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Full text of "Cork insulation; a complete illustrated textbook on cork insulation--the origin of cork and history of its use for insulation--the study of heat and determination of the heat conductivity of various materials--complete specifications and directions for the proper application of cork insulation in ice and cold storage plants and other refrigeration installations--the insulation of household refrigerators, ice cream cabinets and soda fountains"

^oofe^a- 1842.4 







lag 



ItlJtston 



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other person. 




MOA'ARCII OF THE CORK lORI-ST 



Cork Insulation 



A COMPLETE ILLUSTRATED TEXTBOOK OX CORK IXSULATIOX— THE 
ORKHX OF CORK AXD HISTORY OF ITS USE FOR IXSULATION- 
THE STUDY OF HEAT AXD DETERMIXATIOX OF THE HEAT COX- 
DUCTIVITY OF VARIOUS MATERIALS— COMPLETE SPECIFI- 
CATIOXS AXD DIRECTIOXS FOR THE PROPER APPLICA- 
TIOX OF CORK IXSULATIOX IX ICE AXD COLD 
STORAGE PLANTS AND OTHER REFRIGERATION 
IXSTALLATIOXS— THE IXSULATIOX OF HOUSE- 
HOLD REFRIGERATORS, ICE CREAM 
CABIXETS AXD SODA FOUXTAIXS. 



PEARL EDWIN THOMAS 

Engineering Graduate, 1909, The Pennsylvania State College 
Identified with the Cork and Insulati.jn Industries since 1912 




publishers 
Ntckekson & Collins Co. 

CHICAGO 



-7" 



I 



Copyright, 1928, by the 

NICKERSON & COLLINS CO. 

All rights reserved 

PRINTED IN THE UNITED STATES OF AMERICA 



PRESS or 
ICE AND KKIRIGKKATKJN 

CHICAGO -NKW YORK 



To 

the Memory of 
JAMES EDWARD QUIGLEY 



184-^4- 



PREFACE 

In submitting this first complete treatise on the sources, 
harvesting, manufacture, distribution and uses of cork and 
cork insulation products, the author believes that he has 
succeeded in adding to scientific literature a work for which 
there is at this period a real necessity and a genuine demand. 

The collection of data on which tlie matter herein pub- 
lished is based has necessitated many years of careful re- 
search in a field widely scattered and rcc^uiring thought and 
discriminating care in the separation of the grain from the 
chafif in published matter sometimes of a more or less dissolute 
nature and frequently of an unreliable character. Such matter as 
is here presented can be considered authentic and authoritative 
and relied upon unreservedly. 

When consideration is given to the fact that in the half 
century just passed the cork industry has developed and 
progressed from a mere matter of production of bottle 
stoppers to a diversified line of products covering hundreds of 
separate items and involving cork imports valued at millions 
of dollars per annum, some conception of the magnitude and 
importance of the cork industry of the world can be formed. 

For the architect, engineer, consulting expert, equipment 
designer, car and steamship builder, plant owner, industrial 
manager, and for every one interested in any way in refriger- 
ation, ice making, cold storage, the operation of markets, 
dairies, creameries, ice cream plants, the manufacture of house- 
hold and commercial refrigerators, insulating against both 
heat and cold, sound-proofing, moisture-proofing, humidity 
and temperature control, this book will be found indis- 
pensable. 

The rapid strides of the development of the cork industry 
in this country have astonished even those who have been 
and are now directly associated with the cork business, and 
it is appreciated that as yet the possibilities of future applica- 



tion of cork to other and more remote industrial purposes 
have scarcely been touched. 

While the main idea sought to be brought out em- 
phatically in this work is that of insulation, it is thought pos- 
sible that the subjects covered herein may lead to further im- 
portant developments and progress in the industry. 

In addition to the direct credit given in the body of the text, 
and in foot-notes, grateful acknowledgement is also made to the 
following individuals and concerns whose courtesy and coopera- 
tion made possible many of the very valuable illustrations con- 
tained in this work, as follows: Armstrong Cork & Insulation 
Co., United Cork Companies, Cork Import Corporation, Spanish 
Cork Insulation Co., John R. Livezey, Edward J. Ward, Rhine- 
lander Refrigerator Co., Leonard Refrigerator Co., Gifford- 
Wood Co., and the American Society of Refrigerating Engineers. 

P. EDWIN THOMAS. 
Chicago, July, 1928. 



TABLE OF CONTENTS. 

Part I.— The Cork Industry. 
CHAPTER I. 



The Origin of Cork. 



1. Early Uses of Cork — 2. Beginning or' the Cork Indus- 
try — 3. Source of Supply — 4. Home of the Industry — 5. 
Characteristics of the Cork Oak. 



CHAPTER II. 
Cork Stripping 10 

6. Removing the Outer Bark — 7. Virgin Cork — 8. Sec- 
ondary Bark — 9. Boiling and Baling. 

CHAPTER HI. 
Uses of Corkwood and Utilization of Cork Waste. ... 16 

10. Hand Cut Corks— 11. Other Uses— 12. Importance 
of Sorting — 13. Cork Stoppers — 14. Cork Discs — 15. Arti- 
ficial Cork — 16. Cork Insulation. 



CHAPTER IV. 
Early Forms of Cork Insulation 25 

17. Natural Cork and Composition Cork — 18. Impreg- 
nated Corkboard. 

CHAPTER V. 

Discovery of Smith's Consolidated Cork, and the First 
Pure Cork Insulation 29 

19. Smith's Discovery — 20. Cork Covering for Steam 
Pipes — 21. Cork Covering for Cold Pipes — 22. Pure Cork- 
board. 



viii TABLE OF CONTENTS 

CHAPTER VI. 

F.XTENT OF THE CoRK INDUSTRY 



23. Is Source of Supply Adequate ?-24. Cork Stopper 
Industry— 25. Cork a National Necessity— 26. Effects of 
U. S. Tarifif Act of 1913—27. Effect of the World War— 
28. Recovery of the Industry— 29. Changing Demands— 30. 
Tables of U. S. Imports (1892-1924). 



Part II.— The Study of Heat. 
CHAPTER VII. 

Heat, Temperature and Thermal Expansion 

31. Molecular Theory of Heat— 32. Temperature— 33. 
Dissipation of Energy-34. Effects of Heat-35. Ther- 
mometers— 36. Air Thermometer— 37. Expansion and Con- 
traction— 38. Force of Expansion and Contraction— 39. Ap- 
plications of Exiiansion and Contraction— 40. Coefficient of 
Expansion— 41. Determination of the Expansion of Sub- 
stances. 

CHAPTER VIII. 
Measurement of He.\t, Change of State and Humidity 
42. First Law of Thermodynamics— 43. Methods of Heat 
Measurement— 44. Units of Heat— 45. Thermal Capacity of 
a Substance— 46. Specific Heat— 47. Heat of Combustion— 
48. Change of State with Rise of Temperature— 49. The 
Melting Point— SO. Heat of Fusion— 51. The Boiling Point— 
52. Vaporization— S3. Heat of Vaporization— 54. Super- 
heating and Undercooling of Liquids— 55. Critical Temper- 
atures— 56. Saturated Vapor— 57. Effect of Pressure on 
Melting Point— 58. Effect of Pressure on Boiling Point— 
59. Boiling and Melting Points of Mixtures— 60. Cold by 
Evaporation— 61. Condensation and Distillation— 62. The 
Dew Point— 63. Humidity. 

CHAPTER IX. 

Transfer of Heat 

64. Heat Transference- 65. Conduction— 66. Convection— 



33 



67 Radiation-68. Flow of Heat-69. Total Heat Tran,^ 
■ei— 70. Air Spaces-71. Heat Transfer by Conduction Only- 



11. Heat Loss Through Insulation. 



TABLE OF CONTENTS ix 

CHAPTER X. 

Determination of tpie Heat Conductivity of Various 
Materials 115 

7Z. Methods Emi.I.)ycd^74. The Ice-Box Method— 75. 
The Oil-Box Method— 76. The Hot-Air-Box Method— 77. 
The Cold-Air-Box Method— 78. The Hot-Plate Method— 79. 
Tests hy Various Authorities on Many Materials. 



Part III. — The Insulation of Ice and Cold Storage Plants and 
Cold Rooms in General. 

CK AFTER XI. 

Requirements of a Satisf.xctok^' Insulation for Cold 
Storage Temperatures 167 

80. Essential Requirements — 81. .\ Good Nonconductor of 
Heat — 82. Inherently Nona]>sorbent of Moisture — 83. Sanitary 
and Odorless — 84. Compact and Structural!}- Strong — 85. Con- 
venient in Form and Fas\ to Install — 86. A Fire Retardant — 
S7. Easily Ohiaincd and Reasonable in Cost — 88. Permanent 
Insulating Effijienc\'. 



CHAPTl-.R XII. 

Pi^oi'ER Thickness of Corkcoakd to Use a.md Structural 

' SUG(JESTI0NS 178 

89. Economic Value of Insulating Materials — 90. Ten- 
dency Toward More and Better Insulation — 91. Proper 
Thickness of Corkboard to Use — 92. Importance of Proper 
Insulation Design — 93. Types and Design of Cold Storage 
Rooms — 94. Types of Bunkers and Details of Construction — 
95. Circulation, Ventilation and Humidification — 96. Prepa- 
ration of Building Surfaces to Receive Insulation — 97. In- 
sulation of Floors, Columns, Ceilings and Beams — 98. Doors 
and Windows — 99. Interior Finishes for Cold Storage 
Rooms — 100. Asphalt Cement and Asphalt Primer — 101. 
Emulsified Asphalt. 



240 



X TABLE OF CONTENTS 

CHAPTER XIII. 

Complete Specifications for the Erection of Cork- 
board 

102. Scope and Purpose of Specifications — 103. Walls : 
Stone, Concrete or Brick— 104. Walls: Wood— 105. 
Ceilings: Concrete— 106. Ceilings: Wood— 107. Ceilings: 
Self-Supported— 108. Roofs : Concrete or Wood— 109. Floors : 
Wood — 110. Floors: Concrete — 111. Partitions: Stone, Con- 
crete or Brick — 112. Partitions: Wood — 113. Partitions: Solid 
Cork — 114. Tanks: Freezing — 115. Finish: Walls and Ceil- 
ing — 116. Finish: Floors — 117. Miscellaneous Specifications. 



CHAPTER XIV. 

Complete Directions for the Proper Applicaton of 
Corkboard Insulation 279 

118. General Instructions and Equipment — 119. First Layer 
Corkboard, against Masonry Walls, in Portland Cement 
Mortar — 120. First Layer Corkboard, against Masonry Walls, 
in Asphalt Cement — 121. First Layer Corkboard, against 
Wood Walls, in Asphalt Cement — 122. Second Layer Cork- 
board, against First Layer on Walls, in Portland Cement 
Mortar— 123. Second Layer Corkboard, against First Layer 
on Walls, in Asphalt Cement — 124. First Layer Corkboard, to 
Concrete Ceiling, in Portland Cement Mortar — 125. First 
Layer Corkboard, in Concrete Ceiling Forms — 126. First 
Layer Corkboard, to Wood Ceiling, in Asphalt Cement — 
127. Second Layer Corkboard, to First Layer on Ceiling, 
in Portland Cement Mortar — 128. Second Layer Corkboard, 
to First Layer on Ceiling, in Asphalt Cement — 129. Double 
Layer Corkboard, Self-Supporting T-Iron Ceiling, Portland 
Cement Mortar Core — 130. First Layer Corkboard, over Con- 
crete or Wood Floor or Roof, in Asphalt Cement — 131. 
Second Layer Corkl)oard, over First Layer on Floor or 
Roof, in Asphalt Cement^l32. Single Layer Corkboard, be- 
tween Partition Studs with Joints Sealed in Asphalt Ce- 
ment — 133. First Layer Corkboard, Self-Supporting Partition, 
Joints Sealed in Asphalt Cement — 134. Second Layer Cork- 
board, against First Layer of Self-Supporting Partition, in 
Portland Cement Mortar — 135. Second Layer Corkboard, 
against First Layer of Self-Supporting Partition, in Asphalt 
Cement — 136. Double Layer Corkboard, Freezing Tank Bot- 
tom, in Asphalt Cement — 137. Regranulated Cork Fill, Freez- 
ing Tank Sides and Ends, with Retaining Walls — 138. Single 
Layer Corkboard and Regranulated Cork Fill, Freezing Tank 



TABLE OF CONTENTS 

CHAPTER XIV— Continued. 

Sides and Ends- — 139. Double Layer Corkboard, Freezing 
Tank Sides and Ends — 140. Portland Cement Plaster — 141. 
Factory Ironed-On Mastic Finish— 142. Emulsified Asphalt 
Plastic — 143. Concrete Wearing Floors — 144. Wood Floors 
Secured to Sleepers Imbedded in Insulation — 145. Galvanized 
Metal over Corkboard. 



Part IV. — The Insulation of Household Refrigerators, Ice 
Cream Cabinets and Soda Fountains. 



CHAPTER XV. 

History of Refrigeratox Employed to Preserve Food- 
stuffs 317 

146. Early Uses of Refrigeration — 147. The Formation, 
Harvesting and Storing of Natural Ice — 148. The Develop- 
ment of the Ice Machine — 149. Early Methods of Utilizing 
Ice as a Refrigerant — ISO. Early 'Methods of Insulating Cold 
Stores. 

CHAPTER XVI. 

Development of the Corkboard Insulated Household 
Refrigerator 332 

151. Early Forms of Household Coolers — 152. The House- 
hold Ice-Box — 153. The Era of Multiple Insulation in House- 
hold Refrigerators — 154. The Advent of the Household Re- 
frigerating Machine and Early Trials with Pure Corkboard 
in Household Refrigerators — 155. The Modern Corkboard 
Insulated Household Refrigerator — 156. Typical Details of 
Household Refrigerator Construction — 157. Notes on the 
Testing of Household Refrigerators. 



CHAPTER XVII. 

Development of the Corkboard Insulated Ice Cream 
Cabinet 386 

158. Growth of the Ice Cream Industry — 159. Ice and Salt 
Cabinets — 160. Mechnical Ice Cream Cabinets — 161. Typical 
Details of Ice Cream Cabinet Construction — 162. Notes on 
How to Test Ice Cream Cabinets. 



xii TABLE OF CONTENTS 

CHAPTER XVIII. 
The Refrigerated Soda Fountain 403 

163. Automatic Operation of an Intricate Unit Made Pos- 
sible with Corkboard Insulation — 164. Extracts from Manu- 
facturers' Specifications for Modern Mechanically Refriger- 
ated Soda Fountains with Typical Details of Construction. 

Appendix 425 

Refrigeration in Transit — The Ability of Refrigerator Cars 
to Carry Perishable Prockicts — Tlie Utvelopment of the 
Standard Refrigerator Car — Specifications for Refrigerator 
Car Insulation — Cork Paint — Pulverized Cork — Subirine— 
Cork as a Building Material — Some Uses of Corkboard In- 
sulation — Relative Humidity Table — Heat Transmission : A 
National Research Council Project — Air Infiltration — Cork 
Dipping Pan — Protection of Insulation Against Moisture — 
How Insulation Saved a Refinery — Economy of Gasoline 
Storage Tank Insulation — Interior Finish of Cold Storage 
Rooms in Hotels — Concrete — Example of Purchaser's Insula- 
tion Specifications — Freight Classifications, Class Rates, Etc. — 
Pure Corkboard and Sundries — Freight Classifications, Class 
Rates, Etc. — Cork Pipe Covering, Cork Lags, Cork Discs and 
Sundries — ^Cork Pipe Covering Specifications — Instructions 
for Proper Application of Cork Pipe Covering — A Good 
Drink of Water — Fundamental Contract Law — Engineering 
Contracts. 

Topical Index 523 



CORK INSULATION 

Part I — The Cork Industry. 



CHAPTER I. 

THE ORIGIN OF CORK. 

1. — Early Uses of Cork. — The story of cork is so little 
known and shrouded with so much mystery that the world 
has never had a complete and comprehensive account of iU 
The utility and general uses of the "cork of commerce," as 
well as its native land, are no longer a part of the mysticism ; 
but its character, composition and chemical construction are 
still the subject of research and experimentation. 

'The uses of the outer bark of the cork oak tree have been 
traced far back into a dim past, but for our purpose it will be 
cnousjh to go back no further than the first century of the 
Christian era. The elder Pliny wrote al:)()ut the cork oak tree 
then, in his work on natural histor}-. and recognized twenty 
centuries ago at least four of the principal functions that cork 
fills in the world today, which involved a recognition of the 
two principal properties of cork bark that make its use of so 
much value as a commercial insulating material — its marked 
ability to retard the flow of heat and its freedom from capil- 
larity. These two properties, in combination, were provided 

•by Nature to make this interesting and remarkable material 
the foundation, when put through proper manufacturing 
processes, for the best cold storage and refrigerator insulation 
yet known to mankincL 

** As is often the case with many important discoveries, the 
first use of cork probably came through accident ; for its em- 

I ployment "attached as a buoy to the ropes of ships' anchors 
and the drag-nets of hshermen" suggests that a piece of cork 
bark found its way to the sea where its unusual buoyancy was 
first noted and utilized bv fishermen and sea-faring men as 



2 CORK INSULATION 

floats for nets, buoys for anchors, cork jackets for life pre- 
servers, and later as plugs for vintage casks sealed in with 
pitch and as winter sandals for women. ^ 

Since Pliny was writing history, some two thousand years 
ago, it is safe to assume that the very first use ever made of 
cork must date well before his time, perhaps 500 B. C, or 
1000 B. C. — there is now no means of knowing. 




FIG. 1.— CORK MOORING AND ANCHORAGE BUOYS. 

2. — Beginning of the Cork Industry. — During many cen- 
turies of the Christian era the great cork forests, bordering 
the Mediterranean sea, were ravaged by wars and fires and the 
demand for timber and charcoal. But at least some of these 
sturdy cork oak trees managed to escape and later, under 
kindlier treatment, sprpad out over the mountain slopes and 
gave to Spain, Portugal and Algeria one of their chief pres- 
ent sources of revenue — the growing of "corkwood." 

'^ It was not until the sixteenth or seventeenth century, how- 
ever, that the real beginnings of the great cork industry, as 
it is known today, may be said to have begun, with the gen- 
eral introduction of the glass bottle. Then cork bottle stop- 
pers quickly came into general use, being elastic, com- 
pressible, tasteless, odorless, and impervious to water, and 
gave the cork industry such impetus as to establish it upon 
a sound footing for all time.'*' 



ORIGIN OF CORK 3 

3. — Source of Supply. — While southern France and Italy, 
including the isles of Corsica, Sardinia and Sicily, are factors 
in the harvesting and supplying of the crude material, yet 
Spain, Portugal, Algeria and Tunis continue to supply the 
world with the bulk of the raw cork that is consumed. 
Morocco, in north and northwest Africa, provides an 
enormous and for the greater part an undeveloped area of 
cork forests* but this field is now being opened up under 
careful supervision, and should grow rapidly in importance 
as a source of suppl\-. 




FIG. 2.— CORK 1!( 



■!.E STOrPERS. 



The total area covered by cork forests in all countries is 
estimated at from four to five million acres,''^ and the annual 
yield of corkwood in 1913 at about two hundred thousand 
tons.fl The shaded areas on the accompanying map repre- 
sent the principal places in the world where the cork oak 
grows. "Mt flourishes best in an altitude of 1,600 to 3,000 feet, 
in an average mean temperature of 55° F., and the Mediter- 
ranean basin is therefore particularly suitable for the growing 
of the cork oak and the harvesting of its outer bark of qual- 
ity. < 



<• 



Armstrong Cork Company, 1909. 
tU. S. Tariff Commission's 1924 Dictionary of Tariff Information. 



k 



CORK INSULATION 






vfany attem])ts lia\c l_)een made to transplant tliis interest- 
ing tree, Imt the result of e\ery sueh effort has been futile. 
Just before t'n.e Ci\il war, in 1859', the United States Govern- 
ment provided funds to brin;;- I'ortuijLse cork acorns to se\'- 
cral of the Southern States for planting; but after a dozen 
years c^r so it was concluded, in spite of the neglect of the 
seedlings occasioned by the War of tlie Rebellion, that the 
experiment was not a commercial success. Some of these 
cork oak trees are still standing in Mississippi and Georgia, 
but the outer bark never matured satisfactorilw^ "^^ 




FIC. 3— S()UK( E OK IHK WORLDS Sl'PPLY OF CORK. 

*In 1872 another eft'ort was made to grow the cork oak in 
southern California. Init the outcome pro\ed no better there 
than it did at an earlier date in the luist.*Four of these trees 
are now standing in the Methodist churchyard at Fourth and 
Arizona Streets. Santa Monica. California, and a half dozen 
more have recently been located by H. H. Wetzel in Santa 
Monica canyon; ])ut while the trees themselves have flour- 
ished, the quality of their salient ])roduct is inferior and of no 
commercial value. ^ 



ORIGIN OF CORK 




FIG. 4.— CORK OAK TRKE GROWING IN SANTA MONICA, CALIF. 



6 CORK INSULATION 

•^ 4. — Home of the Industry, — The ancient Spanish province 
of Catalonia, in the northeast or Barcelona area, has long been 
recognized as the greatest cork manufacturing district in the 
world, the towns of Palamos, Palafrugell, San Feliu de 
Guixols, Bisbal, Figueras and others being devoted almost 
exclusively to cork and cork products. Domestic cork fac- 
tories are scattered throughout the cork areas of Spain and 
Portugal, to the extent of i)erhaps a thousand different estab- 




FIG. S.— LOADING CORKWOOD FOR EXPORT AT PORT OF PALAMOS, 
SPAIN. 



lishments, while the remainder of the yield, in the form of 
baled corkwood, cork waste, shavings and cork refuse of all 
kinds, is exported to Sweden, Denmark, Russia, Austria, Ger- 
many, France, Great Britain and the United States, the last 
four named ordinarily absorbing perhaps eighty-five per cent 
of the total product of the producing countries, to be worked 
into hundreds of different cork articles of trade. ^ 

\JBecause most people think of Spain as an easy-going 
country of medieval ways, with no great wealth or material 



ORIGIN OF CORK 7 

development, it can not be amiss to say a word about Bar- 
celona, the capital, so to speak, of the cork industry, and 
which jnust be ranked today amoAg the great cities of the 
world. ^*The Barce^kma distnpt-'(5r Spain would be an amazing 
surprise to any one mip^ilTg to it with no better idea of what 
to expect. Barc^krfia is tddaj,:,j m enormous city of nearly a 
million pomil^tion, extending from the sea toTHe^fDDthills of 
the_Byr€mies, filling the plain in between and stretching out 
into the valleys and well along the coast. 

From a point on Tibidabo some 1,500 feet above the 
Mediterranean sea, can be seen an immense metropolis spread 
out with the exact regularity of any of our modern cities of 
the Middle West. Ofif to one side a splotch by the harbor 
faintly marks the old Barcelona of crooked, narrow streets, 
but even this is fast giving way to make room for new, wide 
thoroughfares that link modern highway and transportation 
lines. 

Modern office and public buildings, hotels and shops, flats 
and apartments, broad avenues and boulevards lined with 
trees and completely equipped with excellent electric tram 
and omnibus service, athletic stadiums and open air theatres, 
palatial villas and residences, electric trains every few minutes 
from the heart of the city out into the country, a subway under 
construction, at night the central squares lit up with flashing 
Broadway sky signs — there is little indeed to suggest the 
Spain of our fancy. 

Barcelona began to grow after the International Exposi- 
tion of 1888, when new capital gave an immense impetus to 
its many industries; and while it is the chief seaport of Spain, 
it is as a manufacturing center that it has risen to the position 
of one of the great cities of the world. 

^5. — Characteristics of the Cork Oak. — The botanical name 
for the cork oak is Quercus suher. "It grows and develops in 
ground of little depth, and often quite stony, being seldom 
found in calcareous soil, preferring a sandy soil of felspar."* 
It ordinarily attains a height of from twenty-five to fifty feet, 
but occasionally grows to a height of more than one hundrec 



'Consul Schenck's Report, 1890. 



8 CORK INSULATION 

and fifty feet and to a diameter of as mueh as four feet.f 
Its branches usuall}- are full-spread and are co\ ered with small 
evergreen leaves ha\ing" a veUety feel and a glossy appear- 
ance. Its roots spread considerably and attain much 
strength, often being xisible abo\e ground. 

During- April and Ala} the }ellowish blossoms appear, 
which are followed by the acorns that ripen and at once fall to 
the ground during the last four months of the year. These 
acorns are bitter to the taste, but gi\e a ])eculiarly piquant 
flavor to SiJanish mountain hams when ted to swine. The 




cork oak offers but little shade, which permits the soil to be- 
come very dry and of inferior producing value unless the 
young trees are growii close together until they are about 
twenty-hve xcars olds/ Jf the soil is [xjor, the outer bark is 
thin but of fine texture; if the soil is rich, the bark is thick, 
spongy and inclined to be coarse. These characteristics are 
carefully studied from an agricultural standpoint, in the 
\-arious cork growing districts, and are dealt with as reason 
dictates. 

The outer bark of the cork oak consists of thin-walled cells 
filled with air, is destitute of intercellular spaces, and is im- 
permeable to air and water. These cells are so small that 



tHcnry Vincke, 1925. 



ORIGIN OF CORK 9 

they can be ^■isllalize(l only with a high powered microscope, 
there being about four hundred milHon per cubic inch, but 
each cell contains a microscopic bit of air and is sealed against 
all other cells so that the entrapped air can not move about 
within the material. It is this peculiar structure of cork bark 
that makes it an excellent nonconductor of heat and, at the 
same time, impervious to air and water, which latter property 
is absolutely essential in an insulating material that is to be 
employed in cold storage and refrigerator construction w^here 
moisture is always present. *'A 



CHAPTER II. 
CORK STRIPPING. 

6. — Removing the Outer Bark. — The cork of commerce, or 
corkwood, is the outer bark of the cork tree, which belongs to 
the oak family and which has been described. This outer 
bark can readily be removed during the summer months, gen- 
erally during July and August, without harm to the tree, 
although considerable skill is required if injury to the inner 
or sap-carrying bark is to be avoided. French strippers some- 
times use crescent-shaped saws, but Spanish strippers in- 
variably use a long-handled hatchet, the handle tapered at 
the butt in the shape of a wedge. 

When cork oak trees attain a diameter of about five inches, 
or measure forty centimeters in circumference according to 
the Spanish practice, which fixes the age of the tree at about 
twenty years, the virgin outer bark is removed. It is cus- 
tomary to cut the l)ark clear through around the base of the 
tree and again around the trunk just below the main branches, 
the two incisions then being connected by probably two ver- 
tical cuts. By using the long handle of the hatchet as a wedge 
and lever, the tree's outer bark is easily pried off. The lower 
portions of the limbs are stripped in like manner, frequently 
yielding a liner grade of corkwood than that of the trunk. 
The thickness of this virgin outer bark varies from about one- 
half to two and one-half inches, while the yield per tree also 
varies from a half hundred to several hundred pounds, de- 
pending on both its size and age when the virgin stripping is 
accomplished. 

7. — Virgin Cork. — This virgin cork bark, called "borniza" 
in Spain, is rough, coarse and dense in texture. It is there- 
fore of limited commercial value, except as used by florists 

10 



CORK STRIPPING 



11 



and others for decorative purposes, and, when ground, as 
packing for grapes, although it has of recent years come into 




FIG. 7.— REMOVING THE OUTER BARK FROM THE CORK (»AK 



use also in the manufacture of linoleum and, when treated, 
in the manufacture of cork insulation. 

So long as the inner bark or skin is not injured, the re- 
moval of the outer bark is beneficial rather than harmful to 



12 CORK INSULATION 

the cork oak tree; for this unscarred inner bark, with its Hfe- 
giving sap, immediately undertakes the formation of a new 
covering of better quality. Each year this inner bark, the 
tree's real skin, forms a la\er of cells within, increasing the 




FIG. 8.— VIRGIN CORK AND SECOND STRIPPING BARK. 

diameter of the trunk, and a layer of cells without, adding 
thickness to the covering of outer bark. If the inner bark 
is injured, the growth of the outer bark is permanently 
stopped at that point, the injured area appearing as scarred 




FIG. 9.— CORK BARK— "BACK" AND "BELLY". 

and uncovered for the remainder of the life of the tree. Also, 
stripping is never done during a "sirocco," — a hot southernly 
wind blowing from the African coast to Italy, Sicily and 
Spain, — which would dry the inner bark too rapidly and ex- 
clude all further formation of outer bark. 

8. — Secondary Bark. — After eight or ten years the outer 
bark is again removed, known as "pelas" or secondary bark. 



CORK STRIPPING 



13 



and, while of nnich better quality than the virgin bark, it is 
not as fine in texture as future stripping?, which follow every 
eight or ten years from the time the tree is about forty years 
of age until it is a hundred or more years old. When the 
cork oak has been stripped about live times, or when about 
ninetv rears old, subsequent strippings yield a bark that is 
more grain\- and of less \alue for tajjer corks and cork jiaper. 
The second and all subsec|uent strippings of the outer bark of 



"»-^ 




FIG. 10.— HANDLl.XU C(-)KK\\ OOD I.N THE FOREST. 

the cork oak tree is known a> tlie cork of commerce, wliile 
the term "cork waste" is employed to describe the residue 
from the cutting of natural cork articles, and also the forest 
waste or refuse remaining after the selection of the commer- 
cial bark. 



9. — Boiling and Baling. — As the outer bark of the cork oak 
is remoNcd, under the regulations and j)recautions that are 
prescribed by the different cork growing countries, it is piled 
for a few days to dry out, after which it is weighed, removed 
to the boiling station and there stacked for a few weeks of 



14 



CORK INSULATION 



seasoning preliminary to being boiled. The outer surface of 
cork bark is rough and woody and contains considerable grit, 
due to its long exposure to the elements. After boiling, this 
"hard-back," as it is called, is readily scraped ofT; but since the 
weight is thereby reduced about twenty per cent, and cork- 
wood is sold by weight, it is the tendency to want to slight 
this operation. The same boiling process removes the tannic 
acid, increases the volume and the elasticity of the bark, 
renders it soft and pliable and flattens- it out for baling after 



pPHRT^^P^ '," vi""'' 




"Sjs-ij ~~^'^*^5Si_3BAiii 








■ "^- r 





-CORKWOOD SORTING AND 



first being sorted as to quality and thickness. Sometimes the 
boiling is not done until the raw cork bark comes into the posses- 
sion of those in Spain or Portugal who intend to utilize it in 
their own domestic manufacturing plants, because then the 
complete boiling operation can be carefully supervised and 
controlled. However, it is customary, if the forest is distant, 
water is plentiful and the quantity of bark is ample to justify 
the equipment, to set up the copper vats at a convenient point 
and carry out the boiling operation right in the forest. 

The mountaneous nature of the country, where most of the 
cork trees abound, makes its desirable that the Spaniard's 



CORK STRIPPING 15 

much abused friend, the faithful burro, be employed to trans- 
port corkwood to domestic factories, or to the railway for 
freighting to the seaport warehouses in Spain and Portugal, 
the city of Seville, Spain, being probably the largest deposi- 
tory of corkwood in the world. 

Before exporting, the bales are opened, the edges of each 
piece of bark are trimmed and the corkwood is again sorted 
into many grades of thickness and quality. This final sorting, 
before re-baling for shipment, is done by experts who "know 
cork," because the successful and economical manufacture of 
cork products hinges on it. The large, flat pieces, known as 
planks or tables, are first laid in the baling box to form the 
bottom and sides of the bale, smaller pieces being filled in the 
center and larger pieces used again to cover the top. Pressure 
is then applied to make a compact mass, which steel hoops 
bind securely. 



CHAPTER III. 

USES OF CORKWOOD AND UTILIZATION OF CORK 
WASTE. 

10. — Hand Cut Corks. — Soon after the general introduc- 
tion of tlie glass bottle, in the se\enteenth century, the manu- 
facture of cork stoppers consumed the bulk of the corkwood 




FIG. 12.~.si'A.M.\RI)S ('L-'rTT.\G CORK BY HAND. 

that was harxested. and continued to do so for several cen- 
turies. The manufacture of these "corks" was orginally done 
by hand in the producing countries. The slabs or pieces of 
cork bark were sliced to a width equal to the length of the 
stopper desired, and these strips w^ere then cut into squares, 
or "quarters," from wdiich the corks were rounded by hand. 
The greatest skill was acquired by the Cktalons, who today 
rank as the most adept cork workmen in the world. 

The manufacture of bottle corks by hand was ne\er carried 



USES OF CORKWOOD AND CORK WASTE 17 

on to any great extent in the United States, although prior to 
the Civil War there were a few sucfi establishments in Boston, 
New York and Philadelphia. In Spain and Portugal, how- 
ever, there are to this day many small hand cork manufac- 
tories, although machinery is used by the large and more 
modern plants. While Portugal attained rank with Spain as 
a cork manufacturing country, it has since come to export a 
much- larger proportion of its corkwood in unmanufactured 
form than does Spain. Probably three-fourths of the cork- 
wood grown in Spain is consumed in Spain; that is, is manu- 
factured into some cork product, and in addition, Spain im- 
ports large c^uantities from Portugal and Algeria. Spain, in a 
word, is the cork clearing house of the world, and cork is one 
of the principal industries, if not ihe principal industry, of the 
Spanish people. 

11. — Other Uses. — In addition to "straight'' and "tai)er" 
corks, al)out whiJi more will l)c said ])resently. a great \ariety 






I li;. 13. — C'OKK WASHERS AND (iASKETS— OXE OF MANY USES J'OI^ 
CORK. 

of disks, washers, floats, ]:)UO}S. life rings, balls, mats, handle 
grips, gaskets, bobl^ers, life preservers, as well as shoe insoles, 
polishing disks, cork paper, tropical helmets, rafts, bungs, 
French lieels for shoes, bedding, sound isolation, heat and cold 
insulation, tioor tiles, roof tiles, sweat IkukIs, lining for hats, 
the basis for ladies' hat and dress trimmings, pulley and 
clutch inserts, Spanish black for i)aint. cigarette tips, wadding 
for gun cartridges, ])acking for glass and fruits, bulletin 
boards, the basis of linoleum manufacture, an important in- 
gredient in good stucco i)laster, and probably a hundred or 
so additional items of imj^ortance are manufactured from 
corkwood and cork waste. 




rS CORK INSULATION 

12. — Importance of Sorting. — "In taking up the processes 
of manipulation we naturally start from the beginning, but 
the beginning in this case has a peculiar significance as relat- 
ing to the whole, for it is apparent to utilize corkwood to the 
fullest extent its qualities must be studied and the best used 
first, so that the beginning of the corkwood industry is pecu- 
liar in this fact, that it takes the best part and leaves but 
scrap, which must be studied carefully to realize the value lost 
in the first process; therefore, in the manufacture of one 




FIG. 14.— CORKWOOD STORAGE YARD AT ALGECIRAS, SPAIN. 

article of corkwood it is necessary to make provision for the 
scrap (waste) created, and this is a characteristic of all such 
(cork) establishments."* 

The bulkiness of corkwood is probably its outstanding 
characteristic when considered in relation to its value, ard 
since the harvest occurs but once each year and the corkwood 
comes to market soon after the crop is taken, a large stock 
must necessarily be kept on hand by cork factories. The raw 
material is frequently purchased, or contracted for, a year in 
advance of its fabrication. Thus great piles appear in the 



•Gilbert E. Steelier, 1914, "Cork— Its Origin and Industrial Uses,' 
Nostrand Co., New York, N. Y. 



USES OF CORKWOOD AND CORK WASTE 19 

yards and sheds of cork plants, covering much area and in- 
volving considerable capital, for a shortage in raw material 
would not only throw men out of work and put the plant into 
disuse but would cause the loss of much business through in- 
ability to supply the trade with first-grade cork materials, the 
other grades always being compelled to await a favorable 
market. 

For whatever purpose it is to be used, all corkwood upon 
reaching the factory is again sorted by highly skilled men ; 
and the original twenty or twenty-five grades are re-classed 
into perhaps one hundred and twenty-five or one hundred and 
fifty grades, according to quality and thickness. Success in 
the "cork business" hinges on the care and skill displayed in 
the various sorting operations that are meticulously followed 
at every step from the stripping of the bark to the packing 
of the finished product for delivery to consumers. So slight 
is the difference between many of the grades that the inexperi- 
enced eye would detect none whatever, yet the speed with 
which this sorting work is skillfully done is often astounding. 

The importance of the initial sorting operations is increas- 
ing as the uses of cork increase; because various grades can 
now be used for so many different things, without longer being 
thought of as a by-product. In order that the full value be 
obtained from all corkwood, the sorter must have a thorough 
understanding of the uses to which the many grades of the 
material may be put, and for that reason he is now thought 
of as an expert and a valuable member of the manufacturing 
organization. 

13, — Cork Stoppers. — No account of the uses of corkwood 
and the utilization of cork waste can be given without at least 
a short description of the modern processes followed in manu- 
facturing cork stoppers, for the waste from the production of 
these stoppers has long been an appreciable percentage of the 
total cork waste annually made available for utilization, 
although this percentage is now decreasing. 

The sorted slabs of corkwood are first placed in a steam 
box, which process increases its flexibility greatly, its bulk 
slightly, and otherwise prepares it for the mechanical opera- 
tions that rapidly follow. First, the steamed corkwood is 



20 CORK INSULATION 

usually scraped, often ])y hand and sometimes by knives 
mounted on a \'ertical shaft revolving at about 1,500 r.p.m., to 
remove the hard-lDack, or "raspa," provided this operation was 
not satisfactorily performed at the time of boiling. The cork 
slabs are next cut into strips of width equal to the length of 
the stopper to be cut, because the cutting is done across and 
not with the grain of the bark. A circular knife does this 
slicing, following which the strips go to the "blocking" ma- 
chine. There a tubular punch, with sharpened edges and of 
given diameter, is rotated at about 2,000 r.p.m. to punch or 
cut out thousands of cork stoppers per day, although the 
operator must use caution in avoiding defective spots and at 



FIG. 15.— CORK PUNCHINGS— STOPPERS REMOVED. 

the same time must keep the punchings as close as possible to 
minimize the waste. Next, smaller stoppers are punched from 
the waste from the first punchings, if quality and remaining 
area permit, for every economy of raw stock must be followed. 
These stoppers have straight sides, but if tapered corks are 
desired, larger in diameter at the top than at the bottom, the 
cylindrical pieces must be handled on another machine where 
a circular, razor-edged knife, revolving at top speed and set 
at the proper taper angle to the cork to be shaped, takes off 
the necessary cutting in the form of a very thin cork shaving. 

14. — Cork Disks. — The wide use of the patented "Crown" 
bottle cap, with which the reader is undoubtedly familiar, 
requiring a thin cork disk, created an outlet for very thin 
bark for which there was virtually no previous demand. A 
revolving blade slices the cork bark, on a plane parallel to 
its "back" and "belly", to the required thickness, ranging 



USES OF CORKWOOD AND CORK WASTE 21 

from one-eighth to one-quarter inch, and from these sheets 
the natural cork disks are punched. A great deal of cork 
waste results from this manufacturing process, and its utiliza- 
tion is important enought to form virtually a separate branch 
of the corkwood industry. 

The manufactured stoppers and disks must, in their turn, 
be sorted as to grade and quality. They are then washed 
and bleached by soaking in water and a chemical, and are 




-CORK PU>-CHINGS— DISKS RExMOVED. 



then dried by spinning in a perforated centrifugal cylinder 
mounted within a metal jacket connected to a drain. Some 
stoppers, usually "straights", and all disks, are given a bath 
of hot paraffin, or glycerine and paraffin, which improves their 
resistance and retards discoloration, the operation usually 
being done in a steam jacketed kettle and then "tumbled" to 
remove the excess water and paraffin. 

15. — Artificial Cork. — The working up of the waste from 
corkwood, and virgin cork, which is classed as waste, into 
many products of utility and value is probably the most im- 
portant phase of the cork business today, just as the success- 



22 CORK INSULATION 

ful utilization of by-products in any modern industry is usu- 
ally necessary for successful operation. 

It was noted that in the handling of corkwood the best 
was utilized first; and similarly, in the working up of cork 
waste, the best is granulated in an iron rotary cutter mill, of 
size that will pass a >^-inch mesh, screened and mixed with 
an unusually tenacious glue, dried by steam, hydraulically 
pressed into sheets, dried again, and then punched out into 
"composition" disks for Crown caps, gaskets, insoles and a 
variety of products, frequently termed "artificial" cork 
products. 




:ai^r- 



FIG. 17.— CORK INSOLES FOR SHOES. 

Granulated cork for many purposes is made by grinding 
the waste in a metal roller, cage or bur mill, and screening 
into various degrees of fineness. If cork-flour is recjuired, a 
tube mill is used. 

The manufacture of "Spanish black" for use as a base for 
oil paints of the same color, is produced from cork waste by 
burning inferior grades in a retort, and grinding the carbon- 
ized material in a ball mill until the required fineness is ob- 
tained. 

16. — Cork Insulation. — Probably the most important use 
to which cork waste is now being put, and which rivals the 
cork stopper industry, is in the manufacture of cork insulation 
for the retarding of heat and sound. 

Steam pipes are insulated to prevent heat from escaping; 
cold rooms and cold pipes are insulated to prevent heat from 
entering. Cork is employed as a thermal insulation to prevent 
the entrance of heat, or to preserve cold temperatures ; and 
its success, either in board or slab form for application to 



USES OF CORKWOOD AND CORK WASTE 



23 



floors, walls and ceilings of cold rooms, or in special molded 
forms for ready application to cold pipes and fittings, is due 




FIC. 18.— PURE CORKBOARD INSULATION— 1, H/o, 2, 3, AND 4-INCII 
THICKNESSES, IN STANDARD 12X36 INCH SHEETS. 

ii(_»t alone to its remarkable heat retarding properties and its 
ready adaptability but i^iore particularly to its entire freedom 




ITG. 19.— CORK PIPE COVERING FOR REFRIGERATED LINES AND TANKS. 



24 



CORK INSULATION 



from capillarity. This property, the force that causes a blotter 
to suck up ink, is entirely lacking in cork, as evidenced by 
its long and successful use as stoppers in vessels containing 
liquids. 

Machines are insulated — perhaps more properly spoken of 
today as isolated— to permanently reduce the transmission of 
vibration and sound to an irreducable minimum. Cork iso- 




hm 



r^ 
^ 



Za 






- ". *- . -"- '. "^ :^ ", 



"-.V ^':-'-' 
!■■-■.- r 



FIG. 20.— MACHINE BASE COMPLETELY ISOLATED WITH CORKBOARD 
INSULATION TO REDUCE VIBRATION AND NOISE. 



lation is already widely used in the industries; but, since it 
takes so little to accomplish so much, the total quantity of 
cork consumed in its manufacture is a small factor in the cork 
industry, 

Cork insulation takes on several forms of corkboard, or 
sheet cork, and molded cork pipe covering; and it is the 
detailed treatment of the uses of these remarkable cork prod- 
ucts that shall comprise the greater part of this text. 



CHAPTER IV. 

EARLY FORMS OF CORK INSULATION. 

17. — Natural Cork and Composition Cork. — The first men- 
tion of the use of cork as insulation appears to be by the 
elder Pliny in the first century of the Christian era when he 
called attention to its use by women as winter foot gear. 
Undoubtedly it was utilized as sandals because of its insulat- 
ing qualities and its freedom from capillarity. Pliny spoke 
of cork bark being used as a covering for roofs. John Evelyn, 
the English writer and diarist (1620-1706), mentions that 
cork was much used by old people for linings to the soles of 
their shoes. The poor of Spain laid planks of cork on the 
floor like tiles, to obviate the need for a floor covering that 
would be warm to the touch. They also lined the inside of 
their stone houses with cork bark, to make their homes easier 
to heat and to correct the precipitation of moisture on the 
walls. Ground cork and India rubber formed the basic in- 
gredients of the quiet, resilient floors of the reading rooms 
of the British Museum. Bee hives have long been construcced 
of pieces of cork bark, because of its warmth to the touch. 
Shelves of cork have been used for centuries to preserve ob- 
jects from dampness. The primitive races of northern Africa 
used cork mixed with clay for the walls of their crude dwell- 
ings, and cork slabs as roof tiles. Cork was, and still is, 
the basis in Europe for certain cenents and plastics for pre- 
venting the escape of heat, which are formed to steam pipes, 
and hot surfaces in general. Powdered cork and starch were 
molded into cylinders to fit pipes of different sizes, and were 
then split and made ready for application to pipes requiring 
insulation, after which the cork composition was spirally 
wrapped with cloth and coated with tar or pitch. Narrow 
cork pieces were laid around steam pipes, as lagging, wired 

25 



26 



CORK INSULATION 



in place and spirally wrapped and coated. Cork was early 
used by the medical profession because of its sound isolation 
qualities, as lining for doors of consulting rooms and as floors 
in hospitals. In tropical countries, cork lined hats and cork 
helmets have long served to prevent sunstroke. Brick paste, 
as it was called, was made by mixing the coarsest cork 
poAvder with milk of lime, compressed into bricks and slabs, 
dried and used for the covering of damp walls and pitched 




FGI. 21.— CORK TILE FLOOR IN MODERN OFFICE. 



roofs. In gunpowder plants and powder storage magazines, 
such composition slabs prevented the caking of the powder 
through dampness ; and used under wood flooring, they de- 
stroyed the sound vibrations. 

Thus, it will be noted that the thermal insulating, as well 
as the sound isolating, qualities of cork bark were known 
and utilized, although probably not very clearly understood, 
as early as the year One. Many of these uses have persisted 
through the ages* ; for cork insoles are today an important 



•See appendi.x for "Pulverized Cork — Subirine" and "Cork as a Building Material." 



EARLY FORMS OF CORK INSULATION 



27 



item in the construction of high grade shoes, cork tile floors 
are essential to edifices and libraries, cork linoleum is so 
common in public buildings and in certain types of homes as 
to be classed as essential, and corkboard effectively and effi- 
ciently prevents condensation on and the flow of heat through 
the walls and roofs of buildings. All that was needed to 
establish cork as the standard insulation of the world was 
the discovery of a practical method of utilizing cork waste 




-CORKBOARD INSULATION BEING APPLIED TO SAW-TOOTH 
ROOF CONSTRUCTION. 



in the form of molded slabs or boards of convenient size, 
ample strength and high permanent insulating value under 
actual service conditions. 

18. — Impregnated Corkboard. — About the year 1890 the 
German firm of Griinzweig & Hartmann acquired patents in 
Germany and in the United States for a type of insulation 
known as "Impregnated Corkboard", and soon became the 
leaders in their own country in the manufacture of these 
"impregnated" cork slabs for insulating purposes, particularly 



28 CORK INSULATION 

for cold storage work. The United States patent rights for 
this new type of insulation were subsequently acquired by 
the Armstrong Cork Company of Pittsburgh, about the year 
1900, following which a plant for its manufacture was estab- 
lished at Beaver Falls, Pa., such location being selected 
principally because the necessary clay for the preparation of 
the foreign binder to stick the granules of cork together was 
available there in generous quantity and at a point not far 
distant from Pittsburgh. 

The business grew rapidly, especially among the brewers, 
for the insulation of their cellars ; but it was soon discovered 
that this impregnated corkboard was inferior in insulating 
quality, and in structural strength in service, to a brand of 
"pure" corkboard being made under the patents of one John 
T. Smith, an American, and subsequently the manufacture 
and use of the impregnated, or "composition," corkboard gave 
way entirely to the pure corkboard insulation. 



CHAPTER V. 

DISCOVERY OF SMITH'S CONSOLIDATED CORK, 
AND THE FIRST PURE CORK INSULATION. 

19. — Smith's Discovery. — The manufacture of pure cork 
insulation was begun in 1893, in the United States, under the 
original John T. Smith patents, by Messrs. Stone and Duryee. 
Cork covering was produced first, and then the manufacture 
of pure corkboard followed within a very few years. 

It is interesting to know that the discovery of the process 
of baking cork particles under pressure to bind them to- 
gether, which later made pure cork insulation possible, was 
purely an accident ; and that the process was not thought of 
in connection with cork covering and corkboard until Messrs. 
Stone and Duryee later applied it to that purpose. 

In the "Boat Works" of John T. Smith on lower South 
Street, on the East River, in New York, was a large cast-iron 
kettle with a fire box under it, the kettle being used to steam 
oak framing for row boats that Smith manufactured there for 
many years. He also produced boat fenders, life preservers 
and ring buoys, in the manner common in those days, by pack- 
ing granulated cork in canvas jackets. Girls packed the cork 
in these jackets, using tin forms or cylinders to keep the can- 
vas distended until filled. One of these cylinders became 
clogged in the hands of one of Smith's employees and was 
laid aside for the moment, but it inadvertently rolled into 
the dying embers of the fire box during clean-up late that 
evening. 

Early the next morning. Smith, owner and fireman, cleaned 
out the fire box and found his misplaced utensil. But the 
hot ashes had not consumed the cork particles that had 
clogged it. The heat had been sufficient merely to bind the 

29 



30 



CORK INSULATION 



very substantial chocolate- 
brown cork cylinder. 

Smith noted this peculiar fact with much interest, if not 
with actual astonishment, and put the tin form and cork 
cylinder aside for future secret study and investigation. He 
repeated the original and wholly unintentional experiment 
enough times to satisfy himself that for some good reason a 
certain degree of heat applied for a given time served to glue 
cork particles together without the addition of a foreign 




FIG. 23.— ARTIST'S CONCEPTION OF THE DISCOVERY OF PURE CORK- 
HOARD INSULATION BY JOHN T. SMITH. 

substance or binder of any kind or character, to produce what 
he later termed "Smith's Consolidated Cork". He thereupon 
applied for and was granted basic patents in the United 
States, Germany, France and England covering the broad 
principles involved. 

20. — Cork Covering for Steam Pipes. — In 1893 Messrs. 
Stone and Duryee purchased the Smith patent rights for the 
United States, France and England and began the manufac- 
ture, at No. 184-6 North Eighth street, Brooklyn, New York, 
of asbestos-lined cork covering for steam pipes, the sugges- 
tion probably having come to Junius H. Stone, who had 
previously been engaged in the steam pipe covering business, 
from the original Smith cork cylinder, which, incidentally, 
Smith had failed to utilize to any good purpose whatever. 



PURE CORK ACCIDENTALLY CONSOLIDATED 31 

But not long thereafter the patent rights on "85 per cent 
Magnesia" steam pipe covering expired, and the resultant 
competition so reduced prices as to seriously interfere with 
the further sale of the cork product. 

21. — Cork Covering for Cold Pipes. — Then the Engineering 
department of the United States Navy became interested in 
molded cork covering for cold pipes, to replace hair felt and 
such other fibrous materials as possessed a marked affinity for 
moisture, and it was subsequently tried out as insulation for 
brine lines on one of the large battleships then building. 

The adaptability and suitability of this very early form 
of pure cork covering for cold lines was quickly apparent 
to the Navy's engineers, and the material rapidly found favor 
in other Governmental departments. Thus the real field of 
usefulness for Smith's Consolidated Cork — as an insulating 
material for cold surfaces — was discovered ; and soon there- 
after, with the encouragement of the Navy department again, 
the firm of Stone & Duryee began the manufacture of the 
very first pure corkboard that was ever produced, sold or 
used. 

It cannot be out of place to remark here that the various 
U. S. Governmental departments are constantly on the look- 
out for new and better materials for use in the construction 
of governmental equipment of every conceivable sort. To our 
Government's engineers may be credited the discovery, early 
development or initial successful use of many materials and 
products that have influenced the course of human progress. 
Merely as an instance, this is taken from the August 23d, 
1926, issue of the Chicago Daily Tribune, under the caption of 
"Science Marches On" : 

Army experts in aerial photography, improving a 
process invented by the Eastman Kodak Company, 
are able to take photographs not only at great dis- 
tances but through mist and smoke screens. 

22, — Pure Corkboard. — Mr. Harvey H. Duryee, of the firm 
of Stone & Duryee, was of French Hugenot descent, and it 
pleased him to designate the products of his firm "Nonpareil", 
from the French words "non pared", meaning no parallel, 
or no equal. The firm of Stone & Duryee subsequently be- 



Z2 



CORK INSULATION 



came The Nonpareil Cork Works, and with the construction 
of a factory at Camden, N, J., it became the Nonpareil Cork 
Manufacturing Company. 

In June, 1904, the Armstrong Cork Company purchased 
the patents, plant and business of the Nonpareil Cork Manu- 
facturing Company; and, by the time the patents expired. 




FIG. 24.— AN EXAMPLE OF THE VERSATILITY OF MODERN CORK PIPE 

COVERING, LAGS AND DISKS, ON TANK HEADER, RECEIVER, 

PIPING AND FITTINGS. 



both pure corkboard insulation* and cork pipe covering^ were 
the standard of the world wherever the use of refrigeration 
had been scientifically introduced. 



*See Appendix for "Some Uses of Corkboard Insulation". 
tSee Appendix for "Cork Pipe Covering Specifications" and 
Proper Application of Cork Pipe Covering." 



'Instructions for the 



CHAPTER VI. 
EXTENT OF THE CORK INDUSTRY. 

23. — Is Source of Supply Adequate? — The question that is 
most frequently asked today is this: "Can the production of 
corkwood be increased sufficiently by the cork producing 
countries to keep pace with the world's constantly increasing 
demand for cork products of every kind?" 

In attempting an answer to such a question, if indeed an 
answer should be attempted, it must be remembered that 
corkwood is an agricultural product, and that in agriculture 
price controls production, with certain important limitations, 
rather than production establishing price as it does in many 
of the industries not associated with agriculture. In other 
words, if an agricultural product grown in volume will bring 
a price that will make such growing of the product profitable, 
it will continue to be produced in volume ; otherwise, not. If 
that volume demand should grow beyond the ultimate capac- 
ity of the producing soil and climate, then other soil will be 
prepared and utilized in a suitable climate, if that is possible 
and not too costly. Now a look back into the history of the 
cork industry should furnish much information and possibly 
serve as a guide in reaching conclusions about the ultimate 
extent of the cork industry, with particular emphasis upon 
cork insulation. 

24. — Cork Stopper Industry. — The cork stopper industry, 
which was for many years the most important branch of the 
cork industry, had its permanent origin in the town of 
Llacostera, Province of Gerona, Spain, late in the year 1750,* 
and was incident to the real beginnings of the use of the 



•Gilbert E. Stecher, 1914, "Cork— Its Origin and Industrial Uses," D. 
trand Co., New York, N. Y. 

33 



34 



CORK INSULATION 



glass bottle, although corkwood was used centuries before 
as stoppers for casks and other kinds of liquid-containing 
vessels. The cork trade was later disrupted by the many 
wars that followed one another in rapid succession, which 
drove the industry to the mountains to struggle for years until 
some semblance of peace was restored. The principal dan- 
gers having passed, the cork stopper industry slowly but 
surely grew until it virtually became a necessity in the life 
of Spain. 




FIG. 25.— LOADING CKATEU COKKBOAKD AT PALAMOS, Sl'AlX. 



It was customar}- in those days to hold all manufacturing 
processes as valuable secrets, but the cork stopper industry 
of Spain soon attracted so much attention that other and 
neighboring countries sought to learn the secrets of its pro- 
cesses. French agents in the Province of Catalonia obtained 
sufficient information, it is said, to return to France and 
establish their own plants, which greatly disturbed the Span- 
ish manufacturers because they had never had any competi- 
tion up to that time. But by about 1850 the trade in cork 
and cork products had grown so that there was plenty of 



EXTENT OF CORK INDUSTRY 



35 



business for all. and the industry expanded until it surpassed 
the expectations of the most optimistic. In fact, a shortage 
of corkwood came about in Spain ; and. in an effort to fill 
the demands, the cork bark was stripped from the trees more 
frequently than was usual or desirable, and as a consequence 
the grade deteriorated until the situation became alarming. 

25. — Cork a National Necessity. — The Spanish Government 
then passed the necessary laws to ])rotect its cork forests as 




FIG. 26.— CORK REFUSE— USED IN THE MANUFACTURE OF MANY 
"ARTIFICIAL" CORK PRODUCTS. 

a national necessity, these laws governing the stripping of 
the corkwood from the trees. But the demand for corkwood 
kept right on growing in other countries, and the raw stock 
came to be so heavily exported from Spain and Portugal that 
it finally interfered so seriously with the local production of 
finished cork products as to bring about a convention of the 
principal representatives of the cork industry in Madrid, in 
December, 1911. Resolutions were passed calling upon the 
Spanish Government to impose an export duty on corkwood, 
ranging from about 90 cents to $90.00 per ton. 

New export duties were then decided upon by the Govern- 



36 CORK INSULATION 

merit and an effort was made to put the new laws in force 
in 1912, but all these efforts were without much success. In 
Portugal, one of the restrictive laws that were passed made 
it impossible to export from the country pieces of corkwood 
larger than about 4x8 inches. That law, while almost never 
enforced, still remains to harry the inexperienced buyer who 
has failed to provide in advance for its temporary nonexist- 
ence, so to speak. 

26.— Effect of U. S. Tariff A.ct of 1913.— For one reason or 
another, the governments of Portugal and Spain both failed 
in their efforts to restrict the exportations of raw cork, al- 
though the cork manufacturing industry remains very strong 
in both of these countries, particularly in Spain. Consider- 
able impetus was given the manufacture of cork insulation 
in Spain when the United States Tariff Act of 1913, which 
reduced the United States import on finished cork insulation 
to a specific duty of Y^c per pound, became effective. The Act 
of 1922 restored the former rate of duty of the Act of 1909, 
or 30 per centum ad valorem*, but meanwhile several large 
insulation factories were constructed in Spain and one in 
Portugal and the size of these investments coupled with the 
constantly mounting labor rate in the United States keeps 
these foreign plants of domestic concerns operating at 
capacity. 

The United States Tariff Commission's Comparison of 
Tariff Acts— 1922, 1913 and 1909— subdivides "Cork" into 
eighteen groups, as follows : 

TARIFF SUBDIVISIONS OF CORK INTO GROUPS. 

Paragraph under act of 

Description 1922 1913 1909 

Cork: No. No. No. 

Artificial and manufactures of 1412 340 429 

Bark, squares, etc 1412 340 429 

Bark, unmanufactured 1559 464 547 

Carpet 1020 276 347 

Composition or compressed 1412 340 429 

Disks 1412 340 429 

Granulated or ground 1412 340 429 

Insulation 1412 340 429 

Manufacturers of. n. s. p. f 1412 340 429 

Paper 1412 340 429 

*Duties imposed by a government on commodities imported into its territory from 
foreign countries are designated as specific and ad valorem — the former when fixed 
at a specified amount, the latter when requiring payment of a sum to be ascertained 
by a determined percentage on the value of the goods imported. 



EXTENT OF CORK INDUSTRY 37 

TARIFF SUBDIVISIONS OF CORK INTO GROUPS.— Confinued 

Paragraph under act of 

Description 1922 1913 1909 

Cork: No. No. No. 

Refuse and shavings 15S9 464 547 

Stoppers 1412 340 429 

Substitutes 1412 340 429 

Tile 1412 340 429 

Wafers 1412 340 429 

Washers 1412 340 429 

Waste 1559 464 547 

Wood or cork bark, unmanufactured 1559 464 547 

Act of 1922 
Paragraph 1020. — Linoleum, including corticine and cork carpet, 
35 per centum ad valorem; floor oilcloth, 20 per centum ad valorem; 
mats or rugs made of linoleum or floor oilcloth shall be subject to the 
same rates of duty as herein provided for linoleum or floor oilcloth. 

Paragraph 1412. — Cork bark, cut into squares, cubes, or quarters, 
8 cents per pound; stoppers over three-fourths of an inch in diameter, 
measured at the larger end, and discs, wafers, and washers over 
three-sixteenths of one inch in thickness, made from natural cork 
bark, 20 cents per pound; made from artificial or composition cork, 
10 cents per pound; stoppers, three-fourths of one inch or less in 
diaineter, measured at the larger end, and discs, wafers, and washers, 
three-sixteenths of one inch or less in thickness, made from natural 
cork bark, 25 cents per pound; made from artificial or composition 
cork, 121/2 cents per pound; cork, artificial, commonly known as com- 
position or compressed cork, manufactured from cork waste or gran- 
ulated cork, in the rough and not further advanced than in the form 
of slabs, blocks, or planks, suitable for cutting into stoppers, discs, 
liners, floats, or similar articles, 6 cents per pound; in "rods or sticks 
suitable for the manufacture of discs, wafers, or washers, 10 cents 
per pound; granulated or ground cork, 25 per centum ad valorem; 
cork insulation, wholly or in chief value of cork waste, granulated or 
ground cork, in slabs, boards, planks, or molded forms; cork tile; 
cork paper, and manufactures, wholly or in chief value of cork bark 
or artificial cork and not specially provided for, 30 per centum ad 
valorem. 

Paragraph 1559. — Cork wood, or cork bark, unmanufactured, and 
cork waste, shavings, and cork refuse of all kinds (Free). 

Act of 1913 
Paragraph 276. — Linoleum, plain, stamped, painted, or printed, in- 
cluding corticine and cork carpet, figured or plain, also linoleum 
known as granite and oak plank, 30 per centum ad valorem; inlaid 
linoleum, 35 per centum ad valorem; oilcloth for floors, plain, stamped, 
painted, or printed, 20 per centum ad valorem; mats or rugs made 
of oilcloth, linoleum, corticine, or cork carpet shall be subject to the 
same rate of duty as herein provided for oilcloth, linoleum, corticine, 
or cork carpet. 



38 CORK INSULATION 

Paragraph 340. — Cork bark, cut into squares, cubes, or quarters, 
4 cents per pound; manufactured cork stoppers, over three-fourths 
of an inch in diameter, measured at the larger end, and manufactured 
cork discs, wafers, or washers, over three-sixteenths of an inch in 
thickness, 12 cents per pound; manufactured cork stoppers, three- 
fourths of an inch or less in diameter, measured at the larger end, 
and manufactured cork discs, wafers, or washers, three-sixteenths of 
an inch or less in thickness, 15 cents per pound; cork, artificial, or 
cork substitutes manufactured form cork waste, or granulated cork, 
and not otherwise provided for in this section, 3 cents per pound; 
cork insulation, wholly or in chief value of granulated cork, in slabs, 
boards, planks, or molded forms, ^ cent per pound; cork paper, 35 
per centum ad valorem; manufactures wholly or in chief value of 
cork or of cork bark, or of artificial cork or cork substitutes, granu- 
lated or ground cork, not specially provided for in this section, 30 
per centum ad valorem. 

Paragraph 464. — Cork wood, or cork bark, unmanufactured, and 
cork waste, shavings, and cork refuse of all kinds (Free). 

Act of 1909 

Paragraph 347. — Linoleum, corticene, and all other fabrics or cov- 
erings for floors, made in part of oil or similar product, plain, stamped, 
painted or printed only, not specially provided for herein, if nine 
feet or under in width, 8 cents per square yard and 15 per centum 
ad valorem; over nine feet in width, 12 cents per square yard and 
IS per centum ad valorem; and any of the foregoing of whatever 
width, the composition of which forms designs or patterns, whether 
inlaid or otherwise, by whatever name known, and cork carpets, 20 
cents per square yard and 20 per centum ad valorem; mats for floors 
made of oilcloth, linoleum, or corticene, shall be subject to the same 
rate of duty herein provided for oilcloth, linoleum, or corticene; 
oilcloth for floors, if nine feet or less in width, 6 cents per square 
yard and 15 per centum ad valorem; over nine feet in width, 10 cents 
per square yard and 15 per centum ad valorem; .... 

Paragraph 429. — Cork bark cut into squares, cubes, or quarters, 8 
cents per pound; manufactured corks over three-fourths of an inch 
in diameter, measured at larger end, 15 cents per pound; three-fourths 
of an inch and less in diameter, measured at larger end, 25 cents per 
pound; cork, artificial, or cork substitutes, manufactured from cork 
waste or granulated cork, and not otherwise provided for in this 
section, 6 cents per pound; manufactures, wholly or in chief value 
of cork, or of cork bark, or of artificial cork or cork substitutes, gran- 
ulated or ground cork, not specially provided for in this section, 30 
per centum ad valorem. 

Paragraph 547. — Cork wood, or cork bark, unmanufactured. (Free). 



EXTENT OF CORK INDUSTRY 



39 



27. — Effect of the World War. — While there was an ap- 
parent shortage of corkwood for a brief time just prior to the 
beginning of the World War, yet the demand for corkwood 
by France, Germany. Austria and other belligerent countries 
quickly dropped off to almost nothing, which left the United 
States as virtually the only country requiring any appreciable 
exports of corkwood or cork waste. The situation in the cork 
producing countries became rapidly worse as the war con- 
tinued until the time soon came when it did not pay, in many 
cases, to bring in the cork harvest. 




FIG. 27.— CORKWOOD STOCKS ON HAND IN STORAGE YARD IN SPAIN. 

. In Catalonia, for example, the situation become so acute 
at one time that valuable cork oak trees were cut down and 
burned as fuel and the cork workers threatened to burn all 
cork manufacturing plants if enough employment was not 
*given them to keep body and soul together. The situation 
was quickly recognized as acute, and large owners moved 
rapidly to provide enough relief to tide over the difficulties 
occasioned by the World War. Sufficient capital was "in- 
vested in stocks to provide the cork workers with just enough 
wages to buy necessary food and drink, although it was not 
known then by those owners and operators how long they 
would have to continue the very unusual procedure before 
the war would end and thus give them an opportunity of 



40 CORK INSULATION 

turning those stocks back into capital, regardless of whether 
a profit could be realized or a heavy loss would be suffered. 

Conservation of valuable cork forests and cork manufac- 
tories and the prevention of civil war and incident loss of 
life was the first and only consideration of those large opera- 
tors; but they met the situation with such remarkable fore- 
sight attended by such complete success that the King of 
Spain is said to have personally thanked the men who so ably 
and generously gave of their time and money. 

28. — Recovery of the Industry. — If a crop of wheat is 
wanted next year, the planting usually is done in the fall of 
this year. With cork, however, it is from eight to nine years 
after the stripping of the virgin bark before the secondary 
bark can be stripped and another equal period before the first 
real crop of corkwood is available. When there is not a 
favorable price offered for corkwood, the trees are not stripped, 
that is, the older ones that have previously been brought 
into bearing and are ready for stripping are allowed to go 
over another year, or two, or three, as desired and those 
ready for their initial stripping, of the virgin bark, are not 
touched. Thus it can be seen what happened to much of the 
cork forests during the World War ; and when the demand for 
corkwood suddenly returned to normal again, with the re- 
covery of Europe, and with an unusually brisk demand in 
the United States due to an active cold storage building 
program, to the adoption of corkboard as standard for house- 
hold refrigerators, and to the demand for corkboard as insula- 
tion for roofs and residences, a temporary shortage of raw 
cork waste was felt early in 1926, its price trebled, and the 
price of many finished cork products rose by July first to 
double what they were early in 1925, all because the raw 
product supply could not, by the nature of the industry, ex- 
pand suddenly to take care of wide and sudden fluctuations in 
demand. 

The resultant (August, 1926) price of cork waste aided 
in bringing in a full harvest in the cork producing countries 
for the first time since 1914, many young trees were put in 
line for productivity by receiving their initial stripping, and 
with the complete cessation of the Riffian wars in Northern 



EXTENT OF CORK INDUSTRY 41 

Africa much is being done by France and Spain to open up 
that enormous area of virgin cork forests as a very appreciable 
future source of supply, 

29. — Changing Demands, — The growth of "prohibition" 
throughout the world and the increasing substitution of 
"Crown" caps and screw closures for cork stoppers has ef- 
fected a material decrease in the total quantity of corkwood 
required for use in connection with bottles containing liquids. 
The use of granulated cork for the packing of glass and 
fruit is decreasing in favor of certain very soft woods. The 
world's demand for corkwood for miscellaneous purposes, 
such as life preservers, floats, buoys, etc., probably has not 
changed a great deal in many years and probably will not 
change much in the years to come. The demand for cork 
waste, however, for cork insulation has increased irregularly 
but slowly and certainl}^ ever since pure corkboard insulation 
was first made some thirty-four years ago, the industry get- 
ting its first important impetus when the basic pure cork 
insulation patents expired, and its second important impetus 
in 1925 when corkboard began to be used in large quantities 
as a recognized essential insulation for electric household 
refrigerators and standard insulation for industrial roof slabs. 

At one time the breweries utilized about two-thirds of all 
cork insulation that was produced. Then ice, ice cream and 
cold storage plants replaced the breweries as the large con- 
sumers of cork insulation. The mechanically-cooled cork- 
insulated ice cream cabinet is replacing the ice plant as an 
adjunct to the ice cream factory, the cork-insulated mechan- 
ically-cooled commercial and household refrigerators are mak- 
ing inroads on the use of ice, and thus it will be observed 
that as new applications are made others are slightly reduced, 
so that the world's urgent need for cork insulation, that is, 
for use with cold storage temperatures where cork insulation 
is now essential, has a habit of slowly increasing with the 
growth of population and with the increasing per capita use 
of refrigeration in the preservation of food. A great propor- 
tion of all foodstuffs is today preserved by cooling, one place 
or another, by ice or mechanical refrigeration, and cork in- 
sulation is an essential item of all cold storage equipment. 



42 



CORK INSULATION 




tip 



EXTENT OF CORK INDUSTRY 



43 



Thus the basic essential requirements for cork insulation by 
the industries of the world must be somewhat comparable to 
shfting sands — constantly moving about but added to but 
slowly. On the other hand, there is a growing demand for 
cork insulation for use wherever moisture is encountered, such 
as for the insulation of industrial roofs, which field is enorm- 
ous in scope, and if the demand for corkboard for roofs con- 
tinues at the pace it has already set for itself, then no one 
dare predict the ultimate requirements for cork insulation, 
andvin turn, for cork waste and corkwood. 

Of course, if the ultimate cost were low enough, cork, 
because it combines within itself so many unusual and useful 
qualities, would be utilized in many more ways and to a much 
greater extent than it is at present employed. Cost, how- 
ever, is usually the final determining factor in the industries 
of the world ; and, should the demand exceed the supply, 
additional cork will be made available or the price of cork will 
advance to a point sufficient to discourage further increase in 
its use and consumption. In such event, possibly substitutes 
will be found for enough of the miscellaneous uses to which 
cork is put to release sufficient material for all the essential 
cork products, such as cork insulation, that wr)uld be required. 

30.— Tables of U. S. Imports (1892-1924).— In order that 
the reader may form a comprehensive idea of the cork indus- 
try, past and present, a number of tables of cork imports into 
the United States from various countries are given here. 



IMPORTS OF MERCHANDISE 



Fiscal Year 


Corkwood or Cork Bark 

Unmanufactured 

(Free) 


Cork, Manufactures of 
(Dutiable) 


Total Value of Imports 


1892 

1893 

1894 

189.5 

1896 


$1,368,244.00 
1,641,294.00 
985,913.00 
1,049,073.00 
1,209,450.00 
1,-323,409.00 
1,1.52,325.00 
1,147,802.00 
1,444,825.00 
1,729,912.00 
1,816,107.00 
1,737,366.00 
1.484,405.00 
1,729,113.00 


$ 321,480.00 
351,731.40 
295,069.00 
351,757.00 
409,887.00 
428,243.00 
294,863.00 
394,.565.00 
464,658.00 
541,083.00 
648,827.00 
8.30,214.00 
810,738.00 

1,009.176.00 


$1,689,724.00 
1,993,025.40 
1.280,982.00 
1,400,830.00 
1,619,.337.00 


1897 

1808 


1,751,6.52.00 
1,447,188.00 


1899 


1,542,367.00 


1900 

1901 

1902 

1903 

1904 


1,909,483.00 
2,270,995.00 
2,464,934.00 
2,567,580.00 
2,295,138.00 


1905 


2,738.319.00 



44 



CORK INSULATION 



IMPORTS OF MERCHANDISE— Con<t«Mcd 
FISCAL YEAR OF 1906— JUNE 30, 1905, TO JUNE 30. 1906 



IMPORTS INTO 

UNITED STATES 

FROM 


Cork Bark, 
or Wood 
Unmanu- 
factured' 


Cork Waste. 
Shavings, etc. 


Cork Discs. 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 
Austria and Hungary 


7.194 
224 










5 










18 


Bulgaria 




























67 












Finland 












Francp 


120.953 
25,147 
50.842 










11.405 


Cprmanv 










139082 












30 


Netberlands 










1 


Norway 


1.774 
























988,757 










8,441 


R?miafi^a 

























91 


Spain 


481.675 










.1,300.747 


Sweden 












XlSe^'"^'''™ 


6,553 










15,093 












AMERICA: 












1.248 
































62 










10 


South American Continent 
























ASIA: 

r<hlna 




























ilf othere 


2.734 
151,220 












""^M^S^.- 


























932 


























1,837.134 










1.476.172 















FISCAL YEAR OF 1907-JUNE 


30, 1906. TO JUNE 30, 1907 




EUROPE: 














Belgium 


22.116 










561 




























23 
























France 


82.802 
49.261 
92,758 










6.0!; 


Pprmanv 










171,85; 
























150 


Norway ... • • • • • 












2 5 


















1.333,815 










57,608 














Russia In Europe 

Spain 


s^m 




















1.452,010 














United Kingdom 


16,206 










19,223 












^^l?ad^^ = 


482 










313 


























2 




341 










4 


South American Continent 
























ASIA: 














y "'"* 














ilFothCTS 












1 


AFRICA: 


146.708 






















AH others 


3,067 












Totals 


2,356.052 










1,707,930 















■Includes cork waste, shavings, etc., prior to July I, 1918. 



EXTENT OF CORK INDUSTRY 



45 



IMPORTS OF MERCHANDISE Continued 

FISCAL YEAR OF 1908— JUNE 30. 1907, TO JUNE 30. 1908 



IMPORTS INTO 

UNITED STATES 

FROM 


Cork Bark, 
or Wood 
Unmanu- 
factured' 


Cork Waste, 
Shavings, etc. 


Cork Discs, 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 












116 


Belgium 














Bulgaria 










































Finland 
















*li 










5 735 


oermany 










322:675 
45 






















































1,268.611 










76,940 














Russia in Europe 


7,164 
467,046 










532 
























United Kingdom 


12.694 










22.125 










AMERICA: 


93 










831 


Central American States 












Cuba 












310 


Mexico 


362 






































ASIA: 
Cliina 




























All others 














AFRICA: 

Algeria 


132,060 


























19 
























Totals 


2,092,732 










2,156,274 




1 







FISCAL YEAR OF 1909— JUNE 


30, 1908, TO JUNE 30, 1909 




EUROPE: 
















40 




















































Finland 
















109,263 
53,097 
66,2.58 










2,253 












115,470 












48 












203 






























1,197,430 










42,907 


Ruma^a 












Russia in Europe 

Spain 


73fi 
453,084 




















849,788 












United Kingdom 

All others 


3,347 










14.298 












AMERICA: 












235 


Central American States. . 


88 




















434 


Mexico 














South American Continent 














219 












ASIA: 












Japan 












3 


All others 














AFRICA: 
Algeria 


132,972 
























An fithpri 






























2,016,551 










1,025.639 















'Includes cork waste, shavings, etc., prior to July 1, 



46 



CORK INSULATION 



IMPORTS OF MERCHANDISE — Continued 
FISCAL YEAR OF 1910— JUNE 30, 1909, TO JUNE 30. 1910 



IMPORTS INTO 

UNITED STATES 

FROM 


Cork Barli, 
or Wood 
Unmanu- 
factured' 


Cork Waste. 
Shavings, etc. 


Cork Discs. 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 












9 


Belgium 


58 










4 173 






























22 










n 
















10S.S60 
20,091 
36,801 










8 098 


r-prnvfriv 










200'256 


Italy 










453 












































1,888,738 










51.854 












Russia in Europe 


4,200 
913.528 


































United Kingdom 


17.133 










16 539 












AMERICA: 












1.002 


















184 










232 














Soutli American Continent 


10 






















ASIA: 


























12 
















AFRICA: 


162,655 




















































Totals 


3.152,280 










1 619 111 















FISCAL YEAR OF 1911— JUNE 


33, 1910, TO JUNE 33, 1911 




EUROPE: 














Belgium 














Bulgaria 
















24 






















3 


Finland 
















145,323 
85.941 
56.757 
4.384 












Cermaiiv 
































































1.785,848 
























Russia In Europe 


4,094 
2.010,216 






















Swm?pn 












United Kingdom 

All others 


4,151 






















AMERICA: 


1,046 


































































West IndiM 














ASIA: 

China 


























1 


All others 














AFRICA: 


176,976 










«- 














All others 


50 










582" 
















4.274,810 

























■Includes cork waste, shavings, etc., prior to July 1, 1918. sAuatralia. 



EXTENT OF CORK INDUSTRY 



47 



IMPORTS OF MERCHANDISE Continued 

FISCAL YEAR OF 1912— JUNE 30, 1911, TO JUNE 30, 1912 



IMPORTS INTO 

UNITED STATES 

FROM 


Cork Bark, 
or Wood 
Unmanu- 
factured' 


Cork Waste. 
Shavings, etc. 


Cork Discs. 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 

Austria and Hungary 














Belgium 














Bulgaria 














Czechoslovaltia 
















4,345 












Finland 














122,414 
72,240 










26.758 

283.325 

358 

2.509 






















Netherlands 










Norway 












Poland and Danzig 
















1.440.491 










52.534 


Rumania 










Russia in Europe 


4.525 
1,282.871 






















1.972.758 


Sweden . . 










United Kingdom 


2.108 










8.137 


All others 










AMERICA: 


2 












Central American States 












Cuba 














Mexico . 












2 


South American Continent 














West Indies 














ASIA: 

China 














Japan 












23 


All others 














AFRICA: 

Algeria 


256.385 












Morocco 












All others 






























3,242.319 










2.346.415 













FISCAL YEAR OF 1913— JUNE 


30, 1912, TO JUNE 30, 1913 




EUROPE: 














Belgium 


230 








































5.737 


























106.077 
10.661 
115.330 










-i 






















Netherlands 












Norway 














Poland and Danzig . 
















1.480.329 










47.483 


Rumania 










Russia in Europe 


938 
1.250.722 




















2.229.266 


Sweden 










United Kingdom 

All others 


1.474 










6.097 










AMERICA: 














Central American States 




























Mexico 


721 










3 




























ASIA: 












2 






























AFRICA: 
Algeria 


153.798 
























All others 


26.0532 


























3.152.070 










2,350.684 















'Includes cork waste, shavings, etc., prior to July 1. 1918. sAustralla. 



CORK INSULATION 



IMPORTS OF MERCHANDISE Continued 

FISCAL YEAR OF 1914— JUNE 30, 1913, TO JUNE 30, 1914 



IMPORTS INTO 
UNITED STATES 


Cork Bark, 
or Wood 
Unmanu- 
factured' 


Cork Waste. 
Shavings, etc. 


Cork Discs. 

Wafers and 

Washers 


All Other 
Manufac- 
tures 




Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 














Belgium 












175 


Czechoslovakia 

Denmark 

Finland 














France 

Germany 

Netherlands.'.: :!:;:'.^' 


7.479 
75,227 










14 


Poland and Danzig 


1,94V,618 










86,984 


Rumania 












Russia in Europe 

Spain 


i,42l'.894 










2,478,364 


Sweden 

United Kingdom 


197 










33,399 










4 


AMERICA: 

Canada 












443 


Central American State^;. 












81 


Mexico 

South American Continent 


























ASIA: 

China 












6 
26 


All others 

AFRICA: 


266,435 












Morocco 














3.851.794 


1 






2.647.838 











FISCAL YEAR OF 1915— JUNE 


30, 1914, TO JUNE 30, 1915 




EUROPE: 












39 


Belgium 














Czechosliovakia.'.'..;^^. 














France 

Germany 

Netherlands.'.!:;:;.'. ... 


17.000 
10.:<89 
47:884 










'°li 


Poland and Danzig 
Portugal 


1,595,945 










■ 'eLQei' 


Russia in Europe 


■ "8'98'.4i5' 










1,923.371 















United Kingdom 


3,698 










fiilo 


AMERICA: 

Canada 

Central American States. 













6 


Mexico ■ 

South American Continent 


18.647 










8 
2 


ASIA: 

China 












39' 


aIP others .".':: ::::::.... 

AFRICA: 

Algeria 

Morocco 

All others 


170.917 












Totals 


2.762.895 










2,024.059 



■Includes cork waste, shavings, etc., prior to July 1. 1918 



EXTENT OF CORK INDUSTRY 



49 



IMPORTS OF MERCHANDISE Continued 

FISCAL YEAR OF 1916— JUNE 30, 1915, TO JUNE 30, 1916 



IMPORTS INTO 

UNITED STATES 

FROM 


Cork Bark, 
or Wood 
Unmanu- 
factured' 


Cork Waste. 
Shavings, etc. 


Cork Discs. 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: _ 




















































































?i-nnpp 


86.822 










5,679 
10 

1.985 
14 


r-erninnv 












2.671 


















Norway 

Poland and Danzig 


























i.noo,694 










83.680 


























928.477 










847.224 












United Kingdom 


2.545 
8.207 

lOJ 










2.231 










AMERICA: 










9> 














Cuba 

Mexico 










25 


190,? 66 










3 














West Indies 












ASIA: 
China 






















300 


All others . . • • 












AFRICA: 

Algeria 
























All others 




































941.243 













FISCAL YEAR OF 1917— JUNE 


30, 1916, TO JUNE 30. 1917 




EUROPE: 


























































56.396 


























101.810 










3.633 












Italy 


6,326 












Netherlands 












Norway 














Poland and Danzig 














Portugal 


2.404.678 










105 647 


Rumania 












Russia In Europe 
















1.058.574 










2.026,785 


Sweden 










United Kingdom 


7.304 










3 094 


All others 












AMERICA: 

Canada 


621 










16 799 


Central American States. . 












Cuba 


1.572 
10 
6 










1 111 
1,111 


Mexico 












South A merlcan Continent 
























ASIA: 

China 














Japan 














Alfothers 














AFRICA: 

Algeria .... 


233.062 












Morocco 












All others 




























Totals 


3.870,389 










2 158 447 















■Includes cork waste, shavings, etc.. prior to July 1, 1918. 



so 



CORK INSULATION 



IMPORTS OF MERCHANDISE Continued 

FISCAL YEAR OF 1918— JUNE 30, 1317, TO JUNE 30, 1918 



IMPORTS INTO 

UNITED STATES 

FROM 


Corli Bark, 
or Wood 
Unmanu- 
factured' 


Corli Waste, 
Shavings, etc. 


Cork Discs, 

Wafers and 

Washers 


All Other 
Manufac- 
tures 


Dollars 


Pounds 


Dollars 


Pounds 


Dollars 


Dollars 


EUROPE: 






















































































88,5i8 










7,486 


Germanv 












44,727 










72.548 


Netherlands 










Norway 






























i. 754,750 










152,099 





























946,373 










1,778,279 


Sweden 










United Kingdom 


30,107 










1 474 










3.307 
163 


AMERICA: 


































































90 
















ASIA: 
China 










































AFRICA: 


197,352 




















































Totals 


3,061,827 










2,017,146 













CALENDAR YEAR 1918 



EUROPE: 

Austria and Hungary . . . 






































































Finland 
















6,586 


1,415,529 


19,890 


9,491 


11,304 


8,007 






Tt^^v'^'*^ 


43,928 










72.548 








































Portugal 


1,275,137 


9,558,460 


187.417 


118,282 


32,328 


90,463 
















Spain 


459,087 


21,952,679 


373,112 


434,850 


395,211 


1,133,193 






United Kingdom 












934 


All others 














AMERICA: 












307 




































' 








South American Continent 
West Indies 


























ASIA: 
















26 










881 














AFRICA: 


112,832 


4.237,282 


52.033 
























4,675 


3,110 
















1,898,193 


37,163,950 


632,452 


567,298 


441,953 


1,306,333 







'Includes cork waste, shavings, etc., prior to July 1, 1918. 



EXTENT OF CORK INDUSTRY 



SI 


1 














:iN 


2 
?3 






1 




o 


1 












g 


- 








i 


1 










































































1 






































































- 


1 






































































1 


1 

Q 














S 


5 






i 

CO 




o 






i 
























i 
1 


1 
















2 










1 

i 






t^ 


1 






















i 


Ij 

^1 


2 










1 
o 


00 


1 






1 




p' 




1 




















s 




IN 


1 










1 




i 






1 




xc-. 




2 

o" 




















o" 




1 
TO 


Jl 


1 


















1 






i 

1 




2 

1 








CO 


















1 




1 


1 

1 
























j 




1 








2 


















2 




(N 
5 

1 
? 






1 


: 

1 


s 


.s 


.3 

1 

J 




1 


i 
1 


> 

s 

c 
o 
O 


> 


1 

1 


> 


c 


5 

1 




c 






1 

« 

1 

c 


1 

< 


-< 

II 

Si 


1 

s 

< 

1 

o 


1 

o 


o 
.i 

1 


c 
O 

s 

< 


.i 

1 


o 


< 


% 


1 


1 

o 


1 

1 

< 


o 

1 


1 

o 


2 

■« 

1 





52 



CORK INSULATION 



< i 
2 


1 

Q 
















;co 






;i 




676,457 
25,864 
10,180 

302,502 


t^ 










:n- 








1 


1 
1 






































































^1 
^1 


Q 












































































































































II 
ii 

o 




















(N 






s 




i 


t^ 






1 








B 










CO" 

s 


1 
























1 




1 


-- 






^' 








§ 


t- 








1 


n 


1 














2 


i 


i 
a" 


i 








t>." 






2 












S 




S 

co" 


fS 














1 


i 
1 


i 


1 

s 




S2 
2" 




i 






i 












§ 




lO' 


h 


1 














00 


i 






g 

g 




ri 










1 












g 
1 


o 


1 


-0 

1 














1 


1 






1 

s 














1 












t> 


i 

CO 


1 






.. ci 

ii 


E 

3 


J 

3 

m 


1 
1 
1 


E 
c 

Q 


1 


i 
1 




3 


1 
1 


1 

2; 


c 
t: 
- 

1 


1 


'c 
£ 
1 




c 


1 
02 


1 

1 

c 


< 


< 


g 

S 

< 

1 


^ 
5 


g 


4^ 

I 

a 

1 
O 

1 

s 

1 


1 


o 


< 


1 


1 


1 

o 


i 

1 


1 


£ 

1 

o 

< 


2 
-< 

g 
H 



EXTENT OF CORK INDUSTRY 



53 



cl 


Q 




i 




g 










i 






oc-fc 




f 


















IT 












p 




1 










































































3| 


1 








































































- 


1 








































































ll 


J 














^^ 








i 




TO 






1 




























1 


1 














SI 








t^ 




1 






s 
































1 














i 




EP 
P 




a: 

,-. to 
* 






{^ 












IT 








1 


1 














1 




11 


1 S 






i 


















i 

88 


h 


1 

j2 














"""1 






1 




i 














g 












2 






i 


1 














i^2 






1 





t-" 














t2 

C«5 












1 






i 






> 
J 

9 - 




1 


e 
J 


E 
c 


1 


1 
1 


> 

1 


1 


i 


> 
rt 

c 


1 


t 

i 






1 


J 


i 

1 

1 


< 


ii 


1 
1 

< 


1 

C 


1 


c 
c 
c 

1 

£ 

•< 

a. 


i 


< 




1 


I 


1 

< 


i 
f 

d 
< 




1 

< 




< 





54 



CORK INSULATION 







MC^ 






c^ 




§52!? 






IT 






^^|^^ 
K 




^ 

















s 
■* 
















! 




1 
1 










































































a 


J 






























2 






2 




























© 


! 


























s 




i 






oT 































a 
















(N 





















CM 






'^ 




















s 

g 


1 
1 














lO 
















5? 












M 




















i 




1 






U3 


Is^'l^s" 






K 




1^ 


1 




















2 
0" 






1 

IN 


1 




CO 

i 








i 




^12 


2 
1 




















s 
s 






1 

2 




Q 








i 




i 


1 






05 




ss?s 
























1 






1 


1 








i 




2 


N 
« 












to 
























0. 






2' 

s 


ii 






E 


J 


.2 

J 
J 

1 


c 


1 


1 
1 


£ 




1 
1 
1 


■ 


1 
1 

1 


1 

1 

1 


(2 


1 


1 


c 




1 

< 


< 


5. 

c 

j 

£ 

< 


1 


1 
1 


1 

c 

j 

£ 

■< 


i 


■J 
< 


i 

< 


c 




1 

< 


51 

■< 


£ 

^ 

fe 
S 


1 
1 




2 





EXTENT OF CORK INDUSTRY 



55 



s 

II 

Si 


1 










s 




S5 


s 








1 






o 

s 




s 


t- 
















U3 














i 




1 
1 










8 


CO t^MMi 




00 




°l 


n 




§ 






O 












1 


i 


2 

1 
















Si 






1 




CD<-( 




i 








1 
















i 


1 
















ovoT 






M 




2 




1 
























i 
i 


k 

is 


2 














Si| 






g 




r5 
























1 






1 
(1, 














"Si 






1 




iii 

gco-x 
























s 




1 

i 


15 


2 






S 


1 


I^SS" 


i 




III 


g 




















1 




CO 

1 


-s 

1 






o 

i 


1 


2 «< 


2 

i 




^.xo 






















i 




s 

2 


1- 


1 












i"l 






2 






IM 












S 






I2 ■; 




i 










1 


ill 






§ 

2 
S 






g 












i 






22 • 






i 

i 






i 




1 


1 

E 


(i 


t 
I 


c 
E 


' 


1 

2 


2 


1 


1 


.2 
(1 


1 


I 


J 

i 


1 


1 

z 

i 


OS 


1 

c 
I 

1 
1 


i 

c 


c 


1 

I 

e 

1 

£ 


J 
1 


1 


.J 


1 




z 

i 

c 


1 


c 

i 


1 
< 


< 





56 



CORK INSULATION 





1 


!5 
























i 




1^ 


5, 


CO 












M 




o 










2 

i 


1 
1 


8 ; 








i" 










i 


S2 ^^ 










S 


s 










§ 

^1 


1 














r 






g 

■* 








- 


























2 


T3 

1 














ir 
•* 






i 
g 




1 


00 


1 


























i 


21 
S 


^ 

S 
















t^ 

■* 






s 
s 










g 
























1 


1 
















I 






1 




1 

i 






s 


B 






















i 

i 





1 

i 


S ■ 




1 


5 


io 






1^ 




1 






^ 




S 




















•a 


1; 




1 


o 
1 


1 






1 




1 

i 






- 




e 














§ 




i 


h 

1^ 


00 

1 








3 


OtNCO 






i 

1 




1 


§ 












o 








^ 

2 




i 


1 

(2 








1 








i 






1 












1 






s 


1 




1 


Is 


o 


ti 
1 


. 

2 : 

3 • 

; 3 


c 


2 
I 


1^ 


^t 




5,: 




5 




5 

[ 

y 


p 


hP 


ii 


c 


: = 

u 




III 


1 

c 

i 

i 
< 

1 




)J 


1 

c 

? 

1 


) 

i.l 

= 1 


J 


2 

< 


■1 


c 


j 


: ^ 

< 




3< 


2 



EXTENT OF CORK INDUSTRY 



57 



VALUE OF IMPORTS OF CORK TO THE UNITED STATES (FISCAL YEAR) 
Corkwood, or cork bark, and manufactures of cork 



\T.AR 



VALUE 



1892 $ 1,689,724.00 

1893 1,993,025.40 

1894 1,280,982.00 

1895 1,400,830.00 

1896 1,619,337.00 

1897 1,751,652.00 

1898 1,447,188.00 

1899 1,542,367.00 

1900 1,909,483.00 

1901 2,270,995.00 

1902 2,464,934.00 

1903 2,567,580.00 

1904 2,295,138.00 

1905 2,738,319.00 

14 Years $26,971,554.40 

Yearly Average $ 1,926,539.60 



YEAR VALUE 

1906 $ 3,313,306.00 

1907 4,063.982.00 

1908 4,249,006.00 

1909 3,042,190.00 

1910 4,771,391.00 

1911 6,609,813.00 

1912 5,588,734.00 

1913 5,502,754.00 

1914 6,499.632.00 

1915 4,786,954.00 

1916 4,076,127.00 

1917 5,028,836.00 

1918 5,028,973.00 

1918** 1,840,409.00 

1919* 5,740,910.00 

1920* 8,343,998.00 

1921* 3,418,256.00 

1922* 5,202,537.00 

1923* 5,067,902.00 

1924* 4,328,496.00 

19H Years $96,604,206.00 

Yearly Average $ 4,954,061.88 

♦Calendar Year. 

**July 1 to Dec. .31, 1918. 



58 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION 

FOR FISCAL YEAR. 1903 



CORK, and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 
S 


Duties 

S 


Value 

Unft 

of 
Quan- 
tity 

$ 


Actual 
and 
Com- 
puted 
Ad 
Val- 
orem 
Rate 


Unmanufactured 


Free 




1 ,737.366.00 








Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 








Bark, cut in squares, cubes or quarters. . 
Corks (or cork stoppers) ; 

ii' or less in diam. at large end 

Forrnfg. in bonded whse. and export. 


8clb. 
25c lb. 


4.00 
79.214.40 


2.00 
36,073.00 


0.32 
19,803.60 


.50 
.455 


16.00 
54.90 














Over 'i" in diam. at large end 


1.5c lb. 


1,409,507.16 


704,429.00 


211.426.08 


.50 


30.01 
















Cork disks wafers or washers 














»/ii' or less in thickness 














For mfg. in bonded whse. and export. 




































































Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards. 














Cork Tile 










































Cork Paper 














All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork not 


f 25% 
1 Remitted 




54.290.49 
795.00 


13.572.62 


■■.829 


25 00 


959.00 


























Free 




1.737,366.00 





















Dutiable 




795,589.49 


244,802.62 




30.77 



FOR FISCAL YEAR, 1904 



Unmanufactured 


Free 




1.484.405.00 








Manufactures of 

Artificial cork or cork substitutes mfd. 
from cork waste or granulated cork and 










Bark, cut in squares, cubes or quarters. . 
Corks (or cork stoppers) : 

Ji' or less in diam. at large end 


8c lb. 
25c lb. 


1,580.00 
351.447.76 


212.00 
69.537.00 


126.40 
87,861.94 


.134 
.198 


59.62 
126.35 
















Over ?i' in diam. at large end 


15c lb. 


1.309.663.33 


640.569.51 


196.449.50 


.489 


30.67 


















































































































Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards. 






































































All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes. 


/ 25% 
\ Remitted 




67,289.00 
232.00 


16.822.25 


.792 






293.00 


























Free 




1.484.405.00 








TOTALS 












Dutiable 




777.839.51 


301,260.09 




38.73 



EXTENT OF CORK INDUSTRY 



59 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION-Co/ianuerf 
FOR FISCAL YEAR, 1905 



CORK, and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 

S 


Duties 

S 


Value 

U^^^t 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 

vM 

% 


Unmanufactured 


Free 




1,728.743.00 








Manufactures of 

Artificial cork, or cork substitutes, mfcl 
from cork waste or granulated cork and 
n o p. f 










Bark, cut in squares, cubes or quarters . 
Corks (or cork stoppers): 

% ' or less in diam. at large end 


Sclb. 
25c lb. 


340.00 
110,670.08 


167.00 
54,152.56 


27.20 
27,667.52 


.491 
.489 


16.29 
51.09 
















Over ^i ' in diam. at large end 


15c lb. 


1,633,226.97 


859,780.00 


244,984.06 


.526 


28.49 






























'/ii' or less in thickness 










































Over 3/i»' in thickness 










































Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards. 














Cork Tile 




























Waste shavings or refuse of all kinds . 














Cork Paper 














All other manufactures whoUy or in chief 
value of cork or cork bark, or of 
artificial cork or cork sub.stitutcs, 
granulated or ground cork, not 
specilically provided fnr 


25% 




38.298.55 


9.574.63 




25.00 




















Free 




1,728,743.00 








TOTALS 












Dutiable 




952.398.11 


282.253.41 




29.64 



FOR FISCAL YEAR. 1906 



Unmanufactured 


Free 




1.837.354.00 








Manufactures of 

Artificial cork, or cork substitutes, nifd. 
from cork waste or granulated cork and 




Bark, cut in squares, cubes or quarters. . 
Corks (or cork stoppers) : 

H' or less in diam. at large end 


8c lb. 
25c lb. 


5,993.00 
213.468.47 


1,289.00 
95,629.36 


479.44 
53.367.11 


.215 
.448 


37.19 
55.81 
















Over ?4" in diam. at large end 


/ 15c lb. 
\Remitted 


1.939,781.00 
3.004.00 


1,279,974.50 
1,025.00 


290,967.17 


.660 


22.73 


































































Over 'h" in thickness 




























Reciprocity treaty with Cuba . . . 














Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 
planks, or molded forms . 














Cork Tile 




























Waste shavings or refuse of all kinds 














Cork Paper 














All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


25 T 




83.421.48 


20.855.37 




























Free 




1.S37..354.00 








TOTALS 






Dutiable 




1.461. .3.39.34 


365.669.09 




25.02 



60 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— CoM<int.ed 
FOR FISCAL YEAR. 1907 



CORK, and MANUFACTURES OF: 


Hate 

of 
Duty 


Quantities 
Lbs. 


Values 
$ 


Duties 

$ 


Value 

Uni^t 

Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 

Rate 


Unmanufactured 


Free 




2.358.873.00 








Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 










Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers) : 

h" or less in diarii. at large end 


8c lb. 
25o lb. 


217.00 
91.591.00 


133.00 
54,413.00 


17.36 

22,897.75 


.613 
.594 


13.05 
42.08 
















Over %" in diam. at large end 


/ 15c lb. 
\Remitted 


2,186,088.00 
1.191.50 


1,489.448.00 
494.50 


327.913.51 


.681 
.415 


22.02 








Cork disks wafers or washers 














',«' or less in thickness 




















































































Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards, 














Cork Tile 










































Cork Paper 














All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


25% 




159,541.50 


39.885.38 




25 00 
























Free 




2.358,873.00 




















Dutiable 




1,704,030.00 


390,714.00 





22.93 



FOR FISCAL YEAR, 1908 



Unmanufactured 


8c lb. 
8c lb. 

25c lb. 


00,664.316.00 

3.395.00 
208.00 

49.483.25 


2,092,732.00 

1,638.00 
194.00 

29.863.00 


271.60 
16.64 

12.370.81 


.482 
.932 

.603 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n. o. p. f 

Bark, cut in squares, cubes or quarters . . 

Corks (or cork stoppers) : 

h" or less in diam. at large end 


16.58 
8.57 

41.42 
















Over h" in diam. at large end 

Reciprocity treaty with Cuba 


1 15c lb. 
\Remitted 
/ 15c lb. \ 
lless 20%] 


2.435.154.91 

2.028.00 

450.00 


1.814.519.66 
938.00 
185.00 


365.273.24 
54.66 


.745 
.462 
.411 


20.13 
29.i8 


























































Cork insulation; whoUy or in chief value 
of granulated cork in slabs, boards, 






































































AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes. 
granulated or ground cork, not 


25% 
/25% lessl 
\ 20% j 




159,229.50 
123.00 


39.807.38 
24.60 


















TOTALS 


Free 


60,664,316.00 


2,092,732.00 










Dutiable 




2.006,689.50 


417.818.27 




20.82 



EXTENT OF CORK INDUSTRY 



61 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Condnued 
FOR FISCAL YEAR, 1909 



FOR FISCAL YEAR, 1910 



CORK, and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 


Duties 

S 


Value 
per 
Lnit 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 

rut"e 


Unmanufactured 


Free 


78,330.391.00 


2,016,534.00 




.026 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 




Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers): 

4i' or less in diam. at large end 


8c lb. 
25c lb. 


8.00 
52.762.00 


5.00 
31,362.00 


.64 
13,190.50 


.625 
.594 


12.80 
42.06 
















Over ?4' in diam. at large end 


/ 15c lb. 
IRemitted 
/ 15c lb. \ 
lless 207c/ 


1.163,580.50 

595.00 

1.051. OO 


885,536.00 
324.00 
434.00 


174,537.08 


.761 
.545 
.413 


19.71 


Reciprocity treaty with Cuba 


126.12 


29.06 






























Over lit," in thickness 










































Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards. 






































































AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


25% 




184.765.15 


46.191.29 




25.00 
























Free 


78.130.391.00 


2,016.534.00 




.026 






Dutiable 




1.102,426.15 


234.045.63 




21.23 



Unmanufactured 

Cork wood, or cork bark 

Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n. o. p. f 

Bark, cut in squares, cubes or quarters 

Corks (or cork stoppers) : 

ii" or less in diam. at large end 


Free 

6c Ib.i 
8c lb. 

25c lb. 


109,271,575.00 

183.00 
1,649.00 

41.699.00 


3,152,280.00 

103.00 
310.00 

29,820.00 


10.98 
131.92 

10,424.75 


.029 

.563 
.188 

.715 


10.66 
42.55 

34.96 
















Over H" in diam. at large end 


/ 15c lb. 
IRemitted 
/ 15c lb. 1 

Hess 20%) 


1,709 .941. .55 
557.00 
710.00 


1,344,688.10 
236.00 
232.00 


256,491.24 


.786 
.424 
.327 


19.07 


Reciprocity treaty with Cuba 

Cork disks wafers or washers 


85.20 


36.72 






























Over 'u' in thickness 














or mfg. in bonded whse. or export . 




























Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards. 














Cork Tile ' 
























































AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes. 


/ 25% > 
\ 30% ' 




49,619.00 
126,611.00 


12.404.75 
37,983.30 




25.00 


specifically provided for 




30.00 






















TOTALS 


Free 


109,271,575.00 


3,152,280.00 




.029 




Dutiable 




1,551.619.10 


317,532.14 




20.47 



' Aug 6, 1909 to June 30, 1910, under Act of I 



I Aug. 5, 1909, under Act of 1897. 



62 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Continued 
FOR FISCAL YEAR. 1911 



CORK, and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 

S 


Duties 
$ 


Value 

U^^^t 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 
orem 
Rate 
% 


Unmanufactured 

Cork wood or cork bark 


Free 

6c lb. 
8c lb. 

25c lb. 


139,602,251.00 

1.00 
542.00 

30.771.00 


4,286,700.00 

1.00 
136.00 

23.296.00 


.06 
43.36 

7.692.76 


.031 

1.00 
.258 

.757 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 

Bark, cut in squares, cubes or Quarters . . 
Corks (or cork stoppers) : 

}i' or less in diam. at large end 


6.00 
31.88 

33.02 
















Over U" in diam. at large end 


/ 15o lb. 
\ Remitted 


2.553.357.42 
614.00 


2,155,098.00 
389.00 


383,003.62 


.844 
.633 


17.77 






















Vti' or less in thickness . . 














For mfg. in bonded whse. and exporl 


























Over %' in thickness 














For mfg. in bonded whse. and export 


























Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards. 






































































AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 
specifically provided "■■• 


30% 




210,825.21 


63,247.56 




30 00 






















"^"^^^^ 


Free 


1.39.602.251.00 


4.286.760.00 




.031 






Dutiable 




2..389.745.21 


453,987.36 




19.00 



FOR FISCAL YEAR. 1912 



Unmanufactured 


Free 
6c lb. 


118,432,309.00 
77.00 


3,247,086.00 
8.00 


4.62 


.027 
.104 




cork ^°°'''^^,«^'f^,^f^^- - f 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 


57.75 


Corks (or cork stoppers) : 


25c lb. 


21,998.58 


17.900.00 


5.499.63 


.814 


30.73 










:::::::::: 






Over H' in diam. at large end 


/ 15c lb. 
\ Remitted 


2,346,323.41 
693.00 


1,891,372.00 
341.00 


351,948.53 


.806 
.492 


18.61 






















'/^' or less in thickness 














For mfg in bonded whse. and export 




























Over Mi" in thickness 










































Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards. 






































































AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes. 
granulated or ground cork, not 


30% 




268,464.00 


80,539.20 




30 00 
























Free 


118,432,309.00 


3,247,086.00 





.027 




■ 


Dutiable 




2,178.085.00 


437.991. 98i 


20.11 



EXTENT OF CORK INDUSTRY 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Coriiinwed 
FOR FISCAL YEAR, 1913 



63 



FOR FISCAL YEAR, 1914 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 
S 


Duties 


Value 

Um't 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 

Ra™ 


Unmanufactured 


Free 


133,227,878.00 


3,152,070.00 




.024 




Manufactures of 

Artificial cork, or cork substitutes, mfd 
from cork waste or granulated cork and 




Bark, cut in squares, cubes or Quarters . . 
Corks (or cork stoppers) : 

h' or less in diam. at large end 

For tufg. in bonded whse. and export. 


8clb. 
25c lb. 


99.00 
20,635.50 


32.00 
15,637.00 


7.92 
5.158.88 


.323 
.758 


24.75 
32.99 


Reciprocity treaty with Cuba 














Over H" in diam. at large end 


/ 15c lb. 
IRemitted 


2.490,194.73 
455.00 


2,171,955.00 
275.25 


373.529.21 


.872 
.605 


17.20 




























































































Reciprocity treaty with Cuba 














Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 
planks, or molded forms 














Cork Tile 
























































All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


30% 




157,250.00 


47.175.00 




























Free 


133,227,878.00 


3.152,070.00 













Dutiable 




2.345,149.25 


425.871.01 





18 16 









Unmanufactured 

Cork wood, or cork bark 

Manufactures of 

Artificial cork, or cork substitutes, mfd 
from cork waste or granulated cork and 
n. o. p. f 



Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers) : 

?4* or less in diam. at large end 

For mfg. in bonded whse. and export. 

Over H" in diam. at large end 

For mfg. in bonded whse. and export 



Reciprocity treaty with Cuba 

I Cork disks, wafers or washers 

lit" or less in thickness 

Over ' u" in thickness 

For mfg. in bonded whse. and export 

Cork insulation: wholly or in chief value 

of granulated cork in slabs, boards, 

planks, or molded forms 

Cork Tile 

Granulated or ground cork 

Waste, shavings, or refuse of all kinds.. . 

Cork Paper 

All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 

specifically provided for 

Reciprocity treaty with Cuba 



/ 6c lb.' 
1 3c lb.« 
/ 8c lb.' 
1 4c lb.» 
)2oclb.' 
\ 15c lb.' 
Free ' 
/ 15c Ib.i 
1 12c lb.» 
/ Free ' 
1 Free' 
J 12c less 
120% ' 



15c lb.» 
12c lb.» 



Kc lb.> 
Free '' 



4.717.50 

82,805.00 

71.00 

548.452.25 

251.744.00 

378.00 

127.00 

146.00 



2,065,567.00 
19,469, 
120.00 



90,487,964.00 



151.00 

470.00 

343.00 

298.00 

3,831.00 

53.947.00 

53.00 

477,615.00 

192.517.00 

193.00 

80.00 



1,675,683.00 

9.443.00 

70.00 



67.84 
.179.38 
.429.75 



26.12 
22.76 
30.78 
23.04 



178,771,195.00 3,852,190.00 



387.00 507,422.60 



•Old law, July 1 to Oct. 3, 1913 'New Uw, Oct. 4, 1913 to June 30, 1914. 



64 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Continued 
FOR FISCAL YEAR, 191S 



FOR FISCAL YEAR, 1916 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
I.bs. 


Values 

$ 


Duties 
S 


Value 

U^n[t 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 

orem 
Rate 


Unmanufactured 


Free 

3c lb. 
4c lb. 

15c lb. 
Free 


24,897,803.00 

1,155.00 
6.125.00 

131,269.00 
734.00 


1 420 581.00 

320.00 
1.112.00 

82,576.00 
930.00 




.057 

.277 
.182 

.629 
1.257 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n. o. p. f 

Bark, cut in squares, cubes or quarters . . 

Corks (or cork stoppers) : 

Ji* or less in diam. at large end 

For mfg. in bonded whse. and export. 


34.65 
245.00 

19,690.35 


10.83 
22.03 

23.85 






Over U" in diam. at large end 

For mfg. in bonded whse. and export 


12c lb. 
Free 


194.721.00 
163.00 


166,705.60 
131.00 


23,366.52 


.856 
.805 


14.02 






Cork disks wafers or washers 
















15c lb. 
Free 


1,918,643.00 
126.00 


i.i66.'3l'6.66 
68.00 


287.7'96.45 


.605 
.54 

















i2c lb. 
Free 


7.841.00 
254.00 


4.996.00 
160.00 


940.92 


.638 
.63 














Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 
planks, or molded forms 














Cork Tile . . 




























Waste, shavings, or refuse of all kinds.. . 
Cork Paper 


Free 
35% 

30% 


96,575,427.00 


1.334,262.00 
111.069.00 

41,466.00 


38.874.15 
12.439.80 


.014 
.35 

.301 


35 00 


AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 
specifically provided for 




30 00 
























Free 


121,474,507.00 


2,756,132.00 




.023 






Dutiable 




1,568,560.00 


383,387.84 




24.44 



Unmanufactured 

Cork wood or cork bark 


Free 


32,866,700.00 


1.517.366.00 




.046 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 


















Corks (or cork stoppers) : 

%' or less in diam. at large end 


15c lb. 


143,889.00 


86.681.00 


21.583.35 


.602 


24.90 
















Over U" in diam. at large end 

For mfg. in bonded whse. and export 
Reciprocity treaty with Cuba 


12c lb. 


125.917.00 


84.065.00 


15,110.04 


.672 


17.97 






























15c lb. 


674,066.00 


464.931.00 


101.109.90 


.689 
























12c lb. 


21,710.00 


22.657.00 


2.605.20 


1.044 






















Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards, 


Mclb. 


956,979.00 


39,651.00 


2.392.46 


.041 




Cork Tile . . . . 


















Waste, shavings, or refuse of all kinds.. . 
Cork Paper 


Free 
35% 

30% 


122,577.224.00 


1,617,518.00 
136.615.00 

43,668.00 


' '47.815.25 
13.100.40 


.013 


35 00 


All other manufactures wholLv or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




30.00 
























Free 


155.443.924.00 


3,134,884.00 




.021 







Dutiable 




878,268.00 


203.716.60 




23.20 









EXTENT OF CORK INDUSTRY 



65 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Conhnwed 
FOR FISCAL YEAR, 1917 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 

S 


Duties 


Value 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 

fUt" 


Unmanufactured 


Free 


40,273,005.00 


2,125,633.00 




.055 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or graniJated cork and 




Bark, cut in squares, cubes or quarters 
Corks (or cork stoppers) : 

h' or less in diam. at large end 


4c lb. 
15c lb. 


573.00 
147,394.00 


116.00 
96,289.00 


22.92 
22,109.10 


.202 
.652 


19.76 
22.96 
















Over U" in diam. at large end 


12c lb. 


290,156.00 


178,872.00 


34.818.72 


.458 


19.47 
















Cork disks, wafers or washers 
















15c lb. 


2.759.446.00 


1.933,621.00 


413.916.90 


.616 




For mfg. in bonded whae. and export 




Reciprocity treaty with Cuba 

Over 'i,' in thickness 

Reciprocity treaty with Cuba 

Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 


/ 15c lb. \ 
\less 20%) 

12c lb. 
/ 12c lb. I 
lless 20%; 

J^ic lb. 


1,006.00 

53,186.00 

877.00 

4.038.372.00 


1.111.00 

37.721.00 

889.00 

181.698.00 


120.72 

6.382.32 

84.19 

10,095.93 


1.104 
.711 
1.014 

.045 


10.87 
16.92 
9.47 




















Waste, shavings, or refuse of all kinds.. . 


Free 
35% 

30% 


120.677,624.00 


1,743.184.00 
138,214.00 

58.273.00 


■ ■48,374.90 
17,481.90 


.015 




All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




30 00 






















■■ TOTALS 


Free 


160,950,629.00 


3.868,817.00 




.024 




Dutiable 




2,626,804.00 


553,407.6(1 




21.07 



FOR FISCAL YEAR. 1918 



Unmanufactured 


Free 

3c lb. 
4c lb. 

15c lb. 


30.750.497.00 

100.00 
5.00 

177.292.00 


1,479.072.00 

25.00 
1.00 

70,233.00 


3.00 
.20 

26,593.80 


.048 

.25 
.20 

.399 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 

Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers) : 

H' or less in diam. at large end 


12.00 
20.00 

37.86 
















Over 'i' in diam. at large end 

For mfg. in bonded whse. and export 


12c lb. 


189.585.00 


128,145.00 


22.750.20 


.675 


17.75 




























'/ji' or less in thickness 


15c lb. 


2,258.233.00 


1.401,694.00 


338.734.95 


.62 


24 17 


For mfg. in bonded whse. and export 


















12c lb. 


57.785.00 


44,157.00 


6.934.20 


.762 


15 70 


For mfg. in bonded whse. and export 
















Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 
planks, or molded forms 


Mc lb. 


3,771,294.00 


181.402.00 


9,428.23 


.048 


5.20 
















Waste shavings or refuse of all kinds.. . 


Free 
35% 

30% 


95.051.164.00 


1,582,755.00 
107,462.00 

44.403.00 


37.611.70 
13.320.90 


.017 




All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




30.00 






















™^^^^ 


Free 


125,801,661.00 


3,061,827.00 




.024 






Dutiable 




1,977,522.00 


455,377.18 




23.03 



66 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— ConUnwed 
FOR CALENDAR YEAR, 1918 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 


Duties 

S 


Value 
per 
Unit 

of 
Quan- 
tity 

s 


Actual 
and 
Com- 
puted 
Ad 
Val- 
orem 
Rate 
% 


Unmanufactured 


Free 


22,560,059.00 


1,297,636.00 




.058 




Manufactures of 

Artificial cork, or cork substitutes, mfcl. 
from cork waste or granulated cork and 
n. o. p. f 




Bark, cut in squares, cubes or quarters 
Corka (or cork stoppers) : 

H" or less in diam. at large end 

For mfg. in bonded whse. and export. 


4c lb. 
15c lb. 


5.00 
64,556.00 


1.00 
20,605.00 


9,683.40 


.20 
.319 


20.00 
47.00 














Over H" in diam. at large end 

For mfg. in bonded whse. and export 


12c lb. 


101,021.00 


72.426.00 


12,122.52 


.716 


16.74 






























15c lb. 


2,010,408.00 


1.316,590.00 


301.561.20 


.655 




For mfg. in bonded whse. and export 
















Over V in thickness 


12o lb. 


71,112.00 


46.495.00 


8.533.44 


.654 


18.35 


For mfg. in bonded whse. and export 
















Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards. 


He lb. 


1,349,570.00 


63.704.00 


3.373.92 


.047 




Cork Tile 


















Waste, .shavings, or refuse of all kinds.. . 


Free 
35% 

30% 


72,421,740.00 


1.233.009.00 
116.665.00 

32,546.00 


■40.832.75 
9.763.80 


.017 




All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




























Free 


94,981,799.00 


2,530,645.00 




.027 






Dutiable 




1.669.032.00 


385,871.23 




23.12 



FOR 


CALENDAR YEAR, 1919 








Unnnanufactured 


Free 

3c lb. 
4c lb. 

15c lb. 


28.286.942.00 

175,331.00 
6,135.00 

76,397.00 


1,802.506.00 

116,505.00 
3,129.00 

65.150.00 


5,259.93 
. . . 245.40 

11,459.55 


.064 

.666 
.51 

.853 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n 0. p. f 

Bark, cut in squares, cubes or quarters . . 

Corks (or cork stoppers) : 

Jj' or less in diam. at large end 


4.51 
7.84 

17.59 
















Over h" in diam. at large end 

For mfg. in bonded whse. and export 


12c lb. 


73,728.00 


59,966.00 


8,847.36 


.815 


14.74 






























15c lb. 

/ 15c lb. 1 

lless 20%/ 

12c lb. 


766.947.00 
24,106.00 
12,651.00 


452,331.00 
18,617.00 
8,991.00 


115,042.05 
2,892.72 
1,518.12 


.589 
.773 
.714 




Reciprocity treaty with Cuba 


15.54 
16 88 


For mfg. in bonded whse. and export 
















Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards. 


Mc lb. 


5,719.668.00 


411,472.00 


14,299.17 


.072 






















Waste, shavings, or refuse of all kinds.. . 


Free 
35% 

30% 


131.641.699.00 


2,558,556.00 
101,569.00 

51.286.00 


■ ■35,549.15 
15,385.80 


.019 




All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




30.00 
























Free 


159.928.641.00 


4,361,062.00 




.027 






Dutiable 


1 1,289,016.00 


210.499.25 







EXTENT OF CORK INDUSTRY 



67 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Coniinwed 
FOR CALENDAR YEAR, 1920 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 

Lbs. 


Values 
S 


Duties 
S 


Value 

Unit 

of 
Quan- 
tity 

$ 


Actual 
and 
Com- 
puted 
Ad 
Val- 

R^at^ 


Unmanufactured 


Free 

3c lb. 
4c lb. 

15e lb. 


53,927,976.00 

6.00 
1,387.00 

103,961.00 


2,596,600.00 

1.00 
403.00 

88,509.00 


.18 
55.48 

15,594.15 


.048 

.167 
.291 

.85 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n. o. p. f 

Bark, cut in squares, cubes or quarters. . 

Corks (or cork stoppers) : 

h' or less in diam. at large end 


18.00 
13.77 

17.62 








;:::::::::: 








Over U" in diam. at large end 

Reciprocity treaty with Cuba 


12c lb. 
/ 12c lb. 1 
lless 20%/ 


67.790.00 
176.00 


39,430.00 
74.00 


8,134.80 
16.90 


.58 
.421 


20.63 
22.84 




ISc lb. 


1,382,697.66 


905.429.00 


267,404.55 


.065 




For mfg. in bonded whse. and export 
















Over 'u' in thickness 


12c lb. 


11.764.00 


6,736.00 


1.411.68 


.572 


20.96 
















Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards, 


Ho lb. 


9,000,101.00 


771,123.00 


22,500.25 


.086 


2 92 




















Waste, shavings, or refuse of all kinds.. . 
Cork Paper 


Free 

35 7o 

30% 


169,549,364.00 


3,741,730.00 
62,560.00 

94,938.00 


■ ■21,896.00 
28,481.40 


.022 





AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 






Reciprocity treaty with Cuba. . . . 




















TOTALS 


Free 


223,477,340.00 


6,338,330.00 




.028 






Dutiable 




1,969,203.00 


305,495.39 







FOR CALENDAR YEAR. 1921 



Unmanufactured 


Free 

3c lb. 
4c lb. 

15c lb. 


22.147.868.00 

220.00 
8.00 

72.718.00 


959,947.00 

41.00 
2.00 

59,451.00 


6.60 
.32 

10,907.70 


.044 

.187 
.25 

.818 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 

Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers) : 

H" or less in diam. at large end 


16.10 
16.00 

18.35 
















Over ?4' in diam. at large end 

For mfg. in bonded whse. and export 


12c lb. 


84.519.00 


42.846.00 


10,142.28 


.506 


23.66 














Cork disks wafers or washers 














lit' or less in thickness 


15c lb. 


509.765.00 


380,069.00 


76,464.75 


.748 


20 12 






















12c lb. 


29.205.00 


22,918.00 


3,504.60 


.792 






















Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards 


Mclb. 


8,971,847.00 


517,772.00 


22,429.62 


.058 






















Waste, shavings, or refuse of all kinds.. . 


Free 
35% 

30% 


88,255,141.00 


1.397,212.00 
25,462.00 

51,893.00 


■ ■8,911.70 
15,567.90 


.016 




AU other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 




30.00 
























Free 


110,403,009.00 


2,357,159.00 




.021 






• Dutiable 




1,100.454.00 


147.935.47 







08 



CORK INSULATION 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Conhraued 
FOR CALENDAR YEAR, 1922 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 
$ 


Duties 
S 


Value 

U^n^t 

of 
Quan- 
tity 

$ 


Actual 

Com- 
puted 
Ad 
Val- 

Rat" 


Unmanufactured 

Cork wood or cork bark 


Free 


60.116.486.00 


1.560.059.00 




.026 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 




Bark, cut in SQuares, cubes or quarters . 
Corks (or cork stoppers) : 

H" or less in diam. at large end 


4c lb.' 

/ 15c lb.' 
I 25c lb.» 


1.174.00 

93.528.00 
24.051.00 


105.00 

59,804.00 
20.551.00 


46.96 

14,029.20 
6,012.75 


.64 
.838 


44.72 

23.46 
29.25 


Over h" in diam. at large end 


/ 12c lb.' 
I 20c lb.' 


61.048.00 
24.042.00 


28.464.00 
22,601.00 


7.325.76 
4.808.40 


.465 
.94 


25.74 
21.27 
















'/if" or less in thickness 


/ 15c lb.' 
I 25c lb.' 


260.109.00 
33.496.00 


144,750.66 
15.234.00 


39.016.35 
8.374.00 


.556 
.455 


26.95 
54.97 






/ 12c lb.' 
\ 20c lb.' 

/ He lb.' 
\ 30% ' 
25% ' 
Free 
/ 35% ' 
\ 30% ' 

/ 30% ' 
\ 30% • 


18,014.00 
3,835.00 

13.040,492.00 

1.577.708.00 

25.00 

184,541,464.00 


13.338.00 
2.497.00 

776.655.00 

91.002.00 

9.00 

2.484,321.00 

15,185.00 

1,411.00 

67,397.00 
24.278.00 


2.161.68 
767.00 

32.601.23 

27.300.60 

2.25 

'5,'3i4.75 
423.30 

20,219.10 
7.283.40 


.743 
.65 

.06 
.058 
.36 
.014 

1.32 
".196 


16.21 
30.71 

4.20 
30.00 


Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards 


Granulated or ground cork 

Waste, shavings, or refuse of aU kinds.. . 


25.00 
35.66 




1.070.00 




All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


30.00 




123.780.00 


30.00 


Reciprocity treaty with Cuba 


















Free 


244,657.950.00 


4,044,380.00 




.017 






Dutiable 




1,283.281.00 


175.686.73 







FOR CALENDAR YEAR, 1923 



Unmanufactured 


Free 

/ Oclb.-i 

\ lOc lb.« 

8o lb. 

25c lb. 


62.975.549.00 

590.00 
201.00 
799.00 

123.153.00 


1,776.417.00 

17i:00 
218.00 

163,001.00 


35.40 
20.10 
63.92 

30.788.25 


.028 

.521 
.851 
.273 

1.324 




Manufactures of 

Artificial cork, or cork substitutes, mfd. 
from cork waste or granulated cork and 
n. o. p. f 

Bark, cut in squares, cubes or quarters . . 

Corks (or cork stoppers) : 

H" or less in diam. at large end 


11.49 
11.75 
29.32 

18.89 
















Over W in diam. at large end 


20c lb. 


113.301.00 


112.563.00 


22,660.20 


.994 


20.13 
































25e lb. 


315.333.00 


209.084.00 


78.833.25 


.664 


37 70 






















/ 20c lb.» 
\ 10c lb.« 


65.540.00 
123.00 


53.523.00 
48.00 


11.108.00 
12.30 


.964 
.391 


20.75 
25.63 




Cork insulation; wholly or in chief value 
of granulated cork in slabs, boards, 
planks or molded forms 


30% 
30% 
25% 
Free 
30% 

30% 


13.976.878.00 

16,800.00 

11,273.00 

164.571,128.00 

6,977.00 

1,176,886.00 


496.133.00 

1,875.00 

242.00 

1.951,143.00 

6,211.00 

181,223.00 


148.839.90 
562.50 
60.50 

■ 1,863.30 
54,366.90 


.034 
.112 
.022 
.012 
.891 

.154 


30 00 


Cork Tile 


30 00 




25 00 


Waste shavings, or refuse of all kinds.. . 


30 66 


All other manufactures wholly or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork not 


30 00 






















Free 


227.546,677.00 


3.727,560.00 




.016 






Dutiable 


15,797,854.00 


1,224,600.00 


349,214.52 


.078 





•Old law. Jan. 1 to Sept. 21. Act of Oct. 3. 1913. and Emergency Tariff Act of May 27. 1921. 
law. Sept. 22 to Dec. 31. 'Made from natural cork bark. *Made from Artificial or Composition 
•In the rough, not further advanced than slabs, blocks or planks. 'In rods or sticks suitable for the r 
facture of disks, wafers, or washers. 



EXTENT OF CORK INDUSTRY 



IMPORTS ENTERED UNITED STATES FOR CONSUMPTION— Conh-»ue<2 
FOR CALENDAR YEAR, 1924 



CORK and MANUFACTURES OF: 


Rate 

of 
Duty 


Quantities 
Lbs. 


Values 
S 


Duties 

S 


Value 

ty.![t 

of 
Quan- 
tity 

S 


Actual 
and 
Com- 
puted 
Ad 
Val- 

R'^^te 

% 


Unmanufactured 


Free 

fie lh.» 
8c lb. 

/25c lb.' 
\12;clb.' 


61,556,348.00 

1,025.00 
804.00 

159,781.00 
138.00 


1,234.424.00 

201.00 
267.00 

233,280.00 
70.00 


61.50 
64.32 

39.945.25 
17.25 


03 

.196 
.332 

.146 
.508 




Manufactures of 

Artificial cork or corls; substitutes, mfd. 
from cork waste or granulated cork and 

Bark, cut in squares, cubes or quarters . . 
Corks (or cork stoppers) : 

U' or less in diam. at large end 


30.60 
24.09 

17.12 
24.64 


Over U" in diam. at large end 


/20c lb.' 
\ 10c lb.' 


113,886.00 
25.00 


156.051.00 
16.00 


22.777.20 
2.50 


1.37 
.64 


14.60 
15.63 
















'is' or less in thickness 


25c lb.' 


317,761.00 


275.100.00 


79.440.25 


.855 


28 88 


For mfg. in bonded whse. and export 
















Over 'is" in thickness 


20c lb." 


80,613.00 


110,451.00 


16.122.60 


1.37 


14 60 


For rafg. in bonded whse. and export 

Reciprocity treaty with Cuba 

Cork insulation: wholly or in chief value 
of granulated cork in slabs, boards. 




/ 20c lb. 1 
\less 207c 1 

30% 


122.00 
21.363.488.00 


75.00 
781.568.00 


19.52 
234.470.40 


.eis 

.037 


26.03 








25% 
Free 
30% 


608.221.00 

131.048,779.00 

38.00 

4.099.843.00 


8,097.00 

1,377.714.00 

24.00 

273.867.00 


2.174.25 

7'.20 

82,160.10 


.014 
.011 
.632 

.067 




Waste, shavings, or refuse of all kinds.. . 




All other manufactures whoUy or in chief 
value of cork or cork bark, or of 
artificial cork or cork substitutes, 
granulated or ground cork, not 


30.00 






















Free 


192,005,127.00 


2.612,138.00 




.014 






Dutiable 


26,745,745.00 


1,839,067.00 


477,202.34 


.07 





or compositioD cork. 'In the rough, not further 



70 



CORK INSULATION 



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CORK INSULATION 
Part II— The Study of Heat 



CHAPTER VII. 
HEAT, TEMPERATURE AND THERMAL EXPANSION. 

31. — Molecular Theory of Heat. — The sensation of heat is 
normally recorded by the sense of touch if heat is transferred 
from a gas, liquid or solid to the human body ; and the sensa- 
tion of cold results from a transfer of heat from the human 
body to a gas, liquid or solid. For the purpose of our study 
of heat, it will be best to think principally in terms of heat, 
rather than in terms of cold. 

For many centuries it was generally believed that heat 
was an invisible, elastic and weightless fluid, termed caloric, 
which was responsible for all thermal phenomena by entering 
gases, liquids and solids in some mysterious or hypothetical 
manner, possibly even combining temporarily with them. It 
was not until about the beginning of the nineteenth century 
that the materialistic conception of heat was rather definitely 
disproven by certain experiments conducted by Count Rum- 
ford (Benjamin Thompson) (1753-1814), an American phi- 
losopher who made important contributions to physics and 
agriculture and later become adviser to the King of Bavaria, 
and by Sir Humphry Davy (1778-1829), an English chemist. 
But it remained for James Prescott Joule (1818-1889), an 
English physicist, to prove, about the middle of the nineteenth 
century, that a definite amount of mechanical work is equiv- 
alent to a definite amount of heat, when it soon became evi- 
dent that heat is a form of energy. 

The kinetic theory of heat holds, briefly, that the molecules 
of a body have a certain amount of independent, though irreg- 
ular, motion, and any increase in the energy of that motion 
manifests itself in the body becoming warmer, and any de- 

71 



72 CORK INSULATION 

crease by its becoming cooler, heat, in a word, being con- 
sidered as kinetic energy of molecular motion. 

The molecular theory of heat goes one step farther and holds 
that heat is in part the kinetic energy of molecular motion, 
as just elaborated, and in remaining part the potential energy 
of molecular arrangement. The molecular theory ef heat per- 
mits a readier grasp of the facts concerning heat than seems 
otherwise possible, and for that reason is today generally 
accepted. 

32. — Temperature. — It is a mere matter of observation that 
if .several spoonfuls of ice water are added to a cup of hot 
cofifee, the entire contents of the cup quickly become cooler, 
the heat flowing from the hot cofTee to the cold water until a 
quiescent state, in which there is no tendency to further 
change of any kind, known as thermal equilihrmm, is established 
between them. If the same cup is then allowed to stand in a 
closed room, without outside interference or disturbance of 
any kind, the heat will flow from the coffee to the cup to the 
table to the air of the room until all substances in the room 
settle to a state of thermal equilibrium ; and when a number 
of bodies have settled to such a common state of thermal 
equilibrium they are said to have the same temperature. 

The transfer of heat is alv/ays from the body of higher 
temperature to the one of lower temperature until those tem- 
peratures are exactly the same, or until thermal equilibrium 
is established between them. Temperature may be thought of 
as the thermal condition of a body, or the measure of the degree 
of hotness; but it must not be confused with quantity of heat. 
A cup of coffee may be at exactly the same temperature as the 
water in a l,0(X)-gallon hot water tank, yet the tank contains a 
vastly greater quantity of heat than the cup, owing to the vastly 
greater quantity of liquid held by the tank. 

When a substance is hot its temperature is said to be 
high, and when cold its temperature is said to be low. 

33. — Dissipation of Energy. — Every actual case of motion 
is attended by friction and/or collision on the part of the mov- 
ing body, and that part of its energy not employed in doing 
work is thus dissipated. This dissipation of energy is always 
accompanied by the generation of heat, or, stated another way, 



HEAT AND THERMAL EXPANSION 



71 



such dissipation of energy is the conversion of mechanical 
energy into heat. A familiar example of the generation of 
heat by the dissipation of energy is the stamping of one's feet 
in cold weather to make them warm. Another example of 
the dissipation of energy is furnished by the change in po- 
tential energy resulting from the drop in temperature of 
superheated steam caused by the radiation or loss of heat 
from uninsulated boiler surfaces or steam pipe lines. 

34. — Effects of Heat. — The heating of a substance, by the 
dissipation of energy, by contact with a hot body, or by any 
other means, may produce these effects: 

(a) Rise in temperature. 

(b) Meltage or vaporization. 

(c) Contraction or expansion. 

(d) Dissociation, if a chemical compound. 

(e) Exhibition of electrical phenomena. 

35. — Thermometers. — The most convenient instrument to 
measure temperature, rise and fall, is a mercury thermometer, 

A P B 











Fahrenheit 3 


2 


F 


2 


12 


Centigrade 





C 


1 


00 


Jieaumur 





It 




80 



FIG. 29.— COMPARISON OF THREE TYPES OF THERMOMETERS— (A) 

FREEZING POINT; (B) BOILING POINT; (P) THERMOMETER 

READING. 

which employs a glass tube of uniform bore having a blown 
bulb on one end. A part of the air contained in the bulb 
and tube is expelled by expansion resulting from heating, 
and the open end of the tube is then immersed in pure mer- 
cury. As the tube cools the air within it cools and contracts, 
and atmospheric pressure relieves the condition by forcing 
mercury into the open end of the tube. This method is used 
to fill the bulb completely and the tube only to a point where 
the lowest temperature the thermometer is to measure is to 
be indicated on the tube or glass stem. Then, after heat 
applied to the the bulb has raised the mercury to the very 
top, the open end of the tube is sealed in a blowpipe flame. As 



74 CORK INSULATION 

the tube and mercury cool, the contracting mercury moves 
clown the glass stem, leaving a vacuum at the top of the 
tube. 

Since the temperature of melting ice and that of steam, 
under a constant pressure, have been found by very careful 
experiment to be invariable, their respective temperatures at 
a pressure of 76 centimeters (29 922 inches) of mercury have 
been selected as the fixed points on a thermometer. The in- 
strument is placed in an ice bath and the freezing point is marked 
on the tube; it is then enveloped in steam and the boiling point 
is similarly recorded, proper corrections being made to com- 
pensate for any pressure different from 76 cm. 

The number of spaces, or degrees, into which the distance 
between the fixed points is divided has been subject to much 
discretion, but the three scales most used are the Fahrenheit, the 
Centigrade and the Reaumur. Gabriel Daniel Fahrenheit (1686- 
1736), a German physicist, introduced the Fahrenheit scale 
about 1714, and it is today in common use in all English- 
speaking countries in spite of the unreasonableness of desig- 
nating the freezing point as 32°, the boiling point as 212° 
and dividing the scale between into 180 equal parts. Rene 
Antoine Ferchault de Reaumur (1638-1757), a French physic- 
ist, devised the Reaumur scale in 1731, which is today in 
common use in the households of Europe, the zero point 
corresponding to the temperature of melting ice and 80° to 
the temperature of boiling water. Some erroneously credit 
Anders Celsius (1701-1744), a Swedish astronomer, with the 
Centigrade scale, which fixes zero as the temperature of 
melting ice and 100 as the temperature of boiling water, but 
the Celsius scale (now in disuse entirely) reversed these 
fixed points and designated 100 as the temperature of melting 
ice and zero as the temperature of boiling water. The Centi- 
grade scale was evidently designed as part and parcel of the 
metric system, which originated in France and was there 
definitely adopted in 1799. The Centigrade scale is in general 
use among scientific men throughout the world. 

36. — Air Thermometer. — Galileo Galilei, commonly called 
Galileo (1564-1642), an Italian astronomer and physicist, in- 
vented the air thermometer about 1593 for the use of physi- 



HEAT AND THERMAL EXPANSION 



75 



cians. It consisted of a sizable blown glass bulb on the end of 
a tube of small bore, a scale being attached to the tube. The 



TEMPERATURE CONVERSION TABLE 
Centigrade to Fahrenheit to Reaumur. 



c. 


F. 


R. 


C. 


F. 


R. 


C. 


F. 


R. 


+100° 


+212. 0<= 


+80.0° 


+53" 


+127.4° 


+42.4" 


+ 6° 


+42.8° 


+4.8» 


99 


210.2 


79.2 


52 


125.6 


41.6 


5 


41.0 


4.0 


98 


208.4 


78.4 


51 


123.8 


40.8 


4 


39.2 


3.2 


97 


206.6 


77.6 


50 


122.0 


40.0 


3 


37.4 


2.4 


96 


204.8 


76.8 


49 


120.2 


39.2 


2 




1.6 


95 


203.0 


76.0 


48 


118.4 


38.4 


1 


33.8 


0.8 


94 


201.2 


75.2 


47 


116.6 


37.6 


Zero 


32.0 


Zero 


93 


199.4 


74.4 


46 


114.8 


36.8 


- 1 


30.2 


- 0.8 


S2 


197.6 


73.6 


45 


113.0 


36.0 


2 


28.4 


1.6 


91 


195.8 


72.8 


44 


111.2 


35.2 


3 


26.6 


2.4 


90 


194.0 


72.0 


43 


109.4 


34.4 


4 


24.8 


3.2 


89 


192.2 


71.2 


42 


107.6 


33.6 


5 


23.0 


4.0 


88 


190.4 


70.4 


41 


105.8 


32.8 


6 


21.2 


4.8 


87 


188.6 


69.6 


40 


104.0 


32.0 


7 


19.4 


5.6 


§6 


186.8 


68.8 


39 


102.2 


31.2 


8 


17.6 


6.4 


85 


185.0 


68.0 


38 


100.4 


30.4 


9 


15.8 


7.2 


84 


183.2 


67.2 


37 


98.6 


29.6 


10 


14.0 


8.0 


83 


181.4 


66.4 


36 


96.8 


28.8 


11 


12.2 


8.8 


§2 


179.6 


65.6 


35 


95.0 


28.0 


12 


10.4 


9.6 


81 


177.8 


64.8 


34 


93.2 


27.2 


13 


8.6 


10.4 


80 


176.0 


64.0 


33 


91.4 


26.4 


14 


6.8 


11.2 


79 


174.2 


63.2 


32 


89.6 


25.6 


15 


5.0 


12.0 


78 


172.4 


62.4 


31 


87.8 


24.8 


16 


3.2 


12.8 


V 


170.6 


61.6 


30 




24.0 


17 


1.4 


13.6 


76 


168.8 


60.8 


29 


84:2 


23.2 


18 


-0.4 


14.4 


75 


167.0 


60.0 


28 


82.4 


22.4 


19 


2.2 


15.2 


74 


165.2 


59.2 


27 


80.6 


21.6 


20 


4.0 


16.0 


73 


163.4 


58. 4 


26 


78.8 


20.8 


21 


5.8 


16.8 


72 


161.6 


57.6 


25 


77.0 


20.0 


22 


7.6 


17.6 


71 


159.8 


56.8 


24 


75.2 


19.2 


23 


9.4 


18.4 


70 


158.0 


56.0 


23 


73.4 


18.4 


24 


11.2 


19.2 


69 


156.2 


55.2 


22 


71.6 


17.6 


25 


13.0 


20.0 


68 


154.4 


54.4 


21 




16.8 


26 


14.8 


20.8 


67 


152.6 


53.6 


20 


68^0 


16.0 


27 


16.6 




66 


150.8 


52.8 


19 


66.2 


15.2 


28 


18.4 


22!4 


65 


149.0 


52.0 


18 


64.4 


14.4 


29 


20.2 


23.2 


64 


147.2 


51.2 


17 


62.6 


13.6 


30 


22.0 


24.0 


63 


145.4 


50.4 


16 


60.8 


12.8 


31 


23.8 


24.8 


62 


143.6 


49.6 


15 


59.0 


12.0 


32 


25.6 


25.6 


61 


141.8 


48.8 


14 


57.2 


11.2 


33 


27.4 


26 4 


60 


140.0 


48.0 


13 


55.4 


10.4 


34 


29.2 


27.2 


G9 


138.2 


47.2 


12 


53.6 


9.6 


35 


31.0 


28.0 


58 


136.4 


46.4 


11 


51.8 


8.8 


36 


32.8 


28.8 


57 


134.3 


45.6 


10 


50.0 


8.0 


37 


34.6 


29.6 


56 


132.8 


44.8 


9 


48.2 


7.2 


38 


36.4 


30.4 


55 


131.0 


44.0 


8 


46.4 


6.4 


39 


38 2 


31.2 


54 


129.2 


43.2 


7 


44.6 


5.8 


40 


40.0 


32.0 



Fahrenheit degrees = 1.8 X Centigrade degrees + 32°. 
Centigrade degrees = (Fahrenheit degrees) — 32°-ri.8. 

bulb Avas heated in order to expand and expel some of its air 
content, and then the stem was inserted in a colored liquid, as 
pigmented water or alcohol. As the air in the bulb and stem 



76 



CORK INSULATION 



cooled, the air contracted, and atmospheric pressure caused 
the liquid to rise in the tube. Fixed points were then estab- 
lished on the scale, and any rise in temperature caused the 
colored liquid to drop and any drop in temperature caused 
the liquid to rise. The instrument was remarkable for its 




jelG. 30.— EARLY FORM OF AIR THERMOMETER. 



sensitiveness, but its readings changed for every change in 
barometric pressure. 

The modern "air thermometer" is an apparatus for meas- 
uring the ratio of two temperatures by observation of the pres- 
sures of a confined portion of hydrogen gas at the respec- 
tive temperatures, based on the necessary modification of the 
Law of Charles, laid down in 1787, which claimed to estab- 



HEAT AND THERMAL EXPANSION 11 

lish that "the volume of a given mass of any gas under con- 
stant pressure increases by a constant fraction of its volume 
at zero for each rise of temperature of 1°C." The ratio of 
standard steam temperature (the minimum temperature of 
pure steam at 16 cm. pressure) to ice temperature (the tem- 
perature of pure melting ice at 76 cm. pressure) has been 
found by the air thermometer to be 1.367, or 

Steam temp. S 
=— = 1 .367 



Ice temp. I 

On the Centigrade scale S — I = 100, and from these 
two simple equations we find that S = ZTh° and I = 273°, 
approximately, Centigrade. Any other temperature may be 
determined by measuring its ratio to I or to S by means of 
the air thermometer. Temperatures measured in this way 
are called absolute temperatures, and thus it will be noted that 
the absolute zero on the Absolute scale is 273 degrees below 
the freezing point on the Centigrade scale. It has been 
established, since Jacques Alexandre Cesar Charles (1746- 
1822), a French physicist and aeronaut, gave us his Law of 
Charles, that the volumes of the same mass of gas under 
constant pressure are proportional to the temperature on 
this Absolute scale, or 

V t+213 T 

vi U+213 T, 
if t + 273 is expressed by T, and t^ -f 273 by Tj. 

37. — Expansion and Contraction. — If equal volumes of 
various gases are heated, under constant pressure, they were 
thought by Joseph Louis Gay-Lussac (1778-1850), a French 
chemist and physicist, to expand equivalent amounts for the 
same rise in temperature, but very careful measurements have 
since demonstrated quite perceptible differences of expansion 
of various gases, ammonia, for example, being distinctly dif- 
ferent in its expansion from hydrogen. Gases that are near 
their points of liquefaction depart widely from Gay-Lussac's 
law ; ammonia, sulphur dioxide and methyl chloride gases are 
easily liquefied and are commonly referred to as vapors. 
Hydrogen, on the other hand, is not easily liquefied under 



78 



CORK INSULATION 



ordinary pressures, and hence follows Gay-Lussac's law quite 
closely. The point of importance here is that all gases ex- 
pand when heated and contract when cooled. 

Liquids, with notable exceptions, expand when heated and 
contract when cooled, the amount in any case depending 
entirely upon the volume of the substance. An exception is 
water, which contracts when heated from 0° C. (32° F.) to 
4° C. (39.2° F.). 

Solids, with a few exceptions, expand in all directions when 
heated and contract when cooled. An exception is iodide of 
silver, which, within a certain temperature range, contracts 
when heated and expands when cooled. 

38. — Force of Expansion and Contraction. — The force of 



























/ 
































/ 








1.03 


«A 




















/ 










-J 




tj 














/ 














^ 
^ 




z 












/ 


/ 














1 




s 

5 










/ 


/ 
















cr 




s 








y 


/ 






















1 






y 


/ 






















^ 


1 

1 


^ 


■^ 




TEM 


'ERA1 


URES 















FIG. 31.— GRAPHIC REPRESENTATION OF THE EXPANSION AND CON- 
TRACTION OF WATER WITH CHANGE OF TEMPERATURE. 

expansion or of contraction of a substance is equal to the 
force required to compress or expand it to the same extent by 
mechanical means. This force must be computed by some 
method suited to the conditions, such as illustrated in this 
example*: A bar of iron, one square inch in cross-sectional 
area, if placed under the tension of a ton, increases in length 
0.0001 of itself. The coefficient of linear expansion of this 

'Physics," Allyn and Bacon, 



•Henry S. Carhart and Horatio N. Chute, 1901, 
Boston and Chicago. 



HEAT AND THERMAL EXPANSION 79 

iron is 0.0000122. Since 0.0001 -^ 0.0000122 = 8+, then a 
change of temperature of approximately 8° C. will produce 
the same change in the length of the bar as a force of one ton. 

39. — Application of Expansion and Contraction. — Many of 
the phenomena that are commonly encountered are traceable 
directly to the expansion and contraction that results from 
the rise and fall of temperature. One of the commonest of 
these is the explanation for a pendulum clock losing time in 
hot weather and gaining time in cold weather, due to the 
expansion and contraction, respectively, of its pendulum with 
the seasons. The wagon-maker heats his iron tires, thus 
expanding them, and after being put in place they contract 
and bind the wooden wheel solidly and securely. Very hot 
water if poured into a cold glass will often crack the glass 
due to unequal expansion of the inner and outer surfaces. 
The steel framework of modern buildings is put together with 
red-hot rivets hammered down as tight as possible with pneu- 
matic hammers. When the rivets cool they contract and 
draw the steel members together with an enormous force. 
Virtually all pipe lines must be so arranged or equipped as 
to allow for expansion and contraction, to avoid serious dam- 
age and trouble from leaks. Paved streets, cement sidewalks, 
viaducts, bridges and all such items of general utility must 
be provided with a certain freedom of motion of their stand- 
ardized parts to prevent buckling and cracking from expan- 
sion and contraction. The terrific force exerted by the ex- 
pansion of freezing water splits off the solid rock from the 
side of the granite hills with the ease of a mythological giant. 
J*avements come up, trees are lifted out of the ground, build- 
ing foundations are damaged, water pipes burst, mountain 
ranges slowly crumble away, all because the terrific force 
exerted by the expansion of freezing water is irresistible. 

Other phenomena are traceable to expansion and con- 
traction due to humidity rather than to temperature. 

40. — Coefficient of Expansion. — It has been noted that, 
with very few exceptions, substances expand in every direc- 
tion when heated. Expansion in length is quite naturally 
termed linear expansion, expansion in area is known as super- 
ficial expansion and expansion in volume is called cubical expan- 



80 CORK INSULATION 

sion. If a substance is heated from 0° C. to 1° C, the fraction 
of its length that the body expands is its cofficient of linear expan- 
sion, the fraction of its area that the body expands is its coeffi- 
lient of superficial expansion and the fraction of its volume that 
the body expands is its' coefficient of cubical expansion. 

The expansion of most substances has been found to be nearly 
constant for each degree of temperature, and it is therefore the 
practice to determine the mean coefficient for a change of several 
degrees. If 1^ is the length of an iron bar at temperature t^ 
and I2 the length at temperature tg, then the expansion in 
length for 1° C. is expressed by 

l^li 1,-1, 



i 



ts— t, t 

if tj — ti is expressed by t. Now the fraction of its length that 
a body expands when heated from 0° C. to 1° C. is taken as its 
coefficient of linear expansion, which shall be designated as a. 
Therefore, the original length, l^, times the coefficient of linear 
expansion of the material, a, or 1^ a, must equal the expansion 
in length for 1° C, or 

I2— li U—U 

lia= , or a= , or h^hCl+at); 

t li t 

and, similarly, if k is the coefficient of cubical expansion, Vj 
and V2 the volumes at temperatures t^ and tg, respectively, then 

V2 — Vi Va — Vi 

k= = , or V2=Vi (1+kt). 

Vi (t:— ti) Vi t 

Superficial and cubical expansion for solids are computed 
from the linear expansion, the coefficient of superficial expansion 
being twice and the coefficient of cubical expansion being three 
times the coefficient of linear expansion. 

41. — Determination of the Expansion of Substances. — The 
linear or cubic expansion of a solid may be determined by the 
actual measurement of its dimensions at different tempera- 
tures, or its cubic expansion may be determined indirectly by 
measuring the volume of the solid at various temperatures by 
the gravimetric method, in common use by chemists. 

The determination of the expansion of water and all other 



I 



HEAT AND THERMAL EXPANSION 



81 



volatile liquids is attended by difficulties due to the formation 
of vapor when heated. The most accurate results are obtained 
by first determining the volume of a glass vessel at each of 
various temperatures by weighing the vessel full of mercury 
at those temperatures and then using the vessel to determine 
the density of the given liquid at the various temperatures. 
The accompanying table gives the results obtained in this way 
for water by Edward L. Nichols and William S. Franklin 
(The Elements of Physics; The MacMillan Co., New York 
City). 

DENSITIES AND SPECIFIC VOLUMES OF WATER. 



Temperature 



Density 



Volume 



— 2° 
0° 

-f 1° 
2" 
3° 
4° 
S" 
6° 
T 
8" 
9' 
lO" 
15° 



35' 
40- 
45* 
50° 
55° 
60° 
6S» 
70° 
75° 
80° 
85° 
90° 
95° 
100° 



0.99815 

0.99869 

0.99912 

0.99945 

0.99970 

0.999874 

0.999930 

0.999970 

0.999993 

1.000000 

0.999992 

0.999970 

0.999932 

0.999881 

0.999815 

0.999736 

0.999143 

0.998252 

0.997098 

0.995705 

0.994098 

0.99233 

0.99035 

0.98813 

0.98579 

0.98331 

0.98067 

0.97790 

0.97495 

0.97191 

0.96876 

0.96550 

0.96212 

0.95863 



1.00186 

1.00131 

1.00088 

1.00055 

1.00031 

1.000127 

1.000070 

1.000030 

1.000007 

1.000000 

1.000008 

1.000030 

1.000068 

1.000119 

1.000185 

1.000265 

1.000858 

1.001751 

1.002911 

1.004314 

1.005936 

1.00773 

1.00974 

1.01201 

1.01442 

1.01697 

1.01971 

1.02260 

1.02569 

1.02890 

1.03224 

1.03574 

1.03938 

1.04315 



The cubic expansion of various gases may be obtained by 
mearis of careful measurements employing especially con- 
structed laboratory apparatus. There are perceptible differ- 
ences of expansion of various gases at equal pressures for a 
given rise in temperature; carbon dioxide, ammonia and water 
vapor, for example, being distinctly different from hydrogen, 
nitrogen and oxygen, disproving the accuracy of Gay-Lussac's 
law. 



CHAPTER VIII. 

MEASUREMENT OF HEAT, CHANGE OF STATE, 
HUMIDITY. 

42. — First Law of Thermodynamics. — When a given sub- 
stance is heated by the dissipation of energy there is a definite 
relation between the amount of work done and the thermal 
effect produced, and consequently heat may be measured in 
units of mechanical work. 

43. — Methods of Heat Measurement. — An amount of heat 
required to produce a given thermal effect can be measured 
by the direct determination of the amount of work required 
to produce a like eft'ect, but this direct method of heat meas- 
urement is not easy of accomplishment due in part to the 
difficulty of applying mechanical work wholly to the heating 
of a given substance. The work spent in a given portion of 
an electric circuit, however, can be measured with great accu- 
racy and such work can be readily employed to produce any 
given thermal effect. 

Another method of measuring heat employs the relation 
between the amount of work dissipated in heating water and 
the rise of temperature thus produced. This method is prac- 
tical, even though the energy-values are given indirectly, 
because the procedure may be carried out with accuracy. The 
melting of ice, and the vaporization of water, are also fre- 
quently employed in the measurement of heat, since the heat 
(work) necessary to melt a given quantity of ice or to con- 
vert a given quantity of water into steam are known quantities 
by determination. 

44. — Units of Heat. — The work required to heat a given 
quantity of water has been shown to be approximately pro- 
portional to the rise of temperature, and for most purposes 
this proportion is sufficiently exact. Consequently, the amount 

82 



MEASUREMENT OF HEAT AND HUMIDITY 83 

of heat required to raise the temperature of one gram of water 
one degree Centigrade has been adopted by physicists as a 
practical unit of heat and is known as the calorie. (The 
standard caloric is the amount of heat required to raise one 
gram of water from 14.5° C. to 15.5° C. hydrogen thermometer, 
and is ecjuivalent to 4.189 joules*. Engineers have fixed upon 
the amount of heat required to raise the temperature of one 
pound of zvatcr one degree Fahrenheit as a practical unit of 
heat, called the British thermal unit (B.t.u.), and which is 
equivalent to approximately 778 foot-pounds.) 

45. — Thermal Capacity of a Substance. — The number of 
thermal units (units of work) or the quantity of heat required 
to raise the temperature of a body through one degree is the 
thermal capacity of that body at that temperature; thermal 
capacity varies slightly with temperature, but for many pur- 
poses is assumed to be constant. The thermal capacities of 
equal masses of different substances differ widely, being the 
product of specific heat and mass. 

46. — Specific Heat. — Substances in general have each a 
definite specific heat, which may be defined as the increase in 
heat content of a unit mass of the substance per degree in- 
crease in temperature; or, the number of thermal units (units 
of work) necessary to raise the temperature of a unit mass 
of a substance through one degree, at any temperature, is 
its specific heat at that temperature. Since the Standard ther- 
mal unit (calorie) is the amount of heat required to raise the 
temperature of one gram of water from 14.5° C. to 15.5° C, 
then specific heat may be expressed as the ratio of the amount 
of heat required to raise a given weight of the substance from 

•14.5° C. to 15.5° C, to that required to raise an equal weight 
of water through the same temperature range. By ignoring 

•the variation in the specific heat of a substance at different 

temperatures and by taking one gram as the unit of weight 

and 1° C. as the rise of temperature, the definition becomes: 

Heat units required to raise one gram of substance 1° C. 

Specific Heat = 

Heat units required to raise one gram of water 1° C. 

Taking the calorie as the heat unit, the denominator becomes 



•Edward L. Nichols and Wm. S. Franklin, 1904, "The Elements of Physics,"The 
MacMillan Co., New York, N. Y. 



84 CORK INSULATION 

equal to unity, by definition. Hence the specific heat of a 
substance is equal to the number of calories required to raise 
the temperature of one gram 1° C, and it will be observed that 
the same figure is given by the number of B.t.u. required to 
raise one pound of the substance 1° F., since by definition one 
B.t.u. will raise one pound of water 1° F. 

The mean specific heat of a substance, between any two 
temperatures, is determined by dividing the heat given oflf per 
unit mass in cooling from the one temperature to the other, 
by the difiference in the temperatures. The accompanying 
table gives the specific heats of various substances for the 
mean temperatures shown, and in terms of water at 15° C. 
(5° F.). 

SPECIFIC HEATS OF VARIOUS MATERIALS.* 



Substance 


Mean Temperature 


Specific Heat 


Water 


5" 


1.0041 


Water 


15° 


1.0000 


Water 


20° 


0.9987 


Ice 


—10" 


0.502 


Paraffin 


10° 


0.694 


Copper 


SO' 


0.092 


Zinc 


so- 


0.093 


Iron 


ls- 


0.109 


Platinum 


SO' 


0.032 


Mercury 


20" 


0.033 



47. — Heat of Combustion. — Most chemical actions are ac- 
companied by the generation or the absorption of heat; those 
involving the generation of heat are known as exothermic re- 
actions, and those during the progress of which heat is ab- 
sorbed are called end o thermic reactions. The most important 
case of exothermic reaction is combustion, the heat generated 
per unit mass of a substance burned being the heat of com- 
bustion of that substance. The accompanying table gives the 
heat of combustion of a few substances in B.t.u. per pound of 
substance. 

HEAT OF COMBUSTION OF VARIOUS MATERIALS.f 

Product of Heat of Combustion 

Substance Combustion B.t.u. per pound 

Carbon COo 14,600 

Carbon CO 4,450 

Carbon Monoxide CO2 10,150 

Hydrogen H2O 62,000 
Methane (CO2) 

(H2O) 23,550 

Sulphur SO2 <,050 

48. — Changes of State with Rise of Temperature. — When 
a body changes from the solid to the liquid state by the appli- 



*Carhart & Chute, 1904, "Physics," Allyn and Bacon, Boston and Chicago. 
tThos. A. Marsh, M.E., 1924. 



MEASUREMENT OF HEAT AND HUMIDITY 85 

cation of heat, it is said to melt, or fuse, or liquefy, and the 
temperature at which fusion or liquefaction occurs is the 
melting point. The temperature of the substance then remains 
constant until the complete change to the liquid state has been 
accomplished, when, under continued application of heat, the 
temperature rises again until the liquid begins to boil or 
vaporize, and the temperature at which vaporisation occurs 
is the boiling point. The temperature again remains constant 
until the liquid is entirely changed to vapor, when the tem- 
perature once more begins to rise. 

49. — The Melting Point. — The temperature at which the 
solid and liquid forms of a substance are capable of existing 
together in equilibrium, is the melting point of that substance, 
and such temperature is invariable for every crystalline sub- 
stance if the pressure is constant. Some substances, like wax, 
resin, glass and wrought iron, have no sharply defined melting 
points. They first soften and then pass more or less slowly 
into the condition of a viscous liquid, which property per- 
mits of the bending and forming of glass and the welding 
and forging of iron. 

Most substances expand on melting, or occupy a larger 
volume in the liquid state than in the solid. A notable and 
important exception is water, which upon freezing, or solidi- 
fying, increases its volume nine per cent. Tf this expansion 
is resisted, water in freezing is capable of exerting an enor- 
mous force. 

The accompanying table gives the melting points of some 
solids at atmospheric pressure. 

MELTING POINTS OF VARIOUS SOLIDS. 
Substance Temperature, F. 

Nickel 2732° 

Gold 1947 : 

Aluminum 1Z14 

Zinc 786° 

Lead 620° 

Tin 449° 

Mercury — ^^ 

50.— Heat of Fusion.— When a solid begins to melt, or fuse, 
by the application of heat, the heat-energy imparted to the 
substance is fully employed in producing change of state, its 
temperature remaining constant until fusion is completed. 



86 CORK INSULATION 

The heat of fusion of a substance is the number of thermal 
units required to change a unit mass of a solid at its melting 
point into liquid at the same temperature. The accompany- 
ing table gives the heat of fusion of various substances. 

HEAT OF FUSION OF VARIOUS SUBSTANCES.* 

Substance B.t.u. per Pound 

Bismuth 22.7 

Lead 9.7 

Mercury 5.04 

Nickel 8.3 

Platinum 49.0 

Silver 38.0 

Tin 25.7 

Zinc 50.6 

Ice 144.0 

Hydrogen 28.8 

51. — The Boiling Point. — The temperature at which the 
liquid and its pure vapor can exist together in equilibrium, is 
the boiling point of that liquid, and such temperature is invari- 
able if the pressure is constant. 

The vapor of a substance under given pressure will con- 
dense to a liquid if it is cooled below the temperature that is 
its boiling point at that pressure; and the vapor of a substance 
at given temperature will condense to a liquid if its pressure 
is increased beyond a certain maximum value for that sub 
stance, although all vapors have a critical temperature above 
which they can not be liquified regardless of the amount of 
pressure to which they are subjected. 

The accompanying table gives the boiling points of various 
liquids at atmospheric pressure. 

BOILING POINTS OF VARIOUS LIQUIDS.* 

Substance Boiling Point, F. 

Ether 95° 

Chloroform 142° 

Alcohol 172.2° 

Benzine 176.7° 

Water 212° 

Glycerine 554° 

Mercury 675 ° 

Sulphur dioxide 14° 

Ammonia — 29° 

Carbon dio.xide — 108.5° 

Oxygen — 296° 

Hydrogen — 422° 

52. — Vaporization. — The conversion of a substance into 
the gaseous form is called vaporizatioin. If the change to a gas 
takes place slowly and from the surface of a liquid, at a tem- 

•Chas. R. Darling, 1908. 



MEASUREMENT OF HEAT AND HUMIDITY 87 

perature below the normal boiling point, it is called evapora- 
tion; but if rapid internal evaporation visibly agitates a liquid, 
and the bubbles that rise through the liquid are pure vapor, 
the process is called boiling. If a small quantity of liquid is 
placed on hot metal, it assumes a globular form and vaporizes 
at a rate somev^^here between ordinary evaporation and boiling. 
The vapor acts as a cushion and prevents actual contact be- 
tween the liquid and the metal, while the globular form is 
due to surface tension. This variety of vaporization is called 
the spheroidal state, and the phenomenon is sometimes also 
referred to as the caloric paradox. 

When a substance passes directly from the solid to the 
gaseous state, without passing through the intermediate state 
of a liquid, it is said to sublime. Some substances, such as 
iodine and camphor, sublime at atmospheric pressure but 
melt if the pressure be sufficiently increased. If ice is held at 
a temperature below freezing, it sublimes (evaporates) 
slowly, which fact is of some importance in the storing of ice. 

53. — Heat of Vaporization. — When a liquid begins to boil, 
or vaporize, by the application of heat, the heat-energy im- 
parted to the substance is fully employed in producing change 
of state, its temperature remaining constant until vaporization 
is complete. The heat of vaporization of a liquid is the num- 
ber of thermal units required to change a unit mass of the 
liquid at its boiling point into vapor at the same temperature. 
The accompanying table gives the heat of vaporization of 
various substances at atmospheric pressure. 

HEAT OF VAPORIZATION OF VARIOUS SUBSTANCES.* 

Substance B.t.u. per Pound 

Water 967 

Ether 164 

Mercury 112 

Turpentine 133 

Air 99 

Carbon dioxide °o 

Ammonia 531 

Oxygen ., 101 

Hydrogen ' 360 

54. — Superheating and Undercooling of Liquids. — When 
pure water that is free from air is heated in a clean vessel, its 
temperature usually rises as much as from eight to twelve 
degrees above its normal boiling point before it begins to 

"Chas. R. Darling, 1908. 



88 CORK INSULATION 

vaporize, and when vaporization begins it occurs violently 
and is attended by an immediate fall of temperature to the 
normal boiling point. If pure water is cooled, its temperature 
usually falls a number of degrees below its normal freezing 
point before freezing actually begins, but a large amount of 
ice is then suddenly formed and the temperature quickly rises 
to the normal freezing point. These phenomena are common 
to most liquids, but the converse is not true ; that is, water 
vapor will not condense until it reaches its normal condensing 
point, and ice begins to melt immediately upon reaching its 
normal melting point. 

55. — Critical Temperatures. — When a liquid and its vapor 
are confined in a vessel and heated, a portion of the liquid 
vaporizes, the pressure increases, the density of the vapor 
increases and possibly the density of the liquid decreases. 
When that temperature is reached where the density of the 
liquid and of the vapor become identical, the liquid and the 
vapor are physically identical and this temperature is called 
the critical temperature of the liquid. Thus the heat of va- 
porization of a liquid is zero at its critical temperature. In 
the following table the critical temperatures of various sub- 
stances are given : 

CRITICAL TEMPERATURES OF VARIOUS REFRIGERANTS*. 

Substance Chemical Symbol Degrees F. 

Sulphur dioxide SO2 311.0 

Ammonia NH3 271.4 

Methyl chloride CH3CI 289.0 

Carbon dioxide CO2 88.2 

Ethyl chloride C0H5CI 360.5 

Butane C4H10 311.0 

Nitrous oxide N2O 95.7 

Propane CsHg 216.0 

Ethane C-Ue 90.0 

Methane CH^ ' —115.6 

Ether CiHioO 

56. — Saturated Vapor. — A vapor is said to be saturated 
when it is at its maximum pressure for a given temperature, 
or when it is at its minimum temperature for a given pressure. 

57. — Effect of Pressure on Melting Point. — Change of pres- 
sure varies but slightly the melting points of substances, but 
the lowering of the melting point of ice by increase of pressure 

'Compiled from data by H. D. Edwards and U. S. Bureau of Standards. 



MEASUREMENT OF HEAT AND HUMIDITY 89 

is responsible for several common phenomena. The melting 
of ice at a point where it is subjected to pressure and the 
immediate freezing of the resulting water when it flows out 
of the region of pressure is known as rcgelation. The excep- 
tional ease with which a skater glides over the ice when the 
temperature of the atmosphere is not too low is due largely to 
the formation of a thin layer of water in the region of extra 
pressure under the skate runners, which water freezes almost 
instantly when the skate has passed and the pressure is relieved. 
Similarly, the ready packing of snow into balls is made pos- 
sible by the melting of the snow crystals at their points of 
contact under the extra pressure of the hands and the imme- 
diate freezing of the resulting water as it flows out of the 
small regions of pressure, although snow must be near the 




FIG. 32.— MELTAGE OF LOWER TIERS OF ICE IN LARGE ICE STORAGES 

DUE TO PRESSURE IS AN IMPORTANT CONSIDERATION IN THE 

DESIGN OF SUCH STRUCTURES. 

melting point in order that regelation may be caused by the 
slight pressure produced by the hands. John Tyndall (1820- 
1893), a British physicist, regarded the apparent plasticity of 
glacier-ice as due to continued minute fracture and regelation. 
The phenomenon of regelation is of practical importance to 
the manufacturer of ice because of the meltage of the lower 
layers of ice cakes due to the pressure of the layers stored 
above. 

58. — Effect of Pressure on Boiling Point.— Change of pres- 
sure varies greatly the boiling point of a liquid. At a pressure 
of 9.198 cm. of mercury the boiling point of water is but 50° 
C, at a pressure of 76 cm. its boiling point is 100° C, and at 



90 CORK INSULATION 

a pressure of 358.1 cm. its boiling point is 150° C. At a 
pressure of 86.64 cm. the boiling point of liquid ammonia is 
—30° C, and at a pressure of 1,945.6 cm. its boiling point is 
60° C. The variation of boiling point with change of pressure 
is of utmost importance in connection with mechanical refrig- 
eration, as is shown in any text pertaining to the ammonia 
refrigerating machine. 

59. — Boiling and Melting Points of Mixtures. — When pure 
water has a foreign substance dissolved in it, such as finely 
divided ammonium nitrate, for example, a thermometer will 
show a sensible fall of temperature, known as heat lost in solu- 
tion, while its freezing point is lowered and its boiling point 
is raised. Similarly, ice in a strong solution of common salt 
(NaCl) has a very low melting point, about 5° F. ( — 15" C), and 
remains at that temperature until all the ice is melted by heat 
absorbed from surrounding objects ; thus a vessel of water, or 
a can of ice cream mix, surrounded by cracked ice and salt, 
gives up its heat to the low temperature mixture until the 
water or cream is frozen. 

It is commonly supposed that salt sprinkled on icy side- 
walks melts the ice ; but the fact is that the salt lowers the 
melting point of the ice below surrounding temperatures (if 
they are not below about 5° F.) and these surrounding sub- 
stances then give up heat to the ice, which melts it. 

The use of ice and salt as a freezing mixture is so common 
as to require no further treatment here. However, it is be- 
lieved that it offers such possibilities in the industries as to 
justify serious study and application. 

60, — Cold by Evaporation. — If a few dro]is of ether are 
placed on the bulb of a thermometer, the mercury column will 
drop due to the fact that some of the heat of the mercury will 
be used to do work on the ether in evaporating it. Sprink- 
ling the lawn, shrubbery and trees cools the surrounding air, 
because of the heat expended in evaporating the water. A 
liquid is cooled in a porous vessel by the evaporation from 
the outside surface of that part of the liquid that seeps through 
the vessel. Liquid carbon dioxide (CO,) evaporates so rap- 



MEASUREMENT OF HEAT AND HUMIDITY 91 

idly as to readily freeze itself*. The rapid evaporation of 
liquid ammonia is one of the properties that makes this chemi- 
cal of so much value as a refrigerating medium. 

61. — Condensation and Distillation. — All the heat that dis- 
appears during the vaporization of a liquid is generated again 
when the vapor is condensed back to its original liquid form, 
which principle is employed to advantage in steam heating. 
Some gases will assume a liquid form through their affinity 
for a liquid, as exemplified by the affinity of ammonia gas for 
-water, the gas being rapidly absorbed by the water with a 
marked rise of temperature. 

Pure water, free from foreign substances such as vegetable 
and mineral matter, is obtained by distillation, which involves 
both vaporization and condensation. Alcohol may be sep- 
arated from fermented liquors, for example, through distilla- 
tion, because if two or more liquids are mixed together the 
more volatile will be vaporized by heat first and can be 
condensed and collected by itself. 

62. — The Dew Point. — The dew point of the atmosphere 
at given pressure is the temperature at which the water vapor 
of that atmosphere becomes saturated and begins to condense. 
For examplef, air at 64° F. temperature, 30 inches barometric 
pressure and containing 6.24 grains of moisture per cubic foot, 
when cooled to 62° F. will have reached its dew point, while 
air at the same temperature and pressure but containing 5.19 
grains of moisture per cubic foot must be cooled to 57° F. 
before its dew point is reached. 

The amount of moisture that a given volume of air can 
retain at given pressure depends on the temperature of the air. 
For example, a cubic foot of air at 64° F. temperature and 30 
inches barometric pressure can contain 6.55 grains of moisture 
before precipitation takes place, while a cubic foot of air at 60° 
F. temperature and 30 inches barometric pressure requires but 
5.75 grains of moisture to saturate it. 

63. — Humidity. — The amount of water in the air at any 
given temperature and pressure is called the absolute humidity 



*See "Solid Carbon Dioxide — A New Commercial Refrigerant," by the Dry Ice 
Corporation of America. 50 East 4_'d St., New York City. 
tCarrier Air Conditioning Co., Newark, N. J. 



92 CORK INSULATION 

of such air at that temperature and pressure. However, such 
absolute humidity cannot exceed a certain fixed value, known 
as absolute humidity at saturation, for any given temperature 
and pressure and cannot, of course, be less than zero. For 
example*, air at 64° F. temperature and 30 inches barometric 
pressure cannot have an absolute humidity of more than 6.56 
grains of moisture per cubic foot, nor less than zero, which is 
perfectly dry air containing no moisture. 

The amount of moisture in the air expressed in hundredths 
of what that air would contain were it saturated at the given 
temperature and pressure, is called relative humidity. For 
example*, air at 64° F. temperature, 30 inches barometric 
pressure and having an absolute humidity of 6.24 grains of 
moisture per cubic foot, has a relative humidity of 95 (95/lOOth 




FIG. 33.— SLING PSYCHROMETER. 

of 6.56 grains, the maximum amount of moisture such air 
would contain if completely saturated). When the relative 
humidity is low, the air is said to be dry; and when the 
relative humidity is high, the air is said to be moist. 

The relative humidity and the dew point of air are usually 
determined by the use of an instrument called a psychrometer. 
The sling psychrometer consists of a wet bulb and a dry bulb 
thermometer suitably mounted and attached to a handle so 
that they may be rotated. A wet bulb thermometer is one 
having a piece of soft cloth or wick, which is kept moist with 
water, covering its bulb ; while a dry bulb thermometer has its 
bulb exposed to the air. When the sling psychrometer is 
rotated or whirled at from 150 to 200 revolutions per minute 
(r.p.m.), evaporation takes place on the wet bulb thermome- 
ter and a depressed temperature reading is secured, and by 
means of the temperature readi 
thermometers it is possible to determine 



re readmg is secured, and by _ 
lings on the wet and dry bulb ■ 
termine the relative humidity;t « 



*Carrier Air Conditioning Co., Newark, N. J. 

tSee Appendix for "Relative Humidity Table, Percent." 



MEASUREMENT OF HEAT AND HUMIDITY 



93 



the dew point and the amount of water vapor in the air 
(absolute humidity) from psychrometric tables published by 
the United States Department of Agriculture, Weather Bureau 
Bulletin No. 235*. 

Air that is saturated has a dew point and dry bulb and 
wet bulb temperatures that are identical ; and if such air is 
cooled, the volume will be contracted and some of the moist- 
ure will be condensed. If air is but partly saturated, and the 
temperature is reduced, by removal of heat from such air, the 
dry bulb temperature falls and the wet bulb temperature falls 
until they finally reach the dew point temperature, at which 
point the air is completely saturated, 

RELATIVE HUMIDITIES IN VARIOUS CITIES. 
(U. S. Weather Reports.) 

Average Annual Humidities for Various Cities of United States. 
City 8 a. m. 8 p. m. 



Albany, N. Y. 
Asheville, N. C. 
Atlanta, Ga. 
Atlantic City, N. J. 
Augusta, Ga. 
Baltimore, Md. 
Boston, Mass. 
Hartford. Conn. 
Jacksonville, Fla. 
Key West, Fla. 
Macon, Ga. 
New Haven, Conn. 
New York, N. Y. 
Norfolk, Va. 
Philadelphia, Pa. 
Portland, Me. 
Providence, R. I. 
Savannah, Ga. 
Washington, D. C. 
Wilmington, N. C. 
Birmingham, Ala. 
Galveston, Texas 
Mobile, Ala. 
Montgomery, Ala. 
New Orleans, La. 
Pensacola, Fla. 
San Antonio, Texas 
Tampa, Fla 
Buffalo, N. Y. 
Chattanooga, Tenn. 
Chicago, 111. 



78 
85 
79 
80 
82 

n 

74 
83 
78 
83 
75 
75 
80 
74 
75 
74 
81 
76 
81 
79 
84 
84 
82 
83 
80 
81 
84 

n 

80 
78 



72 
71 
65 
79 
66 
66 
70 
68 

n 

77 

72 
62 

75 
66 
7i 
71 
75 
68 
77 
65 
78 
74 
64 
72 
75 
53 
76 
73 
63 
71 



•Address, "Superintendent of Documents, Government Printing OfKce, Washmg- 
ton, D. C." Price. 10 cents. 



94 CORK INSULATION 

RELATIVE HUMIDITIES IN VARIOUS CITIES.— Continued. 

(U. S. Weather Reports.) 

Average Annual Humidities for Various Cities of United States. 

City 8 a. m. 8 p. m. 

__ 

70 
66 
71 
71 
70 
64 
61 
67 
72 
62 
66 
71 

69 
65 
63 
62 
65 
63 
63 
65 

59 
59 
60 
61 
57 
41 
26 
50 
28 
37 
39 
45 
40 
50 
62 
63 
52 
70 
72 
67 



Cincinnati, Ohio 


76 


Cleveland, Ohio 


77 


Columbus, Ohio 


79 


Detroit, Mich. 


80 


Duiuth, Minn. 


81 


Grand Rapids, Mich. 


82 


Indianapolis, Inc. 


77 


Louisville, Ky. 


76 


Dayton, Ohio 


80 


Milwaukee, Wis. 


78 


Nashville, Tenn. 


80 


Pittsburgh, Pa. 


77 


Rochester, N. Y. 


75 


Syracuse, N. Y. 


77 


Toledo, Ohio 


79 


Davenport, Iowa 


80 


Des Moines, Iowa 


80 


Kansas City, Mo. 


77 


Memphis, Tenn. 


79 


St. Louis, Mo. 


77 


St. Paul, Minn. 


80 


Springfield, 111. 


79 


Fort Worth, Texas 


78 


Lincoln, Neb. 


79 


Oklahoma City, Okla. 


80 


Omaha, Neb. 


78 


Sioux City, Iowa 


81 


Wichita, Kan. 


78 


Denver, Colo. 


63 


El Paso, Texas 


54 


Helena, Mont. 


68 


Phoenix, Ariz. 


54 


Pueblo, Colo. 


64 


Reno, Nev. 


72 


Salt Lake City, Utah 


60 


Santa Fe, N. Mex. 


58 


Spokane, Wash. 


77 


Los Angeles, Cal. 


78 


Portland, Ore. 


86 


Sacramento, Cal. 


82 


San Diego, Cal. 


79 


San Francisco, Cal. 


87 


Seattle, Wash. 


87 



CHAPTER IX. 

TRANSFER OF HEAT. 

64. — Heat Transference. — Heat is transmitted from a region 
of higher temperature to a region of lower temperature by its 
natural and continual tendency toward temperature equilib- 
rium. When such temperature equilibrium does not exist, 
that is, when there is a temperature difference, the natural 
direction of the flow of heat is toward the lower temperature 
level. 

There are three quite distinct processes by means of which 
heat is transferred from one place to another, viz : 

1. Conduction, in which heat is conveyed by matter without any 
visible motion of the matter itself. This method of transfer is assumed 
to be accomphshed by invisible molecular motion or communication. 

2. Convection, in which heat is transferred by the visible motion 
of heated matter, as by a current of warm air or the flow of hot 
water through a pipe circuit. This method of transfer is generally 
accomplished through the fact of the unequal weights of any given 
matter at different temperatures. 

3. Radiation, in which heat is disseminated by a wave motion 
in the ether, as light is propogated, without the aid of matter. It is 
by this method that heat and light reach the earth from the sun. 

The rate of heat transfer from one region to another obvi- 
ously depends, therefore, upon the area of the transmitting 
surface, the difference in temperature levels, and a unit heat 
transfer coefficient that combines the heat that may be trans- 
mitted by conduction, convection and radiation. The actual 
magnitude of this composite heat transfer coefficient is deter- 
mined in practice by calculation based on theoretical analysis 
and experimentation. The actual amount of heat transmitted 
in any case, — being the product of this coefficient, the area, 

95 



96 



CORK INSULATION 



and the temperature difference, — may be expressed in symbols, 
thus: 

H=K A (ti— t.) 

in which H is the total heat transfer in B.t.u. per hour, K is 
the total heat transfer coefficient in B.t.u. per hour per degree 
temperature difference F., A is the area of the heat trans- 
mitting surface in square feet, and (t^—U) is the temperature 
difference in degrees Fahrenheit between the regions of high- 
est and lowest levels. 

It is evident, therefore, that if the heat transmitting area 
and the temperature levels are held constant, the heat transfer 
depends entirely upon conduction, convection and radiation. ; 




FIG 34.— TRANSFER OF HEAT BY CONDUCTION. 

65. — Conduction. — Heat transfer by conduction is accom- 
plished in a body of material by the vibration or impact of 
the molecules or particles of matter that compose the body 
itself, such molecular disturbance being produced by an unbal- 
anced thermal condition within the mass. Thus heat may be 
interchanged between different parts of the same body, or 
between two separate bodies in actual contact, by conduction ; 
but due to friction and adhesion between the molecules of a 
body, the vibration or impact of the particles of matter will 
become slower as the heat energy passes from one molecule to 
the other, and consequently the amount of heat that will be 
transmitted through the body will be something less than 
that applied to it. The amount of heat that will be trans- 
mitted through a given material, due to a given temperature 
difference, depends on the characteristic internal thermal con- 



J 



TRANSFER OF HEAT 97 

ductivity of the material, each material having its own charac- 
teristic rate of conduction. The metals are the best conduc- 
tors of heac. Wood, paper, cloth and organic substances as 
a class are poor conductors, as are pulverized or powdered 
materials, partly because of lack of continuity in the material. 

The rate of heat transfer through a homogeneous material 
having parallel sides, depends on the temperature difference, 
the kind and condition of the material, the thickness of the 
material, and its absolute temperature. The heat transmitted 
by conduction may, in general, be expressed in symbols, thus : 
C 
Hi=— A (U—U) 
X 
in which Hj is the total heat transmitted by conduction in 
B.t.u. per hour, C is the coefficient of specific internal con- 
ductivity in B.t.u. per hour per degree difference in tempera- 
ture Fahrenheit per inch of thickness of the material, X is^the 
thickness of the material in inches, A is the area Oi the trans- 
mitting surface in square feet, and (tj— tg) is the difference 
beween the high and the lov/ surface temperatures. 

Only homogeneous materials' can have a specific internal 
conductivity; and while such conductivity is known to in- 
crease slowly with rise of temperature, it usually may be 
considered as constant for such temperatures as are encoun- 
tered in cold storage work. Resistance to heat flow is the 
reciprocal of conduction; and for a given section of a com- 
pound wall the resistances, not the conductions, are additive, j 

Radial conduction in cylindrical layers of materials is 
not as easily handled as conduction through layers of materials 
having parallel sides. Using the insulated steam pipe as an 
example, the flow of heat will be relatively more rapid through 
the material near the pipe than farther out, since the area for 
the heat to pass through is increasing toward the outside. 
Thus resistances are not directly additive when considering 
radial conduction in cylinders, but the problem is capable of 
mathematical solution. 

The rate at which the temperature of a material rises 
should never be taken as an indication of its internal conduc- 
tivity; because if equal bars of iron and lead, for example, 
are placed so that one end of each is heated alike, the tern- 



98 CORK INSULATION 

perature of the other end of the lead bar will risd first to the 
point of igniting a match, even though iron is a better con- 
ductor of heat, which is accounted for by the fact that iron 
has approximately four times the specific heat of leavH and 
thus requires about four times as much heat to produce .<-he 
same change of temperature. This leads to the consideratio^n 
of conduction with changing temperature. So long as the tem,- 
perature of parts of the conducting or insulating material is 
changing, such as when a heating or cooling process is begiri- 
ning and a steady state has not been reached, the amounts .of 
heat entering and leaving the material are not the same. The 
thermal capacity, or specific heat, of the material determines 
the time required to reach a steady state. 

The thermometric conductivity of a material is th^ change 
in temperature that is produced in a unit vclurne of \|:he mate- 
rial by the heat condueted through a unit area in a unit of 
time with a unit temperature gradient. This value, which is 
entirely different from thermal conductivity, is of importance 
where protection against the effects of fire is the consideration. 

The internal thermal conductivities of various materials, 
as determined under laboratory test conditions, from experi- 
ments by the United States Bureau of Standards and others, 
are shown in the accompanying table. ( Additional'i tables 
containing full data will be found in the Article on "Tests by 
Various Authorities on Many Materials.") 

To determine the heat transmitted by conduction through 
a 4-inch sheet of corkboard, having surface temperatures of 
80° and 20° F., where t^ is 80, t^ is 20, X is 4 and C (from 
the accompanying table) is 0.308, apply such values to the 
formula, thus : 

0.308 

Hi= (80— 20) =4.62 B.t.u. per hour. 

4 

All liquids, except molten metals, are relatively poor con- 
ductors of heat, while the conductivity of gases is very small. 
However, on account of convection primarily and radiation 
secondarily, it is very difficult to determine the conductivity 
of liquids and gases. 

66. — Convection, — Convection is the transfer of heat by 
displacement of movable media, that is, the carrying of heat 



TRANSFER OF HEAT 99 

INTERNAL THERMAL CONDUCTIVITY OF VARIOUS MATERIALS. (C)* 



Description 



3.t.u. per B.t.u. per Lb. per 
24 hours hour cu. ft. 



Air 

Air Cell. K inch. 


. . Ideal air space 

.Asbestos paper and air 


4.2 


0.175 


0.08 






spaces 


11.0 


0.458 


8.80 




Air Cell. 1 inch.. 


.Asbestos paper and air 












spaces 


12.0 


0.500 


8.80 




Aluminum 


.Cast 


24.000 


1000.000 






Ammonia Vapor. 
Aqua Ammonia . 
Asbestos Mill Bd 


32° F. 


3 19 


133 


0.21 
56.50 






75.90 


3.160 




. . Pressed asbestos— not very 








20.00 


0.830 


61.00 




Asbestos Paper. . 


. Asbestos and organic bind- 








12. 


0.500 


31.0 




Asbestos Wood.. 


. Asbestos and cement 


65.0 


3.700 


123.0 




Balsa Wood 


. Very light and soft— across 












grain 


8.4 


0.350 


7.5 




Boiler Scale 




305 


12.700 






Brass 




15.000 


625 . 000 


250. 




Brick 


. Heavy 


120 


5.000 


131. 




Brick 


.Light, dry 

.Salt 


84 


3.500 


115. 




Bnne 


27.1 


1.130 


73.4 




Cabot's Quilt . . . 


. Eel grass enclosed in bur- 












lap 


7.7 


0.321 


16.0 




Calorax 


. Fluffy finely divided min- 












eral matter 


5.3 


221 


4 




Celite 


. Infusorial earth powder. . . 


7.4 


0.308 


10 6 




Cement 


. Neat Portland, dry 


150.0 


6 250 


170. 




Charcoal 


. Powdered 


10.0 


0.417 


11.8 




Charcoal 


. Flakes 


14.6 


0.613 


15 




Cinders 


. Anthracite, dry 


20.3 


0.845 


40.0 




Concrete 




125.0 


5 200 


136.0 




Concrete 


. Of fine gravel 


109.0 


4.540 


124.0 






.Of slag 


50.0 

43. 


2.080 
1.790 


94.5 

7.5 




Concrete 


. Of granulated cork 




Copper 




50.000 


2083 . 000 


556.0 




Cork 


. Granulated J4-3/16 inch. . 


8.1 


0.337 


5.3 




Cork 


.Regranulate 1/ 16- J^ inch. 


8.0 


0.333 


10 




Corkboard 


.No artificial binder — low 












density 


6.7 


279 


6.9 




Corkboard 


. No artificial binder — high 












density 


7.4 


0.308 


11.3 








7.0 
16.0 


0.292 
0.666 


'29'. 6' 




Cypress 


. Across grain 




Fibrofelt 


. Felted vegetable fibers . . . 


7.9 


0.329 


11.3 




Fire Felt Roll. . . 


. Asbestos sheet coated with 














15 
14.0 


0.625 
0.583 


43. e 
26.0 




Fire Felt Sheet.. 


. Soft, flexible asbestos sheet 




Flaxlinum 


. Felted vegetable fibers . . . 


7.9 


0.329 


11 .3 




Fullers Earth . . . 


.Argillaceous powder 


17.0 


0.708 


33.0 




Glass 




124.0 


5.160 


ISO 




Glass . . 




178.0 

600 
7.5 
62.0 
39.0 


7.420 
25.000 
0.313 
2.582 
1.630 


185.0 
166.0 
8.1 
115 
91.25 
















Gravel 






Gravel 


. Dry. fine 




Ground Cork . . . 




7.1 
54.0 

5.9 
27.0 


0.294 
2.250 
246 
1.125 


9.4 

'ii'o 

44.0 










Hair Felt 






Hard Maple .... 


. Across grain 




Ice 




408 


17.000 


57.4 




Infusorial Earth. 


. Natural blocks 


14.0 


0.583 


43.0 




Insule.x 


.Asbestos and plaster 














22.0 


0.916 


29.0 




Insulite 




7. 1 


0.296 


11.9 






.Cast 


7.740 


321.500 


450.0 




Iron 


. Wrought 


11.600 


483 . 000 


485.0 




Kapok 


.Imp. vegetable fiber — 
loosely packed 












5.7 


0.238 


0.88 




Keystone Hair . . 


.Hair felt confined with 












building paper 


6.5 


0.271 


19.0 




Limestone 


. Close grain 


368 


15.300 


185.0 




Limestone 


.Hard 


214.0 


9.330 


159.0 






E., 1926, "Principles of 


Refrigeration," Nickerson S: Coll 




•W. II. Motz, M. 


ns 


Co., Chicago. 













100 



CORK INSULATION 



INTERNAL THERMAL CONDUCTIVITY OF VARIOUS 
MATERIALS {C)—Co7itmiied. 









B.t.u. per 


B.t.u. per 


Lb. per 


Material 


Description 


24 hours 


hour 


cu. ft. 




Soft 


100.0 


4.167 


113.0 


Linofelt 


Vegetable fiber confined 








with paper 


7.2 


0.300 


11.3 


Lithboard 


Vlineral wool and vegeta 










ble fibers ... . 


9.1 
. 22.0 


0.379 
0.916 




Mahogany 


Across grain 


34 


Marble 


Hard 


. 445 


18.530 


175.0 


Marble 


Soft 


. 104 
. 6.6 


4.330 
0.275 


156 


Mineral Wool 


Medium Packed 


12.5 


Mineral Wool 


Pelted in blocks 


. 6.9 


0.288 


18.0 


Oak 


Across grain 


. 24.0 


1.000 


38.0 


Paraffin 


'Parowax," melting point 








52° C. 


. 38.0 
. 24.7 


1.582 
1.030 


56.0 


Petroleum 


55°F 


50.0 


Plaster 




. 132.0 
. 90 


5.500 
3.750 


105.0 


Plaster 


Ordinary mixed 


83.5 


Plaster 


Board 


. 73 


3.040 


75.0 


Planer Shavings. . . 


Various 


. 10.0 


0.417 


8.8 


Pulp Board 


Stifif pasteboard 

Powdered 


. 11.0 


0.458 




Pumice 


. 11.6 


0.483 


20.0 


Pure Wool 




. 5.9 
. 5.9 


0.246 
0.246 


6.9 


Pure Wool 




6.3 


Pure Wool 




. 6.3 
. 7.0 
. 16.0 


0.263 
0.292 
0.667 


5.0 


Pure Wool 




2 5 


Rice Chaff 




10.0 


Rock Cork 


Mineral wool and binder- 










rigid 


. 8.3 


0.346 


21.0 


Rubber 


Soft 


. 45 
. 16.0 


7.875 
0.667 


94.0 


Rubber 


Hard, vulc 


59.0 


Sand 


River, fine, normal 


. 188,0 


7.830 


102.0 


Sand 


Dried by heating 


. 54.0 


2.250 


95.0 






. 265 


11.100 


138.0 


Sawdust 


Dry 


. 12.0 


0.500 


13.4 


Sawdust 


Drdinary 


. 25.0 


1.040 


16.0 


Shavings 


3rdinary 


. 17.0 


0.707 


8.0 






. 14 

. 18.0 


0.583 
0.750 


8.55 


Slag Wool 




15.0 






. 75 
. 17.0 


3.130 
0.707 




Tar Roofing 




55.0 


Vacuum 


Silvered vacuum jacket. . 


0.1 


0.004 




Virginia Pine 


Across grain 


. 23.0 


0.958 


34.0 


Water 


Still, 32° F 


. 100 


4.166 


62.4 


White Pine 


Across grain 


. 19.0 


0.791 


32.0 


Wool Felt 


Flexible paper stock .... 


. 8.7 


0.363 


21.0 



from one point or object to another by means of an outside 
agent, such as air or water, or any moving gas or fluid. The 
phenomenon is due to the fact that, in general, Uquids and 
gases are lighter when warm than when cold. Land and sea 
breezes, trade winds and ocean currents carry great quantities 
of heat from one place on the earth to another; while the 
heating of buildings by hot water circulating through pipes, 
or by hot air furnaces, is another familiar application of 
convection currents. 

It is, at best, a complicated process to attempt to calculate 
heat transfer by convection, because there are so many factors 
involved that are incapable of accurate determination. Per- 



TRANSFER OF HEAT 



101 



haps the most important of these pertains to the conditions 
that exist between the conducting solid material and the gas 
or liquid in contact in which convection occurs. The resist- 
ance to heat transfer at the surface of a solid when in contact 
with a gas or liquid is known to be important, but its nature 
and extent is not generally understood. 

(^ Fluids, in general, conduct heat less rapidly than is com- 
monly supposed, the difficulty of considering their heat con- 
chiction separate from their heat convection probably account- 



In- 
side 
Cold 




FIG. 35.— TRANSFER OF HEAT BY CONVECTION. 

ling for this misconception. The fact is important, however, 
in the consideration of the surface or contact thermal resist- 
ance between solids and fluids ; because the finite layer of 
fluid in actual contact with a soHd is always at rest, and a 
finite thickness next adjacent is moving very slowly. The 
resistance of this stagnant layer of fluid, through relatively low 
conduction, is responsible for the surface resistance to heat 
transfer; and such surface resistance in any example must 
be dependent upon the actual conditions of the case. 

The transfer of heat by evaporation and condensation is 



102 CORK INSULATION 

usually classed as convection, although in several respects it 
differs widely from convection as just discussed. In ordinary 
convection, it has been noted that the surface layer of fluid 
plays an important part; but in the steam boiler the finite 
layer of water next the hot boiler wall is heated and vaporized, 
thus absorbing a very large amount of heat. Such steam is 
instantly replaced by other water and the process is continued, 
a procedure distinctly different from the usual convective 
heating process and one in which the rate of heat transfer is 
much higher. By drainage, on the condenser end of the 
system, the film of condensed water is quickly removed, 
which differs from the usual transfer by convection. 

The transfer of heat by evaporation and condensation has 
a definite bearing on the effect of moisture in insulating 
materials and in air-space construction. 

Thus, in general, the rate of heat transfer by convection 
is dependent on the kind of fluid in contact, the temperature 
differences, the velocity of the convecting fluid, the character 
of surfaces (such as shape and roughness), and the area of 
the surface. 

67. — Radiation.— Radiation is the mode of transfer of heat, 
for example, from the sun to the earth, which is accomplished 
even though the intervening space is entirely devoid of ordi- 
nary matter. The transfer of heat by radiation is effected by 
wave motion exactly similar in general character to the wave 
motion that constitutes light, these waves being transmitted 
by a medium, known as ether, that fills all space, although, 
contrary to popular belief, considerable obstruction is offered 
to the passage of these waves. 

The molecular disturbance in a hot body produces a com- 
motion in the immediate adjacent ether, which spreads out in 
all directions as an ether wave disturbance, and when these 
waves impinge on a cool body they produce a molecular dis- 
turbance in it. In a word, the heat energy of a hot body is 
constantly passing into space as radiant energy in the luminif- 
erous ether, and becomes heat energy again only when and as 
it is absorbed by bodies upon which it falls ; and energy trans- 
mitted in this way is referred to as radiant heat, although it is 
transmitted as radiant energy and is transferred again into 



TRANSFER OF HEAT 



103 



heat only by absorption. Radiant heat and light are phys- 
ically identical, but are perceived through different avenues of 
sensation; radiations that produce sight when received through 
the eye, give a sensation of warmth through the nerves of 
touch. The sensation of warmth felt in bright sunlight on a 
cool day is a good illustration of this phenomenon. 




FIG. 36.— TRANSFER OF HEAT BY RADIATION— 
THE RADIOMETER. 

The rate of heat transfer by radiation depends on the 
characters of both the hot radiating and the cold receiving 
surfaces (the reflecting power of the hot surface and the 
absorbing power of the cold surface), the temperature differ- 
ences, the relative absolute temperatures, and the distance 
between surfaces. 

The blacker an object the more heat it will, in general, 



104 CORK INSULATION 

lose by radiation ; non-metals radiate heat at a much more 
rapid rate than metals of similar surface ; and rough surfaces 
radiate heat at a more rapid rate than smooth, polished sur- 
faces. Thus stoves and radiators* intended to give out heat 
should present a non-metal surface, the color and relative 
degree of smoothness being of lesser importance. Metal cook- 
ing utensils should be tinned or nickeled in order to radiate as 
little heat as possible. A brightly tinned hot air furnace pipe 
may lose less heat by radiation than when covered with thin 
asbestos paper, because the surface of the non-metallic asbes- 
tos paper radiates heat more rapidly than the bright tin. 

The heat radiated to a body may be partly rejected, ab- 
sorbed, or transmitted through the body. The capacity of a 
surface to absorb radiant energy depends both on the lack of 
polish of the surface and the nature of the material. Lamp- 
black is the best absorber of radiant energy and polished brass 
is the poorest. In cold climates dark clothes are worn because 
they absorb and transmit the greatest proportion of radiant 
energy, while in hot climates white clothes are preferred 
because they reject radiant energy to the maximum extent. 
) Tt has been noted that if no heat is supplied or taken away, 
' aTT surfaces in an enclosure come to the same temperature ; 
the rate, however, at which this equalization takes place de- 
pends on the radiating and the reflecting powers of such 
surfaces. Thus the temperature of a surface may be higher 
than the air adjacent to it. A wall in direct sunlight is often 
a good many degrees warmer than the atmosphere, which 
fact is important in the consideration of insulation for build- 
ings since the temperature of the outside wall surface — not 
that of the air — helps determine the heat leakage. 

The Stefan-Baltzmann radiation law for calculating heat 
losses is as follows: 

H2=R A h (T^y—iT^y 
where Hj is the total heat radiated in a given time in B.t.u., 
R is a constant (see accompanying table for values for various 
radiating materials), A is the area of the radiating surface 
in square feet, h is the time in hours, Tj is the higher tem- 

*It must be remembered that heat is transferred by conduction, convection and 
radiation, — not by radiation alone, — and that heat transfer by radiation is spoken of 
here, which is of secondary importance to the total heat transfer. 



TRANSFER OF HEAT 105 

perature absolute in degrees F. and T2 is the lower tempera- 
ture absolute in degrees F. (Absolute temperature is 460 
degrees below zero F., or 273 degrees below zero C.) If large 
temperature differences are not involved, then use the for- 
mula : 

H^=R A h (T)* 

where T is the absolute temperature in degrees F. 

TABLE OF STEFAN-BALTZMANN CONSTANTS (R). 

Material Constant (R) 

Lampblack 0.900 

Smooth glass 0. 1 54 

Dull brass 0.0362 

Dull steel plate 0.338 

Slightly polished copper 0.0278 

Dull oxidized wrought iron 0. 1 54 

Clean, bright wrought iron 0.0562 

Highly polished wrought iron 0.0467 

Polished aluminum plate 0.053 

Water 0.112 

Ice 0.106 

^68. — Flow of Heat. — Generally the transfer of heat takes 

place by all three processes — condviction, convection and radi- 
ation — simultaneously. Thus heat is distributed throughout 
a room from a hot stove or furnace partly by radiation, prin- 
cipally by convection currents of air and to a slight extent 
by conduction. Such a body is said to emit* heat, and the 
rate at which a body emits heat depends upon its excess of 
temperature above its surroundings, upon the extent and char- 
acter of the body and its surface, upon the nature of the 
surrounding gas or liquid, upon the freedom of motion of the 
surrounding fluid, and upon the nature of surrounding bodies. 
Thus it is evident that many variables enter into the 
determination of heat transfer by radiation and by convection. 
Reliable experimental information is lacking, because it is 
very difficult to ascertain the exact effect of each. However, 
the engineer is concerned primarily with the combined trans- 
ference of heat by conduction, convection and radiation. The 
heat transferred by convection and radiation may be deter- 
mined by experimentation. The combined coefficient, or rate, 
of this heat transfer by convection and radiation is the heat 
given off or absorbed per square foot of surface, per hour, per 
degree of temperature difference F. In the case of cold stor- 

*This term is variously used to indicate the emission of heat by a body by radia- 
tion only, by radiation and convection, and by all three methods combined. 



106 CORK INSULATION 

age wall insulation, this temperature difference would be the 
difference between the temperature of the surface of the wall 
and the average temperature of the surrounding air ; while 
the velocity of the air across the surface of such wall must 
affect the coefficient, or rate, of heat transfer by convection 
and radiation. 

The values for the coefficient of convection and radiation 
for various materials undeY still air conditions are given in the 
accompanying table, and are based upon experiments made at 
the Engineering Experiment Station of the University of 
Illinois. 

This coefficient is generally denoted by the symbol K^, 
and is called the coefficient of radiation and convection for 
inside surfaces. In an actual plant, the outside walls are 
exposed to the more rapid movement of the air, so that the 
coefficient of radiation and convection is larger for the outside 
surfaces. The symbol for this coefficient is Kg, and it is, in 
general, 2.5 to 3 times the inside wall coefficient K^, due to 
the greater velocity of the outside air. Thus, as a general 
rule, the value of the outside coefficient, Kj, may be con- 
sidered to be three times the inside coefficient, K^. 

COEFFICIENTS OF RADIATION AND CONVECTION (Kl) IN B.t.u. PER 
HOUR PER DEGREE TEMPERATURE DIFFERENCE F. 

Material Coefficient Ki 

Brick wall 1.40 

Concrete 1.30 

Wood 1.40 

Corkboard 1.25 

Magnesia board 1.45 

Glass 2.00 

Tile plastered on both sides 1.10 

Asbestos board 1.60 

Sheet asbestos 1.40 

Roofing 1.25 

69. — Total Heat Transfer. — In its simplest form, total heat 
transfer is the heat passing into, through and out of a single 
wall of given area. If the surface temperatures and the 
temperatures in the surrounding air are taken, the total heat 
transmission may be separated into internal and external con- 
ductivity, the external conductivity being sometimes called 
"surface effects." In the case of a good insulator, as used for 
cald storage rooms, internal conduction is the essential factor; 
while in the case of a poor insulator, as the metal in a boiler 
tube, good conduction is necessary and surface transmission 



TRANSFER OF HEAT 



107 



is all-important. Between these extreme conditions, the rela- 
tive importance of conduction and surface transmission (con- 
vection and radiation) varies with each case considered. In 
determining the total transmission of three-inch corkboard 
insulation in still air, an error of about ten per cent is intro- 
duced if the surface effects on both sides are disregarded ; 
while in the case of a single thickness of brick, the resistance 



Ou-t 




> ±, 



Kz 



c-X--? 



± 




COLD 


± 




-t 










FIG. 37,— HEAT TRANSFER THROUGH A WALL. 



to the flow of heat of the two surfaces is about eight times 
the internal resistance of the brick. In general, the better the 
substance as an insulator, the less is the error due to dis- 
regarding surface effects. 

It has been observed that heat may be transmitted from a 
region of high temperature through a wall into a region of 
lower temperature by means of conduction, convection and 
radiation. The accompanying figure shows graphically the 
transfer of heat from the outside through a wall to the inside. 



108 CORK INSULATION 

It will be seen that the heat passes by convection and radia- 
tion from the surface of a warm body at to degrees F. to the 
outside surface of the wall, where it is absorbed by that 
surface, conducted through the wall and then given off by the 
inside surface of the wall by means of convection and radia- 
tion to the surface of the cold body at t degrees F. 

The heat is conducted through the wall, due to the tem- 
perature difference between the outside and the inside sur- 
faces of the wall, the temperature at the outside surface being 
noted as t^ and the temperature at the inside surface as tg. 
The amount of heat conducted through this wall, as previously 
mentioned, would depend on the internal thermal conduc- 
tivity (C) and the thickness of the wall (X). Since heat is 
conducted through the wall because of temperature differ- 
ences at the surfaces of the wall, it is proper to say that this 
temperature difference exists within very thin layers of air 
at such surfaces. On the outside of the wall in the figure, 
this is represented by the difference between the tempera- 
ture of the outside air, to, and the temperature at the outside 
surface, t^, and on the inside this is represented by the differ- 
ence between the temperature of the inside surface, tj, and 
the temperature of the inside air, t. 

The total amount of heat passing from the warm body 
on the outside to the cold body on the inside depends on the 
combined conduction, convection and radiation effects. The 
quantity of heat transferred from the outside air to the wall 
depends on the coefficient of the combined radiation and 
convection, K^, sometimes called the surface coefficient, and 
the temperature of the outside air, to, and the temperature at 
the outside surface, t^. The heat given off by the inside sur- 
face of the wall to the inside air will depend on the coefficient 
of the combined radiation and convection for such inside 
surface, K^, and the temperature of the inside surface, t^, 
and the temperature of the inside air, t. 

Thus, the total heat transmission from the surface of the 
outside hot body to the surface of the inside cold body will 
depend on the combined heat transfer coefficient, K, and the 
temperature of the outside air, to, and the temperature of the 



TRANSFER OF HEAT 109 

inside air, t. From this analysis, the value of the unit total 
heat transfer coefficient, K, may be expressed as follows: 

1 
K= 



1 X 1 
K, C K^ 



From til is formula, it will be noted that the unit total heat 
transfer coefficient, K, in B.t.u. per hour, per degree tempera- 
ture difference F., for a given wall, depends on the combined 
convection and radiation coefficient for the inside and outside 
surfaces, K^ and K,, respectively, the thickness of the waW, 
X, and the internal conductivity of the material, C. The 
values of the conductivity, C, for various materials and the 
values of the coefficients of the combined inside convection 
and radiation, K^, are given in the accompanying tables. 
The values of K2, in general, may be taken as three times K^. 
In the case of a solid wall made up of layers of different 
materials, in intimate contact, having different conductivities, 
Ci, Co, C3, etc., of various thicknesses, X^, Xo, X3, etc., re- 
spectively, the foregoing formula becomes : 



K=: 



Suppose it is desired to determine how much heat per 
hour is transmitted through an outside heavy brick wall 18 
inches thick, 20 feet high, and 25 feet long, when the outside 
temperature is 80° F. and the inside temperature is 20° F. From 
the tables, C equals 5, K^ equals 1.4, and K2 equals three times 
1.4, or 4.2. Thus the heat transmission coefficient is found as 
follows : 



1 


Xt 


X, 

-^ — 
C2 


Xs 

-H — 
C3 


-+etc 


■h 


1 



1 

K= =0.2196 

1 



— i - [ — 
1.4 1 5 J 4.2 



The area. A, is equal to 20x25, or 500 square feet, and t^ 
equals 80° F, and t^ equals 20° F, The total heat transfer is 
therefore : 



110 CORK INSULATION 

H=K A (.U—U) 
r=0.2196X500X(80°-20°) 
=:6588 B.t.u. per hour. 

Suppose it is desired to determine the heat transmission of 
a similar brick wall of equal thickness insulated with 4 inches 
of corkboard applied directly to the wall in ^-inch Portland 
cement mortar and finished with Portland cement plaster 
J^-inch thick. From the table, K^ (for plastered surface) 
equals 1.1, C^ equals 5, X^ equals 18, Co equals 0.308, X2 equals 
4, C3 (for 1-inch thick Portland cement) equals 6.25, X3 equals 
1, and Ko equals 4.2. Thus the heat transmission coefficient 
for this composite wall is found as follows : 

1 

K= 1=0.05588 

1 f 18 4 ill 

1.10 L 5 .308 6.25 J 4.2 

The total heat transfer is therefore : 

H=K A (ti— ti) 
=0.05S88X500X(80°-20'') 
= 1676.4 B.t.u. per hour. 

Suppose it is desired to determine the heat transmission 
of a similar brick wall of equal thickness insulated with four 
2-inch air spaces formed by four double layers of 1-inch white 
pine. From the tables, K^ (for inside brick) equals 1.4, K^' (for 
each of 8 inside surfaces of wood) equals 1.4, C^ (for brick) 
equals 5, X^ (for brick) equals 18, Cg (for white pine) equals 
0.791, X2 (8 layers wood) equals 8, K, (for outside brick) 
equals 4.2. The value of K is then as follows : 

1 
K= =0.04906 



L 1.4 J L 5 0.791 J 4.2 



1.4 

The total heat transfer is therefore 

H=K A (ti— t.) 
=0.04906X500X (80^-20°) 
= 1471.8 B.t.u. per hour. 

It will be noticed at once that an 18-inch brick wall in- 
sulated with four 2-inch air spaces formed by four double layers 
of 1-inch white pine shows, by this method of computation, a 



I 



TRANSFER OF HEAT 111 

lower total heat transfer than a similar brick wall insulated 
with 4 inches of corkboard. Experience teaches that the fig- 
ures just shown are not accurate and the same problem is 
solved by a different method in the next Article. 

70. — Air Spaces. — It should be especially noted here that 
a high vacuum is necessary to appreciably lower the normal 
rate of heat transfer by convection across air spaces, and that 
such rate increases very appreciably as the temperature dif- 
ferences increase. Also, that the amount of heat passing 
across an air space by radiation is very much enlarged when 
there is a large temperature difference between radiating and 
receiving surfaces, for it will be remembered that the rate of 
heat transfer by radiation is proportional to the difference 
between the fourth powers of the absolute temperatures of 
the surfaces involved, subject only to correction for losses due 
to imperfections in radiating and absorbing surfaces. 

The United States Bureau of Standards, in the accompany- 
ing table, gives some interesting and valuable data on the 
heat conduction of air spaces, in which X is the width of the 
air spaces in inches and C is the heat conductivity in B.t.u. 
per square foot, per degree difference F., per inch thickness, 
per hour, from which table it should be especially noted that 
the thermal conductivity of air spaces is not proportional to 
the thickness of the spaces. 

THERMAL CONDUCTIVITY OF AIR SPACES (C) IN B.t.u. PER HOUR, 
PER DEGREE DIFFERENCE F., PER INCH THICKNESS. 
Thickness (X) Conductivity (C) 

^-inch . 0.2625 

j4-inch 0.3375 

H-inch 0.4083 

^-inch 0.4833 

f^-inch 0.5667 

^-inch 0.6833 

^-inch 0.8333 

l-inch 0.91 67 

2-inch 1-7917 

3-inch 2.5833 

The determination of the heat transmission of an 18-inch 
brick wall insulated with four 2-inch air spaces formed by four 
double layers of 1-inch white pine, based on the thermal conduc- 
tivities of air spaces as determined by the Bureau of Stand- 
ards, becomes a different problem from that presented in the 
preceding Article. From the tables, K^ (for inside wood) 
equals 1.4, C^ (for brick) equals 5, C^ (for 2-inch air space) 



112 CORK INSULATION 

equals 17917, C3 (for white pine) equals 0.791, X^ equals 18, 
X2 equals 4, X3 equals 8 and Kg equals 4.2. The value of 
K is then as follows : 

1 
K= =0.05915 

1 J 18 4 8 1 1 

TJ 1 5 1.7917 0.791 J 4.2 
The total heat transfer is therefore : 



H=K A iU—U) 
=0.05915X500X(80°— 20°) 
= 1774.5 B.t.ii. per hour. 

71. — Heat Transfer by Conduction Only.-^It will be noted 
that the heat that passes through an insulated wall depends 
mostly upon the internal thermal conductivity of the mate- 
rials that compose the wall, and that the resistance to the 
flow of heat at the surface (convection and radiation) but 
slightly reduces the total heat transfer. This may be seen 
by calculation from the example of the 18-inch brick wall 
insulated with 4 inches of corkboard, as follows : 

1 

K= =0.0597 

18 4 1 

5 .308 6.25 

The heat transfer (by conduction only) is therefore: 

_ : ■; 1?'.H=K A (ti— tz) 

=0.0597x500X(80°-20°) 
= 1791 B.t.u. per hour. 

Thus It is seen that the increase in heat flow in this 
example due to neglecting the surface effects is but 6.8%, 
under the normal conditions assumed ; and for practical pur- 
poses, in connection with the computation of refrigeration 
losses due to heat leakage, the following formula is followed : 
A (t.-t=) 



I 

I 



H: 



Xi X2 X3 

Ci C: C3 



The internal heat conductivities available for the deter- 
mination of heat losses by calculation were, for the most 
part, secured under favorable conditions, in testing labora- 



TRANSFER OF HEAT 113 

tories; and much practical experience with cold storage in- 
sulation and refrigeration teaches that the results obtained 
by computation are about 25% lower than is safe to expect 
in actual service under plant working conditions. 

72. — Heat Loss Through Insulation. — The internal con- 
ductivity of various insulating materials depends, in general, 
upon the structure and density of the material ; and since 
the conductivity of still air is very low, probably because of 
the very loose arrangement of the molecules, then a material 
containing a large percentage of "dead air" will transfer a 




FIG. 3S.— CORK UNDER POWERFUL MICROSCOPE, SHOWING SEALED AIR 
CELL CONSTRUCTION. 

minimum amount of heat. But to keep air still, to keep it 
from circulating, even when it is confined, is difficult, espe- 
cially when it is recalled that heat applied to the surface of 
one side of a compartment containing air will warm up that 
surface, the heat will be transmitted in more or less degree 
through the wall to the air on the inside, it will be taken up 
by the particles of air in contact therewith, and warm air 
being at once lighter than cold air it will rise and be replaced 
by cold air. Thus the heat is quickly and effectively car- 
ried across the air space to the wall on the other side, by 



114 CORK INSULATION 

convection, and by conduction passes through the opposite 
wall to the space beyond. 

An automobile can attain a greater speed on a two mile 
track than it can attain on a quarter mile track. Similarly, 
air can attain a greater velocity in a large space than it 
can in a small one. Thus this principle is one of the two 
main guides in the selection of an efficient insulating material. 
First, the material must contain air in the very smallest pos- 
sible units, such as atoms, so that convection is reduced to 
a minimum ; and since these atoms of air must each be con- 
fined, a material must be selected that is very light and of 
little density so that conduction is also reduced to a mini- 
mum. Secondly, such material must at the same time be 
impervious to moisture, so that its initial ability to retard 
heat will prevail in service. Such a material will be as effi- 
cient from the standpoint of heat transfer as it is possible 
to obtain ; that is, a very light material containing myriads 
of microscopic air cells, each cell sealed unto itself. A mate- 
rial of such character is cork, the outer bark of the cork oak tree, 
native of the Mediterranean basin. 



CHAPTER X. 

DETERMINATION OF THE HEAT CONDUCTIVITY 
OF VARIOUS MATERIALS.* 

73. — Methods Employed. — It is a complicated as well as 
an expensive procedure to determine with any degree of 
accuracy the heat conductivity of given materials. f In spite 
of this fact, a great many experiments and tests have been 
made over a period of many years ; but in the absence of 
any standard in apparatus or uniformity of procedure, the 
results have varied so much as often to be of no real value 
whatever. 

Most common of the test methods employed are : 

(a) Ice-box Method. 

(b) Oil-box Method. 

(c) Hot-air-box Method. 

(d) Cold-air-box Method. 

(e) Flat-plate (or Hot-plate) Method. 

74. — The Ice-box Method. — The most common of all 
methods of comparing the heat insulating value of two mate- 
rials has been by the use of two identical cubical metal boxes 
covered with the materials to be tested, each filled with ice, 
and observing the rate at which the ice melts. Since it is 
difficult to keep the entire box at 32° F., even though con- 
taining ice, this method may lead to inaccurate results even 
as a comparatk'c test of two materials. As a method of test- 
ing any one material, it is far too unreliable to be of any 
practical value whatever. 

75. — The Oil-box Method. — The oil-box method of com- 
parative testing consists in covering two identical cubical 



*For a comprehensive treatment of heat transmission, consult "Heat Transmis- 
sion of Insulating Materials," in eleven parts, published by The American Society 
of Refrigerating Engineers, 37 W. 39th St., New York City. Price, $2.50. 

fFor a comprehensive treatment of methods to be employed in testing insulating 
materials, consult "An Investigation of Certain Methods for Testing Heat Insulators," 
by E. F. Grundhofer, The Pennsylvania State College Engineering Experiment Station 
Bulletin No. 33. Price, 25 cents. Address: State College, Pa. 

115 



116 



CORK INSULATION 



metal boxes with the materials to be tested, each filled with 
mineral oil and the oil surrounding an electrical heater and 
an agitator. By varying the heat supplied, any desired dif- 
ference in temperature may be maintained between the con- 
tents of the boxes and the surrounding air of the room. By 
measuring the electrical input by ammeters and voltmeters, 
the amount of heat lost through the respective materials under 
test can be determined by calculation. Inaccuracies occur 
due to uncertainty of the temperature at the top of the box 
and loss of heat through agitator rod, box supports, evap- 
oration of oil and conduction through overflow pipe. For 



I 




J 



FIG. 39.— THE ICE-BOX METHOD OF TESTING HEAT TRANSMISSION'. 



the comparative testing of two materials of equal thickness, 
the results are reasonably accurate; but as a method of test- 
ing any one material the results will usually be too high, and 
unreliable. 

76. — The Hot-air-box Method. — The hot-air-box method 
of testing consists of a cubical box constructed wholly of the ; 
material to be tested, with only such light wooden reinforcing 
as may be required for strength or rigidity. Inside the box 
is placed an electrical heater and an electrical fan, which per- 
mits of a uniform box temperature maintained at any desired 
temperature difference between the air in the box and the 
surrounding outside air. By measuring the electrical input, 
the amount of heat lost through the material under test can 
be determined b}' calculation, as in the case of the oil-box 



I 



HEAT CONDUCTIVITY 



117 



method, but the inaccuracies are reduced, by comparison, to 
the loss of heat through the box supports, and are corre- 
spondingl}^ more reliable. This method of testing has con- 




FIG. 40.— THE OIL-BOX METHOD OF TESTING HEAT TRANSMISSION. 

siderable merit, and can be used with fairly good results as 
a method of testing any one material alone. 

77. — The Cold-air-box Method. — The cold-air-box method 

t T 

I 




1\. rzj .„ 



FIG. 41.— THE HOT-AIR-BOX METHOD OF TESTING HEAT TRANSMISSION. 

of testing consists in the substituting for the heater and the 
fan in the hot-air-box method, a container of cracked ice sus- 
pended inside the cubical test box near the top. The air in 



118 



CORK INSULATION 



the test box will be maintained at a lower temperature than 
the outside room, and since the amount of heat required to 
melt one pound of ice is definitely known, the amount of 
heat lost through the walls of the test box may be determined 
by weighing the water resulting from the melting of ice and 
carried outside of the box through a small rubber tube. 

The results are reasonably reliable since the suspended 
container of cracked ice sets up a natural circulation of air 
within the test box and keeps it at a very nearly uniform 
temperature. 




FIG. 42.— THE COLD-AIR-BOX METHOD OF TESTING HEAT 
TRANSMISSION. 

78.— The Hot-plate Method.— The hot-plate method has! 
probably been most widely used by investigators, including! 
the United States Bureau of Standards, to determine the| 
relative conductivity of insulating materials. The inaccura- 
cies in this method, for absolute conductivity determination, 
lie in the determination of the heat loss from the edges, which 
is ordinarily considerable, and the uncertainty of the contact 
between the material and the plates. 

The method consists of an electrically heated plate placed 
between two sheets of the material to be tested, and outside 
of these sheets are placed two hollow plates cooled by circu- 
lating water. By measuring the electrical input, the amount 
of heat lost through the insulating materials can be deter- 
mined by calculation. The temperature difference between 



I 



HEAT CONDUCTIVITY 



119 



the hot and the water-cooled plates is measured by thermal 
junctions. Knowing these factors, also the area and the 
thickness, the relative conductivity of the materials under test 
may be computed with precision. 

An instrument of this general character, which shows re- 
finements over previous apparatus, has lately been designed 
and constructed. The hot plate consists of two 5^-inch cop- 
per plates 12 inches square, between which are the heating 




FIG. 43.— THE HOT-PLATE METHOD OF TESTING HEAT TRANSMISSION- 
GENERAL VIEW OF THERMAL CONDUCTIVITY APPARATUS, 8-IN. 
SQUARE. 



coils consisting of nichrome resistance ribbon wound with 
even spacing on a slate core and insulated from the copper 
plates by two sheets of mica bond, /n order to minimize the 
loss of heat from the edges of the hot plate, each copper plate 
is divided into an inner test area 8x8 inches and an outer 
guard ring. A compensating winding for furnishing auxiliary 
current is wound around the outer edges of the plate, to 
prevent the lateral flow of heat from the inner test area to 
the outer guard ring, a 1/16-inch air space being left between 



120 



CORK INSULATION 



the areas and the areas being held in place by four pieces 
of Advance wire soldered to the copper plates. 

By the use of a galvanometer, the inner area and the 
outer guard ring are kept at the same temperature, this con- 
dition being indicated by a zero reading, and under which 
condition it is assumed that no heat flows from the 8x8 inch 



I MAM 






/ / / ^ o^/ 



- EDGE INSULATION 



■TBsrs/ifiPLes 



FIG. 44.— DIAGRAMMATIC SKETCH OF APPARATUS FOR THE PLATE 

METHOD OF MEASURING THE THERMAL CONDUCTIVITY OF 

MATERIALS. 

inner portion of the test area to the outer portion of the 
test area or guard ring. 

Direct current from a generating set is supplied to the 
main heating grid and also to the auxiliary guard ring cir- 
cuit; and to prevent any variation in current due to voltage 
fluctuation, a ballast tube, similar to that used with radio sets, 
is placed in the main line and automatically keeps the current 
constant to the main heating grid. 



HEAT CONDUCTIVITY 



121 




FIG. 45.— DETAILS OF HEATING PLATE FOR THERMAL CONDUCTIVITY 

APPARATUS. 
(A) Copper plates. (B) Micanite insulation. (C) Fibre board — main heater. (D) 
Fibre board — edge heater. (E) Constantan ribbon 1-16-in. No. 36. (F) Brazed 
joints. (G) Steel pins for suspension. (H) Copper leads to main heater. (J) 
Brass screws. (K) Copper leads to edge heater. 




Gua^<(R."J Heirr^jCo'l 



Haii Htar,„j Ctil 



FIG. -46.— ARRANGEMENT OF ELECTRICAL CONNECTIONS TO THERMO- 
JUNCTIONS. 



122 CORK INSULATION 

79. — Tests by Various Authorities on Many Materials. — 

Probably the most comprehensive and the most widely ac- 
cepted data* on the rate of heat flow through most of the 
materials with which an engineer has to deal is given in 
"Results of Tests to Determine Heat Conductivity of Various 
Insulating Materials," by Charles H. Herter,t being the ninth 
section of the "Report of Insulation Committee" of the Amer- 
ican Society of Refrigerating Engineers, published in the Jan- 
uary, 1924, number of "Refrigerating Engineering." The com- 
plete "Report of Insulation Committee," in eleven sections, 
is now available in data pamphlet form from the American 
Society of Refrigerating Engineers, New York City (Price, 
$2.50). 

In his report, Mr. Herter says, in part: 

The original program merely called for a "Summary of Test 
Results," with a tabulation giving but one recommended average 
value for materials such as cork, wood, asbestos, brick, stone, etc. 
When, however, in the course of compiling it was found that each 
material occurs in many varieties with correspondingly differing heat 
resistances, it was thought best to tabulate all values conveniently 
available and to let the reader select the value applying to his mate- 
rial. As explained in detail further on, a close approximation to the 
correct value can be obtained from the attached tables if care is 
exercised to ascertain the important properties of one's material, such 
as density, moisture content, mean temperature exposed to, and 
perhaps the relative size of grains. If these characteristics are alike 
in diflferent articles, their resistance to heat also will lie practically 
alike. 

In most of the older textbooks but one value appears for each 
material, and since no specification is given, and fabricated materials 
are continually being changed in composition, old and indefinite 
values are liable to be misleading. All vague results are intended to 
be excluded from these tables, and the opinion is held that such 
values properly qualified as to density and temperature are more 
trustworthy than those identified merely by name 

Reasons for Method of Classification. 

To facilitate the finding of the heat conductivity value for any 
material it was first suggested to arrange the tables in alphabetical 
order. Since, however, many materials have several designations, 
and in many cases a suitable insulator is sought and not a specific 
product, it was concluded to arrange all values in four groups and 



*See Appendix for "Heat Transmission : A National Research Council Project.' 
tRefrigerating Engineer, New York City. 



HEAT CONDUCTIVITY 123 

to enumerate the items approximately in the order of their insulat- 
ing value, the material with lowest rate of conduction coming first. 
Thus, a glance at a table discloses at once the relative heat resist- 
ance of any material listed, and over how large a range it extends 
due to natural variations in physical condition such as density and 
moisture content. The influence of temperature level is also evi- 
dent from the tables. 

Another important advantage gained by the group method is 
that a comparison can readily be made of similar materials tested in 
various parts of the world. The fact that the results thus obtained 
with similar materials by widely separated experimenters are usually 
in good accord, tends to prove that the values found are correct 
and have been verified. This knowledge forms a good basis for 
estimating the heat insulating quality of some new material which 
may not be listed in these tables 

Results of Tests. 

All the values given are derived from tests. In every instance 
the authority for the result given is indicated in column 10 of the 
tables 

In the past many materials were tested in such a way that the 
resistance at the surfaces, that is the temperature drop caused by the 
inability of the surrounding air to take up heat rapidly enough, was 
included in the insulating power per inch thickness of the material. 
As explained in another section of this report, the proper basis for 
comparing the heat insulating value of materials employed in thick- 
nesses exceeding those of gla*s and paper is their internal conduc- 
tivity. Accordingly, these are the values included in the attached 
tables, and this explains why the results of some widely advertised 
tests could not be included 

Explanation of Tables. 

For simplicity and to prevent error in using these tables, they 
have been given identical arrangement. Each table has 10 columns, 
numbered. 
I Column 1 contains name and particulars of material in question. 

Columns 2 and 3 give the density in two ways, by specific gravity 
or ratio of weight of material to the weight of an equal volume of 
water. In other words, the specific gravity of water is established at 
1, and its weight is figured at 62.35 lb. per cu. ft., while in column 
3 the apparent weight of the insulator as derived from its bulk, is 
given in lb. per cu. ft. 

Density. 

One of the first things to be done in trying to place insulation 
engineering on a scientific basis is to emphasize the importance of 
density. Frequently it is not advantageous for a manufacturer to 
discuss density; first, because it is difficult for him to keep within 



124 CORK INSULATION 

a narrow limit, nature's products not always being uniform; second, 
because moisture absorption from the atmosphere may change it 
against his will, and third, a rival may claim to make an equivalent 
material of a lower density, which, as is well illustrated in Table 
II, (Mineral Matter) would be likely to yield a better insulating effect. 
Thus, in Table II the heat conductivity of the heaviest American 
corkboard listed (15.6 per cu. ft.) is 0.3513 B.t.u. per hour against 
0.2693 B.t.u. for the 6.9 lb. variety. Incidentally, it should be borne 
in mind that the structural strength of porous material diminishes as 
its density is lowered. 

A light variety of corkboard may be a good insulator, and less 
expensive to make because it contains less cork and more air, but 
the delicate product requires great care in shipping and handling, it 
is weaker and, unless specially treated, it will offer less resistance to 
air and moisture penetration. In view of these facts, it is customary 
to employ for moulded cork pipe covering a quality of pure com- 
pressed cork varying in density from 20.5 lb. per cu. ft. ("ice water 
thickness," 1-in. pipe) to 15.5 lb. per cu. ft. ("special thick brine cov- 
ering" for 6-in. pipe) while the weight of American commercial pure 
corkboard now (1923) varies from 10 lb. per cu. ft. in one-inch 
thick boards to 8 lb. per cu. ft. in 6 in. thick slabs. 

Frequently thin boards are obtained by sawing up thick slabs, and 
so the only way to determine the true density is to weigh the 
boards used 

These variations in density involve of course variations in con- 
ductivity. 

A good example of the value of comparison will be found in 
the case of snow and ice, where the values of c found by nine dif- 
ferent experimenters are quite consistent when lined up in the order 
of density. 

Mean Test Temperature. 

Columns 4 and 5 of the tables are intended to state the mean 
temperature of sample while being tested for heat conductivity. 
The Centigrade thermometer scale is preferred in testing labora- 
tories, but the Fahrenheit scale continues to be used by most Eng- 
lish speaking engineers, hence both are given. 

In the past many investigators were not aware that the mean 
absolute temperature has any influence upon the heat conduction of 
a material. When, in 1908, Nusselt extended his tests over a wide 
range of temperature, this fact became evident. For example, by 
increasing the temperature of an infusorial earth block from 32° to 
842° F. he found the conductivity to increase from 0.51 to 1.02 B.t.u. 
or to just double the initial value. The effect of absolute tempera- 
ture is noticeable in all materials, but the rate of change differs and 
is only very roughly proportional to the absolute mean temperature 
of the sample. 



HEAT CONDUCTIVITY 125 

It has aiso been proved that the effectiveness of insulators 
depends upon their containing the greatest possible number of minute 
air cells. The solid portions or thin walls of these air cells conduct 
heat readily, but across the cells heat is conducted chiefly by radia- 
tion. As explained in another section of this report, radiation in- 
creases with the fourth power of the absolute temperature of the 
heat exchanging surfaces, and this explains why in careful testing 
we find that the insulating effect changes as the mean working tem- 
perature is changed. The amount of change varies with each 
material. 

Units of Heat Conductivity. 

Columns 6, 7 and 8 express the heat conductivity in various units 
as defined. The physicist who prefers to work with the Centigrade- 
Gram-Second system expresses his results in gram-calories of heat 
passing in one second through a plate one centimeter square, one 
centimeter thick, per one degree C. difference in temperature of the 
two faces of plate. 

Using this extremely small unit the conductivity even of silver 
is equal to but 1 gram-calorie. For 6.9 lb. corkboard it is 0.00009275 
gram-calorie. In order to eliminate from the tables at least three 
of the decimals, the true numbers in column 6 are given as they 
appear after multiplication by 1000. (It would be wrong to write 
kilogram calories instead.) 

The results of most European tests are expressed in technical, 
metric system units, as shown in column 7. In this case the heat 
flow is measured in kilogram-calories per hour passing through a 
plate of one square meter area one meter thick, which may be writ- 
ten as equivalent to 1 m' (1 meter cube) per degree C. difference in 
temperature between hot and cold faces. 

Finally in column 8 appear the values for heat conductivity in 
technical English units, the figures as given representing the num- 
ber of British thermal units (B.t.u.) passing per hour through a 
plate of the material one square foot in area, one inch thick, and 
per degree Fahrenheit difference in temperature of the two faces. 
These last four words must be added, otherwise those who care- 
lessly omit them invariably think it is understood that the differ- 
ence between warm and cold air each side of board is meant. This 
mistake is cleared up in another section of this report. 

Since in refrigerating plants heat must usually be removed 
throughout 24 hours, it has long been the custom to use 24 hours 
as the time unit for expressing the insulating effect of walls, etc. 
Outside of the laboratory temperature conditions due to atmos- 
pheric changes (sun, wind, rain) are never constant throughout 24 
hours, and so the committee has decided to adopt the hourly basis 
for measuring heat flow. This also conforms with the practice of 
other than refrigerating engineers. 



126 CORK INSULATION 

In addition to the three units appearing in columns 6, 7 and 8, 
a fourth one is being advocated by physicists. Their viewpoint 
is that it is illogical when using the foot (12 in.) as the unit of length 
for determining areas to use some other unit, the inch, for the 
thickness. Accordingly, in modern textbooks such as "Mechanical 
Engineers' Handbook" by L. S. Marks, 1916, page 304, and in "Heat 
Transmission by Radiation, Conduction and Convection," by R. Royds, 
1921, heat conduction per hour is based on a piece one square foot 
in area, and one foot thick. 

Anyone preferring to calculate with this new unit need only 
divide the values per inch thickness (col. 8) by 12. 

In the metric system the same unit, either the meter or the 
centimeter, is used for both area and thickness. 

Conversion Factors Used. 

For the convenience of those accustomed to the use of the units 
employed in either columns 6, 7 or 8, the value appearing at the 
original source was translated into the other units by means of 
the following conversion factors, using a 20-inch slide rule: 

Value in col. 6 X 0.36 = value in col. 7 

Value in col. 6 X 2.90291 = value in col. 8 

Value in col. 7 -f- 0.36 = value in col. 6 

Value in col. 7 X 8.06364 = value in col. 8 

Value in col. 8 X 0.344482 = value in col. 6 

Value in col. 8 X 0.124013 = value in col. 7 

Column 9 simply gives the reciprocals of the values in column 8, 
for convenience in calculations as brought out in another section. 
Thus the values in column 9 represent the heat resistivity of the 
various materials enumerated, that property really being the reason 
for their use by refrigerating engineers and others. 

Column 10 gives the source of the information found in the 
preceding columns. This is quite useful, because it affords an op- 
portunity to look up the references given and to satisfy oneself 
whether or not the testing method used was likely to give trust- 
worthy results. Every investigator publishing his work is convinced 
that his results are of a high order of accuracy, and it is only the 
additional experience acquired from subsequent investigations that 
enables us to critically evaluate past accomplishments. 

Results of Conduction Tests. 

The present survey of the field of heat conductors (there are 
"poor conductors of heat" but no "non-conductors of heat") furnishes 
the desired numerical proof for the existence of a number of pecul 
arities in insulators. 

In these tables an attempt is made to list the various materials 
approximately in the order of their power to resist heat flow, the 
best resistor coming first. This plan could not be strictly adhered 
to, because it was considered desirable for comparison to list together 



HEAT CONDUCTIVITY 127 

material of the same name but of various densities, and to keep 
together materials of the same family, for example, the corkboards. 

It will be noted with surprise that some of the loose insulating 
materials show as low a heat conduction as does air alone. This 
is due to the fact that in a filled space the diminished convection and 
radiation ofifset the conduction proceeding through the fibers of the 
insulator. The packing of an air space with insulating material is, 
therefore, of particular advantage. 

In the absence of a series of tests of each material at various 
densities, it is hardly possible to state just which density or rate 
of packing will result in least heat conduction. Randolph, Table 
III (Animal Matter), obtained lower heat conduction with eiderdown 
at 6.8 lb. per cu. ft. than he did with 4.92 lb., because in the latter 
case there was a better chance for convection. His tests on absorb- 
ent cotton, Table I (Vegetable Matter), lead to the same conclusion. 
The heat conduction of dry granulated cork seems to depend more 
upon the state of division and absence of foreign substances than on 
the density, some grades at 3 lb. per cu. ft. showing just as favorable 
as grades three times as dense. 

Comparisons of this kind should be made at like temperature 
levels. In Nusselt's series of tests on 10-lb. granulated cork it will 
be observed that the heat conductivity increased from 0.25 B.t.u. at 
?i2° F. to 0.44 at 392° F. The temperature coefficient, or the increase 
in c per degree change from standard mean test temperature, such 
as 68° F., is appreciable in all materials, but more so in some than in 
others. All so-called insulators are more effective per degree differ- 
ence at low than at high temperatures, that property being due to 
radiation in the minute air cells, and due to included moisture, but in 
metals there is no uniform behavior in this respect, the conductivity 
increasing in one metal and decreasing in another 

Test Reports to Be Specific. 

It should be evident from the foreging that the heat conductivity 
of any material is not a fixed figure. Honest investigators will not 
fail to carefully describe the sample they tested and to at least give 
its dimensions, density and range of surface temperatures used, other- 
wise their results may not fit in with correctly made tests and will 
be of no service to discriminating engineers. 

Temperature Level Important. 

Heretofore there was no universally recognized mean temperature 
of samples under test. To obtain results within a convenient time a 
fairly large temperature difference is often resorted to. Thus the 
sample is dried out much beyond its normal commercial state of dry- 
ness. Investigators rarely report the state of dryness after tests are 
concluded. They aim to give us a favorable looking value of a bone- 
dry sample, kiln-dried for weeks in some cases, when, in commercial 



128 CORK INSULATION 

applications we are interested in the heat conductivity of samples. 
as received on the job. The low mean temperature should be used in 
the first test, and some higher mean temperature in subsequent tests. 
These results should not be averaged up into a single value. 

The successive drying out of a sample is revealed by a (tempo- 
rary) lowering of the heat conductivity as higher temperatures are 
reached; for illustration see Randolph's diatomaceous earth and 
asbestos compositions, 20.6 lb. per cu. ft. At 50° and 752° F. face tem- 
peratures a value of c was obtained of 0.462 B.t.u. against 0.718 (55% 
more) with 50° and 212° face temperatures, when in reality, with con- 
stant moisture content, the order of these values should be reversed, 
in conformity with the results of other investigations. 

To avoid drying out the sample unduly, the cold side of the plate 
is cooled by refrigerated brine, at the British National Physical 
Laboratory (Table I, Vegetable Matter), and in some European 
laboratories by liquid air or other cold fluid. 

Materials used in refrigeration, and in the construction of build- 
ings, should have their normal rated heat conductivity referred to 68° 
F. (20° C.) arithmetical mean test temperature. 

While in the tables columns 4 and 5 are supposed to give the true 
mean test temperature, or else the range used, this rule could not be 
adhered to in cases where the original investigator neglected to spe- 
cifically state that the temperature given (if any) actually represents 
the mean test temperature. It is possible that some (as Norton) 
meant it to be the temperature of the hot face. Others, like Taylor 
and Griffiths, gave both face temperatures, a method which has much 
in its favor. In general, the data given contain all that is available. 
The results of older determinations were not obtained from the origi- 
nal sources stated, but were taken simply from standard reference 
books, such as the Smithsonian Physical Tables or Landolt-Boern- 
stein's Chemical-Physical Tables, 1912. 

Moisture Content. 

As already pointed out, the subject of moisture has not received 
its full share of attention in the past. From a few isolated tests and 
observations in practice, and knowing that water conducts heat at 
about 14 times the rate at which heat flows across dry air cells, there 
remains no doubt as to the harmful influence of moisture. Quantita- 
tive measurements, however, are as yet incomplete. 

In Table 1 (Vegetable Matter), Biquard gives for French im- 
pregnated corkboard weighing dry 17.17 lb. per cu. ft., c = 0.4195 
B.t.u per hr. After the weight was increased by water absorption to 
19.34 lb., c became 0.613 B.t.u. Here 12.7% increase in weight caused 
the conductivity to increase by 49.7%, equivalent to 4% for each 1% 
gain in weight. 

In Table I, near the end, Nusselt gives for Austrian "cement 
wood," dry, 44.6 lb. per cu.ft., c = 0.968 B.t.u. After moisture had 



HEAT CONDUCTIVITY 129 

increased the weight to 51.4 lb., c was 1.21 B.t.u. Here 15.2% increase 
in weight caused the conductivity to increase by 25%, equivalent to 
only 1.65% loss of heat for each 1% gain in weight. 

In Table II (Mineral Matter), Randolph gives for diatomaceous 
earth and asbestos at 20.6 lb. per cu. ft. a value of c = 0.57777 B.t.u 
for a plain air-dry sample, against c = 0.499 when first dried for three 
days at 572° F. The ratio is 1.158 to 1. Actually such a sample will 
soon go back to air-dry condition, if not worse, and then the won- 
derfully high insulating effect will not longer obtain. 

A similar experiment is Nusselt's who, as shown in Table II, 
decreased, by roasting, the weight of fine river sand from 102.4 to 
94.8 lbs. (excess 8%) thereby lowering c from 7.825 down to 2.26 
B.t.u. The ratio of c is as 346% to 100% or 43% heat loss for each 
1% moisture. 

Under the item masonry. Table II, tests are given of a porous 
brick, showing the following results: 

At 46.1 lb. (100 %) c = 1.17 B.t.u. (100 %) 
At 49.7 lb. (107.7%) c = 1.695 B.t.u. (144.8%) 
At 58.8 lb. (127.5%) c = 2.743 B.t.u. (234.2%) 

It will be noted that for each 1% increase in weight, c increased 
5.82'/ in the second test and 4.88%, on the average, in the third test. 

In the case of the machine made brick weighing 101.1 lb. per 
cu. ft. the addition of moisture increased c from 3.34 up to 6.64 B.t.u. 
per hour. 

Further tests are necessary before the influence of moisture can 
be expressed by a correct formula, but for the time being it may be 
assumed that each 1% gain in weight by moisture absorption causes 
the heat conductivity of previously dry slabs and bricks to increase 
by about 5%. Thus 20% addition in weight is likely to double the 
original conductivity. Cork and other pipe coverings long in use 
afford a good chance for checking this estimate. 

If we figure that the British slag wool. Table II (Mineral Mat- 
ter), originally had a value of c = 0.29, as is probable, then its value 
of c = 0.35, after 14 years use, represents a loss of 0.006 B.t.u.. or 
20.7%. This change in insulating effect is caused by moisture. I^osses 
up to this magnitude must be expected whenever corkboard is incor- 
porated in forms exposed to wet concrete. Hence this practice is 
to be discouraged. 

Observations of this kind from actual practice are of greater 
value to refrigerating engineers than are tests of kiln dried samples. 

Tables I to IV (Vegetable Matter, Mineral Matter, Animal Mat- 
ter and Metals) contain no test results on air spaces and surface 
resistance. Reliable data on these items have appeared but recently, 
but it is intended to compile this information and to include it in a 
future report. 



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155 



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156 



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HEAT CONDUCTIVITY 



157 





1 


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with 
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not agitated. 

Surface 
temperatures 






Knoblauch 
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o 

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0.394 

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d d dd 666 6 


3.73 

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HEAT CONDUCTIVITY 



159 









< » ;C 00 05 N C>3 CO 



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160 



CORK INSULATION 



o ^ 
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1 

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H-L-D 

H. F. Weber, 1911 

Forbes 

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Hecht, 1903 

Weber 

Peirce & Willson 

Desvignes 

Forbes 

Peirce&Willson,1898 

Peirce& Willson, 1898 

Peirce&Willson,1898 

H-L-D 
H-L-D 

Wologdine, 1909 


Resis- 
tance 
per inch 
thickness 
(R) 
1 

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o> 


d 






i§S°§§oS§§o§ss§§5-SS§22S§§ o§-cg 

do oo d66 d6<666<6666o6o6o odd c 


1 

1 


B.t.u. 
hour, sq. 
ft.,lin. "F 
Commer- 
cial con- 
ductivity 


« 


15.83 
to 
16.41 
13.06 
to 
14.5 
12.5 
to 
28.2 
11.6 
14.81 
to 
15.98 
21.8 
23.22 
28.18 
3.34 
9.00 
22.66 
23.8 
17.32 
9.75 
5.14 
19.9 
14.55 
16.14 

12.8 
18.36 
8.42 
to 
15.4 




t^ 


1.9615 

to 
2.035 
1.62 

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3.49 
1.44 
1.837 

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1.980 
2.700 
2.878 
3.490 
0.414 
1.116 
2.807 
2.950 
2.147 
1.208 
0.637 
2.467 
1.803 
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1.589 
2.276 
1.044 

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1.91 




o 


5.45 

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5.65 
4.5 

to 
5.0 
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9.7 
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5.50 
7.5 
8.0 
9.7 
1.15 
3.10 
7.8 
8.2 
5.96 
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1.77 
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HEAT CONDUCTIVITY 



161 












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166 CORK INSULATION 

Section XI of *'Heat Transmission of Insulating Ma- 
terials," published by the American Society of Refrigerating 
Engineers, New York City, is a Bibliography of "References 
to articles and publications treating of heat insulation and 
heat transfer," compiled by Chas. H. Herter, with the cooper- 
ation of A. J. Wood and E. F, Grundhofer of the Pennsylvania 
State College. The source and year of publication, name of 
author and title are given in practically all listings. 

Space does not permit the appending of this Bibliography, 
although its value in connection with the foregoing tables of 
thermal conductivity of various insulating materials will war- 
rant its possession. 






CORK INSULATION 



Part III — The Insulation of Ice and Cold Storage 
Plants and Cold Rooms In General. 



CHAPTER XI. 

REQUIREMENTS OF A SATISFACTORY INSULA- 
TION FOR COLD STORAGE TEMPERATURES. 

80. — Essential Requirements. — The widening knowledge of 
the use of refrigeration created a very definite demand for 
a suitable insulation for cold storage temperatures, which 
resulted in the introduction in 1893 of pure, compressed, baked 
corkboard, the superior qualities of which were apparent 
almost from the beginning; and its application became so 
general during the first quarter century of its use as to prac- 
tically displace all competing materials, and strictly on its 
merits alone has become the accepted standard insulation for 
cold storage temperatures wherever refrigeration is employed. 

It is by no mere chance, of course, that cork bark is the 
foundation for the one satisfactory insulating material for 
cold storage temperatures ; and the reason for its universal 
acceptance and extensive use is easily, though not generally, 
understood. 

Pure corkboard, as an ideal insulating material for cold 
storage temperatures, excels in every single particular; but 
it possesses one inherent quality without which it could not 
have been used for cold storage work at all — it is inherently 
nonabsorbent of moisture, that is, does not possess capillarity, the 
property that causes a blotter to suck up ink ; for cold storage 
temperatures very definitely involve moisture conditions, 
through the medium of the condensation of water against cold 
surfaces, and any material that is to retain its initial insulat- 
ing efficiency in the almost continuous presence of moisture, 
must be impervious to moisture, must be inherently free from 
167 



168 CORK INSULATION 

capillarity, else it will become saturated with water and lose 
its insulating worth entirely. 

A satisfactory insulation for any purpose whatever must 
be able to retard the flow of heat to an unusual degree. Many 
materials will do this, but a satisfactory insulation for cold 
storage temperatures must combine with such insulating 
property the ability to retain its insulating efificiency for an 
indefinite period under the adverse conditions of the constant 
presence of moisture. Pure corkboard meets this very exact- 
ing combination of these two major requirements to a degree 
never yet approximated under actual operating conditions by 
any other insulation. 

Then, too, the delicacy of many foodstuffs makes them 
peculiarly susceptible to tainting, and the insulation must 
keep free from rot, mold and offensive odors, and be germ- 
and vermin-proof; economical building construction requires 
an insulation that possesses ample structural strength and in 
such form that it can be installed easily in all types of build- 
ings ; conservation of valuable space requires an insulation 
that is compact and occupies minimum space; the reduction 
of fire hazard calls for an insulation that is '^low-burning and 
fire-retarding; and in the interests of economy, the insulating 
material must be easily obtained and reasonable in cost. Pure 
corkboard also meets these secondary but nevertheless impor- 
tant requirements better than any other insulating material 
that has ever been offered commercially. 

81. — A Good Nonconductor of Heat. — It has been seen that 
heat transference is accomplished by conduction, convection 
and radiation ; and that when the problem of insulating a cold 
room, for example, is under consideration, the heat transfer 
by conduction is the most important, consisting of ninety per 
cent or more of the total heat leakage into the room when a 
suitable insulating material is employed. 

It will be recalled that the heat conductivity of dense sub- 
stances, such as metal, is high ; that of lighter materials, such 
as wood, is less ; while that of gases is very low. Thus air, 
the most available gas, is the poorest conductor of heat, if a 
vacuum is excepted, but air is a good convector of heat, unless 



I 



REQUIREMENTS OF AN INSULATION 169 

it is broken up into great numbers of minute particles, so small 
in size that the effect of convection currents is reduced to a 
negligible quantit}'. 

Consequently, in an efficient insulating material, air must 
be present in the very smallest possible units, such as atoms, 
so that convection is reduced to a minimum ; and since these 
atoms of air must each be confined, the use of a very light 
encompassing material having little density and thus very Iom^ 
conduction, is essential. Such an insulator will be as efficient 
from the standpoint of heat transfer as it is possible to obtain ; 




FIG. 47.— CORKBOARD UNDER POWERFUL MICROSCOPE, SHOWING 
CONCEALED AIR CELLS. 

' that is, a very light material containing myriads of micro- 
scopic air cells, each one sealed unto itself. 

The outer bark of the cork oak was evidently provided by 
nature to prevent the sun's rays and the hot winds from 

\ drying up the life-sustaining sap that courses through the 
inner bark of this peculiar and remarkable tree ; and an exam- 
ination under the microscope reveals the reason why cork is 
such an excellent nonconductor of heat. It is found to be 
composed of countless air cells, so tiny and infinitesimal that 
it takes many millions of them to fill a cubic inch of space. 
Flow of heat bv convection is therefore reduced to the lowest 



170 



CORK INSULATION 



conceivable minimum, because the velocity that can be ob- 
tained by air in so small a space is virtually nil. Again, these 
cells are separated from each other by thin v^^alls of tissue of 
very low density. Thus the flow of heat by conduction is as 
low as is reasonable to expect in any material extant. 





FIG. 48.— r.OILlNG TEST ON CORKBOARD INSULATION. 

It would therefore l)e but natural to find this outer bark 
an excellent nonconductor of heat, and the experience of 
many years with pure corkboard has amply confirmed this 
deduction. 



82. — Inherently Nonabsorbent of Moisture. — A satisfac- 
tory insulation, however, for any purpose, must retain its 
insulating efficiency indefinitely. That is, it must not pack 



REQUIREMENTS OF AN INSULATION 171 

down and lose its original "dead-air" content ; and it must 
not become saturated with moisture, since water is a rela- 
tively good conveyor of heat. Suitable materials for the insu- 
lation of warm or hot surfaces may possess the property of 
absorbing water, for under normal conditions of service they 
are rarely subjected to severe moisture conditions and are 
almost constantly undergoing a drying out process; but cold 
storage temperatures, on the other hand, involve moisture 
conditions, through the precipitation of moisture from air in 
contact with cold surfaces, and any material that is to retain 
its original insulating efficiency in the almost continuous pres- 
ence of moisture and in the absence of appreciable heat, must 
be impervious to moisture. In a word, a satisfactory insula- 
tion for cold storage temperatures must be inherently free 
from capillarity, as otherwise it will, in the presence of moist- 
ure, become saturated and of no further value as an insulating 
material. 

At least as early as the reign of Augustus Caesar, cork was 
used as stoppers for wine vessels, and has been used during 
the intervening 2,000 years, practically unchallenged, as stop- 
pers for liquid containers, thus amply demonstrating its inher- 
ent imperviousness to moisture. And this important property 
of cork — its entire freedom from capillarity — is in no way 
impaired by the manufacturing process follow'ed in the pro- 
duction of pure corkboard. On the contrary, the inherent or 
natural ciualities of cork that makes it the basis for the best 
cold storage insulation yet discovered or developed on a 
commercial scale, are enhanced by the baking of the granules 
of pure cork bark in metal molds under pressure at moderate 
temperature ; for such manufacturing process brings out the 
natural resin of the cork, which cements the particles firmly 
together and makes the use of an artificial binder unnecessary, 
and by coating the entire surface of each separate granule 
with a thin film of the natural waterproof gum affords an 
additional barrier against the possible entrance of moisture. 

The "Navy Test" was designed by the United States Navy 
Department some years ago to concentrate in a short period 
of time those destructive forces to which all cold storage 
insulation is subject during its term of actual service. The 



172 CORK INSULATION 

test consists of boiling a piece of insulation completely sub- 
merged for three hours at atmospheric pressure without its 
disintegrating and without its expanding more than two per 
cent in any direction. Pure corkboard of standard quality 
easily meets the requirements of this test, merely demonstrat- 
ing in a simple laboratory way that corkboard insulation is 
proof against deterioration in service from the destructive 
action of moisture that is ever present at cold storage tem- 
peratures. 

83. — Sanitary and Odorless. — Any insulating material em- 
ployed at cold storage temperatures usually encounters 
foodstuffs, and should therefore be perfectly sanitary and 
free from mold, rot, appreciable odor or vermin. For these 
reasons any insulation in which binders are used, especially 
pitch, is dangerous, since the delicacy of many foodstuffs 
makes them peculiarly susceptible to tainting and contamina- 
tion. 

Pure corkboard contains no foreign binder of any charac- 
ter and the cork bark of which it is composed is inherently 
moisture-proof. Therefore it will not rot, mold or give off 
offensive odors ; and if corkboard is properly erected, it is 
vermin-proof. Cold storage rooms insulated with pure cork- 
board, and finished with Portland cement troweled smooth, as 
recommended by the United States Department of Meat In- 
spection, are easily and indefinitely kept in sanitary and hy- 
gienic condition by ordinary washing and cleansing methods. 
The sanitary and odorless qualities of an insulation for cold 
storage temperatures are of very real importance, and pure 
corkboard is easily the standard by which all cold storage 
insulating materials are judged. 

84. — Compact and Structurally Strong. — It has been noted 
that a particle of cork bark is made up of a myriad of tiny 
sealed air cells, separated from each other by thin walls of 
tissue of very low density, each cell containing a microscopic 
bit of air. In the manufacture of pure corkboard. of standard 
specifications, the particles of cork bark are sufficiently com- 
pressed in the molds to eliminate the voids between the 



REQUIREMENTS OF AN INSULATION 



173 



particles, which produces a finished material of maximum 
compactness in relation to weight and insulating value. 

This compactness is an essential quality of pure corkboard, 
a quality not possessed in proportionate degree by other insu- 
lating materials. In fibrous materials, or materials not of 
cellular structure, the insulating value is dependent on air 
spaces, which are not independent of each other. The air 
content is merely entrapped between closely matted or inter- 
laced fibres, such interstices or voids being connected one 
with another ; and when moisture contacts with such materials 




[G. 49.— PURE CORKBOARD INSULATION IN MODERN FIBRE CARTON 
CONTAINING 12 BOARD FEET. 

I it is readily communicated, not alone by capillarity but also 

iby gravity, from one air space to another. 

The inherent ruggedness and toughness of cork bark is 
one of its outstanding and well-known qualities; and after it 
has been properly processed into sheets of pure corkboard, the 
resultant product is sufficiently strong to permit of its being 
transported, handled and used as readily as lumber, its 
strength in compression being sufficient to take care of loads 
many times greater than ordinarily encountered. The remark- 
able strength of such an excellent nonconducting material is 
simply another of the very important reasons for its universal 
use for all cold storage purposes. 



174 CORK INSULATION 

85. — Convenient in Form and Easy to Install. — The stand- 
ard sheet of pure corkboard, 12 inches wide and 36 inches 
long", which all American and most foreign manufacturers 
follow as a standard, is the most convenient in form for every 
purpose. It may be handled, sawed, and applied as readily 
as lumber, or put up in Portland cement or hot asphalt cement 
with the same ease as any common building material. Its 
characteristics are such that there need be little, if any, waste 
from sawing and fitting-, because the fractional sheets may be 
neatly and tightly assembled to give as efificient an installation 
as could be had with the full size standard sheets. 




FIG. 50.— APPARATUS FOR SIMPLE FIRE TEST ON PURE CORKBOARD. 

86. — A. Fire Retardant. — In the manufacture of pure cork- 
board, partial carbonization of the raw cork bark is accom- 
plished without destruction of tissue, that is, the baking proc- 
ess, at moderate temperatures, dissolves the resins (inherent 
in cork bark) sufficiently to everlastingly bind the particles 
into a good, strong sheet of insulation, while at the same time 
producing a protection of carbon that a flame penetrates with 
much difficulty. 

A simple experiment to show the slow-burning and fire- 
retarding properties of pure corkboard as compared with other 
materials can be made by anyone by means of an iron rack 
and a gas burner. Place the sample of insulation on the rack 
and record the time it takes to burn a hole clear through and 



- 1 

i 



REQUIREMENTS OF AN INSULATION 



175 



carefully note the condition of each sample at the conclusion 
of each test. A piece of pure corkboard two inches thick will 
not burn through under about four hours if subjected in this 
way to a 1500° F. gas flame; and when this is compared with 
the condition of other kinds of cold storage insulating mate- 
rials at the end of similar tests, it will be clear why the under- 
writers have given their approval to pure corkboard and to no 
other form of cold storage insulation. 




• PIG. 51.— CORKBOARD INSULATION ON BRICK WALL— APPROVED BY 
NATIONAL BOARD OF UNDERWRITERS. 



Many examples of the remarkable value of pure corkboard 
as a fire retardant could be selected from the fire records of 
the past thirty years or so, if it were any longer necessary 
in the minds of insulation users to offer proof of this well- 
known fact ; but possibly it will serve a double purpose to 
make specific mention here of a fire that lasted nine hours in 
the grocery of A. Weber of Kansas City, Missouri, on Decem- 
ber 3, 1914, and which consumed e\'erything of value in the 



176 



CORK INSULATION 



basement except the corkboard insulated cold storage room. 
Fifty hours after the fire started the frost still remained on 
the pipes in this room, which was then found to be only 38° F., 
a rise in temperature of but 10° from the time the fire started. 
Thus not only the fire retarding property of pure corkboard 
was spectacularly demonstrated, — the Portland cement finish 
having been destroyed but the corkboard having escaped 
almost unharmed, — but the remarkable insulating value of 
pure corkboard was most effectivel}- demonstrated as well. 




FIG. 52.— BASEMENT OF WEBER'S STORE AFTER THE FIRE.— NOTE 
CORKBOARD WALLS OF THE COLD STORAGE ROOM IN BACKGROUND. 



Other demonstrationsf of what pure corkboard will do in 
actual fires have been so numerous as to attract considerable 
attention. In cold storage plants in particular, total destruc- 
tion of buildings and equipment has often been prevented 
solely by the corkboard walls of the cold storage rooms. 

87. — Easily Obtained and Reasonable in Cost. — Pure cork- 
board can today be classed as merchandise, and is carried in 
stock in every city of any importance in the United States. In 
addition, large supplies are always on hand in storage ware- 
houses at New York and New Orleans, and at the four facto- 



tSee Appendix for "How Insulation Saved a Refinery.' 



REQUIREMENTS OF AN INSULATION 177 

ries that manufacture corklDoard in the United States. Con- 
sequently, pure corkboard insulation is almost as easily ob- 
tained in this country as is any approved building material 
in common use ; and considering its permanent insulating 
worth and general utility, is fairly priced and often to be had 
at a- cost that makes its purchase an unusually attractive 
investment. 

88. — Permanent Insulating Efficiency.— Thus it will be 
noted that the requirements of a satisfactory insulation for 
cold storage temperatures cover a wide range indeed, and 
may be summed up briefly in the statement that such insula- 
tion must be of such permanent thermal resistivity, obtainable 
in such form, structurally suitable in such degree, readily 
available in such quantity and at such price, as to make tliat 
insulating material one of permanent insulating worth and 
efficiency. 

There are, perhaps, a numl^er of insulating materials of 
various kinds and in various forms, that show, under labora- 
tory tests, when such materials are new and dry and unused, 
a heat resistivity, or an insulating value, as high as, or higher 
than, pure corkboard insulation ; but for many years it has 
been the actual experience of countless insulation users that 
pure corkboard of proper thickness applied in the proper 
manner is the only cold storage insulation for which, from 
every consideration, permanent efficiency can be claimed. 



CHAPTER XII. 

PROPER THICKNESS OF CORKBOARD TO USE 
AND STRUCTURAL SUGGESTIONS. 

89. — Economic Value of Insulating Materials. — During the 
past fifteen years or so there has been considerable time and 
attention given to the study of insulating materials, both 
theoretical and practical ; but the results have taken the form 
of the determination and comparison of the thermal efficiency 
of many materials, and the best methods of erecting and 
caring for them in service, rather than having dealt with the 
determination of the range of profitable expenditure which is 
the real aim and end of industrial research. In the absence 
of any concrete information of generally recognized worth on 
the subject of how much money it is advantageous to expend 
for cold storage insulation, the users of such materials have 
divided into two main classes : First, those who came to 
believe that it was not profitable to employ as much insula- 
tion as generally recommended by responsible manufacturers, 
or who came to believe that cheaper materials in the same 
thicknesses would suffice ; and, secondly, those whose experi- 
ence and judgment taught them that increased thicknesses of 
only the best insulating materials were profitable to install. 

Those in the first class are much in the minority, yet 
their numbers justify careful consideration of their policy. 
It might be expected that a third class exists, consisting of 
those who have not changed their insulation ideas and prac- 
tices during the period of time mentioned ; but it is believed 
that these are now so few in actual numbers as to be of no 
real importance with respect to a discussion of this subject. 

The true economic value of an insulating material must, of 
course, follow rather closely a consideration of the monetary 

178 



STRUCTURAL SUGGESTIONS 



179 



return on the initial insulation investment for the period of 
the useful expectancy of such insulation. The factors to 
which it is possible to assign definite values are : 

(a) Value of heat loss through insulation in terms of total cost to 
remove it. 

(b) Interest on the insulation investment. 

(c) Insurance on the insulation investment. 

(d) Cost of insulation repairs and depreciation. 

(e) Value of building space occupied by insulation. 

In addition, there are certain factors for or against more and/or 
better insulation, the value of which it is often difficult to 
determine or predict, as follows: 

(f) Term of useful expectancy for insulation, or probable obso- 
lescence period. 

(g) Improvement in product from better temperature conditions 
due to insulation. 

(h) Advertising value of better cold storage equipment, 
(i) Saving in cost of bringing product and/or room to tempera- 
ture, 
(j) Saving resulting from ability to anticipate with reasonable 

accuracy the drop in thermal efficiency of the insulation in 

service, 
(k) Type and character of structure to which insulation is to be 

applied. 
(1) Ability to obtain proper application of insulation, 
(m) Effect of type, temperature and continuity of refrigeration 

applied, 
(n) Effect of outside atmospheric conditions, 
(o) Effect of air humidity maintained in insulated rooms, 
(p) Effect of the arrangement of product stored and its influence 

on air circulation over insulation. 
(q) Effect of anticipated abuse of insulation and failure to make 

repairs, 
(r) Funds available. 

Mr. P. Nicholls*, Pittsburgh, Pa., working along these 
lines and taking the general case of a flat surface with insula- 
tion applied to it, developed the formula : 



= 1.74>/. 



0.327P 



A(T:,— t) F + 



K( 



lUO 



R' + 






(T.n-t) 

-^ xc 



+ 8.3S 



in which 

X = economic thickness of insulation in inches, that is, the tbick- 



*P. Nicholls, Supervising Engineer, Fuel Section, Bureau of Mines Experiment 
Station, U. S. Dept. of Commerce, Pittsburgh, Pa. 



ISO CORK INSULATION 



i 



ness that will reduce to a minimum the sum of the expenses 
due to the heat leakage through the insulation plus the ex- 
penses of preventing the additional heat leakage. 

C = average thermal conductivity coefficient of insulation during 
its life, in B.t.u. per square foot, per inch thickness, per hour, 
per degree temperature difference F. 

B = cost of insulation installed, in dollars per square foot, per 
inch thickness, or in dollars per board foot. (Note: 
H 

B = ( h B') where H = the fixed square foot cost to 

X 
cover wall finish, plaster, starting the insulation job, etc., 
and B' = cost of insulation per square foot that is propor- 
tional to the thickness.) 
I = per cent interest allowed on insulation investment, plus per 
cent insurance cost. 

Y = years of life allowed insulation. 

R = yearly repair cost, as per cent of investment in insulation. 

F = fraction of year room is in operation. 
Tm = maximum temperature during the period of yearly opera- 
tion of the outside air adjacent to cold storage room wall, 
in degrees F. 
t = cold room temperature, in degrees F. 

tp := mean temperature of cooling coil piping. 

K =: surface transmission coefficient of pipe surface in B.t.u., per 
square foot, per hour, per degree F. 

A = average cost over period of yearly operation, in dollars, of 
one ton of refrigeration (cost per B.t.u. X 288,000) delivered 
to the room under consideration, exclusive of cooling piping. 

P = cost in dollars of the pipe per square foot of its surface, 
including installation and accessories. 

G = investment in refrigerating equipment, of whatever nature, 
in dollars per ton of refrigeration per day. This excludes 
machinery, the cost burden of which is included in A. 

288,000 P I 

(Note: G = ) 1 

24 K (tp— t) 

P =: per cent interest allowed on refrigerating equipment invest- 
ment covered by G. 

Y' = years of life allowed refrigerating equipment covered by G. 

R' = yearly repair cost, as per cent of investment in refrigerat- 
ing equipment covered by G. 

S = yearly value of one cubic foot of space occupied by insula- 
tion. 

U = the over-all thermal coefficient of heat transmission from air 
to air for the given thickness of the entire wall, other than 
insulation, and including the surface transmission coefficients 
of the outside wall surface and the inside insulated wall 
surface. 

By substituting: 

C = 0.35 B.t.u. 

ro.o4 

B = ^ 1-0.16 (^dollars 



I r= 6 per cent. 
Y = 15 years. 
R = 3 per cent. 
F = 1 year. 



STRUCTURAL SUGGESTIONS 



181 



T» = 50° F. average temperature outside wall. 

Tm=r90° F. 

t = cold room temperature, degrees F., as assigned, 
(t— tp) = 10° F. 

K = 2.0 surface transmission coefficient. 
A = $1.00 per ton. 
P z= $4.35 per square foot. 
I' = 6 per cent. 
Y' = 8 years. 
R' = 3 per cent. 
S = 0. 
U = 0.303. 

the economical thickness, X, of insulation was readily obtained 

for a range of cold room temperatures, t, and curve B of Fig. 

53 was platted. 



\ 

\ eo -lo 

I I 



±s±. 



FIG. 53.— WALL INSULATION— ECONOMIC THICKNESS AGAINST 
TEMPERATURE. 

With the same set of conditions and a cold room tempera- 
ture of 20° F., the true yearly cost, per square foot, based on 
various thicknesses of insulation, were computed and curve B 
of Fig. 54 was platted. 

According to the definition, the economic thickness of 
insulation occurs when the yearly cost is a minimum, which 
thickness is (3.99 — 1.06) 2.93 inches on the curve in Fig. 54; 
and the shape of the curve shows that the refrigeration cost 
per square foot increases at a more rapid rate with a given de- 
crease below the economic thickness than it does for a similar 
increase. It will also be noted that such curve is compara- 
tively flat on each side of the economic thickness, indicating 



182 



CORK INSULATION 



that a small change in insulation thickness, either above or be- 
lozv the true point of maximum economy, zvill not materially 
affect the cost of refrigeration per square foot. 

The real value of the work of Mr. Nicholls is summarized 
in the two deductions just set forth in italics, rather than in 
the numerical results obtained for economic thicknesses of 
insulation as shown by the curves, because values for factors 
(f) to (r) could not be assigned and made a part of the 
formula. 





V 


i 






















\y 










- 




















1 




u 


-• 


\^ 








f 








^ 






1 


; 


k 








-^ 










% 






1 




f 










a/0 


n 


B:i 


iqomi 


■ J 




%i 
















' 














\ 


1 


















^< 


7 




/ A 


w 






L* 


3 


' <5 


f £ 


} /O 



^ Vl 



FIG. 54.— YEARLY WALL COST PER SQUARE FOOT AGAINST THICKNESS 
OF INSULATION. 



90. — Tendency Toward More and Better Insulation. — Many 
years ago a responsible manufacturer of pure corkboard* 
pointed out that : 

The proper thickness of . . . corkboard to install, in order to 
maintain a given temperature economically, depends, as with every 
other type of insulation, upon several factors, which vary in the case 
of each plant: 

(a) The character of the building — whether brick, stone, concrete, 
hollow tile or frame; 

(b) The thickness of the walls, floors and ceilings* 

(c) The temperature to be maintained; 

(d) The climatic conditions; 

(e) The character of the material to be stored or the purpose for 
which the rooms are to be used; 

(f) The cost of producing refrigeration. 



*Armstrong Cork Company, Insulation Department, Pittsburgh, Pa. 



STRUCTURAL SUGGESTIONS 183 

Each case that arises must be considered on its own merits. Gen- 
erally speaking, however, it may be said that under average condi- 
tions, the thicknesses of . . . corkboard that can be economically 
installed for the several temperatures noted, are as follows: 

ORIGINAL RECOMMENDATIONS FOR CORKBOARD THICKNESS 

Temperatures Thickness 

—20° to — S° F 8 inches 

— S° to +5° F 6 inches 

S° to 20° F 5 inches 

20° to 35° F 4 inches 

35° to 45° F 3 inches 

45° and above 2 inches 

For the bottom of freezincj tanks, five inches or preferably six 
inches of . . . corkboard should be employed; around the sides the 
same thickness of corkboard, or twelve inches of granulated cork 
securely tamped in place. 

The method of arri\ing at these recommendations mig-ht 
not now conform with the data and information available, but 
the experience of man_v years has taught that these recom- 
mendations for pure corkboard were then sound to a remark- 
al)le degree. 

Reference has previously been made to a class of insulation 
i:s:rs who came to believe that it Avas not profitable to employ 
as much insidation as rec(^mmended by responsible manufac- 
turers, or wlio came to believe that cheaper materials in about 
tlie same thicknesses would suffice. It was pointed out that 
the}- were much in the minority, yet their numbers justified 
consideration of their policy. 

The factors that influence this class of buyers are: 

(h) Uncertainty as to the success of the undertaking. 

(b) Building on leased property, or building on owned property 
the value and/or utility of which is subject to quick change. 

(c) Excess refrigerating machine capacity available. 

(d) Insufficient initial funds available for best equipment. 

(e) Expansion as part of plan to prepare business for sale, con- 
solidation or refinancing. 

(f) Work in charge of an architect, engineer or contractor who 
follows the practice of specifying materials and labor of but 
average quality for the sake of wide competition and the 
lowest price. 

(g) Influence of the practices of the business being conducted, 
such as one offering average or indififerent quality product at 
average or low prices, upon the purchase of products, sup- 
plies and equipment. 

(h) Lack of true knowledge of the importance of adequate refrig- 
eration and insulation equipment. 



184 



CORK INSULATION 



91. — Proper Thickness of Corkboard to Use. — The original 
recommendations for pure corkboard insulation need be 
changed only slightly to bring them up to date, as follows : 



PROPER THICKNESS OF CORKBOARD. 

Temperatures 
-20° to 10° 1? 


Thickness 
.12 inches 




_ S" F 




5° to 


0° F 


. & inches 


0° to 


IQo F 


. . 7 inches 




20° F 




20° to 


30° F 


. . 5 inches 




40° F 




40° to 


50° F 


. . 3 inches 


50° and 


above 


. . 2 inches 



This table is predicated on a useful expectancy for corkboard 
insulation of about fifteen yearsf, an ideal condition of prod- 




FIG. 55.— VOGT INSULATION DETAILS FOR NEW FREEZING TANK AND 
ICE STORAGE ROOM. 

uct Stored, and a depreciation in thermal insulation efficiency 
of not to exceed 10 per cent for the useful expectancy period. 
Such table follows very closely the general practice of today, 
by the majority of insulation users, whose experience and 
judgment has taught them that generous thicknesses of only 
the best insulating materials are profitable in the long run 
to install. 



tThis time limit fixed bv anticipated obsolescence, 
life of the corkboard insulation. 



rather than by the probable 



STRUCTURAL SUGGESTIONS 



185 



92. — Importance of Proper Insulation Design. — It is now 

customary, when planning an ice or a cold storage plant, to 
treat the entire project as a whole, so that location, building, 
cold rooms, mechanical equipment, and complete cost are all 
properly balanced and correlated, to the end that the purpose 
and intent of the undertaking can be fully and satisfactorily 
carried out. Such a project should be entrusted only to reli- 




(LCVOTCM SECTION I 



FIG. 56.— TYPICAL SUB-STATION FOR STORAGE AND HANDLING OF ICE, 
INSULATED WITH 4-IN. CORKBOARD. 

able architects and engineers competent to handle cold storage 
work; and if so entrusted, the design of the insulation should 
have that major attention that its importance and cost entitles 
it to receive. 

Each new ice plant and each new cold storage plant will 
present its own peculiar problems in design and equipment; 
but the field of insulation experience is now so very broad and 
has yielded up so many lessons, especially lessons in what not 
to do, that no architect and engineer who is really experienced 
in the design and operation of such plants need longer be in 
doubt as to the proper insulating material to use and the 
proper insulation specifications to employ. It must never be 
forgotten, however, that insulation is a branch of engineering 
and construction that is highly specialized, and an architect's 



186 CORK INSULATION 

license alone is in no sense a sufficient recommendation for 
the handling of an ice or cold storage project. Here, as in 
most cases of specialized building construction, it will pay 
to engage the architect and engineer who has had considerable 
experience in cold storage work. 

But in addition to the insulation that is built into ice and 
cold storage plants as part and parcel of their original design, 
there are innumerable small insulated cold storage rooms 
and groups of rooms designed and built for use in connection 
with commercial refrigerating machines, which units are in- 
stalled as adjuncts to businesses usually handling food prod- 
ucts in one form or another. Such installations are made to 
serve the local needs of the individual business, — such as 
creameries, dairies, fruit storages, produce houses, poultry 
and ^gg plants, meat markets, groceries, hotels, clubs, hos- 
pitals, oil refineries, candy factories, ice cream factories, and 
so forth, — and in connection with the installation of which 
no architect or engineer is usually employed. Among such 
rooms there is a great variety of shape and size, design and 
arrangement, method of cooling, and so forth ; because a 
variety of purposes must be served by rooms built into every 
sort of structure, under many different conditions ; and such 
rooms can here be discussed first as a class and then special 
features treated separately as they may apply in certain cases. 

For many years the order for planning such a cold storage 
room, after deciding on its location and size, was to consider 
first its refrigeration and then how it was to be designed and 
insulated. The order is now reversed, in most cases, with 
excellent results ; because it is today better understood that 
the efficiency of the insulation determines in great degree the 
amount of refrigeration that is required and how it should 
be applied. It has been seen how the kind of insulation that 
goes into a cold storage room has a direct bearing not only 
on the amount of the initial investment, but also on the every- 
day cost of operation, yearly repairs, etc. The design of the 
room, however, is equally important; because the very best 
insulation will be inefifective and short lived unless it is prop- 
erly installed, following correct design. Thus in planning 
cold storage rooms, provision must first be made for their 



STRUCTURAL SUGGESTIONS 



187 



adequate insulation, for on this feature more than any other 
will depend their permanence and the economy and efficiency 
of their operation. 

93. — Types and Design of Cold Storage Rooms. — It is well 
known that cold storage rooms and groups of rooms are 
required for ice making and ice storage, creameries and dairies, 
fruit and produce houses, poultry and egg plants, fish and 
meat markets, groceries and ])rovisioneries, candy and ice 




FIG. 57.— BAKER PLAN FOR INSULATED ROOMS IN OLD BUILDING. 

cream factories, hotels and clubs, hospitals and sanitariums, 
precooling and canning plants, oil and gasoline refineries, 
waxed paper and paraffin coating establishments, fur and gar- 
ment storages, brewing and bottling plants, battery and igni- 
tion testing rooms, serum and vaccine rooms, sharp freezers 
and hardening rooms, and so forth. These rooms may readily 
be divided into two main classes ; that is, those operating 
above freezing temperature, and those operating below 
freezing:. 



188 CORK INSULATION 

In new structures, cold storage rooms to operate at any 
desired temperature can be made the exact shape and size 
desired, and in every way suited to their purpose ; but the 
majority of cold storage rooms operating above freezing — 
usually serving the purpose of the storage or handling of food 
products — are erected in existing buildings, and must be con- 
formed to structural limitations. The design of cold storage 
rooms employing pure corkboard insulation is so very adapt- 
able, however, in experienced hands, that there are virtually 
no restrictions on the construction of such rooms. Space, 
shape, height, location, kind of building, single room or a 
group of rooms ; it is all "grist for the mill" when the basic, 
underlying principles of insulation design are understood. 

The two chief points to be kept in mind in the design of 
cold storage rooms are : First, the principle of no voids or 
air spaces in or back of the insulation ; and, secondly, the 
principle of ample air circulation within the cold room. The 
principle of no air spaces in or back of the insulation is of 
primary importance when rooms are to operate below freezing, 
and the principle of ample air circulation is of primary impor- 
tance when rooms are to operate above 32° F., although both 
principles are of major importance in either case. 

The first principle, that of no voids or air spaces in or 
back of the insulation, is especially important where cold 
storage rooms are to operate below freezing, because of the 
greater likelihood of colder temperatures back of the insula- 
tion and the consequent greater likelihood of condensed water. 
If there are no voids in the insulation itself, no voids in the 
finish applied to the surface of the insulation, no voids in 
the material used to bond the insulation to the surfaces to 
which it is applied, no voids or open cracks between the sheets 
of corkboard, no voids or air pockets in the construction of 
the building walls themselves, no voids anywhere, the result 
will be a perfect insulation job, assuming such perfect condi- 
tions obtainable ; for all such voids and air spaces are likely 
to fill up with water, through condensation of moisture from 
the air against chilled surfaces, and deterioration and lowered 
insulation efficiency will be the certain result. 

In practice, the aim is for that which is as near perfection 



STRUCTURAL SUGGESTIONS 189 

as is consistent with a variety of conditions, costs, and so 
forth. If possible, walls, floors and ceilings should be of solid 
construction, that is, without voids or air spaces, as solid brick 
or concrete in preference to hollow tile or sheathed studs and 
joists. The air in such spaces contains moisture in suspension, 
which is likely to be condensed on the cool surfaces next to 
the cold temperature room*; and as the water contained in 
the air in such spaces condenses, it occupies as a liquid less 




FIG. 58.— SAUSAGE COOLER WITH STATIOxNARY AND PORTABLE RACKS, 
TRACKING AND OVERHEAD BUNKERS. 

space than it did as a vapor, an uneven pressure is set up or 
partial vacuum created, more air containing moisture of pro- 
portion indicated by its humidity is drawn in, more precipita- 
tion takes place, and if there is then no opportunity for such 
water deposits to quickly evaporate away again, all such 
spaces will be the source of "moisture trouble." Such moist- 



*Dirty lath streaks on ceilings of offices, residences, etc., furnish a g9od example 
of the precipitation of moisture from the air against cool surfaces. In winter the air 
above the wood lath and plaster is often cooler than the air of the room; and, as a 
result, moisture is condensed on the cool strips of plaster between the lath, and 
minute particles of dust are caught in this moisture. 



190 



CORK INSULATION 



ure, in closed-in spaces, may be the cause of all sorts of 
building construction troubles, such as rotting, and bulging 
and cracking from uneven expansion ; but our thought will 
be primarily for the damage to the insulation itself. In the 
case of ceilings especially, the water slowly finds its way into 
the insulation underneath, and failure of that ceiling insula- 
tion will be the certain result. Where such construction can- 
not be avoided, all such spaces should be left as open as 




FIG. 59.— ICE CREAM HARDENING ROOM WITH PERFORATED PLATES 
OVER PIPE SHELVES. 

possible SO that air may circulate freely through them and 
thus carry ofif by evaporation any condensed moisture. 

The second principle, that of ample air circulation, is even 
more important in cold storage rooms operating above freez- 
ing than it is in rooms maintaining lower temperatures ; be- 
cause refrigeration in its simplest terms is the extraction and 
removal of heat from the goods stored, which is done not by 
immediate contact between the goods and the refrigerant but 
through the medium of the air, and in rooms operating above 



STRUCTURAL SUGGESTIONS 191 

freezing the moderately cooled air does not drop to the floor 
of the room as swiftly as if it were chilled to a lower tem- 
perature. That is, in rooms operating above freezing, the air 
circulation is naturally sluggish, although the process of heat 
interchange, by means of the positive circulation of the air, 
is essential. Room design must therefore promote air circu- 
lation as much as possible, to keep it positive and active, 
especially in rooms used for products containing much moist- 
ure, such as butter, poultr}- and meats, particularly if such 
products are put in warm for quick chilling; because such 
moisture must be taken up by the circulating air and carried 
quickly to the coils and there deposited as frost. Otherwise, 
with poor circulation, moisture will condense on the finish of 
the insulated surfaces, on the goods stored, or remain in the 
air of the room to make it damp and mouldy. 

94. — Types of Bunkers and Details of Construction. — The 

one positi\e way to guarantee a definite circulation of air 
throughout a cold storage room is to construct a separate 
cooling room, or coil bunker room, install air conveying ducts 
from the coil room to and into the cold storage room, and by 
means of blower equipment circulate or pass the air of the 
cold storage room through the system and over the cooliiig 
coils at a predetermined rate. This method of positive circu- 
lation, or cold air distribution, is frequently employed in fur 
rooms, candy dipping rooms, freezing rooms, or wherever the 
demand justifies the initial expense for such extra equipment 
and the cost of its subsequent operation. 

By far the most effective natural means of insuring active 
circulation is the overhead bunker. Air, cooled over such 
bunker by contact with the cooling coils or ice, falls over the 
low side of the bunker and to the floor, due to the fact that 
cold air is heavier than the warmer air it displaces ; and as this 
cold air absorbs the heat of the goods stored as well as the 
heat that leaks into the room through the insulation, doors, 
etc., such air rises over the high side of the bunker, circulates 
through the coils or over the ice, gives up its excess of heat 
to the refrigerant, and begins the cycle over again. Thus the 
circulation follows its natural course, and as the bunker ex- 
tends the length of the room, the air circulation reaches every 



192 



CORK INSULATION 



corner of the room and maintains a fairly uniform temperature 
in practically all parts. 

Single overhead bunkers are the most common type, but 
should not be used for rooms over 16 feet in width. For 
rooms wider than 16 feet, double bunkers should be installed. 
The bunker construction serves to guide the circulating air, 
and this function is greatly assisted by proper bunker design. 
First, the warm air up-take and the cold air down-flow must 




FIG. 60,— cox HOLDOVER TANK COOLING SYSTEM. ILLUSRAT- 

IXG PLAN DETAILS OF BUNKER CONSTRUCTION 

AND CORKBOARD INSULATION. 

be adequate; a "rule-o'-thumb" method that has given excel- 
lent results in rooms operating above freezing is to make the 
total width of these duct openings equivalent to one-third of 
the total width of the room, and then divide that one-third 
equally between the warm and the cold air ducts. Care should 
then be exercised not to "choke" the circulation at any point 
in the bunker construction between the warm air entrance 
and the cold air exit, either by restricting the passage by 
decreased dimensions, or by obstructing it by a crowded 
arrangement of coils or ice, or by counter air currents set 



STRUCTURAL SUGGESTIONS 



193 



up by failure to use sufficient insulation on the bottom* and 
baffle of the bunker. 

The overhead bunker, single or multiple type, requires 
considerable head room, a 10-foot height before the insulation 
is erected on floor and ceiling being necessary for a maximum 
head room of 6 feet under bunker and a coil loft maximum 
height of 2^ feet, A minimum height of 12 feet before insu- 
lation is applied is much better, especially if ice, which re- 



m 




FIG. 61.— COX HOLDOVER TANK COOLING SYSTEM. ILLUSTRATING ELE- 
VATION DETAILS OF BUNKER CONSTRUCTION AND CORKBOARD 
INSULATION. 

quires more head room than coils, is to be used. If the room 
is to contain overhead tracking, additional height will be 
necessary. The natural arrangement of double bunkers is 
to place each warm air up-take next a side wall and the cold 
air down-flow in the center of the room ; because the warmest 
air in the cold storage room is likely, on account of the heat 
leakage, to be a layer adjacent to the walls. In certain cases, 
however, such as chill rooms for fresh killed poultry or pre- 
coolers for fresh beef, this warm and cold air duct order 



•Sufficient insulation on the bottom of bunker will also prevent sweating. 



194 



CORK INSULATION 



should be reversed ; because the greater temperature will then 
come from the fresh goods stored in the room, away from 
the walls, and the natural circulation will be through a warm 
air up-take in the center of the room and down at either side. 

In the case of a single bunker, the warm air up-take should 
be on the entrance door side of the cold storage room, so that 
the in-flow of warm air occasioned by the opening of the cold 
storage door will be carried up and over the bunker before 
coming in contact with the goods stored in the room. 

Where the available ceiling height does not permit of over- 
head bunkers, the side or wall bunker may be used, though 
it is much less effective, except in narrow rooms, a width of 
12 feet probably being the ultimate limit for a single wall 



O O O O O O O O O ' •' '' r -, 
O O O O O O O C- O O O C; O O 

oooooogooooooo 
oooooooooooooo 




FIG. 62.— SECTION OF TYI'ICAL SINGLE OVERHEAD COIL BUNKER. 

bunker. ^Vider rooms of limited ceiling height should have 
wall bunkers along both sides, but not along one side and one 
end. 

Low rooms employing mechanical refrigeration, frequently 
use ceiling or wall coils, or both, instead of the side bunker, 
provided the cold storage room does not contain too much 
moisture requiring an active and positive circulation to dispose 
of it as frost on the cooling coils. Drip pans under ceiling 
coils and open drain spouting under wall coils should be pro- 
vided to care for the water of meltage. Very wide rooms 
and rooms used for long storage, more often use ceiling coils 
than bunkers, regardless of the height available; such ceiling 



STRUCTURAL SUGGESTIONS 



195 



coils are grouped and the groups spaced at proper distances, 
each group equipped with an insulated drip pan, a modified 
form of overhead bunker. The arrangement, when both ceil- 
ing and wall coils are used, should never include an installa- 
tion of piping on ceiling, one side wall and one end wall ; but 
should be limited to ceiling and one or both side walls, so as 
to avoid cross or counter currents and consequent poor air cir- 
culation and "pockets." Where wall coils only are used, the 
coils should be located on opposite side walls, or equally dis- 




FIG. 63.— DETAIL OF HENSCHIEN PIPE LOFT FOR HOG COOLER. 

tributed on all four walls, the shape of the room as it may or 
may not depart from a square being the governing factor. 



95. — Circulation, Ventilation and Humidification. — A good 
deal has previously been said about the necessity for air cir- 
culation in cold storage rooms, but the subject shall now be 
briefly considered in conjunction with the ventilation and 
humidification of rooms used for the handling and storage of 
certain products. 

The question of the hygrometric condition of the air in 



196 



CORK INSULATION 



cold storage rooms, especially in refrigerated warehouses, is 
of much importance for satisfactory results in the preservation 
of various kinds of foods, such as fruits, meats, eggs, etc. 
Humidity is now believed by many to be almost as important 
as temperature itself; and this conviction coupled with the 
further recognition of the desirability, if not the necessity, for 
the ventilation of rooms containing certain products, makes 
circulation, ventilation and humidification of cold rooms an 
important, and it may be said an involved, subject. 

It is a well-known fact that meat cannot stand a higher 
temperature than the freezing point, without it undergoes a 
continuous evaporation through its surface, unless the humid- 
ity of the cold room is kept sufficiently low. For eggs, the 



oooo 
oooo 
oooo 
oooo 
oooo 
oooo 
oooo 
oooo 
oooo 
oooo 
oooo 


1 



FIG. 64.— SECTION OF TYPICAL SIDE BUNKER ARRANGEMENT FOR 
SMALL ROOM OF RESTRICTED HEIGHT. 



air must be kept at a higher degree of moisture than for meat. 
For fresh fruits, the air must be moist enough to prevent the 
drying out of the fruit due to excessive surface evaporation, 
while at the same time the air must not be too moist if decay 
is to be avoided. 

Thus with some products it is essential for best results 
that some form of ventilation and humidification, or air con- 
ditioning, be provided in cold storage rooms to prevent evapo- 
ration and spoilage ; and the proper design and insulation of 
such rooms is even more important than that of the regular 
run of cold storage rooms. The question of the proper method 
and equipment to use for the air conditioning of cold storage 
rooms will not be treated in this text, although permission 
has been given for the partial reproduction of an article, whic 



STRUCTURAL SUGGESTIONS 



197 



should be of general interest at this point, on the subject of 
"Temperature, Humidity, Air Circulation and Ventilation," 
by M. R. Carpenter, Architect and Refrigerating Engineer, 
72 W. Washington St., Chicago, Illinois : 

During the past ten years, or thereabout, the subject of air con- 
ditions in cold storage has been receiving considerable attention from 
those who are in a position to recognize the shortcomings of the aver- 
age cold storage plant as a means of holding and preserving edible 
products, during the time of storage. 




FIG. 65.— INSULATED MEAT COOLER ON BLUE STAR LINE S. S. ALAMEDA, 
SHOWING INSTALLATION OF PIPING ON CEILING AND ALL WALLS. 



Many things are involved in the successful preservation of such 
commodities and it is for the purpose of calling attention to these 
various items that this paper is written. 

As a rule, cold storage plants represent the expenditure of large 
sums of money and are owned and operated by conservative business 
men, who have to be shown before they will adopt any new system, 
or attempt to maintain any condition in their cold storage rooms 
which has not been proved to them to be desirable in practical use. 
This is good business policy, as failure would mean the loss of enor- 
mous sums in spoiled goods, which they would have to assume, due 
to such experiments. 



198 



CORK INSULATION 



In the early days of cold storage, the first consideration was tem- 
perature, and the designers of such plants gave little thought to other 
features. This is still true, for that matter, with a large majority, as 
may be noted by examination of many storages, and by the fact that 
practically all contract forms issued by manufacturers of refrigerating 
machinery guarantee temperatures and nothing further, inside of the 
rooms; but practice soon proved that other things were important, 
especially as some storages were damp and musty, which was disas- 
trous to the goods, due to the growth of fungi or mould; therefore, it 
was found desirable to adopt measures to avoid this condition, and 
the next step was in the direction of obtaining cold, dry rooms; this 
was accomplished either by properly loratine the refrigerating coils 




FIG. 66.— CORKBOARD INSULATED CHOCOLATE DIPPING ROOM WITH 
COLD AIR DUCT CIRCULATING SYSTEM. 

or by some method of drying the air, by means of lime or calcium 
chloride; the various methods for accomplishing this are familiar to 
all, especially the older heads. 

Experience showed that the design of the refrigerating coils and 
the location of them in the rooms to be cooled had a material bearing, 
both on the efiiciency of the cooling effect and on the humidity of the 
air; this was to have been expected as it follows out a simple law of 
nature which, when adhered to consistently, results in an extremely 
dry atmosphere. 

This dry condition naturally leads to shrinkage, or evaporation of 
the moisture from the goods, which, if it was allowed to proceed 
beyond a certain point, caused trouble of another type; therefore, it 
was found desirable to maintain a certain amount of humidity; and 



J 



STRUCTURAL SUGGESTIONS 199 

many practical experiments were, and still are, being made, to deter- 
mine to just what extent relative humidity can be carried before it 
becomes objectionable and dangerous in other respects; this led to 
many differences of opinion, as each example of practical results was 
modified by specific conditions pertaining particularly to the individual 
room; these conditions were not fully understood or taken into con- 
sideration in the conclusions; therefore, a certain relative humidity, 
which proved correct or beneficial in one room, or house, proved 
incorrect in another; then, too, the method and manner employed for 




FIG. 67.— MEAT STORAGE' COOLER WITH OVERHEAD TRACKING AND 
COIL ROOM ABOVE. 

determining humidity was often open to question, as was also the 
correctness of the determination. 

Humidity determinations taken in a room are often of no value in 
fixing the relative humidity immediately surrounding the goods, due 
to sluggish air movement or definite pocketing of the surrounding air, 
such as, for instance, goods contained in tight barrels or other tight 
or semi-tight packages, goods wrapped in paper, or goods piled tight, 
without channels between them. 

As a rule, there is very little trouble encountered in securing 
humidity; the difficulty lies in controlling it and maintaining it con- 
stant; therefore, the tendency is to proceed very carefully and not 
overdo it. 



200 CORK INSULATION 

Until comparatively recent years, there has been no reliable data 
on which to proceed in a practical way. It is true that experiments 
have been made for years; some along the line of best temperatures 
for particular goods, some for humidity in relation to shrinkage, 
humidity in relation to mould, etc., and these experiments have been 
made by individuals fully qualified and capable of carrying on such 
work. Especially is this true of the experiments made by the United 
States Department of Agriculture; however, in most cases there has 
been a lack of some certain conditions, or combination of conditions, 
either through lack of knowledge of new factors entering into the 
experiment, or through a lack of eflficient apparatus to fully cover all 
requirements. No criticism of these experiments is implied, for every 
one, when made with care, has brought us nearer to a solution, and 
a step-by-step advancement in this art is a surer way than to try 
everything at once. 

It probably is universally conceded that all vegetable products 
have a definite life limit, during which time they function as living 
organisms, absorbing or breathing in certain gases and exhaling, or 
giving off certain other gases or esters, during which period they 
continue to develop and change until their physical development is 
complete and their life span is ended, after which, especially in the 
case of fruits, they are spoken of as being dead ripe. 

Assuming the foregoing facts to be true, one may readily appre- 
ciate how necessary it is to have definite air circulation to supply 
fresh air to absorb the heat, as well as to remove the gases given off, 
or ejected, by the goods. 

No vegetable products, in the natural state, are of the same food 
value after becoming dead ripe, as they are at some stage prior to 
reaching that state, after which no temperature or other cold storage 
condition will prevent them from deteriorating at a rapid rate. 

Animal products, on the other hand, are dead and any change is 
either chemical or due to plant or animal organisms. 

Granting that the foregoing statements are correct, let us con- 
sider what means will best serve to prolong the life of fruits, vegetables 
and animal products. In answering this, there need be no hesitancy 
in stating that there are just two factors — correct temperature, and 
pure, conditioned air. By conditioned air, is meant air containing 
the correct amount of moisture for the particular goods under con- 
sideration. This sounds rather simple; yet, to secure these two con- 
ditions requires a knowledge of and a scientific appreciation of nature's 
laws. To even approach a state of perfection in a practical way, 
involves about all that is known at the present time regarding correct 
design, equipment, and operation of cold storage warehouses; so it is 
not as simple as it seems. 

It may be well to consider, at this time, briefly, the subject of 
temperature. What is its function? And pure, conditioned air; what 
part does it play? 



STRUCTURAL SUGGESTIONS 201 

Temperature aflFects the growth of living organisms, both vege- 
table and animal, and, when below the temperature level best suited 
to this growth, or development, has the effect of slowing them up, 
rendering them dormant or destroying them entirely; depending upon 
the decreasing temperature to which they are subjected; therefore, in 
the case of vegetables or fruit products, their life span is increased, 
and, in respect to attack from the outside, they are again protected 
by the dormant condition of their enemies. 

Animal products, which are dead substances, can only be pre- 
served by the prevention of changes due to attack by living organisms, 
either contained in but not a part of them, or by attack from the 
outside; again, as in the case of the vegetable kingdom, these enemies 
are rendered less active as the temperature decreases. 

Our problem may then be divided into two parts. The first is to 
determine the correct temperature and relative humidity of the air, 
for each particular product; and this division may best be left in the 
hands of scientists, who have the proper knowledge and apparatus for 
making scientific tests and determinations for solution. The second 
involves the application of the conditions first found, and naturally 
leads to the designing engineer, with the co-operation of the scientist, 
in providing such construction, apparatus and operation as will secure 
the correct temperature and air conditions. 

Having been instructed regarding the proper temperatures and 
relative humidity, how shall we proceed to secure them? 

Temperature. 

We shall first consider temperature. It is self-evident that if a 
product is to be held at a certain specified temperature, it is the tem- 
perature of the product and not necessarily the temperature of the 
room which is important. 

This being the case, how are we to insure the temperature of 
the product? In answer to this, it is necessary to consider the trans- 
fer of heat. Heat must be taken from the goods and delivered into 
the refrigerant, which is circulating through the refrigerating coils, 
and this heat can only be transferred in two ways — by conduction, or 
by convection. 

Heat transfer by conduction through air is a slow process, and 
altogether out of consideration for practical results; therefore, trans- 
fer by convection is the only practical method, and this involves a 
definite air movement, and the rapidity with which the heat is trans- 
ferred is in direct proportion to the rapidity of the air movement 
through the goods, to and over the refrigerating coils and back to the 
goods. 

There are two methods of circulating air, one way being to take 
advantage of what is called natural circulation, that is, air movement 
in a vertical direction, due to the difference in temperature, or specific 
gravity, which method is slow, uncertain, and with little power to 



202 CORK INSULATION 

overcome obstacles, to reach out into pockets and crevices, or to 
move through piled goods in any direction. 

The other method is by means of mechanically moved or forced 
air circulation, which is powerful and active in entering into all 
crevices, pockets, etc., and which moves through goods in any direc- 
tion, thereby taking up the heat from the interior of packages, as well 
as from the outside, and is therefore efficient in securing quick transfer 
of heat. 

From the foregoing it will be noted that the only practical method 
of insuring the proper temperature of goods in storage appears to 
be to subject them to a forced air circulation, due consideration to be 
given to proper piling, ventilated crates, etc., and with means of con- 
trolling the intensity of the air movement. 

Air and air movement are considered in the foregoing only as a 
medium for holding, and a method of conveying the heat units from 
the goods to the refrigerating coils; later we shall utilize this same air 
and air movement for another purpose. 

Pure Conditioned Air. 

The second condition essential for the preservation of goods is to 
surround them with air which is free from all foreign gases, dust, 
germs, spores, bacteria, etc., but with sufficient moisture content to 
prevent the absorption of the natural moisture content of the goods, 
as otherwise they would be caused to shrink, which is not only objec- 
tionable in itself, but, in the case of vegetable products, also causes 
them to become more susceptible to attack from other sources, and 
hastens the breaking down of the whole organic structure. 

Pure air not only insures against contamination from the exterior, 
but has a decided purifying effect in itself. 

To surround goods with pure air and correct . moisture content, 
it is not sufficient to merely maintain this condition in the open parts 
of the room; because, as in the consideration of temperature, it is the 
products themselves which must be considered, and the air in the room 
is only an approximate indication, depending largely upon the circula- 
tion of the air. 

As in the example under temperature, natural circulation is very 
slow and without the power to penetrate deeply; therefore, air be- 
comes pocketed, in which condition it absorbs moisture from the 
goods until it becomes fully saturated; it also absorbs gases or esters 
and, as a result, becomes foul, the natural effect of which is to pro- 
vide a condition suitable for the growth of moulds, fungi, or other 
destructive agents, which, also due to the lack of proper temperature, 
as shown before by sluggish or stagnant air, are not materially re- 
tarded in their growth. 

The other method — that of forced air circulation — is positive, 
penetrating, and scrubbing in its action. It prevents any accumula- 
tion of dead air, and therefore maintains an ideal condition imnie- 



STRUCTURAL SUGGESTIONS 



203 



diatcly in contact with the goods, assuming, of course, that the method 
of packing and storing the goods is in keeping with the idea of 
thorough and efificient air circulation. 

It will have been noted that use of the term ventilation has not 
been made in any of the foregoing, the term being considered as a 
description covering another process. 

In the foregoing subject of pure, conditioned air, it is assumed 
that the air being circulated is pure and of the correct relative 
humidity; in practice, this is, of course, impossible, unless there is 
provided some means of keeping it pure and of the right moisture 
content. The air is continuously taking up gases and odors from 
the goods, as well as changing in moisture content, due to absorption 




-INSULATED EGG STORAGE WITH OVERHEAD BUNKERS AND 
PATENTED VENTILATING SYSTEM. 



of moisture from the goods or depositing it on the refrigerating coils, 
-thereby becoming impure and with the wrong moisture content, which 
will, in the course of time, cause the air to become foul and dangerous 
and, in the case of forced air circulation, increasingly so, due to the 
ability to distribute dangerous organisms, spores of disease germs, 
quickly and effectively, unless some provision is made for keeping it 
pure; this is where use is made of ventilation. 

Starting out with the storage space clean and free from mould or 
objectionable odors, and with the goods in a clean and altogether 
suitable condition, the preservation is dependent more upon preventive 
measures than upon corrective ones, and it is a very simple matter to 
offset or rectify the slight contamination of the circulated air, due to 
eliminations from the goods, by some system of ventilation, that is, by 



204 CORK INSULATION 

introducing pure, fresh air, in sufficient quantities, while discharging 
an equal amount of stale air, thereby keeping the percentage of im- 
purities down to a low point. Naturally the amount of fresh air 
introduced will depend entirely upon the amount required to rectify 
the foul condition of the old air. 

Where forced air circulation is employed, providing the equip- 
ment is properly designed, the introduction of fresh air is a simple 
matter. 

Normal Humidity. 

The control of moisture content of the circulating air is difficult 
unless proper provision is made for adding or subtracting moisture, 
as occasion demands. 

At this point, the privilege is taken of using one word to indicate 
the proper moisture content of the air for a specific commodity, and 
it is normnl; normal may mean any relative humidity, but when used 
in connection with a specific commodity it is a definite percentage; if 
it is above this percentage, it is normal-plus, if below, it is normal- 
minus. 

Therefore, what may be normal humidity for one class of goods 
may be normal-plus or normal-minus for another. 

To determine what is normal in each instance is the work of the 
scientist, or it may be determined by practical experience, extending 
over a period of years, but in this case it may only apply to a par- 
ticular room or warehouse, as the amount of moisture which may be 
maintained in the air of any room is absolutely dependent on the 
efficiency of the air circulating system and its ability to penetrate to 
all parts of the goods, thereby maintaining the proper temperature 
and air condition. 

As before explained, the air, in circulating through the various 
channels, is ever subjected to conditions which have a tendency to 
vary the moisture content. The most severe conditions are: First, 
the goods in storage; and, second, the refrigerating coils; the first in 
adding to the moisture content and the second in reducing the moist- 
ure content, and, where ventilation is utilized to purify the air, another 
condition is encountered, which may either increase or decrease the 
humidity. 

It has been proved by scientific research, as well as by practical 
experience, that a certain amount of moisture in the air is not only 
beneficial, but is absolutely necessary to the preservation of goods; 
also, that under certain conditions, especially with forced air circula- 
tion, it is absolutely necessary to maintain a high moisture content 
in the air. 

Assuming, therefore, that we carry a relatively high humidity, 
which will prevent the air from taking up moisture from the goods, 
we have eliminated, to a large extent, interference from that source; 
we have then left the drying effect of the refrigerating coils and, 
with forced air circulation, this is sufficient, practically all of the time 



STRUCTURAL SUGGESTIONS 



205 



and under almost all conditions, to produce normal-minus humidity; 
therefore, in order to keep the air up to normal, it is usually neces- 
sary to introduce moisture, either with the fresh, ventilating air, oi 
with the recirculated air. In either case, a fully saturated air may be 
introduced when necessary, without danger of depositing moisture on 
the goods, due to the fact that it will be mixed with a much greater 
volume of normal-minus air before coming into contact with the 
goods. 

At certain seasons of the year, namely, during periods of low 
temperature, when the refrigerating coils are not being used, except 
to a very limited extent, if at all (and therefore their drying effect is 
greatly reduced or stopped entirely), nature still provides ample means 




FIG. 



69.— INSULATED BANANA ROOM EQUIPPED WITH OVERHEAD 
BUNKERS AND PATENTED CONTROL SYSTEM. 



of controlling the humidity, by furnishing cold air which, when raised 
to the temperature requirements of the room, will be comparatively 
dry and may be introduced in sufificient volume to offset other con- 
ditions, and thus maintain the circulating air in normal condition. 

Theoretically, the system which would maintain ideal air condi- 
tions would be one which circulated fresh, pure, conditioned air, at 
the proper temperature, through the goods in ample volume, and 
discharged it after one passage through the goods, but this is imprac- 
ticable, due to the great expense of purifying, conditioning and cooling 
such a volume, and the enormous loss occasioned by discarding the 
air at such a temperature, and unnecessarily, as practically the con- 
ditions may be secured in another manner, that is, by introducing a 
small amount, comparatively, of pure air, which will rectify the air 
consumed or contaminated by the goods. 



206 CORK INSULATION 

Pure air is difficult to secure, especially in or adjacent to thickly 
populated communities or manufacturing districts; however, various 
means may be employed to assist in this respect; to enter into dis- 
cussion of this subject would be beside the point at this time, yet it 
may be well to call attention to one agent, which has been utilized to 
some extent and found beneficial under some conditions, but due to 
poor design or mechanical faults, and to apparatus not adapted to use 
in air with even a low relative humidity, the benefits have not been 
secured in full measure; this agent is "ozone" or "ionized air." Equip- 
ment for the production of ozone is now perfected and being installed 
under a guai'antee, which safeguards the purchaser. 

This agent and the equipment for producing the same is men- 
tioned here, as it is particularly well adapted for use with forced air 
circulation, and gives just the teeth with which we wish to endow 
our air in order to make it function as a purifier. 

In consideration of all that has been brought out heretofore, 
there is but one conclusion possible. In order to secure proper con- 
ditions for the preservation of food products there must be correct 
temperature and air conditions, in and around the products, which can 
be assured in one way only, that is, by mechanically circulated air. 

Air conditions can only be secured by proper humidity control 
and efficient means of ventilating or rectifying, or both. 

96. — Preparation of Building Surfaces to Receive Insu'a- 
tion. — Perhaps the greatest change in insulation practice dur- 
ing the past ten years has occurred in connection with tlie 
method of applying the initial course of insulation to Av.all 
surfaces, especially to concrete, hrick, tile or stone. 

To erect corkboard in any manner against plaster over 
wood or over metal lath, has never been approved ; such lath 
and plaster must be removed and replaced by J^-inch T. & G. 
sheathing boards, solidly secured ; and whether the insulation 
of a cold storage room should be erected against studs closed 
in by sheathing, wull depend entirely upon the conditions sur- 
rounding each case. The dangers from confined air spaces 
back of insulation ha.ve already been pointed out; but the 
purpose, utility, cost, allowable investment, etc., should be 
the final determining factor for each project. 

In the case of stone, concrete, brick and tile surfaces in 
existing buildings, it is necessary to take such surfaces as 
they come along, carefully inspect them, and then properly 
prepare them to receive insulation. Usually such surfaces 
have been whitewashed, painted, or otherwise coated ; and if 



STRUCTURAL SUGGESTIONS 207 

so, they must be carefully and thoroughly cleaned before it is 
possible to apply corkboard insulation to them successfully. 
Such cleaning must usually take the form of hacking, which 
is a difficult job in most instances, and considerable care must 
be exercised if the finished work is to be satisfactory. 

After the complete area of such walls has been hacked, or 
otherwise prepared as required, it will often be found that 
their surfaces are sufficiently irregular to require pointing 
up, unless the first kn^er of insulation is to be erected in a 
bedding of Portland cement mortar, and sometimes even then. 
On the other hand, if the purpose of the insulated room or 
structure makes it imperative that the first layer of insulation 
be erected in hot asphalt to walls that have first been primed 
with suitaljlc asphaltic material, then the pointing up work 
must take the form of a complete leveling and smoothing up 
of the areas to be insulated ; because the thickness of the hot 
asphalt that clings to the sheets of corkboard when they are 
dipped, is quite insufficient to be relied upon for anything 
except a bond, and a uniformly full bond is not possible except 
against reasonably smooth, flat surfaces. Furthermore, if the 
primed surface to which the sheets of corkboard are applied 
is unexcn. the surface of the finished cork work will be just 
as much, or possibly more, uneven, and may seriously inter- 
fere with the making of tight insulation joints and with the 
proper interior room finish over insulation, not to mention 
the air pockets behind the corkboards. Consequently, the 
cost of proper preparation for insulation to be applied in 
existing structures and following the most approved specifi- 
cations, is sometimes prohibitive, and an insulation specifica- 
•tion less expensive must be selected or the project altered or 
abandoned. 

The preparation of surfaces in new structures to receive 
insulation frequently does not have the forethought and atten- 
tion that its importance justifies. Preparation should begin 
with the drafting of the plans and specifications for the build- 
ing itself; but smooth, even, brick walls on the architect's 
drawings are not necessarily smooth, even, brick walls when 
actually erected, unless thought is given to the functioning 
of those walls other than their load-carrying and encompass- 



208 CORK INSULATION 

ing capacity. It costs more to make both sides of a building 
wall equally straight and smooth ; but if the latest, approved 
insulation specifications are to be carried out, this point must 
be given necessary advance attention. 

The insulation specification usually followed for many 
years was to apply the first layer of corkboard to the new, 
clean building wall in a bedding of Portland cement, then 
apply the second layer to the first in a bedding of Portland 
cement, or in hot, odorless asphalt, and then finish the insula- 
tion off with Portland cement plaster, applied in two coats. 
Thus surfaces to receive insulation had to be only reasonably 
smooth ; but failures of insulation applied in this way, espe- 
cially in ice storage houses, became sufficiently numerous, as 
the years passed, to finally justify active investigation of the 
subject by manufacturers and important users; and the fail- 
ures of insulation, aside from those due to poor materials and 
workmanship at the time of installation, were traceable to 
moisture in the insulation, which collected after the corkboard 
had been in service for some time and which in time caused 
disintegration of the corkboard through the decomposition 
of the resin binder in contact with water or which caused 
more rapid disintegration from alternate freezing and thawing 
of moisture in the insulation. These investigations conclu- 
sively demonstrated that this moisture found its way into 
the cork insulation through two distinct and different sources. 

When water is precipitated on the plastered surface of 
an insulated cold storage room, by the condensation of moist- 
ure out of the air against a cool surface, a part of such water 
is absorbed by the plaster by capillarity, which tends slowly 
to disintegrate the plaster while placing a portion of this 
moisture on the surface of the insulation directly behind the 
plaster. The cork, unlike other materials, will not take up 
this water by capillarity, as previously explained, but such 
water may find its way into the corkboards by gravity, travel- 
ing through small interstices or voids between the particles 
of cork bark used in the manufacture of the corkboard. While 
manufacturers now understand and appreciate that the modern 
corkboard product of maximum worth must be compact and 
free from voids to the greatest possible extent, yet it would 



STRUCTURAL SUGGESTIONS 209 

appear that in the manufacturing process all voids, especially 
surface voids, cannot be eliminated. Thus water in contact, 
as just explained, has been knov^-n to penetrate corkboard 
insulation to a depth of an inch or so toward the outside 
building M'alls. 

Water may also find its way into corkboard insulation 
through an entirely different source, that is, from the outside 
of the building. When the temperature of a cold storage 
room is lowered by refrigeration, the air in that room contracts 
with cooling, because cold air occupies less space than the 
same original volume of warm air. Thus the cooling of the 
air in a cold storage room creates in that room a temporary 
partial vacuum, or an unequal pressure between the inside 
and the outside of the room. If the room is tightly closed, 
air will be sucked through the building walls and the insula- 
tion, to balance the unequal pressures, and this air, carrying 
with it water in suspension, the quantity measurable by the 
humidity of the air, wuU precipitate its moisture in the insu- 
lated wall where the dew point is reached. 

The discovery of these two distinct ways in which moist- 
ure is placed in corkboard insulation has been of great value 
in revising insulation specifications. The air-proofing of the 
surfaces to which the insulation of cold storage rooms is 
applied, to be carried out as best as possible under each set 
of conditions, is now done wherever possible or feasible, so 
that instead of air being drawn through the building walls 
and the insulation to compensate a partial vacuum, such air 
will be supplied through some other channel or in some other 
way. For example, it is now frequently the practice in large 
ice storage houses to install a small air compensating vent 
door or opening in or near the ceiling. 

It will be noted that surfaces to receive insulation are 
recommended to be air-proofed, not water-proofed ; and the 
necessity for air-proofing is believed to increase with decrease 
of cold storage room operating temperature, and in a general 
way with the size of the room, that is, the greater the cubical 
content of the room the greater will be the vacuum effect 
produced by the refrigeration. Again, the choice of the kind 
of materials used in the building construction, for instance, 
will decrease or increase the resistance of the passage of air. 



210 



CORK INSULATION 



A hard, repressed brick is to be preferred. If monolithic 
concrete, it should contain a so-called water-proofing material 
to close up the pores as much as possible and provide just 
that much more resistance to the infiltration of air. 

Reasonably smooth and level inside building surfaces must 
be left to receive insulation, if it is to be erected in hot asphalt 
instead of the usual half-inch bedding of Portland cement mor- 
tar ; because there is no appreciable thickness to hot asphalt 




FIG. 70.— :\IILK STORAGE ROOM WITH CEILING OF IRGNED-ON-AT-THE- 
FACTORY MASTIC CORKBOARD AND WALL INSULATION PLASTERED. 



to compensate uneven wall surfaces, as previously noted. To] 
air-proof building walls, two good coats of a suitable "asphalt 
primer" — not ordinary asphalt paint — should be applied, by 
brush or spray gun, as reason dictates. A suitable priming ma- 
terial is a good grade of unfluxed petroleum asphalt cut to the 
proper consistency with a solvent. The corkboards should 
then be erected in hot, odorless asphalt against the primed 
surface of the building walls, and the second course of insu- 
lation erected to the first in the same material and addition-' 
ally secured with hickory skewers. If the building surfaces 
provided in the first place are not reasonably smooth, the 
second layer of insulation may have to be erected to the first 
layer in a bedding of mortar, instead of in hot asphalt, to 



STRUCTURAL SUGGESTIONS 211 

effect a general leveling up of the last course of insulation 
in preperation for the finish over insulation. But hot asphalt 
between the layers of corkboard is preferable, because it gives 
just that much additional air-proofing. Detailed information 
relative to asphalts will be found in a later Article in this 
Chapter; and detailed specifications and directions for apply- 
ing asphalts will be found in their proper order in Chapters 
XIII and XIV, respectively. 

It must not be inferred that the greater proportion of 
moisture in corkboard insulation comes in from the outside 
through the building construction. It is but one of two ways, 
and it will be recalled that the other way in which moisture 
finds entrance is through the Portland cement plaster finish 
that it has been for so many yea^s the universal custom to 
apply ; but the proper preparation of building surfaces to 
receive insulation is one of the most important single con- 
tributing items to the high efficiency and long life of cold 
storage room insulation. 

97. — Insulation of Floors, Columns, Ceilings and Beams. — 

Probably because a cold storage room is colder at the floor 

than at the ceiling, even though the floor insulation may be 

wholly inadequate, some have been tempted to specify either 

very light floor insulation, or none at all. The importance of 

adequately insulating the bottoms of ice-making tanks and 

! the floors of all ice storage houses and cold storage rooms, 

. especially when such floors are located on the ground, is prob- 

: ably not as fully appreciated as is the necessity for proper 

insulation of other surfaces. 

The fact that a cold storage room is colder at the floor 
:-than at other vertical points, even though it has no insulation 
on the floor, is due to the weight of cold air as compared with 
warm air, rather than to the possibility of the heat leakage 
being less through such uninsulated floor than it is through 
the insulated walls and ceiling. This fact, of course, is very 
elemental ; but it evidently persists in the minds of some, and 
should be disposed of before proceeding to the consideration 
of the proper insulation of all floors that rest on the ground. 
The average temperature of the earth varies for different 
years and localities between about 50° and 60° F. If a cold 



212 CORK INSULATION 

storage room is operated throughout the year, the loss of 
refrigeration per unit area through an uninsulated floor resting 
on the ground is surprising; and if such room is operated 
during the warm and hot seasons only, when the average tem- 
perature of the earth for such period is somewhat higher than 
the average for the year, then the loss of refrigeration through 
such uninsulated floor in contact with the ground is even a 
more serious item. Where temperatures below freezing are 
maintained, failure to adequately insulate ground floors is 
quite likely to entail serious losses other than those of unnec- 
essary heat leakage, as the freezing of the earth has been 
known to disturb entire building structures with consequent 
heavy loss to property and business. 

The insulation of floors should have the same careful con- 
sideration as would be given to the insulation of any other 
building surface. Sharp freezer rooms in cold storage plants 
should always be located on the top floor, or floors, not in 
the basement, and not between floors that are to operate at 
higher cold storage temperatures. If sharp freezers are lo- 
cated in the basement, there is unnecessary risk of the freez- 
ing of the ground underneath, even though the floor is heavily 
insulated, with consequent heavy losses; and if they are 
located between floors that are to operate at higher tempera- 
tures, goods stored on the floor directly above, even though 
the building slab between is well insulated, are likely to 
freeze. 

The complete arrangement of cold storage rooms — their 
size, height, location, purpose, and general utility — should be 
most carefully thought out in advance, with the idea of ade- 
quate safeguard and maximum economy in construction and 
operation; and the degree of success obtainable with cold 
storage rooms is directly dependent on the degree of intelli- 
gence and care that is put into such planning. 

Columns and pilasters, of concrete or steel, especially those 
in cold storage rooms situated in basements and lower floors, 
must be adequately insulated, primarily as a safeguard against 
disastrous results to the stability of the entire building struc- 
ture caused by the freezing of the earth at their base. The 
proper insulation of columns and pilasters for the prevention 



STRUCTURAL SUGGESTIONS 



215 



the ceiling construction, as floor insulation, and the insulation 
of the walls can be made continuous, without breaks at floor 
(ceiling) levels, by providing an interior building structure of 
concrete and steel to carry the load of the cold storage section 
of the building and its contents, and casing it in with self- 
sustaining curtain walls, of brick or concrete, entirely inde- 
pendent of the interior structure except for a few small metal 
tic'^. The insulation of outside building walls is then applied 
against the inner surface of the curtain walls in a continuous 
sheet, without breaks at floor lines and connecting with the 




FIG. 73.— DETAILS OF BROKEN WALL INSULATION WITH 3-FOOT CORK- 
BOARD RETURN ON CEILING BELOW (SEE TEXT). 

proper floor (ceiling) insulation Mdierever it may occur; but 
where insulated interior dividing walls are required, such as 
those walls that may divide the cold storage section of the 
building from the dry storage section, provision frequently 
need be made only for self-sustaining cork walls unsupported 
•by interior building walls of any kind. In this way the cold 
storage section of the building is literally enveloped wdth insu- 
lation, loss of refrigeration is reduced to a minimum, and all 
ceiling insulation disappears in favor of floor or roof insulation 
next abo\'e. 

In old buildings of mill construction, it is frequently pos- 
sible, and if so, highly desirable, to remove the ceiling and 
floor coverings at all wall lines where insulation will occur, 
and make such insulation continuous through and between the 



216 CORK INSULATION 

joists of such ceiling and join it with floor (ceiling) insulation 
above. In old buildings containing concrete ceiling slabs so 
supported as to make cutting through for continuous insula- 
tion impossible or not feasible, the wall insulation is some- 
times carried out on the underside of ceiling a distance of 3 
feet and then the entire floor area above is insulated. 

The effect of this is to obtain an insulating value at the 
uninsulated perimeter of the concrete slab of something in 
excess of 36 inches of concrete, which will suffice for normal 
temperatures, and places much the greater part of the ceiling 
insulation on the floor above. 

In old buildings of such design that continuous insulation 
is not possible or feasible, then the insulation must be applied 
to the underside of wood sheathed joists, or to the under- 
side of concrete slab and around all beams and girders. Great 
care should then be taken to properly prepare the surfaces 
for such insulation, to properly apply it, and then finally to 
finish such insulation off in accordance with the most approved 
modern practice. Especial care should be taken to carry the 
insulation around all beams and girders, it never being per- 
missible to construct any kind of false ceiling at the bottom 
line of beams or girders and apply insulation to such false 
work, leaving closed air spaces above, because such spaces 
will fill with water and the insulation will fail. If the height 
between floors of the building is greater than required for the 
cold storage rooms, then false ceilings hung from above are 
permissable if they leave enough space between for good 
ventilation. For rooms of moderate width, under the sarr>e 
conditions, where there will never be extra weight applied on 
top of the cold storage room ceiling construction, T-irons are 
frequently supported on the side wall insulation, 12 inches 
apart, to support two layers of corkboard, one above and one 
below, to form a self-supporting cork ceiling of satisfactory 
utility. 

98. — Doors and Windows. — The three principal heat losses 
that occur in the average cold storage room, after it has been 
brought to temperature, are : 

(a) Heat leakage through the insulated floor, walls and ceiling. 



I 



STRUCTURAL SUGGESTIONS 



217 



(b) Heat entrance permitted by the opening of doors, allowing 
warm air to pass in and cold air to pass out. 

(c) Heat brought into the room in goods placed in storage, 
through the medium of the thermal capacity of such goods. 

The relation of these, or the importance of any one with 
respect to another, in the case of any given cold storage room, 
is dependent on too many variables to permit of comparisons; 
but it is now generally recognized that the modern cold stor- 
age door plays an important part in reducing "door losses" 




FIG. 74.— VICTOR STANDARD INSULATED FRONT FOR CORKAND-CEMENT 
SERVICE REFRIGERATORS. 



! to a very low point. The fact is that the use of special door 
■Equipment, consisting of door and frame and hardware assem- 
bled complete, and built by reliable manufacturers, for cold 
stores, is now so universal in the United States as to be 
standard, the time-honored, ill-fitting, home-made cold storage 
: door having been completely discarded in favor of the modern 
cold storage door that is well braced and heavily constructed 
p of seasoned lumber to withstand years of hard special service, 
I corkboard-insulated for highest permanent thermal efficiency, 



218 



CORK INSULATION 



and delicately fitted to heavy frame on special and reliable 
hardware for quick and easy opening and air-tight closing. 
Cold storage windows, except for retail display purposes, were 
also discarded, following the advent of modern electric light- 
ing equipment. Where windows must be used, they should 
be specially manufactured, with multiple panes and sealed 
air spaces and equipped with modern improved hardware. 

With the use of modern cold storage door equipment, the 
entrance of heat permitted by the opening of doors cannot be 
further reduced except through the employment of such de- 




FIG. 75.— STEVENSON "CAN'T STAND OPEN" TRACK DOOR—RIGHT HAND 
SWING. 



vices as anterooms, vestibule or "flapper" doors, automatic 
door closers, etc., which will reduce the amount of warm air 
that would otherwise enter the cold room. 

Cold storage doors may swing either "right-hand" or "left- 
hand"; and since there is often confusion as to the exact 
meaning of these terms, an explanation shall be given. When 
standing so as to squarely face the front of a cold storage 
door, a right-hand door will have the hinges on the right hand 
side, and when opened with the right hand will swing past the 
right hand side of the body; and a left-hand door will have the 
hinges on the left side and when opened with the left hand 
will swing past the left hand side of the body. Cold storage 
doors may have any one of three kinds of sills; namely, (1) 
beveled or threshold or beveled threshold, (2) high or over- 



STRUCTURAL SUGGESTIONS 



219 



lapping, and (3) no-sill or angle-iron or concrete. Specifica- 
tions for cold stora.ce doors to be equipped with automatic 




FIG. 76.— JAMISON STAN J 



-LEFT HAND SWING 



trap door to accommodate overhead track, must include the 
height of the fop edge of track above the finished floor of the 




7IG. 77.— TYPES OF SILLS FOR COLD STORAGE DOORS— (LEFT) BEVELED 
THRESHOLD; (CENTER) NO-SILL; (RIGHT) HIGH SILL. 

■com just inside doonvay, and the depth of rail. (Allowance 
Js provided by manufacturers for any bevel of sill and any 



220 CORK INSULATION 

slight variation in the height of track rail.) The width and 
height of cold storage doors are always specified as "the 
dimensions inside of frame" or "door in the clear." In the 
case of the no-sill type, the height of the "door in the clear" 
is understood to be the dimension measured from the lowest 
point of frame at top of door to the concrete floor level in 
doorway. (Consult manufacturers for detailed cold storage 
door specifications.) 

99. — Interior Finishes for Cold Storage Rooms. — It has 
been noted that when water is precipitated on the plastered 
surface of an insulated cold storage room, by the condensa- 
tion of moisture from the air upon a cool surface, a part of 
such water is absorbed by the plaster by capillarity, which 
slowly disintegrates the plaster while placing a portion of 
such moisture on the surface of the insulation directly behind 
the plaster. Cork, unlike other materials, will not take up 
this water by capillarity, but such water may by gravity find 
its way into the corkboards through possible small interstices 
or voids between the particles of cork bark that comprise tlie 
sheet of insulation. 

It has also been noted that the modern corkboard product 
of maximum worth must be compact and free from voids to 
the greatest possible extent, although the nature of the raw 
material, and the manufacturing process that must be fol- 
lowed, do not permit of the elimination of all voids, especially 
surface voids. Water in contact with corkboard on the walls 
of buildings can be expected to penetrate the insulation to 
some extent at least, such penetration having been known in 
extreme cases to reach a depth of as much as an inch or so. 

Thus it should be evident that the finish over the cOi'-- 
board insulation on cold storage room walls should have more 
than passing attention, but the subject has long been neg- 
lected and not until comparatively recently has it had serious 
attention. 

Portland cement plaster troweled smooth and hard for the 
finish coat over the last layer of insulation is much better 
than plaster floated ; because the troweled plaster is less porous 
and possesses less capillarity. This fact does not seem to be 
appreciated by many, however, for plaster floated has long 



STRUCTURAL SUGGESTIONS 



221 



been the universal practice, although for many years the 
United States Government has not permited floated plaster in 
government-inspected meat rooms because of its porosity and 
consequent tendency to take up water and become foul. 

Materials not possessing capillarity, for the finish coat 
over cold storage room insulation, are coming into much favor. 
Factory ironed-on mastic finish coated corkboards for the sec- 




FIG. 78.— CORKBOARD INSULATED ICE STORAGE HOUSE WITH PORT- 
LAND CEMENT PLASTER FINISH. 



ond course, with all joints effectively sealed at point of erec- 
tion with the point of a hot tool, are much better where mois- 
ture is encountered in cold storage rooms than is any kind of 
plaster; while a finish having an emulsified asphalt base, which 
may be troweled on at the job, in two coats, in much the same 
way as plaster, is gaining in use, although it has probably not 
yet been tried over a sufficient period of time, and its formula 
has not yet been sufficiently standardized, to permit of an 
unqualified general approval. 

If good troweled plaster on walls is finished off first with a 



222 CORK INSULATION 

filler and then with a good elastic enamel, such surface will 
present an efficient barrier to the entrance of moisture. An 
elastic enamel is required, to withstand the contraction and 
expansion of the room surfaces due to changes in temperature. 
The Portland cement plaster, however, is of such nature as 
to expand and contract a considerable amount, under cold 
storage room conditions, so much so that it has long been 
the practice to score the surface of such plaster finish in four 
foot squares to confine the checking and cracking to such 
score marks, or, if you wish, to provide expansion joints, 
similar to the expansion joints in concrete sidewalks. The 
weak points in enameled troweled plaster are these score 
marks, or expansion joints, and especial care must be taken 
to keep all such cracks so well closed with filler and enamel 
that little, if any, moisture will contact with the insulation 
through that source. To do this is not as difficult as it may 
sound, or as some would have us believe; for it is, in many 
cold storage rooms, entirely feasible and practical to use 
enameled troweled plaster on walls with entire success, and 
if to the plaster mix a small portion of some good and suitable 
integral waterproofing compound is added, the value of the 
plaster as a protective coating will be enhanced. 

The service in cold storage rooms of cold storage buildings 
is not usually as severe, from the standpoint of moisture, as is 
the service in daily ice storages, milk rooms, poultry chill 
rooms, and a host of small cold storage rooms in small plants ; 
because in cold storage buildings the rooms are not, as a 
rule, entered nearly as often as are the cold storage rooms in 
small plants, and when the rooms in a cold storage building 
are entered it is invariably through anterooms that keep 
the warm, outside air from rushing directly into the cold 
storage room and precipitating its moisture upon cool sur- 
faces of every kind. Consec^uently, the need for the most 
efficient protective finish for the interior of cold storage rooms 
will be in rooms operating at moderate temperatures, such as 
from 28° to 35° or 40° F., in which rooms the moisture pre- 
cipitated upon cold surfaces is not converted into frost 
crystals, or not so quickly converted but that there is an op- 
portunity for some of it to be absorbed. 



STRUCTURAL SUGGESTIONS 223 

If insulation is applied to the underside of ceilings in rooms 
where the height is limited and cooling coils are either hung 
near the ceiling or placed close to the ceiling in bunkers, as is 
usual in the small cold storage rooms to be found outside of 
cold storage buildings, the finish over the corkboards should 
always be something more vulnerable than plaster. Either 
factory ironed-on mastic finish, with all joints carefully sealed 
upon application, or the very best emulsified asphalt prepara- 




FIG. 79.— BARUES METAL FLOOR GRIDS. 

tion, troweled on in two coats, should be used on all such 
insulated ceiling areas ; and where coil bunkers are used, such 
special asphaltic waterproof finish should also be used on all 
walls down at least to the lower line of bunker construction, 
and often preferably on the entire wall areas of the room. 
(Plaster should never be applied in rooms to be used for the 
storage or handling of ice.) 

Wall finishes containing asphalt will discolor most paints 
of lighter color unless a continuous coating of orange shellac 
is first applied to the asphaltic surface, but aluminum paint 
can be applied directly over asphalt without fear of discolora- 
tion. Aluminum painted surfaces have the advantage of radi- 



224 CORK INSULATION 

ating less heat than non-metallic surfaces, although since not 
over 10 per cent of all heat normally entering an insulated 
cold storage room through its surfaces is traceable to radiation 
and convection combined, the insulating effect of the alumi- 
num paint is of negligible importance, and the finish should 
be valued alone for its utility as a coating and preserving 
material. 

On floors, it is customary and very satisfactory to use con- 
crete over insulation, such concrete troweled hard and smooth 
and sloped to drain. In ice storage houses the concrete should 
be of increased thickness, or contain reinforcing mesh, or 
both, on account of the weight to be supported. In fur stor- 
ages, the desire is often for a wood floor of maple, which is 
satisfactory in dry rooms if properly laid. In milk rooms, 
and generally wherever metal containers must be moved over 
floors, metal grids should be imbedded flush in the concrete ; 
in fact the use of such metal grids is increasing rapidly in 
cold storage rooms of every kind. 

Lumber in cold storage rooms, as exposed ceiling con- 
struction where insulation is applied above, or as bunker con- 
struction, or as spacing strips on the floors and walls of ice 
storage houses, or as bumper plates around the walls to 
protect the finish from boxes and barrels, should not be creo- 
soted before installation, because of the danger from odors, 
but should be properly painted immediately afterwards and 
before the cold storage room is put in service. 

100. — Asphalt Cement and Asphalt Primer. — Authentic 
evidence exists that asphalt was known for its useful and 
valuable properties almost as far back as our knowledge of 
civilization extends. The earliest recorded use of asphalt 
was by the Sumarians, inhabitants of the Euphrates Valley 
before the ascendency of the Babylonians. Unearthed relics 
demonstrate that as early as 3000 B. C, asphalt was used by 
these people as a cement for attaching ornaments to sculp- 
tures, carvings and pottery. An asphalt mastic cast exca- 
vated at Lagash, near the mouth of the Euphrates, dates back 
to 2850 B. C, and as early as 2500 B. C. the Egyptians utilized 
melted asphalt as a preservative coating for the cloth wrap- 
pings of their mummies. 



!. 



STRUCTURAL SUGGESTIONS 225 

The famous towers of Babylon were protected for some 
twelve stories with a coating consisting of crushed brick 
mixed with bitumen, to effectually retard the encroachments 
of both damp creeping up from the earth and of the flood 
waters of the Euphrates. Arthur Danby says that there 
is no doubt but that the sole reason why the remaining tower 
of Babylon (Birs Nimrod) has stood for such a great length 
of time, is that the builders used bitumen as an admixture in 
its construction. Nebuchadnezzar's father, as king of Baby- 
lon, about 500 B. C, is believed to have first used asphalt as 
a mortar for brick pavements, and Nebuchadnezzar continued 
the practice, as recorded by an inscription on a brick taken 
from one of the streets. 

Thus asphalt, instead of being a product of modern use, 
as may be commonly supposed, has a useful record behind it 
of thousands of years, handed down from the oldest civiliza- 
tion; but prior to about 1900 A. D. the term asphalt was 
restricted almost exclusively to certain semi-solid or solid 
bitumens found in natural deposits, often mixed with silt or 
clay and thus known as asphaltic-sand or rock-asphalt. Trini- 
dad natural asphalt since about 1880, and Bermudez Lake 
natural asphalt since about 1890, have been imported into the 
United States and used for paving purposes. Deposits of 
asphaltic sands and rock asphalt have been found in the 
United States, but they appear to be somewhat unsuited for 
present industrial purposes. Small deposits of hard and nearly 
pure asphalts, commonly known as Gilsanite, Grahamite, and 
so forth, have also been discovered in the United States and 
are well suited for the manufacture of certain asphalt special- 
ties. 

Practically all natural or native asphalt is too hard for 
direct use in the manufacture of asphalt products; and after 
a simple refining process, which consists in heating the crude 
material until water, gas and other volatile material is driven 
off, native asphalt must be softened to suitable consistency by 
combining it with the proper amount of a residual petroleum 
known as flux oil. Petroleum probably always served as an 
important integral part of all asphalt used for industrial pur- 
poses; in fact, it is now generally believed that all natural 
asphalt originated in petroleum. 



226 



CORK INSULATION 



The first petroleum known and used in the United States 
was of the paraffin type and* occurred in Pennsylvania, Ohio 
and Indiana. Distillation of this petroleum, to remove the 
more volatile matter, yielded a thick, greasy oil residue which 
proved quite satisfactory as a flux for natural asphalt, but 
which upon further distillation produced coke; whereas, later, 
with the discovery and refining of California petroleum, fur- 




FIG. 80.— CORKBOARD INSULATED ICE STORAGE HOUSE W^TH IRONED- 
ON-AT-THE-FACTORY MASTIC FINISH. 



ther distillation of California residual oil produced, before 
coke was formed, a semi-solid, sticky or tacky asphaltic 
material resembling native asphalts. Refinements in distilla- 
tion processes improved the California petroleum asphalt until 
it was demonstrated that if recovered by suitable means it 
was essentially the same as certain native asphalts. 

Appreciable quantities of petroleum asphalt were being 
used in the United States for paving, by about 1900. How- 



STRUCTURAL SUGGESTIONS 227 

ever, it was received on trial for over ten years until experi- 
ence with it in service demonstrated that it was equally as 
good for paving purposes as the natural or lake asphalts. By 
about 1911, the asphalt produced from domestic petroleum 
exceeded the Trinidad and Bermudez asphalt importations; 
and since then the production of petroleum asphalt has con- 
tinued to grow rapidly, stimulated by large available quanti- 
ties of Mexican petroleum highly asphaltic in character. 

Statistics of the United States Geological Survey for 1919* 
show the following : 

UNITED STATES GEOLOGICAL SURVEV STATISTICS FOR 1919. 

Asphalt from domestic petroleum 614,692 tons 41.4% 

Asphalt from Mexican petroleum 674,876 tons 45.5% 

Domestic native asphalt (bituminous rock) 53,589 tons 3.6% 

Other domestic native bituminous substances 34,692 tons 2.3% 

Asphalt imported from Trinidad and Tobago 51,062 tons 3.5% 

Asphalt imported from Venezuela 47,309 tons 3.2% 

Other imported asphalts including bituminous rock 7,277 tons 0.5% 



TOTAL ASPHALT 1,483,497 tons 100.0% 

.\sphalt exported from U. S.t 40,208 tons 2.7% 



Approximate consumption of asphalt in U. S 1,443,289 tons 97.3% 

These figures indicate that approximately 87 per cent of 

all asphalt produced by or imported into the United States 

that year was obtained from the distillation of petroleum, and 

since then this ratio has continued to increase in favor of the 

petroleum asphalts. 

; Asphalt would appear to be the oldest waterproof adhesive 

j known to man ; and since the manufacture of asphalt from 

i' petroleum has made it readily available in almost unlimited 

' quantities, it has been adapted to a great many industrial 

; purposes, of which the paving industry leads and the roofing 

j industry is second, consuming together some 85 or 90 per 

; cent of the entire asphalt output. The remainder of the out- 

i put is used for waterproofing, flooring, insulating, and some 

I'ksphalt finds its w^ay into the manufacture of rubber goods, 

I paints, varnishes, bituminous putty, emulsions, sealing com- 

I pounds, floor coverings, etc. 

' As the general term "asphalt" is commonly applied to a 
great variety of asphalts and asphaltic products, the asphalt 



•Asphalts and Related Bitumens in 1919, by R. W. Cottrell. 

Note — See also "Asphalt," by Prevost Hubbard, in "The Mineral Industry during 
•1925," Volume 34, McGraw-Hill Book Co. 

tThis does not include manufactures of asphalt valued at approximately one-half 
' the value of the tonnage of asphalt exported. 



228 CORK INSULATION 

to be used in applying cold storage insulation shall be termed 
"Asphalt cement" and should be carefully selected for certain 
properties and characteristics that are highly desirable where 
foodstuffs are stored and where the success of the installation 
depends to a marked degree on the permanent air-proofing 
and cementing qualities of the Asphalt cement selected. These 
properties are substantially as follows : 

(a) Purity. 

(b) Durability. 

(c) Flexibility. 

(d) Adhesiveness. 

Tests to determine the presence of these properties are 
reflected in the specifications of the American Concrete Insti- 
tute, the American Society for Testing Materials and the 
United 'States Bureau of Standards, which specifications are 
much the same; and by the aid of these specifications, sup- 
ported by the practical knowledge of the requirements of a 
suitable asphalt for use in applying cold storage insulation to 
building or other surfaces, a specification has been prepared, 
as follows : 

Specification for Asphalt Cement for Cold Storage Insulation. 

Impurities. — The Asphalt cement shall contain no water, decom- 
position products, granular particles, or other impurities, and it shall 
be homogeneous. (Ash passing the 200-mesh screen shall not be cc»n- 
sidered an impurity; but if greater than 1 per cent., corrections in 
gross weights shall be made to allow for the proper percentage of 
bitumen.) 

Specific Gravity. — The specific gravity of the Asphalt cement shall 
not be less than 1.000 at 77° F. (25° C). 

Fixed Carbon. — The fixed carbon in the Asphalt cement shall not 
be greater than 18 per cent. 

Sulphur. — The sulphur and sulphur compounds in the Asphalt ce- 
ment shall not be greater than 1^ per cent., by the ash free basis of 
determination. 

Solubility in Carbon Bisulphide. — The Asphalt cement shall be sol- 
uble to the extent of at least 98 per cent, in chemically pure carbon 
bisulphide (CS2). 

Melting Point. — The melting point of the Asphalt cement shall be 
greater than 165° F. and less than 190° F., by the Ring and Ball 
method. 

Flash Point. — The flash point of the Asphalt cement shall be not 
less than 425° F. (218.3° C), by the Cleveland Open Cup test. 



STRUCTURAL SUGGESTIONS 229 

Penetration. — The Asphalt cement shall be of such consistency as 
to show a penetration of more than 15 when tested at 32° F. (0° C.) 
and less than 70 when tested at 115° F. (46.1° C). (0.2 millimeter 
shall be added for each 1.0 per cent, of ash, to give the true pene- 
tration.) 

Volatilisation. — The loss by volatilization on heating of the As- 
phalt cement shall not exceed 1 per cent., the penetration after heating 
shall be not less than 80 per cent, of the original penetration, and the 
ductility after heating shall have been reduced not more than 20 per 
cent. 

Ductility. — When pulled vertically by a motor at a uniform rate 
of 5 cm. per minute in a bath of water, a cylinder of Asphalt cement 
1 cm. in diameter at a temperature of 77° F. (25° C.) shall be elon- 
gated not less than 15 cm. before breaking, and at a temperature of 
40° F. (4.5° C.) shall be elongated not less than 3 cm. before breaking. 

Outline of the Purpose of Specifications for Asphalt Cement 
for Cold Storage Insulation. 

Impurities are a measure of the care with which the Asphalt cement 
has been refined and handled. Usually the presence of impurities in 
'arge quantities indicates a poor grade of asphalt. Water as an impur- 
ity would act as a diluent and would cause foaming in the kettle. Ash, 
3r mineral matter, is not considered an impurity if it is a natural con- 
stituent of the Asphalt cement, but the cementing value must be fig- 
ured on the bitumen alone. 

Specific Grcznty of the Asphalt cement should be over 1.000 be- 
cause Asphalt cements of a pentration satisfactory for cold storage 
insulation work always have a specific gravity greater than 1.000, 
whereas paraffin base and air-blown products frequently have a spe- 
:ific gravity less than 1.000. 

j Fixed Carbon is to some extent a measure of the chemical con- 
i;titution of an Asphalt cement, and is largely used to determine the 
;ource and uniformity of an asphalt. Fixed carbon is not free carbon, 
A^hich latter is practically absent in Asphalt cement, but fixed carbon 
ncludes free carbon. 

Sulphur and sulphur compounds are ordinarily the cause of the 
odor in oils and asphalts, particularly upon heating. An Asphalt 
i^ement that is low in sulphur compounds is necessary for cold storage 
nsulation work. 

Solubility in Carbon Bisulphide is a measure of the purity of an 
A.sphalt cement; and the cementing value, other things being equal, is 
proportional to the CS2 solubility. Any carbonaceous material, such 
IS coal tar or pitch, is detected by this test. 

Melting Point is a measure of the temperature at which the As- 
)halt cement will flow readily. The melting point desired is deter- 
nined by the workability of the Asphalt cement on corkboards when 
lipped, and should have a melting point somewhat higher than the 
lighest temperature to which it will be subjected in place with 
nsulation. 



230 CORK INSULATION 

Flash Point is a measure of the amount of volatile hydrocarbons 
that are present in the Asphalt cement, and of the readiness of the 
asphalt to decompose by heat. 

Penetration is a measure of the consistency of the Asphalt cement. 
It is merely a quick, convenient test for checking up numerous sam- 
ples. The penetration is expressed in degrees, and 1/10 m.m. equals 
one degree. The penetration to be desired will depend upon the 
climate, the ductility and adhesiveness of the Asphalt cement. 

Loss by Volatilization is a measure of the amount of light hydro- 
carbons that are present in Asphalt cement, v^rhich indicates its ten- 
dency to oxidize and to lose its ductility and penetration. 

Ductility is a measure of the ability of an Asphalt cement to ex- 
pand and contract without breaking or cracking. The same asphalt 
at a higher penetration should have a higher ductility, so all ductility 
tests should be based on a certain definite penetration regardless of 
temperature, or should be based on a temperature of 32° F. (0° C). 
Ductility is also a measure of the cementing strength. 

Viscosity is a measure of the ability of the Asphalt cement to im- 
part plasticity and malleability. 

The methods of testing to be followed in connection with 
Specification for Asphalt Cement for Cold Storage Insulation, are 
those of the American Society for Testing Materials, as 
follows: 

(a) Determination of Bitumen in Asphalt Pioducts (Deducted 
from 100 per cent, equals Purity) A. S. T. M., D4-23T. 

(b) Softening Point of Bituminous Materials (Ring and Ball 
Method) A. S. T. M., D36-24. 

(c) Flash and Fire Points of Bituminous Materials (by the Cleve- 
land Open Cup Method) A. S. T. M., D92-24. 

(d) Penetration of Bituminous Materials, A. S. T. M., D5-25 

(e) Loss on Heating of Oil and Asphaltic Compounds, A. S. T. M., 
D6-20. 

(f) Ductility of Bituminous Materials, A. S. T. M., D113-22T. 

(g) Sulphur in Bituminous Materials (Ash Free Basis) A. S. T. M., 
D29-22T. 

The Kansas City Testing Laboratory, in its Bulletin No. 
15, publishes values for the composition of natural and petro- 
leum asphalts, as follows : 

1.— COMPOSITION OF NATURAL ASPHALTS. 





Natural 
Trinidad 


Ber- 

mudez 
94.0% 

2.0% 

1.085 
13.5% 
180 

2.5 

4.0% 

70'0% 
82.5% 
10.3% 
0.7% 


Gil- 

sonite 

99.4% 
0.5% 
1.045 

13.0% 
300 


0.1% 
1.3% 

30.0% 


Gra- 
hamite 




56.0% 


94.1% 


Mineral Matter 


36.8% 

1.400 


5.7% 
1.171 




. 1 1 0% 


53.3% 


Melting Point, °F 

Penetration (77° F ) ... 


190 

... 05 


Cokes 





6.0% 


0.2% 




6 5 % 


2.0% 




65.0% 


0.4% 


Total Carbon (ash free) 


82.6% 


87.2% 


Hydrogen (ash free) 

Nitrogen (ash free) 


10.5% 

0.5% 


7.5% 
0.2% 



STRUCTURAL SUGGESTIONS 231 

2.— COMPOSITION OF PETROLEUM ASPHALTS. 

Mexi- Mid-Continent Calif- Stano- 

can Air Blown ornia lind* 

Bitumen 99.5% 99.2% 99.5% 99.8% 

Mineral Matter 0.3% 0.7% 0.3% 0.3% 

Specific Gravity 1.040 0.990 1.045 1060 

Fixed Carl on 17.5%. 12.0% 15.0% 17.5% 

Melting Point °F 140 180 140 135 

Penetration (77° F.) 55 40 60 SO 

Free Carbon 0.0 0.0 0.0 0.0 

Sulphur (ash frte basis) 4.50% 0.60% 1.657o 0.35% 

Petroleum Ether Soluble 70.0%) 72.0% 67.0%, 70.0% 

Cementing Properties good poor good gooa 

Ductility (squarp mold) 45 cm 2 cm 70 cm 100 + 

Loss at 32° F. 5 hrs 0.2%, 0.1% 0.2%, 0.1% 

Heat test adherent smooth adherent scaly 

These values were obtained by methods of testing as pub- 
lished by the K. C. T. L., Bulletin No. 15, which are in many 
particulars slightly different from the methods adopted by 
the American Society for Testing Materials, and consequently 
the values of the K. C. T. L. are given here for general infor- 
mation only and are in no way to be confused with the values 
called for in a Specification for Asphalt Cement for Cold Storage 
Insulation, or with an Asphalt Primer for Use with Asphalt 
Cement. 

The "Heat Test" mentioned in the K. C. T. L, Table No. 2, 
should be of interest, as follows : 

Resistance of Asphalt Cement to Oxidation, K, C, T. L., 1919 

A strip of thin sheet iron 2 inches wide and 6 inches long is 
covered on its lower 4 inches with the melted asphaltic cement. This 
strip is placed in an oven at 275° F. for 15 minutes and allowed to 
thoroughly drain. 

It is removed from the oven and allowed to cool, then placed in 
an electrically heated oven at a temperature of 450° F. for one hour. 
' At the end of the hour, the door of the oven is opened and the heat 
is turned off, the specimen being allowed to remain in the oven. 

The oven shall be one having outside dimensions of 12x12x12 
inches with an opening in the top 1 cm. in diameter, the heating ele- 
ments being in the bottom of the oven. The resistance shall be so 
distributed that the heat is uniform throughout the oven. The lower 
end of the strip shall be suspended so that it is at least 3 cm. from 
; the bottom of the oven. 

The resistance is preferably so arranged that three different heats 
can be maintained with a snap switch such that the lowest heat is 
325° F., the medium heat is 400° F. and the highest heat is 450° F. 

After being subjected to these tests, the film of asphalt should be 
brilliant and lustrous, should not be scaly and fragile, should adhere 
fi firmly to the metal and should not be dull and cheesy in texture. 

'(Cracked-pressure tar residue. ") 



232 CORK INSULATION 

A suitable Asphalt Primer for initial application to con- I 
Crete and masonry surfaces as preparation for the erection of 
cold storage insulation in Asphalt cement, is as follows: i 

Asphalt Primer for Use With Asphalt Cement j 

The asphalt used in preparing the primer shall be homogeneous i 
and free from water, and shall conform to the following requirements: ■ 

(a) Melting point (R & B) 140 to 225° F. (60° to 107.2° C.) I 

(b) Penetration at 77° F. (25° C.) 100 grams pressure for 5 
seconds 20 to 50 

(c) Flash point (Open Cup).... Not less than 347° F. (175° C.) 

(d) Loss on heating 50 grams at 325° F. (163° C.) for 5 
hours Not more than 1% 

(e) Penetration at 77° F. (25° C.) 100 grams pressure for 5 
seconds, of the residue after heating SO grams at 325' F. 
(163° C.) for 5 hours as compared with penetration of 
asphalt before heating Not less than 60% 

(f) Ductility at 77° F. (25° C.) Not less than 15 cm. 

(g) Insolubles in Carbon disulphide Not more than 2% 

The solvent used in cutting the asphalt (in preparing the primer) 
shall be a hydrocarbon distillate having an end point on distillation 
of not above 500° F. (250° C), of which not more than 20 per cent 
shall distill under 248° F. (120° C). 

The finished Asphalt Primer shall be free from water* and shall 
conform to the following requirements: 

(a) Sediment* Not more than 1% 

(b) Asphaltic base by weight 25 to 35% 

101. — Emulsified Asphalt. — Emulsified asphalt and emulsi- 
fied asphalt plastic, for the interior finish of cold storage 
rooms, and sometimes for the priming of surfaces in prepara- 
tion for insulation to be applied in hot Asphalt cement, has 
had enough publicity — favorable and unfavorable — to justify 
a very careful look into the general subject of asphalt emul- 
sions. 

"Colloid chemistry is the chemistry of grains, drops, bub- 
bles, filaments, and films," according to Bancroft; but colloid 
chemistry actually deals with grains, drops, and bubbles only 
when they are sufficiently small, of diameters ranging from 
ICX) millimicrons to 1 milllmicronf, and when such particles 
are surrounded by, or dispersed in, some other substance, as 
dust in air (smoke), water in butter, oil in water (milk), air 



*To test for Water and Sediment, use A.S.T.M. Method D9S-23T. 

tA millimicron, 1 /jl/i. is one niillicnth of a millimeter, 100 fi/t just barely being 
visilale with the aid ot the best microscope, and the largest molecules approach a 
diameter of l nf/i,, 



STRUCTURAL SUGGESTIONS 



233 



in water (foam), etc, "The colloidal realm ranges from the 
lower limit of microscopic visibility to the upper limit of mo- 
lecular dimensions," says Holmes, and adds that most colloidal 
particles are aggregates of hundreds or even thousands of 
molecules. 

Water, wood, paper, clothing, glass, cement, paints, inks, 
asphalt, cheese, oils, and countless other materials in common 




FIG. 81.— INSULATED ICE STORAGE HOUSE WITH PLASTIC MASTIC 
FINISH APPLIED OVER CORKBOARD AT POINT OF ERECTION. 

I use are colloidal, that is, may be dispersed in or surrounded by 
' some other substance. 

A small quantity of oil may, for example, be dispersed in 
'Water, by vigorous shaking or stirring; but to maintain the 
I dispersion, or keep the emulsion, is the problem. Aside from 
tl the unequal specific gravities of the two substances, the fact 
of the unequal surface tensions of water and oil assists in 
causing the microscopic drops of oil to form together, separat- 
ing from the water, the surface tension of any given liquid 
' being that tension by virtue of which it acts as an elastic 



234 CORK INSULATION 

enveloping membrane tending always to contract the surface 
of the liquid to the minimum exposed area.* When a sub- 
stance is colloidally dispersed, the efifect of gravity is con- 
siderably counteracted, while surface tension, electric (ionic) 
charge, and other forms of energy increase greatly. 

Thus by lowering the surface tension of water, by the 
introduction of an alkali, an oil-in-water emulsion should keep 
longer. But water molecules are always in constant motion 
when above absolute zero temperature, and bombard the sus- 
pended colloids of oil from all sides, tending to move them 
about, and thus to coagulate or unite upon touching due to 
the surface tension of oil. Then, too, particles in the col- 
loidal state bearing unlike electric charges, tend to attract 
each other, and thus coagulate; while particles similarly 
charged, tend to repel, and thus move about, and coagulate 
upon touching. 

It will be seen that lowering the surface tension often 
exerts considerable influence in emulsification, but the con- 
centration of a film of some non-adhesive gelatin substance 
around the suspended colloids, so that they have difficulty in 
touching, is usually of more importance. 

There are several methods of subdividing common sub- 
stances so that they may be colloidally suspended, some meth- 
ods being purely mechanical and others chemical ; but in con- 
nection with proposed chemical methods, it must be remem- 
bered that colloidal suspensions are not true solutions, colloid 
aggregates often being thousands of times as large as a mole- 
cule while molecules only are found in true solutions. 

Colloid particles have an ability to adsorb other substances, 
that is, hold other substances to their surfaces, and it is this 
property that makes it possible to coat or cover such colloids 
with a non-adhesive substance, such as starch or geletin or 
clay, so that the colloids will not coalesce or unite when they 
touch each other. On the other hand, if the particles in sus- 
pension were originally of too great size to fall within the 
range of the colloidal realm, and thus are beyond the help of 



*A cube 1 cm. on edge has a surface of 6 sq. cm. If subdivided in much smaller 
cubes 100 //// on edge, the total surface is 600,000 sq. cm If further subdivided into 
the colloidal realm of cubes 10 /i/i on edge, the total surface is 6,000,000 sq. cm. Sur- 
face tension tends to reduce the colloidal particles to the cube 1 cm. on edge, or, 
more properly, to a sphere. 



STRUCTURAL SUGGESTIONS 235 

the bombardment of the water molecules (Brownian move- 
ment) to keep them suspended, such aggregates will settle. 
Emulsoids are dehydrated and coagulated by excessive 
amounts of salts, by nitric acid, sometimes by heat and by 
shaking. Thus if it is necessary to shake an emulsion a great 
deal, in handling, or shipping, or stirring to counteract settling, 
the particles (having lost their full protective coats by dis- 
turbance) may coagulate an amount sufficient to destroy the 
emulsion. 

It is the non-adhesive substance used to coat the dispersed 
colloidal particles that is known as the emulsifying agent, 
and such agent must be capable of being colloidally dispersed 
also. The emulsifying agent selected, however, must be such 
that the adsorptive power of its colloids is less than that of the 
colloidall}^ dispersed basic substance being emulsified, else the 
dispersed protective colloids of the emulsifying agent will not 
be held to the surface of the colloidal particles of the basic 
material, but the reverse will occur, and the colloidal particles 
of the emulsifying agent will become coated by the dispersed 
colloids of the basic material. The adsorptive power of an 
adhesive type of colloidal particle, for colloidal particles of a 
non-adhesive and protective character, is apparently increased 
by the simple addition of a flocculating agent that will tend 
to coagulate or unite the protective colloids in larger aggre- 
gates about the basic colloids and thus give the basic colloids 
a certain measure of greater protection or isolation one from 
another. 

If even a faint conception of colloid chemistry, and par- 
ticularly the preparation and holding of emulsions, is possible 
from the foregoing paragraphs, then a consideration of the 
preparation, handling, shipping and application of asphalt 
emulsions can follow. 

Asphalt, as has been noted, is a colloidal substance; it is 
one that may be colloidally dispersed in water by admixture 
of the molten material with a hot aqueous alkaline solution ; 
it is a material that is capable of being mechanically dispersed 
in a colloidal state in water that has had its high surface 
tension relieved. But to emulsify asphalt, that is, hold it in 
colloidal suspension, requires the addition of a suitable emulsi- 



236 CORK INSULATION 

fying agent, one that is non-adhesive, capable of colloidal dis- 
persion and of inferior adsorptive power in the presence of the 
basic asphalt colloids. In a word, the colloids of the emulsi- 
fying agent must be such as to be held to the surface of the 
dispersed asphalt colloids in sufficient quantity and with suf- 
ficient bond to prevent the colloidal particles of asphalt from 
sticking together as they touch each other during propulsion 
about through the aqueous alkaline solution by the forces 
that make colloidal suspension possible. 

U. S. Letters Patent No. 1,582,467, for example, sets forth 
as one of its claims the follow^ing: 

A process for producing an aqueous bituminous emulsion 
which consists in melting solid bitumen of the type arti- 
ficially prepared from petroleum, adding thereto with agita- 
tion a proportion less than 10% of an emulsifying agent 
comprising a substance of the starch-dextrin type, and then 
separately adding a dilute aqueous solution of alkali, and 
maintaining the heating and agitation of the mixture until 
emulsification has been efifected. 

U. S. Letters Patent No. 1,567,061 sets forth certain claims 
relating to the admixture of a flocculating agent* to an asphalt 
emulsion to increase the degree of protection to the suspended 
asphalt colloids by causing the colloids of the emulsifying 
agent to more tenaciously cling to the suspended colloidal 
asphalt, as follows : 

A process of forming a non-adhesive emulsion, consisting 
in emulsifying an adhesive bituminous substance with col- 
loidal clay in an aqueous vehicle, adding aluminum sulphate 
to the emulsion to cause the emulsifying particles to more 
tenaciously gather about the bituminous substance. 

The colloidal dispersion of asphalt in water is usually 
accomplished by heating the asphalt to about 225° F. and 
adding it to a hot aqueous alkaline solution under vigorous 
and intimate agitation ; and there have been a number of 
patents issued covering mechanical equipment for many ways 
of accomplishing such dispersion. It would therefore appear 
that the equipment used and the care exercised in the manu- 
facturing process may have considerable to do with the worth 
of the finished product. For instance, if the asphalt were not 
actually broken up into microscopic particles sufficiently small 
to place them in the colloidal realm, then the tendency of that 

*Aromoni3 salts arp frequently used in emulsions as flocculating agents. 



STRUCTURAL SUGGESTIONS 237 

"emulsion" would be to settle in the container, the particles 
of asphalt simply being held apart by their coatings of non- 
adhesive material ; and the disturbances of handling, shipping, 
and stirring to counteract settling may sufficiently dislodge 
the protective coatings from the asphalt particles to cause 
enough coagulation to make the emulsion unfit for practical 
use. The use of an unsuitable emulsifying agent, or incor- 
rect proportions of ingredients, or insufficient heat, or other 
errors of omission or commission, may conceivably be respon- 
sible for an unsatisfactory emulsified asphalt product. 

Back of it all, too, is this important fact : If a good grade 
of a suitable asphalt is used as the basic material to be emulsi- 
fied, then vv^hen dehydrated on the w^alls of a building, or on 
cork insulation, there will remain the same good grade of a 
suitable asphalt as a protective coat; otherwise, not; if a poor 
asphalt is emulsified, it remains a poor asphalt, always. 

Emulsified asphalt is, of course, subject to freezing, which 
is a serious objection to the shipping and handling of the 
material in cold weather. 

The exact determination of the constituents of an asphalt 
emulsion is usually attended with considerable difficulty and 
no predetermined scheme can be made applicable to all mate- 
rials of this character. The following methods, how='ever, are 
used by the United States Office of Public Roads and Rural 
Engineering, according to Prevost Hubbard, and have yielded 
reasonably satisfactory and fairly accurate results : 

Special Tests for Emulsions. 

Fatty and Resin Acids. — In order to break up the emulsion, a 20- 
gram sample is digested on a steam bath with 100 cubic centimeters 
of N/2 alcoholic potash. The digestion is carried out in a flask with 
a reflux condenser for about 45 minutes. The solution is filtered 
and the precipitate washed with 95 per cent alcohol. The filtrate is 
evaporated to dryness, after which the residue is taken up with hot 
water and any insoluble matter is filtered ofif. The aqueous solution, 
which contains the potassium soaps of the fatty acids, is acidified 
with dilute sulphuric acid and then shaken in a separatory funnel 
with petroleum ether. The aqueous portion is drawn off and the 
ethereal layer shaken up with cold water and washed twice, after 
which it is evaporated in a weighed platinum or porcelain dish to 
constant weight, first over a steam bath and then in a drying oven 



238 CORK INSULATION 

at 105° C. The residue consists of the fatty and resin acids present 
in the emulsion. 

Water. — The percentage of water in the emulsion is determined 
by distilling a 100-gram sample in the retort used for dehydration. 
The distillation is carried out in exactly the same manner as de- 
scribed under this test until the volume of water in the receiver shows 
no further increase. Any oils that come over are thoroughly mixed 
with the material remaining in the retort. 

Aiiniionia. — Many emulsions contain ammonia, and when this is 
present a second distillation of the material is necessary. This is 
carried out on a 100-gram sample in exactly the same manner as 
described for the determination of water, except for the fact that 40 
cubic centimeters of a 10 per cent, solution of caustic potash is added 
to the contents of the retort before beginning the distillation. The 
distillate is collected in a measured volume of N/2 sulphuric acid. 
When the distillation is completed the excess acid is titrated with 
N/2 caustic potash, and the ammonia thus determined. 

Ash. — A one-gram sample of the dehydrated material is ignited in 
a weighed platinum or porcelain crucible. The ash will contain any 
inorganic matter from the bitumen as well as the fixed alkali present 
in the soap. The results are, of course, all calculated on the basis 
of the original material. 

Total Bitumen. — A two-gram sample of dehydrated material is 
extracted with carbon disulphide as described in the method for the 
determination of total bitumen, flask method, and in this manner 
the organic matter insoluble in carbon disulphide can be determined. 

Having determined all constituents as above noted, it is assumed 
that the difiference between their sum and 100 per cent, is bitumen, 
which amount is reported accordingly. 

It will be seen that with emulsified asphalt, as with many 
"prepared" products, the average purchaser must rely on the 
manufacturer for the quality and fitness of the emulsion for the 
work in hand. 

The advantage offered by a suitable emulsified asi)halt as 
a priming material for masonry surfaces, as compared with 
an Asphalt primer, is that emulsified asphalt is non-inflam- 
mable ; and the advantage of the Asphalt primer over the 
emulsion is that the asphalt that is cut with a solvent can be 
handled with an air-gun at much higher pressures, and thus 
with greater penetration, than the emulsion can be handled. 
If too great pressure is used with the emulsion, the air-gun is 
liable to foul in the nozzle and clog; because the excessive 
pressure tends to force too much water out of the emulsion 
and coagulate the asphalt in the nozzle. 



STRUCTURAL SUGGESTIONS 239 

Emulsified asphalt plastic is simply emulsified asphalt mixed 
by mechanical means in suitable proportion with asbestos fibre 
and fine sand or other more suitable mineral aggregates, to 
form a plastic material resembling Portland cement mortar in 
consistency and suitability for application with trowel over 
corkboard surfaces. The advantage offered by a suitable 
emulsified asphalt plastic as a protective coating for corkboard 
insulation, as compared with factory ironed-on mastic finish 
corkboard, is found in the versatility of the plastic emulsion. 
Except for the contingency of freezing weather, emulsified 
asphalt plastic may be applied on the job much like plaster, 
to any areas desired, at any time; and, furthermore, a suitable 
emulsified asphalt plastic may be applied so as to present a 
continuous surface that is sufficiently elastic to withstand 
without cracking the contraction and expansion incident to 
cold storage rooms, while it may be difficult to have the joints 
between factory ironed-on mastic finish corkboards effectually 
sealed against the same forces. However, the factory ironed- 
on mastic joints can be properly sealed, under adequate super- 
vision and with reasonable care. 

The choice between the factory finish and the plastic 
emulsion should rest entirely upon all the facts surrounding 
each case. 



CHAPTER XIII. 

COMPLETE SPECIFICATIONS FOR THE ERECTION 
OF CORKBOARD. 

102. — Scope and Purpose of Specifications. — These specifi- 
cations and illustrations are intended to show corkboard insu- 
lation adapted to practically every type of construction to be 
found in old buildings or to be employed in new structures, 
which specifications long experience has demonstrated to be 
practical. In many instances, however, more than one specifi- 
cation is given for the erection of corkboard to a given sur- 
face, and no recommendation is made as to preference ; be- 
cause the use of each and every one of these specifications is 
a matter of selection based on experience and a knowledge of 
all the conditions of the case, as previously elaborated. 

The thickness of corkboard to use must be suited to the 
temperatures to be maintained, and to a less degree to several 
other factors that will vary in each case, all as noted in 
Chapter XII. 

These specifications comprise the following: 

103. — Walls. — Stone, concrete or brick: 

(1) Single layer, in Portland cement. 

(2) Single layer, in Asphalt cement. 

(3) Double layer, first in Portland cement, second in 

Asphalt cement. 

(4) Double layer, both in Portland cement. 

(5) Double layer, both in Asphalt cement 

104.— Walls.— Wood: 

(6) Single layer, in Asphalt cement. 

(7) Double layer, both in Asphalt cement. 

105. — Ceilings. — Concrete : 

(8) Single layer, in Portland cement. 

(9) Double layer, both in Portland cement. 

(10) Double layer, first in Portland cement, second in 
Asphalt cement. 

240 



SPECIFICATIONS FOR CORKBOARD ERECTION 241 

(11) Single layer, in forms before concrete is poured. 

(12) Double layer, first in forms before concrete is 

poured, second in Portland cement. 

(13) Double layer, first in forms before concrete is 

poured, second in Asphalt cement. 

106. — Ceilings. — Self-supported: 

(14) Double layer, T-irons and Portland cement core. 

107.— Ceilings.— Wo o d : 

(15) Single layer, in Asphalt cement. 

(16) Double layer, both in Asphalt cement. 

108. — Roofs. — Concrete or wood: 

(17) Single layer, in Asphalt cement. 

(18) Double layer, both in Asphalt cement. 

109.— Floors.— Wood : 

(19) Single layer, in Asphalt cement, concrete finish. 

(20) Single layer, in Asphalt cement, wood finish. 

(21) Double layer, both in Asphalt cement, concrete 

finish. 

(22) Double layer, both in Asphalt cement, wood finish. 

110. — Floors. — Concrete: 

(23) Single layer, in Asphalt cement, concrete finish. 

(24) Single layer, in Asphalt cement, wood finish. 

(25) Double layer, both in Asphalt cement, concrete 

finish. 

(26) Double layer, both in Asphalt cement, wood finish. 

111. — Partitions. — Stone, concrete or brick: 

(See 103. — Walls. — Stone, concrete or brick.) 

1 12.— Partitions.— Wood : 

(27) Single layer, between studs, joints sealed in Asphalt 

cement. 

(28) Double layer, first between studs with joints sealed 

in Asphalt cement, second in Asphalt cement. 

113. — Partitions. — Solid cork: 

(29) Single layer, joints sealed in Asphalt cement. 

(30) Double layer, first with joints sealed in Asphalt ce- 

ment, second in Portland cement. 

(31) Double layer, first with joints sealed in Asphalt 

cement, second in Asphalt cement. 

114.— Tanks.— Freezing: 

(32) Double layer on bottom, both in Asphalt cement, 

granulated cork fill on sides and ends. 
(23) Double layer on bottom, both in Asphalt cement; 
double layer on sides and ends, both in Asphalt 
cement. 

(34) Double layer on bottom, both in Asphalt cement; 

single layer on sides and ends against studs, with 
granulated cork fill. 

115. — Finish. — Walls and ceilings: 

(35) Portland cement plaster, in two coats. 

(36) Factory ironed-on mastic finish, joints sealed. 

(37) Glazed tile or brick, in Portland cement. 

(38) Emulsified asphalt plastic, in two coats. 



242 



CORK INSULATION 



116. — Finish. — Floors : 

(39) Concrete. 

(40) Wood. 

(41) Galvanized metal. 

117. — Miscellaneous Specifications: 

(42) Ends of beams or girders extending into walls. 

(43) Rat proofing. 

(44) Portland cement mortar. 

(45) Asphalt cement. 

(46) Asphalt primer. 




• 




^ 


' 


CORKBOARD 


4 


' 




■ 


- 







LLLVATION 

MORTAR 

FIG. 82.— WALLS; STONE, CONCRETE OR BRICK 



Fl NISM 
CORKSOARD 
PORTLAMD CtN 



ARTICLE 103 (1). 



103. — Walls. — Stone, concrete or brick. 

(1) Single layer, in Portland cement. 

To the reasonably smooth and clean . . . walls to be insu- 
lated, one layer of . , .-inch pure corkboard shall be erected in 
a J^-inch bedding of Portland cement mortar, with all vertical 
joints broken and all joints butted tight. To the surface of 
the insulation shall then be applied a finish as selected. 

103. — Walls. — Stone, concrete or brick (continued). 

(2) Single layer, in Asphalt cement. 

To the reasonably smooth and clean . . . walls to be insu- 
lated, shall first be applied with brush or air-gun two uniform, 
continuous coats of Asphalt primer, to consist of one gallon 
per 75 square feet for brick surfaces or per 100 square feet for 
concrete surfaces for the first coat, and one gallon per 125 
square feet for brick or concrete for the second coat. To this 
prepared surface, one layer of ...-inch pure corkboard shall 
be erected in hot Asphalt cement, with all vertical joints 



1 



SPECIFICATIONS FOR CORKBOARD ERECTION 243 



broken and all joints butted tight and sealed in the same com- 
pound. To the surface of the insulation shall then be applied 
a finish as selected. 






1/ 1/" 










T 


CORKBOARD 




7 




' 



. FINISH 
C ORKBOARO 
A5PMALT CE.ME.NT 



EILELVATION 



FIG. 83.— WALLS; STONE, CONCRETE OR BRICK. ARTICLE 103 (2). 

103. — Walls. — Stone, concrete or brick (continued). 






.. .,, I. 


■ i ' 1 




\ 




1 




FIRST LA 
CORKBO/ 


YeR\ 








RD H 




SECOND LAYER ^ 






! 




.__j_._ 
















\ i 



FINISH 

CORKBOARD 

ASPHALT CEMENT 

CORKBOARD 

PORTLAND CEMENT MORTAR 



ELEVATION 



FIG. 84.— WALLS; STONE, CONCRETE OR BRICK. ARTICLE 103 (3). 

(3) Double layer, first in Portland cement, second in 
Asphalt cement. 

To the reasonably smooth and clean . . . walls to be insu- 
lated, one layer of . . .-inch pure corkboard shall be erected in 
a 54-inch bedding of Portland cement mortar, with all vertical 
joints broken and all joints butted tight. To the first course, 



244 



CORK INSULATION 



a second layer of . . .-inch pure corkboard shall be erected in ! 

hot Asphalt cement, additionally secured to the first with | 

wood skewers, with all joints in the second course broken , 

with respect to all joints in the first course and all joints \ 

butted tight and sealed in the same compound. To the sur- ; 

face of the insulation shall then be applied a finish as selected. | 

103. — Walls. — Stone, concrete or brick (continued). | 
(4) Double layer, both in Portland cement. ■ 
To the reasonably smooth and clean . . . walls to be insu- 
lated, one layer of . . .-inch pure corkboard shall be erected in j 
a i/4-inch bedding of Portland cement mortar, with all vertical i 








^ 


1/^ 1 


— 1 








1 
SECOND 


LAYER 




\ OF 


CORI 


LBOARD 

r 

1 


' 


, FIRST LA~ER 
OF CORKBC ARD 


\ 




\ 


\ 


1 


- 


' 










) 1 



CORKBOARD 

PORTLAND CEMCNT MORTAR 

CORKBOARD 

PORTLAND CEMENT MORTA' 



ELLLVATION 



FIG. 85.— WALLS; STONE, CONCRETE OK BRICK. ARTICLE 103 (4). 

joints broken and all joints butted tight. To the surface of 
the insulation shall then be applied a finish as selected. 

103. — Walls. — Stone, concrete or brick (continued). 

(5) Double layer, both in Asphalt cement. 

To the reasonably smooth and clean . . . walls to be insu- 
lated, shall first be applied with brush or air-gun two uniform, 
continuous coats of Asphalt primer, to consist of one gallon 
per 75 square feet for brick surfaces or per 100 square feet 
for concrete surfaces for the first coat, and one gallon per 125 
square feet for brick or concrete for the second coat. To this 
prepared surface, one layer of ...-inch pure corkboard shall 
be erected in hot Asphalt cement, with all vertical joints 
broken and all joints butted tight and sealed in the same 
compound. To the first course, a second layer of ...-inch 
pure corkboard shall be erected in hot Asphalt cement, addi- 



k 



SPECIFICATIONS FOR CORKBOARD ERECTION 245 



tionally secured to the first with wood skewers, with all 
joints in the second course broken with respect to all joints 
in the first course and all joints butted tight and sealed in the 




^ 


f "■ II 


/ 


1 
r 




FIRST LA 
OF CORKB 


r^^ 1 i 


/ 1 








/SECOND LAYER 


1 
1 
1_ 

1 


7 




/ 


OF CORkIoARd" 




1 



FINISH 
CORKBOARD 
ASPHALT CEMENT 
CORKBOARD 
ASPHALT CE.ME.NT 



LLEVATION 



FIG. 



-WALLS; STONE, CONCRETE OR BRICK. ARTICLE 103 (5). 



same compound. To the surface of the insulation shall then 
be applied a finish as selected. 
104.— Walls.— Wood. 



^ 

s. 



CR055 
SECTION 



■ 


^1 














CORKBOARD 


' 




' 




A ji 


— t/1 



FINISH 
CORKBOARD 
ASPHALT CEMENT 
SHEATHING 



ELLELVATI ON 



FIG. 87.— WALLS; WOOD. ARTICLE 104 (6). 

(6) Single layer, in Asphalt cement. 

To the reasonably smooth and clean walls to be insulated 
(consisting of ^-inch T. & G. sheathing over wall studding), 



246 



CORK INSULATION 



one layer of ...-inch pure corkboard shall be erected in hot 
Asphalt cement, additionally secured with galvanized wire 
nails, with all vertical joints broken and all joints butted tight 
and sealed in the same compound. To the surface of the insu- 
lation shall then be applied a finish as selected. 

104.— Walls. — Wood (continued). 

(7) Double layer, both in Asphalt cement. 

To the reasonably smooth and clean walls to be insulated 
(consisting of ^-s-inch T. & G. sheathing over wall studding), 
one layer of . ..-inch pure corkboard shall be erected in hot 






V" 


\ 


■^ 


-V 


1 
1 


--T 




' 


s 




^ 


\ 


V- 


— r K 




' 


FIRST 
OF COR 


LAYLR 
KBOARO 


' 


' 










^ 


SECOND LA 
OF CORKB 


)ARD 1 




\ 


1 
J- 












! 


' 


-^/l- 




/* 1 [ -1 





FINII3M 
CORKBOARD 
ASPHALT CEMEMT 
CORKBOARD 
ASPi-iAt-T CEME.NT 
SMEATMINC; 



ELEVATION 



FIG. 88.— WALLS; WOOD. ARTICLE 104 (7). 



Asphalt cement, additionally secured with galvanized wire 
nails, with all vertical joints broken and all joints butted tight 
and sealed in the same compound. To the first course, a 
second layer of . . .-inch pure corkboard shall be erected in 
hot Asphalt cement, additionally secured to the first with 
wood skewers, with all joints in the second course broken with 
respect to all joints in the first course and all joints butted 
tight and sealed in the same compound. To the surface of the 
insulation shall then be applied a finish as selected. 



SPECIFICATIONS FOR CORKBOARD ERECTION 247 

105. — Ceilings. — Concrete. 

(8) Single layer, in Portland cement. 

To the reasonably smooth and clean concrete ceiling sur- 
face to be insulated, one layer of . . .-inch pure corkboard shall 
be erected in a ^-inch bedding of Portland cement mortar, 
with all transverse joints broken and all joints butted tight, 



C E. I l_l NG 



'm%m^mmtm^^;^^><^M><^m^ 



Fl NISM 
CORKBOARD 
PORTLAND CLME-NT MORTAR- 



CROSS 
SECTION 



1 




1 




CORKBOARD 




' 






7 




a 



PLAN OF CEILINQ 

FIG. 89.— CEILING; CONCRETE. ARTICLE 105 (8). 

and the corkboards propped in position until the cement sets. 
To the surface of the insulation shall then be applied a finish 
as selected. 

105. — Ceilings. — Concrete (continued). 

(9) Double layer, both in Portland cement. 

To the reasonably smooth and clean concrete ceiling sur- 
face to be insulated, one layer of . . .-inch pure corkboard shall 
be erected in a >^-inch bedding of Portland cement mortar 
with all transverse joints broken and all joints butted tight, 
and the corkboards propped in position until the cement sets. 
To the first course, a second layer of . . .-inch pure corkboard 
shall be erected in a ><-inch bedding of Portland cement mor- 
tar, additionally secured to the first with wood skewers, 
with all joints in the second course broken with respect to all 
joints in the first course and all joints butted tight. To the sur- 
face of the insulation shall then be applied a finish as selected. 



248 



CORK INSULATION 



CE/LING 



:-)::):-:^)::):^::x-):m 



2^ 



■^m^^:^-^ 



PORTLAND CE:^ 
CORKBOARD 

riMist-f 



[E.NT MORTAR. 



CROSS 
SECTION 





ly 


V ■ i r 1 




I 


; J 


' 


FIRST UAYEIR. 
OP CORKBOAvRD 


\ 


1 . _| . 


\7^ 


1 








\ 


1 


' i 


\ 


s^coMD i_ave:r 

OF lCORK.e.OARC3 


p 




\ 






^ ,,i .; 


1 



PLAN or OEllLINq 

FIG '.:, -c::lLI^G^; cc^:;c. lti.. :.. ■; f 



ESI 



m^mm^yym-:^ 



'^i ■ >■■----■ 



OR.OSS 

SE.CTION 







•kr ••! T 






^ 


J' <, 






FIRST 
OF CO 


LAVE.R ]i 


1 




"'^"■7 






• 


c 


1 






^ 


StCcjMD L.AVe.« 

or JcoRK.oo>^.«> < 


' 






\ 




•1- 


. 


, S .1 .J 





PLAN OF CEIIUNQ 
FIG. 91.— CEILINGS; CONCRETE. ARTICLE 105 (10). 



SPECIFICATIONS FOR CORKBOARD ERECTION 249 

105. — Ceilings. — Concrete (continued). 

(10) Double layer, first in Portland cement, second in 
Asphalt cement. 

To the reasonably smooth and clean concrete ceiling sur- 
face to be insulated, one layer of . . .-inch pure corkboard shall 
be erected in a 5^-inch bedding of Portland cement mortar, 
with all transverse joints broken and all joints butted tight, 
and the corkboards propped in position until the cement sets. 
To the first course, a second layer of . . .-inch pure corkboard 
shall be erected in hot Asphalt cement, additionally secured 
to the first with wood skewers, with all joints in the second 
course broken with respect to all joints in the first course and 
all joints butted tight and sealed in the same compound. To 
the surface of the insulation shall then be applied a finish as 
selected. 

105. — Ceilings. — Concrete (continued). 




WOOD form; 
CORKBOARD 
GALV. WIRE- NAILS. 

FINISM TO BE. APPLIED 

AFTE.R FORM IS RCMOVE-D 



I 


^A kA 






CO R K B OA R D 




7 




" 


1 1 1 



PLAN OF CEILING 
FIG. 92.— CEILINGS; CONCRETE. ARTICLE 105 (11). 



(11) Single layer, in forms before concrete is poured. 

In the concrete ceiling forms, constructed by another con- 
tractor ...inches deeper than would otherwise be necessary, 
one layer of . . .-inch pure corkboard shall be laid down, with 
all transverse joints broken and all joints butted tight, and 



250 



CORK INSULATION 



into which corkboard long galvanized wire nails shall be driven 
obliquely. Into these forms and over this insulation the con- 
crete contractor shall pour the concrete. To the under surface 
of the insulation, after the concrete contractor has removed 
the forms, shall then be applied a finish as selected. 

105. — Ceilings. — Concrete (continued). 

(12) Double layer, first in forms before concr'ite is 
poured, second in Portland cement. 

In the concrete ceiling forms, construed by another con- 
tractor . . . inches deeper than would otherwise be necessary, 



^ 



I, 'V^ 



WOOD f=ORM_ 
CORK BOARD - 
GM_V. WIRE. NAILS. 



i^^m 



^,'A 



^ < " ^ 



CROSS SECTION 

1_ NJOTt: APTtR FORM IS RE- 
MOVED A SECOND COURSE. OF 
CORKBOARD SMALL BE. APPLIED TO 
TME FIRST IN A £"BED OF PORT- 
LAMD CEMENT MORTAR. rINISMTO 
BE APPLIED TO TME EyPOSED SURFACE 




PLAN OF CELILING 
FIG. 93.— CEILINGS; CONCRETE. ARTICLE 105 (12). 

one layer of . . .-inch pure corkboard shall be laid down, with 
all transverse joints broken and all joints butted tight, and 
into which corkboard long galvanized wire nails shall be 
driven obliquely. Into these forms and over this insulation 
the concrete contractor shall pour the concrete. After the 
forms have been removed by the concrete contractor, a sec- 
ond layer of ...-inch pure corkboard shall be erected to the 
underside of the first course in a ^-inch bedding of Port- 
land cement mortar, additionally secured with galvanized 
wire nails, with all joints in the second course broken with 



SPECIFICATIONS FOR CORKBOARD ERECTION 251 



respect to all joints in the first course and all joints butted 
tight. To the surface of the insulation shall then be applied 
a finish as selected. 

105. — Ceilings. — Concrete (continued). 

(13) Double layer, first in forms before concrete is 
poured, second in Asphalt cement. 

In the concrete ceiling forms, constructed by another con- 
tractor . . . inches deeper than would otherwise be necessary, 
one layer of . . .-inch pure corkboard shall be laid down, with 



C E I LIWG 



FORM J 



C0RK60ARD 
CALV. WIRE. NAILS 



^^T-^^ 



■^■/^^./.-^r^l 



CROSS SECTION 

.NOTt: AFTER FORM IS RE-MOVtO 
A SE.COMD COURSE. OF CORK- 
BOARD SHALL BE APPLIED TO 
THt PIRST IM A BtO OF HOT 
ASPHALT CE.ME.K4T. FINISH 
5HAI_L. BE. APPLIED TO THE 

EVPOSE.D Surface,. 





\A 


"( 


<^ \ •" 1 






5E.C 

"oV" 


3ND 1 L.AVE.R 
CORKBOARP ~ 




FIRST L 
OF CORK 


AVER ^v 
BOARD 


, 




7 




V ; 


-. 






1 1 



PLAN OF CELILING 
FIG. 94.— CEILINGS; CONCRETE. ARTICLE 105 (13). 

all transverse joints broken and all joints butted tight, and 
into which corkboard long galvanized wire nails shall be 
driven obliquely. Into these forms and over this insulation 
the concrete contractor shall pour the concrete. After the 
forms have been removed by the concrete contractor, a sec- 
ond layer of ...-inch pure corkboard shall be erected to the 
underside of the first course in hot Asphalt cement, addition- 
ally secured with galvanized wire nails, with all joints in the 
second course broken with respect to all joints in the first 
course and all joints butted tight and sealed in the same com- 
pound. To the surface of fhe insulation shall then be applied 
a finish as selected. 



252 



CORK INSULATION 



106. — Ceilings — Self-supported. 

(14) Double layer, T-irons and Portland cement core. 
Upon the top edges of the side wall insulation shall be 
placed, running the short way of the room,* 2x2xy^-\nch, 




CROSS SECTION 

("PORTLAND CEMENT PLASTER 

CORKBOARD 

2"-Z«^" TE.£ IRON 

^"PORTLAND CEMENT BACKING 

CORKBOARD 

FINISH 



FIG. 95.— CEILINGS; SELF-SUPPORTING. ARTICLE 106 (14). 



or 2x2x5/16-inch T-irons, spaced at a distance of 12 inches 
between the vertical sections of the T-irons (not from center 
to center). Upon the flanges, or horizontal sections, of the T- 
irons, one layer of . . .-inch pure corkboard shall be carefully 
put in place, with all joints butted tight. To the top surface 
of the insulation shall then be applied a 1-inch thick Portland 
cement finish, mixed in the proportion of one part Portland 
cement to two parts clean, sharp sand. 

To the under side of the first course, a second layer of 
. . .-inch pure corkboard shall be erected in a ^-inch bedding 
of Portland cement mortar, additionally secured to the first 
with galvanized wire nails, all joints in the second course 
broken with respect to all joints in the first course and all 
joints butted tight. To the surface of the insulation under- 
neath shall then be applied a finish as selected. 

1 07 . — Ceilings. — Wood. 

(15) Single layer, in Asphalt cement. 

To the reasonably smooth and clean ceiling surface to be 
insulated (consisting of J^-inch T. & G. sheathing to joists), 
one layer of . . .-inch pure corkboard shall be erected in hot 



*About 10 feet is the maximum width that may be spanned safely by T-irons car- 
rying double layer of corkboard, and following this specification. It is not perrnis- 
sable to double the span and center-support the T-irons by rods fastened to ceiling 
of buildino; above ; because water will be condensed on the cool surfaces of these rods 
and will follow through into ceilini? insulation below, tending to destroy it or other- 
wise make it unfit for service within a year. 



SPECIFICATIONS FOR CORKBOARD ERECTION 



253 



Asphalt cement, additionally secured with galvanized wire 
nails, with all transverse joints broken and all joints butted 




SHEATMING J f 



ASPHALT CEMENT _J 

CORKBOARD 

FINISH 



VV-A 



CROS5 SECTION 



, 


' 1 


\ 


7 


CORK BOARD 


^' 


^ 


'■ 


1 , ^ 1 



PLAN OF CLILING 

FIG. 96.— CEILINGS; WOOD. ARTICLE 107 (15). 

tight and sealed in the same compound. To the surface of 
the insulation shall then be applied a finish as selected. 
107. — Ceilings.— Wood (continued). 

(16) Double layer, both in Asphalt cement. 

To the reasonably snfooth and clean ceiling surface to be 
insulated (consisting of %-inch T. & G. sheathing to joists), 
one layer of . . .-inch pure corkboard shall be erected in hot 
Asphalt cement, additionally secured with galvanized wire 
nails, with all transverse joints broken and all joints butted 
tight and sealed in the same compound. To the first course, 
a second layer of . . .-inch pure corkboard shall be erected in 
hot Asphalt cement, additionally secured to the first with 
wood skewers, with all joints in the second course broken 
with respect to all joints in the first course and all joints 
butted tight and sealed in the same compound. To the sur- 
face of the insulation shall then be applied a finish as selected. 

108. — Roofs. — Concrete or wood. 

(17) Single layer, in Asphalt cement. 

To the reasonably smooth and clean . . . roof area to be 



254 



CORK INSULATION 



insulated, one layer of . . .-inch pure corkboard shall be laid 
down in hot Asphalt cement, with all transverse joints broken 




5HE.AT 

ASPHALT CELN 
CORKBOARD 
ASPHALT CEIMENIT 

CORK BOARD 

FIMISH 



^ 1 ; 


V 


1 


\f 




^ 






, 


s 


SECOND LAVE.R 


> 


FIR5T 
OF COP 


LAVE. 
5KBOA 


A 


OF 


COfiKBOARD 




RD 


^ -J- 




- 




7 


/ 








1 



PLAN OF CEIILING 
FIG. 97.— CEILINGS; WOOD. ARTICLE 107 (16). 

and all joints butted tight and sealed in the same compound.* 
The roofing contractor shall then apply, to the surface of the 
insulation, a roofing as required. 

108. — Roofs.— Concrete or wood (continued). 

(18) Double layer, both in Asphalt cement. 

To the reasonably smooth and clean . . . roof area to be 
insulated, one layer of ...-inch pure corkboard shall be laid 
down in hot Asphalt cement, with all transverse joints broken 
and all joints butted tight and sealed in the same compound. 
To the first course, a second layer of . . .-inch pure corkboard 
shall then be laid down in hot Asphalt cement, with all joints 
in the second course broken with respect to all joints in the 
first course and all joints butted tight and sealed in the same 

NOTE — The wall insulation should be carried up so as to connect with the 'oof 
insulation, whecever possible ; and in such cases, insert the following sentence at the 
point starred (*) in the above specification: "The roof insulation shall connect with 
the wall insulation, the joint being sealed with hot Asphalt cement." 



SPECIFICATIONS FOR CORKBOARD ERECTION 255 




ROOFINa BY Atv40THE.R CONTRACTOR. 



fm^Mmmmm 



SECTION A-A 



CORKBOARD . 
ASPHALT CEMCNT_| 
CONCRETE ROOF 5LAB_1 



\j^ 



SECTION SHOWING HOW 
WALL AND ROOF mSUL- 
ATION MAY BE. CONNECTED ^ 



r 


" 








CORKBOARD 




•= 


r 


















' 
















< 






, 





PLAN OF ROOF 
FIG. 98.— ROOFS; CONCRETE OR WOOD. ARTICLE 108 (17). 



ROOFIK/G BY ANOTHtR CONTRACTOR 




SECTION SHOWINq 
MOW WALL AND ROOF 
INSULATIOM MAY BE. 
CONNECTED. 




CR05S SECTION 

CORKBOARD — 
ASPHALT CE:ME.NT_ 
5HE.ATMING_ 







^ 


CORKBOARD 


. 










yi ^ 


. ] 



PLAN OF ROOF 
FIG. 99.— ROOFS; CONCRETE OR WOOD. ARTICLE 108 (18). 



256 



CORK INSULATION 



compounds.* The roofing contractor shall then apply, to 
the surface of the insulation, a roofing as required. 

109.— Floors.— Wood. 

(19) Single layer, in Asphalt cement, concrete finish. 
To the reasonably smooth and clean wood floor to be in- 
sulated (consisting of 1^-inch T. & G. flooring over joints), 



iy a 




1 


r 


CORK.BOARD 


^ 


' 




. 



PORTLAND CEMENT FINISH. 

CONCRELTE 

ASPHALT CE.ME.NT_ 
CORKBOARD 
ASPHALT CE.ME.NT_, 
FLOORINJG 



PLAN 

OF FLOOR 




CROSS SECTION 
FIG. 100.— FLOORS; WOOD. ARTICLE 109 (19j. 

one layer of . . .-inch pure corkboard shall be laid down in hot 
Asphalt cement, with all transverse joints broken and all joints 
butted tight, and the top surface then flooded with hot Asphalt 
cement. Over the surface of the insulation shall then be 
applied a concrete floor finish as selected. 

109. — Floors. — Wood (continued). 
(20) Single layer, in Asphalt cement, wood finish. 
To the reasonably smooth and clean wood floor to be in- 
sulated (consisting of 1^-inch T. & G. flooring over joists), 

NOTE — The wall insulation should be carried up so as to connect with the roof 
insulation, wherever possible; and in such cases, insert the following sentence at the 
point starred (*) in the above specification: "The roof insulation shall connect with 
the wall insulation, the joint being sealed with hot Asphalt cement." 



SPECIFICATIONS FOR CORKBOARD ERECTION 257 

2-inch X ...-inch sleepers shall be put in place on edge on 
38-inch centers. Between these sleepers, one layer of . . .-inch 
pure corkboard shall be laid down in hot Asphalt cement, 
with all joints butted tight, and the top surface then flooded 



, 


A 






■ 


^ 


'•^-^ SLEltPtRS 




7 


CORKBOARD 


^ 



f=l_OORING 
ASPHALT CEME.NT. 
CORKBOARD 



PLAN 

OF FLOOR 




CR05S SECTION 
FIG. 101.— FLOORS; WOOD. ARTICLE 109 (20). 



with the same compound. Over the surface of the insulation 
shall then be applied a T. & G. flooring as selected, securely 
fastened to the sleepers. 

109. — Floors. — Wood (continued). 

(21) Double layer, both in Asphalt cement, concrete 
finish. 

To the reasonably smooth and clean wood floor to be in- 
sulated (consisting of 1^-inch T. & G. flooring over joists), 
one layer of . . .-inch pure corkboard shall be laid down in hot 
Asphalt cement, with all transverse joints broken and all 
joints butted tight. To the first course, a second layer of 
. . .-inch pure corkboard shall be laid down in hot Asphalt ce- 
ment, with all joints in the second course broken with respect 



258 



CORK INSULATION 



to all joints in the first course and all joints butted tight, 
and the top surface then flooded with the same compound 



V ^i- 


— I — i^ — 




^ 


"^ 1 


y 


— ~ — 


------ 


' 


FIR5T LAVtR [^ 
QF CORKBOARD 


"\ JSECONJD LAVE.R_ 
\iOF CORKBOARD - 








~1 




\ 


; { 



PLAN OF FLOOR. 



PORTLANP CEMLNT FINISH 
CONCRETE- 
CORK BOARD 




CROSS 5E.CTION 
FIG. 102.— FLQOKS; WOOD. ARTICLE 109 (21). 

Over the surface of the insulation shall then be applied a 
concrete floor finish as selected. 

109. — Floors. — Wood (continued). 

(22) Double layer, both in Asphalt cement, wood finish. 

To the reasonably smooth and clean wood floor to be in- 
sulated (consisting of 1^-inch T. & G. flooring over joists), 
one layer of . . .-inch pure corkboard shall be laid down in hot 
Asphalt cement, with all vertical joints broken and all joints 
butted tight. Over this insulation, 2-inch x .. .-inch sleepers 
shall then be put in place on 38-inch centers. Between these 
sleepers, the second layer of . . .-inch pure corkboard shall be 
laid down in hot Asphalt cement, with all joints in the second 
course broken with respect to all joints in the first course 
and all joints butted tight, and the top surface then flooded 



SPECIFICATIONS FOR CORKBOARD ERECTION 



259 



with the same compound. Over the surface of the insulation 
shall then be applied a T. & G. flooring as selected, securely 
fastened to the sleepers. 



t ' \' 








\ SLELEPELR 






\ 


1 

N 

o 

1 


.__!__.. 




FIRST LA 
OF CORKE 


V.K I i 


1 OF C 


D LAYER. 


, 


v_ 






Y 


1 



PLAN OF FLOOR. 



ix.r. SLEEPE.RS 
FLOORlM< 
CORKBOARP 




CROSS SECTION 
FIG. 103.— FLOORS; WOOD. ARTICLE 109 (22). 

110. — Floors.— Concrete. 

(23) Single layer, in Asphalt cement, concrete finish. 
To the reasonably smooth and clean concrete floor to be 

insulated, one layer pf ...-inch pure corkboard shall be laid 
down in hot Asphalt cement, with alh transverse joints broken 
«and all joints butted tight, and the top surface then flooded 
with the same compound. Over the surface of the insulation 
shall then be applied a concrete floor finish as selected. 

110. — Floors. — Concrete (continued). 

(24) Single layer, in Asphalt cement, wood finish. 

To the reasonably smooth and clean concrete floor to be 
insulated, 2-inch x ...-inch sleepers shall be put in place on 
edge on 38-inch centers. Between these sleepers, one layer of 



260 



CORK INSULATION 



» 


1/1 




« 






CORK.BOARt> 


^ 








\\ . \ . n 



PLAN OF FLOOR. 



PORTLAND CEME.rsJT FINI 


51- 


- 


















^■^.■■■- ;.■■ * '' ^ . •■ ■'■ 


-\:,t:'.-,:^:--::%i\ 


^'X'/^y^/^^Mm. ^y^'/'>^:^y>>^^'>('mm: 


?t° ■ J . "^ ■' '• '• "^ FLOOR SLAB ■'^ '■^- "^ I, ' '." , ' 



CROSS SECTION 
FIG. 104.— FLOORS; CONCRETE. ARTICLE 110 (23). 



V 




UV t/l 


^ 

1 




? 


^— --^SLEE-PLRS. . 




7 


COR KBOARD 




•! 




1 





PLAN OF FLOOR 



f=LOORINC _ 
CO'RK BOARD 
ASPHALT CEME.NT. 
2"''4" SLEEPER. 




CROSS SECTION 
FIG. 105.— FLOORS; CONXRETE. ARTICLE 110 (24). 



SPECIFICATIONS FOR CORKBOARD ERECTION 261 

...-inch pure corkboard shall be laid down in hot Asphalt 
cement, with all transverse joints broken and all joints butted 
tight, and the top surface then flooded with the same com- 
pound. Over the surface of the insulation shall then be 
applied a T. & G. flooring as selected, securely fastened to 
the sleepers. 

110. — Floors. — Concrete (continued). 



\^' 


b' '■ 1 




V 


ri 


\_. ._ 


i 


■ 


Fl R5T LAVELR. ^ 
OF CORKBOARD 




4 


l5E.CO^40 l_AVE.R 
V. OF corh;board 


' 


^\ 




^"""■""""Ti 


/,. 1 i ., 



PLAN OF FLOOR 



PORTLAND CtMElNJT FINI5h 


^ 
























ASPMAUT CLMENT 


-. 










■' .^- -^- .-^ ■ . - :-. -'- 1. 


id 


:. 


^ 


.-; 


: ■- 


V^\-^^ ::^.J\ 


. '^'v'.'.' ^t,.:'-/,-: ,. ■ 


. 




.... x■^^^^■tvK-\.^: VI 


v-V.-V. /.■■/.■/.-/.'////)('.'/,■//, 


' -> 'A/.'///, 


'/,y.'yyAy///\ 


■j."- • ..*,•;'.' Fl_OOPl SLAB «. 


vm 



CR05S SECTION 

FIG. 106.— FLOORS; CONCRETE. ARTICLE 110 (25). 



(25) Double layer, both in Asphalt cement, concrete 
finish. 

To the reasonably smooth and clean concrete floor to be 
insulated, one layer of ...-inch pure corkboard shall be laid 
down in hot Asphalt cement, with all transverse joints broken 
and all joints butted tight. To the first course, a second 
layer of ...-inch pure corkboard shall be laid down in hot 
Asphalt cement, with all joints in the second course broken 
with respect to all joints in the first course and all joints 
butted tight, and the top surface then flooded with the same 
compound. Over the surface of the insulation shall then 
be applied a concrete floor finish as selected. 



262 



CORK INSULATION 



110. — Floors. — Concrete (continued). 

(26) Double layer, both in Asphalt cement, wood finish. 

To the reasonably smooth and clean concrete base floor to 
be insulated, one layer of . . .-inch pure corkboard shall be laid 
down in hot Asphalt cement, with all vertical joints broken 




PLAN OF FLOOR 



Z>2. 5l_EE.PC.R5 
CORKBOARD 




CROSS SECTION 
FIG. 107.— FLOORS; CONCRETE. ARTICLE 110 (26). 

and all joints butted tight. Over this insulation, 2-inch x . . . 
-inch sleepers shall then be put in place on 38-inch centers. 
Between these sleepers, the second layer of . . .-inch pure cork- 
board shall be laid down in hot Asphalt cement, with all joints 
in the second course broken with respect to all joints in the 
first course and all joints butted tight, and the top surface 
then flooded with the same compound. Over the insulation 
shall then be applied a T. & G. flooring as selected, securely 
fastened to the sleepers. 

111. — Partitions. — Stone, concrete or brick. 

(See 103. — Walls: Stone, concrete or brick; specifications 
(1), (2), (3), (4) and (5). 

Note : It is not always necessary to divide the total thick- 
ness of insulation and put half of it on either side of partition 



SPECIFICATIONS FOR CORKBOARD ERECTION 263 

walls ; instead, it is sometimes sufficient to apply the total 
thickness of insulation to one side or the other, finish it off 
as desired, and then apply the same finish to the uninsulated 
side of the wall. 




V 


f \f^ 




7 


. 




CORKBOARD 


' 


'7 


> 


^. 


.^ ^ 





E. LE.VATION 

FINISH 

CORKBOARD 

ASPHALT eCMENT OR 

PORTLAND CE.ME.NT MORTAR 

-PARTITIONS; STONE, CONCRETE OR BRICK. ARTICLE 111. 



1 1 2 .—Partitions.— Wood. 

(27) Single layer, between studs, joints sealed in Asphalt 
cement. 

Two-inch x 4-inch studding shall be erected 36 inches 
apart, the studs secured so that the 2-inch dimension runs 
with the wall thickness. Between studs, one layer 2-inch 
corkboard shall be erected edge on edge, with all joints butted 
and sealed with hot Asphalt cement, and each corkboard 
secured to the studs and additionally to the adjacent cork- 
board with galvanized wire nails. Over the exposed area of 
the studding shall be put in place 12-inch wide strips of 
galvanized wire square-mesh screen. No. 18 gauge, 3 mesh 
(1/3-inch), securely stapled to the studs and nailed to the 
insulation on both sides of studs. Where cold storage doors 
are to be set, 4-inch x . . .-inch permanent studs, with a lintel 
between them, shall be securely anchored to the floor and 
ceiling in the line of the partition so as to form an opening 



264 



CORK INSULATION 



the size of the cold storage door frame; and after the parti- 
tion has been constructed, the permanent studs and lintel 
shall be covered on both sides with ...-inch pure corkboard 
secured with gahanized wire nails. To the surface of the 



CORKBOARD 




i/— 


(i 

7 

\ 


' 


I 
I 

\ 




^ 




- 


•T' 


A^PHALT CEMENT ON ALL 


OINT5 




CORKBOARD 


'' 


' 


2.. 4 STUDS 
3fa' APAKT 


^> 


'T— 


^ ^ r>- 





ELEVATION 

FINISH 

SQUARE MESM 3CREE.N OVER STUDS 

2>'4. STUDS 34." APART WITH 

CORKBOARD BE.TWEEN 

FrNISM 

FIG. 109.— PARTITIONS; WOOD. ARTICLE 112 (27). 

insulation and over the wire mesh shall then be applied a 
finish as selected. 

1 12. — Partitions. — Wood (continued) . 

(28) Double layer, first between studs with joints sealed 
in Asphalt cement, second in Asphalt cement. 

Two-inch x 4-inch studding shall be erected 36 inches 
apart, the studs secured so that the 2-inch dimension runs 
with the wall thickness. Between the studs, one layer 2-inch 
pure corkboard shall be erected edge on edge, with all joints 
butted and sealed with hot Asphalt cement, and each cork- 
board secured to the studs and additionally to the adjacent 
corkboard with galvanized wire nails. To the first course, a 
second layer of . . .-inch pure corkboard shall be erected in 
hot Asphalt cement, additionally secured with wood skew- 
ers, with all joints in the second course broken with respect 
to all joints in the first course and all joints butted tight and 



SPECIFICATIONS FOR CORKBOARD ERECTION 265 

sealed in the same compound. Over the exposed area of the 
studding shall be put in place 12-inch wide strips of galvanized 
wire square-mesh screen, No. 18 gauge, 3 mesh (1/3-inch), 
securely stapled to the studs and nailed to the insulation on 
both sides of studs. Where cold storage doors are to be set. 








i 

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— ^ r 


1 ^' 
1 

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FIRST LAV 
OF CORKBO 


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ELLELVATION 



FINISH 

CORKBOARD 

ASPHALT CEMtNT 

2-«4 STUDS 3t." APART WITH 

CORKBOARD BE-TVv'E.ELN 

SQUARE. MESH SCRELELKJ OVER STUDS 



FIG. 110.— PARTITIONS; WOOD. ARTICLE 112 (28). 

4-inch X ...-inch permanent studs, with a lintel between them, 
shall be securely anchored to the floor and ceiling in the line 
of the partition so as to form an opening the size of the cold 
storage door frame ; and after the partition has been con- 
structed, the permanent studs and lintel shall be covered on 
both sides with . . .-inch pure corkboard secured with gal- 
vanized wire nails. To the surface of the insulation and over 
the wire mesh shall then be applied a finish as selected. 

113. — Partitions. — Solid cork. 

(29) Single layer, joints sealed in Asphalt cement. 

To form the partition wall, there shall be built up edge 
on edge one layer of . . .-inch pure corkboard, with all vertical 
joints broken and all joints butted tight and sealed in hot 



266 



CORK INSULATION 



Asphalt cement. Each corkboard shall be additionally se- 
cured to the abutting corkboards and, where possible, to the 
wall, floor and ceiling insulation, with long wood skewers. 
Where cold storage doors are to be set, 4-inch x . . .-inch per- 
manent studs, with a lintel between them, shall be securely 
anchored to the floor and ceiling in the line of the partition 
so as to form an opening the size of the cold storage door 
frame ; and after the partition is constructed, the permanent 



W/, 








1'" J/. 






1 




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/ 


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SKEWERS 


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OORKBO/^RD 


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F-frMI.«.M 

















CROSS SECTION E.L.E.VATION 

FIG. 111.— PARTITIONS; SOLID CORK. ARTICLE 113 (29). 



studs and lintel shall be covered on both sides with . ..-inch 
pure corkboard secured with galvanized wire nails. To the 
surface of the insulation shall then be applied a finish as 
selected. 

113. — Partitions. — Solid cork (continued). 

(30) Double layer, first with joints sealed in Asphalt 
cement, second in Portland cement. 

To form the partition wall, there shall be built up edge on 
edge one layer of . . .-inch pure corkboard, with all vertical 
joints broken and all joints butted tight and sealed in hot 
Asphalt cement. Each corkboard shall be additionally se- 
cured to the abutting corkboards and, where possible, to the 
wall, floor and ceiling insulation, with long wood skewers. 
To the first course, a second layer of . . .-inch pure corkboard 
shall then be erected in a ^-inch bedding of Portland cement 



SPECIFICATIONS FOR CORKBOARD ERECTION 267 

mortar, additionally secured to the first with wood skewers, 
with all joints in the second course broken with respect to 
all joints in the first course and all joints butted tight. Where 
cold storage doors are to be set, 4-inch x . . .-inch permanent 
studs, with a lintel between them, shall be securely anchored 
to the floor and ceiling in the line of the partition so as to 
form an opening the size of the cold storage door frame; and 
after the partition is constructed, the permanent studs and 



m 






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V 


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FIN13M 

CORKBOARD 

PORTLAND CE.ME.NT MORTAR 

OORKBOARD 

FINISH 



CR055 SELCTION 



ELLE-VATION 



FIG. 112.— PARTITIONS; SOLID CORK. ARTICLE 113 (30). 

lintel shall be covered ,on both sides with ...-inch pure cork- 
board secured with galvanized wire nails. To the surface 
of the insulation shall then be applied a finish as selected. 

113. — Partitions. — Solid cork (continued). 

(31) Double layer, first with joints sealed in Asphalt 
cement, second in Asphalt cement. 

To form the partition wall, there shall be built up edge on 
edge one layer of ...-inch pure corkboard, with all vertical 
joints broken and all joints butted tight and sealed in hot 
Asphalt cement. Each corkboard shall be additionally secured 
to the abutting corkboards and, where possible, to the wall, 
floor and ceiling insulation, with long wood skewers. To 
the first course, a second layer of . . ,-inch pure corkboard 



268 



CORK INSULATION 



shall then be erected in hot Asphalt cement, additionally se- 
cured to the first course with wood skewers, with all joints 
in the second course broken with respect to all joints in the 
first course and all joints butted tight and sealed in the same 
compound. Where cold storage doors are to be set, 4-inch x 
. . .-inch permanent studs, with a lintel between them, shall be 
securely anchored to the floor and ceiling in the line of the 
partition so as to form an opening the size of the cold storage 



i 






4^ 



t 




FINISH 
CORKBOARD 
ASPHALT CELMEJMT 
CORKBOARD 
FINISH 



CR055 5LCTION 



EILEIVATION 



FIG. 113.— PARTITIONS; SOLID CORK. ARTICLE 113 (31). 

door frame ; and after the partition is constructed, the per- 
manent studs and lintel shall be co\ered on both sides with 
,..-inch pure corkboard secured with galvanized wire nails. 
To the surface of the insulation shall then be applied a 
finish as selected. 

1 14. — Tanks. — Freezing. 

(32) Double layer on bottom, both in Asphalt cement, 
granulated cork fill on sides and ends. 

To the reasonably smooth and clean concrete base, of 
dimensions 2 feet wider and 2 feet longer than the size of 
the freezing tank, one layer of . . .-inch pure corkboard shall 
be laid down in hot Asphalt cement, with all transverse joints 
broken and all joints butted tight. To the first course, a 
second layer of . . .-inch pure corkboard shall be laid down 



Jk 



SPECIFICATIONS FOR CORKBOARD ERECTION 269 



in hot Asphalt cement, with all joints in the second course 
broken with respect to all joints in the first course and all 
joints butted tight, and the top surface then flooded with the 
same compound and left ready for the tank to be set down 
directly on top. 

After the tank has been properly set by others, retaining 
walls of lumber shall be constructed so as to leave a space 
1 foot all around the four* sides of the tank, by erecting 



£ 



i T e,C. BOARDS 
2.UAVELRS OF PAPER 
g' T.S. G BOARDi 



^ 



1^ 



-RaGRANUt-ATEO CORK. 




CR055 SECTION OF TANK 
FIG. 114.— TANKS; FREEZING. ARTICLE 114 (32). 

2-inch X 12-inch studding on suitable centers at right 
angles against the sides of the tank and then sheathing the 
studs with double layer J^-inch T. & G. boards having two 
layers of waterproof paper between. The studs shall be care- 
fully anchored by dropping them into depressions in the con- 
crete base and then wedging them under and securing them 
with metal clips to the flange at top of tank. The space be- 
tween the retaining walls and the tank shall be filled with 
regranulated cork well temped in place, and a curbing 
consisting of double layer %-inch T. & G. boards with two 
layers of waterproof paper between shall then be installed 
so as to rest on the flange of the tank and cover the space 
filled with regranulated cork. 

114. — TanKs. — Freezing (continued). 

(33) Double layer on bottom, both in Asphalt cement; 
double layer on sides and ends, both in Asphalt cement. 



*If the tank is to be set in a corner so that masonry walls of the building act as 
two retaining walls, they should be damp-proofed in a suitable and thorough manner. 



270 



CORK INSULATION 



To the reasonably smooth and clean concrete base, o^ 
dimensions enough wider and longer than the size of the freez- 
ing tank sufficient to overlap the thickness of insulation on 
ends and sides, one layer of .. .-inch pure corkboard shall be 
laid down in hot Asphalt cement, with all transverse joints 
broken and all joints butted tight. To the first course, a sec- 
ond layer of . . .-inch pure corkboard shall be laid down in 
hot Asphalt cement, with all joints in the second course broken 



~~m^y 



SELCTIONAL. PLAN 





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-J 


^_E.J; O M p _ _Lj*,2; 
OP CORKBOAI 


tR." 


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- STUDS fc 




FIRST l-AVE-B, 
OP- CORKBOARD 






1 i i i } 




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c o 


l^:H!S- 


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..";. 




EILEVATION CR055 5E.CTION 

FIG. lis.— TANKS; FREEZING. ARTICLE 114 {2Z) . 

with respect to all joints in the first course and all joints 
butted tight, and the top surface then flooded with the same 
compound and left ready for the tank to be set down directly 
on top. 

After the tank has been properly set by others, suitable 
studding, 2-inch x a dimension equivalent to the thickness of 
the first course of corkboard to be applied, shall be set 36 
inches apart at right angles against the sides and ends of 
the tank, and shall be carefully anchored by dropping them 
into depressions in the concrete base and then wedging them 
under and securing them with metal clips to the flange at the 
top of tank. Between the studs, one layer of ...-inch pure 
corkboard shall then be erected with all joints butted and 



SPECIFICATIONS FOR CORKBOARD ERECTION 271 

sealed with hot Asphalt cement, and each corkboard secured 
to the studs and additionally to the adjacent corkboards with 
galvanized wire nails. To the first course, a second layer of 
. . .-inch pure corkboard shall be erected in hot Asphalt cement 
with all joints in the second course broken with respect to 
all joints in the first course and all joints butted tight and 
sealed in the same compound. To the surface of the insula- 
tion shall then be applied a finish as selected. 

114. — Tanks. — Freezing (continued). 

(34) Double layer on bottom, both in Asphalt cement ; 
single layer on sides and ends against studs, with granulated 
cork fill.' 





,_ __ STUDS 








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5E.CTIONAL. 


PLAN 






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1 CORKl4>o}>R.O ; 


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ELL-E-VATIOM CR055 SE.CTION 

FIG. 116.— TANKS; FREEZING. ARTICLE 114 (34). 

To the reasonably smooth and clean concrete base, of 
"' dimensions enough wider and longer than the size of the 
freezing tank sufificient to overlap the thickness of insulation 
on ends and sides, one layer of . . .-inch pure corkboard shall 
be laid down in hot Asphalt cement, with all transverse joints 
broken and all joints butted tight. To the first course, a sec- 
ond layer of . . .-inch pure corkboard shall be laid down in hot 
Asphalt cement, with all joints in the second course broken 
! with respect to all joints in the first course and all joints 



272 



CORK INSULATION 



butted tight, and the top surface then flooded with the same 
compound and left ready for the tank to be set down directly 
on top. 

After the tank has been properly set by others, 4-inch x 
4-inch studding shall be set on 18-inch centers at right angles 
against the sides and ends of the tank, and shall be carefully 
anchored by dropping them into depressions in the concrete 
base and then wedging them under and securing them with 
metal clips to the flange at the top of tank. Against the studs, 
one layer of . . .-inch pure corkboard shall be secured with gal- 
vanized wire nails, with all joints butted and sealed with hot 
Asphalt cement. The space between the studs, the sides and 
ends of the tank, and the corkboard, shall then be filled with 
regranulated cork well tamped in place. To the surface of 
the insulation shall then be applied a finish as selected. 

115. — Finish. — Walls and ceilings. 



Two COATS 
OF PORTL-AND 
CE.ME.NT PUASTtR 
~^" EACH. 











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MARK 




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CROSS 

SECTION 

FIG. 117.— FINISH; 



E1UE.VATION 
WALLS AND CEILINGS. ARTICLE 



(35) Portland cement plaster, in 2 coats. 

To the exposed surface of the corkboard insulation, a Port- 
land cement plaster finish approximately 3^-inch in thickness 
shall be applied in two coats. The first coat shall be approx- 
imately 34-inch in thickness, rough scratched, and mixed one 
part Portland cement to two parts clean, sharp sand. To the 



SPECIFICATIONS FOR CORKBOARD ERECTION 273 

first coat, after it has thoroughly set, a second coat, mixed in 
the same proportion, shall be applied approximately ^-inch 
in thickness, and troweled to a hard, smooth finish. The sur- 
face shall then be scored in ...-foot squares to confine any 
checking and cracking of the plaster to such score marks. 

115. — Finish.- — Walls and ceilings (continued). 



CORK BOAR D 



ACTORV IRONED 



FINISH, J-QI NITS SEAUELO 



ON4 MASTIC 



ELLEVATION 

FIG. 118.— FINISH; WALLS AND CEILINGS. ARTICLE 115 (36). 

(36) Factory ironed-on mastic finish, joints sealed. 
The exposed surface of the corkboards, used on the second 

or exposed course of insulation, shall be coated to a thickness 
of approximately ^-inch with an asphalt mastic* finish ironed 
on at the factory, the mastic coating having beveled (V) 
edges; and after the corkboard is erected, all joints shall be 
sealed with suitable plastic asphalt mastic put carefully in 
place and gone over with the point of a hot tool, hot enough 
to melt the mastic and the plastic and seal the joints and 
render them tight. 

115. — Finish. — Walls and ceilings (continued). 

(37) Glazed tile or brick, in Portland cement. 

To the exposed surface of the corkboard insulation, a Port- 
land cement plaster finish approximately ^-inch in thickness, 

*Each manufacturer presumably follows its own formula for the particular brand 
of ironed-on mastic finish offered, and its probable worth in service must be judged 
accordingly. 



274 



CORK INSULATION 



mixed one part Portland cement to two parts clean, sharp 
sand, shall be applied in one coat, floated to a reasonably true 




II I ' . 

I i'i' i.i. M 



E.l_E.VATION 

QLA-ZLE-D TILE. OR BRICK 

^" PORT1.A.MD CEME.MT PLASTEt 

ROUan SCRATCI-IE.D 

CORKBOA.RD 

PORTLAND CtMENT MORTAR 

CORKBOARD 

PORTL.AND CE.ME.ISIT MORTAR 



FIG. 119.— FINISH; WALLS AND CEILINGS. ARTICLE 115 (37). 

surface and left rough scratched. A glazed tile or glass brick 



finish, as specified 
tractor. 



hall then be installed by another con- 
Walls and ceilings (continued). 




PUA3TIC 

MA^T/C riniSH 
TRor/etrD to 

tORK BOARD SURFACEi 

AT 

POINT OF Cf?£"CT(OM| 
LEFT UN^COBeiO 



ELEVATION 

PI AXTIC MAATi r FlMI.Sh 

pnwTi Hf^n CCMrMT nnBTAR. 

FIG. 120.— FINISH; WALLS AND CEILINGS. ARTICLE 115 (m. 



SPECIFICATIONS FOR CORKBOARD ERECTION 275 

(38) Emulsified asphalt plastic, in 2 coats. 

The surface of the corkboards to receive the asphalt plastic 
finish shall be made reasonably even and true by trimming 
ofif any slight projections. 

To the corkboard surface thus prepared, shall be applied 
two coats of approved Emulsified Asphalt Plastic. The first 
coat, approximately 3/32-inch in thickness, shall be applied 
under a wet trowel, care being taken to press the material 
firmly into the surface irregularities of the corkboard. When 
this coat has set, a second coat shall be applied under a wet 
trowel, making the total thickness for the two coats not 
less than ^/^-inch. The second coat shall be troweled smooth 
after it has begun to set but before it has hardened. Its sur- 
face shall not be scored. 

116. — Finish. — Floors. 



\ '' 


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: 


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f\ R5T LAVELR ^ 
OF CORKBOARD 


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' IsE-COhslD LAVE.R. 
\^ OF CORKBOARD 


, 




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A 


(,. 1 i .. 



PLAN OF FLOOR 



PORTLAND CEIMELNJT FIKII5M 

CONCRE.TE 

CORKBOARD 



ASPHALT CLMENT 



■....^.-.v-m 



a 



& 



Fl_OOR SLAl 



CROSS SECTION 
121.— FINISH; FLOORS. ARTICLE 116 (39). 



(39) Concrete. 

A ...-inch concrete wearing floor shall be laid down di- 
rectly on top of the asphalt flooded surface of the corkboard, 



276 



CORK INSULATION 



consisting of ... inches of rough concrete, mixed one part 
Portland cement to two and a half parts clean, sharp sand and 
five parts clean gravel or crushed stone, well tamped in place 
until the water comes to the surface, and then followed by a 
1-inch troweled smooth top finish composed of one part Port- 
land cement and one part clean, sharp sand. The concrete 
wearing floor shall be sloped to drain as desired. 

116. — Finish, — Floors (continued). 

(40) Wood. 

The finished wood floor shall be of thoroughly dry and 



\^^ 1/ 


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i 


FIRST LA 
OF CORKE 




|OF C 


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3 RKBOARD 

"T"\ 


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M 


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1 



PLAN OF FLOOR. 



^jtZ. SLEE.PE.RS 
FLOORIMC 
CORKBOARD 




CROSS SECTION 

FIG. 122.— FTNISn; FLOORS. ARTICLE 116 (40). 



seasoned %-inch T. & G. ... lumber, laid with approximately 
1/32-inch between the boards, to eliminate as much as pos- 
sible the tendency of the floor to expand and warp, and secret 
nailed to the sleepers that were provided in the insulation 
underneath, and the floor left perfectly smooth and even. 



SPECIFICATIONS FOR CORKBOARD ERECTION 277 



116. — Finish. — Floors (continued). 
(41) Galvanized metal. 

Over the asphalt flooded surface of the corkboard on the 
fioors and baffles of bunkers, there shall be installed a floor 




-FINISH; FLOORS 



or cover of . . , gauge galvanized iron. The metal shall extend 
over all edges of the bunker at least two inches and be se- 
curely anchored, and all joints and nail heads in the finished 
work shall then be carefully soldered. 



117. — Miscellaneous Specifications. 




FIG. 124.— MISCELLANEOUS SPECIFICATIONS. ARTICLE 117 (42). 

(42) Ends of beams or girders extending into walls. 
All beams and girders extending into the building walls 
shall be insulated on the ends, tops and sides with one layer 



278 CORK INSULATION 

of . . .-inch pure corkboard cut accurately and joints sealed 
tightly with hot Asphalt cement, the corkboard extending be- 
yond the inside face of the wall so as to join and seal with 
the wall insulation. The insulation contractor shall furnish 
the material required for this purpose, but the installation 
shall be made by the general contractor. 

117. — Miscellaneous Specifications (continued). 

(43) Rat proofing. 

As a barrier against rats and mice entering this cold stor- 
age room, there shall be installed over all areas of the room 
and securely stapled in place, with all joints carefully butted 
or lapped, galvanized wire square-mesh screen, No. 18 gauge, 3 
mesh (1/3-inch). The screen shall be located as near as pos- 
sible to the point of expected attack, that is, the screen shall 
be laid across ceiling joists and wall studding before the 
sheathing is applied, fastened to the surface of soft brick or 
laid down over w^ood floor before the first layer of insulation 
is applied, and similarly used elsewhere as required. 

117. — Miscellaneous Specifications (continued). 

(44) Portland cement mortar. ! 
The Portland cement mortar (not the Portland cement ! 

plaster) used in connection with the corkboard insulation on 

walls and partitions shall be mixed in the proportion of one ; 
part Portland cement to two parts clean, sharp sand. 

The Portland cement mortar used in connection with the ' 

corkboard insulation on ceilings shall be mixed in the propor- | 

tion of one part Portland cement to one part clean, sharp ' 

sand. j 

(45) Asphalt cement. 

Note: See specification given in Article 100, under head i 
ing entitled, ''Specification for Asphalt cement for cold stor- : 
age insulation." i 

(46) Asphalt primer. 

Note: See specification given in Article 100, under head- 
ing entitled, "Asphalt primer for use with Asphalt cement." 



CHAPTER XIV. 

COMPLETE DIRECTIONS FOR THE PROPER APPLI- 
CATION OF CORKBOARD INSULATION. 

118. — General Instructions and Equipment. — For many 
years it was considered necessary, or at least highly desirable, 
that all corkboard surfaces to be erected in Portland cement 
mortar and all corkboard surfaces to be finished with Port- 
land cement plaster, should be scored on the side against 
which the mortar or plaster was specified to be applied. This 
scoring had to be done at the factory and consisted of several 
parallel saw grooves running the length of the corkboards, 
and which were put there as a key or bond for the cement. 
Experience has demonstrated, however, that the plain surface 
of corkboard is of such character as to permit an intimate and 
satisfactory bond with Portland cement, as with Asphalt ce- 
ment, and score marks are no longer considered essential. 
The plain corkboard may be scored on the job, if scoring is 
preferred, before being erected in Portland cement mortar, 
by roughening the surface slightly with any pronged tool, 
such as a few wire nails driven through a piece of wood. If 
it is desired to roughen the surface to receive Portland cement 
plaster, then the work is done after the corkboard has been 
put in place and just before the first coat of plaster is applied. 

The Portland cement mortar, in which corkboard is fre- 
quently erected to masonry walls, and the like, should be pre- 
pared by mixing* one part (by volume) of any standard grade 
of Portland cement with two parts of clean, sharp sand. Be 
sure the sand is clean, and be sure that it is sharp. It will 
require 5.0 barrels of Portland cement* and 2.1 cubic yards of 



*The Portland Cement Association, 33 West Grand Avenue, Chicago, Illinois, with 
branches in many cities, gladly furnish complete data relating to the proper mixing of 
Portland cement for any purpose. Also see Appendix of this text. 

279 



280 



CORK INSULATION 



sand* for each thousand square feet of surface. Do not mix 
too much mortar at a time, make it fairly stifif, and do not 
add any lime. 

Portland cement mortar, or "backing," should be uniformly 
one-half inch in thickness over the whole surface of the cork- 
boards and none should be allowed on the sides and ends. 
This cement backing is never applied directly to the area to 




MG. 1-5. CORKBOARD KRECTED TU CONCRETE WAELS AXD COLL'.MXS 
IN PORTLAND CEMENT MORTAR.— xNOTE THE SIMPLE MORTARBOARD 
AND HOPPER DEVICE FOR APPLICATION OF THE "BACKING" DE- 
SCRIBED IN THE TEXT. 



be insulated, as some might suppose, but to the surfaces of the 
individual corkboards before they are set in place. To facili- 
tate the application of the cement backing to the corkboards, 
a mortar board about 4 feet square is equipped with a simple 
runway and hopper attachment that is entirely practical and 
very satisfactory. Across the top of the mortar board nail 
two strips parallel to each other and exactly 12 inches apart, 

*1 barrel cement = 4 sacks = 4 cubic feet = 400 pounds; 1 cubic yard sand = 
approximately 2,400 pounds — based on tables in "Concrete, Plain and Re'nforced," by 
Taylor and Thompson. 



DIRECTIONS FOR CORKBOARD ERECTION 



281 



so that one standard sheet of corkboard (12 inches wide x 
36 inches long) may be laid down between them. Make the 
height of these strips one-half inch more than the thickness 
of the corkboards to be coated. Construct a simple wooden 
hopper about two feet high, having an opening at the top 
about 2 feet x 2 feet and one at the bottom exactly 12 inches 
by 12 inches. Mount the hopper on the two strips so that a 




FIG. 126.— ERECTING CORKBOARD IX ASPHALT CEMENT TO ASPHALT 
PRIMED CONCRET-E WALL SURFACES.— NOTE THE ASPHALT PAX 
AXD OIL STONE ARRAXGEMEXT FOR HOLDIXG ODORLESS ASPHALT 
AT THE CORRECT TEMPERATURE AT POIXT OF ERECTION. 



corkboard can be pushed through the runway (formed by the 
two strips) and under the hopper. Then fill the hopper with 
Portland cement mortar; and by pushing one board through 
ahead of another, butted end to end, the individual boards are 
uniformly coated to a thickness of one-half inch and without 
the liklihood of the mortar getting on the sides and ends of 
the corkboards. 



282 CORK INSULATION 

To prepare Asphalt cement for use with corkboard to walls 
and ceilings requires a large kettle, several small kettles and 
an equal number of gasoline torches, and several buckets. 
Set up the large kettle outside the building and melt down 
sufficient Asphalt cement, or odorless asphalt, computed at 
three-quarters of a pound for each square foot of corkboard 
surface to be coated, using wood as fuel under the kettle, and 
the fire protected from possible wind by a sheet-iron shield. 
Do not overheat the asphalt. Transfer the molten asphalt in 
buckets to the small kettles, or pans, located close to where 
the corkboard is being erected. The pans should be about 18 
inches wide, 42 inches long and 8 inches deep, should be 
rigidly constructed, and should be kept hot by the gasoline 
torches.* To the molten asphalt in these pans, add approx- 
imately 8 per cent, (by weight) of cork dust, or cork flour, 
and stir in thoroughly. The admixture of the cork dust 
stiffens up the molten asphalt just enough so that the proper 
quantity clings to the corkboards when dipped. 

To prepare Asphalt cement for use with corkboard on 
floors and bottoms of freezing tanks, proceed as outlined in 
the foregoing paragraph, except no pans are ordinarily needed 
and no cork dust is mixed with the molten asphalt. 

Ordinary wire nails should never be used in erecting cork- 
board insulation, because they will soon rust away, although 
they are sometimes employed by careless and disinterested 
erectors. Galvanised wire nails having large heads and of 
proper length should always be used where specified, but do 
not use galvanized wire nails where wood skezvers are speci- 
fied and can be employed instead. Wood, even hard hickory, 
is a far better thermal insulator than metal, and consequently 
galvanized wire nails should never be used where wood 
skewers will serve the purpose, for there is always danger of 
frost following in along nails or forming on wall finishes over 
nail heads underneath. Hickory skewers should be used in i 
preference to softer woods, to diminish the chances for damage ■ 
to the hands of workmen from splintering and breaking of the 
skewers when being driven into the insulation. 

*CAUTION — Gasoline torches have been known to explode if not properly con- 
structed, not kept in proper condition, or not properly operated. Charcoal pots are 
less applicable, but safer. See Appendix for description of Oil-Burning Cork Dipping 
Pan. 



DIRECTIONS FOR CORKBOARD ERECTION 283 

If masonry surfaces are to be primed with Asphalt primer 
before the corkboard is applied in Asphalt cement, the work 
should be done with an air-gun, if possible. The complete 
equipment for such application consists of a suitable air-gun 
of approved make and the necessary supply of compressed 
air. 

Extension cords, electric light guards, sand screens, metal 
mortar boxes, hods, hoes, shovels, trowels, rope and tackle, 
hand saws, hatchets, hammers, salamanders, metal w^heelbar- 
rows, water buckets, rubber hose, big asphalt kettle on wheels 
with firebox and stack, these and possibly other utensils con- 
stitute some of the additional equipment that may be required 
to properly handle a corkboard insulation job. 

Where cold storage doors are to be installed, it is neces- 
sary that the outside dimensions of the door frames be known 
in advance, so that if necessary or desirable the door bucks 
and lintels may be properly placed in the line of insulated 
walls or partitions in advance of the actual arrival, or of 
the uncrating, of the door equipment. 

Unnecessary and sometimes very expensive delays in the 
prosecution and completion of a given job of cork insulation 
may be brought about through failure of the job superintend- 
ent to check first of all the actual size of rooms and tanks to 
be insulated against the measurements as originally planned, 
and then, as the materials, supplies and equipment are deliv- 
ered, to check them carefully against the requirements of 
the work. The superintendent must, in a word, anticipate his 
needs well and sufficiently in advance. 

119. — First Layer Corkboard, Against Masonry Walls, in 
Portland Cement Mortar. — See that the walls present a rea- 
• sonably smooth and level surface, remove all dirt, plaster, 
loose mortar, whitewash, paint, or other foreign material, and 
if the walls are very smooth concrete, roughen them by hack- 
ing the surface with a hatchet or hacking hammer, or arrange 
to have these several items taken care of by those responsible 
for such preliminary work, before making preparations to 
erect corkboard to masonry walls in Portland cement mortar. 
Now see that the floor at the base of the wall is free from 
obstruction, and is level; because the first row of corkboards 



284 CORK INSULATION 

must be applied to the wall at the floor, on a level line, so 
that the corkboards on the entire wall area are kept in perfect 
alignment and all vertical and transverse joints in the upper 
rows are made to fit close and tight. 

Prepare suitable Portland cement mortar in reasonable 
quantity, sprinkle the wall to be insulated with clean water, 
coat one side of each corkboard with a half-inch of Portland 
cement mortar. 1\\ the l:()])per method. ]-nt each in prnner posi- 




FIG. 127.— ERECTING FIRST LAYER CORXBOARD AGAIXST iMASOXRY 
WALL IN PORTLAND CEMENT MORTAR. 

tion against the wall, slightly press into place and hold for a 
few moments until the mortar begins to set. Keep cement 
backing oflf edges of corkboards. Do not "vacuum cup" the 
backing before setting the corkboards, by hollowing out the 
mortar with the point of a trowel, because it is impossible 
to spread out the mortar again in setting the corkboards, and 
air pockets behind insulation, with disastrous results, will be 
inevitable. 

Cut a corkboard half-length and with it start setting the 
second row on top of the first, thus breaking vertical joints. 
As each corkboard is set, butt it tightly at all points of con- 
tact against the adjoining boards, but do not loosen boards 
already in position. Join the wall insulation tightly with the 
ceiling, cutting pieces of corkboard neatly to fit and never 
using Portland cement mortar to fill in openings between 
corkboards or pieces of corkboard. 

Give the cement backing ample time to set, say 48 hours. 



DIRECTIONS FOR CORKBOARD ERECTION 285 

betore erecting another layer of corkboard against the first, 
or before applying a finish over the insulation. 

120. — First Layer Corkboard, Against Masonry Walls, in 
Asphalt Cement. — See that the walls present a reasonably 
smooth and level surface, remove all dirt, plaster, loose mortar, 
whitewash, paint, or other foreign material, or arrange to have 
these several items taken care of by those responsible for such 
preliminary work, before making preparations to erect cork- 
board to masonry walls in Asphalt cement. 




FIG. 128.— ERECTING FIRST LAYER CORKBOARD AGAINST CONCRETE 
WALLS, COLUMNS AND COLUMN CAPS IN ASPHALT CEMENT TO 
SUITABLY PRIMED SURFACES.— NOTE PRIMED BUT UNINSULATED 
WALL AND COLUMN SECTION AT TOP LEFT. 

With suitable Asphalt primer and proper air-gun equip- 
ment, apply evenly under a minimum air pressure of 50 pounds, 
to the entire masonry wall surfaces to be insulated, two uni- 
form, continuous coats of the priming liquid, using approx- 
imately 1 gallon per 75 square feet for brick or per 100 square 
feet for concrete surfaces for the first coat, and 1 gallon per 
125 square feet for brick or concrete for the second coat. If 
the Asphalt primer thickens because of exposure to the air, 
or during very cold weather, it may be thinned with suitable 
solvent to permit an even flow through the air-gun nozzle. 
The first coat is to become hand-dry before the second is ap- 



286 



CORK INSULATION 



plied, and the second is to become hand-dry before cork- 
board is applied. 

See that the floor at the base of the wall is free from ob- 
struction, and is level ; because the first row of corkboards 
must be applied to the wall at the floor, on a level line, so that 
the corkboards on the entire wall area are kept in perfect align- 
ment and all vertical and transverse joints in the upper rows 
are made to fit close and are sealed tit^ht. 




FIG. 129.— ERECTING DOUBLE LAYER CORKBOARD TO ASPHALT PRIMED 
CONCRETE WALL SURFACE IN ASPHALT CEMENT, AS CONTINUOUS 
INSULATION THROUGH CONCRETE FLOOR SLAB. 



Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of 
cork dust and mix, dip one flat side, one end and one edge of 
each corkboard in the molten material, put the boards in 
proper position against the wall, slightly press into place and 
hold for a few moments until the Asphalt cement begins to 
cool. 



DIRECTIONS FOR CORKBOARD ERECTION 287 

Cut a corkboard half-length and with it start setting the 
second row on top of the first, thus breaking vertical joints. 
As each corkboard is set, butt and seal it tightly at all points 
of contact against the adjoining boards. Join and seal the 
wall insulation tightly with the ceiling, cutting pieces of cork- 
board neatly to fit. 

Give the Asphalt cement ample time to cool and set, say 12 
hours, before erecting another layer of corkboard against the 
first, or before applying a finish over the insulation. 

121. — First Layer Corkboard, Against Wood Walls, in 
Asphalt Cement. — See that the walls present a smooth, con- 
tinuous, solid surface, free from open cracks and loose or 
warped boards, remove all dirt, plaster, loose mortar, paper or 
other foreign material, or arrange to have these several items 
taken care of by those responsible for such preliminary work, 
before making preparations to erect corkboard to wood walls 
in Asphalt cement. 

See that the floor at the base of the wall is free from ob- 
struction, and is level ; because the first row of corkboards 
must be applied to the wall at the floor, on a level line, so 
that the corkboards on the entire wall area are kept in per- 
fect alignment and all vertical and transverse joints in the 
upper rows are made to fit close and are sealed tight. 

Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of 
cork dust and mix, dip one flat side, one end and one edge 
of each corkboard in the molten material, put the boards in 
proper position against the wall, slightly press into place and 
securely nail in position to sheathing with galvanized wire 
nails driven obliquely, two nails per square foot. 
'^ Cut a corkboard half-length and with it start setting the 
second row on top of the first, thus breaking vertical joints. 
As each corkboard is set, butt and seal it tightly at all points 
of contact against the adjoining boards. Join and seal the 
wall insulation tightly with the ceiling, cutting pieces of 
corkboard neatly to fit. 

Give the Asphalt cement ample time to cool and set, say 
12 hours, before erecting another layer of corkboard against 
the first, or before applying a finish over the insulation. 



288 CORK INSULATION 

122. — Second Layer Corkboard, Against First Layer on 
Walls, in Portland Cement Mortar. — See that the first layer of 
corkboard on the walls is solidly attached, and presents a rea- 
sonably smooth and level surface,* then remove all dust, 
dirt or loose mortar, before making preparations to erect a 
second layer of corkboard in Portland cement mortar. 

Now see that the floor at the base of the wall is free from 
obstruction, and is level ; because the first row of corkboards 
in the second layer must be applied to the first layer at the 
floor, on a level line, so that the corkboards on the entire 
second layer are kept in perfect alignment and all vertical and 
transverse joints in the upper rows are made to fit close and 
tight. 

Prepare suitable Portland cement mortar in reasonable 
quantity, saw sufficient corkboards lengthwise down the center 
so as to have enough half-width pieces to make one row around 
the room, coat the half-width corkboards on one side with 
a half-inch of Portland cement mortar, cut a piece 6 inches 
wide and 27 inches long and with it start putting the half- 
width pieces of corkboard in proper position against the first 
layer of insulation, slightly press into place and additionally 
secure with wood skewers driven obliquely, two skewers 
per square foot. 

Then start with a full-width and 9-inch long piece of 
corkboard and set the second row of full-size corkboards on 
top of the first row, thus breaking vertical joints in the sec- 
ond layer, and all joints in the second layer with respect to 
all joints in the first layer. As each corkboard is set, butt it 
tightly at all points of contact against the adjacent boards 
and additionally secure to the first layer with wood skewers 
driven obliquely, two skewers per square foot. Join the wall 
insulation tightly with the ceiling, cutting pieces of cork- 
board neatly to fit and never use Portland cement mortar 
to fill in openings between corkboards or pieces of corkboard. 

Give the cement backing ample time to set, say 48 hours, 
before applying a finish over the insulation. 



*If necessary, cut off any protruding corners or edges of corkboard with a suitable 
tool. 



DIRECTIONS FOR CORKBOARD ERECTION 289 

123. — Second Layer Corkboard, Against First Layer on 
Walls, in Asphalt Cement. — See that the first layer of cork- 
board on the walls is solidly attached, and presents a rea- 
sonably smooth and level surface,* and then remove all dust, 
dirt or loose mortar, before making preparations to erect a 
second layer of corkboard in Asphalt cement. 

Now see that the floor at the base of the wall is free from 
obstruction, and is level ; because the first row of corkboards 
in the second layer must be applied to the first layer at the 
floor, on a level line, so that the corkboards on the entire 
second layer are kept in perfect alignment and all vertical 
and transverse joints in the upper rows are made to fit close 
and are sealed tight. 

Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of cork 
dust and mix. Saw sufficient corkboards lengthwise down 
the center so as to have enough half-width pieces to make 
one row around the room, cut a piece 6 inches wide and 27 
inches long and with it start putting the half-width pieces 
of corkboard in proper position against the first layer of in- 
sulation, first dipping one flat side, one end and one edge 
of each piece in the molten material, slightly pressing into 
place and additionally securing with galvanized wire nails or 
wood skewers, as specified, driven obliquely, two per square 
foot. 

Then start wuth a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards on top 
of the first row, thus breaking vertical joints in the second 
layer, and all joints in the second layer with respect to all 
joints in the first layer. As each corkboard is set, butt it 
tightly at all points of contact against the adjacent boards 
and additionally secure to the first layer with galvanized 
wire nails or wood skewers, as specified, driven obliquely, 
two per square foot. Join and seal the wall insulation tightly 
with the ceiling, cutting pieces of corkboard neatly to fit. 

Give the asphalt cement ample time to cool and set, say 
12 hours, before applying a finish over the insulation. 

*If necessary, cut off anv protruding corners or edge of corkboard with a suitable 
tool. 



290 



CORK INSULATION 



124. — First Layer Corkboard, to Concrete Ceilings, in Port- 
land Cement Mortar. — See that the ceiling presents a reason- 
ably smooth and level surface, remove all dirt, plaster, loose 
mortar, whitewash, paint, or other foreign material, and if 
the ceiling is very smooth concrete, roughen it by hacking the 
surface with a hatchet or hacking hammer, or arrange to have 
these several items taken care of by those responsible for such 
preliminary work, before making preparations to erect cork- 
hoard to ceiling in Portland cement mortar. 




FIG. 130.— ERECTING FIRST LAVEK CORKBOARD TO CONCRETE CEILING I 
IN PORTLAND CEMENT MORTAR.— NOTE METHOD OF PROPPING . 
UNTIL CEMENT SETS. 

Prepare suitable Portland cement mortar in reasonable i 
quantity, sprinkle the ceiling to be insulated with clean water, 
coat one side of each corkboard with a half-inch of Portland | 
cement mortar, by the hopper method, put each in proper i 
position against the ceiling, press firmly into place and prop I 
until the cement sets. Keep cement backing ofif edges of cork- 
boards. Do not "vacuum cup" the backing before setting the ■ 
corkboards, by hollowing out the mortar with the point of } 
a trowel, because it is impossible to spread out the mortar ' 
again in setting the corkboards, and air pockets behind in- \ 
sulation, with disastrous results, will be inevitable. 

Apply the first row of corkboards against the ceiling along 
one side of the room, in a straight line. Keep the sheets in 
perfect alignment, so that the joints in the rows to follow 
may fit close and tight. 

Cut a corkboard to half-length and with it start setting 
and propping a second row of full-size corkboards adjacent 



i 



DIRECTIONS FOR CORKBOARD ERECTION 



291 



to the first row, thus breaking transverse joints. As each 
corkboard is set, butt it tightly at all points of contact against 
the adjacent boards, but do not loosen boards already in 
position. Join the ceiling insulation tightly with the wall, 
cutting pieces of corkboard neatly to fit and never using Port- 
land cement mortar to fill in openings between corkboards 
or pieces of corkboard. 

Give the cement backing ample time to set, at least 48 
hours, before erecting another layer of corkboard against 
the first, or before applying a finish over the insulation. 

125. — First Layer Corkboard, in Concrete Ceiling Forms. — 

See that the wooden forms for the concrete ceiling slab have 








^s^ 




FIG. 131.— PL..\C1.NG FIRST LAYER CORKBOARD IN CEILING FORMS 
BEFORE CONCRETE IS POURED. 



been lowered the proper distance to allow for the thickness of 
the layer* of corkboard specified to be placed in forms, and see 



'Never put two layers of corkboard in ceiling forms. 



292 CORK INSULATION 

that the forms are reasonably even. Lay down the first row '. 

of corkboards on the forms, along one side of the ceiling area, ; 

in a straight line. Keep the corkboards in perfect alignment, i 

so that the joints in the rows to follow may fit close and tight. I 

If the surface of the forms should be slightly uneven, se- j 

cure the corkboards to the forms with a few headless finishing I 

nails, which will easily pull out of the corkboard when the j 

forms are removed. Break all joints between the different : 

rows, by starting alternate rows with half-length boards, and i 

see that all joints are butted close and made tight, so that j 

none of the concrete can run down between the corkboards I 

and pieces of corkboard when the concrete is poured. When ! 
the opposite end and the opposite side of the ceiling area is 

reached, cut pieces of corkboard neatly to fit the outline of ■ 

the forms. ! 

Drive three galvanized wire nails per square foot obliquely j 

into the corkboard and leave the heads protruding about V/2 ] 

inches to afiford an additional key for the concrete, and leave , 

the insulation in readiness for the concrete contractor to pour 1 

the ceiling slab. ! 

After forms have been removed, permit this layer of cork- 
board on underside of concrete ceiling to dry out thoroughly, j 
not less than an additional 48 hours, before erecting another ' 
layer of corkboard against the first, or before applying a finish ; 
over the insulation. 

126. — First Layer Corkboard, to Wood Ceiling, in Asphalt 
Cement. — See that the ceiling presents a smooth, continuous, 
solid surface, free from open cracks and loose or warped 
boards, remove all dirt, plaster, paper, or other foreign mate- 
rial, or arrange to have these several items taken care of by 
those responsible for such preliminary work, before making 
preparations to erect corkboard to wood ceiling in Asphalt 
cement. 

Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of 
cork dust and mix, dip one flat side, one end and one edge of 
each corkboard in the molten material, lay up the first row 
of corkboards to the ceiling surface and against the edge of 



DIRECTIONS FOR CORKBOARD ERECTION 293 

the wall, in a straight line, slightly press the corkboards into 
place and securely nail in position to sheathing with gal- 
vanized wire nails driven obliquely, three nails per square 
foot. Keep the corkboards in perfect alignment, so that the 
joints in the rows to follow may fit close and seal tight. 

Break all joints between the different rows, by starting 
alternate rows with half-length boards, and see that all joints 
are butted close and sealed tight. When the opposite end 
and the opposite side of the ceiling area is reached, cut pieces 
of corkboard neatly to fit and seal with the wall lines of the 
room. 

Give the Asphalt cement ample time to cool and set, say 
12 hours, before erecting another layer of corkboard against 
the first, or before applying a finish over the insulation. 

127. — Second Layer Corkboard, to First Layer on Ceiling, 
in Portland Cement Mortar. — See that the first layer of cork- 
board on the ceiling is solidly attached, and presents a reason- 
ably smooth and level surface,* and then remove all dust, dirt, 
or other foreign material, before making preparations to erect 
a second layer of corkboard in Portland cement mortar. 

Saw sufficient corkboards lengthwise down the center so 
as to have enough half-width pieces to make one row along 
one side of the ceiling. Cut a piece 6 inches wide and 27 inches 
long with which to start setting the half-width pieces in proper 
position to the ceiling area, in a straight line, against the 
edge of the wall. 

Prepare suitable Portland cement mortar in reasonable 
quantity, coat one side of each piece of corkboard with a 
half-inch of Portland cement mortar, put each in proper 
position against the ceiling, press firmly into place and addi- 
tionally secure with galvanized wire nails or wood skewers, 
as specified, driven obliquely, three per square foot. Keep 
the pieces of corkboard in perfect alignment, so that the joints 
in the rows to follow may fit close and seal tight. 

Then start with a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards adjacent 
to the first row, thus breaking all joints in the second layer, 

*If necessary, cut off any protruding corners or edges of corkboard with a suitable 



294 CORK INSULATION 

and all joints in the second layer with respect to all joints 
in the first layer. As each corkboard is laid up, butt it tightly 
at all points of contact against the adjacent boards, and addi- 
tionally secure to the first layer with galvanized wire nails or 
wood skewers, as specified, driven obliquely, three per 
square foot. Join the second layer of ceiling insulation tightly 
with the opposite wall, cutting pieces of corkboard neatly to 
fit and never using Portland cement mortar to fill in openings 
between corkboards or pieces of corkboard. 

Give the cement backing ample time to set, at least 48 
hours, before applying a finish over the insulation. 

128. — Second Layer Corkboard, to First Layer on Ceiling, 
in Asphalt Cement. — See that the first layer of corkboard on 
the ceiling is sc^idly attached, and presents a reasonably 
smooth and level surface*, and then remove all dust, dirt, or 
other foreign material, before making preparations to erect a 
second layer of corkboard in Asphalt cement. 

Saw sufficient corkboards lengthwise down the center so 
as to have enough half-width pieces to make one row along 
one side of the ceiling. Cut a piece 6 inches wide and 27 
inches long with which to start setting the half-width pieces 
in proper position to the ceiling area, in a straight line, and 
against the edge of the wall. 

Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of 
cork dust and mix; dip one flat side, one end and one edge 
of the special corkboard pieces in the molten material, lay up 
the first row to the surface of the first layer of insulation, 
slightly press into place and additionally secure with galvan- 
ized wire nails or wood skewers, as specified, driven ob- 
liquely, three per square foot. Keep the pieces of corkboard 
in perfect alignment, so that the joints in the rows to follow 
may fit close and seal tight. 

Then start with a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards adjacent 
to the first row, thus breaking all joints in the second layer, 
and all joints in the second layer with respect to all joints 

*If necessary, cnt off any protrudiug corners or edges of corkboard with a suit«ble 



DIRECTIONS FOR CORKBOARD ERECTION 295 

in the first layer. As each corkboard is laid up, butt and seal 
it tightly at all points of contact against the adjacent boards, 
and additionally secure to the first layer with galvanized wire 
nails or wood skewers, as specified, driven obliquely, three 
per square foot. When the opposite end and the opposite side 
of the ceiling area is reached, cut pieces of corkboard neatly 
to fit and seal with the wall lines of the room. 

Give the Asphalt cement ample time to cool and set, say 
12 hours, before applying a finish over the insulation. 

129. — Double Layer Corkboard, Self-supporting T-iron 
Ceiling, Portland Cement Mortar Core. — Before starting the 
construction of this self-supporting, or "false," ceiling, see that 
the wall insulation rises above the line of the under side of 
the finished ceiling to be constructed, a distance equal to the 
thickness of the under layer of corkboard. Cut the T-irons 
to a length equal to the width of the room plus the total thick- 
ness of the two walls, set and space the T-irons on the top 
edges of the side wall insulation, spanning the room, parallel 
to each other and 12 inches between vertical sections (not 12 
inches from center to center), and then anchor the T-irons 
with large head galvanized wire nails driven obliquely into 
the top edges of the wall insulation. 

Place one layer of full-size corkboards between the ver- 
tical sections of the T-irons and resting on the flanges or 
horizontal sections of the T-irons, butting the ends of adjacent 
boards tight. Apply a 1-inch thick Portland cement finish 
over the corkboard and the T-irons, mixed one part Portland 
cement to two parts clean, sharp sand, and give the cement 
time to set, at least 48 hours, before applying the second layer 
of ceiling insulation. 

Prepare a suitable Portland cement mortar in reasonable 
quantity, coat one side of each corkboard with a half-inch of 
Portland cement mortar, by the hopper method, lay up a row 
to the under side of the first layer, in a straight line, against 
the long wall of the room, pressing the boards firmly into place 
and additionally securing with galvanized wire nails, driven 
obliquely, three per square foot. Keep the corkboards in per- 
fect alignment, so that the joints in the rows to follow may fit 
close and seal tight. 



296 



CORK INSULATION 



Break all joints between the different rows, by starting 
alternate rows w4th half-length boards, and break all joints in 
the second layer with respect to all joints in the first layer. 




H 
< 

C/2Q 

2I 



CO 






WQ 

GQ 
O^ 






o5 



As each corkboard is laid up, butt it tightly at all points of 
contact against the adjacent boards, and additionally secure 
to the first layer with galvanized wire nails, driven obliquely, 



DIRECTIONS FOR CORKBOARD ERECTION 297 

three per square foot. Join the second layer of ceiling insula- 
tion tightly with the opposite wall, cutting pieces of corkboard 
neatly to fit and never using Portland cement mortar to fill 
in openings between corkboards or pieces of corkboard. 

Give the cement backing ample time to set, at least 48 
hours, before applying a finish to the under surface of the 
insulation. 

130. — First Layer Corkboard, over Concrete or Wood 
Floor or Roof, in Asphalt Cement. — See that the concrete or 
wood surface to be insulated presents a smooth, continuous 
solid surface, free from pits or open cracks and loose or warped 
boards, remove all dirt, plaster, paper, loose mortar, or other 
foreign material, or arrange to have these several items taken 
care of by those responsible for such preliminary work, before 
making preparations to apply corkboard over a flat surface in 
Asphalt cement. 

Prepare suitable Asphalt cement in reasonable quantity, 
transfer it to the point of erection in buckets, flood the surface 
to be insulated with the molten material, uniformly over a 
small area or strip at a time, lay* down quickly in the hot 
Asphalt cement, first a row of corkboards against the edge of 
the wall, in a straight line, and closely follow with a second 
and a third row of corkboards, each row lagging behind the 
preceding one, in the laying, by the length of one-half board. 
Keep the corkboards in each row in perfect alignment, so 
that the joints in the rows to follow may fit close and seal tight. 

Break all joints between the different rows, by starting 
alternate rows with half-length boards, and see that all joints 
are butted tight. When the opposite end and the opposite 
side of the floor or roof area is reached, cut pieces of cork- 
board neatly to fit and seal with the wall lines. 

When completed, if the corkboard was laid as an only 
layer of floor insulation, flood the top surface with the molten 
material to an even thickness of approximately ^/^-inch, and 
leave in readiness for the concrete* wearing floor ; if the cork- 
board was laid as roof insulation, or as the first layer of a 
double layer floor insulation, leave the surface of the cork- 

*I{ wood floor is desired over single layer of insulation, instead of concrete, then 
sleepers must be embedded in the single layer of corkboard, as outlmed in Article 144. 



298 



CORK INSULATION 



board uncoated and in readiness for the roofing contractor 
to lay the roof, or in readiness for the insulation contractor 
to lay down the second layer of corkboard. 

131. — Second Layer Corkboard, over First Layer on Floor 
or Roof, in Asphalt Cement.— See that the first layer of cork- 
board is solidly laid, and presents a reasonably smooth and 
level surface*, and then remove all dirt, loose mortar, or other 




FIG. 133.— APPLYING FIRST AND SECOND LAYERS CORKBOARD SIMUL- 
TANEOUSLY OVER CONCRETE ROOF IN ASPHALT CEMENT. 



foreign material, before making preparations to lay a second 
layer of corkboard in Asphalt cement. 

Saw sufficient corkboards lengthwise down the center so 
as to have enough half-width pieces to make one row along 
one wall of the area to be insulated. Cut a piece 6 inches 
wide and 27 inches long with which to start laying the half- 



tool, 



If necessary, cut off any protruding corners gr edges of corkboard with a -suitable 



DIRECTIONS FOR CORKBOARD ERECTION 299 

width pieces in proper position to the floor or roof area, in a 
straight line, in the first row against the edge of the wall. 

Prepare suitable Asphalt cement in reasonable quantity, 
transfer it to the point of erection in buckets, flood the sur- 
face to be insulated with the molten material, uniformly over 
a small area or strip at a time, layf down quickly in the hot 
Asphalt cement first the row of half-width corkboards against 
the edge of the wall, follow with a second row of full-size 
corkboards starting off with a full-width and 9-inch long piece, 
and then wuth a third row of full-size corkboards starting off 
with a half-length board, each row lagging behind the pre- 
ceding one, in the laying, by the length of one-half board. 
In this way, all joints in the second layer of insulation will 
be broken with respect to all joints in the first layer. Keep 
the corkboards in each row in perfect alignment, so that the 
joints in the rows to follow may fit close and seal tight. When 
the opposite end and the opposite side of the floor or roof 
area is reached, cut pieces of corkboard neatly to fit and seal 
with the wall lines. 

When completed, if the corkboard was laid as floor insu- 
lation, flood the top surface with the molten material to an 
even thickness of approximately ^-inch, and leave in readi- 
ness for the concrete* w^earing floor; if the corkboard w^as 
laid as roof insulation, leave the surface of the corkboard 
uncoated in readiness for the roofing contractor to lay the roof. 

132. — Single Layer Corkboard, Between Partition Studs 
with Joints Sealed in Asphalt Cement. — Erect 2-inch x 4-inch 
permanent studs, in a vertical position, 36 inches apart, in the 
line of the partition, so that the 2-inch dimension runs with 
the wall thickness. Place permanent studs, with a lintel be- 
tween them, where cold storage doors are to be set, so as to 
form an opening the size of the cold storage door frame. 
Use door bucks and lintels 2 inches in thickness, and anchor 
securely to the floor and ceiling in such manner that they may 
take up and withstand any shock from the operation of the 
cold storage door. 

Prepare suitable Asphalt cement in reasonable quantity, on 
the basis of one-quarter pound per square foot of partition 

*If wood floor is desired over double layer of insulation, instead of concrete, then 
sleepers must be embedded in the second layer of corkboard, as outlined in Article 144. 



300 



CORK INSULATION 



area (one face only), distribute it to heated pans, add the 
proper proportion of cork dust and mix, dip both ends and 
one edge of the 2-inch thick corkboards in the molten mate- 
rial, erect the first row on the floor between the permanent 
studs, on a level line, so that the corkboards in the entire par- 
tition wall are kept in perfect alignment, and all vertical joints 




FIG. 134.— DIAGRAMMATIC ILLUSTRATION OF SINGLE LAYER CORK- 
BOARD ERECTED BETWEEN PARTITION STUDS WITH JOINTS SEALED 

IN ASPHALT CEMENT. 



between corkboards and studs, and all transverse joints be- 
tween corkboards in all rows, are made to fit close and are 
sealed tight. Toe-nail the first or bottom row of corkboards 
securely to the floor, if the floor be of wood, using galvanized 
wire nails, and drive galvanized wire nails through the corners 
of each corkboard into the adjoining studs. 

Join and seal the partition insulation tightly with the ceil- 
ing, cutting pieces of corkboard neatly to fit, additionally toe- 



DIRECTIONS FOR CORKBOARD ERECTION 



301 



nailing if the ceiling be of wood. Cover the permanent door 
bucks and lintels with corkboard, as specified, nailed in place. 
Cover the exposed edges of the permanent 'partition studs 
with 12-inch wide strips of galvanized wire square-mesh 
screen, No. 18 gauge, 3 mesh (J/^-inch), securely stapled to 
the studs and nailed to the insulation on both sides of the 
studs. 




fk;. :,^^ i,kK( rixo mrst i.a^kr corkboard of self-supportii\g 

PARTITION WITH JOINTS SEALED IN ASPHALT CEMENT.— NOTE 
TEMPORARY STUDS, WHICH ARE REMOVED WHEN PARTITION IS 
COMPLETED TO THE POINT OF RECEIXING FINISH ON SIDE STUDS 
APPEAR. 

Give the Asphalt cement ample time to cool and set, say 
12 hours, before applying a finish over the insulation. 

133. — First Layer Corkboard, Self-supporting Partition, 
Joints Sealed in Asphalt Cement. — Erect temporary studding 
on 18-inch centers on a line with one side of the proposed 
partition. The studs must he erected in a vertical position 
and in perfect alignment. Erect permanent studs, with a 
lintel between them, in the line of the partition, where cold 



302 CORK INSULATION [ 

i 
storage doors are to be set, so as to form an opening the size \ 

of the cold storage door frame. Use studs and lintels of the i 

same thickness as the total thickness of corkboard to be ' 

erected, and anchor the permanent studs securely to the floor ' 

and ceiling in such manner that they may take up and with- i 

stand any shock from the operation of the cold storage door. ■ 

Prepare suitable Asphalt cement in reasonable quantity, ' 
on the basis of one-quarter pound per square foot of partition ; 
area (one face only), distribute it to heated pans, add the 
proper proportion of cork dust and mix, dip but one end and i 
one edge of the corkboards in the molten material, erect the i 
first row against the temporary studs, end to end on the floor, I 
on a level line, so that the corkboards in the entire partition , 
wall are kept in perfect alignment and all vertical and trans- ; 
verse joints in the upper rows are made to fit close and are - 
sealed tight. Toe-nail the first or bottom row of corkboard j 
securely to the floor, if the floor be of wood, using galvanized 
wire nails; and drive long galvanized wire nails obliquely ' 
through the corners of each corkboard into the abutting cork- 1 
boards. ' 

Cut a corkboard half-length and with it start setting the i 
second row on top of the first, thus l)reaking vertical joints, i 
As each corkboard is set, butt and seal it tightly against the ', 
adjacent boards and drive long galvanized wire nails obliquely 
through the corners of each corkboard into the abutting cork- 
boards, and at the lower corner of the exposed end of each 
board drive one of these galvanized wire nails obliquely into 
the corkboard of the row below. 

To insure the corkboards being kept in perfect alignment, 
as the rows are erected edge on edge, drive small headless 
nails obliquely through the upper edge of each row of cork- 
boards into the temporary studs at occasional points. These 
nails will readily pull through the corkboards when the tem- 
porary studs are later removed. 

Join and seal the partition insulation tightly with the 
ceiling, cutting pieces of corkboard neatly to fit, and addi- 
tionally toe-nailing if the ceiling be of wood. Cover the per- 
manent studs and lintels, on the side away from the tempo- m 
rary studding, with corkboard, as specified, nailed in place. m 

Before removing the temporary studs, and after the Asphalt 



I 



DIRECTIONS FOR CORKBOARD ERECTION 



303 



cement has had ample time to cool and set on all corkboard 
joints, apply the finish to the free side of the corkboard par- 
tition, as specified. After such finish has had ample time to 
set, take down the temporary studs and apply the finish to 
the other side of the corkboard partition, or leave it in readi- 
ness to receive a second layer of corkboard insulation. 

134. — Second Layer Corkboard, Against First Layer of 
Self-supporting Partition, in Portland Cement Mortar. — See 




FIG. 136.— ERECTING SECOND LAYER CORKliOAKD AGAINST FIRST LAYER 
OF SELF-SUPPORTING PARTITION IN PORTLAND CEMENT MORTAR. 
—NOTE ALSO THE METHOD OF INSULATING COLUMNS AND CAPS 
AND METHOD OF SETTING DOOR BUCKS AND LINTEL. 



that the first layer of corkboard of the self-supporting partition 
is solidly erected, and presents a reasonably smooth and level 



3(X CORK INSULATION 

surface*, and then remove all dust, dirt, or loose mortar, before 
making preparations to erect a second layer of corkboard in 
Portland cement mortar. 

Now see that the floor at the base of the wall is free from 
obstruction, and is level ; because the first row of corkboards 
in the second layer must be applied to the first layer at the 
floor, on a level line, so that the corkboards on the entire 
second layer are kept in perfect alignment and all vertical 
and transverse joints in the upper rows are made to fit close 
and are sealed tight. 

Prepare suitable Portland cement mortar in reasonable 
quantity, saw sufficient corkboards lengthwise down the center 
so as to have enough half-width pieces to make one row along 
the partition, coat the half-width corkboards on one side with 
a half-inch of Portland cement mortar, cut a piece 6 inches 
wide and 27 inches long and with it start putting the half- 
width pieces of corkboard in proper position against the first 
layer of insulation, slightly press into place and additionally 
secure with wood skewers driven obliquely, two skewers per 
square foot. 

Then start "with a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards on top 
of the first row, thus breaking vertical joints in the second 
layer, and all joints in the second layer with respect to all 
joints in the first layer. As each corkboard is set, butt it 
tightly at all points of contact against the adjacent boards 
and additionally secure to the first layer with wood skewers 
driven obliquely, two skewers per square foot. Join the wall 
insulation tightly with the ceiling, cutting pieces of corkboard 
neatly to fit and never use Portland cement mortar to fill in 
openings between corkboards or pieces of corkboard. 

Give the cement backing ample time to set, say 48 hours, 
before applying a finish over the insulation. 

135. — Second Layer Corkboard, Against First Layer of 
Self-supporting Partition, in Asphalt Cement. — See that the 
first layer of corkboard of the self-supporting partition is sol- 
idly erected, and presents a reasonably smooth and level sur- 

*If necessary, cut oflE any protruding corners or edges of corkboard with a suitable 
tool. 



DIRECTIONS FOR CORKBOARD ERECTION 305 

face, and then remove all dust, dirt, or loose mortar, before 
making preparations to erect a second layer of corkboard in 
Asphalt cement. 

Now see that the floor at the base of the wall is free from 




FIG. 137.— ERECTING DOUBLE LAYER CORKBOARD SEI^F-SUPPORTING 

PARTITIONS TO FORM CORRIDOR WALLS OF UNUSUAL HEIGHT.— 

NOTE TEMPORARY STUDS, WHICH ARE LATER REMOVED. 

obstruction, and is level ; because the first row of corkboards 
in the second layer must be applied to the first layer at the 



506 



CORK INSULATION 



floor, on a level line, so that the corkboards on the entire 
second layer are kept in perfect alignment and all vertical and 
transverse joints in the upper rows are made to fit close and 
are sealed tight. 

Prepare suitable Asphalt cement in reasonable quantity, 
distribute it to heated pans, add the proper proportion of cork 
dust and mix. Saw^ sufficient corkboards lengthwise down the 
center so as to have enough half-width pieces to make one 
row along the partition, cut a piece 6 inches wide and 27 




FIG. 138.— ERECTING SECOND LAYER CORKBOARD To FIRST LAYER IN 
PORTLAND CEMENT MORTAR TO WALLS, CEILING AND BEAMS.— 
NOTE SCAFFOLDING, SHORING, EXTENSION CORD, MORTAR BOARD 
AND OTHER EQUIPMENT REQUIRED. 



inches long and with it start putting the half-width pieces of 
corkboard in proper position against the first layer of insula- 
tion, first dipping one flat side, one end and one edge of each 
piece in the molten material, slightly pressing into place and 
additionally securing with wood skewers driven obliquely, 
two skewers per square foot. 



DIRECTIONS FOR CORKBOARD ERECTION 307 

Then start with a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards on top 
of the first row, thus breaking vertical joints in the second 
layer, and all joints in the second layer with respect to ail 
joints in the first layer. As each corkboard is set, butt it 
tightly at all points of contact against the adjacent boards and 
additionally secure to the first layer with wood skewers 
driven obliquely, two per square foot. Join and seal the wall 
insulation tightly wMth the ceiling, cutting pieces of corkboard 
neatly to fit. 

Give the asphalt cement ample time to cool and set, say 
12 hours, before applying a finish over the insulation. 

136. — Double Layer Corkboard, Freezing Tank Bottom, in 
Asphalt Cement. — See that the concrete base is well adapted 
to the ]nirpose and presents a reasonably smooth and level 
surface, remove all dirt, loose mortar, or other foreign mate- 
rial, or arrange to have these several items taken care of by 
those responsible for such preliminary work, before making 
preparations to apply corkboard over the surface of the freez- 
ing tank foundation. 

Prepare suitable Asphalt cement in reasonable quantity, 
transfer it to the point of erection in buckets, flood the surface 
to be insulated* with the molten material, uniformly over a 
small area or strip at a time, lay down cjuickly in the hot 
Asphalt cement, first a row of corkboards in a straight line 
against the outer edge of the area of the tank bottom insula- 
tion, closely follow with a second and a third row of cork- 
boards, each row lagging behind the preceding one, in the 
laying, by the length of one-half board. Keep the cork- 
boards in each row in perfect alignment, so that the joints in 
the rows to follow may fit close and seal tight. 

Break all joints between the different rows, by starting 
alternate rows with half-length boards, and see that all joints 
are butted tight. Carry the insulation on both ends and both 
sides to the outer limits of the end and side insulation of the 
tank, cutting pieces of corkboard as required to finish out such 
dimensions. 



*The dimen-ions of the tank bottom area to be insulated shall be enough wider and 
longer than the size of the freezing tank, so as to overlap the insulation to be in- 
stalled on the vertical ends and sides of the tank. 



308 CORK INSULATION 

See that the first layer of corkboard is solidly laid, and 
presents a reasonably smooth and level surface. Saw suffi- 
cient corkboards lengthwise down the center so as to make 
one row along the one side of the insulated area, laying the 
half-width pieces in the first row of the second layer, in a 
straight line, starting oflf with a piece 6 inches wide and 27 
inches long, then lay a second row of full-size corkboards, 
starting off with a full-width and 9-inch long piece, and then 
lay a third row of full-size corkboards, starting off with a 




FIG. 139.— LAYING SECOND LAYER CORKBOARD ON FLOOR IN ASPHALT 
CEMENT— TANK BOTTOM INSULATION IS APPLIED IN SAME MANNER. 

half-length board, following the same method of laying as 
described for the first layer of insulation. In this way, all 
joints in the second layer will be broken and made tight, and 
all joints in the second layer will be broken with respect to 
all joints in the first layer. When completed, flood the top 
surface with the molten material to an even thickness of 
approximately ^-inch, and leave in readiness for the tank 
to be set. 

137. — Regranulated Cork Fill, Freezing Tank Sides and 
Ends, With Retaining Walls.— See that the tank has been 
properly set, having its bottom edges the proper distance in 
from the edges of the insulation underneath. Erect 2-inch x 
12-inch studs on suitable centers (from 24 to 36 inches) at 
right angles against the sides and ends of the tank*, anchoring 
carefully by cutting slots through tank bottom insulation, 



*If the tank is to be set in a corner, so that masonry walls of the building act as 
two retaining walls, such walls must be damp-proofed before the tank is set and the 
loose fill insulation is placed. 



DIRECTIONS FOR CORKBOARD ERECTION 309 

chiseling slight depressions in the concrete base, dropping the 
studs into these slots and depressions and wedging their tops 
under and securing them with suitable metal clips to the flange 
at the top of the tank. Sheath the studs with double layer 7,i- 
inch T. & G. boards, having two layers of waterproof paper 
between, and securely nail to the studs. 

Fill the space between the retaining walls and the sides 
and ends of the tank with regranulated cork (by-product 
from the manufacture of pure corkboard), and tamp well until 
there is sufficient in place to avoid future settling. Then 
install a curbing, as and if specified, over the regranulated 
cork fill. 

138. — Single Layer Corkboard and Regranulated Cork Fill, 
Freezing Tank Sides and Ends. — See that the tank has been 
properly set, having its bottom edges the proper distance in 
from the edges of the insulation underneath. Erect 4-inch x 
4-inch studs on 18-inch centers at right angles against the 
sides and ends of the tank*, anchoring carefully by cutting 
slots through tank bottom insulation, chiseling slight depres- 
sions in the concrete base, dropping the studs into these slots 
and depressions and wedging their tops under and securing 
them with suitable metal clips to the flange at the top of the 
tank. 

Prepare suitable Asphalt cement in reasonable quantity, 
on the basis of one-quarter pound per square foot of cork- 
board area (one face only), distribute it to heated pans, add 
the proper proportion of cork dust and mix, dip both ends 
and one edge of the corkboards in the molten material, erect 
the first row against the studs, end to end, on a level line, so 
that the corkboards are kept in perfect alignment, and all 
• vertical and transverse joints in the upper rows are made to 
fit close and are sealed tight. Break all joints between the 
different rows, by starting alternate rows with half-length 
boards, and as the rows are erected edge on edge, securely 
fasten the corkboards to the studs by nailing with galvanized 
wire nails, two per square foot. Carry the insulation to the 

*If the tank is to be set in a corner, so that masonry walls of the building act 
as two retaining walls for regranulated cork fill on one side and one end of the tank, 
such walls must be damp-proofed before the tank is set and the loose fill insulation is 
placed. 



310 



CORK INSULATION 



line of the flange at the top of the tank, cutting pieces of 
corkboard neatly to fit. 

Fill the space between the insulation and the sides and 
ends of the tank with regranulated cork (by-product from 
the manufacture of pure corkboard), and tamp well until there 
is sufficient in place to avoid future settling. Then install a 
curbing, as and if specified, over the side and end insulation. 



:.g -4"~t"3TUD5 3&"C.TOC: 

e"co;^»<. BCARD — 

A3PH^LT 

E'COR^ BOM2D NMLCO 
WITH WCDD 3CEWER3 
CEMENT PL^OTEe — » 

ruooR LINE -y 




2 LAvVEC:5 5" 

COQ.^ EO^RD LMD IN 

HOT ASPHALT 



PLAN 



^ 



^^ 



FIG. 140.— PLAN AND SECTION OF FREEZING TANK INSULATION. 

139. — Double Layer Corkboard, Freezing Tank Sides and 
Ends. — See that the tank has been properly set, having its bot- 
tom edges the proper distance in from the edges of the insula- 
tion underneath. Erect studs (2-inch by a dimension equival- 
ent to the thickness of the first layer of corkboard specified to 
be applied to tank sides and ends) at right angles against the 
sides and ends of the tank*, and 36 inches apart, anchoring 
carefully by cutting slots through tank bottom insulation, 
chiseling slight depressions in the concrete base, dropping 
the studs into these slots and depressions and wedging their 



*If the tank is to be set in a corner, so that masonry walls of the building act 
as two retaining walls for regranulated cork fill on one side and one end of the tank, 
such walls must be damp-proofed before the tank is set and the loose fill insulation is 
placed. 



DIRECTIONS FOR CORKBOARD ERECTION 311 

tops under and securing them with suitable metal clips to the 
flange at the top of the tank. 

Prepare suitable Asphalt cement in reasonable quantity, on 
the basis of one pound per square foot of corkboard area (one 
face only), distribute it to heated pans,, add the proper pro- 
portion of cork dust and mix, dip one flat side, both ends and 
one edge of the corkboards in the molten material, erect the 
first row between the studs and against the tank, on a level 
line, so that the corkboards are kept in perfect alignment, and 
all vertical joints between corkboards and studs, and all trans- 
verse joints between corkboards in the upper rows to follow, 
are made to fit close and are sealed tight. Drive galvanized 
wire nails through the corners of each corkboard and into the 
adjacent studs. Carry the insulation to the line of the flange 
at the top of the tank, cutting pieces of corkboard neatly to fit. 

Saw sufficient corkboards lengthwise dowm the center so 
as to have enough half-width pieces to make one row in a 
second layer around the tank, cut a piece 6 inches wide and 18 
inches long and with it start putting the half-width pieces of 
corkboard in proper position against the first layer of insu- 
lation, first dipping one flat side, one end and one edge of each 
piece in the molten material, slightly pressing into place and 
additionally securing with wood skewers driven obliquely, 
two skewers per square foot. 

Then start with a full-width and 9-inch long piece of cork- 
board and set the second row of full-size corkboards on top 
of the first row, thus breaking vertical joints in the second 
layer, and all joints in the second layer with respect to all 
joints in the first layer. As each corkboard is set, butt it 
tightly at all points of contact against the adjacent boards 
and additionally secure to the first layer with wood skewers 
driven obliquely, two skewers per square foot. Carry the in- 
sulation to the line of the flange at the top of the tank, cutting 
pieces of corkboard neatly to fit. Then install a curbing, as 
and if specified, over the side and end insulation. 

140. — Portland Cement Plaster. — See that the exposed sur- 
face of the corkboard to receive the Portland cement plaster 
presents a reasonably smooth and le\cl sr.rfacc* and that all 



*If necessary, cut off any protruding corners or edges of corkboard with a suitable 
tool. 



312 



CORK INSULATION 



corkboards are butted tight, score the surface of the cork- 
board (if preferred) by roughening slightly with a pronged 
tool, such as a few wire nails driven through a piece of wood, 
so as possibly to increase the bond for the cement plaster, and 
then remove all dust, dirt, or other foreign material, or arrange 
to have these several items taken care of by those responsible 
for such preliminary work, before making preparations to apply 
a Portland cement plaster finish to the exposed surface of 
corkboard insulation. 

Prepare suitable Portland cement mortar in reasonable 




FIG. 141.— CORKBOARD INSULATED COLD STORAGE ROOM FINISHED 
WITH PORTLAND CEMENT PLASTER SCORED IN 4-FT. SQUARES. 

quantity, mixed one part Portland cement to two parts clean, 
sharp sand, with no lime added. Be sure the sand is clean 
and free from loam, and that it is sharp. 

Apply the first coat of plaster approximately ^-inch in 
thickness, rough scratch, and leave until thoroughly dried out. 
Then apply the second coat to the first, also approximately 
^^-inch in thickness, and trowel to a hard, smooth finish. 
Score the surface of the finished plaster in squares, as specified, 



DIRECTIONS FOR CORKBOARD ERECTION 313 

using suitable scoring tool only, so as to confine any checking 
or crackingf of the plaster to such score marks. 

141. — Factory Ironed-on Mastic Finish. — See that the ex- 
posed surface of the factory ironed-on mastic finish is reason- 
ably level, and that all joints between the coated corkboards 
are butted tight. 

Prepare suitable mastic filler for the V jomts of the coated 
corkboards, by following the directions furnished by the 
manufacturer, which directions frequently, but not always, 
consist in heating the mastic filler until plastic by immersing 
in hot water and working up a small quantity at a time in the 
hand like putty*. 

Fill the joints between the mastic coated corkboards with 
the prepared mastic material in such practical manner as will 
eliminate all voids. Then follow with an electric iron, or 
heated pointing trowel, applying sufficient heat to melt the 
edges of the coating on the corkboards so that it will flow 
into and amalgamate with the mastic filler in the joints, mak- 
ing a continuous and permanent seal. 

142, — Emulsified Asphalt Plastic. — See that the exposed 
surface of the corkboard to receive the emulsified asphalt 
plastic presents a reasonably smooth and level surface§, and 
then remove all dust, dirt, or other foreign material, or arrange 
to have these several items taken care of by those responsible 
for such preliminary work, before making preparations to 
apply emulsified asphalt plastic finish to the exposed surface 
of corkboard insulation. 

Shake or roll the barrel or cylinder in which the emulsified 
asphalt plastic is supplied, before opening; and if water is 
found standing on the surface, work it into the mass before 
using. After a container is opened, it should be kept covered, 
to prevent the drying out of the material and coalescence of 
the asphalt particles. The emulsified asphalt plastic, if a ready 



tCracks fre(|uently develoii in plaster at the lop corners of door franies. which 
can usuallv be prevented bv setting and stapling pieces of galvanized wire square- 
mesh screen (No. 18 gauge,' 3 mesh) to the corkboard over such comers and at an 
angle of 45 degrees before the plaster is applied. , , ,. r 

*It is essential that the material furnished bv the manufacturer for the sealing of 
the joints be prepared and used as directed by the manufacturer. 

§If necessary, cut off any protruding corners or edges of corkboard with a suitable 
tool. 



314 



CORK INSULATION 



mixed product*, should be applied exactly as received, without 
adding sand or any other material whatever. If, by reason of 
evaporation, the product is too heavy to work easily under a 
trowel, add as little as possible of clean water, working it well 
through the mass. 

Apply the first coat of emulsified asphalt plastic approxi- 
mately 3/32-inch in thickness, keeping the trowel wet, and 
working the material well into the surface voids of the cork- 
board. Then apply the second coat to the first, after the first 
coat has set up, approximately 1/32-inch in thickness, and 
trowel as smooth as the material will permit. After the sec- 
ond coat has taken its initial set, sprinkle with water and 
trowel again, to obtain a smooth, hard surface. 

Do not score the surface of the emulsified asphalt plastic 
finish, unless specified. 

143. — Concrete Wearing Floors. — See that the exposed sur- 
face of the corkboard has been flooded to a thickness of 
approximately ^-inch with hot odorless asphalt, so that the 
entire surface of the insulation is thoroughly protected. 




H 



JN HOT AAPHfi^LT 

E" COU-K, bOA.t2,D — 

HOT Ac5PMAvL.T 

b"cjONcc.LTL rLOOC auNroccLD 

WITH WICLL NLTTlNCj. I" OLMLNT TINI^H 



FIG. 142.— DIAGRAMMATIC ILLUSTRATION OF CONCRETE WEARING 
FLOOR (REINFORCED) OVER DOUBLE LAYER COUKBOARD ON 
COOLER FLOOR. 



Prepare suitable concrete in reasonable quantity, mixed 
one part Portland cement to two and one-half parts clean, 
sharp sand, and five parts clean gravel or crushed stone. 
Cover the corkboard to a depth of 3 inches with the concrete, 
tamp until the water comes to the surface, and let stand until 



*If the emulsified asphalt plastic material is not a ready mixed product, then pre- 
pare the material for use only as directed by the manufacturer. 



DIRECTIONS FOR CORKBOARD ERECTION 



315 



thoroughly dry, about 48 hours, before applying the finish 
coat. 

Prepare suitable Portland cement mortar in reasonable 
quantity, mixed one part Portland cement to one part clean, 
sharp sand, and then apply a top coat, of minimum depth of 
1 inch, over the rough concrete base, slope to drain as specified, 
and trowel to a smooth, hard surface. 

144. — Wood Floors Secured to Sleepers Embedded in In- 
sulation. — Embed wood sleepers, 2 inches wide and of suitable 
thickness, in the single or the second layer of corkboard, as 
the case may be, by putting the sleepers in place, parallel to 




ftcONcaLTE- PLOOR. 

' a'COB-K- BO^CX) 

A^PHAL-T 
S'COTiK. BOA.C.D 
S\a:- NA.1UIMO i)TRJP.' 



FIG. 143.— DIAGRAMMATIC ILLUSTRATION OF WOOD FLOOR OVEK 
DOUBLE LAYER CORKBOARD APPLIED OVER CONCRETE SLAB. 

each other, on 38-inch centers, and lay down a layer of cork- 
board in suitable hot Asphalt cement between the sleepers 
with all joints carefully butted and sealed tight. The top sur- 
face of the corkboards and the sleepers shall then be flooded 
with the same compound to a uniform thickness of approxi- 
mately ^-inch. 

Lay a finished wood floor of thoroughly dry and seasoned 
J^-inch lumber, as specified, with approximately 1/32-inch 
between the boards, to eliminate as much as possible the 
tendency of the floor to expand and warp, secret nail securely 
to the sleepers embedded in the corkboard underneath, and 
leave the surface of the floor perfectly smooth and even. 

145. — Galvanized Metal Over Corkboard. — Embed wood 
sleepers, 2 inches wide and of suitable thickness, in the single 
or the second layer of corkboard, as the case may be, on the 



316 CORK INSULATION 

floors and baffles of bunkers, on such centers as to permit 
lapping the galvanized metal joints 1 inch, over such sleepers, 
and anchoring thereto by securely nailing. 

Apply the metal of specified gauge and suitable width, 
extending it over all edges of the bunker at least 2 inches 
and lapping all joints 1 inch over sleepers, and then anchor 
at all points by securely nailing. 

Carefully and permanently solder all joints and nail heads 
in the finished work, and leave the surface of the metal per- 
fectly smooth and even. 



CORK INSULATION 

Part IV — The Insulation of Household Refriger- 
ators, Ice Cream Cabinets and Soda Fountains. 

CHAPTER XV. 

HISTORY OF REFRIGERATION EMPLOYED TO 
PRESERVE FOODSTUFFS. 

146. — Early Uses of Refrigeration. — Preservation of food 
through the use of snow and ice undoubtedly was practised 
several centuries before the Christian era in those climates 
and regions where the preservation of the snow and ice in 
turn during the short summer season was accomplished by 
Nature through natural storage in caves. During the long 
winters, large quantities of snow and ice accumulated in shel- 
tered spots and never entirely melted away during the warmer 
season of the year that followed. Such crevices and caves 
afforded natural cold storages, for fish and meat, and there is 
every reason to believe that they were so employed. Later, 
perhaps as early as 1000 B. C, snow was artificially stored 
in caves, and used for cooling and preserving. At any rate, 
Simonides, the early Greek poet, who lived about 500 B. C, 
when made angry by observing other guests at the board 
treated to snow poured into their liquor, while he sipped 
warm wine, enscribed the ode that concludes "for no one will 
commend the man who gives hot water to a friend." It is 
also known that Alexander the Great, King of Macedon (336- 
323 B. C.) had trenches dug and filled with snow to cool 
hundreds of kegs of wine to be given to his soldiers on the 
eve of battle, and Nero, Roman Emperor (37-68 A. D.), had 
his wines cooled by snow brought down from the mountains 
by slaves. It may therefore be assumed that by the first 
century the luxury of drinking cooled liquors was enjoyed 
rather generally by kings and emperors and their friends. 

317 



318 



CORK INSULATION 



History also shows that the ancient Egyptians, on the 
other hand, knew the secret of cooling liquids by evaporation, 
which method of cooling is practised today by the natives of 
India, as well as by the desert traveller, and quite probably 
by many others. The ancient Egyptians placed shallow trays, 
made of porous material and filled with water, on beds of 
straw, and left them exposed to the night winds. Through 
the resultant evaporation, the water became chilled sometimes 




•ARTIST'S CONCEPTION OF ANCIENT EGYPTIANS PREPARING 
WATER FOR CHILLING BY EVAPORATION. 



to the extent of a thin film of ice on the surface. Today, in 
the upper provinces of India, water is made to freeze during 
cold, clear nights by leaving it overnight in porous vessels, or 
chilled in containers that are wrapped in moistened cloth. In 
the first instance, the water freezes by virtue of the cold 
produced by its own evaporation ; and in the second instance, 
the water is rapidly cooled by the drying of the moistened 
wrapper. In Bengal the natives resort to a still more elabo- 
rate plan. Pits are dug about two feet deep and filled three- 
quarters full with dry straw, on which are set flat, porous 
pans containing water. Exposed overnight to a cool, dry, 
gentle wind from the northwest, the water evaporates at the 
expense of its own heat with sufificient rapidity to overbalance 



HISTORY OF REFRIGERATION 319 

the slow influx of heat from above through the cooled dense 
air, or from below through the badly conducting straw, and 
the water freezes. The desert traveller carries water in a 
porous canvas water bag so as to have, through slow evapo- 
ration, a supply of drinking water sufficiently palatable to 
dampen his parched lips and cool his throat. 

The use of saltpetre mixed with snow for cooling and 
freezing liquids was known and employed at a remote period 
in India. In 1607 Tancrelus mentioned the use of this mix- 
ture to freeze water, and in 1626 Santono mentioned the use 
of common salt and snow to freeze wine. At about that same 
time, in Italy, iced fruits put in an appearance at table, and 
during the 17th century a method of congealing cream was 
discovered. 

Lord Francis Bacon, English scientist, philosopher and 
statesman (1561-1626), appreciated what a useful thing it 
would be if man could have the same command of cold as of 
heat, and undertook experiments into its possibilities that 
terminated in his death. Among his notes there is this: 

Heat and cold are Nature's two hands whereby she chiefly 
worketh, and heat we have in readiness in respect of the fire, 
but for cold we must stay till it cometh or seek it in deep 
caves or high mountains, and when all is done we cannot 
obtain it in any great degree, for furnaces of fire are far 
hotter than a summer's sun, but vaults and hills are not much 
colder than a winter's frost. 

History is filled with interesting references to the early 
use of snow and natural ice, especially by the French, Span- 
iards and Italians, devotees of better living. In England, the 
sale of natural ice from the wagons of fishmongers was an 
early practice that continues to this day. In the United States 
•a cargo of natural ice was sent from New York to New 
Orleans in 1799, the first delivery of natural ice to an American 
home was made in 1802, and Frederick Tudor exported natural 
ice from the United States to the West Indies in 1805 to help 
stay the ravages of yellow fever. 

147. — The Formation, Harvesting and Storing of Natural 
Ice. — The formation of ice is a very common phenomenon of 
Nature, but the exact process followed in converting water 



320 



CORK INSULATION 



into natural ice is not generally understood by those who make 
use of the resultant product. 

That water freezes at 32° F. at a pressure of one atmos- 
phere is generally understood. When the air above a body 
of water is chilled to a temperature below that of the water, 
heat is transferred from the water to the air, the top layer of 
water is chilled, it becomes denser than the water underneath, 
drops to the bottom, and is replaced by other water rising to 




FIG. 145.— LOADING A CARGO OF NATURAL ICE AT NEW YORK FOR SHIP- 
MENT TO NEW ORLEANS IN 1799. 

be similarly chilled. But this chilling process continues only 
until the entire body of the water is cooled to 39.1° F., which 
is the point of the greatest density of water, the temperature 
at which water is heaviest, but a temperature not yet low 
enough to cause the water to freeze. Further cooling of the 
water on the pond, lake or stream will no longer cause the 
top layer of water to drop, by convection, and the chilling 
efifect is thereafter concentrated on the surface of the water 
instead of being applied generally to the entire body of the 
water. When the temperature of the top layer of water 
reaches 32° F., ice forms, and increases in thickness as the 
water in contact underneath is chilled, by conduction, to the 
freezing point. 



HISTORY OF REFRIGERATION 321 

Each particle of water, in freezing, sets free the air that 
was contained in that water, and the tiny bubbles of air cling 
to the newly frozen ice crystals, unless dislodged. If these 
bubbles are not dislodged, by agitation, then other ice cr3^stals 
forming adjacent to the first ones entrap the clinging air bub- 
bles to form opaque, or "milky," ice. Opaque ice is usually 
found on ponds where the water is not in motion, or on slug- 
gish streams ; while clear, hard ice is frozen on bodies of water 
that are in motion sufficiently to free the newly formed ice 
crystals of all clinging air particles. 




FIG. 146.— HARVESTING XAIVRAL ICE FROM A NORTHERN LAKE 

The development of the scientific harvesting of natural ice 
is an interesting chapter in itself, and second in importance 
only to the development of the use of natural ice as a refrig- 
erant for the preservation of foodstufifs. It must be sufficient 
to mention here that during the latter half of the 19th cen- 
tury enormous quantities of natural ice came to be harvested 
and stored in huge ice houses, ice houses of moderate size 
and little ice houses, located almost in every community in 
the United States where the temperature dropped low enough 
at some time during the winter to freeze ice on the ponds, lakes 
and streams. The very large ice houses were scientifically 
•constructed and equipped, and were insulated between wood 
walls with shavings and sawdust well tamped. The smaller 
ice houses, especially those in the rural communities, were 
often crudely built, simply of wood slabs nailed to one side 
of the timber framing. In the well-built and insulated ice 
houses, straw was frequently used between layers or tiers 
of ice blocks, and sometimes sawdust was thus employed, 
to insulate the several layers from each other and to keep 



322 



CORK INSULATION 



them from freezing together; but the insulation between the 
double walls of the structure was relied upon for the reason- 
able preservation of the ice during the warmer months, while 
the house was being emptied of its valual3le contents. The 
ice was stored in the smaller uninsulated structures in such 
fashion that a space of approximately two feet was left all 
around the house between the walls and the pile of ice blocks. 
This space was filled with sawdust as the tiers of ice were 




FIG. 147.— TVl'ICAL ICE STOR.\GE HOUSES FOR N.\TURAL TCE. SITUATED 
AT SOURCE OF SUPPLY. 



laid, and sawdust was sometimes placed between layers to a 
thickness of several inches. Over the top layer, sawdust was 
piled to a depth of several feet; and louvre-windows at dif- 
ferent levels in either end of the house served to ventilate 
the space over the ice and directly under the uninsulated roof, 
to prevent superheating of the air in that space on summer 
days with consequent excessive meltage of the ice in the top 
layers. 

The business of harvesting, storing and dispensing large 
quantities of natural ice was built on the constantly growing 
demand for the use of such ice by brewers, packers and large 
dealers in food products, the trade gradually extending to the 



HISTORY OF REFRIGERATION 



323 




FIG. 148.— GIFFORD-WOOD ICE STORAGE HOUSE EQUIPMENT. 



324 CORK INSULATION 

smaller establishments, then to the retail stores, and finally 
to countless homes, especially in the congested, large city 
areas. This trade had extended gradually each year and had 
grown to enormous proportions, but its real size and scope 
was not fully appreciated, and the necessity for ice was not 
generally understood, until the summer of 189D, when the 
greatest shortage in the crop of natural ice that has ever 
occurred in the United States resulted from the exceptionally 
mild preceding winter season. This unusual shortage gave 
mechanical refrigeration an impetus such as it never had be- 
fore, and marks the real beginnings of the use of ice as a 
necessity of life. 

148. — The Development of the Ice Machine. — The earliest 
machine to produce ice by purely mechanical means was of 
the "vacuum" type, built by Dr. William Cullen in 1755. In 
this class of "liquid" machine, since the refrigerating liquid 
is itself rejected, the only agent cheap enough to be employed 
is water. The boiling point of water varies with pressure; 
and at a pressure of one atmosphere (14.7 pounds per square 
inch) the boiling point is 212° F., whereas at a pressure of 
0.085-pound per square inch it is 32° F., and at lower pres- 
sures there is still further fall in temperature. Water at ordi- 
nary temperature is placed in an air-tight, insulated vessel, 
and when the pressure is reduced by means of a vacuum 
pump it begins to boil, the heat necessary for evaporation be- 
ing taken from the water itself. The pressure being still 
further reduced, the temperature is gradually lowered until 
the freezing point is reached and ice formed, when about one- 
sixth of the original volume has been evaporated. Dr. Cullen 
is said to have produced the vacuum by means of a pump 
alone. 

In 1810, Sir John Leslie combined with the air pump a 
vessel containing strong sulphuric acid for absorbing the vapor 
from the air, and is said to have produced several pounds of 
ice in a single operation. Val lance of France, in 1824, pro- 
duced another machine for the same purpose. 

Several suggestions had been made with regard to the 
production of ice by the evaporation of a more volatile liquid 
than water, but the first machine actually constructed and 



HISTORY OF REFRIGERATION 



325 



operated on that princii^le was built in 1834 from the designs 
of Jacob Perkins, an American living abroad, who that year 
took out patents in England on an ether machine. This ma- 
chine, though never actually used commercially, is the parent 
of all modern compression machines. James Harrison, of Gee- 
long, Victoria, later worked out the Perkins principle in a 
more complete and practical manner and in 1861 had his ma- 
chine adopted successfully in England for the cooling of oil 
to extract paraffin. 




FIG. 149.— EARLY TYPE REFRIGERATING MACHINE. 



Meanwhile, Michael Faraday, English chemist and physi- 
cist (1791-1867), succeeded in condensing ammonia gas to a 
liquid by applying pressure and then cooling it. When the 
pressure was removed, the liquid boiled off rapidly as a gas, 
absorbing heat, as any liquid will do when it turns into a gas. 
Faraday's discovery, made in about 1826, proved of the great- 
est importance, both practically and theoretically. 

Professor A. C. Twining, of New Haven, Connecticut, and 
Dr. John Gorrie, of Appalachicola, Florida, also contributed 
|o the successful development of the ice machine. Dr. Gorrie 
taking out the first American patent in 1850 for a practical 
process of manufacturing ice. 

In 1858, E. C. Carre adopted the same principle as Sir 
John Leslie, but used a solution of ammonia and water in 
his vacuum machine to make ice. The first one of these 
Carre machines to reach the United States ran the blockade 
of New Orleans in 1863. Dr. A. Kirk invented an air ma- 
chine, in 1862, which was fully described by him in a paper 



326 CORK INSULATION 

on the "Mechanical Production of Cold," being simply a re- 
versed Sterling air engine, the air working in a closed cycle 
instead of being actually discharged into the room to be cooled, 
as is the usual practice with compression machines. It is 
said that Kirk's machine was used commercially with success 
on a fairly large scale, chiefly for ice making, producing about 
4 pounds of ice per pound of coal. 

In 1870, the subject of refrigeration was investigated by 
Professor Carl Linde, of Munich, Germany, who was the first 
to consider the question from a thermodynamic point of view. 
He dealt with the coefficient of performance as a common basis 
of comparison for all machines, and showed that the compres- 
sion vapor machine more closely reached the theoretical maxi- 
mum than any other. Linde also examined the physical prop- 
erties of various liquids, and, after making trials with methylic 
ether in 1872, built his first ammonia compression machine in 
1873. In the next two years, these machines were introduced 
into the United States by Professor Linde, and David Boyle 
of the United States. From then until the ice shortage of 
the summer of 1890, many new forms of apparatus were pro- 
duced and certain important improvements were made, follow- 
ing which the rapid development and practical utilization of 
the art of ice making and refrigeration grew by leaps and 
bounds, until today ice and refrigeration may be had at any 
time and anywhere that power can be obtained. 

149. — Early Methods of Utilizing Ice as a Refrigerant. — 

Just as snow was used in ancient times to cool the cup that 
cheered, so harvested natural ice was probably first employed 
in later times to cool wines and preserve beer. Deep cellars 
were dug, walled with heavy masonry, and divided longitud- 
inally by arched stone ceilings into top cellars and sub- 
cellars. The goods to be preserved were placed in the lower 
or sub-cellars and the ice was filled into the top cellars just 
above, an ingenious and effective arrangement that permitted 
the storing of sufficient quantities of natural ice, as harvested, 
to carry the sub-cellars through the warm summer months at 
temperatures cool enough for many purposes. Such cellars 
were probably the first man-made cold storage houses or 



HISTORY OF REFRIGERATION 



327 



refrigerating plants, the suggestion having no doubt come 
down from the early days of the utilization of snow and ice 
found in the summer months in deep rocky crevices and 
natural caves of the mountains. 

These underground masonry caverns were not insulated, 
except naturally by the earth, but their heavy masonry walls, 
once cooled, acted as enormous reservoirs of cold. Many of 
these storage cellars were constructed in Europe, especially 




FIG. ISO.— SAWDUST INSULATED NATURAL ICE HOUSE. 



in Germany, and many more of them were built later in the 
1 United States, particularly in connection with breweries, in 
*the early days when a simpler and cheaper method of guaran- 
1 teeing summer refrigeration was unknown. However, as 

time passed, ice storages and cooling rooms were arranged in 

single tier cellars, by locating the cold room within the ice 
I storage, so to speak, and having less height, so that the ice 

could be piled, as harvested, around and over the cold room. 
' Another type of cold storage and ice storage combined was 
[ constructed by digging a cellar into the side hill and building 



328 CORK INSULATION 

the four walls of thick masonry, as the food storage compart- 
ment, with a double layer plank ceiling laid over heavy joists, 
and then building a double-thick plank-walled ice house over 
such structure. Then boards and air spaces' took the place 
of the double layer plank walls above ground, and holes were 
cut in the floor to let the cold through. It was only a step, 
of course, from the cutting of holes in the floor alongside of 
the ice to permit the cold air to drop into the room below, 
to a practical bunker arrangement and an efficient air circu- 
lation, which was the forerunner of the present indispensible 
overhead bunker. The sawdust insulated natural ice house 
next came into being along the shores of northern rivers and 
lakes, the first large ice house in the United States having 
been built on the shores of the Hudson river in 1805 ; and 
from then on the development of the use of natural ice as a 
refrigerating medium was rapidly extended. Farmers, for 
instance, put up ice in cheaply constructed ice houses, sur- 
rounded the ice stores with sawdust as insulation, kept fresh 
meats in sacks buried among the blocks of ice, used the ice 
to cool milk, to keep butter, and otherwise to serve useful 
purposes incident to farm life. Simultaneously, in the cities, 
insulated coolers were being constructed in certain retail 
establishments, and in the better homes portable ice chests 
were installed, natural ice delivery service having been estab- 
lished in the larger cities, which functioned as far into the 
summer as the supply of natural ice lasted. 

It may now appear to be a curious fact, but a fact it re- 
mains nevertheless, that the breweries had equally as much 
to do with the extension of the use of natural ice, and later 
of manufactured ice, as had any other single agency. For, 
first of all, the brewing of beer was a profitable business, and 
the industry attracted capital. Some of the finest plants in 
the world were breweries. They could aflford to harvest and 
store ice in their cellars, to be among the very first to install 
ice machines for the manufacture of ice, to re-equip their 
plants for mechanical cooling, and to experiment with dif- 
ferent kinds of insulation. As a means of widening the market 
for beer, especially after the advent of manufactured ice, 
portable coolers in large quantities were built by the breweries 



HISTORY OF REFRIGERATION 329 

and loaned out to inns, hotels, saloons and a variety of estab- 
lishments, ice being delivered daily in generous quantities, 
often at no extra cost whatever, with which to cool the boxes 
and their contents. Perishable foods soon found their way 
into those refrigerators, where it was kept cool with the beer, 
at the expense of the brewery. The conveniences and bene- 
fits accruing, however, from the consistent use of ice-cooled, 
insulated boxes created a demand on the part of others, in 
other lines of business, for a like refrigeration service for 
the handling of perishable foodstuffs, and the breweries were 
the first, in many instances, to provide the public with such 
service and at a very nominal cost indeed. 

150. — Early Methods of Insulating Cold Stores. — Hollow 
walls, or air chambers or spaces, were the very first artificial 
barriers used in cold stores to retard the influx of heat, some 
of the first installations being made on ships, to permit of 
the exporting and importing of perishables, particularly fresh 
meats, from one country to another. Later it became the 
practice, especially in cold storage structures, to lay up double 
walls and fill the space between with a light-weight, loose 
material. Powdered charcoal, sawdust, diatomaceous earth 
and similar materials were thus employed, and except for the 
gradual loss of the insulation from settling and sifting out, the 
loss of storage space due to the bulkiness of the insulation, the 
fire hazard, and so forth, such insulated cold stores proved 
satisfactory in service, using ice as the refrigerant and operat- 
ing at temperatures sufficiently high to obviate the condensa- 
tion of enough moisture within the insulation to seriously 
interfere with its heat retarding qualities. 

But with the real advent of mechanical refrigeration in ice 
and cold storage plants, following the summer of 1890, and 
the gradual use of temperatures lower than were ever ob- 
tained with ice, or with salt and ice mixtures, serious diffi- 
culties began to be experienced with insulated structures. If 
the insulation was l:)()ards and air spaces, or double wall 
frame construction with loose fill insulation, the wood fre- 
quently became soaked with water, and rotted away, or the 
loose fill insulation became water-logged and of no further 
value as an insulator, meanwhile throwing a heavy extra 



330 CORK INSULATION 

load on the refrigerating apparatus and equipment, and of 
course increasing the cost of operation excessively. At such 
points in the insulation where the wood remained perfectly 
dry, there was great danger of dry-rot, consequent weakening 
of supporting members, and danger to the safety of the 
structure. It was not at all uncommon to have the entire 
over-head bunker structure drop to the floor because of dry- 
rot or wet-rot of the supporting timbers at the points where 
the members pie'rced the thick walls of insulation to gain sup- 
port in the outer walls of the building. If the construction 
consisted of double walls of masonry, with inside surfaces 
pitched, and the intervening space filled with a loose insulat- 
ing material, the loose fill material settled and packed down 
and frequently became thoroughly water-logged and of no 
further value whatever as an insulator. 

Every possible precaution was taken to wateruroof the 
walls between which the loose fill insulation was placed, such 
as coating them with expensi^'e pure resin pitch, imported 
from afar, probably on the theory that water got into the 
insulation by penetrating such walls. However, water con- 
tinued to be condensed out of the air in the countless voids 
between particles of the insulation, from the fact of the cold 
storage rooms operating at temperatures low enough to throw 
the* dew point within the insulation, fresh air carrying more 
water was automatically drawn in, the insulation sucked up 
the precipitated water by capillarity and soon became com- 
pletely water-logged, as formerly. 

Meanwhile, in Europe, cork, possessing no capillarity but 
high in insulating value because of its sealed air cell struc- 
ture, was being formed into slabs by gluing the cork particles 
together with a hot mixture of certain clays and asphalt, and 
these slabs were applied to the walls of cold storage rooms 
as insulation, and the results were heralded as being very 
satisfactory. The Armstrong Cork Company subsequently 
acquired the United States patent rights for this "impreg- 
nated" type of corkboard insulation, and constructed a factory 
at Beaver Falls, Pennsylvania, for its production. Large 
quantities of this impregnated corkboard were purchased and 
installed, especially by the breweries ; but it was later dis- 



I 



HISTORY OF REFRIGERATION 331 

covered that such "composition" corkboard was inferior in 
structural strength and insulating quality to pure corkboard 
manufactured under the patents of John T. Smith, and with 
the purchase of the Nonpariel Cork Manufacturing Company 
and the Smith patents, by the Armstrong Cork Company, com- 
position corkboard virtually disappeared from the market. In 
competition with pure corkboard, however, there was offered 
very early a great variety of insulating boards or slabs, made 
from fibrous materials of one sort or another and possessing 
marked affinity for water; but experience in service with all 
such substitutes for pure corkboard clearly and conclusively 
demonstrated wherein they were unsuited for cold storage 
temperatures, and they have virtually disappeared from the 
market as cold storasre insulating materials. 



CHAPTER XVI. 

DEVELOPMENT OF THE CORKBOARD INSULATED 
HOUSEHOLD REFRIGERATOR. 

15L — Early Forms of Household Coolers. — Probably the 
first household "cooler" was a crude box anchored in a nearby 
stream, in which in turn several tall earthen jars or pieces 
of crockery were placed, the ends of the box provided with 
slatted openings to permit the fresh water to pass through, 




FIG. 151.— THE FIRST METHOD OF KEEPING FOOD COOL— A BOX IN A 

NEARBY STREAM SERVED THE PURPOSE OF THE 

MODERN REFRIGERATOR. 

and the top of the box covered with a strap-hinged lid. If 
a spring of water was available, the box was of course an- 
chored just below the overflow and probably in a slight ex- 
cavation made to accommodate it. In either case, perishable 
foods, such as milk, butter, eggs and meat, were placed within 
the jars or crocks, to be cooled and preserved as best as 
possible. 

The objection to this simple type of household cooler was 

332 



CORKBOARD INSULATED REFRIGERATOR 



233 



that the mid-day sun often beat down upon the low, flat lid 
of the box with telling effect on the perishable foodstuffs just 
underneath, and at night the lid was sometimes disturbed 
and the food stolen by prowling marauders of the field and 
forest. So here, as elsewhere, necessity being the mother of 
invention, the next step in the development of the present 
household refrigerator was the construction of a rude shelter 
over the box to protect the food from the elements and from 
unwelcome guests. This shelter was made of logs, as a min- 
iature log cabin, and was usually spoken of as the "milk 
house," or the ''spring house." 




'^mM 



a^}^^ 



-THE SPRING HOUSI-: A RUDE SHELTER BUILT OVER SPRl-NG 
OR STREAM TO PROTECT THE FOOD STORED. 



Long before cellars were excavated under dwellings, some 
provision had to be made for the storing of fruits and, more 
particularly, vegetables in a uniformly cool atmosphere suffi- 
ciently dry to preserve the stores as far into the next season 
as possible. Natural caves were occasionally available, but 

I more often artificial caves were dug out of the side of a hill, 
lined with timbers and equipped with shelves, bins and a 
strong door. Again, where a hillside was not conveniently 

' near, a low, log room was constructed, similarly equipped, 

I and completely surrounded and covered with earth thrown up 
in the form of a mound. The mound was then tamped and 
covered with thick sod, which made a suitable storage con- 

i veniently nearby and which was commonly spoken of as the 



334 



CORK INSULATION 



"root house," the name borrowed from still earlier times when 
similar provision was made for the storing of roots for medi- 
cine. When cellars were first excavated under dwellings, they 




FIG. 153.— THE "ROOT HOUSE,^' COVERED WITH HEAVY SOD— A COOL 
THE YEAR 'ROUND VEGETABLE STORAGE. 

were installed as a substitute for the outside provision cave or 
root house, and the only entrance was through an outside cel- 
lar door so as to avoid direct communication between the 





jfjt--^^''- ^_ ~'^_z — '=^\ 




FIG. 154.— ENTRANCE TO CELLAR— A MORE CONVENIENT STORAGJi 
THAN THE "ROOT HOUSE." 

heated dwelling above and the cool cavern underneath. These 
original cellars were provision storages only and as such were 
little more than pits dug in the ground. 



CORKBOARD INSULATED REFRIGERATOR 



335 



It has been seen how, in ancient times, trenches were dug 
and filled with snow to cool kegs of wine. At a later time, 
pits were dug, filled with ice and roofed over, which was 
probably the earliest form of ice storage or ice house. About 
the middle of the 16th century the rich in America harvested 
and stored ice in private ice houses built of logs and padded 
inside between the logs and the pile of ice with straw packed 
tight, and later with sawdust. The blocks of ice were then 
used in a heavy, wooden chest, about three feet wide by three 
feet high and possibly ten or twelve feet long, resting on the 
floor, usually in an out-building adjacent to the kitchen, in 
which chest earthen containers were used in very much the 




FIG. 155.— FOREFATHER OF THE MODERN HOUSEHOLD REFRIGERATOR 
—A HEAVY CHEST CONTAINING RECEPTACLES FOR FOOD SUR- 
ROUNDED ]}Y NATURAL ICE AND WATER. 

same way as they were in the earlier crude box anchored 
! in the stream or spring. This heavy, water-tight, wooden 

chest, filled with ice and with vessels for liquids and pro- 
ii visions to be cooled and preserved, having as a drain for the 

water of meltage merely a hole in the end of the chest about 

half way up, and equipped with a heavy, hinged lid, was the 
: predecessor of the household ice-box and the crude forefather 

of the modern household refrigerator. 

152. — The Household Ice-box. — It has been seen that hol- 
low walls, or air spaces, were the very first artificial barriers 
' used in cold stores to retard the influx of heat, which method 
of insulating cold temperatures from the higher temperatures 



336 



CORK INSULATION 



of the surrounding atmosphere followed upon the use of thick ; 
masonry walls underground and of walls of heavy timbers ' 
or planks in structures above ground. Following the same i 
development, and true to tradition,* the ice chest in time ' 
became an ice-box, smaller in length, made of oak, chestnut ' 
or other hard wood, with hollow walls lined inside with sheet [ 
zinc, standing upon raised feet formed from prolongations 
of the side posts, a hole in the bottom for the water to drain '• 





FIG. 156.— SLIDING-TOP HOUSEHOLD ICE CHEST. 



away, with perhaps a shallow pan underneath to catch the 
drip. The very first of these ice-boxes had wood pieces laid 
in the bottom to keep the ice and food from contacting with 
the metal lining, but there was no provision for the separa- 
tion of the food from the ice. The lid, usually of double layer 
boards with no air space between, was at first hinged, and; 
later, in some instances, built in two sections and made to 
slide. As time passed, these convenient household ice-boxes 
were provided with a vertical division across the box at the 



*The box, whatever its shape or purpose or the materials of which it is fashioned, 
is the direct descendent of the chest, one of the most ancient articles of domestic 
furnishings. 



CORKBOARD INSULATED REFRIGERATOR 337 

center to separate the food from the ice, but it was at that 
time in no sense a baffle for the promotion of air circulation, 
the idea not then having been adapted to such purpose. 

In due course, it became the practice in cold stores to con- 
struct double walls and fill the intervening space with flaked 
charcoal, silicate cotton, small pumice, sawdust, and similar 
loose or granular materials; and the principle of the over- 




FIG. IS/.— LIFT-LID HOUSEHOLD ICE BOX. 



head bunker was at about the same time being fast developed 
to a point of efficiency that opened up new avenues of use- 
; fulness for cold stores employing ice, or salt and ice mix- 
itures, as the refrigerant. This influence was quickly reflected 
in the large beer and meat coolers of retail establishments and 
in turn in the household ice-box, flaked charcoal becoming the 
preferred type of loose fill insulation between ice-box walls, 
followed later by silicate cotton, or mineral wool. Then for 
the first time the household ice-box was elevated, so to speak. 



338 



CORK INSULATION 



to a new position ; its length was somewhat decreased in favor 
of a much greater height, and the division between the ice and 
the food changed from a vertical one to a horizontal one. In 
a word, the household ice-box became a household "refrig- 
erator," of the kind now known as a lid tyi)e top-icer, b\ virtue i 




FIG. 158.— LID TYPE TOP-ICER HOUSEHOLD REFRIGERATOR. 

of the location of the ice on an overhead support of such 
design as to utilize the fact of the greater weight of cold than 
of warm air to cause a natural circulation to be set up through- 
out the refrigerator. Then came the top-icer with a side ice- 
chamber door; and, later, the side-icer completed the inter- 
esting evolution of the form our modern household refrigerator 
finally came to take. 

Except for the gradual loss of the insulation from settling 
and sifting out, those early household refrigerators proved 
much r^ore satisfactory in service, using ice as the refrigerant, 
than did the cold storage rooms in plants cooled by mechan- 



CORKBOARD INSULATED REFRIGERATOR 



339 



ical means and insulated in exactly the same manner. Of 
course the rooms cooled by mechanical means could be, and 
were, held at lower temperatures than were the household 
refrigerators chilled wdth ice ; and this fact was responsible for 
the different degrees of success experienced with the same 




FIG. 159.— SIDE-DOOR TOP-ICEK HOUSEHOLD REFRIGERATOR. 

•type and kind of insulation under those different conditions 
of service; for it will be recalled that with the gradual use 
in cold stores of temperatures lower by mechanical means 
than were possible with ice, serious difficulties began to be 
experienced with insulated structures from condensation of 

I' water within the insulation. 

153. — The Era of Multiple Insulation in Household Re- 
frigerators. — Pliny, writing in the first century, said: "The 



340 CORK INSULATION 

natives who inhabit the west of Europe have a liquid with 
which they intoxicate themselves, made from corn and water. 
..The people in Spain in particular brew this liquid so well 
that it will keep good a long time. So exquisite is the cun- 
ning of mankind in gratifying their vicious appetites that they 
have thus invented a method to make water itself produce 
intoxication." It has been seen how that same "exquisite 
cunning" of which Pliny wrote also provided means of mak- 
ing that ceria more palatable and soothing by cooling with 
snow, and later with ice ; how the physicist working in the 
laboratory formulated certain laws which apply to the con- 
densation of gases; how the engineer, in his workshop, utilized 
these fundamental principles to develop machines to make ice 
on a hot summer's day ; and it only remained for the prac- 
tical business man of the 20th centur}^ to so organize the ice 
industry that ice is no longer a luxury, to be obtained only by 
the wealthy, but is today within the reach of almost every- 
one. Sixteen million tons of natural ice are harvested and 
forty-two million tons are manufactured each year in the 
United States alone. And of this total ice production of fifty- 
eight million tons (1923), American households used the enor- 
mous total of twenty-five million tons. 

So from practically nothing at the beginning of the 19th 
century, the ice industry of the United States has becon e 
ninth in the list of great commercial activities, with a nioac- 
tary involvement of over one billion dollars, which mav be 
accounted for by the increased cost of foods, a better knov, !- 
edge of the value of very fresh foods in the diet, a more 
thorough understanding of the danger of stale or decomposed 
foods, and the means on the part of countless numbers of 
people not only to purchase fresh foods the year 'round but 
also to provide facilities in the home for the care of such 
perishables. 

The many industries that use refrigeration in their routine 
business have been benefited by careful scientific research 
begun many years ago ; and only by correctly utilizing the 
findings of engineers, chemists, physicists and bacteriologists 
have they been able to reach their present high efficiency. But 
similar studies applicable to the problems of the home were 
never undertaken in similar concerted fashion by either the 



CORKBOARD INSULATED REFRIGERATOR 341 

ice manufacturers or the refrigerator manufacturers, and even 
those principles worked out and established for the benefit and 
guidance of the ice and refrigerating and allied industries, 
and which are directly applicable to the household, often have 
been overlooked, ignored or misapplied. 

For instance, careful scientific research established the fact 
that the flow of heat through a given insulating material was 
retarded by an external or surface resistance as well as by 
an internal resistance, but that its surface resistance virtually 
disappeared if the surfaces of the material were no longer 
in contact with the surrounding atmosphere, as elaborated in 
the section of this book on "The Study of Heat." But this 
scientific fact was either misunderstood, or its true significance 
ignored, because many manufacturers of household refrig- 
erators re-designed their product on the basis of multiple in- 
sulation on the incorrect theory that each layer of material 
in the walls of a refrigerator sets up or offers its own indi- 
vidual surface resistance to the transfer of heat, even though 
these layers are laid one against another or in positions of in- 
timacy and their surfaces are not exposed to the surrounding 
atmosphere. In other words, in theory, the surface resistances 
of many layers of material were incorrectly combined to arrive 
j at a wholly fictitious high total resistance of a given wall to 
[ the infiltration of heat. The claim of superiority based on 
I multiple walls of insulation was a familiar one, and for too 
• many years unsuspecting householders counted the layers in 
comparing prices. 

With the growth of the ice industry, the refrigerator in- 
dustry expanded proportionately, and competition became 
keen and difficult. Little real attention was paid to the actual 
: insulating qualities of a household refrigerator ; for, as some 
["have said, "the ice man wanted to sell ice, the refrigerator 
manufacturer wanted to sell refrigerators, and the householder 
' wanted something low in cost and high in hopes." It is prob- 
ably more to the point, however, that the real need for bet- 
ter insulation in household refrigerators had never been made 
clear to the ice man, the refrigerator builder, or the house- 
holder. In a word, the necessity did not exist, and the need 
was not understood. 



342 CORK INSULATION 

Nevertheless, the more progressive refrigerator manufac- 
turers and the more progressive producers and distributors of 
ice, often in cooperation with various United States Govern- 
mental agencies, State Universities^ and a few private experi- 
mental laboratories, kept up a constant if not intensive search 
for more practical and accurate information on the applica- 
tion of refrigeration principles and appliances in the home 
New and better sanitary refrigerator linings were developed, 
air circulation was ^•astly improved, shelves were rearranged 
to accommodate various foods in the position in the refrig- 
erator where they would keep best, better hardware was 
adopted, doors were sealed with improved wick gasket, drain ! 
pipes were placed so as to permit of ready removal and clean- 
ing, ice compartments were enlarged to an adequate size, 
outside icing doors were provided for the discriminating, and 
better exterior finishes were offered. Very little attention, 
however, was paid to the insulation of what would other- 
wise have been a perfect masterpiece of craftsmanship. A few 
manufacturers, among them those using solid porcelain lin- 
ings, adopted granulated cork as the insulating medium; but 
as refrigerators were not then sold on the basis of compara 
tive permanent efficiency of operation in service, the added 
value of the ground cork insulation was not generally appre- 
ciated even by those manufacturers who used it. 

154. — The Advent of the Household Refrigerating Machine 
and Early Trials with Pure Corkboard in Household Refrig- 
erators. — It has been seen that the practice of cooling food and 
dfink below the temperature of the atmosphere by the use 
of snow and ice was followed for many centuries before natural 
ice came to be stored in caves, in ice pits, and then in ice 
houses, and that within the present generation means were 
perfected for the manufacture of ice in commercial quantities 
for refrigeration purposes. Now we observe that within 
scarcely the past dozen years attention has been directed tO; 
ways and means of producing refrigeration in the home by 
mechanical means directly ; but it is only since the World War 
that the household machine has been manufactured in quan- 
tities and proven a success, the production during recent years 
having been about as follows : 



CORKBOARD INSULATED REFRIGERATOR 343 

Prior to 1923 20,000 

Year 1923 25,000 

Year 1924 50,000 

Year 1925 100,000 

Year 1926 500,000 

Estimated 1927 750,000 

At present the subject of household refrigeration is receiv- 
ing the attention of many inventors and engineers, as well as 




FIG. 160.— TYPICAL AIR-COOLED HOUSEHOLD REFRIGERATI.NG MACHINE. 

of several hundred manufacturers. New and improved me- 
*i chanical devices and processes are being de\eloped almost 
! constantly, several editions of a complete treatise on "the 
principles, types, construction, and operation of both ice and 
I mechanically cooled domestic refrigerators, and the use of 
j ice and refrigeration in the home." having already been pub- 
I lished,* under the title of "Household Refrigeration," by H. B. 
[. Hull, Refrigeration Engineer. 

Mr. Hull, in introducing his subject, says that, "mechan- 
ical household refrigeration is having an important influence 
on refrigerator cabinet construction ; it is necessary to have 
better constructed and insulated refrigerators to operate satis- 
factorily, with the lower food-compartment temperatures pro- 
duced by the mechanical unit" ; and Mr. Hull drew extensively 
on his experience as a refrigeration and research engineer, 
and in turn upon the work and experience of many others in 
allied industries, in setting forth his conclusions with respect 

*.\ickerson & Collins Co., Publishers, 5707 West Lake Street, Chicago, Illinois. 



344 CORK INSULATION 

to the insulation of mechanically cooled household refrig- 
erators. 

It was little suspected, perhaps, in the beg-innings of me- 
chanical refrigeration for the home, that serious trouble would 
be experienced with the operation of the household refrig- 
erator itself; because there was then enough real and poten- 
tial trouble with the mechanical unit, without contemplating 
trouble from a coordinated product manufactured by others, 
especially since household refrigerators had been successfully 
produced, sold and used in the home for a great many years. 
Yet serious trouble there was, and it took a lot of time and 
much money to eliminate it. 

A dozen years or so ago (about 1915), there was need 
for better insulation in household refrigerators, but the neces- 
sity for it did not then exist; and it was not until a serious 
attempt was made to cool such refrigerators by mechanical 
means that the subject of enough permanently efficient in- 
sulation was made a research and engineering consideration. 
The cost of operating one of the early makes of mechancially 
cooled domestic refrigerators, original investment ignored, 
was frequently somewhat greater than the cost of cooling the 
same refrigerator with ice. The much lower temperature that 
could be maintained by the mechanical unit was consequently 
featured "as its greatest advantage, and the plant was adjusted 
and sold on that basis. Thereupon the refrigerator usually 
began to leak, and frequently to smell, and then the motor 
was observed to operate a greater number of hours per day, 
until it was sometimes said to operate almost continuously, 
and general dissatisfaction with the installation on the part 
of the purchaser was, under such conditions, the inevitable 
result. 

Examination of these "leakers" and "smellers" usually 
revealed the fibrous insulation in the hollow walls of the re- 
frigerator water-soaked and odor-saturated ; whereupon, after 
a considerable lapse of time and following much investigation, 
the insulation specifications were changed, and, borrowing a 
page from the experience and practice of commercial cold 
storage plants, pure corkboard was directed to be used. The 
permanent insulating efficien.cy of corkboard in cold storage 
structures was a known quantity, and its well-known freedom 



CORKBOARD INSULATED REFRIGERATOR 345 

from capillarity was expected to rid the correctly insulated 
mechanical refrigerator of the water conditions so consistently 
encountered theretofore. Unfortunately, however, the question 
of the manner and method of installing the corkboard, with 
respect to the refrigerator as a finished unit, was virtually 
left to the discretion of the superintendent of the plant pro- 
ducing the refrigerators; and it was but natural for him to 
cut the corkboards to fit easily into generous wall spaces, and 
in other respects to do with the corkboard just about as had 
always been done with other kinds of insulation in the many 
years preceding the advent of the household refrigerating 
machine. 

The results were almost as unsatisfactory as they had 
been with other kinds and forms of insulation. Leakers and 
smellers continued to be the order of the day, and the insu- 
lating efficiency was below that to be expected with cork- 
I board as the insulating material. Perhaps the refrigerato'- 
did not leak half as much, or smell quite as badly, or run 
■ nearly as long, as formerly, with other kinds of insulation ; 
but it leaked, and it gave off odors, and it cost too much to 
operate ; and these things, coupled with the usual run of 
mechanical troubles incident to the development of a new 
device, were enough to discourage much less courageous man- 
ufacturers than those who blazed trails for the present-day 
mechanical unit. 

If a glass pitcher of ice water is placed on a kitchen talkie, 

it will "sweat," under usual conditions of humidity, such an 

amount that the water of condensation will sometimes run 

on to the table top, although usually it will evaporate away 

I almost as rapidly as it forms ; and just as water vapor in 

; suspension in the surrounding air of the kitchen would be 

••'precipitated on the cool, outer surface of the glass pitcher, so 

would water vapor have been precipitated or condensed at the 

same rate on the outer, exposed surface of the interior lining 

of a refrigerator cooled to the same degree by ice and located 

in the same kitchen. 

If salt is added to the pitcher of ice water and stirred, to 
reduce the temperature of the mixture, the sweating will 
usually exceed the evaporation by such an amount as to 



346 



CORK INSULATION 



quickly form a puddle of water on the table top; and just as 
water vapor in suspension in the surrounding air of the 
kitchen would be precipitated on the cold, outer surface of 
the pitcher containing the low temperature mixture, at a rate 
too rapid to permit of its being evaporated away as fast as 
it formed, so would water A'apor have been condensed at the 
same rate on the outer, exposed surface of the interior lining 
of a refrigerator chilled to the same degree by a mechanical 
household refrigerating machine. 




FIG. 161.— THE SWEATING PITCHER OF ICE WATER POINTED THE WAY 

TO THE PROPER APPLICATION OF CORKBOARD IN 

HOUSEHOLD REFRIGERATORS. 



In either case, the only difference between the action of 
the pitcher and that of the refrigerator would be in the rate 
of evaporation of the condensed water; evaporation from the 
surface of the pitcher would be more rapid than from the 
exposed surface of the interior lining of the refrigerator, 
because there would be greater freedom of air currents about 
the pitcher than there would be about the confined interior 
refrigerator lining. 

The foregoing explains why the mechanically cooled house- 
hold refrigerator frequently "leaked," and why the former ; 
ice-cooled domestic refrigerator rarely if ever gave evidence 
of the same defect ; the rate of condensation of water vapor 
in the case of the mechanical refrigerator was considerably 
greater than the rate of evaporation, whereas the rate of con- 
densation in the case of the ice-cooled refrigerator was usually 



CORKBOARD INSULATED REFRIGERATOR 347 

no greater and was frequently less than the rate of evapora- 
tion. Then, too, in the case of an ice-cooled refrigerator, 
moisture condensed out of air entrapped within the walls of 
the refrigerator would usually be in intimate contact with 
the insulation in such walls, and would be absorbed by it if 
the insulation possessed capillarity in any degree whatever. 

j Water, as is well known, is very susceptible to tainting; 

i a glass of water standing on a dining-room table will pick up 
odors at a rapid rate, and become unfit for human consump- 
tion. Place a glass of water on a kitchen table during the 
preparation of a meal, and two hours later the water will have 
an odor. The water of meltage coming from an iced refrig- 
erator has an odor; because as the air in the refrigerator cir- 
culates over the melting ice, the water of meltage extracts 
the food odors and carries them away through the refrigerator 
drain. Condensed water on the back of an exposed interior 
lining of a refrigerator will quickly become foul, by absorption 
of odors from the air ; and thus we have the explanation for 
the so-called "cork odor" in the structure of the early mechan- 

I ically cooled household refrigerator insulated with corkboards 
so loosely installed as to leave the exterior surface of the 
interior lining exposed. For unless some material with a cer- 

[ tain heat insulating value is in intimate contact with the 

I entire outer surface of a refrigerator lining, such surface must 
be thought of and dealt with as being exposed to the sur- 
rounding atmosphere, at least in so far as the condensation 

I of moisture on its face is concerned. 

1 Odors within the food compartment of a mechanical re- 
frigerator are usually accounted for by the foods stored, or by 

j odors coming in through dry bell-trap or goose-neck of the 
drain pipe from which all water has evaporated. An ice- 
cooled refrigerator is constantly at work to keep its air purified, 
by absorption of odors by the water of meltage and discharge 
to drain ; but a mechanically-cooled refrigerator frequently has 
little or no water of meltage, and other provision must be made 
for the purification of its air. This has been variously accom- 
plished by ventilation through dry drain pipe, where such 

, pipe terminates low enough to escape the odors from the 
refrigerating machine, by ventilation through loosely fitted 
doors, and bv still other means entirely. These items do not 



348 CORK INSULATION 

come within the scope of the subject of the proper insulation 
of a refrigerator, but they are touched upon here because 
insulation was frequently and erroneously blamed for such 
interior odors in the days of the early trials at insulating 
household refrigerators with corkboard. 

155. — The Modern Corkboard Insulated Household Re- 
frigerator. — Early ice storages, ship's cold stores, cold storage 
houses and breweries were insulated with air spaces and loose 
fill materials in hollow walls with reasonable success, all 
things considered, during the days when ice was employed 
as the refrigerant. The advent of mechanical refrigeration 
and lower temperatures in cold stores increased the condensa- 
tion of moisture within the air spaces and the loose fill insu- 
lating materials to such a degree, however, as to frequently 
destroy the insulating capacity of the walls entirely. For it 
will be recalled, from an elaboration of the subject in the 
chapter on "Measurement of Heat, Change of State, and 
Humidity," that the capacity of air to absorb and hold moist- 
ure, or water vapor, in suspension, varies with its temperature ; 
and, warm air being capable of holding more moisture than 
cold air, when warm air is cooled, its moisture capacity is 
lowered until a temperature is reached at which the air can 
no longer hold all of its moisture in suspension, which point 
is the point of saturation, or the dew point. By insulating 
the exposed surfaces of cold stores with a sufficient thickness 
of a material having its air content, upon which it must 
depend for its heat retarding properties, divided into an in- 
finitesimal number of microscopic or colloidal particles dis- 
persed throughout the material in hermetically sealed cells, 
so that such air loses its normal properties as air, the precipita- 
tion of water vapor within such insulation or within the build- 
ing structure back of the insulation, due to exposure of chilled 
surfaces to the atmosphere, was eliminated. Pure corkboard 
was the insulating material that met these conditions, both in 
theory and practice, when properly manufactured and when 
properly applied in intimate contact with the surfaces to be 
insulated. 

Borrowing another page from the experience and practice 
of commercial cold storage plants, through the advice of a 



CORKBOARD INSULATED REFRIGERATOR 



349 



trained insulation engineer* of recognized experience and 
responsibility, pure corkboard was directed to be applied in 
mechanically chilled household refrigerators in a manner that 
would absolutely eliminate air pockets or air spaces of any 
kind between the corkboard and the outside surface of the 




FIG. 162.— SEEGER MODEL SHOWING PURE CORKBOARD APPLIED IN 

ASPHALT CEMENT TO INTERIOR ONE-PIECE ENAMELED-STEEL 

REFRIGERATOR LINING, WITH ALL AIR EXCLUDED. 

interior refrigerator lining; for otherwise water vapor in that 
air would be condensed, due to its contact with the cold 
exterior surface of the lining, the partial vacuum created by 
such cooling and condensing would be balanced by the infil- 
tration of additional air carrying water vapor in suspension, 
which fresh supply of air would in turn be cooled and give up 

*PUBLISHER'S NOTE— The author of this book is credited with formulating 
the suggestions that led to a solution of the problems touched upon here. 



350 



CORK INSULATION 



water, and the c}cle continued so long as the refrigerator 
was in serxice. A certain type of refrigerator, having an opal 
glass panel lining, and usually produced by skilled cabinet- 
makers, escaped almost completely the difficulties with me- 
chanical household refrigeration that were experienced by 
manufacturers of refrigerators having the one-piece enameled 
steel linings. The wall construction of such refrigerators 
consisted of exterior oak, paper, corkboard tightly compressed 




FIG. 163.— CABINETMAKER'S INSULATION DETAILS FOR REFRIGERATOR. 

into position in intimate contact at every point, paper, wood 
sheathing, and a thin pad of builder's felt against which the 
opal glass paneled interior lining was secured. One of the 
first demands placed on the mechanical household refrigera- 
tion industry, however, was for a very much reduced cost of 
the assembled refrigerator units; and the cabinet type of cork- 
board insulated refrigerator with opal glass paneled lining, 
which was virtually a cabinetmaker's product and which did 
not readily lend itself to quantity production, was soon aban- 
doned in favor of the one-piece enameled-steel lining type of 
refrigerator. 

The outside or back of an enameled steel lining does not 
present a level surface, and from desire to have sanitary 
corners within the food compartment the corners were round- 



CORKBOARD INSULATED REFRIGERATOR 



351 



ed. Early types of enameled steel linings were L-shaped, 
necessitating a separate galvanized iron section or lining to 
accommodate the mechanical cooling unit and to be fitted into 



t 




-CABINETMAKER PLACING CoRKl 
BETWEEN DOOR oi' 



-IILFS AND RAILS 



the crook of the L as best as possible and insulated from it. 
The corkboard insulation had to be built around the lining, 
obviously, instead of the insulation being installed in the 
refrigerator v^-alls and the lining fitted in place afterwards. 
Therefore, the use of some waterproof, odorless, elastic, highly 
cementations material, plastic at workable temperatures and 
solid at ordinary temperatures, a material reasonable in cost 
and easily obtained, had to be found in which to lay up or set 
the corkboards in position against the exterior of the refrig- 





FIG. 165.— (LEFT) L-SHAPED REFRIGERATOR LINING, DIFFICULT TO 

INSULATE.— (RIGHT) RECTANGULAR REFRIGERATOR LINING, 

EASY TO INSULATE. 

erator linings. After repeated trials with many materials, an 
unfluxed petroleum asphalt of suitable characteristics and 
mixed with a certain preparation of cork flour, as described in 
the Articles on "Asphalt Cement and Asphalt Primer" and 
"General Instructions and Eciuipment," came to be used with 



352 CORK INSULATION 

success, and such method of application of corkboard in house- 
hold refrigerators and ice cream cabinets came to be known as 
the "hydrolene process"*. 

The equipment for the proper preparation and handling of 
hot Asphalt cement, in the refrigerator manufacturing plant, must 
of course be a separate consideration with each manufacturing 
organization, and for that reason no attempt will be made here to 
give any of the details whatever. A word of caution would 
probably not be out of place, however, with respect to the 
danger from fire. This is probably the only serious manu- 
facturing objection to the Asphalt cement process of install- 
ing corkoard in household refrigerators, but the benefits have 
been of so great an importance to the household refrigeration 
industry as to put such objection, for the present at least, in 
the class of "necessary manufacturing evils." The properties 
of asphalt are at least briefly outlined elsewhere in this book, 
and additional information should be available from reliable 
sources. There is just one simple rule to follow with respect 
to the asphalt to use; namely, start with the correct material 
(not necessarily the most expensive), and if it is not damaged 
by overheating in the process of applying the insulation, the 
finished refrigerator construction will contain the correct As- 
phalt cement as a bonding and sealing material. 

Thus it has been seen how corkboard came to be adapted 
to, and adopted for, the insulation of household refrigerators 
by the mechanical household refrigeration industry, through 
the desirability of using a more efficient insulating material 
to reduce costs of mechanical operation, and an insulating 
material which when properly applied in a unit to be mechan- 
ically cooled would obviate the condensation of moisture 
within the insulation. Also, competition between the enor- 
mous ice industry and the fast growing mechanical household 
refrigeration industry had the usual effect of directing attention 
to the comparative cost and efficiency of the two systems of pre- 
serving foodstuffs in the home. Research on the part of the ice 
industry is said to have made the important discovery that with 
adequate and proper corkboard insulation, with improved air cir- 
culation, with proper i)]acement of foods, and other considera- 



*Registered by Delco-Light Company, subsidiary of General Motors Corporation, 
Dayton, Ohio, manufacturers of Frigidaire Electric Refrigeration. 



CORKBOARD INSULATED REFRIGERATOR 



353 



1 




.]\^.„..„,J. 


1 


11, 


y.. 



\r^^^^ 







ir^l 


\ 11 1 



(HT^^ 



^~Ji 



k 



^ 




fB 



OlJ 



^ 



\ 



Jiy 



l;^ 



FIG. 166.— AIR CIRCULATION IN HOUSEHOLD REFRIGERATORS. 



354 



CORK INSULATION 









lC£. 



|^pnnr,ognn4»i 



ffV 






^r 






T"T 
M 



// 



FIG. 167.— AIR CIRCULATION IN HOUSEHOLD REFRIGERATORS. 



CORKBOARD INSULATED REFRIGERATOR 355 

tions, an ice cooled refrigerator will give results in the correct 
preservation of foods in the home that cannot be expected with 
mechanically cooled refrigerators. Then, too, some of that great 
fraternity of refrigerator manufacturers not identified with 
the mechanical household refrigeration industry, wished, for 
the most part, to have their products adaptable to either sys- 
tem of refrigeration, — ice or mechanical, — and therefore ad- 
justed their insulation specifications to meet the most exacting 
requirements. 

Household refrigeration and the proper insulation of the 
household refrigerator are today important correlated sub- 
jects, and their importance promises to continue to increase 
so long as food is consumed in the home. The National 
Association of Ice Industries, 163 West Washington Street, Chi- 
cago, Illinois, has equipped* to give the subject of refrigeration 
in the home every attention and consideration. From one of its 
many interesting and valuable publications and pamphlets, this is 
extracted : 

WE GO SHOPPING FOR A REFRIGERATOR 

A clever woman once said that it was a wise girl who knew good 
"husband-material" when she saw it! And it is a wise woman who 
knows a good refrigerator when she meets one, for here beauty is 
only skin deep with a vengeance and it's the inside, not the outside, 
of an ice box that counts. A woman's intuition won't help her much 
in looking at it. Nor do white enamel and nickel finishings make the 
refrigerator, any more than clothes make the man. 

Rule one, in a case like this, is to go to a reliable, intelligent 
dealer and buy a box that bears the name of an established builder 
of refrigerators. When a man signs his output with his own name, 
he is apt to be proud of it and to do a good job. 

The main points to look out for in choosing a refrigerator to 
live with are these: 

I 1. Insulation: How are its walls built? 

2. Circulation: Can the air flow freely? 

3. Size: Not only of the whole box in relation to 

the size of the family, but of the ice compart- 
ment in relation to the box itself. 

4. Drain pipes and shelves: Are they easy to adjust 

and hard to rust? 

5. Handles and corners : Are they easy to turn and 

easy to clean? 
What and Why Is Insulation^ — To insulate anything is to cut it 
off from its surroundings, make an island of it. And the walls and 



* Household Refrigeration Bureau of the National Association of Ice Industries, 
Dr. Mary E. Pennington, IDirector. 



356 



CORK INSULATION 



interlinings of a good refrigerator, the doors and top, should cut it 
off from the warm outside air. It's not fair to expect 100 pounds of 
ice to cool the whole outside world! So a poorly insulated refrig- 
erator, however handsome to look upon, is largely an ice-melting plant 
that wastes ice and does not maintain sufficiently low temperatures. 
The ideal is to have a hard-wood case about ^-inch thick (oak 
is best) with the equivalent of at least two inches of corkboard be- 
tween this and the inside lining of porcelain. The "reason why" for 
this is that such an interlining not only keeps heat out, but it will 
not absorb moisture, and is rigid so that it will not sag leaving air 
spaces. 




FIG. 168.— WISE WOMEN KNOW GOOD RKKRIGERATORS. 

Merely wood, paper and air will not keep the heat out of the 
refrigerator, such walls leave the ice badly handicapped in its war 
with outside heat! Ask to see a cross-section of the refrigerator walls. 
If the makers are proud of their box, they will be glad to "show" 
you. 

On these protecting walls and well-insulated and tightly closing 
doors depends largely the coolness of the food compartments. They 
should average 20 to 26 degrees colder than outside the refrigerator 
when the room thermometer reads 70 to 75° F. As the weather 
grows colder, this difference grows less. Under the ice, the coldest 
place, the thermometer should read not more than 45° F., and on 
the top shelf of a side-icer or on the bottom of a top-icer, the tem- 
perature should not be much more than 50° F. when the room is 
70 to 75^ F. 

Circulation Means "Air Move On." — "Side-Icer or Top-Icer"? That 
is a question, too. 



CORKBOARD INSULATED REFRIGERATOR 357 

It's the cold circulating air that cools the foods. To be sure 
that you are getting good circulation, look to see that there is a 
broad unobstructed drop from the ice chamber into the food com- 
partment. 

In a side-icer there should be a solid insulated partition between 
the ice chamber and the food compartments. In this way the cold 
air is "baffled" in any attempt to sneak out into the food compart- 
ment. It must go down and around, collecting heat and odors from 
the food and traveling all the way back to the ice chamber to be 
re-cooled and deodorized. Good circulation is necessary to dryness 
and absence of odors, as well as to evenness of temperature. 

Both side- and top-icers are good if well designed. The side- 
icer is often more convenient to ice; and the top-icer has the advan- 
tage of a broader drop for the cold air and less difference between 
the coldest and warmest place in the box, but the average tempera- 
tures are about the same. 

Sice, Too, Is Important. — Be sure that the refrigerator is big enough 
for the family needs, not only in winter, but in the good old sum- 
mer time when more perishable foods are used, when the refrigerator 
must work harder to keep the temperatures down and when week- 
end guests are abundant. Almost, then, you need elastic, rubber re- 
frigerators! So buy the refrigerator for your greatest need, not your 
smallest one, remembering it won't stretch. 

Also, it is important that the ice chamber be the right size in 
proportion to the remainder of the box. It should occupy about 
one-third of the whole inner space and the smaller the box, the 
larger the relative size of the ice chamber. 

Generally speaking, a family of two can get along with a refrig- 
erator taking fifty pounds of ice. For the average family of four, 
100-pound capacity is required. 

Drain Pipes and Shelves. — "I've missed all the best advantages that 
came my way," said the blonde spinster, "because I had to go home 
and empty the pan under the refrigerator." Don't have a pan! Be 
sure there is a drain pipe, well fitted and easily disconnected, with 
'a good water seal at the floor so that it lends itself gracefully both 
to cleaning and readjustment without danger of leakage. This small 
point means much to the housekeeper's serenity, and keeps her temper 
down, though not so important in lowering refrigerator temperature! 

Again, the blonde spinster needed an automatic ice man. She 
got him by having an outside door into the ice chamber. No longer 
did she need to be at home when the ice man came! 

Shelves should be of woven steel wires, well welded to steel 
bars, so that they, too, are easy to clean, hard to rust, and will 
neither slip nor sag. 



358 CORK INSULATION 

Handles and Corners. — Round corners are easier to clean than 
square ones, but if you have more time than money, the more expen- 
sive round construction may be foregone. It is worth the money, 
however, to be sure that handles are heavy and close the doors easily 
and tightly. No use to buy a refrigerator and let it stand open. 

Always the more you invest, the more interest you draw. The 
money invested in a really good, efficient refrigerator draws big in- 
terest in appetizing, wholesome food, economically stored. 

HOW TO BRING UP A REFRIGERATOR IN THE WAY 
IT SHOULD GO. 

Refrigerators must be properly fed and taken care of if you want 
them to do you credit. Long life and good service from a refrigerator 
are dependent on points like these: 

Location. — Set your refrigerator in as cool a place as possible. 
It is hard on the refrigerator's efficiency to put it for your convenience 
too near the stove, or in the sun for the ice man's pleasure. Give it 
a fair location — no ice box craves a place in the sun. Fill it full of 
ice and allow it twenty-four hours to get the heat out of the box 
before you start to cool foods. 

Feed It Plenty of Ice. — It costs less in the end, and you get more 
for your money, if you keep the ice chamber full. Never let it get 
more than half empty. When there is only a small piece of ice, it 
has more to overcome, melts more quickly and you pay more to get 
back to the necessary low temperatures again. 

Cleanliness. — Cold and Cleanliness are the two slogans of food 
preservation. Keep dirt from getting into the box and you won't 
need to work to get it out. An ounce of prevention is worth several 
pounds of cure here. This means washing the ice, if necessary, be- 
fore it goes into the refrigerator, wiping off milk bottles, washing 
lettuce, etc. 

Have the proper kind of containers to put the food in, to save , 
space, permit proper circulation and prevent spoilage and "spillage." 
There are enamel and glass containers, with and without tops, and , 
attractive nests of bowls to be had at varying prices to suit all purses. 
The many glass bottles with screw tops that foods come in these 
days make perfect and economical containers for food storage. 

With these precautions there will be no need to heat up the 
refrigerator by giving it hot baths. Wfipe it out with cold water 
and sal soda (one tablespoon to four quarts) once a week. Monday 
morning, when food and ice are low, is a good time for this, or 
Friday before loading with ice and food for the week-end. 

Dry with a clean cloth. Work rapidly and use a double strength 
washing soda solution of cold or tepid water to pour down the 
drain to remove slime. There will be little need of extreme measures, 
of long brushes or the use of hot water, if foods are carefully stored. 



CORKBOARD INSULATED REFRIGERATOR 359 

Clear the Way for the Cold Air. — Note the places where the cold 
air drops from the ice and where, when warmed, it goes back to the 
ice, and do not shut them off by stacking food in these spots. Also, 
do not shut off the air passages where the warmed air goes up and 
into the ice chamber again. Air currents (good circulation) are just 
as necessary to efficient refrigeration as is insulation. In other 
words, leave air spaces between everything and everything else, so 
that the cold air can be on its way. When the inside of the refrig- 
erator begins to look like a sardine can, it is a reproach to you. 

A False Economy. — Don't wrap the ice in a mistaken effort to 
make it last. Ice must melt in order to cool. It takes up the heat 
and sacrifices itself to serve you. Hoard it and like a miser's money 
it can do you no good. 

Fair Play. — Never put hot foods into the refrigerator. This is 
taking an unfair advantage. Cool jellies, soups, custards, etc., to room 
temperature before putting them in the ice box. 

Go in and out of the refrigerator quickly and close the door 
behind you every time. Take a tray and remove several things at 
once. Every time you carelessly open the door of a refrigerator into 
a hot room, you cause an appreciable increase in ice meltage. 

156. — Typical Details of Household Refrigerator Construc- 
tion. — It would be impossible to illustrate in this book even a 
fractional part of the many makes and types of refrigerators 
manufactured in the United States, and for that reason but a 
very few of them, selected at random, are illustrated and 
described* in this Article : 

RHINELANDER "AIRTITE" REFRIGERATORS. 

Lini)ig. — One piece patented porcelain lining. All surfaces are 
beautiful, snow white porcelain as smooth as glass — no cracks or 
seams, with broadly rounded corners at top and bottom, greatly 
simplifying cleaning. The inside linings of all doors are full porce- 
lain, pan shaped, in keeping with the beautiful, snow-white interior, 
j Hardzmre. — Heavy brass, nickel plated, hand buffed hardware 

,^ used throughout, made oversize to insure extra wear. Self-acting type 
lock takes immediate action and holds door air-tight. 

Equipped for Ice or Mechanical Refrigeration. — Ice or coil chamber 
is placed inside of the porcelain lining, instead of outside, to insure 
free, unobstructed circulation of cold air around the compartment as 
well as through it. Many models are equipped for ready installation 
of electric refrigerating unit. Hanger bolts, and capped openings in 
the rear near top of ice chamber, are standard equipment on these 
models; suitable either for ice or mechanical refrigeration. Other 



*Descriptions are those of the manufacturer, and are to be accepted only for what 
they may prove to be worth. 



360 



CORK INSULATION 



models, for ice only, have extra-sturdy ice racks, more than twice 
as strong as necessary, made from heavily coated galvanized steel, 
with galvanized iron baffles in ice compartment to direct air cir- 
culation. 

Shelves. — Rhinelander shelves are woven in our factory, electrically 
welded, and then heavily coated with tin giving a clean, bright and 
lasting finish. Shelves designed to insure free circulation of air. 

Casters. — Ball bearing lignum-vitae casters. 




FIG. 169.— DETAILS OF RHINELANDER REFRIGERATOR CONSTRUCTION. 



Insulation. — One and one-half inch pure sheet cork compressed in 
position in intimate contact with waterproof, saturated-felt covered 
lining surface, and sealed in with special waterproof compound. 

Exterior. — Heavy Airtite solid hardwood construction. No thin, 
set-in, sunken panels. Triple coated porcelain or natural hardwood 
finish. 

Manufactured by Rhinelander Refrigerator Company, Rhinelander, 
Wisconsin. 



CORKBOARD INSULATED REFRIGERATOR 



361 



McCRAY RESIDENCE REFRIGERATORS. 

Compartments. — Compartments to be as per manufacturer's stand- 
ard for each size. 

General Constructio)i.— The general construction shall be of cork 
and wood; two inches of 100% pure cork-board. Both sides sheathed 
to approximate thickness of four inches. 

Exterior Finish. — Exterior finish to be as per manufacturer's stand- 
ard for model selected. (a) Exterior front, top and two ends shall 




•'](; 



70.— McCRAY HOUSEHOLD REFRIGERATOR. 



be covered with No. 20 gauge sheet steel finished in white lacquer. 

;i Back and bottom covered with No. 24 gauge galvanized sheet iron. 

i' (b) Exterior front, top and two ends shall be finished in quarter- 
sawed oak, well filled and varnished. Back and bottom to be finished 
with 13/16-inch matched yellow pine, well painted. 

Interior Finish. — The interior finish of food compartments shall 
be lined with highest grade of one-piece porcelain fused on steel. Ice 
or coil compartment shall be lined with No. 24 gauge sheet iron, 
finished with white refrigerator enamel. 



362 CORK INSULATION 

Doors. — Door fronts to be as per manufacturer's standard for 
model selected, (a) Door fronts shall be covered with lacquer fin- 
ished pressed steel to match exterior front finish of refrigerator, (b) 
Door fronts shall be of five-ply veneered wood, flush panel type, 
finished to match exterior front of refrigerator. 

Shelves. — All refrigerators shall be equipped with bar steel shelv- 
ing, electrically welded, heavily tinned and easily removable for 
cleaning. 

Hardware. — All hardware shall be of substantial pattern nickel 
plated bronze. All fasteners shall be of self-closing bar or roller 
type. 

Circulation System. — Ice or coil compartment shall be on left top 
side of refrigerator, well bafifled to insure good circulation of cold 
air, and to have suitable water-sealed drain pipe to outside of unit. 

Base or Foundation. — Refrigerators to have wood base approxi- 
mately four inches high. Ball bearing casters to be supplied where 
necessary. 

Special Equipment. — Special base for enclosure of automatic re- 
frigeration machine to be furnished on order and same to be finished 
to conform with body of refrigerator. Hasps for locks to be fur- 
nished on order, but locks will be furnished by others. 

Detailed Specifications. — All refrigerators shall be constructed of 
100% pure compressed cork-board insulation and thoroughly kiln-dried 
lumber, especially selected and well adapted to the service required. The 
cork-board insulation shall be inserted in a substantial and well braced 
wood framing, all seams of the cork-board to be sealed with odorless, hot 
asphalt cement, each side then covered with heavy, waterproof, odorless 
insulating sheathing, forming sections in which the insulation has been 
hermetically sealed, ready to receive finishing sheathing on both sides 
of the sections. The thickness of cork-board insulation shall be as 
indicated. 

The finishing sheathing on the exterior of all refrigerators shall be 
approximately 13/16-inch thick and consist of suitable material to give 
desired exterior finish. 

All wood surfaces exposed to view, which are to be finished in 
natural wood or stained to match other trim, shall be well sanded and 
finished with one coat of filler, one coat of shellac and two coats of best 
refrigerator varnish. 

Refrigerators for All Purposes. — There is a McCray Refrigerator 
for every purpose, the result of 37 years of experience. 

Manufactured by McCray Refrigerator Co., Kendallville, Indiana. 

GIBSON "ALL PORCELAIN" REFRIGERATORS. 

General Description. — The Gibson "All Porcelain" refrigerators are, 
without doubt, the finest in the country. The beautiful exteriors and 
interiors of dazzling white porcelain are immaculate, sanitary and dur- 



CORKBOARD INSULATED REFRIGERATOR 



363 



able. The new Gibson cast aluminum door frame construction (patent 
pending) is one of the greatest advances that has been made in refrig- 
erator construction in years. It prevents warping or swelling of the 
doors and insures many years of added life to the refrigerator. 

Interior. — Three models are equipped with galvanized iron lined ice 
compartments and seamless porcelain provision compartments. All other 




171.— GIBSON REFRIGERATOR DOOR CONSTRUCTION, SHOWING 
CORKBOARD INSULATION. 



models have porcelain lined ice compartments. All doors are lined with 
porcelain door plates. 

Insulation. — The Gibson "All Porcelain" refrigerators are insulated 
with 100 per cent, pure cork-board, sealed air-tight with hydrolene cement 
and, in addition, have many layers of waterproof asphalt saturated char- 
coal sheathing, insulating felt, and polar board. The insulation and wall 
construction is unexcelled for economy of ice consumption or efficiency 
when used in cmncc' '(^ii wi'.h electric refrigeration. 

Hardzcare. — The locks and- hinges are heavy cast manganese bronze, 



364 CORK INSULATION 

triple nickel-plated and highly polished. The doors are all equipped with 
Wirf's air-tight cushion gaskets. 

Shelves. — The new Gibson flat wire shelves (patent pending) are 
used in all models. They are easier to clean and dishes slide on them 
without tippi^jg. 

Electric Refrigeration.- — Leading manufacturers of electric ice ma- 
chines have approved the "Gibson" for use with their machines. Ice 
machine bases arc carried in stock for Gibson "All Porcelain" refrig- 
erators. The Gibson "All Porcelain" refrigerators are equipped with 
hangar bolts and sleeve outlets, so they are suitable for present ice needs 
and future electric refrigeration requirements. 

All Metal Refrigerators. — A line of Gibson "All Metal" refrigerators 
have an outside case of heavy galvanized steel finished in white enamel, 
with other attractive features. Gibson's "One-Piece" porcelain line of 
white porcelain lined refrigerators has merited great favor. 

iManufaclured by Gibson Refrigerator Co., Greenville, Michigan. 

SEEGER ALL-PORCELAIN REFRIGERATORS. 

Circulation. — A major feature of efficiency in the Seeger refrigerator 
— a remarkaljlc food, ice and power conserving device, whether ice or 
electrical refrigeration is used — is the Seeger system of air circulation, 
the original "Siphon System." It is installed only in Seeger refrigerators 
and accomplishes the successful preservation of foods and the necessary 
low temperature with a minimum consumption of ice or electricity. 

The Seeger original siphon system, briefly, continuously keeps in cir- 
culation, throughout the interior, a vigorous current of air that is dry 
and clean, and keeps the refrigerator's every nook and corner pure and 
sweet at all times. 

The siphons form a partition between the ice or cooling unit cham- 
ber and the food chambers. The cold air — heavier in the ice or cooling 
unit chamber than in the food compartments — continuously sinks to and 
through the grate beneath the ice block or cooling unit, then to the 
slanting deflector plate that is seen beneath the grate. Next the de- 
flector plate projects the air into the food chamber. In the food cham- 
bers the air expands, and in so doing consumes any and all heat atoms 
that are existent there, and picks up all odors, moisture and impurities. 

Finally, the siphons draw the air back into the ice or cooling unit 
chamber where all the odors and impurities that have been gathered 
up are condensed and drained off with the water from the melting ice 
or cooling unit. So long as any ice remains the circulation continues. 

Insulation. — Seeger all-porcelain refrigerators are insulated with pure 
sheet corkboard, 2 inches thick laid between four sheets of waterproof 
paper. 

Interior. — The new seamless, one-piece porcelain interior is made in 
our own factories, of vitreous porcelain on Armco iron and is in one 
entire piece, including food chambers, ice chamber and drip pan. The 
corners are round and the surface is guaranteed non-chippable. A new 



I 



CORKBOARD INSULATED REFRIGERATOR 



365 



improvement is the providing of fastenings, as part of the interior lining, 
for the hanging of electrical refrigeration units. 

Exterior. — The exterior is of the same vitreous porcelain as the in- 
terior and is finished with nickel-silver (German silver) trimmings. The 
porcelain exterior surface, like that of the interior, is guaranteed non- 
chippable. 



^ 




-SEEGER ORIGINAL SYPHON SYSTEM CORK INSULATED 
REFRIGERATOR. 



Hardware. — Each door, large or small, is fitted with locks and hinges 
exactly suited for each refrigerator's requirements. All locks are of 
solid brass and of roller type, fitted with non-breakable springs. 
Where rubber covered compression gaskets are used, the hinges are of 
spring brass and are fitted with steel bushings, washers and pins. Where 
no gaskets are used, the hinges are solid brass. 

Manufactured by Seeger Refrigerator Company, St. Paul, Minnesota. 



366 CORK INSULATION 

JEWETT SOLID PORCELAIN REFRIGERATORS. 

Refrigerator Principles. — Jewett Solid Porcelain refrigerators com- 
bine all four basic essentials by which the true value of any refrigerator 
may be judged: (1) Absolute sanitation, without which no refrigerator, 
regardless of its other features, is safe as a storage place for food; (2) 
Efficient insulation, an unseen essential which really determines the cost 
of operating the freezing unit and the number of years of service it will 
render; (3) Perfect circulation, which produces dry, crisp air in the 
refrigerator instead of a damp, mouldy atmosphere ; and (4) Durable 
construction, without which a refrigerator soon wears out and is a 
poor purchase no matter how cheap its initial price. 

TJie Famous Solid Porcelain Interiors. — It is unfortunate that the 
descriptions of refrigerator linings have never been standardized like 
the nomenclature of bathroom equipment. "Jewett" solid porcelain lin- 
ings are moulded from selected clays with a highly glazed china finish 
fused on the surface in our pottery. All other so-called "porcelain" 
linings are made of thin sheet metal with a coating of enamel painted 
or baked on them. There is just as vast a difference between them 
and "Jewett" linings as between a solid porcelain bathtub and an enam- 
eled iron one. 

These solid porcelain linings are an inch and a quarter thick and 
even without the super-insulation that surrounds them, these crocks alone 
would store up the cold and maintain low temperatures more uniformly 
than most complete refrigerators. 

Insulation. — The illustration shows the construction of the walls, floors 
and ceilings of "Jewett" solid porcelain refrigerators. The aggregate 
thickness is S-Y% inches, which is almost double the thickness of tTie 
wall construction used in any other refrigerator. 

The exterior case is of solid ash, carefully doweled and glued ; next 
come two courses heavy waterproof insulating paper, then a 1-inch sheet 
of pure cork, then two more courses heavy waterproof insulating paper, 
then a course of ^-inch tongued and grooved lumber, then \y^ inches 
more of pure cork, then a course of waterproof insulating paper, then the 
solid porcelain lining 1-^ inches thick. 

Outside of the two courses of lumber necessary to give the proper 
strength and rigidity, the insulation of the "Jewett" solid porcelain re- 
frigerator consists entirely of pure cork, which is the most efficient form 
of insulation known. 

Circulation. — A dry atmosphere in a refrigerator is essential for the 
preservation of food. In a refrigerator with poor or no ciculation, all 
things are damp, moist and moldy. Then there is an odor. Dryness 
prevents all these things. 

The cold air ducts and warm air flues in the "Jewett" solid porce- 
lain refrigerators are designed to take advantage of the well-known 
principle that cold air falls and warm air rises. On account of its 
greater weight, the cold air descends from the ice compartment into the 
food compartment below, and forces the warmer air in the upper part 



CORKBOARD INSULATED REFRIGERATOR 



367 




FIG. 173.— SECTION OF JEWETT SOLID PORCELAIN REFRIGERATOR 
SHOWING CORK INSULATION. 



368 CORK INSULATION 

of the opposite compartment over on to the freezing unit where the 
heat, moisture and odors are absorbed by condensation. After being 
cooled and purified, the air again descends and passes through the re- 
frigerator back to the ice chamber, thus forming a vigorous and con- 
tinuous rotation of the entire atmosphere in the refrigerator. 

The design of the "Jewett" ice compartment is radically different from 
the type prevailing in ordinary refrigerators. Being suspended in the 
metal rack, the freezing unit is constantly surrounded by air and the 
cold air falls easily from all the sides as well as from the bottom. 

Exterior Finish. — The outer case is made of thoroughly seasoned 
brown ash carefully doweled and glued. Solid ash is particularly adapted 
for refrigerator purposes because it is less affected by changes of tem- 
perature and humidity than almost any other wood. 

"Jewett" refrigerators are made in three standard finishes. Finish 
A — exterior of natural color, carefully selected, straight grain, brown 
ash with three coats of varnish. Finish B — exterior painted with five 
coats of white enamel. Finish C — exterior of white opaque glass 7/16- 
inch thick, secured with heavy, solid nickel-silver (not nickel plated) 
trim, highly polished. 

When special finishes are desired, we can furnish the cases with 
three coats of flat white which can be enameled to match surrounding 
woodwork. Or we can build the exterior of any wood desir.ed and 
finish to sample or ship without stain for finish upon installation. 

Hardware. — "Jewett" refrigerators have always been famous for the 
quality and durability of their hardware. The doors are secured by lever 
fasteners that close automatically with the slamming of the door, pre- 
venting the condensation (commonly called "sweating"), swollen jambs, 
etc., which result when doors are not tightly closed. 

The hardware on natural or grey finish "Jewetts" is solid brass, highly 
polished; on white enamel or opaque glass finish it is solid nickel-silver 
(not nickel plated), and is much heavier and more substantial than the 
hinges and latches on any other make of refrigerator. 

Doors. — No matter how well the rest of a refrigerator is built if 
the doors are light and poorly insulated or do not fit tight it cannot be 
a safe and efficient storage chest for your food. The doors on a 
"Jewett" are heavy, substantial and well insulated. They are made of 
solid ash with plain exterior faces; no veneer to peel off; no moldings 
or panels to catch dust; no chance that they will warp or sag. They 
have heavy %-inch overlaps on all sides instead of the usual 5^-inch 
or J/^-inch overlap on ordinary refrigerators and this permits the use 
of a heavy, live-rubber (not fabric) compression gasket which makes 
the doors absolutely air tight. 

Shelves are constructed of ^-inch rod spot welded to 5/16-inch cross- 
bars heavily coated with pure block tin after fabrication. These shelves 
rest on ribs moulded into the porcelain lining and are easily removable 
for cleaning. 

Manufactured by Jewett Refrigerator Co., Buffalo, New York. 



CORKBOARD INSULATED REFRIGERATOR 



369 



REOL "LIFETIME" REFRIGERATORS. 

Construction. — Custom-built to endure. Solid frame-work of ash 
posts, with cross-members of equal strength and durability. Vertical 
posts run the full height of the box reinforced at bottom with pressed 
steel angles. Heavy uiano-type casters are set into lower end of these 
posts. Interlocking joints, rigidly securing the cross members to 




IFIG. 174.— DETAILS OF CONSTRUCTION OF REOL CUSTOM BUILT REFRIG- 
ERATOR— ARROWS (3) POINT TO CORKBOARD INSULATION 
AND (4) TO ASPHALT CEMENT. 

the vertical members. Glued and screwed into a rigid solid foundation 
to hold the balance of the structure. Cores for doors milled from one 
solid piece of ash, made so that they will fit closely and not warp. 
Rabbits on the doors, fitting into ledges on the framework, effectually 
diminishing leakage. 

Insulation. — Two inches of solid sheet cork, fastened securely to 
the framework. Fits close at all sides, forming an efifective and per- 
manent barrier against the passage of heat, and protected with heavy 



370 CORK INSULATION , 

waterproof coating. Solid insulated doors, with extra insulation fill- j 
ing out air space formed by vitreous porcelain lining. Insulation | 
extends through front stiles and rails, thus eliminating, to a large { 
degree, one of the points where heat leakage is most evident in i 
ordinary refrigerator construction. Insulated baffle board, directing j 
downward the flow of cold air, and affording complete circulation and i 
even temperatures in all sections of the food compartment. 

Interior. — Extra heavy, one-piece vitreous porcelain crock fused i 
on heavy rustless Armco iron, with corners rounded and curved lips '< 
provided at front, making the inside sanitary and easy to clean. Extra ' 
heavy interwoven steel wire shelves, rust-proof. | 

Exterior. — Flush hardwood exterior, with sections firmly joined \ 
together to form one solid piece. Top set flush, making a smooth ' 
finish. Rounded corners at top. Heavy and substantial hardware i 
that is solidly fastened to the framework, operates easily and amply 
supporting doors when open or closed. Springless latches that are ; 
self-closing, without effort or slamming. 1 

Manufactured by Reol Refrigerator Co., Baltimore, Maryland. ! 

BELDING-HALL "ALL PORCELAIN EXTERIOR" 

REFRIGERATORS. \ 

Description. — Belding-Hall all porcelain refrigerators are constructed i 

with porcelain exterior and one-piece seamless porcelain lined ice and | 

provision chambers. Insulated especially for mechanical refrigeration. ! 




FIG. 175.— CORNER SECTION OF CORKBOARD INSULATED nELDING-IIALL 
REFRIGERATOR. 

Materials. — The best grade of 18-gauge Armco Rust Resisting Ingot 
Iron is used throughout. The lumber used in the construction of the 
walls of these cases, also in the doors, has been chosen with care to 
avoid swelling from climatic changes. 

Insulation. — The corner section illustration shows our 2-inch cork- 
board insulation, and all joints and corners are filled with an odorless 



CORKBOARD INSULATED REFRIGERATOR 



371 



pitch which prevents air leakage as it seals all the crevices where the 
cork cannot fit absolutely tight. The door construction is identical with 
the walls of the refrigerator. 

Hardware.— AM locks, strikes and hinges, as well as all screws, are 
heavy solid brass, nickel-plated, of the latest and most efficient design. 
The trimming around the doors and corners of the refrigerator is heavy 
aluminum, nickel-plated. 

Metal Ice Rack. — One of the greatest improvements is our solid 
metal ice rack for which we claim, and the trade concedes, many points 
of excellence. Also, our new air trap. 

Manufactured by Belding-Hall Electrice Corporation, Belding, 
Michigan. 



SCHROEDER "THERMO FLO" REFRIGERATOR. 

Refrigerating Unit. — The Inman Thermatic unit which operates on 
nature's thermo-syphon principle is described in detail as follows : Tank 

TANK B 



TANK A 



(SU^ 



dH^ 




FIG. 176.— SCHROEDER THERMO EI O REFRIGERATOR TANKS. 



B fits inside of tank A as shown in the illustration. The ice is placed 
in tank B and cold water is poured over the ice until it reaches the 
level of the lower row of holes in Tank B. As the colder water seeks the 



372 



CORK INSULATION 




CORKBOARD INSULATED REFk'IGERATOR 



Z72, 



lower levels this immediately creates a circulation of water from top to 
bottom of ice chamber. This circulation is maintained as long as there 
is even a small piece of ice in the tank. Tank B has 54-inch corruga- 
tions vv^hich increase the cooling area of the ice compartment from 2550 
to 7072 square inches — or nearly three times the area of a flat surface. 
As the ice melts the over-flow is carried off through a row of holes near 
the top of one side of tank A. Inasmuch as the warmer water rises to 
the top and is carried off through these holes, the coldest water always 
remains in the refrigerating unit. The over-flow is carried off through 




FIG. 178.— SCHROEDER THERMO FLO REFRIGERATOR. 



a drain at the bottom of the ice chamber. The fact that it utilizes 
water as a refrigerant in addition to the ice, results in: (1) Uniform low 
temperature; (2) Practically 100% efficiency out of every piece of ice; 
(3) Economical consumption of ice. 

Circulation of Air. — The circulation of air within the refrigerator is 
'always at the maximum because the refrigerant is always above the 
insulated baffle plate which separates the ice and food compartments. 
When ice alone is used as the refrigerant, the circulation of air dimin- 
ishes as the ice melts away below the top of the bafile plate. The cir- 
culation of air is a highly important factor in maintaining constant, low 
temperatures. 

Insulation. — In order that the thermatic unit may function at its 
highest efficiency, the influence of outside temperatures and air currents 
must be field to a minimum. For this reason 2-inch sheet cork, laid in 
mastic asplialt is used in all walls and doors. 



374 CORK INSULATION 

Top Iccr. — The Thermo Flo is a top icer due to the thermatic unit. 
This feature eHminates the customary abuse, by the housekeeper, of 
putting all kinds of foods in the ice compartment. 

Reserve Compartment. — The reserve compartment above the food 
chamber is entirely separate from the rest of the refrigerator. It is 
designed to hold reserve ice, chipped ice, or for special cooling purposes. 
Its drain connects with the main drain pipe. 

Exterior Finish. — The outer cabinet of the Thermo Flo refrigerator 
is built of selected ash, and reflects the skill of master cabinetmakers. 
A variety of finishes including white and gray lacquer are furnished 
as specified. Only high grade fittings and hardware are used. Self- 
locking door handles are standard equipment. 

Interior. — The interior is finished in white enamel of highest quality. 
Three shelves in the food compartment are made of heavily tinned wire. 

Humidity. — The fact that the Thermo Flo uses both ice and water 
results in just the right amount of humidity for proper food preservation. 

Size. — The Thermo Flo refrigerator is made in two sizes, the 50- 
Ib. re-icer and the 75-lb. re-icer, requiring 75 lbs. and 100 lbs. original 
icing, respectively. The 50-lb. re-icer has outside dimensions of 
33^x22^x52^ inches and a food compartment capacity of 6 cubic feet. 
The 75-lb. re-icer has outside dimensions of 38^x22^x52j/2 inches and a 
food compartment capacity of 8 cubic feet. 

Manufactured. — The Thermo Flo refrigerator is manufactured by 
the same organization which introduced the JaSeL ice box and the Na- 
tional ice chest — The J-S Refrigeration Division of the John Schroeder 
Lumber Co., Milwaukee, Wisconsin. 

SERVEL ELECTRIC REFRIGERATION FOR 
HOUSEHOLD USE. 
Exterior. — The Servel new steel cabinets are constructed of espe- 
cially selected "Armco" steel carefully lead-coated as an absolute pro- 
tection against rust. The steel shell is given two applications of oil 
base primer coat, after which the ground coat is slowly and carefully 
baked on under a low temperature, producing a finish which will neither 
peel nor scale. Next, several coats of genuine white Duco are applied, 
which are each allowed to air dry. The slow process of air drying, 
while it creates an additional factory cost, produces a much better ap- 
pearing and more lasting finish than can ever be expected under artificial 
or forced drying. 

Interior. — The porcelain liners are of the box type, and are so con- 
structed, with double lock flanges, that bolt holes or screw holes are 
entirely eliminated except those required for tank and shelf supports. 



CORKBOARD INSULATED REFRIGERATOR 



375 



This produces an absolutely sanitary liner and eliminates all chance of 
flaking of the porcelain finish, due to uneven strain such as results 
from the use of screws or bolts. 

Chilling Unit. — The chilling units are of tinned copper and have 
front panels and ice cube tray-fronts of genuine porcelain. 

Insulation. — The insulation is, of course, pure compressed corkboard 
thoroughly impregnated with hydrolene, U/i inches thick on top and sides 
on the S-5, 2 inches thick top and sides on the S-7 and S-10; with a 
3-inch bottom thickness on all models. 




FIG. 179.— SERVEL ELECTRIC CORKBOARD INSULATED REFRIGERATOR. 

All seams in the corkboard are filled with hydrolene. Waterproof 
paper is then applied over the corkl)oard as added seal against air leaks. 
The insulation is applied against the liner, and there is an air space of 
from 34-inch to 3^-inch between the insulation and the exterior metal. 

Manufactured by the Servcl Corporation, Evansville, Indiana. 



i 



376 



CORK INSULATION 



COPELAND "DEPENDABLE" ELECTRIC REFRIGERATORS. 

Model. — No. C-5-P; 60^/4 inches high, 22 inches deep, 28 inches wide. 
(One of 5 models for small homes and apartments. Also two styles of 
mode! No. 215, with machine overhead and covered with hood ; also four 
Copeland-Seeger models.) Construction, rugged and accurately mortised. 

Interior. — White, vitreous porcelain, with rounded coves. Ice cube 
drawers have bright metal finish. Ice cube cap.icity, 90 cubes, or 6 
pounds at one freezing. Shelf space, 7.64 square feet ; shelves, woven 



I 




Cross section through wnll of box shoicing 

insulation — Solid corkboard, 3-ply wood 

•panel and water-proof ing felts 

-EXTERIOR VIEW AND WALL SECTION OF COPELAND ELECTRIC 
REFRIGERATOR. 



wire, retinned. Food storage capacity, 5 cubic feet. Defrosting receiver 
eliminates drain pipe. 

Insulation. — Two inches solid corkboard, walls, top, door and bottom, 
hermetically sealed and moisture-proofed by special hydrolene treatment 
and protected by all-metal sheathing, prevents odors and deterioration. 

Exterior. — Exterior finish, white pyroxylin lacquer on steel. Trim, 
bright metal molding. Hardware, extra-heavy automatic. 

Refrigeration. — Efficient % horsepower motor ; quiet operation, well- 
designed valves, accurately fitted bearings, high grade materials, skilled 
workmanship, exceptionally fine inspection, most efficient of its kind 
Connects with electric light socket. 

Manufactured by Copeland Products Co., Detroit, Michigan. 



CORKBOARD INSULATED REFRIGERATOR Zll 

157. — Notes on the Testing of Household Refrigerators. — 

While there are no g-enerally accepted and approved methods 
for the testing of either ice or machine cooled household re- 
frigerators, and \irtuall}' all tests made thus far are subject 
to considerable interpretation as to the results obtained. }et 
nuich progress has been made and there is reason to expect 
that some suitable and satisfactory standard method of testing 
household refrigerators may soon be arrived at and be gener- 
ally accepted by those most interested in the su1:)ject. 

The Chicago Tribune originall)' published some data and 
suggestions by Dr. A\\ A. Evans for a practical "Refrigerator 

'. Score Card," for refrigerators using ice, which Forest O. Riek 
later combined with data from various sources, including the 
U. S. Bureau of Standards and the Good Housekeeping Insti- 
tute, to produce a refrigerator score card substantially as 

I follows : 

REFRIGERATOR SCORE CARD. 

Xame of manufacturer 

Name or other method of designaling refrigerator 

Te'it Item : Perfect Scot? 

1. Temperature of food cham'ier 45% — — % 

2. Ice economy 20 — — 

3. Humidity 8 

4. Circulation • 7 — — 

5. Interior finish 12 — — 

6. Drainage 3 — — 

7 Exterior finish 5 — — 

Total lOOP'o % 

EXPEAXATIOX OF SCORE' CARD 

1. Tciiipcralurc Test — Standard conditions for test demand rcfrig- 
I erator to be in a rooin free from drafts and at an even temperatnrc. Box 
' should not contain food. Door ■should not be oriened except when taking 
: readings. Refrigerator shoi.'d be thoroughh- chilled for 4S hours l)cfore 
I making test. Have the ice chamber full. Place thermometer in the ccn- 
"tcr of the food chamlier. ^lake twelve readings at intervals of one hour. 

Take room temperature simultaneously. Score as follows: 

SCORE FOR TEMPERATURE 

Temperature, F Rate 

40° 45 

45 43 

50 36 

55 23 

60 9 

over 60 

2. Ice Ecfliioiiiy. — Refrigerator should be thoniugblx chilled for 48 



378 CORK INSULATION 

hours before starting test. Weigh ice at the start of test proper. Weigh 
ice left at termination of test proper. Obtain data: 

(a) Temperature of food chamber (t). 

(b) Temperature of room (T). 

(c) Square feet of surface exposure (S), calculated on exterior di- 
mensions. 

To determine Ice Economy, substitute in the following formula: 
IX 144 

R = 

Sx (T— t) 
where R is the rate of heat transmission, which may be defined as the 
number of B.t.u. that pass through one square foot of surface daily when 
the difference between the surface is 1° F. ; I is the number of pounds 
of ice melted daily; 144 is the B.t.u. required to melt one pound of ice; 
S is the surface exposure; T is the average atmospheric temperature; 
and t is the average temperature of food chamber. Score as follows : 

SCORE FOR HEAT TRANSMISSION 
Value for R Rate 

1.13 20 

1.63 18 

2.0O 16 

2.33 14 

2.66 12 

3.00 10 

3.33 8 

3.66 6 

4.00 4 

4.33 2 

4.66 1 

5.00 

3. Humidity. — In making humidity tests, a wet and dry bulb ther- 
mometer should be used. Take twelve readings at intervals of one hour. 
See U. S. Bureau of Standards' tables* for readings calculated upon dif- 
ferences in temperatures of wet and dry bulb thermometers. Score as 
follows : 

SCORE FOR HUMIDITY 
Humidity Rate 

55 to 65% 8.0 

65 to 76 7.5 

45 to 55 7.5 

40 to 45 7.7 

75 to 80 6.4 

30 to 40 6.0 

80 to 85 4.8 

20 to 30 4.8 

85 to 95 2.4 

90 and over 0.0 

20 and under 0.0 

4. Circulation of Air. — ^Credit a maximum of 5 for probability that 
cold air will readily pass from the ice compartment to and through the 
food compartment and back again to the ice. If ice compartment is 
ample, credit 2. If doors do not fit snugly, subtract 1. If any wall is 
moist, subtract 3. 

5. Interior Finish. — Ease of cleaning refers to cleaning of food cham- 
ber, all shelves therein, and the drain pipes. If ease of cleaning is ideal, 
credit 5. If interior finish is hard and non-absorbent, credit 2. If color 
is white, credit 5. 

*See Appendix for tables mentioned. 



CORKBOARD INSULATED REFRIGERATOR 379 

6. Drainage. — See that the trap in the drain pipe works. If there is 
proper trapping, credit 2. If there is proper tubing, credit 1. 

7. Exterior Finish. — If exterior, including doors, has soHd surface, 
easily cleaned, credit 1. If finish is durable and lasting, instead of easily 
flaked or chipped, credit 2. If hardware is simply constructed, durable 
and easily handled, credit 2. 

John R. Williams, M.D., carried on considerable research 
into refrigeration in the home to obtain data for a paper to 
be presented before the Third International Congress of Re- 
frigerating Industries. Dr. Williams obtained considerable 
interesting information in reference to the construction and 
performance of household refrigerators in actual use, the 
room temperatures under which they operate, the box tem- 
peratures at which food is stored, the relative amounts of ice 
used, and so forth. He points out most emphatically that 
the weakness of most "ice boxes" is in poor insulation, having 
found that very few refrigerators in common use have an 
efficiency above 25 per cent. He says : 

Indeed the low priced boxes used in the homes of working people are 
probably less than 15 per cent, efficient. This means that of 100 pounds 
of ice put into a refrigerator, at least 80 pounds were used in neutralizing 
the heat which percolates through the walls. It is worthy of note that the 
market is flooded with these shoddy ice boxes. No less than 75 different 
makes were found among the 243 examined. 

The U. S. Bureau of Standards, the New York Tribune 
Institute, the University of Illinois, the Good Housekeeping 
Institute, the National Electric Light Association, the Armour 
Institute of Technology, the Geo. B. Bright Engineering Lab- 
.oratory, and probably many others, have performed interesting 
and valuable tests on ice and mechanically cooled refrigera- 
tors. The methods of testing have varied so widely, how- 
ever, that the results of one laboratory are not safely com- 
parable with the results of another; and it is in the direction 
of standardization of method of testing, so as to make the 
results of all properly conducted tests readily and safely 
available for comparison, that attention should be given. 



380 CORK INSULATION j 

Household refrigerators, as at present produced, may be 1 
dhided into three main classes: 

(a) Ice cooled. ' 

(b) Ice or mechanically cooled. { 

(c) Mechanically cooled. i 

I 
It is not, in general, satisfactory to design and build refriger- 
ators for dual service; that is, a refrigerator correctly designed 
for mechanical cooling may possibly be adjusted to ice, but 
the average ice refrigerator, though satisfactory with ice, 
usually is not satisfactory when mechanically cooled, for rea- j 
sons having to do with temperature and insulation, as elabo- j 
rated throughout this Chapter, and for still other reasons to be ! 
noted. Tlie ice cooled refrigerator, on the one hand, aims to : 
fulfill one major function: j 

1. To maintain at a suitable and reasonably uniform temperature a ! 
compartment for the storing of ]ierishable foodstufifs. i 

The mechanically cooled refrigerator, on the other hand, must ; 

fulfill an additional major function: I 

2. To supply at all times cul)e-ico lor table use. 1 
These functions are sufiiciently unrelated, or require sufficient j 
correlation, as to make the two types of refrigerators some- ; 
what dissimilar in design. Consequentl}', for the present, all j 
tests on household refrigeratt)rs should be made from the 
standpoint of either ice cooling or mechanical cooling. 

Considering first the ice cooled refrigerator, it is well 
understood that a "suitable" temperature must of necessity 
fall within a higher zone than would be possible with mechan- 
ical refrigeration, which higher zone of temperatures has both 
its advantages and its disadvantages. It imposes a narrow 
limit of safet}' for temperature fluctuations from the zone of 
satisfactory temperature operation; ])ut it provides a tem- 
perature zone in which miscellaneous "moist foods" may be 
stored in the same compartment with the minimum loss of weight 
and natural flavor, and, because of the air purifying process 
constantly carried on by the absorption of odors by the water 
of ice meltage, it guarantees against the tainting of one food 
from the odors of another. 

The temperature of melting ice being Z2° F., the coldest 
air dropping into the t'ood compartment will range from about 



CORKBOARD INSULATED REFRIGERATOR 381 

40° to 50° F., depending on the amount of ice in the ice 
chamber, the rate of air circulation, the room temperature and 
humidity, and the insuhition of the refrigerator. The rise in 
temperature of the air in passing through the food compart- 
ment may range front 10 to 20 degrees, circulation, room 
temperature and insulation being the determining factors. 
United States Government tests* on a number of standard 
refrigerators show that the comparative rate of air flow in 
nine different refrigerators varied as much as 100 per cent 
under identical operating conditions. A wide range of tem- 
perature between the coldest and the warmest points in the 
food compartment indicates sluggish air circulation, if ice 
supply is adequate, not active air circulation. The \'ariation 
in the food comj)artment temperature of an ice refrigerator 
should not l)e more than about 10 degrees ; because since 40° 
F. is about the lowest temperature to be reasonably expected, 
50° F. would then be the highest temperature, and 50° F. is 
near the temperature limit at which many perishable food- 
stuffs can be safely preserved. 

The refrigerator using ice may be expected to have an 
average temperature in the food compartment from 20, or 25. 
to 35 degrees lower than the room temperature, but only the 
better types of refrigerators will ap])r()ach the 35 degree tem- 
perature difference with a good su])ply of ice in the ice com- 
partment and the room temperature at about 90° F. The 
average temperature of the food compartment of the better re- 
frigerators under such conditions would then be about 55° F., 
and in the poorly constructed ones the average temperaHu'e 
would be 65° F. or more. 

The average temperature of the food compartment of an 
ice cooled refrigerator ma}' be reduced in three ways : 

1. By breaking u]i the ice in the ice compartment so as to expose more 
surface to the circulating air. 

2. By increasing the air circulation. 

3. By increasing the insulation in the walls of the refrigerator. 

If the ice is broken up to expose more surface to be melted 
and thus cause more heat to l^e absorbed from the circulating 
air of the refrigerator, a lower temperature will be produced 

*U. S. Bureau of Standards Circular No. 55. 



382 CORK INSULATION 

at the daily expense of labor and ice ; and some improvement I 
may be effected by the manufacturer through a change in { 
the interior design of the refrigerator that will locate the ice 
compartment in a top-center position, and at no additional 
expense; but by increasing the thickness of permanently effi- j 
cient insulation in the walls of the refrigerator, at a low per- > 
centage of increase in manufacturing cost, the food compart- 
ment may be so effectively isolated from outside heat influ- 
ences as to make the maintenance of correct temperatures by 
the melting of ice a practical matter even on the hottest and 
the most humid days of the year. Experience has safely fixed 
this insulation at three inches of pure corkboard, when prop- 
erly incorporated in the construction of the refrigerator. 

From these few observations, it would appear to be of but 
limited value to test poorly designed and badly constructed 
refrigerators that are to be cooled with ice. Consequently, 
the first point to cover in planning for a test of an ice refrig- 
erator should be a careful investigation into the design and 
construction of the unit; and if this research reveals a lack 
of reasonable consideration for basic principles of design and 
construction, as they are then generally known and under- 
stood, there probably will be good reason to abandon the 
intention to perform the test. Otherwise, the following test 
conditions should be observed : 

(a) Refrigerators of identical shape and size must be selected for 
comparative test purposes. It is suggested that standard sizes be deter- 
mined upon for a top-icer apartment refrigerator, a side-icer small resi- 
dence refrigerator and a center-icer large residence refrigerator, and that 
all future tests be run on refrigerators as near those sizes as possible. 

(b) A constant temperature room should be used, the temperature 
held uniform to within one degree Fahr. by electric heater placed within 
hollow walls of the test room and controlled by thermostat. A room tem- 
perature of at least 85° F. is suggested for test purposes. 

(c) Control of the humidity of the constant temperature room should 
be effected by suitable means, tests having demonstrated that a consider- 
able increase in the percentage of ice melting is effected by increasing the 
percentage of relative humidity in a constant temperature room from a low 
to a high point. 

(d) The ice should be carefully regulated on the basis of weight, and 
of one piece, of size or shape suitable for the ice compartment of the 
class of unit tested. 

(e) The ice should be only hard, "black" ice. 



CORKBOARD INSULATED REFRIGERATOR 



383 



(f) The ice should be prepared outside the test room, and placed in 
the refrigerator during a fixed period, at the same hour, every day (24- 
hour icing), old ice to be removed and weighed simultaneously. 

(g) The food compartment of the refrigerator should be empty, it 
being known that over 90 per cent, of refrigerator losses are caused by 
the heat leakage through the walls of the refrigerator, and less than 10 
per cent, in cooling food and opening doors, under normal household 
operation. 

(h) Record of refrigerator temperatures should be made every hour, 
by suitable means, such record to be taken at three designated points in 





^ 


^- - — , 




1 

1 

I 




<:r^ 




THERMOST>Or 6WITCH AND 


1 

f 

1 


FOSES FOR HEATERS 






ACBtSTOS — 
LINED 

ELECTRIC- 
HEATERS 

RlMOVABLt 




RCFRIQeRAToa 




ooot< -^ 


r ^ 


-^ — 







181.— CONSTANT TEMPERATURE TESTING ROOM— HOLLOW 
WALL TYPE. 



the food compartment of the apartment refrigerator, at four points in the 
small residence refrigerator and at five points in the large residence 
refrigerator. 

(i) Record of the relative humidity of the food compartment should 
be made simultaneous with temperatures, by suitable means. 

(j) Drip water should be weighed every hour, and the record used as 
a check on the actual weight of ice melted during the test. 

(k) Three days preliminary operation should be allowed to establish 
a temperature equilibrium in the walls of the refrigerator before the test 
proper should be started, and the test should then continue for 30 more 
days. 

Tests performed under standardized conditions, values for 
such standards to be fixed upon a practical basis for test 



384 CORK INSULATION 

purposes and a basis most nearly conforming to the practices 
of the ice industry as regards service to the household, should 
be comparable, as to ice consumption, food compartment 
temperatures and humidity. And if to such test results is 
appended a record of the exact condition of the refrigerator 
wall construction, as to moisture, observed immediately after 
the conclusion of the 30-day test by cutting all the way 
through the wall construction to the interior lining, the ability 
of the refrigerator to maintain its efficiency will be more easily 
predicted. 

Considering next the mechanically cooled refrigerator, the 
operation of the apparatus is intended to be automatic but 
conditions arise at times that make the simultaneous carrying 
on of its two major functions, previously mentioned, almost 
impossible. In designing the automatic control, a compromise 
is therefiore effected in order to obtain the best all 'round per- 
formance possible. 

By pressure or thermostatic control, the temperature of 
the cooling element is held at a more or less constant tem- 
perature at all times, because of the necessity of producing 
cube ice, instead of the machine being automatically controlled 
directly by the temperature of the food compartment. 

It is thus apparent that the commonly used method of 
control is not capable, without readjustment, of maintaining 
a constant temperature in the food space under wide varia- 
tions in room temperatures, such as are occasioned by the 
hour of the day or the season of the year. In general, there 
may reasonably be expected a three degree change in refrig- 
erator temperature for each ten degrees alteration of room 
temperature, which will give some idea of the probable tem- 
perature fluctuation in the food compartment of a fair quality 
refrigerator under any given adjustment of automatic control. 
If the unit operates in a heated room where the temperature 
is subject to but slight variation day or night, winter or sum- 
mer, its regulation is likely to be fairly good, without making 
seasonal adjustments of the regulating device ; but under 
conditions not approaching such an ideal, foods are likely to 
be either frozen or insufficiently cooled. 



CORKBOARD INSULATED REFRIGERATOR 385 

These obserxations are based on a refri^^erator cabinet 
of fair quality, as respects insulation; but as the permanent 
insulating qualities of mechanically cooled household refrig- 
erators are improved, so the difiticulties of food compartment 
temperature control are reduced. The well insulated unit, 
such as a cabinet containing three inches of pure corkboard set 
tightly against the interior lining at all points, is not sensitive 
to room temperature fluctuations to any appreciable degree, 
and consequently may easily perform its two major functions 
with that degree of accurac}- required by a discriminating 
owner. At the same time, such a mechanical unit can be 
operated at a cost that will be low enough to justifv the 
extra investment. 

In testing mechanical units, the same test conditions 
should be observed as outlined for ice refrigerators, with but 
a few changes. The kiloAvatt-hours power consumption is 
measured instead of ice melted. A gi\en quantity by weight 
of water at say 70° F. temperature is filled into standard cube 
trays that have been cooled to the same temperature, and the 
trays are placed in the refrigerator once e\'ery day for the 
cubes to be frozen, the frozen cubes from the day before being 
simultaneously removed. If it is desired to put a normal 
"food load" on either the ice cooled or the mechanically cooled 
refrigerators, same should amount to 8 B.t.u. per hour, per 
cubic foot of cabinet contents, same being introduced electric- 
ally by an immersion heater in a container of oil placed at a 
given point in the food compartment. 

On account of the lower temperatures in general desired 
by owmers and maintained in mechanical units, especial 
attention must be paid to the subject of condensed moisture 
within the wall construction of the mechanically cooled cabinet 
at the end of the 30-day test period. 



CHAPTER XVII. 

DEVELOPMENT OF THE CORKBOARD INSULATED 
ICE CREAM CABINET. 

158. — Growth of the Ice Cream Industry. — Ancient records 
reveal that Saladin, Sultan of Egypt and Syria, sent Richard I, 
King of England, a frozen sherbet in the 12th century; that 
Marco Polo, the great Italian navigator, brought recipes for 
water and milk ices from Japan and China in the 13th century; 
and that Catherine d'Medici when leaving Florence, Italy, for 
France, in the 16th century, took with her certain chefs skilled 
in the preparation of frozen creams and ices. 

Frozen desserts were, however, regarded as luxuries, to 
be indulged in only upon occasion, until comparatively recent 
times. In the United States, ice cream became popular as a 
table dessert among the colonists. The first public advertise- 
ment of ice cream appeared in The Post Boy, a New York 
paper, in 1786; but it was not until about 1851 that an attempt 
was made to manufacture ice cream in wholesale quantities. 
In that year John Fussell, a milk dealer in Baltimore, Mary- 
land, became interested in ice cream in an effort to find a 
profitable outlet for surplus sweet cream that he had on hand 
from time to time. The manufacture of ice cream was under- 
taken as a side line, and sold at wholesale, but the business 
proved so profitable that Fussell disposed of his entire milk 
business and devoted his whole attention to the new industry. 
His remarkable success may be judged from the fact that he 
later established ice cream factories in Washington, Boston 
and New York City. 

Perry Brazelton, of Mt. Pleasant, Iowa, studied the whole- 
sale ice cream business in Fussell's Washington plant; and 
later established his own plant in St. Louis, Missouri, followed 
by still others in Cincinnati, Ohio, and Chicago, Illinois, which 

386 



CORKBOARD ICE CREAM CABINET 



387 



is indicative of the success that attended his efforts in the 
new industry in the Middle West. From then on there was a 
steady growth in this branch of the dairy industry, but rapid 
expansion did not begin until the shortage of natural ice in 
1890 gave the art of ice making and refrigeration the impetus 
necessary to establish that industry on a successful commer- 
cial basis. Then great improvements in machinery, and meth- 
ods of ice cream manufacture, were rapidly introduced during 




FIG. 182.— CORKBOARD INSULATED LONG-DISTANCE REFRIGERATED 
ICE CREAM TRUCK. 

the next two decades, until by the end of 1912 there was a 
reported total output of 154 million gallons of ice cream valued 
at 160 million dollars. 

The National Association of Ice Cream Manufacturers was 



organized in 1906, to more effectively promote the interests of 
ice cream manufacturers by assisting the industry to develop 
along permanent, substantial lines, through standardization of 
factory operations, pure food laws, and so forth. Trade asso- 
ciations and trade papers did much to promote the welfare of 
the industry, by teaching a common-sense code of ethics and 
by acting as a clearing house for its numerous activities. Many 
schools and colleges took up the teaching of the principles 



I 



388 CORK INSULATION 

and practices pertaining- to the manufacture of ice creams and 
ices. Through the cooperation of these useful agencies, the 
public was enabled to receive such ample protection against 
impure and unsatisfactory ice cream products as to so solidly 
establish the industry that by the end of 1926 the output was 
325 million gallons valued at 300 million dollars (wholesale). 

159. — Ice and Salt Cabinets. — It has been noted that salt- 
petre mixed with snow was used for cooling licpiids centuries 
ago in India, but the 17th century saw probably the first seri- 
ous attempt to utilize that method of refrigeration to produce 
ice and frozen desserts. The low temperature produced by 
mixing ice and salt is due of course to the fact that salt lowers 
the melting point of ice to about 5° F. (-15° C.) and keeps it 
there until all the ice is melted by heat rapidly absorbed from 
surrounding objects, which explains wdiy a can of freshly made 
ice cream placed in an insulated cabinet and surrounded with 
cracked ice and salt will harden by giving up its heat to the 
low temperature mixture at the expense of melting the ice, all 
as elaborated in the section of this book on "The Study of 
Heat." Since the ice is melted by heat extracted from the ice 
cream, and from the walls of the cabinet, which gets its heat 
from the surrounding atmosphere, it is necessary to set up in 
those cabinet walls an efficient barrier against the infiltration 
of heat from the warm air of the room. 

The ice cream industry was founded upon the fact of .the 
melting point of ice being lowered in the presence of salt. 
A mixture of ice and common salt was the only refrigerant 
used to congeal cream, and to keep the frozen mass in a satis- 
factory state of preservation for palatable consumption, for 
many years before and after the advent of mechanical refrig- 
eration. Low temperature brine produced by a mixture of 
cracked ice and salt, or low temperature brine produced by 
adding salt to water and cooling the mixture by mechanical 
means, differ, in so far as the manufacture, hardening and 
storage of ice cream in the plant is concerned, only in that 
the salt and ice mixture is more dif^cult to handle and its 
temperature is not as easily controlled. In either case, about 
equally good manufacturing results were possible, although 
mechanical refrigeration in the plant eft'ected a very great 



CORKBOARD ICE CREAM CABINET 



389 



saving in cost of production by placing all manufacturing 
operations under the complete and accurate control of rela- 
tivel}' few workmen. 

Outside the plant, however, on delivery wagons and trucks, 
on railway cars, in retail cabinets and soda fountains, the 
salt and ice mixture was depended on exclusively, until the 
last few years, for necessary refrigeration for the preserva- 
tion of ice cream until consumed. Early cabinets were built 
of heavy tongued and grooved planks of wood, with no insu- 




FIG. 183.— ARTIST'S CONCEPTION OF THE OLD UNINSULATED ICE 
CREAM CABINET. 

lation other than the wood itself, just about as the early 
household ice chest was constructed; but cabinets with hollow 
walls, filled usually with sawdust, came into early use and 
remained a long time. They left much to be desired, how- 
ever, because the low temperature necessary for the holding 
of ice cream caused heavy condensation of moisture within 
the air entrapped between the sawdust particles, and the 
cabinet walls became ice laden and water-soaked. Granu- 
lated cork was next tried as the loose fill insulating material, 
with better success, but still with much to be desired both 
from the standpoint of insulating efficiency and a dry condi- 
tion of the walls of the cabinet. 

In those days it was necessary, in summer, for the ice 



390 CORK INSULATION 

cream manufacturer to service or ice his cabinets in retail 
stores twice daily. In an effort to cut this expensive service 
to one daily icing, the Rieck ice cream interests, of Pittsburgh, 
Pennsylvania, undertook experiments w^ith ice cream cabinets 
insulated with sheets of pure corkboard, an insulation specifi- 
cation for retail ice cream cabinets almost unheard of up to 
that time (about 1912), and an extravagance thought to be 
wholly unjustified. The experiments started with cabinets 




FIG. 184.— MODERN' CORK INSULATED ICE CREAM SHIPPING CONTAIN- 
ER; REPLACES ICE PACKED TUB. 

containing one inch thick corkboard, which thickness was then 
increased little by little until satisfactory results were obtained, 
in conjunction with the use of a suitable ice and salt mixture. 
The results of these experiments did much to establish pure 
corkboard as the standard insulation for retail ice cream 
cabinets, and it has so remained, the only improvement being 
in the methods followed in putting the corkboard in place and 
in an economical distribution throughout the cabinet of the 
thickness of corkboard used. In general, the details of cab- 
inet assembly, with respect to insulation, should be predicated 
on a thorough understanding of the basic principles pertain- 



CORKBOARD ICE CREAM CABINET 391 

ing to the insulation of walls and structures to be subjected 
to low temperatures, as previously elaborated in this text, 
to the end that ice cream cabinets may contain adequate insu- 
lation installed so as to insure permanent cabinet efficiency. 

160. — Mechanical Ice Cream Cabinets. — The trend in the 
development and applications of mechanical refrigerating- ma- 
chinery was slowly but constantly from large many-ton plants 
toward smaller units, much as in the development of electric 
power the large-motor main-shaft drive gave way a little at 
a time to individual drive by small motors. But the high 
pressures at which ammonia compression refrigerating ma- 
chines operate, placed restrictions on the smallness, the light- 
ness, and the cost of production of the ammonia units of 
fractional-ton capacity, past which it was not practical for 
the manufacturer to go. And that minimum cost was too 
high for general application to small refrigeration duty, such 
as the cooling of household refrigerators and retail ice cream 
cabinets, when in competition with ice, and ice and salt 
mixtures. 

The use of a refrigerant that could be effectively operated 
at relatively low pressures, such as sulphur dioxide, proved 
to be the solution of the problem, which development estab- 
lished the small fractional-ton refrigerating machine as a 
practical and economical refrigerating unit through much 
lighter and simpler construction and greatly reduced cost. 
However, in the practical application of such household re- 
frigerating units, as they quickly came to be known, it was 
determined that their successful operation, as well as their 
low manufacturing cost, depended on a certain restriction of 
the unit refrigerating capacity. 

Thus the efforts to reduce the cost of production of the 
fractional-ton ammonia compression machine to the point of 
successful competition with ice and salt mixtures were, m 
general, unsuccessful; while the efforts to economically raise 
the unit refrigerating capacity of the sulphur dioxide type of 
machine enough to handle the heavier duty cabinets were, in 
general, unavailing. But virtually by the simple expedient 
of increasing the thickness of the corkboard insulation in ice 
cream cabinets to be mechanically cooled, and by so setting 



392 CORK INSULATION 

the insulation in the walls of the cabinet as to guarantee the 
permanent thermal efficiency of the cabinet, the small low 
pressure carbon dioxide type of machine was adapted to retail 
ice cream cabinet refrigeration loads, and took the field from 
the fractional-ton high pressure ammonia machine. 

These considerations are briefly set forth here, emphasized 
in their relation to insulation, merely to show the part cork- 
board played in the preliminary research and engineering 
development work incident to the beginnings of what is now 
a large industry — the mechanical ice cream cabinet industry, 
which the Crouse-Tremaine interests, of Detroit, Michigan, 
are given considerable credit for having pioneered. 

161. — Typical Details of Ice Cream Cabinet Construction. 
— It would serve little purpose to illustrate in this book all 
the different makes and types of ice cream cabinets — ice and 
salt cabinets and mechanical cabinets — manufactured in the 
United States, and for that reason but a very few of them, 
selected at random, are shown and described* in this Article : 

BROOKS NEW DOUBLE ROW TWO-TEMPERATURE 
DRYPAK CABINET. 

Frame. — Built of 2 x 2 long leaf heart pine lumber, possessing great 
tensile strength and durability, without excessive weight. This material 
contains a large amount of turpentine and rosin that prevents decay. 

The Bottoms. — Made of 1-inch gulf cypress are strong and securely 
fastened to the frame, reinforced with skids made of long leaf heart pine. 
The bottoms of the Brooks Drypak Cabinets are made to hold their weight. 
They can never sag or be pushed out. 

Pure Corkboard Insulation.— The insulation is extra heavy pure cork- 
board, consisting of 6 inches in the bottom and 4 inches in the sides and 
ends. We do not attempt to save cork by tapering the insulation in the 
side walls, as it is just as necessary to keep the heat out at the top of the 
side walls as it is at the bottom of the side walls. We therefore use 4 
inches of pure corkboard in the sides and ends all of the way up to the 
top of the cabinet. 

Hermetically Sealed. — Besides the precaution taken to have all joints 
lapped, or perfectly butted, the entire corkboard insulation is sealed by 
flowing on a thick layer of hot asphaltum. This assures the filling and 
closing up of all pores, joints and cracks, which prevents the leakage of 
refrigeration or the penetration of heat. 



•Descriptions are those of the manufacturer, and are to be accepted only for what 
they may prove to be worth. 



CORKBOARD ICE CREAM CABINET 393 

A^7 Substifutcs for Corkboard. — There are no substitutes for cork- 
board used in any part of these cabinets. The insulation will remain in 
l)lace and retain its efficiency during the entire life of the cabinet. Buy 
plenty of insulation once and save icing expenses daily. There is no 
better investment for ice cream manufacturers than plenty of pure cork- 
board insulation in ice cream cabinets. It pays big dividends every day 
the cabinets are in use. 

Tlic Corners. — Nickel zinc angles protect the corners and add a 
pleasing appearance to these cal)inets. They are fastened with brass nails 
and will not rust or corrode. 

Tops. — The tops are made from heavy, straight grain gulf cypress 
lumber, the corners are rigidly secured and the construction throughout 




1-IG. 185.— BROOKS COliKBOARD INSULATED DRVPAK ICE CREAM 
CABINET. 

strong and substantial. These tops are arranged to make filling easy, 
without undue loss of time or refrigeration. 

The Lids. — The lids are large enough to remove empty cans and 
replace them with full cans of cream without removing the top of the 
cabinet and exposing other compartments. The lids are also insulated 
with pure corkboard. A "hand grip" is carved into the one-piece cover, 
so that there are no metal handles to break off or rust, no knobs to 
obstruct an even surface. The edges are designed to seal against loss of 
refrigeration and yet make opening and closing easy. 

The I'iiiish. — .Solid, laminated, three-ply, waterproof panels, selected 
for graining and durability, arc used on all sides and ends. The finish is 
rich old mahogany, four-coat work, giving a smooth, hard surface that 
resists wear. 

Sheet Metal //'or/.'.— The linings and cans are made from genuine 
Armco Ingot iron. This well-known l)rand of copper-bearing metal, 



394 



CORK INSULATION 



heavily galvanized, is further assurance of the definite and dependable 
values built into Brooks Drypak Cabinets. 

Ice Compartments. — The Brooks Drypak Cabinet ice compartments are 
large enough to provide ample capacity to care for exceptional conditions 
during the summer months. These cabinets will keep cream in perfect 
condition for forty-eight hours or more. 

Drains. — One-piece, leak-proof and non-corrosive Smith and Mann 
valves are used. They are of ample size to perfect quick drainage and 
are threaded for three-quarter inch hose connection. 

Mounted on Skids. — For a sanitary base and to facilitate moving, 
Brooks Drypak Cabinets are mounted on sturdy skids ; there arc no legs 
to break oflF. 

Workmanship. — The workmanship throughout the cabinets is first 
class in every particular. The design is the result of long experience 
with the problems of ice cream manufacturers, by the men who actually 
manufacture Brooks Drypak Cabinets. 

Manufactured by Brooks Cabinet Co., Norfolk, Virginia. 




FIG. 186.— SECTION OF NELSON DUPLEX-ZERO DRY-PACK CABINET. 



NELSON DUPLEX-ZERO DRY-PACK CABINETS. 

Insulation. — A cabinet can be no more efficient than its insulation. 
The high efificiency of Duplex-Zero cabinets is guaranteed by the perfect 



CORKBOARD ICE CREAM CABINET 395 

design and the massive insulation of solid slabs of sheet cork, tapering 
from 3 inches on sides and ends at the top to 5 inches at and on 
bottom, heat treated with a special asphaltum base formed into a solid, 
continuous, air-tight, moisture-proof and settle-proof wall around and 
under the ice chamber. This construction insures maximum refrigerating 
results — 48 to 72 hours on one icing. 

Lining. — The metal lining is of 22-gauge copper bearing iron, heavily 
galvanized, fitting snugly against the corkboard, giving maximum wear, yet 
easily removed and replaced. 

Finish. — Added insulation and durability are assured by the use of 
California redwood on all Nelson cabinets. 

Corners. — Duplex-Zero Dry-Pack cabinets are equipped with bright metal 
corner irons. 

Dram.^Drains quickly with Nelson patented brass drain. 
Manufactured by C. Nelson Manufacturing Co., St. Louis, Missouri. 




FIG. 1S7.— SECTION OF GRAND RAPIDS CABINET CO. TRAY-PACK ICE 
CREAM CABINET. (PATENTED JAN. 25, 1926.) 

GRAND RAPIDS CABINET CO. "TRAY-PACK" ICE CREAM 
CABINETS. 

Description.—Tht accompanying figure shows the position of the 
trays, the abundance of scientifically distributed corkboard insulation, and 
the individual servicing covers for each side of cabinet. These covers 
permit servicing without exposing ice cream — a dccidely worthwhile sani- 
tary feature. 

Operaton. — The "Tray-Pack" service method simply consists of the 
removal of the trays by the service man from the Tray-Pack cabinet, the 



396 



CORK INSULATION 



dumping of the brine at the curb or other suitable place, the repacking of 
Ihe trays at the truck, and the replacement of the trays in the Tray-Pack 
cabinet. That's all. No drip, no dirt, no muss in the dealer's store. Just 
a few minutes' work, and all is set for two days or more of perfect 
refrigeration. 

Sizes. — Made in standard 2-, 3-, 4-, 5-, and 6-hole "Tray-Pack" sizes. 
Finish is rich walnut color. Also, obtainable with two separate compart- 
ments, suitable for: (1) two temperatures for ice cream; (2) one com 
partmcnt shut off during dull season; (3) one compartment for milk or 
bottled goods. 

Insulation. — Only the best insulation obtainable is used in "Tray- 
Pack" ice cream cabinets — pure compressed corkboard, it being more imper- 
vious 1o water than any other known insulating material. Asphaltum and 
other products are applied hot on both sides of the corkboard as assem- 
bled in the cabinet, so as to exclude all air from between the insulation 
and the inner cabinet tank and from between all joints in the corkboard 
sheets and thus exclude all condensed water from the insulation' and obvi- 
ate destruction of the insulation by the expansion of freezing. 

Manufactured by Grand Ra])ids Cabinet Co., Grand Rapids, Michigan. 



nT'^"" 




188.— SECTIONAL VIEW OF NIZER SELF-CO .\T.\IXED \V.\TER COOLED 
ELECTRIC ICE CREAM CARIXKT. 



NIZER WATER-COOLED SELF-CONTAINED ELECTRIC 
ICE CREAM CABINET. 

General. — The figure shows a sectional photograph of one of ibe many 
Nizer ice cream cabinets, which illustrates particularly the corkboard 
insulation. 



I 



CORKBOARD ICE CREAM CABINET 



397 



Insulation. — There are 3 inches of pure compressed corkboard on 
the bottom, 2 inches on the sides and 1 inch on top. The insulation is 
not composed of single thicknesses of corkboard, but, with the exception of 
the top, of two thicknesses, separated by sheets of heavy waterproof paper. 
There are also several sheets of this paper between the insulation and the 
brine tank, as well as on the outside surface of the insulation. Such 
places as cannot be efifectively sealed with corkboard (around the gas line 
for example) are packed tightly with cork plastic insulation. 

Assembly. — The method of assembly of the insulation in the cabinet, 
consists in using sheets of cork made slightly oversize and pressed firmly 
into position, thus making perfectly tight joints without the use of sealing 
material. All joints in one layer of corkboard are staggered with respect 
to the joints in the other layer, so as to further prevent the passage of 
heat. 

]\Ianufacture<! liy Kelvinator, Inc., Xizer Division, Detroit, Michigan. 




FIG. 189.— UXIVRSAL COOLER CORP. ELECTRICALLY REFRIGERATED ICE 
CREAM CABINET. 

UNIVERSAL COOLER CORPORATION ELECTRICALLY 
REFRIGERATED ICE CREAM CABINET. 

Requirements. — In undertaking to supply the trade with an acceptable 
electrically refrigerated ice cream cabinet, there were two problems which 
presented themselves. The first had to do with creating a machine for 
producing a low temperature within the cabinet of such a degree as would 
keep the ice cream in the best possible condition, and the second having to 
do with the maintenance of this temperature. 



398 



CORK INSULATION 



The Machine. — The Universal Cooler Corporation were readily able to 
satisfy this first requirement, with a unit that was both simple, compact 
and economical, and could produce the low temperature required. 

The Cabinet. — The second problem which attached to the maintenance 
of this low temperature was one which depended entirely upon the con- 
struction of the cabinet. 

Low Power Cost. — If the cabinet was properly built and correctly 
msulated, it meant that the mechanical cooling unit was only called upon 
to operate for the shortest possible time, with a consequent low current 
consumption, and, of course, a longer life for the machine. 

The Insulation. — Therefore, they undertook to devise a cabinet which 
employed corkboard as the insulating material. The cork employed in 
the ice cream cabinet adopted by the Universal Cooler Corporation is in 
solid slabs, which lap at corners, top and bottom, and are treated with a 
hot asphaltum base product known as "Hydrolene," so that the interior 
of the box is a solid, continuous, air-tight, moisture-proof, and settle- 
proof wall around and under the ice chamber. 

Corkboard. — The necessity for having the cork in continuous slabs 
is for the purpose of eliminating cracks and voids which would permit 
ordinary atmospheric humidity to creep in, become solidified when the 
cabinet is in operation and thus dissipate some of the effectiveness of the 
box, and when the cabinet is not in use this moisture would melt, run down 
into the bottom of the box, become stagnant, and cause unpleasant odors. 

Manufactured by the Universal Cooler Corporation, 18th and Howard 
streets, Detroit, Michigan. 




FIG. 190.— SERVEL 8-IIOLE, DOUBLE ROW, TWO TEMPERATURE ELEC- 
TRICAL ICE CREAM CABINET. 

SERVEL ALL-STEEL ICE CREAM CABINETS. 

Insulation. — The Servel line of ice cream cabinets is considered the 
best insulated cabinet on the market. For the single row, two layers of 



I 



CORKBOARD ICE CREAM CABINET 



399 



3-inch thick sheet cork is used on the bottom, two layers 2-inch thick sheet 
cork on the ends and sides, and one layer 2-inch sheet cork on the top. 
The double row cabinets, however, in order to stay within the 30 inches 
width, have one layer 2-inch and one layer IJ/^-inch sheet cork on the 
ends and sides. 

Manufactured by Servel Corporation, Evansville, Indiana. 



ABSOPURE ELECTRIC ICE CREAM CABINET. 

Description. — The accompanying photograph shows the cover- 
ing removed from the ice cream can section of an Absopure 4-hole, 
in line, self-contained, air-cooled electric ice cream cabinet, display- 




FIG. 191.— ABSOPURE 4-HOLE, IN LINE, SELF-CONTAINED. AIR-COOLED 

ELECTRICAL ICE CREAM CABINET (COVERING REMOVED 

SHOWING CORKBOARD INSULATION). 

ing the sturdy framework of steel, the solidly placed pure com- 
pressed corkboard insulation and the position of the refrigerating 
coils. 

Insulation. — The insulation of this unit consists of two layers 
3-inch thick pure compressed corkboard on the bottom of the cabi- 
net, two layers 2-inch thick pure compressed corkboard on the ends 
and sides of the cabinet, and one layer 2-inch thick pure compressed 
corkboard in the cabinet top. This insulation is carefully pressed 
into position, using a waterproof sealing material on all joints and 
surfaces to obviate the possibility of the collection and freezing 
of water within the cabinet construction, due to the condensation of 
moisture from concealed air spaces or pockets, and the consequent 
disintegration of the insulation, damage to the cabinet and serious 



400 CORK INSULATION 

loss of efficiency in operation. Such spaces that cannot be effectively 
sealed with corkboard sheets, are packed tight with a special water- 
proof sealing material combined with a suitable proportion of pre- 
pared cork particles. 

Maintenance Cost. — It is believed that the construction of this 
cabinet is an effective guarantee of lowest power and maintenance 
costs, when operated in conjunction with the Absopure refrigerating 
unit. 

Manufactured by the General Necessities Corporation, Detroit, 
Michigan. 

162. — Notes on How to Test Ice Cream Cabinets. — There 
are no generally accepted and approved methods for the test- 
ing of either ice and salt cabinets or mechanical ice cream 
cabinets, and most all tests made thus far are subject to more 
or less inaccuracies and interpretation as to the meanings of 
the results obtained. For instance, as mentioned for house- 
hold refrigerators, it has been for years a well-understood 
fact in the cold storage industry that the efficiency of a new 
cold storage room is in itself of ver}' minor importance, if of 
any real importance at all. What is important to the owners i 
and operators of large cold storage plants, is what the effi- j 
ciency of that room will be one year or ten years after it has 
been in operation ; for it is possible to construct hollow walls 
of wood, fill the space with chimney soot and show under 
accurate test an initial cold room insulating efficiency far 
greater than could probably be shown with any commercial 
insulating material procurable, }et the soot would retain its 
remarkable efficiency for a very short time only. Glass wool, 
fluxed limestone, wood flour, medicinal cotton, nail polish, and \ 
many other materials* in common use, are very efficient ther- i 
mal insulators, but quickly lose their heat retarding properties 
by settling and packing down and by saturation with con- | 
densed water vapor, if used in connection with cold tempera- j 
tures. 

The first point to cover in planning for tests of any ice ; 



*In a number of the "Berichte" (1899), Prof. Hempel describes a series of experi- 
ments undertaken by him, in order to determine which substance was best suited 
for isolating freezing mixtures in experimental wcirk in the laboratory. Starting 
with a temperature of about -75° to -80° C. (-103° to -112° F.) produced by solid 
carbon dioxide and ether, the rate of rise of temperature with time was measured, 
and, as a result, eiderdown was found to be the lust irsiilator. woo', carefully dried 
at 100° C. (212° F.) being nearly as good, and having the advantage of cheapness. 
Thus wi"tfi eiderdown a rise of 12° C. occurred in eighty-eight minutes, with dry wool 
a rise of 20° to 24° C. in the same time. 



» 



CORKBOARD ICE CREAM CABINET 401 

cream cabinet must tlierefore he a careful investigation and 
research into the ability of the insulating material to retain 
its initial insulating efficiency under the conditions of its appli- 
cation in the walls of the cabinet and for an indefinite period 
of time under known or anticipated conditions of service. If 
such research rexeals that the insulation cannot be expected to 
stand up under the conditions to be imposed, there probably 
will be fewer reasons for going ahead with the plans to test 
out the cabinet. 

Ice cream cabinet service is much more severe than the 
service that household refrigerators receive. Thus the proper 
insulation to use and the correct specifications to be followed 
in installing it, are of much more importance in the ice cream 
cabinet than they are in units that operate at considerably 
higher temperatures. The experience of the dairy and ice 
cream industries for the past several decades in the insulation 
and operation of refrigerated milk rooms, cream rooms, ice 
storage rooms, hardening rooms, antl cold rooms in general, 
is of value as research into the fitness or lack of fitness of any 
insulating material for ice cream cabinet construction and 
temperatures. I'ure corkboard is the standard material for all 
such rooms in countless plants all over the United States, the 
reason for which was elaborated in the section of this text on 
"The Insulation of Ice and Cold Storage Plants and Cold 
Rooms in General," and which amounts to the fact that cork- 
board is the onl)- suitable material employed for such purpose 
that when intelligently installed will retain approximately 90 
per cent of its initial insulating efficiency for ten years or 
more. 

I In testing various kinds and sizes of corkboard insulated 

ice and salt cabinets, assuming that virtually the same or 

' equally satisfactory specifications were followed in installing 
the corkboard in the cabinets, and assuming that the results 
are to be made available for general comparison with the 

I'.i results of other tests made at different times and places, the 
following conditions sh(ndd be obserxed : 

(a) A constant temperature room should be used, the temperature 
[ held uniform to within one degree Fahr. hy electric heater placed within 
|| hollow walls of the test room and controlled hy thermostat. 



402 CORK INSULATION 

(b) Control of the humidity of the constant temperature room should 
be effected by suitable means, tests having demonstrated that a consider- 
able increase in the percentage of ice melting is effected by increasing the 
percentage of relative humidity in a constant temperature room from a 
low to a high point. 

(c) The mixture of ice and salt should be carefully regulated on the 
basis of weight. 

(d) The salt should be of standard specifications. 

(e) The ice used should be only hard, "black" ice, and should be 
crushed to uniform size. The finer the ice is crushed and the more salt 
used, the lower, within limits, will be the resultant temperature. 

(f) Ice and salt should be mixed thoroughly in suitable mixing box 
located outside the test room, and packed in the ice cream cabinet during a 
fixed period, at the same hour, every other day (48-hour icing), no ice 
and salt to be put on top of cans and brine to be drained off cabinet before 
each re-icing. 

(g) The ice cream to be used for test purposes should be a product of 
rigid specifications, because different mixtures and flavors require differ- 
ent temperatures to keep them in satisfactory condition, and the volume 
of ice cream in the cabinet should be a fixed quantity. 

(h) Special long-bulb thermometers should be used in ice cream cabi- 
nets, of such length as to obtain average temperature readings for the 
total depth of the ice cream and for the empty can of each cabinet. 

(i) Four days preliminary operation should be allowed to establish 
a temperature equilibrium in the walls of the cabinet before the test proper 
should be started, and the test should then continue for 30 more days. 

Tests performed under standardized conditions thus sug- 
gested, values for such standards to be fixed upon a practical 
basis for test purposes and a basis most nearly conforming to 
the practices of the ice cream industry, should be comparable, 
as to ice consumption, cabinet air temperature, ice cream tem- 
perature, and condition of the ice cream throughout the test. 

An electric ice cream cabinet may be tested in much the 
same fashion, the electric power consumption by the cabinet 
machine, instead of the ice consumption, being comparable 
with results of other electric cabinet tests. 



CHAPTER XVIII. 
THE REFRIGERATED SODA FOUNTAIN 

163. — Automatic Operation of an Intricate Unit Made Pos- 
sible with Corkboard Insulation. — Soda fountain design has 
kept well abreast of all modern trends and developments in 
automatic carbonation, mechanical refrigeration, scientific in- 
sulation, pure food preservation, efficient operation, and rapid 
dispensation of popular delectation. And as a result the 
"fountain" is popular. Few of its patrons probably realize, 
however, that the modern soda fountain is an intricate and 
delicate assembly of beautiful store fixture, refrigeration plant, 
cold storage, chemical plant, and food and drink dispenser. 
Five different temperature zones must be automatically estab- 
lished and accurately maintained ; and all in a space often less 
than a dozen feet long and a quarter as high and wide! The 
modern soda fountain deserves admiration ; its successful op- 
eration is made possible by permanently efficient corkboard 
insulation, scientifically adjusted to the service desired. 

For it is one thing to produce refrigeration, and another 
thing to conserve it and apply it to good purpose. When a 
quarter-score temperatures must be maintained and controlled 
within such narrow confines as twenty cubic feet, the cold 
storage problem takes on a new interest and importance in- 
deed. Corkboard insulation, properly utilized, permits of the 
most delicate and accurate operation of the most modern soda 
fountain, just as it has been of so much use and assistance 
wherever temperatures below that of the atmosphere are arti- 
ficially produced, efficiently maintained and advantageously 
utilized. 

164. — Extracts from Manufacturers' Specifications* for 



•Descriptions are those of the manufacturer, and arc to be accepted only for 
what they may prove to be worth. 

403 



404 



CORK INSULATION 



Modern Mechanically Refrigerated Soda Fountain with Typi- 
cal Details of Construction. — Tlie foUuwini;' excerpts from a 
manufacturer's complete soda fountain specification are pre- 
sented to illustrate the scope of the work of designing and 
l:)uilding" such equipment, in which corkboard insulation plays 
such an important part ; by courtesy of The Bastian-Blessing 
Company, Chicago, Illinois, and Grand Haven, Michigan : 

DETAILS OF SODA FOUNTAIN CONSTRUCTION. 

Note the heavy construction throughout and the unexcelled cork insu- 
lation. There are 4-inch walls all around, front, bottom, back and two 
ends. These walls are provided with 3-inch pressed pure corkboard insu- 
lation. To correctly understand this construction is to appreciate the 
superiority of the material and workmanship, and the correctness of the 
fundamental principles empkned in the construction of the Guaranty 
fountains. 




IG. 192.— Si:CTIOX.\L \"IEW OF FOL'-XTAIX CABIXET. 



1. Raised edge creamer capping and top in one piece, 16-gauge nickel silver. 

2. 3-inch removable top insulated with 2-inch pressed pure corkboard. 

3. Fabric base special non-conductor practically prevents all refrigeration loss. 

4. K'o. IS' porcelain white enamel Armco iron front; can also be faced with 7/16 
vitrolite or marble, when specified. 

5. 1-inch waterproof cypress wall. 

6. 3-inch pressed pure corkboard insulation. 



REFRIGERATED SODA FOUNTAIN 405 

7. 20-ounce hot rolled copper lining of brine compartment. 

8. Brine solution. 

9. 32-ounce hot rolled tinned copper ice cream tanks with galvanized copper steel 
sleeve. 

10. Strong adjustal)Ie legs, .screwed in brass flanges bolted through creamer 
bottom. 

11. Special non-conductor frame practically eliminates all sweating. 

12. Double acting nickel silver hinged lid insulated with 1-inch pressed pure 
corkboard. 

13. Removable gutter easily cleaned. 

14. No. 18 porcelain white enamel Armco iron facing for syrup jar enclosure. 
l.S. 1-inch waterproofed cypress wall. 

16. 16-ounce cold rolled tinned copper lining in syrup unit. 

17. Special non-conductor, breaking all metal to metal contact with the outside. 

18. Nickel silver syrup unit capping. 

19. Open gutter, to take off draft arm spillage, easily cleaned. 

20. Waterproof airtight seal. 

21. Solid 2x3 inches interlocking frame. 

22. Metal conductor strips insure positive and constant refrigeration of syrup 
unit. 

23. Dead air space forming additional insulation. 

24. Heavy copper bearing steel facing bottom, back and ends. 

Complete Refrigeration With One Frigidaire Unit. 

The application of mechanical refrigeration to soda fountains required 
considerable study, many experiments and much caution. Mechanical re- 
frigeration in itself was nothing new and had been in commercial use 
for many years. However, its application to the soda fountain at once 
brought out the difficulty of supplying the many temperatures needed for 
the successful operation of these fountains with one refrigerating unit. 

In designing the Guaranty fountain in its simple and practical way to 
secure the five necessary temperatures, the engineers have scored a com- 
plete triumph. 

The many months spent in experimenting, simplifying and in other 
ways adding to the all-around efficiency of this type of fountain, resulting 
in the 100 per cent, mechanically refrigerated Guaranty, was well worth 
while. The operation of thousands of these fountains in every-day use 
has completely demonstrated not only Guaranty's ability to serve supremely 
well and economically, but also to deliver many years of continuously 
satisfactory service. 

Maintaining Five Correct Temperatures Automatically. 

The Guaranty soda fountain is constructed in a simple and practical 
way to secure the five necessary soda fountain temperatures. 

The soda and city water coolers and the Frigidaire boiler, located in 
the first, or cooling chamber, are immersed in a water bath as shown 
more clearly in the sectional view. Fig. 199. The temperature is auto- 
matically maintained at approximately 33° F. by a regulating control valve. 

The dry storage refrigerator is located second from the left in which 
a temperature ranging from 40° to 45° F. is maintained. This compart- 
ment is equipped with a sliding shelf, thus providing double-deck arrange- 
ment for bottle goods. Refrigeration for this compartment is secured 
through a semi-insulated partition from the cooling compartment. 

On the extreme right is located the brick compartment, where a 



406 



CORK INSULATION 




REFRIGERATED SODA FOUNTAIN 407 

temperature of 0° to 5° F. is maintained. The Frigidaire boiler producing 
this temperature is automatically controlled by the compressor itself. 

Separating the brick compartment from the bulk compartment at its 
left is a correctly proportioned baffle partition which permits the exact 
amount of refrigeration in order that the bulk cream may be kept at a 
temperature of from ten to twelve degrees above zero. 

The syrup unit secures its refrigeration through copper conductor 
plates attached to the bottom of the syrup unit lining and extending down 
into the brine of the bulk compartment. The refrigeration necessary to 
produce a temperature of from twenty to thirty degrees under the room 
temperature of from ten to twelve degrees above zero. The bulk 
compartment and storage refrigerator are separated by a 2i/2-inch 
corkboard partition. 

Study well the illustrations in Fig. 193. Take note of the arrange- 
ment and the method and system of operation of the refrigerating unit, 
and remember that continuous operation and efificient functioning requires 
the utmost in simplicity and practicability of construction, all so clearly 
shown in Fig, 193. 




FIG. 194.— CORKBOARD INSULATED CREAMER. 

Creamer. 

Frame. — Constructed of genuine Louisiana red cypress, a product of 
the Southern swamps, inured to all kinds of weather, accustomed to moist- 
ure and exposure and, above all, possessing a long life. Front and rear 
paneled, tenoned, glued and nailed to a chestnut supporting frame, all 
thoroughly impregnated with preservative paint, making it truly the "box 
eternal." 

Insulation. — In addition to the 1-inch cypress walls the insulation con- 
sists of 3-inch pressed pure corkboard, all joints cemented with a spe- 
cially prepared cork cement, making a jointless wall. Insulating qualities 
of corkboard are based on the natural quality of the cork plus the dead 
air space so long in use as a barrier of heat. The cork is pressed into 
a board under heat and the natural resin cements the cork together, impris- 



408 CORK INSULATION 

oning millions of tiny dead air cells forming a veritable deadline against 
the entrance of heat into the soda fountain. 

Ice Cream Compartment Linings.— AW materials that enter into the 
construction of the Guaranty are selected with a view to securing the 
best for the use intended. Tests and experiments have fully and clearly 
demonstrated that copper is the most practical and durable for soda foun- 
tain linings. The Guaranty fountain is lined with 20-ounce hot rolled 
copper, front, bottom and back in one piece. Ends are double seamed, 
interlocked and soldered. The bottom is reinforced with 20-gauge Key- 
stone copper-bearing steel to insure greater strength and resistance. 

Tank and Sub-Covers. — Water-tight tanks and sub-covers are required 
to hold the ice cream cans. Tank bodies are made of 32-ounce hot rolled 
tinned copper and have one vertical double seam soldered on the outside. 
Tank bottom is also 32-ounce hot rolled tinned copper and is double 
seamed and soldered to the bodies. A galvanized copper-bearing steel 
sleeve extending 6 inches down into the tank is soldered to it. This sleeve 
protects the copper and prevents dents, or perhaps punctures from care- 
lessness in removing or inserting the ice cream cans. The complete tanks 
are sweated to a sub-cover made of 32-ounce hot rolled copper. 

The sub-cover has the proper number of oval openings carefully 
machine stamped and also has an opening through which the coil can be 
removed should it ever become necessary. 

In the bottom of each tank there is placed a 20-gauge galvanized 
copper-bearing steel plate as additional reinforcement to prevent the tank 
bottom from being dented when the ice cream cans are dropped into place. 

After the tank and sub-cover unit have been assembled as described, 
it is placed into the creamer box and the sub-cover is sweated to the 
lining. The Frigidaire boiler is then installed and the entire unit is filled 
with water and tested for leaks. 

Cooler and Dry Storage Refrigerator. — An integral part of the 
creamer, separated from the ice cream compartment by 2^-inch cork 
partition; lined with 16-ounce cold rolled copper tinned one side, front, 
bottom and back in one piece, ends double seamed, interlocked and soldered. 
This compartment is divided by a semi-insulated partition. One side con- 
tains a water bath and refrigerating coil for cooling soda and city water 
and the other side is a dry storage compartment which secures its refrig- 
eration through the semi-insulated partition. An outlet with an overflow 
pipe topped with a funnel is provided to drain the syrup unit and cooler 
compartment when necessary. 

Brick Compartment. — This compartment is separated from the bulk 
cream compartment by a metal baffle partition. This compartment con- 
tains the boiler which is regulated to maintain a temperature of approxi- 
mately zero. All Guaranty standard plans are shown with one rectangu- 
lar brick compartment with a capacity of 50 one-quart bricks. 

Bulk Compartment. — The correctly proportioned metal baffle which 



REFRIGERATED SODA FOUNTAIN 409 

separates ihe brick and bulk compartments retards refrigeration sufficiently 
to produce a tcmiierature of from 8 to 12 degrees above zero in the bulk 
compartment. 

Frigidairc Coils. — In order to suppl\ 100 per cent, mechanical refrig- 
eration under ])ositivc automatic- control, two coils and one regulating 
valve, in addition to the compressor suitable for the refrigeration of the 
creamer, arc required in all cases. 

The standard installation consists of one coil for suppl\ing refrigera- 
tion to the cooler and cold storage compartment, and one coil for the 
refrigeration of the ice cream compartments. They are installed at the 
factory in a neat and workmanlike manner and the entire tank is tested 
for leaks before it leaves the plant. All Guaranty interiors are equipped 
at the factory with the standard installation of coils and shipped complete 
with the regulating valve. 

Facings. — Front is faced with No. 18 Armco Iron with three coats of 
white porcelain enamel fired at a temperature above 1700° F. All facings 
are made to exact dimensions before coating, and there are never any 
crazed edges so often found when sheared to size after being enameled. 
Both ends, bottom and back arc covered with 20-gauge copper-bearing 
galvanized steel, coated with aluminum bronze paint. 

Bindings. — The bindings are 20-gauge nickel silver, neatly made up, 
attached with brass nickel plated screws. 

Adjustable Legs. — Creamer units are equipped with heavy metal legs 
adjustable to allow for ordinary irregularities in the floor without resort- 
ing to the use of wedges. 

The legs arc fitted with rounded caps which provide a smooth sliding 
surface, and are turned in heavy solid brass flanges, securely fastened to 
the creamer box with bf)lts, which i)ass through the entire thickness of the 
creamer bottom. 

FIG. 195.— CORIvBO.\RD INSULATED CREAMER TOP. 

Creamer Top. 

Frame— L\ke the creamer box, the frame of the top is constructed of 
genuine Louisiana Red Cypress, the "wood eternal," thoroughly impreg- 
nated with a wood preservative. 

In.uilafion. — Pure corkboard 2 inches thick is used for insulation. The 
surface of the cork is effectively sealed against moisture by a heavy coat- 
ing of hydrolene. 

Capping.— One solid piece of 16-gauge Grade A 18% nickel silver 
(weighing approximately two pounds to the square foot) forms the cover- 



41C CORK INSULATION 

ing for the top. The front edge is raised and beveled to prevent water 
from dripping on the floor. Machine cut oval openings provide access to 
the ice cream cans and a rectangular opening to the cooler and cold stor- 
age compartment. A raised rim in each oval opening prevents seepage 
into tanks and ice cream cans. 

Non-Conductor. — Great care was exercised in the selection of 
Guaranty Non-Conductor. After countless experiments had determined 
that Bakelitc with a fabric base possessed the needed strength, ability 
to withstand moisture and above all, had the required insulating property, 
it was chosen for use with Guaranty 'soda fountains and the actual opera- 
tion of these fountains in daily use has fully justified this selection. 

Removable Gutter. — Leakage through the hinge of the twin packer lid 
has not been overcome nor completely eliminated by anyone. In some 
cases the covers have been built up to such a height that most of the 
water can be carried off to the top of the creamer. The height of this 
projection or of the complete cover itself, hinders ease in operating and 
cleaning, besides which it is unsightly. The Guaranty solution of the 
problem consists of a removable gutter attached to lugs directly under- 
neath the hinge, as shown in Fig. 192. What little water has occasion to 
seep through the lid is caught by this gutter and its removal and sub- 
sequent cleaning is both simple and easy. At the same time, a beautiful 
smooth and even creamer top is maintained. 

Twin Packer Cover. — An ingenious hinged cover divided in the center 
provides access to both ice cream cans, making each can a dipping can. 
This cover folds back completely either way so that both cans can be 
emptied completely without removing the front can and bringing the rear 
can forward as is necessary in so many other types. 




FIG. 196.— CORK INSULATED TWIN PACKER COVER. 

Non-Conductor Lid. — The operation of the twin packer cover is shown 
above, and the accompanying illustration shows this lid in complete detail. 
It is made with a frame of special insulating material, strong, durable and 
non-absorbent. The lid top is 14-gauge nickel silver, fastened to the non- 
conductor frame with nickel silver brackets electrically welded to the 






REFRIGERATED SODA FOUNTAIN 



411 



underside of the top. It is insulated with one inch of pressed pure cork- 
board, and a nickel silver bottom, binding the entire cover together, is 
sprung into a groove in the non-conductor frame. The front and rear 
half are each provided with rubber tipped knobs, doing away with the old 
thumb nip, thus eliminating the slight opening, and providing additional 
precaution against refrigeration loss, at the same time making the operation 
of these covers easy and noiseless. The illustration shows clearly that all 
metal to metal contact is broken practically eliminating all refrigeration 
loss. 




FIG. 197.— INSULATED SYRUP UNIT. 

Syrup Unit. 

Frame. — The usual unbeatable Louisiana red cypress is used in the 
construction of the syrup unit frame. The bottom is 5-ply, ^-inch Haske- 
lite panel board, which gives the necessary strength to insure that quality 
of endurance. 

Non-Conductor. — Wherever it has been necessary Guaranty soda 
fountains are equipped with special non-conductor to practically eliminate 
all refrigeration loss. The syrup unit is so constructed, and special non- 
conductor strips, completely breaking all metal-to-metal contact with the 
outside, are provided in the con.slruction, as shown by the accompanying 
illustration. 

Drain for Draft Arm Spillage. — All Guaranty interiors are constructed 
with an open drain, leading from the drip pan to the creamer outlet. This 
is attached to the rear syrup unit wall, a convenient and out of the way 
location. No spillage resulting from mixing drinks at draft arms reaches 
the syrup jar enclosure bottom, making it easy to keep dry and clean. 

Lining. — 16-ounce pure cold rolled tinned copper forms the lining, 
made of one piece with ends double seamed and soldered. 

Capping. — The front rail and top capping are heavy Grade A 18% 
nickel silver. 



412 



CORK INSULATION 



Adjusliiii) Plates. — The product of the best porcchin manufacturers 
in the country is used, but it is impossible to guarantee absolute, precise 
uniformity in jar sizes. 

In order to insure a perfect fit, adjusting plates are provided at each 
end of the syrup unit to take up any excess opening. These are stamped 
of 18-gauge nickel silver. 

Facing. — The ends are faced with No. 18 ])orcelain white enamel 
Armco iron, the back with galvanized copper-bearing steel painted with 
aluminum bronze. 




I'K;. 198.— cork IXSULATKD DRAl-T ARM. 



Filler Iiilcls.—hi the bottom of the syrup unit and directly to the rear 
of the boiler, provision is made for filling the outfit with brine or for in- 
serting a siphoning hose should it ever become necessary to remove the 
brine. These consist of heavy brass ^-inch filler tubes just long enough 
to extend through the sub-cover. The upper end is threaded on the inside 
to fit a brass plug. Convenient and out of sight. 

Workboards. 

Clear Counter Service Cork Insulated Draft Arms.— The draft arms 
used in all Guaranty interiors are as shown in the accompanying illustra- 
tion. They are made of bronze, heavily silver plated, hand burnished, 



REFRIGERATED SODA FOUNTAIN 



413 



and are supplied with block tin tubing for the passage of the carbonated 
water through the draft arm to the head. Refrigeration loss is reduced to 
a minimum by the cork insulation which is used. The soda and city water 
after it leaves the coolers travels through the refrigerated syrup unit and 
is connected directly to this cork insulated Guaranty draft arm. In the 
design of these draft arms all sharp lines are eliminated, thus avoiding 
the premature wearing of silver plating through the ordinary process of 
polishing. 

The soda leader pipes running from the coolers to the draft arms are 
equipped with individual shut-ofif valves for each draft, thereby making it 
possible to replace a tumbler or washer when necessary without turning 
off the entire service supply. These valves are located at a convenient 
point in the syrup unit, and are readily accessible. 

Cooling System. 

Soda and city water in all Guaranty interiors are cooled by what was 
formerly known as the Iceless system, or since the advent of mechanical 
refrigeration as the 100% method. This consists of coolers submerged in 
a fresh water bath, cooled by a boiler used in connection with the refrig- 
eration unit which is used to refrigerate the ice cream. 




199.— COOLER AND BOILER ARRANGEMENT, 56-IN. AND 64-IN. 
GUARANTY BOXES. 



The refrigerator section is divided into two compartments by a semi- 
insulated partition ; one for cooling soda and city water, known as the 
cooler compartment ; the other provides cold storage facilities for bottled 
goods, etc., known as the cold storage compartment. In the 56-inch and 
64-inch tall and squat and 77-inch and 82-inch squat creamers, the coolers 
arc located at the rear of the cooler compartment with the Frigidaire boiler 



414 CORK INSULATION 

exactly in front center. In all of the other creamers, the coolers are placed 
on each side of the cooler compartment with the Frigidaire boiler between 
them. The boiler and coolers are submerged in a water bath; jce forms 
around the boiler cooling the water bath and in turn the soda and city 
water. 

The refrigeration is controlled by an automatic regulating valve located 
at the end of the creamer, directly under the drainboard. A temperature 
sufficiently low is maintained, but controlled to prevent freezing. 

The balance of the refrigerator compartment furnishes dry cold 




FIG. 200.— COOLER AND BOILER ARRANGEMENT, ALL OTHER 
GUARANTY BOXES. 

Storage for bottled goods, etc. It secures its refrigeration, through the 
semi-insulated wall from the cooler compartment, and there is no difficulty 
in maintaining the correct temperature for this compartment. 

Coolers. — In the 56-inch and 64-inch creamer boxes is provided a 6- 
cylinder upright soda cooler installed to the rear of the Frigidaire boiler. 
In all other creamers is provided a S-cylinder soda cooler 19 inches long. 
Either of these coolers has ample capacity to assure cold water. The 
outside wall of these coolers is heavily tinned, seamless copper tubing; the 
inside lining is of pure seamless block tin tubing with die cast tin ends. 
All coolers are thoroughly tested under heavy pressure before they leave 
the factory. There are absolutely no flexible connections to become twisted, 
choked or broken. Carbonated water passes through the series of cylinders 
and is finally drawn from the top cylinder. The Guaranty iceless coolers 
reduce wear and tear to a minimum and are properly designed and con- 
structed to insure cold soda water. 

The water cooler used is the same style and capacity as that for the 
soda, except that it is tinned inside instead of being lined with block tin 



REFRIGERATED SODA FOUNTAIN 415 

tubing. This large capacity water cooler insures plenty of cold water and 
is a feature not found in many other makes of fountains. 

Syrup System. — The syrup unit is one of the most important features 
of the soda fountain, the effectual operation of which adds materially to 
the right kind of service, sanitation and cleanly appearance of the fountain 
itself. It is just as necessary to supply adequate refrigeration for this unit 
as it is in the balance of the fountain. 




FIG. 201.— COOLER. 



The Guaranty fountains' refrigeration is provided by means of metal 
contacts between the syrup unit lining and the lining of the bulk cream 
compartment. Wide copper conductor strips are attached to the bottom of 
the syrup unit lining, the other end of which is submerged in the cold 
brine. This metal contact is a positive conductor, and heat is absorbed 
from the syrup unit, just as certain as the fiow of electricity over copper 
wire. A temperature of from 20 to 30 degrees less than the room tempera- 
ture is maintained, and fruits and syrups never sour. 

To conserve all of the refrigeration supplied, a special non-conductor 
I breaks all metal to metal contact with the outside, as fully described and 
1 illustrated previously. 

^ This method of supplying refrigeration to the syrup has been success- 
fully used by Guaranty for years, and the application of it when used with 
[;: mechanical refrigeration is not only highly approved by prominent refrig- 
||i eration engineers but has proven an outstanding success in actual use. 

Compressor Installation under Drainboard. — Standard Guaranty plans 
shown contemplate installation of the Fridigaire compressor in the base- 
ment or other convenient place, removed from the soda fountain. Where 
this is impossible and it is necessary to keep the refrigerating unit in the 
same room with the soda fountain, installation can be made under the 
drainboard, as shown in Fig. 202. 



416 



CORK INSULATION 



These compressor enclosures are made of paneled cypress, contain a 
floor for the machme and are vented to allow free circulation of air, which 
not only insures a dry enclosure, but permits the operation of the com- 
pressor to its fullest efficiency. They are faced with porcelain white enamel 
Armco iron to confirm to the rest of the fountain. Minimum plain drain- 
board space required is 38 inches. 




FIG. 202.— COMPRESSOR UNDER DRAINBOARD. 



Backbar Bases. 

Refrigerator Bases. — Where cold storage in addition to that provided 
in the interior is desired, bases can be supplied either partially or wholly 
refrigerated. Bases of this construction are metal lined and equipped with 
hardwood racks. The bottom, back, top and both ends are insulated with 
2-inch thick pressed pure corkboard, as are the doors which are of heavy 
refrigerator construction with stainless vitrolite panels. Bases constructed 
as above are 22 inches wide overall. 

The installation of the Frigidaire cooling coils is a simple matter and 
consists of placing one of the ordinary ice box coils in the base. Tiie unit 
required depending on the number of cubic feet it is intended to refrig- 
erate. The local Delco Light dealer can give the desired information and 
recommend the coil to be used. 

Three Door Refrigerator ijicltiding Biological Drawer Section. — 
Fig. 203 illustrates a standard cabinet base with a section refrigerated by a 
Frigidaire remote installation as shown. A standard drawer section for 
storage of biologicals is included. This is a handy arrangement for use 
in drug stores. The two end cabinets are not refrigerated, but these also 
can be included if so desired. 

Three Door Refrigerator Section. — The base shown in Fig 204 is 
designed to accommodate the installation of the necessary compressor in 
the base. A compact arrangement where no basement space is available. 



I 



REFRIGERATED SODA FOUNTAIN 417 

The doors of the compressor enclosure are metal with ventilating oi)enings, 
finished in baked white enamel. \'rntilator holes are also provided thru 
the back and end. 




FIG. 203.— REFRIGERATOR T.ASE WITH BIOLOGICAL DRAWER SECTION. 

A convenient auxiliary for those soda fountain owners who require 
much space for storage of bottled goods. 




CROSS StCTlON A ft , 



FIG. 204.— REFRIGERATOR BASE WITH FKIGHJAIRE MACHINE 
COMPARTMENT. 

Cubical contents of refrigerated sections in Ijackbar bases with size of 
Frigidairc coil recommended : 

DIMENSIONS OF REFRIGERATED SECTIONS AND COIL RECOMMENDED. 



Size 



Depth 



Height 



Length 



Cubic Feet 



Coil 



3 Door 15'/2 inches 

4 Donr ISyi inches 

5 Door LS ',4 inches 

6 Door L^ J'S inches 



29 inches 63 inches 

29 inches 35 '/< inches 

29 inches ICS inches 

29 inches 130'/. inches 



16.4 No. 10 

22.25 No. 12 

2S'.l No. 14 

34.0 No. 14 



Backbar Bases With Recessed Ice Cream Cabinet. 

When it is not practical to imt sufficient ice cream cabinets in the 
iterior. the use of this base will be found desirable. The standard size is 



418 CORK INSULATION 

made to take six S-gallon ice cream packing cans (twin packer style con- 
struction). The width overall of this base is 30 inches. It is regularly 
built with cabinet base ends but may be built with full refrigerator ends 
at an additional price if so specified. 




FIG. 205.— BACKBAR BASES WITH RECESSED ICE CREAM CABINET. 

The overall dimensions of the standard recessed ice cream cabinet are 
29 inches high, 28^ inches deep from front to back and 46^ inches long. 
A standard 30-gallon capacity recessed ice cream cabinet as illustrated, 
occupies the same space as is required for three regular standard door 
compartments. 

If squat cans are used the overall width of the base is 32 inches and 
the overall dimensions of the cabinet are: Height, 29 inches; depth, 30^ 
inches; length, 49>^ inches. 

The following specifications have been extracted, through 
the courtesy of the manufacturer, from the literature of The 
Liquid Carbonic Corporation, Chicago, Illinois: 

UNIVERSAL MECHANICOLD SODA FOUNTAIN. 

Fig. 206 is a marble constructed cooler box, insulated throughout with 
pure corkboard. The top capping is one piece 18-gauge nickel silver with 
a beaded or rolled edge. 

Two boilers and a control valve are supplied and a Y^ h.p. Frigidaire 
compressor is required to operate. 

The box has two openings for bulk ice cream storage. Each opening 
is equipped with a double hinged black insulating cover and is capable of 
holding two 5-gallon bulk ice cream cans. This gives a capacity of four 
S-gallon cans of bulk ice cream or 20 gallons, all of which is maintained 
at a uniform temperature from the top to the bottom of the cans. 

The extreme left hand opening is a package storage compartment 
which has a storage capacity of 10 gallons with an insulating cover the 
same as those over the bulk ice cream compartments. It is maintained at 
a special low temperature, around zero to insure proper storage for pack- 
age ice cream. 



NOTE— All references to positions in illustration and diagrams are made as if 
standing in front of counter. 



REFRIGERATED SODA FOUNTAIN 419 

A dry cold storage compartment is located next to the attemperating 
chamber. This compartment is extra large and roomy being 24x24 inches. 
There is ample room for the storage of milk, grape juice and other bottled 
goods. No ice is used in this compartment; it is maintained at a low 
temperature by means of the ice formation in the attemperating chamber. 

In the top of this compartment is a large size chipped ice pan, the drip 
from which is carried into an outlet pipe, keeping the interior of the cold 




FIG. 206.— UNIVERSAL MECHANICOLD SODA FOUNTAIN (ONE STATION 
COOLER BOX). 

storage compartment dry. If desired this pan may be used as a container 
for whipped cream. 

There are three octag6nal pattern stamped silver, silver-plated, cork 
insulated, draft arms in the center of the box. The box is also equipped 
with 14 "Mechanicold" double support, silver-plated pumps with black 
insulating tops and 14 white vitreous syrup jars. In place of any of the 
syrup pumps a white vitreous two compartment spoon holder can be sup- 
plied. 

If additional crushed fruit jars are required a short jar can be supplied 
to take the place of the regular syrup jar. This jar is equipped with a 
black insulating hinged cover in which is fitted a porcelain name plate. 
These covers are similar to those used on the crushed fruit jars in the 
cooler box. 

A double capacity Coca-Cola jar can be furnished in place of two 
regular jars. This double capacity jar can be equipped with either two 
syrup pumps or one syrup pump and one crushed fruit cover ; permitting 
the filling of the jar without the removal of the pump. 

In the cooler box are three crushed fruit bowls and ladles. These are 
placed between the storage compartment and the attemperating chamber. 
In place of two of these crushed fruits a double capacity jar may be sup- 
plied at no additional cost which can be used as a whip cream container. 
A milk pump may be substituted for all three jars if desired. An addi- 
tional charge is made if the milk pump is wanted. 

The cooler box may also be equipped with six crushed fruit bowls over 
the attemperating chamber in place of the corrugated drain cover which is 
regularly supplied. If the crushed fruits are desired, there will be an 



420 



CORK INSULATION 



additional charge. All of ihese crushed fruit jars are equipped with black 
insulating hinged covers in which are fitted porcelain name plates. Ladles 
are supjilied for each jar. 




■:w OF THE rM\ i;rs.\i. miv 

CORKBOARD INSULATION. 



WICOLl), SHOWING 



Iiisiilatioii. — It IS not possible to build a perfectly insulated box. The 
best that can be done is to take every possible jirecaution against permitting 
unnecessarv losses through fauU\ insulation or construction. 




FIG. 208.— PURE fORKI'.OARl) INSl LAT 



USKD 1!Y MECHANICOLIX 



Pure cork board is the best insulator known, other than a perfect 
vacuum and it is not possible to obtain a vacuum in building a fountain. 
Therefore, the next best thing is used, pure cork board as shown in 
Fig. 208. 

A minimum thickness of three inches of cork is used in front, ends, 
bottom, and top, and there are five inches in the back. This 3-inch mini- 
mum of pure cork board is supplemented with additional ground cork, 
which fills every inch of space in the interior of the box around the brine 
tank. 



REFRIGERATED SODA FOUNTAIN 421 

Insulated Draft Ann. — This is another exclusive Liquid feature that 
helps to produce the wonderful results certified to by Prof. Gebhardt of 
The Armour Institute. 

Metal is a thermal conductor, that is, it conducts heat just as a wire 
conducts electricity. An uninsulated metal draft arm will pick up heat 
from room temperature and raise the temperature of the water drawn 
from the coolers. 

The Liquid draft is made of stamped nickel silver, silver plated, and is 
filled with cork, insulating the block tin tube which carries the water from 
the coolers to the head of the draft arm. 

Aside from its actual value in conserving refrigeration, the draft is 
worth while by reason of its attractive appearance. 

The old stereotyped design is gotten away from and the new type 
outfit adds materially to the appearance of the fountain. 

There is also provided a perfectly sanitary channel for the flow of 
soda water from where it leaves the coolers up to the time it is dispensed 
into a glass for service to a customer. 

Block tin is the only sanitary metal impervious to the chemical action 
of soda water or carbonic gas. 

RUBBER 

MOULDED COVER 



MOULDED 
INSULATING 
RING 



TUBULAR 
RUBBER GASKET? 

FIG. 209.— SECTION THROUGH COVER AND LID, SHOWING CORKBOAKD 
INSULATION. 

Breaking Metal Co>ifacfs.—\leta\ is a thermal conductor, that is, it 
conducts heat or cold. Fig. 209 shows how all metal contacts between 
the top cappings nad the linings are broken. 

If this was not done the heat from the room temperature would be 
communicated to the metal capping and carried into the box through con- 
tact with the metal linings. This would result in putting an unnecessary 
load on the refrigerating unit, soft ice cream, and loss through shrinkage. 

Completely Insulated Syrup Enclosure.— The illustration shows some 
very radical changes in the construction of the Syrup Enclosure, all made 
to conserve refrigeration. 

The syrup jars are completely enclosed and the enclosure is insulated 
with slabs of pure cork board at front, ends, top and back. 

The front of the enclosure is faced with Bakelite panels, mahogany 
color, which add to the appearance and afford additional insulation. 




422 



CORK INSULATION 



The bottom lining in the enclosure is contacted with the walls of the 
brine tank. Metal is a thermal conductor, i.e., heat units flow through it 
as does an electric current. The contact between the walls of the brine 
tanks, with their zero temperature, and the tinned copper lining of the 
syrup enclosure, serves to carry the cold to this enclosure. 



^ x^ 




FIG. 210.— SECTION OF CORKBOARD INSULATED SYRUP ENCLOSURE. 

Metal contacts between the enclosure linings and the capping around 
the top of the enclosure are broken by strips of non-conducting material, 
so that this capping will not conduct heat into the enclosure. See also, 
in description of Bakelite pump plate, the additional precaution exercised 
at this point. 




FIC. 2n.— CORK INSULATED COVER RING. 



REFRIGERATED SODA FOUNTAIN 



^23 




424 CORK INSULATION 

Covers for Junior Box. — As there is but a single opening on the 
Junior type Mechanicold, the full opening cover is supplied with dou- 
ble point hinges. 

These lids are made of 16-gauge nickel silver (weighing 2^/4 pounds 
to the square foot). The linings, also of nickel silver, are formed so as to 
fit inside the turned down edges of the top. This is known as telescoping 
and the joint is flooded with solder, making what amounts to one piece 
construction. 

Between the top and lining is insulation of pure cork board. 

The double point hinge permits of the full opening of the lid. 

The raised edge around the opening in the capping which received the 
lid, is die stamped and will not break down. It prevents moisture on the 
cover getting into the ice cream can. 



CORK INSULATION 

Appendix 



REFRIGERATION IN TRANSIT* 

By Dr. M. E. Penningtux. 

Chief, Food Research T.ahoratory, Bureau of Chemistry, 
United States Departnient of Agriculture. 

The people of the United States are as dependent upon refrig- 
erator cars for their food supply as are the people of England up- 
on her ships. The English refrigerated food ship is the result of 
a systematic evolution; the American refrigerator car, like Topsy, 
has "just growed." The United States has now well over one 
hundred thousand refrigerator cars belonging to railroads. It costs 
at least $1,500.00 to build a refrigerator car, and most of them are 
in need of rebuilding after five years of service. With such an in- 
vestment and cost of maintenance, and with the responsibility of 
transporting fresh food to the people, we may well inquire into 
the efficiency of the car for the work it is performing, and into the 
expense involved. 

The United States Department of Agriculture, through the Bur- 
eaus of Plant Industry and Chemistry, has for some years been 
studying the temperatures required to preserve perishable produce 
in transit. The Department has obtained definite information on 
fruits, vegetables, dressed poultry and eggs. It is now determining 
the most efficient and economical means of transporting these per- 
ishables. The problem is of great importance to the shippers, to 
the railroads, and to the consumer as well. 

The efficiency of the refrigerator car depends upon such factors 
as the quantity and kind of insulation, the type and the capacity 
of the ice bunkers, the size of the car, the temperature of the en- 
tering load, the manner of stowing the packages, the circulation of 
cold air from the ice bunkers, and the freedom of the insulating ma- 
terial from moisture. The economy of operation depends on such 
factors as the weight of the car in relation to the weight of the 
load, the amount of ice required to cool the product in transit or 
to maintain the initial temperatures of the precooled load, and the 
length of life of the car. All these, and other questions are the 



'Address before the Chicago Traffic Chib, October 5th, 1916. Reprint from the 
Waybill. October, 1916. N'olume No. 7. 

425 



426 CORK INSULATION 

subject of investigation in the Department of Agriculture in con- 
nection with the study of the preservation of the good condition 
of perishables vi^hile in transit. 

Apparatus and methods of investigation had to be developed 
to obtain the necessary data. Gradually there has been evolved an 
arrangement of electrical thermometers which can be installed not 
only in appropriate locations in the car, but within the packages, 
and even inside an orange, peach, chicken or fish. The wires from 
these thermometers run out between the packings of the door, 
and the terminals are permanently or temporarily attached to the 
indicators installed in an accompanying caboose. 

Fundamental Facts Established. 

To complete this investigation will require years of detailed 
study. Certain fundamental facts, however, have been established 
and are outlined in this paper. For example, the distribution of 
the cold air from the ice bunker throughout the car is vital to the 
preservation of the lading. The circulation of the air is produced 
and maintained by the difference in weight of warm and cold air. 
The actual difTerence between the weight of a cubic foot of air at 
65° F. (1.18 oz.) and 32° F. (1.27 oz.) is only 0.09 ozs. Experi- 
ments with stationary precooling plants, cooled by ice or by ice 
and salt, have shown that the best and most economical results 
are obtained by hanging a basket of suitable ice capacity close to, 
but actually free from the walls of the room, and closing off the 
basket by an insulated bulkhead open about twelve inches, both at 
the top and bottom, to permit entrance and exit of air. In this 
way a large surface of ice is exposed to air contact and the air is 
compelled to travel over the entire column of ice before it escapes. 
The insulated bulkhead prevents the absorption of heat from the 
commodity and from the car, varying in quantity according to the 
distance from the ice. The bulkhead also facilitates a steady ascent 
and progression of the warm air in the car toward the top of the 
bunker. To further facilitate the distribution of cold air throughout 
the space, floor racks four inches high have been installed. 

Now let us see what practical results such a combination pro- 
duces when applied to a refrigerator car which is, in other respects, 
of the usual type. Chart I* shows the average temperature in 
three cars of oranges in the same train in transit between Los An- 
geles and New York, each car containing 462 boxes of fruit. Car 
"A" had the box bunker and open or slatted bulkhead so commonly 
seen in present day refrigerators. The lading was placed directly on 
the floor. Car "B" had a basket bunker, insulated solid bulkhead, 
and a rack four inches off floor. Car "C" was of the same con- 
struction as car "B" but the ice was mixed with nine per cent salt 

•The study of fruits and vegetables is being conducted by the Bureau of Plant 
Industry, under the supervision of Mr. H. J. Ramsey. I am indebted to him for the 
data on oranges and also such other facts concerning the transportation of fruits 
and vegetables as are brought out in this paper. 



REFRIGERATION IN TRANSIT 



427 




CHART I. 



the first day and five per cent of the added ice on the second. The 
temperature of the load in the car "A" averaged 54.4° F. The tem- 
perature of the load in the car "B" averaged 49.5° F., while car "C," in 
which salt had been added to the ice, not only cooled the oranges 
more quickly but reduced the average temperature of the load to 
45.5° F., a gain of 9° F. as compared with car "A." The amount of 
ice placed in the bunkers in car "A," including that remaining in 
them at destination, was approximately 23,200 pounds. In car "B" 
the ice amounted to 18,675 pounds, a saving of more than two tons. 
Car "C," which had been salted, had 22,750 pounds of ice, still a 
little less than car "A." 

The results obtained with car "C" open up great possibilities 
in the better distribution of such extremely perishable products as 
strawberries, raspberries and cherries, widely produced under con- 
ditions which generally preclude proper precooling before loading 
into the car. The insulated bulkhead prevented the frosting of the 



428 CORK INSULATION 

lading next to the bunker, and the floor rack provided a quick run- 
way for the very cold air, which soon lost its temperature of 20° F., 
or even less, by the absorption of the heat of the lading and of the 
car. 

Such results with the basket bunker, insulated bulkhead and floor 
rack, combined, naturally raise the question of the relative value of 
each of the three factors in producing and maintaining circulation, 
and gaining the available refrigeration from the ice. Experimentation 
shows that a rack on the floor of the car hastens the cooling of the 
load, and affords very decided protection to the lower layer of goods 
against both frost and heat. The floor rack, alone, however, is far 
less efficient than the combination of the basket bunker and insulated 
bulkhead with the floor rack. The addition of insulation to bulkhead 
increases circulation and the lading is more rapidly and completely 
cooled than when the bulkhead is either not insulated or is open. 
For example. Chart II shows two cars of similar size and construc- 
tion, one of which was provided with a floor rack and an insulated 
bulkhead, the other as commonly used. Both were loaded with eggs. 
The car with the insulated bulkhead and the floor rack reduced the 
average temperature of the load 17° F. in sixty-four hours. The load 
in the ordinary car showed a reduction of 7.5° F. during the same 
period. The average temperature of the car with the insulated bulk- 
head and the floor racks was 5.5° F. lower than the ordinary car. 
That it is not advisable to cease improvements with the floor rack 
and the insulated bulkhead is indicated by experiments which show 
that quick cooling by ice and salt safely performed with basket in- 
sulated bulkhead and floor rack is not possible without it. The 
pocketed cold air at the box bunker, which is always observed with 
bunkers of the box type, causes frosting of the goods against the 
bulkhead even when that is insulated. 

The failure of refrigerator cars to maintain even temperatures 
throughout the load has been a serious menace to extremely perish- 
able products. In order to produce temperatures at the top of the 
load between the doors — commonly the warmest place in the car — 
low enough to carry dressed poultry safely, it has been necessary to 
freeze the birds at the bunker. While freezing in transit does not 
injure the food value of dressed poultry, it does lower its money 
value at certain seasons or in some markets. Better air circulation 
tends to equalize temperatures, as shown in Chart III. In the car 
with the box bunkers and open bulkhead (car B), where the load 
was placed on floor strips, the package at the bunker on the floor 
froze solidly (23° F.) during a four-day haul, although the package 
on the top of the four foot load was 35.4° F. A similar car (car A), 
except that it had a basket bunker with insulated bulkliead and a 
floor rack, maintained an average tcm])eraturc of 29.3° F. at the 
bunker and 34.1° F. in the package on the top of the load between 
the doors. In the one case, the average difference between the 



REFRIGERATION IN TRANSIT 



429 




430 CORK INSULATION 

warmest and the coldest points in the car was 12.3° F., in the other 
4.8° F. 

The reduction of the temperature on top layers can be increased 
by better and more judiciously applied insulation, especially in the 
roof of the car. Most of the cars in service have the same amount of 
insulation throughout, regardless of the additional strain on the roof 
during the heat of summer, and on the floor when frost protection' 
is necessary. Experiments are now under way to determine just 
how much insulation it is advisable to have in roof and floors as 
well as in the body of the car. At present the work indicates that 
there is scarcely a refrigerator in the country which is sufficiently 
well insulated to be an economical as well as a safe carrier of perish- 
ables. A large proportion of the refrigerator cars now in service have 
one inch of insulating material over the entire car. Some have two 
inches throughout, and a few, comparatively, have had special care 
bestowed on the insulation of the roof and the floor. The lack of 
sufficient insulation, especially on the roof of the car, has been 
responsible for the fact that the top layers of such fruits as peaches, 
strawberries and cherries are so different in quality from the rest of 
the carload that they must be sold as separate lots. The higher 
temperature of the upper half of the car has led the shippers to urge 
longer cars, that they might extend rather than heighten the stacks 
of packages. As a result of this, and also in line with a general 
increasing of capacity of all cars, the refrigerator has been lengthened 
regardless of the fact that heat transmission increases directly as 
the number of square feet of surface enclosing the car space. For 
example, a car whose roof, walls and ends aggregate 1170 square 
feet and which is 33 feet between linings, has the same amount of 
temperature protection with two inches of insulation as a car with 
2.5 inches of insulation whose surfaces aggregate 1407.5 square feet, 
and whose length between lining is 40 feet 6 inches. 

To determine the economical size of a refrigerator car in rela- 
tion to the height of the lading, the consumption of ice, the total 
weight of the car and its initial cost, is an economic problem of im- 
portance. Studies to obtain such information are now in progress. 

The most obvious results due to increased insulation are, first 
better protection to the lading against both heat and cold, and 
second, a saving in the use of ice. The modern trend in the han- 
dling of perishables is to include precooling as a preparation for 
shipment, and it is a highly desirable practice from all viewpoints. 

When the goods enter the car at a temperature conducive to 
preservation, it is the business of the car to maintain that tempera- 
ture. The goods need no further refrigeration, and the ice in the 
bunkers is required only to overcome the heat leakage through the 
walls. The difference in performance of a car with one inch of insu- 
lation as compared with a similar car, except that the latter was pro- 
vided with two inches, is shown in Charts IV and V. Both cars were 
loaded with eggs and closed without patting any ice in the bunkers. 



I 



REFRIGERATION IN TRANSIT 



431 




432 



CORK INSULATION 




CHART IV 



The weather at the loading point was cool enough to ensure a cool 
car. The possible dangers — against which the insulation was to 
protect — lay ahead. Chart IV, showing the performance of the car 
with one inch of insulation, indicates very plainly that it could not 
protect the eggs. Chart V, on the other hand, shows that two inches 
of insulation, even with higher atmospheric temperatures, delivered 
the eggs at destination at practically the same temperature as they 
entered the car, and the maximum variation was but four degrees. 

The one inch car needed 10,000 pounds of ice — the two inch car 
needed none. Is it any wonder that wide-awake shippers are picking 
out their refrigerator cars more and more carefully? 

Experimentation indicates that marked economies can be effected 



REFRIGERATION IN TRANSIT 



433 



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ill the consumption of ice in transit aside from the question ot insu 
lalion. Raising the load ofif the floor, inducing a circulation of air 
in the car, and bringing a large surface of ice into contact with the 
air, tends to reduce the amount of ice used. As stated in another con- 
nection in this paper, a carload of oranges in a car having box 
bunkers with open bulkheads, and without a rack on the floor, had 
23,200 pounds of ice put into the bunkers between Los Angeles and 
New York. A similar car provided with basket bunkers, insulated 
bulkheads, and a floor rack, had 18,675 pounds. Neither load was 
precooled. 



434 



CORK INSULATION 




That precooling of the lading means fewer icings in transit is 
a matter of common knowledge. That hard freezing of the goods, 
whereby they not only do not require additional chilling in transit, 
but actually furnish refrigeration to the car, is not so commonly 
recognized. Chart VI shows the temperatures in transit of 20,000 
pounds of poultry which went into the car at 0° F. The railroad 
icing record shows that 4,700 pounds of ice was added during the 
eight-day haul, and 470 pounds of salt. Other experiments, under 
comparable conditions, show that nearly 5,000 pounds of ice is used 
by cars carrying 20,000 pounds of poultry chilled to 30-32" F. during 
a four-day haul, or approximately twice as much. 

The temperature records show that the poultry grew gradually 
warmer, faster on the top and bottom of the load, where the heat 
leakage from the roof and floor was most pronounced, and most 
slowlv in the center of the load, where the packages protected one 



REFRIGERATOR CARS 435 

another. The chart also shows that the amount of salt added during 
transit is insufficient to maintain the temperature produced on the 
initial salting, when the full ten per cent of the weight of the ice 
was present. It must be remembered that the salt bores through the 
ice and escapes as brine more rapidly than the bulk of the ice melts, 
hence it is in constantly decreasing proportion. Icing and salting 
rules take no account of the fact. It is quite obvious that different 
rules must be formulated if efficiency is to be secured. 

This problem, like all the other problems confronting the shipper 
and the carrier who are engaged in getting perishables to market in 
good condition, can be solved only on the basis of exact knowledge. 
That knowledge the United States Department of Agriculture, in co- 
operation with the shippers and the railroads, is now endeavoring to 
acquire and to pass on to all whom it may benefit. 



THE ABILITY OF REFRIGERATOR CARS TO CARRY 
PERISHABLE PRODUCTS.* 

By Dr. M. E. Pennington. 

Chief, Food Research Laboratory, United States Department of Agriculture, 

Bureau of Chemistry, Philadelphia, Pa. 

Mr. Herman J. Pfeifer (Terminal R. R. Ass'n, St. Louis): Mr. 
President, ladies and gentlemen: At our last meeting, Mr. Aishton, 
President of the Chicago & Northwestern Railroad, made the remark 
that on the advice of Dr. Pennington, his road appropriated the sum 
of $200,000 for improvements in the matter of refrigerator cars in a 
shorter time than an equal sum of money had ever been appropriated 
by that railroad. 

The question of food conservation is intimately connected with 
its transportation, and a great deal of our food being of a perishable 
nature, which must be transported in refrigerator cars, makes the 
consideration of this subject a very vital one at this time. The sub- 
ject, therefore, about which Dr. Pennington is to speak, namely, the 
ability of refrigerator cars to transport perishable products safely, 
is one of vital interest, under present conditions. 

Dr. Pennington is recognized throughout the country as an 
authority on food conservation and preservation, and it now gives 
me great pleasure to introduce to you Dr. M. E. Pennington, Chief 
of the Food Research Laboratory of the United States Department 
of Agriculture. (Applause.) 

•Reprint from the Official Proceedings, St. Louis Railway Club, October 12th, 
1917, Vol. 22, No. 6. Address delivered before the St. Louis Railway Club, 
October 12th, 1917. 



436 



CORK INSULATION 



Mr. President, Members and Guests of the St. Louis Raihvay Club: 

It is with a great deal of embarrassment that I undertake to 
address you railroad men upon a subject dealing with facts with 
which so many of you are already well acquainted. 



TYPC I 
BOX aUNKCK. OPCN BULKMCAO, 

PCRMANCNT rcOOfl iTDIPS. 
INSULATION BPOMCIf Br AIR iPACCS 




>i imuLATION 



V.9. 0£fT or ASRICULTUHC 



FIG. I. 

The responsibility of appearing before you is great, dealing, as I 
shall, with matters which are of daily occurrence in your own line 
of business, and inasmuch as I come here, talking to you in your own 
bailiwick, the only excuse that I can plead is that we are at war, 
that we need food, and that food must be saved. Anything that we 
can do to save the chicken, the tg%, the fish, no matter to how small 
an extent, we must do, as a part of the work that we all have in 
hand, to the end that we may win this war. 



i 



REFRIGERATOR CARS 



437 



If I can do just a very little bit by placing before you some of 
the results of the investigations of the Department of Agriculture in 
the matter of saving foodstuffs, I will be more than glad, and I 
know that you, as patriotic American citizens, will rejoice, also. 



i 



RErRIGERATOR CAR 
TrP€ i 

BASKCT eU/VKCff. INiULArCD 

BULKMCAD, FlOO" fTACrS 

MAiS£D INSULATIOM 




PCKIS 


"ABLCS I 


V 


TKANSn 


INVCSTIGATI0N5 


U S DCPT 


cr Arsaico 


lturc 



We are being daily more and more impressed with the evidence 
to show that this war will be won by food. 

The task of feeding the Allies and ourselves becomes more im- 
portant as it becomes more difficult. The President urges increased 
production and agriculture is fostered as never before — yet we know 
that the calling of men to the colors and to the many activities of 
war means greater and greater difficulty in the production of the 
foodstuffs necessary to win the war. Therefore, conservation and. 



438 CORK INSULATION 

the elimination of food waste and spoilage has become a world 
question of vital interest. 

The question of transportation has also become of overwhelming 
importance. Our railroads are taxed to their utmost, and, as in the 
food question, the future seems to hold problems even harder to 
solve than those now at hand. Every rail, locomotive and car must 
be utilized for maximum service. The refrigerator car, especially, 
becomes an object of renewed interest, because upon it depends 
very largely our ability to render available the crops produced and 
food animals raised. It must carry a full load, yet we must not, in 
our zeal to transport perishables, permit any spoilage or damage in 
transit that can possibly be avoided. 

The investigation of the transportation of perishables which is 
now under way in the United States Department of Agriculture has 
shown that the refrigerator equipment on the various lines differs 
widely in ability to protect against heat and cold. This variation 
depends to a certain extent upon the size and character of the load 
as well as upon the construction of the car. It is my purpose to 
discuss with you some of the results of these investigations, com- 
paring the performance of cars of varying types when loaded with 
varying quantities of the commodity to be transported. First, how- 
ever, let me very briefly outline the major dififerences in the con- 
struction of the cars used in these experiments. In the general pur- 
pose refrigerator car we find two types of bunker — one known as the 
"box bunker," illustrated in Fig. I, in whhich the ice rests directly 
against the end and sides of the car — and the other, known as the 
"basket bunker" in which the ice is held in a wire container two 
inches away from walls and bulkhead (see Fig. II). The box bunker 
usually has an open bulkhead of wood or metal. Sometimes we find 
a solid wooden partition open at top and bottom. The basket 
bunker commonly has a solid, wooden bulkhead, open twelve inches 
at the bottom and fourteen inches at the top, and in the new cars 
this bulkhead is insulated with one inch of a recognized insulator. 
The new cars, also, have a rack, on the floor, four inches in the clear, 
made of 2x4 runners and 1x3 cross slats, lJ/2 inches apart. These 
racks are fastened to the sides of the car with hinged bolts. They 
are divided in the middle so that they can be turned up against the 
walls when the car is cleaned. They are absolutely necessary for 
the safe carrying of perishable loads. Most of the cars now on the 
lines are without racks. Some have permanent strips on the floors 
one or one and one-half inches in height. These strips are practically 
valueless. The insulation varies from a few layers of paper to three 
inches of some recognized insulator. In some cars the layers of 
insulation are broken by spaces — in others the insulation is massed. 
The cars in the experiments were from approximately twenty-nine 
feet between bulkheads to approximately thirty-three feet. 

The majority of the experiments used as illustrations are taken 
from the investigations on the transportation of eggs, because that 



REFRIGERATOR CARS 



439 



; TenPef>AT</n£ m.TtfANSIT ej(P£/ilMCfiT-5334(SuMMARY) 

Floha.Ill. TO New Yodfr.HY ' 



. PACKAOC.THC/tHOMCrenS 



OAD. BCTWCCM OOORiCtffTCIt 




CHART VII. 



field of work is under my charge. Whenever the shipment of fruits 
or vegetables is used to emphasize a fundamental, the facts have 
been furnished me by Mr. H. J. Ramsey, of the Bureau of Plant 
Industry, under whose direction all such commodities are being in- 
vestigated. Of course, all temperatures were taken by means of 
electrical thermometers inserted when the cars were loaded, and 
the mechanism was such that neither the doors nor the hatches were 
opened to take records nor was the car modified in any way. 



440 



CORK INSULATION 



Now let me proceed to the work done by such classes of cars 
as above indicated. 

The car factors which determine the size of the load which can 
be safely carried are insulation, bunkers and floor racks. Each exer- 














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CHART \TII. 

cises a specific influence as indicated in Chart VII. This experiment 
consisted of three cars which had been in experimental service for 
about ten months. As shown on the chart, cars A and C were pro- 
vided with basket bunkers and floor racks; car B had a box bunker 
and strips on the floor. Cars A and B had three inches of insulation 



A 



REFRIGERATOR CARS 



441 



in the roof, two inches in side walls and ends and two inches of 
cork in the floor. Car C had one and one-half inches in the walls 
and two inches in the roof and floor. Each was loaded with six 
hundred cases of eggs consolidated from pickup cars, and each re- 




CriART IX. 

ceived the same amount of ice accurately weighed into the bunkers. 
About twelve thermometers were put into each car. For our pur- 
poses the temperatures in the cases of eggs on the bottom and top 
of the load are especially significant, and indicate very plainly the 
amount of work which the car can do. For example, the temperature 



442 



CORK INSULATION 



of the eggs on the floor of car B, between the doors, was 66.5° F. 
on arrival; car C, in the same location, was 45.5° F. and car A, 
44.5° F. The packages between the doors on the top of the load — 
in this case five layers high — showed for car B, 64°, for car C, 56.5°, 
and for car A, 55.5° F. 

The behavior of the packages on the floor of car B between the 
doors is especially noteworthy. They were continuously higher in 
temperature than the packages on the top of the load, a condition 



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CfiLirOKHIA TO A/Cir rOUK 


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quite contrary to the generally held idea that the coolest place in a 
refrigerator car is its floor. That is only true when the construction 
is such that the cold air from the bunkers can travel along the car 
floor. This experiment, and many others that we have made, shows 
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goods on the bottom of the load in the two middle quarters of the 
car are to be refrigerated. It is of interest to note, also, that the 



REFRIGERATOR CARS 



443 



insulation in cars A and B is unusually heavy, in fact, more than 
twice as much as in most of the refrigerator cars now in service, 
yet, because of the construction of the bunkers in car B and the 
absence of a rack on the floor, there was practically no refrigeration 
except near the bulkheads. 

Manifestly, car B is not a satisfactory carrier for a heavy load 
of eggs. Car A, on the other hand, has done its work well, and at 
first sight car C, having less insulation, appears to be efficient for a 



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load of 600 cases of eggs during hot summer weather. Further study, 
however, shows that the packages around the walls of car C came 
into destination over 6° higher than the corresponding packages in 
car A (Chart VIII), though when loaded they were but 3° apart. 

Car C used about 1,000 pounds more ice than car A and, on the 
whole, did less satisfactory work, especially around the walls, where 
actual deterioration due to heat undoubtedly occurred. 



444 



CORK INSULATION 



It may be said that in the experiment cited, car B, having the 
box bunker and open bulkhead, was unfairly treated in that the 
temperature of the entering load was distinctly higher. The facts 
illustrated in Chart IX tend to nullify the significance of such an 
argument. In this experiment, the cars had two inches of insula- 




c ITART Xll. 



tion throughout, but car A was of the box bunker type, while car B 
had a basket bunker and its adjuncts. Here the eggs entering car A 
were cooled to between 50 and 60° F., while those in car B ranged 
between 55 and 65° F. However, car A could not even maintain the 
initial temperature. At destination the packages in the middle of the 
car on the floor were nearly 5° warmer than when they entered the car and 



REFRIGERATOR CARS 445 

those in the top layer were over 2° higher. Car B, on the contrary, 
brought in the load from 6 to 14° lower than car A. These two cars 
were loaded with 600 cases of eggs and, so long as the atmospheric 
temperatures were above 80° F., refrigeration was of doubtful efifi- 
ciency. The third and fourth days of the trip were unseasonably 
cool and also rainy, which compensated for the lack of insulation in 
the roof and permitted the load in the car B to drop below 55° F. 
before the end of the fourth day. 

The performance of a poorly built car, said to contain an inch 
and a half of insulation throughout, as compared with a well built 
car known to have one and a half inches of insulation, is well illus- 
trated in Charts X and XI, where cantaloupes were hauled for 
eleven days across a hot territory. The top layer in car A, loaded 
six wide and four high at the bunkers, was in such bad condition on 
arrival that claims were filed for damage in transit. Car B, on the 
other hand, was in good condition, although the load was seven cases 
wide and four cases high. In car A the combination of a lack of 
cold air circulation and of insulation proved disastrous, even though 
the load was light and open in character, and much easier to refrig- 
erate than a load of eggs. In fact, we know that eggs can not be 
safely loaded more than three layers high in summer weather in 
cars having one inch of insulation. Cars having one and one-half 
inches of insulation, if provided with a basket bunker and a floor 
rack, can carry four layers. To load five high, we must have three 
inches in the roof and two inches in the walls, ends and floors, and 
good air circulation. Beyond five layers of egg cases we have not 
succeeded in getting good refrigeration. 

This is illustrated in Chart XII, showing top and bottom layer 
temperatures in two cars stowed six layers high, making 700 cases 
to the load. Car A is of the same type as was used in Chart VII, where 
with 600 cases it did good work. With 700 cases there was practi- 
cally no refrigeration except in the bottom layer. The companion 
car, B, with the same insulation but having a box bunker, did not 
even refrigerate the lower layers. The packages on the floor, middle 
of the car, were often warmer than the top of the load, which was 
only 12 inches from the ceiling. It varied more than 5° with the 
daily rise and fall of the atmosphere and arrived at destination 
showing an increase of 7.5°. 

Encouragingly good results have been obtained in refrigerating 
heavy loads of fruit in the basket bunker cars by adding salt to the 
ice in the bunkers. On a long haul across a hot territory salt has 
been added to the ice at the first three icing stations. By that time 
(the third day) the load was cooled and very frequently no more ice 
was needed, even though the haul continued for five to eight days. 
The air issuing from the bunkers is far below 32° F., but the circula- 
tion is so rapid that there is no pocketing at the bulkhead. The in- 
sulated bulkhead also protects the load so that frosting does not 



446 



CORK INSULATION 



occur. Salting ice in a box bunker, open bulkhead, merely freezes the 
load next to the bulkhead. The packages in the middle of the car 
are not benefited because of a lack of air circulation. 

We have used salt to assist in refrigerating heavy loads of eggs 
and with some success, but we have not succeeded in refrigerating 




(HART Xll 



700 cases in a car 33 feet between bulkheads. The records of car A, 
in Chart XII, bring out this fact. Three per cent of salt was added 
after the load had been placed in this car and salt was again put into 
the bunkers at three icing stations. While the car was not able to 
handle so heavy a load during the very hot weather prevailing, it 
nevertheless did rather remarkable work and furnished valuable in- 
formation on which to develop a more economical and efficient icing 



I 



REFRIGERATOR CARS 



447 



system. Car A, which brought the sixth layer of eggs from 85° 
down to 66.5° F., used 12,660 pounds of ice and 540 pounds of salt; 
car B, which did not refrigerate either the top or bottom of the 
middle part of the load, used 19,755 pounds of ice. 

A great many experiments have been made with fruits and eggs, 




CHART XI\', 



all of which confirm the foregoing; namely, that a suitable use of 
salt saves ice on a long haul and greatly increases the efficiency of 
the work done on both short and long hauls. 

The experiment recorded in Chart XIII adds still further to our 
knowledge of car construction and car performance when salt is used 
with the ice. In this case we had short cars, so that by comparison 



448 CORK INSULATION 

the two inches of insulation became nearly 2.5 inches, and the air 
circulation was more rapid because of lessened distance. Car B was 
of the usual box type; car A had a box bunker with an insulated 
bulkhead and a floor rack; car C was of the standard basket type. 
Cars A and C received salt on the initial icing. They were neither 
iced nor salted in transit on an 88-hour haul. Car B was iced once. 
All contained from 400 to 500 cases of eggs. The three lower layers 
were seven cases wide, spaced for air circulation, and the upper 
layers were eight cases across. The average of all the thermometers 
in the packages in various parts of car B showed that it was far 
above cars A and C until the last day of the trip. An analysis of 
temperatures in different locations shows, further, that the floor of 
car B paralleled the top layer of car C. Car C did much the best 
work of the three. Car A, having the rack and the insulated bulk- 
head, but not the basket bunker, did not succeed in maintaining a 
sufficiently rapid air circulation to cool the top layer more than 5°. 
The packages on the floor, on the contrary, were exaggeratedly 
chilled because of the pocketing of the cold air. The conclusion 
follows that even with an openly stowed load, the car must be pro- 
vided with a basket bunker, an insulated bulkhead, a floor rack and 
ample insulation, if our present loads are to be materially increased 
with safety to the commodity. 

Car C (Chart XIV) of the foregoing experiment, was again 
used with a load of about 600 cases, stowed eight across. The ice 
was salted at the start and 40 pounds was added on the second day. 
Thermometers in the first, fourth, fifth and sixth layer packages give 
an instructive picture of the rise in temperature with the height of 
the load. Without salt, the fourth layer would be the stopping 
point. The fifth layer cases around the walls of the car would 
suffer if the weather were hot, if salt were not used. With the salt, 
as this experiment shows, we can load five high with impunity, but 
not six, because of damage to wall cases. A study of the chart shows 
that the 40 pounds of salt added at the first icing station was 
enough to cause a drop in temperature in all except the sixth layer 
wall packages. Had another charge of 40 pounds been added the 
next day, the rise shown in the lower layers would have been avoided 
and the fourth and fifth layers would have continued to cool instead 
of remaining practically stationary. 

The investigation has convinced us that in the future ice and 
salt will be used for more commodities than fresh meats, poultry 
and fish. Indeed, it is the only way that we now see by which very 
perishable small fruits can be transported in good condition through- 
out the entire car. Of course, a definite routine for its application 
must be worked out. The experiments for the summer just ending 
have yielded much information. We hope that by the end of another 
summer we can bring you specific instructions for a number of 
commodities. 



REFRIGERATOR CARS 



449 



Such instructions must, however, be based on the type of car 
used. Far too many cars now on our lines would be useless no 
matter what treatment they received. For example, we still have 




(HART XV. 



cars with one-half inch of some insulator posing as refrigerators, and 
we still have cars, the walls of which contain only paper and air 
spaces. Considering the relation of foodstuffs to the winning of this 
war, I cannot look upon the use of such cars to transport perish- 



450 



CORK INSULATION 



ables as anything short of a wasteful practice and should be dis- 
continued. 

Look at Chart XV. One of the cars represented is of the paper 




CHART XVI. 

variety, the other well insulated. There is a variation of more than 
15° between the two cars. The floor of the one is often six or more 
degrees warmer than the ceiling of the other. The paper car follows 
the atmospheric temperature and the refrigerant in the bunkers is 
almost powerless. Yet again and again this summer, eggs, fruit. 



REFRIGERATOR CARS 451 

vegetables and dressed poultry have been shipped in these cars and 
sometimes they have been loaded ahnost to their cubical capacity! 

The relative value of the air space and paper as an insulator 
may be further emphasized by comparing a car built with what is 
termed, especially in the south, "a double-felt-lined" car. Such a 
car is considered to be a greater protection than a box car but in 
no wise is it a refrigerator. Indeed, it is not provided with ice 
bunkers. Chart XVI shows how the temperatures on the ceiling of 
such a car follow the atmosphere. Compare its performance with that 
of the paper car on the same chart, and I think you will agree with 
me that there is a decided similarity between the two. 

Summary 

Summing up the results of such experiments as these we are led 
to the following conclusions: 

1. A combination of basket bunker, insulated bulkhead and 
floor rack, produces a circulation of air which is not obtained in a 
car having a box bunker, open bulkhead and bare floor or permanent 
strips. 

2. Such a basket bunker car, approximately 33 feet between 
bulkheads, can refrigerate the top and bottom of the load in the 
two middle quarters of the car, provided it is sufficiently well insu- 
lated and not overloaded. 

3. Cars which depend for insulation on paper and air spaces 
should not be used for the transportation of such perishables as 
fruit, delicate vegetables, poultry, eggs and fish. 

4. Cars having one inch of insulation will not carry eggs suc- 
cessfully during hot weather when loaded more than three layers 
high. 

Cars having one and one-half inches of insulation in the side 
walls and two inches in the roof and floor will not carry eggs suc- 
cessfully during hot weather when loaded more than four layers 
high. 

Cars having three inches of insulation in the roof, two in the 
side walls and ends, and two inches of cork in the floor will carry 
• eggs five cases high, but not six. 

The box bunker car, regardless of quantity of insulation, does 
not refrigerate the two middle quarters of the load when it is tightly 
stowed. Even with an open load the performance is unsatisfactory. 

5. The use of salt with the ice in a well insulated basket bunker 
car will permit an increase in the load of from 25 to 40 per cent. 

6. While each commodity must be studied separately in order 
to determine the maximum load, the principles of the relation be- 
tween car efficiency and tonnage of eggs as indicated in this dis- 
cussion can be applied to perishables in general. 



452 CORK INSULATION 

We are continuing, of course, such work as I have outlined to 
you this evening; it will be a long study before all of the many 
questions which have come to your minds, and which have come to 
our minds, can be answered. It is only by co-operation of the rail- 
roads and the shippers that we can come anywhere near solving the 
many questions that we will have to answer. You railroad men 
have abundantly furnished the co-operation, and we of the Depart- 
ment of Agriculture feel ourselves very greatly your debtors. 

If we can be of any further service to you, please call upon us. 
We want to be of service, of course, that is what the money is ap- 
propriated for, and that is what we are all working for. 



THE DEVELOPMENT OF THE STANDARD 
REFRIGERATOR CAR.* 

By Dr. M. E. Pennington. 

Chief, Food Research Laboratory, United States Department of Agriculture, 

Bureau of Chemistry, Philadelphia, Pa. 

A short time ago the Railroad Administration issued a circular 
the opening paragraph of which reads as follows: "In order to in- 
sure the greatest possible degree of efficiency in refrigeration and 
conservation of food stuffs, refrigerator cars having trucks of 60,000 
pounds capacity or over, will, when receiving general repairs or 
being rebuilt, be made to conform to the following United States 
Standard refrigerator car requirements." Then follow specific details 
and references to blue prints for the construction of the car in 
general, its insulation, its ice boxes and the many details which go 
to make up a refrigerator car. Throughout one finds that the rail- 
roads are instructed to build in conformity with the "United States 
standard refrigerator car." 

Knowing the difficulties which attach to obtaining agreement 
among car builders, the desire of the financiers of the railroads to 
minimize the outlay for equipment and the great variety of perish- 
ables to be transported, one may well ask how such an order has 
come about, and upon what it is based. 

Considering the fact that we have in this country more than one 
hundred thousand refrigerator cars, and that ultimately all will 
probably conform to the essentials just laid down by the Railroad 
Administration, it may not be amiss to review the circumstances 
which have led to the issuance of "Mechanical Department Circular 
No. 7." 

In the latter part of the '90's and early lOO's the difficulties in 



Reprint from the American Society of Refrigerating Engineers Journal, July, 
1919, Vol. 6, No. 1, presented at •the fourteenth annual meeting. New York, Dec, 
2nd. 3nd and 4th, 1918. 



STANDARD CAR 453 

the distribution of our perishables attracted an increasing amount of 
attention because the length of the hauls increased as more distant 
markets demanded supplies, and the losses from decay in transit 
kept pace with the distance traveled. Some of the shippers applied 
to the United States Department of Agriculture for assistance, among 
them the Georgia peach growers. These growers were in trouble; 
they could not successfully ship their product to northern markets 
because of the losses from decay. So in 1903 Mr. G. Harold Powell 
and his associates undertook to investigate the matter. They studied 
the effect on ripening of cooling the fruit quickly after picking and 
before loading in the car as well as the development of decay in 
transit. Precooling, however, was not a reliable remedy because the 
insulation of the refrigerator car of the south was, and is, insufficient 
to retain the chill imparted to the fruit and the air circulation in the 
cars was, and is, inadequate to transfer the refrigeration from the ice 
bunkers to the center and top of the load. This is a handicap which 
limits the distribution of the Georgia peach crop and from which the 
industry has never been able to escape. So universal is the failure 
of the cars to refrigerate the top layers and the middle of the car, 
that receivers expect to market the load as at least two grades, 
though the pack may have been uniform when shipped. To anticipate 
the story somewhat, I may say here that when carloads of peaches 
in adequate refrigerator cars came into the market during the sum- 
mer of 1918, with top, bottom, middle and ends all in like condition, 
the astonishment of the trade was interesting to contemplate. The 
higher prices to the shippers, likewise, were gratifying in the ex- 
treme, and the railroads had no claims to pay. 

From Georgia peaches the investigators were called to California 
oranges. The industry was severely handicapped because of decay 
in transit. Again the inadequacies of the refrigerator cars were 
apparent. The investigations of the temperature in cars in transcon- 
tinental trips brought out the differences in the different parts of the 
car and their relation to the excessive decay in the middle of the 
load and its upper portion. With oranges which ripen slowly after 
picking, careful handling in orchard and packing house to eliminate 
decay could go much farther toward ensuring preservation than with 
quick ripening peaches. It is interesting to observe, too, the im- 
provements in insulation and general construction undergone by the 
far western refrigerator cars, in response to the definite information 
furnished and the demands of the great western fruit business. How- 
ever, these improvements were practically all based on the require- 
ments of citrus fruits, which are, as we now know, extremely easy 
to refrigerate if they are well picked, graded and packed. The needs 
of deciduous fruits, poultry, eggs, butter, fish and delicate vegetables 
were still little known and uncared for. 

In 1908 the Food Research Laboratory, which had been studying 
the effect of long cold storage on poultry, extended the work to the 
handling of the fresh goods in the packing houses and in transit. 



454 CORK INSULATION 

Our object was to prevent deterioration, and to that end the best 
packing house methods available were sought. However, we soon 
found that standardized methods at the packing house did not give 
standardized results at the market; in other words the refrigerator 
cars were a variable factor. This was proven, not only by the 
chemical and bacteriological analysis of the poultry, but by the tem- 
perature records on the thermographs placed in various parts of the 
load. Again we found the packages on the top of the load and those 
in the middle of the car more or less injured by lack of refrigeration. 
Indeed, it was not and is not uncommon to find chickens on the 
floor at the bunker hard frozen, those quarterway of the car in a 
good chilled condition, and between the doors green struck, and this 
in spite of the fact that the condition of the packages was practcially 
uniform when they were loaded. 

After several years of such work, during which shipments had 
been made from various poultry packing houses in the corn belt 
both west and east of the Mississippi to eastern markets and a num- 
ber of car lines had been used, a tabulation of the data showed, 
among other things that deterioration in transit was increased when 
the cars of certain lines were used. 

Then began the study of the construction of these cars, using 
the blue prints showing the plans on which the cars were built, and as a re- 
sultant further confirmation of the close relation between the condition of 
the goods on arrival and the quantity and placing of the insulation 
and the type of ice bunker. In 1913 the results were published as 
Bulletin No. 17 of the United States Department of Agriculture. The 
conclusions presented in that bulletin outline fairly well the lines of 
work since followed by the investigators and which have led to the 
information on which the construction of the standard refrigerator 
car is based. The concluding paragraph of the bulletin says, "It is 
eminently necessary that such questions as the most efificient and 
economic size of the refrigerated car, the exact amount of insulation 
required to insure the maintenance of low temperatures, or, con- 
versely, to protect the contents of the car against frost, the equaliza- 
tion of temperatures in all parts of the car, .and many others, be 
pressed for more exact and far reaching answers." The bulletin 
points out the importance of roof and floor construction in relation 
to insulation efficiency, especially the waterproofing of the floor. It 
also calls attention to the efficiency of the wire basket bunker which 
permits of abundant air access to the refrigerant. 

Throughout the period between 1908 and 1913 the investigators 
of the transportation of dressed poultry and eggs were in constant 
touch with the men of the Bureau of Plant Industry who were per- 
forming a like service for fruits and vegetables. Their field of 
operations had rapidly widened and data was being assembled on 
apples, pears, berries, cantaloupes, lettuce, celery and many other products. 
It is needless to state that the defects found in the cars hauling plant 
products were identical with those hauling animal products. It 



STANDARD CAR 455 

was obvious, too, that no amount of work to teach better field, 
orchard and packing house methods would have the desired result — 
namely, freedom from decay at the market — until the construction 
of the refrigerator cars was suited to the work which they were ex- 
pected to perform. To determine in detail what that construction 
must be, opened a new phase of the problem. 

In the first place the thermograph was relegated to the garret. 
It was no longer sufficiently exact for our purposes nor could its 
information be made sufficiently specific. We substituted the resis- 
tance thermometer, so constructed that it might be plunged into the 
orange, chicken or fish, as well as hung in the air of the car or placed 
firmly against the car body. These thermometers were sensitive to 
a tenth of a degree Fahrenheit. They were attached to long wires 
which were passed between the packing of the door and the jamb 
without admitting air and were collected into cables with terminals 
on top of the car, or which extended from car to car and so into a 
caboose, or living car, where all the thermometers in the cars under 
observation might be read by plugging into a switch board attached 
to an indicator. In this manner the environment of all cars was 
kept the same and, if the variables in each car were reduced to one, 
a direct comparison of the temperatures observed furnished valuable 
information. 

The number of cars under observation in the same train, loaded 
with the same commodity, has varied from two to fourteen. The 
hauls have been from one hundred to three thousand miles, during 
which the cars were not opened. Readings of the thermometers were 
made, on the average, once every four hours. The ice and salt 
which went into the bunkers were weighed by the investigators and 
in some experiments the water issuing was measured. When salt 
was used with the ice, the specific gravity of the issuing brine was 
taken at frequent intervals. 

Gradually a uniform plan was developed for the placing of the 
thermometers in the commodity and in the car, as key positions were 
located. Ordinarily twelve thermometers are used in each car, dis- 
tributed as follows: 

( 1) On the floor, midway between the doors, middle of car. 

( 2) On the ceiling midway between the doors, middle of car. 

( 3) On the wall, quarter way of car, door height. 

( 4) In air, bottom bulkhead opening, midway between walls. 

( 5) In air, floor, midway between doors, middle of car. 

( 6) In air, ceiling, midway between doors, middle of car. 

( 7) In package, bottom layer, first stack, middle row. 

( 8) In package, top layer, quarter way stack, wall row. 

( 9) In package, bottom layer, middle stack, middle row. 

(10) In package, top layer, middle stack, middle row. 

(11) In package, quarter way stack, middle layer, middle row. 

(12) In package, top layer, first stack, middle row, 



456 CORK INSULATION 

As air circulation is one of the most important items to be 
studied, it was necessary to adopt uniformity in the placing of the 
air thermometers. Results which are comparable and practical have 
been obtained by mounting each air thermometer on a block of cork 
board, two inches thick and long enough to extend well beyond the 
ends of the instrument. These blocks of cork were fastened to the 
floor and ceiling beside the thermometers which were intended pri- 
marily to register the dififerences in heat leakage and which were 
fastened down tightly by two staples. The thermometers in the 
commodity were imbedded between four and five inches whenever 
possible. Every effort was made by the cooperating shippers to 
furnish comparable lading, and the placing of the loads was super- 
vised by the investigators. 

It must not be inferred that the railroads were either indifferent 
or antagonistic toward this research work. On the contrary, they 
had almost without exception cordially assisted the investigators. 
As the facilities for the acquisition of information became more 
exact, and as closer correlation between car building and temperature 
was shown, it was evident that cars must be built with insulation and 
bunkers of varied construction, and, so far as possible, the cars to 
be compared must be duplicates except for the one variable on which 
information was desired. This need was explained to certain co- 
operating roads, and they were also given just as much information 
concerning the performance of their own refrigerator cars as we 
possessed. A number of them were willing to build a few experi- 
mental cars, and a few practically put their shops at our disposal. 
What was quite as advantageous to the work, was the better under- 
standing on the part of the railroads of the aims of the Department 
and the methods employed. These were personally explained to the 
Vice Presidents of Traffic and Operation of practically every large 
system in the country and in many cases to the Presidents as well. 
Members of the Interstate Commerce Commission were also infor- 
mally kept in touch with the progress of the work. The fact that 
the study of commodities in transit had shown that the same kind 
of car was necessary to carry fruits, vegetables, dairy freight and 
fish, and that the building of specialized cars for certain products 
was unnecessary, was, of course, greeted with approbation by every- 
one interested in the economics of railroading. 

One of the favorable happenings in the doing of this transporta- 
tion work was the fact that the men engaged upon it were also in 
close touch or actually engaged upon cold storage investigations and 
were familiar with many phases of the precooling and storage prob- 
lems. In the course of the fruit and vegetable precooling work, the 
investigators had observed the increase in efficiency when a slatted 
rack, a few inches above the floor, was used. The addition of such a 
rack to a refrigerator car seemed eminently desirable. Accordingly, 
we asked the railroads to add them to certain cars for trial purposes. 



STANDARD CAR 457 

The studies already reported in Bulletin No. 17 had shown the de- 
sirability of the basket bunker. To this we asked the roads to add 
an insulated, solid, bulkhead, open top and bottom for air inlet and 
outlet. We had found such a bulkhead to be an essential in maintain- 
ing air circulation in small, ice cooled chill rooms designed especially 
for dressed poultry and eggs with bunkers of either the overhead or 
the upright type, and had worked out the details of the construction 
in such rooms. We also asked for cars containing varying amounts 
of insulation and we suggested that it be installed with and without 
air spaces. 

By the early spring of 1916 we had ready quite a number of 
experimental cars built by four roads in as many shops. The details 
of construction varied widely. This we considered advisable because 
we first had to establish the fundamentals of construction, such as 
the type of bunker and the action of floor racks, regardless of the 
sfze or particular desirability of the car itself. In every case the 
principle of one variable, only, was maintained, hence the cars were 
built and used in series. For example, in order to test the bunker, 
of the basket type with solid insulated bulkhead, such a car had for 
comparison another, built at the same time and identical in every 
respect except that it was provided with a box bunker and an open 
bulkhead. To reduce the information to still simpler terms, a third 
car had a box bunker with an insulated bulkhead, and a fourth car 
had a basket bunker with an uninsulated bulkhead. When this series 
was loaded with the same commodity and run in the same train to 
the same destination, with resistance thermometer equipment as pre- 
viously described, variations in temperature could be referred with a 
fair degree of certainty to the one variation in construction. 

A similar series was used to determine the relative value of the 
floor rack and also the details of its construction, such as height, 
width of slats and width of space between the slats. The insulation 
series contained cars having one, two and three inches, respectively, 
of hair felt, flaxlinum and linofelt. In order to determine the points 
of heavy strain on the insulation roofs, floors and walls were given 
unequal amounts. 

Of course, these experimental cars were not all built at once, 
and, as we were in close co-operation with the shop superintendents, 
the facts, as gleaned, were at once incorporated into the building. 

To go into the details of the many experiments, with various 
products, in various parts of the country and under varied weather 
conditions, will be a lengthy task even for a government bulletin. 
What concerns us here are the broad facts and the deductions which 
have been drawn from them, especially those concerning air circula- 
tion and the amount and distribution of insulation. Let us begin 
with air circulation. 

It did not take long to decide that the basket bunker, insulated 
bulkhead and a rack four inches ofif the floor, with lengthwise string- 



458 CORK INSULATION 

ers and cross slats about three inches wide and about two inches- 
apart, are essentials for the distribution of the refrigerated air. The 
wire basket hanging free in the end of the car permits the warm air 
entering at the top to flow without obstruction over the entire surface 
of the ice and, as it cools, to fall to the floor. At the floor it is not 
pocketed, but finds a ready exit under the rack, and so along the car 
floor and up through the load, gathering heat as it goes and carrying 
it to the upper bulkhead opening where again the ice has a chance to 
absorb it. 

If we place thermometers in the air of the car to determine its 
temperature at the lower bunker opening, again at the middle be- 
tween the doors, then %t the ceiling midway of the car, then at the 
ceiling quarter way, and finally about ten inches in front of the 
upper bunker opening, we find a steady rise in temperature, the 
upper bunker opening thermometer being the highest. Generally, 
we find from two to four degrees difference between the air in the 
upper, middle part of the car and that at the upper bunker opening. 
If the thermometers are similarly placed in a car equipped with a 
box bunker with open bulkhead and without the floor rack 
the graduations of temperature in the upper part of the car are just 
reversed. Here the temperature at the upper bunker opening is 
ordinarily from two to four degrees lower than at the iniddle of car. 
This observation has been made again and again and is further con- 
firmed by the performance of a box bunker combined with solid 
bulkhead and a floor rack, with which there is good cooling in the 
top of the load at the bunkers, but unsatisfactory results in the 
upper, middle parts of the load. In other words, we have only a 
partial air circulation. Even more striking are the results obtained 
when salt is added to the ice in the basket bunker combined with the 
insulated bulkhead, and floor rack, or the "standard type" bunker, as 
it is now termed. So rapid is the removal of the very cold air from 
the bottom of the bunker that fruit and eggs may be rapidly cooled 
throughout the car without frosting the packages at the bulkhead. 
Of course, the bulkhead, insulated with one or two inches of a 
standard insulator, is an essential if the packages against it are to 
be protected from the frigid air close to the ice and salt; but, that 
this protection is not due entirely to the bulkhead, is proved by the 
pocketing of the cold at the bottom of the bunker when the box 
bunker with an insulated bulkhead is salted. Then the packages at 
the bottom of the load, next to the bunker, are frosted. In other 
words, there is no force to the air movement and it cannot be dis- 
tributed with sufficient rapidity to prevent the intensive chilling of 
itself. With the standard bunker and floor rack and a lading such as 
cantaloupes or oranges, as much as 9 per cent of salt may be safely 
used in the initial icing, and the same percentage, or a little less, may 
be used on the two successive days, by which time the load is cooled 
throughout. It is unnecessary to point out the great advantages 
accruing to the transportation of such perishables as berries, peaches 



STANDARD CAR 459 

and cherries bj' this ability to cool them rapidly while rolling. It is 
also of benefit to eggs, which because of the character of the com- 
mercial package and the tight load are exceedingly slow to cool in 
the ordinary car. Indeed, the top and middle of the load is but 
little affected by the refrigerant. 

The question of insulation has been more complex. We have 
not only a compound wall, but one which is continually in vibration 
and which is moving constantly. To this constant movement of the 
insulator must be added the difficulties of making it continuous be- 
cause of the framing of the car and the habitual use of tie rods and 
bolts which oflfer runaways for heat. The sills as usually placed in 
the floor, the belt rails and the carlines were very real obstacles to 
the efficient placing of the insulation. The thickness of the insulator 
was by no means the only question to be answered; how it should 
be attached to the framing was almost as important. It was also 
necessary to determine the most vulnerable parts of the car and 
guard them accordingly. 

The thermometers which were fastened tightly against the lining 
of the car very promptly and consistently indicated that roofs and 
floors must be better protected than the walls and, in the case of the 
floor and the lower part of the walls, it is imperative to waterproof. 
Comparisons of cars having varying amounts of insulation, loaded 
with representative commodities, showed that for the safety of the 
load, as well as economy in loading and in refrigerant, it is neces- 
sary to have the equivalent of two inches of pure cork board in the 
sidewalls and ends, at least two and one-half inches in the roof, and 
at least two inches in the floor, the insulation in the floor to be con- 
tinuous from side to side and end to end. In other words, the insu- 
lation on the floor must not be broken by sills and it must be at 
least two inches of pure cork board. 

It has not been possible, heretofore, to waterproof the floor. 
Consequently there has been wet insulation and a serious loss of 
efficiency. Therefore, the findings of the Department emphasize the 
need of cork board in the floor. 

Such essentials of a refrigerator car as an adequate amount of 
insulation and air circulation, had been agreed upon by the investi- 
gators prior to government control of the railroads, and certain lines 
had incorporated some or all of the findings into their new cars and 
rebuilds. When the Railroad Administration took up the matter of 
the standardizing of equipment, it appointed a committee to draw 
plans and specifications for a United States standard refrigerator car. 
This committee first met on March 13, 1918, and appointed a sub- 
committee of six members, who were ordered to prepare plans in 
accordance with certain definite instructions given by the general 
committee. W^ithin six weeks these plans and specifications had 
been presented to and accepted by the Director General's Mechanical 
Committee. So far as possible, the trucks, draft gear, framing and 
other general construction features, are standardized with the United 



460 CORK INSULATION 

States standard double wall box car. The essentials upon which rest 
efficiency in protecting perishables against heat and cold have fol- 
lowed very closely the findings of the investigators of the Depart- 
ment of Agriculture. The committee's plans include unbroken insu- 
lation on both floor and roof. On the walls the insulation is con- 
tinuous from door post to door post. It was not possible to devise 
a scheme by which the insulation could be run over the belt rails, 
but the exposed surface was reduced. All the insulation is applied 
in a solid mass, unbroken by air spaces. It is supported by pressure 
and not by direct nailing. The excess space afiforded by the framing 
is left on the inner side, under the lining, to receive such nails as the 
shipper cannot be prevented from driving into the walls and which 
have played havoc with the insulation. Bolt heads and tie rod exits 
are protected by insulation. The bunker is a woven wire basket hold- 
ing approximately ten thousand pounds of ice, surrounded by a two 
inch space and separated from the body of the car by a bulkhead 
carrying at least one inch of insulator; and last, but far from least, 
is a floor rack, four inches in the clear, built of 2x4 runners with 1x3 
cross slats Ij^ inches apart. This rack is hinged to the side walls. 
Each half may be turned up and the doorway section folds back to 
facilitate cleaning the car. The length of the car over end sills 
should be approximately 41 feet, and the loading space should be 33 
feet; it must not be more than 33 feet 3 inches. 

The foregoing is a very brief description of the essentials of the 
car designed to protect perishables in transit which the Railroad 
Administration has designated as "standard" and to which the lines 
when rebuilding must conform. Such instructions to the railroads 
should insure quick results in an increase of reliable refrigerator cars. 
Of course, there should, and doubtless will be, a program covering 
the building of new cars to replace at least ten thousand so-called 
refrigerator cars now in the service which are camouflaged box cars 
and a menace to every pound of foodstuff loaded in them. 

On the basis of a standard car, the Department is now predicat- 
ing a standard icing service which should save foods and money. 
It is also working on standardized methods of stowing loads and 
the standardization of packages. The ability to quickly cool certain 
commodities in transit by the use of salt with the ice has given a 
new impetus to orchard, field and packing house handling, while the 
reasonable assurance of proper care in transit of such products as 
dressed poultry lends a stability to the industry which is much 
needed. There has been much discontent on the part of shippers of 
products requiring intensive refrigeration because they could not 
obtain such cars as the large meat packers are using. The United 
States standard refrigerator car will carry meat hung from rails 
quite as successfully as the cars built especially for meat. In addi- 
tion it will carry package loads on the floor under the meat better 
than the meat cars. An important difference in the standard car as 
compared with the meat car is the reserve of ice in the bunkers 



I 



CAR SPECIFICATIONS 461 

which are often amply supplied when the tanks of the meat cars 
need replenishing. Neither is there visible in practical results the 
advantages supposed to accrue from the retention of the brine, pro- 
vided coarse rock salt is placed on top of the ice and so forced to 
bore its waj- through the whole mass before finding an exit. We 
have wasted much salt, in the past, as well as ice and foodstuff for 
lack of knowledge of car requirements. 

For every standard car turned out of the shops there will follow 
a saving of food, a saving of money and a saving of labor. To that 
end the Department of Agriculture has worked long and patiently, 
and to that same end the Railroad Administration has now issued 
"Mechanical Department Circular No. 7" and has also indicated its 
intention of reminding the railroads of the instructions. 

Truly, facts, faith, and friends, by co-operation have brought 
about a consummation long and earnestly desired. 



SPECIFICATIONS FOR REFRIGERATOR CAR 
INSULATION. 

The Atchison, Topek.jl and Santa Fe Railway System. 

(No. C-52 — Insulation for cars — nonpareil cork board) 
Adopted January 1, 1923. 

1. Scope: These specifications cover an insulation material for 
freight and passenger cars. 

I. Manufacture. 

2. Material: This insulation material shall consist entirely of 
pure ground compressed cork, properly baked and held togethe; by 
the natural resinous matter of the cork, without the use of any 
foreign binder, and shall be capable of providing adequate insulation. 

II. Physical Properties and Tests. 

3. Tests: (a) The thermal efficiency of the material shall be 
determined by the "Hot Box" method with air to air flow. The sec- 
tions to be tested shall truly represent the material as used and 
disposed in the car. 

(b) In following this method, a calorimeter as illustrated and 
described in R.M.S. Drawing, Sheet 18, Proceedings of Master Car 
Builders' Association, 1918, shall be used. It shall be carefully con- 
structed and of the materials indicated and before used must be 
standardized for its thermal loss factor. The heat must be supplied 
by direct electric current of constant voltage, measured by standard- 
ized instruments. The difference between the inside and outside tem- 
peratures must be held as nearly 70° F. as possible. Readings of 



462 CORK INSULATION 

temperature and current shall not be recorded until 48 hours after 
heat is turned on and test begins, in order to insure thorough heat 
saturation of calorimeter and test sections. The duration of actual 
test shall be eight (8) hours, during which time temperature and 
electric readings shall be made and recorded each hour or more fre- 
quently if considered necessary. The average of all readings thus 
recorded shall be taken as the final result. 

4. Conductivity: Cork board one square foot in area and one 
thickness of one inch (1 in.), shall not transmit heat to exceed 6.4 
B.t.u. per degree Fahr. diflferencc in temperature per 24 hours. 

5. Weight: The weight of one square foot of this cork board 
shall be as follow's: 

'/4 in. thick — 4 oz. 

^ in. thick — 6 oz. 

yi in. thick — 8 oz 

?4 in. thick— 12 oz. 

1 in. thick — ISyi oz. 
1^ in. thick — 1 lb. 5 oz. 

2 in. thick — 1 lb. 11 oz. 

3 in. thick— 2 lb. 7J^ oz. 

with a permissible variation allowed in weight of 10 per cent either 
above or below the weights given above. 

6. Compression Test: A sample of this cork board, two-inches 
thick and one-foot square, when subjected to a compressive load of 
2,000 lbs. shall not show a decrease in thickness of more than 0.164 
inches. 

7. Expansion Test: Representative samples of the cork shall be 
submerged in boiling w'ater at atmospheric pressure for three hours 
without disintegrating. Immediately upon removal from the boiling 
water, samples shall be measured for lineal expansion, which shall 
not exceed two per cent in any direction. The pounds of water re- 
tained in insulation, after being boiled three hours and then drained 
twenty-four (24) hours, shall not exceed 12 per cent of light weight 
of sample. 

8. Dimensions : The material will be furnished to the dimensions 
specified on order and will be cut perfectly square and true to di- 
mensions. 

9. Permissible Variations: The thickness of the material shall 
be determined by placing a sample between two flat smooth boards 
or plates, at least 6 in. wide, the ends of which shall project about 
Ys in. beyond the edge of the cork board. Upon hand pressure being 
applied to the top board or plate, the measurement as taken be- 
tween the inner faces of the two boards or plates between which the 
sample is compressed, shall not be more than ^-2 in. per inch over 
or under the thickness specified. It is desired, however, to secure 
the material to the exact thickness specified. 



J 



CAR SPECIFICATIONS 463 

III. Inspection and Rejection. 

10. Inspection: (a) The inspector representing the purchaser 
shall have free entry at all times while work on the contract of the 
purchaser is being performed, to all parts of the manufacturer's works 
which concern the manufacturer of the material ordered. The manu- 
facturer shall afford the inspector free of charge, all reasonable facil- 
ities and necessary assistance to satisfy him that the material is be- 
ing furnished in accordance with these specifications. Tests and 
inspection at the place of manufacture shall be made prior to ship- 
ment. 

(b) The purchaser may make the tests to govern the acceptance 
or rejection of the material in his own laboratory or elsewhere. Such 
tests, however, shall be made at the expense of the purchaser. 

(c) The manufacturer must notify the General Material In- 
spector, Chicago, 111., or his representative at the plant, at least three 
days before the material is ready for inspection. 

11. Rejection: (a) Material represented by samples, which fail 
to conform to the requirements of these specifications, will be re- 
jected. 

(b) Alaterial which, subsequent to test and inspection at the 
factory or elsewhere and its acceptance, shows defects or imperfec- 
tions will be rejected and shall be replaced by the manufacturer. 

12. Rehearing: Samples tested in accordance with these speci- 
fications, which represent rejected material, shall be held for four- 
teen days from date of test report. 

13. All specifications of previous date for this material are hert 
by annulled. 

(Signed) M. J. Collins, 
General Purchasing Agent. 



464 CORK INSULATION 

CORK PAINT.* 

For all surfaces, except ceiling and insulation, the surface of 
the metal, in addition to the priming coats already applied, will be 
given a thick coat of "under cork" or cork size (Formula No. 15). 
The ground cork, which should be fairly large grained (large enough 
to pass through a No. 8 sieve and be held on a No. 12), will then 
be sifted and applied, and left until the paint is slightly set, when, 
if required to efficiently cover the surface, a second coat of "under 
cork" and ground cork will be applied in a similar manner to the 
first coat in order to secure the adherence of the maximum amount 
of cork. Over this will be applied two or more coats of white paint, 
the first coat of which may be either applied by compressed-air spray 
or by hand, the other coats to be applied by hand. The coating of 
cork paint to be continuous and of substantial thickness. The above 
method will be applied also to the outboard surface of metal plates 
of ceiling and insulation, except that this plating will be laid flat to 
receive the application of ground cork, and that the final average 
thickness of cork paint is to be about ^-inch. 

The inboard surface of all metal ceiling will be finished white 

(not cork painted) glossed in officers' quarters. Cork painting should 

be limited to the minimum absolutely required to prevent excessive 

sweating, but where for instance, a part of the deck overhead would 

require to be cork painted, the remainder of the deck, if of metal, 

within the same compartment should be so painted in order to obtain 

a uniform appearance. In a compartment generally finished in white, 

glossed, where a portion of the surface is cork painted, the cork 

paint will also be glossed. 

AUTHOR'S NOTE: Formula No. 15.— "Under cork," for one gallon, consists 
of: (a) Whiting, 10 pounds; (b) Hard Oil, J^-gallon ; and (c) Japan Drier, y^- 
gallon. One gallon of "under cork" will cover approximately 20 square yards, at 
the weight of 2^ pounds per 100 square feet of surface. Ground cork, "Newport 
Special," consists of natural cork bark ground to such size as to pass a screen 
having 8 meshes per inch and be caught on a screen having 12 meshes per inch. 



PULVERIZED CORK— SUBIRINE.t 

It is said that considerable use is now being made of the newly 
introduced French article to which the name of "subirine" has been 
given. The substance consists of pulverized cork of different degrees 
of fineness, known as impalpable, fine, medium and coarse, the pul- 
verization being effected by very simple means, such as a horizontal 
grindstone. Among these the medium powders have for some time 
been employed in the French navy and by various navigation com- 
panies for painting the sheet iron and partitions of the insides of 



^^ 'Extracted from specifications of the United States Navy Department for 
cork paint" to reduce sweating of metal surfaces. 

tExtracted from Ice and Refrigeration, January, 1894. 



USES OF CORK 465 

vessels; the effect of such coatings is said to be to considerably 
diminish the conductibility of the sheet iron, and the vibrations so 
unpleasant, which are produced as soon as the sea becomes a little 
rough. Another use for these cork powders is in the preparation of 
a substance called "liegine," which consists of the powder mixed with 
fine plaster in the proportion of about ten per cent. This liegine 
composition is turned out in all shapes and sizes, and is stated to be 
specially useful as a protection alike from heat or cold, or for 
partitions, roofs, lofts, ceilings, and coatings of all descriptions; also 
as packing for boilers, ice houses, conservatories, coverings for 
wagons, steam pipes and similar uses — in short, for the large number 
of cases where it is desirable to maintain an equal temperature. 



CORK AS A BUILDING MATERIAL.* 

By S. Sampolo. 

Cork is one of the lightest and the worst conductors of heat and 
sound substances. It is also somewhat elastic, and when moderately 
compressed does not absorb water. These evident properties have 
for a long time given a great extension to the use of cork for indus- 
trial purposes, principally for the manufacture of stoppers for any 
kind of vessels containing liquids which do not attack organic sub- 
stances. 

Everybody knows that cork is the bark of a particular oak grow- 
ing, not in America, but on the coasts of northern Africa and south- 
ern Europe. After being deprived of its hard, nonelastic and useless 
elements, this cork bark is cut into square pieces and turned on a 
special lathe, where the stopper shape is acquired. In this manufac- 
ture the waste should, theoretically, be about 20 per centum; in fact, 
how much larger is the quantity of scraps thrown away by the 
machine? It is an interesting industrial problem to try and make 
the best use of them in a judicious way. 

So far, the only important application of this refuse material has 
been made in the manufacture of linoleum, which can utilize but a 
small percentage of the waste. Render possible the introduction of 
cork refuse for building purposes, and at once all scraps and cuttings 
will find an important application. If, at first, the idea may not 
appear realizable on account of the little resistance of cork, we may 
say that thousands and thousands of bricks and tile have already 
been made in France with pulverized cork refuse, and have worked 
satisfactorily. Labor and patience have not been spared, and 

•Extracted from Ice and Refrigeration, June, 1895. 



466 CORK INSULATION 

strengthening cements, which can be poured into any shape, size and 
thickness, have been in use. 

Two kinds of cements can be manufactured; the first containing 
powder or small pieces of cork, plaster of Paris, dextrine and sesqui- 
oxide of iron. The second, besides all those substances, also contains 
an oxychloride such as the oxychloride of zinc, which makes that 
composition perfectly waterproof. Like cork itself, these cements 
are non-conductors of heat and sound; they carbonize without giving 
any flame when exposed to a high temperature, do not decay, and 
absorb very little or no water. Moreover, this product is better 
than cork, because of its great resistance to compression. Experi- 
ments have been made, and it is now demonstrated that the bricks 
begin only to crack under a pressure of 190 pounds per square inch. 
Therefore, if, with the cements, bricks and tiles are molded or con- 
crete is poured ofif, we will obtain very valuable building materials, 
the main applications of which we will examine here. 

First. Every time heat or cold is to be kept in a room, or a heated 
or cool pipe or other recipient, cork refuse may be used with advan- 
tage. The coefficient of conductibility of heat determined by Pictet 
for cork is 0.143 in French measures, which will be used now for 
convenience sake. To demonstrate how comparatively small is this 
figure, and therefore how efficient would be the use of that material 
for such a purpose, we will calculate the quantity of steam condensed 
per hour in a steam pipe insulated with a 1-inch thick covering 
(0.025 gramme). 

For example, let us assume a pipe 0.10 in diameter, the live steam 
being at a temperature of 125° C, and circulating at a speed of forty 
meters per minute, the temperature of the room being supposed to 
be 15° C. The quantity of steam passing through that pipe for one 
meter of length is per hour: 

3.14 

1.25 X X 0.10 — = X 1 X 40 X 60 = 23.40 kilos. 

4 

If we neglect the radiation and convection, the quantity of heat 
lost for that surface of pipe will be: 

3.14X0.125 X 1 X0.143(125°— 15°) _ 6 

— — — ■ = 24 calories and — 

0.025 10 

And as one kilo of steam gives out by being condensed 600 calories, 
in round numbers, the percentage of steam lost will evidently be: 

24.6 1 1 

about or - of 1 per cent. 

600 X 23.40 600 6 

These figures show all the benefit we can derive from using cork 
refuse for boilers and pipe coverings, and also for building purposes. 



I 

I 



I 



USES OF CORK 467 

Many a time, in a light construction, the loft is not habitable on 
account of the difference of temperature which tenants would have 
to support. Cork tile nailed on inclined joists and on ceiling boards 
would make this loft as comfortable as any other story of the flats. 
In hot countries, for instance in Algeria, where heat is considerable 
during the summer, they use now cork tiles to coat the walls inside, 
and Russians are also protected in the same way from cold. In a 
word, there are numerous applications of this material as a protection 
against heat and cold. 

Second. As has been already mentioned, cork material does not 
conduct sound. We will give you an example of this, as we had 
occasion to observe it in Paris. It was in the Menier house Festival 
hall. That house, six stories high, was occupied "by dififerent tenants, 
and the use of the hall for meetings and private parties was quite 
objectionable to them on account of the disturbing noise at night. 
By replacing the plaster ceiling by cork concrete, all objections were 
removed. This fact proves how much sound deadening is a cork' 
concrete floor, and how useful it will prove to have such a material 
where quietness is required, as in library reading rooms, telephone 
closets, etc. 

Third. A third important property of cork compositions is to 
attenuate the vibrations to a great extent; for instance, when near 
engine or dynamo rooms are located places where vibrations can be 
troublesome, as in drawing rooms or offices, and especially in rooms 
%here crystallization of certain salts is carried on. In fact, crystal- 
lization is always disturbed and sometimes prevented by a constant 
trepidation; and we quote a circumstance in which, having to produce 
chrome crystals, the manufacturer had to leave the town and go to 
a quiet country place to carry on his work. A cork floor would 
have saved all that trouble. 

In regard to elasticity of cork, I will mention here the follov.-ing 
happy application of that material. To prevent dampness in a gun- 
powder factory, all walls had been protected by a cork brick coat, 
and all partitions had been made with cork tiles. One day they had 
a terrible explosion, as dangerous as they are sure to be in such 
cases. If the walls and partitions had been in stones or bricks, the 
loss of life would have been serious. The cork product (after having 
greatly slackened the vibrations) crumbled to powder, and only a 
shower of small pieces of harmless cork dropped on workingmen, 
and no one was injured. 

Fourth. Lightness and waterproof quality have not to be spoken 
of. In a country like the United States, where high buildings are 
getting in favor, light partitions are a very desirable device. Every- 
thing has been tried in that line, and a quantity of materials have 
been worked on. Among all these, porous brick is as yet probably 
the best. But cork tile is a great deal lighter. The specific gravity 
of porous brick is represented by 0.70 when that of cork brick is 



468 



CORK INSULATION 



only 0.38; that is to say, that nearly half of the weight is saved. I 
will merely mention here again the importance of waterproof material 
in cellars, basement walls, bath rooms, etc. 

Fifth. Is cork fireproof? That is the question of today. Insur- 




213.— MODERN APPLICATION OF PURE COMPRESSED BAKED CORK 
SHEETS FOR THE REDUCTION OF VIBRATION AND SOUND 
IN BUILDING STRUCTURES. 



ance companies will not take any risk for the highest stories on 
account of the difificulty of extinguishing fire; and of course, fireproof 
material is carefully looked for. Positively, there is no entirely 
fireproof material. Brick partitions crack and flames can spread out 
in every direction. What should be required from a partition is that 
it shall not propagate fire. Cork cement answers the purpose, as it 
carbonizes very slowly and gives out smoke but no fiame. 



USES OF CORK 



SOME USES OF CORKBOARD INSULATION.* 



Cold Storage Rooms 

Apple storage 

Banana storage 

Battery testing 

Berry storage 

Butter storage 

Candy storage 

Cheese storage 

Chocolate dipping 

Commissaries 

Daily ice storage 

Dough, mixing and proving 

Ducts, cooling 

Ducts, ventilating 

Egg storage 

Fever (clinical) 

Fish freezer 

Fish storage 

Flower storage 

Fruit pre-cooling 

Fruit storage 

Fur storage 

Garment storage 

Ice cream hardening 

Ice stations 

Ice storage 

Meat freezers 

Meat pickling 

Meat pre-cooling 

Meat storage 

Paraffin 

Potato storage 

Poultry pre-cooling 

Poultry storage 

Public auditoriums 

Sausage 

Serum storage 

Scientific 

Syrup storage 

Testing 

Tobacco humidor 

Boxes and Refrigerators 

Apartment house refrigerator 

Bottle box 

Confectioners' refrigerator 

Dairy products refrigerator 

Fish box 

Florists' refrigerator 

Meat box 

Mortuary box 

Oyster box 



Pie refrigerator 
Residence refrigerator 
Vegetable box 

Display Counters and Cases 

Candy 

Cut flower 

Delicatessen 

Meat 

Milk, butter and eggs 

Cars 

Passenger railway 
Refrigerator 
Street railway 
Tank 

Cabinets 

Bottled goods 
Chocolate cooler 
Ice cream dispensing 
Ice cream storage 
Soda fountain 

Tanks 

Brine storage 
Gasoline storage 
Ice making 
Ice water 
Milk cooling 
Milk storage 
Railway 

Steel tempering 
Water cooling 

Trucks 

Fish 

Ice 

Ice cream 

Meat 

Milk 

Miscellaneous 

Bank vaults 
Bee hives 
Incubators 
Industrial buildings 
Humidifiers 
Machine base 
Residence insulation 
Roof insulation 
Sound deadening 
Vibration absorption 



*Cork Pipe Covering is employed as permanent insulation for refrigerated lines 
ind tanks and drinking water systems. 



I 



470 



CORK INSULATION 





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RESEARCH PROJECT 471 

HEAT TRANSMISSION: A NATIONAL RESEARCH 
COUNCIL PROJECT.* 

By F. E. AIatthews. 

Member Engineering Division National Research Council; Official Representative of 

the American Society of Refrigerating Engineers. 

Heat transmission, than which there is no subject more basicallj 
important to so many lines of engineering, has been made the subjecl 
of a recently authorized project of the Engineering Division of the 
National Research Council,' with two main sub-committees dealing 
specifically with heat transfer — viz., heat transmission through build- 
ing and insulating materials, and heat transmission between fluids 
and solids. The refrigerating industry, with its numerous refriger- 
ating media, primary and secondary, the former occurring in both 
the liquid and gaseous phases, is vitally interested in both of these 
subjects. 

Just how inadequate and generally chaotic present information 
bearing on heat transmission really is, is most frankly admitted by 
those engineers most vitally interested and most familiar with such 
data. There seem to be two generally admitted outstanding facts 
regarding heat transmission data: that they are fundamentally im- 
portant and shamefully inadequate. The responsibility of providing 
himself with reliable data in order that he may turn out accurate 
results (impossible without them), is the engineer's and his alone. 
Rough rules have been employed for determining necessary areas of 
the heat transmitting members of refrigerating systems, such as 
evaporators and condensers of refrigerating media, based on certain 
conditions, but not necessarily on the most advantageous conditions 
realizable. Similar rules' have been employed for determining the 
amount of insulation employed for the conservation of the refrigera- 
tion produced at the expense of the fuel by the refrigerating machine. 
Rare indeed are the instances in which due recognition is given to 
the fact that the more it costs to develop refrigeration the more one 
can afford to spend for its conservation. 

Numerous sporadic efforts have been made to procure better heat 
transmission data, but the results have fallen far short of the objec- 
tive which the time and money expended should have insured, due 
largely to poor physical equipment, unscientific procedure, and in- 
complete description, which should be eliminated by the standardiza- 
tion of method, procedure, and specification proposed for building 
and insulating materials, heat transmission investigations, and made 

•Extracted from Proceedings of the Fourth Internstional Congress of Refrigeration, 
London, 1924, Volume 1. 

' Means for carrying on research work in America under governmental supervision 
was originally provided for in 1863, when the Charter of the National Academy 
of Science was approved by President Lincoln. The National Research Council 
was established in 1916 by the National Academy of Science for war purposes, and 
perpetuated by executive order of President Wilson in 1918, for the "promotion 
of scientific research and the dissemination and application of scientific knowledge." 
It was organized with the cooperation of over seventy major scientific and technical 
societies, in thirteen major divisions of which Engineering is one of the most im- 
portant. 



I 



472 



CORK INSULATION 



possible through the correlation of scattered eflforts by means of the 
machinery of a national organization such as that of the National 
Research Council. 



AIR INFILTRATION. 



Following are some of the air infiltration values obtained on erec- 
tion materials from investigations and tests conducted in the labora- 







tICPCUar LCVZLIHG BULB 
TMC»nOMe.T£ft 




FIG. 214.— ARMSTRONG'S INFILTRATION APPARATUS— ARGO LABORA- 
TORY, GLOUCES'lER, N. J. 



tory of the Armstrong Cork & Insulation Co. Illustration of the 
apparatus used in making the determinations is shown. 

AIR INFILTRATION VALUES ON ERECTION MATERIALS 

Cu. ft./sq. Cu. ft./sq. 
ft./hr. 10 ft./hr. 40 

^ lbs, pressure pet, pressure 

(1) 13-in. brick wall Yz-'m. cement plaster cracks in plaster 

between bricks .. 115 

(2) 13-in. plastered brick wall two spray coats Armstrong's 

asphaltic paint 

(3) J^-in. film erection asphalt. No cracks 

(4) 178' Samples Armstrong's corkboard 2-in. thick 335 

(5) 2:1 Portland cement plaster 4^-in. thick. No cracks .. 22 

(6) Same. 10 pet. added lime . . 2 

(7) 2:1 Portland cement plaster .5^-in. thick. No cracks.... 

(8) 2:1 Portland cement plaster i^-in. thick. Fine cracks.. .. 19 

(9) 22 Samples sprayed on asphalt emulsion from skin coat 

to Yi-'wi. thick, nine showed tight, other 13 varied 
from 2.75 to 5.60 cu. ft./sq. ft./hr./40 lbs. 
Values of (3) and from (5) to (9) inclusive taken by 
applying the material to two inch corkboard. 



ASPHALT 



473 



Another series of tests were conducted on the relative infiltration 
of corkboard in respect to thickness. Following is a typical average 
of these tests: 

DENSITY OF CORKBOARD 0.854 LBS. PER BD. FT. AIR INFILTRATION 
VALUES GIVEN IN CU. FT./SQ. FT./HR./40 POUNDS PRESSURE. 

Thickness 
of 
Corkboard Cii. Ft. 

1 inch 485 

2 inch 343 

3 inch 239 

4 inch 186 

5 inch 163 

6 inch 1 SO 

7 inch 132 

8 inch 124 

9 inch 105 

10 inch 98 

1 1 inch 97 

12 inch 95 

The following specifications cover an oxidized asphalt obtained 
from an asphaltic base crude oil, usually Mexican: 

SPECIFICATIONS FOR 180/200° F. STANDARD OXIDIZED ASPHALT 

Minimum Maximum 

Specific gravity at 60° F 1.045 1.065 

Melting point (ball and ring) 180° F. 200° F. 

Flash point (open cup) 460° F. 

Penetration : 32° F. 200 gram 60 seconds 6 25 

77° F. 100 gram 5 seconds 15 

115° F. 50 gram 5 seconds 45 

Volatility, 50 grams 5 hrs. at 325° F 1% 

Bitumen soluble in CSa 99.5% 



CORK DIPPING PAN. 

Specifications. — This oil-burning cork dipping pan is used for melt- 



>Vi7 //AEROJL TORCH 
con /*> uaet^ /or ae/rf- pvrpinri 




pil3 P^A'^c an /•<■ uar^ for heo/iHf a3^ir/f,far.piM, mr*. 
fair', cAf*'jiccr/3 «(c, ar/se Ant^/wf ■sand 

-MODERN CORKBOARD DIPPING PAN, MANUFACTURED BY 
AEROIL BURNER CO., UNION CITY, N. T- 



474 



CORK INSULATION 



ing and heating asphalt in connection with cork insulation work. A 
standard size slab of cork can be easily dipped into the hot asphalt 
and permits rapid application of the cork. Being smokeless, the 
pan can be used indoors, right close to the job. 




The pan is 42 inches long, 16 inches wide and 6 inches deep, inside 
measurements. It is made of No. 14 gauge steel throughout properly 
braced and reinforced with lJ4xl^xf5-inch angle iron all around and 
equipped with four handles. 

The burner is removable and can be used for many other heating 
purposes, such as drying out wet spots in concrete or brick walls or 
floors, melting ice and snow, etc. Shipping weight about 175 pounds. 



INSULATION PROTECTION 475 

PROTECTION OF INSULATION AGAINST 
MOISTURE.- 

By Charles H. Hertkr. 

This paper is to record the latest methods used in safeguarding 
cold storage insulation against the entrance of moisture. Corkboard, 
which is now being employed almost exclusively, has been erected 
and finished off with Portland cement motar and plaster for so 
many years now (March, 1927) that this method continues to be 
specified by those who have not been informed of improvements 
made in the art. 

Manufacturers of corkboard declare that their material is moisture 
resistant of itself, that it can be boiled for hours and yet remain dry 
inside. However, in actual use, where the material is exposed to 
the influence of moisture for months and years, it does lose its insu- 
lating value, and decays. This applies to all insulating materials, 
because all depend upon minute air cells for their ability to retard 
heat flow, and as condensed moisture (water) is denser than air, the 
air is gradually being crowded out by the water. 

Moisture Detrimental. — In the wall of a cold storage room the 
corkboard lining is exposed to moisture from both outside and inside. 
A 12-inch brick wall may be rain tight, and yet it is not moisture 
tight even if all joints between the brick are filled solid with mortar. 
Both the brick and the mortar are porous and allow moisture to 
penetrate by capillary attraction, as has often been verified by actual 
tests. Under the influence of wind the exposed surface of a brick 
wall will dry very soon, but this drying action does not reach the 
water already drawn in, especially if the room is being refrigerated, 
the temperature within the wall getting lower and lower toward the 
inside. 

At 90° F. a cubic foot of air can hold up to 14.79 grains of moist- 
ure; at 60°, 5.745 grains, and at 30°, 1.935 grains. As the air and 
moisture become cooled, the excess moisture will be precipitated. 
At the room side of the insulation we have this condition: When the 
door is opened, or if people are present, moisture at relatively high 
temperature mixes with the air; and the goods in the room, such as 
meat or other perishables, also lose moisture. Very soon the air is 
fully saturated, and whatever moisture is not gathering as frost upon 
the refrigerating pipes will be precipitated as condensation upon any 
cold surface or wall. These phenomena were studied years ago and 
the conclusion was reached that special efforts must be made to 
prevent the entry of moisture into the insulation. 

The detrimental effect of moisture on insulation has been investi- 
gated to some extent. In the Insulation Committee Report of the 
American Society of Refrigerating Engineers, 1924, p. 78, it is shown 

*Paper presented before New York Chapter, No. 2, N. A. P. R. E., at its meeting 
of March 4, 1927. Reprinted by permission from the April, 1927, "Ice and Refrig- 
eration," Chicago. 



I 



476 CORK INSULATION 

that for each one per cent moisture absorbed the heat conduction 
increases four to forty per cent, depending upon the material used. 

In most branches of engineering progress is being made by de- 
grees only. When, over thirty years ago, corkboard first came into 
use, it was being protected against air and moisture by means of 
waterproof insulating paper on both sides. Also the pure corkboard 
used to be more dense; it weighed fully fourteen pounds per cubic 
foot as against nine or eight pounds now. The lighter board is a 
better insulator, but is, of course, not so strong and durable as the 
dense board. Formerly the finish for floors, walls and ceilings used 
to be one or two layers of %-in. tongued and grooved sheathing, 
nailed with galvanized nails against furring strips imbedded between 
the corkboards. This construction when varnished looked well, but 
was rather expensive. It was not fire resistive, and at low tempera- 
ture the boards dried out, shrank, and allowed moisture to enter the 
cracks, which caused rotting to take place. 

The next step was the erection of corkboard in hot asphalt. Walls 
on the inside have to be pointed up with cement mortar so as to be 
reasonably flat, to avoid hollow spaces behind the corkboard because 
these would hold moisture and might freeze, forcing off the insula- 
tion. The wall was mopped with hot asphalt, although with the 
rapid chilling on the bare wall the resulting surface could not be 
air-tight. The corkboard also was mopped over with hot asphalt 
and thus cemented against the wall. The second layer of corkboard 
was again dipped in hot asphalt, and wooden skewers used to pin 
the various slabs together. The exposed face of insulation also 
might have been mopped over with hot asphalt, but this was not 
done because fire insurance companies prefer a Portland cement 
plaster finish, at least j4-in. thick, the ^-in. thick coat of asphalt 
being incapable of withstanding abuse and contact with trucks and 
packages, although wood fenders might be erected for this purpose. 

Insulation asphalt necessarily has to be odorless so as to impart 
no foreign odor to the products stored. It is difficult to employ hot 
asphalt in ceiling work due to hot drippings. The heating of the 
asphalt by maintaining fires in the building is a nuisance, and so the 
insulation contractors soon avoided the use of asphalt and recom- 
mended Portland cement mortar and plaster in nearly all cases. 
Simple home-made boxes of wood were designed facilitating the rapid 
coating of cork slabs with a uniform thickness of cement mortar. 
Thus mortar exclusively was used next to the wall, between courses, 
and cement plaster finish in two %-\n. coats, applied to the erected 
insulation. 

The moisture in cement mortar occupies a certain amount of 
space, one cubic foot for every 62.4 pounds of water. In due time 
all this moisture disappears and causes shrinkage cracks. When the 
air is saturated, moisture re-enters every pore in the plaster, and 
the open cracks especially. In an eflfort to hide these cracks plas- 
tered surfaces are usually marked off in 3-foot squares or scores, the 



INSULATION PROTECTION 477 

plaster naturally breaking first in these grooves. Evidently a plastered 
surface of this kind is but an imperfect moisture protection for in- 
sulation. 

Keep Cork Out of Wet Forms. — In concrete construction, which 
method came into vogue at the same time, it was deemed good prac- 
tice and economy to place the ceiling cork right into the form, and 
to pour the wet mixture on top of it, this being the recommendation 
of the insulation contractor. It was hoped that the corkboard would 
bond perfectly and securely with the concrete, and as corkboard had 
been declared immune against moisture, no one suspected that the 
insulating effect would diminish under this method. However, the 
writer knows of many cases where such corkboard continues to 
drop ofif the ceiling, consequently this method must be condemned 
as very unsatisfactory. The rule that insulation should always be 
kept out of contact with moisture must ever be borne in mind. 

In ceiling work it is frequently possible to apply the insulation 
above the ceiling, where there is no danger of its coming loose. The 
work there is cheaper and better than at the underside of ceiling, 
especially if girders and beams have to be covered. 

The cement mortar construction has now been in use for about 
twenty years, but since about 1920 its shortcomings have been recog- 
nized by many users. Cement mortar in the thin layers used with 
insulation is porous and not only imparts the initial quantity of 
moisture to the corkboard, but it cracks readily and thereby permits 
moisture from the air to enter day after day. Now that a far better 
bonding material which is strictly waterproof is available, the use of 
cement mortar is to be avoided whenever possible. 

Asphalt for Damp-proofing. — The modern protection of all sorts of 
insulating materials is an asphalt emulsion, equivalent to a pulverized 
pure asphalt mixed with a certain amount of cold water, prepared 
in accordance with a process first developed in Germany and covered 
by a number of United States patents. Under this method the 
asphalt is broken up into minute particles averaging 0.001 to 0.005-in 
in the presence of an inert mineral colloid such as asbestos fibres. 
At the factory the asphalt flows into a high speed emulsifying ma- 
chine whose propellers whip the stream of asphalt into the most 
minute particles and at the same time combine it with the water and 
the colloid. In this way the particles of asphalt are held in suspen- 
sion until after the emulsion has been applied on the job, when the 
water disappears by evaporation, leaving the mixture of asphalt and 
asbestos fibres behind, in the form of a homogeneous coating. This 
emulsion can be applied cold with a brush by hand or by means of a 
spraying machine. 

This emulsified asphalt is being marketed under various trade 
names such as Korkseal; Krodeproof; Rex Flintkote — emulsion and 
mortar; Stonewall Plastic; Par-Lock Bond; Vorco Waterproofing 
Cork Mastic, etc. There must be differences among these as in the 



478 CORK INSULATION 

case of other goods of different manufacture, but so far as we can 
see the main difference is in their water content and consistency. The 
liquid emulsion flows like cream and can be applied like a paint to 
metal, stone and wood surfaces with a cheap fibre brush or a spray, 
while the thick emulsion, or asphalt mortar, simply contains less water. 
It is plastic and can be troweled on, successfully taking the place of 
cement or gypsum plaster and forming one continuous waterproof 
sheet, requiring no scoring. 

Securing Air Tightness. — Tests have been made to ascertain the 
degree of air tightness obtained with various cork coatings. When 
exposed to forty pounds per square foot excess air pressure on one 
side of an insulated wall, the rate of air leakage was in one case, 
unprotected, 240 cubic feet of free air, 75 cubic feet when the first 
coat had been applied, and 10 cubic feet after the second coat (pre- 
sumably plaster) had been applied. When Korkphalt (asphalt) was 
used in joints the leakage without finish was 222 cubic feet air; 0.036 
cubic feet after a coat of Krodeproof asphalt emulsion had been ap- 
plied, and no loss whatever after this had been covered with a coat of 
Korkseal asphalt mortar. This type of asphalt finish is therefore 
indispensable in dry ice cream hardening rooms and other places 
where an excess air pressure is being created by forcing air with a 
fan over the cooling coils in the bunker. 

Modern Construction. — This approved method of erecting cork- 
board insulation will be best understood by describing the various 
operations required when insulating masonry walls: 

In the first place the surface to be insulated must be made as flat 
as possible because no crevices or hollow spaces can be allowed 
behind the smooth flat corkboard. Such cavities are apt to hold 
water of condensation, freezing to ice, which requires more space 
and thus breaks the bond between cork and surface. Concrete walls 
may be smooth enough, but other constructions usually require true- 
ing up with cement mortar or plaster. 

Next apply over the flat wall that has been freed of all dirt and 
dust at least one coat of asphalt emulsion for the purpose of filling 
every pore and providing a base for the asphalted corkboard. Spray- 
ing the emulsion on under an air pressure of fifty pounds or more 
will drive in the asphalt more effectively and cheaper than can be 
done by hand. Two coats will be better than one. Also the wall 
need not be dry because the emulsion contains water, while hot 
asphalt should not be laid direct against any cold wall because it 
will chill and contract at oncet leaving pin holes, and it will not bone? 
well with the wall. The emulsified asphalt also should be kept from 
freezing during application, and it will flow much better if the air 
tempterature is not below 45° F. 

The first course of corkboard is to be erected in a dip coat of hot 
asphalt, starting this course level and breaking all joints. The second 



INSULATION PROTECTION 479 

layer is again erected in hot asphalt and preferably secured with 
wood skewers, breaking joints in both directions. 

One brand especially adapted for sticking up corkboard is known 
as Korkphalt, its melting point being 180° F. This is relatively soft 
at low temperature, rigid at high temperature, very adhesive at nor- 
mal temperature, and serves to thoroughly air-proof and damp-proof 
the insulation at the weatherside. 

Asphaltic Plaster. — Then comes the surface protection, which is 
very important. Spray or trowel onto the cork surface one thorough 
application of pure asphalt emulsion; one brand is called Korkseal, 
say iV-in. thick, which will completely fill all small holes and cracks. 
Allow to get dry, then finish with a layer of thick emulsified asphalt 
mortar a full :^-in. thick, floated to an even surface and then trow- 
eled. 

Where it is intended to follow up with a white enamel finish, the 
black asplialt surface can be allowed to toughen up and then be 
troweled extra smooth by being sprinkled with clean water and again 
troweled. 

After this has thoroughly dried, the entire surface can be given two 
or three coats of white enamel. One odorless enamel is known as 
Korkseal Enamel. If a less expensive coating is desired, Korkseal 
Aluminum may be applied in one coat directly to the black surface, 
but this is not equal in illuminating effect to the beautiful white 
enamel. The cost of material for white enamel is about one cent per 
square foot of coat. The aluminum paint costs about half as much 
because one coat is used. These paints stand washing with hot water, 
insuring a strictly sanitary cold storage room. 

Most white paints or enamels will in time get yellowish, espe- 
cially in dark rooms. Some enamels containing acetone or solvents 
used in the manufacture of celluloid will keep their whiteness, but 
they also keep their strong celluloid odor, which is very objectionable 
in refrigerators. A white glossy paint is quite popular with some 
users. 

Asphalt Paint. — The thin creamy asphalt emulsion, such as Krode- 
proof, comes in the proper consistency for painting or spraying, and 
is recommended as a positive protective coating against weather, 
water, acids, gases, brine and all corrosive substances. It may be used 
on steel and other metals, on wood, concrete, cement or brick. It is 
also used for dampproofing masonry, foundations and walls, and for 
coating prepared and built-up roofings. If it is to be thinned at all, 
add but a little clean water and always stir well. 

For best results, surfaces should be clean and free from all loose 
particles, oil or grease. Steel brush metal surfaces, whether dry or 
damp, down to bright metal, but masonry surfaces should be wetted 
with water before applying. Daub it on thick. Brushes (of white 
vegetable fibre) to be cleaned with soap and water after using. Do 
not apply at lower air temperatures than 45° F., and not during rain 



I 



480 CORK INSULATION 

because it will be washed off. It must be given time to set. With 
sunshine it will dry in two to three hours. A man will soon learn i.. 
give 350 to 400 square feet surface per hour one coat. The quantity 
of the various materials required per 100 square feet of surface may 
be obtained from the manufacturers. The following data were ob- 
tained from the Lewis Asphalt Engineering Corp.: 

Karnak Korkphalt 70 lb. per layer of corkboard 

Korkseal (or Krodeproof), first coat 4 gal. 

Korkseal Mortar (finish coat) 5 gal. 

Korkseal Enamel, white, per coat Ys gal. 

Korkseal Aluminum, per coat % gal. 

Strength. — Tests have been made for the United Cork Companies, 
New York, to determine the tenacity of adhesion of a 3-in. thick 
slab of corkboard cemented to concrete. When a pull was exerted 
of 1,360 pounds per square foot cork, the cork yielded, but not the 
asphalt emulsion, which proves conclusively that the emulsified 
asphalt furnishes a very reliable bond. In fact, the adhesive strength 
of Par-Lock asphalt alone was found by the Investigating Commit- 
tee of Architects and Engineers, New York, to exceed 125 pounds 
per square inch, equivalent to 18,000 pounds per square foot. Its 
ductility is rated at four to five centimeters at 77° F. The penetra- 
tion of a needle bearing a 200 gram weight is twenty-five to thirty 
millimeters per minute at 77° F. The re-melting point of these surfac- 
ing asphalts is between 200° and 215° F. when tested by Bureau of 
Standards ring and ball method. The re-melting point of the hot 
asphalt used for dipping one face and two edges of corkboard should 
be between 180° and 200° F. It should be heated to the consistency 
of molasses, the slabs firmly pressed against the surface asphalt, 
such as Krodeproof, until the asphalt in the joints chills. 

Mastic Asphalt Facing. — The Korkseal or asphalt mastic fin- 
ish, J/^-in. thick, above described, is an improvement over the 
method of ironing on the asphalt plaster at the factory to 
each slab of cork, because the subsequent patching up of the 
many lineal feet of joint is a difficult and expensive task, 
and the result is not equal in air and water tightness to that of a 
continuous troweled facing. Not to chip off readily, a tough grade 
of asphalt is used which is hard on the saw when fitting slabs into 
place. This asphalt becomes very brittle at low temperature. It has 
to be a hard variety so as not to run during shipping in summer. 

Some insulation manufacturers do not urge the use of the Korkseal 
asphalt plaster where the cork is exposed to injury from the handling 
of goods. There they recommend again the old Portland cement 
plaster finish, at least J^-in. thick; but even here the advantage of 
moisture proofing should not be sacrificed. One can erect suitable 
fenders, rails and baseboards to prevent truck wheels from damaging 



FIRE RETARDANT 481 

the wall, or one can provide a cement wainscoat 54-in- thick over the 
asphalt dampproof emulsion. 

Detailed instructions for waterproofing and dampproofing in build- 
ing construction are contained in circulars issued by manufacturers. 

Asphalt emulsion, like Korkseal, is also effective for sealing pipe 
coverings and is greatly to be preferred to the black crude oil paint 
or tar commonly employed for this purpose. 



HOW INSULATION SAVED A REFINERY.* 

An interesting example of how material installed for one purpose 
may render valuable service in a quite unexpected way occurred last 
summer at the plant of the Island Petroleum Co., Neville Island, 
Pittsburgh, Pa. 

The company had recently completed three steel cold settling 
tanks, 20 feet in diameter by 25 feet high, for bright stock. Being 
operated part of the time at low temperature produced by brine 
refrigeration, these tanks were insulated with three inches of Non- 
pareil corkboard furnished and installed by the Armstrong Cork & 
Insulation Co. At the time of this incident they were practically 
filled with oil. 

On August 25, 1921, during a violent electrical storm accompanied 
by unusually heavy rain, lightning struck one of the crude oil tanks. 
The resulting explosion released a large quantity of burning oil 
which spread out over the partially flooded yard and practically sur- 
rounded the nearest settling tank; hastily constructed dikes shut it 
off from immediate contact with the others. 

For nearly three hours the fire raged around this tank, and for 
almost an hour, the flames were leaping directly against its sides, 
while the officials and employees, striving to stop the spread of the 
fire, momentarily expected the big tank to "let go" with consequent 
disaster to the entire plant. Three times the hatch on the roof lifted 
to allow the escape of accumulated gas, but the remarkable heat 
retarding quality of the corkboard insulation kept the temperature 
below the danger point, and the fire finally burned itself out with no 
further loss of property or damage to the insulated tank beyond a 
slight charring of the outer surface of the corkboard insulation. 

The Island Petroleum Co. officials are unanimous in the opinion 
that nothing but the protection afforded by the insulation prevented 
the destruction of all three tanks and the heavy loss such an ex- 
plosion would have entailed. 

Though insulation may seldom be called upon to withstand so 
severe a test, the record of this performance is convincing proof 
of the nonconducting property and fire resistance of corkboard. 

*Extracted from Ice and Refriyeratwn, June, 1922, Page 460. 



482 CORK INSULATION 

ECONOMY OF GASOLINE STORAGE TANK INSULA- 
TION. 

In a paper prepared by the Armstrong Cork and Insulating Co., of 
Pittsburgh, Pa., in April, 1918, an interesting detailed description is 
given of various methods of manufacturing gasoline from both gas 
well and oil well products, on the distillation, compression and ab- 
sorption methods of gasoline separation from gas and oil. 

By permission the following reproduction of that portion of the 
paper referring particularly to the economical results secured through 
cork insulation of gasoline storage tanks in three separate refining 
plants, has been extracted: 

Early in March, 1917, the United Fuel Gas Company, of Charles- 
ton, West Virginia, requested quotations on insulation for a number 
of gasoline storage tanks located at their various stations. Upon 
calling on the above company at Charleston, West Virginia, it w^as 
learned that they were losing by evaporation approximately 600 to 
1,800 gallons of gasoline per day at each of their several plants in 
operation. Before proceeding further the reason for this loss shall 
be explained. 

The temperature of the gasoline as it passes from the coolers and 
condensers to the storage tanks is much lower than the temperature 
of the air, due to the cooling methods employed. This product is 
of low boiling point and readily evaporates even at the low tempera- 
ture at which it leaves the condensers. As the temperature increases, 
the evaporation becomes more pronounced and for this reason it is 
desirable that the gasoline be kept at as low a temperature as pos- 
sible. The tanks in which the material is stored are, as a rule, located 
outside of buildings and exposed to the weather. If the tanks are 
not insulated the gasoline contained therein soon acquires the same 
temperature as the outside air and in the summer months when the 
hot sun constantly beats down upon the tanks the temperature of 
the gasoline becomes very high. The gasoline evaporating freely 
increases the pressure in the tanks, which are equipped with safety 
valves to permit of the vapors passing off whenever the pressure 
exceeds that at which the valve is set. 

In cool or cloudy weather the valve does not "blow off" as often 
as in hot weather and the evaporation loss past the man-hole cover 
is reduced. The evaporation loss in the summer months is naturally 
considerably more than in the cooler months of the fall and winter. 

At the Cobb Station of the United Fuel Gas Company the evapora- 
tion loss early in the spring averaged close to 600 gallons of liquid 
gasoline per day, and at the Sandyville Station of the same company 
the loss ran as high as 1,500 gallons per day. The gasoline lost by 
evaporation is valued at 20c per gallon by the company producing 
the material, and it was obviously necessary for the United Fuel Gas 
Company to take steps to reduce their evaporation loss which 
amounted to approximately $300.00 per day at each plant. 



ECONOMY OF INSULATION 483 

Armstrong secured contracts for insulating the gasoline storage 
tanks at three of the United Fuel Gas Company's six absorption 
plants — Cobb Station, Sandyville Station and Leach Station. The 
first two stations are owned and operated by the United Fuel. Gas 
Company, while the Columbia Gas and Electric Company, of Cin- 
cinnati, Ohio, own the Leach Station and lease it to the United Fuel 
Gas Company for operation. These tanks were insulated throughout 
with Armstrong's Corkboard, whereas the tanks at the other three 
stations, contracted for by a competitor, were insulated with felt 
on the cylindrical surfaces and Impregnated Corkboard on the tops 
and ends. It might be in order to state that Armstrong's prices were 
higher than the prices on felt and Impregnated Corkboard. 

The specifications followed in erecting the Armstrong's Corkboard 
Insulation were briefly as follows: 

The cylindrical surface and ends of all horizontal tanks were 
insulated with two layers of l>^-inch Armstrong's Corkboard. Both 
layers were applied in hot asphalt and both securely wired in place 
with copper-clad steel wire. The second layer was additionally 
secured to the first layer with galvanized wire nails. 

The vertical tanks were insulated in practically the same manner. 
As they rested directly upon the ground, no bottom insulation was 
used. The cylindrical surfaces received two layers of Ij^-inch Arm- 
strong's Corkboard, applied as specified on the horizontal tanks, 
while the tops were insulated with two layers of 2-inch Armstrong's 
Corkboard, both applied in hot asphalt with the top surface flooded 
with the same material. 

As the tanks were located outside of buildings, the insulation was 
protected against the weather by the application of one layer of 
2-ply (the very best grade) roofing paper. Weatherproofing was 
applied with all edges lapped and the seams securely sealed with 
Nonpareil Waterproof Cement. Bands of copper-clad steel wire 
were used to hold the paper in place. 

The melting of asphalt at one of these gasoline plants is danger- 
ous business if a fire of any kind is used and it is necessary, there- 
fore, that the owners provide live steam for this operation. If live 
steam is not obtainable. Nonpareil Waterproof Cement instead of hot 
asphalt should be used in erecting the Armstrong's Corkboard. 

To give some idea of the tank insulation requirements, the follow- 
ing is submitted: At the Cobb Station two horizontal tanks each 8 
feet in diameter x 32 feet long and one vertical tank 20 feet in diam- 
eter X 20 feet high, were insulated, at a contract price of $2,270.00. 
At the Leach Station two vertical tanks each 8 feet 6 inches in di- 
ameter X 9 feet 11 inches high and one vertical tank 20 feet in di- 
ameter X 20 feet high were insulated at a contract price of $1,447.50. 
At the Sandyville Station the same number and size tanks as at the 
Leach Station, were insulated at a price of $1,440.00. The total for 
the three installations amounted to $5,157.50. 



484 CORK INSULATION 

That this amount of money was well spent shall be seen upon 
reading the following paragraphs: 

The manager of the Cobb Station advises that the saving 
effected directly through insulating the tanks averages close to 600 
and runs as high as 900 gallons of gasoline per day. These figures 
are true for the 1917 summer months, and as the capacity of this 
plant is 5,500 gallons per day, over 10% is saved. At the Sandyville 
Station losses reported as high as 1,500 gallons per day in the cooler 
weather of early spring with the tanks uninsulated, were reduced to 
18 gallons per day during the hot summer months after the insulation 
was applied. The storage capacity at this plant runs about 40,000 
gallons. It is understood that the temperature in the insulated tanks 
does not vary more than two or three degrees F. during the operating 
day of 24 hours. 

From the figures given above, estimating the loss at 20c per 
gallon, it can readily be seen that the insulation paid for itself at each 
station in less than ten days. As the insulation will last for years, 
it is a wonderful investment. The foregoing is conclusive proof that 
all gasoline manufacturing stations using storage tanks should have 
them properly insulated when erected. 

A comparison between felt and Armstrong's Corkboard insulated 
tanks can be secured from a letter written by Mr. R. N. Parks, of 
the United Fuel Gas Company to Mr. C. C. Reed of the Hope 
Natural Gas Company. This letter, which follows, is in answer to 
an inquiry regarding the experience of the United Fuel Gas Company 
with insulated tanks: 

"I enclose blue print showing evaporation losses from 100- 
barrel tanks standing side by side, one insulated and the 
other non-insulated. 

"Both were filled with 87.4 degrees Baume gasoline on 
March 17th, and on April 7th the loss from the insulated tank 
was 88 gallons while the non-insulated tank showed a loss 
of 423 gallons. 

"One of our stations has reported evaporation as high as 
1500 gallons under cooler weather conditions than we are 
having now, but showed on their last report evaporation 
loss of only 18 gallons with over 40,000 gallons in stock. 

"Three of our stations were insulated with cork entirely by 
the Armstrong Cork & Insulation Co. of Pittsburgh. We 
insulated two 100-barrel run tanks and one 40,000-gallon 
stock tank at each station." 

In explanation of the above letter, paragraphs one and two refer 
to felt insulated tanks while paragraph three refers to Armstrong's 
Corkboard insulated tanks. Felt insulated tanks show a saving of 
423 minus 88 gallons, while the cork insulated tanks show a saving 



INTERIOR FINISH 485 

of 1500 minus 18 gallons. It is not very difficult to choose the bet- 
ter insulation with these figures at hand. 

The insulation on these tanks is exposed to the rain, sleet, snow 
and all kinds of weather; consequently, only insulation that is non- 
absorptive of moisture should be used, even though an attempt is 
made to waterproof it. The Armstrong's Corkboard applied at the 
stations mentioned above remains in excellent condition. The felt 
at one of the stations already appears to be coming loose. This 
work was installed about eleven months ago, May, 1917. Provided 
care is exercised to keep the weatherproofing in good condition, the 
Armstrong's Corkboard will long out-last the felt and although the 
first cost is slightly greater, its superior insulating value alone makes 
it by far the best money investment. 



INTERIOR FINISH OF COLD STORAGE ROOMS IN 
HOTELS. 

The proper construction of cold storage rooms for hotels is a 
highly important matter. The rooms must not only be efficient from 
an insulation standpoint when they are new, but they must retain 
this efficiency over a period of many years. Then, too, the design 
must be correct in order that the rooms give satisfactory and eco- 
nomical service in the proper handling of perishable foods. 

These items involve proper insulation, proper placing of cooling 
coils and correct bunker construction. Positive circulation of air at 
all times is necessary to maintain temperatures sufficiently low to 
protect the stores, and to prevent condensation of moisture on walls 
and ceilings which would soon result in damp, moldy conditions so 
fatal to many items included on the hotel menu. 

Aside from these considerations, however, practical experience has 
taught that some interior finishes over cork insulation are satisfac- 
tory for hotel conditions, and some are not. It must be borne in 
mind that these cold storage rooms receive a great deal of abuse, 
so to speak, and the interior finish that would be quite satisfactory 
for a cold storage warehouse, for example, is entirely unsatisfactory 
in hotels where rooms are small and doors are opened and closed 
repeatedly throughout the entire day. The influx of warm air each 
time doors are used carries with it a certain proportion of water held 
in suspension. As it comes in contact with chilled surfaces this 
water condenses. Unless this warm air is carried directly up over 
cooling coils by an active air circulation in the room, it will condense 
on walls and stores. While correct design of the interior arrange- 
ment of hotel cold storage rooms is a reasonable safeguard against 
damp, moldy conditions, yet some little moisture is always likely to 



486 CORK INSULATION 

form on walls and ceil-ing and the interior finish must be such that it 
will successfully resist such temporary conditions and permit of 
sanitary and hygienic conditions at all times through proper cleansing. 

To tile the entire interior of hotel cold storage rooms in white is 
the most satisfactory way, but is expensive. An alternate specifica- 
tion, considerably less expensive, if now in use with satisfactory 
results. It consists of two coats of Portland cement plaster troweled 
smooth and hard for the walls, ironed-on at the factory mastic finish^ 
corkboard for the ceilings, and hard concrete wearing floor over 
floor insulation, with metal floor grids embedded flush in the 1-inch 
cement top finish. The plaster is marked of? in suitable squares to 
confine hair line check cracks to the score marks, and the joints in 
the ironed-on mastic finish corkboard are sealed flush with a mastic 
filler, by ironing with a hot tool. This ironing process causes the 
filler to combine with the mastic material so that the finished surface 
is a continuous sheet, sufficiently elastic at low temperatures to elimi- 
nate the possibility of cracking and absolutely impervious to moisture. 

The walls and ceiling can then be painted two coats of white prime 
and one good coat of white elastic enamel. Two coats of orange 
shellac.should be applied to the mastic surface before the prime is 
applied, as otherwise the oils in the mastic material will cause the 
white prime and enamel to stain. 

In quite a few instances, ironed-on mastic finish corkboard has 
been used on walls, as well as ceiling, with excellent results. It, 
unquestionably, is superior to Portland cement plaster but does not 
finish oflf as smoothly unless unusual care is taken in erection and 
sealing of the mastic joints. 

It is quite difficult to obtain concrete wearing floors hard enough 
to successfully withstand hotel service. For that reason the use of 
metal floor grids is essential, and a cold storage room floor so 
constructed will outlast steel plates. 

These items, naturally, make the cost of a strictly modern hotel 
cold storage room somewhat more than the cost of ordinary equip- 
ment, but the first cost is practically the last cost and is far cheaper 
in the long run. 



1 Since this article was written in 1918, plastic mastic finish, hand troweled to 
corkboard surfaces at point of erection, has been developed to a satisfactory standard 
by the use of a high grade emulsified asphalt mixed and handled according to proven 
formula and tested method. — The Author. 



HANDLING CONCRETE 487 

CONCRETE.* 

Anyone who is careful to observe the simple rules for doing con- 
crete work such as that outlined herewith can make and place con- 
crete satisfactorily, even though he may have had no previous 
experience. 

What Concrete Is.— Concrete is made by mixing portland cement, 
sand, pebbles or broken stone and water in certain definite propor- 
tions according to the kind of work for which the concrete is to be 
used, and then permitting the mixture to harden under proper condi- 
tions in forms or molds. As soon as concrete has been mixed, if 
left undisturbed, it begins to harden and soon becomes like stone. 
The hardening process, which is a chemical change that takes place 
in the cement when mixed with water, continues for a long time 
after the concrete has acquired sufficient strength for the purpose 
intended. This continual increase of strength is the quality by which 
concrete differs from all other materials. Concrete grows ever 
stronger, never weaker by age. 

Theory of Mixing Concrete. — Pebbles, sand and cement must be 
mixed together in correct proportions in order to make a dense, 
strong concrete. 

For this reason, in mixing concrete, stone and sand are used in such 
proportions that the amount of spaces or voids between them is as 
small as possible, and all the surfaces of the sand and pebbles are 
coated with a film of cement. The smaller the voids are, the 
stronger and more dense will be the concrete. A dense concrete is 
also watertight; if the voids are not all completely filled, the concrete 
will be porous and will not be impervious to water. 

It is very important that no dirt or finely powdered sand be used, 
as the use of such material interferes with the action of the cement 
in hardening. The strength of the concrete depends upon the 
adhesion of the cement mixture to the clean surfaces of sound, hard 
particles of sand or stone. 

Portland Cement. — Portland cement is a uniform, reliable product. 
Any of the standard brands produced by members of the Portland 
Cement Association are tested and guaranteed and will produce 
good concrete when properly combined in correct proportion with 
the other materials necessary for a concrete mixture. 

Portland cement is packed and shipped in standard cloth sacks or 
in paper bags holding 94 pounds net weight. For convenience in 
determining the necessary quantity of the several materials entering 
into a concrete mixture, a sack of portland cement may be con- 
sidered as one cubic foot. 



"Courtesy of Portland Cement Association. 



488 



CORK INSULATION 



Practically all building material dealers handle portland cement. 
Cloth sacks are charged to the cement purchaser. When empty they 
should be returned to the cement dealer, who will buy them back if 
they are fit for further use as cement containers. Cement sacks 
which have been wet, torn or otherwise rendered unfit for use are not 
redeemable. 

Paper bags are not returnable. 

Cement should always be kept in a dry place until used. 



ICuJt. 




12" 



K P« P C P 



li^ 



4CU.FT. 



CEMENT 



Sand 



12" 



^M¥^ 



4.5 Cu.Ft. 

?;p:;P.:.-9,jj^K 



P£E>E)LE5oR STONLS CONCRETE 



FIG. 217.— CEMENT, SAND AND PERIU.ES IN THE PROPER PROPORTIONS 

WHEN MIXED WITO WATER HARDEN INTO THE SOLID MASS THAT 

IS CONCRETE.— NOTE THAT 7 CU. FT. OF MATERIALS 

MAKE BUT 4.5 CU. FT. OF CONCRETE. 



Aggregates. — Sand and pebbles or broken stone are usually spoken 
of as "aggregate." Sand is called "fine aggregate" and pebbles or 
crushed stone "coarse aggregate." Sand or other fine aggregate, 
such as rock screenings, includes all particles from very fine (exclu- 
sive of dust) up to those which will just pass through a screen having 
meshes Y/^-mzh. square. Coarse aggregate includes all pebbles or 
broken stone ranging from J4-'nch up to Ij/^ or 2 inches. The maxi- 
mum size of coarse aggregate to be used is governed by the nature 
of the work. In thin slabs or walls the largest pieces of aggregate 
should never exceed one-third the thickness of the section of con- 
crete being placed. 

Sand should be clean and hard, free from fine dust, loam, clay and 
vegetable matter. These "foreign" materials are objectionable be- 



HANDLING CONCRETE 489 

cause they prevent adhesion between the cement and sound, hard 
particles of sand aggregate, thereby reducing the strength of the 
concrete and increasing its porosity. Concrete made with dirty 
sand or pebbles hardens very slowly at best and may never harden 
enough to perm.it the concrete to be used for its intended purpose. 

Sand. — Sand should be well graded, that is, the particles should 
not all be fine nor all coarse, but should vary from fine up to those 
particles that will just pass a screen having meshes ^-inch square. 
If the sand is thus well graded the finer particles help to occupy the 
spaces (voids) between the larger particles, thus resulting in a 
denser concrete and permitting the most economical use of cement 
in filling the remainder of the voids or air spaces and binding the 
sand particles together. 

Coarse Aggregate. — Pebbles or crushed stone to be used in a con- 
crete mixer should be tough, fairly hard and free from any of the 
impurities that would be objectionable in sand. Stone containing a 
considerable quantity of soft, flat or elongated particles should 
not be used. 

Bank-run Gravel. — The natural mixture of sand and pebbles as 
taken from a gravel bank is usually referred to as bank-run material. 
This is not suitable for concrete unless first screened so that the 
sand may be separated from the pebbles and the two materials 
reproportioned in correct ratio. Most gravel banks contain either 
more sand or more pebbles than desirable for concrete mixture. 
Usually there is too much sand. 

Water. — Water used to mix concrete should be clean, free from 
oil, alkali and acid. In general, water that is fit to drink is good 
for concrete. 

Proportioning Concrete Mixtures. — In order to obtain a strong, 
dense, durable concrete, the materials entering into it must be defi- 
nitely proportioned. For a given purpose, a certain quantity of 
Portland cement with a certain quantity of sand, pebbles or crushed 
rock and water will make the best concrete. The several materials 
entering into concrete must be so proportioned that the cement will 
fill the voids or air spaces in the sand and when combined with the 
correct quantity of water will coat every particle of sand, thus 
making a volume of cement-sand mortar slightly in excess of the 
volume required to fill the air spaces or voids in the volume of 
broken stone or pebbles to be used. Some concrete work requires 
denser concrete than other kinds, so it is good practice to vary the 
mixture according to the job. 

A 1:2:3 mixture means 1 sack (1 cubic foot) of cement, 2 cubic 
feet of sand and 3 cubic feet of pebbles or crushed stone. The first 
figure stands for the cement, the second for the sand and the third 



490 



CORK INSULATION 



for the pebbles or broken stone. A 1:2 mixture means 1 sack (1 
cubic foot) of Portland cement and 2 cubic feet of sand . A 1 :2 mix- 
ture would be called a mortar, since it contains no pebbles or broken 
stone (coarse aggregate). 

The following table shows the usual proportions recommended 
for several classes of construction: 

Table of Recommended Mixtures and Maximum Aggregate Sizes. — 

1:1:1J4 — Mixture for: Max. Size Agg. 

Wearing course of two-course pavements 54 i"- 

1:2:3 — Mixture for: 

One-course walks, floors, pavements 1 H in. 

Basement walls exposed to moisture 1^ in. 

Sills and lintels without mortar surface 54 '"■ 

Tanks 1 in. 

1:2:4 — Mixture for: 

Foundations for light machinery 2 in. 

Concrete work in general 1 J^ in. 

1:2>^:4— Mixture for: 

Building walls above ground 1^ in. 

Walls of pits or basements 1 ^ in. 

Base of two-course floors or pavements 1 in. 

1:2 — Mixture for: 

Wearing course of two-course floors and pavements % in. 




FIG. 218.— BOTTOMLESS MEASURING BOX OF 1 CU. FT. CAPACITY FOR 
DETERMINING THE EXACT BATCH PROPORTIONS. 



Don't Guess at Quantities. — All materials should be accurately 
measured. This can be done easily by using a measuring box made 
:o hold exactly 1 cubic foot, 2 cubic feet or any other volume desired. 
Such a box is in reality a bottomless frame. An illustration of a 
measuring box is shown here. To measure the materials the box 
is placed on the mixing platform and filled. When the required 
•amount of material has been placed in it, the box is lifted of? and 



HANDLING CONCRETE 



491 



the material remains on the platform. Cement need not be meas- 
ured because, as already explained, one sack can be considered as 1 
cubic foot in volume. A pail might also be used in proportioning 
concrete. For example, a 1:2:3 batch of concrete would be meas- 
ured by taking 1 pail of portland cement, 2 pails of sand and 3 pails 
of pebbles or stone. 




FIG. 219.— SIMPLE TOOLS FOR MAKING AND PLACING CONCRETE— WATER 
BARREL AND BUCKET; STEEL-PAN WHEELBARROW FOR HANDLING 
DRY AGGREGATE, AND CONCRETE TO FORMS; SAND SCREEN FOR 
PROPER GRADING OF AGGREGATES; SQLTARE POINTED SHOVEL FOR 
TURNING AND MIXING CONCRETE; WOODEN FLOAT FOR FINISHING. 

Mixing the Materials. — Concrete may be mixed either by hand or 
by machine. Machine mixing is to be preferred as in this way thor- 
ough mixing is easier to obtain and all batches will be uniform. 
However, first-class concrete can be mixed by hand. Whichever 
way mixing is done, it should continue until every pebble or stone 
is completely coated with a thoroughly mixed mortar of sand and 
cement. 

Mixing Platform. — For hand mixing a watertight platform at 
least 7 feet wide and 12 feet long should be provided. A platform of 
this size is large enough to permit two men using shovels to work 
upon it at one time. Such a platform should preferably be made of 
boards at least IH inches thick, tongued and grooved so that the 
joints will be tight and the platform rigid. These planks may be 



492 CORK INSULATION 

nailed to three or more 2 by 4's set on edge. Two sides and one 
end of the platform should have a strip nailed along the edge and 
projecting 2 inches above the mixing surface of the platform to 
prevent materials from being washed or shoveled ofif while mixing. 

Hand Mixing. — The usual procedure in mixing concrete b.v hand 
is as follows: 

The measured quantity of sand is spread out evenly on the plat- 
form. On this the required amount of cement is dumped and evenly 
distributed. The cement and sand are then turned over thoroughly 
with square pointed shovels enough times to produce a mass of 
uniform color, free from streaks of brown and gray. Such streaks 
indicate that the sand and cement have not been thoroughly mixed. 
The required quantity of pebbles or broken stone is then measured 
and spread in a layer on top of the cement-sand mixture and all of 
the material again mixed by turning with shovels until the pebbles 
have been uniformly distributed throughout the mixed cement and 
sand. At least three turnings are necessary. A depression or hollow 
is then formed in the center of the pile and water added slowly 
while the materials are turned with square pointed shovels, this 
turning being continued until the cement, sand and pebbles have 
been thoroughly and uniformly combined and the desired consistency 
or wetness obtained throughout the mixture. 

It is very important that no more water be used than necessary, 
as too much will reduce the strength of the concrete. Too little 
water will also reduce its strength and make it porous. For gen- 
eral use, concrete, after thorough mixing, should be wet enough to 
form a mass of pasty or jelly-like consistency, but never so wet as 
to flow easily or be soupy. 

Placing Concrete. — Concrete should be placed into forms as soon 
as possible after mixing and in no case more than 30 minutes after 
mixing. It should be deposited in layers of uniform depth, usually 
not exceeding 6 inches. When placed in the forms it should be 
tamped and spaded so as to cause it to settle thoroughly everywhere 
in the forms and produce a dense mass. By "spading" is meant the 
working of a spade or chisel-edge board in the concrete and between 
it and the side of the forms, moving the spading tool to and fro and 
up and down. This working of the concrete next to the forms 
forces the large pebbles or stone particles away from the form face 
into the mass of the concrete and insures an even, dense surface 
when forms are removed. 

Finishing Concrete. — The surface of a floor or walk should be fin- 
ished by using a wood float. A metal trowel should be used spar- 
ingly, if at all, because its use brings a film of cement to the surface, 
which lacks the wearing quality of the cement and sand combined 
and may cause the surface to develop "hair cracks" after the con- 
crete hardens. A trowelled surface is smoother, but does not wear 
so well as a floated surface and is likely to be slippery. 



HANDLING CONCRETE 



495 



Protecting Newly Placed Concrete.— If concrete is left exposed 
to sun and wind before it has properly hardened, much of the water 
necessary to hardening will evaporate and the concrete will simply 
dry out. Moisture is necessary to the proper hardening of concrete 
because, as already mentioned, the hardening process is a chemical 
change which takes place in the cement when mixed with water. 

Concrete floors, walks, pavements and similar large surfaces can be 
protected by covering with moist earth, sand, or other moisture-re- 
taining material as soon as the concrete has hardened sufficiently to 
permit doing so without marring the surface. This covering should 
be kept moist in warm weather by frequent sprinkling during a 
period of ten days or so. Walls or other sections which cannot con- 



S pacf e. 



l\4-"Tie. 

/-Spacer 
removable. 



Wire 




Wire he. 



V-IG. 220.— "SPADING" OF CONCRETE IN WALL FORMS FORCES THE 
COARSE AGGREGATE BACK FROM THE FACE AND PRODUCES A 
SMOOTH SURFACE ON THE FINISHED WALL. 

veniently be covered in the manner suggested can be protected by 
hanging moist canvas or burlap over them and wetting down the 
entire work often enough to keep it always moist for ten days after 
placing. During cold weather protection is equally important, but 
the concrete need not be kept moist as evaporation is not so rapid. 

Concrete in Winter.— There is no difficulty in doing concrete work 
in cold weather if a few simple precautions are taken. The booklet 
"Making Concrete and Cement Products in Winter" describes the 
rules to be followed. A copy may be obtained free by addressing 
the Portland Cement Association, Chicago, 111. 



494 



CORK INSULATION 



QUANTITIES OF CEMENT, FINE AGGREGATES AND COARSE AGGREGATES 
REQUIRED FOR ONE CUBIC YARD OF COMPACT MORTAR OR CONCRETE. 



MIXTURES 


QUANTITIES OF MATERIALS 






C. A. 


Cement 


Fine Aggregate 


Coarse Aggregate 


P . 






. 










Stone 


Sacks 


Cu. Ft. 


Cu. Yd. 


Cu. Ft. 


Cu. Yd. 




1.5 




15.5 


23.2 


0.86 








2.0 




12.8 


25.6 


0.95 








2.5 




11.0 


27.5 


1.02 








3.0 




9.6 


28.8 


■1.07 








1.5 


3 


7.6 


11.4 


0.42 


22.8 


0.85 




2.0 


3 


7.0 


14.0 


0.52 


21.0 


0.78 




2.0 


4 


6.0 


12.0 


0.44 


24.0 


0.89 




2.5 


4 


5.6 


14.0 


0.52 


22.4 


0.83 




2.5 


5 


5.0 


12.5 


0.46 


25.0 


0.92 




3.0 


5 


4.6 


13.8 


0.51 


23.0 


0.85 



1 Sack Cement = 1 cu. ft.; 4 sacks — 1 bbl. 

Based on Tables in "Concrete, Plain and Reinforced," by Taylor and Thompson. 



MATERIALS REQUIRED FOR 100 SQ. FT. OF SURFACE FOR VARYING 
THICKNESSES OF CONCRETE OR MORTAR. 



Proportion 


1 : IH 


1 : 2 


1 : 2K 


1 : 3 


Thickness 


























in Inches 


C. 


F.A. 


C.A. 


C. 


F.A. 


C.A. 


C. 


F.A. 


C.A. 


c. 


.F.A. 


C.A, 


H 


1.8 


2.7 




1.5 


3.0 




1.3 


3.2 




1 I 


3.4 




l| 


2.4 


3.6 




2.0 


4.0 




1.7 


4.3 




1.5 


4.4 




tI 


3.6 


5.4 




3.0 


6.0 




2.5 


6.3 




2.2 


6.8 




1 


4.8 


7.2 




4.0 


7.9 




3.4 


8.4 




3.0 


8.9 






6.0 


9.0 




4.9 


9.9 




4.2 


10.5 




3.7 


11.1 




1/^ 


7.2 


10.8 




5.9 


11.9 




5.1 


12.7 




4.4 


13.3 




i% 


8.4 


12.6 




6.9 


13.9 




5.9 


14.7 




5.2 


15.7 




2 


9.6 


14.4 




7.9 


15.8 




6.8 


16.9 




5.9 


17.7 


5 




. 


: 2 : 


3 


1 


: 2 : 


4 


1 


: 2H : 


4 


1 


: 23^ : 


3 


6.5 


13.0 


19.3 


5.6 


11.2 


22.4 


5.2 


12.9 


20.6 


4.6 


11.5 


23.0 




8.6 


17.2 


25.8 


7.5 


14.9 


29.8 


6.9 


17.1 


27.5 


6.2 


15.4 


30.7 




10.8 


21.6 


32.2 


9.4 


18.7 


37.4 


8.6 


21.5 


34.3 


7.7 


19.2 


38:3 




12.9 


25.8 


38.6 


11.2 


22.4 


44.7 


10.3 


25.8 


41.2 


9.2 


23.0 


45.9 




17.2 


34.4 


51.6 


15.0 


29.8 


59.7 


13.7 


34.3 


54.9 


12.3 


30.7 


61.3 


10 


21.5 


43.2 


64.4 


18.7 


37.4 


74.8 


17.2 


43.0 


68.6 


15.3 


38.3 


76.6 


12 


25.8 


51.6 


77.2 


22.4 


44.7 


89.4 


20.6 


51.6 


82.4 


18.4 


45.9 


91.«^ 



C. = Cement in Sacks. 
F. A. = Fine Aggregate (sand) in Cu. Ft. 

C. A. =: Coarse Aggregate (pebbles or broken stone) in Cu. Ft. 
Quantities may vary 10 per cent either way depending upon character of aggregate 

used. 
No allowance made in table for waste. 



1 



HANDLING CONCRETE 495 

How to Use Materials Table for Calculating Quantities. 

Problem 1: — What quantities of materials are required for a mono- 
lithic concrete foundation wall 34 feet square, outside measurements, 
12 inches thick, 7 feet high, with a footing 12 inches thick and 18 
inches wide, using a 1:2:4 mixture in both the wall and footing? 

Solution: — The wall contains 924 square feet of surface, 12 inches 
thick, deducting for duplication at corners. 

Referring to table under 1:2:4 mixture for 12 inch walls, 22.4 sacks 
of cement are required for each 100 square feet of surface. Dividing 
924 by 100 gives the number of times 100 square feet are contained 
in the total wall surface and multiplying by 22.4 gives the total num- 
ber of sacks of cement required. Similar calculations are made for 
the fine aggregate and the coarse aggregate in both the wall and 
the footing, noting that the width of the footing, 18 inches, is IJ/2 
times the 12 inches thick. 

924 X 22.4 

■ = 207 sacks of cement. 

100 

924 X 44.7 

= 413 cu. ft. fine aggregate. 

100 

924 X 89.4 

= 826 cu. ft. coarse aggregate. 

100 

The footing contains 132 square feet of surface, 18 inches thick 
(1^x12 inches), deducting for duplication at corners. 

132x22.4x13^ 

= 44.4 sacks cement. 



= 88.5 cu. ft. fine aggregate. 
= 177.0 cu. ft. coarse aggregate. 





100 




132 


x44.7x 


1/2 




100 




132 


x 89.4 X 


1/2 



100 



Total materials required for footing and wall: 251.4 sacks cement, 
501.5 cu. ft. fine aggregate, 1003 cu. ft. coarse aggregate. 

Probcm 2: — What quantities of material are required for a 1:2 
cement plaster coat, one inch thick on the lower four feet of the 
above foundation? 

5"o/m<!o;i;— Perimeter of foundation: 4x34 feet = 136 feet. This 
multiplied by height of plaster coat, 4 ft., equals 544 square feet. 

544x4.0 

= 21.8 sacks of cement. 

100 

544 X 7.9 

= 42.5 cu. ft. sand. 

100 



496 CORK INSULATION 

EXAMPLE OF PURCHASER'S INSULATION 
SPECIFICATIONS.* 

Furnish and erect pure corkboard and sundry materials necessary 
to construct cold storage rooms, of arrangement, location and size 
as outlined by drawings, dated . . . and as per the following specifi- 
cations: 

REFRIGERATED BANANA ROOMS. 

Floor Insulation. — It is understood that the base floor is depressed 
7" below the general level of the floor of the building, which base is 
reasonably smooth and level and in readiness to receive insulation. 

Upon such reasonably smooth and level concrete base, the con- 
tractor shall furnish and apply one layer 2" Pure Corkboard in hot 
asphalt with the top surface flooded with the same compound, and 
left in readiness to receive 5" concrete wearing floor to be put in 
place by owners or others. 

Ceiling Insulation. — To the underside of concrete ceiling surface, 
in proper condition to receive insulation, the contractor shall furnish 
and erect two layers 2" Pure Corkboard. The first layer shall be 
erected in a Yz" bedding of Portland cement mortar and propped 
in position until the cement sets, following which the second layer 
shall be erected to the underside of the first in hot asphalt and ad- 
ditionally secured with galvanized wire nails driven obliquely, three 
to the square foot. The exposed surface of such insulation shall 
then be finished as hereinafter specified. 

Tile Wall Insulation. — To a tile wall surface running the length of 
one Banana Room, in place for the contractor and in proper con- 
dition to receive insulation, the contractor shall furnish and erect 
two layers 2" Pure Corkboard. The first layer shall be erected in 
a Yz" bedding of Portland cement mortar, following which the second 
layer shall be erected to the first in hot asphalt and additionally 
secured with wood skewers driven obliquely, two to the square foot. 
The exposed surface of such insulation shall then be finished as here- 
inafter specified. 

Pilaster, Column and Caps Insulation. — To the concrete surfaces 
of pilasters, columns and caps, wherever insulation is required as in- 
dicated by drawings, the contractor shall furnish and erect one layer 
3" Pure Corkboard in a J/2" bedding of Portland cement mortar and 
prop in position or otherwise secure in position until the cement 
sets. The exposed surface of such insulation shall then be finished 
as hereinafter specified. 



*Insulation specifications for The Kroger Grocery & Baking Co., Charleston, W. Va., 
Warehouse. 



PURCHASER'S SPECIFICATIONS 497 

Outside Cork Wall Insulation.— To construct the self-sustaining 
outside cork walls, the contractor shall furnish and erect two layers 
2" Pure Corkboard, with the sheets in the first layer set edge on 
edge in hot asphalt and toe-nailed to each other with galvanized 
wire nails, following which the second layer shall be erected to the first 
in hot asphalt and additionally secured with wood, skewers driven 
obliquely, two to the square foot. The exposed surfaces of the in- 
sulation shall then be finished as hereinafter specified. 

Cork Partition Wall Insulation. — To construct the self-sustaining 
cork partition walls, the contractor shall furnish and erect one layer 
3" Pure Corkboard, with the sheets set edge on edge in hot asphalt 
and toe-nailed to each other with galvanized wire nails. The exposed 
surfaces of the insulation shall then be finished as hereinafter specified. 

Cold Storage Doors. — The contractor shall furnish and set, where 
indicated by drawings, six standard cold storage doors, 4' 6" wide x 
6' 6" high, three right hand swing and three left hand swing, no sill 
type, and three standard bunker doors, 4' 6" wide x 2' 0" high, left 
hand swing, high sill type. 

REFRIGERATORS AND EGG ROOM. 

Floor Insulation. — It is understood that the base floor under Re- 
frigerators in the basement, is depressed 7" below the general level 
of the floor of the building, which base is reasonably smooth and 
level and in readiness to receive insulation. It is understood that 
the base floor under Egg Room, on second floor, is not depressed 
below the general level of the floor but is reasonably smooth and 
level and in readiness to receive insulation. 

Upon such reasonably smooth and level concrete base floors, the 
contractor shall furnish and apply two layers 2" Pure Corkboard in 
hot asphalt with asphalt between the layers and the top surface 
flooded with the same compound, and left in readiness to receive 4" 
concrete wearing floor to be put in place by owners or others. 

Ceiling Insulation. — To the underside of concrete ceiling surfaces, 
in proper condition to receive insulation, the contractor shall furnish 
and erect two layers 2" Pure Corkboard. The first layer shall be 
erected in a ^" bedding of Portland cement mortar and propped in 
position until the cement sets, following which the second layer shall 
be erected to the underside of the first in hot asphalt and additionally 
secured with galvanized wire nails driven obliquely, three to the 
square foot. The exposed surface of such insulation shall then be 
finished as hereinafter specified. 

Tile Wall Insulation.— To a tile wall surface running the short way 
of the Egg Room, in place for contractor and in proper condition to 
receive insulation, the contractor shall furnish and erect two layers 2" 
Pure Corkboard. The first layer shall be erected in a V2" bedding of 



498 CORK INSULATION 

Portland cement mortar, following which the second layer shall be 
erected to the first in hot asphalt and additionally secured with weed 
skewers driven obliquely, two to the square foot. The exposed sur- 
face of such insulation shall then be finished as hereinafter specified. 

Building Wall Insulation. — To the brick building wall extending 
along one long side of the group of Refrigerators, and to the brick 
building wall extending the length of the Egg Room, in place for 
the contractor and in proper condition to receive insulation, the con- 
tractor shall furnish and erect two layers 2" Pure Corkboard. The 
first layer shall be erected in a Yz" bedding of Portland cement 
mortar, following which the second layer shall be erected to the 
first in hot asphalt and additionally secured with wood skewers driven 
obliquely, two to the square foot. The exposed surface of such in- 
sulation shall then be finished as hereinafter specified. 

Pilaster, Column and Caps Insulation. — Same as specified for Re- 
frigerated Banana Rooms. 

Outside Cork Wall Insulation. — Same as specified for Refrigerated 
Banana Rooms. 

Cork Partition Wall Insulation. — Same as specified for Refrigerated 
Banana Rooms. 

Cold Storage Doors. — The contractor shall furnish and set, where 
indicated by the drawings, four standard cold storage doors, 4' 6" wide 
x 6' 6" high, right hand swing, no sill type. 

Coil Bunkers. — It is understood that the owners shall provide in 
proper locations in concrete ceiling slabs in advance of the insula- 
tion work being done, a suitable number and kind of expansion 
anchors to receive Yz" hanger bolts as supports for coils and coil 
bunkers. 

After the insulation work has been completed, the contractor shall 
provide, on the floor of each of thcoc rooms, an insulated coil 
bunker with all necessary material for supporting it at the proper 
distance below the ceiling, but it is understood that another con- 
tractor shall raise the bunkers into place after adjusting coils in 
position thereon. 

The bottoms of the bunkers shall be insulated with one layer 2" 
Pure Corkboard on ^" T&G lumber, while the bafifles of the 
bunkers shall be double layer T&G lumber with insulating paper 
between the layers. The floors of the bunkers shall be covered 
with No. 24 gauge galvanized iron, flashed at all edges, with all 
joints and nail heads soldered. Galvanized iron drain pipe shall be 
provided to carry drip from low point of each bunker to the floor 
of the room. 

CORKBOARD FINISH. 

Where mentioned hereinbefore, except ceiling areas, the con- 
tractor shall furnish and apply to the exposed insulation sur- 
faces a Y2" Portland cement plaster finish, in two coats, each 



1 



PURCHASER'S SPECIFICATIONS 499 

approximately %" thick, mixed in the proportion of one part Port- 
land cement to two parts clean sharp sand, the second coat brought 
to a float finish and scored in suitable squares to reduce and confine 
checking to such score marks. 

Where mentioned hereinbefore for ceiling areas, the contractor 
shall furnish and apply by hand with trowel to the exposed insula- 
tion surfaces one uniform coat of Plastic Mastic Primer, mixed one 
bag asbestos fibre to one drum approved asphalt emulsion. Over this 
coat the contractor shall then furnish and apply a uniform coat of 
Plastic Mastic Finish, mixed one bag asbestos fibre and three bags 
hard silica grits to one drum approved asphalt emulsion, such finish 
troweled to as smooth a surface as the material will permit and left 
uiiscored. The contractor may furnish Pure Corkboard for the 
second layer on the ceiling having an asphalt mastic finish approxi- 
mately Ys" thick ironed on at the factory, in which case all mastic 
joints in the finished work shall then be filled in with suitable Plas- 
tic Mastic material and thoroughly sealed in approved manner. 

GENERAL. 

Owners shall assume all risk of any damage to, or de- 
struction or loss of, all goods furnished whether by fire or otherwise 
after they, or any part of them, shall have been delivered on or 
about owner's premises, though the erection or installation of the 
same has not been begun or completed by the contractor. Owner 
will have building in readiness and all surfaces left in proper con- 
dition, so that the work once begun may be pushed to completion 
without delays. Owner will supply satisfactory storage room under 
cover and protection at point of erection for the materials called for, 
allow the contractor the use of elevator and such additional facili- 
ties as may be available for handling materials, and shall furnish 
all scaflEolding, electric current, artificial light, heat and water re- 
quired. It is understood that there is a side track at the building so 
that materials shipped in carlots need not be drayed by the con- 
tractor, but it is understood that the contractor shall handle all his 
own materials at the building. 



500 



CORK INSULATION 



FREIGHT CLASSIFICATIONS, CLASS RATES, C/L MINIMUMS IN THOUb- 
ANDS OF POUNDS, ETC. 

Pure Corkboard and Sundries 



Railroad 
Description 



Containers 



Official I Western | Southern 
L OL-CL-MFN | LCL-CL-MIN | LCL-CL-MIN 



•'Granulated cork 
compressed in sheets 
without binder," or 
"cork sheets com- 
pressed without 





binder" 




2 


i 


20 


2 


4 


20 


2 


4 


20 


Granulated 
cork 


■■Oranulated cork" 


Bags 


1 


3 


12 


1 


3 


12 


1 


3 


12 


Asphalt 


"Asphalt, solid" 


Drums or bbls. 


4 


6 


40 


4 


D 


40 


6 


A 


40 


Galvanized 
wire nails 


"Galv. wire nails" 


Kegs or boxes 


4 


5 


36 


4 


5 


36 


6 


G 


30 


Wooden 
skewers 


"Wooden skewers" 


Boxes or 

cartons 


3 






2 












Insulating 
paper 


"Building paper, 
plain or satur- 
ated" 


Rolls 


R2(> 


5 


30 


3 


5 


30 


5 


A 


30 


Cold storage 
doors 


"Doors or windows, 
insulated, cold 
storage, not 
glazed" 


Crates 


3 


5 


24 


3 


B 


24 


4 


6 


24 


Kettles, over 
100 lb. wt. 


"Kettles, iron or 
steel, other than 
steam jacket" 


Bulk 


1 


5 


30 


1 


A 


30 


2 


5 


?,0 


Emulsified 
asphalt 


"Asphalt, liQuid, 
other than paint, 
stain or varnish" 


(a) M e t a 1 
cans, in bxs. 
or crates 

(b) Barrels 


3 
4 


6 


40 
40 


3 

4 


D 
D 


40 
40 


3 

r, 


A 
A 


40 
40 



Elastic 


"Paint (no label re- 


(a) Pails or 


enamel 


quired) " 


metal cans. 
in bbls. ,or 
boxes; or 
bulk in kits 
or pails 3 
(b) Barrels 


Mixed C/L 


(See descrlptlwia 


Bulk, cork- 


Corkboard 


above) 


board; bags. 


and gran. 




gran. cork. 


cork 




Corkboard 
may be in 
packages, 
also X 



FREIGHT DATA 



501 



FREIGHT CLASSIFICATIONS, CLASS RATES, C/L MINIMUMS IN THOUS- 
ANDS OF POUNDS. ETC. 
Cork Pipe Covering, Cork Lags, Cork Discs and Sundries 



Railroad 

Description j Containers |LCL-CL-MTXj L€L-CL-MIn'| LCL CL-MIN 



^ I - _5'''''l-'''' __ '. _ Western | Soutliern 



"Cork pipe covering 
with or without 
binder" 



2 4 20 2 4 20 



Cork) lagging 
and discs 



'Cork pipe or tank 
covering without 
binder" 



Waterproof 
cement 



"Cement paste 
]at>el required)' 



metal cans, in 
bbls. or boxes; 
or bulk in kits 
or palls 



Asphaltic 
paint 


"Asphaltum paint 
(no label re- 
quired)" 


Do 


3 


5 


36 


4 


5 


3(; 


4 


5 


30 


Brine putty 


"Putty" 


Do 


3 


5 


36 


4 


5 


36 


4 


5 


30 


Seam filler 


"Asphaltum. liquid 
other than paint, 
stain or varnish" 


(a) M e t a 1 
cans, in boxes 
or crates 

(b) Barrels 


4 


G 


40 


3 

4 


D 


40 


3 


A 


40 


Copper clad 
steel wire 


"Copper clad steel 
wire" 


Bbls.. boxes, 

coils, bdls., 
crates, tubs. 


3 


4 


30 


, 


4 


30 




4 




Gal. band iron 
and clips 
and bolts 


"Band or hoop 
iron" 


Loose or In 
packages 


4 


5 


3G 


4 


5 


36 


6 


g 


36 


Plastic cork, 
no simdries 


"Cork pipe covering 
with or without 
binder" 


Cartons or 
boxea 


2 


4 


20 


2 


4 


20 


2 


4 


20 


Plastic cork 
and sundries 


"Plastic cork with 
sundries" 


Cartons or 
boxes 


1 






1 






1 






Plastic cork 
sundries 


"Plastic cork 
sundries" 


Cartons 
or boxes 


1 






1 






1 







Mixed C/L 
Cork covering 
& Corkboard 



(See description above) Crates or bxs. 

"Granulated cork 
compressed in Bulk or crates 
sheets without or cartons 
binder" 



502 CORK INSULATION 

CORK PIPE COVERING SPECIFICATIONS. 

Brine and Ammonia Lines Operating Between 0° and 25° F. — 
Cover all brine and ammonia lines operating at from 0° to 25° F., 
after they have been tested, cleaned and approved, with Brine Thick- 
ness cork pipe covering having a mineral rubber finish ironed on at 
the factory. 

Use sectional covering on all pipe lines up to and including 8-inch 
nominal pipe size. On all larger sizes use segmental covering, 
beveled to the proper radius. Cement all joints with waterproof 
cement, all end joints being broken by making one-half of the first 
section 18 inches long and the other half the full length of 36 inches. 
Place all longitudinal joints on top and bottom. Wire the covering 
in place with copper clad steel wire, applying not less than six wires 
per section or its equivalent of three feet. Draw wires up tight all 
around the covering and not just at the point of twist. 



FIG. 221.— METHOD OF APPLYING SECTIONAL CORK PIPE COVERING 'lu 
BREAK END JOINTS. 

Use cork fitting jackets on all screwed fittings up to and including 
6-inch, and on all flanged fittings up to and including 6-inch. On 
all larger sizes use cork segments, beveled to the proper radius. 
Cement all joints with waterproof cement and wire securely with 
copper clad steel wire, applying not less than six wires per fitting. 
Fill all spaces between the cork jackets and/or the cork segments 
with brine putty, so applied as to leave no void spaces whatever 
behind the insulation. 

After the insulation is thus applied, fill all seams and broken edges 
with seam filler so as to leave a smooth, workmanlike surface. 
Paint the entire exposed surfaces of the insulation with one good 
coat of asphaltic paint, or finish as otherwise specified. 

Carry all insulated lines on hangers fitted to the outside of the 
covering, which shall be protected by a 6-inch wide sheet iron 
shield shaped to fit the covering and extending halfway up the 
sides of the covering. 

Brine and Ammonia Lines Operating Below 0° F. — Note: Follow 
same specifications as given for Brine Thickness cork pipe covering, 
except: 

(a) Substitute Sl>ccia! Thick Brine for "Brine Thickness." 

(b) Use sectional covering on all pipe lines up to and including 
6-inch nominal pipe size, and segmental covering on larger sizes. 



COVERING SPECIFICATIONS 503 

(c) Use cork fitting jackets on all screwed fittings up to and 
including 5-inch, and on all flanged fittings up to and including 4-inch. 
On all larger sizes use cork segments. 

Ice Water and Cold Lines Operating Above 25° F. — Note: Follow 
same specifications as given for Brine Thickness cork pipe covering, 
except: 

(a) Substitute Ice Water for "Brine." 

(b) Use sectional covering on all pipe lines up to and including 
10-inch nominal pipe size, and segmental covering on larger sizes. 

(c) Use cork fitting jackets on all screwed fittings up to and 
including 6-inch, and on all flanged fittings up to and including 
4-inch. On all larger sizes use cork segments. 

Cylindrical Tanks Operating at Various Temperatures. — 

Below 5° F. use one layer 6-in. cork lags. 
5° to 20° F. use one layer 5-in. cork lags. 
20° to 32° F. use one layer 4-in. cork lags. 
Z2° to 55° F. use one layer 3-in. cork lags. 
55° F. and up use one layer 2-in. cork lags. 

Cover the cylindrical tank operating at from ....° to ....° F., 
after it has been tested, cleaned and approved, with .... inch thick 
cork lags and discs weighing approximately 1.25 lbs. per board foot 
and having a mineral rubber finish ironed on at the factory on both 
the inner and outer surfaces. 

Insulate the cylindrical surface of the tank with one layer of cork 
lags beveled to the proper radius. Insulate any and all flanges of the 
tank with one layer of cork lags projecting beyond the heads of the 
tank the equal of the thickness of the discs and applied so as to 
have a bearing of at least one foot on the lags of the body of the 
tank. (If either head of the tank has no flange, extend the body 
lags beyond the end of the tank the equal of the thickness of the 
disc.) 

Apply body and flange lags with waterproof cement on all joints, 
and secure in place with 1-inch bands (or l]^-inch bands) of not 
lighter than No. 26 gauge brass drawn up tight by means of bolts 
and clips riveted to the ends of the bands. Space these bands not 
more than one foot apart for body lags and use not less than three 
for lags on each flange. 

Apply discs directly against the heads of the tanks, and hold in 
place by means of flange or body lags as the case may be. Fill all 
spaces between the tank heads and the discs with regranulated cork 
well packed. 

Build boxes of tongued and grooved boards around the supports 
on which the tank rests, so as to leave from four to six inches of 
space on all sides, and fill these spaces with regranulated cork well 
packed. (To obviate the necessity of boxing in the tank supports and 



504 



CORK INSULATION 



to give a better insulation job, it is preferable, where weight per- 
mits, to carry a horizontal tank on saddles outside the body lags, 
so that the insulation will be continuous between the tank and the 
saddles.) 




FIG. 222.— CORK PIPE COVERING, LAGS AND DISCS ERECTED IN 
APPROVED MANNER TO VARIOUS SURFACES 



After the insulation is thus applied, fill all scams and broken 
edges with seam filler so as to leave a smooth, workmanlike surface. 
Paint the entire exposed surfaces with one good coat of asphaltic 
paint, or finish as otherwise specified. 



COVERING ERECTION 505 

INSTRUCTIONS FOR THE PROPER APPLICATION 
OF CORK PIPE COVERING. 

The service that cold pipe insulation encounters is the most severe 
service that insulation of any kind or character is called upon to 
withstand. Therefore, it is important: 

1. That only the very best cold pipe insulation should be selected 
for use. 

2. That it should be intelligently chosen as to the proper thick- 
ness for the service encountered. 

3. That it should be very carefully erected in conformity with 
proven specifications and methods of application. 

4. That it should have attention at least once each year. 

Basic Fitness. — Experience of many years has taught that the most 
satisfactory results have been obtained by the use of an insulation 
that does not possess capillarity (the inherent property of certain 
materials that causes them to absorb water, as a blotter sucks up 
ink), and this experience in service with coverings for brine, am- 
monia and ice water lines has limited the materials that are entirely 
suitable for cold pipe insulation to those composed of cork, having 
no foreign binder used in the manufacturing process. 

The "cork of commerce" is the outer bark of the cork oak tree — 
native of Spain. The air cell structure of cork and its freedom from 
capillarity, in combination, are the two properties provided by Nature 
to make this remarkable material, when put through the proper 
manufacturing processes, the best cold pipe insulation known. 

Description. — Cork pipe covering is made of pure granulated cork, 
compressed, molded and baked in sectional form to fit the different 
sizes of pipe and fittings. It is coated inside and out with a mineral 
rubber finish. Properly applied, it is a thoroughly satisfactory 
insulation, which is impervious to moisture and which will last 
longer than the pipe if given reasonable care in service. 

Advantages. — Cork pipe covering possesses maximum insulating 
efificiency, due to the clean cork waste used in its manufacture and 
to the manufacturing processes employed; is remarkably durable in 
service, is clean and neat in appearance and is easy to apply. Under 
average conditions, on brine and ammonia lines, it will pay for itself 
in one year. 

Three Thicknesses. — Cork pipe covering is manufactured in three 
thicknesses, to meet different service conditions, as follows: 

1. Brine Thickness, from two to three inches thick, is designed for 
brine and ammonia gas lines, and generally where the refrigerant 
ranges from 0° to 25° F. 

2. Heavy Brine Thickness, or Special Thick Brine, from three to 
four inches thick, is for brine lines where the temperature runs below 
0° F. 



506 



CORK INSULATION 



3. Ice Water Thickness, approximately one and one-half inches 
thick, is intended for use on refrigerated drinking water lines, liquid 
ammonia lines and generally where temperatures of 25° F. and 
higher are carried. 

It is important, if satisfactory results are to be obtained, that the 
correct thickness of cork pipe covering be used in every instance. 

Must Be Properly Applied. — But it is also essential that cork pipe 
covering be properly applied if satisfactory results are to be obtained 
over a long period of years, and the following points must be kept 
firmly in mind when erecting the material. 




d 



lU 



J 



FIG. 223.— TYPE OF PIPE HANGER FOR CORK PIPE COVERING. 



Sj)acing of Lines. — All pipe lines and fittings should be erected 
and spaced so as to permit of the free application of cork pipe cover- 
ing without the necessity for the cutting away of the insulation in 
any way. Dimensions required for the proper spacing of pipe lines 
and fittings to receive cork pipe covering are as follows: 

Space Space 

Required Required 

Between Between Pipes 

Thickness of Covering Parallel and Adjacent 

Pipes Surfaces 

Brine Thickness 

Screwed Fittings up to and including 6 inch 8 6 

Screwed Fittings larger than 6 inch 14 8 

Flanged Fittings 14 8 

Special Thick Bri)ie 

Screwed Fittings up to and including 3 inch 10 8 

Screwed Fittings larger than 3 inch 18 12 

Flanged Fittings 18 12 

Ice Water Thickness 

Screwed Fittings up to and including 6 inch 6 4 

Screwed Fittings larger than 6 inch 10 5 

Flanged Fittings 10 5 

Preparation of Lines. — Cork pipe covering must never be erected 
until all lines have been tested, made tight, cleaned of foreign matter, 
freed of frost and made perfectly dry. 

Pipe Hajigers and Shields. — All pipe hangers must be placed on 
the outside of the cork pipe covering, and the insulation should be 
protected from each hanger by a sheet iron shield shaped to fit the 
curvature of the covering and extending at least four inches on each 
side of the hanger and up the sides to the center of the pipe. 



COVERING ERECTION 507 

Branch Lines, By-pass Lines, Rods, Etc. — All unused or infre- 
quently used branch or bj'-pass lines leading oflE from lines being 
covered must be insulated to a distance of not less than three feet 
from the main insulated pipe line. Where this section of insulation 
ends it must be carefully sealed off with seam filler. No uninsulated 
pipe, rod or metal of anj- kind must be allowed to remain near 
enough to an insulated pipe line so that such metal enters or cuts 
into the cork pipe covering at any point. 

Insulation Sundries. — In order that cork pipe covering and cork 
fitting jackets may be properly applied, the following sundry ma- 
terials are supplied by the manufacturer without extra cost: 

1. Waterproof Cement for the cementing of all lateral and end 
joints. 

2. Brine Putty for the filling of any and all spaces between the 
covering and the pipe or the fittings. 

3. Copper Clad Steel Wire for the holding of the covering in 
place. (Ordinary copper wire or galvanized wire is unsatisfactory 
in service.) 

4. Seam Filler for the finishing up of seams and broken edges. 

5. Asphaltic Paint for the painting of the outside surfaces of the 
insulation so as to give it a neat and finished appearance and to 
enhance its value. 

The quantity of these insulation sundries shipped is intended to be 
sufficient if used as directed. 

Waterproof Cement. — Waterproof cement sets quickly when ex- 
posed to the air. Consequently, it must not be applied to any surface 
until the joint is ready to be made, as otherwise a film forms that 
prevents a proper bond. Coat only as much of a surface as is to 
be placed immediately in contact with another surface. Use cement 
on but one of two adjoining surfaces— the last to be applied. Do not 
coat both surfaces zcith tuaterproof cement. Stir the cement thoroughly 
before applying it, and keep cover of the container on tight when not 
in use. 

Screwed Fitting Jackets. — Apply cork fitting jackets to all screwed 
fittings before the sectional covering is installed on the pipes incident 
thereto. This is necessary because the cork jackets extend beyond the 
beads of the screwed fittings. By installing the sectional covering 
last, tight end joints can be made with the cork jackets by slightly 
wedging the sectional covering in place. Eliminate all voids between 
the fitting and the cork jacket by filling with brine putty. Use water- 
proof cement on all joints of the cork jackets, and then wire securely 
in place using not less than four wires to each jacket. 

Sectional Covering. — Waterproof cement must be used on all 
lateral and end joints of sectional covering. All joints must be 



508 CORK INSULATION 

brought tightly together before a film has had a chance to form on 
the cement. All end joints must be broken by making one-half of 
the first section 18 inches long and the other half the full length 
of 36 inches. Place all lateral or longitudinal joints on the top and 
bottom. 

The slightest opening througli either the lateral or end joints of the 
covering will allow moisture to condense and frost to form to damage 
or destroy the insulation. Thus exceptional care must he taken to use 
waterproof cement properly, and the cork pipe covering must be secured 
in place with copper clad steel wire, using not less than six wires for 
each section of covering. These wires must be drawn up tight all 
around the covering — not just at the point of twist — tight enough so 
that the wire is embedded in the mineral rubber finish around the whole 
circumference. Never use any kind of wire except copper clad steel 
wire, as other kinds are not satisfactory. 

Flanged Fitting Jackets. — Cork fitting jackets for flanged fittings 
rest on the outside of the sectional covering. For this reason, it is 
necessary to apply the sectional covering first on pipe lines having 
flanged fittings incident thereto. Butt the sectional covering against the 
flanges of the fittings, wedging it slightly between them, following 
instructions just given. 

Then insulate the flanged fittings by first applying one-half of the 
cork jacket in a temporary manner and carefully filling the space 
between the fitting and the half jacket with brine putty packed tight. 
Remove this half jacket and repeat the process with the other half 
jacket on the other side of the fitting. Now put both in place to 
test the workmanship as to the elimination of all voids between the 
insulation and the fitting. When satisfactory, use waterproof cement 
on all joints and wire in place securely with not less than six wires 
to each jacket. 

Mitered Bends. — Pipe bends should be insulated by mitering sec- 
tional covering to fit the bend. Insulate the straight pipe on both 
sides of the bend up to the points where the bend starts. Determine 
the radius of the bend and the angle of the mitre, and cut pieces 
sufficiently short to give practically straight pipe contact between the 
pipe and the mitered covering. Cut the center piece for a good tight 
fit. After all mitered pieces are ready, put them in place with water- 
proof cement on all joints, using two wires to each mitered section, 
working from each end of the bend toward the middle. The last or 
key section should be applied while the cement is still soft on all 
other mitered joints, to insure perfection of the finished work. 

Seams and Chipped Edges. — Smooth up all seams and chipped 
edges along the lateral and end joints of the covering and the fitting 
jackets with seam filler, so applied as to leave a smooth surface. 



COVERING ERECTION 509 

Painting. — After the seam filler has been applied, give the exposed 
surfaces of the completed insulation work one good coat of asphaltic 
paint. This is the only finish that is required on inside lines; but 
outside lines, or lines passing through cold rooms, tunnels, pipe 
shafts, etc., must be further protected by weather-proofing. 

Weather-proofing. — Wrap with one layer of 2-ply roofing paper, 
with a 3-inch lap on side and ends. Point the exposed end of the 
side lap down. Apply asphaltic paint on all laps to cement them in 
place, and additionally secure lateral laps with copper staples. Paint 
the finished work with one good coat of asphaltic paint. 

White Finish Over Mineral Rubber. — If white finish, or color other 
than black, is desired for cork pipe covering, it may be obtained by 
painting the mineral rubber finish with two good coats of orange 
shellac followed by any selected paint or enamel. Some enamels, 
specially prepared, are suitable without the use of orange shellac. 

Segmental Covering. — Piping and fittings larger than the sizes for 
which sectional covering and sectional fitting jackets are furnished 
are insulated with segmental covering. Instructions for proper ap- 
plication are supplied by the manufacturer with every such shipment, 
and should be followed carefully. 

Lags and Discs. — Brine coolers, tanks, accumulators, etc., are in- 
sulated with cork lags and discs. Separate sheets sent by the manu- 
facturer with every shipment of lags give complete and detailed 
instructions for proper application. See that they are received, and 
follow such instructions carefully. 

Care and Maintenance. — The seroicc that cold pipe insulation en- 
counters is the most severe service that insulation of any kind is called 
upon to zinthstand. Therefore, it is important that it should have care 
and attention if it is to be kept in good condition. Properly applied and 
properly cared for, cork pipe covering vuill last longer than the pipe. 

Inspect the installation at regular intervals for: 

1. Loose or broken wires. 

2. Joints opening up. 

3. Cracks in mineral rubber finish and seam filler coming loose. 
If a loose or broken wire is found, replace it without delay. If 

any open joints are found, the section of covering or the fitting 
jacket should be removed the very next time the refrigeration is oflf, 
dried out and replaced, or new insulation installed. 

Close up any cracks that may have developed in the mineral rubber 
finish with seam filler. At least once each year give the entire 
exposed surface of the cold pipe insulation one good coat of asphaltic 
paint. 

Such attention is inexpensive and will add materially to the long 
life and the high efficiency of cold pipe insulation. 



510 CORK INSULATION 

A GOOD DRINK OF WATER.* 

Speaking of Values. — Years ago an authority on economics pointed 
out that values were of two different kinds: Value in exchange, and 
value in use. Gold, for example, was xnentioned as possessing a rela- 
tively high exchange value, due to its scarcity and the demand for it 
for ornamentation; but as having practically no real value in use, 
as it was in no sense necessary to mankind. Water, on the other 
hand, was referred to as having no exchange value, as it was never 
sold; but as possessing an extraordinary high value in use because 
it was an absolute necessity to mankind. 

While these examples can still be used today for the purpose of 
illustrating the difference between these two classes of values, yet 
the real value of gold and the exchange value of water have both 
increased immeasurably since about the ISth century. Gold is today 
considered necessary as the basis of our monetary exchange; and 
good water has a very definite monetary value to those who are in 
position to dispense it. 

A Good Drink of Water. — Especially is this true of good drink- 
ing water. But good water and good drinking water may be two 
wholly different things; especially in the industries and in most pub- 
lic buildings. While water may be pure, it is not necessarily fit for 
human consumption. It must be available at the proper temperature. 
If it is too warm it does not satisfy and workers complain or seek 
employment elsewhere. If it is too cold the health of the consumer 
is very vitally impaired. Medical science has conclusively demon- 
strated that at 45° to 50° F. pure drinking water is best; in fact, ex- 
tremely essential to the health and well-being of all classes of 
workers. 

Thus, pure drinking water of the proper temperature has a high 
exchange value today, considering that the efficiency or productive- 
ness of workers depends so very much upon the condition of their 
minds and bodies. And if such wholesome drinking water is easily 
available in adequate quantity, procurable without risk of contamina- 
tion, and does not cost too much to provide, it can easily be a source 
of large monetary profit to the individual or concern supplying it. 
While this profit is an indirect one, yet it is a real profit notwith- 
standing in that it constitutes a saving over old methods of sup- 
plying workers with drinking water. 

Consider the Facts. — In too many factories, mills and public build- 
ings, the worker, in order to obtain his daily requirement of drink- 
ing water, must be away from his employment for a considerable 
period of time each day. He must usually walk an appreciable 



•Advertisement, copyright, 1923, Armstrong Cork & Insulation Company, Pitts- 
burgh, Penna. Reprinted by permission. 



DRINKING WATER SYSTEMS 511 

distance to a faucet or tank; perhaps he must wait his turn there, 
and while he waits, he gossips a bit, usually to no good purpose. 
If the supply is city reservoir water, he runs off a certain quan- 
tity in the belief that he can get it cool; if it is tank water, it is 
either too warm to be satisfying or, if iced, too cold to be healthful. 
It is a well-established fact that the usual methods of drinking 
water supply are wasteful to a high degree— wasteful of time and 
water, conducive to ill health, and frequently responsible for a 
good share of the peevishness and unrest so manifest among work- 
ers in the warmer months of the year. 




FIG. 224.— CORK PIPE COVERING ON THE LINES OF A REFRIGERATED 
DRINKING WATER SYSTEM. 

The Solution. — Progressive and well-informed managements are 
in complete agreement with doctors on the important part that 
drinking water plays in maintaining health, morale and efficiency 
under modern working conditions. And thus the refrigerated drink- 
ing water distribution system has come into extensive use. It 
has been found not only completely practical and satisfactory from 
the hygienic and the production standpoints, but actually cheaper to 
operate than the cruder methods previously used. 

This modern system is very simple both in principle and operation. 
It consists of refrigerating equipment, an insulated water tank lo- 
cated at the correct point, and properly insulated distributing lines 
connected to sanitary drinking fountains conveniently and correctly 
placed throughout the plant or building. It is readily adaptable to 
any industrial requirements, and is elastic enough to be expanded or 
contracted as future needs may require. With it a constant supply 
of properly cooled water is instantly available, without waste or effort, 
with no slop or muss, and at no risk of contamination from dirt or 
communicable disease. Its operation vastly simplifies a problem 
that has become more and more troublesome with the passing of 
time, and which in many mill?, factories and public buildings is to- 
day crying for solution. 



512 CORK INSULATION 

The Cost and the Return. — Most of these modern installations 
show a marked reduction in operating cost as compared with the 
superseded method. One plant, for example, kept a careful record 
of the cost of supplying drinking water by the bucket-and-dipper 
method and, later, for refrigerated water through a modern distribu- 
tion system and fountains. The results showed a saving of over 60% 
in the cost of distribution in favor of the improved system. But the 
actual saving in money was not all. There were also the less-tang- 
ible but none-the-less real factors of safety, health and improved 
morale. 

Design Is Individual. — Of course, a refrigerated drinking water 
system is not a standard piece of equipment. It must be designed 
for each individual plant or building, and its cost depends upon local 
conditions. The number of employees and the nature of their 
work determines the amount of water required. The size of the 
refrigerating machine, velocity of flow, pipe sizes, proper insulation 
of lines and equipment are technical matters that are not fully cov- 
ered by ordinary engineering books. 

Realizing the need for making such information available to archi- 
tects, engineers and plant executives, this Company's Engineering 
Department has made a thorough study of the subject over a long 
period of time, the results of which have been compiled in a 48-page 
book, "Drinking Water Systems." This book will be gladly sent on 
request and without charge to all who are seriously interested in 
learning more about the benefits and economies of this method of 
handling the drinking water supply. 

Engineering Assisistance. — The drinking water problem being a 
specific one for each individual plant or building requires a careful 
survey of conditions and an estimate of the complete cost. For the 
purpose of preliminary investigation as well as for practical engi- 
neering assistance, the experience and resources of the Armstrong 
Cork & Insulation Co., Pittsburgh, Pennsylvania, arc at the service 
of architects, engineers and executives, without charge or obligation. 



CONTRACT LAW 513 

FUNDAMENTAL CONTRACT LAW* 
Cost of Litigation. — It should be and usually is the policy of every 
servant corporation to avoid litigation so far as possible. Lawsuits 
arc very costly, not only in attorneys' fees, the taking of evidence, 
the court proceedings, the loss of time of salaried employees and 
officials, but also in the loss of "good-will," which alone amounts to 
more than the gain through litigation, if the cost incident to litigation 
is ignored. 

As it is very rarely necessary to resort to litigation, or to make 
concessions or render credits to avoid litigation, if the original con- 
tract is properly drawn and having been so drawn is executed or 
carried out in a spirit of fairness and a business-like manner, it is 
highly important that the sales engineer, who must draft such con- 
tracts, understands the enormous cost of litigation and the funda- 
mentals of contract law to guide him in avoiding resort to the courts. 
The law of contracts is as simple and as readily understood as any 
department of the law. Nevertheless, the average engineer is usually 
unable to avoid complications and weaknesses in the preparation of 
specifications and other documents pertaining to contracts. The im- 
portance of understanding and knowing the contents of the following 
paragraphs of this chapter can not, therefore, be exaggerated, and 
the sales engineer can do well to make them the basis of much 
thought and study. 

Kinds of Contracts. — A contract is a promise to do or refrain 
from doing some act or series of acts that law will enforce. There 
are, in general, two kinds of contracts: 

(1) Sealed contracts, or specialties. 

(2) Parol contracts. 

A sealed contract, or specialty, is a contract made under seal; while 
a parol contract is a simple oral or written agreement not made 
under seal. 

A sealed contract may be described in greater detail as a written 
agreement signed by the parties with a seal appended to the signa- 
tures. Formerly a seal consisted of "an impression on wax, or 
paper, or some other tenacious substance capable of being impressed." 
Now, however, an impression of a seal on the paper itself is con- 
strued as a proper seal, and in many states by statute a scroll en- 
closing the word seal made opposite the name of the signer is quite 
sufficient. Engineering contracts are now very rarely executed under 
seal; although the bond which holds the sureties for the faithful 
performance of the work by the contractor must be under seal, be- 



* Chapters on "Fundamental Contract Law" and "Engineering Contracts,' 
printed by permission from Sales Engineering, by P. Edwin Thomas. 



514 CORK INSULATION 

cause the agreement of the bondsmen to become responsible is not 
often supported by a valuable consideration. 

While any contract may be executed under seal, and thus become 
a sealed contract, under the common law the following must be exe- 
cuted under seal to become binding: 

(1) Gratuitous promises. 

(2) Contracts with corporations. 

(3) Conveyances of real estate. 

(4) Bonds. 

We are interested here only with contracts with corporations. The 
common law rule that contracts with corporations must be executed 
under seal no longer obtains in the United States of America. In this 
country a contract entered into with the proper officers of a corpo- 
ration is valid without being sealed, the same as though made with 
an individual, unless the charter of the corporation specifically re- 
quires all contracts to be made under seal. 

All contracts, either oral or written, not executed under seal are 
called simple or parol contracts. An oral contract has all the force 
of a written contract; but an oral contract is subject to difficulties 
in the way of establishing or proving its terms, from which a prop- 
erly written contract is practically, if not entirely, free. A large part 
of the litigation arising from the non-fulfillment of contracts is 
caused by a failure to reduce the terms of the contract to writing; 
and the rest of the litigation, in connection with written contracts, is 
caused by weaknesses of various kinds in such written documents. 

A written contract has another advantage over an oral contract. 
An oral contract can be modified by subsequent oral agreements; 
while a written contract is presumed in law to embody all the under- 
standings and agreements made at the time of or prior to the sign- 
ing of the contract. No oral evidence, therefore, can be admitted as 
to agreements or understandings made at the time of or previous to 
a written agreement that would modify its terms or conditions, except 
for the purpose of establishing proof of fraud, duress, deception, mis- 
take in the drafting of the contract, or to explain any latent ambig- 
uity, unusual phraseology or technical words. 

Essentials of a Legal Contract. — The law will not enforce an agree- 
ment or contract unless: 

(1) The parties are competent to make the agreement. 

(2) The subject matter is lawful. 

(3) The parties have mutually agreed to the conditions set forth, 
or they were of the same mind and intention concerning the subject 
matter. 

(4) There is, excepting sealed contracts, a valuable consideration. 



CONTRACT LAW 51c 

The four essentials of a legal contract are, therefore: 

(1) Competency. 

(2) Legality. 

(3) Agreement. 

(4) Consideration. 

Competency — A sane person who has attained his majority is con- 
sidered competent to make any legal agreement or contract. The 
disabilities of married women in the matter of contracts are too nu- 
merous to touch upon here. Without intent to cast aspersion on mar- 
ried women, we shall also omit reference to those disabilities per- 
taining to aliens, convicts, infants, insane persons, and drunkards. 

The Federal or any state government may become a party to a 
contract, and may sue on their contracts and enforce them; but the 
reciprocal of this is not true. Neither the United States nor any 
state of the union can be sued without its consent. However, all 
public corporate governments subservient to that of the state can 
be sued on their contracts. 

A corporation has no powers for entering into or performing con- 
tracts beyond those given it by the state in its charter, because 
officers of corporations are not in such case held to be personally 
liable. Its capacity for transacting business, however, is not limited 
by the specific privileges granted in its charter, but by implication is 
necessarily extended to include such other powers as may be required 
for the complete consummation of its specific purposes. 

A contract by an agent or representative is not valid unless the 
principal is himself competent to enter into a contract. Nevertheless, 
a contract by an agent is valid if the principal is competent even 
though the agent be incompetent to enter into a contract as princi- 
pal. The legality of the acts of an agent or representative is sim- 
ilar to the legality of the acts of a corporation. As a corporation 
receives its authority from the state for the conduct of a particular 
kind of business, so an agent receives his authority from his prin- 
cipal. Should the agent exceed his express and implied authority, 
the principal is privileged to repudiate his acts; and the other party 
to the contract has no recourse except against the agent himself. In 
order that an agent may relieve himself from all responsibility in 
the signing of a contract, the documents must reveal, either in its 
body or in the signature, who the principal is; as a mere signing of 
a contract by a person as agent will not relieve the one so signing 
from personal responsibility unless the document does reveal the 
principal. The eminently satisfactory way is to have the document 
specifically state that it is not to be construed as a contract until 
approved by some officer of the corporation, unless the corporation 
elects to delegate unusual authority to the agent and the other 
party to the agreement is willing to trust the agent not to exceed 
his express and implied authority. 



516 CORK INSULATION 

Legality — In general, no contract is legal, and can not be enforced 
in the courts, that involves an agreement to perform an act that is: 

(1) Forbidden by statutory law. 

,2) Contrary to the rules of common law. 

(3) Opposed to public policy. 

It will not be necessary for us to elaborate upon the first and 
second, but in connection with the third there is a class of agree- 
ments frequently entered into by the principals to all engineering 
contracts that are often construed in the courts as against the public 
policy. An agreement that provides that matters which may arise 
between the parties shall be referred to an arbitrator or arbitrators 
— such as the engineer or architect — is not binding, and either party 
may have recourse to the courts notwithstanding it'. 

Agreement — In order that a contract shall be binding on both par- 
ties to an agreement, it must have been understood and accepted by 
both in the very same sense. However clear the agreement may ap- 
pear to be on its face, if evidence can be introduced to show that it 
was not mutually understood in the same sense, it can not in general 
be enforced. The inference must not be drawn, however, that all 
claims of having misunderstood the plain and express provisions of 
a written contract will relieve the party making such claim from 
liability under it. That is to say, the mental agreement is evidenced 
by the language used in expressing such agreement and the law will 
presume that such words were understood, provided only that their 
meaning is plain and evident to the court. 

A person or corporation making an offer, bid or proposal whether 
orally, by messenger, by mail, by telegraph, or by public advertise- 
ment, must allow a reasonable time for its acceptance, provided no 
time limit is stated in the proposal or provided meanwhile it is not 
withdrawn. Any proposal may be withdrawn at any time before it 
is accepted, unless a consideration has been paid for the privilege 
of acceptance for a definite time. It is presumptuous to say what 
the law will consider a reasonable time. Such time period might de- 
pend upon the nature of the transaction and the construction of the 
particular court. For that reason a majority of corporation letter- 
heads, used in quoting prices, contain this printed clause: "All quo- 
tations subject to immediate acceptance or withdrawal without no- 
tice." 

Whenever a proposal made by one party is accepted by another 
with any kind of qualification or change of the conditions or word- 
ing of the original proposal, such an acceptance is simply the making 
of a counter proposal to the first party; and does not constitute an 
agreement until such first party has in turn assented fully to the en- 



^ Since this was originally written, some states have passed commercial arbitration 
laws fostered by the American Arbitration Association, which legalize arbitration by 
prior agreement, under certain conditions. 



CONTRACT LAW 517 

tire proposal as amended — which makes of it a new proposal to the 
second party — and it is again accepted by the second party: then 
only does it become binding. The assent which finally makes of 
the proposal a binding contract is the full, absolute and uncondi- 
tional acceptance of its terms as presented. 

The party making an offer has the right to stipulate in it the time, 
place, form and other conditions of acceptance, in which case such 
offer can.be accepted only in the manner prescribed. This privilege 
on the part of the bidder does not permit him to impose the con- 
dition, however, that a failure to receive an acceptance within a cer- 
tain time will be construed as an acceptance. In other words, he 
may not impose the condition of refusal. 

As a general rule, fraud vitiates all contracts. 

Consideration — All engineering, or parol, contracts must in every 
instance be supported by a valuable consideration; as otherwise they 
are not enforceable. However, in the case of a money consideration, 
it is not necessary that the amount named shall be adequate to sup- 
port the promise. A contract under seal, as previously stated, does 
not require a consideration to enforce it. 

Subsequent Changes and Agreements. — In general it can be said 
that any oral or written agreement may be altered at pleasure after 
such agreement has been entered into, if done by mutual consent. 
Any such change makes a new contract out of the original, and be- 
cause of this fact a surety or a third party to the agreement not 
consenting to the change is automatically released from all obliga- 
tion. In all cases where sureties or bondsmen guarantee faithful 
performance, they must always be consulted and their consent ob- 
tained to any material change in the original contract. As "material 
change" is likely to be a subject for dispute and as changes are in- 
variably made in engineering contracts without thought of consult- 
ing the bondsmen, said bondsmen are as a rule thereby released from 
all obligations, and the bond becomes of no effect, unless the follow- 
ing type of clause is added: "And the said surety does hereby stip- 
ulate and agree that no change, extension, alteration or addition to 
the terms of the contract or specifications shall in anywise affect 
obligation on this bond". 

Even though a written contract has a clause stipulating that no 
change shall be made in it except in writing, thus forbidding oral 
alterations of any kind, such a provision is void and the contract 
may be altered by oral agreement notwithstanding. This is because 
in law oral and written contracts are of the same class, both being 
parol contracts, and consequently are of equal force and effect. No 
one may forfeit his legal rights even by agreement. Where contracts 
are illegal except when they are in writing, as under the Statute of 
Frauds, then such written contracts can not be modified except by 
agreement in writing. 



518 CORK INSULATION 

In general, unless every change entered into or agreed upon after 
the contract has been consummated is supported by some kind. of 
legal consideration, the contract can not be enforced. 

Discharge of Contracts. — Any contract entered into under any of 
the methods mentioned may be discharged and the parties to the 
contract freed from all obligations involved, in any one of the fol- 
lowing ways: 

(1) By performance. 

(2) By impossibility of performance. 

(3) By agreement. 

(4) By operation of Law. 

(5) By breach. 

The usual method of discharging a contract is, of course, by each 
party fully performing the duties prescribed for him in the agree- 
ment. In such case the performance by each party must be strictly 
in accordance with all of the terms of the contract. However, in en- 
gineering work it is seldom that the fulfillment is in all details strictly 
in accordance with the plans and specifications; but while in law the 
contract requires a strict and full compliance, yet in equity a sub- 
stantial compliance is accepted in place of a full and complete per- 
formance. 

Some contracts are based on the specifications of an engineer or 
architect that contain the unfair provision that the work must be 
done to the complete satisfaction of some party named. The court in 
every such case will construe this meaning reasonable satisfaction. 

A common example of the operation of a condition precedent, 
with reference to a third party, is where a contractor binds himself 
to receive payments only on the certificate of the engineer or archi- 
tect. Without such certificate he must prove that the engineer or 
architect has acted fraudulently in withholding the certificate, or has 
acted under gross mistake and in bad faith, or has negligently refused 
to honestly examine the work. It is always extremely difficult to 
establish such proof; and, consequently, it is very bad policy to 
operate under such a condition. 

ENGINEERING CONTRACTS. 

Specific Provisions. — An engineering contract consists of a number 
of specific provisions, each one of which defines some one element 
of the contract. These provisions are usually grouped under the fol- 
lowing headings, and in the order indicated: 

(1) Scope and purpose, including plans, if any. 

(2) Specifications relating to and describing the work in detail. 

(3) Business relation of the parlies to the contract. 

Thus the first essential of a good engineering contract is to make 
clear the scope and purpose of the "work to be done"; then describe 



ENGINEERING CONTRACTS 519 

the work in detail; and follow these specific clauses quite naturally 
with the general clauses setting forth the business relation of the 
parties to the contract, such as price, terms of payment, delivery, time 
of completion, guarantee, and other provisions which shall be touched 
upon later. 

Scope and Purpose. — Too much care can not be exercised in setting 
forth as briefly, yet as clearly as possible, the extent and intent of 
the work to be performed under the terms of the contract. It has 
been pointed out that the first principle of the successful manage- 
ment of any project is a thorough analysis of the job. That is to 
say, it is necessary to know what is expected to be accomplished 
before it is possible to work out an effective and proper plan for 
doing it. The general clauses referred to may then be thought 
of as the rules by which the work shall be done. 

The general principles of technical writing can well be followed 
in fixing the scope and purpose of the contract, as the chance for 
uncertainty or misunderstanding at this point would be fatal to the 
sales engineer. This is true not only from a legal and an engineer- 
ing standpoint, but even more especially from a sales standpoint. 
These introductory statements must be worded so as to infer the 
quality of our mind, the measure of our ability, the responsibility and 
integrity of our employer, in order to win instant respect and open 
the door for a quick consummation of a profitable business transac- 
tion; for if a prospective customer is entirely satisfied with the out- 
line of the scope and purpose of the contract, and the drawings, he 
will frequently pass over the body of the contract proposal, or the 
specifications, with but a hasty survey, and, if the price, terms and 
other general conditions are satisfactory, will accept the proposal 
with full confidence that he is quite safe in doing so. Needless to" 
say, such confidence must never be violated, for the confidence of a 
purchaser is the one BIG asset of the sales engineer. The value of 
being able to execute a high class drawing, nicely lettered, as pre- 
viously mentioned, is here emphasized in its true relation to sales 
engineering work. 

Specifications. — We have shown that the work to be done should 
be described as a whole, and then in detail. That portion of an en- 
gineering contract that relates to and describes the work in detail 
is called the specifications. 

The writing of specifications calls for the most careful application 
of the principles of technical writing, and every portion and detail of 
the work should be described in clear and simple language that can 
be understood by all. The descriptions should have reference to 
the ultimate end to be accomplished rather than to the means and 
methods to be employed, unless some particular method is prefer- 
able to all others. The clauses in the specifications should be made, 
so far as possible, mutually exclusive; that is to say, no part of 



520 CORK INSULATION 

the work should be specifically described in more than one place, 
as repetition weakens specifications and makes for ambiguity. 

Before an attempt is made to prepare a specification, it is neces- 
sary to brief the work carefully and establish the proper major- 
headings, main-headings and sub-headings. This is necessary not 
only from the standpoint of English composition, technical writ- 
ing and legality, but also from a sales standpoint. The suggestion 
has been made that if the first or "scope-and-purpose" section of 
the contract proposal be properly presented and the drawings well 
executed, it will materially assist the sales engineer to secure a 
quick acceptance of the contract proposal, other things being equal. 
While, in general, this is true, yet many buyers scrutinize the com- 
plete document most carefully; and if weaknesses are found in 
the specifications, even though the remainder of the contract pro- 
posal be well drafted, it tends to destroy confidence in the abil- 
ity of the sales engineer to have the proposed work carried out in 
a satisfactory manner, and thus operates very much against him. 
Furthermore, specifications, correct in every detail, are essential to 
the construction corps, if difficulties are to be avoided while prose- 
cuting the work. The importance of this correlation is usually 
either not well understood or carelessly disregarded by the sales 
engineer. 

The most common errors committed by sales engineers when 
writing specifications are failure to brief the work properly and 
neglect to make the clauses mutually exclusive. Major-headings, 
main-headings and sub-headings are frequently jumbled so as to 
make the complete specification subject to many interpretations, even 
though the choice of words and their order of arrangement, the 
sequence of clauses composing sentences, and the arrangement of 
sentences in each paragraph, are above criticism. 

General Clauses. — The general clauses in an engineering contract, 
which set forth the business relation of the parties to the contract, 
may relate to any or all of the following: 

(1) The valuable consideration. 

(2) Terms of payment. 

(3) Time of commencement, rate of progress and time of com- 
pletion. 

(4) Provision for monthly and final estimates. 

(5) Kind of workmen to be employed. 

(6) Appliances to be used. 

(7) Liquidated damages. 

(8) Workmen's compensation insurance. 

(9) Public liability insurance. 

(10) Owners' liability insurance. 

(11) Contractors' contingent liability insurance. 

(12) Special contingent damage insurance. 



ENGINEERING CONTRACTS 521 

(13) Landlords' and tenants' liability insurance. 

(14) Fire and loss insurance. 

(15) Surety bond. 

(16) Protection against claims for use of patents. 

(17) Provision for heat, light, water, drainage, elevator, telephone, 
drayage, storage, street traffic. 

(18) Inspection of materials and v^rork. 

(19) Claims for damage due to unforseen difficulties, strikes, ac- 
cidents, acts of the government, delays, suspension of the work, etc. 

(20) Subsequent agreements. 

(21) Assignment, release, cancellation and abandonment of con- 
tract. 

(22) Protection of finished work. 

(23) Discharge of unpaid claims of workmen and material men. 

(24) Cleaning up after completion. 

(25) Settlements of disputes and provisions for arbitration. 

(26) Extra work and credits. 

(27) Guarantee. 

While this list is not intended to be complete, it will serve as a 
general guide, and other items may be added as desired or required. 

Modified Forms. — Often an engineering contract is based on de- 
tailed plans and specifications of an architect or engineer. In such 
case the preparation of a contract proposal by the sales engineer is 
indeed hazardous, unless he makes a most careful study and correct 
interpretation of the complete plans and specifications so as to in- 
sure against errors of omission in estimating and to satisfy himself 
that no conditions or requirements are at variance with his employer's 
prescribed business policy. Once satisfied that all terms and con- 
ditions can be complied with, the contract proposal by the sales 
engineer should be very brief, simply setting forth the scope and pur- 
pose of the work to be done by specific reference to numbered and 
dated plans and specifications of the architect or engineer handling 
the commission, the commission number, the specific branch of the 
work involved, and close by stipulating the price or valuable con- 
sideration. 

If certain terms or conditions can not be complied with, and it is 
the desire, nevertheless, to bid for the work, the objectionable terms 
and conditions should be carefully listed as exceptions; thus: 

The materials to be furnished and the work to be done 
under this proposal shall be in accordance with plans and 
specifications of Mr. Albert Q. Simmons, Architect and En- 
gineer, Chicago, Illinois, his commission S7056, drawings 
$9852, sheets 1-5 inclusive, dated March 17, 1927, specifica- 
tions S8540, pages 1-10 inclusive pertaining to General Con- 
ditions and pages 45-87 inclusive pertaining to Mechanical 
Equipment, with the following exceptions: 



522 CORK INSULATION 

(1) Page $8, paragraph 3. A 1-year guarantee shall be 
extended instead of the 5-year guarantee specified. 

(2) Page J9, paragraph 4. Bidder does not bind him- 
self to receive payments only upon the certificate of the 
architect and engineer. 

(3) Drawing $9852, sheet 3. Size of unit "B" is at va- 
riance with the specifications, page S48, paragraph 5; speci- 
fications are understood to take precedence. 

Price: Nine Thousand ($9,000.00) Dollars. 

Bidders are frequently provided with printed forms, especially for 
large projects and municipal, state and government work, that leave 
only the price to be inserted. 

Many times an architect or engineer will prepa-re general plans 
and specifications, limit the bidders to a select class of reliable con- 
tractors and corporations with reputations to lose if inferior work 
is done, and allow them to fix the details within the limits of the 
general plans and specifications. In such case, the sales engineer 
should merely use the general plans and specifications as a guide 
in the preparation of his own drawings and his own complete con- 
tract proposal. 

The sales engineer should always strive to make his contract pro- 
posal exclusive in itself, avoiding unnecessary entanglements, but 
this is not always possible or desirable when dealing with a reliable 
architect or engineer. 



TOPICAL INDEX 



rage 

A good drink of water 510 

Ability of refrigerator cars to carry 

perishable products 435 

Absolute humidity 91, 92 

temperature 77, 105, 234 

Absopure electric ice cream cabinet.. 399 

Absorbing powers of surfaces 104 

Acorns of the cork oak 8 

Ad valorem duty 36 

Adsorption 234. 235,236 

Advantage of cabinet type of house- 
hold refrigerator 350 

Advent of household refrigerating 

machine 342 

Aeroil Burner Co 473 

Affinity of ammonia gas for water... 91 

Age attained by the cork oak 13 

Aggregates in concrete 488 

Air cells in cork bark 172 

cells per cu. in. in cork bark... 9, 169 

cells, sealed 169 

circulation in cold rooms 

190, 191, 197, 485 

circulation in household refrigera- 

. tors 353, 354, 381 

circulation in refrigerator cars, 

effect of poor 445 

circulation in refrigerator cars, 

importance of 426, 456 

circulation in refrigerator cars of 

South inadequate 453 

Air, conditioned 202 

Air duct system 198 

infiltration 472, 478 

infiltration, resistance to 210 

infiltration values on corkboard of 

different thicknesses 473 

infiltration values on erection ma- 
terials 472 

pockets 195 

pockets eliminated in refrigerator 

insulation 349 

spaces Ill 

spaces, dangers from 206 

spaces in construction 213, 216 

Air. saturated 93 

Air thermometer 74 

cell construction of cork 113 

gun for Asphalt primer 283 

proofing of surfaces 209 

Alexander the Great 317 

Aluminum paint in cold rooms... 223, 479 
American Arbitration Association... 516 

Concrete Institute 228 

Society for Testing Materials 228 

Society of Refrigerating Engineers 

122, 471, 475 

Ammonia as a refrigerant, first use 

of 325 

compression refrigerating machine, 

the first 326 

compression refrigerating machines 391 

salts in emulsions 236 

Ancient uses of cork 25 

Apparatus for fire test 174 

Applications of pure cork insulation. 167 

Applying roof insulation 296,298 

Architects' and Engineers' Investi- 
gating Committee 480 

Architects' relation to insulation 

projects 185 

Armour Institute of Technology.... 379 

Armstrong Cork Co 27, 32 

Armstrong Cork & Insulation Co. 

472, 481, 482, 512 



Page 

Artificial cork products 21, 22, 25 

Asphalt, a colloidal substance 235 

Asphalt cement. 224. 228, 229, 230, 231, 282 
cement in refrigerator construction 

349, 352 

Asphalt, emulsified 232, 237 

Asphalt for damp-proofing 477 

freight classifications, etc 500 

heating kettle 474 

kettles 282 

paint as damp-proofing 479 

pans 282 

per sq. ft. of corkboard 282 

plastic finish, emulsified. . 221, 232, 239 

primer ..... 210, 224, 232, 238 

Asphalt, specifications for standard 

oxidized 473 

Asphalt with insulation, use of 476 

Asphalt, uses for 224, 227 

Asphaltic paint — freight classifica- 
tions, etc 501 

plaster finish on corkboard 479 

Asphalts, natural 230 

petroleum 231 

Atchison, Topeka and Santa Fe Rail- 
way System 461 

Atmospheric pressure 324 



B 



280 



Backing, how to apply 

how to mix 280 

Bacon, Lord Francis 319 

Baker insulation in old buildings.... 187 

Baking cork under pressure 28 

Baking of cork bark, effect of... 171, 174 

T5anana room 205 

I'.ancroft 232 

Bark of the cork oak, the outer .... 8 

Barometric pressure 76 

Basket bunker type of refrigerator 

car 438 

Bastian-Blessing Co., The 404 

Beginning of the cork industry 2 

Belding-Hall refrigerator constiuctio.i 370 

Bibliography 166 

Binders in insulation 172 

Bitumens and their origin ... 225 

Black ice, formation of 321 

I>lossoms of the cork oak 



ioiimg 



8/ 



and baling of cork bark. 13, 14 

and melting points of mixtu-es. . . 90 

point 85, 86, 324 

point, the effect of pressure on.... 89 

points of various liquids 86 

Bottle caps 20, 22, 41 

corks 16 

Bottles, glass 2, 16, 34 

Box bunker type of refrigerator car. 438 

Boyle, David 326 

Brazelton, Perry 386 

Breweries advance use of ice 328 

Brewery cellars, types of 327 

Bright Engineering Laboratory, Geo. 

B 379 

Brine and ammonia lines, insulation 

specifications for 502 

Brine putty — freight classifications, 

etc 501 

British thermal unit ^ 83 

Page 
Broken insulation in refrigerator 

cars 438 

wall insulation 215 



523 



524 



CORK INSULATION 



Brooks ice cream cabinet 392, 393 

Brownian movement 235 

Building construction troubles 190 

wall insulation specifications 498 

Bunkers 191, 192, 193, 194, 195, 196 

development of 328 

Buoyancy of cork 1 



c 

Cabinetmaker's insulation details.... 350 

Caesar, Agustus 171 

California Orange Growers 453 

Caloric 71 

paradox 87 

Calorie 83 

Capacity to absorb radiant energy... 104 

Capillarity 1, 24, 

25, 167, 171, 173, 208, 220, 345, 347 

Capital of the cork industry . 7 

Care and maintenance of cork pipe 

covering 509 

Care of refrigerators 358 

Carpenter, M. R 197 

Carre, E. C 325 

Cartons for corkboard 173 

Causes of insulation trouble in house- 
hold refrigerators 345, 346 

Caves for vegetable storage 333 

Ceiling, concrete.. 247, 248, 249, 250, 251 
Ceiling insulation as floor insulation 

above 215 

insulation as roof insulation above 477 

insulation specifications 496, 497 

Ceilings, insulation of 214, 216 

self-supporting 252 

wood 253, 254 

Celsius, Anders 74 

Centigrade thermometer scale 73 

Change of state 82, 87 

of state with rise of temperature.. 84 

Changing demands for cork 41 

Charcoal as insulation 329, 337 

Charles, Jacques Alexandre Cesar... 77 

Chicago & Northwestern Railroad... 435 

Chocolate dipping room 198 

Circulation, air 190, 195 

Classes of household refrigerators... 380 

Cleaning of surfaces for insulation. . 207 

Coagulation 234 

Coefficient of expansion 79 

of heat transfer 95, 105, 106 

Coil bunker specifications 498 

Cold-air-box method of testing 117 

Cold by evaporation 90 

rooms after a fire 176 

rooms, classes of 187 

rooms, types and design 187 

storage 40, 41 

storage cellars 326, 327 

storage door specifications ....497, 498 

storage doors 218, 219, 283 

storage doors — freight classifica- 
tions, etc SCO 

storage temperatures 167 

storages, first artificial 326 

Colloidal materials 232 

realm 232, 234, 236 

suspension 233, 234 

Columbia Gas & Electric Co 483 

Columns, insulation of 212 

Combustion 84 

heat of 84 

Comparison of types of thermometers 73 

Composition cork products. .. .21, 22, 25 

of natural asphalts 230 

of petroleum asphalts 231 

Compressed corkboard 172 



Page 

Compression strength of corkboard.. 173 

Concrete 487 

finishing 492, 493 

how to calculate quantities of ma- 
terial required 495 

in winter 493 

ingredients of 488 

measuring box 490 

mixing of 487 

mixing platform 491 

mixtures, proportioning of 489 

mixtures, table of 490 

wearing floors 314 

what it is 487 

Condensation.. .86, 91, 189, 220, 345, 348 

in insulation 339 

transfer of heat by 102 

Conduction 95, 105, 106, 168, 320 

in cylindrical layers 97 

of fluids 101 

through parallel layers 97 

with changing temperature 98 

Conductivity, methods to determine.. 115 

of liquids and gases 98 

Consolidated cork, discovery of 

Smith's 28 

Construction of refrigerators ...359- 376 

Continuous curtain wall insulation... 214 

Contract law, fundamental 513 

Contraction and expansion of sub- 
stances 77 

Contracts, changes in 517 

discharge of 518 

engineering 518 

essentials of legal 514 

kinds of 513 

Convection 

95, 98, 101, 105, 168, 169, 320 

currents, application of 100 

Cooler arrangement in modern soda 

fountain 413, 414 

Coolest point in refrigerator cars.... 442 
Copeland electric refrigerator con- 
struction 376 

Copper clad steel wire — freight clas- 
sifications, etc 501 

Cork a national necessity 35 

as a building material 465, 466 

as condensation preventative 467 

as fire retardant 468 

as roof insulation 467 

as sound isolation 467 

bark 167, 170, 171, 174 

bark, air cells in 172 

bark — "back" and "belly" 12 

bark, volume and elasticity of 14 

buoys 2 

clearing house of the world 17 

compositions as insulation 329 

dipping pan 473 

disks 20 

dust 282 

factories 6 

flour 282, 351 

for vibration absorption 467 

forests 2, 3 

industry, beginnings of the 2 

industry, capital of 7 

industry, extent of 33 

inherently nonabsorbent of mois- 
ture 170 

insoles for shoes 21 

insulated ice cream shipping con- 
tainer 390 

insulated soda fountain draft arm. 412 

insulated soda fountain cover ring. 422 
insulated soda fountain packer 

cover 410 



TOPICAL INDEX 



Page 

insulation 22, 25, 28, 31, 42 

insulation an essential item 41 

isolation 24 

jackets for flanged fittings 508 

jackets for screwed fittings 507 

lags and disks 32, 509 

lags and discs — freight classifica- 
tions, etc 501 

machinery isolation 468 

miters for pipe bends 508 

oak 2, 3, 7, 8, 13 

oak, outer bark of 169 

oak trees growing in Calif 5 

odor in refrigerators, so-called.... 347 

of commerce 10, 13 

paint to reduce sweating of metal. 

surfaces 464 

pipe covering. 23, 24, 28, 29, 31, 32, 466 

pipe covering, advantage of 505 

pipe covering, basic fitness of 505 

pipe covering, description of 505 

pipe covering — -freight classifica- 
tions, etc 501 

pipe covering, lags and discs 

erected in place 504 

pipe covering on branch and by- 
pass lines . 507 

pipe covering on lines of refrig- 
erated drinking water system... 511 
pipe covering seams and chipped 

edges 508 

pipe covering, sectional 507 

pipe covering, segmental 509 

pipe covering specifications 502 

pipe covering sundries 507 

pipe covering, three thicknesses of. 505 

pipe covering, uses of 469 

punchings 20, 21 

refuse 35 

some of the many uses for.... 17, 25 

stoppers 2 3, 16, 19, 20, 33, 41, 171 

stripping 10 

the story of 1 

under powerful microscope 113 

wall insulation specifications. . .497, 498 

waste 13, 16, 22 

Corkboard, a fire retardant 174, 176 

a good nonconductor l')S 

approved by underwriters 175 

as floor insulation in refrigerator 

cars 441 

as merchandise 176 

asphalt per sq. ft 2S2 

compact and strong 172, 173 

compression strength of 173 

convenient in form 174 

directions for erection 279- 315 

easily obtained 176 

easy to install 174 

erecting 

280, 281, 284, 285, 286, 290, 
296, 298, 300, 301, 303, 305, 305 

erection, directions for 279- 315 

erection, outline of practice in.... 476 
erection, specifications for.... 240- 278 

finish specifications 498 

tire test on 1 74 

for export, loading 34 

freight classifications, etc 5U0 

handles like lumber 173 

impregnated 329, 483 

in cartons 173 

in cold storage structures 344 

in concrete forms, danger from... 477 
in household refrigerators, benefits 

of 352 

in household refrigerators, early 
use of 342 



Page 

in household refrigerators, method 

of installation important 345 

in ice cream cabinet construction.. 39] 

in ice cream cabinets, early use of 390 

in refrigerator cars, how to apply. 459 

in refrigerator cars, thickness of. . 459 

in refrigerators, thickness to use. . 382 

installations 

185, 189, 190, 197, 198, 203, 

205, 210, 213, 221, 226, 233, 308, 312 

insulated ice cream cabinet 386 

insulated soda fountain cover and 

lid 421 

insulated soda fountain creamer. . . 407 
insulated soda fountain creamer 

top 409 

insulated soda fountain syrup en- 
closure 422 

insulated soda fountain syrup unit 411 
insulation and the modern "soda 

fountain 403 

insulation for refrigerator cars 461 

insulation for refrigerator rars, in- 
spection and rejection 463 

insulation for refrigerator cars, 

manufacture of 461 

insulation for refrigerator cars, 

physical properties and tests 461 

insulation in Knight soda fountain 423 
insulation in Mechanicold soda 

fountain 420 

insulation saved a refinery 481 

insulation, sizes of . 23 

insulation, some uses of 469 

is standard cold room insulation.. 301 

loss in efficiency of 184 

now standard insulation for ice 

cream cabinets 390 

permanently efficient 177 

protective coating for 239 

pure compressed baked 330 

reasonable in cost 176 

sanitary and odorless 172 

scoring of 279 

specifications for erection 240- 278 

the standard cold storage insulation 475 

thickness to use 183 

undiT powerful microscope 169 

useful expectancy for 184 

Corks, hand cut 16 

Corkwood 2, 3, 10, 21, 34, 35, 40 

for export, loading 6 

ill the forest 13 

storage yards 14, 18, 39 

Cost of corkboard installed on gaso- 
line storage tanks 483 

of insulation, comparison 182 

of litigation 513 

of refrigerators 350 

Cox holdover tank cooling system. 192, 193 

Critical temperatures 86, 88 

Crouse-Tremaine Interests 392 

Crown bottle caps 20, 22, 41 

Cubical expansion 79 

Cullen, Dr. William 324 

Cylindrical tanks, insulation speci- 
fications for 503 



D 

Danby, Arthur 225 

Davy, Sir Humphry 71 

Dead air 113, 168, 171 

Dehydration of emulsions 235, 237 

d' Medici, Catherine 386 

Densities and specific volumes of 

water 81 



526 



CORK INSULATION 



Page 
Depreciation in efficiency of cork- 

board •■ lg-+ 

Depressed temperature reading ..... ^^ 
Design of cold rooms for hotels nn- 

portant • • : • "t^^ 

Deterioration of poultry in transit in 

refrigerator cars '•54 

Determination of the expansion of 

substances .• • • °^ 

of the heat conductivity of various 

materials .• • '■^^ 

Development of the corkboard in- 

sulated household refrigerator . . 332 

of the ice machine 324 

of the modern cold storage room 3.^8 

Dew point •. 91, 348 

Diameter of the cork oak 7 

Diatomaceous earth as insulation 329 

Difficulties with early insulated 

structures 3.-9 

Directions for corkboard erection: 
Application of emulsified asphalt 

finish , • 313 

Application of ironed-on mastic 

finish ; • : • • %\i 

Application of metal over insulation 315 
Application of Portland cement 

plaster 311 

Double layer on tank bottoms 307 

First layer in ceiling forms 291 

First layer in cork partitions 3U1 

First layer over floors or roofs . . . 297 
First layer to concrete ceilings ... 290 
First layer to masonry walls. .283, 285 

First layer to wood ceilings 292 

First layer to wood walls 287 

General instructions and equipment 279 
Insulation of tank sides.. 308, 309, 310 
Laying of concrete floors over in- 
sulation ;■•■,•■ ^^"^ 

Laying of wood floors over insula- 
tion 315 

Second layer of cork partitions. 303, 304 
Second layer over floors or roofs.. 298 

Second layer to ceilings 293, 294 

Second layer to walls 288, 289 

Self-supporting ceilings 295 

Single layer partitions 299 

Directions for the proper application 

of cork pipe covering 505-509 

Discharge of contracts 518 

Discoloration of natural cork 21 

of paint by asphalt 223 

Discovery of Smith's consolidated 

cork 28 

Disks, cork 20 

Dissipation of energy 72 

Distillation and condensation 91 

Distribution of insulation in refrig- 
erator cars in terms of corkboard 459 

Door losses, refrigeration 217 

Door sills, kinds of 218 

Doors and windows 216, 217, 218, 219 

Drinking water, problem of supply of 510 

water problem, solution of 511 

water, proper temperature of 510 

water systems, comparison of 512 

water systems, cost of 512 

water systems, design of 512 

water systems, insulation of 512 

water, value of 510 

Drip pans, insulated 195 

Dry rot of lumber 213 

Ducts in bunkers, size of 192 

Duryee, Harvey H 31 

Duties on cork, export 35 



E 

Page 

Earliest form of ice storage 335 

Early forms of cork insulation 25 

forms of insulation in ice cream 

cabinets -. 389 

type of refrigerating machine 325 

Earth, average temperature of 211 

Economic thickness of insulation. 179, 181 

value of insulating materials 178 

Economical size of refrigerator cars. 430 
Economy of operation of refrigerator 

cars 425 

Effect of insulation of refrigerator 

car bulkhead 427, 445 

of insulation on temperature in 

household refrigerators . 382 

of mechanical refrigeration on in- 
sulated structures 329 

of pressure on boiling point 89 

of pressure on melting point 88 

of proper distribution of insulation 

in refrigerator cars 430 

of the World War on the cork in- 
dustry 39 

Efficiency of corkboard in service. . . 401 

of ice cream cabinets 400 

of insulation due to moisture pene- 
tration, loss in 476 

of refrigerators, low 379 

of the refrigerator car 425 

Efficient insulation, guide in select- 

ing 114 

Egg storage 203 

Eggs in transit, temperature varia- 
tions 428, 429 

Egyptians -. 318 

Eighty-five percent magnesia cover- 
Elastic" enamel in cold rooms. .. .479, 486 
Electrical connections for insulation 

testing 121 

Emission of heat 1^5 

Emulsification ■• 234 

Emulsified asphalt 2i2, All 

freight classifications, etc. 500 

Emulsified asphalt plastic finish.... 

.221, 232, 239 

Emulsions, ammonia salts in 236 

dehydration of 235, 237 

destruction of 235, 237 

Enamel, elastic — freight classifica- 
tions, etc 500 

Enameling of plastered surfaces.... 222 
Enameled steel refrigerator linings.. 330 

Endothermic reaction 84 

Energy, dissipation of •. . ^^2 

Engineering contracts 518-522 

general clauses of 520 

modified forms of 521 

scope and purpose of 519 

specific provisions of 518 

specifications of •. 519 

Equipment for corkboard erection... 279 

Erecting corkboard 

280, 281. 284, 285, 286, 290, 

291, 296, 298, 300, 301, 303, 305, 306 
Erection of corkboard, directions for 

279-315 

of corkboard, specifications for 

240-278 

Error due to ignoring surface effects 108 
Essential requirements of a cold stor- 
age insulation 167 

Essentials of a legal contract 514 

Establishments using small cold 

rooms 187 

Ether 102 

Evans, Dr. W. A 377 



TOPICAL INDEX 



527 



Page 

Evaporation 90, 3-45 

cooling by 318 

of liquid ammonia 91 

transfer of heat by 102 

Evelyn, John 25 

Evolution of the household refrig- 
erator 337, 338 

Example of purchaser's insulation 

specifications 496 

Exothermic reaction 84 

Expansion and contraction of sub- 
stances 77, 78, 79, 81) 

joints in plaster 222 

of the refrigerator industry 341 

Expenditure for insulation, profitable 178 
Experience of many years with cork 

.bark 170 

with insulation, iield of 185 

Experiments with insulation 328 

with refrigerator cars in transit, 

summary of 451 

Export duties on cork 35 

Extent of the cork industry 33 

External conductivity 106 



Factories, cork 

Fahrenheit, Gabriel Daniel 

Fahrenheit thermometer scale 

Faraday, Michael 

Felt insulation 

Fibrous insulating materials 

insulation 330, 

Field of insulation experience 

Finish; floors 275, 276, 

Finish on corkboard, asphalt plaster. 

over corkboard on ceilings 

over insulation 

207, 211, 220. 221, 222, 232, 

Finish; walls and ceiling. . .272, 273, 

Finishing concrete 

Fire resistance of corkboard 

retardant, cork as 

retardant, corkboard a 

test on corkboard 

First artificial cold storages 

First law of thermodynamics 

First methods of keeping food cool. . 

Fixed points on a thermometer 

Flocculating agents in emulsions.... 
Floor grids 222, 223, 

insulation, need for 

insulation specifications 496, 

racks in refrigerator cars, impor- 
tance of 426, 

Floors, concrete 260, 261, 

wood 256, 257, 258, 

Flow of heat 1, 

Fluids, conduction of 

Flux oil 

Force of expansion and contraction. 
Forced air circulation in cold rooms 

Foreign binders in insulation 

Formula for economic thickness of 

insulation 

Freezer rooms, proper location of... 
Freezing mixtures 90, 

of emulsions 

tank insulation 1 84, 

Freight classifications, etc. — cork pipe 
covering and sundries 

classifications, etc. — corkboard and 

sundries 

Functions of household refrigerator. 

Fundamental contract law 513- 

Fusion, heat of 

Fussell, John 



G 

^ ,., . „ ,., Page 

Galilei, Galileo /4 

Galvanized band iron — freight clas- 
sifications, etc 501 

wire nails 282 

wire nails — freight classifications, 

^ etc 500 

Gases and liquids, conductivity of... 98 

expansion 77 

Gasoline, loss of by evaporation 482 

storage tank insulation, economy of 482 
storage tank insulation, specifica- 
tions for 483 

savings with diflferent insulations, 

comparisons of 484, 485 

torches 282 

Gay-Lussac, Joseph Louis 77 

General clauses of an engineering 

contract 520 

General conditions of corkboard 

specifications 499 

Georgia Peach Growers 453 

Gibson refrigerator construction .362, 363 

Glass bottle 34 

bottle, introduction of 2, 16 

wool as insulation 400 

Glycerine 21 

Good Housekeeping Institute. . .377, 379 

Gorrie, Dr. John 325 

Grand Rapids Cabinet Co. ice cream 

cabinet 395 

Granulated cork 22, 41 

cork — freight classifications, etc.... SOD 

Gravel in concrete 489 

Gravimetric method 80 

Grids, metal floor 222, 223 

Grit in cork bark 14 

Growth of ice making and refrigera- 
tion 326 

of the ice cream industry 386 

of the ice industry 340 

Griindhofer, E. F 166 

Griinzweig & Hartmann 2b 

Guaranty soda fountain construction 404 

Guide for efficient insulation 114 



H 



Hacking of surfaces for insulation.. 207 

Hair felt 31 

Hand cut corks 16 

Handling corkwood in the forest .... 13 

Hand mixing concrete 492 

Hard-back 14, 20 

Harrison, James 325 

Harvesting natural ice 319, 321 

Heat, absorption of 84 

Heat and sound, the retarding of. ... 22 
Heat conductivity of materials, de- 
termination of 115 

effects of 73 

emission of IO5 

flow of 105 

generation of 72, 84 

loss through insulation 113 

lost in solution 90 

measurement, methods of 82 

of combustion of materials 84 

of fusion 85 

of fusion of substances 86 

of vaporization 87, 88 

of vaporization of substances 87 

quantity of 72 

retarding quality of corkboard re- 
markable -181 

temperature and theimal ex,',ian- 

sion 71 



528 



CORK INSULATION 



test of asphalt 

the study of ; : ' ' V ' , , 1 



111 



114 



471 



transfer 95, 101 

transfer by conduction. .. .95, 112, 

transfer by convection 100, 

transfer by radiation 

transfer through a wall 

transmission data important and 

inadequate • • 

transmission investigations, stand- _ 

ardization necessary 4/1 

units ^~ 

Height of the cork oak / 

Herter, Charles H 122, 166, 475 

Holmes 232 

Home of the cork industry 6 

Hope Natural Gas Co 484 

Hot-air-box method of testing 116 

Hot-plate method of testing 118, 121 

Household coolers, early forms of... 332 

ice-box 336, 337 

ice chest ■'•56 

refrigeration 343 

refrigerators 40, 338 

How to calculate quantities of ma- 
terial for concrete 49.S 

to load eggs in refrigerator cars... 445 

to select a good refrigerator 355 

Hubbard, Prevost 237 

Hull, H. B 343 

Humidification 195 

Humidity 189, 196, 197.204 

tables, relative, percent 470 

Hydrolene process 352 

Hygrometric condition of air in cold 

rooms 195 



Ice and salt ice cream cabinets 

and salt mixtures 345, 

and salt mixtures, effect of 

as a refrigerant in the home 

as refrigerant, early uses of 

cellars 

chest, early form of 

chest, household 

consumption in refrigerator cars.. 
427, 432, 434, 

consumption in refrigerator cars, 

effect of precooling on.. 

Ice cream cabinet construction, de 



388 
388 
90 
340 
326 
326 
335 
336 

443 

434 

-399 

390 

389 

389 

390 



tails of 390 

cream cabinets, corkboard stand- 
ard for . 

cream cabinets, early forms of in- 
sulation in 

cream cabinets, early types of un- 
insulated 

cream cabinets, early use of cork- 
board in 

cream cabinets, effect of corkboard 
insulation on suitable refrigerat- 
ing machines 391 

cream cabinets, efficiency of 400 

cream cabinets, electrical 396-399 

cream cabinets, ice and salt .. .392-395 
cream cabinets, inijiortance of in- 
sulation in 388, 401 

cream cabinets, insulation of 317 

cream cabinets, testing of 400 

cream hardening room 190 

cream plants 41 

industry, growth of 340 

Ice machine, development of 324 

making, growth of 326 

plants 41 



Page 

shortage of 1890 324 

storage, earliest form of 335 

storage house... 184, 185, 221, 226, 233 
storage house equipment, natural.. 323 
storage houses, typical natural.... 322 

Ice, sublimation of 87 

the storing of 87 

Ice water and cold lines, insulation 

specifications for 503 

Ice-box, household 336 

Ice-box method of testing.. 115 

Importance of insulation in ice cream 

cabinets 388 

of sorting corkwood 18 

Imports of cork to United States. .43-70 
Impregnated corkboard insulation... 

26, 329, 483 

Improvements in refrigerator con- 
struction 342 

Industrial roofs, insulation qf 43 

Infiltration of air, resistance to 210 

Influence of household refrigerating 
machine on refrigerator construc- 
tion 343 

Injury to inner bark, result of 12 

Insoles for shoes, cork 21 

Installations of corkboard 

185, 189, 190, 197, 198, 203, 

205, 210, 213, 221, 226, 233, 308, 312 
Instructions for the proper applica- 
tion of cork pipe covering, 505 

Insulated truck bodies 387 

Insulating cold stores, early methods 

of 329 

paper — freight classifications, etc.. 500 
Insulation committee report, A. S. 

R. E 122 

construction, suggested methods... 478 

cork 22, 42 

design, importance of 185 

design, principles of 188 

economic thickness of 179 

economic value of 1 78 

effect on refrigeration 186 

engineering . 185, 349 

experiments with 328 

finish over 

207, 211, 220, 221, 222, 232, 239 

important in refrigerators 356 

impregnated corkboard 329 

in ice cream cabinets, importance 

of 401 

in mechanical household refrigera- 
tors, importance of 385 

in old buildings 187 

in refrigerator cars, effect of poor 445 

of bunkers 193 

of cold rooms in hotels 485 

of cold storage doors 217 

of cold stores 167 

of drip pans 195 

of floors, columns, ceilings and 

beams 211 

of gasoline storage tanks 483 

of gasoline storage tanks, savings 

due to 484 

of household refrigerator made a 
research and engineering con- 
sideration 344 

of household refrigerators 317 

of ice cream cabinets 317 

of mechanical household refrigera- 
tors 344 

of refrigerator car roof, effect of.. 430 

of refrigerator cars 425, 438 

of refrigerator cars a complex con- 
sideration 459 

of refrigerator cars controls per- 
formance 448 



TOPICAL INDEX 



529 



Page 
of refrigerator cars of South in- 
adequate 453 

of refrigerator cars of West im- 
proved 453 

of refrigerator cars, specifications 

for 460, 461 

of roofs 25, 26, 40, 43 

of soda fountains 317 

practice, changes in 206 

projects. Architects' relation to... 185 

specifications 242-278 

specifications, example of pur- 
chaser's 496 

trouble in household refrigerators, 

causes of 345, 346 

Interior finish of cold storage rooms 

in hotels 485 

finishes for cold rooms 220 

Internal conductivity 99. 106 

International Congress of Refrigerat- 
ing Industries 379 

International Exposition of 1888 7 

Ironed-on mastic finish 

210, 221, 226, 486 

Island Petroleum Co 481 

Isolation cork 24 



J 

Famison standard track door 219 

fewett refrigerator construction. 366, 367 

Joints in insulation 207 

Joule, James Prescott 71 



Kansas City Testing Laboratory.... 230 

Kettles for heating asphalt 

282, 473, 474 

Kettles — freight classifications, etc... 500 

Kinds of cold rooms 187 

Kinds of contracts 513 

Kinetic theory of heat 71 

Kirk, Dr. A 325 

Knight Co., Tlie Stanley 423 

Knight soda fountain construction... 423 

Kroger Grocery & Baking Co 496 



Law, fundamental contract 513 

Law of Charles 76 

Leslie, Sir John 324 

Lewis Asphalt Engineering Corpora- 
tion 480 

Liegine — cork composition 465 

Linde, Carl.. 326 

Linear expansion 79 

Liquefaction 85 

Liriuid ammonia, evaporation of 91 

Liquid Carbonic Corporation, The... 418 
Liquids and gases, conductivity of. . . 98 

Liquids, surface tention of 233, 234 

Litigation, cost of 513 

Loading corkboard for export 34 

corkwood for export 6 

Loads in refrigerator cars, require- 
ments for increased 448 

Loss in efficiency of corkboard 184 

Loss of gasoline by evaporation 482 

Losses of perishables in refrigerator 

cars 453 

J.unil;er in cold rooms, treatment of. 224 



M 

Page 

McCray refrigerator construction... 3i)l 

Machine base completely isolated.... 24 

Mass 83 

Massed insulation in refrigerator cars 438 
Mastic asphalt facing over corkboard 

insulation 480 

finish, ironed-on 210, 221, 226 

finish, plastic 213, 233 

Materials required for one cu. yd. of 

concrete 494 

required for 100 sq. ft. of concrete 494 

Meat cooler 197, 198,213 

Metal floor grids 223 

Methods of heat measurement 82 

of heat transfer 95 

to determine conductivity 115 

Metric system 74 

Mean specific heat 84 

Measurement of heat, change of 

state, humidity 82 

Mechanical household refrigerator, 

operation of 384 

ice cream cabinets 391 

refrigeration 90 

Mechanicold soda fountain construc- 
tion 418, 419 

Medicinal cotton as insulation 400 

Melting and boiling points of mix- 
tures 90 

Melting point 85 

point of ice 388 

point, the effect of pressure on... 88 

points of solids 85 

Method of applying cork pipe cover- 
ing 502 

of installing corkboard in house- 
hold refrigerators important.... 345 

Milk storage room 210 

Mill constructed buildings, insulation 

of 215 

Mineral wool as insulation 337 

Miscellaneous specifications 277 

Mixed carloads — freight classifica- 
tions, etc 500, 501 

Mixing materials for concrete 491 

Modern cold storage room, develop- 
ment of 328 

Modified forms of an engineering 

contract 521 

Moisture detrimental to insulation.. 475 

Moisture in cold rooms 191 

in insulation . 189, 208 

in insulation, protection against.. 475 

Molecular disturbance 96 

theory of heat 71 

Mortarboard for coating corkboard.. 280 
Multiple insulation in refrigerators, 

era of 339, 340, 341 

N 

Nail polish as insulation 400 

Nails, galvanized wire 282 

National Association of Ice Cream 

Manufacturers 387 

National Association of Ice Indus- 
tries 355 

National Board of Underwriters 175 

National Electric Li^ht As.sociation. 379 
National Research Council of the 

U. S 471 

Natural air circulation m cold rooms 191 

asphalts 230 

cork 25 

ice, development of the use of 320 

ice, early uses of 319 



530 



CORK INSULATION 



Page 

ice, formation of 319, 320 

ice, harvesting of 319, 321 

ice houses, sawdust insulated 327 

ice shortage of 1890 387 

ice, storing of 319, 321 

Navy test 171 

Nebuchadnezzar 225 

Neglect of insulation \n household 

refrigerators 342 

Nelson ice cream cabinet 394 

Nero 317 

New York Tribune Institute 379 

Nichalls, P 179 

Nonabsorbent, corkboard 170 

Nonpareil Cork Manufacturing Co.. 32 

Normal humidity 204 



Odors in refrigerators 347 

Oil-box method of testing 115 

Opaque ice, formation of 321 

Orange shellac 223, 486 

Oranges in transit, average load tem- 
peratures 427 

Origin of cork 1 

Original recommendations for cork- 
board thickness 183 

Outer bark of the cork oak 

167, 169, 171, 172, 174 

Output of ice cream in 1912 387 

of ice cream in 1926 388 

Oxidation of Asphalt cement 231 



Paint, aluminum 223 

dscoloration of 223 

Painting cork pipe covering 509 

Pans for heating asphalt 282 

Papers: 

Cork as a building material 465 

Economy of gasoline storage tank 

insulation 482 

Heat transmission: A National 

Research Council project 471 

Interior finish of cold storage 

rooms in hotels 485 

Protection of insulation against 

moisture 475 

Refrigeration in transit 425 

Results of tests to determine heat 
conductivity of various insulat- 
ing materials 122 

Sales engineering 513 

Temperature, humidity, air circula- 
tion and ventilation 197 

The ability of refrigerator cars to 

carry perishable products 435 

The development of the standard 

refrigerator car 452 

Paraffin 21 

Parks, N. R 484 

Partitions, solid cork 266, 267,268 

stone, concrete or brick 263 

wood 264, 265 

Pennington, Dr. M. E 425, 435, 452 

Pennsylvania State College 166 

Performance comparison of refriger- 
ator cars with different thick- 
nesses of insulation 430 

Perishables in transit, apparatus and 

methods for study of 426 

Perkins, Jacob 325 

Permanent insulating efficiencv 1/0 

Petroleum '. 225 

asphalts 226, 231, 351 



Page 

Pilaster, column and caps insulation 

specifications 496, 497 

Pipe covering, cork... 24, 28, 29, 31, 

502, 503, 504, 505, 506, 507, 508, 509 

hanger for cork pipe covering. . . . 506 

Placing concrete 492 

Planning cold storage rooms 186 

Plaster, expansion joints in 222 

Portland cement 220 

scoring of 222 

PJastic cork — freight classifications, 

etc 501 

Plate method of testing 120 

Pliny, the elder 1, 25, 339 

Pointing up of surfaces for insula- 
tion 207 

Polo. Marco 386 

Portland cement 487 

Portland Cement Association. .. .487, 493 

Portland cement plaster 220 

Poultry in transit, effect of freezing 428 

Powell. G. Harold 453 

Precision Thermometer & Instrument 

Co. 470 

Precooling of fruit, effect on ripen- 
ing 453 

of perishables 430 

Preparation for insulation, cost of. . . 207 
of lines to receive cork pipe cover- 
ing 506 

of surfaces for insulation 206 

Preservation of foodstuffs 317 

Pressure, atmospheric 324 

barometric 76 

on boiling point, effect of 89 

on melting point, effect of 88 

Principles of insulation design 188 

Production of household refrigerat- 
ing machines 343 

Proper thickness of