhouse, because of less time required for developing
the mature bloom, and second, the leaves and blossoms of the
"Cold Storage Valley" are stronger and fresher, and as they
are developed or grown at a lower temperature, they endure
better and with less wilting.
"WHAT "cold storage VALLEY^' REALLY IS.
The bulbs do not become cold storage bulbs until they are
about a year old, or at least, as generally handled they do not.
When received from Europe in October or November, the
bulbs iQ bunches of twenty-six or twenty-eight are generally
repacked in convenient sized boxes with sand or soil around
and between the bunches. The boxes are then placed in out-
door or cold frames, where they may be got at as needed for
successive forcing. (Please note that the bulbs are fresh and
new, and at this age they really require high temperature
579
580 PRACTICAL COLD STORAGE
and real foxcing.) After about February 15th to March 1st,
it is not safe to leave the bulbs in the outdoor frames longer,
and they are then repacked, this time for cold storage. The
bunches, after having been immersed in water, are stood up-
right in a closely packed tier with moss all around them,
under, between and over the tips of the bulbs. The boxes are
usually nailed up with lath and then piled in the cold storage
room one above the other, but a better way would be to use a
tightly nailed box, as a better protection against changes in
temperature would result.
It is, of course, possible, (and in fact the larger importers
do this) to repack the bulbs promptly when received from
Europe in the fall, and at once place in cold storage where they
remain during the winter and following summer or until
wanted for bringing into bloom. Better and more certain
results are obtainable in this way.
TEMPERATURE.
It is understood that the correct temperature at which to
store the pips depends on the kind and on the time to be held
in cold storage. Those adapted for short storage are carried
at 26° F. to 28° F., while those to be carried longer are best
carried at 23° F. to 25° F. A very uniform temperature is
recommended, but here again the question of a suitable tight
box might be of much help in overcoming some of the bad
effects of change in temperature.
SELECTION OP BULBS FOB COLD STORAGE.
Those grown on sandy soil are reputed to be good for early
forcing but not good for cold storage. The so-called Berlin
pips are of this type. They have a bunch of long fibrous roots
and tapering crowns of pinkish hue, and are generally more
fully ripened and may be forced earliest of all, while for long
keeping in cold storage they are not the best by any means. An
experienced florist thus describes the crowns best suited for
cold storage: "The individual pip should be thicker and more
stubby, and generally the crown should be characterized by a
ranker and more vigorous and coarser appearance than the
LILY OF THE VALLEY BULBS 581
Berlin pips used for Christmas forcing. They sometimes have
a purple or violet tint. By these characteristics they plainly
show that they have been grown on a very heavy rich soil,
and that in point of maturity they are far behind those grown
on sandy soil."
SUGGESTIONS.
If a suitable selection of high quality bulbs is secured it
would seem that the chief requirements of successful cold stor-
age would be proper packing and a low and uniform tempera-
ture. The bulbs should be wet thoroughly and packed in care-
fully dampened moss. Then they should be placed in a room
at not above 25° F. if for long storage, where they should be
piled loosely, with a couple of inches of space all around, for
a week; then they may be piled up in a solid pile, but kept
from walls and floor at least two inches. It would surely
seem that a tight box, possibly lined with paper, would be
preferable to the slatted covers, as it is necessary to keep from
the air and prevent drying out, which means loss of vitality.
It is also suggested that the shorter the time the bulbs re-
main under refrigeration the higher temperature and longer
time required for blooming; and the reverse is also true that
those bulbs long in cold storage bloom quickly, and there-
fore, should not be exposed to the high temperatures in use
for forcing, as it is destructive to the strength and durability
of the leaves and flowers. A temperature of 60° F. is high
enough.
CHAPTER XXIX.
WILD RICE SEED.
One of the products which cannot be handled without
cold storage is wild rice to be used for seed. This grain has
great food value and is one of the chief foods of wild ducks and
other game birds in some localities. It may be grown over
large areas and even in water which is slightly brackish. It
does best in the fresh water lakes and river sloughs. The
water should not be stagnant, and yet not with too much
current, and it does best where the bottom of the stream or
lake is soft and muddy. It is important that there be a
slight change in the water level from one season to another,
but this variation should not be greater than eighteen inches
to two feet, and the water should be constantly freshened by
slight movement, with its resulting aeration. The plant is an
annual, and is propagated from year to year by the seed fall-
ing directly into the water, where it lies until the following
spring when it will grow if conditions are favorable.
Many failures have resulted from the planting or sowing
of wild rice seed. This has been due to the seed becoming
dry while stored. The fact that this destroys its vitality was
not understood for some time and a large amount of seed was
distributed from which practically no results were obtained.
It is natural for the seed to fall into the water as soon as ma-
tured, therefore the natural method in preparing for storage
is by immersing in water.
The Department of Agriculture has done some work in
ascertaining the facts in connection with the saving of seed
and growing of wild rice, from the report of which are extracted
the following facts: The seed should be gathered as soon
as matured and placed loosely, with the hulls still on, in
burlap sacks and sent at once to the cold storage house. It is
582
WILD RICE SEED 583
perhaps needless to say that seed which has been threshed,
cleaned or parched for food will not germinate. If the wild
rice fields are some distance from the cold storage the sacks
should be sent by express unless time of transit can be guaran-
teed by freight. It is very important that the period from
time of harvesting and the placing in cold storage be as short
as possible. If this time is long, fermentation results, or the
seed on the outside of the bag will become dry. In either
case its vitality is deteriorated. It is not practicable to give
any definite length of time which may elapse between har-
vesting and storing, as conditions of temperatures, humidity,
etc., must be taken into consideration. It is, however, im-
portant that the seed remain moist and also that it does not
ferment. Here is where cold storage comes in.
To prepare the seed for cold storage it should be taken
while still fresh and moist, and before any fermentation has
commenced, and put into any clean water-tight receptacle
without tight covering. Tin packages or barrels or vats may
be used. If there is any quantity of light immature seed or
sticks or other refuse mixed with the good seed it will float
to the top and can be removed. Water-tight barrels are mostly
used, standing on end without heading up and placed one
tier above another. The mature seed from the harvest fields
is first dumped into the barrels and they are then filled with
water. The temperature of the storage room for wild rice
seed when prepared in this way should be just about the freez-
ing point, 33° to 34° F.
When removing from storage the seed should not be
allowed to dry out before planting, as a few days in a warm,
dry air will destroy every germ. Seed properly stored has been
held for more than a year and more than 80% germinated.
It must be remembered that the vitality of the cold stored
seed is more quickly destroyed than that of fresh seed, owing
to the fact that it has been soaked in water for so long a period.
It is, however, for this reason in better shape to start growth
when planted.
For shipping after storage the seed should be carefully
packed in dampened sphagnum moss, or fine excelsior, or
584 PRACTICAL COLD STORAGE
planing mill shavings in a loosely covered box or crate. No
special precaution needs to be taken in connection with tem-
perature if it is not on the road more than five or six days.
Should some of the seed germinate or sprout during transpor-
tation, it will grow just as well, providing it is quickly sown
after receiving. If the time of transportation is long it is
recommended that some provision for reducing temperature,
like shipping in refrigerator cars, or icing the packages, should
be provided. Fair results, however, may be obtained by hand-
ling and shipping as above described.
• The seed may be sown either in the autumn as soon as har-
vested or in the spring. Spring sowing is preferable, as the
seed is more likely to stay where it is desired to have it grow.
It should not be sown in water more than four feet in depth
and preferably a depth of one foot to three feet.
The possibilities of development in the growing of wild
rice as a food product and as an attraction for wild waterfowl,
make the facts which have so far been ascertained of consider-
able value, and they have, therefore, been given here in some
detail.
CHAPTER XXX.
POULTRY.
DRAWN VS. UNDRAWN METHODS OF HANDLING.
It was long a mooted point as to whether poultry should
be handled, shipped, frozen and stored in a drawn or un-
drawn condition. Drawn poultry means that from which
the entrails or viscera have been removed, and it was thought
by many to be the only correct way of handling, and some
of the larger cities even went so far as to pass laws forbidding
the sale of poultry which had not been drawn. This brought
such a storm of protest from the poultry handlers that laws
of this kind did not live long, but it was not until the Depart-
ment of Agriculture through its Bureau of Chemistry, as
represented especially by Dr. Mary E. Pennington, carried on
during the season of 1909 and 1910, a series of studies to
determine the relative rate of decomposition and deterioration
in undrawn poultry as compared with that from which the
viscera had been either completely or partly removed, that
guesswork was set aside, and some actual facts determined.
The tests began at the packing house where the poultry was
killed and did not end until it was sold through the retailer
direct to the consumer. Actual observations and records were
kept at every stage in the marketing. The aim was to com-
pare the relative keeping qualities of the drawn and undrawn
poultry under actual market conditions, and to place each
method of dressing strictly on its own merits.
In these tests and experiments, temperature conditions
were one of the most important points of observation, and
the temperature records were made by thermographs which
followed the shipments of poultry from start to finish. The
S8S
586 PRACTICAL COLD STORAGE
experiments extended over a period of six months, from mid-
winter to midsummer.
The dressing of the carcasses was done according to three
methods known as "full drawn," "wire drawn" and "Boston
drawn;" the "wire drawn" and "Boston drawn" being a sort
of partial step toward "full drawn." The undrawn fowls
were shipped with the heads and feet on. The birds were
cooled at an average temperature of 34° F.; wrapped in parch-
ment paper ; boxed and shipped in a refrigerator car which had
been iced and salted, and which was on the road averaging
7j^ days. From the refrigerator car the goods were handled
through a chillroom at between 32° F. and 33° F. At the
retailers the average temperature of the exhibition window
was 48° F.
An elaborate set of charts was prepared by Dr. Penning-
ton showing the history of drawn poultry and undrawn poultry
from the beginning, and the comparative keeping qualities
of each. The conclusions reached were that undrawn poultry
decomposed more slowly than either the wholly or partially
drawn, and that the full drawn as completely eviscerated
poultry decomposed most rapidly, and that the "Boston drawn"
and "wire drawn" stood midway between the undrawn and
"full drawn" in the rapidity of decomposition. These de-
ductions are based on a number of shipments of dry packed,
unwashed fowls and were studied at every stage of marketing
from the shipper to the consumer, and the fowls used in the
experiments were handled promptly, as ordinarily understood.
It is, of course, understood that for best results poultry for
slaughter should not be fed for 12 hours prior to killing.
There is then little food in the crop and entrails to ferment
and sour.
As it is, therefore, now fully understood and determined
that undrawn poultry is the only correct way of handling
for commercial purposes, we will consider that the applica-
tion of refrigeration as explained more fully in what follows
applies to undrawn poultry. The proper feeding, killing,
bleeding, picking, etc., of poultry is a separate subject and
should be studied separately. What is said here applies to
POULTRY 587
the proper cooling and freezing mostly, assuming that the
poultry has been properly handled according to modern prac-
tice.
COOLING AFTER PICKING.
The tendency toward "dry picking" and "dry packing"
of poultry for shipment and marketing, is so marked as to
indicate that the scalding of poultry to facilitate picking, a;nd
the packing of poultry in ice for shipment to prevent deteriora-
tion, will be abandoned in favor of the more cleanly and
sanitary "dry" methods.
The fact that a picker will pick from four to ten times
as many fowls when scalded, is certainly a strong tempta-
tion to handle in that way, but the big and increasing demand
for the "dry" poultry, and the decidedly higher price which it
brings, more than pays for the increased cost. In dry pick-
ing and dry packing prompt cooling after killing is a prime
essential, and poultry shippers are beginning to appreciate
the fact that they cannot get along without artificial refrigera-
tion of some kind to take the heat out of the birds quickly
after killing. ]\Iany shippers have tried to get along with a
makeshift outfit, using an ordinary ice refrigerator or direct
ice cooling arranged in some way, while others have provided
a real cold storage outfit of one kind or another. Large
capacity for cooling is necessary, and the space used for
cooling should be divided into at least two rooms, and three
rooms are even better than two. The reason is that it will
not do at all to put warm, freshly killed poultry into a room
with poultry which has been cooled down to correct packing
and shipping temperature — 30° F. to 35° F.— even if it is
partially cooled down. If this is done the result is that
moisture or steam from the freshly cooled poultry will con-
dense on the colder poultry in the room, making it flabby
and damp, and resulting in poor color, liability to deteriorate
in transit or after arrival on the market, and thus losing one
of the great advantages of the "dry" method.
It has been thought by some that by providing a large
room in proportion to the work to be done that the temperature
588 PRACTICAL COLD STORAGE
could be held without serious danger, and that the cooling and
packing could be handled in one room. This theory has
proved to be incorrect, and it is generally understood that at
least two rooms must be provided in order to produce the
best possible results in cooling, packing and shipping. Where
two rooms are in service one of the rooms can be used today
and the second room tomorrow, or after the poultry is partly
cooled in the first room it can be removed to the second room,
which may be used as a packing room and from which the
poultry may be transferred to refrigerator cars for shipment.
If it is desired to freeze poultry on the premises three rooms
should be provided, two of them to be used as suggested, and
the third room or freezer to receive the poultry after cooling
and packing in the cooling rooms, and freezing it to the re-
quired temperature.
TEMPERATXJRES.
It is not necessary that the room in which the poultry is
first placed should be maintained at a very low temperature,
but a large refrigerating capacity should be available so that
the moisture and heat may be taken up quickly. The second
room for receiving poultry after being partially cooled down,
say to 40° F. to 45° F. or 50° F. should be maintained at
a temperature of 30° F. to 32° F., as near as practicable, and
the poultry should be reduced to 30° F. to 35° F. before
packing into boxes ready for freezing.
The correct temperature for freezing and storing poultry
has not been determined with sufficient accuracy so that it
is possible to name any particular temperature, but where
poultry is killed, cooled, packed and frozen at one place and
where the various stages are handled properly, promptly and
carefully, a temperature of from 10° F. to 15° F. for freezing
will produce completely satisfactory results if poultry is
packed in small boxes, not more than 10 inches in thickness
for the heavier poultry, and proportionately less for the lighter
birds. The large city cold storage houses maintain their
freezers at zero and even below, but these temperatures are
not necessary for freezing poultry in the country or at the
POULTRY 589
point where killed. These low temperatures are useful and
necessary in big cities as the poultry is very often greatly de-
teriorated before placing in the freezer, and it often comes
to the city freezers in large boxes and barrels which are slow
in giving up their heat, and the poultry, therefore, takes a
long time to freeze to the center of the package.
After being properly cooled and packed at a temperature
of 30° F. to 35° F. poultry may be frozen, as above stated,
in a temperature of 10° F. to 15° F. In placing the boxes
in the freezer they must not be piled tightly, and a circula-
tion of air of at least 2 inches between all packages and under
the packages on the floor should be allowed. A good method
is to set the boxes on end on 2x4's on the floor, allowing a
space of 3 to 4 inches between the boxes, and piling them
but one tier in depth. The boxes should be set edgewise to
the circulation of air or toward the coils if the room is equipped
with direct piping. If the room is equipped with the Cooper
false floor and false ceiling system of air circulation, it is
not necessary to leave more than 2 inches of space between
the packages and no attention need be paid to just how the
packages are placed in the room except to keep them 2 inches
apart all around, and an inch off the floor.
After the poultry has been thoroughly frozen to the
center of the box it may be stacked up solidly in the room,
but a space of 1 inch to 2 inches must be left on the floor
and a similar space around the sides of the room and at the
ceiling. Much damage has been caused on other frozen prod-
ucts as well as poultry, by piling them tightly against the
outside or warm wall, or failing to leave space on the floor
for the cold air to circulate and thus preventing the heat from
entering. A thawing or high temperature will result from
improper piling, and mouldy, decayed and spoiled poultry
results.
METHODS OF COOLING.
Those who are to continue in the poultry business must,
in future, provide artificial means of cooling, or they cannot
possibly compete with their better equipped competitors. Ar-
tificial means of cooling does not necessarily mean a compli-
S90 PRACTICAL COLD STORAGE
cated refrigerating machine system. The same results can be
had with the Cooper brine system, using ice and salt for cool-
ing. Any method of cooling which will give a temperature
of about 30° F. in the cooler is all that is required, but this
cannot possibly be had with any method of cooling with air
directly off from melting ice.
Satisfactory results can be had in the cooling of freshly
killed poultry by locating the cooling pipes directly in the
room, providing the room is of fair height and the pipes are
hung from the ceiling so that a good circulation of air will
be present. If the room is a low one and rather large and the
pipes located around the walls, the circulation will be defective
and the results from cooling inferior. If the pipes are to be
located in the room, they should be hung edgewise from the
ceiling and located not more than a pair together, so that drip
pans may be arranged under them, and so that the cold air will
drop off the coils very quickly, and thus result in a good cir-
culation and uniform temperatures in the room. Then the
warm and moisture laden air will rise to the top of the coil and
the moisture be condensed thereon. The Cooper chloride of
calcium process is especially desirable in a poultry cooling
room on account of the excess of moisture which must be dis-
posed of.
Better than any direct piped room, however, is the fan
system of air circulation. This does not mean to cool a room
by means of piping in the room and then simply to put in one
of the small electric fans. This is not air circulation by any
means and only a poor makeshift of doubtful value. The
very best method of circulating air for cooling purposes, as
already mentioned, is the Cooper improved false floor and false
ceiling system of air circulation, wherein cold air is distri-
buted through a perforated false floor and the comparatively
warm and moisture laden air drawn out of the room through a
perforated false ceiling. This gives a perfectly uniform cir-
culation of air in all parts of the room, resulting in a quick
cooling and positive prevention of condensation of moisture on
the poultry. This system will quickly dry the fowls as well as
cool them. The air from the false ceiling is taken to the coil
POULTRY
591
room or bunker room in which cooling pipes are located, and
these pipes may be cooled by a refrigerating machine, or they
may be the secondary coil pipes of the Cooper brine system, us-
ing ice and salt for cooling. On account of the temporary or
transient nature of the work, the Cooper brine system, which
needs no skilled engineer nor slow and expensive overhauling
of plant prior to starting up, is preferable to an ice machine.
FIG. 1.— MAIN FLOOR PLAN.
The length of time required for cooling poultry depends on
its temperature when placed in the room, capacity of refriger-
ating system, etc. It is really not desirable to turn a blast of
frosty air on warm goods. Poultry should be reduced in tem-
perature rather slowly, and from 24 to 36 hours would be
the natural period through which to cool it from a temperature
of 80° F. or 85° F. down to 30° F., the temperature suitable
for packing.
If killing a large amount of poultry and necessary to
crowd the apparatus to the utmost, 24 hours or even 18 hours
592
PRACTICAL COLD STORAGE
in the chill room is permissible, but otherwise 36 hours is ad-
vocated as more desirable for the best results. The very best of
results are only obtainable by using two separate methods of
cooling and two separate rooms, so that when necessary to put
extremely warm poultry in the cooling room during warm and
humid days, the poultry is first exposed to only a moderately
cold air, say at a temperature of 40° F. to 50° F. After taking
the high temperature out of the poultry a colder circulation of
air may be employed and the poultry reduced to the correct
packing temperature, 30° F.
Several different arrangements may be made to produce
these results. An example of a correct plant is illustrated in
Fig. 1. This, as will be noted, consists of two poultry rooms,
one a poultry cooler and the other a poultry storage room. An
ice room extends along one side of these rooms. Both rooms
FIG. 2.— FIRST FLOOR PLAN.
are equipped with the Cooper false floor and false ceiling sys-
tem of air circulation and the air handled by means of the
fan system. When first killed the poultry is introduced into
room marked "Poultry Cooler," where it takes its initial cool-
ing, and after being reduced to 45° F. or 50° F. it is run into
the poultry storage room where it is still further cooled and
packed at a temperature of 80° F. The poultry cooler is cooled
by air directly from the ice room, while the poultry storage
and packing room is cooled by air from the coil room of the
Cooper brine system, using ice and salt for cooling.. The room
marked, "Poultry Storage" is used for accumulating a carload
and shipping it out in the best possible condition. This room
may be used for egg storage during the egg season and when
not in use in connection with the poultry business.
POULTRY
593
Figs. 2 and 3 show an entirely different arrangement, al-
though operating on the same general principle. There are
two poultry rooms which are used for the cooling of poultry
for shipping, but the poultry is not moved from one room to
the other as in Fig. 1. The same result is obtained by an ar-
rangement of gates. For instance : Freshly killed poultry is
run into room No. 3 and has the direct air from ice room on
second floor turned on for a period of from 6 to 12 hours. Aft-
er cooling the poultry to a temperature of 40° to 50° F. the
direct air is turned off and air from the coil room containing
^^
FIG. 3.— TRANSVERSE SECTION "C-D."
secondary coils of the Cooper brine system is turned on and
the poultry reduced to a tempei-ature of 30° F. to 32° F. It
is then packed for shipping without removing from room and
held at a correct temperature until shipped. By using the rooms
alternately, with direct air for a portion of the day, and the
Cooper brine system for another portion, poultry may be cooled
continuously day after day. Should it be desired to hold the
poultry for some days before shipping it can be removed from
S94 PRACTICAL COLD STORAGE
one room to the other essentially as in Fig. 1.
Plan shown in Mgs. 2 and 3 has a retail cooler as this
plant is located in quite a large town where the local business
is considerable. This room is cooled by the Cooper brine sys-
tem and maintained at a temperature of 32° F, or lower if de-
sired.
With both plans the fans are so arranged as to take the
air directly from outside when the temperature is sufficiently
low to make this practice desirable. This makes a very rapid
method of cooling, much more so than opening windows and
doors, as the distribution of air is more thorough.
The false floor and ceiling system is the most perfect theo-
retically of any in service as the cold air is distributed over the
entire surface of the floor and the comparatively warm and
moisture-laden air is drawn off from the entire surface of the
ceiling, making a very free and penetrating circulation. This
results in a very thorough and quick cooling; yet the circula-
tion is not so rapid nor strong as to be objectionable.
RACK FOR HANGING POULTRY FOR COOLING.
For cooling poultry quickly and for handling it economi-
cally, it is best to use metal racks which are mounted on casters
or wheels, and on which the poultry may be hung in the kill-
ing room, then run directly to the cooling and packing rooms.
Such a rig has been described by Dr. Mary E. Penning-
ton in connection with her poultry work for the Bureau of
Chemistry, U. S. Department of Agriculture, and illustrated
herewith. These rigs are now being made as a regular article
of manufacture and they may be had at reasonable cost all
ready for business.
The specifications for the rig are as follows: Height over
all, 69 inches; width over all, 38 inches; width of base, 38
inches; length of base, 61 inches; width of top of frame, 33
inches; height to top of frame, 68 inches; end supports, four
inches apart at base; bend in end supports, 19 inches from
floor; first cross bar, 29 inches from floor; cross bars eight
inches apart; two bottom cross bars, nine inches apart; end
cross brace, 26 inches long and 57 inches from floor; center
POULTRY
59S
brace rods, 76 inches long; top of base, 8 inches from floor;
corner brace plates, 10 inches on square edges; end brace plate,
10 inches wide, 9 inches high (upper corners beveled) ; cast-
FIG. 4 — POULTRY CeiOLING RACK.
ers, 6 inches in diameter; base frame, 2xi4-inch angle iron;
end supports, 11/2 by i/g inch angle iron; cross bars, 1^4 by Vs
596 PRACTICAL COLD STORAGE
inch angle iron; end cross bars, 1% by %, inch flat iron; cen-
ter brace rods, % inch round iron, threaded at both ends, one
end passing through center of end cross bars, the other end
replacing one of the bolts fastening end supports to end brace
plate; corner and end brace plates, Vi inch flat iron; fingers
for holding feet of birds made of No. 10 tinned steel wire.
The fingers are formed by bending thfe wire continuously
around three pins placed in a triangular position. The
fingers axe 3% inches long and approximately 1% inches
apart, center to center, being spaced so as to allow 30 openings
to hold 15 chickens within a distance of SS^A inches, which is
the clear distance along the cross bars between the upright
supports on either end. The slots between the fingers are
% inch wide at the bottom and then widen to a round point
at the top as shown.
The finger wire is fastened on with % inch and V4, inch
oval-headed bolts, galvanized, with washers. It requires 32
bolts to each cross bar. All other bolts or rivets are % by %
inch, galvanized, except the caster bolts which are 1 by V^
inch, galvanized.
The upright supports are fastened to end brace plates
with two bolts each. The corner base plates are riveted to
base.
The caster spindles are %-inch in diameter, turning in
an extra strong socket, as considerable strain comes at this
place.
All metal is galvanized except the finger wire, which may
be either tinned or galvanized.
These dimensions are adapted for a truck that will pass
readily a refrigerator door four feet wide and six high.
One inch of space in width can be saved by moving the
end supports together at the base, making them three inches
apart from outside instead of four inches as stated.
In this truck, all four wheels are casters. This makes
the truck harder to handle by one man. Wherever plenty of
refrigerator and floor space is available, two of the casters may
be replaced by fixed wheels, which makes the truck steer much
more easily.
POULTRY
597
For smaller doors than 4x6 feet, the base could be nar-
rowed and the top narrowed and the height decreased to use
only five cross bars instead of six. This, however, also cuts
down the capacity of the truck.
As it now stands, these trucks will hold 180 broilers,
fowls or rabbits, and 48 turkeys each.
The advantages of hanging poultry by the legs while cool-
ing are many, such as more rapid cooling, better circulation of
air around the bird, the skin of the bird is not torn liy com-
FIG. 5 — COOLING POULTRY IN A ROOM EQUlrPEED WITH COOPER
FALSE FLOOR AND FALSE CEILING SYSTEM OF AIR
CIRCULATION.
ing in contact with shelves, the heads of the fowls are easily
wrapped, and the grader can see the stock more easily. Also,
the method is more cleanly.
MISCELLANEOUS.
A practical poultry operator in Chicago offers some sug-
gestions with reference to preparing poultry for freezing, which
598 PRACTICAL COLD STORAGE
are worth considering. He says that much of the trouble ex-
perienced in freezing poultry is due to faulty handling by the
commission men; that they expose it on sale all day in warm
weather, pack it up toward evening, and put it into the freezer.
The result of this is that it may look all right when taken out
of the freezer, but as soon as the frost comes out of it, it becomes
sticky and slimy and not fit for food. This practical poultry
man states that his experience in putting away matured and
well fed turkeys, capons and roasting chickens is that they
should be placed in the cooler promptly when killed, and ,the
animal heat taken out of them within twenty-four hours, and
then frozen. He says that such poultry will be far better when
removed from the freezer in the spring than freshly killed
poultry after running all winter. He says further that spring
chickens put away before they are matured may not hold
their flavor like properly matured birds, and that while they
appear all right, the delicate flavor of freshly dressed stock is
gone.
Some actual records made by Dr. Mary E. Pennington of
the Bureau of Chemistry, U. S. Department of Agriculture,
will doubtless be interesting. They may be summarized as
follows :
The tests covered various temperatures and various per-
iods of storage, from carrying poultry in a temperature of 65°
F. to 75° F. for three days, to sixteen months in a freezer at
a temperature of 10° F. It is reported that chickens at- 65°
F. to 75° F. for three days' time were in bad order at the
end of that period, and it is also reported that poultry held for
sixteen months were in rather poor condition for eating pur--
poses, although not spoiled or inferior by any means. Practi-
cally perfect results were secured by storing poultry at a tem-
perature of 10° F. above zero for four months, and the same
experiment continued for eight months gave poultry which
was in commercially perfect condition, although certain
changes were noted which indicate that the fair life of the
poultry as held in freezers at this temperature had been
reached. At twelve months in the freezer the poultry was still
POULTRY 599
in good condition, but proportionately poorer than at eight
months.
It will be noted that these experiments show the possi-
bilities of freezing and storing poultry at 10° F. above zero.
This does not at all correspond with the claims of some of the
big storage houses where it is said that temperatures below
zero are necessary for best results. It is the author's opinion,
and he has constantly held this opinion for some years, that
10° F. above zero is amply low for the freezing and storage
of poultry, butter, game, etc., for periods which are repre-
sented naturally by the commercial limitations of the product.
It is not ordinarily necessary to store any of these goods for
more than six to eight months, but for this length of time 10°
F. above zero for all practical purposes is just as good as 10°
below zero.
Mr. R. II. Tait in a paper read before the "Missouri Car
Lot Shippers' Association"* gives some interesting suggestions
and facts which are always acceptable. He states that for
poultry cooling two rooms are desirable, one double the size
of the other ; the larger room to be used for chilling and pack-
ing, and the other for storing after chilling. He also states that
provision for fresh air circulation in these rooms is of import-
ance, second only to refrigeration, and that with rooms prop-
erly designed this can be done without the use of fans, by
placing the cooling coils in a bunker above the storage space.
The temperature of the chill room, he says, should not go
above 38° F., while putting in fresh poultry, and should be
reduced to 32° F. After thorough chilling the birds should
be moved to the storage room maintained at 32° to 30° F.,
and there held and packed.
Mr. Tait states that a packing station to handle from two
to three cars of poultry per week should have a floor space of
about 1,200 sq. ft. with a ceiling 10 ft. high, and that the
two rooms used in connection with the poultry business should
be arranged accessible to loading platform or railroad
track, and recommends an enclosed flexible vestibule adjacent to
car door to avoid exposure of cold goods to warm air during the
*Ice and Refrigeration, April, 1912, page 258.
600 PRACTICAL COLD STORAGE
summer. Such a plant with a capacity of two to three cars
per week, he states, will cost from $6,000 to $7,000 including
building, machinery, etc., and that it will require 15,000 gal-
lons of water per day at temperature of 70° to 80° F. under
severest conditions, and that it would not be practical to take
this quantity of water from the city mains.
It might be remarked that where the quantity of poultry
to be handled does not exceed two to three cars per week or an
average of 8,000 to 10,000 lbs. per day, and where ice, either
artificial or natural, is available at reasonable cost, the Cooper
brine system, using ice and salt for cooling, is recommended
in preference to a refrigerating machine. The cooling of
poultry is a transient or intermittent service anyway, and
there are many times during the heavy poultry shipping sea-
son when natural outside temperatures furnish all the refrig-
eration that is necessary. A plant equipped with the Cooper
brine system can be built for very much less than the figures
Quoted above.
CHAPTER XXXI.
FREEZING AND STORING FISH.*
IMPORTANCE AND GROWTH OF THE INDUSTRY.
In the artificial freezing of fish and their subsequent reten-
tion in cold storage is found one of the most recent methods of
food preservation, originating about forty years ago, and
while it has acquired considerable importance in certain locali-
ties, its practical value is scarcely appreciated by the general
public. It is applied in the various marketing centers of the
United States, and to some extent in the countries of Europe
and South America. Its greatest development and most ex-
tensive application exists along the great lakes, in freezing
whitefish, trout, Herring, pike, etc., about 7,000,000 pounds of
which are frozen each year. On the Atlantic coast of the United
States it is used in preserving bluefish, squeteague, mackerel,
smelt, sturgeon, herring, etc., the trade in these "tailing on"
or immediately following the season for fresh or green fish. On
the Pacific coast large quantities of salmon and sturgeon are
frozen and held in cold storage until shipped, the trade extend-
ing to all parts of America and northern Europe. At various
points throughout the interior of the country there are cold
storage houses where fishery products are held awaiting demand
from the consumers. In Europe there is comparatively little
freezing of fish, although the process is applied very extensively
to preserving beef, mutton, etc., and the markets of Hamburg
and other continental cities receive annually several million
pounds of frozen salmon from our Pacific coast. In England
large fish freezers were erected several years ago at Grimsby and
Hull, and trawlers are in some cases supplied with refrigerat-
*By Charles H. Stevenson in Ice and Refrigeration, February, 1900.
601
602 PRACTICAL COLD STORAGE
ing plants where the fish are plunged alive into cold brine
which freezes them solid.
During warm weather the temperature of the fish storage
room can never be kept below 32° F. by the use of ice alone.
While a temperature of 32° F. retards decomposition, the fish
acquire a musty taste and loss of flavor, and eventually spoil.
To entirely prevent "decomposition the fish must be frozen im-
mediately after capture, and then kept at a temperature of sev-
eral degrees below freezing. The belief held by some persons
that freezing destroys the flavor of fish is not well founded, the
result depending more on its condition when the cold is ap-
plied and the manner of such application than upon the effect
of the low temperature. Fish decreases less in value from freez-
ing than meat does, but it is especially subject to two difficul-
ties from which frozen meat is free ; first, the eye dries up and
loses its shining appearance after considerable exposure to cold,
and second, the skin, being less elastic than the texture of the
fish, becomes hard and somewhat loose on the flesh. Frozen
fish is not less wholesome than fish not so preserved. The
chemical constituents are identical, except that the latter may
contain more water, but the water derived from injested fish
has no greater food value than water taken as such. The prin-
cipal objection to this form of preservation is the tendency to
freeze fish in which decomposition has already set in, and the
prosperity of the industry requires that any attempt to freeze
fish already slightly tainted should be discountenanced. When
properly frozen and held for a reasonable period, the natural
fiavor of fish is not seriously affected and the market value
approximates that of fish freshly caught. The process is of
very great value to the fishermen supplying the fresh fish trade,
since it prevents a glut on the market, and it is also of benefit
to the consumer in enabling him to obtain almost any variety
of fish in an approximately fresh condition throughout the
year.
DEVELOPMENT OF COLD STOEAGE.
The first practical device for the freezing and cold storage
of fish was invented by Enoch Piper, of Camden, Me., to whom
a patent was issued in 1861. His process, based on the well
FREEZING AND STORING FISH 603
known fact that a composition of ice and salt produces a much
lower temperature than ice alone, consisted in placing the fish
on a rack in a box or room having double sides filled with non-
conducting material, and metallic pans containing ice and salt
were set over the fish, and the whole inclosed. The temperature
in the room would soon fall to several degrees below the freez-
ing point of water, and in about twenty-four hours the fish
would be thoroughly frozen. The fish were then covered vfifii ,
a coating of ice by immersing them a few times in ice cold
water, forming a coating about %-inch in thickness, after
which the fish were wrapped in cloth, and a second coating of
ice applied. In some instances they were covered with a mate-
rial somewhat like gutta percha, concerning which much
spcrecy was exercised. The fish were then packed closely in
pother room well insulated against the entrance of warmth,
find in which were a number of perpendicular metallic tubes,
several inches in diameter, filled with a mixture of ice and salt
to keep the temperature below the freezing point.
The process was also patented in the Dominion of Canada,
and a plant was established at Bathurst, New Brunswick, in
1865, the output consisting almost entirely of salmon, a large
proportion of which were imported into the United States. In
order to hold the frozen fish in New York, while awaiting a
market, Piper constructed a storage room in a shop on Beekman
street, that being the first cold storage room for fish in the
United States. The walls of the room were well insulated, and
around the sides were two rows of zinc cylinders, ten inches in
diameter at the top, and decreasing in size toward the bottom,
connecting at the lower end with a drainage pipe, ' The cylin-
der's were filled with a mixture of ice and saltji-iwhich was re-
newed whenever necessary. Whatever may have been tlh^
imperfections in his process of freezing, the system of st^age
■was quite satisfactory, and differs little from that in iise-Bt T&e
present time. Piper refused to sell rights to others for the use
of his process, and after maintaining a monopoly of the busi-
ness for three or four years his exclusive right to it was success-
fully contested by other fish dealers in New York, who applied-
it to storing other fish besides salmon.
604
PRACTICAL COLD STORAGE
The principal objection to Piper's process is that the fish
are not in contact with the freezing mixture during the oper-
ation of freezing, and, consequentlj', too much time is required
for them to become thoroughly frozen. Several devices have
been used for overcoming this objection, among which are cov-
FIG. 1— PANS OP FROZEN WHITEPISH, SHOWING ARRANGEMENT
OF FISH IN THE PANS. — DAVIS SYSTEM.
ering the fish with thin sheet rubber or other waterproof mate-
rial, and packing them in the mixture of ice and salt.
The greatest improvement, and the one used almost ex-
FREEZING AND STORING FISH 605
clusively when ice and salt form the freezing agency, originated
in 1868 with Mr. William Davis, of Detroit, Mich., the descrip-
tion being as follows : Two thin sheet metal pans are made to
slide one over the other, the object being to place the fish in one
pan, slide the other pan vertically over it, and the box is then
placed in direct contact with the freezing mixture. By having
the box constructed in this manner, it is capable of being ex-
panded or contracted to accommodate the size of whatever may
be placed therein, and the top and bottom always be in contact
with the articles to be frozen. After the fish are inclosed in the
pans, the latter are placed in alternate layers with layers of the
freezing mixture between and about them. When the fish are
thoroughly frozen they are removed from the freezing pans and
placed in cold storage at 10° or 12° F. below freezing.
As the trade developed the size of the storage rooms in-
creased and improvements were adopted in the arrangement and
form of the ice and salt receptacles, and in the method of
handling the fish. But the freezing with pans immersed in
ice and salt, as in the Davis process, and the subsequent stor-
age in the manner used by Piper, continued without great
modification until the introduction of mechanical refrigeration
into the fishing trade in 1892. At that time ice and salt freez-
ers and storage rooms existed at nearly all the fishing ports on
the great lakes; eight or ten small ones were in New York City,
and several were in use on the New England coast. Some of
those on the great lakes were quite large, with storage capacity
of 700 or 800 tons or more, and the aggregate capacity of all
in the country approximated 8,000 tons. Cold storage houses
fitted with ammonia machines had been established at vari-
ous places along the coast and in the interior during the ten
or fifteen years preceding, and in these some frozen fish had
been stored. But the first establishment using a refrigerating
machine for freezing fish exclusively was erected at Sandusky,
Ohio, in 1892. The method of freezing in these establishments
differs from the ice and salt process in that the pans of fish are
placed on and between tiers of pipes carrying cold brine or
ammonia instead of being immersed in ice and salt. In the
storage rooms less difference exists, coils of brine carrying pipes
606 PRACTICAL COLD STORAGE
taking the place of the ice and salt receptacles, the blocks of
fish being removed frbm the pans and stored as in the older
process.
DESCRIPTION OP ICE AND SALT FREEZERS.
The outfit of an ice and salt freezer consists principally of
temporary stalls or bins where the fish are frozen, and insulat-
ing rooms where the frozen fish are stored at a low temperature.
In addition to these there are ice houses, salt bins, freezing pans,
and the various implements for the convenient prosecution of
the business. The freezing bins are usually temporary struc-
tures within the fish house, and are generally without insula-
tion. The walls of the fish house may form the back, while
loose boards are fitted in to form the sides and front as the bin
is filled, in the manner hereafter described. A better way is to
construct the bin with permanent sides and back four or five
inches thick, fitted with some non-conductor, with double or
matched floor, and with movable front boards.
The storage rooms are commonly arranged in a series side
by side and separated from each other by well insulated parti-
tions, the capacity of the rooms ranging from 25 to 250 tons
each. The outer walls of these rooms, as well as the floors and
ceilings, are well insulated, made usually of heavy matched
boards, with interior packing of some non-conductor of heat,
such as planing mill shavings, sawdust, pulverized charcoal,
chopped straw, rock wood, slag wood, etc. Most of the walls
are sixteen or eighteen inches thick, filled with planing mill
shavings or sawdust, and in some freezers the damaging effect
of rats is obviated by placing linings of cement between the
shavings and the board walls. Most of these loose materials
have their economic drawbacks, chiefly because of their strong
hygroscopic tendency, the material losing its insulating power
and decaying, this decay also attacking the wood of the walls.
Because of this, many of the storage rooms recently constructed
are insulated by having the walls made up of a combination of
rock or mineral wool, insulating paper, air spaces and inch
boards.
The sides, and in some cases the ends of the room, are lined
with the ice and salt receivers, consisting of galvanized sheet
FREEZING AND STORING FISH 607
iron tanks, eight or ten inches wide at the top, narrowing to
three or four inches at the bottom, and placed about four inches
from the wall in order to expose their entire surface to the air
in the room. These tanks open at the top, which extends above
the ceiling, so that they may be filled without opening the stor-
age rooms. At the bottom is usually a galvanized iron gutter,
into which the water resulting from the melting ice flows,
whence it is conducted through the floor of the room by a short
pipe, protected from the entrance of air at its lower end by a
small drip cup, into which the brine falls and runs over at the
top. The ice and salt tanks must be cleaned from time to
time in order to rid them of dirt and sawdust. Their capac-
ity should be in proportion to the size of the room and the
excellence of the insulation, and they should be large enough
to render it unnecessary to fill them oftener than once a day,
even in the warmest weather.
FREEZING BY MECHANICAL EEFKIGERATION.
In the freezing houses using mechanical refrigeration there
is, as customary with cold storage houses used for other prod-
ucts, a machinery room containing the boilers, compression
pump or absorption tank, according to the system employed,
brine pump, etc. Apart from these, and within well insulated
walls, are the cold rooms, of which there are two kinds, one for
the freezing of fish and the other for their storage after being
frozen, the capacity of the latter being usually much greater
than that of the former. In the freezing room the circulating
pipes containing the cooling material are one-half inch to two
inches in diameter, and arranged in shelves or nests with hori-
zontal layers four or five inches, and sometimes ten inches
apart, ranging from the floor to the ceiUng, the entire room
being occupied with these nests, except sufficient space for mov-
ing about. The temperature depends, of course, on the quan-
tity of green fish and the progress of the freezing process ; but
with direct expansion, or using brine made of chloride of cal-
cium as the circulating medium, a temperature of — 10° F.,
or less, is obtainable. In this room the fish are frozen, and
then they are removed to the storage rooms.- These are con-
608 PRACTICAL COLD STORAGE
structed similarly to the storage rooms in ice and salt freezing
houses, the only difiference being that brine carrying pipes are
substituted for the ice and salt receptacles. The pipes in the
storage rooms are usually larger, but are not so numerous as in
the freezing room. They are arranged at the ceiling, and some-
times about the upper side walls also.
In freezing fish, as in preserving most food products, close
attention must be given to the economy of the process as well
as to the excellence of the product, and the expense of the best
process frequently prevents its use. To secure the best results,
the stock to be frozen should be perfectly fresh and free from
bruises and blood marks. It improves the appearance, and
therefore increases the value, if the fish are graded according to
size, but this is rarely done. All kinds of fish keep and look
best when frozen just as they come from the water, with heads
on and pntrails in, and it is b'jtter that the fish be not eviscer-
ated before freezing, except in case of very large fish, such as
sturgeon. But since the freezers receive the surplus from the
fresh fish trade, many have been already split and dressed.
Generally, fish that are frozen with heads off and viscera re-
moved are not strictly fresh, but this rule has several exceptions.
Whether round or eviscerated, the fish are first washed by
dumping them into a wash box or trough containing fresh cold
water, which is frequently renewed, and stirring them about
with an oar-shaped paddle or cloth swab, to remove the slime,
blood, etc. Some freezers consider it inadvisable to wash flat
fish, because of their being too thin. From the wash box the
fish are removed by hand and placed in the pans in such a
manner as to make a neat and compact package entirely filling
the pan, so that the cover will come in contact with the upper
surface of the fish. It is desirable, when the size of the fish so
admits, that the bellies be placed upward, since that portion
ha? greater tendency to decompose, and, as the cold passes
down, this arrangement results in freezing the upper portion of
the block first, and also in less compression of the soft portion
of the fish by removing the weight therefrom. It is also desir-
able to have the backs of the fish at the sides of the pan and
the heads at the ends, so as to protect the blocks in handling,
FREEZING AND STORING FISH 609
but this is by no means a uniform practice. In case the fish
have been split and eviscerated it is desirable to place them
slanting on the sides, but with backs up, so as to permit the
moisture to run from the stomach cavity. Some freezers place
herring and other small fish on their sides, two layers deep in
the pans, while others place a bottom layer of three transverse
rows, the end rows with the heads to the edge of the pan, and a
top layer of two transverse rows laid in the two depressions
formed between the bottom rows. In case of pike and some
other dry fish a small quantity of water is sprinkled over them,
since they do not ordinarily retain sufficient moisture to hold
together when frozen, as is the case with most species. As soon
as the pans have been filled and the covers fitted on they are
placed in the sharp freezers, which have been described.
In those houses using ice and salt as the freezing medium
the arrangement of the ice, salt and fish pans is as follows : The
ice, after being passed through a grinder, where it is crushed
into small particles, is mixed with salt in the proportion of
from eight to sixteen pounds of salt to one hundred pounds of
ice. The mixing is most conveniently done by scattering salt
over each shovelful of ice as the ice is shoveled from the grinder
to a wheelbarrow. Many varieties of salt are used, most houses
preferring a coarse mined salt because of its cheapness. Others
use finer salt because it comes into closer contact with the ice
and results in a lower degree of cold and the more rapid freez-
ing of the fish, although the mixture does not last as long.
The amount of ice and salt required in freezing a given
quantity of fish depends principally on the fineness of the ma-
terials and the proportions in which they are used, and to a
less extent on the outside temperature, the amount of moisture
in the atmosphere, the size of the pans and the manner
in which the fish are placed therein. The finer the ice and salt,
the quicker the freezing and the consumption of the ice. A
larger proportion of salt results also in quicker freezing. The
most economical quantities appear to be about eighty-five
pounds of salt and 1,000 pounds of ice to each 1,000 pounds of
fish, although some freezers use much more salt and less ice.
Much larger quantities of ice and salt are required during warm
610 PRACTICAL COLD STORAGE
weather, and more is necessary also when the atmosphere is
moist than when it is dry. Some of the ice and salt generally
remains unmelted, and this may he used over again in connec-
tion with fresh materials, additional salt being mixed with it ;
and as it is weaker than new ice it should be used mainly at
or near the bottom, the top of the pile taking care of the bot-
tom, since the cold descends.
In making the freezing pile, an even layer of ice and salt,
about three or four inches deep, is placed at the bottom, on
which is laid a tier or layer of pans filled with fish, about three
inches of ice space intervening between the pans and the sides
of the bin. This is followed successively by a layer of ice and
salt about two or three inches deep, and a layer of pans, the
surface of each layer of ice being made even and smooth by
means of a straight edge. Sideboards are placed as the height
of the pile requires, and a wide board laid on the pile furnishes
a walk for the workmen in placing the freezing mixture and
the pans. Some freezers place the pans in double tiers between
the layers of ice and salt, and in this case the thickness of the
layers of freezing material must be increased. In some freezers
a light sprinkling of salt is thrown on top of the pans as they
are successively placed. The pile is built up as high as it is con-
venient for handling the pans of fish, which usually does not
exceed six feet. A double quantity of the freezing material
is put on top, and the whole should be covered with wood or
canvas to exclude the air. The fish are usually frozen com-
pletely in about fifteen or eighteen hours, but they usually
remain in the pile until the following morning, when they are
ready to be placed in cold storage.
METHOD OF STORING THE FROZEN FISH.
Being moist, the fish are frozen solidly to each other and
to the surfaces of the pans while in the sharp freezer. To
remove them from the pan the latter is usually passed for a
moment through cold water, which draws the frost sufficiently
from the iron to allow the fish to be removed in a block without
breaking apart. In one or two freezing houses the thawing of
the fish from the sides of the pan is omitted, the cover being
FREEZING AND STORING FISH
611
loosened and the block of fish removed by striking the pan at
the ends and sides, after which the block of fish is dipped for
a moment in cold water.
Considerable moisture adheres to the fish from its beino-
dipped in water, and this being frozen by the surplus cold forms
a coat of ice about one-fiftieth inch thick, entirely surrounding
the irregular block. The process of freezing dries the fish to
FIG. 2 — SHARP FREEZER FOR PISH.— PIPES HAVE BEEN CLEANED
PREPARATORY TO RECEIVING A NEW BATCH OF FISH IN PANS.
some extent, the loss in weight amounting to about 2 per cent,
but the ice coating adds about 4 per cent to the weight.
After the coating of ice has been applied, the fish are
passed to the cold storage room, where they are arranged in neat
piles, the blocks being placed vertically in some instances ; but
more frequently they are arranged horizontally in piles extend-
612
PRACTICAL COLD STORAGE
ing from the floor nearly to the ceiling. Strips two or three
inches thick are laid on the floor to keep the fish slightly ele-
vated, and allow the cold air to circulate underneath.
The quantity of ice and salt required in the establishments
which use those materials in the storage rooms is dependent on
the outside temperature and the excellence of the M'all insula-
FIG. 3-
-SHARP FREEZER FOR FISH. — THE PANS IN THIS CASE CON-
TAIN STURGEON TO BE FROZEN.
tion, and is independent of the amount of frozen fish in the
room, requiring no more freezing material to keep fifty tons of
frozen fish at an even temperature than to keep two tons in a
room of equal size. With 16-inch or 18-inch walls, well insu-
lated, it requires the melting of about forty pounds of ice per
day for each 100 square feet of wall surface when the outside
FREEZING AND STORING FISH 613
temperature is 60° F., to maintain a temperature of 18° F.
inside, this calculation leaving the opening of doors and the
cooling of fresh material out of consideration. The temper-
ature in the storage room should be constant, and about 16°
or 18° F. is considered the most economical. Above 20° F. the
fish are likely to turn yellow about the livers, a result generally
attributed to the bursting of the "gall."
The storage rooms should be free from moisture, since the
latter offers a favorable place for the settlement and' develop-
ment of micro-organisms of all kinds, which tend to mold the
fish. To reduce excessive moisture, a pan of unslaked lime,
chloride of calcium or other hygroscopic agency, may be placed
in the room, the material being renewed as exhausted. If the
storage rooms are very moist, they should be dried out before
storing fish in them, this being readily accomplished by using
a small gas, coke or charcoal stove. The storage rooms cooled
by refrigerating machines may be dried by passing hot water
through the pipes, which, of course, should, under no circum-
stances be done when there are fish in the rooms. In case of
mold appearing on the fish, it might be well to try spraying
them with a solution of formalin, consisting of ten parts of
formalin and ninety parts of water, which should be used at
the first sign of mold.
DETERIORATION OF FISH AFTER FREEZING.
All fish deteriorate to some extent in cold storage, depre-
ciating both in flavor and firmness. The amount of this de-
crease is dependent primarily on the condition of the fish before
freezing and the care exercised in the process of freezing, and,
secondarily, on the length of time they remain in cold storage.
The loss in quality during storage is due principally to evapo-
ration, which begins as soon as the fish are placed in storage,
and increases as the ice coating is sapped from the surface.
Evaporation proceeds at very low temperatures, though
not so rapidly as at higher ones; even at a temperature of 0° F.
the evaporation during two or three months is considerable.
The heavier the ice coating the less the evaporation; but it is
almost impracticable to entirely prevent it, and under ordinary
614 PRACTICAL COLD STORAGE
conditions it amounts to about 5 per cent in weight in six
months, but the loss in quality is greater than the loss in
weight.
The most practicable method of restricting evaporation,
other than coating with ice, is to wrap the fish in waxed or
parchment paper and place them in shipping boxes, whose
length and width are slightly greater than the blocks and deep
enough to contain four or five blocks, or 120 to 150 pounds of
fish.
Along the great lakes the most popular fish for cold storage
are whitefish, lake trout, lake herring, blue pike, saugers, stur-
geon, perch, wall eyed pike, grass pike, black bass, codfish and
eels. In addition to these species, the great lakes freezers receive
large quantities of blue fish and squeteague (sea trout) from
the Atlantic. On the Atlantic coast bluefish, halibut, sque-
teague, sturgeon, mackerel, flat fish, cod, haddock, Spanish
mackerel, striped bass, black bass, perch, eels, carp and pom-
pano are frozen. Salmon, sturgeon and halibut are the prin-
cipal species frozen on the Pacific coast.
Some varieties of fish are so very delicate that it is not
deemed profitable to freeze them, especially shad, but even these
are frozen in small quantities. Oysters and clams should never
be frozen, the best temperature for cold storage being 35° to 40°
F., and when stored in good condition they will keep about six
weeks. As an experiment they have been kept twelve weeks,
but storage for that length of time is not advisable. Caviar also
should never be frozen, but held at about 40° F. Scallops and
frogs' legs, however, are frozen hard in tin buckets and stored
at a temperature of 16° to 18° F. Sturgeon and other fish too
large for the pans are frequently hung up in the storage rooms
by large meat hooks, and when frozen are dipped in cold water
and stored in piles.
In some of the largest freezing houses on the Atlantic sea-
board, which freeze and store fish' as well as other food products,
the fish to be frozen are simply hung up in the sharp freezer,
the heads being forced on to the sharp ends of wire nails pro-
truding from cross-laths arranged in series. After the fish are
frozen they are removed and piled in storage rooms, where the
FREEZING AND STORING FISH 615
temperature is from 15° to 18° F. When the handling of fish
is of minor importance compared with other food products,
they are generally placed on slat-work shelves in either a special
freezing room or in a storage room where the. temperature is
kept below 20° F., or they are retained in bulk in baskets, boxes
or barrels in the same room. But these methods are not pro-
ductive of results even approximating those in the great lakes
freezers.
, The cost of cold storage and the deterioration in quality
make it inadvisable to carry frozen fish more than nine or ten
months, but sometimes the exigencies of trade result in carry-
ing them two and even three years. In the latter case they are
scarcely suitable for the fresh fish trade unless the very best of
care has been exercised in the freezing and storage, and it is
usually better to salt or smoke them.
The rate of charges in those houses which make a business
of freezing and storage for the general trade is usually from a
half cent to one cent for freezing and storage during the first
month, and about half of that rate for storage during each sub-
sequent month, depending on the quantity of fish. However,
the cost of running a first-class plant at its full capacity is prob-
ably less than one-third, or even one-fourth, of the minimum
above quoted, since it costs no more to run a storage room full
of fish than one-fifth full.
CANADIAN BAIT FREEZING METHODS.
The Canadian Government, in promoting the organiza-
tions of associations for bait freezing and storage, pays a bonus
of one-half the cost of such freezers under certain restrictions
and regulations, and also $5.00 per ton for fish properly pre-
served each season, but the Government-aided product may not
be sold commercially. Prof. E. E. Prince, Commissioner and
General Inspector of Fisheries for Canada, describes in "The
Fishing Gazette" the bait freezing methods of small plants,
which cost from $500 to $2,000. There are two methods in use
known as the pan system and the crate system. The pan
method is essentially the same as already described in the fore-
going, and is, doubtless, the best method. The crate freezing
616 PRACTICAL COLD STORAGE
system is older and not as rapid nor as efficient. The pan sys-
tem is described as follows:
"1. The fish are placed in galvanized iron pans 28x18x3
inches, made of No. 26 to 20 iron, and provided with a tight-
fitting lid. Each pan holds 30 to 40 pounds of fish, and costs
50 to 60 cents.
2. The filled pans are transferred to an insulated freezing
box or pen, with insulated sides and double-boarded fioor. In-
sulating paper is placed between the boards. The front is closed
by means of sliding boards, and the fioor is pierced with drain-
age holes or outlets.. A space of four inches must be left around
each pan.
3. The pans are placed on a layer of sawdust covering the
floor of the pen a few inches deep, upon which crushed ice and
a little salt to a depth of five inches have been scattered.
4. The first tier of pans is then covered with four inches
of crushed ice, mixed with one-sixth or less of salt. Successive
tiers of pans and layers of ice and salt (four inches deep) are
piled up to a height of five or six feet.
5. The top tier of pans having been duly covered with its
layer of ice and salt, the empty salt bags are used as a cover.
In twelve to twenty-four hours the fish being moist, are
frozen together in a solid cake in each pan. The pans are then
dipped in water, the cakes of fish become detached and are
dropped out, and are neatly piled in the storage room to be kept
until required for use.
The process of crate freezing is as follows:
1. Forty pounds or fifty pounds weight of fish is placed
in a lath crate or cage 24x18x3 inches.
2. The filled crates are passed into the freezing chamber
for a period of twenty-four to thirty-six hours.
3. The fish in the crates, after being frozen, are trans-
ferred to the storage room and preserved until required.
The freezing chamber resembles in its essential features
the storage room. It is not only insulated like the freezing
■pan in the "pan freezing" process, but the sides are formed of
large freezing plates or tanks eight inches wide, passing up
from the floor to the roof and through the ceiling, and fixed at
FREEZING AND STORING FISH 617
right angles to the adjacent wall of the room. These tanks are
filled with a freezing mixture of ice and salt, which can be
placed in them without opening the freezing room. Between
each tank projecting into the chamber above is an air-tight
shutter, and an arrangement is made for draining away the
overflow of brine. More salt is used in the freezer than in the
battery of tanks in the storage room, and it is requisite that
from one-third to three-quarters of a square foot of freezing sur-
face should be provided for every cubic foot of space in the
freezer."
CHAPTER XXXII.
KEEPING COLD STORES CLEAN.
CARE OP COLD STORAGE ROOMS WHEN EMPTY.
The care of cold storage rooms during periods of idle-
ness, or when no goods are in storage, is of the greatest im-
portance for the reason that good results in storage of goods de-
pend largely on the condition of the storage room. With this
fact in mind the author sent out a circular letter of inquiry
to a number of cold storage warehousemen containing a list of
questions which embrace the subject of whitewashing ; whether
it should be done by hand or machine; whether any other
preparation is as good as whitewash; whether it would prop-
erly purify rooms for the storage of such goods as eggs after
storing apples or other fruits ; whether it is necessary to white-
wash each year and also in regard to painting, at the time of
whitewashing, the pipes or refrigerating surfaces which cool
the room. Questions were also asked in regard to the methods
of preparing whitewash and whether means of ventilating
are provided at the time of whitewashing. Further informa-
tion of a general character was solicited.
The number of replies received was rather disappointing,
but some of the more careful and conscientious cold storage
men gave detailed and very full information. It is evident
from a majority of the answers received that comparatively
little attention is given to the cold storage rooms when they
do not contain goods. Cold storage rooms need as careful at-
tention, although in a different way, when they do not contain
goods, as when goods are stored therein. When the flow of
refrigerating medium (usually ammonia or brine) is shut off
at a time when there is frost on the pipes, this frost will evapor-
ate in the form of air moisture, even though it does not actually
618
KEEPING COLD STORES CLEAN 619
melt, and cause the air of the room to become damp. Damp-
ness with a comparatively high temperature will in time cause
a growth of mold and a musty condition of the room. Sys-
tematic whitewashing with ventilation will kill this growth of
mold, but it is much better to prevent a trouble of this kind
than to overcome it after it has obtained a foothold.
As soon as the goods are removed from cold storage rooms
the frost on cooling pipes should be removed and taken out
of the room. If the fan system of air circulation is employed,
with the coils all located in a coil room or bunker, this is a
comparatively easy matter to attend to. Where the pipes are
directly in the room, the resulting slop will necessarily causi-
the floor and walls to become damp to a greater or less extent.
Moisture on floors of cold storage rooms should be taken up
by throwing down dry sawdust or air slaked lime. It should
be removed at once and not allowed to soak into the floor
lining or insulation. A few barrels of dry sawdust should be
on hand at all times for the purpose of soaking up melting
frost or possible leakage from any cause. With the coil room
and fan sy.stem the floor of coil room is usually water tight
and properly connected with outlet to drain system so that
damage to insulation cannot occur in this way.
After removing the frost from refrigerating pipes, meas-
ures should be taken to keep the rooms dry and pure. This
may be done by exposing a quantity of quicklime in the room.
It may be placed on the floor, but should not be placed on any
wet spots unless it has already been air slaked and is in pow-
dered form. It might under some circumstances cause the
starting of a fire from the heat of slaking. Chloride of calcium
placed on trays or pans or supported on a screen shelf above
a water-tight pan, as illustrated in the chapter on "Uses of
Chloride of Calcium," may be used to good advantage. Where
the coil room and fan system are in use, chloride of calcium
may be supported in the coil room as in the author's patented
chloride of calcium process, or in any other suitable way, and
by operating the fan a short time at intervals the room may be
kept in a pure and dry state. During cool or cold weather it
is a good plan to allow the air to blow through the rooms when
620 PRACTICAL COLD STORAGE
it is dry outside and about the same or a little lower than the
temperature of the room, What is still better is the cold
weather ventilating system, which is described in the chaptei
on "Ventilation." With this system fresh air may be taken
from outside the cold storage building and forced into the
room in large quantities and the foul air from the room is
allowed to escape through a suitable vent. The incoming air
may be forced directly into the room without heating, or it
may be heated to any required temperature by passing it over
a steam coil or jacketed heater.
A few words in regard to the proper preparation of
new cold storage buildings for the receiving of goods may not
be out of place here. In the finishing up of a cold storage
building it very often occurs that the work has to be rushed
and enough time is not allowed for the proper whitewashing
of the wood lining or interior surfaces of the room. This situa-
tion demands care and rapid work and advantage must be
taken of all opportunities for whitewashing the rooms as fast
as they are ready or as soon as a portion of their surfaces is
ready. Keep men at work whitewashing following up the car-
penters. By keeping the doors open and using the ventilating
system intelligently, if one is installed, some of the rooms may
be ready to receive goods as soon as the refrigerating equip-
ment is ready to supply refrigeration. If no other means of
properly drying are at hand, use chloride of calcium as illus-
trated in chapter referred to. In whitewashing cold storage
rooms for the first time, it is advisable to apply first a thin coat
of whitewash so that it may penetrate the wood as much as
possible. It will also make a better ground for the second
coat. The second coat may be somewhat thicker and should
not be applied until the first coat is thoroughly dry.
WHITEWASHING AND MAKING WHITEWASH.
The proper drying out of whitewash in cold storage rooms
is a difficult matter, owing to the inclosed nature of the rooms,
which are usually provided with but one opening, also to the
low outside and inside temperatures which usually prevail at
the time of whitewashing. The cold weather ventilating sys-
KEEPING COLD STORES CLEAN 621
tem, already referred to, is of great assistance at such a time.
By applying heat to the rooms and allowing the cold, moist air
to escape as the dry, warm air is forced in, the whitewash may
be dried very thoroughly. It is customary in some plants,
especially in the larger cities where some of the rooms are in
service during the greater part or all of the year, to dry out
the rooms by placing a "salamander," or sheet iron heater
for burning coke or charcoal, in the room. This is not a very
scientific nor practical method, as the moisture driven out of
the room in which the salamander is placed is conveyed to
other rooms of the house or into the corridor to some extent;
besides this, the salamander will dry out only a portion of the
room at a time. The gas generated is also very objectionable
and even dangerous to persons working in the room. In
using a salamander it is best to light the fire and allow it to
get well started before taking into the storage room. In this
way a large part of the gas is avoided. For the most nearly
perfect job of whitewashing from five to eight days are re-
quired to dry thoroughly. If the whitewash dries rapidly, as
it may Avhen a salamander is used, it will flake off and not be
permanent. On the other hand, if it does not dry within a
reasonable length of time, the water in same will soak into the
wood and, in finally drying, the whitewash will have a dark
or mottled appearance. Rapid drying, therefore, should be
avoided as well as slow drying.
The importance of attending to the matter of whitewash-
ing in new houses which are rushed to completion can-
not be too strongly dwelt upon. The author has repeatedly
come in contact with this situation and much time and effort
have been expended by him in trying to get whitewashing
properly done and at the right time. Those new to the busi-
ness do not appreciate the importance of whitewashing and
the necessity of looking after it carefully. Very bad results
have in numerous cases followed the careless daubing on of
whitewash, and allowing it to dry at its own pleasure. In
some cases butter has been very strongly flavored in a way
which could not be accounted for; again, eggs are damaged,
and other goods to a greater or less extent, depending on their
622 PRACTICAL COLD STORAGE
sensitiveness. If whitewash is plastered on the walls too thick
and does not dry, the water contained therein penetrates the
wood and may cause a fermentation, which leads to a peculiar
bitter or strong smell in the room, which in turn will flavor
the goods. If the case is an aggravated or serious one, mold
will develop, and the serious nature of this trouble is too well
understood to need description. Whitewashing should be done
in the winter or during weather when the air is about as cold
or colder outside than inside the storage rooms. It is then
much easier to get the rooms dry. Bad effects have followed
whitewashing during warm weather, because it is so difficult to
get the rooms to dry properly.
It is a popular idea, and yet entirely wrong, that most
anybody can prepare and apply whitewash. Of those who
think they know how to whitewash, probably not one in ten
knows how to slake the lime. This should be done in one of
two ways, either of which is good. The author recommends
the following: Take one-half bushel of lime and place it in
a half-barrel (an oil barrel or vinegar barrel which has been
cut down makes a good utensil for this purpose) ; pour on a
small quantity of boiling water, barely sufficient to cover the
lumps of lime; keep the lime well stirred clear to the bottom
(a piece of one-inch gas pipe about five or six feet long is the
best stirring stick). In case the lime is very quick, it should
require two persons to slake the lime, one to pour on the water
as needed and one to stir. The stirring should be kept up
continuously from the time the lime begins to slake until it
is reduced to a paste, and water should be added as fast as the
lime slakes, so as to keep it at a rather thin, pasty consistency.
It is very common to see lime placed in a barrel and water
turned on and the lime allowed to slake itself. The result is
that the whitewash is full of small pieces or lumps which are
not slaked, but are burned as the result of water not coming in
contact with the lime at the right time. It is not absolutely
necessary that boiling water should be used, but unless the
lime is quite quick, it facilitates the operation and results in
more thorough slaking. Another method which may be em-
ployed is to place the lump lime on a cement floor and sprinkle
KEEPING COLD STORES CLEAN 623
water on slowly as the lime slakes. If this is handled care-
fully and attended to the result will be a finely-powdered
slaked lime, which may be mixed with water to a proper con-
sistency. The author does not recommend this method as
compared to the one first described, as it is slower and there is
much more danger of burning the lime and causing the white-
wash to be lumpy.
A large number of those who replied to the circular letter
of inquiry are using the Government formula for making
whitewash, but one of the ingredients of this formula is rice
boiled to a thin paste, which makes it seem difficult to the
average person, and, further than this, the author does not
believe in using any organic substance in preparing whitewash.
For those who prefer the Government formula it is here given :
TJ. S. GOVERNMENT FORMULA FOR WHITEWASH.
Slake half a bushel of quick lime with boiling water, keep it cov-
ered during the process. Strain it and add a peck of salt dissolved in
warm water, three pounds of ground rice put into boiling water and
boiled to a thin paste, half a pound of powdered Spanish whiting, a
pound of clean glue, dissolved in warm water; mix these well together
and let the mixture stand for several days. Keep the wash thus pre-
pared in a kettle or portable furnace and put it on as hot as possible
with either painters' or whitewash brushes.
It is better to use the mineral substances, and the follow-
ing has given good satisfaction under most circumstances:
One-half bushel of lime, slaked with hot water, as previously
described. When the lime is thoroughly slaked, add one-half
peck of salt. It will be necessary to add more water as the salt is
added, in order to keep the whitewash at the proper con-
sistency ; or the salt may be dissolved separately in as small an
amount of hot water as will absorb it readily. The proper con-
sistency for whitewash is a thin paste and it may be tempered
as it is used. To each twelve-quart pail of whitewash, com-
posed of lime and salt as above, add a good, fair handful of
Portland cement and about a teaspoonful of ultramarine blue.
The cement and blue should be added only as the wash is being
used and should be thoroughly stirred into the whitewash;
otherwise, when applied, it will be streaked. Cement is used
for the purpose of giving the whitewash a better setting prop-
erty so as to make it adhere better to the surface to which it is
624 PRACTICAL COLD STORAGE
applied. The ultramarine blue is used simply to counteract
the brownish color of the Portland cement. If white hydraulic
cement is obtainable, it is better to use than Portland cement,
and in this case the ultramarine blue may be dispensed with.
It is, however, best to use a small amount, say half a teaspoon-
ful to the pail, as a whiter surface results. The wash should be
strained through a fine wire-cloth strainer before using, to re-
move the lumps if there are any present.
WHITEWASHING MACHINES.
The advisability of using whitewashing machines or
spraying pumps in cold storage work has been an open question
for some time. Of the replies received, about one-half recom-
mend the use of the machine. Some say the machine will do
the best work, but this is not the author's experience. There
are some situations where the machine is a decided advantage ;
for instance, on overhead work, between open joists, or any
surface which is difficult to get at with a brush. It is hardly
possible to get as smooth and even a job with the machine as
it is by hand, and, besides, a machine will necessarily put a
good deal more whitewash on a given amount of surface than
is put on with brushes. This is objectionable, for the reason that
a heavy bed of whitewash on drying will flake off much more
quickly. In some cases, those who use a machine go over it
with a brush while still green in order to make it smooth
and even. Another objection to a machine is that it will
cause a mist in the air and the whitewash will spatter over any
object in the room. A room must be entirely empty in order
to use a machine. It should not, of course, be inferred that it
would be practicable to whitewash a room while goods are
stored in same, but it is necessary to clean a room out of
everything that is liable to be injured by the whitewash in
order to use a machine. The spray is also very uncomfortable
for the operator. A moderately thin coat of whitewash on old
work is as good for purifying purposes as a thick one ; and for
this reason hand-work is to be preferred to machine, as much
less material may be applied. The more whitewash put on
the more water to be gotten rid of in some way, and if the
KEEPING COLD STORES CLEAN 625
water is not removed promptly very bad effects may result,
as already noted in discussing the drying out of cold storage
rooms after whitewashing.
The author's impression is strongly in favor of hand-
work, but it is not a desirable job for the man who has to do
the work. It is probable for this reason that the machines are
gaining headway. They have also l)een perfected to quite
an extent during the past few years. There are a good many
different makes of first-class machines on the market. The
same machine that fruit growers use for spraying trees is
available for whitewashing and the same machine is com-
monly sold for both purposes.
Good work in whitewashing should look well, be perfectly
white or nearly so, should be hard and not liable to flake off
or dust off onto the hands or clothing, and should have com-
plete disinfecting and germ-killing properties. The slaking
of the lime is the most important part of the operation and
the success of same depends upon the caxe and attention given.
Too much care can not be given to this detail, and cold stor-
age men should see to it that whoever had this in charge looks
after same conscientiously. Lime that is burned or drowned
in slaking is not firm in texture when applied and is not as dis-
infecting nor fireproof as it should be.
PAINT FOR ROOMS AND PIPING.
There are many good cold-water paints on the market
under various names which are advisable in some places for
which whitewash is not well adapted, and many use them for
all interior surfaces. For butcher's boxes or retail coolers es-
pecially they are preferred to whitewash, for the reason that
they will not flake off readily. It is also good for doors and
corridors of cold storage houses. Most of these cold-water
paints are composed of secret ingredients, and some contain
organic substances like glue, which makes their use inadvisable
for cold storage purposes, except in special situations. Shellac
is also largely in use for cold storage rooms, but it has no dis-
infecting or cleasing properties like whitewash. It makes a
beautiful finish where the lumber in use has a good natural
626 PRACTICAL COLD STORAGE
grain. Shellac has the advantage of being waterproof, and
therefore walls may be easily washed at any time. It is, per-
haps, unnecessary to state that any oil paint, or any other
preparation with strong odor, has no place about the cold stor-
age rooms or the corridors or other approaches thereto.
In connection with the whitewashing of rooms and their
care during periods of idleness, it has seemed proper to take
up the cleaning and painting of the pipes or refrigerating sur-
faces which cool the room. The answers to the questions cover-
ing this subject indicate that it is not customary among cold
storage men to paint their pipes after they are once installed,
and this is strictly in line with the author's ideas and experi-
ence on the subject.
There are two good reasons why the painting of pipes is
not advisable after they are once put in place in the cold storage
plant; first, it does not pay; second, it is dangerous. It does
not pay, because after the pipes are once put in place a good
job of painting cannot be done unless the coils are entirely
removed from their supports so that they can be painted on
both sides. The labor involved in removing the refrigerant,
taking down the pipes, cleaning them and applying the paint
is considerable, and the cost of the paint is no insignificant
item. A good paint put on the pipes before they are set up
in the cold storage house will protect them fairly for a period
of from two to three years, more or less. Before the coils are
set in place it is comparatively easy to paint them and it is
recommended that coils should be painted when new. It is
especially desirable to paint them at this time, as the pipes
are clean and free from scale or rust. After the pipes become
rusty from service, it is almost impossible to get them suffi-
ciently clean so that the paint will adhere properly. Consid-
ering the low price of pipe and its comparatively long life
when used with ammonia or chloride of calcium brine, it does
not seem to warrant the expense. It is dangerous to paint pipes
in a cold storage room for the reason that no paint known to
the author is non-odorous or anywhere near it. The pipes
should, therefore, be removed from the rooms for painting and
allowed to dry and deodorize before they are returned to the
KEEPING COLD STORES CLEAN 627
cold storage room. This, however, is rather impracticable and
it adds to the expense.
For painting pipes, various preparations have been used
with more or less success. There are a number of patented and
proprietary preparations on the market which are good and are
sold at a reasonable price. Eed lead and boiled oil is also an
old stand-by for this purpose, but it is much more expensive
than some of the preparations above mentioned. Boiled lin-
seed oil without any pigment as a coating for refrigerating sur-
faces will give good protection from rust for a limited time,
but the commercially prepared products will be found superior
though somewhat more expensive.
CHAPTER XXXIII.
ICE BOXES AND REFRIGERATORS.
PRINCIPLES THAT SHOULD GOVERN CONSTRUCTION OF REFRIG-
ERATORS.
The construction of refrigerators for domestic purposes,
for butchers and other small users, is mostly in the hands of
companies who manufacture them in large quantities. In the
main they are only fairly well designed and very poorly in-
sulated; and in a large number of cases poorly designed as
regards the circulation of air. Besides the large manufacturers
there are many small concerns, and the construction of small
rooms for retailers, butchers, etc., is to a considerable extent
in the hands of the local carpenter, contractor and builder.
The points covering the design of such work will no doubt be
of interest to those having occasion to build, and to users of
refrigeration as well. An English writer* on this subject makes
the following sensible suggestions:
The most usual location for the ice in a refrigerator is on the
side of the box, and when this arrangement is in use (and it must be
remembered that it is an absolutely necessary one in all cases in
which the refrigerator is limited in height) it is best to keep the Ice
tanks or receptacles as high up as practicable, and to provide cold
air ducts leading downwards to near the bottom of the refrigerator,
thus insuring a sufficient air circulation.
When the ice tanks or receptacles are placed centrally in the
box, In order to secure a uniform circulation of air throughout its
length and width, it is necessary to provide warm air ducts which
rise from the highest point in the cooling chamber to a level above
that of the ice in the ice tanks or receptacles, and also cold air ducts
from the bottom of the ice tanks or receptacles to a low level in the
refrigerator chamber. This arrangement will be found fairly effec-
tive where the boxes are not of too large an area.
An arrangement which would probably be found to give con-
siderably superior results to the above is the placing of the ice tanks
or receptacles right at the extremities of the box. This location of
the ice tanks or receptacles would give two means of producing cir-
*In the Refrigerating Engineer, London.
628
ICE BOXES AND REFRIGERATORS 629
culating currents, and in this manner would of course tend to appre-
ciably improve the refrigerating effect produced.
Whenever practicable, however, there can be no doubt that
the most advantageous place for the ice is overhead. A refrigerator
with a top Ice tank or receptacle gives by far the best results in prac-
tice, that is to say of course provided that the warm and cold air
ducts are properly placed. The first of these, or the warm air ducts,
must be taken from the most elevated point in the cooling chamber
up to a level somewhat higher than that of the ice in the ice tank or
receptacle. The second, or the cold air ducts, should be led from
the bottom of the ices tank or receptacle down to near the bottom of
the refrigerator chamber. In this manner, a regular and continuous
circulation of air will be maintained, and the warm, impure air will
be forced to rise upward into the space above the ice in the ice tank
or receptacle, the impurities becoming condensed upon the surface
of the ice in the latter, and being carried away with the water re-
sulting from the meltage of this ice.
There are few if any refrigerators in service which fulfill
the above ideal conditions, even to an approximate degree.
Seldom has the author seen anything in the shape of a cold
air duct extending from the bottom of the ice chamber
to near the bottom of the storage space, and the warm air duct
from the top of storage space to near top of ice chamber is in
many cases lacking. The principle of air circulation in re-
frigerated rooms is more fully set forth in the chapter on
"Air Circulation in Cold Stores."
It is not to be wondered at that the small refrigerators
are not properly insulated, as it can hardly be expected that
the manufacturers are well informed on the subject when
those who make a specialty of the cold storage business are
not commonly familiar with its underlying principles.
Further, competition between makers leads to a cheapening of
construction, and as the appearance must be maintained, that
part of the work not exposed to view must suffer. A refrigera-
tor known to the author, when taken apart for examination,
revealed no insulation at all, simply a two-inch air space. A
dollar or two extra cost on the average refrigerator would be
easily saved in one season where ice costs $5.00 per ton, put in
the box. It is difl&cult to state exactly what material should
be used and in what thickness and how applied. This can
only be determined when character of work, cost of ice and
service are known. The chapter on "Insulation" may profit-
ably be studied by those interested in improved methods of
insulating;
CHAPTER XXXIV.
REFRIGERATION FOR RETAILERS.
GENERAL SUGGESTIONS.
The conservation of dairy products consisting of milk and
its manufactured products, butter and cheese, constitutes one
of the most important uses to which refrigeration is applied.
At present it is, in fact, difficult to imagine how a dealer in
this class of goods, either as a wholesaler or a retailer, could
do business without some form of cold storage, cooling room
or ice box. In the United States even the smallest retailer has
his refrigerator, and it is a rare exception to find such an
establishment without one. Our European neighbors generally
do business on a radically different basis, buying only a day's
supply at a time, in the same way that vegetables and green
groceries are handled. The losses resulting from this practice
are considerable.
AVithout refrigerating facilities, goods must necessarily be
purchased in a hand-to-mouth manner, obtain supplies daily
so as to have them in a more marketable condition. A large
aggregate loss results from this method. Goods purchased in
a small way necessarily pay a higher percentage of profit to
the wholesalers, and in some cases, also, much difficulty may
be experienced in purchasing supplies daily, owing to failure
of transportation from any cause, or a natural scarcity of goods
in the open market. A retailer need not go into the cold stor-
age business to the extent of putting away his season's supply
(although many of the larger ones do this, and make a good
yearly profit thereby) , but every retailer, no matter how small,
should have cooling space. If his business is properly systema-
tized and advantage taken of his storage for perishable goods,
630
REFRIGERATION FOK RETAILERS 631
a sure profit may be realized by buying in round lots at a time
when the products are obtainable at the lower price.
The form of refrigerator suitable for the widely varying
requirements of dealers doing a large or small business, may
vary from the cheap ice chest which can be built ' by any
carpenter for $10 to a completely equipped cold storage plant,
which will keep dairy products in good condition for several
months. There are several large retail establishments in the
East operating what are known as "chain stores," the pro-
prietors of which own and operate cold storage plants and in
addition do some storing with the regular cold storage houses.
For an average business, the large refrigerator which
only requires to be filled with ice once or twice a week, is in
use. In general all retailers use ice only for cooling purposes,
except the large users who do practically a cold storage busi-
ness with their own goods. Ice will produce, when used in
the ordinary way, a temperature of 38° to 50° F., and prob-
ably most of the larger refrigerators would show a temperature
of about 40° F. to 45° F. in warm summer weather. This
temperature answers nicely for temporary storage from day to
day, or for two or three weeks, or even longer on some classes
of goods, but for long storage of several months, only an
apparatus that will give a control of temperature at all times
should be used, such as the Cooper brine circulating system
cooled by ice and salt described elsewhere, or a mechanical
system of refrigeration.
The dairy products; butter, cheese, milk and eggs (eggs
are not strictly speaking a dairy product, but are generally so
called) are all more or less liable to deterioration. Butter,
especially when exposed to the air and heat of summer, becomes
rancid and unfit for use in a few days. In days gone by base-
ment rooms or cellars were used very generally, and a cool
cellar was a thing to be proud of so long as people did not
know the value of ice or artificial refrigeration. A dairyman
who would store his June butter in a cellar for winter use in
these days would find it very unprofitable when compared with
the results from a modern cold storage house. This would
show bevond a doubt that modern methods must also be applied
632 PRACTICAL COLD STORAGE
by the dealer if he is to meet competition and keep abreast of
the times.
America has led, and is still leading the old world in re-
frigeration. Even the smallest retail dealers who handle butter
and other dairy products, have large, well built refrigerators
similarly constructed to those used for domestic purposes. Some
of these are indeed a work of art, with beautiful glass fronts
so arranged as to show off the goods to advantae[e and so con-
structed that they may be opened for cutting out the goods
without exposing the interior of the room to warm currents
of air. Some are arranged so that each package of butter or
cheese rests on a pivoted table, one-half enclosed by glass. By
turning this table half way around the goods are accessible and
the glass front of the table is turned back, shutting off the
interior of the refrigerator from outside air. These are in use
very largely for butter and cheese, but may be used for other
goods as well.
The facilities needed by retailers for the correct and eco-
nomical handling and sale of dairy products depend largely
on the quantity of goods to be handled, length of time to be
cared for and climatic conditions of the locality in question.
In the northern part of the United States and throughout
Canada the use of natural ice is universal, as the ice crop is a
certainty. In the southern states manufactured ice and
mechanical refrigeration are a necessity.
Ice (either natural or manufactured), when used in a
refrigerator or cooling rooms, will give a fairly dry air at a
temperature of 40° to 45° F., providing proper arangement!=
are provided for promoting a circulation of air over the ice.
At this temperature well made fresh butter will remain firm
in texture and will not lose quality to any great extent for
several weeks. Cheese at this temperature will remain in good
condition for a much longer period. Cheese is often retailed
from the original package without the use of refrigeration,
but during the warm weather of summer it will dry out and
lose quality rapidly. It must also be sold very quickly when
cut. Eggs may be kept for a few days or even longer at tem-
peratures above mentioned.
REFRIGERATION FOR RETAILERS
633
Eggs and butter should be kept separated from fruits,
meats or strong smelling cheese, as they give off odors very
rapidly. Milk and cream are kept from day to day in a re-
frigerator to prevent souring, which takes place at high sum-
mer temperatures very quickly. Meat is one of the chief
commodities sold from refrigerated rooms, and no retailer of
meats can do business without refrigeration. The limit of
time at which fresh meat may be stored in a temperature of
40° F. or thereabouts is two to four weeks. It is well known
that meat kept at a temperature of the ordinary ice cooler for
two weeks is in more palatable condition then when first
killed if atmospheric conditions of the cooler are correct.
Small refrigerators may be purchased ready made and
set up ready for business, and the larger ones which may be
FIG. 1.-
-PLAN OF COOPER'S BRINE SYSTEM APPLIED TO
BUTCHERS' BOX.
dignified by the name of rooms are to be had from the makers
in sections to be put together by any carpenter. If a first
class and economical job is wanted, a skillful cold storage
ai'chitect or engineer should be employed to furnish plans, as
it is well known that the average refrigerator is not half in-
sulated, nor properly constructed. Regular cold storage rooms
intended for storage of goods for long periods must be designed
and arranged with care, and only a thoroughly competent
architect should be employed for this work. The construction
634
PRACTICAL COLD STORAGE
should be carefully attended to, and the rooms should be
handled with the utmost intelligence, if good results are to
be expected. Retailers should not go into this unless their
volume of business is large enough to warrant it. It will pay
much better to purchase supplies during the flush of the pro-
ducing season, when the quality is best and price lowest, and
store in a regular well-handled and thoroughly equipped cold
FIG. 2.— SECTION OP COOPER'S BRINE SYSTEM APPLIED TO
BUTCHERS' BOX.
storage warehouse. It is better to do this, paying the moderate
charges which are now made for such service than to put away
goods for a long carry in a common refrigerator. A refrigera-
tor cooled by ice is not intended for any such work. Its duty
is the temporary safe keeping of goods and all dealers should
have one for this purpose, and it should be used for this purpose
only.
REFRIGERATION FOR RETAILERS 635
KEFEIGERATION FOE BUTCHEKS' BOXES.
One of the hardest services to which refrigeration can be
applied is that of cooling small rooms, such as "Butchers'
Boxes," as they are called. The continued running in and out
of the room admits a large quantity of comparatively warm
air, and at times when the atmosphere is damp on the outside,
this leads to a condensation not only on the ceiling of the
room, which naturally gets the first flow of warm air which
rises as it enters the room, but also on the goods themselves.
Much thought has been applied to the design of rooms for
retail business and considerable improvement has been made
in the utilization of ice (which is mostly used) for this purpose.
'The difhculty from condensation, however, cannot be entirely
eliminated by any method of cooling without providing a
vestibule or ante-room of some character, so that the condensa-
tion will occur in the vestibule and not in the room itself. The
arrangement of the anteroom or vestibule is moreover a cum-
bersome affair, as it necessarily means that two doors instead of
one must be opened and shut every time the room is entered.
About the best that can be done is to locate the refrigerating
surfaces so that the warm moist air from the outside as it enters
the room will deposit its moisture on these surfaces instead of
on the goods in storage. The trouble can also be obviated to
some extent by providing a spring on the door so that it will
close itself quickly when opened. Another very desirable
feature is a tightly fitting door which will not stick or bind.
There is at present no such satisfactory door for cold rooms,
especially those of small size, as the patented doors now on
the market, owing to rapidity and ease of operation.
The plan and section (Figs. 1 and 2) show the applica-
tion of the author's brine system to the cooling of small rooms
for butchers' boxes or for grocers or others requiring refrigera-
tion in small units. This arrangement shows the system ap-
plied to a store room which is 13 feet high. This makes the
cold room or refrigerator 9 feet in the clear, and allow access
to the primary tank from the floor above, which is a decided
advantage, as all of the rough work and muss of the icing is in
636 PRACTICAL COLD STORAGE
this way entirely removed from the store itself. As will be seen
by the plan, the pipes which cool the room extend across one
side and to the ceiling. They also are near the door so that
warm moist air entering from the inside will come in contact
with the pipes and moisture be deposited thereon. The coils
are provided with drain gutters underneath so that the drip
from the pipes is caught without any spatter and led outside
the room to the sewer. The cooling coils in the room, attached
to the top pipe, as shown in the sections, are also provided
with chloride of calcium gutters for the application of the
Cooper chloride of calcium process for preventing frost on
pipes and purifying and drying the air of the room. If neces-
sary to keep the room sufficiently dry these gutters may be
made extra large, providing in that way for an extra quantity
of chloride of calcium to be supported thereon. The humidity
of the room can be controlled at will in this way by using a
greater or less quantity of chloride of calcium. This chloride
of calcium process, as it is called, is described elsewhere in
this book, as is also the Cooper brine system.
CHAPTER XXXV.
REFRIGERATION FROM ICE.
CHEAP, SAFE AND UNLIMITED REFRIGERATION.
The quantity of cold, (if the author may be pardoned for
using so unscientific a term), which is present and active dur-
ing the season of cold weather, is so enormous as to be stagger-
ing when presented in the form of actual figures. The practic-
ability of storing this almost unlimited refrigeration during
the winter for use during the heated period, has been only
partially understood &nd very imperfectly developed.
It is well known that a great deal of ice is harvested during
the winter and is put into structures which are known as ice
houses, but just what any given quantity of ice means in energy
and in its equivalent refrigerating capacity or heat units, is
not generally known. It is, of course, admitted that ice is a
good thing to have when the weather is hot, to cool drinking
water and to maintain a house refrigerator at low temperature
for the purpose of keeping a few table foods for a day or two,
etc., but many seem to think that when it comes to a cold
storage plant where foods are stored for longer periods that an
expensive and complicated system is necessary to do the work.
It is desired to show by the few figures which follow, the utter
absurdity of rejecting Nature's refrigeration and substituting
refrigeration by artificial means.
In the North Temperate Zone, take it for instance, from
the latitude of the Ohio River and the southern boundary of
Pennsylvania and the same general latitude westward to
Nebraska, and north of this latitude and throughout Canada
ice forms regularly each winter to a thickness which may be
housed at nominal cost. Further south than that there are
many localities where thin ice may be put up without much
637
638 PRACTICAL COLD STORAGE
difficulty and without fail each winter. In the localities first
mentioned the average thickness of natural ice forming on
ponds, lakes and quiet and shallow bodies of water, would
range in the southern part from a few inches up to two or three
feet or even more in the northern part. Take therefore, an
average locality like New York, Michigan and Wisconsin, and
assume that the average thickness of ice formed each winter
is 20 inches, and then as a matter of information and as a basis
to work on and as a very common unit, take a square mile for
purposes of calculation. This gives the following interesting
and altogether surprising figures :
One square mile or 27,878,400 square feet of ice, 20 inches
or 1 2/3 feet in thickness, assuming 57 pounds to the cubic
foot or 95 pounds to each square foot (20 inches thick) would
weigh 2,648,448,000 pounds or 1,324,224 tons.
Multiply 2,648,448,000, the number of pounds of ice in
1 square mile 20 inches thick, by 142 the latent heat or heat
absorbing capacity of ice per pound, we get 376,079,616,000
British thermal units. Dividing this by 14,000 the number
of B. T. U's. per pound, heating capacity of the best grades
of steam coal, we- find we have 26,862,830 pounds or 13,432
tons; the amount of coal that would be necessary to melt the
ice on a surface one mile square and 20 inches thick.
It will be noted from the above that ice 20 inches thick
which will form on a square mile amounts to the enormous
total of 1,324,224 tons. If all the heat energy in coal could
be applied to the melting of this quantity of ice on a basis of
the above figures, it would require about 13,432 tons of coal
to again reduce this quantity of ice to water.
Why stand idly by and allow the most of this valuable
cold which nature provides during winter to evaporate and
slip away? And then, as soon as warm weather comes, start
coal fires for producing refrigeration by artificial means and
begin to talk about fuel conservation at the same time.
The author's father once stated that he believed that "ex-
pensive steam driven machinery could not successfully com-
pete with God Almighty and a Minnesota winter" in produc-
ing refrigeration. The above figures prove this to be true
REFRIGERATION FROM ICE 639
beyond a doubt, and the unlimited refrigeration which is going
to waste each winter, not only in Minnesota, but in localities
much further south, has not been fully appreciated. There
can be no possible reason for using good heat producing coal,
which represents a large amount of human labor, for the pro-
duction of refrigeration, where it is possible to store up nature's
refrigeration during winter in the highly concentrated form
which is called ice. The storage of ice during winter is only
in its infancy, and the author takes the risk of predicting that
cold storage and refrigeration will in future, where ice can be
obtained at all, be accomplished to a great extent by means
of ice and not by means of the more or less expensive and
complicated systems which cost a great deal of money to install
and which require a great deal of care and attention in their
operation, and which, even with the utmost care, are liable to
get out of order when in greatest need.
Our foods are mostly grown or produced in the summer
time during the heated period and stored and preserved in
various ways for winter use. The cold or refrigeration which
nature produces in winter can be stored and conserved for
use during summer for the purpose of preserving perishable
foods. The consuming of coal or other fuel to make refrigera-
tion is like raising corn in a hot house. It is contrary to na-
ture's laws and commercially impracticable, and therefore, the
scope and possibilities are very limited.
It is now practicable to put up ice of very moderate thick-
ness or to allow the ice to freeze right in the ice storage house,
and improved appliances and methods for this purpose are
decribed elsewhere in this book.
PRINCIPLES OF ICE EEPBIGERATION.
A cold storage house may be successfully cooled by ice
mixed with a small proportion of salt. Many persons who
employ ice in an ordinary refrigerator or otherwise, are perhaps
not fully aware that it may be employed with entire success
for practical cold storage, even when placed in direct competi-
tion with the ammonia or other mechanical systems. Tempera-
tures as low as from 5° to 10° F. are maintained in freezing-
640 PRACTICAL COLD STORAGE
rooms, and eggs are held at 29° F. with a pure and dry atmos-
phere. These facts should establish beyond a question the
possibilities of ice in the cold storage field. The system of
natural ice cold storage which will produce these results is
fully described further on in this chapter. Numerous plants are
in operation which use manufactured or artificial ice with a
small admixture of salt as a primary refrigerant. Artificial ice
is as useful for this purpose as natural ice and for small plants
is very desirable as compared with a small ice machine.
The immense natural ice crop is, for the most part, consumed
in the temporary safe keeping of perishable products, which are
stored in the common house refrigerator or the larger refrigera-
tor of the retailer. Many cold storage houses utilizing natural
ice are in operation, which give more or less satisfactory results :
generally the latter. Some persons have an idea that a cold
storage house is a room with sawdust-filled walls with ice in it,
but there are many points about cold storage not understood by
the average person. It is the purpose in this chapter to discuss
the various methods of cold storage by means of ice so that
the careful reader may discriminate between them and under-
stand the underlying natural laws.
In discussing ice cold storage, it may be admitted at the
outset that the use of ice in any form for the preservation of
food products, like eggs, butter, cheese and fruits, for what is
known as long-period storage, has fallen into disrepute, owing
to defects in the older systems. There are reasons for this, al-
though the idea that the ammonia system is so much superior
has been carried to an extreme not warranted by the existing
facts. The real reason why the ammonia system has a better
reputation is that natural ice has usually been misapplied to
the M'ork of cold storage, that is, it has been improperly used.
The problem of cooling storage rooms by utilizing the stored
refrigeration of the winter months in the form of natural ice
has had the attention of many persons, among them the author
and his father before him. Several systems had previously
been developed with varying success, but it is believed that up
to the time the "Cooper System Gravity Brine Circulation"
was first put in service, no system was in existence which could
REFRIGERATION FROM ICE 641
successfully compete with the ammonia or other mechanical
systems.
The use of ice as a refrigerant was long antedated by the
use of natural refrigeration, which may be obtained in cellars
or caves. It is well known that at a depth of a few feet below
the surface, the earth maintains a comparatively uniform tem-
perature, of about 50° F. to 60° F. during all seasons of the
year. This temperature varies somewhat, but above would cover
a great majority of cases in any northern latitude where snow
falls, and as compared with a summer heat ranging from 70°
F. to 90° F. it will be readily observed that this natural low
temperature of the earth is of considerable service in retarding
decay and the natural deterioration of perishable products.
By digging beneath the surface of the earth a cellar was formed
which would produce results in refrigeration which were quite
satisfactory during the early history of the perishable goods
business, but would hardly withstand the critical test to which
goods from modern cold storage houses are subjected. With the
advent of the natural ice trade, ice came into use for house-
hold and other refrigerating purposes. Ice is at present and
will probably always remain the most practical means of plac-
ing concentrated refrigeration at the disposal of the compara-
tively small consumer. It seems that prior to the nineteenth
century the great cooling effect to be obtained from a small
quantity of ice was not known nor appreciated by the world
at large. The preservation of natural ice was likewise not
thought practicable for a time sufficiently long to allow of its
use as a cooling agent during the heat of summer. With a
knowledge of the cooling power possessed by the earth during
warm weather the first ice houses were constructed below
ground, without provision for drainage. The result of such an
arrangement is easy to understand. Now ice men are careful
to build above ground and provide good drainage as being
necessary to the successful keeping of the ice. The first ice
house did not provide protection for the ice, other than a roof
overhead; all ice. houses now employ sawdust or some other non-
conductor of heat to protect the ice from contact with the air,
and prevent the penetration of heat. Ice stored in the under-
642 PRACTICAL COLD STORAGE
ground ice houses was mostly melted by July, while ice stored
in a modern ice house may be kept until fall with a meltage
of only ten or fifteen per cent. The evolution of the modern
ice house from the underground pit has been gradual, and
was not made all in one jump. It seems remarkable that the
loss from meltage in the house is now so little, and this is ac-
counted for only by considering the tremendous amount of re-
frigeration which is stored up in a small quantity of ice, and a
knowledge of proper means for protecting same. (For fur-
ther information on ice harvesting and storing and the con-
struction of ice houses, see separate chapters on these sub-
jects.)
The refrigerating value of ice as compared with an equal
weight of cold water at 32° F. is as 142 is to 1. That is, ice
has 142 times as much cooling power in passing from ice at
32° F. to water at 32° F., as an equal weight of water in pass-
ing from 82° F. to 33° F. It has perhaps been noticed that ice
forms quite slowly even in extremely cold weather. This is
because the water must give up a large amount of heat before
it will become ice. The natural bodies of water are quickly
reduced in temperature to about the freezing point by a cold
spell of weather in the fall, but the freezing of the water into
ice at the freezing point (32° F.) is quite a different matter.
This natural phenomenon is accounted for by what is known
as latent heat. It is this latent heat in water which makes it
so slow to freeze, and when once frozen, makes the ice so slow
in melting, as the same latent heat which is given off in freez-
ing must be absorbed from surrounding objects before the ice
will melt into water. To fully understand this it is neces-
sary to become familiar with the unit of measurement used in
determining quantity or amount of refrigeration produced by
melting ice, and the relation between heat and cold.
Heat is a positive quantity, that is, possesses character, so
to speak, while cold is simply the absence of heat. It follows,
therefore, that any unit of measurement applicable to heat will
also measure refrigeration. If heat is extracted from any ob-
ject it becomes cold, and it becomes cold in exactly the same
amount or proportion as the heat is absorbed. The quantity of
REFRIGERATION FROM ICE 643
heat absorbed is measured by the British Thermal Unit, gen-
erallj^ abbreviated to B. T. U. One B. T. U. is equal to the
raising in temperature of one pound of water one degree, as
shown by an ordinary thermometer. The standard American
thermometer is named after its originator, Fahrenheit, and
measurements by this thermometer are usually abbreviated to
a simple F., to distinguish from some other thermometers in
use. In writing temperatures the F. is placed after the de-
gree mark. We would say then that one pound of ice in chang-
ing from ice to water at 32° F. absorbs 142 B. T. units. When
a pound of water is raised in temperature from 32° F. to 83°
F., only one B. T. U. is absorbed. In other words ice in melt-
ing has 142 times the refrigerating value that the same weight
of water has when raised in temperature 1° F. This latent heat
of liquefaction, as it is called, explains why ice melts so slow-
ly, and why a comparatively small quantity will perform such
a large refrigerating duty.
When used for cold storage purposes, the temperatures ice
alone will produce are limited. As the melting point of ice is
32° F., the temperature which can be obtained in a room
cooled by ice only must necessarily be somewhat higher. The
lowest practicable temperatures are, about 36° F. to 38° F.
during warm weather. By mixing finely crushed ice with a
small proportion of salt the melting of the ice is hastened, and
a much lower temperature results. This is caused by the great
affinity which salt has for water. When salt comes in contact
with ice this property causes it to extract the water from ice
rapidly, reducing it from a solid to a liquid, causing a rapid
production of refrigeration or rather the absorption of heat.
A pound of ice will do a given amount of work in refriger-
ation regardless of whether it is melted naturally at 32° F.
or at some lower temperature in combination with salt. The
lowest temperature obtainable with a mixture of ice and com-
mon salt is slightly below zero, Fahrenheit. This is directly
in the mixture. A room cannot be cooled as low as this with
ice and salt. By using chloride of calcium salt mixed with
crushed ice a temperature many degrees below zero may be
644 PRACTICAL COLD STORAGE
obtained. This salt costs about double what common salt does,
and is not at present in use for freezing purposes.
From tests conducted by the author it is evident that
chloride of calcium cannot be successfully used for practical
freezing purposes in a freezing mixture of ice and salt. While
the tests referred to are not accurate or conclusive it seems evi-
dent that chloride of calcium when first applied to ice has the
property of generating heat which consumes the ice rapidly.
The ultimate temperature is extremely low but the consump-
tion of ice in proportion to the actual refrigeration produced is
too great to make the use of calcium practicable. It is possible
that some special preparation of calcium, perhaps the cal-
cined calcium in granular form may be better adapted and
will produce different results than the commercial calcium
which was used in the experiment referred to.
Moisture in cold storage rooms has been the source of much
discussion and solicitude among cold storage operators, and a
knowledge of the action of this condition in rooms artificially
cooled, and its relation to temperature, will assist in our pres-
ent study. When a storage room is cooled by ice only, the
higher the temperature at which the room is held the dryer
will be the atmosphere, and the better will be the circulation.
This statement is general, and may be modified by exceptional
conditions. A moderately dry air and a good circulation are
necessary to successful cold storage, but with these two condi-
tions must go, as an imperative adjunct, a low temperature if
good results are to be obtained. It has been stated already that
the lowest dependable temperature with ice only was 36° F. to
38° r". Comparatively few products are now stored in a tem-
perature above 32° F. to 34° F., and a large bulk of the busi-
ness is handled at a temperature ranging from 30° F. to 32°
F. It is therefore evident that ice alone will not produce tem-
peratures sufficiently low for the handling of a successful cold
storage business. Temperatures sufficiently low can be ob-
tained only by ice mixed with salt or by the use of refrigerat-
ing machinery. As before stated, in a room cooled directly
from ice, the nearer the temperature of the storage room ap-
proaches the temperature of melting ice, the poorer will be the
REFRIGERATION FROM ICE 645
Circulation, and the higher per cent of moisture the air will
contain. Circulation of air within a storage room is caused
by a difference in weight of air in different parts of the room.
The air in immediate contact with the ice is cooler and heavier,
and therefore falls to the bottom of the storage room. The
warmer and lighter air at the top of the storage room at the
same time rises to the ice chamber. As long as the difference
in weight and temperature exists, circulation will take place.
The principle underlying air moisture is quite complicated, but
may be understood by a little study. It is well known that
when warm, moist air is circulated in contact with a cold sur-
face the moisture will be condensed upon the cold surface. This
is illustrated by the so-called '"sweating" of a pitcher of ice-
water in warm, humid weather. This same action takes place
in every cold storage room. When the room is cooled directly
by ice, moisture contained in the comparatively warm air of the
storage room is continually being condensed on the cold sur-
face of the ice. As the air becomes nearer and nearer the tem-
perature of the melting ice, less and less moisture will be con-
densed, and the air becomes in consequence more and more
saturated with moisture. If it were possible to cool a stor-
age room to 32° F. with ice melting at 32° F., the air of the
room would be fully charged with moisture, and totally unfit
for the storage of any food product. If a room is cooled
to 35° F. with ice melting at 32° F. the per cent of moisture
in the air would be 91 per cent of what it would be if the room
were cooled to 32° F. in the manner above indicated. If the
room is cooled to 38° F. the air would contain 79 per cent,
and if the room be cooled to 40° F., it would contain 70 per
cent. In the actual practice these air moistures would be
somewhat higher, owing to the presence of moisture which is
^continually given off by the goods in storage. Even the tem-
peratures with their corresponding percentages of air moisture
as here stated are known to be too high for the successful pres-
ervation of food products for long periods of three months and
upwards, and even for shorter periods results will not be as
perfect as with a dryer atmosphere and lower temperature.
Further than this the circulation, temperature and humid-
646 PRACTICAL COLD STORAGE
ity in a room cooled by ice only are largely dependent on out-
side weather conditions. The temperature will, of course, be
higher during the hot weather of summer. The humidity is, as
we have seen, controlled by the temperature of the air in the
room, as is also the circulation. When the temperature out-
doors during fall and winter is at or near the melting point of
the ice in the storage room (32° F.) no circulation will take
place. The air will become very damp and impure from the
moisture and impurities given off by the goods in storage, the
goods will mold and decay rapidly. This is a condition to be
met with in every house which is cooled by placing natural ice
in direct contact with the air of the storage room. (Further
information on the relation between humidity and air circula-
tion see separate chapters under these headings.)
EARLY SYSTEMS OF ICE COLD STORAGE.
Eeasons have been given why natural ice, as generally
used, will not produce satisfactory conditions for the storage
of food products for long periods. This information will en-
able the reader to fully understand the weak as well as the
strong points of the various systems here described which util-
ize ice as a refrigerant. Ice alone may produce useful and even
satisfactory results if the goods need only to be carried for a
period of one, two or even three months, but where it is de-
sired to erect a building with the idea of handling a variety of
products for long storage and with intention of building up a
permanent business, the old primitive methods of overhead,
or side, or end ice, will result in disappointment and loss. This
has been the history of at least nine-tenths of the public cold
storage warehouses cooled in this way. If those who con-
template embarking in the business cannot build a house which
will carry the various products successfully, it is better to keep
out of the business altogether. The author has had occasion
to remodel and even tear down cold storage houses in which
ice was the only refrigerant, and in not a single instance known,
has a house, operated in this way, been able to build up a sub-
stantial and profitable business for its owner. Quite a number
of such houses are now in use, and a few are being put up ai
REFRIGERATION FROM ICE
647
the present time, but they are mostly operated for private
use for one or two products only, and for comparatively short
time storage. They do not give successful results when used
for sensitive goods like butter and eggs.
The first application of natural ice to the preservation of
food products was that of placing goods directly in contact
with the ice, in a similar manner to the method now employed
in shipping fish or poultry or in cooling melons for tempor-
ary holding. This method can be employed for but few prod-
ucts, because the goods become wet and water soaked. The air
in such a chamber has not the benefit of the purifying and dry-
FIG. 1.— THE FISHER SYSTEM— SECTIONAL VIEWS.
ing influence of circulation, and goods in condition favorable
for such action mold and decay rapidly. As an improvement
on this method, it was natural to separate the goods from the
ice, by placing the ice at one end or side of the chamber and
the goods at the other, and not in contact with each other.
The wetting of the goods is thus avoided, but when the goods
are not placed in contact with the ice, they are of course car-
ried at a somewhat higher temperature. No circulation of
consequence is present, and the air becomes moist and im-
pure very rapidly. Improving on the side or end icing plan.
648 PRACTICAL COLD STORAGE
a two-compartment refrigerator was constructed, with the ice
above and the goods to be preserved stored below. By pro-
viding openings for the flow of cold air from the ice down
into the storage compartment, and for the flow of comparative-
ly warm air up into the ice compartment, a circulation of air
was produced, which was the first really important principle
discovered in cold storage work. Air is purified and dried by
circulation under proper conditions. The reason for this is
discussed in the chapter on "Air Circulation." The first suc-
cessful ice cold storage houses were built with ice above the
storage chamber, and a large n)ajority of those still in use are
of this general plan, with, of course, many modifications. As
before stated, they are useful mostly for short-time storage.
When placed in competition with a house equipped with a
system which gives positive control of circulation, moisture,
temperature and purity of the atmosphere, they soon lose busi-
ness and fall into disuse. Many patents have been issued on
the various systems of ice cold storage. A few only of those
system which have come to the author's attention will be
briefly described, with the idea of showing the development
of ice cold storage, and also that the reader may form some im-
pression as to the relative merits and weak features of the
different systems which have been more or less prominent in
the past.
The Fisher System. — One of the oldest systems of ice cold
storage and one on which many houses have been erected, is
the "Fisher System," (See Fig. 1.) The points of this system
which are covered by patent are not known to the author, but
the main essentials of the houses as constructed by Fisher, were
an ice chamber located above a storage room with an insulated
waterproof floor separating the two. Openings were provided
for the circulation of air from the ice chamber to the storage
room, and flues from the storage rooms to the top of the ice
chamber. One who is familiar with the operation of this sys-
tem says that Fisher's houses, when new, would do fair work,
but when they became old the results were very bad. None of
these houses known to the author are now in operation. The
principle was very simple, and as good results might be ob-
REFRIGERATION FROM ICE
649
tained by this system as with a majority of the later ones using
ice only.
The Wickes System.~The "Wickes System" has been
largely introduced among certain lines of trade, more particu-
larly in the refrigerator car service. It is claimed that several
FIG. 2.— THE WICKES SYSTEM.
thousand of the Wickes cars were in constant service. The
Wickes company some years ago installed a number of cold
storage plants, but it is believed that they do not now recom-
mend their system for such use. The devices which make up
the Wickes system (see Fig. 2) consist of a basket-work ice
bunker, composed of galvanized iron strips. Attached to the
650
PRACTICAL COLD STORAGE
strips where the air flows into the ice bunker are projecting
tongues, which, it is claimed, give largely increased cooling
and moisture-absorbing surface, which dry and purify the
air more thoroughly. AVhere the air flows out at the bottom
of the ice bunker, it passes down over a network of galvanized
wire, which is kept cold and moistened by the water dripping
from the melting ice above. These devices which have been
added to the ordinary construction of the ice box no doubt add
somewhat to the efficiency of the system, but are scarcely worth
their cost. Any system like the Wickes, employing side or
end icing, must be greatly inferior to the overhead ice sys-
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FIG. 3— THE STEVENS SYSTEM— SECTIONAL VIEWS.
tern, because the circulation of the air becomes stagnant when
the ice is reduced in the ice bunker. The temperature also
rises under these conditions, and unless a very large ice bunker
is provided and the supply of ice fully maintained it is not
possible to produce as low temperatures as with an overhead
ice system.
The Stevens System. — A good many houses have been
erected on what is known as the "Stevens System." (See
Fig. 3.) This differs somewhat from other systems of over-
head icing in having an arrangement of fenders and drip
REFRIGERATION FROM ICE
(551
troughs forming an open pan over the entire floor of the ice
room, except at the ends and sides, which are left open for the
flow of warm air upward from the storage room. The cold
air from the ice works down through the open pan. The pan
is formed by a series of gutters suspended between the joists and
FIG. 4.— THE NYCB SYSTEM— SECTIONAL. VIEW.
capping pieces over the joists to cause the water to drip into
the gutters, at the same time allowing a circulation of air be-
tween gutters and capping pieces. Those who have used the
system state that trouble resulted from spattering of water from
the troughs. This system has the advantage of maintaining
fairly uniform temperatures, regardless of the amount of ice in
652
PRACTICAL COLD STORAGE
the ice chamber. Quite a number of these old houses are still
in use. The results obtainable are not essentially different from
those to be had by other overhead ice systems.
The Nyce System. — The system invented by Professor
Nyce is one of the old-timers still to be found in use. In this
system (see Fig. 4) the cooling effect of melting ice, and the
drying and purifying effect of chloride of calcium, are de-
pended upon to produce the desired result. It is an overhead
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PIG. 5.— THE JACKSON SYSTEM— SECTIONAL VIEW.
ice system, but the air is not circulated from the ice chamber
into the storage room. The storage room is cooled by contact
with the metallic ceiling of the storage room, which also forms
the floor of the ice chamber. Professor Nyce no doubt studied
out this system from having observed the bad effects which re-
sult in the ordinary overhead ice cold storage during cool or
cold weather. To absorb the moisture which is given ofif by
the goods and from the opening of doors, the well-known dry-
REFRIGERATION FROM ICE 653
ing qualities of chloride of calcium were used. The results
obtained by cooling and drying a room in this way were quite
satisfactory, and compared favorably with any of the other
ice systems in general use. The patents on this system have
long ago run out, but the system was not sufficiently success-
ful to encourage its general use, and so far as known, no new
houses of this kind are being built at present.
The Jackson System. — The "Jackson System" of overhead
ice cold storage is one of the most general in use, and it is
claimed that over three hundred houses have been constructed.
The system (see Fig. 5) is extremely simple, and the chief
patent is on a removable pan suspended under an open ice
floor. It is, of course, an overhead ice system, with air circu-
lating from the ice chamber down into the storage room. The
spaces between the joists supporting the ice are left open, and
aprons of galvanized iron protect the girders which support the
joist, and conduct the drip to the removable pans before re-
ferred to. In some cases cylindrical tubes or tanks of galvan-
ized iron are provided. These are filled with ice and salt for
the purpose of reducing the temperature still lower than is
possible with the ice alone. The use of tanks in a room pro-
vided with a circulation of air from the ice cannot result in
any great benefit to the rooms, as the circulation is retarded
or stopped, and a pollution of the air results to a considerable
extent. Tanks of different shapes and sizes are used in a num-
ber of systems, and will be considered by themselves in an-
other paragraph. The "Jackson System," so-called, is princi-
pally a pan hung below the ice joist so as to promote a circula-
tion of air from the ice chamber into the storage room. Other
devices as simple will accomplish the same result. Nothing
new of consequence has been added to this system for a num-
ber of years, but a few houses are being installed on this plan,
largely because it has been advertised and pushed in former
years.
2%e Dexter System. — The Dexter patents cover a much
more complicated apparatus than any system or prior inven-
tion which utilizes ice as a refrigerant. The "Dexter System"
of indirect circulation is a very ingenious device. (See Fig.
654
PRACTICAL COLD STORAGE
6.) It consists of a series of air flues between the exterior and
interior walls of the cold storage room. The cold air from the
ice chamber flows through another set located outside of the
first set. This effectually prevents the penetration of outside
heat, and makes the regulation of temperature comparatively
PIG. 6. — THE DEXTER SYSTEM— SECTIONAL VIEW.
easy, even in warm weather. This is practically like putting
one cold storage room inside of another. Dexter uses also the
galvanized tubes or tanks filled with ice and salt for bringing
down the temperature to the desired point. The circulation of
air within a room cooled in this way is sluggish, and the air
REFRIGERATION FROM ICE 6S5
too moist for most products which are generally placed in cold
storage for safe keeping. Dexter also has patents on a method
of circulating air from the ice chamber down through or
around tanks filled with ice and salt, into the storage room, but
the writer is not aware that these devices have proven to be
possessed of any particular merit or that they have been brought
into general use. Other patents have been taken out on a
scheme for constructing an ice floor or pan. This has been
found leaky in a number of cases, and has been removed and
built over. Still other patents are on a system of ventilation,
and a method of insulating the ends of joist where they enter
the walls of a building.
Any system of cooling storage rooms in which the air is
circulated directly from the ice has the constant trouble with
dampness of the ice room or bunker. Moisture always con-
denses on the ceilings or side walls of the- ice receptacle, and
mold results very soon. The air circulating over the molded
surface carries mold spores into the storage room. The goods
stored therein suffer in almost every case. A house which has
been in service for some time may be very bad in this re-
spect, especially during cool weather of fall or eai'ly winter,
as the temperature is lower and the air of storage room more
moist. Dampness of ice room also causes decay, of woodwork
and insulation.
The Direct Tankage System. — There are or have been a
number of cold storage houses, cooling rooms and freezers re-
frigerated by what the author calls the "Direct Tankage Sys-
tem." This system consists simply of placing metal recepta-
cles filled with ice and salt in the room to be cooled. There
are several forms of tanks in service, the more common of
which are the square cornered or rectangular tanks, the thin
tanks, or what are sometimes called "freezing walls," and the
cylindrical or round tanks. Usually these tanks are made of
galvanized iron. They may be made of a thickness of iron
ranging from gauge 18 to gauge 24 metal. Gauge 20 iron is
usually the best to use. These tanks are almost invariably
filled from the top through the ceiling, or what would natur-
ally be the floor of the room above. They have, however, in
656 PRACTICAL COLD STORAGE
some extreme cases been filled from the side, either from with-
out or from within the room.
The rectangular or square tanks, as at first employed, have
gradually gone out of use, because they are difficult to make
•and keep in shape and, as built in a number of cases, were so
large that the meltage of ice would be largely near the tank
sides, and very little towards the center. Tanks of this class
have been used which were as large as three feet in their small-
est dimension, and as the meltage was almost entirely within
eight or ten inches of the outer surface, the waste of space and
lack of economy are at once apparent.
The thin or flat tanks, which are sometimes called "freez-
ing walls," as usually constructed, are only about four to ten
inches in thickness, and are sometimes narrower at the bottom
than at the top. These of course are iced from the top, and
many fish freezers, built years ago, did good service when
equipped in this manner. One serious objection was that only
one surface of the tank was available to any considerable ex-
tent for cooling service, as the back or that portion of the tank
near the wall received comparatively little air circulation, in
fact, in many cases the back of the tank was placed directly
against the wall of the room with no space left between. The
construction of these tanks, also, is difficult.
Furthermore, any flat surface when used for a purpose of
this kind has a tendency to bulge outward, owing to the pres-
sure of the ice and salt within. The result is that the tanks
become leaky and will rust out rapidly.
The cylindrical tanks are very much the best of the three
kinds mentioned. They are easy to make, and owing to the
cylindrical shape will not readily get out of order and are much
more practical than either the freezing walls or the rectangu-
lar tanks. It has been found in actual practice that in produc-
ing refrigeration through a metallic surface from the meltage
of ice, where one side of the metal is exposed to the air of the
cool room, and the other has ice and salt in direct contact,
comparatively little refrigerative effect is obtained from the
ice lying more than six inches away from the exposed metal-
lic surface. Cylindrical tanks, therefore, have been built of
REFRIGERATION FROM ICE 657
a diameter of eleven inches, that being a size readily con-
structed mechanically and one which will give best results
when used for freezing or cooling. In the illustration of the
Dexter System (page 449) may be seen the cylindrical tanks
suspended from the floor of the ice chamber.
The direct tankage system, while it has been in use quite
extensively, is not at present being installed to any great ex-
tent, as its disadvantages are many. The nastiness and muss
occasioned by the icing of tanks through the ceiling of the
storage room is in itself sufficient to condemn the system.
The continuous slop resulting from handling the ice and salt
upon the floor above the storage room will result in the rotting
and decay of timbers and insulation in a comparatively short
time. It will also readily be seen that the great amount of
space wasted by thus icing the tanks is a serious drawback
to this system. Practically nearly as much space is required
for the mere charging of the tanks as is available for refrig-
erating purposes. Another disadvantage of the direct tankage
system is that it is wasteful of space in the storage rooms, as
the tanks do not present as much surface to the air of the room
proportionately as does iron piping in the form of coils. The
tanks in the room axe also sloppy and wet and the pan under-
neath is liable to become choked up and overflow on the floor
of the storage room. Further than this it is extremely difficult
to regulate the temperature of a room with this system, owing
to the fact that there is no control or balance on the refrig-
erating effect. Directly after charging the tanks, the tem-
perature will run down and then slowly rise until the next
time of charging. The author has worked with this system
for a number of years and has abandoned its use entirely in
favor of the Cooper brine system cooled with ice and salt, which
is described further on in this chapter.
John A. Ruddick, Dairy and Cold Storage Commissioner,
Department of Agriculture, Ottawa, Canada, has this to say
regarding the disadvantages of the direct tankage system: "I
am doubtful, after some years' experience, if it is the best sys-
tem to recommend. The cylinders are not always kept full,
causing insufficient and irregular refrigeration, and excessive
658 PRACTICAL COLD STORAGE
dampness is likely to result because of insufficient air circula-
tion or because of the moisture from the cylinders whenever the
ice is allowed to melt off the outside of the cylinders."
WHY THE AMMONIA SYSTEM IS SUPERIOR TO ICE.
These various systems of ice refrigeration which have come
into geperal use during the past thirty-five years, have been
briefly outlined and commented on by the author, so that the
reader may comprehend, roughly, the history of and the rea-
sons why ice refrigeration has not given satisfaction when
placed in competition with the mechanical systems which are
now generally understood to be the best for all purposes. It
is now necessary for. us to make an investigation of the "am-
monia" or "mechanical" systems, (see chapter on "Systems of
Refrigeration") when allied to cold storage, in order to as-
certain in what vital particular this system surpasses the old-
time ice systems. In visiting such a cold storage warehouse,
we find a building with insulated walls not differing from
those of an ice cold storage. The interior we find divided by
insulated partitions into separate rooms for various products;
goods having a strong or disagreeable odor being carefully
isolated from delicate goods like butter and eggs. In this re-
spect the ammonia cold storage has the advantage over the old
style ice cold storage, as the latter, even if divided into differ-
ent rooms, generally has an ice chamber common to all, mak-
ing contamination of one product from another probable. Each
room of an ammonia cold storage is equipped with a coil or
coils of piping placed on the walls or any convenient location.
Through this piping flows a liquid or a gas at a low tempera-
ture. This cools the piping, which in turn cools the air of the
storage room. The surface of the pipe being at a low tempera-
ture, frost accumulates on the pipe. This frost is moisture
which is taken from the air of the room. The low temperature
of the pipe thus causes a constant drying of the air of the room.
The main difference between a room cooled in this way and
oiie cooled by ice, is that it is much dryer, because cooled by
frozen surfaces at a temperature which will collect moisture
from the air of the room in the form of frost. In three houses
REFRIGERATION FROM ICE 659
out of four, no circulation of air is provided for, nor means for
supplying fresh air. If we pursue our investigation further
and enter the machine room, we find a complete steam plant,
with which we are all fairly familiar, and much other ma-
chinery and apparatus besides, which takes a bright engineer
some time to successfully master in all its details. This, then,
is the average "ammonia" cold storage, as seen by an outsid-
er. The real and only reason why such plant produces bet-
ter results than the average ice system, aside from a control of
temperature, may be summed up in the two words "DRY
A.IE." It is now purposed to describe a system which has all
the advantages of the ammonia system in the respect of pro-
ducing a dry atmosphere in the storage room, and yet has the
advantage of the ice systems in being simple to operate, eco-
nomical and sure against breakdown.
THE COOPER SYSTEM OF BRINE CIRCULATION.
It has already been pointed out that it is impossible to
produce a dryness or humidity of air in a cold storage room
cooled by ice, beyond a percentage which is fixed by the tem-
perature of the room. That is to say, practically no control of
humidity is possible in such a room. Further than this, the
air in an ice-cooled room is almost invariably moister than
in a room of the same temperature cooled by pipe surfaces. In
a room cooled by frosted pipe surfaces, the moisture which is
given off by the goods, and that which finds its way into the
room when doors are opened or otherwise, is frozen on the
pipes in the form of ice or frost. This is because the pipes have
a temperature below the freezing point of the moisture in the
air, causing the moisture to freeze on the surface of the pipes,
and leading to a greater drying of the air than where ice is
the cooling agent. Not only will pipe surfaces at a tempera-
ture below the freezing point of the air moisture produce a
dryer room, but they will also produce a lower temperature,
and make the control of temperature possible. It has already
been stated that the reason why the ammonia cold storage
houses produced better results aside from a control of tem-
perature, was their ability to give a dryer air. A system which
660 PRACTICAL COLD STORAGE
will utilize ice as a primary refrigerant and yet give a dry
air and low temperature, would then necessarily be able to
compete on an even basis with the ammonia or mechanical sys-
tems of refrigeration.
With a due appreciation of the facts as stated above, there
was begun a series of experiments to demonstrate the possibili-
ties of ice refrigeration, and the refrigerating apparatus now
known as the Cooper systems is the result. At the time of be-
ginning these experiments, the house experimented with was a
nearly new one, equipped with what was at that time supposed
to be the very best and latest system of ice refrigeration (Dex-
ter System), and at that time the writer was familiar with
nearly all the prominent systems of ice cold storage, as already
described. It was thought that if brine cooled by the ammonia
system and circulated through pipes for cooling storage rooms
would give better results than ice, the same results might be
produced by cooling brine with a mixture of ice and salt, and
circulating the brine through pipes in the same way. To
demonstrate the practicability of the idea, a small room was
fitted up for a test. An insulated tank was constructed, in
which was placed a pipe coil surrounded by ice and salt. An-
other coil was placed on the wall of the room, and the two con-
nected together. A pump driven by an electric motor, caused
the brine to flow from the coil in the tank through the coil
on the wall, and then again through the tank coil continuous-
ly. A temperature of brine ranging from 12° F. to 18° F.
was readily obtained, and the experiment was such a marked
success, even with this crude apparatus, that it was extended to
two other rooms, larger than the first. This time the pipes
were so arranged that a partial circulation of brine would take
place without the operating of the pump, but still another trial
was necessary to fully demonstrate that the system could be
operated entirely without a pump; that is, by the natural or
gravity circulation of brine. This was obtained in a manner
similar to the circulation of water in the hot water heating sys-
tems used in heating buildings. In the Cooper gravity brine
system, the tank which contains the ice and salt, and the
tank coils or primary coils, as they are called, are located at
REFRIGERATION FROM ICE 661
a higher level than the secondary coils which do the air cool-
ing in the rooms. Fig. 7 shows the arrangement of coils in
use. When the tank is filled with ice and salt, the brine stand-
ing in the primary or tank coil is cooled by contact with the
ice and salt which surrounds the pipes, to a lower temperature
than the brine contained in the secondary coils, and conse-
quently flows down into the secondary coils. At the same time
' SEconoflRr COILS in
3TORflGE P?OOM
FIG. V.-DIAGRAM ^Ho^O^^N^ ^B^^iI^^^I^It^eV^ =^™^ °°^^^ ^^•
the brine from the secondary coils rises into the primary coils,
where, as it is cooled, it repeats the circuit in the direction
shown by the arrows. The term "gravity," as applied to this
system of brine circulation, refers to the cause of circulation
which is owing to the difference in specific gravity (weight)
between the cold brine in the primary coils and the compara-
tively warm brine in the secondary coils. The temperature
of the circulating brine will range from 0° F. to 20° F. or
662 PRACTICAL COLD STORAGE
25° F. It is comparatively easy to cool a room to 10° F. or
12° F. with the Cooper brine system. Regular temperatures
as low as 5° above zero, Fahrenheit, have been maintained with-
out difficulty. The brine which circulates in the primary
and secondary coils is usually a solution of chloride of cal-
cium, which is used in preference to common salt brine for
the reason that it rusts the pipes less and will not freeze as
readily. The circulating brine is entirely independent of the
brine which runs out of the tank as a result of the mixture of
ice and salt. The refrigeration in the waste brine is utilized
for cooling purposes by running it through a coll of pipe of
suitable size at any convenient place in the building^ and it
is afterwards led to the sewer. The chloride of calcium brine,
on the other hand, remains always in the pipes, the only loss
being from leakage, which is, of course, very small. It will be
appreciated, by experienced persons, that this system of cool-
ing is simple in principle, very unlikely to get out of order, and
when once in operation, will continue as long as the supply of
ice and salt is maintained in contact with the primary coils
in the tank. In operation it is usually necessary to fill the
tank but once each day with ice and salt, and the circulation
will remain continuous and automatic through the twenty-four
hours. The ice in the tank will melt down one to four feet
per day, depending on how hard the apparatus is being worked,
and it is only necessary to refill with enough ice and salt to keep
the tank full. (See directions for operating further on in this
chapter.)
Rooms cooled by the Cooper brine system are subject to
precisely the same drying and purifying influences as are
rooms cooled by any of the mechanical systems of refrigera-
tion. The moisture and impurities in the air are, to a great
extent, frozen on the surface of the pipes, and temperatures
are easily controlled. In applying ice to cold storage work
by this system, the ice has no more connection with the air of
the storage room than if it were miles away. The ice is, in
fact, generally placed in an ice room of cheap construction,
built independently of the cold storage rooms. Where the
ice room is already built, it is only necessary to build the cold
REFRIGERATION FROM ICE 663
storage rooms alongside of the ice house, equip them with cool-
ing apparatus and means for getting the ice ta the tank con-
taining the primary coils. Even the location of ice house is
not important. The cold storage house may be located in the
center of the business district, and the ice on the ice field. The
necessary quantity may be hauled each day. This is entirely
practicable, and its feasibility has been demonstrated in sev-
eral different localities.
Except in plants of very small size, the ice is usually
crushed and elevated to the tank by machinery. This saves
much labor, and results in better work. The machine for
crushing the ice is generally located at or near the floor of the
ice room. The ice is fed into the crusher through a chute,
which is made in sections. As the ice is worked down in the
house, a section is removed to bring the top of the chute about
on a level with the top of the ice. The ice is first chopped in-
to irregular pieces of twenty or thirty pounds or less, then
shoveled into the chute, which drops the ice into the crusher.
From the crusher, in pieces not larger than a hen's egg, it
drops into a bucket elevator which raises it to a point near the
tank, and somewhat above it, where the elevator dumps the
ice into an inclined tube terminating in a flexible spout. The
flexible spout is pivoted, and will deliver ice to any part of the
tank without shoveling. The only hand labor necessary on
the ice is the chopping of the ice and shoveling it into the
chute. Two men will easily handle four tons of ice an hour
in this way. Four tons of ice a day will cool a storage house
with forty carloads capacity, during average summer weather.
The section. Fig. 8, on following page, shows the ice-handling
apparatus in conjunction with the other parts of a fully-
equipped storage house. It may be noticed that the storage
rooms have no communication with the ice house, and that the
cooling is effected by circulating the air of the rooms in con-
tact with the .secondary coils of the Cooper brine system.
The storage rooms are cooled and the temperature regu-
lated directly by the above named system. This may be done
by placing the secondary coils of the brine system directly in
the room, but a better method is by using the forced air cir-
664
PRACTICAL COLD STORAGE
culation system, especially if the rooms are fairly large. For
this purpose, the secondary coils are placed in a room by them-
selves, known as the coil room. A fan draws the air from the
coil room and distributes it to all parts of the storage room.
The air is returned to the coil room by being drawn off at the
^^°-,.,?^'~II^I^USTRATING THE COOPER SYSTEM OP COLD STORAGE.
This diagram is for the purpose of showing the different systems
clearly, but is not in good proportion, as the storage room Is shown much
smaller than It is. The apparatus Is really quite small as compared
with the rooms.
REFRIGERATION FROM ICE 665
top of the storage room through a perforated false ceiling.
Depending on various conditions, either perforated side air
ducts or perforated false floors are used for distributing the
air uniformly throughout the room. (In the chapter on
"Air Circulation" are discussed the various phases of air cir-
culation and the relation of refrigerating surfaces thereto, de-
scribing the various designs by the author for improving air
circulation. See also chapter on "Ventilation" and "Uses of
Chloride of Calcium" for other simple devices which are in-
stalled in combination with the Cooper brine system as illus-
trated in Fig. 8.)
DISCUSSION AND DIEECTIONS AS .'i^PPLIED TO THE COOPER BRINE
SYSTEM AND OTHER ICE AND SALT SYSTEMS.
It has been thoroughly demonstrated by the author that
tanks of a greater length than 10 feet were usually unnecessary
and the additional length when used was practically wasted.
In practical operation ice in the tank does not settle or melt
down generally, more than from one to three feet per day of
twenty-four hours. All that is required, therefore, in the
length of the tank is that it should be sufficiently long to allow
the salt brine which is dripping down through the ice to be-
come thoroughlj'^ diluted and expend its ice-melting power
before reaching the bottom. While the largest amount of re-
frigerating duty is accomplished where the ice and salt are in
direct contact with one another, near the top of the tank, yet
there is considerable refrigerating value or ice-melting power
in the brine which results from a union of the ice and salt.
This brine trickles down through the finely crushed ice in the
tank and has the same action on the ice as the salt, only to
a lesser extent. As the brine becomes more and more dilute, i1
has less and less value in this respect and finally possesses prac-
tically none, if the tank is of sufficient length.
As before stated, the practical limit of length for the tank
is ten feet, although for some purposes a length of twelve
feet may give more satisfactory results. The author has had
in service for freezing purposes tanks which were sixteen feet
in length. With tanks of this length the meltage in the lower
666 PRACTICAL COLD STORAGE
three or four feet is very small. In fact, the bottom six feet
of these tanks will not do any considerable amount of work.
The further down in the tank, the less meltage of ice there
will be, depending on the temperature at which the room is
being carried.
The work of charging the tanks with ice and salt is com-
paratively simple, but at the same time there is a chance for
the exercise of considerable skill and sound common sense.
It is an old idea in connection with freezing ice cream that the
ice and salt should be filled into the freezer in alternate layers
instead of being thoroughly mixed together. There is no ques-
tion at all but that this is a mistake. The more thoroughly
the ice and salt can be mixed together, the better the freez-
ing action to be obtained, and the greater the economy of ice
and salt.
If the ice and salt are filled into the tank in alternate
layers there are two bad results which interfere with the prac-
tical and efficient operation of the plant. One is that the salt
will cake and form lumps, which will probably go clear to
the bottom of the tank without entirely dissolving; another
is that quite a large portion of the refrigeration which is de-
veloped where the ice and salt do come in direct contact is
used in the freezing together of the ice which has no salt
mixed with it. This is especially true at the top of the tank,
where there would be very little or no brine dripping down
through.
A greater amount of work may be done with a given size
of apparatus if the ice and salt are thoroughly mixed together.
Greater efficiency may also be obtained ; that is, more work out
of a given quantity of ice and salt.
The proper M'ay to charge the tanks of the Cooper brine
system, therefore, is to thoroughly mix the ice and salt to-
gether. In a few cases this is done before the ice is filled into
the tanks, but a better way is to salt the ice as the tanks are
being filled. If the ice is crushed by a machine and the tanks
are filled through a spout, this is a comparatively easy mat-
ter. Where the ice has to be crushed by hand it should be
broken as finely as possible and no pieces of ice larger than a
REFRIGERATION FROM ICE 667
man's fist allowed to go into the tank. This is sometimes dif-
ficult to do where the ice is broken with a sledge hammer or
an axe, but with care big pieces may be avoided. It might
be stated here that the finer the ice is broken the better is the
action obtained from the salt ; that is, the less salt it will take
to do a given amount of refrigerating.
In refilling tanks it is well to first put on a certain amount
of salt, whatever is required, and then settle the honeycombed
ice already in the tank by stirring with a stirring stick. After
the tank is filled a small amount of salt may be placed on top
and thoroughly stirred into the ice by the use of the stirring
stick. This stirring stick may be constructed of a piece of
1>4 by 3 inch hard wood with a tapering point at one end,
smoothed off to a handle at the other end, and made about four
to six feet in length.
The tanks of the Cooper brine system should be cleaned
out at least once a year, as a certain amount of mud and dirt
will accumulate at the bottom even with the most careful
handling of salt and cleanest possible ice employed. In fill-
ing the primary tanks of this system the instructions above may
be followed closely and may be much more readily carried
out, as plenty of space is available for the stirring of the ice and
salt. The best way to proceed in filling the primary tanks of
the Cooper brine system is to detail two men in the tank house,
one for salting the tank, and the other for stirring the salt in-
to the ice. If only one man is available the ice should be
handled slowly so he may get salt fully stirred into the ice.
In this way a very thorough mixture can be obtained and
economy will result. The flexible spout which feeds the ice
into the primary tank can be arranged so that it may be held
in any position by the use of a rope. It is not necessary that
this should be held in the hand.
The direction and remarks regarding the Cooper brine sys-
tem as above, apply equally to any tank system employing ice
and salt. No exact directions can be given as to quantity
of ice and salt required for the reason that the conditions are
constantly changing. It may be remembered as a rule, how-
ever, that the quantity of ice melted, goods cooled and tem-
658 PRACTICAL COLD STORAGE
peratures produced are in almost direct proportion to the
amount of salt used in the tank. The more salt, the more ice
melted, the more refrigeration produced, the more goods cooled,
or the lower temperature obtained. Pay no attention what-
ever to the amount of ice being used. It is the salt on which
you depend for gauging the operation of the house. As a
guide it may be said that from five to fifteen pails (25 lbs.
each) will be used on a primary tank of the Cooper brine sys-
tem which has a dimension of about 4x5 feet at the top and
10 feet deep, under average conditions.
KIND OP SALT TO BE USED.
The kind of salt to be used is a question which always
comes up in the operating of an ice and salt refrigerating sys-
tem. That most suitable for use will depend on locality of
plant to some extent. The old salt wells at Syracuse, N. Y.,
have for years manufactured a solar or sun evaporated salt
which has a coarse cubical grain and which is useful for freez-
ing purposes. It is not quite as good, however, as the better
grades of rock or mined salt for the reason that it dissolves
more quickly. The rock salt is more dense in structure and
dissolves slower. The rock salt is mined from the earth much
the same as coal, and is crushed and screened to various sizes.
That known as "CC" and No. 1 and No. 2 is best adapted for
freezing purposes. The "CC" is finer grain, about like wheat,
and is good where the apparatus needs to be crowded or pushed
for capacity. The No. 1 is good for even temperature and
easy work and No. 2 only in deep tanks where the capacity does
not need to be crowded or pushed in any way. Crushed rock
salt is now obtainable from mines in Western New York,
Louisiana, Kansas and more recently along the St. Clair River
in Michigan. There are doubtless many other localities where
salt will be mined as the demand increases. The price is al-
ways low and it is doubtful if it will ever go higher as im-
proved methods of mining and handling make it one of the
cheapest natural products. Locality, of course, governs price
but very few localities have prices higher than $7.00 per ton
in bulk, and $5.00 per ton to $6.00 per ton is quite com-
mon.
REFRIGERATION FROM ICE 669
In some cases where operators of cold storage plants have
run short of regular freezer salt they have substituted com-
mon barrel salt. The results from same are very unsatis-
factory. Steam evaporated salt, especially of fine grain dis-
solves so quickly that the refrigerating effect is very small. It
might be noted in this connection that the greatest refriger-
ating effect is at the point of direct contact between the ice
and salt, and the brine resulting from a union of ice and salt
has comparatively little refrigerating or ice melting value.
CHAPTER XXXVI.
ICE STORAGE UNDER REFRIGERATION.
HISTORICAL.
The storage of ice in refrigerated rooms or houses is com-
paratively new, and there are no methods or types of con-
struction or arrangements of apparatus which may be called
standard.
Ice storage originated with the storage of natural ice,
and as everyone knows, natural ice has been stored for many
years in most any sort of a structure with or without insulated
walls, but relying largely or wholly for protection on pack-
ing in sawdust or other material of a porous nature to prevent
the penetration of heat. Artificial or machine-made ice was at
first stored in the same way and for comparatively short periods,
or it was stored in an insulated room without refrigeration and
for a few days at a time. Later, storage rooms for artificial ice
were refrigerated in connection with ice making plants, and
brine or ammonia piping run from the freezing tank for the
purpose of cooling the room, and these rooms were mostly used
simply as in-and-out room's to protect a few days' supply, or
possibly to give a reserve stock of ice in case of breakdown to
the machine, or to take care of extraordinary demand in ex-
tremely hot weather.
As the demand for ice became larger and the capacity of
the manufactured ice plant was taxed, it was appreciated that
ice might be stored in a comparatively large ice storage room
during cool Aveather when the demand for ice was compara-
tively slack, and thus the real ice storage houses for storing
ice under refrigeration were developed. At first they were very
crude affairs, being simply rooms with piping, but during re-
cent years there has been some tendency to systematize con-
670
ICE STORAGE UNDER REFRIGERATION 671
struction and there have been some very large ice storage houses
built for artificial ice.
First experience with the storage of artificial ice was, in
general, unsatisfactory for several reasons, and there is yet a
prevailing opinion in many places that artificial ice cannot be
successfully stored. One of the chief reasons why results were
bad at first was that sufficient insulation was not used and the
ice not properly stored in the room and the piping arrange-
ments were neglected. At the present time there is no greater
difficulty in the storage of artificial ice for practically unlimited
periods, than there is in the storage of other goods which are
held under refrigeration to the limit of their natural life.
vlt first ice was piled into the ice storage room in a solid
mass directly oh the floor and tightly against the side walls
and the result of this, in many cases, where poor insulation was
employed, was that even though the temperature near the ceil-
ing where the piping was located was maintained below the
freezing point, yet the ice melted on the floor and on the sides
where the cold air could not get to it. Another effect of poor
insulation was that the cooling pipes, arranged generally on
the ceiling, absorbed too much moisture from the air, causing
a drying out of the ice, which lead to a honey-combing, which,
when the ice was removed from storage and exposed to warm
air, would result in its splintering and falling to pieces; hence
the impression that artificial ice could not be successfully stored
gained much headway.
There are several points in connection with the storage
of ice under refrigeration (and this applies to natural ice as
well as to artificial) which can be set down as a basis to work
on, and we may list them as follows :
1. Suitable insulation.
2. Ample piping properly located.
3. Proper packing of ice in the room.
4. A temperature below the freezing point in all parts of
the room.
The first requisite, insulation, is subject to much discus-
sion, as what one man would call prime insulation, another
would not ; but it may be stated here that the average insulation
672 PRACTICAL COLD STORAGE
as applied to cold storage houses and also to ice storage houses
is usually not more than half enough. Unless good insulation
is used a much larger piping equipment must be provided, and
this in turn means a greater drying of the air of the room, and
this leads to a tendency to an evaporation of the ice, causing
the honeycombing and splintering above referred to. Good
insulation, therefore, is necessary as a matter of economy, as
well as to successful storage. Those who advocate the use of
expensive high grade insulating materials without reference
to the character of goods to be stored and the type of building,
usually for the ice storage plant, advocate a thickness of insula-
tion of from three to five inches. This is really absurd from
an engineering standpoint, as there is no material known which
has sufficient insulating value to give what might be called
prime insulation in this thickness. Cheaper materials and more
of them would be better economy.
The arrangement of piping in an ice storage room is
usually given small attention and generally is arranged where
most convenient. The ceiling is sometimes covered with pip-
ing, and then whatever is left over to make a full complement
is distributed around the side walls, and there are many ice
rooms where the cooling coils are located on the side walls only.
The correct arrangement of piping for an ice room is on the
ceiling, and ordinarily sufficient piping may be located on the
ceiling to cool the room if the insulation is adequate. In
very high rooms of from 50 to 60 ft. or more it might be
advisable to locate a portion of the piping on the side walls
as well as on the ceiling. Locating the piping so as to pro-
duce a circulation of air is what is desired in a cold storage
room for the storage of perishable food products, but contrary
to this piping in an ice room should be located with regard to
preventing a circulation of air to any marked extent, as circu-
lation dries the air, and this tends to evaporation or drying out
of the ice. Theoretically the correct way of cooling an ice
storage room would be with an indirect air circulating system
either by using a fan or possibly by a gravity circulation, with
a thin cold air circulating space within the insulated wall.
There is no heat to be extracted from the goods stored, and it is
ICE STORAGE UNDER REFRIGERATION 673
only a question of intercepting the heat which leaks through
the insulation, and this could better be done by an indirect air
circulating system than any other way.
Tn storing ice in the room the former practice was, as
above stated, to pile it in a mass promiscuously without regard
to the maintaining of temperatures throughout the room. This,
as above stated, leads to a meltage of ice on the sides and floor,
and this in turn brought out the idea to store ice on strips
placed on the floor, usually 2x4's, and in many cases the ice
was also stored with strips between the tiers. Considering
the fact that the ice itself has no heat to be taken up, and
assuming that the ice goes into the room below the freezing
point and in a perfectly dry condition, it is only necessary to
store it in the room so that the heat which leaks through the
insulation will be absorbed by the cooling pipes before reach-
ing the ice. As the amount of heat coming through the floor
insulation is small as compared with the side wall and ceiling
insulation, it is usually not necessary to store ice on strips on
the floor, as the irregularity of the ice cakes will allow sufli-
cient circulation of air through the ice to prevent meltage.
Depending on how the ice is piled and the height and size of
the room it may be necessary to leave a space of 2 to 4 inches
around the sides of the room so that the heat coming through
the wall can find its way to the cooling coils. Artificial ice
made in cans is larger at one end than at the other, and the
storing of every alternate cake in the opposite direction is
common, but it is better, if cooling pipes are located on the
ceiling, to store the cakes in the same direction, so as to leave
some small amount of space for circulation of air. The cold
air will then drop down through the middle of the mass of
ice and circulate out to the side walls, and thus take up the
heat coming in and rise to the cooling pipes. In piling ice in
the house it should be arranged so that it does not pack too
tightly, for the reason stated above. Sometimes it may be
necessary to store the ice on 4-inch strips on the floor as well
as leave from 2 to 4 inches all around the sides of the room,
and in very large rooms an air circulating space through the
center may be necessary. No exact rule which would apply
674 PRACTICAL COLD STORAGE
to every ice storage house can be laid down, but one or two
seasons' experience will be necessary to determine the very
best course to pursue.
Temperature in the storage of ice is important only in that
it must be below the freezing point of water in all parts of the
room. If suitable strips are arranged for the right circulation
of air, as above stated, a temperature of 28° F. in the room is
all that is necessary, but if the circulation of air is not pene-
trating, the temperature of the room should be proportionately
lower in .order to maintain all parts of the ice pile below the
freezing point. In this connection it may be remarked in
passing that the conductivity of ice is very low indeed, and if
ice is piled tightly unless there is a low temperature at the
ceiling, the heat of the earth coming through the floor under
a fairly solid mass of ice will cause meltage as it is impossible
for the refrigeration to do its work. In some houses it may be
necessary to carry a lower temperature in warm weather than
when comparatively cool.
It is desirable to have the ice storage room as near a cube
as practicable, but it is not, of course, well to make a room
too high on account of danger of collapsing in a high wind.
Sixty feet is a suitable height for ice storage providing the walls
are sufficiently well designed and braced. Care must be also
taken that a suitable foundation is provided as the weight of
60 feet of solid ice produces severe pressure, and it will not
do at all to have this load on newly filled earth. In case of
unequal settlement the ice might shift to an extent which would
bulge the walls or possibly wreck the house. The author was
the first to recommend an ice storage room as high -as 50 feet,
and this was used for natural ice in connection with the storage
of ice for use in a Cooper brine system plant. Later the
author recommended the construction of a storage room for
manufactured "plate" ice to be 60 feet in height, and many
of the new plants are being built of this height. There seems
no practical reason why a room cannot be made still higher
providing a good foundation can be secured and correct design
to withstand wind pressure is adopted. The old style ice stor-
cost of construction as well as increased loss of refrigeration or
ICE STORAGE UNDER REFRIGERATION
675
age rooms and houses were generally built of a height ranging
from 24 to 40 feet, and but very few of them more than 36 feet
in height. This means a large roof exposure and increased
ice meltage. What is said here applies to the storage of ice
in an insulated room and with no covering material on the
ice, and in a room which is held under refrigeration so that
there is no ;iieltage.
A suitable vestibule or forecooler should be provided in
connection Avith every refrigerated ice storage room into which
n
"~
~
r -1 n
1 "
J
--
__^
FIG. 1.— FLOOR PLAN FOR ICE STORAGE HOUSE.
the ice is run as fast as taken from the tanks, and where the
temperature is maintained below the freezing point, so that
the ice will dry off nicely before it is stored in the main room.
This is of the utmo.«t importance to best results. It is also
necessary to prevent penetration of outside air to the storage
room, and this can only be done by using the automatic ice
doors or chutes for putting the ice into the room and for remov-
ing it. These patented automatic doors are quick in action
and close tightly and no other device should be used.
676
PRACTICAL COLD STORAGE
The above statements are based on the storage of what in
the ice trade is known as "can" ice, which is frozen in galvanized
cans suspended in tanks of brine, and is considered the most
difficult to successfully store. "Plate" ice, frozen on metal plates
from one side only and more slowly frozen, is denser and has
much the same character as natural ice . "Natural" ice frozen
by nature, we are all familiar with, but natural ice. is just now
beginning to be stored under refrigeration. The next ten
years will see some large developments along this line. Ice
storage under refrigeration — any kind of ice — is only begin-
ning, comparatively speaking.
FIG. 2.— LONGITUDINAL, SECTION.
A BRANCH PLANT ICE STORAGE.
The plan shown in Fig. 1, was designed for the storage of
a carload or two of artificial ice at branch plants where the ice
is shipped in cars from a central factory. The plant as ar-
ranged is equipped with the Cooper brine system, using ice
and salt for cooling for maintaining a temperature of 28° F.
to positively prevent the meltage of ice while being stored in
the room.
The main ice .storage room, 15x15x12 feet is protected
from direct access of warm air by a vestibule 8x15 feet and
ICE STORAGE UNDER REFRIGERATION
677
12 feet high. This vestibule is not refrigerated. The cakes of
ice are passed in and out by means of the ice chutes shown
and the vestibule can be used for the temporary storage of
small quantities of ice. Sufficient ice may be hauled out into
this room for loading a wagon, and the vestibule may be used
for the temporary storage of perishable goods, Hke fruits, etc.
A convenient platform eight feet wide is intended to give
access to teams on one end and one side to railroad track on
the other end.
Good construction in a building of this kind will pay for
Itself in a very short time, and the plan shown in Fig. 1 may
FIG. 3.— MAIN FLOOR PLAN.
serve as a model to those who handle ice at outlying points
.and at some distance from the place where it is made.
AXOTHER BRANCH PLANT ICE STORAGE ROOM.
The illustrations Figs. 2, 3 and 4, show another applica-
tion of the Cooper brine system to the cooling of a storage
room for artificial ice, and this arrangement is applicable to
many situations where ice is shipped in by the carload or
hauled from a central plant to outlying storage houses for
distribution. In the present case the ice storage room is
shown within a main building which is used for office and
other purposes, and the ice storage room, therefore, occupies
but a small portion of the total available space in the building.
The ice storage room is quite well protected from outside ex-
678
PRACTICAL COLD STORAGE
posure as there are but two walls of the room adjoining
exterior walls of the building.
The general plan as shown is applicable to almost any
size or capacity of room, but the one here shown is 71/2 feet
and 16x18 feet, inside dimensions. This would store approxi-
mately 50 tons of ice, but deducting for space occupied by
cooling coils and assuming that ice would not be piled more
than 6 feet in height, the comfortable capacity of the room
would be from 35 to 40 tons or what would now be a maximum
or very large car of ice. It may be here suggested that it is
far more economical of space, cost of plant and cost of opera-
tion to make a room much higher than the one shown. For
instance: A room 16x18 feet could just as well be 15 to 20
PIG. 4.— TRANSVERSE SECTION.
feet in height as the cost of refrigerating would be very little
more than a room 7j4 feet in height.
The arrangement of coils shown in the plan is very econo-
mical of space. With practically the entire ceiling covered
with coils it prevents to a great extent the circulation of air in
the room. The primary tank of the Cooper brine system
stands directly above the ice storage room, and ice for supply-
ing same is secured through a trap door in the ceiling of the
ice room, the ice being crushed in the room and hoisted to
the top of the tank in a bucket. A hand winding drum is
provided and a carrier and track for delivering the ice directly
ICE STORAGE UNDER REFRIGERATION 679
over the primary tank. With good insulation the amount of
ice required for refrigerating is comparatively small.
ADVANTAGES OF LARGE ICE STORAGE CAPACITY.
The advantages of large ice storage capacity with a com-
paratively small ice making capacity have been discussed at
length and both methods have their advocates. It would
seem, however, that the advantages in favor of large ice stor-
age capacity are so great that this will be the coming method.
R. P. Kehoe in Power gives some figures which may be in-
teresting in this connection as follows :
First, a 100-ton ice making plant, costing $84,000; daily operating
expenses, $98.50; total yearly expenses, $30,075; estimated profit,
$14,925; percentage of profit to investment, 17.8%. Second, a 60-tOD
can ice mailing plant and 5,000-ton ice storage, refrigerated, costing
$75,000; daily operating expense, $67.00; yearly expense, $31,060;
estimated profit, $13,940; percentage of profit to investment, 18.6%.
Third, a 60-ton plate ice making plant and 5,000-ton ice storage, not
refrigerated; investment $100,000; daily operating expenses, $41.50;
total yearly expense, $23,840; estimated profit, $18,660; percentage of
profit to investment, 18.66%.
Mr. Kehoe states that his figures are based on wooden
structures with cheap insulation and a 50 per cent yearly
load factor. Other figures may be made on this subject which
will show still better results from large ice storage capacity,
and we believe that when actual figures are taken from such
a plant they will show the economy. Ice storage is being more
and more generally used in connection with ice making plants.
CHAPTER XXXVII.
HARVESTING, HANDLING AND STORING NATURAL
ICE.
THE GENERAL ICE CROP.
It is not expected that this chapter will be of much assist-
ance to the experienced ice harvester, but those new in the busi-
ness and persons having a comparatively small amount of ice
to house may be able to obtain some information in regard to
the methods used, and select such tools and devices from those
described as will best suit their particular needs. Natural ice
has been talked down, legislated against and generally speaking
has come to be regarded as a back number for cold storage pur-
poses, but a large percentage of the perishable goods stored in
the two northern tiers of states and in Canada are stored in
structures cooled with natural ice and are likely to be for many
years to come, and the harvesting, handling and storing of the
natural ice crop is therefore of sufl&cient importance to war-
rant a fair description. In the states which are in about the
same latitude as New York and Minnesota and throughout Can-
ada, a failure of the ice crop is unknown, and ice forms quite
regularly to a thickness of from ten to twenty inches. In
Pennsylvania and Iowa and the states in the same latitude and
isothermal conditions, ice is usually harvested of a thickness
ranging from six to twelve inches, sometimes thicker.
Before the introduction of the ice machine, natural ice
was harvested as far south as Tennessee and Missouri and in
the mountain regions of Virginia and North Carolina. In
some cases this is still done, but the crop is uncertain, and as
the ice is thin it is expensive to harvest. Probably the thickest
ice on record is harvested at Winnipeg, Manitoba, Canada,
where it reaches a thickness of forty inches, at times even more,
680
NATURAL ICE 681
and almost invariably of excellent quality. The lake ice har-
vested in Minnesota and Wisconsin is almost marvelous in its
purity and brilliancy. Ice has been cut in these states during
three successive winters, eighteen or more inches in thickness,
free from snow or white ice, and clear and transparent as spring
water. Lake Superior ice, owing to the beautiful, clear water
from which it is frozen, is of excellent quality. It is on record
that ordinary newspaper print has been read through a cake
of Lake Superior ice twenty-nine inches in thickness. The im-
mense harvests of the Kennebec and Penobscot rivers of Maine
and the Hudson in New York, are of national reputation. Ice
from these rivers is used largely among the populous coast cities
of the East, and before the advent of the ice machine, was used
extensively in the Southern states. The shipment of ice south
has now practically ceased, and even some of the chief cities
of the North Atlantic seaboard now use the manufactured ar-
ticle to a large extent.
Ice of a thickness of from ten to sixteen inches handles
well and cuts up economically if used for retailing by wagon —
a thickness of twelve or fourteen inches being probably the
most desirable. It is not of course always possible to get the
thickness desired owing to the exigencies of the weather dur-
ing harvest. The maximum thickness which is formed in the
locality where harvested, also necessarily limits in this direc-
tion. In southern locations it is difficult to get ice thick
enough, while further north the ice often becomes too thick
to handle to best advantage. To get a good quality of ice into
the house at a low per ton cost is the serious problem of the ice
harvester during the winter. To the end that advantage may
be taken of favorable conditions of the weather and other
related matters, these should be closely studied.
COST OF HARVESTING AND HOUSING ICE.
No dependable figures that may be relied upon to apply to
any specific case can be given as to the cost of ice delivered
in the ice house, owing to local conditions, which are of neces-
sity different. in every instance. Ice was housed in a Lake
Michigan town in Wisconsin some years ago for the seem-
682 PRACTICAL COLD STORAGE
ingly impossible cost of six cents per ton. The conditions
were ideal for the cutting of ice, and were as follows : House
on lake shore ; steam hoist, with low fuel cost, for hoisting ice
directly from water into house ; no snow to contend with ; per-
fect ice harvesting weather with temperature ranging from
zero to twenty degrees above; ice of a uniform thickness of
eighteen to twenty inches; labor cost 75 cents per day for ex-
perienced men. It may be noted that these exceptional condi-
tions are exceedingly rare, so that the cost as here given prob-
ably could not be duplicated at this time, but by taking the
above as a basis for calculation, it is possible to estimate approx-
imately the cost of harvesting under conditions varying from
the above.
Ice cut and handled during fairly favorable weather and
hauled not more than a mile, may be housed in northern lati-
tudes for twenty-five cents per ton, in comparatively large quan-
tities, perhaps somewhat less. Further south, with ice much
thinner and contending perhaps with more or less snow, rain,
or thawy weather, the cost will be from two to four times as
much. Should the house be situated at the ice field, the cost
may be reduced ten to fifteen cents per ton, or more, accord-
ing to the length of haul avoided. It is assumed in these esti-
mates that no haul will exceed four miles.
The cost of hauling ice depends also greatly on whether the
ice is hauled on runners or wheels, as a much larger load may
be hauled on runners. A fall of snow sufficient for sleighing
is therefore a boon to the harvester whose house is located at
some distance from the field. The snow must of course be
removed from the field, but this is more than offset by the im-
proved facility afforded for transportation. An excessively
heavy snowfall, however, may add much to the cost of harvest-
ing, as the ice has to be uncovered. Should a heavy rain fol-
low the plowing and making ready of the field, the rain being
perhaps followed by sleet and snow, the ice harvester's lot is not
a happy one. Not only must the work be done over again,
but perhaps the recent fall of snow must be removed, or the
snow ice resulting planed off. Other minor items, like loss or
breakage of tools, and contingencies which come up from time
NATURAL ICE 683
to time, influence the ultimate per ton cost of ice delivered in
the house.
OARE AND PREPARATION OF THE ICE FIELD.
Before undertaking to harvest a supply of ice the harvester
should inform himself regarding the legal and sanitary regula-
tions of his locality. He should be fully satisfied that the field
is lawfully his property, and that all Board of Health and other
rules are fully complied with. Most of the larger cities and
many of the smaller ones have quite stringent ordinances regu-
A
PIG. 1.— STARTING CHISEL.
lating the harvesting and sale of ice. When used for refrigera-
tion or cooling purposes only and not for family use, ice can
usually be cut from any source. Some cities, however, will not
allow ice to be harvested for any purpose whatever from waters
suspected of pollution by sewage or otherwise.
The selection in the first place and the care of the field
prior to harvesting, are both essential for securing a good qual-
ity of ice, and an economical cut. The prompt removal of
snow from the surface of the field as fast as it falls constitutes
the chief labor of preparing the field for harvest. It is seldom
that a field. of ice freezes sufficiently thick to cut without one
or more snowfalls upon it. Flooding, or "wetting down," the
ice, is resorted to by some with the first fall of snow, especially
in the southern tier of natural ice states. When the ice is in-
o
FIG. 2.— RING CHISEL.
tended for family trade this process should not be resorted to,
as all dirt and impurities lying on the surface of the ice are
frozen on and become imbedded in the ice.
The "wetting down" process consists simply in flooding
the surface of the ice, which saturates the snow with water so
that it may be frozen into ice, protects the under strata of
684
PRACTICAL COLD STORAGE
clear ice from thawing weather, and serves to increase the thick-
ness of the ice rapidly. A snow ice coating is also thought to
make the cake tougher and less liable to break in cutting and
handling. The "wetting down" is accomplished by a gang of
men armed with narrow bladed ice chisels. A starting chisel
(Fig. 1), or ring chisel (Fig. 2) may be used. The men
should proceed in a row across the field, punching holes at
intervals of say six feet, and working at a distance apart from
six to twenty-five feet, depending on the thickness of the ice
and amount of snowfall. A small hole only is necessary.
"Wetting down" should be done on a cold, still day, when it
is reasonable to suppose that the wet snow will be frozen solid.
In comparatively warm climates, where the natural ice crop is
FIG.
-HOME-MADE SCRAPER.
precarious, a fall of snow must be dealt with promptly by "wet-
ting down" or removing from the field. As small a quantity
as an inch of dry snow greatly retards the freezing, and the
surface of the ice shoiild therefore be kept free from the pro-
tecting snow blanket.
In northern latitudes flooding is not often resorted to, and
the snow is removed largely to prevent the formation of snow
ice in case of a thaw or rain. Should a rain come on with
snow on the ice, the snow becomes saturated with water, which
when frozen makes snow ice. Snow ice also results from a
thaw when snow lies on the surface of the field. It will thus
be seen that in some localities snow ice is desired and in others
it is avoided. Snow ice is porous and white, because it contains
air in fine cells. Its presence lessens the selling value of the
NATURAL ICE 685
ice, but does not interfere with its refrigerating value. Per-
fectly clear ice is desired and readily obtained in the North,
but nataral ice free from snow is seldom seen in the southern
tier of ice states. Any heavy fall of snow must necessarily he
removed before the marking out and plowing can be com-
menced, and a field of ice perfectly free from snow is desirable
at all times. An experienced ice harvester will know how to
proceed under these different weather conditions and varying
stages of the harvest, and these must be taken into consideration
at all times if the novice would proceed intelligently.
For the removal of snow from the field, various devices
are in use, depending on the magnitude of the work in hand.
Good progress can be made on a small field by the use of a hand
FIG. 4.— IMPROVED SNOW SCOOP SCRAPER.
scraper or large snow shovel, especially where the snowfall is
dry and light. This method is also useful where the snow is to
be removed from ice which will not bear the weight of ai horse.
For general use in harvesting small crops in northern latitudes,
the home-made scraper illustrated in Fig. 3 will be found of
service. It is easily and cheaply made, and can be made of
any desired size to suit the work in hand. An oak plank, two
or three inches thick and ten to sixteen inches wide may be
used, of any length up to twelve or fourteen feet. A piece of
%xiy2 inch iron fastened to the lower edge will improve the
efficiency and wearing qualities greatly. A small scraper of
this kind may be fitted with shafts for one horse and the larger
ones with a pole for two horses. A small one may be con-
structed to be operated by two men. A handle of round iron
686
PRACTICAL COLD STORAGE
llatteiicd and screwed to plank, as shown, is useful in swing-
ing the scraper into position or in lifting over banks at the
dump and as a means of holding on. If preferred, a rope may
be attached in a similar manner for this purpose.
Fia.
-SI1?PLE SNOW Si'-RArEn.
The larger and more dural)le cleaning-oflf scrapers which
are used on larger fields may be purchased from the manufac-
turers. Fig. 4 illu.strates a very good machine for this jjurpose.
Fig. 5 is a common form to be purchased at a low cost. Its
FTG. n. — ."^COOr SCRAPER.
operation is similar to the home-made scraper shown in Fig.
3. Where the snow is heavy or deep the scoop scraper illus-
trated in Fig. 6 is used. These range from six to eight feet in
NATURAL ICE 687
width, depending on tlie character of tlie work. After the
heaviest snow is removed the cleaning-off scraper may be put
on for removing the loosened snow. Should a thick crust form
on the snow some expedient must be resorted to for loosening
^%{^^^{^i;4i;if^f^j^
1
PIG. 7,— ICE AUGER.
it, so that it may be scraped; a disc harrow or a modern ice
tield cultivator will sometimes be found useful for this pur-
pose.
As the snow is .scraped from the ice it is generally best to
remove it to some distance from the place of cutting, either to
t ■^■1 -n
PIG. S. — MEASURING IRON.
the shore, or far enough from the field to prevent the ice from
"flooding," either before or after cutting commences. Where
the field is located on a large body of water, the snow is some-
times scraped into piles or windrows known as '■'dumps." The
"dumps" may be hauled away on sleds or with the scoop
PIG. 9.— PIELD ICE PLANER.
scrapers or self dumping scrapers, or they may be allowed to
remain on the ice. If allowed to remain on the ice a deep
groove is sometimes plowed around the "dump," the weight of
the snow causing the ice in this place to break loose and sink
beneath the level of the cutting field. This method is not re-
688
PRACTICAL COLD STORAGE
Sorted to except on large fields and in case of an exceptionally
heavy fall of snow.
A careful harvester will observe the thickness of his field
from the time it will safely bear his weight, and will know
from day to day the exact thickness he can deiaend upon, so
that when the time comes he may act promptly. The thick-
ness is accurately determined by the use of an ice auger (Fig.
7) , and measuring iron (Fig. 8) . The measuring iron has inch
FIG. 10. — ELEVATOR PLANER.
marks on it, and is bent up on the end, so that it can be inserted
through the hole made by the ice auger and drawn up against
the under side of the ice. The thickness of snow ice, if any,
may be noted at the top. For more accurate work three holes
may be bored, forming a triangle, and slanting toward each
other at the bottom; a small saw is used for cutting the tri-
angular plug by sawing from hole to hole.
If sufficient snow ice or dirty ice is present to be a detri-
ment to the quality of the crop, in the northern latitudes, it is
NATURAL ICE
689
lefdi'c the ico is housed. This may be done
uuw ice planer on the field, or by the ele-
generally removed
by the use of the
vator ice planer as the cakes pass up the incline. Where the
endless chain elevator is not in use, the snow ice must of
course be removed on the field. The field planer (Fig. 9)
is used in connection with the marker with swing guide. The
planer is usually set to remove two inches of ice at a time, as a
FIG. 11. — ICE CHIP CONVEYOR.
smoother job results than where a deeper cut is made. If it is
necessary to remove more than this, a second or third grooving
and planing takes place. The best job of planing may be done
by using a 21-inch guide on the marker and using a check
gauge, by which the groove is cut to the exact depth of the
snow 'ice"^ to be removed. Then the plane being twenty-two
inches wide, and the knife set at the bottom of the guide
690 PRACTICAL COLD STORAGE
plates, will lap over one inch on the planed portion, remov-
ing the marked grooves completely, and leaving the surface as
smooth as new ice. An improved ice field cultivator requir-
FIG, 12.— HAND ICE PLOW.
ing no marking has now largely superseded the above method.
A marker with guide which can be adjusted from twenty-
m^mmmmmmimmvMmf! i ,'.'..,''..«miMmiiiiiiiiii wii ihiiiiwmiiiiih pum^
FIG. 13.— LINE MARKER.
two to twenty-one inches is very convenient for use in planing.
The chips of ice resulting are removed in the same way that a
FIG. 14.— IIARKER PLOW WITH SWING GUIDE.
heavy fall of snow would be. The chips being very heavy
make the planing of snow ice on the field a very expensive
operation. Where the harvest is of sufficient magnitude to
NATURAL ICE 091
warrant, the use of the elevator planer (Fig. 10) is greatly to
be desired. This will remove any thickness of snow ice, re-
duce the cakes to the same thickness and leave the upper sur-
face of the ice corrugated, which will prevent breakage when
removing ice from the house. A chip conveyor (Fig. 11)
PIG. 1.5. — FIELD ICE PLOW.
removes the ice chips and slush a distance from the elevator,
and is almost a necessity in conjunction with the elevator
planer.
HARVESTING THE ICE.
With the field clean, free from snow and of the desired
thickness, the marker is put to work. It is best to start the
FIG. 16. — .SWING GUIDE ICE rl.i^W.
marking plow by stretching a strong line between two stakes
driven into auger holes in the ice about 200 feet apart, to
serve as a guide. As all following marks are made from the
first, it is important that this should be straight. A long
692 PRACTICAL COLD STORAGE
plank as a straight edge is used to guide the hand plow (Fig.
12) or a line marker (Fig. 13) may be used as a substitute.
Either is followed by the regular marker (Fig. 14) with
guide which goes o\'er the field, cutting grooves parallel to
the first. The marker is used only for the first grooving, the
FIG. 17. — ICE PLOW ROPE.
greater part of the cutting being done by the deeper field
plow (Fig. lo). In marking out the first groove the operator
should take care to hold the marker upright to prevent cut-
ting irregular shaped cakes. After the first groove is made
the guide on the marker runs in this groove, gauging the
distance of the second. This is repeated over the entire field.
PIG. 18. — ICE PLOV^r HARNESS.
It is important that the cross marking should be at right
angles to the first, or parallel marking, for which purpose a
large wooden square ten or twelve feet long is used. By this
method it is comparatively easy to have the cakes square.
Cakes 22x22 inches or 22x32 inches are the common sizes.
NATURAL ICE
693
Marking and plowing may be done with one machine, where
the ice field is small. The swing guide plow (Fig. 16) is the
one used for this purpose. After the ice is marked out the
guide is removed and the field plowed over as with the regu-
lar field plows. Swing guide plows are generally made with
seven teeth and either six, seven or eight inches in depth.
A well equipped harvester has several different plows for
the different purposes. Following the marker a six-inch nine-
1
MOUSSE ^
5
NJ
1 fiei/ATOR
m wcLwe
^_: : :
1 : +
^ T_„
e :. ,\ __
*t^'
:f:"r —
----- - , t''--
.(i
~'l\^' 1""!---:
e^^ : :
FIG. 19. — DIAGRAM FOR ICE HARVEST.
tooth plow is run in the marker grooves, making these about
five inches deep. Following immediately behind is another
plow, eight inches deep, with eight teeth, making the grooves
seven inches deep. This is deep enough for ten or twelve-inch
ice, but if the ice. is fourteen or sixteen inches thick, still an-
other plow follows, ten inches deep with six teeth, making
the grooves about eight or eight and a half inches deep.
694
PRACTICAL COLD STORAGE
Should the plows be somewhat dull, perhaps this depth is not
reached, and a second plowing with the ten-inch plow be-
comes necessary, probably making the grooves nine or ten
inches deep, which is sufficient for ice sixteen inches thick, or
even more.
The headlines in which the large floats are to be barred
off are run deeper, some of the large companies having a
FIG. 20.— ICE SAW.
twelve-inch, five-tooth plow for this purpose; still others deem
it economical to use a fourteen-inch plow on very thick ice.
AVhere the harvest is comparatively small, a number of the
plows mentioned may be dispensed with, even to doing the
total cutting with the swing guide plow (Fig. 16). A set of
plows commonly used by the smaller harvester consists of a
marker, an eight-inch, eight-tooth plow and a ten-inch plow.
If the ice to be cut does not exceed twelve inches the ten-inch
plow may be dispensed with; a marker and a nine-inch
FIG. 21. — CHANNEL BRACE.
seven-tooth plow is used as a set also, and is a favorite with
the small harvester.
The plow rope (Fig. 17) by \^hich markers and plows are
drawn, should be nine or ten feet long. This prevents the front
end of the plow from rising and causing a "chatter," or irregu-
NATURAL ICE
695
lar cutting. Many, however, use shorter ropes or none at all.
The regular plow or grooving harness with whiffle-tree well
FIG. 22.— CAULKING BAR.
elevated as shown in Fig. 18, is more convenient and easier on
horses than the ordinarj' harness. Generally speaking, about
FIG. 23.— BREAKING BAR.
half or two-thirds of the thickness of the ice should be cut
through by the plow ; but not less than four inches of ice should
PIG. 24.— KNOB HANDLE PORK BAR.
be left between the bottom of the groove and the water below.
Four inches of solid ice is necessary to safely bear the weight of
FIG. 25.— RING HANDLE FORK BAR.
a team of horses. Too much ice should not be plowed in ad-
vance of the housing capacity ; enough for two or three days is
■o
PIG. 26.— RING HANDLE SPLITTING FORK.
ample; then in the event of a thaw or rain labor is saved, as
the grooves freeze up very quickly.
i^B
SO
PIG. 27.— WOOD HANDLE CANAL CHISEL.
No matter how small the harvest of ice, floats of some size
are used, as they facilitate the floating of the ice to the chan-
696 PRACTICAL COLD STORAGE
nel where they are separated. A float consists of a number of
cakes of ice, usually from fifty to one hundred, and if floated
some distance they are made much larger. The size on large
fields is determined by the deep grooves already referred to as
forming headlines for floats. The channel to the elevator ex-
tends across the end of the field. The deep grooves for sawing
PIG. 28. — STEED HANDLE CANAL CHISEL.
are located about twelve or fifteen cakes apart and run length-
wise of the field, while barring-off grooves run in the opposite
direction, or parallel to the channel and are from four to eight
cakes apart. By barring off the longest side of the float much
sawing is saved.
PIG. 29. — KNOB HANDLE 3-TINBD PORK BAR.
Fig. 19 shows a diagram of the layout of an ice field, house,
channel, etc. The location of the channel for floating the cakes
to the incline should, of course, be selected before marking out
and plowing the field. The channel should be plowed with a
deep groove on each side, and the ice removed by sawing out
with the hand ice saws (Fig. 20). Or, if plows are not plenti-
PIG. 30.— HOUSE AXE.
ful, the channel may be sawed out while the field is being
plowed. The ice from the channel may be sunk under the ice
along the sides of the channel, as it is usually more or less irreg-
ular and broken.
In sawing out for a channel the cakes should be sawed
NATURAL ICE
697
slightly narrower at the top, so that they may be readily sunk
under the channel sides. Any broken or odd shaped pieces
which come into the channel should also be sunk in the same
manner. This disposes of them easily, and as this broken ice
PIG. 31. — SIMPLE ICE LIFT.
freezes to the under side of the ice field it aids greatly in sup-
porting the channel sides, which have a strong tendency to
flood from the continued weight and travel. Where the field
FIG. 32. — ^WINDLASS OR CRAB HOIST.
is on a river, or where the channel is long, it may be necessary
to put braces across to prevent the channel from closing. A
simple device of this kind is shown in Fig. 21. It should extend
the same distance above and below the ice, and be out of the
698
PRACTICAL COLD STORAGE
vray of passing cakes. Water sprinkled around the uprights
where they pass through the ice will soon freeze solid and make
a strong anchorage.
In breaking out the floats from the planed field, it is best
to select only a sufficient area for the days' pack. The grooves
in the field adjoining this area are calked tightly with chips to
*5^a^^S=..
PIG. 33. — INCONED SLIDE AND TABLE.
prevent the water running into and freezing in the grooves.
The caulking bar (Fig. 22) is used for this purpose. With the
ice saws the grooves at the end of the selected area are sawn
through and a float is broken off by striking into the groove at
the back, in several places, with the barring-off tool, or breaking
All
II"'" Mi;ii'iii;i|iiii""""..-
FIG. 34.— TABLE WITH SLIDE AND DRAW ROPE.
bar (Fig. 23). The fork bars (Figs. 24 and 25) are likewise
used for this purpose. The splitting fork (Fig. 26) is also
much used for barring off thick ice, and is a general favorite for
the purpose, even on moderately thin ice.
The floats at the channel are broken up into strips, or small
floats of single or double rows of cakes, and when these are in
NATURAL ICE
699
the channel they are separated into single cakes. For this pur-
pose the channel chisels (Figs. 27 and 28) are used. When the
grooves are much frozen the three-tined fork bar (Fig. 29) is
used to good advantage. When 'the weather is frosty and the
grooves in good condition the ice will, cleave very accurately
from top to bottom of the grooves ; but if the weather be soft
PIG. 35.— JACK GRAPPLE.
and the grooves badly frozen, it is often necessary; on thick ice,
to use the house-axes (Fig. 30) to trim up the cakes. It is only
possible to do this on a comparatively small harvest where the
ice is hauled out on a table before loading. This house-axe
trimming is impossible where the endless chain elevator is used.
.i^toaJ!teklhliBBi''li'ta^
FIG. 36. — ILLUSTRATING DIRECT PULL ACROSS TABLE
When trimming with the house-axe it is best to hew the cakes
a trifle narrower at the bottom, as the ice will then loosen
much easier from the house and with less breakage.
The methods of removing the cakes of ice from the water
are so numerous that the ice harvester may easily select the one
700
PRACTICAL COLD STORAGE
NATURAL ICE
701
best ;ula])led to bis needs. Vox tbe bandling of a small harvest
of less Iban one buiulred tons an inexpensive rig must of course
be selected, but when housing several thousand tons or more
the most improved endless chain elevators make a great saving
in the cost per ton. Two men with tongs will pull a small cake
of ice from the water, but some simple device is generally to be
preferred even for the filling of a farm ice house of ten to
twenty-five tons capacity.
A simple and easily portable rig for raising ice from the
water and placing it directly on the conveyance is shown in Fig.
FIG. 3S.— HOISTING CRAB.
31. It consists of a simple lever or pole, supported or a post set
in a base or platform. The lever is supported from the top of
the post by a rope or chain giving play enough so that the cakes
may be lifted and swung over the sleigh or wagon. The neces-
sary leverage for lifting any size of cake may be obtained by
adjusting the chain at the required point on the pole. A rope
attached to the long end of the pole enables the operator to .se-
cure a lift which would otherwise be impossible. Fig. 32 shows
a rig frequently used, especially in some parts of the West. It
will raise the ice with little eiTort and deposit it directly on
the conveyance, but has the disadvantage of not being easily
transported, and is very slow in action.
702 PRACTICAL COLD STORAGE
The inclined slide and table (Fig. 33) is the most common
device in use for removing the cakes from the water and placing
them in a position to be easily loaded. Two active men with ice
hooks will pull out on the table a great many cakes per day,
but quite often a horse is employed, in which case a draw-rope
is used, that passes through a pulley fixed to a cross-bar above
the table (see Fig. 34). The jack (Fig. 35) is also used for this
work. Sometimes the horse or horses pull directly across the
table without using the pulley; two horses, working both ways
and using a grapple on both sides of the incline, will haul out a
FIG. 39.— HOISTING TONGS.
surprising number of cakes, enough to keep busy a large num-
of teams. Fig. 36 shows a good arrangement of table on shore
and a direct pull across the table. Where a table is used, it
should, to facilitate handling, be slightly higher than the con-
veyance.
HOUSING AND PACKING THE ICE.
The endless chain elevator already referred to, may be pur-
chased from the manufacturers with almost any variation to fit
individual needs, and is a necessity for the economical housing
of ice on a large scale. Fig. 37 shows an apparatus of this kind.
NATURAL ICE
703
Some of the large companies harvest and place ice in the houses
at an almost incredible speed with these improved facilities. It
is on record that 720 tons of ice per hour have been transported
from the M'ater to the houses by a single apparatus.
Where ice is hauled from the field to the house, the sim-
plest method in use for elevating into house where a very small
amount is stored, is the inclined slide, up which the ice may be
pushed by two men with ice hooks. The hoisting crab (Fig.
FIG. 40.— SINGLK GIG ELEVATOR.
38) with hoisting tongs, (Fig. 39), together with the slide, may
also be used, or the single gig elevator as shown in Fig. 40. In
this cut it is shown raising ice directly from the water. It is
also well adapted to handling ice delivered by conveyance. A
double gig elevator, operated by means of a hoisting engine,
makes a first-class rig for moderately large houses, and where
the amount of ice is sufficiently large, the regular endless chain
elevator with bars, same as used for removing ice from the
704 PRACTICAL COLD STORAGE
water, is largely in use. Hoisting tongs (Fig. 39) are in some
localities largely in use for housing ice, and are used for lifting
cakes directly from the water to the chute conducting it to the
house ; usually two pairs of tongs are arranged so that one pair
goes down as the loaded pair goes up. This is a comparatively
slow process, but it is a good outfit where small quantities are
handled.
FIG. 41.— STARTING CHISEL.
The method of storing ice in the house should be governed
by the purpose for which it is to be used. If the ice is to be
used for cooling purposes in the old overhead ice cold storage
house, and none of it to be removed, it should be packed as
closely as possible, and the joints between the cakes calked or
packed with chips, using the calking bar already illustrated in
Fig. 22. This method is satisfactorily employed where the ice
is not to be removed from the house, but in other cases it is not
PIG. 42.— EDGING UP TONGS.
to be recommended, as the ice freezes together quickly as soon
as the top tier begins to melt. When the ice is to be removed
from the house it is best not to pack it too closely.
There are several ways of packing, any of which will make
it possible to remove the ice from the house with very little
labor or trouble. Where the ice is quite thick the cakes may be
hewn narrower at the bottom, as already suggested, and the
cakes stored as closely as they will pack. With thinner ice it is
NATURAL ICE 70S
best to leave a space of one to three inches on the sides of the
cakes all around. Care must be taken to have the seams in a
straight line in each direction. The starting chisel (Fig. 41)
is useful for this purpose. Should the cakes be of different
thicknesses, as when harvested from a running stream, they
should be adzed off to an even thickness, if this work has not
already been done by the snow ice plane or the elevator planer.
No matter what method of storing is used, the successive
tiers of ice should be so placed as to break joints, the object
being to bind the ice into one solid body and prevent it from
caving or spreading. If this simple rule is followed, pressure
on the sides of the house is avoided. Disastrous results have, fol-
lowed the careless packing of ice. Ice 22x32 inches is very
good for breaking joints, as one tier may be placed in one direc-
tion, and the next in the opposite. Where the 22x22 inch cakes
are stored, it is best to harvest some double-sized cakes for bind-
ing purposes. Many harvesters do not break joints oftener than
every six or eight feet but "every tier broken" is better and
safer. Where some kind of covering is used, usually the two
top tiers of ice in the house are packed closely together to pre-
vent the covering from working down into the seams. The
more modern method of ice storage is to have the rooms insu-
lated in the floor, side walls and ceiling and then no covering
of any kind is necessary on the ice.
Some harvesters pack ice largely on edge, placing only
enough on the flat side to form a binder to prevent the ice from
moving. The small edging-up tongs (Fig. 42) are much used
for this method of storing. The main advantage claimed for
edge storing is that for a given space used, ice will loosen much
more easily from the house and with less waste. One tier on
edge and one flat makes a good combination for easy loosening.
For covering ice in the old style house, shavings, sawdust,
straw or hay is used. Salt or marsh hay is thought best for the
purpose. Ice dealers, as before stated, sometimes use covering
material, but for cold storage uses it is not customary and
really undesirable on account of the extra labor required.
It should be borne in mind in every case that where ice
is to be removed from the house for sale or use, chips made in
706 PRACTICAL COLD STORAGE
the house during the filling of same should be thrown out
and not chinked into the ice. Where ice is chinked the chips
melt first, running down into the seams of the lower tiers, freez-
ing there and forming a solid body of ice, difficult to remove
without much labor and breakage.
The prevailing idea that thick ice will keep better and
longer than that which is comparatively thin, is erroneous. Re-
gardless of the thickness of the ice, the cakes in the interior
of the pile do not melt until exposed to the action of the air,
the meltage being almost wholly on the top, sides and bottom
of. the mass. When ice is put into the house in quite cold
weather, it will take the temperature of the outside air when ex-
posed during transit to the house. If the house is filled with ice
at the temperature of the air, say at 20° F., the first ice to melt
is at the top of the house, and the water from the meltage runs
down into the joints between the cakes of ice lower down in the
pile. These being at a temperature somewhat below the freez-
ing point of water, the meltage from above is frozen into ice, in
some cases cementing the cakes into a solid mass, as above de-
scribed. Ice removed from the interior of the house in the fal-l
generally shows no signs of meltage whatever.
TOOLS FOR HARVESTING AND HANDLING ICE.
The following lists are given as a guide to those who are
unaccustomed to cutting ice. The five lists here given, with the
size of the harvest for which each is suited, are offered as a basis
on which the new beginner may form an estimate for his own
particular conditions.
Set No. 1. — Suitable for use in harvesting up to 100 tons.
1 ice plow with swing guide. 2 ice hooks.
1 splitting chisel. ,2 pairs ice tongs and 1 4-foot saw.
Set No. ^.—Suitable for harvesting 100 to 1,000 tons.
1 ice plow with swing guide.
1 breaking bar — pad end used as calking chisel.
1 splitting chisel.
1 4-foot saw.
1 grapple — to raise up incline — or 1 market tongs if sweep
arrangement is used.
1 plow rope.
1 line marker.
2 to 6 ice hooks.
3 tongs.
NATURAL ICE 707
Set No. 5.— Suitable for harvesting 1,000 to 2,000 tons of
ice, using six to ten men and two horses; hoisting with one
grapple.
1 8-in. swing guide plow. 1 plow rope.
1 breaking bar. 1 line marker.
1 calking bar. 2 to 3 doz. 4%-ft. ice hooks.
1 bar chisel. 1 to 6 doz. 6-ft ice hooks.
1 No. 2 splitting chisel. 1 to 12 doz. 14-ft. ice hooks.
2 5-foot saws. 1 12-in. top gin.
1 grapple and handle. 1 12-in. wharf gin.
Set No. .4.— Adapted for harvesting 2,000 to 5,000 tons of
ice, using ten to fifteen men and three or four horses ; hoisting
with two grapples.
1 3%-in. marker, 22-in. Sw. Gd. 2 grapples and handles.
1 9-in. plow (or 8-in.). 2 plow ropes.
1 No. 1 splitting fork. 1 line marker.
1 breaking bar. 1 doz. 4%-ft. ice hooks.
1 calking bar. 1 to 6 doz. 6-ft. ice hooks.
2 bar chisels. 1 to 6 doz. 14-ft. ice hooks.
1 No. 1 splitting chisel. 2 12-in. top gins.
3 5-ft. saws. 2 12-in. wharf gins.
Set No. 5.— Outfit for harvesting 10,000 to 15,000 tons of
ice, or more, engaging, say, fifty men and four horses ; hoisting
with incline elevator, and filling three chambers at once.
1 3%-in. marker, 22-in. sw. gd. 6 bar chisels.
(extra 32-in. guide for 22x32- 1 No. 1 canal chisel.
in. ice.) (Extra 44-in. guide 2 No. 2 splitting chisels.
for 22x44-in. or 44-in. sq. ice.) 6 5-ft. saws.
1 6-in. 7-tooth plow. 4 plow ropes.
1 8-in. 7-tooth plow. 1 scoop net.
1 10-ln. 6-tooth plow. 1 auger.
1 6-in. hand plow. 1 measure.
2 No. 1 splitting forks. 4 doz. 4%-ft. ice hooks.
1 No. 1 fork bar. 1 to 4 doz. 8-ft. ice hooks.
2 calking bars. 1 to 2 doz. 12-ft. ice hooks.
The quality or number of tools required is largely gov-
erned by the speed with which it is desired to harvest the crop.
The sets listed above are for average work; if fewer men are
employed the sets may be decreased, and for rapid work in-
creased. It is of course desirable to get the ice housed as quickly
as possible to avoid changes in the weather, snows, etc. Many,
however, prefer to harvest slowly, with a small crew of men,
so as to keep their hands at work during the winter, in which
case, of course, they run the risk of having their ice break up
because of mild weather before they have their houses filled.
CHAPTER XXXVIII.
ICE STORAGE HOUSES.
STOKING ICE AND SNOW IN PITS.
By freezing, water expands so that eleven volumes of water
become about twelve volumes of ice. Consequently the specific
gravity of ice is less than that of water, and ice will float on
water. When water is transformed into ice its temperature is
not changed, but remains at the "freezing point" so long as it
remains in contact with water. So also when ice is melting, the
temperature remains at 32° F. until all the ice is transformed
into water. By freezing, the latent as well as the sensible heat
of the liquid is liberated, and when the ice melts a certain
amount of heat is absorbed, being taken from the surroundings.
Snow is equal to ice in refrigerating value, and a pound of
dry snow has the same cooling effect as a pound of dry ice, but
if the ice or snow contain water, their cooling effect is corres-
pondingly reduced. If, for instance, one-tenth part of the ice is
water, there only remains nine-tenths to be melted, and the
cooling effect is reduced correspondingly. Usually, however,
ice harvested in a thaw does not contain to exceed 3% of water,
and its cooling effect is nearly equal to that of dry ice. On the
other hand, "frozen ice" (ice below the freezing point of
32° F.) requires but one-half the heat required by water to raise
it to the freezing point.* Even during a hard frost the ice on the
surface of the water is only at 32° F., and while harvested it is
more or less submerged in water at 32° F., so that its tempera-
ture will rarely be much below the freezing point, except when
carted for long distances in very cold weather. Supposing it
is put into the ice house at ten degrees below the freezing point,
it only takes five heat units to bring it to the freezing point,
•So stated by the late Prof. N. J. Fjord, of Copenhagen, Denmark.
708
ICE STORAGE HOUSES
709
and its cooling value is therefore only equal to one-half that of
water through the same range of temperature. It follows that
it is of comparatively small moment whether ice is harvested in
a thawing or freezing condition. The difference in its value
varies only about 5%.
It is more important, however, that the ice be packed
closely in the house. A solid block of ice, a foot cube, weighs
FIG. 1.— INTERIOR ODD STYLE ICE CELLAR.
about 57 pounds, but a cubic foot of the ice house will hold
only of :
Ice thrown in at random, about 30 to 35 lbs.
Ice thrown in and knocked to pieces 35 to 40 lbs.
Ice piled loosely fc ^° in u^'
Ice piled closely and chinked with fine ice 45 to bO lbs.
The limits in ordinary practice are usually between 40 and
50 pounds, a difference of 20%. The same amount will melt in
the ice house whether the ice is packed loosely or carefully.
Suppose 15 pounds per cubic foot would melt in the summer,
FIG. 2.— ROOF OP OLD STYLE ICE CELLAR.
there would be left only 25 pounds, where there was originally
40 pounds, but 35 pounds when 50 pounds were stored. The
difference in the ice left would therefore be 40%. So it is evi-
dent that it pays to pack the ice well and fill the house to its
710
PRACTICAL COLD STORAGE
utmost capacity, consistent with ease in removing, cost of the
ice, and the purpose for which the ice is to be used.
EVOLUTION OF THE MODERN ICE HOUSE.
The common use of ice is comparatively recent, and the
modern ice house is therefore of recent development. History
FIG. 3. — MODERN ICE PIT.
records that the Romans made use of a form of underground
cellar or pit to preserve snow, which was used for cooling bev-
erages during the heated term. A similar receptacle has been
used in many places in this country, especially in the South,
and may still be met with in remote and thinly settled neigh-
PIG. 4. — CONSTRUCTION OP MODERN ICE PIT.
borhoods. Figs. 1 and 2 show the outline of the construction
adopted in the old style, and the construction of the modern ice
pit is seen in Figs. 3 and 4.
PRIMITIVE CONSTRUCTIONS.
The first commercial ice houses were built below the sur-
face of the ground, but at present all are constructed above
ICE STORAGE HOUSES 711
ground, for the reason that drainage is more easily secured,
and the ice is more easily removed from the house. The protec-
tion afforded by the earth is of comparatively small value when
the disadvantages of storing below ground are taken into con-
sideration. Nevertheless, in places where ice forms only one,
two or three inches in thickness, or where snow is housed to be
used for cooUng purposes, the ice pit has its sphere of useful-
ness. Mr. J. W. Porter, of Virginia, gives the following inter-
esting information, which, among other things, shows that one
of our most esteemed presidents was a progressive and up-to-
date man :
Pits are dug in the ground, of such size and depth as is desired to
hold from thirty to fifty loads of ice. The shape is an inverted truncated
cone. The walls are lined with slabs of wood, split or sawed, or they
may be walled with brick or stone. My own is 14 feet deep, 18 feet across
the top and 10 feet across bottom, walled up with stone and then lined
with boards standing on end. A one-story tool room projecting beyond
walls two feet is erected; a very common way is to have a half pitch
shingle roof start from sills laid outside of walls, with door to pitch in
and take out. After filling, it is leveled fine and filled with clean straw
or forest leaves. The ice is rapidly gathered in pieces and shoved in
from the wagon, with much less labor than cutting, laying and packing
which would be impracticable. Sometimes when ice is not produced,
great snow balls are rolled and pitched in and trodden. Upon "Issen-
tiallo," where Jefferson lived and died, within a rifle shot from where I
write, is such an ice house, built by Jefferson, which is 54 feet deep and
is still used for ice or snow.*
In packing snow in the ice house, it is advisable to have it
thoroughly wet when it is put in. More cooling material can
be packed into the same space when the snow is wet all through
than when dry and frozen, because it may be tramped together
and packed more nearly solid. It is then possible to get 50
pounds of wet snow into each cubic foot of space, 44 pounds of
which is dry and as durable and good in every respect as 44
pounds of solid ice. Many people think that the snow should
be frozen, but that is a mistake. If it is dry, wet the snow as it
is stored or wait until it rains. When it is thoroughly wet it is
time to harvest and pack it.
The water is expelled by trampling, and drains off, leaving
comparatively dry cooling material, which is as effective and
keeps practically as well as an equal amount of dry ice. One
active man can pack and trample together 500 to 1,000 cubic
•From Green's "Fruit Grower."
712 PRACTICAL COLD STORAGE
feet of snow a day, and with this insignificant amount of labor,
snow may be used to the same advantage as ice. On the other
hand, of newly fallen, light snow thrown into the ice house and
carefully trampled, only 25 to 30 pounds can be packed within
a cubic foot, and it will keep no longer than wet snow.
Ice may be put up and protected from the heat of summer
at very small expense. The simplest method is "stacking,"
which consists simply of piling up the ice and enclosing it with
a fence-like structure, leaving space between the ice and the
fence for a couple of feet of sawdust or other filling material.
No roof is put on, but the ice is covered with a goodly quantity
of the same material that is used for the sides. This method is
not practicable for a small harvest as the wastage is too great,
but where a thousand tons or more are put up in this way, the
meltage is sometimes surprisingly small, perhaps no greater
than 20% to 30%. Some ice dealers fill their houses and put
up a certain amount in stacks as well, using the stacks first.
This method is, of course, only possible where ice can be cut of
sufficient thickness to tier up regularly and could not be used
where it was desired to put up thin ice or snow, as with the ice
pit. It is at best only a crude makeshift and can not be recom-
mended except in case of insufficient capacity or temporary dis-
abling of ice house. Sometimes it is desirable to put up ice in
this way while awaiting the completion of the cold storage house
in which it is to be used.
By the smaller users a variety of means are employed. We
have known farmers who selected sloping ground that would
have good drainage and then put down some old rails and cov-
ered them well with straw. On this foundation the blocks of
ice were placed, and when the weather was freezing they would
pour water over the ice and thus freeze the entire mass into one
huge block. This was then well covered with straw and boards
and a temporary roof put over it. Ice thus packed on the north
side of the barn by one farmer furnished the family ice for
making butter and ice cream during an entire summer. Ice
may be kept piled in a heap on a 2-foot thick layer of sawdust
or peat, and covered with the same material.
ICE STORAGE HOUSES 713
CONSTRUCTION AND INSULATION OF ICE HOUSES.
It is a common idea that the insulated walls of an ice house
should have air spaces, which if "dead" — that is, all connection
with the outside air prevented — are supposed to be fully as good
or even better insulators than the same space filled with sawdust
or other filling material. This is a mistake. In a vacant space
between a cold and warm wall, a circulation of the air will
always take place, conducting the heat from the warm wall to
the cold one. If such space is closely packed with dry chafiF,
sawdust, mill shavings, or a like material, the circulation, while
not entirely prevented, is greatly retarded. Of course tight
walls effectively stop circulation and prevent, to an extent, con-
duction, and several partitions of paper or boards in the wall
are therefore useful, but' the "dead air space" itself is of com-
paratively small account. It is important that the insulating
material with which the space is filled, should be dry, and how-
ever well it is packed, there will always be a slight circulation,
the air passing down along the cold side of the wall, and up on
the outer or warm side, and unless the outer surfaces of the wall
are air tight, moisture will find its way in, will be deposited on
the cold side of the wall, and will gradually saturate the insulat-
ing material. In such cases it may be advisable, if convenient,
to take the insulating material out occasionally to be dried be-
fore it is replaced, or it may be entirely renewed. The moisture
which cqllects in the material nearest the inside wall, is gen-
erally supposed to pass through the woodwork from the ice.
It is, however, really due to a circulation of air, as stated, and
which can not be entirely prevented. The reader is referred to
the chapter on "Insulation" for further information and details.
PILLING WITH ICE.
In filling an ice house care should be taken to have the ice
piled in such a manner that in melting or shrinking it will not
press upon the walls. This is easily accomplished by having
the floor slightly pitched towards the center of the house, then
there is less danger of ice sliding towards the outer walls. Dis-
astrous results have sometimes occurred from this cause. If
covering material is used on top of the ice it should be inspected
714 PRACTICAL COLD STORAGE
frequently and any holes found must be filled at once. Bad
meltage toward the center of the pile may cause a portion of
the ice to break away and damage the house.
In refilling an ice house or the ice room of a cold storage
plant, it is best to cut away any portion of ice remaining in the
room which has melted in an irregular way, and remove it from
the house. This applies to the top layer of ice and the sides.
Fill around the old ice with the new, adzing off so that both are
level at the top and form a level bed on which to begin refilling.
Do not attempt to fill up the spaces left from meltage by throw-
ing in irregular shaped pieces or fine chips, as they have no
sustaining power and when the weight comes on them will set-
tle and may result in a wrecked or badly sprung building. A
case is in mind where the chips and loose ice were used for fill-
ing and after the house was filled it was found necessary to
remove a considerable amount of ice at great expense and stay
up the front of the building with heavy timbers. This job cost
nearly as much as the total cost of filling the house with ice.
WASTE OF ICE IN HOUSE.
Waste of ice in an ice chamber is largely caused by meltage
from the top, the sides and bottom. Under proper ice house
conditions no serious waste ever takes place inside a pile of ice.
The melting from the sides, bottom and top is caused by in-
complete insulation. During the summer in some houses in
Denmark (the experiments on which the following figures are
based were made in Denmark, and in applying them to this
country proper allowance must be made for difference in cli-
matic conditions; they are too high for average conditions in
natural ice territories of the United States) the waste from the
bottom may vary from one foot to five feet according to more
or less careful insulation. If the ice house is provided with an
absolutely tight floor, laid on a thick layer of dry sawdust, the
bottom waste rarely exceeds eight to twelve inches during the
year. On the other hand, if the ice is piled in the house on the
bare ground the waste may reach five feet. Placed on a layer
of two feet (after being pressed together by the weight of ice)
of sawdust or peat, the ice heap will not be wasted from the
ICE STORAGE HOUSES 715
bottom to the extent of more than one to one and one-half feet.
The causes of waste from the top and sides are, first, circulation
of air ; second, penetration of heat through walls and loft.
Circulation of air is produced by cracks or openings near
the floor through which cold air escapes, being replaced by
warm air entering at the top of the house and striking the ice on
its downward passage. Such circulation is prevented by having
the walls as tight as possible, especially near the bottom. It is
of less consequence whether the house is more or less tight at
the top, if only the cold air can not escape at the bottom. This
fact also shows the importance of having the door or doors to
the ice house as high up on the walls as convenient. In a well-
built ice house but little waste is caused from a circulation of air
coming into the house from the outside.
The main source of waste is the penetration of heat through
the insulated walls. Experiments have shown that in ice boxes
of the same construction and all exposed alike, the ice melted
in the following proportions according to the insulating ma-
terial used, chaff (cut-up straw) being considered the standard,
and the ice melted in the ice box insulated by that material
being expressed by the figure 100 :
Cotton dried in a warm room 79
" on a loft 88
Husk of barley, dried on loft 90
Husk of wheat, dried on a loft 92
Husk of oats, dried on a loft 94
Leaves " " " " 96
Chaff " ' 100
Husk of rice " " " " 101
Wheat straw " " " " 110
Saw-dust " " " " 114
Peat, dry " 116
Saw-dust, green 170
Peat, moist 260
■ Saw-dust, thoroughly wet 260
Peat " " 320
Loam " " 560
Sand " " 630
From this it is evident that the more moisture there is in
the material the better it conducts the heat, and the poorer it is
as insulating material. The difference in the value, as non-
conductors, of the materials usually at hand is comparatively
small, so that material should be used which is most easily pro-
cured, be it husk of any grain, or chaff, or sawdust. Only see to
716 PRACTICAL COLD STORAGE
it that it is dry. For the bottom under the ice, however, chaff or
leaves, or husks should not be used, as these easily ferment,
develop heat, and rot. Sawdust or mill shavings is usually the
best available material for the bottom layer. Branches of spruce
or the like may also be used to advantage.
The waste from top and sides of the pile of ice depends
upon the temperature outside and upon the. proportion of sur-
face inside of the house as compared with the ice capacity. As
the result of many careful experiments with large and small ice
houses, Professor Fjord, of Denmark, established a law accord-
ing to which the daily waste in a well built ice house, for every
100 square feet of inside surface is 1.7 pounds for each degree
Centigrade of average heat. Thus in a house of 1,000 square
feet inside surface, in thirty days of an average temperature of
15° C. (59 F.) the waste would be 1.7 pounds x 15 x 30 x 10,
equals 7,650 pounds.
If there is 45 pounds of ice to the cubic foot, the waste
would be 170 cubic feet, and if there is only 35 pounds to the
cubic foot, the waste would be 220 cubic feet. In Denmark,
the yearly waste would be about 45 pounds for every square
foot of the inside surface, or if there is 45 pounds to the cubic
foot, 1% cubic feet; and with only 35 pounds to the cubic
foot, 1 2/7 cubic feet.
If the house is filled with ice to its fullest capacity, the bal-
ance of ice left, i. e., the house full, less the yearly waste, which
represents the ice that can be taken from the house during the
year (it makes very little difference whether much or little is
taken first or last, provided some is to be kept the year around,
for whether there is much or little left in the house, the amount
melted in a day is practically the same) varies according to the
size of the house, and it may be calculated from the accompany-
ing table, the headings of the last three columns representing
the amount of ice packed in each cubic foot of the house.
In this table the waste from the bottom is calculated at one
foot. If the bottom is poorly insulated, more waste should be
calculated, as mentioned before. Supposing the bottom waste
to be two feet instead of one foot, an additional waste of 8 1/3%
of the ice harvested must be expected in a pile twelve feet high.
ICE STORAGE HOUSES
717
Inside of Ice House.
Balance Left in a Well-Built
Ice House, Cu. Ft.
No.
Dimensions,
Feet.
Surface,
Sq. Ft.
Volume,
Cu. Ft.
45 Lbs.
40 Lbs.
35 Lbs.
1
10x10x10
600
1000
400
325
229
2
12x12x10
768
1440
672
576
453
3
13x13x12
962
2028
1066
946
791
4
15x15x12
1170
2700
1530
1384
1196
5
18x18x12
1512
3888
2376
2187
1944
6
20x20x12
1760
4800
3040
2820
2547
7
25x20x12
2080
6000
3920
3660
3326
8
30x25x12
2820
9000
6180
5828
5374
9
40x25x12
3560
12000
8440
7995
7423
10
50x25x12
4300
15000
10700
10163
9471
11
60x25x12
5040
18000
12960
12330
11520
12
80x25x12
6520
24000
17480
16665
15617
By means of these figures it is possible to calculate the size
of an ice house needed for any purpose in which the amount of
ice required is known. In the United States a waste of more
than 20% is considered excessive, and in the larger houses from
10% to 15% is commonly figured. Professor Fjord's figures
here given represent too great a wastage, but as they are the
only known data obtainable they are used as a basis and are
given for what they are worth.
SIMPLE FARM ICE HOUSE.
For a good simple plan for a farm ice house, that given
below has been designed by the author. It will be found cheap
to construct and thoroughly practical. The advantages of a
supply of ice on the farm which will last through the summer
are well understood by those who are provided with an ice
house. Those who have never put up ice should arrange to do
so during the next harvesting season.
Once tried, and the advantages of a supply of ice in hot
weather experienced, it will become a permanent rule to house
ice every winter. A systematic course can then be followed,
and the use of labor-saving tools and methods which expedite
the work employed. While securing the ice is the chief con-
sideration, no one should be content with anything short of the
best methods obtainable ; this is a necessity during mild winters,
when the crop must be secured speedily or not at all.
The ice house as here illustrated in Fig. 5, by plan and
section, is twelve feet square outside and eleven feet high. After
718
PRACTICAL COLD STORAGE
FIG. 5 — SECTION AND PLAN FOR SIMPLE FARM ICE HOUSE.
ICE STORAGE HOUSES 719
allowing for a foot of sawdust or other filling material at top,
bottom and sides, about eighteen tons of ice can be stored in it.
If the house is to be built on a sand or gravel soil where drain-
age is good, no precaution need be taken in regard to the drain-
age. If, on the other hand, the house is built on a clay soil,
it would be advisable to excavate a few inches and fill with
coarse gravel or pounded stone, and if necessary, a porous drain
tile may be laid through the center of the house and carried to
a low place outside for conducting away the meltage from the
ice.
The sills consist of double 2 x 4's on which are erected 2 x
4 studding, 24-inch centers. These are topped with a double
plate of two 2 x 4's on which rest 2x6 joists, 24-inch centers.
The studs are boarded up outside with novelty or drop siding.
There is no inside boarding, the sawdust being allowed to fill
the space between the studs. The roof is constructed of 2 x 4
rafters, 16-inch centers, boarded and covered with shingles. In
each gable is a louvre or slat ventilator for the purpose of allow-
ing free circulation of air. One of these may be made remov-
able or hung on hinges to allow access for covering the ice with
packing material. The ice door should be built in two or more
sections hinged to open outwardly.
On the inside, pieces of 2-inch plank are placed to keep
the sawdust or other filling material away from the outer doors.
As the ice is removed from the house the pieces of plank are
removed as necessary. The actual material for constructing this
ice house will cost, under average conditions, from $30 to $40,
and after figuring labor, the entire cost of the house should
not exceed $60.
This plan is subject to modification as to size and con-
struction. By using 2 x 8's or 2 x 6's for studs a larger house
may be constructed with the plan otherwise unchanged. If
the joists above ice are objectionable, they may be omitted by
using heavier studs and rafters, in which case the ice door is
extended up into gable, making top sections of door in the form
of a slat ventilator.
FILLING THE HOUSE.
If ice-cutting tools are not available, it is no reason why
720 PRACTICAL COLD STORAGE
you should be discouraged. With two or three cross-cut saws,
an axe or a pointed bar, two or three ice hooks and a pair of
tongs, the house can be filled. It is desired to secure a more
extended kit of tools for next season, it would be well for several
farmers to combine and exchange work in filling their ice
houses. (See chapter on "Harvesting, Handling and Storing
Ice" for further particulars.)
The standard size of an ice cake is 22 by 22 inches or 22
by 32 inches. From 40 to 50 cubic feet of ice-house measure
will represent a ton. If the ice is packed solid, 40 feet is cor-
rect, whereas if it is packed an inch or two apart, as some prefer,
50 feet is about right.
When filling ice into the house about a foot of sawdust,
chopped straw or mill shavings should be placed under the first
tier of cakes.
Leave at least a foot of space inside the studding all around,
which should be filled with packing material as the ice is put in,
and it is also advisable to fill on top of the ice with a foot or
more of sawdust or up to the top of the joists. It is advisable
to cut the cakes of ice as regular in shape as possible, oblong
rather than square. In this way each alternate tier can be
reversed so that the joints will be broken, as shown in section.
This will bind the ice together and prevent it from sliding or
breaking apart.
As the ice is removed from the house, see that the remain-
ing ice is kept covered with sawdust, and if any holes appear,
fill them at once. If dry sawdust is not available, straw, marsh
grass or mill shavings or tanbark may be used. Whatever is
used should be tramped down solidly.
Ice houses are sometimes built with double walls, with a
space of one to two feet wide between, firmly filled with dry
sawdust or other similar material. It is cheaper and serves the
purpose well to pile the ice without a floor directly on the
ground, on a thick layer of sawdust or brush wood. Good
drainage must be provided, though sometimes in a porous soil
no direct outlet for water is needed. The outside wall should
rest on a stone foundation built up slightly above the ground,
on the top of which the wall may be built of studding and
ICE STORAGE HOUSES 721
matched boards, the inside wall should also be made of matched
boards, the space between being filled with closely packed insu-
lating material. On the beams a loft floor should be laid of
loosely packed boards, which may be removed while the house
is being filled with ice. On the loft floor a layer of insulating
material should also be laid. The entrance should be placed
near the top of the wall and be provided with double doors which
may be furnished with windows to allow light to enter.
It often occurs that an ice house may be placed inside of
another building, for instance in the corner of a barn. Instances
are known where ice has been successfully kept in a hay mow
or under a straw stack, by providing an opening with double
doors. Where a room is built within a building, it is best to
construct the sides, floor and ceiling double, with some non-
conducting filling material between. The walls should be at
least one and one-half feet thick, and the ice inside of the room
protected by a foot or two of marsh hay or clean straw. This
is to be kept in place as the ice is removed. In building inside
of a structure used for other purposes provision should be made
for draining away the drip from the melting ice, so that this
may not serve to rot the timbers or injure the foundation of the
building.
The following is a description of a house which has given
good service to its owner: The ground was tiled thoroughly
for drainage and a shallow surface gutter made all around the
outside. The foundation was hollow, square building tiles,
10 X 10 X 36 inches, being used. The sills, 2x8, were doubled
and lapped and well bound at the corners. The 2x6 studs were
toe-nailed to the sills, so that the sills projected two inches over
studs on the outside; girths, 2x4, were spiked two and one-
half feet apart horizontally and flatwise on the studs, so as to be
flush with plates and sills. The weather boards were put up and
down and battened. The lining of 1 x 12-inch boards was
nailed horizontally on the studs so an 8-inch air space was left,
and one inch of said space left open at the top for the escape of
warm air. (The author believes that if this 8-inch air space
was filled with a good insulating material like dry sawdust or
mill shavings better protection would be afforded.) For free
722 PRACTICAL COLD STORAGE
circulation and to accelerate the escape of hot air a ventilator
was placed in the middle of the ridge of the roof and an open-
ing left in each gable end close under the roof. The door ex-
tended from three feet above the ground level to the level of the
eaves, and was placed on the up-hill side of the ice house. There
was a small door in the gable to receive the last two layers.
The following description is of an ice house intended for a
somewhat larger harvest than the preceding and the building is
more thoroughly constructed. It also presents a better appear-
ance architecturally. The foundations and floors are of cobble
stones to provide drainage. The course of cobble stones should
be a foot or eighteen inches thick, and project slightly above the
surface of the ground. The sills are double 2-inch stuff ten or
twelve inches in width ; the studding of 2 x 10 or 2 x 12 set 24-
inch centers ; the rafters or roof joists to be of sufficient strength,
depending on the size of the building and kind of material em-
ployed. Floor joists of 2 x 8, or 3 x 8 may be used, or a floor
may be laid down loosely on the sawdust which is filled in over
the cobble stones to a depth of a foot or more. If floor joists
are used the floor should be of 2-inch stuff, laid open at joints
to allow meltage to drain readily. The studs are boarded with
matched lumber outside and inside, and the space between filled
with insulating material, preferably of sawdust (perfectly dry)
or mill shavings, well rammed down. The rafters should like-
wise be boarded underneath and filled, or ceiling joists may be
run across at the top of the studs forming a floor and an attic.
This space should be suitably ventilated by slat ventilators in
the gable ends over attic floor. If an attic floor is put in, the
rafters need not be filled, the attic floor being filled instead.
The general description of a model creamery ice house a little
further on may be consulted in connection with the above. It
is not necessary to place hay or straw on the ice where all the
surfaces in the building are insulated as above described, and
the room may be filled full to the ceiling or within a few inches
of same. A little experience will show whether or not a cover-
ing of any kind is necessary or advisable.
The above methods of constructing ice houses, with one
exception, are not minutely described with drawings because of
ICE STORAGE HOUSES
723
their simplicity and because individual ideas and judgment can
best modify them to suit local conditions. The information
given will enable any experienced carpenter, or even a person
FIG. 6 — PLAN OP DANISH ICE HOUSE.
FIG. 7_SECTION OP DANISH ICE HOUSE.
ordinarily familiar with tools, to take the material at hand, and
erect a structure of suitable size and character to meet the condi-
tions. The houses already described are not well adapted for ice
724
PRACTICAL COLD STORAGE
a
PIG. 9 — SECTION SMALL DANISH ICE HOUSE.
PIG. 10 — SECTION ON C-D SMALL DANISH ICE HOUSE.
ICE STORAGE HOUSES 725
houses intended to hold more than 100 to 150 tons of ice. For
larger houses one of the designs described further on is more
suitable. In any case the amount of money which can be profit-
ably expended on an ice house depends largely on the cost of
delivering ice to the house. If it costs but twenty cents per ton
to store the ice in the house, it is not advisable to spend much
money in building a house to preserve same ; it would be better
business policy to build a cheap house, making it larger to allow
for greater meltage. On the other hand, if the ice in the house
costs from seventy-five cents to a dollar per ton, it would pay
well to build in a first-class manner after the best plans obtain-
able. Between these two extremes are all the variations which'
may be met by considering cost of ice and cost of construction.
These remarks apply equally well to ice houses of any capacity.
The greater the cost of the ice the more money can be profitably
expended in protecting same from meltage when housed.
Although a similar construction may not be advisable or
practicable in this country, on account of the expense, yet a
description of the Danish methods herewith given, may be of
interest. The designs shown have been particularly recom-
mended for creamery use.*
The illustrations taken from Bernhard Boggild's Maelkeribruget repre-
sent an ice house as usually built for creameries or dairies in Denmark.
The larger one (Figs. 6 and 7) will hold 15,000 cubic feet of ice, and
is built in connection with the creamery. Fig. 7 is a section through
A-B of Fig. 6. The inside lining is of matched and varnished boards
placed vertically, on the outside walls, but horizontally on the partition
and ceiling. D represents the drainage; M is doors for putting in ice;
L, doors for renewing the sawdust ; V, window ; T represents peat or
sawdust on the floor; H, chaff, husk, sawdust, or other insulating
material in the hollow walls. All doors are made as tight-fitting as
possible by tacking cloth on the edges. A, small hall, K connects the
ice house with the creamery, the ice being thrown out through the flue, t,
through the upper door, later through the lower ones.
The small ice house, Figs. 8, 9 and 10, will hold 1,650 cubic feet of
ice. Fig. 9 is a section through E-F, and Fig. 10 is a section through
C-D of Fig. 8. M is a door through which the ice is put into the house ;
L, a door for renewing the sawdust; v, window.
For the benefit of our readers we subjoin an estimate of the materials
needed for, and the cost of building these two houses. This estimate
was made by an American builder.
COST OF BUILDING.
Large Ice House of Brick $1,343.30
Large Ice House of Wood 1,044.70
Small Ice House of Brick 389.50
Small Ice House of Wood 393.50
•Abstracted from J. H. Monrad's Dairy Messenger.
726 PRACTICAL COLD STORAGE
The outside walls are represented in the illustration as built of brick,
[n the estimates, the cost is figured for brick as well as for wood. It
will be noticed that the small house costs about the same whether built
of brick or wood, while for a large house wood is the clheaper. Of
course, wages and the price of material differ in various sections of
the country, and these figures can only be a guide, which we trust may
be useful to dairymen contemplating the erection of ice houses.
MODEL CREAMERY ICE HOUSE.
The plans and details shown in Figs. 11, 12 and 18, repre-
sent a building designed by the author for a model creamery
ice house. The cost of this building is very much less in pro-
portion to its capacity than that for any of the buildings con-
structed according to the customary Danish practice as de-
scribed in the foregoing. The walls also are much thinner and
it is quite probable that the ice will not keep as well under the
same condition of outside temperature; at the same time the
difference in the melting of ice in the house insulated as de-
tailed and the Danish houses would probably not exceed 20%
if the ice were carried through to the end of the season without
removing any from the house. In Northern latitudes, where
natural ice may be stored cheaply at a cost ranging from 15 to
50 cents per ton, it is not good practice to invest too much
money in an ice house for its protection. It is better to build
the ice house a little larger to allow for additional meltage.
This model ice house is intended to be insulated with mill
shavings in the floor, ceiling and sides, and the ice is not to be
packed in any way. This is a very decided advantage over
the older methods of storing ice, as when the ice is clean, with-
out any hay, sawdust or chaff thereon, the labor of removing
from the house and applying to the purposes for which it is
to be used is probably not more than one-half what it is where
some covering material is employed. No doubt those who have
had experience in digging ice out of the old style ice house will
appreciate this method of construction. The cost of construc-
tion, too, is not greatly in excess of what the old method
would be.
Referring to the plans, it will be seen that the house is
27 feet 8 inches long by 17 feet 8 inches wide, inside measure-
ment, giving an outside measurement of 20x30 feet. The
ICE STORAGE HOUSES
727
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PRACTICAL COLD STORAGE
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ICE STORAGE HOUSES
729
height is 20 feet, making the house very nearly a cube and
with comparatively small outside exposure. The space inside
is a rectangle, as it is intended to fill the house just a? close to
Sra{> Ailing-
pLnU Z'.p.rt
FIO 13— DETAILS OF CONSTRUCTION COOPER'S MODEL, ICE
' HOUSE FOR CREAMERIES.
the ceiling as possible, and this may readily be done, as the
outside doors open up to the top of the ice storage space. The
roof is what is known as a "half pitch roof" and is provided
730 PRACTICAL COLD STORAGE
with ventilators at both ends, one of which is in the form of
a door for entering the attic space. This allows for circulation
of air through the space above the ice and prevents to a large
extent the penetration of heat from the roof.
The house as planned shows doors for icing at the side and
removing from the end, but both the filling and removing
doors may be placed in any location desired. The door for
removing ice is fitted with a frame work within the room which
leaves a space in the body of ice which may be utilized for
lowering ice from the top of pile or it may be removed through
the filling door. A ladder is located in the space inside the
door for ascending to the top of the ice. There is no opening
whatever through the ceiling of the ice room into the attic.
There is an old popular idea that ventilation over the ice is
necessary, but this is only true where the ice is covered with a
packing or non-conducting material like sawdust, hay, etc.
It should not be employed where ice is not covered, as it is
unnecessary and results in melting the ice badly.
As shown in the drawings, the walls of the building are
erected on a stone foundation which is carried down to a suffi-
cient depth. A deep foundation is not necessary, however, as
the entire weight of the ice rests on the ground and not on the
foundation of the building. Good drainage may be provided
by filling in gravel between the walls of the building to form a
floor "to the depth of twelve inches. If the soil should be of
clay, it would be well to lay a porous tile drain through the cen-
ter of the house connected with some drainage point. If the
soil is sandy or gravelly, the layer of gravel and tile drain may
be dispensed with entirely.
The floor is formed by placing 2x8 joists 24-inch centers
and slanting them slightly towards the center to the drain tile.
On the top of the 2x8 joists is laid a floor consisting of 2 x 6
plank laid two inches apart. The space between the joists is to
be filled with mill shavings, tightly rammed. Mill shavings
are specified all the way through this building, although other
materials like dry sawdust, cut straw or tan bark might be used.
Mill shavings are, however, to be preferred. The floor of the
ice house is entirely independent of the walls of the building
ICE STORAGE HOUSES 731
and is intended to be laid last, and the floor joists not set over
the foundation wall. This allows the ice to settle independently
of the building. The side walls are constructed by laying a sill
of 2 X 10 stuff on the stone wall. On this sill are erected the 2 x
10 studding, placed 24-inch centers. As planned, these stud-
dings are double-boarded inside and out, with water-proof insu
lating paper between and filled with mill shavings. If it is
desired to cheapen the cost of the house, the studding may be
single-boarded on each side with paper underneath, care being
taken not to tear the paper when filling the space with shav-
ings.
The roof is designed to be of shingles, but it may be of any
other material. The doors where the ice is to be filled into the
house are made in sections and hinge on the outside. Remov-
able plank pieces are placed inside and the space between filled
with shavings.
Ice houses of the character similar to the one here described
have been built of a capacity of 1,000 tons ; and, considering the
cost, are very successful in every way. The estimated cost of
the house which is described is, under ordinary conditions
where lumber can be obtained from nearby mills, $300.00 to
$400.00. If lumber is expensive and labor high, and ice may
be housed cheaply, the house may be cheapened by leaving out
the gravel and stone foundation wall and single boarding the
studs inside and outside instead of double boarding. The ceil-
ing joists likewise can be single-boarded, and in case of neces-
sity the floor can be left out entirely. The details for a house
of this kind depend upon the location and must be selected by
the builder or architect in order to provide proper protection for
the ice and at the same time not have the cost too high.
MODEL COMMEKCIAL ICE HOUSES.*
The accompanying plans show in detail the construction of
two ice houses on the most modern ideas in the art of ice house
building. The endeavor has been to devise a house which will,
according to the opinions of experienced men, not only offer
every facility for putting up the ice quickly and economically
*From Ice Trade Journal. Plans by Gifford Bros., Hudson. N. Y.
732 PRACTICAL COLD STORAGE
and removing it in quantities as desired at lowest possible cost,
but also to preserve the ice for the longest possible periods with
the least possible waste, and at a cost for construction which is
not prohibitive.
As two different uses are made of ice houses, differing con-
siderably in their effect upon the ice itself, it is necessary to ac-
commodate the house to the purpose. Some houses are used for
retail delivery only, and a room is opened several times a day
perhaps and ice removed in small lots of a few tons during a
number of weeks. Such a house should be planned differently
from those from which the ice is taken by the car or boat load
as fast as it can be broken out and stowed away. The first plans.
Figs. 14 to 19, inclusive, are for a house for the former purpose,
and Figs. 20 to 29, inclusive, are for a house from which large
shipments are made and the house soon emptied.
The first plans are for a twelve-room, single-posted house.
The capacity is 6,400 tons. The house is 126 feet 11 inches
long by 83 feet 6 inches wide and 30 feet 2 inches high from sill
to plate. The outside walls are 14 inches thick, the partitions
are 11 inches wide and the middle walls, dividing the interior
of the house into two sections, each of which is again divided
into six rooms, is 14 inches thick, just as are the outside walls.
■Each room is, then, 40x20 feet in the clear, and has a capacity
of 535 tons.
The posts are 3 x 12 inches and 4 x 12 inches, all 30 feet
long. They are covered on the outside by 1-inch novelty siding,
laid horizontally, and on the inside by 1-inch matched boards,
laid diagonally. It is recommended that a high grade of build-
ing paper be used on the inside and outside of the posts under
the novelty siding and the matched boards. The space between
posts should be filled with either mill shavings, fine dry sawdust
or dry tan bark well packed down. These three materials are
recommended in the order named.
The posts beside the doorways are each 4 x 12 inches for
additional strength at these points. The partition posts are 3 x
10 and 30 feet long, that width being sufficient for the inside
of the rooms. The plans call for 1-inch matched boarding
put on diagonally on one side of the partition only. If thought
ICE STORAGE HOUSES
733
desirable for better insulation, the boards may be put on both
sides and the space filled with sawdust or shavings, as in side
walls. In some houses boards are put across between partition
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734
PRACTICAL COLD STORAGE
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ICE STORAGE HOUSES 737
The diagonal boarding on partition walls and inside of
front and side walls is called for by the plans, as that method of
covering adds some to the strength of the structure, but it is
more wasteful of lumber than horizontal boarding, and the lat-
ter may be substituted for the diagonal at the discretion of the
one doing the building.
The posts are placed 24 inches apart, center to center, for
greater strength, but 30 or 36 inches is considered by many as
not too great a distance. Such changes in detail may be made
in several places, as will be readily seen from the plans, in the
interests of economy, but they do not affect the general condi-
tion materially. Such departures from the plans are not, how-
ever, recommended, as the better the house is built the better it
will keep the ice and the longer it will last without repairs.
Parsimony does not pay in ice house building in the long run.
The detailed instructions for boarding and filling in the
doorways are sufficiently elaborate without further description.
The drawings give the sizes and position of the trusses, so that
no difficulty should be experienced in understanding the roof
construction and supports.
If of any advantage in ffiling, as it probably would be, ex-
cept in very unusual natural surroundings, doorways four feet
wide may be cut in the middle partition at the back of each
room, so that the back rooms may be filled through the front.
To get rid of chips and give more light, doors are also frequently
cut in the center of end walls and the partition walls at the
sides of the rooms. As no loft floor is provided for in the plans,
this being considered unnecessary, the openings under the
eaves are left free for ventilation.
With these brief explanations, the drawings should be
easily comprehended not only by any builder, but by any ice
man, however unfamiliar with building operations; and by
their aid, no matter how inexperienced, he should be able to
erect a house at once moderate in cost and correct in structure
and one most likely to give excellent results.
Nothing has been said in connection with the first house
as to the foundation and the much mooted drainage question,
but as advice on these important points will apply as much to
738
PRACTICAL COLD STORAGE
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739
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Ti'TO 20— DIAGRAM SHOWING FOUNDATION PLAN FOR A LARGE
jjiLr. <iu. ±Ji WHOLESALE ICE HOUSE.
740
PRACTICAL COLD STORAGE
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FIG. 21.— DETAIL PLAN OF CORNER, SIDE AND REAR WALLS.
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FIG. 22.— ELEVATION OF CORNER, FRONT AND SIDE "WALL.
ICE STORAGE HOUSES
741
the second house, now to be considered, as to the first, they will
be touched upon now.
The foundations should be of stone laid in cement, and the
same should be liberally applied, both inside and outside, so as
to prevent air and dampness from finding its way in and under-
mining the stored piles of ice. Most of the damage done by the
shifting and sliding of ice, by which side and end walls are
pushed out of position, is due to imperfectly protected founda-
tions. These walls are not intended to support or hold up the
I4"S5
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FIG. 23.— DETAIL, OP PARTITION.
Door 5-0"
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FIG. 24. — DETAIL PLAN FRONT AND REAR DOORS.
ice. That is supposed to stand square and true, and will if the
various tiers are reversed so as to tie the whole in an erect posi-
tion, as it should be. Some ice men reverse every other tier and
some every second or third one. The first plan is considered the
safer and better practice, as affording better security to the ice
house. In a house built on these plans, sawdust between the
walls and the ice is entirely unnecessary, if good quality of
paper and well dried and tamped filling is used between the
posts. The sills should be laid in cement of course.
742
PRACTICAL COLD STORAGE
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744
PRACTICAL COLD STORAGE
ICE STORAGE HOUSES 745
The matter of putting in drains is such an open question —
experienced men differing entirely as to their value and their
construction if used — that it should be determined entirely by
the geological structure of the land where the house is to be
erected in each case. A gravelly or sandy soil with a substratum
of blue clay is desirable, but not always to be found or made.
If a drain of any kind is used, its construction requires the very
greatest care, because where water can flow out air not only
may, but almost invariably does, find an easy access. Hemlock
boards laid loosely along the floor will serve both to distribute
the weight of the ice and to allow the meltage to settle into the
ground.
Figs. 20 to 29 are plans for a house of 24,888 tons; 227
feet long by 151' feet wide, and 36-foot posts, divided into 12
rooms, each 36 x 72 feet clear, and each of 2,074 tons capacity.
This house has double walls. The construction is of 1-inch nov-
elty siding, one layer of paper, 3 x 10 posts, one layer of paper,
1-inch matched boarding, 18-inch air space, 1-inch matched
boarding, one layer of paper, 3x4 posts, one layer of paper,
1-inch matched boarding. The spaces between posts in both
walls to be filled with either mill shavings, sawdust or tanbark,
as in first house. The partition walls consist of 1-inch matched
boarding, 3 x 10 posts and 1-inch matched boarding. They
may be lined with paper and filled for entire or part height if
desired. Whenever any partition or wall is filled with any
insulating material, each side of the posts should be covered with
a good quality of building paper, not only for additional insula-
tion, but for protection of the filling from dampness, which
destroys its usefulness. The outer and inner walls are sup-
ported by 1-inch iron ties, which hold them rigidly. The
posts at the doorways are 4 x 10. The sills are 6 x 12 and 6x6
for the outer and inner walls respectively. The posts are dis-
tanced four feet center to center in the walls.
This house requires from its size and use a loft fioor, which
the plans indicate is to be placed five feet two inches above the
plate, so as to allow room for stowing ice to the plate and cov-
ering with hay. Hinged doorways should be provided in the
floor over each room to allow easy access, light, etc.
746
PRACTICAL COLD STORAGE
Ventilation is afforded by the doorways, which are carried
up above the plate to the roof and provided above the loft floor
with doors on hinges, which may be opened or closed according
to season, wind direction, etc. The roof is carried out beyond
the eaves, and openings left between the rafters for additional
ventilation. There should be no openings of any kind into the
FIG. 28."
-INTERIOR OF WHOLESALE ICE HOUSE SHOWING
TRUSS SUPPORTING ROOF.
ice rooms. Plenty of air is needed through the loft to break up
radiation through the roof, but none should be permitted to
enter the ice chambers. The whole purpose of the construction
of this house is to keep air from penetrating, in even the slight-
est amount, to the ice. Above the plate, plenty of air ; below it,
none whatever. Openings may be cut in the roof and scuttles
ICE STORAGE HOUSES
747
put on which may be readily opened and closed if the loft is
found too warm with the doors open and the eave spaces free.
COLD STORAGE IN CONNECTION WITH ICE HOUSE.
A cold storage plant may be operated in combination with
the storage and sale of natural ice at a comparatively small cost.
Tvua^ tec ii'dt Roomi
FIG. 29. — DETAIL OF TRUSS CONSTRUCTION OF WHOLESALE ICE
HOUSE.
There are many localities, especially in large towns and the
smaller cities, where the natural ice dealer could work up a good
business in the cold storage line, especially as he sells ice to
many produce dealers who would become his customers for cold
storage space as well. In many cases where an artificial ice
plant has been installed, a cold storage house has been erected
as an adjunct and made a success. There is no reason why the
same thing cannot be done with the natural ice business. Here-
748
PRACTICAL COLD STORAGE
tofore owing to the fact that there has not heen a successful
system of refrigeration which could be operated by the use of
natural ice, nothing of any consequence has been attempted
along this line, but with the introduction of the Cooper brine
system, using ice and salt as the refrigerant, equally good re-
FIG. 30.— FRONT ELEVATION COMBINATION ICE AND COLD STOR-
AGE HOUSE.
FIG. 31.— SIDE ELEVATION COMBINATION ICE AND COLD STOR-
AGE HOUSE.
suits may be obtained down to a temperature of 10° F. as by
the mechanical systems of refrigeration. Many of these plants
are now in operation and uniformly successful. This system is
fully described elsewhere in this book.
ICE STORAGE HOUSES 749
Figs. 30 to 32 show the outlines of the plan, sections and
elevations of the combination ice storage and cold storage house
which has been designed by the author. These plans may of
course be adapted to any location. The cold storage part may
be built in any shape and of any size and for any purpose. It
may be built in one, two or three floors, or more if desired. The
plant, as designed and illustrated in the sketches, shows the cold
storage part, with its ice house, as separate from the regular ice
storage rooms. This is for the reason that the ice produced in
many localities is not a very sure crop and in other cases it is
contaminated by sewage, etc. The ice used for the cold storage
part of the building need not be from a pure source, as it is
used for cooling purposes only or for icing cars. The ice stored
in the regular ice storage rooms is supposed to be from a pure
source, and may, if necessary, be shipped in cars.
In connection with the cold storage part of this plant an
ice crusher and ice elevator are employed for handling the ice.
The spout leading from the elevator is arranged so as to deliver
ice at several points on the railroad track for the purpose of
icing refrigerator cars with crushed ice. Cars may be iced with
this device with great rapidity, and it is consequently econom-
ical, as the ice need not be handled except to feed it into the
ice crusher in large pieces. The ice storage rooms of this plant
are insulated with mill shavings, are separated into two divi-
sions and protected inside and outside by the best grade of insu-
lating paper. The floor and ceiling are insulated in about the
same manner, and no packing or covering material is used on
the ice. Ice men will appreciate the advantage of this method,
as it saves a large amount of labor, and that, too, at a time
when labor means a good deal to the ice man. It is calculated
that the meltage of ice in this house will not exceed 15%, and
under ordinary conditions should not exceed 10% or, 12%%,
which is about as small as any ice man can figure on.
As shown by the plan, the receiving room for the cold stor-
age department is located on the corner and a platform runs
around three sides of the building. This makes the loading
and unloading of goods from cold store and cars a compara-
tively small matter, and, as the receiving room fronts on the
750
PRACTICAL COLD STORAGE
FIG. 32. — FIRST FLOOR PLAN AND TRANSVERSE SECTION ON A-B
COMBINATION ICE AND COLD STORAGE HOUSE.
ICE STORAGE HOUSES 751
street, makes deliveries to and from wagons equally simple.
The office, which is located in the receiving room, is intended
to be used not only for the cold storage department, but for the
ice business as well, and is so located that the ice business may
be readily looked after. In this plant no basement is con-
structed, and the cold storage plant is all on the first floor. It
will be noted, however, that the second and third floors are re-
served and may be insulated and equipped with cooling appa-
ratus as the business is extended. An elevator serves the second,
third and attic floors, and the attic over the cold storage and
also over the ice storage rooms may be utilized for ordinary
warehouse purposes.
The cold storage rooms, as divided, are intended for eggs
or fruit, one room for butter and two rooms for meat or beer.
These meat or beer rooms open directly onto the platform,
making them accessible from the railroad siding and from the
street. These rooms may be rented to the meat or beer agen-
cies and the owner need not have anything to do with the same
except to regulate the temperature. The insulation of the cold
storage department consists of mill shavings and hair felt prop-
erly divided and protected by the best grades of insulating
paper. The butter room, meat or beer rooms are cooled by
piping placed directly in the room. The egg or fruit rooms are
cooled by the forced circulation of air, the coils for which are
located over the corridor. A ventilating system furnishes fresh
air at any season of the year to all of the rooms. The "Cooper
systems" : brine system, forced air circulation, ventilating sys-
tem and chloride of calcium process, with which the plant is
equipped, are fully described elsewhere in this book.
CONCRETE ICE HOUSES.
The subject of concrete ice houses is one prolific of discus-
sion, and there has actually been several such houses built, but
the author failed to locate a concrete ice house of modern con-
struction, wherein the side walls, floor and ceiling are insulated
and wherein the ice is not covered with some protective ma-
terial which has been even a moderate success. It is, of course,
practicable to build an ice storage house of concrete of the old
style, where the ice is placed in the room a foot or more from
7S2 PRACTICAL COLD STORAGE
the walls, and the space between the ice and the walls filled with
sawdust or other similar material; but this method of ice stor-
age is rapidly going out of use for anything except the smaller
purposes and, therefore, it is hardly worth while to discuss con-
crete ice house construction except for such small uses. Further
than this, there is no question but what small ice storage houses
will in future be built according to the modern idea of com-
plete insulation on side walls, floor and ceiling, rather than the
protective covering and filling between the ice and the walls as
in the days of old.
Concrete ice houses, if they ever become practical, struc-
turally and mechanically, are very many years in the future,
and it will be necessary to introduce some very greatly improved
design to make them commercially feasible. Concrete construc-
tion is all very well in its place, and concrete is a most useful
material when properly applied, but its application does not
belong to ice house construction at the present time except for
foundations only.
TIGHT LOFT FLOOR CONSTRUCTION.
The model ice house for creameries, plans and details of
which are shown elsewhere in this chapter, has the "tight loft
floor," which has within a few years been advocated by a few
of the more progressive ice men. A "tight loft floor" means
nothing more than an insulated ceiling, and the expression
"tight loft floor" is used by ice men for the reason that they
have been accustomed to a loft in their ice storage houses. A
loft is really unnecessary and if an ice house with a flat roof
were built, insulation could be applied right in the roof and no
loft would be necessary. An ice storage house insulated not
only in sidewalks and floor but insulated in the ceiling as well
has been advocated by the author for many years, and he was
the first one doubtless to use this construction. It is good com-
mon sense and saves money in construction as well as resulting
in the saving of ice meltage.
SUGGESTION FOR IMPROVED CONSTRUCTION.
The author having originated the so-called "tight loft
floor" construction referred to in the previous paragraph now
ICE STORAGE HOUSES 753
advocates the omitting entirely of the attic which is commonly
a part of an ice house. A flat roof with a pitch of not more than
a half inch to the foot can be made to support sufficient insu-
lation so that it is not necessary to have a space at the top of
the building such as is ordinarily contained between the attic
floor and the roof. It is entirely practicable to use sufficient
insulation in the roof to make up for the protection which the
attic ordinarily gives, and this is the construction commonly
employed and advocated by the author.
As a still further advance in the methods of storing ice,
both artificial and natural, the maintaining of temperatures in
the ice room below the freezing point so that no meltage occurs
is now suggested as wholly practicable and desirable. This is
especially true for natural ice where the cost is pretty high on
account of shipping by freight or for some other reason, and
where natural ice is cut from a pure source there is no reason
why it is not worthy of as good treatment and storage as arti-
ficial ice. The reader is referred to the chapter on "Ice Storage
Under Refrigeration."
CHAPTER XXXIX.
THE COOLING OF INHABITED BUILDINGS.
COOLING DWELLINGS IN THE TROPICS.
Much has been said on this subject, but comparatively
little has been actually done. This is not because the problem
is difficult of solution mechanically or practically, but rather
because the cooling of inhabited buildings has not been con-
sidered necessary up to the present time. In the tropics
it would be very desirable to cool buildings during a consider-
nble portion of the year, but in the temperate zone the over-
heated period consists, ordinarily, of only a few days or two
or three weeks at most, and up to the present stage of civiliza-
tion people have preferred to accustom themselves to the high
temperature as best they can and endure it, rather than make
the necessary outlay for artificial means of cooling.
At the Second International Congress of Refrigeration
held at Vienna in 1910 there were presented three different
papers on the subject of cooling inhabited buildings, and these
three papers were written from three different viewpoints. The
first by J. F. H. Koopman of Holland considered the problem
of the cooling of living rooms in the tropics, and his conclu-
sions are summed up under three headings as follows :
First : The wind pressure is greatest in the warmest hours
of the day.
Second: The differences between maximum day tempera-
ture and minimum night temperature are greater in the warm
months than in the cold months.
Third: The relative humidity of the air is least during
the warmest hours of the day.
Mr. Koopman concluded that for a sufficient and econo-
mical cooling of buildings in the tropics conditions were neces-
754
COOLING INHABITED BUILDINGS 7S5
sary which he outlined under several headings as follows : .
(a) The bililding must be faultlessly insulated in all
respects and provided with well-closed double windows and
doors (the latter with so-called air vents) .
(b) With the exception of the air inlets and outlets,
the house must be quite closed; thereby human health and
durability of furnishings will be safeguarded.
(c) Walls, floors, ceilings, as also ducts, should be of
stone of the greatest capacity for absorbing heat. This ma-
terial must not pollute the air.
(d) The storage ducts are placed on the ground floor,
or if there is not enough room there, or other reasons make it
necessary, in the attic.
(e) The airing during the day is aided by the wind, the
inflow openings being provided with pressure heads and the
outflow with suction heads.
(f) The ventilating plant should be so designed and
operated that there is a slight super-pressure in the rooms
during the day, so that no warm outer air can enter. Care
must also be taken that the air introduced into the rooms does
not deposit moisture.
(g) During the night the air is for the most part cir-
culated through the storer, and a small percentage only goes
through the building, so that not only cooling of rooms but
also walls is achieved, so that this second storing assists the
day cooling. The circulation of the night air is done by a
fan, but in special cases it can also be done by deflectors if
there is sufficient wind. The quantity of air passing through
a bedroom in one hour should not be more than six times
the contents of such room, to avoid unpleasant draughts.
(h) Where dry night air and clean water are available
evaporation of water should be employed in the ducts to in-
crease the storage. Here care must be taken that all water
sprayed in the ducts evaporates during the night, so that the
moistening of the day air may be avoided. For the same rea-
son the use of water during the day is objectionable.
(i) If one has cool, clean water, but not in sufficient
quantities for completely effecting the air cooling, such cool-
756 PRACTICAL COLD STORAGE
ing can be used additionally. A. moistening of the air will only
take place if the air be exceedingly dry, otherwise the cooling
of the air will generally be combined with a decrease of its
moisture.
Mr. Koopman may be congratulated on his summary of
the requirements, and these may be taken as covering the points
necessary to consider in the artificial cooling of inhabited
spaces. His suggestion that a building must be faultlessly
insulated and provided with well-closed double windows and
doors would, the author believes, hardly be required in the
north temperate zone. Besides faultlessly insulated does not
mean anything particular, and as a matter of fact, a com-
paratively simple and cheap form of insulation would answer
very nicely. Some of the larger buildings, in fact, need not
have insulation at all as ordinarily considered from a cold stor-
age standpoint. It is, however, positively necessary to see that
windows and doors are tight and kept closed, and that the
cooling or ventilating of the space be through suitable inlets
aud outlets. Mr. Koopman's section "c" is understandable
only when it is known that he proposes to store up some refrig-
erating effect in the stone walls, etc.
COOLING OF LIVING ROOMS IN AFRICA.
Mr. Bourgoin, a Naval Engineer, under the title of "Cool-
ing of Living Rooms in Africa" deals particularly with the
problem as it applies to the Soudan. His cooling scheme is by
the dripping of water over a material which gives it a large
surface, and the absorption of heat by evaporation is utilized
for the cooling of air, a fan being used to increase the cooling
effect. He also suggests the use of compressed air for cooling
as well as the use of ice and mechanical refrigeration. His
description is rather long and technical, but as he gives calcu-
lations showing energy expended and results obtained his paper
is useful for reference purposes.
COOLING OF STOCK EXCHANGE, NEW YORK.
Henry Torrance, Jr., of New York City, in a paper en-
titled "Refrigeration and Ventilation of Inhabited Places"
COOLING INHABITED BUILDINGS 7S7
gives a description of the absorption refrigerating plant in-
stalled by the Carbondale Machine Company for cooling the
large Board of Trade room of the New York Stock Exchange.
About 40,000 cu. ft. of air per minute was cooled by passing
it over brine pipes cooled by refrigerating machines. The
air is first cooled to about 60° F. and then warmed slightly to
about 15° below that of the outside atmosphere. The plant
is operated only as required by high temperature weather con-
ditions. The calculations show that the flow of heat into the
room amounts to only 54 tons of refrigeration per day, while
276 tons of refrigeration were required to obtain the necessary
result.
The magnitude of this installation is shown by the fol-
lowing data:
Size of room 1,240,000 cu. ft.
Temperature of room 75° to 78° F.
Outside conditions 85° — 85% Humidity-
Cubic feet fresh air blown in per minute 40,000 to 50,000
Maximum tonnage required to handle this work 276
Usual tonnage 200 to 220
Cubic feet in building per maximum ton 4,500
Square feet exposed area in building per maximum ton. . . .670
Humidity of room runs 60% to 70%
Condensed water running off pan below bunker coils
2,000 lbs. per hr.
OTHER INSTALLATIONS FOE COOLING LIVING SPACES.
Several other refrigerating installations have been made
for the cooling of telephone exchanges, schools, hospitals,
theaters, banks, office buildings, etc. These installations have
been described and their operation quite generally commented
on by the public press, but as before stated, people generally
are not as yet educated up to the desirability of artificial re-
frigeration of living rooms during the heated term. While
we all "swelter" and suffer with the heat more or less each
season it seems that this discomfort with its accompanying loss
of efficiency, is quickly forgotten as soon as the heated term
is past. Even those people who could well afiFord to make any
reasonable investment for a few days comfort each year do
not seem to be sufficiently interested to install the necessary ap-
paratus.
758 PRACTICAL COLD STORAGE
The cooling of school buildings and educational institu-
tions during the summer season has been suggested. Ordi-
narily students are given a vacation of three months or so dur-
ing the summer, as much on account of the difficulty of con-
centrating on the work in hand as because the vacation is real-
ly necessary. Some of our prominent educators after consid-
era.ble experience with special classes during "summer schools"
are advocating what is known as the "all the year round" plan
of education. Normal schools and colleges keep many of their
buildings in use during the summer quarter and much of the
best and most highly useful work is often done during this
period. If refrigeration could be applied to school rooms
during the extremely heated term students could work up to
their maximum efficiency and not exhaust their vitality, as
they do under unfavorable conditions of temperature and hu-
midity at the present time. There are enormous investments
in high school, college, normal schools and university build-
ings throughout the country, and it would really seem, that by
increasing this investment by a small amount the capacity
of these institutions for usefulness could be greatly increased,
and for the reasons outlined.
There is really nothing difficult about the problem of
cooling rooms to a comfortable and livable temperature during
weather when the temperature ranges above 80° F. It is a
simple engineering problem, and it depends purely on h&ving
the building or rooms suitably arranged to. start with and un-
derstanding the natural laws governing refrigeration. Most
aiiy well-grounded refrigerating engineer can cool any given
space to any temperature required and do it practically and
economically. It is only a question of giving him means to do
it with. Generally speaking it is impractical to take a building
as ordinarily constructed and refrigerate it with success. The
building should be designed with this in view. A prime requi-
site is that all doors and windows be kept closed during the
period of refrigeration. Ventilation must be supplied through
the means of cooling, and the Fan System is preferable in all
cases. We look for increased interest in this matter and it is
certainly only a question of time when all the better class build-
COOLING INHABITED BUILDINGS 759
ings will have means of cooling in hot weather as well as means
of heating in cold weather.
The author may be pardoned for enthusing over the propo-
sition for the reason that this comment is being dictated in an
office temperature of 100° F.
CHAPTER XL.
ACCOUNTING.
ESSENTIAL PEATUKES.
The essential feature is a record book in which entries
are made when goods are received, and when goods are deliv-
ered. The auxiliary books consist of an "In" receipt book on
which the original entry of delivery to the warehouse is made
and an "Out" receipt book on which the original delivery en-
try of goods going out is made. In addition there is a negotia-
ble warehouse receipt book. This simple set of books is sub-
ject to endless variation depending on the complication and
character of business handled, and these books it should be
borne in mind in no way form a part of a double entry sys-
tem of bookkeeping, but are purely books of memorandum
and record.
When goods are received at the warehouse for storage,
an "in" receipt is given showing date, lot, number, and, if
practicable, the room and section of house where stored. An
entry of this kind should give number of packages with their
weight if storage is charged by weight and any special marks
if necessary. Goods as received are commonly entered on the
left hand side of a double page in the storage record and as
delivered out are entered on the right hand side, and thus a
subtraction of the entries on the right hand page from the
entries on the left hand page will give the quantity of goods
of any particular mark, or lot number, or kind, in storage for
that particular account at any time.
Auxiliary books to the storage record consist of what may
be called an "In" receipt book on which is entered a tally of
the goods as above outlined, and from which the entries into
storage record are made. The "In" receipt book is common-
760
ACCOUNTING 761
ly in duplicate or possibly in triplicate and one copy is either
given to the drayman when the goods are delivered or mailed
to the owner. They are numbered consecutively and the num-
ber of the "In" receipt may conveniently correspond with the
lot number of the goods as they are received. If a customer
requires a negotiable warehouse receipt he may return the "In"
receipt as evidence that the goods were delivered by him to the
storage house and receive a negotiable receipt which carries
title to the goods in storage, a form of which is shown in Fig. 1.
The "Out" receipt book may be similar in form and ar-
rangement to the "In" receipt book, and is used essentially as
in the "In" receipt book only this book checks deliveries from
the house to the owners, and from the out receipt book entries
are made on the storage record book. When goods are deliv-
ered out, the person receiving them signs the "out" receipt
stub and takes one copy by which to check his load.
Charges for storage may be made on the storage record
and posted to the journal monthly, or charges may be made
and posted as goods go out. This is, however, a mere ques-
tion of arrangement between the cold storage house and the
owner of the goods. It is becoming more and more common
to render bills for storage each month, and it is really no more
than fair. The storage house, for instance, which stores eggs
chiefly, otherwise would have no income until the stock be-
gan to go out in the fall of the year.
The laws of the various states compel those who are do-
ing a storage business for others or what is known as a public
storage business to keep a storage record, and to have a printed
form of receipt, and as the perishable goods business is now
handled, a negotiable warehouse receipt is positively neces-
sary as goods in storage are used largely as collateral for bank
loans.
An important feature of handling goods for storage is to
mark them distinctly if they have not already a distinctive
mark and as a matter of safety it is better to number each lot
as received consecutively for the reason that the lot number
will then designate the time when stored, and in case pack-
ages should be used only once there would be no liability of
762 PRACTICAL COLD STORAGE
confusion. Should customers object to having the lot number
stamped directly on the package, tags may be attached and
lot number stamped on the tags. Positive identification of
every package of goods and its location in the house is a very
important feature of warehouse accounting.
The above gives in outline the simple requirements of
an accounting system for cold storage houses. There may be a
considerable variation from the details without omitting the
essentials. Some of the large houses use a card system ex-
clusively, while others have some such system as is employed
by the Milwaukee Cold Storage Co., Milwaukee, Wis., blanks
of which are shown herewith and which President John A.
Hill has outlined as follows:
On receipt of a consignment, receiving clerk fills in triplicating
blanks with date, name of owner, quantity and description of goods,
weight if necessary to show it, lot number, location in warehouse,
owner's marks, railroad car number, and his signature. The charge
bill No. 2, printed on yellow paper, and No. 3, printed on green paper,
are kept in receiving clerk's office, and original accompanies the
goods to storage room, where quantity is rechecked by "Jones," who
returns No. 1 to receiving clerk, who files all three copies in general
office. Here the charges are filled in, and the storage rate; then
No. 3 is given to teamster, if goods came in by wagon, or sent to
owner, as his receipt. The original, after entering the lot on the
storage record, is filed, and the yellow charge bill is entered on a
weekly statement, the total charges on weekly statement being taken
to ledger account. All charges on goods in and out for a week are
shown on the weekly statement, and vouchers for each item mailed
with the weekly statement.
On goods going out the general office fills in the date on white
triplicating sheets, also the quantity and description of goods, lot
number, location, owner's name and name of firm getting the goods,
if other than owner. The plain, unprinted and punched copy is
retained in general office in case of loss of others; the original and
No. 2 go to delivery clerk, who fills the order, and signs his name
to original under "checked." Teamster signs original "John Green,"
and takes No. 2 for his load check by owner. Original is returned
to general office, where time, rate and charges are filled in, and
amount entered on weekly statement. Delivery is charged oflf stock
record, completing the transaction.
This system works satisfactorily for our needs, but the No. 3
green sheet, which is the non-negotiable receipt, should be worded
to conform to the warehouse laws of the State where used.
ACCOUNTING FOR A COMBINED ICE MAKING AND COLD STORAGE
PLANT.
Combined ice making and cold storage plants are increas-
ing in number rapidly, and surely the ice plant is able to op-
ACCOUNTING
763
t10n«a« VOUOHIN.
o
^JK
MILWAUKEE COLD STORAGE CO.
n y, ^ .0.1 »...«,-! Milwaukee, wis., ^^^-^-190vir~
"^^ liiri^^q^
S:^ I /^^^,Ht_ ^
w
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il ^
-#
Slorig* ^O^ >.!^__ Chargod to y^^^^ff.^fRate Bftor that datu <-^~^ par (^^^ par monlh^
Fr,m MILWAUKEE COLD STORAGE CO,
•MSB.WSU..I Milwaukee, Wis.,.
W .J-''''o^^n^.^,..^(3^_
i^WtA.
~This B)1l )■ fgr Chargoa (flNcapt Msuraoce) on abov» Qooda-lo
MBTAIN THia TO eM«<
■TONAOI VOUCHER.
Received from
M_
MILWAUKEE COLD STORAGE CO. ^
»o.62R.,d.t«.t Milwaukee^ Wis,, H^^ ' 190-^=
"'^^a....^
^
^
^
icr
\-ah~>.
<:*")
AS
^-fTTat. •".' 'h.t dBlo.
j;C_P8r-^2^P«
"VdZZ.
FIG 1 — ORIGINAL, DUPLICATE AND TRIPLICATE FORM OF "IN"
RECEIPT BOOK.
764
PRACTICAL COLD STORAGE
rir'f^ „„v- MILWAUKEE COLD STORAGE CO.
^
^
*^-
Ac
'f.
v^
*A
v^
;^<r
fi^ns \
/
V
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(jkip
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/
-y
—T'JL.^^ '° ^— ' -^
ik-r Of^' "-m^.^
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WITHDRAWAL VOUOHCR
«»«..... Jg^==_„»c-MILWADKEE COLD STORAGE CO.
Thrs Copy ts to be taken
by Teamster, and retained
by owner to check current
.^
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^^
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«ri
(— <;j»o
"^'""°j2.2^c.j»e ™/i
%^9m.K^
^ 1
FIG. 2. — ORIGINAL, DUPLICATE AND TRIPLICATE FORM OF "OUT"
RECEIPT BOOK.
ACCOUNTING 765
erate a cold storage plant in connection at much lower cost than
an equipment of machinery operated for cold storage alone.
If the ice manufacturer could only know how much he is actu-
ally making out of his cold storage department, doubtless more
attention would be given to developing this end of the busi-
ness. The following from one of the author's most esteemed
friends will no doubt prove valuable to those who also "want
to know." While the method in finding cost of ice making is
doubtless subject to some correction for time of year, and
changing efficiency of machine, etc., yet no better way is ap-
parent, and a close approximation is so much better than the
methods of estimate and guess work commonly employed.
As you know, we operate ice-making plants, and in connection
therewith cold storage houses. When the cold storage end of the
business amounted to but little, it was our custom to credit in our
monthly cost sheets all the earnings of the cold storage houses to
ice making. This, at certain times of the year, made a considerable
reduction in the apparent cost of making ice, but it was perhaps a
good enough method of accounting until the cold storage business
grew to greater magnitude. But, as this was gradually taking place,
we became somewhat dissatisfied with the fluctuations shown in our
ice cost, due to the full amount of the cold storage earnings being
credited to the cost of ice making. We saw that this process was
giving us a somewhat fictitious cost for our ice, which, in months
when we were doing a heavy cold storage business was shown to be
much less than in other months when we were making just as much
ice, and under just as favorable conditions, excepting for these cold
storage earnings. While these earnings added to the profit of our
company, they had, beyond the actual cost of furnishing the refriger-
ation, nothing to do with the true cost of making ice.
;We then began to grope about for some method by which we
could make a proper charge for refrigeration, to our cold storage
department, this same item, the actual cost of the refrigeration only,
to be credited to ice making, and not any profit which there might be
in the cold storage, just as though it were owned by a separate con-
cern. We obtained from various sources what information we could
as to the generally accepted cost of refrigerating a given number of
cubic feet to certain temperatures. But, we imagined that our insula-
tion was perhaps better than the average, and that other conditions
with us might be so different from those prevailing in other plants
that we wished to have some rule based on our own experience which
would give us a proper charge for refrigeration to be made against
our cold storage houses, and a corresponding credit to be made to.
our ice-making department. It so happened that we were able to
operate at ice making alone, during months when there was practi-
cally nothing in our cold storage houses. In this way, we obtained
the cost of fuel when we were running at different speeds. Let us
say, for example, that we found we spent so much for fuel when we
were making half our capacity of ice, and so much, when we were
making our full capacity of ice. This also gave us the fuel cost per
ton of ice made under these different conditions. Then, in months
766 PRACTICAL COLD STORAGE
when we were doing work in the cold storage department, whether
we were making much ice or not, we took the amount of fuel con-
sumed, and compared this with the amount used in one of such
months as described above. In this way, we take the quantity of fuel
consumed and say that this quantity would have made, upon the
ratios determined as above, so many tons of ice. Then, we find that
we did make so many tons during the month. And hence, the equiva-
lent of the balance, in tons of ice, at the cost price shown for the
month, is the charge which we set up against the cold storage depart-
ment for refrigeration. This amount is credited to ice making, by
our cost sheet showing that we made the number of tons actually
produced, and that the equivalent of the number of tons arrived at as
above, was furnished the cold storage department in refrigeration.
This number of tons is added to the amount actually produced, and
then this total is divided into the sum expended in operating the ice
department. This department thus gets credit for the refrigeration
furnished the cold storage, and that department only pays actual cost
for this refrigeration.
We also have separated our investment in cold storage buildings,
and land occupied thereby, from the investment items shown for our
factory, and we keep a separate record for all items of insurance,
interest, taxes, depreciation, repairs, and labor for these two depart-
ments, so that each has its own system of accounting, just as though
operated by different owners. This seems to us to give an accurate
and fair charge based upon our own actual experience month after
month, and not upon a theoretical rule as to the cost of refrigeration,
even though that may have been made after long experience, in many
plants operating under varying conditions.
In these days of modern accounting, other managers of ice
making and cold storage plants may have been confronted by this
same problem, and I am giving you the above for what it may be
worth to these men.
CHAPTER XLI
THERMOMETERS.
HISTORICAL.
Correct temperatures being the most important matter to
be considered in the successful refrigeration of perishable goods,
it follows that some accurate instrument must be used for meas-
uring same. The common instrument in use is called a ther-
mometer. The word thermometer is of Greek derivation and
means a measure for heat. This instrument is constructed on
the well-known principle that heat expands all bodies. After
Fahrenheit, the name which our common thermometer bears,
and who was a native of Dantzig, failed in business, he turned
his attention to mechanics and chemistry.
He began a series of experiments for the production of
the thermometer. And it is owing to his determination to
succeed, and to his loyalty to the conviction that he must give
to the world the instrument which has proved so serviceable
to mankind, that we are enabled to have a definite way of speak-
ing of hot, or very hot ; cold, or very cold. For his first instru-
ment, Fahrenheit used alcohol. But before long he became
convinced that a more suitable article to use in the glass tube
was the semi-solid mercury. By this time, about the year 1720,
Fahrenheit had moved from Dantzig to Amsterdam. And
here, in the capital city of Holland, he made the mercury ther-
mometer.
The basis of Fahrenheit's plan was this: To mark on the
tube the two points respectively at which water is congealed
and boiled, and graduate the space between. He commenced
with an arbitrary marking, beginning with 32 degrees, because
he found that the mercury descended 32 degrees before coming
to what he thought the extreme cold resulting from a mixture
767
768 PRACTICAL COLD STORAGE
of ice, water and sal ammoniac. In 1724 he published a dis-
tinct treatise on the conclusions that had resulted therefrom.
Not long afterwards, Celsus, a Swedish scientist, produced
the centigrade thermometer, which suggested the graduation
of 100 degrees between the freezing and boiling point. Reau-
mur, a French scientist, also proposed another graduation, and
one which has been accepted by the French.
The mercury thermometer graduated to the Fahrenheit
scale, with the freezing point of water at 32° F., is the most
common, and, in fact, practically the only instrument in use
in America. The accuracy of some of the cheaper thermome-
ters cannot be depended upon. The ordinary cheap thermom-
eter where the figures are stamped on the scale and with gradu-
ations separate from the stem are inaccurate sometimes to the
extent of five degrees to ten degrees. It does not pay to use
cheap thermometers for cold storage purposes. Often those
given as advertising matter are in use, and some years ago an
eastern firm sent out a large number of such thermometers as
prizes. One of these was used for reading outside weather tem-
peratures. It was finally discovered that the readings were
more than twenty degrees out of the way. This is exception-
ally bad, but it is frequently the case that the thermometers are
two, three or four degrees incorrect, and, in fact, the greater
part of the common thermometers are two or three degrees or
more off. Of course, where a number of thermometers are in
use, it is not probable that any one of them could be very
much off without it being found out, and it is easy to hang them
all in one room and make a comparison. On receiving a new
lot of thermometers it is a good scheme to hang them up side
by side in the cold storage room with a thermometer which
has been in use and known to be fairly accurate. Then if any
one of the new thermometers is incorrect it may be returned to
the manufacturer. Thermometers are not expensive, even
the high-class ones. At a cost of from $15 to $24 per dozen, spe-
cial cold storage thermometers graduated, say, from zero to 70°
F., may be obtained. The best ones have the graduations
(scaled to read to one-half of a degree) etched on the stem and
the figures on a metal or enamel scale. In this way, if they
THERMOMETERS
769
are correct when tested they cannot become materially incor-
rect without being broken. These thermometers cost more
than those which are not etched on the stem, but are more
reliable. It is important that a thermometer for cold storage
rooms should be graduated with one-half degree marks. Then
a slight variation in temperature may be quickly noticed; Some
gi?
Soiling
UfiO. 'point of
%vater
Jl67
U77
m-
-point of
v/aler
-18
JO-
-M.-*
Free-zin^
=2^-point of
mercury
Cenl'i^nide f^hrenheil I^BOumur
PIG. 1. — COMPARISON OF CENTIGRADE, FAHRENHEIT AND
REAUMUR.
thermometers are only graduated on one-degree or two-degree
divisions, in which case it is difficult to notice a variation of
less than one-half a degree to one degree. It is a good plan to
gather up thermometers not in use and have one certain place
for hanging them in a cold storage room. Then they may be
compared, and if any of them are injured or inaccurate from
770 PRACTICAL COLD STORAGE
any cause it will be discovered. It is a good plan to make such
comparison once each year, perhaps in the winter or when few
goods are in storage.
COMPARISON OF CENTIGRADE, FAHRENHEIT AND REAUMUR
°C. to °R., multiply by 4 and divide by 5.
°C. to °F., multiply by 9, divide by 5, then add 32.
°R. to °C., multiply by 5 and divide by 4.
°R. to °F., multiply by 9, divide by 4, then add 32.
°F. to °R., first subtract 32, then multiply by 4 and
divide by 9.
°F. to °C., first subtract 32, then, multiply by 5 and
divide by 9.
On the Fahrenheit thermometer, the freezing point is
32 degrees above zero, while on the Centigrade thermometer the
freezing point is at zero. The size of the degree on the Fahren-
heit instrument is smaller than on the Centigrade, the boiling
point of water being represented by 212 degrees on the former
as compared with 100 on the latter. Thus it will be seen that
on the Centigrade thermometer the difference between the
freezing and boiling points is 100 degrees, while on the Fahren-
heit thermometer it is 180 degrees, or the difference between
32 and 212.
A Fahrenheit degree is only five-ninths of a Centigrade
degree, and accordingly a degree of the latter is nine-fifths or
one and four-fifths times the size of a Fahrenheit degree.
In working out the temperature in terms of the Centigrade
thermometer, assuming that the Fahrenheit thermometer reg-
istered 32 degrees below zero, it would first be necessary to add
the 32 degrees below zero to the 32 degrees above zero, because
the freezing point starts at 32, and the sum would be 64 de-
grees. As a Fahrenheit degree is only five-ninths the size of a
Centigrade degree, 64 should be divided by nine, giving a
result of 7.11, which, multiplied by five, would give 35.55, the
number of degrees below zero on the Centigrade thermometer.
THERMOMETERS 771
THERMOMETER SCALES COMPARED.
On page 769 a diagram is shown with the thermometer
scales in common use compared. The Fahrenheit scale is used
most exclusively in America, while the Reaumur and Centi-
grade scales are in common use in foreign countries. The freez-
ing and boiling point of each are made to show the figure used
at these points, and thus a rough comparison may be made.
CONVERSION OP THERMOMETER DEGREES.
c.
F.
R.
10
50.0
8.0
9
48.2
7.2
8
46.4
6.4
7
44.6
5.8
6
42.8
4.8
5
41.0
4.0
4
39.2
3.2
3
37.4
2.4
2
35.6
1.6
1
33.8
0.8
Zero
32.0
Zero
— 1
30.2
0.8
2
28.4
1.6
' 3
26.6
2.4
4
24.8
3.2
5
23.0
4.0
6
21.2
4.8
7
19.4
5.6
8
17.6
6.4
9
15.8
7.2
10
14.0
8.0
11
12.2
8.8
12
10.4
9.6
13
8.6
10.4
14
6.8
11.2
15
5.0
12.0
16
3.2
12.8
17
1.4
13.6
18
0.4
14.4
19
2.2
15.2
772
PRACTICAL COLD STORAGE
RECORDING THERMOMETER.
The recording thermometer has come into use rapidly
during the past few years, and has a useful purpose in many
places. For the private cold storage plant which is equipped
with a perfect system of refrigeration in which the temperature
is closelv under control, it is a matter of great satisfaction to the
FIG. 2.— SELF-CONTAINED TYPE RECORDING THERMOMETER.
owner to make a record of the perfect temi^eratures produced
and maintained. For the concern or man who depends on
hired assistants or engineers to run the plant and control the
temperatures, a record of the work done is almost a necessity.
For the plant doing a public cold storage business, and where
THERMOMETERS Hi
a mere clerical, or watchman record is liable to be questioned
by dissatisfied customers, a continuous record by a recording
thermometer sets all doubt at rest, and may prove useful in a
court of law.
There are various styles and makes of recording thermome-
ters on the market, and the illustration shows that known as
the Self-Contained Type Columbia Recording Thermometer.
A chart graduated from 10 degrees below zero to 50 de-
grees F. above zero might be used for freezers, and one gradu-
ated from 20 degrees F. above to 70 degrees F. above zero for
high-temperature cold storage rooms. An instrument making
one revolution in seven days would be preferable, although one
making a revolution in twenty-four hours might be used if it
could be given close attention.
A type of recording thermometer known as the "Distance
Reading Thermometer" cata be applied where the dial may be
located at any reasonable distance from the space in which the
temperature is desired to be recorded. Flexible steel tubing is
used for making the connection.
CHAPTER XLII.
MISCELLANEOUS.
INTRODUCTORY.
The following miscellaneous information and facts bear-
ing on cold storage matters is added here in the form of notes
or paragraphs for the reason that a larger part of it cannot be
properly classified under the regular chapter headings of the
balance of the book. The various products which are placed
in cold storage and treated here in a brief manner are not gen-
erally as important as those which are treated under the various
chapter headings. No doubt, as the business is developed, many
of the products here mentioned will become more genera:lly im-
portant and the information obtainable will be sufficiently in
detail so that they may be treated as a separate chapter. There
are many products not mentioned in detail which are given in
the alphabetical list of correct temperatures for cold storage.
RURAL SITE FOR COLD STORE.
The advantages of a location somewhat remote from the
large cities as the site of a cold storage house for perishable
products, especially the more sensitive, like butter and eggs, is
well known, and it is the author's opinion that the tendency is
more and more toward the establishment of storages for the
greater bulk of products and perishable goods in the country at
or near the locality where produced. The pure country atmos-
phere is far better than the gaseous and comparatively polluted
air of our large cities. This is especially true during cool or
cold weather when the purifying effect of the refrigerating sur-
faces is very small or entirely absent. It has been remarked to
the author by a prominent produce dealer that eggs and butter
would keep better in cold storage in the air where they were
774
MISCELLANEOUS 775
produced than they would if shipped to a distance and stored
in a different atmosphere. There is considerable question about
this but there seems to be no question whatever about the ad-
vantage of a rural location for the perfect keeping of perishable
goods.
Further than this operating expenses will be less, and
goods will be much fresher and in more perfect condition for
storage when delivered at the storage house. The owner also
has the advantage of being able to ship to the market where
the best price is to be had, and the goods are at all times under
his oversight and control.
SHAVINGS AND SAWDUST AS INSULATION.
The comparative value of sawdust and mill shavings for
insulation purposes has been a much discussed problem among
cold storage men. Thoroughly dry sawdust is beyond doubt a
better insulator than mill shavings, but thoroughly dry sawdust
is practically out of the question in anything like sufficient
quantity to make it a commercial practicability. The greater
part of the sawdust available is wet or green just as it comes
from the mills, sawed generally from wet logs from the water.
Mill shavings on the contrary are generally fairly dry, being
taken from the surface of the lumber which dries out very
quickly after being sawed. Mill shavings though partially
green or damp are far better to use than sawdust which is even
slightly so. If shavings are thoroughly rammed into the wall
they will not settle down in drying out, as they are elastic and
will hold their place. Sawdust on the contrary cannot be
packed sufficiently tight so that it will not settle down when it
dries out, leaving open spaces in the insulated wall. Dry saw-
dust, in case it becomes wet or damp from any cause, at any
time after it is placed in the wall, is liable to heat or ferment
and disintegrate or dry rot, and so lose its insulating value.
Baled mill shavings which are received in a damp condition
may be much improved by shaking out the bales and allowing
them to lie exposed to a free circulation of air. Stirring them
occasionally will also facilitate the drying process. They also
may be kiln dried without opening the bales if facilities are
776 PRACTICAL COLD STORAGE
available. (Chapter on "Insulation" gives some further infor-
mation.)
PAINTING METAL SURFACES.
The question as to whether it is advisable to paint gal-
vanized iron piping, galvanized iron tanks and other iron and
steel surfaces, whether galvanized or not, is one which comes
up very often in cold storage practice. In many cases it is not
advisable to paint, as it is cheaper to renew the piping, etc., than
it is to go to the expense of painting periodically. In other
cases it is a positive detriment to paint piping in a cold storage
room. An odor may be created which cannot be easily re-
moved.
Whether or not it is advisable to paint metal surfaces de-
pends a great deal on whether they are readily accessible and
easily cleaned or not. Good galvanized surfaces should stand
well without painting and this is one of the reasons why gal-
vanized surfaces are used instead of black. For painting metal
surfaces use nothing but the very best obtainable preparations.
A number of these are on the market and sold at a reasonable
price. A good homemade paint may be prepared from red lead
and boiled linseed oil. It will require about twenty-five pounds
of dry lead to a gallon of oil. A pound of lamp black to each
twenty-five pounds of lead will give a rich dark brown color
which is more agreeable than the natural color of the red lead.
(See also chapter on "Keeping Cold Stores Clean.")
DEODORIZING COLD STORAGE ROOM.
Questions are frequently asked the author in regard to
properly deodorizing cold storage rooms which have been used
for the storage of vegetables, fruit, etc., so as to make them suit-
able for the storage of sensitive products like butter, eggs, etc.
In some cases it is possible to do so, in others not. If rooms
have been used for some years for some strong-smelling product
and have not been properly aired out, whitewashed, etc., it is
hardly possible to disinfect them sufficiently to make them
available for the storage of eggs or butter. Thorough venti-
lating and whitewashing will do a great deal, however, to im-
MISCELLANEOUS m
prove rooms in a bad condition. (See chapter on "Keeping
Cold Stores Clean.")
WHITEWASHING.
Whether or not it is necessary to whitewash cold storage
rooms each year is a problem which comes up very often. The
most thoroughgoing cold storage manager insists that rooms
which are used for the storage of eggs must be whitewashed
every year while the rooms are empty, and the author recom-
mends that it is a very good practice to whitewash all other
rooms yearly as well as egg rooms. It is perhaps not absolutely
necessary but if a rule is established of yearly whitewashing it
will be attended to, whereas if it is understood that it is only
necessary to whitewash occasionally, the rooms may not be
whitewashed for several years, or possibly riot at all. The ex-
pense is comparatively small and the work is usually done at a
time of year when there is very little for the help to do in the
regular line of business. Practically speaking the cost of white-
wash is nothing, and it is a sort of insurance against must and
mold. It will not absolutely prevent must and mold, but if
carefully done it will at least demonstrate the fact that these
troubles are not caused by the bad condition of the interior
wood work of the room itself.
HUMIDITY.
The influence of a large or small quantity of goods stored
in a given space on the humidity of such space is not generally
considered or understood. The pipes which cool a storage room
act as moisture absorbing surfaces. These moisture absorbing
surfaces are constantly in action, as it requires the same amount
of refrigeration to maintain the temperature of an empty room
as it does a room which is filled with goods. If a room is only
partly filled with eggs, for instance, the humidity of such a
room will be much lower (i. e. much less moist) than would be
the same room filled to its capacity. This point is of no conse-
quence where there is no attempt to regulate humidity, but in a
modern and progressive plant these things should be watched
closely. A room partly filled with eggs and carried through the
778 PRACTICAL COLD STORAGE
season will certainly turn out shrunken or evaporated eggs as
compared with a similar room which is carried through the sea-
son filled to its capacity. Owing to the fact that a room filled
with goods will be much more moist than one only partly filled,
in some cases where circulation is imperfect this will lead to
must or mold. A complete and thorough system of air circula-
tion makes the control of conditions of cold storage rooms very
simple. Such a room may be filled with goods just as full as
possible without any bad effect resulting.
SPACE REQUIRED FOR STORING VARIOUS PKODUCTS.
In estimating the storage capacity of a cold storage room
or house it is frequently convenient to know the space required
by different products. The following is given as the author's
personal experience : A sixty-pound tub of butter will require
about 2% cubic feet of space; a case of eggs containing thirty
dozen requires about 3 cubic feet of space ; a sixty pound box of
cheese requires about 2 cubic feet and a three-bushel barrel of
apples from 8 to 10 cubic feet. These figures allow a reasonable
margin for what is known as "piling alleys;" that is, space
leading from the door back through the piles of goods so that
different lots may be accessible. The actual cubic space re-
quired therefore is somewhat less than the figures given. These
figures have, however, been found in actual practice to work out
quite closely. The space required by any particular product
may be ascertained by finding the cubic space required for
each package and adding thereto from 15 per cent to 25 per
cent. In making such calculation it is necessary to figure the
actual space occupied by each package as it will be placed in
stowing in the house. It is perhaps unnecessary to state that
the capacity of a given room depends greatly on how carefully
the goods are piled. The careless man may waste a large
amount of space which might be saved by careful work.
TRUCKS FOR HANDLING GOODS FOR STORAGE.
The correct method of handling goods, when delivered by
car or by wagon at the platform, into the storage rooms, and
again from the storage rooms to the car or wagon and platform,
appears to be a simple matter; nevertheless, there is a vast
MISCELLANEOUS 779
amount of valuable time wasted by not adopting the most prac-
ticable and labor-saving method. In smaller plants a hand
truck with two wheels on which may be handled three or four
tubs of butter or cases of eggs is best adapted to the work pro-
viding the distance which is to be covered is not too great. These
hand trucks are very convenient for the handling of small loads
even in comparatively large plants, and therefore should be pro-
vided even where the larger trucks are generally used. In com-
paratively small plants a four-wheel truck 30 inches wide and
5I/2 feet long is the most convenient means of handling goods
in and out of the storage room. A truck of this size is all that
one man can conveniently handle when it is fully loaded with
goods. In larger plants a wider and somewhat longer truck
may be used, in which case it is necessary that the doors and
corridors be proportioned wider to allow proper turning of
same. The four-wheel trucks are generally of two types. One
with two large wheels about in the center and a smaller wheel
or caster at either end, and another kind with two large wheels
a short distance from one end and two castors at the other end.
If there are inclines which must be traveled this latter type is
by far the best and they are now generally used. Trucks should
be provided with a hand rail at one end only. For hand trucks
the regular cheese truck of a somewhat modified type is the
most convenient, as boxes, barrels, tubs and cases may be read-
ily handled on same. The foot of a cheese truck is generally
half round. By special order these can be made square and
should be placed at such an angle with the frame that the truck
will stand up without leaning against anything when not in use.
STOWING GOODS IN COLD STOEAGB.
In piling goods in the refrigerated room there are two ob-
jects which should be borne in mind. The goods must be so
stacked or piled that they may be subjected to the best possible
conditions, and they must be so stacked or stored that they
will occupy the least room consistent with the keeping of them
in good condition. It is also desirable to handle goods in such
a way that they may be easily stored and quickly removed as
they are wanted. It is, however, hardly necessary to speak of
this especially as most warehouse foremen will see to it with-
780 PRACTICAL COLD STORAGE
out being told, that he does not do any more work than is neces-
sary in getting the goods in and out. He is much more likely •
to sacrifice his space unnecessarily, or carelessly pile goods, so
that they may be injured while in storage.
Goods may be materially injured by piling to a great
height without properly providing for sustaining the weight
which tends to crush the lower tiers, or by piling goods so
closely in a compact mass that the air cannot circulate between
and around the packages. A familiar instance of damage from
crushing will be seen in almost every warehouse when apples
are being removed in the spring of the year. If apples are piled
more than five or six tiers in height they should be piled one
barrel directly above another with a 2 x 4 inch strip on each
end between each tier so that the weight of the upper tier of
barrels is supported on the heads of the barrels and not on the
center or bilge. Damage from too close piling often occurs
when eggs are stored without placing strips between the cases
and leaving spaces on the sides and ends. Directions for each
separate product cannot very well be given here, but by bearing
in mind the principle which makes it necessary to pile goods
so that the air may circulate freely, the cold storage manager
can determine for himself what is necessary in connection with
the particular product he is handling. Goods like eggs, cheese,
apples, oranges, or any products which give off moisture, must
not be piled closely. If such goods are piled so that the air
cannot circulate freely through them they are liable to become
moldy and musty from the collection of moisture in the centre
of the pile. On the other hand goods like butter, canned fruit,
dried fruit, etc., cannot be piled too closely, as these goods do
not give off moisture or at least it is not necessary that they
give off moisture in order that they be preserved properly. The
same is true of the greater proportion of goods which are
actually frozen, like poultry, fish, etc. Where carefully kept,
as much as possible, from contact with air the better the results,
generally speaking.
What is said above will make it clear to the reader why
a forced circulation of air is better than a gravity circulation,
both as regards economy of space in storing goods and the best
results obtainable. The chapter on "Air Circulation in Cold
Stores" treats this subject thoroughly.
MISCELLANEOUS 781
REMOVING GOODS PROM STORAGE.
The reasons for the sweating of goods when removed from
cold storage to the comparatively warmer outside atmosphere
are not generally understood. This phenomenon is caused by
a condensation of the moisture on the cold surface of the goods
and may be prevented by protecting them from direct contact
with the warm outside air. A method which has been used
with success is to pile the goods closely on the receiving room
floor and cover them tightly sides and top with a tarpaulin or
heavy canvas like a wagon cover. It will take somewhat longer
for the goods to acquire the temperature of the outer air but
they may be warmed in this way without sweating. In ex-
tremely warm weather it may take thirty-six hours or possibly
forty-eight hours, but in comparatively cool weather, if goods
are removed at night and covered in this way, they may be
ready for delivery the next morning. This method of hand-
ling is only possible where sufficient notice may be had in ad-
vance and is particularly useful for the removing of eggs from
cold storage during a warm spell in summer or early fall. This
method of treatment prevents the depositing of moisture or
"sweating" and the goods are warmed more slowly, which aids
greatly in their preservation. Those who operate their own
cold storage plant in connection with the produce business will
find this method very useful and beneficial as they can gen-
erally anticipate their needs. For the removing of eggs before
candling it is especially desirable, as it always musses and soils
the eggs to handle them while damp, to say nothing of the
actual damage to the quality likely to occur.
SLOW COOLING OP GOODS FOE COLD STORAGE.
Economy of cooling goods which are to be stored at low
temperatures, by stages, is not perhaps well understood. Take
for instance: Butter which is now sometimes stored at zero
and below. It is not only far more economical but it is better
for the goods to cool gradually than to place them immediately
in the room which is carried at the extremely low temperature
of zero. If a temporary cooling room at a temperature of say
25° to 35° F. be provided, where the butter could be run in
782 PRACTICAL COLD STORAGE
temporarily before placing in the sharp freezer, it would be
easier to maintain a low temperature in the freezer and at the
same time result in a better carry in the stored goods. It also
makes it unnecessary to provide a large amount of piping in
the permanent sharp freezing room. What is said here cannot
be applied to poultry or other goods which deteriorate rapidly
if not frozen. Poultry, for instance, as generally frozen in the
large cities, is sometimes from one to two weeks killed before it
is finally placed in storage. Under these conditions it is neces-
sary to freeze as quickly as possible. Any product, however,
which does not deteriorate rapidly is kept better, when cooled
slowly when placed in storage and warmed slowly when re-
moved from storage, than the reverse. Some storage people
have an idea that if goods are frozen quickly the original flavor
and aroma will be preserved, which, if the goods are thawed
slowly, will be better retained than if cooled or frozen by stages.
This idea is erroneous so far as it applies to any goods known
to the author.
STORING VARIOUS PRODUCTS IN THE SAME ROOM.
There is a strong temptation in the comparatively small
cold storage plant, say, for instance, one which is operated in
connection with an ice factory, and where one or two or a few
rooms at the most are available, to store several different prod-
ucts in the same room. This is in fact done as a matter of reg-
ular practice and is one of the reasons why the small auxiliary
cold storage plant is not considered a success. Satisfaction can-
not be given the owners of a miscellaneous line of goods which
are all stored together and at the same temperature. There are
but few classes of goods which may be successfully stored in the
same room and at the same temperature for comparatively long
periods with good results. For instance: Butter requires a
lower temperature than cheese, and fruit and vegetables a
higher temperature than cheese, so they cannot be successfully
stored in the same compartment for any length of time. Gen-
erally speaking, each product should be stored by itself, but for
short periods of a few days, it is customary to use a room for
the storage of several different products like cheese, butter,
fruits, eggs, etc. If a small quantity of eggs or butter is stored
MISCELLANEOUS 783
in a room with a large quantity of fruit and vegetables they are
very likely to absorb an odor within a very few days. Nothing
definite, of course, can be stated in this respect, as conditions
vary widely, especially as to ventilation. For anything like
regular cold storage purposes it is not. only advisable but almost
absolutely necessary to provide different rooms for different
products. This, however, may be qualified to some extent by
storing fruit and vegetables together under favorable condi-
tions. Dried fruits, nuts, flour, etc., known as grocers' sundries,
are also stored in the same room at a temperature varying usu-
ally from 35° to 45° F. Any temperature under 45° F. will
keep them in fair condition. See proper heading for tempera-
ture at which to store various goods.
MOLD IN COOLING ROOM.
Troubles from mold forming on the walls or ceiling of
meat rooms or other small temporary storage rooms which are
used by retailers and others is quite frequent. This is caused
in a large number of cases by a lack of circulation of air in the
room ; by improperly locating the ice bunker or cooling pipes ;
or by improperly locating a door, or the excessive opening
of same. ( Mold always results from a surplus of moisture and
comparatively high temperature. ] If the circulation is inferior
the air near the ceiling of the room becomes charged with
moisture and this may be deposited on the ceiling or side walls.
This will quickly cause a growth of mold. If a door is left
standing open in warm humid weather the warm air rises to
the ceiling of the room and is condensed thereon. This also
causes mold. If the cooling surfaces and the door into the
room are properly located with reference to each other, the
warm air which comes in when the door is opened will come
in contact first with the cooling surfaces. Mold which has
formed may be removed by wiping with a damp cloth. Small
retail rooms may be whitewashed, or if it is desirable to wash
them out frequently, shellac finish is best.
STORING EGGS AND LEMONS.
It is absolutely unsafe to store eggs and lemons in the same
building. This has been done in a few cases without damage
784 PRACTICAL COLD STORAGE
to the eggs, but it cannot be recommended for the reason that
some heavy losses have been sustained from the eggs becoming
flavored with the odor of lemon. Eggs which have become
flavored even slightly with this odor are almost unsalable and
will not be taken by the best class of trade. Oranges as well
as lemons will cause this trouble. The citrous fruits, as they
are called, after being in storage for some length of time give
off a gas which is very penetrating. It has even been claimed
that this gas would penetrate a solid brick wall. This is hardly
probable, but the fact remains that it is very dangerous to store
citrous fruit in the same building with sensitive goods like
butter and eggs. The best large houses have separate buildings
detached from their main building, for the storage of citrous
fruits and other odorous products, and the first-class smaller
houses have rooms independent of their main building. In the
designing of houses for the handling of general products in-
cluding fruits, etc., the author recommends, and in his regular
practice plans to have, a room of this character which is en-
tered from a separate outside entrance. The room may pos-
sibly be in the same building but it is better to erect it as an
addition to the main building.
STORING VEGETABLES IN CELLARS.
Vegetables are not usually placed in cold storage, but bet-
ter results may be obtained from cold storing than by storing
in the old fashioned way in the cellar. A few notes on cellar
storage, however, are here given as a matter of general informa-
tion. A suitable cellar for the storage of vegetables during
winter must be clean and should either have a cement floor or a
clean sand floor. It should have a few openings to the outside
atmosphere which are provided with curtains to exclude the
light. The correct temperature for most vegetables is a few
degrees above the freezing point, say from 35° to 40° F. It is
very difficult or impossible to regulate the humidity of a cellar.
It should not be damp so as to promote mold, neither should it
be so dry as to cause a drying out and shrinkage of the stored
products. If the cellar is damp it is well to use a pail or two
of lime, which must be renewed from time to time or as soon
as it absorbs moisture enough to make it fine and powdery.
MISCELLANEOUS 785
The lime will not only absorb dampness, but it will absorb the
unpleasant odors and purify the air in the cellar. A cellar
should be ventilated from time to time during the winter, as
the outside temperature will permit. Too much ventilation
will destroy the flavor of vegetables and cause them to dry out
and shrivel. This, however, applies more to ventilation during
cold weather and is not true to as great an extent during the
fall or spring. A ventilator extending from the floor of the
cellar to a few feet above the ground outside is sometimes used,
but such an arrangement is more or less inoperative and it is
better to depend on the opening of windows as opportunity pre-
sents itself.
Do not store vegetables in too large bulk. It is also best
to keep each variety by itself. They should be well matured
and gathered before they are chilled or frozen. If gathered
on a warm day, allow them to cool before placing in the cellar.
Onions and potatoes are best stored on shelves or in bins. Pump-
kins and squashes require more air and must be kept dryer than
the softer vegetables like carrots, turnips, beets, etc. Onions
keep best without removing the tops. Pumpkins and squashes
should be placed on a shelf near the top of the room and should
not touch each other. Inspect them frequently, and when one
becomes soft it can be used or removed.
Cabbage may be wrapped in newspaper, packed in barrels
and stored in the coolest part of the cellar. If it is desired to
keep potatoes, beets, carrots, turnips, etc., for late spring use
pack them closely in boxes or barrels, fill in between and cover
with sand or garden soil.
CABBAGE IN COLD STORAGE.
For the best results in the cold storage of cabbage, they
should be grown especially for this purpose. Late planted cab-
bage, which barely close the heads before frost, keeps much
better than early cabbage. The "Holland Seed" variety is
known to be very satisfactory as a good keeper. It is essential
that only good firm heads be accepted for storage. It is desir-
able that the cabbage be "trimmed" before storing about in the
same manner as is required for shipping to market. The cab-
bage should be either packed in crates not more than 2% feet
786 PRACTICAL COLD STORAGE
in height or they should be piled on racks spaced about this
distance apart. A fair circulation of air is necessary to the
best results. Racks are easily constructed by erecting upright
sides, placing cross pieces six inches wide horizontally on cleats.
The cross pieces should only be close enough together to pre-
vent the cabbage from dropping through. The racks may be
of any width and height when constructed in this way, and it
is customary to allow two or three tiers of cabbage to rest on
each set of cross pieces. A thickness of 3 to 4 feet of cabbage
would not be objectionable if a thorough system of air circu-
lation is installed.
Owing to the fact that cabbages are composed largely of
water and are of a porous nature, it is necessary to provide a
good circulation of air throughout the storage room and ample
moisture absorbing surfaces. This may be done by the use of
chloride of calcium in cold weather. Ventilating the room by
introducing outside air will prevent an undue accumulation of
moisture and gases. Care must be taken in ventilating in this
way to prevent freezing the goods by admitting air which is
too cold or by causing dampness or too high a temperature by
letting in warm air. A fan system of air circulation and a
thorough ventilating system is very desirable, and the best re-
sults cannot be obtained without them. (See chapter on "Air
Circulation and Ventilation.")
It has been found that a temperature of 31° F. will pro-
duce the best results in cold storing cabbages, 32° to 36° F.,
however, have been used with success, but if the higher tem-
peratures are employed it is especially necessary to hold them
reasonably steady and uniform in all parts of the room. Un-
der favorable storing conditions, and when stored in a well
equipped house, cabbages may be carried from fall until spring
with a shrinkage of not more than 5 to 10 per cent, which is
practically nothing as compared with the shrinkage experi-
enced when storing in the old style frost-proof house without
refrigeration.
COLD STORAGE OF ONIONS.
This vegetable may be successfully cold stored for long
periods, and if carefully harvested and properly cared for prior
to being placed in the cold storage room, they may be taken out
MISCELLANEOUS 787
of storage in good condition as late as May or June following
the season of production. It is best not to store in large bulk,
but rather in trays, or crates, or racks, so that the air may cir-
culate freely. A temperature of 32° F. is thought best for the
storage of onions and the room should be only moderately dry.
Onions do not freeze easily and require a temperature several
degrees below the freezing point of water (32° F.) to materially
injure them, providing they are thawed slowly. In some cases
onions have been stored where they have been purposely frozen
so as to keep them in better condition, but this practice is not
recommended, as better results are obtainable by keeping a uni-
form temperature in cold storage.
COLD STORAGE OF CELERY.
The storage of celery varies a great deal in different places.
In some of the large cities celery is kept in storage the year
round. Generally, however, celery is stored early in the fall or
on maturity of the plant, and the goods are not placed in stor-
age until the ground freezes in the fall. A temperature of as
near the freezing point as possible is recommended. Celery
storage rooms are usually held at from 32° to 34° F. The
keeping qualities vary with the different varieties and condi-
tion of the goods. Hardy varieties and "green top" keep well
for three months or possibly more. Some of the varieties will
not keep longer than from one to two months. Celery after
being trimmed, or what is known as "dressed goods," will not
keep for any length of time. A few days only being about the
limit.
COLD STORAGE OP FRUITS.
Cantaloupes. — This fruit may be stored with good success
at a temperature of 33° F., but for a few days' storage only a
temperature of 35° to 40° F. is sufficiently low. A great deal
depends on the condition of the goods when received as to how
long they may be carried, but from four to six weeks is the ex-
treme limit under favorable conditions, and they must be in
prime and sound condition to be held more than a few days
or a couple of weeks. They are usually stored only for a short
period to tide over a temporary glut in the market.
788 PRACTICAL COLD STORAGE
Bananas.— These are not considered a cold storage product
as they are generally received in an unripe condition and are
only cold stored in exceptional cases for a short period to pre-
vent ripening. The rapidity of ripening depends on the tem-
perature in which they are stored. Some recommend a tem-
perature as low as 40° to 50° F., but usually a temperature of
55° to 60° F. is considered suitable for the temporary or short
period for which they are stored. Care must be taken that they
do not get too low in temperature or they will become chilled
and turn black and therefore unsalable.
Oranges. — These will keep best for from one to three
months at a temperature of 34° for the average fruit. The fan
system of air circulation is best, and a ventilating system which
will supply pure, cold and dry air to force out the gas which
accumulates from the citrous fruits is also beneficial. This will
also lessen the danger of contaminating other goods, such as
butter and eggs. Do not store these products in the same build-
ing with citrous fruits. See what is said elsewhere in this
chapter on storing "Eggs and Lemons."
Lemons. — This fruit should have the same general treat-
ment as oranges, but a temperature of 38° F. is considered as
low as is safe for average fruit. A lower temperature is detri-
mental and will cause them to decay.
Melons. — These are put in storage but very little, and for
short holding only, the value of the product and limited possi-
bility of keeping not as yet warranting a large business in this
line. By removing from the vines very carefully, cutting the
stem an inch or so from the melon, then shellacing the stem
and wrapping the melon in wax paper, they may be stored
from two to three months. Care must be taken not to bruise or
mar the rind of the melon. Provide racks and store as loosely
as possible to prevent bruising and crushing. A temperature
of from 34° to 36° F. is considered best for long period hold-
ing, and a temperature of 40° F. is sufficiently low for short
periods.
Plums.— This fruit is extremely perishable and not gen-
erally considered as cold storage goods except for a few days at
a time to tide over an overstocked market. By rigid attention
to quality of stock and providing the best facilities for cold
MISCELLANEOUS 789
storage good results may be obtainable on a comparatively long
time carry. Green gage plums have been kept in good condi-
tion for a period of ten weeks at a temperature of 32° F.
Cherries. — Quite perishable and can only be stored for
comparatively short periods at best. A temperature of 32° to
34° r. is recommended.
Strawberries. — It is practically out of the question to cold
store this fruit. They are only placed in refrigerated rooms
at a temperature of 40° to 50° F. to prevent rapid ripening and
deterioration. Some experimenting has been done in freezing
strawberries and holding in this condition for a long period.
The actual results cannot be given and it is doubtful if this is
commercially practicable. Nevertheless, some experimenting
along this line might prove interesting.
Currants. — These may be kept from four to six weeks at a
temperature of from 32° to 34° F. The red varieties keep bet-
ter than the black or white currants. They should be pro-
tected from the air by paper coverings.
DRIED FRUIT IN STORAGE.
Dried fruit has been stored in large quantities of late years •
for the purpose of preventing loss of weight by evaporation
during warm weather and to prevent mold and fermentation.
One of the objects of storing is also to prevent the development
of insect life. Certain forms of grubs or worms germinate at
comparatively high temperatures and damage the stock. A
temperature of from 40° to 45° F. is sufficient to prevent this,
and is in common use for these products, but a temperature of
from 36° to 38° F. is said to absolutely prevent any insect life
from maturing or germinating. If a room is available at a
somewhat lower temperature there is no damage to most goods
of this class even as low as 25° F.
florists' goods in cold STORAGE.
Florists are storing quite a variety of goods at the present
time and a constantly increasing variety is being stored each
year. The following are a few of the common goods which are
placed in storage for safe keeping. Lily-of-the-valley pips at a
temperature of about 25° F., storage period November until
790 PRACTICAL COLD STORAGE
spring (see chapter heading) ; Chinese, Japanese and Bermuda
lily bulbs stored at a temperature of 34° to 36° F., storage
period from fall to spring ; wild smilax, temperature 32° to 34°
F., through the winter season; galaxia leaves at 25° F. ;
lucothia, at a temperature of 30° F., through the winter season.
REGULATION OP PLANT GROWTH BY REFRIGERATION.
Plant growth may be regulated by maintaining proper
temperatures. This principle is applied in retarding the de-
velopment of bulbs and flowering plants so as to produce blos-
soms at any time of the year as the demand may be. Lily-of-
the-valley, for instance, is made to blossom at Easter time, and
roses which naturally blossom in summer, are made to blossom
at Christmas. Potted plants are held at a temperature of 30°
to 35° F., and then transplanted to the comparatively high
temperature of the green-house at such a time as will bring
them to flowering or fruitage at the date desired entirely inde-
pendent of outside weather conditions. The possibilities along
this line are being developed as rapidly as the demand war-
rants.
REFRIGERATION APPLIED TO THE SILK INDUSTRY.
One of the serious obstacles to be overcome in applying
refrigeration in the silk industry is the danger that the silk
worm will hatch from the eggs at the time when the mulberry
leaves have not reached sufficient maturity to constitute a
proper food. Refrigeration has been applied to prevent prema-
ture hatching of the eggs, if on account of a backward season or
for any other reason the matured mulberry leaves are not to be
had. A temperature of about 32° F. will retard the hatching
of the eggs at will and without affecting the silk worm in any
way whatever.
EXPERIMENTS IN GRAIN GROWING.
It is reported from Stockholm, Sweden, that experiments
are in progress whereby it is expected to produce a hardier
grain for severe weather conditions. These experiments have
been undertaken owing to failure to secure a grain which would
be hardy under the severe climate of Norway and Sweden.
MISCELLANEOUS 791
Canadian and other grains have been sown, but have not shown
proper seed producing qualities after having been thoroughly
tested.
Paul Hellstrom, Chief of the Government Biological Insti-
tute at Luela, has undertaken the experiment whereby he ex-
pects to harden oats, barley and other grains so as to make them
sufficiently hardy to withstand a considerable degree of frost.
Green-houses have been erected, which are in reality cold stor-
age houses, in which the plants may be subjected to the lowest
temperatures they can stand without being frozen. In this way
the seed that matures from the most hardy plants will be used
for propagation. By repeating this operation, and gradually
lowering the temperature, it is expected that after five or six
years' freezing, the nature of the grains will have been so ma-
terially changed that they will stand several degrees of frost
without damage. The experiment looks reasonable and should
meet with success, but it will require very delicate handling in
order to regulate the temperatures sufficiently close for the pur-
pose required.
The possibilities along this line, not only for propagating
grain, but in propagating other hardy plants and fruits are un-
limited, and the experiments referred to will be watched with a
great deal of interest. This matter is mentioned here as a sug-
gstion to those who are interested in the production of hardy
fruits and plants.
MANUFACTURE OF PAEAFFINE.
The appUcation of mechanical refrigeration in the manu-
facture of paraffine was the first use of mechanical refrigeration
in connection with a manufactured product. Paraffine wax is
extracted from paraffine oil by cooling same to the correct tem-
perature to cause the wax to crystallize. In this way paraffine
wax of varying densities or melting points may be extracted.
The mechanical details of the apparatus may be any arrange-
ment which will present a surface at the correct temperature
which may be immersed in a tank of paraffine oil. A revolv-
ing surface from which the paraffine may be scraped off as it
revolves is desirable.
792 PRACTICAL COLD STORAGE
COLD STORAGE AND FREEZING TEMPERATURES.
The temperatures given opposite the various goods named
below may fairly be stated to give the average of the best pres-
ent practice. In some cases comparatively little is known of
the correct temperatures at which the various products should
be stored, as no tests have been made. For those goods with
which the author is familiar, embracing the more important of
the perishable products which are cold stored, temperatures are
given which he believes to be correct as applied to average prac-
tice. For many of the special or uncommon goods the best
obtainable authority has been consulted. Owing to the small
amount of accurate information available until recently, the
present list shows some marked changes from the temperatures
regarded as correct a few years ago. No doubt future changes
will be made, but hardly to the same extent.
Arbitrary temperatures are given for each commodity ; but
the condition of the goods, length of time to be stored, condi-
tions of air circulation, humidity, etc., are factors in determin-
ing the best suitable temperature. The following list of prod-
ucts and temperatures should be considered as a guide only,
subject to change to meet varying conditions under which
goods are stored:
COLD STORAGE AND FBEEZINO TEMPEEATUBES FOR VARIOUS PRODUCTS.
Products Deg. P. Products Deg. P.
Apple butter 42 Cheese (long carry) 35
Apples 30 Chestnuts 34
Asparagus 33 Chocolate dipping room 65
Bananas 58 Cider 32
Beans (dried) 45 Cigars 42
Beer (bottled) 45 Corn (dried) 45
Berries, fresh (few days only) . 40 Com meal 42
Buckwheat flour 42 Cranberries 33
Bulbs 34 Cream (short carry) 33
Butter 14 Cucumbers 38
Butterine 20 Currants (few days only) .... 32
Cabbage 31 Cut roses 36
Canned fruits 40 Dates 55
Canned meats 40 Dried beef 40
Cantaloupes (one to two Dried fish 40
months) 33 Dried fruits 40
Cantaloupes (short carry) 40 Eggs 30
Carrots 33 Ferns 28
Caviar 36 Field grown roses 32
Celery 32 Pigs 55
MISCELLANEOUS
793
COLD STORAGE AND FREEZING TEMPEEATUBES FOR VARIOUS PRODUCTS
CONTINUED.
Products Deg. F.
Fish, fresh water (after
frozen) 18
Pish, not frozen (short carry) . 28
Pish, salt water (after frozen) 15
Pish (to freeze) 5
Progs legs (after frozen) 18
Pruit trees 30
Pur and fabric room 28
Purs (undressed) 35
Game (after frozen) 10
Game (short carry) 28
Game (to freeze) 0
Ginger ale 36
Grapes 36
Hams (not brined) 20
Hogs 30
Hops 32
Huckleberries (frozen, long
carry) 20
Ice cream (few days only) .... 15
Ice storage room (refrigerated) 28
Japanese fern balls 31
Lard 40
Lemons (long carry) 38
Lemons (short carry) 50
Lily of the valley pips 25
Livers 20
Maple sugar '. 45
Maple syrup 45
Meat, fresh (ten to thirty
days) 30
Meats, fresh (few days only) . 35
Meats, salt (after curing) .... 43
Mild cured pickled salmon. ... 33
Milk (short carry) 35
Nursery stock 30
Nuts in shell 40
Oatmeal 42
Products Dee F
Oils 45
Oleomargarine 20
Onions 32
Oranges (long carry) 34
Oranges (short carry) 50
Oxtails 30
Oysters, iced (in tubs) .• 35
Oysters (in shell) 43
Palm seeds 38
Parsnips 32
Peach butter 42
Peaches (short carry) 50
Pears 33
Peas (dried) 45
Plums (one to two. months) . . 32
Potatoes 34
Poultry (after frozen) 10
Poultry, dressed (iced) 30
Poultry (short carry) 28
Poultry (to freeze) 0
Raisins 55
Ribs (not brined) 20
Salt meat curing room 33
Sardines (canned) 40
Sauerkraut 38
Sausage casings 20
Scallops (after frozen) 16
Shoulders (not brined) 20
Strained honey 45
Sugar 45
Syrup 45
Tenderloin, etc 33
Tobacco 42
Tomatoes (ripe) 42
Veal 30
Watermelons (short carry) ... 40
Wheat flour 42
Wines 50
KEINFOECBD CONCRETE IN COLD STORAGE CONSTRUCTION.
The use of reinforced cement concrete as a material for
the construction of cold storage warehouses has come into
prominence during the past ten years. Owing to the reduced
price of cement, concrete makes an economical material for
building construction of many kinds, but for cold storage
houses it is not so well adapted as to some other purposes, and
the difficulty of securing satisfactory insulation with concrete
construction is not the least of the troubles encountered by re-
frigerating engineers.
794 PRACTICAL COLD STORAGE
A type of construction which is more flexible and perhaps
better in every other way is to employ brick for exterior walls
and reinforced concrete for posts and floors only. Even with
this type of construction the conduction from one floor to
another through the floors and posts makes insulation a serious
problem. This is especially true where a great difference in
temperature is necessary on different floors of the same build-
ing. In large plants this can be overcome by insulating sepa-
rately the low temperature rooms and placing them in a sepa-
rate section of the building.
Another important disadvantage of concrete construction
is the practical impossibility of making any important changes
in the arrangement of rooms, equipment, etc., after the build-
ing is once built and insulated. This applies particularly to a
building which is used for workroom and other purposes not
requiring refrigeration, as well as for cold storage. While con-
crete will, doubtless, find application in many places and espe-
cially in connection with large cold stores, it is doubtful if this
material will in the near future come into general use for com-
paratively small plants. The saving in insurance, which is the
chief advantage, is, in small plants, more than offset by the
disadvantages mentioned above and by the increased cost of
construction.
TOBACCO AND HOFS IN COLD STORAGE.
The American Warehousemen's Association in response to
inquiries received sent out letters to its members relative to the
storage of tobacco and hops, and the suggestions made in con-
nection therewith are interesting and may be summarized as
follows :
Tobacco. — "We have stored tobacco in bales at tempera-
ture of 38° to 40° F. with satisfactory results.
"We have handled Havana and Sumatra tobacco in bales,
always carrying it at a temperature of 32° F. At this tem-
perature there seems to be just enough moisture in the air to
keep the tobacco in good shape, yet not enough to allow it to
mold. It must be stored in a separate room from other com-
modities on account of the penetrating odor which will cer-
tainly spoil dried fruits, eggs, butter, and even apples will ab-
sorb it to a considerable extent.
MISCELLANEOUS 795
"We have never stored tobacco except when made up in
cigars, and this we held at 26° F. with good results."
Hops. — "The proper way to store them is to see that there
is at least three or four inches space between each bale in piling.
They are required to be kept in an absolutely dry room. The
temperature should be held closely about 32° F. ; any consider-
able change is apt to cause mold and render them unfit for
use.
"Hops are generally stored at a temperature of about 32° F.
If held closely at this temperature results should be satisfac-
tory.
"We have had considerable experience with hops. They
are a delicate thing to store, and must be kept in very dry
atmosphere, and should not be stored with other goods, as they
readily take the smell and taste of other goods, and the odor
of the hops is likely to prove injurious to the other goods ; are
very susceptible to mold if any dampness is in the room. Usual
rate of storage about %c per pound per month.
"We store hops at a temperature of 32° F. They come in
bales of about 350 pounds, and storage charge is %c per pound
per month. We have had no difficulty in turning out hops in
satisfactory condition.
"Have stored both domestic and imported hops for a num-
ber of years with good success. We store at a temperature of
38° to 40° F. ; the imported bales are stood on end, and the
domestic bales piled up on sides three high."
PEE-COOLING OF CELERY.
The Florida Vegetable Growers' Association has recently
been conducting some experiments in pre-cooling or temporary
cold storing celery before shipment, and as reported the scheme
seems to be a success as compared with the old method. It
seems that there is considerable natural heat of fermentation
arising from celery, and the pre-cooling tends to check this, as
it also tends to check "blight" and what is known as "black-
heart"; both troubles caused doubtless by fungus diseases,
which are held in check by low temperature. We may look for
pre-cooling to be applied to celery as well as other products
which deteriorate rapidly at ordinary temperatures.
796 PRACTICAL COLD STORAGE
THE BREATHING OF FRUITS IN COLD STORAGE.
The deterioration or destructive processes which take place
in fruit are greatly retarded by low temperature, but these de-
structive processes are operative and just as certain at low tem-
peratures as at high temperatures, and this action has been
likened to the breathing of animals for the reason that fruits
absorb oxygen and give out carbon dioxide or what is com-
monly known as carbonic acid gas.
Fruit before picking and while still attached to the twig
has its food supplied to it, but just as soon as the fruit is
picked, with nothing to make good the losses, the destructive
processes commence. There is, therefore, a constant reduction
in weight and vitality. Cold storage makes the absorption of
oxygen and the transpiration of carbon dioxide much slower as
they are the result of complicated chemical action and all
chemical actions progress much slower at low temperature. The
loss of weight from fruit in cold storage is not due entirely to
the mere drying out of water, but to the natural progressive
starvation or destruction referred to.
This action in the life of fruit was the subject of a bulletin
of the New Hampshire Experiment Station, published in Feb-
ruary, 1908, entitled, "The Respiration of Fruit." Reference is
also made to Bulletin No. 142, Bureau of Chemistry, United
States Department of Agriculture, entitled, "Studies on Fruit
Respiration." As scientifically considered these publications
are quite interesting. As long as fruit remains on the parent
branch it is alive and growing, but immediately when picked
it becomes inert, begins to die, and the action of cold storage
is merely to retard the dying processes and postpone the ulti-
mate decay which is the natural end of all fruit.
TOPICAL INDEX.
A u 1. Page.
Absorbent, chloride of calcium as..
,. 210, 212
lime as 209
Absorbents 208
Absorption system, ammonia 42
Accounting, essential features of 760
Air, for ventilation, treated 189
handling of 185
leakage of 183
protection of insulation from. ... 74
Air circulation^ Cooper system of... 174
forced, objection to 164
historical 148
importance of 147
improved systems of 162
in storage of furs 565
Air machines, cold 39
Air seal, necessity for perfect 71
Air spaces 1 16
Air system, cold 39
Ale, ginger, temperature for 793
Ammonia, in mechanical refrigeration 22
Ammonia absorption system 42
Ammonia compression system 41
Ammonia system vs. ice and salt.37, 658
Apple butter, temperature for 792
Apple scald 372
Apples, author's suggestion in stor-
age of 423
barrels vs. boxes _ — 396, 408
behavior of different varieties of 402
behavior of when removed from
storage 370
clarifying juice of 481
cold storage of 30, 341, 353
cold stored varieties compared.. 381
commercial results from cold
storage of 384
cost of storage for 30
delay in storage of 360
double wrapping for 402
experiments with, by J. P. Roe 391
experiments with, by Mr.
Young^ers 392
factors influencing the keeping
quality of , 354
growing of, commercially 345
handling of, after cold storing. . 406
importance of good fruit. ....... 371
influence of cultural conditions
on 367
influence of fruit wrapper on... 365
influence of storage temperature 362
influence of type of package on. 369
N. H. Experiment Station ex-
periments with 390
packages suitable for cold stor-
age of 394
packing of 406, 411
piling barrels of 404
summary of experiments of U. S.
government with 382
"swell" in box packing 417
temperature for 33, 792
Page.
Apples, time limit for storage of.... 393
U. S. government experiments
with 351
ventilation of packages of 419
Asparagus, temperature for 792
Asphalt, as a water proofing material 134
B
Bait, Canadian methods of freezing 615
Bananas, cold storage of 788
shipping of 547
temperature for 788, 792
Beans, temperature for 792
Beef, shippmg of 543, 553
temperature for 792
Beer temperature for 34, 792
Berries, temperature for 792
Brick, Cabot's preservative, for wa-
terproofing 135
tests on waterproofing 136
Brine, chloride of calcium 223
preparation of 227, 230
properties of 229
circulation. Cooper system of... 659
Brine system, Cooper's, cost of 28
directions for operating 665
for creameries 334
for storage of ice 676
Buckwheat flour, temperature for... 792
Bulbs, cold storage, produce best re-
sults 579
selection of for cold storage 580
temperature for 792
Butchers,^ refrigeration for 635
Butter, circulation of air in storage
for 288
cold storage of 277
creamery 284
fishy flavor in 285
flavor and aroma 280
freezing of 278
humidity for 288
ladle 284
mold in packages of 286
preparing for cold storage 280
process^ 281
protection from the air 278
shipping of 544
specific heat of 287
storing in tubs 282
temperature for 32, 277, 544, 792
use of jars for storage of 282
ventilation in storage for 288
Butterine, storage of 283
temperature for 792
C
Cabbage, in cold storage 785
temperature for 34, 786, 792
Calcium chloride, as an absorbent
210, 212
breaking 222
devices for application of 215
handling 221
797
798
TOPICAL INDEX.
„ . Page.
Calcium chloride, uses of 213
Calcium chloride brine 223
preparation of 227, 230
properties of 229
Calcium process, Cooper's chloride of 217
Candling room, construction of 265
Canned fruit, temperature for 792
Canned meats, temperature for 792
Cantaloupes, cold storage of 787
temperature for 786, 792
Carbon dioxide 22
Carbon dioxide system 40
Car cooling, method illustrated 520
Car pre-cooling 511
Carrots, temperature for 792
Cars, appliances and methods 539
refrigerator 515, 540
ventilated 541
Caviar, temperature for 792
Celery, cold storage of 787
pre-cooling of 795
temperature for 787, 792
Cellars 19
Centigrade, thermometer scale
768, 769, 770, 771
Chaff, straw, etc., as insulation 11
Charcoal, as insulation 83
Cheese, author's remark on storing. 322
cold curing of 291
conditions under which to cold
cure 301
desirability of cold storage for.. 289
influence of parafifining on., 305, 317
influence of temperature on....
298, 302, 305, 316
scoring of 297
shrinkage of cold cured 300
temperature for ...ZZ, 296, 544, 792
weighing 301
western experiments in cold cur-
ing 295
Cherries, cold storage of 789
Chestnuts, temperature for 792
Chloride of calcium, as an absorbent
210, 212
breaking 222
devices for application of 215
handling 221
uses of 213
Chloride of calcium brine 223
preparation of 227, 230
properties of 229
table for making 230
Chloride of calcium process, Coop-
er's 217
Chocolate dipping room, temperature
for 792
Cider, clarifying 481
eliminating chemical preservative 479
preparation and handling of 483
summary of experiments with. . . 482
temperature for 792
Cigars, temperature for 792
Circulation, importance of 147
purifying the air by 1 53
Cold storage, advantages of local. 350, 455
applied to ^rain growing 791
applied to living rooms, etc 754
benefits of 14, 23
breathing of fruits in 796
bulbs from, produce best results 579
classes of goods in. 31
comparison of varieties of apples
in 381
cost of, for apples 30
demand for 23
Page.
Cold storage, designs for small 458
development of ., 19
development of, as applied to fish 602
early systems of ice 646
experimenting in construction
not advised 36
florists* goods in 789
for fruit, cost of 475
freezing temperatures 792
humidity in Ill
importance of 15
in connection with ice house. . . . 747
influence of on peach industry. . 448
influence of on pear industry... 425
insulation of warehouse 65
moisture in 154
mold in 154. 783
of apples (see Apples)
of bananas (see Bananas)
of butter (see Butter)
of butterine 283, 792
of cabbage (see Cabbage)
of cantaloupes 786, 787, 792
of celery (see Celery)
of cheese (see Cheese)
of cherries 789
of cider (see Cider)
of cream (see Cream)
of currants (see Currants)
of dried fruit 788, 789, 792
of eggs (see Eggs)
of eggs and lemons together... 783
of fabrics 573, 793
of fruit (see Fruit)
of furs (see Furs)
of grapes 505, 533, 793
of hops 793, 794, 795
of lemons (see Lemons)
of Lily of the Valley pips (see
Lily of the Valley)
of meat (see Meat)
of melons 788
of milk (see Milk)
of nursery stock (see Nursery
Stock)
of oleomargarine 283, 793
of onions 786, 793
of oranges (see Oranges)
of plums 788, 793
of potatoes (see Potatoes)
of potted plants 790
of poultry (see Poultry)
of strawberries 7S8, 789
of tobacco 793, 794
of wild rice seed 582
rates for 35
reinforced concrete for 793
removing goods from 781
slow cooling of goods for 781
space required for storing prod-
ucts 778
storing various products in same
ro9m 782
stowing goods in 119
treatment of fruit 476
trucks for handling goods in . . . 778
variety of uses for 10
whitewash for 777
windows and doors 183
Cold storage and commercial apple
growing 345
Cold storage and ice making plant,
accounting 762
Cold storage houses 7
Cold storage rooms, care of 618
TOPICAL INDEX.
799
Pa.Ke.
Cold storage warehouse, function of 351
Cold store, capacity required 26
cheap inefficient 25
cost of 27
deodorizing '.'.'776, 777
earnings of .' 36
geometry of 44
necessity for ventilation in 181
organizing and starting 23
site for 774
Concrete, ice houses of 751
reinforced, for cold storage 793
Conduction of heat 53, 70
Conductivity, relative table of 55
Conductors of heat 54
table of poor 56
Convection of heat 52, 70
Cooper brine system, cost of 28
directions for operating 665
for creameries 334
for ice storage 676
Cooper chloride of calcium process. 217
Cooper system of air circulation 174
Cooper system of brine circulation. . 659
Cooper system for warm weather
ventilation 193
Cork, as insulation 84
Cork sheets, erecting of 86
Corn, temperature for 792
Corn meal, temperature for 792
Cost of cold storage for fruit 475
of harvesting and housing ice. . . 681
of insulation 47
of pre-cooling 533
Cranberries, temperature for 792
Cream, cooling of 339
temperature for 792
transportation of 333
Creamery, Cooper brine system, for 334
refrigeration for 324
Creamery ice house, model 726
Cucumbers, temperaturer for 792
Currants, cold storage of 788
temperature for 789, 792
Cut roses, temperature for 792
D
Dairy, refrigeration for 324
shipping of products from 544
Dates, temperature for 792
Dexter system 653
Doors in cold storage 143, 183
Dried beef, temperature for 792
Dried fish, temperature for 792
Dried fruits, temperature for 789, 792
Dwellings, cooling of in the tropics 754
E
Egg candling room, construction of. 265
Eggs, absorbents in cold storage for 255
air circulation in cold storage
for 251
cold storage of. 239
freezing m bulk. ... ............ 271
handling and refrigeration of. . 557
hints in the storage of 362
humidity for ^4K
packages for ^^o
shipping of ■ ■ ■ • u-.^ • VV/ 7Q2
temperature for 32, 240, 544, 79Z
ventilation for. .......... • • • ■ - • • • ^J^
Eggs and lemons, storing together of 783
F Page.
Fabrics, cold storage of 573
temperature for 793
Fahrenheit, thermometer scale
767, 768, 769, 770, 771
False ceiling system 177
False floor system 177
Fan circulation, electric, inefficient. 167
Fans for ventilation 187
Fern balls, Japanese, temperature for 793
Ferns, packing, sorting, etc 576
picking, time and details 576
temperature for 577, 792
uses and markets for 575
Field-grown roses, temperature for. 792
Figs, temperature for 792
Fireproof insulation 124
Fish, cold storage of 601
deterioration of after frozen..... 613
ice and salt freezers for 606
method of storing 610
shipping of 545
temperature for 792, 793
Fish industry, growth and impor-
tance of 601
Fisher system '. 648
Floor, tight loft, construction of 752
Florists, goods put in cold storage
by 789
Flour, temperature for 793
Forced air circulation, objection to 164
Forced circulation, different systems 169
Freezers, description of ice and salt. 606
Frogs legs, temperature for 793
Fruit, advantages of pre-cooling. 509
breathing of in cold storage 796
cold storage of 455, 787
dried, in storage 788
methods of pre-cooling 510
model,, small storage for 467
possibilities for pre-cooling 513
pre-cooling of 509
rapidity of cooling 536
removing from storage 476
respiration of 420
shipping of 545
storage for in country 470
storage in large capacity 474
temperature for 792
used for cider experiment 480
Fruit trees, temperature for 793
Furs, advertising matter on storage
.of 570
air circulation in storage of... 565
cold storage of 559
education of customers to store 568
handling and storage of 570
humidity for 563
rates for storage of 571
storage of, profitable 561
temperature for 34, 562, 793
ventilation in storage of 567
warehouse receipts for 572
Game, temperature for 793
Geometry of cold storage houses. ... 44
Ginger ale, temperature for. 793
Grain, experiments in growing 790
Grapes, long storage of 505
pre-cooling of 533
temperature for 793
800
TOPICAL INDEX.
r. . Page.
Gravity circulation, methods of as-
sisting 158
H
Hair felt, as insulation 88
method of applying 89
Hams, temperature for 793
Harvesting ice 691
Heat, conduction of 53, 70
conductors of 54
convection of 52, 70
latent, of freezing 235
table of non-conductors of 58
table of poor conductors of 56
theory of 51
radiation of 70
relative table of 55
transmission of 51
units of 53
Heat conductivity, method of deter-
mining 101
Heat transmission, table of co-
efficients of 63
through walls 64
variation of 60
Historical .• 19
Hogs, temperature for 793
Honey, temperature for 793
Hops, cold storage of 794
temperature for 793, 795
Huckleberries, temperature for 793
Humidity 200, 777
for butter in storage. .■. 288
for eggs 248
for furs 563
for nursery stock 491
for potatoes 503
table of relative 206
Hygrometer 202
* I
Ice, advantages of, on the farm.... 717
as a refrigerant 20
care and preparation of, field of 683
Cooper brine system for storage
of ;... '676
cost of harvesting and housing. 681
for cold storage 21
harvesting of 691
harvesting, handling and storage
of 680
housing and packing. 702
machinery for handling 335
natural and artificial 6
quantity required in pre-cooling 531
refrigeration from 639
storage of under refrigeration . . 679
storing in pits 708
temperature for storing 793
tools for harvesting and handling 706
used for cold storage^ purposes 646
vs. refrigerating machine 326
waste of in house 714
weight of 709
Ice and salt vs. ammonia systems.. 37
Ice and salt system, directions for
operating 665
Ice boxes 628
Ice cream, temperature for. 793
Ice crop, in various localities 680
Ice house, cold storage in connection
with 747
concrete 751
Page.
Ice house, construction and insula-
tion of 713
filling 713, 719
model commercial 731
model creamery 726
modern, evolution of 710
primitive construction of 710
simple form 717
Ice house and refrigerator combined 332
Ice making and cold storage plant,
accounting in 762
Ice storage, tight loft floor construc-
tion 75^
Insulating material, tests of 62
Insulation, brine pipe 128
carefully constructed 141
chaff for 77
charcoal for 83
cold storage 48
composite 96
composite, test of 103
cork for 84
cost of 47
cost of constructing 139
durability of 121
fireproof 124
hair felt as 88
materials for 49
mineral wool for 80
nails used in 95
of cold storage warehouses 65
of ice houses 713
of walls, testing of 98
paper used in 93
quilt 90
requirements of 76
sawdust for 78, 773
shavings for 79, 773
straw for 77
tank 123
testers of 97
testing value of 100
tests of SO
types of 119
value of materials for 77
wood for 94
Introduction 12
J
Jackson system 653
Japanese fern balls, temperature for 793
Lard, temperature for 793
Latent heat of freezing 235
Lemons, cold storage of 788
shipping of 547
temperature for 788, 793
Lemons and eggs, storing tojgether 783
Lily of the Valley bulbs, cold stor-
age of 579, 580, 789, 793
temperature for 580, 789, 793
Lime, as an absorbent 209
Linseed oil as a waterproofing mate-
rial 135
Livers, temperature for 793
M
Machines, cold air 40
Maple sugar, temperature for 793
Maple syrup, temperature for 793
TOPICAL INDEX
801
Page.
Meat, canned, temperature for 792
cold storage of 633
salt, temperature for 793
shipping of 543
temperature for 34, 793
Melons, cold storage of 788
Mild cured pickled salmon, tempera-
ture for 793
Milk, cooling of 337
shipping of 544
temperature for 544, 793
transportation of 333
Mineral wool, as insulation 80
manufactured forms of 82
Moisture, disposal of 196
in cold storage rooms 154
Mold in cold storage rooms. ... 154, 782
Mutton, shipping of 553
N
Nails u-sed in insulation 95
New York stock exchange, cooling
of 756
Nursery stock, buildings and appa-
ratus for storage of 492
humidity and temperature for. . 491
notes on care of 497
temperature for 491, 792
winter storing of 485
Nuts, temperature for 34, 793
Nyce system 652
O
Oatmeal, temperature for 793
Oils, temperature for 793
Oleomargarine, storage of 282
temperature for 793
Onions, cold storage of 786
temperature for 786, 793
Oranges, cold storage of 788
pre-cooling of 47, 519
refrigeration required to pre-
cool 537
shipping of_ 519, 547
shipping without ice 529
temperature for 34, 788, 793
Oxtails, temperature for 793
Oysters, shipping of 545
temperature for 793
P
Paint, for metal surfaces 776
for rooms and piping 625
Palm seeds, temperature for 793
Papers, insulating 93
Paraffine, manufacture of 791
Parsnips, temperature for 793
Peach butter, temperature for 793
Peaches, cold storage of 425
difficulties in storage of 449
influence of cold storage on the
industry 448
outline of experiments in stor-
age of 450
results of experiments with 451
temperature for 793
Pears, cold storage of 425
effect of cold storage on. 443
outline of experiments in stor-
age of 426
results from storage of . . . . . . . . 445
suggestions on storage of 446
Page.
Pears, temperature for 793
various influences affecting keep-
ing quality of
428, 429, 433, 435, 442
Peas, temperature for 793
Pipe, paint for 625
Pipe insulation, brine 128
Pipes, placing of cooling 155
Plant, growth of regulated by refrig-
eration 790
Plums, cold storage of 788
temperature for 793
Pomona Valley Ice Co., plant of... 526
Pork, shipping of 543
Potatoes, '^fitting" for storage 499
for early crop planting 498
humidity for 503
methods of preserving 498
package for 500
temperature for 34, 502, 793
Potted plants, temperature for 790
Poultry, cooling after picking 587*
cooling methods of 589
cooling rack for 594-
dtawn vs. undrawn 58S
icing 554
shipping of 544, 555
temperature for 34, 588, 793
Pre-coolmg, car 511
in Pomona Valley Ice Com-
pany's plant ; 526
in Upland Heights Orange As-
sociation's plant 523
of celery 795
of fruit 509
of fruit, cost of 533
of fruit, possibilities of 513
of grapes . . . ^ 533
of oranges 47, 519
quantity of ice required for 531
warehouse 512
Preface, first edition 5
second edition 10"
Psychrometer 202
Quilt insulation 89
R
Radiation of heat ..." 70
Raisins, temperature for 793
Reaumur, thermometer scale
768, 769, 770, 771
Refrigerating, machine vs. ice 326
Refrigeration, amount required to
pre-cool oranges 537
applied to the silk industry 790
cheap, safe and unlimited 637
determining British thermal
units in 231
economy of 13
estimates of needed for various
capacities 236
for butcher's boxes 635
for retailers 630
mechanical 22
mechanical, fish freezing by.... 607
necessity for 324
plant growth regulation by 790
principles of ice 639
specific heat in 234
systems of 39
uses of 12
802
TOPICAL INDEX.
Page.
Refrigerator cars 515, 540
Refrigerators, construction of 628
Ribs, temperature for 793
Rice seed, wild 582
Root cellars 19
Roses, temperature for. 792
Ruddick, Hon. John A., on cost of
construction 29
S
Salmon, temperature for 793
Salt, kmd used with ice for refrig-
eration 668
Salt meat, temperature for 793
Sardines, temperature for 793
Sauerkraut, temperature for 793
Sausage casings, temperature for 793
Sawdust for msulation 78, 775
Scald, apple, influence of temper-
ture on 376
Scallops, temperature for 792
Shavings for insulation 79, 775
Shoulders, temperature for 793
Silk industry, refrigeration applied
to the 790
Sling psychrometer, method of using. 204
Snow, storing in pits 708
St. Clair system 161
Stevens system 650
Stock exchange. New York, cooling
of 756
Strained honey, temperature for 793
Straw, chaff, etc., as insulation 11
Strawberries, cold storage of 788
Sugar, temperature for 793
Syrup, temperature for 793
T
Tank insulation 653
Tank system 653
Temperature for commodities in
cold storage. Look under
name of the commodity.
Temperature, question of 17
table 551
Temperatures, cold storage and freez-
ing 792
Tenderlom, temperature for 793
Tester for cold storage room 101
Testing apparatus, insulation 97
Testing room, insulated 100
Tests, for insulation 97
of insulating materials 62
Page.
Thermometer, recording 772
Thermometers 1^1
Tobacco, cold storage of 793, 794
Tomatoes, temperature for 793
Tools for harvesting and handling
ice 706
U
Unit of heat S3
Upland Heights Orange Asso., pre-
cooling plant of 523
U. S. Dept. of Agric, experiments
with grapes 506
U. S. Government, experiments on
apple storage 351, 382
Vacuum, non-conductor of heat.... 59
Veal, temperature for 793
Vegetables, shii)ping of 548
storing of, in cellars 784
temperature for 784
Ventilation, cold weather 195
cold weather, hints on 198
fans for 187
for eggs in storage 254
in storage of furs 567
necessity for 181
of packages of apples 419
practices to avoid in 184
pressure and exhaust method... 186
warm weather 193
W
Warehouse, method of precooling. . . 523
precooling 511
Watermelons, temperature for 793
Waterproof, walls and insulation
should be 131
Weather reports, use of 548
Wheat flour, temperature for 793
Whitewash, for cold storage
rooms 620, m
U, S. Government formula for. 623
Whitewashing machines 624
Wickes system 649
Wild rice seed 582
Windows in cold storage 144, 183
Wines, temperature for 793
Wood for insulation, kinds of 94
preparation of. . ; 95
PRACTICAL COLD STORAGE.
803
DOORS
D
OORS are just a big valve, and are a weak point in all cold storage.
Insulation is important, tightness and quickness are vastly more so.
Leaks are an endless expense. Doors that bind and work badly are shut
only when the workman can find no excuse for leaving them open, which
is seldom, if ever.
The diagrams show a patented construction, contrived to avoid these
troubles. The thick portion of the door fits loosely, so that considerable
change of size, form and position, due to wear, swelling, etc., does not
make it leak or bind.
The door is held to its seat against the front of the door frame, by
powerful elastic hinges. Its self-acting Roller Fastener has enormous
strength — is arranged^ for pad-lock — ^no slackening, as it latches — the soft
hemp gasket in the joint is always in sight. A mere touch, frees and
opens it from either side.
Old style doors when they
work badly or leak, must be
eased, thus forever destroy-
ing their fit. A slight re-
adjustment of the door frame
of these doors, restores them
to perfect fit and freedom in
a minute, at no expense.
As they do not stand in
the doorway when open, its
width can be six inches less
than old style doorways — an
important economy in re-
frigeration.
As constructed in this year, 1913, the opening in wall to receive
these door frames should be 3J^ inches wider and 4^4 inches higher than
the clear size of the doorway. Follow construction numbered 1 and 2.
For Overhead Track doors this rough opening should extend 135^
inches above the lower edge of the track bar. Door frames are secured
with lag screws ^x4 inches inserted through front casing, inserted at A.
Fig. B shows wooden bevelledf threshold 1^ inches thick.
Connects lower ends of door frame, forms^ part of it and is let
down into the floor. No feather edge, no jolt, no splinters. For
warehouses. Accommodates Trucks. •
Fig. C, concrete floors: shows lower ends of door frame
extending down, into the floor 3 inches, and connected by angle-
irons extending across doorway from one side to the other, below
the surface.
_Fig. S shows door frame
with full standard sill and
head, used on all sizes of
door frames. Suited only to
walking through.
Special Freezer doors, on
a modified plan for inter-
mittent or continuous freezers, as well as for general purposes. Perfectly
tight and perfectly free regardless of temperature, moisture or accumu-
lation of ice in any degree.
Metal covered Fireproof Doors.
Revolving Ice Cream Doors — (Iron). Do not swell and bind.
Combined self-closing Ice Door and Chute of three styles. Ice
Counters.
Form of specification: To guard against infringers and substitutes
for our work* specifications should read, "Cold storage doors and door-
frames with self-tightening hinges and fastener, complete, to be furnished
by Stevenson Cold Storage Door Co., Chester, Pa."
Patents are granted or applied for on every valuable feature of this
work. Infringers will be prosecuted.
STEVENSON COLD STORAGE DOOR CO.
m
m&..
Chester, Pa.
804 PRACTICAL COLD STORAGE.
Madison Cooper Co.
135 COURT STREET
CALCIUM, N. Y.
Refrigerating Engineers
and Architects
Complete Plans and Specifications furnished for
Cold Storage
Warehouses
from the simplest farm cold store
to the largest modern warehouse of
the city. Many years' experience in
the handling of perishable goods
and in the operating and planning
of refrigerating work.
PRACTICAL COLD STORAGE. 805
J^V. .TAIIISOX T. B. SOUTH J. V. JAMISON, JR. R.L.JAMISON
P«s. Vice-Pres. Sec.-Treas. Order and Ship'. Dept.
Cold Storage
and Freezer
Doors, Either
Standard or
Fireproof
DOORS
Our doors are built with DOUBLE and TRIPLE Seals of Con-
tact between the Door and Frame.
Our Jones Automatic Fastener and Adjustable Spring Hinges
holds the Door tight against the multiple seals. The Door can't
warp or sag.
Our Hinges and Fastener are practically indestructible, weighing
60 pounds per set.
Our Doors are built for strength, durability and insulating effi-
ciency. Guaranteed against injury and breakage from every
day hard usage.
Our 68 page catalog fully illustrates in detail both the " Jones "
and "Noequal" types of Doors as well as Jones Cold Storage
Windows. Jones Automatic Ice Recording Doors and Chutes,
Jones Platform Ice Passing Chute and Door combined, Noequal
ALL STEEL Automatic Ice Chutes, Noequal Revolving Ice
Cream Doors (wood or steel), Noequal Vertical Sliding Doors.
Jamison Cold Storage Door Co.
Formerly Jones Cold Store Door Co.
Hagerstown, Maryland, U. S. A.
806
PRACTICAL COLD STORAGE.
The Record Line
Tells the Story
\T7'RONG temperatures in chill
rooms, cold storage rooms,
etc., mean inferior, perhaps spoiled
products — lost profits. Can you
afford to lose money thru sheer
carelessness ? Stop these losses —
insure right temperature s — by
installing a
Columbia' Recording
Thermometer
It will furnish authentic written records
of temperatures maintained for every
minute, day and night. A knowledge
of results and existing conditions will
be at your finger tips. Trace the
trouble and elimmate it. Install the
Col um bia "
RIGHT
NOW
and de-
mand right temperatures.
Write for Catalog 28
The Schaeffer &
Budenburg Mfg.|Co.
Makers of 'Indicalincr and'" Recordinjr
Industrial Thermometers. Indicating
and Recordine Gauges, etc., etc.
BROOKLYN, N. Y.
Chicago
Pittsburgh
New Orleans
Washington
PRACTICAL COLD STORAGE.
807
r
^
The Leading and Largest
Exclusive Builders of
Exhaust Steam Absorption
Ice and Refrigerating
Machinery in the U. S.
Forged Steel Ammonia Fittings
Valves and Flanges a Specialty
HENRY VOGT MACHINE CO.
LOUISVILLE, KY.
^.
J
Save Ice! Save Money!
Do as 75 per cent of the
Creameries of the
Northwest Have Done !
We show a photograph of the
immense plant of the Quincy
Market Co. in Boston. It is insu-
lated with Water-Proof Lith In-
sulation that 75 per cent of all
the creameries in the Northwest
have adopted.
Water- Proof
Lith Insulation
Absolately guaranteed. Comeg in extra larpe sheets 18x48 inches. Twice the size of the ordi-
nary insulating material. Presents only half the number of joints or cracks for heat to creep
in. It saves 50 per cent on ice bills. Also learn about
Union Cork Board
Write for our Free Thereis morecork ineveryinchof Union Union Fibre Co-
n , ■•. , ,. c Cork Board than you get in any other in- «4j ■> ■ c-.
DOOK — Insulation ror euUting material — odc and one quarter poundBOfpuTd ' '^ UniOD Mreet
Cold Temperatures." cork toeverj equaro foot one inch thjoki Winona. Minn.
808
PRACTICAL COLD STORAGE.
Cork Insulation
Furnished and
Installed Complete
United Cork Companies of New York
Main Office and Factories: Lyndhurst, N. J.
REMINGTON
VERTICAL SINGLE ACTING
REFRIGERATING MACHINES
16 Sizes — V4 to 32
Tons Refrigeration
Belt Driven
Direct
Connected to
Steam Engine
Direct
Geared to
Electric Motor
The Most
Durable,
Economical
and Reliable
Remington
Machine Co.
Wilmington, Del.
PRACTICAL COLD STORAGE.
809
I C E
Harvesting Machinery
Let us solve your problems concerning the best equipment
tor handling your ice. Take advantage of our experience.
ESTABLISHED 1814
Finest Quality
Ice Tools
Large Variety and Stock
Catalogs
Send for pamphlet: "How to
Harvest Ice."
'^4^M!iUd^
Xew England Headquarters
BOSTON
HUDSON, N. Y.
Western Headquarters
CHICAGO
FOURTH EDITION
1915
^tt unh l^^fng^rattnit Mm look
The Official Directory of the
Ice Making, Cold Storage, Refrigeration and Auxiliary Trades
Containing
A Complete List of Ice Machine Builders, Ice Factories, Cold Stores,
Packing Houses, Breweries, Dairies, Creameries, Meat Markets, Hotels,
Restaurants, Confectioners, and all Establishments using Mechanical
Refrigeration in the United States and Canada.
Fifteen Thousand Names in This Edition
Bound in Cloth - - $5.00
PRICE
Bound in Flexible Morocco 5.50
Sent prepaid to any address on receipt of price
NICKERSON & COLLINS CO.
PUBLISHERS
431 South Dearborn Street, Chicago
810
PRACTICAL COLD STORAGE.
The Recognized Authority
in all matters relating to
Mechanical Refrigeration
A monthly Review of the Ice, Ice Making Re-
frigerating, Cold Storage and Kindred Industries.
The only medium through which can be obtained all the
reliable, technical and practical information relating to the
science of mechanical ice making and tefrigeration.
SUBSCRIPTION PRICE
In U. S., Possessions and Mexico, $2.00 per year
In aV other countries 3.00 per year
Nickerson & Collins Co.
431 South Dearborn Street, Chicago
PRACTICAL COLD STORAGE. 811
EIGHTH EDITION
Compend of
Mechanical Refrigeration
and Engineering
By PROF. J. E. SIEBEL
The Most Popular Book Yet Written on
Mechanical Ice Making and Refrigeration
This book is recognized as the standard work on
theoretical and applied refrigeration. It presents
in a convenient form the rules, tables, formulae
and directions which are needed by contractors
and engineers of refrigerating machinery. It is
indispensable to the operator of an ice making,
refrigerating or cold storage plant.
Every User of Ice Making or Refrigerating Machinery
Should Have a Copy.
p . /Bound in Cloth ...$3.50
*^"*^*t Bound in Flexible Morocco... 4.00
Sent Prepaid to Any Address on Receipt of Price
Nickerson & Collins Co.
PUBLISHERS
431 So. Dearborn Street, Chicago
812 PRACTICAL COLD STORAGE.
SECOND EDITION
Mohun
On Warehousemen
A COMPILATION OF
Warehouse Laws and Decisions
By BARRY MOHVN
A compilation of the laws of the several states and territo-
rial possessions pertaining to Warehousemen and the
Warehousing business.
Since the publication of the first edition, the Uniform
Warehouse Receipts Act, in the drafting of which the
author assisted, has been passed by Congress to be in force
in the District of Columbia, and by the legislatures of
twenty-eight states. The act is also in force in the Philli-
pine Islands and Alaska.
This volume also contains all the statutes pertaining to
warehousemen now in force in the several states, including
all the Cold Storage Laws in full so far adopted.
There is also included an annotated copy of the Uniform
Warehouse Receipts Act showing all reported decisions
containing or pertaining to same.
1000 Pages — Price in Full Law Buckram, $7.30
Sent prepaid to any address upon receipt of price
Nickerson & Collins Co.
PUBLISHERS
431 South Dearborn Street, Chicago
PRACTICAL COLD STORAGE. 813
THIRD EDITION
STORAGE
RATE GUIDE
CONTAINING
STORAGE RATES ON GENERAL MERCHANDISE.
FREE AND IN BOND; COLD STORAGE; HOUSE-
HOLD GOODS; AGRICULTURAL IMPLEMENTS
AND MUCH VALUABLE INFORMATION ON
WAREHOUSING.
Compiled by the
AMERICAN WAREHOUSEMEN'S ASSOCIATION
Rates given here carefully compiled from all parts of the
country and have been accepted by commercial bodies as
fair rates. This guide should be in the hands of every cold
storage warehouseman.
I Bound in Cloth Sl^OO
^"^^ 1 Bound in Flexible Morocco 1-50
Sent postpaid to any address on receipt of price
NICKERSON & COLLINS CO.
Publishers
431 So. Dearborn Street CHICAGO
814 PRACTICAL COLD STORAGE.
The Most Useful Book for the
Operating Engineer
Refrigeration Memoranda
By JOHN LEVEY
Vest Pocket Size for Ready Reference
Just the book for the operating engineer of an ice making or
refrigerating plant. Contains such information as is required in the
daily operation of a plant. Written in plain engine room language
so that the text may be readily understood.
PRICE — Bound in Flexible Morocco 75 cents
Sent Prepaid to Any Address Upon Receipt of Price
NICKERSON & COLLINS CO.
431 South Dearborn Street, Chicago
Learn All About
The Modern Packing House
By F. W. WILDER
The Construction and Operation of Packing Houses.
The Costs and Profits of Killing and Dressing Cattle, Hogs and Sheep.
The Treatment of all By-Products, Yields, Costs and Profits.
Formulae for Curing and Preserving all Packing House Products.
Formulae for Making and Preserving all kinds of Sausage, etc.
Formulae and Temperatures for Oleo Oil, Stearine, Lard and Butterine.
Also gives a vast amount of other useful and valuable information never before
made public.
ToU for the first time by a man who knows
$10.00
!.00
DOI/-I7 J Bound in Cloth - $I0.(
*^'*'^'^lBound in Full Morocco I2.(
Sent Prepaid to Any Address Upon Receipt of Price
NICKERSON & COLLINS CO.
431 South Dearborn Street, Chicago
PRACTICAL COLD STORAGE. 815
The Absorption
Refrigerating Machine
By GARDNER T. VOORHEES
A complete practical elementary treatise
of the Absorption System of refrigeration
involving the broad general principles of
all types of absorption refrigerating ma-
chines. Profusely illustrated.
PRICF i B°""'^ ™ Cloth , - $1.00
1 Bound in Full Morocco 1 .30
Sent to Any Address Upon Receipt of Price
NICKERSON & COLLINS CO.
431 South Dearborn Street, Chicago
Indicating the Refrigerating
Machine
By GARDNER T. VOORHEES
To enable the refrigerating engineer to readily detect
and discount trouble with the compressor or engine, and
to secure full capacity of their machine has led the
author to explain fully the application of the indicator
card to the ammonia compressor and steam engine,
with practical instructions relating to the construction
use and computing thereof. Profusely illustrated.
DDir^r J Bound in Cloth - $2.00
*^**'^'^1 Bound in Full Morocco 2.50
Sent to Any Address Upon Receipt of Price
NICKERSON & COLLINS CO.
431 South Dearborn Street, Chicago
816
PRACTICAL COLD STORAGE.
A Permanent Investment
There is no greater fallacy than buying ice-making
refrigerating machinery on a basis of first cost, regard-
less of what that cost covers.
No reputable builder is going to take advantage of
his customers, for a satisfied customer is one of the
most valuable assets a builder could have.
In comparing the prices of the De La Vergne equip-
ment with that of another, analyze the various items
which the price covers. You will find that our machines
represent maximum value on a basis of permanent
profit paying capacity.
And you must consider your machine equipment as
a permanent investment — not as an initial expense to
be paid and forgotten.
Your best, safest, most profitable investments are not
the ones which you buy at the cheapest rate.
We are prepared to meet any conditions from our
standard line. Write us your requirements and let
us make you a quotation on a "quality" equipment.
Refrigerating Machines
Oil Engines
De La Vergne Machine Company
1160 East 139th Street
New York City
50% Of Oil Saved
BY USING
ROCHESTER
Automatic Lubricators
Read This Letter from Another Enthusiastic User
GREENE, TWEED & CO.
109 Duane Street, New York.
Gentlemen: —
We have five of your Rochester Automatic Lubri-
cators at our ice plant, three of which were recently
placed on three well pumps.
We have had much trouble with our old lubricators,
as we could not depend on the proper distribution of the
oil, particularly so in cold weather, when they needed
considerable attention.
Yourlubricator worked so satisfactorily on one of our
ice machines that we decided to place more of them on
our well pumps. We now use less than half the amount
of oil formerly used and we do not get any
more oil mixed with the water, which has
greatly improved our ice.
Yours very truly,
IjH (Signed) JOHN SCHNEIDER, C. E.
1^^ Peoples Hygienic Ice & Coal Co.
Jr Brooklyn, N. Y.
Let Us Send
A Rochester
On 30 Days' Trial
Catalog on Request
GREENE, TWEED & CO.
109 Duane Street, NEW YORK CITY
Why It Pays to Use
This Ammonia
To use Bower Braiadf Anhydrous Ammonia is to
safeguard your plant against impure ammonia, and the
expense and trouble it causes.
For impure ammonia generates trouble-making
gases. And no pure ammonia gases can . penetrate the
pipe space occupied by these foreign gases. Thus no
cold can be produced.
The result is high working pressure and a costly
reduction in profits. •
Bower Brand
Anhydrous Ammonia
represents the utmost in ammonia purity. No other
ammonia is so perfectly pure. Because no other maker
can use our exclusive purifying process.
In our process of manufacture we remove every
vestige of organic impurity of ammonia. Our guar-
antee for strict purity and dryness accompanies every
cylinder of B. B. Ammonia.
Send for Our Free Book
Our new book is a gold mine of information to everyone who is inter-
-ested in refrigerating and ice-making plants. Send for it today.
For your convenience we have placed stocks of
B. B. Anhydrous in the principal cities. You will find
the names of these distributors in the current number
of "Ice and Refrigeration." Please send your order to
the agency nearest you. You will be promptly supplied.
Henry Bower Chemical Mfg. CompaHy
tSth Street and Gray's Ferry Road PHILADELPHIA, PA.
Practical Cold Storage
can be made more practical by using a YORK
Refrigerating Machine. In a Cold Storage
Plant so much depends upon the proper oper-
ation of the Refrigerating System, that it pays
to buy a machine of recognized worth. York
Machines are in successful operation today in
the largest Cold Storage Plants in this country.
If in doubt — investigate. We build
COMPRESSION MACHINES
ABSORPTION MACHINES
AMMONIA FITTINGS
and all the apparatus necessary
to equip a complete plant.
Write for Catalog
YORK MANUFACTURING COMPANY
Main Office and Works:
York, Pa.
Branches in all Principal Cities
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