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EGGS IN COLD STORAGE 
 
 THEORY AND PRACTICE IN PRESERVING EGGS BY RE- 
 FRIGERATION. DATA, EXPERIMENTS, HINTS ON 
 , CONSTRUCTION, ETC., FROM PRACTICAL 
 EXPERIENCE, WITH ILLUSTRATIONS. 
 
 BY 
 
 MADISON COOPER. 
 
 CHICAGO : 
 H. S. RICH & CO. 
 
 1899. 
 

 
 Copyrighted 1898, IX 1 )') 
 BY MADISON COOPER. 
 
 PKKSS OK 
 
 ICK AND RKFRIOIOK \ riox. 
 
 CHICAGO. 
 
PREFACE. 
 
 IN the interest of a better understanding 1 and dissem- 
 ination of knowledge on the cold storage of eggs, 
 the writer has communicated with quite a large num- 
 ber of individuals and companies, asking their ideas 
 and requesting that they give full answers to a printed 
 list of questions sent them. Although, at first, the 
 replies were rather slow in coming in, the total result 
 of these letters has been most gratifying; nearly one- 
 half acknowledging receipt of the inquiry, and more 
 than one-half of this number giving fairly full replies 
 to the questions submitted. Considering the fact 
 that the inquiries were regarded by some as being of 
 a rather personal nature, the proportion of managers 
 sending full replies is large. Several gentlemen were 
 frank enough to say that personal considerations pre- 
 vented them from giving any information; others 
 gave guarded or partial replies. In the main, how- 
 ever, storage men have been willing to give informa- 
 tion and exchange ideas. 
 
 The list of inquiries sent out covers the subject 
 very thoroughly, and divides it into six different 
 parts, with three separate questions relating to each. 
 To the data so cheerfully furnished by others is added 
 information from thewriter's experience and practice, 
 with such explanation of theory and practice as may 
 seem necessary to a clear understanding of the prin- 
 ciples of successful egg refrigeration. It is hoped 
 that those who are new to the business may obtain 
 valuable information from these collected data, and 
 that those with experience may derive some benefit 
 in the way of a review, and possibly pick up some 
 new ideas as well. 
 
 A large portion of the matter contained in these 
 
 Q C U fi x - 
 
4 PREFACE. 
 
 pages appeared in Ice and Refrigeration as a series 
 of articles entitled: "Eggs in Cold Storage." The 
 present book is printed for the purpose of putting 
 the matter in permanent form, believing that those 
 who have followed the original articles would find it 
 convenient for future reference. While the present 
 book has many shortcomings, and there is no doubt 
 room for the addition of much information, reliable 
 data, and the results of extended observations and 
 tests, there has not heretofore been anything like a 
 complete write-up of the subject; and in consideration 
 of this fact the reader is asked to be liberal in his 
 criticism. 
 
 If any errors or lack of details are noted, the 
 author would gladly acknowledge and explain the 
 points at fault if his attention is called toany. No other 
 object has been in mind in writing these articles than 
 a furtherance of scientific knowledge on the subject 
 of refrigeration as applied to the preservation of per- 
 ishable products, and the great assistance rendered 
 by those who have written painstaking replies to the 
 list of inquiries is hereby acknowledged. The com- 
 bination and comparison of information are beneficial, 
 and if those who have further data or records of tests 
 will only put them before others in their line of busi- 
 ness, no loss will be sustained by the individual giv- 
 ing the information, while much general good will 
 result. 
 
INTRODUCTION. 
 
 THE value of the eggs placed in cold storage for 
 preservation is estimated at about $20,000,000 
 annually for the United States alone. Considering 
 the importance the industry has already attained, its 
 rapid growth and future outlook, the amount of ac- 
 curate 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 structure are not usually explained by 
 those interested in promoting new enterprises in this 
 line, and consequently not appreciated by those mak- 
 ing the investment. Financial disaster has over- 
 taken many large companies who have erected costly 
 refrigeratingwarehouses; thosewhich have succeeded 
 have been forced to install new systems, make expens- 
 ive changes, and make a thorough study of the prod- 
 ucts handled. The experience 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 the business may find food for 
 thought in the above, and the history of a dozen 
 houses, in diiferent localities, will be good information 
 for would-be investors. 
 
 The scarcity of knowledge on the subject in hand, 
 while being partly the result of the half developed 
 state of the art until very recently, is also very 
 largely owing to narrow-mindedness on the part of 
 some of the older members of the craft, who have 
 largely obtained their skill by years of experience 
 and study, some of them having expended large sums 
 on experimental work. The same experiments have 
 
6 INTRODUCTION. 
 
 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 at this stage in the de- 
 velopment of refrigeration, that the improvements to 
 be made during- the next twenty years will be of very 
 much less importance than those made during- the 
 twenty years just ending-; trade secrets, so jeal- 
 ously guarded by some, must disappear, as they have 
 in other branches of engineering-. Storag-e men have 
 been oblig-ed to work out their own salvation in stor- 
 ing- problems, sometimes sending their most difficult 
 points to be answered through the columns of Ice and 
 Refrigeration, and, perhaps, comparing ideas with 
 those of their personal friends in the same line of 
 business. It is to be observed that the most pro- 
 gressive and up-to-date manufacturing concerns in 
 the United States to-day are giving their contempo- 
 raries every opportunity of observing their methods, 
 and are very willing and anxious to talk over matters 
 pertaining to their work, from an unselfish stand- 
 point. So, too, the successful cold storage of the 
 future will be sure to make " visitors welcome." 
 
 In anything which will appear in these articles, it 
 is not the writer's intention to convey the idea that 
 any mere theoretical knowledge, which can be ac- 
 quired by reading and study, or even by an exchange 
 of ideas in conversation, can take the place of practi- 
 cal observation in actual house management; but 
 there are applications of well known natural laws, 
 which are not generally understood by storage men, 
 and their progress is handicapped from lack of this 
 theoretical knowledge. The two following illustra- 
 tions, bearing on temperature and ventilation, are 
 among the common errors made in practice, yet easily 
 understood when studied and tested: Some storage 
 houses have formerly held their egg rooms at 33 F., 
 fearing any nearer approach to the freezing point of 
 
INTRODUCTION. 7 
 
 water (32 F.), thinking- the eggs would freeze. A 
 simple experiment would settle this point, giving the 
 exact freezing- temperature, as well as the effect of 
 any low temperature on the egg tissues. Again, 
 others have thought to ventilate by opening- doors 
 during- warm weather. It never happens that storag-e 
 rooms can be benefited by this treatment at any time 
 during- the summer months, and only occasionally 
 during* spring- and fall. The dew point of outside air 
 is rarely below 45 F. during- summer, and when 
 cooled to the temperature of an eg-g- room, moisture 
 will be deposited on the goods in storage, causing- a 
 vigorous -growth of mildew. 
 
EGGS IN COLD STORAGE. 
 
 CHAPTER I. 
 
 TEMPERATURE. 
 
 TEMPERATURE is selected for first considera- Temperature 
 . . . ., ,, ,. . . more important 
 
 tion, as it is the primary elementoi reingeration, than any other 
 
 Jf -,.,. ^ A condition. 
 
 and more important than any other condition. Correct 
 temperature alone, however, will not produce success- 
 ful results, anymore than a g-ood air circulation, or cor- 
 rect ventilation, would give good results with a wrong- 
 temperature. This applies more especially to egg re- 
 frigeration, someproducts requiringonlyalowtemper- 
 ature for preservation. The common impression of 
 cold storage is what the name implies simply a build- 
 ing in which the rooms may be cooled to a low degree 
 as compared with the outside air. Even those who 
 build, sell and erect refrigerating machinery and appa- 
 ratus often show either gross carelessness or ignor- 
 ance 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 writer gets the 
 impression that the architects regard temperature 
 as the only requisite for perfect work. Some of the unskiiifuiiy 
 rooms in these new houses are simply insulated and e^j? m?ms. 
 fitted with brine or ammonia pipes, the location of the 
 coils having 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 ne- 
 cessity of providing for air circulation seemed not 
 worthy of consideration, to say nothing of the lack of 
 anything like an efficient ventilating system. 
 
 Questions regarding the correct temperature of Opinions 
 egg rooms have been asked repeatedly of storage correct'"* 
 
 , - j.i ' i i temperature. 
 
 men who have been in the business long enough to be 
 
10 EGGS IN COLD STORAGE. 
 
 looked to for advice, the same person, perhaps, 
 giving- a different answer, from time to time, as his 
 ideas changed. The query has also been asked and 
 answered through the columns of ICE AND REFRIG- 
 ERATION a number of times. At present, however, 
 there is no temperature on which a large majority of 
 persons can agree as being- rig-ht, and as giving- su- 
 perior results to any other. The claims made by the 
 advocates of different temperatures will be consid- 
 ered, to determine, if possible, what degree is giving 
 the best results in actual practice. 
 
 The three questions relating to temperature were 
 temperature. wr itten to draw out opinion as to the right tempera- 
 ture, the lowest safe temperature, and what delete- 
 rious effect, if any, the egg sustained at low tempera- 
 tures, 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 
 lowest limit at which eggs may be safely stored? 
 
 Third. What effect have you noticed on eggs held 
 at a lower temperature? 
 Fig-ures All the replies received contained answers relative 
 
 received relat- 
 
 to temperature, 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 the freezing 
 point, none recommended a temperature lower than 
 28 F., and for a very obvious reason, this being near 
 to the actual freezing temperature of the albumen of 
 a fresh egg. A very respectable minority say a tem- 
 perature ranging from 30 F. to 31 F. is giving them 
 prime results; and several 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 
 
EGGS IN COLD STORAGE. 11 
 
 they are unable to maintain a uniform low tempera- 
 ture below 33 F., without danger of. freezing- eggs 
 where they are exposed 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 eg-g-s. A very successful east- 
 ern house issued a pamphlet in 1892. At that time 
 they maintained a temperature of 32 F. to 34 F. in 
 their rooms. In sending- out this little book during 
 the winter of 1897-98 a postscript was added, as fol- 
 lows: " This pamphlet was published in 1892, when 
 our plant was started. Since that time all first- 
 class cold storag-e houses have lowered their temper- 
 atures materially." No better illustration than this 
 can be cited to show the tendency of the times. 
 These people now use a temperature of 30 F. for 
 eg-g-s. 
 
 Most of the replies received contained answers to Re P liesto 
 
 query No. 2. 
 
 question No. 2, and the greater portion state this as 
 being- about 2 F. lower than that recommended for 
 long- period storag-e. It is presumed that these two 
 degrees are allowed as leeway, or margin of safety, 
 for temperature fluctuations. Some state that eg-g-s 
 cannot be safely held below 32 F., but give no reason 
 why, while two or three say a temperature of 27 F. 
 will do no harm to eg-g-s in cases. One reply states 
 that egg's held in 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 contin- 
 uously maintained for a length of time sufficient to 
 allow the heat to escape; and we know that eggs will 
 positively freeze at 25 F., as proven by experiments 
 mentioned in another paragraph. 
 
 The answers to question No. 3 were few in num- Replies to 
 
 . ., __... . , 1 query No. 3. 
 
 ber, but cover a wide range. The scarcity of data on 
 this point indicates that few have experimented with 
 
12 EGGS IN COLD STORAGE. 
 
 eggs at temperatures ranging- from 25 F. to 30 F. 
 Some say: "Dark spot, denoting germ killed"; others, 
 "white gets thin"; others, "eggs will decay more 
 quickly"; or, "they wnl 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 C F, 
 for any length of time. 
 
 As far as possible, we will dig out reasons for the 
 tempatureB W c ^ a i ms made by advocates of both high and low tem- 
 peratures, 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 keep well, that the consis- 
 tency 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 temperature. As against a low tem- 
 perature they say: A temperature of 30 F. is expen- 
 sive to maintain; the yolk of the egg becomes 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 some- 
 what higher temperature, resulting in more harm to 
 the eggs. Some claim that the keeping qualities are 
 impaired by holding at a temperature as low as 30 C 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 mildew, 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 
 
EGGS IN COLD STORAGK. 13 
 
 held sweet and reasonably full at this temperature 
 from six to eight months. This last claim is a broad 
 one, and very 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 Je 
 men in the business, who has spent much money and 
 time on experiments, and studied the question for 
 years. He says: "A temperature 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 gen- 
 tleman 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 
 above as a white film. The worst hing 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 ascertain 
 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 preservation of eggs. 
 
 Heat and moisture are the two conditions lead ing- Causes operat- 
 
 & ing- to produce 
 
 to its rank growth, and the opposite dry ness and cold [J I 8rrow1 JJ 1 of s 
 will retard or stop the growth entirely. In moist, in oM storage, 
 tropical countries many species of this parasite grow, 
 while in the cold, dry regions of the north its exist- 
 ence is limited to a single variety. The causes lead- 
 ing to a growth of the fungus on the outside of an egg 
 are not far to seek. It feeds on the moisture and 
 products of decomposition which are being constantly 
 given off by an egg, from the time it is first dropped 
 
14 EGGS' IN COLD STORAGE. 
 
 until its disintegration, unless immersed in a liquid, 
 or otherwise sealed from contact 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 eg-g- meat. Conditions of excess- 
 ive moisture and the presence of decaying- animal or 
 vegetable matter, tog-ether with a moderate degree of 
 heat, are essential to the formation of fungus of the 
 species which are found growing- on eg-g-s 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 decomposition of an egg results in a 
 growth of the fungus, as before explained, when con- 
 ditions of temperature and humidity are favorable. If 
 the temperature is low, this growth is slow; for in- 
 stance, 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 humidity here, the reader is referred to 
 what is said under this head in another chapter, 
 someexperi- Returning to the objections urged against low 
 
 <Skng n po int temperatures, we will see what damage is claimed 
 from the use of a temperature of 29 to 30 F. The 
 objections are: Liability of freezing; germ is killed; 
 white becomes thin; yolk is hardened, and eggs will 
 not keep as long when removed from storage. Some 
 interesting results are obtained from experiments 
 made by the writer. Half-rotten or "sour" eggs 
 freeze at temperatures just a trifle under 32 F. 
 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 depressed 
 from 1 to 2 F. An egg which is leaky will freeze at 
 2 to 3 higher temperature than one which is sound, 
 probably owing to the evaporation resulting in a lower 
 
EGGS IN COLD STORAGE. 15 
 
 temperature. The freezing point of eggs, as above, 
 is understood as being the degree at which they begin 
 to form ice crystals inside. Of the replies received 
 touching on the freezing point of eggs, nearly all agree 
 with above experiments. The " dead germ " theory Dead germ 
 the writer has never been able to locate in fact, hav- 
 ing 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 sea- 
 son. 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. With refer- 
 ence to the above, it is the writer's opinion that a dif- 
 ference 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 temperature 
 on the egg yolk, it has been demonstrated that 
 any temperature, 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 writer that no difference was noted 
 between 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 A test showing 
 
 ,, .. r i'iii, .... keeping- quali- 
 
 three dozen of eggs, which had been carried m storage ties of eggs 
 
 at a temperature of 28 F. to 30 F. for five months, temperature. 
 
16 
 
 EGGS IN COLD STORAGE. 
 
 in a case along- with three dozen fresh eggs. After 
 three weeks no pronounced change was noted in 
 either, both showing- considerable evaporation as a 
 result of exposure to the dry fall atmosphere. They 
 were exposed to the temperature of the receiving- 
 room, fluctuating- from 50 F. to 80 F. The eg-g-s 
 from storage went throug-h a "sweat," while the fresh 
 were not subjected to any such trial. As most eggs 
 are consumed inside of three weeks after being re- 
 moved 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 30 F., while readily appreciated 
 and admitted, seems of very small importance, when 
 a positive advantage can be obtained by carrying eggs 
 at the lower temperature; and a difference of 4 F. to 
 5 F. would be scarcely worth considering. 
 
 uire fc relents" ^ n a( l vantage f l w temperature, not yet men- 
 "spot" rotten tioned, is the increased stiffness, or thickness, of the 
 white of the egg while in storage, holding the yolk in 
 more perfect suspension. 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 rotten eggs, known 
 as "spots." It is usually understood that the yolk set- 
 tles; but, being of a fatty composition, it is lighter than 
 the albumen, and rises instead. If the albumen is 
 maintained 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 season, to prevent the above 
 trouble, and some recommend it even now; but the 
 practice has been generally abandoned with the ad- 
 vent of low temperatures for egg storing. 
 
 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 temperature. This is especially true 
 
 from storage, 
 
EGGS IN COLD STORAGE. 17 
 
 where egg's 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 albumen. 
 If this process of cooling and warming could be prac- 
 ticed carefully (which is not always practicable com- 
 mercially), a well kept storage egg would' come out of 
 storage with nearly the same vitality it had when fresh. 
 
Data available 
 on humidity 
 practically 
 nothing-. 
 
 Evaporation 
 and mold can 
 be prevented. 
 
 Questions 
 relating- to 
 humidity. 
 
 CHAPTER II. 
 
 HUMIDITY. 
 
 INFORMATION on the subject of humidity, as 
 J. applied to the cold storage of eggs, is very meager. 
 Not more than a dozen of the replies received in 
 answer to the li& t of inquiries sent out contain infor- 
 mation on the three queries under the head of hu- 
 midity. Considering the amount of talk we have all 
 heard, with dry air as a subject, this scarcity of knowl- 
 edge is rather surprising. Those who have had ex- 
 perience with cold storage work and the products 
 handled are well aware that an essential for good re- 
 sults in egg refrigeration is a dry atmosphere 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 writer, 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 in storage 
 would show either a considerable evaporation or a 
 radical " musty " flavor. To some extent this is true, 
 but with a penetrat-ing circulation, careful ventilation 
 and a judicious use of absorbents (all of which will 
 be considered under their proper heads) egg 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 informa- 
 tion on the subject, and were designed to locate, if 
 
 18 
 
EGGS IN COLD STORAGE. 19 
 
 possible, those who were making* tests of air moist- 
 ure, and get opinions on the correct humidity for a 
 given temperature. The following- are the queries: 
 
 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? 
 
 Third. What instrument do you use for testing 
 air moisture? 
 
 Questions 1 and 3 are practically the same, the 
 latter being written simply to make the query more 
 plain and indicate whether an instrument or some 
 other test was used for determining air moisture. 
 Four houses reporting are using the dry and wet bulb 
 thermometers; the others are using hygrometers of 
 French or German make. 
 
 The answers to question 2 vary greatly ; some 
 also giving the actual testing humidity of their rooms humidity. 
 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 writer, 
 nearly all show a similar humidity, with one occasion- 
 ally going as high as 85 per cent, and some as low as 
 65 per cent. Two answers recommend a humidity 
 of 65 per cent, and one a humidity of 60 per cent, 
 with a temperature of 30 F. to 32 F. Others hold 
 that their testing humidity of 70 to 80 per cent is 
 correct. The matter of correct humidity will be dis- 
 cussed further on. 
 
 The humidity of a room depends on the season 
 a moderate extent, and the condition of the room, as humidity. 
 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 absorbents, serious consequences are 
 sure to follow. 
 
20 
 
 EGGS IN COLD STORAGE. 
 
 what relative To enable us to thoroughly understand the mean- 
 humidity . J 
 signifies. mg- of relative humidity, as it is called, we will study 
 
 a few extracts from " Instructions to Voluntary Ob- 
 servers," issued by the Weather Bureau at Washing-- 
 ton, D. C. 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 the point at 
 which air contains no moisture whatever. The vari- 
 ous percentag-es 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 instructions, but are from the 
 issue of 1892, which is now superseded by that of 1897. 
 
 Quoted from 
 "Instructions 
 to Weather 
 Observers." 
 
 WATER VAPOR IN AIR. 
 
 The air contains vapor of water, transparent and color- 
 less like its other g-aseous components. It only becomes visible 
 on condensing 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 vapor, 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 vapor con- 
 tained 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 temper- 
 atures, the weight of vapor, in grains, contained in a cubic 
 foot of air is as follows: 
 
 Temperature of 
 Saturation, Degrees F. 
 
 
 10 
 20 
 30 
 40 
 50 
 60 
 70 
 80 
 90 
 100 
 
 Weig-ht in a 
 Cubic Foot, Grains. 
 
 0.56 
 
 0.87 
 
 1.32 
 
 1.96 
 
 2.85 
 
 4.08 
 
 5.74 
 
 7.98 
 10.93 
 14.79 
 19.77 
 
EGGS IN COLD STORAGE. 21 
 
 The air is never perfectly saturated, not even when rain 
 is falling-; neither is it ever perfectly dry at any place. Rela- 
 tive humidity 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 represents a great 
 deal. 
 
 The most important law relating- to above concise 
 statements, and one which, if carefully noted and 
 applied, will make, all work in humidity easily under- 
 stood, is best expressed thus: The capacity of air for 
 moisture is increased with its temperature.* 
 
 At a temperature of 40 F., air will hold in sus- 
 pension more water vapor than at any lower tempera- 
 ture (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. 
 
 Under the head of "Temperature," it is stated . th 
 
 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 humidity. Refer- 
 ring again to the table, we see that a cubic foot of air, 
 when saturated at a temperatureof 40 F.,contains2. 85 
 grainsof water vapor, while at 30F. it contains but 1.96 
 grains, or only about two-thirds as much as at 40 F. 
 The same holds true with any relative humidity, the 
 same as when the air is saturated. Take, for instance, 
 air at a temperature of 40 F., with a humidity of 75 
 per cent, then a cubic foot of air holds 2.14 grains of 
 water vapor per cubic foot; and at a temperature of 
 
 * Strictly speaking, air has no capacity for moisture, the water vapor being 
 simply diffused through the air, after the nature of a mechanical mixture. For 
 all practical purpases, we may regard it as being absorbed by the air, and it is 
 usually so treated. 
 
22 EGGS IN COLD STOKAGK. 
 
 30 F., with the same relative humidity, it would hold 
 but 1.47 grains. This great difference in the amount 
 of moisture contained in the air at different temper- 
 atures, 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 
 Result of too atmosphere with a lower relative humidity, the result 
 r<Sm anef?? 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. 
 humwit r y l not v& 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 tem- 
 perature lower, and the result cannot fail to be as de- 
 scribed. The writer has already given a summary of 
 the replies to the questions relating 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 follow- 
 ing table of correct humidity for a given temperature 
 in egg rooms has been compiled. There are no data on 
 the subject in 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 
 
EGGS IN COLD STORAGE. 23 
 
 and distribution of the air circulation employed. (See 
 Chapter III on "Circulation.") 
 
 CORRECT RELATIVE HUMIDITY FOR A GIVEN TEMPERATURE 
 IN EGG ROOMS. 
 
 Temperature Relative Humidity, Humidity table 
 
 in Decrees F. Per Cent. for egg rooms. 
 
 29 78 
 
 30 76 
 
 31 74 
 
 32 71 
 
 33 69 
 
 34 67 
 
 35 65 
 
 36 62 
 
 37 60 
 
 38 58 
 
 39 56 
 
 40 53 
 
 There are two kinds of instruments in use for de- Hygrometers. 
 termining- humidity, hygrometersand psychrometers. 
 The hygrometer depends on the expansion and con- 
 traction 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 chang-es its 
 leng-th. The scale reads from to 100. The chief 
 advantag-e of these instruments is that results are 
 obtained at once, the reading- corresponding- to the 
 percentag-e of saturation or relative humidity; but 
 these instruments are affected by chang-es 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, 
 g-etting- observation 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 Psychrometers. 
 mounted on a frame ; the bulb of one being- covered 
 
24 KGGS IN COLD STORAGE. 
 
 with rnuslin so as to retain a film of water surround- 
 ing it. The working- of this instrument depends on 
 a law which may be roughly expressed, as "evapora- 
 tion carries off heat." The evaporation of water from 
 the bulb incased in muslin, known as the wet bulb, 
 cools it somewhat, depending- on how dry the air sur- 
 rounding- 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, give's the relative 
 humidity of the air at the time of making- the observa- 
 tion. Psych rometers are of two kinds, stationary 
 and sling-. 
 
 The stat i nar y 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 muslin covering- the 
 wet bulb being connected by a porous cord with a 
 reservoir of water, to keep the supply of water con- 
 tinuous. 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 cord feed- 
 ing water to it, become clogged with solid matter and 
 fungous growth affecting its accuracy. At any tem- 
 perature below 32 F. this instrument is useless, as 
 the water will freeze in the cord supplying the mus- 
 lin on the wet bulb, and the muslin becomes dry in 
 consequence. 
 
 For practical, accurate and quick results at any 
 
 psychrometer. . 
 
 temperature there is no instrument so reliable and 
 convenient as the sling psychrometer, preferably of 
 the pattern known as Prof. Marvin's improved psy- 
 chrometer, shown in the illustration. This is a 
 standard Weather Bureau instrument, and when used 
 
EGGS IN COLD STORAGE. 
 
 25 
 
 in connection with the tables of hu- 
 midity 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 thetop, the frame or plate 
 supporting- the thermometers is pro- 
 vided with a handle for whirling-, 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 ther- 
 mometer is wet at the time of making- an ob- 
 servation, Ihe muslin serving- to retain a film 
 of water, surrounding- and in contact with 
 what is known as the wet bulb of the psy- 
 chrometer. 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 accumulation of dust from the air. 
 The muslin in this condition will neither ab- 
 sorb nor evaporate the water readily. 
 
 To make an observation dip the muslin Directionsfor 
 
 using 1 the sling 
 
 covered bulb in a small cup or other wide-P s y chrometer - 
 mouthed receptacle containing- water. Whirl 
 the thermometer for ten or fifteen seconds, 
 then dip the wet bulb of the psychrcmeter 
 into the water again. Whirl again for ten or 
 fifteen seconds, stop and read quickly, read- 
 ing- the wet bulb first. Repeat once or twice, 
 noting- the reading- each time. When two 
 successive readings of the wet bulb agree 
 very nearly, the lowest point has been 
 Dip the wet bulb only after the 
 
 f 
 
 SLING 
 PSYCHRO- 
 METER. -reached. 
 
26 EGGS IN COLD STORAGE. 
 
 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 read- 
 ing, but the accuracy will not be impaired, if sufficient 
 time is allowed for the mercury to settle. It is very 
 important that the muslin covered 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 getting accurate readings down to 
 29 F., as indicated by the dry bulb. At about this 
 temperature, and with the wet bulb at about 27 F., 
 ice will form on the wet bulb and cause the psychro- 
 meter to become somewhat erratic in its behavior.* 
 
 Jt is difficult to describe the proper movements 
 psychrometer. f or whirling the sling psychrometer, a little practice 
 being the best instructor. The handle is held in 
 a horizontal position, the frame mounting the ther- 
 mometers revolving around the pivot, after the man- 
 ner 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 thermometer from the high- 
 est point of the circle of rotation, whereby the radius 
 of the path of the psychrometer is increased, and the 
 momentum overcome. The stopping can be accom- 
 plished 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. 
 
 * The writer is in receipt of a special report on this point, prepared by 
 Prof. C. F. Marvin, in charge of the instrument division of the Weather Bureau, 
 and will gladly give any one having difficulty with the psychrometer at these 
 temperatures information so far as he can; but the point involved is somewhat 
 intricate, and so few are using temperatures as low as 29 F. that it is thought 
 best to omit a discussion of this phenomenon. 
 
EGGS IN COLD STORAGE. 
 
 27 
 
 In making- observation in a storage room, the psy- 
 chrometer should be held as far as convenient from 
 the body, and toward the direction from which the 
 circulation comes the observer standing- to the lee- 
 ward, 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 di- 
 rection of the psychrometer, so 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 a common practice with the 
 writer to hold his breath while reading a thermome- 
 ter. It is unnecessary to caution ag-ainst allowing- the 
 psychrometer to strike any object while whirling*. 
 In case it should, the observer will have $5 worth of 
 experience, but no psychrometer. 
 
 RELATIVE HUMIDITY, PER CENT. 
 
 0) 
 
 >> 
 
 Difference between the dry and wet thermometers (tf). 
 
 Table of rela- 
 v tive humidity. 
 
 K.-*- 1 
 
 Q 
 
 0.5 
 
 1.0 
 
 1.5 
 
 2.0 
 
 2.5 
 
 3.0 
 
 3.5 
 
 4.0 
 
 4.5 
 
 5.0 
 
 5.S 
 
 6.0 
 
 Q 
 
 28 
 
 94 
 
 88 
 
 82 
 
 77' 
 
 71 
 
 65 
 
 60 
 
 54 
 
 49 
 
 43 
 
 38 
 
 33 
 
 28 
 
 7.9 
 
 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 
 
 59l 
 
 54 
 
 50 
 
 45 
 
 40 
 
 32 
 
 33 
 
 95 
 
 90 
 
 85 
 
 80, 
 
 75 
 
 70 
 
 65 
 
 60 
 
 56 
 
 51 
 
 47 
 
 42 
 
 33 
 
 34 
 
 95 
 
 91 
 
 86 
 
 8ll 
 
 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 i 
 
 96 
 
 92 
 
 88 
 
 84 
 
 80 
 
 76 
 
 72 
 
 68 
 
 64 
 
 60 
 
 56 
 
 53 
 
 40 
 
 The above short table needs no explanation fur- 
 ther than has been already given. It will cover any 
 case in egg room observations. This table was not 
 intended for cold storag-e work, being- a part of the 
 regular humidity tables published by the Weather 
 Bureau. The full set of tables can be had by 
 
 table 
 
28 EGGS IN COLD STORAGE. 
 
 addressing- the chief of the Weather Bureau, Depart- 
 ment of Agriculture, Washington, D. C. They are 
 published in pamphlet form, along 1 with tables giving- 
 dew point temperatures. Observers must work out 
 the small fractions for themselves, if they think 
 necessary, but results within the limits covered by 
 the table are near enough for present practical pur- 
 poses. 
 
 It is of no use to test for moisture unless having* 
 the ability to control it, any more than a thermometer 
 would be of use unless the means of regulating* tem- 
 perature were at hand. Humidity can be controlled 
 by ventilation and the use of absorbents, which are 
 considered elsewhere. 
 
 V'J 
 
 
A 
 
 CHAPTER III. 
 
 CIRCULATION. 
 
 vigorous and penetrating* circulation of air must circulation 
 
 * . . essential. 
 
 be maintained in a cold storage room for eggs if 
 good results are to be insured. The importance of 
 this condition, as applied to eggs especially, is quite 
 generally appreciated, and it is noticeable that the 
 warehouses producing the most perfect work have 
 scientific and carefully designed air circulating sys- 
 tems. It is also a fact that a strong, searching circu- 
 lation will do much to counteract defects in a cooling 
 apparatus, or wrong conditions in the egg room in 
 some other particular. In proof of this, the writer is 
 familiar with a number of successful houses where 
 prominence is made of the air circulating system 
 only, some of the other conditions being neglected al- 
 together, or attended to in a perfunctory manner. 
 
 Before going farther, it is best that we separate circulation n 
 
 * . ventilation. 
 
 circulation from its tangle with ventilation. These 
 two terms are quite commonly confused when applied 
 to cold storage work. Circulation, as here discussed, 
 applies to the motion of air within the storage room 
 air currents resulting from a difference in tempera- 
 ture of the air in different parts of the room, or the 
 result of mechanical force applied to the air by use of 
 fans, blowers or exhausters. In distinction from cir- 
 culation, ventilation means the renewal of the air of a 
 storage room, either by forcing fresh air from the 
 outside atmosphere into the storage room, or by ex- 
 hausting the foul air from the room. Ventilation is 
 not under consideration here, but will be taken up as 
 a separate subject. 
 
 The reason why a vigorous and well distributed circulation 
 
 ~ ^ and moisture 
 
 circulation of air in an egg room will give superior absorbing 
 results over a sluggish or partial circulation may not 
 be readily apparent. A circulation of air is of benefit 
 in combination with moisture absorbing capacity in 
 
 29 
 
30 EGGS IN COLD STORAGE. 
 
 the form of frozen surfaces or deliquescent chemicals. 
 Stirring- up the air merely, as with an electric motor 
 fan, without provision for extracting- the moisture, is 
 of doubtful utility, and may, in some instances, prove 
 positively detrimental, as it is liable to cause conden- 
 sation of moisture on the goods, or walls of storag-e 
 room, instead of its correct resting- place: the cooling- 
 coils and absorbents. Let us see how the circulation of 
 air in a storag-e room operates to benefit its condition. 
 Under head of temperature, we have seen that 
 circulation. fo Q evaporation from an eg-g- contains the putrid ele- 
 ments resulting- from a partial decomposition of the 
 eg-g- tissues, and that the air of a storag-e room carries 
 them in suspension. It is probable that these foul 
 elements are partly in the form of g-ases absorbed in 
 the moisture thrown off from the egg-; and if, there- 
 fore, this moisture is promptly frozen on the cooling- 
 pipes, or absorbed by chemicals, the poisonous gases 
 and products of decomposition are very largely ren- 
 dered harmless. This is also true of the germs 
 which produce mold and hasten decay, which are ever 
 present in the atmosphere of a 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 immediate vicinity of the egg gets fully 
 charged with elements which will produce a growth of 
 fungus on its exterior, affecting and flavoring the in- 
 terior the flavor varying in intensity, depending on 
 how thoroughly impregnated with fungus-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 effluvia which are always 
 being thrown off by the eggs, even at very low tem- 
 peratures. It has been suggested that a brisk circu- 
 
EGGS IN COLD STORAGE. 31 
 
 lation of air which will keep in motion the whole 
 volume of air in the storage room will have a purify- 
 ing- influence independent of any moisture absorb- 
 ing- capacity, but no satisfactory reason has been 
 assig-ned. There may be such an influence opera- 
 tive when the air is mechanically circulated. If so, 
 there seems to be no scientific or practical explana- 
 tion of it. 
 
 Manv patents have been granted for improve- circulation in 
 
 A natural ice 
 
 ments in storag-e rooms or refrig-erators using- ice only refrigerators. 
 for a cooling- ag-ent; house refrig-erators, refrigerator 
 cars and refrigerator buildings are represented in 
 number about in order named. A large portion of the 
 patents granted have been on claims for the improve- 
 ment of circulation, and this is the keynote of what- 
 ever success has been attained by the various sys- 
 tems which use ice only for cooling. As any system 
 of cooling whereby the air is caused to circulate in 
 contact with melting ice is now quite generally re- 
 garded as obsolete for the successful refrigeration of 
 eggs for long period storage, a discussion of the 
 merits of the various devices applied to this work 
 will be omitted.* It may be said to their credit, how- 
 ever, that the builders of ice refrigerators have orig- 
 inated ideas on circulation which have been of much 
 value to the present-day refrigerating engineers, and 
 there are still those who may obtain good information 
 from this source the provision for circulation (or 
 rather, lack of circulation) in a few of the new me- 
 chanical cold storage houses being simply ridiculous. 
 In the more progressive mechanically refrigerated 
 houses there are a number of devices, which have 
 been introduced for assisting natural gravity air cir- 
 culation, also the various modifications of the me- 
 
 * The above must not be construed as condemning- the use of ice as a 
 refrigerant when rightly applied. The writer has in successful operation a sys- 
 tem of gravity brine circulation, cooled by ice and salt, with which he will under- 
 take to produce at moderate expense any possible results in refrigeration down 
 to a temperature of 15" F. 
 
32 
 
 KGGS IN COLD STORAGE. 
 
 Questions 
 rel atinar to 
 circulation. 
 
 Answers to 
 Query 1. 
 
 chanical forced circulation system. Some of these 
 will continue to gain favor because of the improved 
 results obtained by their use. The main requisite 
 in any air circulating- system is an ability to cause an 
 equal distribution of the moving- air, as it comes from 
 the moisture absorbing- surfaces, forcing it uniformly 
 to all parts of the room and compelling- it to flow 
 throug-h and around the. piles of stored g-oods. As a 
 secondary consideration may be mentioned the equal- 
 ization of temperature and humidity in all parts of the 
 room. The writer is somewhat biased in favor of 
 forced circulation, having- developed a very complete 
 system on this line, with some new features. Aside 
 from a matter of economy of space and operation, 
 the system employed matters little, if an effective cir- 
 culation is produced. 
 
 The questions bearing 5 upon circulation contained 
 in the list of inquiries sent out by the writer are as 
 follows : 
 
 First. In piping- your rooms what provision was 
 made for air circulation? 
 
 Second. What difference in- temperature do you 
 notice in different parts of the same room? 
 
 Third. Do you use a fan or any kind of mechanical 
 device 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 tangible replies to all three inquiries. 
 Several of the answers confounded circulation with 
 ventilation, as before alluded to. Question 1, in par- 
 ticular, was badly neglected, indicating, 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, mantle, apron, false ceiling or partition, as 
 illustrated in Figs. 3, 4 and 5. Many of these have 
 been put up after the house has been in operation for 
 
EGGS IN COLD STORAGE. 33 
 
 some time, and are very crude affairs, applied in all 
 conceivable combinations 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 one side, and with sur- 
 prising" improvement to the room, considering- the 
 simplicity of the device. Forced circulation with a 
 complete system of distributing- air ducts is coming 
 into g-eneral use, as the meritsof this way of producing 
 circulation are better understood and appreciated. 
 
 Query 2 was answered more generally, but that Answers to 
 some of the answers were mere guesses, or state- 
 ments 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 impossibility it is only possible 
 with a perfectly designed forced circulation system. 
 In contrast to this claim some answers state a differ- 
 ence in temperature of as high as 4 F. to 5 F., but 
 most answers show a difference of 1 F. to 2 F.; a 
 few ^ F. 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 sometimes partly to 
 location of room as to outside exposure, proximity 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 otherwise 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 hanging 
 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 cir- 
 culation and more or less variation in temperature 
 between floor and ceiling. 
 
34 
 
 EGGS IN COLD STORAGE. 
 
 Answers to 
 Query 3. 
 
 Gravity air 
 circulation. 
 
 In reply to Question 3, about a dozen state that 
 they are using- some form of mechanical forced cir- 
 culation. The advantages of this method will be 
 discussed quite fully later on. About double this 
 number are using- the small electric fans. These 
 also will be treated in the discussion of mechanical 
 air circulation in another chapter. 
 
 As air circulation is a somewhat neglected subject, 
 and comparatively few have experimented enough to 
 have positive opinions, based upon practical expe- 
 rience, reg-arding- the merits of different devices and 
 methods, some of the more prominent and successful 
 ones are illustrated and discussed in this article. 
 
 In considering- the following- outlined arrange- 
 ments of piping- in the storag-e room and the various 
 locations of screens, partitions, etc., in combination 
 with the coils, for the purpose of separating- the 
 warm and cold currents of air (the one on its way 
 upward from lower part of room to the top of 
 cooling- coils; the other downward from cooling- 
 coil toward floor), the principle on which this 
 movement of air operates should be noted, so 
 that the underlying- law may be understood. The 
 cause of a circulation of air in a storag-e room with 
 direct piping- is a variation of temperature, which 
 causes a difference in weig-ht of the air in different 
 portions of the room. The air in the immediate 
 vicinity of the pipes is cooled to a lower temperature 
 than in the balance of the room, causing- it to drop 
 toward the floor by reason of its greater specific 
 gravity what is designated as gravity air circulation. 
 Just as long- as the flow of the refrig-erant is main- 
 tained within the cooling- pipes, the air will circulate 
 by the action of gravity, the lig-hter warm air in top 
 of room descending- to replace the air in contact with 
 pipes, which falls, as cooled, toward the floor. Should 
 the refrig-erant passing- through coils be shut off, the 
 cooling effect is checked, and as a result air circula- 
 
EGGS IN COLD STORAGE. 35 
 
 tion over the pipes ceases. This should make plain 
 the fact that uniform temperatures in all parts of the 
 room are not even an approximate possibility in any 
 room depending- on natural gravity air circulation. It 
 may also be observed that the eg-g-s exposed to the 
 flow of cold air near bottom of coils will stand in a 
 dryer and colder atmosphere than those in top and 
 center of room. 
 
 Fig-. 1 shows an outline sketch of piping- suspende 
 from the ceiling- of a room the most unscientific way 
 possible for a room to be piped, as it provides for no 
 
 * " 
 
 ) ' f j*f 
 
 v j ^ ^ J ; ( V j ^ s 
 
 air circulation whatever. The only possible reason 
 why air will circulate over pipes in this position is be- 
 cause of the fact that the whole ceiling- is not covered 
 by pipes, which allows of a partial circulation, as 
 shown by the arrows. The volume of circulation in 
 the lower half of room is practically nothing-. It is 
 larg-ely confined to the top of room, the lower part 
 being- cooled by conduction and radiation almost en- 
 tirely. It may be asked : How can a room be cooled 
 by radiation? In the same way that a room is heated 
 by radiation, except that in cooling- a room the heat is 
 radiated_/>wft the objects in the room, and not to them, 
 as when heating-. This gives us ample reason why a 
 room should be cooled by circulating- the air over 
 
36 
 
 EGGS IN COLD STORAGE. 
 
 Open side wall 
 Piping. 
 
 frozen surfaces located outside of the room, or at 
 least in a position so that no radiation or conduction 
 can occur. The use of insulated screens or mantles, 
 as shown in Figs. 3, 4. and 5, is recommended as being- 
 superior to any arrangement of open piping-; but, of 
 course, it is not equal to forced circulation, in which 
 the pipes are located outside of room entirely. 
 
 Fig-. 2 shows another very common and faulty 
 arrang-ement of piping for cooling an egg room. The 
 only improvement over the arrangement shown in 
 Fig. 1 is that it allows of a moderate action of gravity 
 
 K 
 
 f ( 
 
 f 
 
 \ 
 
 \v 
 
 near the coils, as shown by the arrows. It is open to 
 the same objection on the ground of conduction and 
 radiation as No. 1, but to a lesser degree. The coils 
 are placed a few inches out from the walls, to allow 
 the air to circulate around the pipes freely, and to 
 provide room for an accumulation of frost. The top 
 of the coil should be quite close to the ceiling. If the 
 coil is placed, say midway between floor and ceiling 
 (unless it covers nearly the whole space), it is sure to 
 result in the air becoming stratified, a warm layer of 
 air in top of room resting on a colder one near floor, 
 perhaps to an extent so great as to cause a difference 
 of 10 F. in temperature between floor and ceiling of 
 room. A case with exactlv these conditions is on 
 
EGGS IN COLD STORAGE. 
 
 37 
 
 record. Another very bad arrangement of side wall 
 piping- came to the notice of the writer recently. A 
 room exceeding- fifty feet square was piped completely 
 around from floor to ceiling with the exception of the 
 doors. Circulation could penetrate but a compara- 
 tively small portion of the space in this room, and in 
 a large area of the central portion the air was conse- 
 quently very foul, and mold and must were rampant. 
 
 Fig. 3 gives us the first primitive improvement A 
 over open coils, and it is along step in the right direc-pip in 
 tion, but it fails to take care of the center of the room, 
 
 /'/> 
 
 f/j. 
 
 especially near the ceiling. The usefulness of this 
 device consists in its ability to increase the velocity, 
 and consequently the volume of air passing over the 
 cooling coils. The increased velocity of air causes it 
 to cover a greater area, and spread toward the center 
 of room further. The apron or screen used before 
 the coils should be constructed of any moderately 
 good non-conductor. Separating the warm and cold 
 currents of air increases the draft, on the same prin- 
 ciple that a fire burning in a flue creates a greater 
 suction or a more rapid displacement of air than when 
 burning in the open. 
 
 Fig. 4 is simply an addition to No. 3, of a false 
 ceiling or curtain extending well out toward the 
 
38 
 
 KGGS IN COLD STORAGE. 
 
 Gay's system 
 of box coils. 
 
 center of the room. This obliges the circulation to 
 spread so as to cover a large portion of the cross-sec- 
 tion area of the room, as indicated by the arrows, but 
 has the effect of reducing its volume to some extent. 
 This ceiling apron should have a slant of not less than 
 one foot in ten. It occupies some considerable space, 
 but is richly worth it. The opening into outer edge 
 of apron in center of room need not exceed three 
 inches in depth in most cases, and, as some space 
 must be left at the top of room for air circulation 
 
 with the wall coils, without ceiling apron, not much 
 space is wasted by its addition. 
 
 Fig. 5 gives us an entirely different arrangement 
 of piping, but with essentially the arrangement of 
 aprons shown in Fig. 4. This is the system advo- 
 cated by Mr. C. M. Gay on page 106 of the August, 
 1897, number of Ice and Refrigeration, and the 
 writer believes it to be the best idea for air circula- 
 tion of any having pipes directly in the room. The 
 following is quoted from Mr. Gay's description: 
 " Upper pipes of box coils should be about ten inches 
 below the ceiling of the room, to prevent sweating. 
 When brine or ammonia is turned into these pipes 
 (as shown in Fig. 5), the cold air around the pipes 
 seeks an outlet downward and passes between the 
 
EGGS IN COLD STORAGE. 
 
 39 
 
 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 hig-hest point, each by reason of its rela- 
 tive gravity. Thus as the cold air falls from the cool- 
 ing- surfaces it is replaced by the warm air from 
 hig-hest 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-." 
 
 Fie-. 6 is the St. Clair or pipe loft system, which st. ciair, or 
 
 i_ 1-jj j i j t. j Pipe loft 
 
 has been applied to many remodeled overhead ice system, 
 cold storag-es, by placing- the pipes in a part of what 
 formerly was the ice space, and, in some cases, using- 
 the original air ducts for circulation. The sketch 
 here shown represents one room only, but as many as 
 five or six different floors have been operated from a 
 single pipe loft, using- one main air duct for the down, 
 and one for return air circulation, each floor having- a 
 connection with the mains in which the flow of air is 
 reg-ulated by g-ates. A better arrang-ement, when 
 more than one floor is to be operated on this system, 
 is to have independent ducts for each room, and the 
 cooling- coils separated likewise; then any room or 
 rooms may be used for other products at any time 
 
40 
 
 EGGS IN COLD STORAGE. 
 
 Size of 
 egg rooms. 
 
 when free of eggs. This latter arrangement, of 
 course, requires more space and is slightly objection- 
 able on this account. The circulation is more vigor- 
 ous with this system than with any pipe-in-the-room 
 system, depending- on the law that the higher the 
 column of air the stronger the draft, on the same 
 principle that a tall chimney gives 
 greater draft than a short one. It is, 
 therefore, better than any room pip- 
 ing, and has the added advantage of 
 
 f / 
 
 being easily shut off from the room, when the weather 
 no longer requires cooling power. The need of keep- 
 ing the air of the room from contact with the frost 
 on pipes will be looked into under ventilation and 
 absorbents. 
 
 Refrigerator rooms for the storage of eggs should 
 not exceed thirty or thirty-five feet in width. The 
 cross-section illustrations of rooms cooled by gravity 
 air circulation, which have already been illustrated, and 
 the two sketches shown herewith of the arrangement 
 of air distributing ducts used in two systems of forced 
 circulation, are sufficient to show why a room should 
 not be excessively wide as compared to its height. In 
 a wide room it may be seen that the air from cold 
 air ducts, in case^of forced circulation, or from the 
 
BGGS IN COLD STORAGE. 41 
 
 bottom of cooling- coils in case of room piping-, is 
 required to pass over more eggs in its flow to the 
 return air duct or false ceiling-. The eg-g-s, then, 
 are not all exposed to the same drying- and puri- 
 fying- influence, because the air as it comes from the 
 cooling- coils is at its maximum dryness and purity, 
 and becomes impregnated with moisture and impuri- 
 ties more and more as it flows through the goods. If 
 the length of piles of goods is great from side to cen- 
 ter of room, the eggs in top and center of room will be 
 exposed to air which is much more impure and moist 
 than the eggs first exposed to the flow of air directly 
 from cooling coils. This applies more especially to 
 the gravity systems of air circulation. With forced 
 circulation, the air moves probably three or four 
 times as fast as when a gravity system is used, con- 
 sequently the air in top and center of room does not 
 carry the amount of impurities that it does if depend- 
 ing only on gravity for its motion. This fact in itself 
 is a very good reason why forced circulation is supe- 
 rior to any gravity system. 
 
 It has been claimed that eggs will lose weight by 
 shrinkage more rapidly when stored in a room iH 
 which the air is circulated by mechanical means than 
 in a room operated on the gravity air circulation prin- 
 ciple. This assertion is based on the assumption 
 that the air is circulated at a much higher velocity 
 when forced circulation is employed, and is only 
 partly true because no account is taken of humidity. 
 If the humidity was the same in both cases, the claim 
 would be strictly true. Every intelligent housewife 
 knows that linen hung in the open air to dry, will be 
 freed of moisture quicker when a strong breeze is 
 blowing, than when the air is nearly still. The same 
 principle applies moderately to eggs in a refrigerator 
 room. With the same per cent of moisture, the more 
 rapid the circulation the greater the evaporation from 
 the eggs; but if the facts were known, it would be 
 
42 KGGS IN COLD STORAGE. 
 
 found in every instance where trouble from excessive 
 shrinkage of the egg meat was experienced, that no 
 attempt was made to regulate humidity. It is as easy 
 to control humidity as it is to control temperature, and 
 with no bad effect on the other conditions in the storage 
 room, if we go about it in the right way. Ventilation 
 and the use of absorbents are agents which can be 
 utilized for this purpose. 
 
 toie With a vigorous circulation of air, an egg room may 
 circulation. be maintained at a humidity which would be disas- 
 trous, if only a sluggish circulation was operative. 
 Why? Because a brisk movement of air around the 
 eggs removes the moisture and impurities as fast as 
 given off by the eggs. They are not allowed to remain 
 in the vicinity of the eggs to work mischief, but are 
 promptly hurried off to the cooling coils or absorb- 
 ents, where they are, for the most part, rendered 
 harmless. This seems to explain how eggs may be 
 carried sweet, and with very little evaporation, when a 
 well distributed forced circulation of air is employed. 
 With any gravity system, the circulation of air can- 
 not be controlled, because depending on the tempera- 
 ture of refrigerant flowing in the pipes for its velocity; 
 and as the temperature of refrigerant is regulated to 
 correspond with outside weather conditions (lower in 
 warm weather and higher in cold weather) the velocity 
 of circulation is not constant being least in the cold 
 weather of fall, when it is most needed. With a good 
 system of forced circulation installed, the problem, 
 then, is to proportion the circulation of air to the 
 humidity. We might take our humidity at the degree 
 which would come naturally, if no attempt were made 
 to control it, and speed our blower up or down to pro- 
 duce a circulation to match, but it would probably be 
 best to provide a circulation which would handle a 
 large volume of air at a brisk speed, and raise our 
 humidity to as high a point as would be safe. Refer- 
 ring to the table of correct humidity given in Chapter 
 
EGGS IN COLD STORAGE. 43 
 
 II, page 23, it will be noted that an arbitrary 
 percentage is given for each temperature. These 
 are the most desirable percentages of air moisture 
 for average conditions of circulation, as when using 
 the most scientific forms of gravity air circulation 
 during warm weather. When using a good system 
 of forced circulation, these percentages may be in- 
 creased moderately. Exactly how much will depend 
 on conditions, and can be told only by trial, but it will 
 be much greater in proportion at the high tempera- 
 tures, ranging from 2 per cent or 3 per cent on the low, 
 to 7 per cent or 8 per cent on higher temperatures. 
 
 Before taking up the forced circulation systems Electric fan in 
 
 egg room not 
 
 proper, the electric fans used in so many large houses desirable. 
 will be considered. These little fans are a four to 
 six-bladed disk fan, from twelve to eighteen inches in 
 diameter, attached directly to the shaft of a J/s or 
 ^ -horse power electric motor. /The wires supplying 
 the electric current to the motor are usually con- 
 nected to the socket for an ordinary incandescent 
 lamp. Electric fans are usually placed on the floor 
 in the back end of alleyway, or in an opening in the 
 piles of goods, creating a draft of air from one ex- 
 tremity of the room toward the other. As the air 
 from the fan will follow a path of least resistance, the 
 circulation resulting from their operation is largely 
 confined to the alleyways or openings in the piles of 
 stored goods it does not penetrate through and be- 
 hind the piles of eggs. It may be readily observed 
 that this is of doubtful utility, and may at times lead 
 to positive harm by causing a condensation of mois- 
 ture upon goods as a result of the comparatively 
 warm, moisture laden upper strata of air coming in 
 contact with the flow of cold air from the cooling 
 pipes. Electric fans have also been utilized to propel 
 the air from the cooling pipes, for which purpose they 
 are placed in an opening in a screen or mantle cover- 
 ing the pipes, forcing the cooled air outwardly into the 
 
44 EGGS IN COLD STORAGE. 
 
 room. In any other position, they are only useful as a 
 "talking* point," as it is likely to impress a prospective 
 customer favorably with the cooling- power of a refrig- 
 erator, to allow him to stand for a few seconds in the 
 breeze created by one of these higii-speed fans. The 
 use of electric fans has been adopted to an extent not 
 warranted by the results possible to attain with them, 
 and their use will no doubt be gradually discontinued 
 as the fallacy of the idea becomes apparent. 
 Primitive The first svstem of true forced circulation to con- 
 
 torccQ a, ir * 
 
 circulation. s ider is not illustrated and needs no sketch to explain 
 the working- of it, as there are practically no distribut- 
 ing- air ducts, the cold air being- forced into the room 
 at two or three larg-e opening's, and taken out in the 
 same way. There are two prominent houses using 
 an air system constructed on these lines, one having 
 the cold air inlet near floor and warm air outlet near 
 ceiling-, the other having both cold and warm air open- 
 ings near ceiling. No distribution of circulating air 
 of any consequence is provided, the idea being simply 
 to cool the room by forcing in air which has been 
 cooled by coming in contact with cooling pipes located 
 outside of the rooms. The cold air is taken in at one 
 extremity of room and the warm air out at the other, 
 or the cold air is taken in at ends of room and warm 
 air out at center, or the reverse. This is what may 
 be called a primitive form of forced circulation, and is 
 quite similar to the systems of indirect steam heating 
 as first employed. It needs no argument to show that 
 a room equipped in this way has varying degrees of 
 temperature, humidity and circulation, depending on 
 the remoteness or proximity to the direct route be- 
 tween cold air inlet and warm air outlet the air mov- 
 ing through the area of least resistance, which is 
 usually along the center alley of room. 
 
 Linde-British Fig. 7 shows the arrangement of ducts for air 
 
 air-circulation 3 . 
 
 system. circulation used in the Linde-British air system; a a, 
 
 cold air ducts; b b, warm air duct. This system of 
 
EGGS IN COLD STORAGE. 45 
 
 refrigeration originated in Europe, and has found 
 favor to some extent on this side of the water, three 
 houses known to the writer being- operated on this 
 system. Mr. E. H. Johnson describes the apparatus 
 used in cooling, purifying and circulating the air on 
 page 96 of the February, 1898, issue of Ice and Refrig- 
 eration. This consists essentially of a tank containing 
 brine, which is cooled by direct expansion piping. 
 Slowly revolving in the tank, with a portion of their 
 surface exposed above the surface of the brine, are 
 large metallic disks. A fan causes the air to circu- 
 
 late rapidly over the brine moistened surfaces of the 
 disks, and the moisture is extracted, and impurities 
 and odors absorbed by the cold brine. In a modifica- 
 tion of this apparatus the direct expansion coils do the 
 cooling and take the place of the disks as well. The 
 coils are exposed to the air circulation, and the brine is 
 pumped over them in a shower, a shallow pan or tank 
 being provided under coils as a reservoir and recep- 
 tacle for the brine the same brine flowing over coils 
 again and again. It has been claimed for this system 
 that almost any product can be stored in different 
 rooms, all of which were fed by the same air circuit 
 and cooling apparatus, without any injury to the most 
 sensitive. A statement of this kind must first be 
 
46 
 
 EGGS IN COLD STORAGE. 
 
 proven before we can accept it. There is no doubt, 
 however, but that some good features are embodied 
 in above described apparatus. It is well known that 
 water, and especially salt water, has a great affinity 
 for impurities contained in the air, and when the air 
 is circulated in contact with the brine, as in the Linde 
 system, many of the gases and impurities common to 
 a storage room are absorbed. That they are ab- 
 sorbed to any greater extent than when the moisture 
 is simply frozen on the pipe coils, the writer is not 
 prepared to assert. An objection to this brine or wet 
 surface air cooling is the liability of trouble when 
 brine gets polluted with impurities. After some use 
 the brine will no longer act as a purifier, and in this 
 condition will contaminate, rather than purify, the 
 air. If attended to, this trouble can be prevented by 
 a periodical renewal, or by supplying a certain amount 
 of fresh brine at regular intervals and allowing a 
 portion to overflow. In discussing absorbents we 
 will find a description of a device which seems to have 
 all the advantages of the Linde method, and without 
 some of the objections. 
 
 The location of air ducts as adopted by the Linde- 
 British company seems to call for some attention. It 
 is evident from their location that gravity is depended 
 upon for a circulation of air near floor, as both warm 
 and cold air ducts are placed on ceiling of room. The 
 flow of air into room is controlled by means of sliding 
 gates, which are adjusted to openings placed five or 
 six feet apart in the air duct. This does not provide 
 a well distributed circulation, as those goods directly 
 opposite openings in cold air ducts will be exposed to 
 a sharp blast of air, while others get practically none. 
 As a result of placing the cold air duct on ceiling, 
 there will be little or no movement of the air near 
 floor, when rooms are filled with goods. 
 
 Fig. 8 shows a cross-section of a room fitted with 
 a system of air ducts and false ceiling for the circu- 
 
EGGS IN COLD STORAGE. 
 
 47 
 
 lation of air in a cold storage room, which the writer 
 has developed after several seasons' experiment, 
 and which is regarded as very nearly theoretically 
 perfect. In practical working- it gives very superior 
 results, and is believed, by those who are using- it, to 
 be in advance of any other system now in use. By 
 referring- to the sketch it may be seen that the air is 
 forced to cover very uniformly the entire cross-sec- 
 tion area of the room a result not possible with any 
 other device. This is obtained by the use of a false 
 ceiling, b b, perforated at intervals with small holes 
 
 / 
 
 
 v 
 
 the "Cooper 
 system" of 
 forced air 
 circulation. 
 
 which covers the whole ceiling of room ; and the side 
 air duct, a a, perforated with small holes on top, bot- 
 tom and sides. The air from cooling coils is forced 
 into ducts, a a, and flows out through the perforations. 
 Passing through the piles of eggs, as shown by the 
 arrows, the air moves upward through the perfora- 
 tions in the false ceiling, and thence through space 
 between false ceiling and ceiling, to cooling coils 
 again. This circulation is actuated by an exhauster, 
 or blower, preferably located on the main cold air 
 duct, between the cooling coils and cold air ducts, a a. 
 This has a tendency to put the egg room itself under 
 a slight pressure, and the coil room under a vacuum. 
 In this way the air leakage from outside, if there is 
 
48 EGGS IN COLD STORAGE. 
 
 any, is into the coil room, and not into the storage 
 room. The perforations for outflow of air from cold 
 air duct, a a, are twice as numerous on bottom as on 
 the top, and some are placed in the face or side of 
 duct also. The perforations are comparatively small 
 holes placed quite near tog-ether, obviating- all strong- 
 drafts, and at the same time insuring- a very pene- 
 trating- circulation which will not allow of any dead 
 corners. The false ceiling- is perforated likewise, the 
 holes being- most numerous throug-h the center of 
 room at farthest point from cold air ducts, and more 
 widely separated as they approach sides of room 
 directly over cold air duct. If air ducts are correctly 
 proportioned, the perforations properly located and of 
 correct size, and eg-g-s are piled uniformly from side 
 toward center of room, the air is forced to percolate 
 throug-h the piles of eg-g-s where its presence has such 
 a salutary effect, for reasons already discussed. The 
 exhauster for handling- the air can be placed in almost 
 any location handy to power, and the air conducted to 
 it, but a more desirable arrang-ement is a direct con- 
 nected or a direct belted electric motor. Then the 
 fan may be placed advantageously to get direct and 
 shorter air ducts, saving both space in the storage 
 room and expense in construction. 
 
 A saving of space can be obtained by using this 
 tiois tern a ~ system of air circulation, amounting in some cases to 
 fully 10 per cent of the total space cooled, and a sav- 
 ing of 5 per cent can be had in any house, if skill and 
 care are used in arranging cooling coils and air ducts. 
 Where rooms are moderately high the space over a 
 hallway or corridor may be utilized for cooling coils. 
 As the cooling coils are located entirely outside of the 
 storage room proper, the room itself can be filled 
 with goods snug up to the false ceiling at the top and 
 against air ducts on sides. The side ducts and false 
 ceiling only occupy about two inches of space in their 
 respective locations, so the space occupied by the air 
 
EGGS IN COLD STORAGE. 49 
 
 system is very small. Storage men will at once ap- 
 preciate that a saving- of even 5 per cent in space adds 
 that much to the profits of the season's business, as 
 it is as expensive to cool vacant space as it is to cool it 
 when occupied by goods. 
 
 As an objection to the forced circulation system, g. fans 
 it has been urged that the expense of running fans 
 continuously for handling the air was so large as to 
 be a serious item of expense. With a well constructed 
 apparatus and a large light weight fan wheel running 
 at a slow speed, the air in a room containing 15,000 
 cubic feet, which will store about 5,000 cases of eggs, 
 may be circulated with an expenditure of effort not 
 exceeding one-half a horse power. 
 
 The selection of a fan for propelling the air is of 
 considerable moment when installing an air circulat- 
 ing system in a cold storage room. Fans also play an 
 important part in handling air for ^ventilating, and the 
 merits of the different kinds and forms of fans will be 
 discussed under "ventilation." 
 
CHAPTER IV. 
 
 VENTILATION. 
 
 value of T N discussing- humidity and circulation, it has been 
 
 ventilation. J 
 
 1 explained how a large portion of the gases of de- 
 composition 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 mat- 
 ter 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 impurities and gases, detrimental to the wel- 
 fare of the stored goods, which have little or no affin- 
 ity for the water vapor in the air, and consequently 
 accummulate in the storage room. Ventilation is 
 necessary to rid a refrigerator room of these perma- 
 nent gases. The introduction of a large volume of 
 fresh air is not essential, however, 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. 
 Ventilation by This subject of ventilation for refrigerator rooms 
 
 has been very much talked about recently, but about 
 which really little is known, so far as any tangible in- 
 formation is concerned. Some of the more progress- 
 ive cold storage managers have given some attention 
 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 stor- 
 age or removed therefrom, is relied on to supply ven- 
 
 50 
 
EGGS IN COLD STORAGE. 51 
 
 Illation. This is quite inefficient, because eggs are 
 mostly stored during two or three months in the 
 spring, and removed from storage during the fall and 
 winter, leaving three or four months when no fresh 
 air of consequence can penetrate to the room, except 
 as the doors may be opened for the purpose of taking 
 the temperature of the room. Furthermore, this 
 kind of ventilation during the warm weather of sum- 
 mer and during a large part of the spring and autumn 
 months is worse than no ventilation at all. Some stor- 
 age 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 hang- 
 ing so that it can be read from the outside without 
 opening the door. While the writer has not practiced 
 this method, it seems to be a good idea, and it is cer- 
 tainly preferable to ventilating the room through 
 doors which open to the outside air. When doors 
 into rooms open into a corridor, the evil can be partly 
 prevented by piping the corridor overhead, so that 
 the moisture and impurities may be taken up in this 
 way; but opening the door or window of a storage 
 room directly to the outside air when the temperature 
 outside is materially higher will always result in 
 more or less bad effect on the goods, as a result of the 
 water vapor, in the warmer incoming air being con- 
 densed on same. 
 
 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- 
 
52 EGGS IN COLD STORAGE. 
 
 posure and poor insulation this air leakage is consid- 
 erable, but in the big- refrigerators of several hundred 
 thousand cubic feet capacity, and with thorough insu- 
 lation, 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 refrigera- 
 tion, aside from a matter of keeping out the warm, 
 moist air, is well enough understood not to need re- 
 peating here, but a word about windows and doors is 
 properly in line with the present discussion. 
 use of windows Rather than consider what might be a good way 
 
 for eg-g- rooms. -" 
 
 of placing 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 refrigeration 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 storage work. Barring the 
 small amount of heat given off, the incandescent elec- 
 tric lamp is an ideal device for lighting cold storage 
 rooms, as the air is not vitiated as when using gas, 
 kerosene or candles. 
 
 Doors which will shut tight, forming a nearly per- 
 fect 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 re- 
 fuse to open except after many persuasive kicks and 
 surges we all know how it is. While having no in- 
 terest in furthering the sale of the Stevenson door, 
 
EGGS IN COLD STORAGE. 53 
 
 which will be advertised in Ice and Refrigeration, the 
 writer believes it to be head and shoulders above any- 
 thing else in this line, and does not hesitate to recom- 
 mend it to those wanting- a door which will prevent 
 air leakage. The price is very reasonable, consider- 
 ing- the excellent material and fine work put into its 
 construction. The slig-ht additional cost over the 
 common door will be quickly saved, by reason of its 
 quick action opening- instantly when the lever is 
 grasped. 
 
 Having- g-ot into the subject of air leakag-e, we may 
 as well see how it is caused and why it must be airleaka ^ e - 
 g-uarded ag-ainst. It is operative from the same law 
 as gravity air circulation, which was explained quite 
 thoroug-hly in the first part of the chapter on " Circu- 
 lation." When the outside air is warmer than that 
 of the storage room, the air in the storage room pro- 
 duces a pressure on the floor and lower part of the 
 room, by reason of its greater weight, and conse- 
 quently it seeks to escape there. If there are open- 
 ings 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 bot- 
 tom and the comparatively warm air of the room out 
 at the top. This action is nicely illustrated by not- 
 ing the air currents in a door which is opened into a 
 cold room when the temperature is very warm out- 
 side. 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 stora ^ e 
 with sheet metal, with soldered joints. The interior 
 conditions would then be under more perfect control. 
 
54 EGGS IN COLD STORAGE. 
 
 It is hardly necessary to do this (although it has 
 been done in case of some old time houses), as a 
 practically tight job may be had by using- the right 
 materials, well put on. Air leakage may not be ex- 
 actly ventilation, but it is a kind of ventilation which 
 has given the writer some trouble in the past, and 
 does still, consequently the difficulties of operating 
 a house with defective insulation and large outside 
 exposure, and still turn out first-class eggs, are very 
 thoroughly appreciated. 
 
 4Jn f m r uIt e be la ' Methods of ventilation which are permissible 
 when applied 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 caus- 
 ing 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 outside atmosphere, there will be little or no 
 circulation of air into 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 eggs, and the 
 introduction of fresh air, which is warmer than the 
 storage room, is not permissible, for reasons already 
 given, the matter reduces itself to not ventilating at 
 all during warm weather (which most houses prac- 
 tice), or of properly cooling and purifying the air be- 
 fore forcing it into the storage room. It will bear 
 repeating that it is positively bad practice to allow air 
 from the outside to get into an egg room during the 
 
EGGS IN COLD STORAGE. 55 
 
 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 de- 
 posited 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- psychrometer, de- 
 scribed in discussing- humidity, will give an accurate 
 indication of the result of this unscientific method of 
 ventilating-. 
 
 Any natural means of handling- air for ventilation *}Jf Bri ** s 
 is inaccurate and inoperative, or it may be positively ventllatlon - 
 harmful, except under favorable conditions. If de- 
 pending- on natural gravity for ventilation it will be 
 g-uesswork, to a greater or less extent, because de- 
 pending on conditions which vary with the season, 
 temperature, direction and force of the wind, etc. 
 The late Robert Brig-g-s, an authority on ventilation, 
 makes a concise statement of the advantages of using 
 fans for ventilation, in his " Notes on Ventilating and 
 Heating."* He says: "It will 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 numerous publications, but the con- 
 clusion 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 results 
 at certain times or seasons, or under certain con- 
 ditions. One method will work perfectly with certain 
 differences of internal and external temperature, 
 while another method succeeds 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 
 
 * Proc. Am. Soc. Civil Engineers, May, 1881. 
 
56 
 
 KGGS IN COLD STORAGE. 
 
 Plenum vs. 
 vacuum 
 method of 
 ventilation. 
 
 Advantages of 
 the plenum 
 or pressure 
 method. 
 
 controllable to suit the demands of those who are 
 ventilating-." 
 
 There are two general methods, with some modifi- 
 cations, 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 storag-e 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 storag-e 
 room, by heating- the air in a stack or ventilation flue 
 connected at its lower end with the room to be ven- 
 tilated. In some cases no provision is made for an in- 
 flow 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 out), bring- 
 ing- a load of moisture and g-erms of disintegration 
 into the storag-e 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 storag-e 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, throug-h proper ab- 
 sorbents, 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 dang-erous air leakag-e 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 outlet for the escape of the foul 
 gases which it is desired to be rid of, should be pro- 
 vided 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, 
 
EGGS IN COLD STORAGE. 57 
 
 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 storag-e room, we will 
 determine 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 under head of circulation. 
 
 It is admitted by a majority of experts on air mov- 
 ing- machinery that the disk or propeller wheel ty pe type of fan - 
 of fan, throug-h which the air moves parallel to the 
 axis of fan, is not efficient or desirable for work where 
 the air has to travel throug-h a series of tortuous air 
 ducts, as in the forced air circulation system for cold 
 storag-e work, or for ventilation purposes where there 
 is some resistance. Where any resistance of import- 
 ance is encountered, the disk fanjnust be driven at a 
 hig-h rate of speed, and at an immense loss of power, to 
 compel it to deliver its full quota of air. Another dis- 
 advantage of the disk type is the difficulty of belting 
 to the shaft, or of g-etting- 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 
 centrifug-al, or peripheral discharg-e fan taken up. 
 
 This type of fan draws the air in at its center Advantages of 
 
 J r the centrifugal 
 
 parallel to the shaft, and delivers it at rig-ht ang-les 
 the shaft at the periphery or rim of the fan wheel, 
 the law g-overning- its action being- the well under- 
 stood centrifug-al force, which is commonly illustrated 
 when we see the mud fly from a bug-g-y wheel or the 
 water off a grindstone. The advantag-e 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 cir- 
 culation in the storage room, or for forcing in fresh 
 air for ventilation, it should be noted that a large slow 
 
58 EGGS IN COLD STORAGE. 
 
 running- fan wheel is very much more economical of 
 dtffertntspe a eds power than a small fan running- at a hig-h rate of speed, 
 both doing- the same amount of work. The loss of 
 ref rig-eration, too, in a rapidly moving- fan, is of conse- 
 quence, because the air is warmed by impact with the 
 blades. The proportion of power saved by the use of 
 a larg-e fan running- at a slow rate of speed, rather than 
 a small fan running- at a hig-h rate of speed, both de- 
 livering- the same amount of air, is almost phenomenal, 
 and does not seem at all reasonable at first view. The 
 volume of air delivered by a fan varies very nearly as 
 the speed, while the power required varies about as 
 the cube of the speed. That is, doubling- the speed 
 doubles the volume of air, while the power required is 
 increased eig-ht times. We will take a specific case. 
 A 45-inch fan wheel, revolving- at a speed of 200 revo- 
 lutions 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 
 fig-ures are theoretical, but within certain limits are 
 approximated in practice. 
 LOSS of power p or use [ n co id storage work the objection com- 
 
 from excessive J 
 
 fan weights. mon to nearly all the air moving- machinery found 
 listed by the manufacturers is the seemingly unnec- 
 essary amount of metal used in its construction. 
 The heavy weig-ht of the fan wheels, and the larg-e 
 diameter of shaft necessitated by such weig-ht, causes 
 much friction on the journals, so that when running- 
 at the slow speeds desirable for cold storag-e work, 
 more power is required to overcome the mechanical 
 friction than is actually required to move the air.* 
 
 *Having been unable to find a fan wheel well suited to the requirements of 
 cold storage duty, the writer 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. 
 
EGGS IN COLD STORAGE. 59 
 
 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 person to fan himself 
 with a dinner plate it would do the work, but would 
 not be economical of power. 
 
 So far we have found out what kind of ventilation 
 is not desirable, and have an inkling- of what kind 
 would be desirable. The question before us now is to 
 properly treat the air before introducing- it into the 
 storag-e room, so that it may be fresh /. <?., pure 
 oxyg-en and nitrog-en, without excessive moisture, 
 and free from the impurities and germs which may 
 contaminate the product which is being- refrig-erated. 
 
 The questions referring- to temperature contained Questions 
 in the letter of inquiry sent out by the writer before ventilation. 
 beg-inning- to write these articles 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- Miscellaneous 
 
 replies to ven- 
 
 talked-of subject were of no value whatever for our tiiation queries 
 purpose. Most of those answering- do not ventilate ; 
 many others get their ventilation through the opening 
 of doors; some ventilate through an elevator shaft, by 
 opening doors at top and bottom, etc. Only three or 
 four are properly cooling and drying the air before in- 
 troducing 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 adding to his troubles by send- 
 ing in more air loaded down with the same mischief 
 makers. As before pointed out, unless the air to be 
 
60 EGGS IN COLD STORAGE. 
 
 used for purifying- the rooms is itself first cooled and 
 purified, this man's idea is perfectly correct. 
 impurities ex- The free outside air during- warm weather, espe- 
 
 isting-inthe . ... 
 
 free outside air. cially in the vicinity of our large cities, contains, 
 among- many others, g-erms which produce the para- 
 sitic plant growth which is called mildew or mold. The 
 exhalation from the lung-s of the many animals and 
 men who inhabit our cities, and the evaporation 
 from the dust, dirt and decaying matter of various 
 kinds peculiar to the street, render the air a recep- 
 tacle and conveyor 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 rapidly, 
 throwing off more germs of their kind, which impreg- 
 nate the air in an increasing ratio as the humidity and 
 temperature are increased. The humidity of the 
 outside air is not necessarily increased with the tem- 
 perature, but it is always increased to some extent, 
 and as the temperature of the 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 refrigerator rooms. 
 
 ^ * s rea -^^y 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 ventila- 
 
EGGS IN COLD STORAGE. 61 
 
 tion, and one which the writer has practiced, but it is 
 open to criticism, 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 article. 
 
 Several houses known to the writer ventilate by inefficient 
 letting the warm outside air in at a high point of the 
 ceiling, directly over cooling coils, expecting that the 
 air will be properly cooled and dried before it flows 
 into the room itself. The same objections are appli- 
 cable 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 impurities. 
 
 If we ventilate by simply cooling the air, the sim P le air 
 
 of . cooler. 
 
 simplest and most effective method, as shown in 
 Fig. 9, 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 brine or 
 ammonia pipes, which may be arranged anywhere 
 along the wall of a room, outside of the storage en- 
 tirely, if more convenient. An exhaust fan takes the 
 air from the coils in the ventilating flue and forces it 
 into the room to be ventilated, allowing it to escape in 
 the neighborhood of the cooling coils, where it will 
 mix with the air circulation, and flow into 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 
 
62 
 
 EGGS IN COLD STOKAGK. 
 
 I3RIMEOR 
 
 AMMONIA 
 COIL, 
 
 Coi u 
 
 FIG. 9. 
 
 pipes. The casing around the cooling coil should, of 
 course, be insulated moderately, as well as the pipe 
 
EGGS IN COLD STORAGE. 63 
 
 leading- from it to the storage room, wherever exposed 
 to the warm outside air. The size of apparatus 
 necessary for this purpose need not be large, as the 
 quantity of air necessary for ventilating egg rooms is 
 quite small, comparatively. 
 
 "Americus" mentions a method of washing air 
 ventilation, in the July, 1898, number of Ice and Re- 
 frigeration, 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 benefit to the air is very small. Experiments 
 conducted by the writer along this line were consid- 
 ered failures. 
 
 Shown in Fig. 10 is what appears as a rather com- 
 plicated apparatus, but on investigation it proves to 
 be quite simple. There are three members to this 
 system, as follows: First, The air washing tank, in 
 which the air flows upward against a rain of water 
 from a perforated diaphragm above, as clearly shown 
 in the sketch. This not only cools the air to the tem- 
 perature of the water, say 55 F. 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 comparatively pure and cool state to be still fur- 
 ther cooled. Second, The cooling tank, in which the 
 air is cooled to several degrees lower temperature 
 than that of the storage room. This removes the 
 moisture which holds in suspension the few impuri- 
 ties which may have passed the washing tank, the 
 moisture being deposited on the frozen surfaces 
 within the cooler. From the cooler the air is passed 
 into, third, the drying box, which contains chloride of 
 
64 
 
 EGGS IN COLD STORAGE. 
 
EGGS IN COLD STORAGE. 65 
 
 calcium. This chemical is a well known absorber 
 of moisture, what is technically known as a deliques- 
 cent 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. The "microbes, bac- 
 teria, moisture, etc." (which influenced the gentle- 
 man mentioned previously not to ventilate), are ef- 
 fectually disposed of by this method. It would be a 
 hardy germ, indeed, that would not succumb to such 
 vigorous treatment. 
 
 The volume of air necessary for ventilating- a 
 given size of egg 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 the 
 foul gases which we can be rid of by ventilation ac- 
 cumulate but slowly in an egg room, and it is probable 
 that the introduction of a volume of fresh air, properly 
 treated, equaling that of the egg 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 
 developed yet in the direction of ventilation of refrig- 
 erator rooms, more particularly in the way of some 
 method of knowing when a room requires ventilating. 
 Perhaps Prof. Siebel or some equally bright chemist 
 may be able to assist us on this point by informing us 
 what the gases are which we must dispose of, and 
 indicate some simple method of determining their 
 presence, and in what proportion. 
 
 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 
 
66 EGGS IN COLD STORAGE. 
 
 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 temperature 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. 
 Si a dstora C e in -^ ^as ^ on S been a well understood fact that eggs 
 cooi weather. an( j other products held at about the same or a higher 
 temperature take more harm in cold storage during 
 the cool or cold weather of fall and winter than during 
 a long- carry throug-h the heated term. Much has 
 been said and written about why the old style over- 
 head ice cold storag-es g"ive such poor results during 
 fall and winter, the reason assig-ned being- lack of 
 circulation, as the meltag-e of ice ceases when the 
 cool weather comes. This is true; further, 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. 
 Pipe cooled Now are we who cool our storage rooms with brine 
 
 rooms in . . 
 
 cold weather. O r ammonia pipes very much better off in this one re- 
 spect than those who have these much despised over- 
 head ice cold storages? Our rooms are cooled by 
 frozen surfaces, on which accumulates 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 sur- 
 faces, which absorb moisture during warm weather, 
 become evaporating surfaces, and give back to the air 
 of the room a considerable portion of the various im- 
 purities and germs which have been accumulated dur- 
 ing the warm weather of summer. To make this point 
 
EGGS IN COLD STORAGE. 67 
 
 more plain it may be considered 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 usually done by circulating- brine or ammonia 
 throug-h pipes, and the air of the room is circulated in 
 contact with the pipes. When the outside tem- 
 perature is hig-h, more of the refrig-erant must be 
 circulated, or its temperature must be lowered; 
 as the weather turns cooler in the fall, less re- 
 frigerant, or the same amount at a higher temper- 
 ature, must be circulated, and when the air with- 
 out reaches the temperature of the room, the 
 circulation of refrigerant must be discontinued al- 
 together. When this is done the moisture on the 
 cooling pipes begins to evaporate. This evaporation 
 added to that which is given off by the eggs them- 
 selves soon renders the air saturated with very im- 
 pure and poisonous vapors, which cause the eggs to 
 deteriorate very rapidly. 
 
 The influence which the temperature of the refrig- influence of 
 
 & temperature of 
 
 erant flowing in the cooling pipes has on the condition refrigerant in 
 
 cooling- pipes. 
 
 of a storage room may be better understood by tak- 
 ing 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 precipitates moisture) 
 of 25 F. Therefore any cold surface (as a pipe sur- 
 face), 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 moisture 
 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 
 
68 EGGS IN COLD STORAGE. 
 
 surface the room can be kept at its normal tempera- 
 ture. 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 to 
 the air of the room, whether in the form of frost or 
 otherwise, must beat or below the temperature of the 
 dew point, or no moisture will be absorbed. The 
 value of suitable moisture 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 storag-e under bad condi- 
 tions in cold weather will do more harm to the eggs 
 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 to not allow 
 the frost, to accumulate on the pipes at all, by using- a 
 device, described further on under head of absorb- 
 ents. 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 impossi- 
 bility. 
 Evaporation With a system of screens arranged around coils, 
 
 from frost J 
 
 accumulated on as described in the first part of the paper on circula- 
 
 cooling- pipes. L 
 
 tion, trap doors may be fitted to the opening's and the 
 air circulation shut off in this way; but the simplest 
 and best way is to equip the rooms with forced cir- 
 culation, and locate the pipes outside of the room en- 
 tirely. Then it is only a matter of shutting- off the 
 circulation over coils, allowing- it to continue throug-h 
 a by-pass, or if the device shortly to be described is 
 used, the circulation may be allowed to continue over 
 coils. It seems quite clear, from what has been writ- 
 ten, why a storage room gets foul quickly during cool 
 weather, and also that the bad conditions. may be bet- 
 
EGGS IN COLD STORAGE. 69 
 
 tered by cold weather ventilation. The harm result- 
 ing- 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 
 eg-g-s themselves must be taken up by other means 
 when cooling- surfaces are no long-er operative. 
 
 By carefully observing- conditions a storag-e room 
 mav nearly always be kept in prime condition during- ventilation, 
 cold weather by no other means than the introduction 
 of fresh outside air at as frequent intervals as rig-ht 
 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 brig-ht fall day, and many such 
 are available for our purpose in the latitude of Min- 
 nesota and New York, and a somewhat smaller num- 
 ber, perhaps, in the latitude of Iowa or Ohio. It is only 
 a matter of handling- the free air of heaven under- 
 standing-ly. One's impressions, however, will hardly 
 do in judging- what air is g-ood to use for ventilating- 
 purposes. If you have a brig-lit, clear day, or, what is 
 still better, a clear, cold nig-ht, which has the appear- 
 ance of being- what you want, g-et out your sling- 
 psychrometer and set all g-uesswork aside. It is 
 frequently possible to fill your eg-g- 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 1 for the-opportunity. Provide a g-ood 
 big" fan wheel, which will handle a larg-e volume of air 
 in a short time, and when conditions are rig-ht blow 
 your rooms full of it. Repeat this whenever the 
 weather conditions will permit. 
 
 We may now consider cold weather ventilation 
 under another condition, viz.: When it is colder out- weather - 
 side than inside the storage room. Whenever the out- 
 side air is 8 C or 10 below that of the storag-e room it 
 is always perfectly safe to introduce it into the stor- 
 
70 KGGS IN COLD STORAGK. 
 
 age room, after it has been first warmed to the tem- 
 perature of the room to be ventilated. That is, it is 
 safe so far as introducing- moisture or impurities is 
 concerned. If we should ventilate in this way con- 
 tinuously our humidity would be lowered to a point 
 where the eggs might suffer from evaporation. It is 
 necessary, therefore, that observation of the humidity 
 of the room so ventilated be taken, so that this kind 
 of ventilation may not be overdone. 
 Manner of in- The method of getting- air into the rooms under 
 
 troducmg- air. & 
 
 these last two systems of ventilation is of no special 
 moment, except that it be under control, and we have 
 already noted that the only good way of handling- air 
 w r as by the use of fans, preferably large and of light 
 weight, and running at a slow speed. Where the 
 forced circulation is installed, it is sometimes practi- 
 cable 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 seeming 
 more complicated is really simpler to operate, because 
 handled independently. When using an independent 
 fan or when using the forced circulation fan for ven- 
 tilating, 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 venti- 
 lation, especially, must be handled scientifically or 
 trouble may result instead of benefit. No absolute 
 rules can be given for handling ventilation because of 
 widely varying conditions, but if what has been writ- 
 ten is read and studied carefully the subject can be 
 taken up intelligently and followed out to its legiti- 
 mate conclusion. 
 
T 
 
 CHAPTER V. 
 
 ABSORBENTS. 
 
 HE use of absorbents in cold storage rooms has Purifying air 
 
 Toy absorbents. 
 
 been common since the industry was in its in- 
 fancy; their use originating-, no doubt, from an appre- 
 ciation 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 ven- 
 tilation are applied to refrigerator 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 where 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 Prof. Nice's 
 
 . . . . . . .... system which 
 
 absorbing the moisture which is usually condensed on utilizes an 
 
 . absorbent. 
 
 the cooling coils, as illustrated in one style of the 
 antiquated overhead ice cold storages. If the writer 
 remembers correctly, the system is called Prof. 
 Nice'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 eggs 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 suspend- 
 ing it in pans at the ceiling of the room, or in 
 some cases on the floor under the goods. Prof. 
 Nice's system gave good results years ago in com- 
 petition with the Jackson, Dexter, McCrea, Stevens, 
 etc., systems of overhead ice cold storage, which low 
 
 71 
 
72 
 
 EGGS IN COLD STORAGE. 
 
 Queries 
 relating- to 
 absorbents. 
 
 Whitewash a 
 good wall 
 coating-. 
 
 temperatures, and the improved systems of air cir- 
 culation now in use have rendered obsolete to a greater 
 or less extent. Mention is made of this system, not 
 as recommending- it, but to show the possibilities of 
 absorbents in drying- and purifying- egg rooms. 
 
 The letter of inquiry sent out by the writer con- 
 tained three questions referring to absorbents, writ- 
 ten with an idea of ascertaining- the coating- used for 
 the walls of a storag-e to the greatest extent; what ab- 
 sorbent was the favorite, and in what manner applied. 
 The questions are as follows : 
 
 I. Do you use an absorbent or purifier in your 
 egg rooms? 
 
 II. In what way do you use or apply them? 
 
 III. 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 pro- 
 portions of lime and salt. Several recommend one 
 part of lime and one of salt. This makes a very 
 good whitewash, giving a firm, hard surface, but un- 
 less 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 appearance. A better proportion 
 for ordinary cold storage work is two parts of lime 
 and one of salt. This mixture will dry faster, and 
 will give a white surface which will not easily rub or 
 flake off. There are many formulas for good white- 
 wash, some of them so complicated as to be impracti- 
 cable; but plain lime and salt, with perhaps the addi- 
 tion of a little Portland cement, will be good enough 
 for our purpose. 
 
 This last formula would then be six parts white 
 lime, three parts salt, one part Portland cement. In 
 preparing this wash, proceed as follows: Slake the 
 quicklime by pouring on boiling water, stirring 
 
EGGS IN COLD STORAGE. 73 
 
 thoroughly during- the process. A half bushel of Thebest 
 
 formula for 
 
 lime is all that can be handled easily. Pour on only whitewash. 
 a little water at first, adding- more as the mixture 
 thickens, and do not allow the lime to become dry, or 
 it will "burn" and become lumpy. When the lime is 
 thoroug-hly slaked and reduced to the consistency of 
 cream, add the salt while the mixture is still hot the 
 salt will dissolve better adding- more water as is 
 necessary to keep it to the proper consistency. The 
 Portland cement should be added only to each pail- 
 ful as used, as it sets if allowed to stand, and does 
 not retain its tenacity. A good sized handful to each 
 pailful of the wash is about rig-ht. By the addition of 
 a teaspoonful of ultramarine blue to each pailful, the 
 brown effect resulting- from the addition of the cement 
 will be neutralized. 
 
 Storag-e rooms should be whitewashed during- whitewashing- 
 
 storage rooms. 
 
 cool, dry weather, with the doors- open, or warm, dry 
 air from a steam coil should be circulated throug-h 
 the room. This is quite a simple matter where a 
 house is equipped with forced circulation. Cover the 
 walls, ceiling- and floor with a coat of whitewash 
 each spring-, and allow ample time for the rooms to 
 air and dry out before goods are placed in them. If 
 whitewash is to have a nice white appearance it must 
 not be too long- in drying-; on the other hand, if dried 
 too quickly it will flake or cleave off more readily. 
 The quickest method of applying whitewash is with 
 a compressed air spray. It will make a fair job, and 
 is done much quicker than by hand. 
 
 The cold water paints, which are now quite com- cold water 
 
 j . r paint. 
 
 mon under various names, are good for many places 
 where whitewash will not do, as on doors and in the 
 corridors, or wherever the clothing- may come in con- 
 tact with the woodwork, or where a product is handled 
 which may be injured by the flaking off of whitewash. 
 Whitewash will generally rub or flake off to some 
 extent, but the best of these cold water paints are 
 
74 
 
 EGGS IN COLD STORAGE. 
 
 Shellac for 
 wall coating. 
 
 Lime as an 
 
 absorbent of 
 moisture and 
 impurities. 
 
 nearly as impervious as so much oil paint, and quite 
 valuable for nearly all interior and some exterior 
 work. Many houses use nothing else for their refrig- 
 erator rooms, but the expense is not warranted, as 
 whitewash will do equally well in most places. It is 
 a good idea to keep some of this cold water paint on 
 hand, and apply it at intervals to doors, etc., when 
 they become soiled by handling. This is much better 
 than to paint doors some dark color so they will not 
 show soil nothing compares with a pure white and 
 oil paint has no place about a storage room. 
 
 Shellac is an old stand-by finish for refrigerator 
 rooms, and if selected ceiling is used, it makes a very 
 neat piece of work, as it brings out the natural grain 
 of the wood, than which there is no more beautiful 
 finish. The surface scratches easily and will look 
 mussy unless renewed frequently, but there is no 
 serious objection to shellac (barring the expense), as 
 it is strictly odorless and w r aterproof. It has no puri- 
 fying or disinfectant properties like lime and salt 
 whitewash, in appearance is very little superior, and 
 the much increased expense makes it very little used 
 at present. Many other preparations are in use 
 under various names, but whitewash is as good as any 
 of them, with the exception previously noted. 
 
 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, as before mentioned.) Occasionally 
 waste bittern from salt works is used, but the active 
 principle of bittern is chloride of calcium. 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 com- 
 pared with chloride of calcium, and when exposed to 
 
EGGS IN COLD STORAGE. 75 
 
 the air it will simply air slake, which means that it 
 will absorb moisture enough from the air to disinte- 
 grate into the form of a powder. Lime in this form is 
 known as air slaked lime, and is used to a large ex- 
 tent in egg- 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 2X4's (which are used at the bottom of 
 each pile of eggs), to the depth of an inch or more. 
 This must necessarily be done when the eggs 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 
 cases. 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. 
 
 Chloride of calcium is the most vigorous absorb- 
 ent (or drier, as it is called) which we are discussing. absorbent - 
 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 cal- 
 cium is much the more energetic of the two. Where, 
 in a 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 puri- 
 fying refrigerator rooms, and in this capacity has 
 been a general favorite for years. The most primi- 
 tive method of applying it is to place it in a simple 
 iron pan, allowing the brine to run off into a pail as 
 
76 EGGS IN COLD STORAGE. 
 
 fast as formed. A better way is to support the cal- 
 cium 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. 
 
 ^ st ^ better way of applying chloride of calcium, 
 ~ wn i n makes the calcium do two separate and distinct 
 duties, is a method recently designed by the writer. 
 It has proven itself especially valuable for use in 
 rooms where the air is circulated by mechanical 
 means, and in which the air is cooled by passing over 
 brine pipes, through which the brine is circulating at 
 a comparatively high temperature. If low brine tem- 
 peratures are used in combination with the device 
 about to be described, the tendency may be to dry the 
 air to such an extent as to be detrimental, and ample 
 pipe surface must be provided and the quantity of 
 brine flowing through pipes reduced so that no ex- 
 cessive drying effect will take place. The device 
 consists simply of supporting a quantity of chloride 
 of calcium above the cooling coils, so that the brine, 
 resulting from the absorption of moisture by the cal- 
 cium, will trickle down over the pipes. This effect- 
 ually prevents any formation of frost on the pipes, 
 and therefore keeps them at their maximum efficiency 
 at all times. The air, in passing over the brine 
 moistened surface of the coils is purified, and as the 
 brine, after falling to the floor of the coil room, goes 
 to the sewer, no contamination can take place. 
 
 Do not in any method of using chloride of calcium 
 evaporate 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 
 
EGGS IN COLD STORAGE. 77 
 
 large extent. The quantity of calcium necessary Quantity of 
 
 j ,, ,.,. . - , . , ., . , J chloride of cal- 
 
 depends on the conditions under which it is to becium necessary, 
 
 used, but in any case it is safe to use much more than 
 
 the writer saw in use in an eastern house recently. 
 
 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. 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 VI. 
 
 Experiments 
 proving 1 that 
 eggs must 
 evaporate. 
 
 PACKAGK. 
 
 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 writer 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 hermeti- 
 cally 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 independ- 
 ently and without knowledge of the writer's experi- 
 ment. He used an ordinary fruit jar, with screw top 
 fitting onto a rubber ring. His results were similar. 
 In addition 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 experiments 
 prove beyond a doubt that an egg must evaporate 
 continually, and they prove further that the eggs 
 must be surrounded by some medium which will 
 absorb this evaporation. 
 
 We have noted in the chapter on "Circulation," 
 how the air is best circulated so as to remove the 
 
 78 
 
EGGS IN COLD STORAGE. 79 
 
 moisture and impure gases from the vicinity of the 
 eggs. This must be done, otherwise the fillers and 
 package containing- the eggs would shortly be in as 
 bad condition as the fillers in the experiment just 
 mentioned. The theory and explanation of the other 
 conditions in the storage room necessary for success- 
 ful egg- refrig-eration have also been taken up under 
 the various heads. We will now look into the require- 
 ments of the packag-e containing the eggs while in 
 cold storage. 
 
 The questions contained in the letter of inquirvQ ueries 
 
 J relating- to 
 
 relating to the egg package are as follows: package. 
 
 1. What egg package have you found to turn out 
 the sweetest eggs? 
 
 2. Have you used any kind of ventilated egg case, 
 and with what results? 
 
 3. Have you ever used open trays or racks, and 
 with what results? 
 
 As many different people have experimented with various woods 
 
 . m use for cases. 
 
 different packages, hoping to get something which 
 would turn out perfectly sweet eggs, with little evap- 
 oration, the replies received to the questions relating 
 to packages are interesting, and many contained in- 
 formation valuable as data. The favorite package is 
 the ordinary 30-dozeii egg case, made of white- 
 wood, using the so called odorless fillers. The term 
 whitewood is usually meant to include either poplar, 
 cotton wood or bass wood, but two or three other vari- 
 eties 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 
 writer says that basswood is as properly a whitewood 
 as poplar or southern whitewood. Poplar and cotton- 
 wood are most in use for storage purposes, and many 
 insist that basswood 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 writer, and if all were thor- 
 
80 EGGS IN COLD STORAGE. 
 
 oughly dry, no difference could be noted in the carry- 
 ing- 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 cottonwood, but it 
 is always advisable to get stock for egg cases in the 
 fall and have them nailed up during- the winter, allow- 
 ing- two or three months for the cases to season 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 divid- 
 ing or separating boards which form for each egg an 
 individual cell in the case are usually 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 pe- 
 culiar 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 result- 
 ing from a growth of fungus has been laid to the fill- 
 ers, and much of the flavor resulting from fillers has 
 been laid to a growth of fungus or must, but there is 
 no question but what strawboard fillers are not the 
 thing for cold storage use. Many kinds of fillers have 
 been tried, and many ideas suggested for the improve- 
 ment of cold storage eggs. A white wood 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 
 be very soft, and they were objectionable on this ac- 
 count. A good manila odorless is now on the market 
 
EGGS IN COLD STORAGE. 81 
 
 which is giving- good satisfaction where tried. Ordi- 
 nary strawboard fillers have been coated with various 
 preparations, shellac, paraffine, whitewash, etc. Any 
 substance 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 experiments 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 writer. A better way is to de- 
 crease the humidity 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 ven- 
 tilation, as already discussed in their proper places. 
 Fillers made of thin wood have been used in years 
 gone by with fair success, but tlieir 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 fill- 
 ers are light brown or buff in color, and from the best 
 information the writer can obtain, are composed 
 largely of scrap paper stock, with some long fiber like 
 manila added for strength. In the manufacture the odorless 
 stock is treated to a thorough washing and deodoriz- 
 ing 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 strawboard fillers, 
 generally come out of cold storage markedly superior. 
 
82 EGGS IN COLD STORAGE. 
 
 A number of imitations of the original odorless filler 
 are now on the market, some of them almost if not 
 quite the equal of the original. Another filler which 
 has given good results is the fiber filler, which is made 
 from a material similar to the now well known fiber 
 ware. They have very little odor, and remain hard 
 and firm while in cold storage. A new odorless filler 
 made from pure spruce pulp has been put on the 
 market this season. This is a beautiful appearing 
 filler, and unless appearances and the ordinary tests 
 are deceptive will make its mark after a trial of a year 
 in cold storage to prove what it can do. 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. Whatever 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. * 
 
 ventilated Many styles of ventilated egg cases have been 
 
 tight cases. 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 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 
 
EGGS IN COLD STORAGE. 83 
 
 from the egg's. As pointed out elsewhere in these 
 articles, humidity and circulation have much to do 
 with the evaporation from eggs; in fact, are more of 
 a ruling factor 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 moder- 
 ately tight package is the thing, but in a compara- 
 tively moist room with poor circulation the more open 
 the package the better. 
 
 An appreciation of the poor circulation and damp storing eggs m 
 
 r r f trays or racks. 
 
 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 storing 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 re- 
 ceived 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 proportionately higher than on an equal grade 
 of eggs stored in ordinary cases and fillers. The ad- 
 vantage of trays, if any, for some houses, is that con- 
 tamination 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 result 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 with the case, and so that they will 
 
84 
 
 KGGS IN COLD STORAGE. 
 
 Excelsior 
 
 TS. 
 
 cork shaving-s 
 for cushion. 
 
 Packing- eggs 
 in oats. 
 
 carry in shipping-, is generally either excelsior, which 
 is finely shaved wood, usually basswood, or the chips 
 made in the manufacture of corks, known as cork 
 shaving's. The big- cold storages recommend cork 
 now 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. A company known 
 to the writer manufacture a beautiful grade of bass- 
 wood excelsior, which is always fairly dry when re- 
 ceived, and makes as fine a cushion for protecting the 
 eggs as can be desired. 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. 
 
 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 im- 
 proved in quality from year to year. Oats, if dry, 
 will absorb moisture from the egg 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." There- 
 fore the main difficulty in using oats as packing for 
 eggs in cold storage is to have them at the correct de- 
 gree 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 
 
EGGS IN COLD STORAGE. 85 
 
 being- filled with oats, excepting- the small space taken 
 by the fillers themselves, the object being-, of course, 
 to prevent the "fillers taste." 
 
 At intervals we read of some method of preserving- complicated 
 
 ~ and obsolete 
 
 eg-g-s, which is said to be sure, to supersede or di- methods of pre- 
 serving- eg-g-s. 
 
 nary cold storag-e for the good keeping- of egg-s. A 
 scheme was tried on a larg-e scale somewhere across 
 the water, in which the eg-g-s were suspended in racks 
 in a cold room the racks being- turned at regular in- 
 tervals by automatic machinery to keep the eg-g-s from 
 spoiling-, that is, to keep the yolk from attaching- to 
 the shell. A low temperature will prevent this, as 
 pointed out in the chapter on temperature, and why 
 a man should waste good energy inventing such a ma- 
 chine is passing all comprehension. The quantity of 
 various chemical preparations manufactured and sold 
 for egg pickling or preserving 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. 
 
CHAPTER VII. 
 
 REMARKS. 
 
 some "dont's" ^ I ^HERE is a long string- of "don'ts " in regard to 
 SSHJtSf' 1 packing-, handling- and storing- egg's which might 
 be put down, but the writer 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 
 new ones. Don't ship eggs in cold cars, or set eggs 
 which are intended for storage in ice boxes. In ship- 
 ping 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 ar- 
 rive at their destination 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 porous, and allow of a freer 
 circulation of air around the egg. As already stated, 
 odorless fillers are better than any strawboard fillers. 
 Don'tlise 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 
 
 86 
 
KGGS IN COLD STORAGE. 87 
 
 already cooled when it can be avoided. For this rea- 
 son very large 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 temperature is 
 at times excessive, causing condensation on the goods, 
 which will propagate must quickly. 
 
 To illustrate: We will suppose the egg room partly Don't put 
 
 r J warm egg's into 
 
 filled with goods cooled to a temperature of 30 F. Sev- acoldroom 
 
 1 along with eggs 
 
 eral cars of eggs at a temperature of, say, 70 F. are run already cooled. 
 into the same 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 object 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 writer has had some experience which amply 
 justifies this explanation. That the moist vapor given 
 oif 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 extremes 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 materi- 
 ally 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 receiv- 
 ing room in which the goods coming in warm may be 
 cooled to very near 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. 
 
 If you wish to progress compare your results with 
 those of others. Don't say: "My eggs are as good as 
 
88 EGGS IN COLD STORAGE. 
 
 fresh"; test carefully from time to time through the 
 season, and compare quality with those from other 
 houses. 
 
 In the foregoing" articles I have given my own im- 
 pressions combined with the data and experience re- 
 ceived from others; but I do not care to be held abso- 
 lutely to any of the statements made, and reserve the 
 right to progress with the rest of you, and do not 
 consider myself bound by any hard and fast rule. 
 
 It should be positively understood that a mere 
 theoretical information on this subject is of only lim- 
 ited assistance; and those who undertake new work 
 are advised to put a man in charge who has had expe- 
 rience with the product which it is proposed to handle 
 in storage, as well as acquaintance with the mechanical 
 details of the plant. 
 
ADVERTISEMENTS 
 
 Testing Eggs by Electric Light. 
 
 This picture is from a photograph of a couple of candling- booths, designed by the 
 author of "Eggs in Cold Storage." Each candler works by herself in a small room 
 closed on three sides by matched stuff, and on the fourth or front side by a heavy 
 curtain to keep out the light. These curtains are seen pushed back in the picture, so 
 that the interior of the booth may be photographed. The white boxes in the center of 
 the booths are candling boxes. They are pierced with two holes, and have an electric 
 light suspended inside A shelf, showing in the picture, runs around three sides of the 
 booth at a convenient height above the cases, for supporting fillers, dividing boards, 
 nails, hatchet, etc. The barrel is for the litter of various kinds (old newspapers, etc.) 
 which alwaj's accompany country packed eggs. The pail just above the barrel is for 
 rotten eggs. Cork shavings may be seen in the box between the two booths. The 
 advantage of each candler working independently will be appreciated by all familiar 
 with the work. The concise arrangement of this style booth makes a great saving in 
 space as compared to the ordinary candling room. 
 
 MADISON COOPER, 
 
 Refrigerating Engineer, 
 
 MINNEAPOLIS, MINN., 
 
 410 First St., N. 
 
 Designer of "The Cooper Systems," Gravity Brine Circulation; 
 
 Positive Fan Ventilation and Forced Air Circulation. 
 Plans, Estimates and Personal Supervision of Construction. 
 
 Expert on the Successful Refrigeration of Perishable Products. 
 
ADVERTISEMENTS 
 
 NEW YORK 
 
 OFFICE, 
 
 85 CHAMBERS 
 
 STREET 
 
 LONDON 
 
 OFFICE 
 
 106 HATTON 
 
 GARDEN, E. C. 
 
 41 ELIZABETH STREET 
 
 MAKERS OF 
 
 thermometers 
 
 FOR ALL 
 
 REFRIGERATING 
 ICE MAKING AND 
 COLD STORAGE 
 
 PURPOSES 
 THERMOMETER FOR 
 
 BRINE TANKS, PUMPS 
 
 AMMONIA PIPES 
 
 AND STILLS 
 
 INSULATED BRINE PIPE 
 
 THERMOMETER 
 FREE FROM FROST 
 
 CERTIFIED EGG ROOM 
 
 THERMOMETER, ETC. 
 
 FIG. A-L 
 
 uime for Refrigerating Catalogue 
 
 FIG. 31. 
 
ADVERTISEMENTS 
 
 THE WHITLOCK COIL PIPE CO 
 
 ELMWOOD, CONN., II. S. A. 
 
 Pipe Coils of every descrip- 
 tion for all purposes made 
 of all kinds of metal, tubing- 
 or pipe. Manifolds and Re- 
 ceivers Quarter Turns and 
 Manufacturers Return Bends. 
 of... 
 
 Wrought Iron Ammonia Coils 
 
 Dally capacity, 8,000 to 10,000 ^or Ice and Refrigeration Machines- 
 feet. Range, H to 4-inch pipe by the latest improved process, from 
 or tube. First-class workman- wrought iron pipe of the finest quality, 
 ship, prompt Tested by hydraulic or air pressure. 
 
 THE WHITLOCK COIL PIPE CO. 
 
 ELMWOOD, CONN., U. 5. A. 
 
 Cable Address, "Whitlock," Hartford 
 
 Directory Code. 
 
 Telephone Address, Elmwood 
 
 Carbonic -Anhydride System 
 
 ECONOMY | SAFETY 
 
 ODORUESS !SO!S-COI*ROIVI. 
 
 This is the COMING ICE AND REFRIGERATING MACHINE ; applicable to all com- 
 mercial purposes. Superiorit}' established in numerous trials. Uses a harmless but 
 most efficient gas, and is equipped with reliable safety devices. Our Catalogue explains 
 all theoretical and technical details. If you are interested, write to 
 
 KROESCHELL BROS. ICE MACHINE Co, 
 
 29=39 ERIE STREET, CHICAGO, ILL. 
 
ADVERTISEMENTS 
 
 44 " 
 
 The Cooper System 
 
 Forced Air Circulation. 
 
 BY THOSE 
 
 WHO KNOW. 
 
 F. R. NOONAN & CO* Wholesale Butter and Eggs 
 and Cold Storage, Minneapolis, Minn. 
 
 "We have used your Forced Air Circulation in our Egg- Rooms for 
 the past two years, and are fully convinced that it is the only proper 
 way to carry eggs in cold storage.'' 
 
 E. F. DUDLEY Wholesale Butter and Eggs, 
 Owosso, Mich. 
 
 "I consider your Forced Air Circulation for Eg-g- Rooms very 
 fine. It gives the rooms bright, clear, fresh-smelling air and very 
 even temperature ; much better in this respect than the more com- 
 mon method of simply taking 1 in fanned air at one or two opening's 
 in a room to say nothing- of the behind-time systems of natural 
 draft." 
 
 PORTLAND ICE WORKS and PORTLAND ARTI- 
 FICIAL ICE CO,, Portland, Ore. 
 
 "I placed eight registered thermometers in different locations 
 in this larg-e Egg- Room. I never witnessed such a remarkable, 
 even scale of temperatures. With your system of Air Circulation 
 there is not a spot in this room where there is a difference of one- 
 tenth of a degree. The temperature is easily controlled. It can be 
 placed at any point desired, and held there without risk of any 
 kind.'' 
 
 W. E. HARRIS, 
 
 Sup't Mechanical Department. 
 
 MADISON COOPER, Designer, 
 
 Minneapolis, Minn. 
 
 Compressed 
 
 Published monthly. Now in its fourth year. The only periodical devoted exclu- 
 sively to this subject. It is both theoretical and practical, progressive and up-to-date. 
 Subscription, $1.00 a 3 r ear. Foreign, $1.50. Send for sample copy. 
 
 Compressed Air> 26 CORTLANDT ST., N. Y. 
 
ADVERTISEMENTS 
 
 EUGENE T. SKINKLE 
 
 ("THE BOY") 
 
 lice flftaktri anb 
 
 IRefrioeratlng Engineer 
 
 ROOMS 30 AND 32 
 
 177 LA SALLE STREET 
 
 CHICAGO, ILL. 
 
 Plans and specifications for Ice Making and Refrig- 
 erating establishments, and consultation in relation to 
 buildings, machinery and apparatus, alterations and 
 repairs. 
 
 IReferences: 
 
 BIRMINGHAM ICE FACTORY CO., Birmingham, Ala. 
 CITY ICE MANUFACTURING CO., Chicago, 111. 
 LITTLE ROCK ICE CO., Little Rock, Ark. 
 
 EAST ST. LOUIS ICE AND COLD STORAGE CO., E. St. Louis, 111. 
 KINGSTON ICE MAKING CO., Limited, King-ston, Jamaica, West Indies 
 GEO. CHALLONER'S SONS CO., Oshkosh, Wis. 
 
 EL RENO ICE AND COAL CO., El Reno, Okl. 
 MONROE CATERING CO., Chicago, 111. 
 
 KING'S RESTAURANT, Chicago, 111. 
 
 AMERICAN RESTAURANT, Chicago, 111. 
 And Many Others. 
 
 Hce flDafeitiQ anfc IRefrigeratiriQ Supplies 
 
AD VKR TISEMENTS 
 
 The Recognized Authority in all 
 Cold Storage Matters. 
 
 A MONTHLY REVIEW OF THE ICE, ICE MAKING, REFRIGERATING. COLD STORAGE AND 
 
 KINDRED TRADES. 
 
 SUBSCRIPTION PRICE 
 
 In United States, Canada and Mexico, . . - . 
 
 In all other countries, . . 
 
 PAYABLE IN ADVANCE. 
 
 $2.00 per year 
 3.00 per year 
 
 H. S. RICH & CO. 
 
 206 Broadway, NEW YORK 
 
 PUBLISHERS 
 
 177 La Salle Street, CHICAGO 
 
 Also publishers of the following Standard Rooks on Cold Storage, Ice Making 
 and Refrigeration: 
 
 Gompenft of /Ibecbanfcal IRefrigeration 
 
 By PROF. J. E. SIEBEL. 
 
 PRICE. PREPAID. CLOTH, $3.00; MOROCCO. $3.50. 
 
 The only work treating- of all the various branches of theoretical and applied 
 refrigeration, and will be found to contain a larg-e amount of information which would be 
 looked for in vain elsewhere. 
 
 practical 1lcc /Rafting and IRefruieratuui 
 
 By EUGENE T. SKINKLE. 
 PRICE, PREPAID, CLOTH, $1.50; MOROCCO $2.00. 
 
 Ever} 7 branch of ice making and refrigerating- is handled.in this work, with a view 
 to setting- out the best and most economical practice in the construction and operation 
 of the plant. 
 
 Ifnfcicattns tbe 1Refn0eratin0 
 
 By GARDNER T. VOORHEES. 
 PRICE. PREPAID. CLOTH, $1.00; MOROCCO, $1 50. 
 
 Treats of the application of the indicator to the ammonia compressor and steam 
 eng-ine, with practical instructions relating- to the construction and use of the indicator 
 and reading- and computing- indicator cards. 
 
ADVERTISEMENTS 
 
 HEADQUARTERS FOR 
 
 Chloride 
 Calcium 
 
 Prime white, full strength, packed in 600-pound iron drums. 
 Representing- the largest output in the country, we are in condi- 
 tion to name interesting- prices for car lots or less quantities. 
 
 PETER VAN SCHAACK & SONS 
 
 138-140 LAKE STREET,-CHICAGO. 
 
 ACCURATE THERMOMETERS. 
 
 Thermometers bought from us at one time give the same result 
 
 as thermometers bought from us at 
 
 any other time. 
 
 Prof. Marvin's Sling Psychrometer 
 
 for the exact determination of moisture in the air, is made 
 with the utmost care and is the best of its class. 
 
 ALL THERMOMETERS MADE BY US ARE 
 GRADUATED AND ETCHED ON THE STEM. 
 
 Send for a Sample of our Storage Room Thermometer. 
 Price, $1.00 each. 
 
 SCHNEIDER BROS. 
 
 265 Greene Street.. ..NEW YORK 
 
 Makers to.. .UNITED STATES WEATHER BUREAU. 
 
 SIGNAL CORPS UNITED STATES ARMY. 
 FISH COMMISSION. 
 
ADVERTISEMENTS 
 
 25 BEIiOOl ZERO 
 
 OBTAINED WITH THE 
 
 FEATURES: 
 
 MAXIMUM CAPACITY SIMPLICITY 
 
 HIGHEST ECONOMY- DURABILITY 
 SPECIALLY ADAPTED FOR VENTILATING SYSTEMS 
 
 FOR PARTICULARS ADDRESS 
 
 THE 
 
 CARBONDALE, PA. 
 
 NEW YORK OFFICE, 1012 HAVEMEYER BUILDING. 
 
 NONPAREIL CORK 
 
 Che Ideal 
 Insulation 
 
 Sheets for 
 Walls 
 Rooms 
 Ceilings. 
 
 3- feet 
 
 Sections for 
 
 Steam, Brine 
 
 Ammonia 
 
 and 
 Water Pipes 
 
 Ui^b WOtvK! says"THEBOY" 
 
 in his Practical Ice Making and Refrigerating, 
 page 164, 
 
 "In the selection of insulating- substances 
 their power to withstand moisture plays an im- 
 portant part in most cases. In this respect Cork 
 is a very desirable material," says Professor 
 J. E. SIEBEL in his Compend of Mechanical Refrig- 
 eration, page 155. 
 
 The Nonpareil Cork Mfg. Co. 
 
 28 QUEEN STREET, 
 
 LONDON, E* C, ENG. 
 
 92 WEST BROADWAY, 
 
 NEW YORK, N. Y. 
 
A D VKK TISKMEN TS 
 
 Tee and Refrigerating machines 
 
 FOR CREAMERIES AND 
 PRODUCE DEALERS 
 
 Refrigerating Machines are rapidly taking the place of 
 ice for refrigerating purposes. A lower temperature can 
 be secured. The cold is absolutely dry. It will pay you to 
 investigate and get estimate on plant. 
 
 SIMPLE 
 STRONG 
 COMPACT 
 DURABLE 
 
 ijr 
 
 LARGEST 
 EFFICIENCY 
 POSSIBLE BE- 
 CAUSE ABSO- 
 LUTELY NO 
 CLEARANCE 
 
 THE ONLY SMALL MACHINES OF DUPLEX TYPE 
 
 EQUIVALENT TO TWO INDEPENDENT MACHINES. ONE 
 ALWAYS IN RESERVE AS PROTECTION AGAINST 
 LOSS FROM STOPPAGES AND BREAK DOWNS. 
 
 Small Plants from 2 to 10 Coits Refrigerating Capacity Our Specialty 
 
 Estimates Cheerfully and Promptly Given. 
 
 Write for our Handsomely Illustrated Booklet named ''Cold Making." 
 
 CREAMERY PACKAGE MANFG. Co, 
 
 1, 3 AND 5 WEST WASHINGTON STREET 
 
 CHICAGO, ILL. 
 
Doo 
 and 
 
 THIS BOOK IS DUE ON THE LAST DATE 
 STAMPED BELOW 
 
 AN INITIAL FINE OF 25 CENTS 
 
 WILL BE ASSESSED FOR FAILURE TO RETURN 
 HIS BOOK ON THE DATE DUE. THE PENALTY 
 WILL INCREASE TO SO CENTS ON THE FOURTH 
 
 OVERDUE. T $ '- N E SEVEN DAY 
 
 fasten 
 
 fix 
 
 iru 
 
 I They 
 ^mplete 
 Wftt 3 1933 1 place, 
 
 air in either direction. 
 
 le with 
 
 f-ewith, 
 hresh- 
 [e d to 
 go on a 
 th nei- 
 thresh- 
 have 
 erhead 
 d corn- 
 in ad- 
 pr so it 
 [mashed 
 trolley. 
 
 , or all 
 
 opened 
 re cush- 
 
 LD 21-50m-l,'33 rush of 
 
 _ 
 
 ' 
 
 ; 
 
 Complete information, diagrams and illustrations 
 in our circulars. 
 
FRICK COMPANY 
 
 ..ENGINEERS... 
 
 Established 
 
 Incorpo 
 188: 
 
 E( 
 
 288 
 
 ies 
 
 IVERSITY OF CALIFORNIA LIBRARY 
 
 References and new Ice Machine Circular, describ- 
 ing 1 latest improvements ->"^ " .vinR; 
 Ice arul u.- ,:.,. .eratir.- iild< . fir* 
 class STEAAl oNUiNES, AMMON. 
 VALVES, FLANGES, COILS, etc. 
 
 CORLISS STEAM ENGINES 
 
 ICE MAKING MACHINERY, 
 
 STEAM BOILERS, 
 AMMONIA FITTINGS. 
 
 FRICK COMPANY, 
 
 WAYNESBORO, FRANKLIN COUNTY, PA.