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+Project Gutenberg's Paint Technology and Tests, by Henry A. Gardner
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
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+
+Title: Paint Technology and Tests
+
+Author: Henry A. Gardner
+
+Release Date: September 13, 2011 [EBook #37420]
+
+Language: English
+
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+  |                      TRANSCRIBER'S NOTES                         |
+  |                                                                  |
+  | * Where the original work uses text in italics or bold face, this|
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+  +------------------------------------------------------------------+
+
+
+
+
+  PAINT TECHNOLOGY AND TESTS
+
+
+  Published by the
+  McGraw-Hill Book Company
+  New York
+
+
+  Successors to the Book Departments of the
+
+  McGraw Publishing Company                      Hill Publishing Company
+
+
+  Publishers of Books for
+
+  Electrical World                    The Engineering and Mining Journal
+  Engineering Record                                  American Machinist
+  Electric Railway Journal                                      Coal Age
+  Metallurgical and Chemical Engineering                           Power
+
+
+
+
+  PAINT TECHNOLOGY
+  AND TESTS.
+
+  BY
+
+  HENRY A. GARDNER
+
+  _Assistant Director, The Institute of Industrial Research,
+  Washington, D. C._
+
+  _Director, Scientific Section, Paint Manufacturers' Association
+  of the United States, etc._
+
+  McGRAW-HILL BOOK COMPANY
+  239 WEST 39TH STREET, NEW YORK
+  6 BOUVERIE STREET, LONDON, E.C.
+  1911
+
+
+
+
+  _Copyright, 1911, by the_ MCGRAW-HILL BOOK COMPANY
+
+  THE·PLIMPTON·PRESS·NORWOOD·MASS·U·S·A
+
+
+
+
+  TO
+  MY MOTHER
+
+
+
+
+PREFACE
+
+
+A few years ago the producer and consumer of paints possessed
+comparatively little knowledge of the relative durability of various
+pigments and oils. There existed in some cases a prejudice for a few
+standard products, that often held the user in bondage, discouraging
+investigation and exciting suspicion whenever discoveries were made,
+that brought forth new materials. Such conditions indicated to the more
+progressive, the need of positive information regarding the value of
+various painting materials, and the advisability of having the questions
+at issue determined in a practical manner.
+
+The desire that such work should be instituted, resulted in the creation
+of a Scientific Section, the scope of which was to make investigations
+to determine the relative merits of different types of paint, and to
+enlighten the industry on various technical problems. Paint exposure
+tests of an extensive nature were started in various sections of the
+country where climatic conditions vary. This field work was supplemented
+in the laboratory by a series of important researches into the
+properties of pigments, oils, and other raw products entering into the
+manufacture of protective coatings. The results of the work were
+published in bulletin form and given wide distribution. The demand for
+these bulletins early exhausted the original impress, and a general
+summary therefore forms a part of this volume.
+
+The purpose of the book is primarily to serve as a reference work for
+grinders, painters, engineers, and students; matter of an important
+nature to each being presented. Without repetition of the matter found
+in other books, two chapters on raw products have been included, and
+they present in condensed form a summary of information that will prove
+of aid to one who desires to become conversant with painting materials
+with a view to continuing tests such as are outlined herein. In other
+chapters there has been compiled considerable matter from lectures and
+technical articles presented by the writer before various colleges,
+engineering societies, and painters' associations.
+
+The writer wishes to gratefully acknowledge the untiring efforts of the
+members of the Educational Bureau of the Paint Manufacturers'
+Association, whose early endeavors made possible many of the tests
+described in this volume. Kind acknowledgment is also made to members of
+the International Association of Master House Painters and Decorators of
+the United States and Canada, who stood always ready to aid in
+investigations which promised to bring new light into their art and
+craft.
+
+HENRY A. GARDNER.
+
+WASHINGTON, October, 1911.
+
+
+
+
+CONTENTS
+
+
+  CHAPTER                                                  PAGE
+
+     I PAINT OILS AND THINNERS                                1
+
+    II A STUDY OF DRIERS AND THEIR EFFECT                    21
+
+   III PAINT PIGMENTS AND THEIR PROPERTIES                   42
+
+    IV PHYSICAL LABORATORY PAINT TESTS                       70
+
+     V THE THEORY AND PRACTICE OF SCIENTIFIC PAINT MAKING    93
+
+    VI THE SCOPE OF PRACTICAL PAINT TESTS                   105
+
+   VII CONDITIONS NOTED AT INSPECTION OF TESTS              114
+
+  VIII RESULTS OF ATLANTIC CITY TESTS                       124
+
+    IX RESULTS OF PITTSBURG TESTS                           135
+
+     X A LABORATORY STUDY OF TEST PANELS                    149
+
+    XI ADDITIONAL TESTS AT ATLANTIC CITY AND PITTSBURG      174
+
+   XII NORTH DAKOTA PAINT TESTS                             182
+
+  XIII TENNESSEE PAINT TESTS                                201
+
+   XIV WASHINGTON PAINT TESTS                               207
+
+    XV CEMENT AND CONCRETE PAINT TESTS                      214
+
+   XVI STRUCTURAL STEEL PAINT TESTS                         220
+
+  XVII THE SANITARY VALUE OF WALL PAINTS                    252
+
+
+
+
+PAINT TECHNOLOGY
+
+
+
+
+CHAPTER I
+
+PAINT OILS AND THINNERS
+
+
+=Constants and Characteristics of Oils and Their Effect upon Drying.= An
+attempt has been made to give in this chapter a brief summary of the
+most important characteristics of those oils finding application in the
+paint and varnish industry. For methods of oil analysis, the reader is
+referred to standard works on this subject; the analytical constants
+herein being given only for comparative purposes.
+
+It is well known that one of the most desirable features of a paint oil
+is the ability to set up in a short period to a hard surface that will
+not take dust. This drying property is dependent upon the chemical
+nature of the oil. If it is an unsaturated compound, like linseed oil,
+rapid absorption of oxygen will cause the film to dry rapidly and become
+hard. If the oil be of a fully satisfied nature, like mineral oil,
+oxygen cannot be taken up to any great extent and drying will not take
+place. The various animal and vegetable oils differ in their power of
+oxygen absorption to a lesser or greater extent. This difference is
+referred to by the chemist in terms of the iodine value. The iodine
+value of linseed oil is approximately 190, meaning that one gram of the
+oil will take up 190 centigrams of iodine. Oils with high iodine values
+have good drying powers, while those with low iodine values are, as a
+rule, very slow drying in nature.
+
+For a description of the working and drying properties of various oils
+used in paints, see Chapter XIV. The oxygen absorption of various oils
+and mixtures is shown in Chapter II.
+
+=Linseed Oil.= The seed of the flax plant which is extensively grown in
+North Dakota, Argentine Republic and Russia, contains approximately 36%
+of oil which may be obtained by grinding, heating, and expression. Ripe
+native seed generally produces a pale oil of little odor; the oil from
+Argentine seed often having a greenish tint and an odor resembling
+sorghum. While filtering, pressing and ageing will remove considerable
+of the ("foots") mucilaginous matter, phosphates, silica, etc., from the
+oil, the better grades which are intended for varnish making are often
+refined with sulphuric acid. A light colored oil which may be heated
+without "breaking" results from this treatment, but such oils are apt to
+contain considerable free fatty acid, unless they are washed with alkali
+subsequent to the sulphuric acid treatment. On account of its rapid
+drying properties and general adaptability for all classes of paints and
+varnishes, linseed oil has never been supplanted by any other oil.
+Chemically it consists of the glycerides of linoleic, oleic, and
+isolinoleic acid, its constitution being responsible for its very high
+iodine value.
+
+[Illustration: Field of Flax in bloom in North Dakota]
+
+Boiled linseed oil, a heavier and darker product, is made by heating the
+raw oil in open kettles to high temperatures, generally with the
+addition of metallic driers such as litharge, and black manganese. The
+resinates of lead and manganese are often added to oil heated at a lower
+temperature, to obtain a boiled oil of lighter color.
+
+[Illustration: New type of Flax Harvester which pulls plant up by the
+roots, thus preventing infection of soil]
+
+[Illustration: Modern Concrete Elevators for storing Flaxseed]
+
+[Illustration: View of Linseed Oil Factory showing hydraulic press,
+tanks, etc.]
+
+[Illustration: _Photographs courtesy of Spencer Kellogg Sons_
+
+Flaxseed Crushers]
+
+[Illustration: Filter Presses for removing extraneous matter from
+linseed oil]
+
+[Illustration: Linseed Cake from Oil Press]
+
+[Illustration: Glycine Hispida
+
+Mammoth soya bean plants]
+
+[Illustration: _Photographs courtesy of David Fairchild, Plant Explorer,
+U. S. Dept. of Agriculture_
+
+Glycine Hispida
+
+Soya bean plants under cultivation at Arlington, Va.]
+
+By blowing air through linseed oil that has been heated to approximately
+200 degrees Fahrenheit, either with or without drier, heavy bodied oils
+are obtained, which find special application in varnishes and technical
+paints. As the viscosity of these oils increase, the iodine values
+decrease, and a slight rise in saponification value and specific gravity
+is observed. The following analyses of various types of linseed oil were
+recently made by the writer:
+
+  ===========+========+========+=========+========+=========+=========
+             |Pure Raw| Boiled | Boiled  | Blown  |  Litho. |  Old
+             |Linseed |  L. O. |  L. O.  | L. O.  |  L. O.  |Treated
+             |  Oil   | (Lino- | (Resin- |        |         |  Oil
+             |        | leate) |  ate)   |        |         |
+  -----------+--------+--------+---------+--------+---------+---------
+  Color      | Amber  |  Dark  | Reddish |  Pale  |  Dark   |  Amber
+             | Clear  | Brown  |  Brown  |        |  Brown  |  Clear
+             |        |        |         |        |         |
+  Sp. Gr. at |   .933 |  .941  |   .930  |  .968  |  .970   |  .943
+  15° C.     |        |        |         |        |         |
+             |Average |        |         |        |         |
+  Iodine No. |   180  |  172   |   176   |   133  |   102   |   172
+             |        |        |         |        |         |
+  Saponifi-  |   191  |  187   |   186   |   189  |   199   |   197
+  cation No. |        |        |         |        |         |
+             |        |        |         |        |         |
+  Free Fatty |   3.2  |  2.7   |   2.2   |   2.8  |   2.7   |   6.9
+  Acid       |        |        |         |        |         |
+             |        |        |         |        |         |
+  Unsaponi-  |   1.4  |   --   |    --   |    --  |    --   |   1.8
+  fiable     |        |        |         |        |         |
+             |        |        |         |        |         |
+  Maumene    |   111  |   --   |    --   |    --  |    --   |   96
+             |        |        |         |        |         |
+  Moisture   |   .2%  |   --   |    --   |    --  |    --   |  none
+  ===========+========+========+=========+========+=========+=========
+
+[Illustration: Glycine Hispida
+
+Mammoth soya bean plant]
+
+[Illustration: Glycine Hispida
+
+Soya bean plant, showing nitrogen gathering tubercles on roots]
+
+=Soya Bean Oil.= The soya plant which is extensively cultivated in Asia
+produces a seed bearing up to 22% and over of a golden colored oil
+having a peculiar leguminous odor. The oil, which probably consists of
+the glycerides of oleic, linoleic, and palmitic acids, is secured by
+crushing, steaming and pressing the seed. There are several varieties of
+the plant, and they are said to be the best annual legume for forage,
+the straw and fruit being rich in nitrogen and very fattening as a
+cattle food. Soya may be grown in nearly any country and is a great
+carrier of nitrogen to land deficient in this element. Although the oil
+has been used abroad for many years for soap-making purposes, its use as
+a drying oil is comparatively recent; being introduced into the paint
+industry of the United States during the year 1909, when linseed oil
+started on its phenomenal rise in price.
+
+The oil has given fair service in some paints when mixed with upwards of
+75% of pure linseed oil. It is of a semi-drying nature, but may be made
+to dry rapidly when mixed with manganese and lead linoleate driers. By
+compounding it under heat with tung oil and rosin, a substitute for
+linseed oil is produced, which some claim to be quite valuable.
+
+     Table I gives the constants of several samples of soya oil
+     examined by the writer. Table II shows the iodine value of
+     mixtures of soya and linseed oils. Table III shows the results of
+     drying experiments on soya oils containing different percentages
+     of lead and manganese driers.
+
+TABLE I
+
+CHEMICAL CHARACTERISTICS OF SOYA BEAN OIL
+
+  =======+==========+===========+============+==========+===========
+  Sample | Specific | Acid No.  |  Saponifi- | Iodine   |Per cent.
+    No.  | gravity  |           |   cation   |   No.    | of foots
+         |          |           |    No.     |          |
+  -------+----------+-----------+------------+----------+-----------
+    1    |  0.9233  |   1.87    |   188.4    |  127.8   |    3.81
+    2    |  0.9240  |   1.92    |   188.3    |  127.2   |     --
+    3    |  0.9231  |   1.90    |   187.8    |  131.7   |     --
+    4    |  0.9233  |   1.91    |   188.4    |  129.8   |     --
+    5    |    --    |    --     |     --     |  130.0   |     --
+    6    |    --    |    --     |     --     |  132.6   |     --
+    7    |    --    |    --     |     --     |  136.0   |     --
+  Average|  0.9234  |   1.90    |   188.2    |  130.7   |     --
+  =======+==========+===========+============+==========+===========
+
+TABLE II
+
+IODINE VALUES OF LINSEED OIL AND MIXED OILS
+
+  ==============+============+============+============+============
+                |            |    Soya    |    Soya    |    Soya
+    Sample No.  |  Straight  |25 per cent.|50 per cent.|75 per cent.
+                |  linseed   |  Linseed   |  Linseed   |  Linseed
+                |            |75 per cent.|50 per cent.|25 per cent.
+  --------------+------------+------------+------------+------------
+        1       |   190.3    |   175.2    |   160.7    |   140.4
+        2       |   189.5    |   175.9    |   161.7    |   140.8
+        3       |   188.0    |   175.4    |   160.3    |   139.0
+  --------------+------------+------------+------------+------------
+     Average    |   189.3    |   175.5    |   160.9    |   140.4
+  ==============+============+============+============+============
+
+TABLE III
+
+SOYA BEAN OIL AND LEAD DRIER
+
+  =========+==========+====+====+====+====+====+====+====+====
+  Per cent.|          |    |    |    |    |    |    |    |
+    PbO    |          |0.05|0.10|0.30|0.50|0.70|1.00|1.30|1.60
+  ---------+----------+----+----+----+----+----+----+----+----
+           | {  1 day | -- |0.07|0.63|1.34|1.05|1.53|0.93|1.35
+           | {  3 days| -- |0.07|3.52|4.31|2.75|4.86|4.82|4.12
+  Per ct.  | {  5 days| -- |0.09|5.04|6.06|6.09|6.75|6.66|5.52
+  gain     | { 12 days| -- | -- |6.88|7.54|7.43|7.76|7.32|6.47
+           | { 15 days| -- | -- |8.84|8.93|8.59|8.81|8.44|7.46
+           | { 20 days|0.05|0.20|9.02|9.08|8.90|9.03|8.65|7.83
+  ---------+----------+----+----+----+----+----+----+----+----
+
+SOYA BEAN OIL AND MANGANESE DRIER
+
+  -----------------+----------+----+----+----+----+----
+  Per cent. MnO_{2}|          |0.01|0.05|0.15|0.26|0.30
+  -----------------+----------+----+----+----+----+----
+                   | {  1 day | -- | -- |0.02|0.02|0.01
+    Per ct. gain   | { 10 days| -- |5.06|6.48|6.10|5.97
+                   | { 20 days|0.05|9.07|8.80|6.78|6.51
+  -----------------+----------+----+----+----+----+----
+
+SOYA BEAN OIL, MANGANESE AND LEAD DRIER
+
+  -------------+----------+----+----+----
+  Per cent. PbO|          |0.20|0.30|0.50
+  -------------+----------+----+----+----
+  MnO_{2}      |          |0.05|0.15|0.25
+  -------------+----------+----+----+----
+               | {  1 day |3.04|3.77|3.74
+  Per ct. gain | {  8 days|5.96|6.43|6.47
+               | { 12 days|6.33|6.78|6.67
+  =============+==========+====+====+====
+
+=Tung Oil.= There are grown in China and Japan many varieties of the
+"aleurites cordata," popularly known as the tung tree. This tree bears
+great quantities of large sized nuts containing as high as 40% of an oil
+which yields itself in a viscous yellow form upon heating and crushing
+of the fruit. The raw oil, which chemically consists of the glycerides
+of oleic, oleo-margaric, and probably isomeric acids, is distinguished
+by its rapid drying properties. When spread in a thin layer it produces
+a hard film with an opaque frosted surface, often showing a tendency to
+wrinkle. Treated tung oil will dry to a clear, water-shedding, elastic
+film. This oil is made by heating the raw tung oil at a comparatively
+low temperature with other oils and a metallic drier such as litharge.
+
+[Illustration: _Photographs courtesy of David Fairchild_
+
+Aleurites Cordata (Chinese Wood Oil)
+
+Barrel Factory at Cooperage Shop]
+
+[Illustration: _Photographs courtesy of David Fairchild_
+
+Aleurites Fordii (Chinese Wood Oil)
+
+Fruit from trees at the end of fourth year]
+
+The affinity of tung oil for rosin has resulted in the production of a
+series of moderate-priced varnishes most suitable for use in floor and
+deck paints or wherever great hardness is required. These varnishes are
+also finding application in the manufacture of concrete, steel, and flat
+wall paints; being especially suitable for the above purposes when
+compounded with kauri gum japan.
+
+[Illustration: Aleurites Fordii
+
+Flowering specimen of the Chinese Wood Oil tree, thirty feet high and
+three feet in diameter, on banks of Yangtse River, Western Szechuan,
+China. Opium Poppy in the foreground]
+
+[Illustration: Aleurites Cordata
+
+Wood Oil tree at Riverside, California, planted in 1907. Photograph
+taken in 1910, when tree had borne fifty fruits]
+
+During the boiling of raw tung oil the temperature must not exceed much
+over 400 degrees Fahrenheit. Otherwise a peculiar "hamming" will take
+place, the whole mass becoming solid and of no further value as a
+varnish or paint vehicle. Some peculiar internal disturbance or
+rearrangement of the molecules is evidently effected by heat, and
+although the reaction is not clearly understood, it has been ascribed to
+auto-polymerization. Scott has stated that the phenomenon of
+gelatinization is due to the exposure of the surface of the oil to the
+air, and that boiling in vacuo obviates such results. The lusterless
+surface produced when tung oil varnishes are dried in vitiated air would
+tend to confirm the conclusion that the oil is very subject to
+atmospheric influences.
+
+Lumbang Oil, which is obtained from a tropical species of Tung, is very
+similar in appearance and properties to Linseed Oil.
+
+CONSTANTS OF TUNG OILS
+
+  =====+=========+============+==============+==========
+       | Sp. Gr. | Iodine No. |Saponification| Acid No.
+       |         |            |     No.      |
+  -----+---------+------------+--------------+----------
+  No. 1|   .944  |    166     |     188      |   3.6
+  No. 2|   .940  |    164     |     184      |   1.8
+  =====+=========+============+==============+==========
+
+[Illustration: _Photographs courtesy Alpin I. Dunn_
+
+Menhaden Net drying in the Sun]
+
+[Illustration: Transporting Menhaden from net to deck of boat, in
+swinging basket]
+
+[Illustration: A big catch of Menhaden made off Narragansett Bay]
+
+=Menhaden Oil.= Of all the marine-animal oils, such as seal, herring,
+sardine, whale, and menhaden, the latter is the most valuable. It is
+produced by steam digestion and pressure of the menhaden or "piogey"
+fish, which are caught in great quantities off the Atlantic Coast.
+Prompt cooking and treatment of the fish results in a light-colored oil
+having very little odor, the residue left in the presses being of great
+value as a fertilizer. Although several grades of oil termed crude,
+brown, light, etc., are produced, the most satisfactory for use in paint
+is that grade termed "light winter pressed." This oil is of a pale straw
+color and has a high iodine number which is responsible for its rapid
+drying value. It contains less of the stearates that precipitate from
+crude oil, but sufficient to render its film water-shedding and elastic.
+The presence of too great a quantity of stearates is apt to result in a
+very soft film, and the use of hard driers, such as the metallic
+tungates, is therefore advisable with menhaden oil. When mixed with
+linseed oil paints the odor of menhaden oil is sometimes noticeable, but
+it disappears entirely after such paints are applied. Its use with
+linseed oil in technical paints exposed to the salty air of the Coast
+has given good results, often preventing "checking" and "chalking."
+
+The following constants were determined on samples of menhaden oil
+received in the writer's laboratory:
+
+  ========+==========+==========+==============+==========
+          | Sp. Gr.  |  Iodine  |Saponification|   Acid
+          |          |  Value   |    Number    |  Number
+  --------+----------+----------+--------------+----------
+  Light   |   .927   |  175.8   |    187.9     |   7.55
+  Medium  |   .925   |  178.7   |    187.6     |   6.19
+  Dark    |   .927   |  178.0   |    187.3     |   7.19
+  ========+==========+==========+==============+==========
+
+=Whale Oil.= While ordinary whale oil is too dark and odorous to ever
+come into extensive use as a paint oil, it is probable that the refined
+oil will be utilized in the manufacture of certain technical paints.
+Whale oil is boiled from chopped whale blubber, the first trying being
+the lightest in color, while the later tryings, as well as the product
+made from bones, are of darker color and of very bad odor. Oil of
+mirbane is often used to mask this odor. The oil contains large
+quantities of stearin and palmitin, as well as wax-like constituents
+which are apt to be thrown out of solution in very cold weather, or when
+the oil is mixed with other oils. The refined oil, when ground with lead
+and zinc pigments and mixed with equal parts of linseed oil and treated
+tung oil, dries to an elastic and soft film. Experiments are being made
+to utilize whale oil in the linoleum industry.
+
+The analyses of samples of whale oil tested by the writer are as
+follows:
+
+  =============+=========+========+==============+============
+               | Sp. Gr. | Iodine |Saponification| Free Fatty
+               |         | Value  |    Number    |    Acid
+  -------------+---------+--------+--------------+------------
+  Light Refined|  .924   |  148   |    190.2     |    1.2
+  Dark Yellow  |  .920   |  142   |    187       |    7.0
+  Dark Brown   |  .910   |  140   |    184       |   18.0
+  =============+=========+========+==============+============
+
+=Sunflower Oil.= Sunflower oil is produced largely in Russia and
+Hungary, finding favor in those countries as an edible oil. The ripe
+seeds of the sunflower plant contain over 30% of oil which is very pale
+in color and of a pleasant smell. It has been found that sunflowers may
+be grown to advantage in dry parts of the United States, and if suitable
+yields are obtained from a few experimental acres now being cultivated,
+the industry may receive encouragement in this country. The oil should
+be well suited for varnish making, and although the iodine number is not
+very high, it dries quite rapidly.
+
+[Illustration: Russian Sunflower Seeds]
+
+CONSTANTS OF SUNFLOWER OIL
+
+  ========+============+================+======
+  Sp. Gr. | Iodine No. | Saponification | Acid
+          |            |      No.       |  No.
+  --------+------------+----------------+------
+    .929  |    128     |      188       |  4
+  ========+============+================+======
+
+=Cottonseed Oil.= This oil is expressed from the seed of the cotton
+plant, varying in color according to the time of its pressing and degree
+of refinement. Being edible as well as highly suited for soap making,
+very little of it comes into the market as a paint oil. It contains
+large quantities of stearin and has a low iodine value, making it a slow
+drying oil. Some samples are extremely light in color and contain less
+mucilaginous matter and foots than is present in ordinary varieties.
+
+CONSTANTS OF COTTONSEED OIL
+
+  ========+============+================+======
+  Sp. Gr. | Iodine No. | Saponification | Acid
+          |            |      No.       |  No.
+  --------+------------+----------------+------
+    .922  |    106     |      190       | 2.4
+  ========+============+================+======
+
+=Corn Oil.= As a by-product in the manufacture of starch and alcoholic
+liquids, this material comes into the market having a golden yellow
+color, and an odor resembling fermented grain. It has a lower drying
+value than cottonseed oil, and its use in the paint industry will
+probably be limited to color grinding, where an oil with a semi-drying
+value is often desired. Like cottonseed oil, it belongs more properly to
+the soap oil class. It contains glycerides of linoleic and especially
+palmitic acid.
+
+ANALYSIS OF CORN OIL
+
+  ========+============+================+=====
+  Sp. Gr. | Iodine No. | Saponification | Acid
+          |            |      No.       |  No.
+  --------+------------+----------------+-----
+    .925  |    118     |      191       | 9.5
+  ========+============+================+=====
+
+=Rosin Oil.= By the dry distillation of rosin, there is yielded a series
+of heavy dark oils consisting principally of hydrocarbons, resinous
+bodies, and free acid. These oils vary in their saponification number
+from 10 to 60, while their unsaponifiable value averages about 80. Of
+the grades termed first, second, third, and fourth run, the latter two
+are superior for use in paints, as a rule containing less free acid than
+the preliminary runs. Treatment with steam and alkali serve to
+neutralize the acid nature of the oils and to remove impurities. Refined
+oils are lighter in color and are often blown and bodied to fairly rapid
+drying products, especially when treated with manganese driers. Rosin
+oils are seldom used with lead pigments, on account of the presence of
+sulphur in the oils, which would result in darkening. Rosin oil paints
+work very smoothly, even when they are curdled, producing glossy
+surfaces. The rapid checking of rosin oil paints on wooden surfaces bars
+the use of this oil for such purposes.
+
+ANALYSES OF ROSIN OILS
+
+  ==+=========+============+================+======
+    | Sp. Gr. |   Iodine   | Saponification | Acid
+    |         |   Value    |      No.       |  No.
+  --+---------+------------+----------------+------
+  A |   .966  |     41     |       27       | 16.7
+  B |   .99   |     48     |       38       | 10.0
+  ==+=========+============+================+======
+
+=Hydrocarbon Oils.= Several grades of neutral or mineral oils, varying
+somewhat in gravity, color, and quality, are produced as the last
+distillate in the refining of petroleum. These oils when mixed with
+drying oils and strong driers find application in the manufacture of
+some freight-car, barn, and other paints which sell at a low price. A
+small percentage of mineral oil is said to be valuable in structural
+steel paints, acting as a preventative of hard drying and thus keeping
+the film soft and elastic. Streaking and sweating is apt to ensue if any
+great quantity is used. Mineral oils have a characteristic bloom,
+showing a greenish fluorescence when examined by transmitted light. This
+bloom is due to the presence of some strongly fluorescent material which
+is shown up with intensity when mineral oils are exposed to ultraviolet
+rays such as emanate from an enclosed arc light. Outerbridge[1] first
+proposed this test for mineral oils, and he has worked out a
+"fluorescent scale," by which very small percentages of hydrocarbon oils
+may be detected in other oils. Several types of so-called debloomed oil
+have been placed upon the market, and although such oils appear under
+ordinary light conditions to be free from bloom, they fluoresce quite
+strongly when given the Outerbridge test.
+
+  [1] Alexander E. Outerbridge, Jr.: "A Novel Method of Detecting
+      Mineral Oil and Resin Oil in Other Oils." Proc. 14th Annual Meet.,
+      Amer. Soc. for Testing Mater., Atlantic City, N.J., June 28, 1911.
+
+[Illustration: View of Stills Where Petroleum Paint Thinners are
+Manufactured (Waverly)]
+
+ANALYSIS OF DEBLOOMED MINERAL PAINT OIL[2]
+
+  ========+============+================+=====
+  Sp. Gr. | Iodine No. | Saponification | Acid
+          |            |      No.       |  No.
+  --------+------------+----------------+-----
+    .92   |     12     |       4        |  0
+  ========+============+================+=====
+
+  [2] Oil of mirbane present, probably as a deblooming agent, or to mask
+      the odor.
+
+=Pine Oil.= This oil is produced by the redistillation of the heavy,
+high boiling point fractions resulting from the steam distillation of
+wood turpentine. It is a heavy straw-colored oil, and should be of some
+use in the paint and varnish industry, where a high boiling point
+solvent with an oxidizing principle is desired. It will probably find
+application in the manufacture of Baking Japans, Asphalt Paints and
+Enamels. Its oxidizing and solvent values are very high. It has a
+distinctive sweet pine smell, which makes it popular in the manufacture
+of turpentine substitutes from petroleum spirits.
+
+The writer has examined samples of this material, and the following
+appear to be of the best grade:
+
+CONSTANTS OF PINE OILS
+
+  ==========================+======================+====================
+                            |        No. 1         |         No. 2
+  --------------------------+----------------------+--------------------
+  Color                     |Straw Color           |Light Yellow
+  Specific Gravity at 15° C.|.934                  |.936
+  Boiling Point             |192° C.               |202° C.
+  Distillation              |95% distils between   |95% distils between
+                            |  192-270° C.         |  202-280° C.
+  Residue on Evaporation    |14.34%                |14.60%
+  Polymerization Test       |3-2/3% unpolymerized  |2-1/2% unpolymerized
+                            |  at end of 1/2 hour  |  at end of 1/2 hour
+  Flash-Point               |72° C.                |76° C.
+  Spot Test                 |Leaves no grease spot |Same as Pine Oil No.
+                            |but only evaporates   |1.
+                            |completely in 24 hours|
+  ==========================+======================+====================
+
+=Turpentine.= By direct fire or steam distillation of the sap drippings
+collected in pockets cut into pine trees, there is obtained the
+turpentine of commerce. It consists largely of pinene and isomeric
+terpenes, and has the property of attracting oxygen, with the formation
+of peroxides which stimulate the drying of oils. It is a high-grade
+solvent for various gums, and is therefore used in the manufacture of
+many lacquers as well as for thinning down oil-gum varnishes.
+
+REQUISITE CONSTANTS OF PURE GUM TURPENTINE
+
+  Color                        Water White
+  Specific Gravity at 15° C.   .862-.875
+  Boiling Point                About 156° C.
+  Distillation                 95% should distil between 153 and 165° C.
+  Residue on Evaporation       Not over 2%
+  Polymerization               Not over 5% should remain unpolymerized
+                               at end of half hour
+  Flash-Point                  Over 40.5° C.
+  Spot Test                    No grease spot should remain when dropped
+                               on paper and allowed to evaporate
+  Water                        None
+
+=Wood Turpentine.= High-grade wood turpentine is now produced by the
+steam distillation of finely cut fat pine wood. The lower-grade
+qualities are often produced from the destructive distillation of
+sawdust, stumpage, etc., and these products, on account of their content
+of formaldehyde, are objectionable in odor. In the steam distillation
+process, however, a high quality product is obtained by cutting out the
+heavy fractions and redistilling the lower and purer fractions. It has a
+high oxidizing value, causing the rapid drying of paints and varnishes
+to which it has been added. Its solvent value is often greater than that
+of gum turpentine. When properly refined it has a sweet smell and is to
+be highly recommended.
+
+Analyses of samples of pure wood turpentine which have come to the
+writer for examination follow:
+
+  ======================+==========================+====================
+                        |           No. 1          |        No. 2
+  ----------------------+--------------------------+--------------------
+  Sp. Gr. at 15° C.     |.862                      |.862
+  Boiling Point         |158° C.                   |162° C.
+  Distillation: 95%     |                          |
+    distils between     |158 and 185° C.           |162 and 177° C.
+  Residue on Evaporation|1.03%                     |3.06%
+  Polymerization Test   |4.1% remains unpolymerized|0.1 cc. out of 6 cc.
+                        |at end of 1/2             |  unpolymerized =
+                        |hour                      |  1.66%
+  Spot Test             |No grease spot on         |No grease spot on
+                        |  evaporation             |  evaporation
+  Odor                  |Excellent                 |Not objectionable
+  Color                 |Water White               |Water White
+  Flash Point           |                          |47.6° C.
+  ======================+==========================+====================
+
+=Petroleum Spirits.= There are produced from Texas crude oil which has
+an asphaltum base, and Pennsylvania crude oil which has a paraffin base,
+high boiling-point petroleum spirits which have come into wide use as
+paint and varnish thinners. When such materials have the proper
+evaporating value, high flash-point and freedom from sulphur, they are
+to be highly recommended as paint thinners. The following shows the
+analyses of a few of these materials examined in the writer's
+laboratory:
+
+PETROLEUM SPIRITS
+
+  =======================+=============+============+==============
+                         | Texas Base  | California | Penna. Base
+                         |             |    Base    |
+  -----------------------+-------------+------------+--------------
+  Color                  | Water White | White      | Water White
+  Specific Gravity       | .811        | .79        | .81
+  Boiling Point          | 156° C.     | 138° C.    | 146° C.
+  Flash-Point            | 44° C.      | 40.5° C.   | 43° C.
+  Residue on Evaporation | .2          | .15        | .12
+  =======================+=============+============+==============
+
+=Benzol.= "Solvent naphtha" or 160-degree benzol is a product obtained
+from the distillation of coal tar, differing from benzine, a product
+obtained from the distillation of petroleum. It is a valuable thinner to
+use in the reduction of paints for the priming of resinous lumber and
+refractory woods such as cypress and yellow pitch pine. The penetrating
+and solvent values of benzol are high, and it often furnishes a unison
+between paint and wood, that is a prime foundation to subsequent
+coatings, preventing the usual scaling and sap exudations which often
+appear on a painted surface. Because of the great solvent action of
+benzol, it should never be used in second and third coatings. The writer
+has successfully painted inferior grades of cypress with a paint
+containing benzol in the priming coat.
+
+=Benzine.= Benzine is seldom used in paints on account of its rapid
+evaporation, which is apt to cause pinholing of films and other surface
+defects. In paints of the dipping type where rapid evaporation is
+essential, benzine finds its widest application.
+
+
+
+
+CHAPTER II
+
+A STUDY OF DRIERS AND THEIR EFFECT
+
+
+The proper drying of oils and their behavior with various siccatives in
+varying quantity is an interesting problem, and obviously of
+considerable importance from a practical standpoint. Unfortunately there
+is a decided scarcity of reliable literature dealing with the subject
+for the guidance of those concerned in the manufacture or application of
+siccative products. Furthermore, when the problem is investigated, it is
+not difficult to see why this is so.
+
+=Uniform Conditions.= At a glance it is evident that a decided obstacle
+in experimentation on the drying properties of oils is the difficulty in
+obtaining identical conditions for comparative purposes. Inasmuch as a
+multitude of factors, such as uniformity and homogeneity of the driers
+and the oils themselves, intensity and source of light, temperature,
+uniformity of application, and many others, play a decisive part in the
+siccative tendencies of oils, the resources and ingenuity of the chemist
+engaged in the research are severely taxed.
+
+=Oxygen Absorption.= It is a well-known fact that linseed oil, when
+applied to a clean surface, such as a glass plate, will undergo
+oxidation and take up oxygen to the extent of about 16%, forming a hard,
+elastic, non-sticky product which has been called linoxyn. This
+material, unlike the oil from which it has been formed, is insoluble in
+most solvents. Other oils, such as cottonseed, hemp, rape, olive, etc.,
+are more fully satisfied in nature and have not the power to absorb the
+amount of oxygen taken up by linseed oil.
+
+In carrying out the following tests, on the drying of oils, a quantity
+of pure linseed oil of the following analysis was secured:
+
+  Specific gravity at 15° C.             0.934
+  Acid number                            5
+  Saponification number                191-1/2
+  Iodine number                        188
+
+This oil was distributed into a number of 8-oz. oil sample bottles, and
+to a series of these bottles was added varying quantities of a very
+concentrated drier made by boiling oil to 400 degrees Fahrenheit in an
+open kettle, with the subsequent addition of lead oxide. The amount of
+drier added to each bottle varied according to the percentage desired;
+being calculated on the lead content of the drier, which was very
+accurately determined by analysis.
+
+There was secured in this manner a series of oils containing varying
+amounts of lead oxide, and from this lot was selected a certain number
+of samples which would be representative and typical of paint vehicles
+now found in the market.
+
+Another series of tests were made by combining with a large number of
+samples of pure linseed oil as used above, various percentages of a
+manganese drier made by boiling oil at 400° F. and incorporating
+therewith manganese dioxide.
+
+Still another series of tests were made upon a number of oils into which
+were incorporated various small quantities of lead oxide and manganese
+oxide together, using the standard driers made in the above manner, all
+of which were carefully analyzed to determine their contents.
+
+In view of the errors in manipulation that could occur where so many
+tests were made, it was not deemed advisable, in carrying out the tests,
+to use glass plates on which only a minute quantity of oil could be
+maintained. A much better solution of the difficulty presented itself in
+using a series of small, round, crimped-edge tin plates, about three
+inches in diameter, such as are used for lids of friction-top cans.
+
+With paints it is impossible to secure films as thin as those presented
+by layers of oil on glass, nor would it be desirable to secure films of
+this same relative thickness. For this reason an endeavor was made to
+conduct the following tests with films of the same relative thickness as
+that possessed by the average coating of paint. The drying of the films
+did not take place in the same short period, nor in the same ratio, as
+with the thin layer that is secured by flowing oil upon glass. The
+results, however, are more practical, and of greater value to the
+manufacturer.
+
+The cans were carefully numbered in consecutive order, corresponding to
+the numbers on the various samples of oil. A very small quantity of oil
+was placed in each of the can covers, which were previously weighed, and
+allowed to distribute itself over the bottom surface thereof. Reweighing
+of the covers gave the amount of oil which was taken for each test. The
+test samples in the covers were all placed in a large box with glass
+sides, having a series of perforated shelves. In the side of this box is
+an opening through which a tube was passed, carrying a continual current
+of air washed and dried in sulphuric acid. Oxidation of the oil films
+commenced at once, and the amount of oxygen absorbed was determined at
+suitable periods by weighing, the increase in weight giving this factor.
+This test was kept up for a period of twenty days.
+
+A test was also made in the same manner with a current of damp air
+passing into the box, to observe the relative oxidation under such
+conditions. A chart of the results obtained has been made (Table VI), to
+show the effect of the various driers.
+
+=Results of Tests.= The following outline will present to the mind of
+the reader the most salient points which have been gleaned from these
+experiments, and which should give the manufacturer definite knowledge
+as to the best percentage of oxides to use either in boiled oil, paints
+or varnishes.
+
+In the case of lead oxide, an increase in the percentage of lead oxide
+in the oil causes a relative increase in the oxygen absorption, but when
+a very large percentage of lead has been added, the film of oil dries to
+a leathery skin.
+
+In the case of manganese oxide, the increase in oxygen absorption on the
+first day is much more pronounced than is the case with lead oxides.
+Furthermore, the oxidation of manganese oils seems to be relative to the
+increase in manganese up to a certain period, when the reverse of this
+law seems to take place, and beyond a certain definite percentage of
+manganese, added percentages seem to be of no value. It was furthermore
+observed that the films dry to a more brittle and harder skin than is
+the case when lead oxide is used. The oxygen absorption with oils high
+in manganese has been noticed to be excessive, and the film of oil
+becomes surface-coated, drying beneath in a very slow manner; a
+condition that often leads to checking. The critical percentage where
+the amount of manganese appears to give the greatest efficiency seems to
+be 0.02%. This critical percentage, as it may be termed, should not be
+exceeded, and any added amount of manganese has the effect of making the
+film much more brittle and causes the so-called "burning up" of the
+paint. The loading of paint with drier and the bad result therefrom may
+be explained to some extent from the above results.
+
+TABLE VI--LINSEED OIL AND MnO_{2} (MANGANESE) DRIER--TEST NO. 1
+
+  =========+=========+====+====+====+====+====+====+====+====+====
+  Per cent.|         |0.02|0.05|0.15|0.25|0.35|0.45|0.55|0.70|1.00
+  MnO_{2}  |         |    |    |    |    |    |    |    |    |
+  ---------+---------+----+----+----+----+----+----+----+----+----
+           |{  1 day |0.08|0.11|0.16| -- |3.21|3.46|3.27|3.01|2.76
+           |{  2 days|0.16|5.88|4.48| -- |3.63|4.01|3.70|3.51|3.18
+           |{  3 days|0.21|6.79|4.61| -- |3.83|4.31| -- |3.91| --
+           |{  4 days| -- | -- |4.64| -- | -- | -- | -- | -- | --
+           |{  5 days|3.01|6.84| -- | -- |4.13|4.68|4.19|3.91|3.99
+           |{  6 days|8.00| -- |4.88| -- |4.37| -- |4.51|4.32|4.13
+  Per      |{  7 days|8.58|6.92|4.90| -- |4.48| -- |4.61|4.52|4.23
+  cent.    |{  8 days|9.06| -- |5.03| -- |4.55|5.23|4.77|4.62|4.44
+  gain     |{  9 days| -- | -- |5.12| -- |4.63|5.40|4.94|4.79|4.51
+           |{ 10 days|9.07|6.89|5.18| -- |4.81|5.47| -- |4.98|4.73
+           |{ 11 days|9.15|7.03| -- | -- | -- | -- | -- | -- | --
+           |{ 12 days| -- | -- | -- | -- |4.98| -- |5.45|5.33|5.22
+           |{ 13 days|9.22|7.17| -- | -- |5.25|6.00|5.60|5.42|5.33
+           |{ 14 days|9.25|7.18|5.55| -- | -- | -- | -- | -- | --
+           |{ 20 days| -- |7.21|5.81| -- |5.84|6.70|5.94|5.84|5.77
+  =========+=========+====+====+====+====+====+====+====+====+====
+
+TABLE VII--LINSEED OIL AND MnO_{2} (MANGANESE) DRIER--TEST NO. 2 (CHECK)
+
+  =========+=========+====+====+====+====+====+====+====+====+====
+  Per cent.|         |0.02|0.05|0.15|0.25|0.35|0.45|0.55|0.70|1.00
+  MnO_{2}  |         |    |    |    |    |    |    |    |    |
+  ---------+---------+----+----+----+----+----+----+----+----+----
+           |{  1 day | -- |3.12|4.42|3.86| -- |3.19|2.98|3.27|2.56
+           |{  2 days| -- |6.15|4.73| -- | -- |3.51|3.28|3.70|2.96
+           |{  3 days|0.28|6.29| -- |4.12|3.72| -- |3.39|3.71|3.15
+           |{  4 days|3.83|6.32|4.75|4.21|3.87|3.61|3.58|4.05|3.43
+  Per      |{  5 days|6.64| -- |4.84|4.23|3.94|3.73|3.65|4.21|3.56
+  cent.    |{  6 days|8.61| -- |4.87| -- |4.08|3.81|3.78|4.35|3.73
+  gain     |{  7 days|9.07|6.35|5.00|4.41|4.18|3.91|3.85|4.54|3.87
+           |{  9 days|9.25|6.39|5.16| -- |4.44|4.11|4.21|4.63|4.26
+           |{ 11 days| -- | -- | -- |4.63|4.59|4.36|4.31|5.07|4.46
+           |{ 16 days| -- |6.43|5.30|4.91|4.83|4.72|4.71|5.40|4.87
+  =========+=========+====+====+====+====+====+====+====+====+====
+
+TABLE VIII--LINSEED OIL AND PbO (LEAD) DRIER
+
+  =====+=====+=====+=====+=====+=====+======+======+=====+======+=====+====+====
+   Per |     |     |     |     |     |      |      |     |      |     |    |
+  cent.|     | 0.00| 0.05| 0.10| 0.30| 0.50 | 0.70 | 1.00| 1.30 | 1.60|1.30|1.60
+   PbO |     |     |     |     |     |      |      |     |      |     |    |
+  -----+-----+-----+-----+-----+-----+------+------+-----+------+-----+----+----
+       |{ 1  |0.042|0.049|0.092|0.058| 0.066| 0.062|0.062| 0.079|0.039|0.14|0.72
+       |{day |     |     |     |     |      |      |     |      |     |    |
+       |{ 2  |0.098|0.104|0.153|0.116| 0.158|  --  |0.194| 4.83 |4.79 |5.27|6.11
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{ 3  |0.128|0.159|0.170|0.137| 0.279| 0.185|7.11 | 8.60 |5.35 |7.89|8.28
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{ 4  |0.164|0.214|0.206|0.178|   -- | 4.07 |7.39 | 9.55 |8.53 |7.93|8.68
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{ 5  |0.176|  -- |0.306|  -- | 0.340| 7.60 |7.47 | 9.87 |8.78 |8.18| --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+  Per  |{ 6  |0.188|0.231|  -- |0.243| 0.472| 9.36 |7.64 |10.01 |9.00 |8.24|9.09
+  cent.|{days|     |     |     |     |      |      |     |      |     |    |
+  gain |{ 7  |0.206|0.251|  -- |0.253| 1.080|10.06 | --  |10.14 | --  | -- | --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{ 8  |0.212|0.253|  -- |0.280| 4.80 |10.38 |7.70 |10.22 |9.05 | -- | --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{ 9  |0.226|0.291|0.306|0.331| 7.36 |10.41 |7.73 |10.23 |9.07 | -- | --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{13  |0.327|0.428|0.510|0.674|11.01 |10.67 |7.91 |10.48 |9.29 |8.62| --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{15  |0.466|0.455|0.650|2.41 |11.05 |  --  |7.92 |10.50 |9.30 | -- | --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+       |{20  |0.521|1.08 |1.78 |8.76 |11.25 |10.67 |7.98 |10.52 |9.36 | -- | --
+       |{days|     |     |     |     |      |      |     |      |     |    |
+  =====+=====+=====+=====+=====+=====+======+======+=====+======+=====+====+====
+
+TABLE IX--LINSEED OIL AND PbO (LEAD) AND MnO_{2} (MANGANESE)--COMBINATION
+DRIER
+
+  =================+========+=====+=====+======+======+====+=====+====
+  Per cent. PbO    |        | 0.1 | 0.3 | 0.5  | 0.7  |0.9 | 1.1 |1.4
+  -----------------+--------+-----+-----+------+------+----+-----+----
+  Per cent. MnO_{2}|        |.005 |.015 | 0.025| 0.35 |0.45| 0.55|0.7
+  -----------------+--------+-----+-----+------+------+----+-----+----
+                   |{ 1 day |0.026|0.061| 0.055| 0.022|0.16| 0.11|3.06
+                   |{ 2 days|0.094|0.087| 0.143| 0.16 |5.21| 6.28|3.37
+                   |{ 3 days|0.118| --  | 0.17 | 4.23 |7.63| 8.31|3.74
+                   |{ 4 days| --  |0.11 | 0.23 | 7.36 |8.87| 9.20|4.02
+                   |{ 5 days|0.120|0.12 | 0.29 | 9.04 |9.13| 9.37|4.17
+  Per cent. gain   |{ 6 days|0.17 |0.13 | 1.44 | 9.88 |9.26| 9.51|4.34
+                   |{ 7 days|0.21 |0.18 | 4.65 |10.11 |9.28|  -- |4.45
+                   |{11 days|0.30 |0.26 |10.03 |10.35 |9.61| 9.85|5.11
+                   |{12 days| --  | --  |  --  |10.45 |9.66|  -- | --
+                   |{13 days|0.35 |0.54 |10.37 |10.51 |9.67|10.03|5.33
+                   |{18 days|0.49 |3.43 |10.38 |10.62 |9.68|  -- |5.73
+  =================+========+=====+=====+======+======+====+=====+====
+
+In the same way with lead driers, excessive amounts of lead oxide seem
+to have no beneficial effects on the drying of an oil, and when the
+percentage which seems to be the most beneficial, namely 0.5% lead
+oxide, is exceeded, the film is apt to become brittle.
+
+Oils containing lead oxide driers are less influenced in their drying
+tendencies by conditions of moisture in the atmosphere than oils
+containing manganese, but frequently, however, the former dry much
+better in a dry atmosphere. As a general rule, varnishes rich in
+manganese dry more quickly in a dry atmosphere, while those containing
+small quantities dry more quickly in a damp atmosphere.
+
+=Volatile Products Formed.= It was furthermore noticed in these tests
+that sulphuric acid, placed in dishes on the bottom of the large box in
+which the samples of oil were drying, was discolored and turned brown
+after several days, showing that the acid had taken up some material of
+a volatile nature that was a product of the oxidation.
+
+Another curious feature of these tests was the development of a peculiar
+aromatic odor which was given off by the oils upon drying in dry air.
+When the oils were dried in moist air, a rank odor resembling propionic
+acid was observed, and this led the observer to believe that a reaction
+was effected by the absorbed oxygen, that caused the glycerin combined
+with the linoleic acid as linolein to split up into evil-smelling
+compounds. It has been suggested that the oxygen first attacks the
+glycerin, transforming it into carbonic acid, water, and other volatile
+compounds, which are eliminated before the oil is dried to linoxyn.
+Toch,[3] however, has shown that the drying of linseed oil gives off
+only very small percentages of carbon dioxide. Mulder has observed that
+in the process of linseed oil being oxidized, glycerin is set free,
+which becomes oxidized to formic, acetic, and other acids, while the
+acid radicals are converted by oxygen into the anhydrides, from which
+they pass by further oxidation into linoxyn.
+
+  [3] Toch: The Chem. and Tech. of Mixed Paints, p. 89. D. Van Vostand
+      Co., N. Y.
+
+=Auto-Oxidation of Oil.= The theory of auto-oxidation of linseed oil has
+been very ably treated by Blackler, whose experiments indicated that
+during the drying process the slow absorption of oxygen was, at a
+critical period, followed by a rapid absorption, which he attributes to
+the presence of peroxides. The materials produced by this peroxide
+formation may act as catalyzers and accelerate the formation of more
+peroxide. Lead and manganese oxides may also be oxidized to peroxides by
+the action of oxygen, and in this event might act as very active
+catalyzing agents or carriers of oxygen. Blackler's statement, that the
+presence of driers do not increase, but have a tendency to decrease the
+initial velocity of oxygen absorption, has been confirmed by these
+experiments, but it has been noticed throughout the tests that the
+driers have an accelerative action at a later period.
+
+=Effect of Metals on Drying of Oils.= Some most interesting results were
+secured by dipping extremely fine copper gauze into linseed oil, and
+then suspending the gauze in the air. The adhesion of the oil to the
+copper caused the formation of films between the network, and remarkable
+drying action was observed. The copper or any superficial coating of
+copper oxide which may have been present on the metal, undoubtedly
+affected the result to some extent. It has been found that metallic lead
+is even more efficient than copper in this respect, but this may be due
+to the action of free acid in the linseed oil, forming lead linoleates,
+products that greatly accelerate drying. Another interesting experiment
+was made by immersing pieces of gauze cloth in linseed oil. After the
+excess oil had been removed, by pressing, the cloth was again weighed to
+determine the amount of oil used for the experiment. The increase in
+oxygen absorption in this case was very rapid, and the result obtained
+confirmed the results in the other experiments.
+
+In order to secure a more evenly distributed state of the oil, tests
+were conducted by saturating pieces of stiff blotting papers, and, after
+exposure, weighing as usual.
+
+=Influence of Light.= The influence of light on the drying of oils is
+unquestionably a potent one. The practical painter knows that a certain
+varnish will dry quicker when exposed to the light than when in the
+dark.
+
+Chevreul was one of the first pioneers in this field of research to
+observe the effects of colored lights on drying, and he claimed that oil
+exposed under white glass dried more rapidly than when exposed under red
+glass, which eliminates all light of short wave lengths.
+
+Genthe obtained interesting results in the drying of oil submitted to
+the effect of the mercury lamp. Oxidation without driers was effected
+probably through the formation of peroxides. In commenting on this
+subject, Blackler[4] gives a description of the use of the Uveol Lamp,
+which is similar to the mercury lamp, but has, instead of a glass casing
+which cuts off the valuable rays, a fused-quartz casing which allows
+their passage.
+
+  [4] M. B. Blackler: "The Use and Abuse of Driers," P. and V. Society,
+      London, Sept. 9, 1909.
+
+=Driers in Boiled Oil.= In the boiling of linseed oil, by certain
+processes the oil is heated to 250° F. and manganese resinate is
+incorporated therein. It goes into solution quite rapidly. In other
+processes the oil is heated to 400° F. or over, and manganese as an
+oxide is boiled into the oil. Although it is unsafe to say that a small
+percentage of rosin, such as would be introduced by the use of resinate
+driers, is not harmful, yet it appears that this process should give a
+good oil, inasmuch as it has been found that no matter whether the
+manganese is added to the oil, as a resinate, borate or oxide,
+practically the same drying effect is noticed in every case where the
+percentage of manganese is the same. It is the opinion of some, however,
+that the resinate driers are not as well suited for durability as oxide
+driers. However, if a boiled oil is found to contain on analysis a small
+percentage of rosin less than 0.5% or a percentage only sufficient to
+combine with the metal present, it should not be suspected of
+adulteration. Practical tests should be made with such oil along with an
+oil made with an oxide drier, before pronouncing on their relative
+values. Inasmuch as the addition of certain driers to linseed oil
+lessens the durability of the film, it is more practical to use the
+smallest amount of drier that will serve the purpose desired, that is,
+set the oil up to a hard condition which will not take dust and which
+will stand abrasion.
+
+The results of this investigation would indicate that when lead or
+manganese linoleates are used, the most efficient drying is shown with
+0.5% lead or with 0.02% manganese, or with a combination of 0.5% lead
+and 0.02% manganese.
+
+Until more definite results have been obtained with the _tungates_,
+which will probably prove of exceptional interest as driers, the above
+driers will probably be used to the greatest extent.
+
+=Co-operative Drying Tests.= A series of important drying tests made by
+members of a special committee[5] appointed by the American Society for
+Testing Materials, of which the writer was chairman, is herewith shown:
+
+  [5] Sub-Committee C of Committee D-1, on Testing Paint Vehicles. Proc.
+      Amer. Soc. for Test. Mater., 1911.
+
+"At the January meeting of Committee D-1, a sub-committee consisting of
+the following members was appointed to investigate paint vehicles:
+
+  G. B. Heckel,
+  Glenn H. Pickard,
+  Allen Rogers,
+  A. H. Sabin,
+  H. A. Gardner, _Chairman_.
+
+"At a subsequent meeting of the sub-committee it was determined to start
+the investigations with a series of tests on certain drying,
+semi-drying, and non-drying oils, determining their drying values, rate
+of oxygen absorption, etc., when spread out in thin films. A quantity of
+the following oils was selected for the tests and subsequently secured
+from sources known to be reliable:
+
+  Lead and manganese linoleate drier.[6]
+  Lithographic linseed oil.
+  Boiled linseed oil (resinate type).
+  Boiled linseed oil (linoleate type).
+  Blown linseed oil (containing drier while being blown).
+  Heavy mineral oil.
+  Rosin oil.
+  Soya bean oil.
+  Corn oil.
+  Cottonseed oil.
+  Sunflower oil.
+  Menhaden oil.
+  Chinese wood oil, raw.
+  Chinese wood oil, treated.
+  Perilla oil.[7]
+  Lumbang oil.[7]
+  Dry rosin 20%, boiled in 80% linseed oil.
+
+  [6] The drier used, upon analysis, showed the presence of 4.36% PbO
+      and 2.51% MnO_{2}.
+
+  [7] The lumbang and perilla oils were imported and arrived subsequent
+      to the starting of the tests. They were therefore not included in
+      the tests.
+
+"Four-ounce sample bottles of each oil were sent to the Committee
+members, with the request to proceed with the tests along the lines
+agreed upon at the Committee meeting. The instructions for making these
+tests are outlined as follows:
+
+(_a_) A series of small glass plates, approximately 5 by 7 ins., are to
+be prepared by each member of the Committee. These plates are to be
+thoroughly cleaned and carefully numbered and weighed upon a chemical
+balance. The oils to be used for the tests are to be numbered
+corresponding to the plates. A test of each oil is to be made by
+painting it upon the surface of a glass plate with a camel's-hair brush,
+subsequently weighing the plate and the oil. These tests are to be
+exposed under constant conditions of temperature, if possible, for three
+weeks' time, making weighings of each plate every day for six days and
+then every other day for twelve days.
+
+(_b_) Another series of tests shall be made, in which 80% of raw linseed
+oil is to be combined with each of the above oils named. Previous to
+making any of the tests, _there should be added to each oil, or to each
+combination, 5% of a drier containing lead and manganese_. The drier to
+be used is of the standard grade submitted, together with the oil
+samples. The results of the tests are to be charted and submitted at the
+end of the tests, so that they may be compared with the results obtained
+by each member of the Committee.
+
+(_c_) If possible, the oils and mixture of oils used in the above tests
+are to be ground with pure silica and painted out upon sized paper,
+three-coat work, the films to be stripped and tested for strength upon a
+paint filmometer, at two periods two months apart."
+
+The drying of oils to a firm surface when spread in a thin layer is
+accompanied by an increase in weight, due to the absorption of oxygen.
+The percentage of oxygen absorbed often affords a criterion of the
+drying of the oil under examination, and this factor, together with data
+regarding the appearance of the oil film, should be taken into
+consideration when judging the value of an oil or oil mixture.
+Conditions of light, air, temperature, etc., often cause great
+variations in the drying of oils and the percentage of oxygen absorbed,
+as shown by the results obtained in the following tests. Although it was
+impossible in these tests to have the conditions under which each
+experimenter worked parallel in nature, the tests afford nevertheless
+considerable information for guiding future work of a similar nature.
+
+An examination of the results obtained showed generally that the
+greatest increase in weight occurred during the period in which the oil
+dried up to a firm film. This occurred in most cases within 48 hours.
+After this period a slight increase in weight was often noticed, and
+then a more or less steady decline, varying with the oil examined. Had
+the oil tests been continued for a greater length of time, a much
+greater loss might have been observed.
+
+It was impossible to include in the tests the oil-silica film work, on
+account of lack of time. It is believed, however, that these tests
+should be conducted, as they would throw much light on the elasticity
+and strength given to paint films by various oils.
+
+  TABLE I.--(_a_) BOILED LINSEED OIL (RESINATE TYPE)    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1997   |   0.6242  |   0.5027  |  0.6024
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    11.9    |   14.42   |   10.21   |  13.69
+             |  2 |    12.5    |   13.37   |   10.00   |  13.01
+             |  3 |    12.7    |   12.53   |    9.57   |  12.50
+             |  4 |    13.1    |   11.7    |    9.65   |  12.29
+             |  5 |    12.8    |   11.03   |    8.99   |  12.00
+             |  6 |    12.7    |     --    |     --    |  12.25
+             |  7 |     --     |   10.17   |    8.57   |    --
+             |  8 |    12.7    |   10.34   |     --    |  11.64
+             |  9 |     --     |   10.12   |    8.93   |    --
+  Percentage | 10 |    12.6    |   10.00   |     --    |  10.73
+  Increase   | 11 |     --     |     --    |    8.81   |    --
+  in Weight, | 12 |    12.8    |    9.69   |     --    |  10.68
+  in Days.   | 13 |     --     |     --    |    9.31   |    --
+             | 14 |    12.8    |     --    |     --    |  11.18
+             | 15 |     --     |    9.04   |    9.43   |    --
+             | 16 |    12.7    |     --    |     --    |  10.68
+             | 17 |     --     |    8.68   |     --    |    --
+             | 18 |    12.9    |     --    |    9.11   |    --
+             | 19 |     --     |    8.13   |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Dried to    |           |           |Tacky at end
+                  |firm, smooth|           |           |of 1st day.
+                  |film in 2   |           |           |Nearly dry,
+                  |days        |           |           |end of 2d day.
+                  |            |           |           |Perfectly dry,
+                  |            |           |           |end of 10th
+                  |            |           |           |day.
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) BOILED LINSEED OIL (RESINATE TYPE)    20 PER CENT.
+        RAW LINSEED OIL                       80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1933   |   0.3660  |   0.4640  |     --
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    13.6    |    0.57   |   12.48   |     --
+             |  2 |    14.7    |    1.66   |   11.92   |     --
+             |  3 |    14.9    |   10.50   |   11.49   |     --
+             |  4 |    14.9    |   13.30   |   11.10   |     --
+             |  5 |    14.8    |     --    |   10.84   |     --
+             |  6 |    14.8    |     --    |     --    |     --
+             |  7 |     --     |   12.51   |    9.48   |     --
+             |  8 |    14.8    |     --    |     --    |     --
+             |  9 |     --     |   11.40   |    7.41   |     --
+  Percentage | 10 |    14.8    |     --    |     --    |     --
+  Increase   | 11 |     --     |     --    |    7.56   |     --
+  in Weight, | 12 |    14.7    |   10.20   |     --    |     --
+  in Days.   | 13 |     --     |     --    |    8.36   |     --
+             | 14 |    14.5    |     --    |     --    |     --
+             | 15 |     --     |    9.84   |    8.54   |     --
+             | 16 |    14.7    |     --    |     --    |     --
+             | 17 |     --     |     --    |     --    |     --
+             | 18 |    14.7    |     --    |    8.51   |     --
+             | 19 |     --     |     --    |     --    |     --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Dried to    |           |           |
+                  |firm, smooth|           |           |
+                  |film in 2   |           |           |
+                  |days.       |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE II.--(_a_) BOILED LINSEED OIL (LINOLEATE TYPE)    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+---------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+---------------
+  Wt. of Oil for  |   0.1226   |   0.5384  |   0.5696  |  0.3306
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    10.9    |   14.34   |   10.25   |  12.09
+             |  2 |    12.2    |   13.26   |   10.41   |  11.33
+             |  3 |    12.7    |   12.18   |   10.22   |  10.94
+             |  4 |    12.5    |   11.29   |   10.16   |  11.10
+             |  5 |    12.8    |   10.75   |    9.90   |  10.86
+             |  6 |    12.2    |     --    |     --    |  11.25
+             |  7 |     --     |    9.88   |    9.60   |    --
+             |  8 |    12.2    |   10.25   |     --    |  10.87
+             |  9 |     --     |   10.01   |    9.72   |    --
+  Percentage | 10 |    12.4    |    9.91   |     --    |   9.72
+  Increase   | 11 |     --     |     --    |    9.48   |    --
+  in Weight, | 12 |    12.1    |    9.60   |     --    |  10.02
+  in Days.   | 13 |     --     |     --    |    9.97   |    --
+             | 14 |    12.     |     --    |     --    |  10.62
+             | 15 |     --     |    9.12   |   10.36   |    --
+             | 16 |    12.1    |     --    |     --    |  10.46
+             | 17 |     --     |    8.37   |     --    |    --
+             | 18 |    12.1    |     --    |    9.59   |    --
+             | 19 |     --     |    8.30   |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Dried firmly|           |           |Tacky at end
+                  |with smooth,|           |           |of 1st day.
+                  |even film in|           |           |Slightly
+                  |2 days.     |           |           |tacky, end 2d
+                  |            |           |           |day. Dry, but
+                  |            |           |           |curled, end of
+                  |            |           |           |10th day.
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) BOILED LINSEED OIL (LINOLEATE TYPE)    20 PER CENT.
+        RAW LINSEED OIL                        80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1843   |   0.5790  |  0.4653   |    --
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    11.8    |   10.14   |  12.40    |    --
+             |  2 |    13.9    |   15.71   |  11.90    |    --
+             |  3 |    15.1    |   13.29   |  11.50    |    --
+             |  4 |    15.2    |   12.12   |  11.11    |    --
+             |  5 |    15.0    |   11.43   |  10.90    |    --
+             |  6 |    14.6    |     --    |    --     |    --
+             |  7 |     --     |   10.05   |   9.37    |    --
+             |  8 |    14.6    |   10.26   |    --     |    --
+             |  9 |     --     |    9.55   |   8.53    |    --
+  Percentage | 10 |    14.5    |    9.32   |    --     |    --
+  Increase   | 11 |     --     |     --    |   7.48    |    --
+  in Weight, | 12 |    14.4    |    8.84   |    --     |    --
+  in Days.   | 13 |     --     |     --    |   8.43    |    --
+             | 14 |    14.4    |     --    |    --     |    --
+             | 15 |     --     |    8.46   |   8.02    |    --
+             | 16 |    14.6    |     --    |    --     |    --
+             | 17 |     --     |    7.68   |    --     |    --
+             | 18 |    14.7    |     --    |   7.27    |    --
+             | 19 |     --     |    7.55   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Dried with  |           |           |
+                  |smooth film |           |           |
+                  |in 2 days.  |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE III.--(_a_) LITHOGRAPHIC LINSEED OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+---------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.4011   |   0.8733  |  0.8812   |  2.7318
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+-------------
+             |  1 |     6.9    |    0.87   |   3.60    |   .051
+             |  2 |     8.5    |    3.85   |   5.10    |   .051
+             |  3 |     8.9    |    5.14   |   5.00    |   .051
+             |  4 |     8.9    |    6.07   |   6.78    |   .041
+             |  5 |     8.7    |    6.40   |   6.97    |   .081
+             |  6 |     8.0    |     --    |    --     |   .169
+             |  7 |      --    |    6.84   |   7.38    |    --
+             |  8 |     8.0    |    7.22   |    --     |   .19
+             |  9 |      --    |    7.36   |   7.42    |    --
+  Percentage | 10 |     8.0    |    7.57   |    --     |   .752
+  Increase   | 11 |      --    |     --    |   7.44    |    --
+  in Weight, | 12 |     8.0    |    7.75   |    --     |  1.184
+  in Days.   | 13 |      --    |     --    |   8.01    |    --
+             | 14 |     8.4    |     --    |    --     |  1.641
+             | 15 |      --    |    7.98   |   8.03    |    --
+             | 16 |     8.4    |     --    |    --     |  2.00
+             | 17 |      --    |    7.83   |    --     |    --
+             | 18 |     8.3    |     --    |   7.99    |    --
+             | 19 |      --    |    7.80   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Dried to    |           |           |Remained
+                  |glossy, firm|           |           |sticky to 10
+                  |film,       |           |           |days, and even
+                  |slightly    |           |           |at end of 38
+                  |crinkled in |           |           |days was
+                  |2 days. Oil |           |           |slightly
+                  |made very   |           |           |tacky.
+                  |thick film  |           |           |
+                  |on account  |           |           |
+                  |of heavy    |           |           |
+                  |body.       |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) LITHOGRAPHIC LINSEED OIL    20 PER CENT.
+        RAW LINSEED OIL             80 PER CENT.
+
+  ----------------+------------+-----------+-----------
+   Observer.      |  Gardner   |   Sabin   |  Pickard
+                  |            |           |
+  ----------------+------------+-----------+-----------
+  Wt. of Oil for  |   0.1300   |   0.7750  |  0.6538
+  Test, grams     |            |           |
+  -----------+----+------------+-----------+-----------
+             |  1 |    10.2    |   11.35   |   9.94
+             |  2 |    11.3    |   11.48   |  10.41
+             |  3 |    11.9    |   10.93   |  10.39
+             |  4 |    12.0    |   10.77   |  10.35
+             |  5 |    11.8    |   10.25   |   9.93
+             |  6 |    11.8    |     --    |    --
+             |  7 |      --    |    9.51   |   9.54
+             |  8 |    11.8    |    9.93   |    --
+             |  9 |      --    |    9.80   |   9.36
+  Percentage | 10 |    11.8    |    9.68   |    --
+  Increase   | 11 |      --    |     --    |   8.99
+  in Weight, | 12 |    11.8    |    9.65   |    --
+  in Days.   | 13 |      --    |     --    |   9.61
+             | 14 |    11.8    |     --    |    --
+             | 15 |      --    |    9.51   |   9.70
+             | 16 |    11.9    |     --    |    --
+             | 17 |      --    |    9.07   |    --
+             | 18 |    11.9    |     --    |   9.13
+             | 19 |      --    |    8.67   |    --
+  -----------+----+------------+-----------+-----------
+  Remarks.        |Dried to    |           |
+                  |firm, glossy|           |
+                  |film in 2   |           |
+                  |days.       |           |
+  ----------------+------------+-----------+-----------
+
+  TABLE IV.--(_A_) BLOWN LINSEED OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2105   |   0.8394  |  0.8457   |  1.0398
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     8.5    |    9.30   |   5.07    |   4.41
+             |  2 |    10.2    |    8.97   |   6.16    |   4.91
+             |  3 |    10.2    |    5.30   |   6.48    |   5.22
+             |  4 |    10.2    |    9.30   |   6.94    |   5.62
+             |  5 |    10.0    |    8.99   |   6.73    |   5.73
+             |  6 |     9.9    |     --    |    --     |   6.06
+             |  7 |      --    |    8.49   |   6.99    |    --
+             |  8 |     9.8    |    8.89   |    --     |   6.43
+             |  9 |      --    |    8.73   |   6.89    |    --
+  Percentage | 10 |     9.8    |    8.89   |    --     |   6.18
+  Increase   | 11 |      --    |     --    |   7.11    |    --
+  in Weight, | 12 |     9.7    |    8.73   |    --     |   6.51
+  in Days.   | 13 |      --    |     --    |   7.60    |    --
+             | 14 |     9.8    |     --    |    --     |   6.95
+             | 15 |      --    |    8.52   |   7.95    |    --
+             | 16 |     9.8    |     --    |    --     |   7.00
+             | 17 |      --    |    8.07   |    --     |    --
+             | 18 |     9.9    |     --    |   7.86    |    --
+             | 19 |      --    |    7.74   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Ropiness of |           |           |Formed skin,
+                  |oil made    |           |           |end 1st day.
+                  |very thick  |           |           |Slightly
+                  |film, but   |           |           |tacky end 2nd;
+                  |dried in    |           |           |dry, but
+                  |less than 2 |           |           |curled, end of
+                  |days to     |           |           |10th day.
+                  |smooth film.|           |           |
+                  |Films       |           |           |
+                  |exhibited   |           |           |
+                  |ridges.     |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_)BLOWN LINSEED OIL         20 PER CENT.
+       RAW LINSEED OIL           80 PER CENT.
+
+  ----------------+------------+-----------+-----------
+   Observer.      |  Gardner   |   Sabin   |  Pickard
+                  |            |           |
+  ----------------+------------+-----------+-----------
+  Wt. of Oil for  |   0.0774   |   0.5329  |   0.6218
+  Test, grams     |            |           |
+  -----------+----+------------+-----------+-----------
+             |  1 |    10.4    |   11.82   |   10.71
+             |  2 |    12.8    |   12.76   |     --
+             |  3 |    13.1    |   10.98   |     --
+             |  4 |    12.9    |   10.39   |     --
+             |  5 |    12.1    |    9.81   |     --
+             |  6 |    11.9    |     --    |     --
+             |  7 |     --     |    8.69   |     --
+             |  8 |    12.0    |    9.15   |     --
+             |  9 |     --     |    8.91   |     --
+  Percentage | 10 |    11.8    |    8.97   |     --
+  Increase   | 11 |     --     |     --    |     --
+  in Weight, | 12 |    11.8    |    8.67   |     --
+  in Days.   | 13 |     --     |     --    |     --
+             | 14 |    11.7    |     --    |     --
+             | 15 |     --     |    8.22   |     --
+             | 16 |    11.6    |     --    |     --
+             | 17 |     --     |    7.63   |     --
+             | 18 |    11.8    |     --    |     --
+             | 19 |     --     |    7.32   |     --
+  -----------+----+------------+-----------+-----------
+  Remarks.        |Dried to    |           |Glass broke.
+                  |very glossy |           |
+                  |film in 2   |           |
+                  |days.       |           |
+  ----------------+------------+-----------+-----------
+
+  TABLE V.--(_a_) MINERAL OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1632   |    --     |    --     |  0.1975
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |  [8]12.5   |    --     |    --     | [8] 8.12
+             |  2 |  [8]14.2   |    --     |    --     | [8]16.22
+             |  3 |  [8]16.7   |    --     |    --     | [8]21.23
+             |  4 |  [8]19.4   |    --     |    --     | [8]25.58
+             |  5 |  [8]19.4   |    --     |    --     | [8]28.41
+             |  6 |  [8]19.5   |    --     |    --     | [8]28.92
+             |  7 |      --    |    --     |    --     |      --
+             |  8 |  [8]19.5   |    --     |    --     | [8]35.25
+             |  9 |      --    |    --     |    --     |      --
+  Percentage | 10 |  [8]19.5   |    --     |    --     | [8]35.76
+  Increase   | 11 |      --    |    --     |    --     |      --
+  in Weight, | 12 |  [8]19.3   |    --     |    --     | [8]43.86
+  in Days.   | 13 |      --    |    --     |    --     |      --
+             | 14 |  [8]19.4   |    --     |    --     | [8]45.28
+             | 15 |      --    |    --     |    --     |      --
+             | 16 |  [8]19.5   |    --     |    --     | [8]48.08
+             | 17 |      --    |    --     |    --     |      --
+             | 18 |  [8]19.5   |    --     |    --     |      --
+             | 19 |      --    |    --     |    --     |      --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Oil lost in |Broken be- |Broken be- |Remained oily
+                  |weight      |fore weigh-|fore weigh-|during entire
+                  |throughout  |ings were  |ings were  |test.
+                  |test on ac- |made.      |made.      |
+                  |count of    |           |           |
+                  |presence of |           |           |
+                  |volatiles.  |           |           |
+                  |No drying   |           |           |
+                  |action ob-  |           |           |
+                  |served. Film|           |           |
+                  |wet at end  |           |           |
+                  |of test.    |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  [8] Lost in weight throughout test.
+
+  (_b_) MINERAL OIL                 20 PER CENT.
+        RAW LINSEED OIL             80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1884   |   0.5663  |   0.405   |   0.2598
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     6.4    |   11.51   | [9]9.66   | [9]6.69
+             |  2 |     6.8    |    8.21   | [9]8.92   | [9]5.06
+             |  3 |     7.2    |    6.51   | [9]6.82   | [9]2.88
+             |  4 |     7.8    |    5.19   | [9]6.03   | [9]1.52
+             |  5 |     8.1    |    4.36   | [9]4.68   | [9]1.29
+             |  6 |     7.9    |     --    |     --    | [9]1.68
+             |  7 |     --     |    2.72   | [9]2.64   |     --
+             |  8 |     7.9    |    3.12   |     --    |[10]2.07
+             |  9 |     --     |    2.82   |[10]0.30   |     --
+  Percentage | 10 |     8.1    |    2.59   |     --    |[10]0.08
+  Increase   | 11 |     --     |     --    |[10]0.56   |     --
+  in Weight, | 12 |     7.8    |    2.35   |     --    |[10]0.93
+  in Days.   | 13 |     --     |     --    |[10]0.04   |     --
+             | 14 |     7.8    |     --    |     --    |[10]0.54
+             | 15 |      --    |    1.36   |[10]0.14   |     --
+             | 16 |     7.8    |     --    |     --    |     --
+             | 17 |     --     |    0.53   |     --    |     --
+             | 18 |     7.8    |     --    |[10]0.86   |     --
+             | 19 |     --     |[10]0.14   |     --    |     --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Fair drying |           |           |Sticky, end of
+                  |observed end|           |           |1st day;
+                  |of 2d day.  |           |           |tacky, end of
+                  |Film tacky  |           |           |2d day and end
+                  |until end   |           |           |of 38 days.
+                  |8th day;    |           |           |
+                  |after that, |           |           |
+                  |fairly firm |           |           |
+                  |film shown. |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+   [9] Gained in weight throughout test.
+
+  [10] Lost in weight throughout test.
+
+  TABLE VI.--(_a_) SOYA BEAN OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1377   |   0.3972  |  0.4366   |  0.3564
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     7.5    |    9.79   |   9.87    |   8.25
+             |  2 |     8.4    |    9.69   |   9.87    |   7.58
+             |  3 |     9.5    |    8.56   |   9.35    |   7.02
+             |  4 |    12.8    |    7.60   |   8.66    |   6.74
+             |  5 |    12.9    |    7.09   |   8.13    |   6.46
+             |  6 |    12.7    |     --    |    --     |   6.74
+             |  7 |     --     |    6.00   |   6.44    |    --
+             |  8 |    12.6    |    6.22   |    --     |   6.46
+             |  9 |     --     |    6.00   |   4.88    |    --
+  Percentage | 10 |    12.5    |    5.54   |    --     |   5.40
+  Increase   | 11 |     --     |     --    |   4.26    |    --
+  in Weight, | 12 |    12.4    |    5.36   |    --     |   5.59
+  in Days.   | 13 |     --     |     --    |   4.99    |    --
+             | 14 |    12.3    |     --    |    --     |   5.80
+             | 15 |     --     |    4.73   |   4.94    |    --
+             | 16 |    12.3    |     --    |    --     |   5.67
+             | 17 |     --     |    4.23   |    --     |    --
+             | 18 |    12.3    |     --    |   4.94    |    --
+             | 19 |     --     |    3.70   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film tacky  |           |           |Sticky, end of
+                  |until 3d    |           |           |1st day;
+                  |day. Clear  |           |           |tacky, end of
+                  |and fairly  |           |           |2d day;
+                  |firm after  |           |           |slightly
+                  |4th day.    |           |           |tacky, end of
+                  |            |           |           |10th and 38th
+                  |            |           |           |days.
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) SOYA BEAN OIL       20 PER CENT.
+        RAW LINSEED OIL     80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2218   |   0.2877  |  0.4581   |  0.2249
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    11.5    |   12.78   |  13.16    |  11.74
+             |  2 |    11.8    |   12.78   |  12.64    |  12.27
+             |  3 |    12.5    |   11.74   |  11.84    |  10.38
+             |  4 |    13.9    |   12.23   |  11.50    |   9.43
+             |  5 |    14.0    |   10.60   |  11.01    |   9.66
+             |  6 |    14.0    |     --    |    --     |   9.75
+             |  7 |     --     |    9.35   |   9.15    |    --
+             |  8 |    14.1    |   10.08   |    --     |  10.29
+             |  9 |     --     |    9.76   |   7.29    |    --
+  Percentage | 10 |    14.1    |    9.59   |    --     |   9.08
+  Increase   | 11 |     --     |     --    |   6.61    |    --
+  in Weight, | 12 |    13.8    |    9.59   |    --     |   8.18
+  in Days.   | 13 |     --     |     --    |   7.43    |    --
+             | 14 |    13.6    |     --    |    --     |   8.95
+             | 15 |     --     |    9.00   |   6.96    |    --
+             | 16 |    13.6    |     --    |    --     |    --
+             | 17 |     --     |    8.09   |    --     |    --
+             | 18 |    13.6    |     --    |   6.66    |    --
+             | 19 |     --     |    8.00   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Clear, firm |           |           |Tacky at end
+                  |film ob-    |           |           |of 1st and 2d
+                  |served at   |           |           |days. Dry, end
+                  |end of 2d   |           |           |10th day.
+                  |day.        |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE VII.--(_a_) ROSIN OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2590   |    --     |    --     |  0.4822
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     1.5    |    --     |    --     |   2.24
+             |  2 |     1.5    |    --     |    --     |   2.53
+             |  3 |     1.8    |    --     |    --     |   2.32
+             |  4 |     3.0    |    --     |    --     |   1.27
+             |  5 |     5.2    |    --     |    --     |   1.06
+             |  6 |     4.9    |    --     |    --     |   0.66
+             |  7 |     --     |    --     |    --     |    --
+             |  8 |     4.8    |    --     |    --     |   0.24
+             |  9 |     --     |    --     |    --     |    --
+  Percentage | 10 |     4.8    |    --     |    --     |   0.78
+  Increase   | 11 |     --     |    --     |    --     |    --
+  in Weight, | 12 |     4.8    |    --     |    --     |   0.68
+  in Days.   | 13 |     --     |    --     |    --     |    --
+             | 14 |     4.8    |    --     |    --     |   0.41
+             | 15 |     --     |    --     |    --     |    --
+             | 16 |     4.8    |    --     |    --     |   0.39
+             | 17 |     --     |    --     |    --     |    --
+             | 18 |     4.8    |    --     |    --     |    --
+             | 19 |     --     |    --     |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Tacky       |           |Too much   |Oily on 1st
+                  |throughout  |           |on. Showed |and 2d days.
+                  |test.       |           |constantly |Tacky, end of
+                  |            |           |increasing |10 and 38
+                  |            |           |loss owing |days.
+                  |            |           |to the fact|
+                  |            |           | that it   |
+                  |            |           |did not dry|
+                  |            |           |and ran off|
+                  |            |           |glass.     |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE VII.--(_b_) ROSIN OIL          20 PER CENT.
+                  RAW LINSEED OIL    80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1636   |   0.7105  |  0.4016   |  0.3263
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     7.4    |    6.64   |   12.21   |  11.48
+             |  2 |     7.8    |    6.40   |   11.45   |  12.02
+             |  3 |     8.5    |    6.05   |   11.13   |  10.60
+             |  4 |     8.5    |    5.63   |   10.53   |  10.26
+             |  5 |     8.4    |    5.23   |   10.13   |  10.42
+             |  6 |     8.1    |     --    |     --    |  10.42
+             |  7 |     --     |    4.42   |    8.8    |    --
+             |  8 |     8.0    |    4.92   |     --    |  10.95
+             |  9 |     --     |    4.83   |    8.12   |    --
+  Percentage | 10 |     8.0    |    4.57   |     --    |   9.96
+  Increase   | 11 |     --     |     --    |    7.45   |    --
+  in Weight, | 12 |     8.0    |    4.68   |     --    |   9.53
+  in Days.   | 13 |     --     |     --    |    8.27   |    --
+             | 14 |     7.9    |     --    |     --    |   9.96
+             | 15 |     --     |    4.13   |    8.52   |    --
+             | 16 |     7.9    |     --    |     --    |    --
+             | 17 |     --     |    3.81   |     --    |    --
+             | 18 |     8.2    |     --    |    8.62   |    --
+             | 19 |     --     |    3.43   |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film dried  |           |           |Oily at end of
+                  |up nicely   |           |           |1st and 2d
+                  |during 3d   |           |           |days. Slightly
+                  |day, but re-|           |           |tacky, end of
+                  |mained      |           |           |10th day.
+                  |slightly    |           |           |
+                  |soft.       |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE VIII.--(_a_) CORN OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.0574   |   0.5858  |  0.4981   |  0.3300
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     1.9    |[11]0.22   |     1.22  |   4.63
+             |  2 |     4.2    |    7.03   |     5.86  |   7.27
+             |  3 |     4.6    |    8.79   |     7.27  |   7.14
+             |  4 |     4.8    |    7.43   |[12]11.35  |   6.99
+             |  5 |     7.5    |    7.17   |    11.35  |   6.69
+             |  6 |     7.1    |     --    |      --   |   6.93
+             |  7 |     --     |    5.85   |    11.37  |    --
+             |  8 |     7.1    |    6.02   |      --   |   6.84
+             |  9 |     --     |    5.84   |     6.26  |    --
+  Percentage | 10 |     7.1    |    5.58   |      --   |   5.11
+  Increase   | 11 |     --     |     --    |     4.97  |    --
+  in Weight, | 12 |     7.2    |    5.38   |      --   |   5.17
+  in Days.   | 13 |     --     |     --    |     5.62  |    --
+             | 14 |     7.1    |     --    |      --   |   5.38
+             | 15 |     --     |    4.78   |     5.34  |    --
+             | 16 |     7.0    |     --    |      --   |   5.17
+             | 17 |     --     |    4.15   |      --   |    --
+             | 18 |     6.9    |     --    |     5.34  |    --
+             | 19 |     --     |    3.63   |      --   |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film soft   |           |           |
+                  |and sticky  |           |           |
+                  |throughout  |           |           |
+                  |test. Very  |           |           |
+                  |soapy in    |           |           |
+                  |appearance. |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  [11] Lost in weight throughout test.
+
+  [12] Moth got in.
+
+  (_b_) CORN OIL           20 PER CENT.
+        RAW LINSEED OIL    80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |  0.1664    |   0.5469  |  0.3716   |  0.1711
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    7.5     |   13.01   |  13.81    |  11.87
+             |  2 |    8.4     |   12.41   |  12.92    |  11.69
+             |  3 |    8.6     |     --    |  12.16    |   9.78
+             |  4 |   10.2     |   11.13   |  11.71    |   8.33
+             |  5 |   10.4     |   11.52   |  11.11    |   8.50
+             |  6 |   10.6     |     --    |    --     |   8.62
+             |  7 |    --      |   11.22   |   9.23    |    --
+             |  8 |   10.5     |   10.98   |    --     |   9.61
+             |  9 |    --      |   10.38   |   8.29    |    --
+  Percentage | 10 |   10.3     |    9.64   |    --     |   8.16
+  Increase   | 11 |    --      |     --    |   7.24    |    --
+  in Weight, | 12 |   10.3     |    9.07   |    --     |   7.00
+  in Days.   | 13 |    --      |     --    |   8.42    |    --
+             | 14 |   10.3     |     --    |    --     |   8.28
+             | 15 |    --      |    8.38   |   8.26    |    --
+             | 16 |   10.2     |     --    |    --     |    --
+             | 17 |    --      |    8.77   |    --     |    --
+             | 18 |   10.0     |     --    |   7.94    |    --
+             | 19 |    --      |     --    |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film tacky  |           |           |Tacky, end of
+                  |at end of   |           |           |1st and 2d
+                  |test.       |           |           |days. Dry, end
+                  |            |           |           |10th day.
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE IX.--(_a_) COTTON SEED OIL  100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |  0.2026    |   0.7247  |  0.4135   |  0.3583
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    4.5     |    8.03   |   7.04    |   6.67
+             |  2 |    4.8     |    7.48   |   7.16    |   5.61
+             |  3 |    4.8     |    6.68   |   6.62    |   4.85
+             |  4 |    5.1     |    6.00   |   6.24    |   4.65
+             |  5 |    8.6     |    5.65   |   5.78    |   4.37
+             |  6 |    8.7     |     --    |    --     |   4.71
+             |  7 |    --      |    4.85   |   3.72    |    --
+             |  8 |    8.1     |    5.09   |    --     |   4.57
+             |  9 |    --      |    4.95   |   2.08    |    --
+  Percentage | 10 |    7.9     |    4.80   |    --     |   2.97
+  Increase   | 11 |    --      |     --    |   1.72    |    --
+  in Weight, | 12 |    8.0     |     --    |    --     |   3.11
+  in Days.   | 13 |    --      |     --    |   2.52    |    --
+             | 14 |    8.0     |     --    |    --     |   3.39
+             | 15 |    --      |     --    |   2.35    |    --
+             | 16 |    8.1     |     --    |    --     |   3.39
+             | 17 |    --      |     --    |    --     |    --
+             | 18 |    8.0     |     --    |   2.32    |    --
+             | 19 |    --      |     --    |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film showed |           |           |Slightly
+                  |very little |           |           |tacky, end
+                  |hardening   |           |           |10th and 38th
+                  |and remained|           |           |days.
+                  |soft and    |           |           |
+                  |tacky.      |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) COTTON SEED OIL    20 PER CENT.
+        RAW LINSEED OIL    80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |  0.1516    |   0.9498  |  0.6160   |  0.2553
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    8.5     |   11.00   |   10.94   |  11.83
+             |  2 |    8.7     |   11.15   |   10.81   |  11.83
+             |  3 |    9.1     |   10.58   |   10.51   |  10.15
+             |  4 |   10.8     |   10.17   |   10.37   |   9.29
+             |  5 |   11.9     |    9.82   |    9.87   |   9.29
+             |  6 |   11.8     |     --    |     --    |   9.45
+             |  7 |    --      |    9.02   |    8.93   |    --
+             |  8 |   11.9     |    9.42   |     --    |  10.00
+             |  9 |    --      |    9.35   |    8.90   |    --
+  Percentage | 10 |   11.9     |    9.27   |     --    |   8.95
+  Increase   | 11 |    --      |     --    |    8.70   |    --
+  in Weight, | 12 |   11.8     |    9.32   |     --    |   8.06
+  in Days.   | 13 |    --      |     --    |    9.29   |    --
+             | 14 |   11.8     |     --    |     --    |   8.61
+             | 15 |    --      |    8.81   |    9.63   |    --
+             | 16 |   11.8     |     --    |     --    |    --
+             | 17 |    --      |    8.24   |     --    |    --
+             | 18 |   10.7     |     --    |    8.47   |    --
+             | 19 |    --      |    7.92   |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Fair drying |           |           |Tacky on 1st
+                  |observed at |           |           |and 2d days.
+                  |end of 4th  |           |           |Dry on 10th
+                  |day. Film   |           |           |day.
+                  |slightly    |           |           |
+                  |tacky at end|           |           |
+                  |of test.    |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE X.--(_a_) SUN FLOWER OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1414   |   0.6292  |  0.5837   |  0.2540
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     6.3    |    9.69   |   7.85    |   8.39
+             |  2 |     8.2    |    9.42   |   7.73    |   6.94
+             |  3 |    11.5    |    7.99   |   7.45    |   6.21
+             |  4 |    11.6    |    7.43   |   7.02    |   6.13
+             |  5 |    11.5    |    7.04   |   6.36    |   5.81
+             |  6 |    11.5    |     --    |    --     |   6.01
+             |  7 |     --     |    6.12   |   5.16    |    --
+             |  8 |    11.3    |    6.45   |    --     |   6.09
+             |  9 |     --     |    6.12   |   4.57    |    --
+  Percentage | 10 |    11.3    |    5.92   |    --     |   4.81
+  Increase   | 11 |     --     |     --    |   4.20    |    --
+  in Weight, | 12 |    11.3    |    5.69   |    --     |   4.73
+  in Days.   | 13 |     --     |     --    |   4.54    |    --
+             | 14 |    11.3    |     --    |    --     |   4.81
+             | 15 |     --     |    5.24   |   4.61    |    --
+             | 16 |    11.2    |     --    |    --     |   5.01
+             | 17 |     --     |    4.57   |    --     |    --
+             | 18 |    11.0    |     --    |   4.30    |    --
+             | 19 |     --     |    4.26   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film fairly |           |           |Sticky, end
+                  |firm, end of|           |           |1st day;
+                  |3d day.     |           |           |tacky, end 2d
+                  |            |           |           |day; slightly
+                  |            |           |           |tacky, end
+                  |            |           |           |10th day.
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE X.--(_b_) SUN FLOWER OIL    20 PER CENT.
+                  RAW LINSEED OIL   80 PER CENT.
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1600   |   0.5030  |  0.4470   |  0.2261
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     9.5    |   14.21   |   12.62   |  11.54
+             |  2 |    11.0    |   14.21   |   12.02   |  11.85
+             |  3 |    11.1    |   12.66   |   11.48   |   9.92
+             |  4 |    11.3    |   14.01   |   11.65   |   9.13
+             |  5 |    11.4    |   11.59   |   10.25   |   8.95
+             |  6 |    10.9    |     --    |     --    |   9.04
+             |  7 |     --     |   10.24   |    8.14   |    --
+             |  8 |    10.8    |   10.63   |     --    |   9.52
+             |  9 |     --     |   10.34   |    6.26   |    --
+  Percentage | 10 |    10.8    |   10.34   |     --    |   8.55
+  Increase   | 11 |     --     |     --    |    5.54   |    --
+  in Weight, | 12 |    10.8    |   10.27   |     --    |   7.67
+  in Days.   | 13 |     --     |     --    |    6.22   |    --
+             | 14 |    10.6    |     --    |     --    |   8.20
+             | 15 |     --     |   11.33   |    5.82   |    --
+             | 16 |    10.6    |     --    |     --    |    --
+             | 17 |     --     |   10.73   |     --    |    --
+             | 18 |    10.9    |     --    |    5.35   |    --
+             | 19 |     --     |   10.30   |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Good firm,  |           |           |Dry on 1st, 2d
+                  |glossy film |           |           |and 10th days.
+                  |shown at end|           |           |
+                  |of 2d day.  |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE XI.--(_a_) MENHADEN OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1944   |   0.5282  |  0.7005   |  0.3150
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     7.7    |   12.47   |  10.79    |  11.27
+             |  2 |     8.1    |   12.17   |  10.98    |  10.16
+             |  3 |     8.9    |   11.70   |  10.85    |   9.72
+             |  4 |    10.1    |   11.47   |  10.90    |   9.97
+             |  5 |     9.8    |   11.13   |  10.57    |   9.94
+             |  6 |     9.8    |     --    |    --     |  10.27
+             |  7 |     --     |   10.28   |   9.27    |    --
+             |  8 |     9.8    |   11.20   |    --     |  10.36
+             |  9 |     --     |   11.15   |   8.48    |    --
+  Percentage | 10 |     9.8    |   11.02   |    --     |   8.80
+  Increase   | 11 |     --     |     --    |   8.27    |    --
+  in Weight, | 12 |     9.8    |   11.37   |    --     |   9.22
+  in Days.   | 13 |     --     |     --    |   8.91    |    --
+             | 14 |     9.6    |     --    |    --     |   9.40
+             | 15 |     --     |   10.85   |   8.75    |    --
+             | 16 |     9.6    |     --    |    --     |   9.31
+             | 17 |     --     |   10.34   |    --     |    --
+             | 18 |     9.6    |     --    |   9.21    |    --
+             | 19 |     --     |    9.90   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Good drying |           |           |Sticky, end
+                  |during 2d   |           |           |1st day.
+                  |day. Fairly |           |           |Slightly
+                  |firm film.  |           |           |sticky, end 2d
+                  |            |           |           |and 10th days.
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) MENHADEN OIL    20 PER CENT.
+        RAW LINSEED OIL 80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2448   |   0.4959  |  0.4201   |  0.2456
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     8.5    |   14.11   |  13.19    |  10.99
+             |  2 |    10.4    |   13.47   |  12.88    |  11.28
+             |  3 |    12.2    |   12.68   |  12.23    |   9.56
+             |  4 |    12.9    |   12.04   |  11.81    |   8.90
+             |  5 |    12.9    |   11.59   |  11.17    |   8.72
+             |  6 |    12.9    |     --    |    --     |   8.72
+             |  7 |     --     |   10.44   |   9.50    |    --
+             |  8 |    12.9    |   11.09   |    --     |   9.34
+             |  9 |     --     |   11.04   |   8.48    |    --
+  Percentage | 10 |    12.9    |   10.74   |    --     |   8.40
+  Increase   | 11 |     --     |     --    |   7.77    |    --
+  in Weight, | 12 |    12.9    |   10.90   |    --     |   7.37
+  in Days.   | 13 |     --     |     --    |   8.33    |    --
+             | 14 |    12.8    |     --    |    --     |   8.11
+             | 15 |     --     |   10.18   |   8.24    |    --
+             | 16 |    12.7    |     --    |    --     |    --
+             | 17 |     --     |    9.48   |    --     |    --
+             | 18 |    12.9    |     --    |   8.12    |    --
+             | 19 |     --     |    8.93   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Good firm,  |           |           |Nearly dry on
+                  |elastic film|           |           |1st and 2d
+                  |shown after |           |           |days.
+                  |2d day.     |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE XII.--(_a_) RAW CHINESE WOOD OIL    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2266   |   0.5545  |  0.4933   |  0.4036
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     4.1    |     --    |   0.59    |   0.54
+             |  2 |    11.2    |     --    |   2.09    |   2.80
+             |  3 |    14.9    |   11.02   |   5.13    |   5.10
+             |  4 |    14.4    |   11.53   |   7.56    |   6.00
+             |  5 |    14.4    |   11.03   |   8.68    |   6.27
+             |  6 |    14.2    |     --    |    --     |   7.09
+             |  7 |     --     |   10.53   |  10.11    |    --
+             |  8 |    14.2    |   10.74   |    --     |   8.39
+             |  9 |     --     |   10.47   |   9.65    |    --
+  Percentage | 10 |    14.2    |   10.27   |    --     |   8.01
+  Increase   | 11 |     --     |     --    |   9.43    |    --
+  in Weight, | 12 |    14.2    |   10.22   |    --     |   8.55
+  in Days.   | 13 |     --     |     --    |   9.77    |    --
+             | 14 |    14.2    |     --    |    --     |   9.13
+             | 15 |     --     |    9.80   |   9.73    |    --
+             | 16 |    14.2    |     --    |    --     |   9.27
+             | 17 |     --     |    9.25   |    --     |    --
+             | 18 |    14.5    |     --    |   9.33    |    --
+             | 19 |     --     |    8.86   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Film crys-  |           |           |Sticky, end of
+                  |tallized and|           |           |1st and 2d
+                  |remained    |           |           |days; dry but
+                  |soft until  |           |           |drawn, end of
+                  |3d day. Hard|           |           |10th day.
+                  |but opaque  |           |           |
+                  |film shown  |           |           |
+                  |after 4th   |           |           |
+                  |day.        |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  (_b_) RAW CHINESE WOOD OIL    20 PER CENT.
+        RAW LINSEED OIL         80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2087   |   0.2967  |  0.3683   |  0.2285
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     9.0    |   14.46   |  14.37    |  11.99
+             |  2 |    12.1    |   13.11   |  13.66    |  11.90
+             |  3 |    12.9    |   11.72   |  13.11    |  10.14
+             |  4 |    12.8    |   10.68   |  12.41    |   9.30
+             |  5 |    12.8    |    9.77   |  11.78    |   9.08
+             |  6 |    12.8    |     --    |    --     |   9.30
+             |  7 |     --     |    8.66   |  10.51    |    --
+             |  8 |    12.7    |    8.86   |    --     |   9.70
+             |  9 |     --     |    8.80   |   8.72    |    --
+  Percentage | 10 |    12.6    |    8.49   |    --     |   8.90
+  Increase   | 11 |     --     |     --    |   7.0     |    --
+  in Weight, | 12 |    12.6    |    8.15   |    --     |   7.34
+  in Days.   | 13 |     --     |     --    |   8.82    |    --
+             | 14 |    12.5    |     --    |    --     |   7.78
+             | 15 |     --     |    8.05   |   8.39    |    --
+             | 16 |    12.5    |     --    |    --     |    --
+             | 17 |     --     |    7.41   |    --     |    --
+             | 18 |    12.7    |     --    |   7.98    |    --
+             | 19 |     --     |    7.04   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Clear and   |           |           |Dry at end of
+                  |firm film   |           |           |1st day.
+                  |shown after |           |           |
+                  |3d day.     |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE XIII.--(_a_) CHINESE WOOD OIL (TREATED)    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1678   |   0.4159  |  0.2934   |  0.3937
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |[13]38.0    |[13]19.06  |[13]0.92   |   3.53
+             |  2 |[13]30.0    |[13]20.16  |[13]0.41   |   3.58
+             |  3 |[13]28.0    |[13]20.47  |    0.72   |   3.25
+             |  4 |[13]28.0    |[13]20.47  |    0.79   |   3.25
+             |  5 |[13]28.0    |[13]20.80  |    0.13   |   3.33
+             |  6 |[13]28.0    |     --    |     --    |   2.93
+             |  7 |     --     |[13]21.09  |    0.22   |    --
+             |  8 |[13]28.0    |[13]20.87  |     --    |   2.55
+             |  9 |     --     |[13]20.98  |    0.46   |    --
+  Percentage | 10 |    27.5    |[13]20.78  |     --    |   3.40
+  Increase   | 11 |     --     |     --    |    0.44   |    --
+  in Weight, | 12 |[13]26.0    |[13]20.70  |     --    |   3.23
+  in Days.   | 13 |     --     |     --    |    0.43   |    --
+             | 14 |[13]26.0    |     --    |     --    |   2.61
+             | 15 |     --     |[13]20.97  |    0.42   |    --
+             | 16 |[13]26.0    |     --    |     --    |   2.48
+             | 17 |     --     |[13]21.22  |     --    |    --
+             | 18 |[13]26.2    |     --    |    0.43   |    --
+             | 19 |     --     |[13]21.11  |     --    |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Loss ob-    |           |           |Dry at end of
+                  |served due  |           |           |1st day.
+                  |to presence |           |           |
+                  |of vola-    |           |           |
+                  |tiles. Firm,|           |           |
+                  |clear film  |           |           |
+                  |shown at end|           |           |
+                  |of 1st day. |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  [13] Lost in weight throughout test.
+
+  TABLE XIII.--(_b_) CHINESE WOOD OIL (TREATED)    20 PER CENT.
+                     RAW LINSEED OIL               80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1638   |   0.6572  |  0.4892   |  0.2644
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |     8.4    |    9.25   |   8.93    |   3.21
+             |  2 |     9.4    |    8.07   |   8.71    |   3.48
+             |  3 |     9.8    |    7.36   |   8.44    |   2.15
+             |  4 |     9.7    |    6.75   |   8.16    |   1.58
+             |  5 |     9.9    |    6.25   |   7.95    |   1.56
+             |  6 |     9.9    |     --    |    --     |   1.77
+             |  7 |      --    |    5.49   |   6.75    |    --
+             |  8 |    10.0    |    5.87   |    --     |   2.30
+             |  9 |      --    |    5.70   |   5.99    |    --
+  Percentage | 10 |     9.6    |    5.67   |    --     |   1.62
+  Increase   | 11 |      --    |     --    |   5.50    |    --
+  in Weight, | 12 |     9.5    |    4.37   |    --     |   0.86
+  in Days.   | 13 |      --    |     --    |   6.40    |    --
+             | 14 |     9.5    |     --    |    --     |   1.50
+             | 15 |      --    |    5.15   |   6.01    |    --
+             | 16 |     9.5    |     --    |    --     |    --
+             | 17 |      --    |    4.69   |    --     |    --
+             | 18 |     9.6    |     --    |   5.87    |    --
+             | 19 |      --    |    4.17   |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Clear and   |           |           |Dry at end of
+                  |hard film   |           |           |1st day.
+                  |shown during|           |           |
+                  |2d day.     |           |           |
+  ----------------+------------+-----------+-----------+---------------
+
+  TABLE XIV.--(_a_) 20 PER CENT. DRY ROSIN IN 80 PER CENT. LINSEED OIL
+                    100 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.2030   |     --    |  0.5185   |  0.2554
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    12.0    |     --    |   3.76    |   1.80
+             |  2 |    14.1    |     --    |   8.76    |  11.78
+             |  3 |    14.8    |     --    |   9.20    |  12.17
+             |  4 |    14.2    |     --    |   9.20    |  12.29
+             |  5 |    14.5    |     --    |   8.49    |  12.02
+             |  6 |    14.0    |     --    |    --     |  12.49
+             |  7 |     --     |     --    |   9.07    |    --
+             |  8 |    14.1    |     --    |    --     |  13.15
+             |  9 |     --     |     --    |   9.01    |    --
+  Percentage | 10 |    14.1    |     --    |    --     |  11.85
+  Increase   | 11 |     --     |     --    |   9.09    |    --
+  in Weight, | 12 |    14.0    |     --    |    --     |  11.78
+  in Days.   | 13 |     --     |     --    |  10.50    |    --
+             | 14 |    14.0    |     --    |    --     |  12.69
+             | 15 |     --     |     --    |  10.16    |    --
+             | 16 |    14.0    |     --    |    --     |  12.83
+             | 17 |     --     |     --    |    --     |    --
+             | 18 |    14.1    |     --    |  10.18    |    --
+             | 19 |     --     |     --    |    --     |    --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Rapid drying|           |           |Oily, end 1st
+                  |observed.   |           |           |and 2d days;
+                  |Hard film   |           |           |slightly
+                  |shown during|           |           |tacky, end
+                  |2d day.     |           |           |10th day.
+  ----------------+------------+-----------+-----------+---------------
+
+  (_b_) 20 PER CENT. DRY ROSIN IN 80 PER CENT. LINSEED OIL  20 PER CENT.
+        RAW LINSEED OIL                                     80 PER CENT.
+
+  ----------------+------------+-----------+-----------+--------------
+   Observer.      |  Gardner   |   Sabin   |  Pickard  | { Rogers }
+                  |            |           |           | { North  }
+  ----------------+------------+-----------+-----------+--------------
+  Wt. of Oil for  |   0.1500   |   0.7105  |  0.4568   |     --
+  Test, grams     |            |           |           |
+  -----------+----+------------+-----------+-----------+--------------
+             |  1 |    10.9    |   14.19   |  12.86    |     --
+             |  2 |    13.5    |   13.17   |  12.73    |     --
+             |  3 |    13.6    |   11.84   |  12.13    |     --
+             |  4 |    13.0    |   11.46   |  12.02    |     --
+             |  5 |    13.0    |   10.87   |  11.30    |     --
+             |  6 |    13.0    |     --    |    --     |     --
+             |  7 |     --     |    9.80   |  10.95    |     --
+             |  8 |    13.1    |   10.33   |    --     |     --
+             |  9 |     --     |   10.40   |  11.21    |     --
+  Percentage | 10 |    13.1    |   10.04   |    --     |     --
+  Increase   | 11 |     --     |     --    |  10.53    |     --
+  in Weight, | 12 |    13.0    |   10.35   |    --     |     --
+  in Days.   | 13 |     --     |     --    |  11.21    |     --
+             | 14 |    12.9    |     --    |    --     |     --
+             | 15 |     --     |    9.64   |  10.88    |     --
+             | 16 |    13.0    |     --    |    --     |     --
+             | 17 |     --     |    8.98   |    --     |     --
+             | 18 |    13.2    |     --    |  11.43    |     --
+             | 19 |     --     |    8.62   |    --     |     --
+  -----------+----+------------+-----------+-----------+--------------
+  Remarks.        |Clear, hard |           |           |
+                  |film after  |           |           |
+                  |2d day.     |           |           |
+  ----------------+------------+-----------+-----------+--------------
+
+  TABLE XV.--(_a_) RAW LINSEED OIL    100 PER CENT.[14]
+
+  ----------------+-----------+-----------
+   Observer.      |   Sabin   |  Pickard
+                  |           |
+  ----------------+-----------+-----------
+  Wt. of Oil for  |   0.5274  |  0.5326
+  Test, grams     |           |
+  -----------+----+-----------+-----------
+             |  1 |    0.26   |  12.42
+             |  2 |    0.51   |  12.39
+             |  3 |    0.11   |  11.88
+             |  4 |    2.35   |  11.83
+             |  5 |    9.14   |  11.08
+             |  6 |     --    |    --
+             |  7 |   14.48   |  10.29
+             |  8 |   14.48   |    --
+             |  9 |   14.18   |   9.56
+  Percentage | 10 |   13.86   |    --
+  Increase   | 11 |     --    |   9.85
+  in Weight, | 12 |   13.00   |    --
+  in Days.   | 13 |     --    |  10.30
+             | 14 |     --    |    --
+             | 15 |   12.23   |  10.12
+             | 16 |     --    |    --
+             | 17 |   11.66   |    --
+             | 18 |     --    |  10.78
+             | 19 |   11.07   |    --
+  -----------+----+-----------+-----------
+  Remarks.        |           |
+  ----------------+-----------+-----------
+
+  [14] The test of this oil was made without the addition of 5 per cent.
+       of drier, the quantity used in all the other tests.
+
+  (_b_) DRIER    100 PER CENT.
+
+  ----------------+--------------
+   Observer.      | { Rogers }
+                  | { North  }
+  ----------------+--------------
+  Wt. of Oil for  |  0.3445
+  Test, grams     |
+  -----------+----+--------------
+             |  1 |  48.95
+             |  2 |  48.53
+             |  3 |  48.68
+             |  4 |  48.68
+             |  5 |  48.48
+             |  6 |  48.26
+             |  7 |    --
+             |  8 |  48.43
+             |  9 |    --
+  Percentage | 10 |  48.89
+  Increase   | 11 |    --
+  in Weight, | 12 |  48.22
+  in Days.   | 13 |    --
+             | 14 |  48.22
+             | 15 |    --
+             | 16 |    --
+             | 17 |    --
+             | 18 |    --
+             | 19 |    --
+  -----------+----+--------------
+  Remarks.        | Dry at end of
+                  | 1st day.
+  ----------------+--------------
+
+
+
+
+CHAPTER III
+
+PAINT PIGMENTS AND THEIR PROPERTIES
+
+
+For the student of paint technology, who is not already acquainted with
+the chemistry and physics of the various raw pigments which are largely
+used in the manufacture of paints, the writer advises a careful reading
+of this chapter, in which the matter has been condensed as much as
+possible. In order to more thoroughly acquaint the reader with the
+physical constitution of the pigments under consideration, there has
+been included photomicrographs, which show to advantage the structure of
+each.[15]
+
+  [15] The author gratefully acknowledges the assistance of Dr. J. A.
+       Schaeffer in the preparation of the photomicrographs shown in
+       this chapter.
+
+[Illustration: By Polarized Light
+
+By Transmitted Light
+
+Basic Carbonate-White Lead]
+
+=Basic Carbonate-White Lead.= This pigment is made by stacking clay pots
+containing dilute acetic acid and lead buckles, in tiers, and covering
+them with tan bark. Fermentation of the tan bark, with subsequent
+formation of carbon dioxide acting on the acetate of lead formed within
+the pots, produces basic carbonate of lead. After complete corrosion,
+the white lead is ground, floated, and dried. Corroded white lead has a
+specific gravity of 6.8 and contains about 85% lead oxide and 15% of
+carbon dioxide and water. Its opaque nature and excellent body renders
+it extremely valuable as a constituent of paints. Checking and chalking
+progress rapidly when the pigment is used alone. The various sized
+particles, both large and small, resulting from the corrosion process,
+are prominently shown in the photomicrograph.
+
+[Illustration: Crystals of Cerussite in Old Dutch Process White Lead.
+(Greatly magnified)]
+
+[Illustration: White Lead (Quick Process)]
+
+On account of its alkaline nature, this pigment acts upon the
+saponifiable oil in which it is ground, forming lead soaps which
+accelerate chalking of white lead--the greatest evil attending its use.
+Solubility in carbonic acid of the atmosphere and decay in the presence
+of sodium chloride may be active causes of the rapid chalking of this
+pigment at the seashore. Checking in some climates appears to proceed
+rapidly on white lead paints, in a deep hexagonal form, leaving a series
+of rough crests and cracks. This checking is secondary to the chalking
+which takes place.
+
+[Illustration: Corrosion cylinders used for making Quick Process White
+Lead]
+
+[Illustration: Lead Melting Pots]
+
+=White Lead (Quick Process).= By acting on atomized metallic lead,
+contained within large revolving wooden cylinders, with dilute acetic
+acid and carbon dioxide, the quick-process white lead is produced. Its
+value is equal to the Dutch-process white lead, and it is considered by
+some as possessing greater spreading value.
+
+[Illustration: Sheet iron box luted at bottom with water. Atomized lead,
+blown into box with steam, falls to bottom and becomes hydrated (Mild
+Process)]
+
+[Illustration: _Photographs courtesy of Stowe Neal_
+
+View of agitation tanks for making Mild Process Lead]
+
+[Illustration: Steam Jected Pans for Drying White Lead]
+
+=White Lead (Mild Process).= The Mild Process of manufacturing white
+lead consists of first melting the pig lead and converting it into the
+finest kind of lead powder, then mixing thoroughly with air and water.
+The lead takes up water and oxygen and forms a basic hydroxide of lead.
+Carbon dioxide gas is next pumped slowly through the cylinders which
+contain the basic hydroxide of lead. The result is basic carbonate of
+lead--the dry white lead of commerce. The process is called "Mild"
+because it is the mildest process possible for the manufacture of white
+lead. It is the only method in practical operation which does not
+require the use of acids, alkalis or other chemicals, every trace of
+which should be removed from the finished product by expensive purifying
+processes. The failure of such washing and purifying means a product of
+inferior quality, which necessarily reduces the durability of any paint
+in which it is used.
+
+=Basic Sulphate-White Lead (Sublimed White Lead).= By the action of the
+oxygen of the air on the fume produced by the roasting and subsequent
+volatilization of galena, this fine, white, amorphous pigment is made.
+On analysis, its composition shows approximately 75% of lead sulphate,
+20% of lead oxide, and 5% of zinc oxide. It has a specific gravity of
+6.2. Possessed of extreme stability, it finds wide use as a constituent
+of paints and as a base for tinting colors. The photomicrograph of this
+pigment shows its extremely fine, amorphous nature with complete absence
+of crystals. In fineness it closely approaches zinc oxide. On account of
+its non-poisonous properties it is replacing corroded lead in many
+places. Unified paints containing sublimed white lead are of great
+value, showing upon long exposure very little decay.
+
+[Illustration: View of Furnace for Making Sublimed White Lead]
+
+[Illustration: View of Goosenecks Used for Collecting Sublimed White
+Lead Fume]
+
+[Illustration: Bag Room Where Sublimed White Lead is Deposited
+
+_Photographs courtesy of Picher Lead Co._]
+
+[Illustration: Sublimed White Lead]
+
+[Illustration: View of largest Zinc Oxide Works in America, at Hazards,
+Pa.]
+
+
+=Sublimed Blue Lead.= Sublimed blue lead is made by burning coarsely
+broken lumps of galena, admixed with bituminous coal, in a special form
+of furnace. The fumes which are volatilized from this mixture are very
+complex in their chemical make-up, and in color are white, blue, and
+black. After being drawn through the cooling pipes by the suction of
+huge fans, whereby the fumes are cooled, the pigment is deposited in
+bags. This pigment is bluish black in color, and has been highly
+recommended for use on iron and steel. Its composition runs
+approximately as follows:
+
+  Lead sulphate      50%
+  Lead oxide         35%
+  Lead sulphide       5%
+  Lead sulphite       5%
+  Zinc oxide          2%
+  Carbon              3%
+
+[Illustration: View of Zinc Oxide Furnaces]
+
+[Illustration: _Photographs courtesy Geo. B. Heckel and N. J. Zinc Co._
+
+View of Zinc Oxide Fume Pipes with electrically driven Suction Fans]
+
+The color of the pigment is largely due to the carbon and the lead
+sulphide. Its specific gravity is 6.4, and it grinds in 10% of oil to a
+stiff paste, 100 lbs. of which may be thinned with about 26 lbs. of oil
+to working consistency. Paint manufacturers use it in mixture with iron
+oxide and other pigments for the production of paints for metal
+surfaces. Wood and others have found it of great value for this purpose.
+It has a tendency to chalk, but this may be overcome by admixture with
+other pigments such as zinc oxide and iron oxide. Lane has found it to
+be very durable when admixed with lampblack.
+
+[Illustration: View of Bag Room receiving Zinc Oxide]
+
+=Zinc Oxide.= This extremely white and fine pigment is prepared by the
+roasting and sublimation of franklinite, zincite, and other zinc-bearing
+ores largely found in New Jersey. Its purity approaches in most
+instances 99.5 or more. It has a specific gravity of 5.2. On account of
+its stability, whiteness, and opacity, it is invaluable as a pigment
+when a constituent in a combination formula. Its extreme hardness
+renders it less resistant to temperature changes, when used alone. Under
+the microscope the fineness and structure of the particles are clearly
+evident. The French-process zinc oxide produced in America by the
+sublimation and oxidation of spelter is the purest made, and superior to
+imported grades which often contain ultramarine blue as a whitening
+agent.
+
+[Illustration: Zinc Oxide]
+
+[Illustration: Zinc Lead White]
+
+[Illustration: Zinc Lead. By transmitted light
+
+(_The Pigment shows black_)]
+
+[Illustration: Lithopone]
+
+[Illustration: Magnesium Silicate (Asbestine)]
+
+=Zinc Lead White.= This extremely fine pigment, consisting of about
+equal parts of zinc oxide and lead sulphate, results from the reduction,
+volatilization and subsequent oxidation of sulphur-bearing lead and zinc
+ores. It has a specific gravity of 4.4. Its slightly yellowish tint bars
+it from being used alone very extensively, but when mixed with white
+lead, zinc oxide and inert pigments, or used as a base for colored
+paints, it is of considerable value. The magnification of the particles
+shows the peculiar way in which the pigment agglomerates, and the
+characteristics of a fine, uniform pigment.
+
+[Illustration: Asbestine Mine at Easton, Pa.]
+
+[Illustration: American Barytes. Transmitted light
+
+(_The Pigment shows black_)]
+
+[Illustration: German Barytes. Mag. 250 Diam.
+
+(_The Pigment shows white_)]
+
+=Lithopone.= Lithopone, probably the whitest of pigments, results from
+the double decomposition of zinc sulphate and barium sulphide, thereby
+forming a molecular combination of zinc sulphide and barium sulphate.
+The peculiar property which it possesses, of darkening under the actinic
+rays of the sun, makes it essential that it be combined with other, more
+stable pigments to prolong its life when exposed to weather. Lithopone
+contains approximately 70% barium sulphate, 25 to 28% zinc sulphide, and
+as high as 5% of zinc oxide. Its specific gravity is about 4.25. It is
+excellently suited for interior use in the manufacture of enamels and
+wall finishes. When properly mixed with other pigments, such as zinc
+oxide and calcium carbonate, fair results are obtained as a pigment for
+outside work. Lead pigments are never used with lithopone, as lead
+sulphide results, giving a black appearance. Its characteristic
+flocculent, non-crystalline nature is plainly evident when examined
+under the microscope.
+
+[Illustration: By Polarized Light
+
+By Transmitted Light
+
+Barium Sulphate (Barytes)]
+
+=Magnesium Silicate (Asbestine and Talcose).= This pigment comes in two
+forms: as asbestine and as talcose (talc, etc.). The former is very
+fibrous in nature and is a very stable pigment to use in the manufacture
+of paint, on account of its inert nature and tendency to hold up heavier
+pigments, and prevent settling. It also has the property of
+strengthening a paint coat in which it is used. The talcose variety is
+very tabular in form. Both varieties are transparent in oil, and very
+inert. They have a gravity of about 2.7 and grind in about 32% of oil.
+
+[Illustration: Barium Carbonate. Mag. 250 Diam.
+
+(_The Pigment shows white_)]
+
+[Illustration: Barium Sulphate (Blanc Fixe)]
+
+[Illustration: Calcium Carbonate (Whiting)]
+
+[Illustration: Calcium Carbonate. By transmitted light
+
+(_The Pigment shows black_)]
+
+[Illustration: Calcium Sulphate. By transmitted light
+
+(_The Pigment shows black_)]
+
+[Illustration: Calcium Sulfate]
+
+[Illustration: Calcium Sulphate (Gypsum)]
+
+[Illustration: Silica (Silex)]
+
+[Illustration: Silex. Mag. 250 Diam.
+
+(_The Pigment shows white_)]
+
+[Illustration: China Clay. By transmitted light
+
+(_The Pigment shows black_)]
+
+=Barium Sulphate (Barytes).= By grinding the crude ore, treating with
+acid to remove the iron, and finally washing, floating, and drying,
+there is produced the commercial form of this valuable pigment. It is
+used in large quantity as a base upon which to precipitate colors, and
+also together with other white pigments in the manufacture of
+ready-mixed paints. It renders the paint coating more resistant to
+abrasion, and gives to the paint certain very important brushing
+qualities. It is a very stable pigment, not being materially affected by
+either acid or alkali, and can be used with the most delicate colors. In
+oil it is transparent and must be mixed with opaque pigments when used
+in ready-mixed paints. It is generally used with lighter pigments, such
+as asbestine, in order to prevent settling. Under the microscope, both
+by polarized and transmitted light, the sharp angles of the particles
+appear distinctly, with no tendency to mass into a compact form.
+Although transparent in oil, it is valuable in moderate percentage in a
+ready-mixed paint.
+
+=Barium Sulphate (Blanc Fixe).= Blanc fixe is the precipitated form of
+barium sulphate, resulting from the action of soluble barium salts on
+soluble sulphates. The specific gravity (4.2) of this compound is lower
+than that of barytes. Possessing greater opacity in oil, it is of more
+value as a paint pigment for some purposes. It comes in for its greatest
+use as a base on which to precipitate lake colors. The very fine
+particles show a slight tendency to agglomerate.
+
+=Calcium Carbonate (Whiting).= The natural form of calcium carbonate,
+prepared from chalk, has a much higher specific gravity (2.74) than that
+of the artificial form (2.5) prepared by the precipitation of calcium
+carbonate. The latter, however, possesses greater hiding properties.
+Both grades find a wide use in distemper work and in the manufacture of
+putty. It is often used in small percentage in many ready-mixed paints.
+The photomicrograph of the pigment shows the presence of many large
+particles.
+
+=Calcium Sulphate (Gypsum).= The mineral gypsum, consisting of calcium
+sulphate and about 21% of water of combination, is sometimes used as a
+paint pigment after grinding and dehydration. Being slightly soluble in
+water it has a tendency to pass into solution when exposed to
+atmospheric agencies. It lacks hiding power in oil. Its specific gravity
+is 2.3. As in the case of all pigments prepared directly from mineral
+substances, the many-sized and shaped particles appear clearly when
+enlarged. Partially and wholly dehydrated forms of gypsum are also used
+in paint.
+
+=Silica (Silex.)= This white pigment possesses great tooth and spreading
+properties. It is of use as a wood filler and as a constituent in
+combination paints. It wears especially well when used in combination
+with zinc oxide and white lead. Its purity often approaches 97%. The
+particles when enlarged are seen to have sharp angles and are not
+uniform in size, which accounts for its marked tooth and properties.
+
+[Illustration: Aluminum Silicate (China Clay)]
+
+[Illustration: Ochre]
+
+[Illustration: Raw
+
+Burnt
+
+Sienna]
+
+[Illustration: Raw
+
+Burnt
+
+Umber]
+
+=Aluminum Silicate (China Clay).= China clay, or aluminum silicate, is a
+permanent and valuable white pigment showing very little hiding power in
+oil. It is found widely distributed in granitic formations. It is very
+stable, with a gravity of 2.6. Particles are found in many shapes and
+sizes, showing sharp and definite angles.
+
+=Ochre.= Ochre is a hydrated ferric oxide permeating a clay base,
+largely used as a tinting material. It has a specific gravity of about
+3.5, and a decidedly golden yellow color. A good quality should contain
+20% or over of iron oxide. The particles of this pigment are flocculent
+and very uniform in appearance.
+
+=Sienna.= Sienna, like umber, is essentially a silicate of iron and
+alumina, containing manganic oxide. It contains, however, a lower
+percentage of the latter than in the case of umbers. The photomicrograph
+of the burnt variety shows clearly the fine condition of the pigment,
+while large particles are shown in the raw variety.
+
+=Umber.= Umber, another naturally occurring pigment, consists of iron
+and aluminum silicates, containing varying proportions of manganic
+oxide, its color and tone varying according to the percentage of the
+latter. The raw variety is drab in color, which in burning changes to
+reddish brown. A marked percentage of large-sized particles exist in
+this pigment.
+
+=Indian Red.= Indian red is the term applied to natural hematite ore
+pigments and to those produced by the roasting of copperas (iron
+sulphate). They generally contain 95% or more of iron oxide, with
+varying percentages of silica. The pigment is heavier (specific gravity
+5.2) than that of Metallic Brown. The crystalline, mineral-like
+structure of the particles differ greatly from the amorphous particles
+of Metallic Brown.
+
+=Metallic Brown.= The natural hydrated iron oxide or carbonate as mined
+largely in Pennsylvania, yields, when roasted, a sesquioxide of iron
+known as Metallic Brown. It contains a high percentage of alumina and
+silica, and has a characteristic brown color with a gravity of 3.1. It
+finds wide application as a pigment for protective purposes. The
+particles when enlarged show the usual appearance of a natural compound
+which has been roasted and ground.
+
+  ==========+=====+===========+==========+=============+=======+=========
+  No. Name  |Iron |   Calc.   | Alumina  |  Insoluble  | Color |
+            |Oxide|  Sulph.   |          |             |(Silica|
+            +-----+-----------+(CaSO_{4})|(Al_{2}O_{3})|  and  |
+            | FeO |Fe_{2}O_{3}|          |             | Sili- |
+            |     |           |          |             | cates)|
+  ----------+-----+-----------+----------+-------------+-------+---------
+            |   % |      %    |     %    |      %      |    %  |
+   0 Bright | 0.71|    96.52  |    --    |     --      |   .30 |Bright
+     Red    |     |           |          |             |       |Scarlet
+   1 Bright |  .71|    95.92  |    --    |     --      |   .30 |Scarlet
+     Red    |     |           |          |             |       |Tone
+   2 Indian |  .57|    96.00  |    .78   |    1.40     |   .90 |Indian
+     Red    |     |           |          |             |       |Red,
+            |     |           |          |             |       |Medium
+            |     |           |          |             |       |Shade
+   3 Indian | 0.29|    97.82  |    .85   |     --      |   .52 |Indian
+     Red    |     |           |          |             |       |Red,
+            |     |           |          |             |       |Dark
+            |     |           |          |             |       |Shade
+   4 Indian | 0.28|    95.72  |   1.21   |    1.26     |   .58 |Indian
+     Red    |     |           |          |             |       |Red,
+            |     |           |          |             |       |Light
+            |     |           |          |             |       |Shade
+   5 Persian| 4.53|    62.25  |   1.75   |     --      | 27.64 |Rich,
+     Gulf   |     |           |          |             |       |Medium
+     Mix    |     |           |          |             |       |Red
+   7 Native | 0.85|    89.00  |    --    |    0.91     |  6.09 |Medium
+     Red    |     |           |          |             |       |Red,
+     Oxide  |     |           |          |             |       |Brownish
+            |     |           |          |             |       |Tone
+   8 Special| 0.57|    43.87  |  50.88   |    2.03     |  1.30 |Scarlet
+     Red    |     |           |          |             |       |Tone
+  10 Red    | 1.44|    60.25  |    .78   |    5.41     | 15.78 |Brownish-
+     Oxide  |     |           |          |             |       |Red
+  11 Vene-  |  .30|    34.08  |  52.60   |    2.20     |  3.39 |Bright
+     tian   |     |           |          |             |       |Red-
+     Red    |     |           |          |             |       |Brown
+  12 B.     | 0.58|    67.68  |    --    |    2.48     |  1.97 |Dark Red
+     Oxide  |     |           |          |             |       |Brown
+  13 Vene-  | 0.29|    25.92  |  58.62   |    2.16     |  1.42 |Medium
+     tian   |     |           |          |             |       |Red
+     Red    |     |           |          |             |       |Tone
+  14 Vene-  | 0.57|    35.36  |    .99   |   12.06     | 47.97 |Brown
+     tian   |     |           |          |             |       |
+     Red    |     |           |          |             |       |
+  15 Metal- | 2.59|    64.00  |    .63   |    5.82     | 23.42 |Rich
+     lic    |     |           |          |             |       |Brown
+     Brown  |     |           |          |             |       |
+  16 Crimson| 0.57|    66.24  |   1.77   |    3.60     | 25.63 |Rich
+     Oxide  |     |           |          |             |       |Dark
+            |     |           |          |             |       |Red
+  17 Red    | 2.30|    80.39  |    .37   |     .03     |  9.63 |Medium
+     Oxide  |     |           |          |             |       |Brown
+  18 Red    | 0.57|    61.28  |    .97   |    2.68     | 15.94 |Light
+     Oxide  |     |           |          |             |       |Choco-
+            |     |           |          |             |       |late
+            |     |           |          |             |       |Brown
+  20 Red    | 7.78|    46.72  |   1.70   |    7.64     | 20.38 |Dark
+     Oxide  |     |           |          |             |       |Reddish
+            |     |           |          |             |       |Brown
+  23 Special| 0.58|    72.48  |    --    |    8.80     |  4.48 |Deep
+     French |     |           |          |             |       |Choco-
+     Oxide  |     |           |          |             |       |late
+            |     |           |          |             |       |Brown
+  24 Mica-  | 2.02|    86.27  |    --    |    2.04     |  9.50 |Dark
+     ceous  |     |           |          |             |       |Gray
+     Black  |     |           |          |             |       |Tone
+     Oxide  |     |           |          |             |       |
+  25 Black  |33.12|    57.12  |    --    |    1.44     |   --  |Jet
+     Oxide  |     |           |          |             |       |Black
+  26 Red    | 0.57|    84.16  |   5.00   |    2.00     |   .63 |Deep
+     Oxide  |     |           |          |             |       |Red
+  27 Special| 0.57|    38.40  |  55.62   |    2.12     |  1.53 |Medium
+     Red    |     |           |          |             |       |Red
+  28 Oxide C|  -- |    30.40  |    .94   |   13.60     | 42.30 |Brown
+  ==========+=====+===========+==========+=============+=======+=========
+
+=Analysis of Iron Oxide Pigments.= Because of the great consideration
+now being given to iron oxide paints, the writer secured a series of
+oxides widely used in this country, and has determined the most
+important constituents of each.
+
+=Basic Lead Chromate (American Vermilion).= By boiling white lead with
+chromate of soda and subsequently treating with small quantities of
+sulphuric acid, American vermilion, or basic lead chromate, is prepared.
+It contains 98% of lead compounds, frequently free chromates, and has a
+gravity of 6.8. The particles appear granular and large, frequently
+assuming a square structure.
+
+=Red Lead.= By the continued oxidation of litharge in reverberatory
+furnaces, red lead is produced as a brilliant red pigment with a
+specific gravity of 8.7. The pigment particles appear to be of many
+sizes, showing a slight tendency to form a compact mass.
+
+=Paranitraniline Red.= Paranitraniline red, a very bright red material
+largely used in tinting paints, is prepared by diazotizing
+paranitraniline in hydrochloric acid by means of sodium nitrite in the
+cold. This compound is rendered insoluble when precipitated directly on
+barytes, by acting on it with an alkaline solution of beta naphthol. It
+is the most stable and permanent bright red organic pigment which the
+paint manufacturer uses. The particles of this pigment appear in various
+sizes, due, no doubt, to a massing of the particles in the precipitation
+process.
+
+=Chrome Yellow.= The neutral chromate of lead, made from either the
+nitrate or acetate of lead and chromate of soda, finds wide use as a
+tinting pigment. When precipitated on a white pigment base, various
+trade names are given to it. The microscope shows clearly the physical
+character of this pigment.
+
+=Zinc Chromate.= This pigment is made either from zinc salts and
+bichromate of potash or zinc oxide heated with chrome salts, frequently
+in the presence of acid. Like the rest of the chromate pigments, it is a
+very slow-drying material, often requiring over a week to set up, unless
+considerable drier is added. In spite of the impurities which it
+carries, it has shown itself to be one of the most inhibitive pigments
+known and has demonstrated its value in even small percentages in paints
+for iron and steel. It dries to a hard adherent film that tends to
+protect metal from corrosion.
+
+[Illustration: Indian Red]
+
+[Illustration: Metallic Brown]
+
+[Illustration: Basic Lead Chromate (American Vermilion)]
+
+[Illustration: Red Lead]
+
+[Illustration: Paranitraniline]
+
+[Illustration: Chrome Yellow]
+
+=Prussian Blue.= On oxidizing the precipitate resulting from the
+interaction of solutions of prussiate of potash and copperas (iron
+sulphate), Prussian blue as used in the paint trade is prepared. It has
+a specific gravity of 1.9. The pigment shows an amorphous structure, the
+particles varying greatly in size.
+
+=Ultramarine Blue.= This bright blue pigment is prepared by burning
+silica, china clay, soda ash and sulphur in pots or furnaces. It has a
+specific gravity of 2.4. It is of little value as a paint pigment on
+account of its sulphur content, which causes darkening when mixed with
+lead pigments, and corrosion when applied to iron or steel. The darkness
+of the photograph is due to the massing of the pigment particles.
+
+=Chrome Green.= Chrome green is prepared as a paint pigment from nitrate
+of lead, Chinese blue, and bichromate of soda. It has a gravity of 4 and
+is liable to contain slight traces of lead salts. The particles when
+magnified appear very fine and flocculent. This color is often
+precipitated on pigments, such as barytes, which do not reduce its tone.
+
+=Bone Black.= By grinding the carbonaceous matter resulting from the
+charring of bones, in iron retorts, the pigment bone black is prepared.
+It contains about 15% of carbon and 85% of calcium phosphate. It has a
+gravity of 2.7. Comparatively large particles of charred bone can be
+seen scattered throughout the mass, resulting from the difficulty of
+grinding to a uniform size.
+
+=Carbon Black.= This form of very pure carbon results from the
+combustion of gas. Its gravity, 1.09, is lower than that of lampblack,
+which shows a gravity of 1.8. It is used in much the same way and for
+the same purposes as lampblack. In physical appearance it shows great
+similarity to the particles of lampblack.
+
+=Lampblack.= This pigment, made from the combustion of oils, consists
+very often of more than 99% carbon. It has wonderful tinting value. The
+particles show a fine, fibrous structure with a tendency toward
+agglomeration. They differ greatly in physical appearance from those of
+either graphite or bone black, being exceedingly more uniform than the
+latter.
+
+[Illustration: Zinc Chromate]
+
+[Illustration: Prussian Blue]
+
+[Illustration: Ultramarine Blue]
+
+[Illustration: Chrome Green]
+
+[Illustration: Bone Black]
+
+[Illustration: Carbon Black]
+
+=Graphite.= Graphite, both in the natural and artificial form, contains
+impurities such as silica, iron oxide and alumina, but the natural form
+has a much greater percentage of these foreign materials, in some cases
+as high as 40%. Graphite is usually mixed with other pigments, such as
+red lead and sublimed blue lead, thus serving better as a paint coating.
+The difference in physical appearance of the various carbon pigments is
+interesting, as each pigment has characteristics of its own. In graphite
+we find a great tendency toward agglomeration or massing of particles.
+
+=Mineral Black.= Mineral black is a pigment made by grinding a black
+form of slate. It contains a comparatively low percentage of carbon and
+consequently has low tinting value. It finds use as an inert pigment in
+compounded paints, especially for machine fillers. The pigment has a
+flocculent appearance, the particles showing a strong tendency to mass.
+
+Photomicrographs of two combination paint pigments are here given, to
+show the various pigments as they appear under the microscope, when in
+combination.
+
+PERCENTAGES OF OIL REQUIRED FOR GRINDING VARIOUS DRY PIGMENTS INTO
+AVERAGE PASTE FORM
+
+  White lead (corroded)                           9%
+  White lead (sublimed)                          10%
+  Zinc lead (American)                           12%
+  French process zinc oxide                      17%
+  American process zinc oxide                    16%
+  Blanc fixe                                     30%
+  Barytes (natural)                               9%
+  Paris white (whiting)                          20%
+  Terra alba (gypsum)                            22%
+  Floated silica or Silex                        26%
+  Kaolin (China clay)                            28%
+  Asbestine                                      32%
+  Blue, ultramarine                              27%
+  Blue, Chinese or Prussian                      50%
+  Black, gas carbon                              82%
+  Black, lamp                                    72%
+  Black, drop                                    60%
+  Black, bone                                    50%
+  Brown, mineral                                 24%
+  Brown, vandyke                                 50%
+  Chrome yellow, lemon                           23%
+  Chrome yellow, medium                          30%
+  Chrome yellow, orange                          20%
+  Chrome yellow, dark orange                     15%
+  Chrome green, Chem. pure light                 21%
+  Chrome green, Chem. pure extra dark            25%
+  Chrome green, 25%, color light                 13%
+  Chrome green, 25%, color extra dark            17%
+  Graphite (pure)                                40%
+  Indian red, (98%)                              20%
+  Ochre, yellow, American                        26%
+  Ochre, yellow, French                          28%
+  Ochre, golden                                  28%
+  Red, Venetian                                  23%
+  Red, Oxide                                     25%
+  Red, Tuscan                                    27%
+  Red, Turkey                                    28%
+  Red, lead                                      12%
+  Red, lake                                      55%
+  Sienna, Italian, raw                           52%
+  Sienna, Italian, burnt                         45%
+  Sienna, American, burnt                        38%
+  Sienna, American, raw                          40%
+  Ultramarine green                              28%
+  Umber, Turkey, raw                             48%
+  Umber, Turkey, burnt                           47%
+  Umber, American, burnt                         36%
+  Umber, American, raw                           38%
+  Verona green (terra verte or green earth)      32%
+  Vermilion, English (quicksilver)               14%
+  Vermilion, American (chrome red)               16%
+  Paris green, American                          23%
+  Zinc chromate (permanent yellow)               15%
+
+[Illustration: Lampblack]
+
+[Illustration: Graphite]
+
+[Illustration: Mineral Black]
+
+[Illustration: Asbestine and Whiting]
+
+[Illustration: Silica and Asbestine]
+
+
+
+
+CHAPTER IV
+
+PHYSICAL LABORATORY PAINT TESTS
+
+
+For the paint chemist who desires to familiarize himself with the more
+recent analytical methods worked out in American laboratories, reference
+may be had to treatises on the analysis of paints, by Gardner and
+Schaeffer,[16] and Holley and Ladd.[17] Analytical methods are not
+included in this chapter, the writer's desire being to treat the subject
+from the standpoint of the physical properties of painting materials.
+The work outlined herein is of a nature that affords a wide field of
+research, and a brief study will doubtless suggest similar work to the
+student of paint.
+
+  [16] The Analysis of Paints and Painting Materials. McGraw-Hill Book
+       Co., New York, 1910.
+
+  [17] Mixed Paints, Color Pigments and Varnishes. John Wiley & Sons,
+       New York, 1908.
+
+=Preparation of Paint Films.= The study of paint films is one that has
+become of vital importance, and is receiving at the present time great
+attention. Among the many methods which have been suggested and
+attempted for securing paint films, a few already well known may be
+mentioned.
+
+By painting upon zinc and eating away the zinc with acid: The objection
+to this method is very evident, namely, the action of the acid upon the
+paint coating, which is likely to be very severe. Another method has
+been to spread paraffin on a glass plate, and painting upon this
+surface. When the paint is dried, the paraffin is melted off and thus
+the film is obtained. This method is open to objections, in that the
+paraffin surface is not a comparable one upon which to paint, and also
+that the complete removal of the paraffin is not assured.
+
+Another method consists in covering a piece of glass with tin foil,
+painting out the film upon the foil, and after drying properly, to
+remove the sheet of foil with its coating of paint and immerse in a bath
+of mercury which, by amalgamation of the tin, leaves the paint film.
+
+We now come to a method worked out in our laboratories, which can be
+recommended as being not only simple but efficient and practical. It has
+been found that a size from noodle glue, when painted upon ordinary
+fair-quality paper, makes a surface from which the paint may be
+subsequently stripped. The paint is applied in the ordinary way to the
+paper, which is held during the operation by thumb tacks, and allowed to
+dry. The paint may be separated by immersion in water kept at about 50
+degrees Centigrade. By this method large films may be obtained, but it
+has been found very unhandy to work with films exceeding an area of
+eight inches square. When the film of paint has been detached from the
+sized paper through the dissolving of the noodle glue, the paint film is
+then immersed in a fresh solution of water, in order to remove whatever
+excess of noodle glue there may be remaining. A glass rod is then
+introduced into the bath, in which the paint film is floated upon the
+glass rod, which is then hung up to dry in a suitable container to
+prevent the accumulation of dust, etc.
+
+[Illustration: Bottles Showing Relative Permeability of Films by Amount
+of Whiting Formed Within]
+
+=The Permeability of Paint Films.= A series of tests were made to
+determine the water-excluding values of various combinations of painting
+pigments ground in pure linseed oil. White pine boards, six inches long,
+four inches wide, and one inch thick, were carefully prepared and
+numbered and given three coats of a white paint formula of the
+corresponding number. After drying, the boards were carefully weighed
+and immersed in a tub of water for three weeks. After removal, the
+surfaces of the boards were dried with blotting paper and the boards
+weighed. The gain in weight, corresponding to the amount of water
+penetrating through the pores of the wood, was observed. The boards were
+again immersed and at the end of two months the following results were
+obtained:
+
+                                  Grammes of water
+  Formula                            absorbed
+    No.                            through paint
+
+   1. Soya bean oil                    120
+   2. Linseed oil                      102
+   3. Calcium sulphate                  93
+   4. Barytes                           88
+   5. Asbestine                         74
+   6. Corroded white lead               59
+      { Basic carb.--White lead  25% }
+      { Basic sulph.--White lead 20% }
+   7. { Zinc oxide               25% }  58
+      { Calcium sulphate         25% }
+      { Calcium carbonate         5% }
+   8. Sublimed white lead               56
+   9. Zinc oxide                        56
+       { Zinc lead white         30%  }
+  10.  { Zinc oxide              40%  } 42
+       { Basic carb.--White lead 20%  }
+       { Calcium carbonate       10%  }
+  11. { Basic carb.--White lead  50% }  42
+      { Zinc oxide               50% }
+       { Basic carb.--White lead 38%  }
+  12.  { Zinc oxide              48%  } 38
+       { Silica                  14%  }
+
+The test boards were then exposed, with their content of water, to the
+action of the sun's rays. Blistering of the painted surfaces took place
+in many cases, caused by the rapid withdrawal of the water and its
+consequent action on the paint film. The tests seem to indicate that a
+mixture of white lead and zinc oxide, with or without a small percentage
+of the inert pigments, is not as subject to the action of the water as
+the single pigment paints. In order, however, to corroborate these
+tests, it occurred to the writer to develop a more visible means of
+demonstrating the passage of moisture through paint films.
+
+[Illustration: Bell Jar Apparatus for Testing Permeability of Paint
+Films
+
+Paint films sealed over mouths of Bottles containing Lime Water.
+Carbonic Acid Gas generated under Bell Jar passes through Plate Films
+and precipitates Calcium Carbonate]
+
+Another series of white pine boards were therefore soaked in a solution
+of iron sulphate for several hours. After removal, the surface of each
+board was dried and coated with one coat of the paints previously
+tested. After thorough drying for forty-eight hours, there was placed on
+the surface of each board a few drops of a solution of potassium
+ferrocyanide. This solution has the effect of producing a blue
+coloration with iron sulphate, and in every case when it was placed on a
+paint of considerable porosity, the solution penetrated through and
+formed a blue coloration beneath the paint. The results corroborated the
+original tests referred to above.
+
+A series of sheets or films of paints were then prepared according to
+the method referred to on page 71. These films were placed over glass
+dialyzing cups, allowing the inner surfaces to sag so as to hold a small
+amount of dilute ammonium chloride solution. Distilled water was placed
+on the reverse side of the dialyzing apparatus and the tests started. At
+the end of six days the distilled water in each test was examined and
+the following results obtained:
+
+     Test No. 1 (corroded white lead and asbestine film) allowed the
+     passage of 0.002 gm. ammonium chloride. Test No. 2 (corroded
+     white lead and zinc oxide film) allowed the passage of 0.0003 gm.
+     ammonium chloride.
+
+Tests were also made with dilute solutions of other salts such as ferric
+chloride, having a dilute solution of potassium sulpho-cyanide on the
+reverse side of the apparatus. In the latter case the formation of a
+pink color, characteristic upon the mingling of these solutions, was
+obtained in a few hours.
+
+=Film-Testing Machine.= A film-testing apparatus, termed a "filmometer"
+by its originator, Mr. R. S. Perry, was constructed, with the following
+features: A graduated upright tube is fixed by means of sealing wax to
+two metallic plates which carry an evenly bored hole, exactly under the
+hole in the upright tube. This hole measures exactly one square
+centimeter in area, and is circular. The upright tube is graduated into
+lineal centimeters and is called the pressure tube.
+
+[Illustration: Gardner Accelerated Test Box]
+
+[Illustration: Perry Film Testing Machine]
+
+Attached to the lower end of this pressure tube, close to the metallic
+plates which serve as carriers for the paint film to be tested, is a
+side-neck, which is inclined at an angle of 45 degrees to the pressure
+tube, and serves the purpose of introducing the mercury, as will be
+described later. Immediately under the openings in the metallic plates
+which carry the film are arranged two pieces of iron inclined at a
+90-degree angle, so arranged that when the pressure of mercury is
+applied and causes rupture of the film, the falling mercury shall be
+caught between these two insulated plates and cause contact. These two
+plates are connected up by wire with a pair of magnets, thence to an
+electric bell, and from there to storage batteries which supply the
+current.
+
+A film of paint is tested in the following manner: A piece of film one
+inch square is cut out and placed between the two metallic plates which
+hold the film immediately under the pressure tube. Mercury is run in
+from a burette through the side-neck and applies pressure upon the film
+by gravity. As the mercury is run in it rises of course in the tubes
+until this pressure becomes so great as to finally break the film. At
+this point the mercury will run out, and, falling upon the two insulated
+iron plates immediately below, will cause contact and close the circuit
+which rings an electric bell, which is a signal for the operator to shut
+off the inflow of mercury through the side-neck from the burette.
+
+The pressure tube is also supplied with a piston which is made of a
+piece of thin iron wire having a disc attached to its lower end. As the
+mercury rises in the pressure tube this iron wire is pushed up, being
+very delicately counterpoised over a wheel. Upon the breaking of the
+film the mercury runs out, but upon falling upon the two iron plates
+underneath causes contact to be made, which causes the current to run
+through the pair of magnets before mentioned, which, becoming
+electrified, attract the piston in the pressure tube, giving a reading
+for the maximum height of the column of mercury.
+
+[Illustration: Diagram of Perry Filmometer]
+
+The supply of mercury being shut off, the operator is now in a position
+to determine the total sum of both the elasticity and ductility of the
+paint film, and also the pressure at which the film broke. The breaking
+pressure of course is read directly upon the pressure column, which is
+divided into centimeters as has been described above, the piston
+indicating the maximum height of the mercury column. What may be termed
+the elasticity of the film can now be calculated. As is perfectly
+evident, the film in stretching does so by distending from a flat
+surface to a curved or cup-like surface. If the pressure tube is
+calibrated in cubic centimeters reckoned from a flat surface where the
+film was introduced, the stretch of the paint film in distending from a
+flat surface to a curved surface may be determined. The cubic contents
+of the pressure tube and side-arm become increased, owing to the
+cup-like shape the paint film takes on. By subtracting the amount of
+mercury indicated by the piston in the pressure tube from the amount of
+mercury delivered from the burette, the amount contained in the
+distended paint film is obtained, which serves as a measure of
+elasticity. The temperature is a most important point to consider in
+running daily tests upon the filmometer. The tests made by the writer
+were conducted at 70 degrees Fahrenheit throughout.
+
+[Illustration: Gardner-de Horvath film testing apparatus]
+
+=Gardner-de Horvath Filmometer.= Another type of filmometer which gives
+very concordant results was recently devised by the writer and de
+Horvath. This apparatus is shown above.
+
+It consists of a three-necked Wolff bottle having provision at one of
+its necks for exhausting the air from the bottle. The reverse neck is
+provided with a gauged glass tube dipping into a porcelain crucible
+containing mercury, thus acting as a manometer. The middle neck is
+fitted to accommodate two ground glass plates. Both these plates are
+provided with a central orifice one millimeter in diameter. Between the
+plates is placed a small section of paint film. The plates may be
+pressed together or clamped together and placed over the middle neck of
+the bottle, a close contact being made with Canada balsam. As the air is
+exhausted from the bottle, the mercury in the tube will rise and
+continue in its ascent until the film, which is exposed to atmospheric
+pressure, has offered it maximum resistance, which is shown by the
+breaking point. This point is observed on the manometer and the result
+expressed in centimeters of mercury.
+
+=Table of Film Testing Results.= By means of the Perry film-testing
+apparatus, described in the above, interesting results have been
+obtained, which are embodied in the following table:
+
+COMPARATIVE STRENGTHS OF FILMS AS OBTAINED BY THE BREAKING MACHINE
+
+  ============================+=========+==========+===========+========
+                              |No. Coats| Pressure | Thickness | Stretch
+  ----------------------------+---------+----------+-----------+--------
+   1. Zinc oxide              |    3    |   33.2   |    0028   |  .30
+   2. Zinc lead               |    3    |   32.7   |    0034   |  .35
+   3. Asbestine               |    3    |   28.0   |    0045   |  .15
+   4. Sublimed white lead     |    3    |   17.9   |    0024   |  .38
+   5. Barytes                 |    3    |   13.3   |    0042   |  .33
+   6. Lithopone               |    3    |   13.1   |    0024   |  .49
+   7. Whiting                 |    3    |   13.0   |    0033   |  .32
+   8. Quick process white lead|    3    |   11.3   |    0025   |  .38
+   9. Gypsum                  |    3    |   10.8   |    0039   |  .29
+  10. China clay              |    3    |   10.8   |    0035   |  .16
+  11. Silex                   |    3    |    9.6   |    0032   |  .32
+  12. Blanc fixe              |    3    |    8.5   |    0030   |  .28
+  13. Corroded white lead     |    3    |    7.3   |    0020   |  .33
+  14. Barium carbonate        |    3    |    7.2   |    0028   |  .16
+  ============================+=========+==========+===========+========
+
+By means of this machine it is possible to obtain very valuable
+information concerning the effect of age upon a paint as influencing its
+strength and elasticity. These are two vital qualities in a paint, as it
+is through its strength that a paint resists abrasion, cracking,
+peeling, and blistering. That elasticity is a vital qualification of a
+paint may easily be seen through the checking of oil paintings, which,
+as Ostwalt has pointed out, is due to the unequal coefficients of
+expansion between the ground and the paint. This is particularly
+noticeable in the alligatoring of many enamels which contain large
+percentages of zinc.
+
+Curves have been prepared having pressure as an abscissa and elasticity
+as ordinate. These curves show remarkable differences in different
+pigments. For instance, in the case of white lead, the curve takes a
+steep upward trend when it apparently reaches a maximum, the curve then
+flattening out and finally taking another steep upward trend just before
+breaking. This may be construed as follows: That under low pressures the
+white lead film is perfectly elastic, when a maximum is obtained, beyond
+which elasticity does not extend. This point is the maximum point of the
+upward trend. From here on pressure may be applied without any increase
+in stretch, this being represented by the flat part of the curve, while
+the steep upward trend just before breaking shows where the paint begins
+to tear, finally culminating in breaking. In the case of asbestine,
+however, the curve is more of a straight line up to the breaking point,
+which would go to prove that elasticity is proportionate to pressure in
+the case of this pigment.
+
+=Moisture Absorption.= The structure of certain pigments is such that
+when they are ground in linseed oil and painted out, films are produced
+which are very water-resistant. This action is possibly due to the
+filling of the voids in the oil, thus making a compact and
+water-resistant film. Pigments which are coarse and which present an
+angular crystalline structure, often produce films which contain a
+relatively large number of voids and are less waterproof. Certain
+pigments are chemically active and tend to produce, when ground in oil,
+metallic soaps which act for a time more or less as varnish gums, in
+keeping out moisture. Later on, however, such films are apt to break
+down and admit moisture in quantity. The tests herein described were
+designed by the author to determine the water-excluding value of a
+number of typical pigments when ground in linseed oil and painted out
+into films. Unfortunately, no method has been devised by which films of
+the same gauge could be prepared. The variations in the thickness of the
+films used in these experiments, however, are not very great.
+
+[Illustration: Apparatus for Determining Excluding Properties of Paint
+Films]
+
+A series of small glass bottles with wide mouths, holding about two
+ounces, were half filled with concentrated sulphuric acid, and paint
+films were tightly sealed over the mouths of the bottles with Canada
+balsam. The bottles were then carefully labeled, numbered, and
+accurately weighed upon chemical balances. Later they were exposed under
+a large glass bell jar containing air saturated with moisture and kept
+at a constant temperature. The bottles were removed from the receptacle
+every week and reweighed. The increase in weight, due to the amount of
+moisture which had penetrated through the films, and absorbed by the
+sulphuric acid, owing to its hygroscopic nature, was thus determined. In
+another series of bottles, lumps of calcium chloride were substituted
+for the sulphuric acid. The results obtained from these tests correspond
+to those of the former tests, and led to the conclusion that the
+porosity of linseed oil films varied when different pigments were used
+in the oil.
+
+MOISTURE EXPERIMENTS
+
+Figures Given Express Percentage Gain in Weight, e.g., Water Absorbed
+
+  ==========================+=========+=========+=========
+                            |  7 days | 21 days | 49 days
+  --------------------------+---------+---------+---------
+  White lead and zinc oxide |  0.043% |  0.115% |  0.266%
+  Zinc lead white           |  0.049  |  0.130  |  0.284
+  Red lead                  |  0.049  |  0.130  |  0.295
+  Sublimed white lead       |  0.049  |  0.128  |  0.292
+  Zinc chromate             |  0.064  |  0.176  |  0.417
+  Zinc oxide                |  0.065  |  0.172  |  0.391
+  Barytes                   |  0.074  |  0.202  |  0.466
+  Willow charcoal           |  0.077  |  0.236  |  0.694
+  Lithopone                 |  0.083  |  0.228  |  0.550
+  Chinese blue              |  0.092  |  0.276  |  0.671
+  Natural graphite          |  0.104  |  0.350  |  0.951
+  Ultramarine               |  0.119  |  0.336  |  0.814
+  ==========================+=========+=========+=========
+
+Another series of tests was started, in which were used films prepared
+from various oils and varnishes made especially for the test from
+different gums. The results of this series are very interesting, as they
+indicate that certain gums are more powerful than others in making oils
+resistant to moisture. The reader should study with care the data on
+treated Chinese wood oil, most excellent results having been obtained
+when it was used in the proper percentage.
+
+EXCLUDING TESTS ON OIL VEHICLES AND VARNISHES SHOWING PERCENTAGE OF
+MOISTURE ABSORBED AT VARIOUS PERIODS
+
+  ===================================+=========+=========+=========
+                                     |  6 days | 18 days | 24 days
+  -----------------------------------+---------+---------+---------
+  Linseed oil, 100%                  |  .233   |  .686   |  .895
+  Soya bean oil, 100%                |  .340   | 1.06    | 1.39
+  Linseed oil, 80%  }                |  .250   |  .755   |  .987
+  Soya bean oil, 20%}                |         |         |
+  Linseed oil, 60%   }               |  .289   |  .857   | 1.125
+  Soya bean oil, 40% }               |         |         |
+  Linseed oil, 40%  }                |  .355   | 1.05    | 1.39
+  Soya bean oil, 60%}                |         |         |
+  Linseed oil, 20%   }               |  .260   |  .789   | 1.03
+  Soya bean oil, 80% }               |         |         |
+  China wood oil treated, 100%       |  .130   |  .297   |  .375
+  Linseed oil, 80%           }       |  .182   |  .559   |  .728
+  China wood oil treated, 20%}       |         |         |
+  Linseed oil, 60%            }      |  .173   |  .540   |  .708
+  China wood oil treated, 40% }      |         |         |
+  Linseed oil, 40%           }       |  .119   |  .348   |  .450
+  China wood oil treated, 60%}       |         |         |
+  Linseed oil, 20%            }      |  .127   |  .375   |  .494
+  China wood oil treated, 80% }      |         |         |
+  Kauri gum, 33%  }                  |         |         |
+  Linseed oil, 33%}                  |  .061   |  .191   |  .302
+  Turpentine, 33% }                  |         |         |
+  Kauri gum, 25%   }                 |         |         |
+  Linseed oil, 50% }                 |  .096   |  .266   |  .346
+  Turpentine, 25%  }                 |         |         |
+  Kauri gum, 20%  }                  |         |         |
+  Linseed oil, 60%}                  |  .122   |  .367   |  .449
+  Turpentine, 20% }                  |         |         |
+  Kauri gum, 15%   }                 |         |         |
+  Linseed oil, 70% }                 |  .187   |  .421   |  .601
+  Turpentine, 15%  }                 |         |         |
+  Congo copal gum, 20% }             |         |         |
+  Linseed oil, 50%     }             |  .228   |   --    |   --
+  Turpentine, 30%      }             |         |         |
+  Sierra Leone copal, 20% }          |         |         |
+  Linseed oil, 50%        }          |  .099   |   --    |   --
+  Turpentine, 30%         }          |         |         |
+  Zanzibar gum, 20% }                |         |         |
+  Linseed oil, 50%  }                |  .082   |   --    |   --
+  Turpentine, 30%   }                |         |         |
+  Amimi gum, 20%   }                 |         |         |
+  Linseed oil, 50% }                 |  .080   |   --    |   --
+  Turpentine, 30%  }                 |         |         |
+  Boiled linseed oil (linoleate type)|  .210   |   --    |   --
+  Collodion solution (6 oz.), 80% }  |  .201   |   --    |   --
+  Boiled linseed oil, 20%         }  |         |         |
+  ===================================+=========+=========+=========
+
+[Illustration: Microscopic view of section of cedar]
+
+[Illustration: Microscopic view of section of maple]
+
+[Illustration: Microscopic view of section of white pine]
+
+[Illustration: Gardner photomicroscope in position against painted
+surface]
+
+[Illustration: Inside White on White Pine]
+
+=Use of the Microscope.= 4. The microscope is a necessary adjunct of
+every well-ordered paint laboratory, as has been recognized throughout
+the whole paint industry. The writer has attempted to collect certain
+data which may materially assist those manufacturers who employ this
+instrument to judge of the quality of their raw and finished products.
+The fineness of grinding considerably affects the quality of the paint,
+and this can be easily controlled through the intelligent use of the
+microscope. This instrument may also be used to detect certain
+adulterations. Appended is a table giving the fineness of grinding of
+the various pigments, together with their characteristics under the
+microscope. In this table measurements are given both in millimeters and
+in inches, in order to accommodate itself to the use of those chemists
+employing a millimeter stage micrometer, or those employing the English
+or inch system. Although it is not yet certain that any and all
+combinations of pigments may be detected under the microscope the writer
+is working toward a method which will allow a manipulator to judge of
+the composition of the paint under observation.
+
+In order to properly prepare a paint for microscopic examination, the
+following method is recommended: A microscopic turn-table is a
+convenient accessory of the microscope, and its use is to be
+recommended. A glass slide being placed in position upon the turn-table,
+a very small amount of either the pigment rubbed up in oil, or the
+paint, is applied to the slide; a small drop of Canada balsam is then
+applied by means of a glass rod dipped in a solution of balsam in xylol,
+and dropped upon the slide. The rod is then used to thoroughly
+incorporate the pigment with the balsam, and a cleaned cover glass is
+dropped over the whole and pressed down tightly, so that a small amount
+of balsam will exude from under the edges and thus firmly seal the
+glass. In order to make permanent slides it has been found advisable to
+rim the cover glass with balsam and even follow this up with some
+suitable black varnish, the slide being then carefully labeled and
+placed in the collection. Following is a table of the characteristics of
+the fourteen chief pigments:
+
+TABLE OF THE SIZE OF PARTICLES OF THE CHIEF PIGMENTS WITH THEIR
+CHARACTERISTICS UNDER THE MICROSCOPE
+
+  ===+===================+======================+=======================
+     |                   |      Diameter in     |      Diameter in
+     |                   |      Millimeters     |        Inches
+     |                   +-------+-------+------+-------+------+--------
+  No.|Name               | Small | Aver. |Large | Small | Aver.| Large
+  ---+-------------------+-------+-------+------+-------+------+--------
+    1|Asbestine          |.002   | --    |.12   |.00015 | --   |.049
+    2|China clay         |.003   | --    |.065  |.00009 | --   |.025
+    3|Barium carbonate   |.00076 |.0055  |.0172 |.00003 |.00024|.0011
+    4|Blanc fixe         |.00073 |.0037  |.0073 |.00003 |.00014|.0003
+    5|Silex              |.0037  |.0092  |.03   |.00014 |.00036|.0012
+    6|Gypsum             |.0037  |.011   |.05   |.00014 |.00044|.0022
+    7|Amer.-Paris white  |.0015  |.0050  |.04   |.00006 |.00022|.0018
+    8|Barytes            |.0015  |.0092  |.05   |.00006 |.00036|.0021
+    9|Zinc lead          |.00037 |.0018  |.0037 |.000014|.00007|.00014
+   10|Sublimed white lead|.00037 |.0018  |.0037 |.000014|.00007|.00014
+   11|Lithopone          |.00076 |.0018  | --   |.00003 |.00007| --
+   12|Zinc oxide         |.00046 |.0018  |.00037|.00002 |.00007|.00014
+   13|Quick Pro. lead    |.00061 |.0030  |.0048 |.00002 |.00012|.00018
+   14|Dutch Pro. lead    |.00061 |.0018  |.0066 |.00002 |.00007|.00026
+  ===+===================+=======+=======+======+=======+======+========
+
+=Film Sectioning and Deductions to be Drawn Therefrom.= 5.
+Investigations were undertaken into the innermost structure of paint
+films as revealed under the microscope. Up to the present time, work has
+been done upon barytes, asbestine, blanc fixe, and white lead, painted
+upon wood, and a combination paint upon wood. The films, the preparation
+of which has been described in the foregoing, were sectioned and
+prepared for microscopic examination in the following manner:
+
+A solidifying dish was partly filled with low melting-point paraffin
+which was allowed to harden, when a small piece of paint was thrown upon
+it and then more paraffin poured over it. After hardening, sections were
+obtained of the paint film by means of a microtome.
+
+[Illustration: Section Barytes Film]
+
+A view of these sections of paint films under the microscope gave to the
+operator a better idea of the structure of a paint than had ever been
+afforded heretofore. It was easy to perceive the relative position of
+the pigment particles and the three coats. The penetration of one coat
+into another was easily discernible, and measurements were made upon the
+sections in order to determine the average thickness of coat and its
+general appearance.
+
+Sections were also made of Inside and Outside White upon wood. These
+sections revealed under the microscope the thickness of the coats and
+also the penetration of the priming coat into the wood. Appended is a
+table giving microscopic measurements.
+
+PAINT SECTION MEASUREMENTS UNDER MICROSCOPE
+
+  ======================+=============+===========+======
+                        |             |Millimeters|Inches
+  ----------------------+-------------+-----------+------
+  Barytes               |3 coats (sum)|  .1068    |.00421
+                        |Single coat  |  .0356    |.00140
+                        |             |           |
+  Inside. White on wood |3 coats (sum)|  .1624    |.00639
+                        |Outside coat |  .0230    |.00091
+                        |Next coat    |  .0443    |.00175
+  Field in photographs  |Next coat    |  .0620    |.00245
+                        |Penetration  |  .0294    |.00116
+  White lead            |Inside       |  .0215    |.00085
+                        |Middle       |  .0405    |.00159
+                        |Outside      |  .0184    |.00073
+                        |3 coats (sum)|  .0811    |.00319
+  Asbestine             |3 coats (sum)|  .1840    |.00725
+                        |             |           |
+  Blanc fixe            |3 coats (sum)|  .1068    |.0042
+                        |Single coat  |  .0356    |.00014
+                        |             |           |
+  Outside. White on wood|Outside coat |  .1329    |.00523
+                        |Inside       |  .1845    |.00727
+                        |Penetration  |  .0737    |.00290
+  ======================+=============+===========+======
+
+=Polar Micro-Examinations and Photomicrographs.= By Polar
+Micro-Examination is meant the examination of pigments under polarized
+light. A polarizing apparatus, though not an essential in the hands of
+the paint chemist, is nevertheless much to be desired, for by its help
+deductions may be drawn as to the contents of a paint, which by other
+means might not be possible. The polarizing apparatus as marketed by
+most manufacturers of the microscope is attached in the following
+manner:
+
+The diaphragm immediately under the sub-stage container is swung out and
+opened to its widest limit, allowing the insertion of the polarizer.
+This polarizer carries one of the pair of Nicols prisms and is
+countersunk to allow of the introduction of gypsum or selenite plates.
+The analyzer fits over the eyepiece on the tube.
+
+The use of polarized light upon paint is valuable on account of its
+action upon crystalline substances. The re-enforcing pigments, such as
+Asbestine, China Clay, Gypsum, Silex, Barytes, etc., are crystalline and
+consequently act upon the polarized light. In most cases these pigments
+are used in ready-mixed paints in small amounts, varying between 5 and
+25%. When a slide containing a small amount--for example, less than
+3%--of these crystalline pigments is examined under the microscope by
+ordinary transmitted light, they will often escape observation, owing to
+the small amount in which they are present. However, in the case of
+polarized light, this could hardly happen.
+
+[Illustration: Microscopic View of Barytes under Polarized Light]
+
+A slide of paint containing these re-enforcing pigments is prepared in
+the usual manner. On examining this under the microscope and using the
+polarizing apparatus, the crystalline pigments are at once detected by
+revolving the analyzer. At one position of the analyzer, one sees an
+ordinary field, as with transmitted light, but if one revolves the
+analyzer, the field gradually becomes darker until total darkness is
+obtained throughout, except in such places where crystalline substances
+are present, when the crystal is shown up with beautiful distinctness.
+Photomicrographs of various single pigments and pigment combinations are
+shown under Chapter III.
+
+=Effect of Pigments on Oil.= Certain pigments have the property of
+acting upon the linseed oil in which they are ground, forming metallic
+linoleates which accelerate the drying of oil. This is especially true
+of lead and zinc pigments. The inert crystalline pigments, when ground
+in linseed oil and painted out, distribute the oil so as to allow a
+great surface to be exposed to the air. Thus by physical action, and
+possibly catalytic or contact action, these inert pigments stimulate the
+drying of oil paints in which they are ground. Lead and zinc paints, of
+course, have the greatest drying values on account of the added effect
+of the linoleates formed, as outlined above. The writer has made a
+series of tests in which the action of various pigments upon linseed oil
+is shown. The tests were made in the following manner:
+
+Five grams of each of a series of commonly used paint pigments,
+including those of inert crystalline nature as well as the more valuable
+amorphous pigments which are considered more or less chemically active,
+were ground separately in an agate mortar, with 5 grams of raw linseed
+oil. The ground paste in each case was placed in a marked glass beaker,
+and allowed to stand in a dustless section of the laboratory for one
+month. The oil-pigment paste from each beaker was then separately
+extracted with benzine to remove the linseed oil from the pigment. The
+benzine solutions of oil were then heated to remove the benzine and the
+residue of oil burned to ash in crucibles. The ash from each test was
+weighed, and if it ran above the percentage of ash determined on a blank
+sample of linseed oil (namely, .003%), the ash was analyzed
+qualitatively for metallic constituents. The following table of results
+shows the percentage increase in ash, as well as the constituents of ash
+on the various samples tested:
+
+TABLE OF RESULTS
+
+  ===============================+==============+========================
+                                 | Per cent. of |
+                                 |  Ash in Oil  |
+  Pigment in Oil                 |Extracted from|Analysis of Ash
+                                 | Oil-Pigment  |
+                                 |    Paste     |
+  -------------------------------+--------------+------------------------
+  Raw linseed oil without pigment|    0.003     |      --
+  Barytes                        |    0.003     |      --
+  Blanc fixe                     |    0.003     |      --
+  Silica                         |    0.003     |      --
+  Asbestine                      |    0.005     |      --
+  China clay                     |    0.007     |      --
+  Whiting                        |    0.008     |      --
+  Chrome yellow                  |    0.025     |Lead oxide (PbO)
+  Lithopone                      |    0.031     |Zinc oxide (ZnO)
+  Prussian blue                  |    0.032     |Iron oxide (Fe_{2}O_{3})
+  Sublimed white lead            |    0.033     |Lead oxide (PbO)
+  Zinc oxide                     |    0.105     |Zinc oxide (ZnO)
+  Corroded white lead            |    0.116     |Lead oxide (PbO)
+  Red lead                       |    0.2112    |Lead oxide (PbO)
+  ===============================+==============+========================
+
+Observation of these results shows that pigments such as Barytes, Blanc
+Fixe, and Silica have no chemical action on the linseed oil. The results
+on Asbestine and China Clay also are negative, the extremely slight
+increase in amount of ash from these samples probably being due to
+traces carried over mechanically into the oil mixture; the last named
+pigments being more fluffy and difficult to separate from oil. Slight
+action seemed to be apparent in the case of whiting, a pigment somewhat
+alkaline in nature. A longer test might have shown this pigment to have
+possessed still greater action. Corroded white lead showed considerable
+action, resulting in the formation of lead linoleate or some other
+organic compound. Zinc oxide and lithopone, the latter pigment
+containing 30% of zinc sulphide, both indicated action on the oil.
+Chrome yellow (chromate of lead) showed some action, as did also
+Prussian blue, the ash from the last named pigment showing a heavy
+percentage of iron oxide.
+
+Red Lead showed a most astounding gain in these tests, chemical action
+of the pigment on the oil being apparent soon after the tests were
+started, as shown by the formation of a hard cake with the linseed oil.
+
+The Raw Linseed Oil which was used in these tests had an acid value of
+1.84%, which is very low. The neutralization of this free fatty acid by
+some of the alkaline pigments used, may account for part of the
+increased percentage of ash, but in most cases the pigments, and more
+especially the basic pigments, had a direct saponifying action upon the
+glycerides of the oil.
+
+
+
+
+CHAPTER V
+
+THE THEORY AND PRACTICE OF SCIENTIFIC PAINT MAKING
+
+
+=Laws of Paint Making.= To secure a proper comprehension of the
+composition of paints, and to be able to interpret the functions of
+their various constituents, requires an understanding of the general
+physical principles involved. The modern grinder has accepted the Law of
+Minimum Voids, and upon this law he bases the design of paint formulæ,
+aiming toward the production of what have been properly termed
+Scientifically Prepared Paints. Perry's formulation of the Law of
+Minimum Voids in a paint coating, and the analogy which he has drawn
+between a scientifically prepared paint and a well-proportioned
+concrete, was the result of genuine scientific thought following
+observation and experimentation. It must be admitted that analogies are
+not always safe to draw conclusions from, but it surely is no fallacy in
+reasoning to draw analogies between these two materials, when they
+resemble each other in so many ways. To carry out processes of
+reasoning, and to formulate laws from such close analogies, is certainly
+a step in the right direction.
+
+A graphic summary of the analogies between a properly proportioned
+concrete and a paint, are shown on next page.
+
+Although this table graphically summarizes the principles involved, the
+matter is presented with greater clearness in the following:
+
+Law No. 1--The law of minimum voids to be observed in constructing a
+paint formula--this law having already been accepted as mathematically
+correct and technically proved in the technology of concrete and cement.
+
+Corollary--The requisite thickness of a paint film together with the
+utmost attainable strength and impermeability can best be obtained by a
+properly proportioned blend of pigments of three or more determinate
+sizes.
+
+
+AN EXHIBITION OF CERTAIN ANALOGIES GOVERNING THE MANUFACTURE OF CONCRETE
+AND OF PAINT
+
+  1 Concrete aggregate = solids + vehicle|Paint aggregate = solids + vehicle
+                                         |
+  2 Solids = coarse + medium + fine      |Solids = coarse +     medium  + fine
+             (stone) (gravel) (sand)     |        {pulverized }{precipi-}
+                                         |(pig-   {cryst'lline}{tated   }(fume)
+                                         |(ments  {(etc.)     }
+                                         |
+  3 Vehicle =                            |Vehicle =
+    = reactive binder + evapor'g thinner |= reactive binder+evaporating thinner
+     { cement and com- } (excess water)  |     (linseed oil)    (volatiles)
+     { bining water    }                 |
+                                         |
+  4 Solids + compacting =                |Solids + compacting =
+             (tamping)                   |         (brushing)
+    = elimination of accidental voids +  | = elimination of accidental voids +
+    + proper adhesive contact            | + proper adhesive contact
+                                         |
+  5 Vehicle + reaction = hydrosilicates, |Vehicle + reaction = linoxyn
+    etc.                                 |
+              (setting)                  |          (drying)
+                                         |
+  6 Solids + vehicle +                   |Solids + vehicle +
+    + lubrication + chemical reaction =  | + lubrication + chemical reaction =
+    = final product { solidified binder+}| = final product {solidified binder+}
+                    { + solids          }|                 {+ solids          }
+                                         |
+  7 Final product = concrete             |Final product = paint coating
+                       { shearing       }|              { strength       }
+    (of max. strength  { tensile        }| (of maximum  { impermeability }
+                       { crushing, etc. }|              { durability     }
+
+                         *       *       *       *       *
+
+  If we assume for both paint and concrete
+        proper lubrication
+        proper proportion of vehicle and solids
+  Then the _essential difference_ between a thin film of
+
+                        Concrete        and             Paint
+                                        is
+
+                      Cement Binder                     Linoxyn Binder
+
+                                  _Disadvantages_
+
+  Non-elastic and hence an impracticable |Slowly perishable from oxidation by
+  binder for a film to protect non-      |the air.
+  similar structural surfaces.           |
+
+                                    _Advantages_
+
+  Durable and with the qualities of a    |Semi-elastic and therefore a practic-
+  natural mineral.                       |able binder for a film to protect
+                                         |structural surfaces.
+
+  Postulate (def. Webster's Dictionary--A self-evident problem)
+
+     Postulate No. 1--The organic linoxyn or semi-elastic binder of the
+     paint vehicle (unlike the cement binder) is perishable and its purity,
+     strength and protection from attack means life to the paint coating,
+     and hence the _life_ of the oil is the _life_ of the paint.
+
+     Postulate No. 2--The inorganic or powdered mineral solids of a paint
+     coating will crumble unless held together by the binder, but the
+     imperishable pigments must be so ground and blended in the binder that
+     they will protect the binder and present the greatest possible solid
+     front to the atmospheric attack.
+
+                         *       *       *       *       *
+
+  A paint, to secure the greatest protection and life for the linoxyn,
+  together with the durable qualities of cement,
+
+                                    _Therefore_
+
+                            Should expose to air decay
+
+  within limits of physical strength     |within limits required for elasticity,
+  The greatest amount of pigm't material |etc. The least amount of exposed
+                                         |linoxyn
+              (which is)                 |                or
+  Durable and with the inert qualities of|Considering the linoxyn present be-
+  natural mineral                        |tween pigment particles as the void
+                                         |or point of attack,
+                                         |               Then
+                                         |the minimum exposure of linoxyn
+  or minimum voids obtainable by proportioned pigments of different particle
+  sizes.
+
+Law No. 2--The law of the flat arch in paint coatings--i.e., the fact
+that in studying the fundamental physical principles governing the
+strength and durability of a paint coating it is necessary to regard the
+coating as consisting of a series of flat arches, in which the pigment
+particles of largest characteristic size serve as the piers or supports
+for the flat arches of which the continuous film is composed.
+
+Corollary A--The strength and durability of a paint coating is
+determined by the strength and durability of the piers or supports
+(which consist of the characteristic pigment particles of the largest
+size).
+
+Corollary B--Owing to their inherent strength and durability the pigment
+particles of largest characteristic size which serve as supports for the
+paint coating should consist, in part at least, of chemically inert
+pigments, such as natural crystalline barium sulphate, calcium
+carbonate, magnesium silicate, etc.
+
+Corollary C--It follows directly that the thickness of a paint coating
+is determined by the particles of pigments having the largest
+characteristic size, even if that pigment be present only in moderate
+percentage. Upon this principle depends the comparatively great
+thickness of film and moderate spreading rate of paints composed of such
+pigments as basic carbonate--white lead, red lead, barytes, etc., and
+the strongly contrasted thinness of film and high spreading rate of
+paints composed of the sublimated pigments such as lamp black, zinc
+oxide, basic sulphate--white lead, zinc-lead white, leaded zinc, etc.
+
+In commenting upon the announced laws set forth above, Heckel says: "The
+recognition of these laws was an exercise of pure deduction. Paint
+manufacturers before Mr. Perry's announcement were producing paints
+containing three or more pigments with particles of varying
+characteristic sizes; but their procedure was based largely on empirical
+knowledge, the result of accumulated experience, due to a conscientious
+endeavor to produce the highest type of paints for economic service. In
+the absence of any law to govern or to limit the use of the reinforcing
+pigments, inexperienced manufacturers had brought upon the market paints
+which were badly proportioned as to the several pigments, or burdened
+beyond the limits of effectiveness with reinforcing pigments. To all
+paint manufacturers Perry rendered a substantial service in deducing for
+them the laws set forth in his address. In the results following a
+recognition of these laws there was nothing new or startling, but Perry
+was the first to give the principles from which it can be determined in
+advance whether a paint formula will prove to be physically good or bad
+in practice.
+
+[Illustration: Series of Paint Chasers, Mixers, and Grinders]
+
+[Illustration: Overhead Churn Mixer]
+
+[Illustration: Battery of Paint Mixers and Grinders of Modern
+Underdriven Type]
+
+[Illustration: _Photographs courtesy of Ernest Heath_
+
+View showing Shrinkage in Bulk of Paint Pigment after being ground in
+Oil. Filled Barrel on Right with the Oil forms one-third Barrel Paste as
+shown in Barrel on Left]
+
+[Illustration: View showing careful Dressing of Bull Stone Mill from
+Grinder]
+
+"As has been before stated, he was not the first to recognize the law
+governing minimum voids, but by that scientific use of the imagination
+which Tyndall so highly commends, he recognized, as by inspiration, the
+fundamental similarity existing between a film composed of solid
+particles cemented together by a semi-solid homogeneous menstruum and a
+layer of concrete composed of solid particles cemented together by a
+solid homogeneous medium. His application of the law permits the paint
+manufacturers to design a paint formula with full knowledge of the
+controlling conditions, so that it shall produce a coating neither too
+thick, and therefore uneconomical and subject to excessive internal
+strains, nor too thin, and thus weak and inefficient for protection.
+That Mr. Perry's contention was well-founded, other paint technologists
+have since demonstrated; notably Mr. Wirt Tassin, in his microscopic
+studies of paint films in situ, and Prof. G. W. Thompson who, in his
+address to the Penna. Association of Master Painters at Reading,
+said:--"I want to agree with Mr. Perry * * * where he says that a
+pigment should be made up of particles of different sizes. Mr. Perry
+also draws a further parallel between paint and concrete where he refers
+to the form of the reinforcing pigment particles and suggests that in
+paint coatings as in concrete a field can be found for the chemically
+inert pigments with rod-like or hair-like structure, to strengthen the
+film, just as the steel rods and iron mesh are used to reinforce
+concrete in structural work--a suggestion which, since the first
+publication of the address, has been widely accepted as a practical aid
+in the manufacture of good paints.""
+
+=Use of Inert Pigments.= There seems to be no reasonable doubt as to the
+efficiency of a small amount of inert pigments in paint, and the writer
+has often compared the manufacture of paint of the above type to the
+making of various alloys wherein zinc, copper, and other metals are
+added to gold in order to make a product possessed of greater
+durability, etc.
+
+[Illustration: Batteries of Color Grinding Mills]
+
+There has been considerable inquiry as to just what is meant by the
+statement that "a moderate percentage of inert pigments, combined with
+properly adjusted mixtures of white lead and zinc oxide, have given
+wonderful service in all the tests." The writer has been asked to define
+what "moderate" means. A "moderate percentage of inert pigments" should
+be defined as that amount of natural crystalline pigments that will,
+when mixed with white lead and zinc oxide, not materially detract from
+the hiding power of white lead and zinc oxide. It is possible to mix a
+certain percentage of these crystalline pigments with white lead and
+zinc oxide, and, by thorough grinding, incorporate them in such a manner
+that the mixture will show nearly as good a hiding power as the straight
+white lead and zinc oxide. When certain limits have been reached,
+however, and these limits must be determined by the manufacturer and
+painter in making practical tests, the further addition of inert
+pigments lowers the hiding power of the paint and therefore lowers the
+value of the paint. These remarks do not apply to artificial crystalline
+pigments, such as precipitated whiting, which possess greater hiding
+values than the natural pigments.
+
+=Perry's Principles of Paint Making.= Parts of the original paper[18] in
+which Perry so clearly set forth the principles from which the preceding
+laws were formed, follow:
+
+  [18] Physical Characteristics of a Paint Coating. R. S. Perry.
+       Michigan Chapter, Amer. Institute of Architects, 1907.
+
+=Sealing Quality or Imperviousness of the Coating.= "It has been
+emphasized that for durability and protection, the strength and
+imperviousness of a paint coating are vital factors. The protective
+value of the paint coating of course ceases with its chalking or
+disintegration, but, while it is true that the protecting or final life
+of the coating ceases with this disintegration, it is also true that a
+paint coating has always during its true life more or less porosity from
+the nature of the linoxin or oxidized linseed oil. Therefore during its
+protecting life the degree of its imperviousness influences its
+resistance to attack upon its own life and its protection of the
+underlying materials. The more impervious the paint coating without loss
+of strength, the slower the oxidation or disintegration of the paint
+coating itself and the greater protection to the underlying material.
+
+"A coating of linseed oil alone is not only weak, but the simplest and
+crudest experiments will show its porosity and this porosity increases
+rapidly with progressive oxidation, the porosity of course definitely
+hastening the over-oxidation or chalking. In proportion, therefore, to
+our success in filling the voids in the linseed oil film with proper
+pigment materials, we will in that degree succeed in excluding agencies
+of decay, not only from the mass of the paint coating itself, but also
+from the surface to be protected. These conditions are exactly parallel
+in the requirements and performance of the best-made concrete, and
+Taylor & Thompson in their work on concrete have clearly stated that to
+obtain imperviousness there must be freedom from voids, and that to
+obtain these conditions, the materials used must have at least three
+determining sizes.
+
+[Illustration: Equal Volume (One Cubic Centimetre) of Each Size of Shot
+Taken. Note that the Smaller Shot Cover more than Half as much again as
+the Larger Shot and the Voids are Smaller.]
+
+[Illustration: Diagram Illustrating Two Determining Sizes of Solid
+Particles in Concrete]
+
+[Illustration: Diagram Illustrating Three Determining Sizes of Solid
+Particles in Concrete]
+
+"'It is a fact that with particles of different sizes as against uniform
+size the densest mixture can be obtained. This is so evident as to
+require no proof.' It follows that the least density and hence the
+largest percentage of voids occur when the grains are all of the same
+size, and it is shown that the most voids occur in a mass of large
+particles. The least voids occur when the voids between the large
+particles are filled with smaller particles and when these smaller voids
+between the smaller particles are in turn filled with still finer
+particles. In other words--particles with three determining sizes will
+fill up a given space more completely than particles of two determining
+sizes and very much more completely than particles of one size.
+
+=Elasticity and Strength.= "The paint coating here again is governed by
+many of the laws which govern the similar material, i.e., concrete. We
+find, by again referring to Taylor & Thompson, on Concrete, page 275,
+that tests at the Watertown Arsenal on concrete convinced the
+investigators that the ultimate strength of a concrete is identical with
+the shearing strength of particles of stone making up the aggregate.
+
+"This means that in its ultimate form the good concrete will crack or
+shear through the broken rock contained therein, and resistance to
+shearing is directly proportionate to the strength of the broken rock
+chosen for the mixture. The film of semi-liquid linseed oil when fresh
+is extremely weak, but as it hardens, its characteristics and physical
+properties will obviously be those qualities which are a composite of
+the qualities of the solid particles and of the semi-solid linolein
+incorporated together in the paint coating. These physical properties of
+the suspended and incorporated pigments profoundly modify the film in
+this respect.
+
+"The dried vehicle, linoxin, is notable for its elasticity, and it is
+weak in crushing and tensile strength, and in hardness or resistance to
+surface wear. The fact that it is a semi-solid furnishes an opportunity
+to modify and improve those characteristics of a solid in which it is
+deficient. The semi-solid, rubber-like linoxin between the coarser
+particles of the pigment obviously uses these coarser particles as
+supporting points. The medium sized particles of the second group of
+alteration products serve the same purpose as the broken rock in
+concrete. The coarser particles absolutely do not, and can not, serve
+the purpose of stiffening or of reinforcing or modifying the consistency
+and qualities of the semi-solid linoxin, for a number of reasons, one
+of which may be mentioned, namely, that particles of the first, or
+coarse, class have a determining size which is a large fraction--a heavy
+percentage--of the total thickness of coating, and are in some instances
+thicker in diameter than the thickness of an oil coating not reinforced
+with the fine or fire group.
+
+"We must think of the coarser particles as piers. The mixture of linoxin
+with the other two groups of particles in the spaces between these
+coarser particles, or piers, is the true paint body and consists of flat
+reinforced arches which have the extra support of falsework, in the
+shape of the structural material on which the coating rests. Asbestine
+pulp, a natural product and one of our most important natural
+reinforcing pigments, serves not only in the coarse group as supporting
+particles for the linoxin arch, but also because of its peculiar
+properties serves the more important purposes of reinforcement. It
+retains, no matter how finely ground, its peculiar needle-like, or
+rod-like, form of particles, and obviously serves the purpose of
+reinforcing the flat arch of linoxin, exactly as iron bars or iron
+netting serve in reinforced concrete arches. The medium sized particles
+of the second group of pigments produced by chemical alteration or
+precipitation, serve the purpose of the broken rock in concrete, and
+together with the coarser supporting particles and the finest
+reinforcing particles, give minimum voids and a maximum imperviousness
+to agencies of internal decay.
+
+"It goes without saying that the pigments of any one group contain
+particles of dimensions which fall into the other two groups, but no one
+pigment supplies the correct proportion of each of the three required
+dimensions, and each pigment has so large a percentage of approximate
+dimensions as to bar it from exclusive use in the other two groups.
+Given similar homogeneous coatings under identical conditions, we
+recognize the law that elasticity will vary directly with thickness.
+Direct deduction from this law teaches us that of two paint coatings
+equal in wear, in strength, opaqueness, and in all other qualities
+except thickness, we should choose the thinner coating. Therefore if we
+have two paint coatings fulfilling every requirement, the first
+compounded with pigments giving a thicker coating and the second with
+pigments yielding a thinner coating, we must choose the second formula
+and obtain the thinner coating.
+
+=Adhesive Power.= "The adhesion of the linoxin to the coarse group of
+particles and to the underlying material is vital to the life of the
+paint coating. If the coating parts from the surface beneath, we have
+scaling or peeling. It is universally admitted that this will result
+from use of zinc oxide as the sole pigment. We have only to conceive of
+our flat arch of reinforced linoxin and leave out our points of support,
+to realize that this is the inevitable result if the coating be subject
+to extreme exposure, although good results may be obtained from zinc
+oxide used alone, as, for instance, in interior house painting where
+extreme changes of temperature and exposure are avoided.
+
+"Three major lines of force hold our linoxin in place--adhesion toward
+the underneath surface, adhesion to the coarse particles, and cohesion
+within the linoxin itself. These lines must be represented by a flat
+arch of linoxin with a downward pointing magnet therefrom, to represent
+adhesion to the surface. Magnets on each side of the arch pointing
+toward the supporting coarse particles, and two magnets within the arch
+and pointing toward each other, or to the centre of the arch, these
+latter to represent the force of cohesion."
+
+
+
+
+CHAPTER VI
+
+THE SCOPE OF PRACTICAL PAINT TESTS
+
+
+=The Pigment Contention.= During the year 1906 officials of the North
+Dakota Agricultural Experiment Station examined a number of paints on
+sale in the northwestern States. The presence of large quantities of
+inert pigments as well as water, in some of these paints, prompted
+agitation for State laws requiring the formula-labeling of paints.
+Certain paints made of white opaque pigments such as white lead and zinc
+oxide were exempted from the statute. The white opaque pigments used in
+these paints were believed by certain manufacturers as well as by many
+prominent paint authorities of high standing to be benefited in their
+wearing value by the addition of small percentages of inert crystalline
+pigments, such as barytes, silica, China clay, etc. Laboratory
+experiments had already determined that these inert crystalline pigments
+had a certain definite action in increasing the life of paints, but it
+had become evident that they should be used with discretion, in
+moderation, and with a proper understanding of their limitations, if the
+best results were to be obtained. The addition of very large quantities
+of such pigments was not indulged in by discriminating manufacturers,
+but the exact percentage to use was a matter of great doubt, even to the
+most experienced. In order to determine just what percentage of
+crystalline pigments, admixed with white opaque paint pigments, would
+give the best service and results, it seemed imperative that practical
+paint tests should be made. A series of paint tests on commercial brands
+of paint had already been started at the Fargo Agricultural College,
+and, at the suggestion of the Paint Manufacturers' Association of the
+United States, another series of practical paint tests were instituted,
+and carried out under the supervision of Dr. E. F. Ladd, Director of the
+North Dakota Experiment Station.
+
+=Test Fences to Solve the Problem.= It was apparent that the pigment
+question could be solved only through field tests made on a
+comprehensive basis and placed under the control of scientific and
+technical societies of renown, so that they might be fair and unbiased
+from every standpoint. In order to secure a comparison of the wearing of
+different paint formulas in various sections of the country and under
+differing climatic conditions, another series of tests was started in
+the East soon after the North Dakota tests had been started.
+Simultaneously fences were erected at Atlantic City, N. J., and
+Pittsburg, Pa. The site of the Atlantic City fence is a strip of land
+running due north from Atlantic and Savannah Avenues and within a short
+distance from the Atlantic Ocean, the exposure being a severe one. The
+site of the Pittsburg fence is back of the athletic field of the
+Carnegie Technical Schools, the fence running east and west and being
+exposed to the heavily charged sooty atmosphere coming from the many
+industrial plants near by.
+
+=Construction of Framework of Fences.= At these two locations framework
+fences were built, upon which were placed a series of painted panels.
+Heavy yellow pine posts six inches square were set in the ground about
+six feet apart and to the depth of about four feet, upon a concrete
+base. The posts were solidly tamped and then braced at the top with
+supplementary studding braces two inches thick. Connecting the posts was
+a line of studding six inches by two inches, forming a solid framework,
+the bottom of which was approximately fifteen inches from the ground.
+The bottoms and tops of the fences were protected by heavy boards two
+inches thick, so that the moisture and rain might be prevented from
+working itself up into the wood. The whole fence was sheathed with
+twelve-inch planed white pine, thus forming a solid background for the
+test panels.
+
+=Lumber for Panels.= The lumber for the test panels was most carefully
+selected, being of three grades--white pine, yellow pine, and cypress. A
+large amount of each grade of lumber was secured, and after the best
+portion had been made up into panels, the panels were inspected by an
+expert lumber classer; nearly 40% being rejected on account of the
+presence of knots or sappy places which appeared upon the surface. Each
+of the panels finally passed upon as suitable for the test was branded
+with a hot iron with consecutive numbers running from 1 to 186. The
+grade of wood used for each panel was indicated by an abbreviated
+mark--W for white pine, C for cypress, and Y for yellow pine. In order
+that a record of each panel might be kept on file, previous to the
+application of paint to the panels, a complete series of photographs was
+taken of the panels in sets of four. This work seemed advisable so that
+the future failure of paint on any one panel, which might be thought due
+to faulty wood, could be either verified or refuted by a reference to
+the series of photographs made of the bare panels.
+
+[Illustration: View of Atlantic City Test Fence]
+
+=Construction of Panels.= The panels were constructed of Dutch weather
+boarding, tongued and grooved together in strips of three pieces and
+capped at the top with a weather strip, forming a finished surface three
+feet long and fifteen and a half inches high. They were firmly braced
+together at their backs and nailed in such a manner that no portion of
+the nails would appear on the surface of the panel, thus preventing the
+staining of the panel from rust. The construction of the framework of
+the fences at Atlantic City and Pittsburg was of such a nature that they
+would each accommodate 560 panels of this type.
+
+=Starting of Tests.= On account of the lateness of the season, it was
+found necessary to do the painting of the tests within a building, so
+that each formula might be subjected to fair and equal conditions of
+application, thus excluding the blowing of dust or rain upon the painted
+surfaces, which would have taken place had the panels been painted upon
+the fence. The painting of the panels began in January, 1908, the
+temperature within the buildings in which the work was done averaging 50
+degrees Fahrenheit throughout the work.
+
+It was decided to test each formula in three colors, in duplicate, and
+on each grade of wood, exposing the duplicates on either side of the
+fence. Thus for one paint formula there were required 18 panels, or 6
+painted in each color and on 3 grades of wood.
+
+=Paints for Tests.= The mixed paints received for the tests were in
+quart cans, having been especially prepared from the formulas submitted
+to manufacturers by the technical committee in charge of the work. They
+were properly labeled with their number and color, in each case. The
+formulas decided upon for the test are described later. The various
+white leads and other single pigment paints which were used were
+received in kegs weighing 12-1/2 pounds each, having been bought in the
+open market and then given a formula number. The formulas of the paints
+designed for both the Atlantic City and Pittsburg tests, as well as the
+numbers of the panels upon which the paints were applied, are shown on
+pages 131-133-145. The analysis of one of the combination paints applied
+is herewith given, to show the correct method of stating the composition
+of a paint.
+
+FORMULA NO. 20, ATLANTIC CITY TEST FENCE
+
+Percentage Composition
+
+  ===================+=======+=======+=======+=======
+                     |Pigment|Vehicle| Total |
+  -------------------+-------+-------+-------+-------
+  Corroded white lead| 67.01 |   --  | 42.84 |
+  Zinc oxide         | 19.89 |   --  | 12.71 |
+  Asbestine          |  3.86 |   --  |  2.47 |
+  Calcium carbonate  |  9.24 |   --  |  5.91 |
+  Raw oil            |   --  | 94.30 | 34.02 |
+  Japan drier        |   --  |  3.89 |  1.40 |
+  Turpentine         |   --  |  1.81 |  0.65 |
+  -------------------+-------+-------+-------+-------
+                     |100.00 |100.00 |100.00 |
+  ===================+=======+=======+=======+=======
+
+=Brushes.= Heavy 7-O round bristle brushes were used for the priming
+coat so that the paint might be well worked into the wood, while for the
+second and third coats three-inch chisel edge brushes were used. These
+brushes were, of course, washed several times with turpentine after
+painting each panel, so that pigments from one paint could not be
+carried over into a paint containing other pigments.
+
+[Illustration: Cypress Panels]
+
+=Shellacking Panels.= The shellacking of any bad places of minor nature
+which may have been present on the surfaces of some of the panels, was
+done with the highest grade orange shellac. It was thought advisable to
+determine whether shellacking over the priming coat of paint or on the
+bare wood previous to the application of the priming coat, was the
+better method. Panels Nos. 1 to 8 in each test were therefore shellacked
+over the priming coat, while on all other panels the shellacking was
+done directly on the bare wood previous to the application of the
+priming coat of paint.
+
+=Application of Paints.= In order to determine just how much paint was
+applied to each panel and to reckon the spreading rate therefrom,
+careful weighings were made during the application of every paint. This
+was carried out by placing a quart can of paint as received, upon a
+laboratory balance, the gross weight being taken and recorded. The can
+was shaken and its contents transferred to a quart-size enameled cup
+where with the aid of a paddle it was broken up into a mixture of even
+consistency. A portion of this paint was then transferred to two small
+sample cans carefully numbered with the formula number, for future
+reference and analysis. The reduction of the paint was then made. The
+brush used on the priming coat was placed with the pot and the paint on
+the balance and the weight taken by the official weigher. The pot was
+then given to the painter who applied the priming coat to one panel. The
+brush, pot, and paint were then handed back to the official weigher and
+the difference in weight recorded. From these data could be reckoned the
+spreading rate of the formula applied.
+
+The drying of the panels was noted every few hours and observations made
+to determine whether the paints were penetrating properly into the
+surface of the wood. A period of eight days was allowed between each
+coat in order that thoroughly hard setting might take place.
+
+During the application of the second coat of paint to the panels, fresh
+cans of paint were used in every case so that fresh reductions could be
+made of the proper consistency. Full data were also recorded on the ease
+of application, working, and nature of drying shown, as well as
+appearance presented by each paint after each coat had been applied. New
+packages of paint were also used for the third coat, and, as a rule, the
+paint was applied without reduction or with full oil reduction,
+turpentine being eliminated in nearly every case for the third coat
+work.
+
+=Reductions.= The single pigment paints, such as white leads, were
+reduced by the so-called ounce system, each ounce of oil added to 12-1/2
+ounces of paste pigment representing one gallon of vehicle to one
+hundred pounds of lead. A complete report of the reductions, spreading
+rates, etc., used in the tests would take up three or four hundred pages
+of printed matter. The reductions shown on the following formulas are,
+however, fairly representative of the reductions used on the combination
+and single pigment paints.
+
+REDUCTIONS ON FORMULA NO. 2
+
+_White and Yellow_
+
+     1st Coat Condition when opened--good. Consistency when broken
+     up--heavy. Reduction recommended by manufacturer--none. Reduction
+     used--3 pints raw oil, 1 pint turps, 1 gallon paint. Consistency after
+     reducing--good, stiff. Working--fair. Drying--fair on pines;
+     cypress--poor. Penetration, pines--good; cypress--poor.
+
+     2nd Coat Consistency when broken up--heavy. Reduction used--1-1/2
+     pints turpentine, 1 pint boiled oil. Consistency after reducing--good.
+     Working--good. Hiding--medium. Drying on pines--good; cypress--poor.
+     One-half pint japan added to gallon of paint. Penetration--fair.
+
+     3rd Coat Reduction used--1-1/2 pints oil, 1/2 pint turpentine.
+
+     _Reductions for Lead Pastes_ Calculated on 100 lb. keg.
+
+     Formulas Nos. 37-38. (Corroded White Lead.)
+
+     1st Coat 6-1/2 gallons oil, 1/2 gallon turpentine, 1 pint turpentine
+     japan.
+
+     2nd Coat 3-1/2 gallons oil, 1 gallon turpentine, 1 pint japan.
+
+     3rd Coat 3 gallons oil, 1 pint turpentine, 1/2 pint japan.
+
+=Hiding Power of Paints.= When the priming coat had thoroughly dried on
+each panel, the painter carefully stencilled a black Geneva cross over
+the priming coat with lampblack in oil. The object of this black cross
+was to make a determination of the comparative opacity or hiding power
+of the different paints applied. It is well known that various pigments
+when ground in oil differ in their hiding power in direct proportion to
+the difference in the refractive indices of the pigments and oils used,
+those containing high percentages of pigments such as white lead and
+zinc oxide being superior in hiding power. After the second and third
+coat of paint had been applied to each panel, there was evident a
+remarkable difference in the hiding power, as the black cross showed
+through in some cases quite clearly, while in other cases it was almost
+completely hidden. The hiding power of a paint is one of the properties
+which the master painter looks upon as most essential, but it should, of
+course, be accompanied in a satisfactory paint by good spreading power
+and longevity.
+
+=Actinic Light Tests.= After the drying of all the paints, it was
+decided that it would be of extreme interest to conduct a test on the
+resistance of certain paints to actinic light. It is well known that the
+ultraviolet or chemical rays of the sun are most energetic in causing
+chemical reactions that result in the early decay of certain types of
+paint. It was thought that the disintegrating effect of these rays, as
+well as their effect in the bleaching out of colors, might be prevented
+by placing upon certain panels small orange colored glass slides which
+would prevent the passing of these rays to the painted surface. The
+slides used were five inches long and three inches wide and were placed
+upon the middle board of certain panels, with picture framing, putty,
+and galvanized iron tacks. The preservation of the underlying surface
+from the sun's rays would, it was thought, prevent the deterioration of
+the paint, and at the same time preserve its original color so that it
+might be compared to the color of the exposed portion at the time of
+inspection.
+
+=Supervision of Tests.= The Atlantic City tests were under the constant
+supervision of Committee E of the American Society for Testing
+Materials, this committee having accepted the inspection of the fence. A
+representative was constantly present throughout the work in order to
+see that each formula received fair treatment. The actual painting work
+was under the supervision of the writer, together with a master painter
+representing George Butler who was chosen by the Master Painters'
+Association of Philadelphia as the official painter of the Atlantic
+City test fence. Mr. J. B. Campbell of Chicago also acted as an official
+of the Paint Manufacturers' Association in the application of the
+formulas to both the Atlantic City and Pittsburg fences.
+
+At Pittsburg the fence was placed directly under the supervision and
+control of the Carnegie Technical Schools, who chose for the fence work
+a committee of their technical force. Drs. James and Schaeffer of this
+institution were present throughout most of the work and were constantly
+represented during the test. The Pittsburg Master Painters' Association
+appointed a committee consisting of Messrs. Dewar, Rapp, and Cluley, for
+the actual painting work, and they were represented with the writer
+throughout the tests.
+
+Great interest was exhibited in the work by the committees in charge,
+and the skill of the practical painters, combined with the care of the
+inspectors, made the treatment of each formula fair and satisfactory.
+
+
+
+
+CHAPTER VII
+
+CONDITIONS NOTED AT INSPECTION OF TESTS
+
+
+=Inspection of Atlantic City Tests.= During the month of March, just one
+year after the placing of the painted panels on the Atlantic City fence,
+an inspection was made jointly by a committee representing the Master
+Painters' Association of Pennsylvania, the Scientific Section of the
+Paint Manufacturers' Association of the United States, and certain
+members of sub-Committee E of the American Society for Testing
+Materials.
+
+=Methods Used at Inspection.= One of the most important tests made when
+inspecting paint is the determination of the chalking taking place.[19]
+There was developed during the inspection of the Atlantic City panels a
+new method for determining the comparative chalking of the various
+paints. It was thought desirable to secure a method, if possible, that
+would show results which might be photographed and even tabulated in
+percentage form, if desired. The apparatus for the new test consisted of
+a small strip of black felt three inches wide by five inches long,
+placed across a small block of wood which would fit in the palm of the
+inspector's hand. This outfit resembled a blackboard eraser and was used
+in a similar way. By holding the apparatus firmly against the panel and
+drawing it half-way across the panel in a straight line toward the
+operator, there was obtained on the black cloth a white mark
+proportional in intensity to the amount of chalking which had taken
+place on the given area. When a series of these cloths were made, they
+were assembled and photographed for comparison. It should be noted that
+the above chalking test is useful only where the painted panels under
+examination have been exposed over a period of one to two years, during
+which period the chalking of paints has been shown to be greatest and
+the chalked surface of a fairly adherent nature. Where longer exposures
+have been made and where rains have removed from the painted panels a
+considerable amount of the chalked pigment which has formed, such a test
+would not be fairly representative of the amount of chalking which had
+taken place.
+
+  [19] Mr. Macgregor of the Picher Lead Co. has just developed a new
+       test to determine the relative imperviousness of paints which
+       have begun to chalk. He draws a mark about two inches long upon
+       the painted surface with a fountain pen. The ink mark will spread
+       rapidly to a wide area if the chalking is of a bad order. If the
+       chalking is slight and the film in good condition, the ink mark
+       will not spread.
+
+[Illustration: Series of Black Felt Cloths used in making the Chalk
+Tests on the Various Formulas. Numbers over Cloths represent Panels]
+
+[Illustration: CHALKING.--Type of Decay Exhibited by Improperly Made
+Paint (magnified view)]
+
+[Illustration: CHECKING.--Type of Decay Exhibited by Improperly Made
+Paint (magnified view)]
+
+[Illustration: BLISTERING.--Type of Decay Exhibited by Improperly Made
+Paint (magnified view)]
+
+[Illustration: CRACKING.--Type of Decay Exhibited by Improperly Made
+Paint (magnified view)]
+
+[Illustration: GENERAL DISINTEGRATION.--Type of Decay Exhibited by
+Improperly Made Paint (magnified view)]
+
+[Illustration: SCALING.--Type of Decay Exhibited by Improperly Made
+Paint (magnified view)]
+
+=Gloss.= The gloss of the various panels was a condition which was also
+reported upon, the middle board of each panel being washed with a wet
+sponge one day before the inspection so that any surface dirt might be
+removed. By looking at a panel from the side, a day after the washing,
+the inspector was enabled to get a fair idea of the degree of gloss
+exhibited by each formula.
+
+=Hiding Power.= The hiding power of each paint was determined, as before
+described, by observing the degree to which the stencilled lampblack
+cross on the priming coat was visible through the second and third
+coats. Single pigment paints such as white lead possessed very great
+hiding power and obscured the black cross almost completely, while the
+cross was quite visible through paints containing high percentages of
+crystalline pigments.
+
+=Checking.= The checking of each panel was determined by examining with
+a small high-power hand glass magnifying fifteen diameters. It is well
+known that examinations with such a hand glass will not determine
+whether so-called fine matt checking is taking place, but it will
+determine whether checking has appeared to any marked extent. Fine matt
+checking is the first sign of the decomposition of a paint, and is
+preliminary to the visible checking seen by the naked eye, which is
+often followed by alligatoring. Examination of some formulas disclosed
+this so-called alligatoring and even the exposed wood between the
+fissured surface which had developed from what were at first fine hair
+checks. It is, in the opinion of the writer, possible to predict with a
+fair degree of accuracy by examination of a painted surface, one year
+after exposure, how the paint will wear in the future and what its
+appearance will be at the end of another year.
+
+=Hardness.= The hardness of each panel could not be determined with any
+degree of accuracy, but the inspectors were able to roughly determine
+this condition by very close inspection. From practical experience of
+the wearing of white lead and zinc oxide, and the comparative hardness
+of these two pigments, zinc oxide was selected as the maximum for
+hardness and termed number 10, while white lead was selected as the
+minimum and termed number 1. The varying degrees of hardness exhibited
+by the formulas were recorded in terms from one to ten. This comparison
+of course was only an approximate one.
+
+=General Condition.= The so-called general conditions of the panels was,
+as a rule, the consensus of the judgment held by the various inspectors,
+with due regard to such properties as chalking, checking, gloss, hiding
+power, color maintenance, condition of surface, etc.
+
+
+
+
+CHAPTER VIII
+
+RESULTS OF ATLANTIC CITY TESTS
+
+
+=Results on Various Woods.= On the Atlantic City Fence all the tests
+made on yellow pine and cypress were found to be in an unsatisfactory
+condition for a report, for in every case the sap and small knots
+contained in such wood had a very bad effect upon the paint, causing
+peeling and scaling. The white pine panels were in very much better
+condition, and it was therefore decided to make the inspection entirely
+from the white pine panels and in the future to remove the yellow pine
+and the cypress panels from the fence and from the test. The Committee
+advised that all future tests be made on white pine, as it is obviously
+unfair to use anything but the highest grade wood for a paint test in
+which the desire is to determine the comparative wearing value of
+pigments.
+
+     NOTE.--Recent tests have shown that Cypress may be successfully
+     painted when the priming coat of paint is thinned with Benzol
+     (Solvent Naphtha).
+
+[Illustration: Panels on Atlantic City Fence Two Lower Sets of Panels
+are painted with Lithopone Paints. Rapid Failure shown]
+
+[Illustration: Panels on Atlantic City Fence]
+
+[Illustration: Panels on Atlantic City Fence
+
+Two Lower Sets of Panels are Painted with Combination Pigment Paints.
+Excellent Results shown]
+
+=Paints Containing Lithopone.= One of the most striking exhibitions of
+paint disintegration in the whole test was the failure of nearly all the
+lithopone formulas tested. At the time these formulas were suggested for
+the test, various European technical journals had advocated the use of
+lithopone in large percentage for paints to be used on exterior
+surfaces. Good results had been obtained in the northwestern section of
+Europe, with this pigment in certain mixtures, and the object of these
+lithopone tests at Atlantic City and Pittsburg was to determine whether
+satisfactory paints could be made of this pigment for exposure in this
+country. Failure of the tests, however, in nearly every case except
+where zinc oxide and whiting were mixed with the lithopone, indicated
+that pigments such as zinc and whiting are necessary in order to prevent
+the decomposition of lithopone pigment paints. The decay of lithopone
+paints after they are applied seems to start with rapid oxidation of the
+linseed oil, and this oxidation seems to continue in a progressive and
+even accelerated way; after six months' exposure the surface of the
+paint being chalked to a great extent and showing rapid decomposition of
+the binder or vehicle. Inasmuch as lithopone is really an inert pigment,
+this rapid decomposition of its vehicle cannot be explained in the same
+way as the decomposition of the vehicle of pure white lead paints, where
+the alkaline nature of the lead is probably responsible for the
+formation of easily destroyed compounds. As complete failure had taken
+place in nearly every case where lithopone had been used, it was decided
+to condemn the lithopone panels on the fence, consisting of formulas 21
+to 27, including panels 151 to 164 in white, panels 131 to 144 in
+yellow, and 109 to 122 in gray. These lithopone tests were later on
+replaced by new tests in 1909, which will be reported upon later in this
+book.
+
+=General Results.= From these tests, the inspectors reached the
+unanimous conclusion that a paint made from any mixture of more than one
+white opaque pigment, either when used alone or in combination with
+small percentages of inert pigments, is far superior to any one single
+pigment paint. It was found that the straight white lead paints failed
+in every case, and this failure was so marked as to make it a conclusive
+demonstration of the unfitness of white lead along the Atlantic coast,
+when used without other pigments. Paints made with large percentages of
+white lead, however, gave excellent results.
+
+Gypsum was found unsafe to use in any large proportion in a paint,
+because of its solubility and liability to percolate through the coating
+of linoxyn or dried film, thus destroying the surface of the paint.
+Whiting, or calcium carbonate, demonstrated that it could be used in
+moderate percentage with some efficiency, but it was evident that any
+great excess of this pigment must also be avoided on account of its
+tendency towards rapid chalking. Magnesium silicate, aluminum silicate,
+and silica are three inert pigments which proved to be of great value in
+strengthening and reinforcing paints, especially when they were used in
+small percentage. In the same way, black fixe and barytes, or barium
+sulphate, also appeared to be useful in strengthening a paint. As these
+two last named pigments are chemically the same but physically
+different, the use of both in a paint formula is considered
+advantageous, because of the differences in size and form of their
+particles.
+
+=Color Tests.= It was the unanimous conclusion of all the inspectors
+that panels of all formulas which were tinted either gray or yellow were
+showing far superior wear and less chalking and checking than those
+which were painted in plain white. The reinforcing action of the tinting
+materials must be credited for this lengthening of the wear of such
+paints. Formulas 5, 6, 9, and 16, for instance, in the gray, were in
+most excellent condition, and in these formulas were used ochre, umber,
+bone-black, carbon-black, Venetian red and other inert bases. On the
+yellow panels, formulas 5, 6, 9, and 16 were also in very superior
+condition, and in these formulas chrome yellow and inert pigments were
+also used.
+
+Some of the color tests included the priming of boards with white lead,
+zinc oxide, sublimed white lead, lithopone, and other single pigment
+paints. Over these priming coats was placed a high grade brilliant
+paranitraniline red. Fairly good results were obtained in every case,
+but especially when lithopone or zinc oxide was used as a priming base.
+These pigments seemed to have no effect upon the constitution of the
+para red.
+
+Prussian blue, a colored pigment largely used, but one liable to react
+with certain paint pigments, was admixed with various paints applied to
+certain panels. This color was found in some cases to have faded
+materially, especially when mixed with alkaline pigments such as white
+lead. Sublimed white lead and zinc oxide, which are more inert in
+nature, did not have such action on Prussian blue, and the tinted bases
+of these pigments stood up in a remarkable manner. The greens which were
+tested were all in very good condition, with absence of fading, and
+showing only slight mildew.
+
+=Condensed Results of Inspection.= The results of inspection as obtained
+by the fence committee[20] having in charge the inspection of the test,
+have been condensed into table form, and are presented on pages 130-131.
+
+  [20] R. S. Perry, Director Scientific Section, Paint Manufacturers'
+       Association of the U. S.; George Butler, Official Painter,
+       representing Master House Painters' & Decorators' Association, H.
+       A. Gardner, Asst. Director.
+
+=Second Annual Inspection of the Atlantic City Test Fence.= After the
+original paints which had been applied to the Atlantic City Fence had
+been exposed for over two years, another inspection was made by a
+committee representing the Master Painters' Association of Philadelphia
+and the Scientific Section of the Paint Manufacturers' Association of
+the United States. A digest of the report of this committee[21] follows:
+
+  [21] George Butler, Official Painter Atlantic City Test Fence,
+       representing Philadelphia Master Painters' Association; Charles
+       Macnichol, Master Painter; Henry A. Gardner, Director Scientific
+       Section, Paint Manufacturers' Association of the U. S.
+
+"The painted panels were all carefully inspected by the inspectors in
+the usual manner. With the aid of high-power magnifying glasses,
+checking was determined. The degree of chalking exhibited by the various
+paints was ascertained by rubbing a piece of black cloth across the
+surface of each paint. Close observance was made to determine scaling,
+peeling, cracking, gloss, color, and the other factors to be considered
+when examining a painted surface. From these observations it was
+possible for the inspectors to state whether a panel exhibited general
+good condition, general fair condition, or general poor condition.
+
+CHART OF RESULTS--FIRST INSPECTION--ATLANTIC CITY TEST FENCE
+
+  ==============================+=================================+
+  Formula                       |         INERT PIGMENTS          |
+  No.                           |---------------------------------|
+    |Carbonate                  |Calcium                          |
+    |Lead                       |Carbonate                        |
+    |      |Zinc                |     |Calcium                    |
+    |      |Oxide               |     |Sulphate                   |
+    |      |      |Sublimed     |     |     |Magnesium            |
+    |      |      |White        |     |     |Silicate             |
+    |      |      |Lead         |     |     |     |Barium         |
+    |      |      |      |Zinc  |     |     |     |Sulphate       |
+    |      |      |      |Lead  |     |     |     |    |Silica    |
+    |      |      |      |White |     |     |     |    |    |Blanc|
+    |      |      |      |      |     |     |     |    |    |Fixe |
+  --+------+------+------+------+-----+-----+-----+----+----+-----+
+    |   %  |   %  |   %  |   %  |  %  |  %  |  %  |  % |  % |  %  |
+   1| 30.0 | 70.0 |      |      |     |     |     |    |    |     |
+   2| 50.0 | 50.0 |      |      |     |     |     |    |    |     |
+   3| 20.0 | 50.0 | 20.0 |      |10.0 |     |     |    |    |     |
+   4| 48.5 | 48.5 |      |      | 3.0 |     |     |    |    |     |
+   5| 22.0 | 50.0 |      |      | 2.0 |     |26.0 |    |    |     |
+   6|      | 64.0 |      |      |     |     |     |36.0|    |     |
+   7| 37.0 | 63.0 |      |      |     |     |     |    |    |     |
+   8| 38.0 | 48.0 |      |      |     |     |     |    |14.0|     |
+   9|      | 73.0 |      |      |     |     | 2.0 |    |25.0|     |
+  10| 44.0 | 46.0 |      |      | 5.0 |     | 5.0 |    |    |     |
+  11| 50.0 | 50.0 |      |      |     |     |     |    |    |     |
+  12| 60.0 | 34.0 |      |      |       6% Inert  Pigments        |
+  13|      | 27.0 | 60.0 |      | 3.0 |     |10.0 |    |    |     |
+  14| 25.0 | 25.0 | 20.0 |      | 5.0 |25.0 |     |    |    |     |
+  15| 20.0 | 40.0 |      | 30.0 |10.0 |     |     |    |    |     |
+  16| 33.0 | 33.0 |      |      |     |     |     |34.0|    |     |
+  17| 40.0 | 40.0 |      |      |     |     | 3.0 |13.0|    | 4.0 |
+  18| 75.0 | 25.0 |      |      |     |     |     |    |    |     |
+  19|      | 25.0 | 75.0 |      |     |     |     |    |    |     |
+  20| 67.0 | 19.5 |      |      |10.0 |     | 3.5 |    |    |     |
+  33| 15.0 | 30.0 | 25.0 |      |     |     |     |    |30.0|     |
+  34| 38.95| 33.58|  4.81|      |19.48|     | 3.18|    |    |     |
+  35| 37.51| 25.87|  7.84|      |20.36|     | 8.42|    |    |     |
+  36|100.0 |      |      |      |     |     |     |    |    |     |
+  37|100.0 |      |      |      |     |     |     |    |    |     |
+  38|100.0 |      |      |      |     |     |     |    |    |     |
+  39|      |      |      |100.0 |     |     |     |    |    |     |
+  40|      |      |100.0 |      |     |     |     |    |    |     |
+  45|      |100.0 |      |      |     |     |     |    |    |     |
+  46|      | 61.0 |      |      |     |     |     |39.0|    |     |
+  47|      |100.0 |      |      |     |     |     |    |    |     |
+  ==+======+======+======+======+=====+=====+=====+====+====+=====+
+
+  ======================+==========+======+=========+======+
+  Formula               |Panel     |Hiding|Color    |Hard- |
+  No.                   |No.       |Power |         | ness |
+    |First              |   |Condi-|      |         |      |
+    |Coat               |   | tion |      |         |      |
+    |   |Second         |   |      |      |         |      |
+    |   |Coat           |   |      |      |         |      |
+    |   |    |Third     |   |      |      |         |      |
+    |   |    |Coat      |   |      |      |         |      |
+    |   |    |    |Aver-|   |      |      |         |      |
+    |   |    |    | age |   |      |      |         |      |
+  --+---+----+----+-----+---+------+------+---------+------+
+    |   |    |    |     |   |      |      |         |      |
+   1|610| 987| 664|  754|  1|Good  |Good  |Excellent| 8    |
+   2|913|1066| 948|  976|  3|Good  |Good  |Good     | 5    |
+   3|912| 914| 786|  871|  5|Good  |Fair  |Good     | 4    |
+   4|759| 939|1047|  915|  7|Good  |Good  |Good     | 5    |
+   5|714|1000| 709|  808|  9|Good  |Weak  |Good     | 8-1/2|
+   6|928|1189| 863|  993| 11|Fairly|Weak  |Good     | 8    |
+    |   |    |    |     |   |Good  |      |         |      |
+   7|763| 972| 891|  875| 13|Good  |Good  |Off Color| 7    |
+   8|786| 910| 767|  821| 15|Good  |Good  |Good     | 8-1/2|
+   9|716|1081| 812|  870| 17|Fair  |Poor  |Good     | 9    |
+  10|861|1014| 862|  912| 19|Good  |Fair  |Good     | 5    |
+  11|822| 959| 918|  900| 21|Good  |Good  |Excellent| 7-1/2|
+  12|862| 965| 734|  854| 23|Good  |Medium|Good     | 4    |
+  13|916|1031|1121| 1073| 25|Good  |Good  |Good     | 4    |
+  14|564| 806| 785|  718| 27|Bad   |Medium|Good     | 5    |
+  15|935|1044|1359| 1113| 29|Good  |Medium|Good     | 8-1/2|
+  16|799| 903| 994|  899| 31|Fair  |Fair  |Good     | 7-1/2|
+  17|806|1016| 884|  902| 33|Good  |Fair  |Good     | 4    |
+  18|788|1257| 973| 1006|145|Good  |Good  |Excellent| 3    |
+  19|700|1183|1400| 1094|147|Good  |Good  |Excellent| 2    |
+  20|776|1063| 877|  905|149|Good  |Good  |Good     | 5    |
+  33|512| 836| 689|  679|176|      |Fair  |         |      |
+  34|523| 800| 810|  711|175|Good  |Medium|Good     | 4    |
+  35|450| 893| 724|  689|180|Good  |Good  |Good     | 4    |
+  36|408| 711| 861|  660|181|Bad   |Good  |Good     | 1    |
+  37|524|1065| 828|  806|182|Bad   |Good  |Good     | 1    |
+  38|555| 888| 794|  746|177|Bad   |Good  |Good     | 1    |
+  39|550| 941| 916|  802|178|Good  |Fair  |Good     | 6    |
+  40|643| 810| 998|  817|168|Good  |Good  |Good     | 2    |
+  45|850|    |    |     |170|Fair  |Fair  |Good     | 9    |
+  46|783|    |    |     |169|Fair  |Good  |Good     | 9    |
+  47|730|    |    |     |172|      |Good  |Good     |10    |
+  ==+===+====+====+=====+===+======+======+=========+======+
+
+  ==============+===========+===========+===============================
+  Formula       |           |           |
+  No.           |           |           |
+    |Checking   |Chalking   |Gloss      |Remarks
+  --+-----------+-----------+-----------+-------------------------------
+    |           |           |           |
+   1|           |Very Slight|High       |Like rubbed varnish work.
+   2|Hard Matt  |Moderate   |Med. High  |
+   3|           |Medium     |Slight     |
+   4|           |Very Slight|Med. High  |
+   5|           |Slight     |High       |Hard surface.
+   6|Matt       |           |Good       |Surface rough.
+   7|           |Slight     |High       |
+   8|           |Slight     |High       |
+   9|Heavy Matt |Medium     |High       |Peeling started.
+  10|           |Some       | Med. High |
+  11|Med. Matt  |Some       |Med. High  |Some washing and discoloration.
+  12|Heavy Matt |Bad        |Medium     |
+  13|           |Medium     |Fair       |
+  14|Evident    |Some       |Medium     |Dead, spongy, surface. White
+    |           |           |           |incrustations.
+  15|Coarse Matt|Slight     |High       |
+  16|Bad        |Slight     |Good       |White incrustations.
+  17|           |Some       |Fair       |
+  18|Hard Matt  |Moderate   |Medium     |
+  19|Hard Matt  |Slight     |Very Little|
+  20|           |Very Little|Medium     |
+  33|           |           |Good       |Rough surface.
+  34|Evident    |Slight     |Egg Shell  |
+  35|Matt       |           |Egg Shell  |
+  36|Very       |Bad        |Egg Shell  |Same as 177, but
+    |Apparent   |           |           |checking not so bad.
+  37|Very       |Bad        |Egg Shell  |Same as 177 but wood
+    |Apparent   |           |           |shows more plainly.
+  38|Bad        |Bad        |Egg Shell  |Cracking and perishing evident.
+  39|           |Some       |Good       |
+  40|           |Consider-  |Egg Shell  |
+    |           |able       |           |
+  45|Very Evi-  |           |High       |
+    |dent       |           |           |
+  46|Some       |           |Good       |
+  47|Apparent   |           |Good       |Indication of scaling.
+  ==+===========+===========+===========+===============================
+
+"An inspection of the white lead paints on the fence indicated in every
+instance a rough, chalked, and disintegrated surface that seemed to be
+well worn, in some cases nearly to the wood. The strongly oxidizing air
+of the seacoast is probably responsible for the early decay of this
+pigment.
+
+"It was observed that the combination type of paint showed better hiding
+power than white lead, over the black crosses placed on the priming coat
+of each panel, as a hiding power test.
+
+[Illustration: Front of Fence showing Present Rearrangement of Panels]
+
+TESTS INAUGURATED IN 1907
+
+CHART OF RESULTS OF SECOND ANNUAL INSPECTION OF ATLANTIC CITY TEST
+FENCE, MAY, 1910
+
+  =========================================================+
+                           FORMULAS                        |
+  --+------------------------+-----------------------------+
+  F |                        |        INERT PIGMENTS       |
+  o |                        +-----------------------------+
+  r |Basic Carbonate         |Calcium                      |
+  m |White Lead              |Carbonate                    |
+  u |      |Zinc Oxide       |     |Calcium                |
+  l |      |      |Basic     |     |Sulphate               |
+  a |      |      |Sulphate  |     |  |Magnesium           |
+    |      |      |White Lead|     |  |Silicate            |
+  N |      |      |    |Zinc |     |  |    |Barium         |
+  u |      |      |    |Lead |     |  |    |Sulphate       |
+  m |      |      |    |White|     |  |    |     |Silica   |
+  b |      |      |    --+   |     |  |    |     |   |Blanc|
+  e |      |      |      |   |     |  |    |     |   | Fixe|
+  r |      |      |      |   |     |  |    |     |   --+   |
+  --+------+------+------+---+-----+--+----+-----+-----+---+
+    |  %   |  %   |  %   |  %|  %  | %| %  | %   | %   |  %|
+   1| 30   | 70   | --   | --| --  |--|--  |--   |--   | --|
+   2| 50   | 50   | --   | --| --  |--|--  |--   |--   | --|
+   3| 20   | 50   | 20   | --|10   |--|--  |--   |--   | --|
+   4| 48.5 | 48.5 | --   | --| 3.0 |--|--  |--   |--   | --|
+   5| 22   | 50   | --   | --| 2   |--|26  |--   |--   | --|
+   6| --   | 64   | --   | --| --  |--|--  |36   |--   | --|
+   7| 37   | 63   | --   | --| --  |--|--  |--   |--   | --|
+   8| 38   | 48   | --   | --| --  |--|--  |--   |14   | --|
+   9| --   | 73   | --   | --| 2   |--|--  |--   |25   | --|
+  10| 44   | 46   | --   | --| 5   |--| 5  |--   |--   | --|
+  11| 50   | 50   | --   | --| --  |--|--  |--   |--   | --|
+  12| 60   | 34   | --   | --| --  |  6% Inert Pigment | --|
+  13| --   | 27   | 60   | --| 3   |--|10  |--   |--   | --|
+  14| 25   | 25   | 20   | --| 5   |25|--  |--   |--   | --|
+  15| 20   | 40   | --   | 30|10   |--|--  |--   |--   | --|
+  16| 33   | 33   | --   | --| --  |--|--  |34   |--   | --|
+  17| 40   | 40   | --   | --| --  |--| 3  |13   |--   |  4|
+  18| 75   | 25   | --   | --| --  |--|--  |--   |--   | --|
+  19| --   | 25   | 75   | --| --  |--|--  |--   |--   | --|
+  20| 67.0 | 19.5 | --   | --|10.0 |--| 3.5|--   |--   | --|
+  33| 15   | 30   | 25   | --| --  |--|--  |--   |30   | --|
+  34| 38.95| 33.58|  4.81| --|19.48|--|--  | 1.59| 1.59| --|
+  35| 37.51| 25.87|  7.84| --|20.36|--|--  | 4.21| 4.21| --|
+  36|100   | --   | --   | --|--   |--|--  |--   |--   | --|
+  37|100   | --   | --   | --|--   |--|--  |--   |--   | --|
+  38|100   | --   | --   | --| --  |--|--  |--   |--   | --|
+  39| --   | --   | --   |100| --  |--|--  |--   |--   | --|
+  40| --   | --   |100   | --| --  |--|--  |--   |--   | --|
+  45| --   | 90   | --   | --|10   |--|--  |--   |--   | --|
+  46| --   | 61   | --   | --| --  |--|--  |39   |--   | --|
+  47| --   |100   | --   | --| --  |--|--  |--   |--   | --|
+  ==+======+======+======+===+=====+==+====+=====+=====+===+
+
+  ==+========================================+===
+  F |                                        |
+  o |                                        |
+  r |                                        | P
+  m |                                        | a
+  u |                                        | n
+  l |                                        | e
+  a |                                        | l
+    |          REPORT OF INSPECTION          |
+  N +-----------+------------+------+--------+ N
+  u |           |            |GENE- |        | u
+  m |           |            |RAL   |        | m
+  b |           |            |CON-  |        | b
+  e |           |            |DI-   |        | e
+  r |CHALKING   |CHECKING    |TION  |REMARKS | r
+  --+-----------+------------+------+--------+---
+   1|Very slight|Very slight |Good  |--      |  1
+   2|Medium     |Slight      |Very  |--      |  3
+    |           |            |good  |        |
+   3|Medium     |Slight      |Good  |--      |  5
+   4|Very slight|Slight      |Good  |--      |  7
+   5|Slight     |Slight      |Good  |--      |  9
+   6|Very slight|Slight      |Good  |--      | 11
+   7|Medium     |Slight      |Good  |--      | 13
+   8|Slight     |Very slight |Good  |--      | 15
+   9|Very bad   |Deep, with  |Poor  |--      | 17
+    |           |scaling     |      |        |
+  10|Heavy      |Deep        |Medium|--      | 19
+  11|Medium     |Medium      |Fair  |--      | 21
+  12|Medium     |Deep        |Fair  |--      | 23
+  13|Medium     |Slight      |Very  |--      | 25
+    |           |            |good  |        |
+  14|Medium     |Lateral     |Fair  |--      | 27
+  15|Slight     |Visible with|Poor  |--      | 29
+    |           |naked eye   |      |        |
+  16|Slight     |Slight      |Good  |--      | 31
+  17|Medium     |Slight      |Good  |--      | 33
+  18|Medium     |Slight      |Very  |--      |145
+    |           |            |good  |        |
+  19|Consider-  |Deep        |Good  |--      |147
+    |able       |            |      |        |
+  20|Medium     |Slight      |Good  |--      |149
+  33|Medium     |Slight      |Very  |--      |176
+    |           |            |good  |        |
+  34|Slight     |Slight      |Good  |--      |175
+    |           |lateral     |      |        |
+  35|Slight     |Lateral     |Good  |--      |180
+  36|Consider-  |Heavy       |Fair  |Rough   |181
+    |able       |            |      |surface |
+  37|Consider-  |Heavy and   |Poor  |Rough   |182
+    |able       |deep        |      |surface |
+  38|More than  |Very deep   |Poor  |--      |177
+    |Panel no.  |            |      |        |
+    |182        |            |      |        |
+  39|Consider-  |Very slight |Good  |--      |178
+    |able       |            |      |        |
+  40|Heavy      |Slight      |Good  |--      |168
+  45|Slight     |Slight      |Good  |--      |170
+  46|Slight     |Medium      |Fair  |--      |169
+  47|None       |Very deep   |Poor  |--      |172
+  ==+===========+============+======+========+===
+
+"There are no pigments possessing greater hiding properties when first
+used than white leads, but the lack of hiding power on the white lead
+panels after two years' exposure was caused by the chalking away of the
+lead. The superior hiding power of the composite paints was due to the
+action of the other pigments in these combination paints in preventing
+the lead from chalking away.
+
+"The Committee finds that the addition of a reasonable percentage of
+zinc oxide to white lead increases its durability and retards its
+chalking, renders it whiter, and forms a surface that presents a much
+better repainting condition. The combinations of white lead and zinc
+oxide on the Atlantic City Test Fence were in general good condition
+throughout.
+
+"Corroded white lead, sublimed white lead, zinc oxide, and zinc lead are
+the standard white opaque pigments. They were all tested on the Atlantic
+City Fence and it was found that to use any one alone results in
+inferior protection to the wood. Barium sulphate, silica, asbestine,
+china clay, and calcium carbonate are the standard crystalline pigments.
+In the past, the overloading of paints with these crystalline or inert
+pigments has been the cause of the prejudice that painters have had
+against their use. It has been established beyond controversy, however,
+that the use of these pigments, in moderate percentage, combined with
+any of the standard opaque white pigments, such as white leads, zinc
+oxide, etc., undoubtedly results in better service from every standpoint
+and forms the most satisfactory white paint for general outside use.
+Some of the most perfect painted surfaces on the fence were those made
+on the above basis as reference to the charted report will show."
+
+
+
+
+CHAPTER IX
+
+RESULTS OF PITTSBURG TESTS
+
+
+The First Annual Inspection of the Pittsburg Test Fence took place
+during May, 1909, a little over one year after the painted panels had
+been placed in position. The inspectors found that in Pittsburg a heavy
+deposit of soot had formed on the panels, and they considered it
+therefore inadvisable to make a detailed report of the inspection until
+the second year of the exposure. The general results of the Pittsburg
+inspection as reported by the three committees[22] having supervision
+over the work, is, however, given herewith.
+
+  [22] J. H. James, Chairman Test Fence Committee, Carnegie Technical
+       Schools.
+       A. C. Rapp, Chairman Fence Committee, Pittsburg Branch
+       Pennsylvania State Association of Master Painters.
+       R. S. Perry, Director Scientific Section, Paint Manufacturers'
+       Association of the U. S.; H. A. Gardner, Asst. Director.
+
+[Illustration: Pittsburg Test Fence]
+
+During the inspection of the Pittsburg tests it was decided to condemn
+the lithopone panels on the fence, which consisted of formulas 21 to 27,
+including panels 151 to 164 in white, 131 to 144 in yellow, 109 to 122
+in gray. Almost complete failure had taken place in every case where
+lithopone had been used. These lithopone tests were later on replaced by
+new tests which are described later in this book.
+
+"=Wood Most Valuable for Test.= As on the Atlantic City Fence, the white
+pine panels afforded the best results and gives the best indication of
+the comparative wearing of the paints and affords no unfair condition,
+such as other woods might offer, to interfere with the test.
+
+"=Condition of Cypress.= Cypress showed inferior conditions, except that
+it was more pronounced and more discoloration of the panels was noticed
+on this grade of wood, which seems to be extremely greasy in nature and
+difficult to properly prime, even when the paint used upon this wood
+contains a large percentage of volatile diluent.
+
+"=Removal of Lithopone Panels.= The Joint Committees confirmed the
+previous recommendation to remove all the lithopone formulas, and they
+decided to remove the cypress and the yellow pine panels in every
+formula except in the white paints.
+
+"It was decided to reassemble all the white pine panels and group them
+together for purposes of comparison, and in place of the panels
+condemned and removed, to substitute a series of new formulas, to
+further widen the scope of the tests.
+
+"=Ultimate Value of Mixed Paints.= The results of the inspection
+conclusively show that a mixture of more than one prime white pigment,
+whether this mixture be alone or in combination with a small percentage
+of inert pigment, produces a paint far superior to a paint manufactured
+from one pigment alone.
+
+"As a general statement of the comparative wearing of the paints, it
+might be said that the composite formulas are less advanced toward
+destruction than the paints made from single pigments such as
+lithopones, white leads and zinc oxides. It is not to be understood from
+this statement that it is the opinion of the committee that all of the
+composite formulas are of equal value or that all of them are to be
+recommended, but it is meant that the higher types, as evidenced by the
+appearance of the panels, are in the above relation to the single
+pigment paints.
+
+[Illustration: Panels on Pittsburg Test Fence]
+
+"=Lithopone Destroyed Rapidly at Pittsburg.= It was evident some time
+ago that the formulas containing large percentages of lithopone were
+rapidly failing, and their appearance was very much the same as those
+formulas of a similar type at Atlantic City. There seems, however, to be
+some difference in the way these formulas broke down; those on the
+Pittsburg Fence having shown the quicker destruction, possibly due to
+the action of the acid gases in the air upon the paint coating. This
+further confirms the statement that paint compositions containing such
+heavy percentages of lithopone and intended for outside use must be
+designed with relation to the particular uses of the product and to the
+climate in which they are to be used. It will also be necessary to
+consider more carefully the vehicle of the paints which are to be made
+of this pigment.
+
+"=Possible Value of Excluding Vehicle for Lithopone.= It was the belief
+of the committee that much better paints containing lithopone could be
+designed by varying the percentages of the materials contained in the
+formulas, and it was suggested that a less penetrable vehicle, made more
+on the line of a varnish, and not as easily affected as straight
+linoxyn, should be experimented with in connection with these lithopone
+formulas.
+
+"The success of certain European countries in using lithopone as a
+pigment, even in a very high percentage, may be due to the use of a
+special vehicle, and, if it is found in future tests that this material,
+which has been reported as well suited in Northern European climates,
+may be benefited and made of service by the addition of special oils and
+special vehicles, then this test would be of great value to the whole
+paint trade at large.
+
+"Preliminary inspections were made on October 6th and later on December
+12th, 1908, and a marked difference was observed at the two inspections
+in the wearing of the various formulas.
+
+"The lapse of the two months between these inspections gave opportunity
+during which cold weather caused contraction of the paint film which had
+been previously subjected to the hot summer sun, and caused marked
+chalking of the white lead formulas. On October 6th this chalking was
+just commencing, while in the December inspection it was well advanced,
+and at the annual inspection, had proceeded to such an extent that the
+pigment had been washed from the panels representing those paints which
+had started early chalking.
+
+"Panel 177, representing Zinc Lead, was found to be extremely dark in
+color throughout the coating and was more on the order of a grayish
+tint. It resisted all attempts to wash it down to a white surface. The
+panel, however, in other respects, was in fairly good condition.
+
+"=Condition of Corroded White Lead Panels.= Panel 174, representing Type
+B Pure Basic Carbonate-White Lead, was very badly perished and
+discolored, and an examination of the surface showed very bad checking.
+Long continued washing with a sponge removed a discolored surface and
+showed but a rather thin coating. Panel 175, representing Type C Pure
+Basic Carbonate-White Lead, showed most marked checking and was in very
+much the same condition as 174 and 176. Panel 176, representing Type A
+Pure Basic Carbonate-White Lead, was in the same condition as the Type B
+and C Basic Carbonate-White Leads.
+
+"=Condition of Sublimed White Lead.= Panel 178, representing Sublimed
+White Lead (Basic Sulphate-White Lead,) was chalking, and the paint coat
+was somewhat disintegrated. The chalking present on this formula,
+however, showed that the disintegration of the paint coat had not taken
+place for several months after the Basic Carbonate-White Leads. This
+panel maintained good color, not being acted upon by sulphur gases.
+
+"=Blackening of Corroded White Lead.= The black and gray formation on
+all the Basic Carbonate-White Lead panels was probably due to the action
+of sulphur gases which are present in the district immediate to
+Pittsburg, and which may cause the formation of black sulphide of lead.
+
+"Possibly a general conclusion from all these panels might be described
+as a perishing of the paint coating, with the formation of sulphide of
+lead which to a certain extent protects the coating beneath it, but the
+perishing has proceeded to such an extent that the unaltered paint
+coating left is but a slight protection to the wood, being extremely
+thin.
+
+"The committee resolved that the detailed observations of the panels
+could not be made and that they would not be justified in making
+detailed comparisons between the various formulas, giving the gloss,
+hardness, general condition, checking, etc. Precision in this work at
+such a time was impossible, and it was decided that a further period
+would have to elapse before such a detailed comparison could be made
+between the various blended or composite formulas on the fence.
+
+"=Report on Colors.= It was resolved that at the next inspection of the
+Pittsburg Fence, portions of the original samples of the original paints
+used for the yellows and grays should be on hand, previously painted out
+on small panels for comparison for the deterioration of the colors on
+these same panels on the fence.
+
+"An examination of the combination formula grays by the committee led to
+the general conclusion that those grays which did not contain a very
+large percentage of white lead were superior in their maintenance of
+tone and tint and general condition to any of the other grays upon the
+fence. However, the presence of umber, ochre, and red oxide in some of
+the grays which showed to the best advantage may account for their
+permanence of tone. Some of these grays were the so-called warm grays
+and were much darker in tone and tint than the ordinary drab which is
+generally applied.
+
+"The straight pure Basic Carbonate-White Lead paints were not painted
+out in grays or yellow, the test upon this material being only in white.
+
+"On Panels 120 and 126, which represent formulas 6 and 9 respectively,
+the grays are in most excellent condition, and it will be found, by
+reference to formulas 6 and 9, that there is an absence of white lead in
+their composition. These formulas, however, contained a small percentage
+of umber and ochre. Formulas 5 and 16 contained over 20% White Lead and
+the gray of these formulas maintained their blue tone very well. These
+formulas were tinted solely with lampblack.
+
+"An inspection of Panel 138, which represents Formula 15, showed good
+maintenance of color in the gray, and was in much better condition as
+regards permanence of color than the other grays containing white lead.
+
+"A study of the yellow panels on the fence led to the unanimous
+conclusion that a liberal amount of Basic Carbonate-White Lead seemed to
+have a beneficial result in preserving the bright tone of the chrome
+yellow in tints so strong as those used on the fence. It was noted that
+Panel 108, which represents Formula 28, and in which zinc yellow was
+used, showed great permanence of tone and tint. Unfortunately this zinc
+chromate was added to a formula containing a large percentage of
+lithopone, and the destruction of the lithopone to a great extent
+affected the value of this test.
+
+[Illustration: Whiteness of Sublimed White Lead
+
+Darkness of Corroded White Lead
+
+On Pittsburg Test Fence]
+
+"=Maintenance of Para Reds.= A study of the paranitraniline or azo reds
+painted over the various pigments as priming coats demonstrated that the
+reds on this fence are in better condition than the reds at Atlantic
+City. As is well known, para red is manufactured by precipitation in an
+acid solution and is best maintained under acid conditions. The acidity
+of the Pittsburg atmosphere, caused by the large amount of acid gases
+which are being poured into the air, day in and day out, and which are
+constantly condensing on the surface of structures, may account for the
+better preservation of these reds.
+
+"It was noted that the para reds which were applied to panels prime
+coated with white lead seemed to be brightening in color and seemed to
+be gradually working over toward a lightening which may in the future
+show a pinkish tint.
+
+"=Report on Greens.= The bronze green is in most excellent condition and
+shows an absence of the mildew appearance which was observed at Atlantic
+City.
+
+"The chrome green is standing up exceedingly well, there being
+practically no change whatsoever in the color since it was exposed.
+
+"=Best Base for Blues.= An inspection of the blues showed that those
+which gave the greatest permanence and the least amount of fading were
+applied in combination with either Sublimed White Lead (Basic
+Sulphate-White Lead), or zinc oxide, while those blues which were
+applied in combination with Basic Carbonate-White Lead showed marked
+failure and were completely bleached out, due, of course, to the
+alkaline nature of the corroded white lead; Prussian blues being
+transformed by alkalies to a white compound.
+
+"=Superior Value of Composite Formulas.= Some of the mixed leads, or
+so-called graded leads, which are combinations of white leads with other
+high-grade pigments and containing some inert pigments, were not
+deteriorated so far as the white lead formulas, and the general
+conclusion was that they were upward of six months behind the
+deterioration of the straight white leads, and this was confirmed by the
+presence of moderate chalking, showing an excellent repainting surface
+and a better thickness and condition of the paint coating.
+
+"The same conclusions which were reached at Atlantic City, as to the
+best method of shellacking, obtained also on the Pittsburg Fence,
+namely, that application of the shellac to the wood previous to the
+first coat is the better method.
+
+"=Analysis of Paints.= At the time of the painting of the fence a sample
+of each paint was placed in small friction top cans, carefully labeled,
+and sent to the Carnegie Technical Schools' laboratory for analysis.
+The analyses of these paints were made by members of the Test Fence
+Committee, representing the schools, and appear in this bulletin. The
+results obtained conform very closely to the formulas which were applied
+to the fence, a variance of only one or two per cent. being shown in the
+amount of the different pigments."
+
+=Second Annual Inspection of Pittsburg Test Fence.= The second annual
+inspection of the Pittsburg Test Fence was made on Thursday, May 7th,
+1910. The panels in Pittsburg after having weathered for over two years
+presented an appearance which allowed the making of a detailed
+inspection, this having been found impossible during the first annual
+inspection. The inspection party[23] included those master painters who
+represented the Pittsburg Master Painters' Association, who were in
+charge of the application of the paints in 1907, 1908, and 1909,
+together with the test fence committee from the faculty of the Carnegie
+Technical Schools, and representatives of the Scientific Section. A
+summary of the report issued by this committee follows:
+
+  [23] A. C. Rapp, Chairman, Test Fence Committee, Pittsburg Branch,
+       Master Painters' Association; John Dewar, member Fence Committee,
+       Pittsburg Branch, Pennsylvania State Association of Master
+       Painters; J. H. James, Chairman, Carnegie Technical Schools' Test
+       Fence Committee; John A. Schaeffer, member Test Fence Committee,
+       Carnegie Technical Schools; Henry A. Gardner, Director Scientific
+       Section, Paint Manufacturers' Association of the U. S.
+
+"Two of the members of the inspection party have been impressed with the
+lumber lottery existing in some field tests, which have been conducted,
+and feel that when the object of a test is to determine the relative
+value of paints, such tests should be conducted on a standard grade of
+wood, such as white pine. The use of cypress, pitch pine, and other
+faulty woods, is often the cause of the failure of a paint, which on
+good wood would show up well. For this reason, only the white pine
+panels painted with white paints were considered in the inspection, the
+yellow pine panels and cypress panels having been thrown out of the test
+at last year's inspection.
+
+"Checking, cracking, and alligatoring on the painted surfaces were
+determined by using a magnifying glass. The degree of chalking existing
+was decided upon by using small pieces of black felt cloth, rubbing
+them against the surface of the panel; the degree of whiteness removed
+upon the cloth being indicative of the amount of chalking taking place.
+General condition was decided upon after carefully weighing the opinion
+of each member of the inspection party, as regards the general
+characteristics shown by each paint, such as checking, chalking,
+scaling, condition for repainting, hiding power, etc. The results have
+been charted and presented in this manner:[24]
+
+  [24] An endeavor was made to use uniform terms in reporting on each
+       formula. In some cases it was necessary to bring out more
+       forcibly the condition by the insertion of qualifying remarks.
+
+[Illustration: Panel on Left Painted with Single Pigment Paint; Panel on
+Right Painted with Combination Pigment Paint. Photograph taken after Two
+Years' Exposure on Pittsburg Test Fence]
+
+"=Conclusions Reached from the Test.= The primary object of the test
+made at Pittsburg was to determine whether a combination paint, made of
+two or more pigments, would be equal or superior to single pigment
+paints. After one year's exposure, the combination type of paint proved
+more durable than the single pigment paints.
+
+"It was early apparent that the combination type of paints, that is,
+those paints made of more than one pigment, indicated in most cases very
+excellent wear, with a minimum of blackness and a general good condition
+of surface.
+
+TESTS INAUGURATED IN 1907
+
+CHART OF RESULTS OF SECOND ANNUAL INSPECTION OF PITTSBURG TEST FENCE,
+MAY, 1910
+
+  =========================================================+
+                            FORMULAS                       |
+  --+------------------------+-----------------------------+
+  F |                        |        INERT PIGMENTS       |
+  o |                        +-----------------------------+
+  r |Basic Carbonate         |Calcium                      |
+  m |Wh. L'd                 |Carbonate                    |
+  u |      |Zinc Oxide       |     |Calcium                |
+  l |      |      |Basic     |     |Sulphate               |
+  a |      |      |Sulphate  |     |  |Magnesium           |
+    |      |      |Wh. L'd   |     |  |Silicate            |
+  N |      |      |    |Zinc |     |  |    |Barium         |
+  u |      |      |    |Lead |     |  |    |Sulphate       |
+  m |      |      |    |White|     |  |    |     |Silica   |
+  b |      |      |    --+   |     |  |    |     |   |Blanc|
+  e |      |      |      |   |     |  |    |     |   | Fixe|
+  r |      |      |      |   |     |  |    |     |   --+   |
+  --+------+------+------+---+-----+--+----+-----+-----+---+
+    |  %   |  %   |  %   |  %| %   | %| %  | %   | %   | % |
+   1| 30   | 70   | --   | --|--   |--|--  |--   |--   |-- |
+   2| 50   | 50   | --   | --|--   |--|--  |--   |--   |-- |
+   3| 20   | 50   | 20   | --|10   |--|--  |--   |--   |-- |
+   4| 48.5 | 48.5 | --   | --| 3.0 |--|--  |--   |--   |-- |
+   5| 22   | 50   | --   | --| 2   |--|26  |--   |--   |-- |
+   6| --   | 64   | --   | --|--   |--|--  |36   |--   |-- |
+   7| 37   | 63   | --   | --|--   |--|--  |--   |--   |-- |
+   8| 38   | 48   | --   | --|--   |--|--  |--   |14   |-- |
+   9| --   | 73   | --   | --| 2   |--|--  |--   |25   |-- |
+  10| 44   | 46   | --   | --| 5   |--| 5  |--   |--   |-- |
+  11| 50   | 50   | --   | --|--   |--|--  |--   |--   |-- |
+  12| 60   | 34   | --   | --|--   |   6% Inert Pigment    |
+  13| --   | 27   | 60   | --| 3   |--|10  |--   |--   |-- |
+  14| 25   | 25   | 20   | --| 5   |25|--  |--   |--   |-- |
+  15| 20   | 40   | --   | 30|10   |--|--  |--   |--   |-- |
+  16| 33   | 33   | --   | --|--   |--|--  |34   |--   |-- |
+  17| 40   | 40   | --   | --|--   |--| 3  |13   |--   | 4 |
+  18| 75   | 25   | --   | --|--   |--|--  |--   |--   |-- |
+  19| --   | 25   | 75   | --|--   |--|--  |--   |--   |-- |
+  20| 67.0 | 19.5 | --   | --|10.0 |--| 3.5|--   |--   |-- |
+  33| 15   | 30   | 25   | --|--   |--|--  |--   |30   |-- |
+  34| 38.95| 33.58|  4.81| --|19.48|--|--  | 1.59| 1.59|-- |
+  35| 37.51| 25.87|  7.84| --|20.36|--|--  | 4.21| 4.21|-- |
+  36|100   | --   | --   | --|--   |--|--  |--   |--   |-- |
+  37|100   | --   | --   | --|--   |--|--  |--   |--   |-- |
+  38|100   | --   | --   | --|--   |--|--  |--   |--   |-- |
+  39| --   | --   | --   |100|--   |--|--  |--   |--   |-- |
+  40| --   | --   |100   | --|--   |--|--  |--   |--   |-- |
+  45| --   | 90   |--    | --|10   |--|--  |--   |--   |-- |
+  46| --   | 61   |--    | --|--   |--|--  |--   |39   |-- |
+  47| --   |100   |--    | --|--   |--|--  |--   |--   |-- |
+  ==+======+======+======+===+=====+==+====+=====+=====+===+
+
+  ==+========================================+===
+  F |                                        |
+  o |                                        |
+  r |                                        | P
+  m |                                        | a
+  u |                                        | n
+  l |                                        | e
+  a |                                        | l
+    |          REPORT OF INSPECTION          |
+  N +-----------+------------+------+--------+ N
+  u |           |            |GENE- |        | u
+  m |           |            |RAL   |        | m
+  b |           |            |CON-  |        | b
+  e |           |            |DI-   |        | e
+  r |CHALKING   |CHECKING    |TION  |REMARKS | r
+  --+-----------+------------+------+--------+---
+   1|Slight     |None        |Good  |Slight  |  2
+    |           |            |      |scaling;|
+    |           |            |      |fairly  |
+    |           |            |      |white   |
+    |           |            |      |surface |
+   2|Medium     |Very slight |Fair  |Panels  |  4
+    |           |            |      |quite   |
+    |           |            |      |dark and|
+    |           |            |      |some    |
+    |           |            |      |scaling |
+   3|Consider-  |None        |Good  |Fairly  |  6
+    |able       |            |      |white   |
+   4|Consider-  |Lateral and |Fair  |White   |  8
+    |able       |irregular   |      |surface |
+   5|Medium     |Very        |Very  |Extreme-| 10
+    |           |slight      |good  |ly white|
+    |           |            |      |surface |
+   6|Very slight|Very bad;   |Poor  |Black   | 12
+    |           |rough sur-  |      |surface |
+    |           |face        |      |        |
+   7|Slight     |Slight      |Good  |Medium  | 14
+    |           |            |      |white   |
+    |           |            |      |surface |
+   8|Slight     |Slight      |Good  |White   | 16
+    |           |            |      |surface;|
+    |           |            |      |slight  |
+    |           |            |      |scaling |
+   9|None       |Deep;       |Very  |Film    | 18
+    |           |peeling in  |poor  |brittle |
+    |           |places      |      |and sur-|
+    |           |            |      |face    |
+    |           |            |      |dark    |
+  10|Medium     |Slight la-  |Good  |Surface | 20
+    |           |teral in    |      |very    |
+    |           |places      |      |white   |
+  11|Consider-  |Deep matt   |Fair  |Consi-  | 22
+    |able       |checking    |      |derable |
+    |           |            |      |scaling;|
+    |           |            |      |forma-  |
+    |           |            |      |tion of |
+    |           |            |      |black   |
+    |           |            |      |coating |
+    |           |            |      |shat-   |
+    |           |            |      |tered   |
+    |           |            |      |off     |
+  12|Medium     |Slight      |Fairly|Surface | 24
+    |           |            |good  |white   |
+  13| Medium    |None        |Excel-|Very    | 26
+    |           |            |lent  |white   |
+  14|Consider-  |Medium      |Fair  |Panel   | 28
+    |able       |            |      |fairly  |
+    |           |            |      |white   |
+  15|Slight     |Medium      |Good  |Surface | 30
+    |           |            |      |quite   |
+    |           |            |      |dark    |
+  16|Medium     |Very slight |Good  |Quite   | 32
+    |           |            |      |white   |
+  17|Consider-  |Slight,     |Fair  |Surface | 34
+    |able       |along       |      |fairly  |
+    |           |lateral     |      |white   |
+    |           |lines       |      |        |
+  18|Medium     |Slight, with|Good  |Surface | 36
+    |           |some scaling|      |has be- |
+    |           |            |      |come    |
+    |           |            |      |quite   |
+    |           |            |      |dark    |
+  19|Consider-  |None        |Excel-|No black| 38
+    |able       |            |lent  |coating;|
+    |           |            |      |surface |
+    |           |            |      |very    |
+    |           |            |      |white,  |
+    |           |            |      |due to  |
+    |           |            |      |inert-  |
+    |           |            |      |ness of |
+    |           |            |      |pigment |
+    |           |            |      |or pro- |
+    |           |            |      |gressive|
+    |           |            |      |chalking|
+  20|Medium     |Medium      |Good  |        | 40
+  33|Heavy      |None        |Fair  |White   |168
+    |           |            |      |surface |
+  34|Consider-  |Very slight |Good  |Surface |172
+    |able       |            |      |is very |
+    |           |            |      |white;  |
+    |           |            |      |progres-|
+    |           |            |      |sive    |
+    |           |            |      |chalking|
+    |           |            |      |may have|
+    |           |            |      |prevent-|
+    |           |            |      |ed for- |
+    |           |            |      |mation  |
+    |           |            |      |of black|
+    |           |            |      |coating |
+  35|Bad        |None        |Good  |Very    |173
+    |           |            |      |white;  |
+    |           |            |      |no black|
+    |           |            |      |coating |
+    |           |            |      |evident |
+  36|Bad        |Bad         |Fair  |Surface |174
+    |           |            |      |is dead |
+    |           |            |      |black;  |
+    |           |            |      |shatter-|
+    |           |            |      |ed in   |
+    |           |            |      |places  |
+  37|Extremely  |Medium      |Fair  |Very    |175
+    |bad        |            |      |black   |
+    |           |            |      |surface |
+    |           |            |      |and     |
+    |           |            |      |mottled |
+    |           |            |      |in      |
+    |           |            |      |places  |
+  38|Very bad   |Very bad,   |Poor  |Black   |176
+    |and quite  |with scaling|      |surface |
+    |dusty      |            |      |is loose|
+    |           |            |      |and     |
+    |           |            |      |shatter-|
+    |           |            |      |ed      |
+  39|Consider-  |Slight      |Good  |Panel   |177
+    |able       |            |      |surface |
+    |           |            |      |quite   |
+    |           |            |      |white   |
+  40|Very bad   |Slight      |Good  |Surface |178
+    |           |            |      |very    |
+    |           |            |      |white,  |
+    |           |            |      |possibly|
+    |           |            |      |due to  |
+    |           |            |      |progres-|
+    |           |            |      |sive    |
+    |           |            |      |chalking|
+    |           |            |      |or in-  |
+    |           |            |      |ertness |
+    |           |            |      |of pig- |
+    |           |            |      |ment    |
+  45|Slight     |Considerable|Fair  |White   |169
+    |           |            |      |surface |
+  46|Slight     |Slight      |Fair  |Consi-  |170
+    |           |            |      |derable |
+    |           |            |      |scaling |
+    |           |            |      |present;|
+    |           |            |      |surface |
+    |           |            |      |fairly  |
+    |           |            |      |white   |
+  47|Bad        |Bad         |Bad   |Bad con-|171
+    |           |            |      |dition  |
+    |           |            |      |through-|
+    |           |            |      |out     |
+  ==+===========+============+======+========+===
+
+[Illustration: Middle white panel is painted with a combination pigment
+formula
+
+Middle white panel is painted with pure Corroded White Lead
+
+Notice Difference in Color after Two Years' Wear]
+
+"=Recommendation.= On account of the peculiar conditions which obtain in
+and around Pittsburg, as exemplified by these tests, the committee
+finds, as a result thereof, that the best white paint for general
+exterior use is made of white lead combined with zinc oxide and a
+moderate percentage of inert pigments, such as silica, asbestine, or
+barytes.
+
+"=Some Peculiar Conditions Affecting the Tests.= The inspectors were
+most impressed during the inspection by the blackness exhibited to such
+a high degree by certain panels, and the fair degree of whiteness by
+others. It is well known that in Pittsburg nearly all paints become
+darkened by the deposition on their surface of carbon particles
+emanating from the combustion of soft coal. Certain of the paints,
+however, presented fairly white surfaces, and it would thus appear that
+the extreme darkness shown by other paints was due to their composition.
+Corroded white lead when used alone was uniformly covered by black
+particles, and the higher the percentage of corroded white lead in a
+paint the darker was the surface. It was at first thought that this
+darkness was due to the softness of the white lead pigment or to its
+roughened surface, in causing adherence of soot particles. Sublimed
+white lead, however, which is also a soft pigment, chalked even more
+progressively than corroded white lead, but its surface was not rough,
+and presented a very white appearance. Scrapings from the different
+panels are being taken, and after a careful analysis the findings from
+the investigations will be reported by a member of the Inspection
+Committee."
+
+  A. C. RAPP.        _Chairman Test Fence Committee, Pittsburg Branch,
+                     Master Painters' Association_
+
+  JOHN DEWAR.        _Member Fence Committee, Pittsburg Branch, Penna. State
+                     Association of Master Painters_
+
+  J. H. JAMES.       _Chairman Carnegie Technical Schools' Fence Committee_
+
+  J. A. SCHAEFFER.   _Instructor in Chemical Practice, Carnegie Technical
+                     Schools Pittsburg, Pa._
+
+  H. A. GARDNER.     _Director Scientific Section, Paint Mfrs. Asso. of U. S._
+
+_May 31, 1910_
+
+
+PITTSBURG TEST FENCE
+
+COMPARATIVE SPREADING RATES OF WHITE PAINT ON WHITE PINE PANELS
+
+_Average Spreading Rate 266 Square Feet_
+
+  =======+===========+===========+===========+==========+==============
+  Formula|First Coat |Second Coat|Third Coat | Average  |Spreading Rate
+  Number | (sq. ft.) |(sq. feet) | (sq. ft.) |Spreading |    Rate
+         |           |           |           |  Rate    | 3-Coat Work
+         |           |           |           |(sq. feet)| (sq. feet)
+  -------+-----------+-----------+-----------+----------+--------------
+    1    |   759     |  1020     |    768    |   849    |   283
+    2    |   694     |   975     |   1229    |   966    |   322
+    3    |   743     |   873     |    770    |   795    |   265
+    4    |   537     |   987     |   1019    |   848    |   283
+    5    |   509     |   896     |    886    |   764    |   255
+    6    |   765     |  1045     |    994    |   935    |   312
+    7    |   734     |   922     |    996    |   884    |   295
+    8    |   565     |   862     |    854    |   760    |   253
+    9    |   622     |   926     |   1160    |   903    |   301
+   10    |   610     |  1013     |   1070    |   900    |   300
+   11    |   651     |   933     |   1010    |   865    |   288
+   12    |   675     |  1027     |    623    |   775    |   258
+   13    |   663     |   892     |    981    |   845    |   282
+   14    |   498     |   785     |    807    |   697    |   232
+   15    |   688     |  1000     |    984    |   891    |   297
+   16    |   669     |   880     |    860    |   803    |   268
+   17    |   635     |   982     |   1077    |   900    |   300
+   18    |   636     |   959     |   1031    |   875    |   292
+   19    |   626     |  1076     |   1037    |   913    |   304
+   20    |   591     |  1015     |    929    |   845    |   282
+   21    |   595     |   948     |    910    |   818    |   273
+   22    |   617     |   868     |    810    |   765    |   255
+   23    |   549     |  1002     |    986    |   846    |   282
+   24    |   539     |   918     |    783    |   747    |   249
+   25    |   530     |   929     |    850    |   770    |   257
+   26    |   532     |   916     |   1011    |   820    |   273
+   27    |   520     |   850     |    656    |   675    |   225
+   33    |   600     |  1340     |    810    |   917    |   306
+   34    |   471     |   743     |    690    |   635    |   212
+   35    |   402     |   598     |    645    |   548    |   183
+   36    |   398     |   668     |    838    |   635    |   212
+   37    |   579     |   653     |    838    |   690    |   230
+   38    |   463     |   615     |    704    |   594    |   198
+   39    |   474     |   954     |    849    |   759    |   253
+   40    |   446     |   815     |    871    |   711    |   237
+   45    |   527     |   841     |    916    |   761    |   254
+   46    |   605     |   740     |    818    |   721    |   240
+   47    |   735     |   961     |    993    |   896    |   299
+  =======+===========+===========+===========+==========+==============
+
+
+
+
+CHAPTER X
+
+A LABORATORY STUDY OF TEST PANELS
+
+
+=Panel Sections for Laboratory Test.= In order to make a laboratory
+study of the painted panels on the Atlantic City and Pittsburg fences,
+it was thought advisable to remove small sections from representative
+areas and transfer them to the laboratory for such work. The fences were
+visited by the official inspection committees soon after the first
+annual inspection, and the panels were carefully looked over. Upon each
+was marked out a representative portion, care being exercised to select
+areas where previous inspections had not disturbed the surface of the
+film in any manner. The inspectors then placed the number of the panel
+upon the areas which had been marked off, as well as their initials. The
+marked sections were sawed out, wrapped in tissue paper, and then
+transferred to the laboratory where they were placed upon models of the
+respective fences from which they had been removed. The illustration
+shows the model test fences set up together. It is very apparent that
+the Pittsburg panels are much the darker in color, due to the soot, and
+in some cases lead sulphide formed upon their surfaces. This difference
+was undoubtedly due to the atmospheric conditions prevailing where the
+tests were made. One would be led to suppose that a paint film exposed
+to an atmosphere such as is found in Pittsburg would show deterioration
+more rapidly than one exposed in Atlantic City. In all the tests and
+experiments, however, the Atlantic City panels appeared broken down to a
+much greater extent; though it is true that the Pittsburg panels had
+darkened considerably and presented a rather mottled appearance. The
+deposit of soot on the Pittsburg panel seemed to act as a preservative
+coating for the film beneath, and prevented marked disintegration.
+
+[Illustration: Sections of Atlantic City and Pittsburg Fences Arranged
+for Laboratory Examination]
+
+[Illustration: Sections of Atlantic City and Pittsburg Fences]
+
+[Illustration: Upper set of tests made on Panels from Atlantic City
+Fence
+
+Lower set of tests made on Panels from Pittsburg Fence
+
+Figures at left indicate Formula Number
+
+Figures at right indicate Degree of Chalking]
+
+[Illustration: Color Standard used in Comparison of Panel Section]
+
+=Chalking Test.= Small strips of black felt, about one inch square, were
+firmly attached to a block of wood, and by a clamp having the same
+pressure in each case, the wood with its surface of black felt was fixed
+to the panel. This apparatus, which resembles a blackboard eraser, is
+firmly drawn across the panel in one direction for a certain definite
+distance, during which time it gathers all the chalked surface presented
+by the painted wood. Upon detaching the apparatus from the panel it is
+observed that the black cloth becomes whitened to an extent
+proportionate to the chalking that has taken place on the given area.
+
+After each one of the panels had been treated in the same manner by the
+same operator, the black cloths were assembled on one large board and
+photographed. A definite standard of chalking was made up, and the
+operator was enabled to put down opposite the report on each panel the
+degree of chalking which had taken place, No. 1 representing the least
+amount and No. 10 the greatest amount of chalking.
+
+=Degree of Whiteness Shown by Panels.= It was a very simple matter to
+gauge the whiteness of the various panels, by comparing them with a
+series of standard boards painted with three coats of white paint.
+Florence Brand, New Jersey zinc oxide, was used as the standard for
+whiteness and termed "No. 1." In making "No. 2" standard, to the zinc
+oxide was added .01% of lampblack. By adding .02% of lampblack to the
+zinc, standard "No. 3" was obtained, and so on, increasing the amount of
+lampblack in each case by .01%. These standards were run up to "No. 30,"
+and the various panels on the different fences compared with them. The
+degrees of whiteness are recorded in progressive numbers, No. 1 being
+the standard for whiteness and No. 30 the darkest. The Atlantic City
+panels ranged from 3 to 8 in the scale of whiteness, while the Pittsburg
+panels required the use of the entire range of standards.
+
+=Resistance to Abrasion.= The apparatus used for determining the
+abrasion resistance of a paint was made of a glass tube about six feet
+long, having an internal bore of 7/8 inch. This was supported in an
+upright position over a dish which held the panel under test at an angle
+of 45 degrees. The abrasive material consisted of No. 00 emery, which
+was dropped into the tube through a funnel having a bore of 5 mm. When
+the emery reached the bottom of the long tube it scattered itself so as
+to strike a surface on the panel about an inch in diameter. The emery
+was constantly poured in until the paint coating had worn away, showing
+the bare wood. The weight in pounds of emery powder required to show the
+disruption of the coating is recorded and reported as the measure of the
+"abrasion resist." The panel requiring the greatest weight of emery to
+cause abrasion is evidently the most resistant to abrasion. Paint is
+often subjected to serious abrasion, through the blowing of sand,
+especially at the seashore, and to withstand such action should contain
+a proportion of pigments especially resistant to abrasion, such as
+silica, zinc oxide, asbestine, and barytes.
+
+[Illustration: Apparatus for Determining the Abrasion Resistance of
+Paints]
+
+[Illustration: Formula No. 1, A. C.]
+
+[Illustration: Formula No. 2, A. C.]
+
+[Illustration: Formula No. 3, A. C.]
+
+[Illustration: Formula No. 4, A. C.]
+
+[Illustration: Formula No. 5, A. C.]
+
+[Illustration: Formula No. 6, A. C.]
+
+     NOTE: The author wishes to acknowledge the assistance of Dr. J.
+     A. Schaeffer in the preparation of the photomicrographs herewith
+     shown.
+
+[Illustration: Formula No. 7, A. C.]
+
+[Illustration: Formula No. 8, A. C.]
+
+[Illustration: Formula No. 9, A. C.]
+
+[Illustration: Formula No. 10, A. C.]
+
+[Illustration: Formula No. 11, A. C.]
+
+[Illustration: Formula No. 12, A. C.]
+
+[Illustration: Formula No. 13, A. C.]
+
+[Illustration: Formula No. 14, A. C.]
+
+[Illustration: Formula No. 15, A. C.]
+
+[Illustration: Formula No. 16, A. C.]
+
+[Illustration: Formula No. 17, A. C.]
+
+[Illustration: Formula No. 18, A. C.]
+
+[Illustration: Formula No. 19, A. C.]
+
+[Illustration: Formula No. 20, A. C.]
+
+[Illustration: Formula No. 33, A. C.]
+
+[Illustration: Formula No. 34, A. C.]
+
+[Illustration: Formula No. 35, A. C.]
+
+[Illustration: Formula No. 36, A. C.]
+
+[Illustration: Formula No. 37, A. C.]
+
+[Illustration: Formula No. 38, A. C.]
+
+[Illustration: Formula No. 39, A. C.]
+
+[Illustration: Formula No. 40, A. C.]
+
+[Illustration: Formula No. 45, A. C.]
+
+[Illustration: Formula No. 46, A. C.]
+
+[Illustration: Formula No. 47, A. C.]
+
+=Making Photomicrographs.= The photomicrographs which are herewith shown
+were made in the following manner: A part of a panel was placed upon the
+stage of the microscope and held firmly in place with clips. By varying
+the adjustment and carefully running over the field the condition of the
+surface was readily given, using the same eye-piece and objective
+throughout the tests, and obtaining a magnification of thirty-three.
+Great care was exercised to secure an average field showing the general
+and typical appearance of every panel. Little difficulty was experienced
+in so doing, as the laboratory panels gave very representative surfaces
+of the large panels on the fence. The instrument was then inclined
+horizontally and the eye-piece was fitted into the camera nose. In the
+back of the bellows of the camera was placed the ground glass for
+focusing. To secure illumination the light from an electric arc lamp
+was reflected from a mirror directly upon the painted surface of the
+panel, which in turn was reflected through the camera on to the ground
+glass. The plate-holder was then put in position and six-second
+exposures were made, afterward developing and printing.
+
+=Checking and Cracking.= What was termed "fine matt checking" at the
+First Annual Inspection was not visible at the time to certain members
+of the Inspection Committee, but it is an established fact that the
+checking was an existing condition, as the photomicrographs have shown.
+This checking has a very peculiar characteristic in that the lines are
+very narrow and hair-like, being somewhat interlaced and peculiarly
+forked. That this hair matt checking is a preliminary condition which
+afterwards develops into matt checking and into marked or heavy checking
+seems to be indicated.
+
+It appears from an examination of the photomicrographs of the paint
+films that a paint coating closely resembles the surface of the earth,
+and is subject to the same basic laws that have caused the various
+geodetic changes in the earth's crust. Observation of a dried pond or
+lake bed will disclose types of fissuring and cracking similar to those
+shown by dried paint coatings in which the oil has been fully oxidized,
+and especially in the case of paints containing pigments which act upon
+the oil to produce compounds brittle in nature.
+
+At Atlantic City the panels were all clean and free from dirt,
+presenting continuous exposure of the films, and thus maintaining
+conditions for active checking. At Pittsburg, soon after the panels
+began to chalk, the large amount of dust and black soot in the
+atmosphere completely covered the panels with a very thick, resistant
+coating of carbon, which acted as a seal or protector, preventing
+disintegration to a great extent. This coating was extremely hard to
+remove, and photomicrographs, before and after removal of this coating
+by rubbing with a damp cloth, failed to reveal marked checking on any of
+the formulas except those made of strictly pure basic carbonate-white
+lead. The checking, even on these, was not as marked as at Atlantic
+City. It is presumed that after the chalking had taken place and the
+chalked pigment had been washed from the panels, the gradually
+increasing coat of carbon and lead sulphide had protected the panels
+from checking, or possibly the atmosphere of Pittsburg, which in other
+respects had deteriorated the panels to a greater extent than at
+Atlantic City, did not have the extreme action in causing checking that
+the Atlantic City atmosphere seemed to have effected.
+
+[Illustration: Combination Formula No. 1, Pittsburg
+
+BEFORE WASHING
+
+Mottled surface due to external coating of impurities.]
+
+[Illustration: AFTER WASHING]
+
+[Illustration: Formula No. 4, Pittsburg
+
+BEFORE WASHING]
+
+[Illustration: AFTER WASHING]
+
+[Illustration: Formula No. 38, Pittsburg
+
+Basic Carbonate--White Lead Panels on Fence
+
+BEFORE WASHING
+
+Checking evident even through the outer covering of foreign matter.]
+
+[Illustration: AFTER WASHING]
+
+[Illustration: Formula No. 36, Pittsburg
+
+Basic Carbonate--White Lead Panels on Fence
+
+BEFORE WASHING
+
+Peculiar network-like checking appearing through outer coat of
+impurities.]
+
+[Illustration: AFTER WASHING]
+
+[Illustration: Formula No. 40, Pittsburg]
+
+[Illustration: Formula No. 45, Pittsburg]
+
+=Results on Combination Pigment Paints.= It will be noticed that the
+checking on most of the combination pigment paints made of lead, zinc,
+and inert pigments, was moderate, and in many cases of a fine order. It
+has been observed that the percentage of zinc oxide in a paint is not
+always a criterion upon which future checking may be judged. Nor could
+it be said that the checking is dependent upon the percentage of basic
+carbonate-white lead added to the paint. However, it appears that
+scientific blending of the various pigments, with regard to their
+physical properties in oil, such as their strength and elastic limit,
+develops the greatest resistance to both cracking and checking.
+Elasticity is vital, but strength must be combined therewith in order to
+prevent disruptions of the paint coating. Paint films made of certain
+inert pigments, when tested on the filmometer, were relatively high in
+strength, but relatively low in elasticity. Such pigments, when used in
+large percentage, form coatings which are hard and apt to crack. The
+use, however, of these pigments in moderate percentages seems very
+beneficial in overcoming the effect of using an excessive percentage of
+white lead, or of zinc oxide.
+
+=Results on White Lead Paints.= The maximum checking was observed on the
+basic carbonate-white lead panels, the size of the checks in some cases
+being several times larger than those on the other panels.
+
+On some of the basic carbonate-white leads the checking was of a very
+peculiar nature, consisting of very broad fissures in the paint coating,
+disclosing the wood surfaces beneath. The type of checking existing was
+also distinct in its structure, being hexagonal in shape. One of the
+most marked features shown by the basic carbonate-white lead films was
+the extreme roughness of their surfaces. This roughness is most likely
+due to the excessive chalking which had taken place.
+
+=Results on Silica and Barytes Paints.= The checking of paints very high
+in silica resolved itself into fine hair-like lines which are generally
+lateral to each other, and indicate a cracked appearance. The checking
+of paints containing very high percentages of barytes was also of a
+distinct nature, being generally forked in appearance and of no definite
+striation.
+
+=Surface Condition of Fume Pigment Paints.= The panels painted with
+basic sulphate-white lead (sublimed white lead) showed complete absence
+of checking. This was also true of the panels painted with zinc lead.
+These are both fume products and are extremely fine in their physical
+size, which may account for this condition. Although zinc oxide is made
+in a similar manner, it gives a much harder paint coating than either of
+the afore-mentioned pigments, and presents a surface which develops
+considerable checking, generally of a medium order. The past theories
+regarding zinc oxide, in which it has been maintained that zinc oxide
+gives the maximum checking, are evidently incorrect, as the checking
+found on the zinc oxide panels was not as marked or deep as the checking
+on the basic carbonate-white lead panels; in fact, the checking might be
+more in the line of a cracking, possibly due to the brittle nature of
+the coating composed of straight zinc. This is especially true of zinc
+paints containing insufficient oil.
+
+=The Importance of the Physical Nature of Pigments.= It appears that
+very fine grinding of materials, chosen for their characteristic
+fineness, with the absence of any unfavorable physical condition or
+chemical sensitiveness, are important factors in the making of a paint
+to resist cracking or checking. The purity of the essential materials,
+as well as the scientific compounding of these materials, with due
+regard to the law of minimum voids, are great factors which enhance the
+qualities of paints, greater, perhaps, than the variation of percentages
+of the various pigments which go to make up a paint.
+
+
+
+
+CHAPTER XI
+
+ADDITIONAL TESTS AT ATLANTIC CITY AND PITTSBURG
+
+
+A series of new test panels to take the place of those panels which were
+condemned and subsequently removed from the Atlantic City and Pittsburg
+fences, were painted and exposed during June, 1909. These new test
+panels are of white pine, this wood having been selected by the joint
+inspection committee as offering the best condition for future tests.
+The method used in painting these panels was the same as in the previous
+tests, together with the adoption of certain refinements in the
+reductions, application, etc. Thirty-six formulas were selected with
+careful regard to the percentage of components, including several paints
+containing lithopone combined with whiting and zinc oxide,[25] two
+pigments which gave promise of supporting the lithopone for outside use.
+Some of these lithopone paints contained special vehicles which it was
+thought would prevent the destructive action which lithopone seems to
+have upon linseed oil. In order to obtain a criterion of the value of
+the new formulas applied, as against the wearing of straight white
+leads, the original white leads used in the previous tests were
+included, and other brands were added. Each formula was painted out in
+white, yellow, and gray, upon panels of white pine wood arranged in
+sequence upon the fence, and properly identified. The customary opacity
+test, in the form of a small black square, was stencilled over the
+priming coat of each panel, as in the former tests. The composition of
+the vehicle in all the new tests was standard, using pure linseed oil
+with a small percentage of turpentine drier. The tints used in each
+formula were secured at the time of application by the use of standard
+colors, lampblack, and medium chrome yellow, using an approximate amount
+for each formula.
+
+  [25] A brief study of the theory of solutions (See Cushman and Gardner
+       on "Corrosion and Preservation of Iron and Steel"), involving the
+       modes of iron formation, will be invaluable to the student who is
+       inquiring into the cause of the peculiar fogging of lithopone,
+       with the idea in view of correcting this evil by physical or
+       chemical treatment. Inasmuch as our observations thus far have
+       led us to believe that the fogging of lithopone takes place in
+       the presence of moisture, with the contributory and necessary
+       action of chemically active rays from the sun or other source, it
+       is fair to assume that under these conditions the insoluble
+       molecule of zinc sulphide and barium sulphate reverts by
+       intricate molecular disturbance and ionization back to the
+       soluble barium sulphide and zinc sulphate from which the
+       lithopone is formed by metathesis. If this be true, then the acid
+       nature of these soluble salts is no doubt combated and overcome
+       at the moment of formation by the basic nature of zinc oxide and
+       calcium carbonate, which tend to ionize to an alkaline reaction.
+       The value of zinc oxide and calcium carbonate in lithopone paints
+       as detergents of blackness, has been demonstrated at both
+       Atlantic City and Pittsburg." H. A. G.
+
+[Illustration: Section of Fence Showing New Panels Recently Placed]
+
+[Illustration: Appearance of 1909 Tests]
+
+An inspection of these new tests was made during June, 1910, and the
+results of the inspection are shown on pages 178 to 181. The results of
+the inspection prove that it is unsafe to use lithopone in a paint
+containing white lead of any type, early darkening and failure being
+shown in every case where such a combination existed. The formulas in
+the new test, which were properly balanced and which had a low
+percentage of lithopone combined with zinc oxide and whiting, presented
+in some cases very good surfaces. A rough, sandy surface, however, was
+shown where lithopone was used in any great quantity.
+
+TESTS INAUGURATED IN 1909
+
+RESULTS OF INSPECTION OF ATLANTIC CITY TEST FENCE, MAY, 1910
+
+  ===============================================+
+                    FORMULAS                     |
+  --+-----------------------+--------------------+
+  F |                       |                    |
+  o |                       |                    |
+  r |Basic Carbonate        |                    |
+  m |White Lead             |                    |
+  u |    |Zinc Oxide        |                    |
+  l |    |  |Basic Sulphate |                    |
+  a |    |  |White Lead     |  INERT PIGMENTS    |
+    |    |  |   |Precipi-   +--------------------+
+  N |    |  |   |tated      |Calcium Carbonate   |
+  u |    |  |   |White Lead |  |Silica           |
+  m |    |  |   |   |Zinc   |  |   |Asbestine    |
+  b |    |  |   |   |Lead   |  |   |  |China Clay|
+  e |    |  |   |   |  |Li- |  |   |  |  |Barytes|
+  r |    |  |   |   |  |tho-|  |   |  |  | |Blanc|
+    |    |  |   |   |  -pone|  |   |  |  | +-Fixe|
+  --+----+--+---+---+---+---+--+---+--+--+--+----+
+    |  % | %|  %|  %|  %|  %| %|  %| %| %| %|  % |
+   1| -- |--| 45| --| --| 40|15| --|--|--|--| -- |
+   2| -- |--| 45| --| --| 40|--| 15|--|--|--| -- |
+   3| -- |45| --| --| --| 45|10| --|--|--|--| -- |
+   4| -- |--| 45| --| --| 45|10| --|--|--|--| -- |
+   5| -- |40| --| --| --| 40|20| --|--|--|--| -- |
+   6| -- |--| 45| --| --| 35|--| --|20|--|--| -- |
+   7| 50 |--| --| --| 36| --|--| --| 2| 8| 4| -- |
+   8| -- |--| 50| --| --| 36|--| --| 2| 8| 4| -- |
+   9| -- |--| 50| --| --| 36|--| --| 2|--|12| -- |
+  10| -- |36| 50| --| --| --|--| --| 2| 8| 4| -- |
+  11| 28 |55| --| --| --| --|--| --| 3|--| 7|  7 |
+  12| -- |55| 28| --| --| --|--| --| 3|--| 7|  7 |
+  13| -- |60| --| --| --| 30|10| --|--|--|--| -- |
+  14| -- |30| 30| --| --| 30|10| --|--|--|--| -- |
+  15| -- |--| 60| --| --| 30|--| --|10|--|--| -- |
+  16| -- |--| --| --| --|100|--| --|--|--|--| -- |
+  17| -- |--| --| --| --|100|--| --|--|--|--| -- |
+  18| 33 |33| --| --| --| --|--| 17|--|17|--| -- |
+  19| 34 |33| --| --| --| --|--| 33|--|--|--| -- |
+  20| 34 |33| --| --| --| --|--| --|--|33|--| -- |
+  21|100 |--| --| --| --| --|--| --|--|--|--| -- |
+    |[26]|  |   |   |   |   |  |   |  |  |  |    |
+  22|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  23|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  24| -- |--|100| --| --| --|--| --|--|--|--| -- |
+  25| -- |--| --| --|100| --|--| --|--|--|--| -- |
+  26| -- |--| --|100| --| --|--| --|--|--|--| -- |
+  27|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  28|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  29| 24 |45| 13| --| --| --|--| --|18|--|--| -- |
+  30| 45 |--| --| --| --| 40|15| --|--|--|--| -- |
+  31| 45 |--| --| --| --| 40|--| 15|--|--|--| -- |
+  32| 45 |--| --| --| --| 35|--| --|20|--|--| -- |
+  33| 50 |--| --| --| --| 36|--| --| 2|--|12| -- |
+  34| 75 |--| 25| --| --| --|--| --|--|--|--| -- |
+  35| 50 |--| 50| --| --| --|--| --|--|--|--| -- |
+  36| -- |--| --| --| --| --|--|100|--|--|--| -- |
+  ==+====+==+===+===+===+===+==+===+==+==+==+====+
+
+  [26] This pigment on analysis proved to be zinc lead.
+
+  ==+===============================================+==
+  F |                                               |
+  o |                                               |
+  r |                                               | P
+  m |                                               | a
+  u |                                               | n
+  l |                                               | e
+  a |                                               | l
+    |                                               |
+  N |                                               | N
+  u |                                               | u
+  m |              REPORT OF INSPECTION             | m
+  b |---------+---------+----------------+----------+ b
+  e |CHALKING |CHECKING |GENERAL         |REMARKS   | e
+  r |         |         |CONDITION       |          | r
+  --+---------+---------+----------------+----------+--
+   1|None     |None     |Rough surface,  |          | 1
+    |         |         |but fair for re-|          |
+    |         |         |painting        |          |
+   2|None     |None     |Fair; rough sur-|          | 2
+    |         |         |face and slight-|          |
+    |         |         |ly dark         |          |
+   3|Very     |Very     |Good; very white|          | 3
+    |slight   |slight   |surface         |          |
+   4|None     |None     |Rough surface   |          | 4
+    |         |         |and slightly    |          |
+    |         |         |dark            |          |
+   5|Very     |Very     |Good; very white|          | 5
+    |slight   |slight   |surface         |          |
+   6|None     |None     |Rough surface;  |          | 6
+    |         |         |dark            |          |
+   7|None     |Very     |Good            |          | 7
+    |         |slight   |                |          |
+    |         |lateral  |                |          |
+    |         |checking |                |          |
+   8|Heavy    |Slight   |Excellent; very |          | 8
+    |         |         |white           |          |
+   9|Heavy    |Some     |Excellent; very |          | 9
+    |         |         |white           |          |
+  10|None     |Slight   |Good            |          |10
+  11|None     |Slight   |Good; slightly  |          |11
+    |         |         |dark            |          |
+  12|None     |Slight   |Good            |          |12
+    |         |lateral  |                |          |
+  13|Very     |Consider-|Fair            |          |13
+    |slight   |able     |                |          |
+    |         |lateral  |                |          |
+    |         |running  |                |          |
+    |         |along    |                |          |
+    |         |grain of |                |          |
+    |         |wood     |                |          |
+  14|Very     |Consider-|Fair            |          |14
+    |slight   |able     |                |          |
+    |         |lateral  |                |          |
+    |         |running  |                |          |
+    |         |along    |                |          |
+    |         |grain of |                |          |
+    |         |wood     |                |          |
+  15|Heavy    |Slight   |Fair            |          |15
+    |         |lateral  |                |          |
+    |         |checking |                |          |
+  16|Heavy    |Consider-|Dark color;     |          |16
+    |         |able     |rough surface   |          |
+  17|Consider-|Medium   |Better than No. |          |17
+    |able     |         |16; not as rough|          |
+    |         |         |or dark         |          |
+  18|Very     |None     |Good            |          |18
+    |slight   |         |                |          |
+  19|Very     |Slight   |Good            |          |19
+    |slight   |         |                |          |
+  20|Very     |None     |Good            |          |20
+    |slight   |         |                |          |
+  21|Slight   |Slight   |Fair; rough     |          |21
+    |         |         |surface         |          |
+  22|Very     |Lateral  |Fairly good     |          |22
+    |slight   |cracking |                |          |
+  23|Medium   |Lateral  |Fair            |          |23
+    |         |cracking |                |          |
+  24|Slight   |Slight   |Good for        |          |24
+    |         |cracking |repainting      |          |
+  25|Medium   |None     |Good surface    |          |25
+  26|Heavy    |Slight   |Fair; surface   |          |26
+    |         |cracking |rough & dark    |          |
+  27|Heavy    |Lateral  |Fair            |          |27
+    |         |cracking |                |          |
+  28|Medium   |Consider-|Poor; very      |          |28
+    |         |able     |rough, dark     |          |
+    |         |         |surface         |          |
+  29|Slight   |None     |Good            |          |29
+  30|Heavy    |Heavy    |Poor            |          |30
+    |         |checking |                |          |
+    |         |and alli-|                |          |
+    |         |gatoring |                |          |
+  31|None     |Alliga-  |Rough surface;  |          |31
+    |         |toring   |dark            |          |
+  32|Slight   |Medium   |Dark and rough  |          |32
+    |         |         |surface         |          |
+  33|Consider-|Slight   |Poor; dark      |          |33
+    |able     |         |surface         |          |
+  34|None     |None     |Fair; dark      |          |34
+    |         |         |surface         |          |
+  35|None     |Slight   |Fair; rough     |          |35
+    |         |         |surface         |          |
+  36|Extremely|Medium   |Fair            |Vehicle   |36
+    |bad      |         |                |disinte-  |
+    |         |         |                |grated;   |
+    |         |         |                |spotted in|
+    |         |         |                |places    |
+  ==+=========+=========+================+==========+==
+
+TESTS INAUGURATED IN 1909
+
+RESULTS OF INSPECTION OF PITTSBURG TEST FENCE, MAY, 1910
+
+  ===============================================+
+                    FORMULAS                     |
+  --+-----------------------+--------------------+
+  F |                       |                    |
+  o |                       |                    |
+  r |Basic Carbonate        |                    |
+  m |White Lead             |                    |
+  u |    |Zinc Oxide        |                    |
+  l |    |  |Basic Sulphate |                    |
+  a |    |  |White Lead     |   INERT PIGMENT    |
+    |    |  |   |Precipi-   +--------------------+
+  N |    |  |   |tated      |Calcium Carbonate   |
+  u |    |  |   |White Lead |  |Silica           |
+  m |    |  |   |   |Zinc   |  |   |Asbestine    |
+  b |    |  |   |   |Lead   |  |   |  |China Clay|
+  e |    |  |   |   |  |Li- |  |   |  |  |Barytes|
+  r |    |  |   |   |  |tho-|  |   |  |  | |Blanc|
+    |    |  |   |   |  -pone|  |   |  |  | --Fixe|
+  --+----+--+---+---+---+---+--+---+--+--+--+----+
+    |  % | %|  %|  %|  %|  %| %|  %| %| %| %|  % |
+   1| -- |--| 45| --| --| 40|15| --|--|--|--| -- |
+   2| -- |--| 45| --| --| 40|--| 15|--|--|--| -- |
+   3| -- |45| --| --| --| 45|10| --|--|--|--| -- |
+   4| -- |--| 45| --| --| 45|10| --|--|--|--| -- |
+   5| -- |40| --| --| --| 40|20| --|--|--|--| -- |
+   6| -- |--| 45| --| --| 35|--| --|20|--|--| -- |
+   7| 50 |--| --| --| 36| --|--| --| 2| 8| 4| -- |
+   8| -- |--| 50| --| --| 36|--| --| 2| 8| 4| -- |
+   9| -- |--| 50| --| --| 36|--| --| 2|--|12| -- |
+  10| -- |36| 50| --| --| --|--| --| 2| 8| 4| -- |
+  11| 28 |55| --| --| --| --|--| --| 3|--| 7|  7 |
+  12| -- |55| 28| --| --| --|--| --| 3|--| 7|  7 |
+  13| -- |60| --| --| --| 30|10| --|--|--|--| -- |
+  14| -- |30| 30| --| --| 30|10| --|--|--|--| -- |
+  15| -- |--| 60| --| --| 30|--| --|10|--|--| -- |
+  16| -- |--| --| --| --|100|--| --|--|--|--| -- |
+  17| -- |--| --| --| --|100|--| --|--|--|--| -- |
+  18| 33 |33| --| --| --| --|--| 17|--|17|--| -- |
+  19| 34 |33| --| --| --| --|--| 33|--|--|--| -- |
+  20| 34 |33| --| --| --| --|--| --|--|33|--| -- |
+  21|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  22|100 |--| --| --| --| --|--| --|--|--|--| -- |
+    |[27]|  |   |   |   |   |  |   |  |  |  |    |
+  23|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  24| -- |--|100| --| --| --|--| --|--|--|--| -- |
+  25| -- |--| --| --|100| --|--| --|--|--|--| -- |
+  26| -- |--| --|100| --| --|--| --|--|--|--| -- |
+  27|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  28|100 |--| --| --| --| --|--| --|--|--|--| -- |
+  29| 24 |45| 13| --| --| --|--| --|18|--|--| -- |
+  30| 45 |--| --| --| --| 40|15| --|--|--|--| -- |
+  31| 45 |--| --| --| --| 40|--| 15|--|--|--| -- |
+  32| 45 |--| --| --| --| 35|--| --|20|--|--| -- |
+  33| 50 |--| --| --| --| 36|--| --| 2|--|12| -- |
+  34| 75 |--| 25| --| --| --|--| --|--|--|--| -- |
+  35| 50 |--| 50| --| --| --|--| --|--|--|--| -- |
+  36| -- |--| --| --| --| --|--|100|--|--|--| -- |
+  ==+====+==+===+===+===+===+==+===+==+==+==+====+
+
+  [27] This pigment on analysis proved to be zinc lead.
+
+  ==+===============================================+==
+  F |                                               |
+  o |                                               |
+  r |                                               | P
+  m |                                               | a
+  u |                                               | n
+  l |                                               | e
+  a |                                               | l
+    |                                               |
+  N |                                               | n
+  u |                                               | u
+  m |              REPORT OF INSPECTION             | m
+  b +---------+---------+----------------+----------+ b
+  e |CHALKING |CHECKING |GENERAL         |REMARKS   | e
+  r |         |         |CONDITION       |          | r
+  --+---------+---------+----------------+----------+--
+    |         |         |                |          |
+   1|Consider-|Slight   |Fair            |Dark in   | 1
+    |able     |         |                |places.   |
+    |         |         |                |Diffused  |
+   2|Slight   |Bad      |Fair            |Dark in   | 2
+    |         |         |                |places    |
+   3|Medium   |None     |Good            |Darkening | 3
+    |         |         |                |shown in  |
+    |         |         |                |places    |
+   4|Consider-|None     |Good            |Medium    | 4
+    |able     |         |                |dark      |
+   5|Slight   |None     |Good            |No exces- | 5
+    |         |         |                |sive dark-|
+    |         |         |                |ness      |
+   6|Medium   |Slight   |Good            |Surface   | 6
+    |         |         |                |fairly    |
+    |         |         |                |white     |
+   7|Medium   |None     |Excellent       |Whitest   | 7
+    |         |         |                |surface of|
+    |         |         |                |new tests |
+   8|Extremely|Slight   |Fair            |Surface   | 8
+    |bad      |         |                |darkening |
+   9|Extremely|Slight   |Fair            |Not as bad| 9
+    |bad      |         |                |as No. 8  |
+  10|Slight   |None     |Good            |Excellent |10
+    |         |         |                |surface;  |
+    |         |         |                |very white|
+  11|Slight   |None     |Excellent       |Surface   |11
+    |         |         |                |fairly    |
+    |         |         |                |white;    |
+    |         |         |                |thin soot |
+  12|Medium   |None     |Good            |Surface   |12
+    |         |         |                |white     |
+  13|Medium   |Very bad |Fair            |Slight    |13
+    |         |in spots |                |darkening |
+  14|Heavy    |Consider-|Fair            |Slight    |14
+    |         |able     |                |darkening |
+  15|Extremely|Slight   |Fair            |Fairly    |15
+    |bad      |         |                |white     |
+  16|Extremely|Advanced |Bad             |Surface   |16
+    |bad      |and deep |                |rough with|
+    |         |         |                |consider- |
+    |         |         |                |able dis- |
+    |         |         |                |integra-  |
+    |         |         |                |tion and  |
+    |         |         |                |much dark-|
+    |         |         |                |ness      |
+  17|Not as   |Less ad- |Fair            |Not as    |17
+    |bad as   |vanced   |                |dark as   |
+    |No. 16   |than No. |                |No. 16;   |
+    |         |16       |                |slightly  |
+    |         |         |                |mottled in|
+    |         |         |                |places;   |
+    |         |         |                |buff color|
+  18|Very     |Practi-  |Fair            |Surface   |18
+    |slight   |cally    |                |white     |
+    |         |none     |                |          |
+  19|Very     |None     |Good            |Surface   |19
+    |slight   |         |                |fairly    |
+    |         |         |                |white     |
+  20|None     |None     |Good            |Surface   |20
+    |         |         |                |fairly    |
+    |         |         |                |white     |
+  21|Slight   |Slight   |Fair            |Surface   |21
+    |         |         |                |very rough|
+    |         |         |                |and dark  |
+  22|Medium   |Slight   |Fair            |Surface   |22
+    |         |         |                |fairly    |
+    |         |         |                |white     |
+  23|Slight   |Bad      |Fair            |Surface   |23
+    |         |         |                |rough and |
+    |         |         |                |darkest on|
+    |         |         |                |fence     |
+  24|Bad      |None     |Good            |Surface   |24
+    |         |         |                |white     |
+  25|Slight   |None     |Good            |Fairly    |25
+    |         |         |                |white     |
+    |         |         |                |surface   |
+  26|Medium   |Slight   |Fair            |Rough and |26
+    |         |         |                |very dark;|
+    |         |         |                |chalking  |
+    |         |         |                |is dis-   |
+    |         |         |                |rupting   |
+    |         |         |                |black     |
+    |         |         |                |coating   |
+  27|Medium   |Slight   |Good            |Surface   |27
+    |         |         |                |fairly    |
+    |         |         |                |white     |
+  28|Medium   |Deep;    |Poor            |Surface   |28
+    |         |evident  |                |rough and |
+    |         |without  |                |very dark |
+    |         |glass    |                |          |
+  29|Slight   |Slight   |Good            |Very white|29
+    |         |         |                |surface   |
+  30|None     |Slight   |Fair            |Color dark|30
+  31|Very     |Advanced |Fair            |Color very|31
+    |slight   |         |                |dark      |
+  32|Extremely|Consider-|Fair            |Color very|32
+    |slight   |able     |                |dark;     |
+    |         |         |                |rough     |
+    |         |         |                |surface   |
+  33|Extremely|Slight   |Fair            |Surface   |33
+    |slight   |         |                |dark and  |
+    |         |         |                |rough     |
+  34|Slight   |Deep     |Fair            |Surface   |34
+    |         |         |                |medium    |
+    |         |         |                |dark      |
+  35|Consider-|Slight   |Fair            |Surface   |35
+    |able     |         |                |medium    |
+    |         |         |                |dark      |
+  36|Extremely|None     |Fair            |Vehicle   |36
+    |bad      |         |                |disinte-  |
+    |         |         |                |grated,   |
+    |         |         |                |leaving   |
+    |         |         |                |very      |
+    |         |         |                |white,    |
+    |         |         |                |chalked   |
+    |         |         |                |surface of|
+    |         |         |                |pigment   |
+  ==+=========+=========+================+==========+==
+
+
+
+
+CHAPTER XII
+
+NORTH DAKOTA PAINT TESTS
+
+
+An inspection of the original test fence, erected and painted by the
+North Dakota Agricultural College, on the grounds of the agricultural
+Experiment Station at Fargo, was made by the inspection committee[28]
+representing the Paint Manufacturers' Association of the United
+States, on the 19th and 20th of November, 1909. The fence was erected
+in 1906 and painted with commercial paints, procured in the open
+market. The east side of the fence was built of soft pine and cedar
+weather-boarding, such as is almost universally used on houses in that
+locality, presenting a very good surface for test purposes, while the
+west side was built largely of flat trimmed boards of hard pitch pine
+which, unfortunately, contained knots, pitch pockets, and uneven
+surfaces, causing to a greater or lesser extent cracking, scaling, and
+bad general results on all paints applied thereto.
+
+  [28] Henry A. Gardner, Director Scientific Section, Educational
+       Bureau, Paint Manufacturers' Association of U. S.; George Butler,
+       Master Painter; Charles Macnichol, Master Painter.
+
+The fences built in 1907 and 1908 at the suggestion of the Paint
+Manufacturers' Association, were inspected on the 20th, 21st, and 22nd
+of November, 1909, and the detailed results of the inspection of all
+these fences follow in this report. The same general conclusions as to
+the woods represented in the 1906 fence also apply to the 1907 and 1908
+fences, and because of the general bad quality of wood used on the
+western exposure of all fences, the detailed reports were made only from
+an examination of the eastern side of the fences, both on cedar and soft
+pine.
+
+The following general summary of the inspection and its results applies
+to all the test fences on the grounds of the college and is the
+unanimous conclusion drawn by the inspectors from this work:
+
+[Illustration: North Dakota Test Fences]
+
+[Illustration: Typical Sample of Hard Pine Trim Board Showing Knot and
+Sappy Grain]
+
+[Illustration: Test No. 13--1906 Fence
+
+Complete Disintegration and Failure of Cheap Paint]
+
+"Non-absorbent woods, difficult to penetrate, such as those on the west
+side of the fences, would undoubtedly have given much better results had
+they been painted with paints properly reduced to suit the nature of the
+wood. This treatment seems to have been overlooked in the North Dakota
+tests, and the painting of the hard pine boards was done with the same
+consistency of mixtures and the same reductions as upon soft pine.
+Scaling of course resulted. One of the chief purposes of the fences,
+however, was to study the different types of wood, and compliance with
+this desire resulted in the bad conditions herein noted. It has been
+shown in many other field tests that adherence of paints to hard wood
+surfaces can be obtained only by causing the priming coat to become
+amalgamated with the woody fibre, by the use of a large percentage of
+volatile diluent turpentine, benzole, asphaltum spirits, etc., to secure
+penetration. If such treatment is omitted, failure soon results, as was
+evidenced by the uniformly bad conditions presented by the paints on the
+hard pine panels.
+
+[Illustration: Pine Weatherboarding Showing Knots and Grain]
+
+[Illustration: Condition of Lumber Affecting Paint, West Side 1906
+Fence]
+
+[Illustration: Hail-stone Abrasions on House Repainting Tests]
+
+[Illustration: Hail-stone Effect, West Side of 1907 Test Fence]
+
+"During July, 1908, a violent hailstorm occurred in Fargo, and left its
+impression on nearly every wooden structure; in many cases deep dents
+being made into the wood. The west side of the test fences, which
+received the most injury from this storm, was covered with these dents
+over almost its entire surface, causing cracks in the form of concentric
+rings to appear on the abraded paint coatings. The bad condition of the
+wood, improper method of applying priming coat, combined with the
+hailstorm effect on the painted surfaces on the west side of the fences,
+were undoubtedly responsible for the universal failure of the paints
+thereon, and, for these reasons, the west side was eliminated from the
+detailed inspection, only general observations of these tests being
+made. These general observations, however, showed that paints Nos. 6 and
+8 on the 1906 fence, and paints Nos. 8, 10, and 13 on the 1907 fence,
+proved the most satisfactory on the western exposure.[29]
+
+  [29] These formulas were the same as those respectively numbered on
+       the Atlantic City and Pittsburg fences.
+
+[Illustration: Peculiar Crystallization Effect on Section 41. New
+Special Fence Paint Applied During Cold Weather]
+
+"Ochre was tried out as a priming coat on several formulas, but it was
+found to be most unsatisfactory, affecting the subsequent coats of paint
+and causing early failure, as evidenced by broad checking,
+discoloration, and general bad condition. These conditions also apply
+to those panels on the 1908 fence coated with shellac as a primer.
+
+"The colored formulas in every case showed a great superiority over the
+same paints in white untinted, and demonstrated that a percentage of
+color has a wonderful influence on the preservation of the paint
+coating, reducing chalking, checking, and general disintegration. This
+condition is probably due to the reinforcing value of the color pigments
+used.
+
+"It is safe to state that the combination formulas tinted yellow were of
+better appearance than the corroded white leads tinted yellow, the
+latter appearing quite dark in many cases.
+
+"The wearing of the paints made solely from white lead and zinc oxide
+seemed to indicate that a percentage of a third pigment, of an inert
+nature, would have been beneficial.
+
+"The high-type mixtures of pigments containing lead and zinc, with
+moderate percentages of inert pigments, on good wood, were in most
+excellent general condition; in fact, much superior to the single
+pigment paints. Their surface exhibited only minor checking and moderate
+chalking with good maintenance of color, and presenting surfaces well
+adapted to repainting.
+
+"The sublimed white lead was in fair condition, with very little
+checking, and offering a fair repainting surface. The corroded white
+lead was somewhat whiter than the sublimed white lead, but a careful
+observation of the surface of the corroded lead revealed deep checking.
+
+"It was clearly demonstrated, however, that in climates of the North
+Dakota type, white lead alone is not entirely satisfactory. The addition
+of zinc oxide to white lead forms paint that has proved much superior to
+the white lead alone.
+
+"It was conclusively demonstrated that mixtures of white lead and zinc
+oxide, properly blended with moderate percentages of reinforcing
+pigments, such as asbestine, barytes, silica and calcium carbonate, are
+most satisfactory from every standpoint, and are superior to mixtures of
+prime white pigments not reinforced with inert pigments.
+
+"The white leads painted out on the 1908 fence exhibited different
+degrees of checking, the mild-process lead and sublimed white lead which
+presented the best surfaces, being free from checking, while the
+old-process leads seemed to show very deep and marked checking, even
+after one year's wear.
+
+[Illustration: Corroded White Lead
+
+Sublimed White Lead
+
+Condition of Two White Leads on Two Grades of Wood]
+
+[Illustration: Photomicrographic Apparatus and Method of Use]
+
+CONDENSED REPORT OF INSPECTION OF "1906" TEST FENCE
+
+FARGO, N. D., NOV. 19-23, 1909
+
+_No gloss shown by any of the paints. Formulas in white on white pine
+only included here, on east side of fence_
+
+  ==+=========================================================================++
+   T|                                     FORMULAS                            ||
+   e+--------------------------------------------+----------------------------++
+   s|                   PIGMENT                  |          VEHICLE           ||
+   t+--------------------------------------------+----------------------------++
+    |Corroded                                    |Linseed Oil                 ||
+   N|White Lead                                  |    |Turp. and Drier        ||
+   o|     |Sublimed                              |    |    |Japan Drier       ||
+   .|     |White Lead                            |    |    |  |Water          ||
+    |     |     |Zinc Oxide                      |    |    |  |    |Benzine   ||
+    |     |     |    |Calcium                    |    |    |  |    |Drier     ||
+    |     |     |    |Carbonate                  |    |    |  |    |    |Vola-||
+    |     |     |    |    |Silica and            |    |    |  |    |    |tile ||
+    |     |     |    |    |Silicates             |    |    |  |    |    |Oil  ||
+    |     |     |    |    |   |Barium Sulphate   |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |Magnesium    |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |Silicate     |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |Clay and |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |Silica   |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |   |Bary-|    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |   |tes  |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |   |and  |    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |   |Sili-|    |    |  |    |    |     ||
+    |     |     |    |    |   |    |   |   |cate |    |    |  |    |    |     ||
+  --+-----+-----+----+----+---+----+---+---+-----+----+----+--+----+----+-----++
+    |  %  |  %  |  % |  % |  %|  % |  %|  %|  %  |  % |  % | %|  % |  % |  %  ||
+   1|100  | --  | -- | -- | --| -- | --| --|  -- | -- | -- |--| -- | -- | --  ||
+   2| --  |100  | -- | -- | --| -- | --| --|  -- | -- | -- |--| -- | -- | --  ||
+   3| 50  | --  |50  | -- | --| -- | --| --|  -- |90  |10  |--| -- | -- | --  ||
+   4| --  | 60  |40  | -- | --| -- | --| --|  -- |90  | -- |10| -- | -- | --  ||
+   5| 28.7| --  |71.3| -- | --| -- | --| --|  -- |93  | 7  |--| -- | -- | --  ||
+   6| 40.2| --  |50.3| 4.1|5.4| -- | --| --|  -- |90.7| 9.3|--| -- | -- | --  ||
+   7| 21.9| 21.9|45.8|10.4| --| -- | --| --|  -- |89.6| 9.7|--| 0.7| -- | --  ||
+   8| 44.1| --  |46.0| 4.6| --| -- |5.3| --|  -- |86.0|12.6|--| 1.4| -- | --  ||
+   9|                     In gray only   No report.                           ||
+  10| 13.9| --  |34.9|26.8| --| -- | --| --| 24.4|72.2| -- |--|24.0| 3.8| --  ||
+  11| 55.0| --  |15.2| -- | --| -- | --| --| 29.8|     Test not finished      ||
+  12| --  |  5.1|25.0| -- | --| -- | --| --| 69.9| -- | -- |--| -- | -- | --  ||
+  13| --  | --  |31.3|45.4| --|22.8| --|0.5|  -- |57.2| -- |--|16.1|26.7| --  ||
+  14| 34.8|  5.4|59.2| -- | --| -- | --| --|  -- |86.0|13.7|--| 0.3| -- | --  ||
+  15| --  | --  |64  | -- | --|36  | --| --|  -- |98  | -- |--| -- | -- |  2  ||
+  ==+=====+=====+====+====+===+====+===+===+=====+====+====+==+====+====+=====++
+
+  ==+==============================================
+    |              REPORT OF CONDITION
+    +--------+-----------+-------+-------+---------
+   T|        |           |       |       |
+   e|        |           |       |       |
+   s|        |           |       |       |
+   t|        |           |       |       |
+    |        |           |       |       |
+   N|        |           |       |       |CONDITION
+   o|CHALKING|CHECKING   |HIDING |COLOR  |FOR RE-
+   .|        |           |POWER  |       |PAINTING
+  --+--------+-----------+-------+-------+---------
+   1|Very bad|Extremely  |Good   |Good   |Only fair
+    |        |deep       |       |       |
+   2|Bad     |Very slight|Good   |Light  |Fair
+    |        |           |       |yellow-|
+    |        |           |       |ish    |
+    |        |           |       |tint   |
+   3|Medium  |Fine matt--|Good   |Fair   |Fair to
+    |        |deep in    |       |       |good
+    |        |places     |       |       |
+   4|Medium  |Surface    |Good   |Good   |Fair
+    |        |checking,  |       |       |
+    |        |very slight|       |       |
+   5|Slight  |Quite deep |Medium |Good   |Poor.
+    |        |           |       |       |Coating
+    |        |           |       |       |wrinkled
+    |        |           |       |       |and hard
+   6|Medium  |Slight     |Good   |Good   |Good
+    |        |surface    |       |       |
+    |        |checking   |       |       |
+   7|Medium  |Surface    |Fair   |Good   |Slight
+    |        |checking   |       |       |shelling
+    |        |with slight|       |       |from wood
+    |        |cracking   |       |       |
+   8|Medium  |Very slight|  Good |Good   |Good
+   9|        |           |       |       |
+  10|Slight  |Very bad   | Bad condition throughout.
+  11|        |           |       |       |
+  12|Medium  |Medium     |Defici-|Good   |Shelling
+    |        |           |ent    |       |from wood
+  13|  Worst looking surface in North Dakota tests.
+  14|Medium  |Slight     |Fair   |Good   |Good
+    |        |surface    |       |       |
+    |        |checking   |       |       |
+    |        |and peeling|       |       |
+  15|Slight  |Lateral    |Good   |Good   |Hard film
+    |        |cracking   |       |       |
+    |        |quite deep |       |       |
+  ==+========+===========+=======+=======+=========
+
+CONDENSED REPORT OF INSPECTION OF "1907" TEST FENCE
+
+FARGO, NORTH DAKOTA, NOV. 19-23, 1909
+
+  ===+==========================================================================
+   T |                                  FORMULAS
+   e +-------------------------------------------+------------------------------
+   s |                  PIGMENT                  |           VEHICLE
+   t +-------------------------------------------+------------------------------
+     |Corroded White Lead                        |Linseed Oil
+   N |    |Sublimed White Lead                   |    |Turpentine
+   o |    |   |Zinc Oxide                        |    |Drier
+   . |    |   |    |Calcium Carbonate            |    |    |Turpentine
+     |    |   |    |   |Aluminum and             |    |    |and
+     |    |   |    |   |Magnesium Silicate       |    |    |Japan
+     |    |   |    |   |  |Barytes               |    |    |  |Water
+     |    |   |    |   |  |  |Silica             |    |    |  |    |Turpentine
+     |    |   |    |   |  |  |    |Inert         |    |    |  |    |and Benzine
+     |    |   |    |   |  |  |    |  |Magnesium  |    |    |  |    |Japan Drier
+     |    |   |    |   |  |  |    |  |Silicate   |    |    |  |    |  |Drier
+     |    |   |    |   |  |  |    |  |   |Calcium|    |    |  |    |  |  |Vola-
+     |    |   |    |   |  |  |    |  |   |Sul-   |    |    |  |    |  |  |tile
+     |    |   |    |   |  |  |    |  |   |phate  |    |    |  |    |  |  |Oil
+     |    |   |    |   |  |  |    |  |   |  |Zinc|    |    |  |    |  |  |  |[B]
+     |    |   |    |   |  |  |    |  |   |  |Lead|    |    |  |    |  |  |  |
+  ---+----+---+----+---+--+--+----+--+---+--+----+----+----+--+----+--+--+--+---
+    1| 30 | --|70  |-- |--|--| -- |--|-- |--| -- |93  | 7  |--| -- |--|--|--|--
+    2| 50 | --|50  |-- |--|--| -- |--|-- |--| -- |86  | -- |10| 4  |--|--|--|--
+    3| 20 | 20|50  |10 |--|--| -- |--|-- |--| -- |90  | -- |--| -- |10|--|--|--
+    4|48.5| --|48.5| 3 |--|--| -- |--|-- |--| -- |83  | -- |--| -- |17|--|--|--
+    5| 22 | --|50  | 2 |26|--| -- |--|-- |--| -- |90  | -- |--| -- |--|10|--|--
+    6| -- | --|64  |-- |--|36| -- |--|-- |--| -- |98  | -- |--| -- |--|--| 2|--
+    7| 37 | --|63  |-- |--|--| -- |--|-- |--| -- |85  |13  |--| 2  |--|--|--|--
+    8| 38 | --|48  |-- |--|--|14  |--|-- |--| -- |91  | 9  |--| -- |--|--|--|--
+    9| -- | --|73  | 2 |--|--|25  |--|-- |--| -- |66  |--  |--|12  |22|--|--|--
+   10| 44 | --|46  | 5 |--|--| -- |--|-- |--| -- |86.0|12.5|--| 1.5|--|--|--|--
+   11| 50 | --|50  |-- |--|--| -- |--| 5 |--| -- |78  |22  |--| -- |--|--|--|--
+   12| 60 | --|34  |-- |--|--| -- | 6|-- |--| -- |91  | 7  |--| 2  |--|--|--|--
+   13| -- | 60|27  | 3 |--|--| -- |--|10 |--| -- |90  | -- |--| -- |--|10|--|--
+   14| 25 | 20|25  | 5 |--|--| -- |--|-- |25| -- |90  | -- | 6| -- |--|--|--| 4
+   15| -- | 20|40  |10 |--|--| -- |--|-- |--| 30 |90  | -- | 8| 2  |--|--|--|--
+   16| 33 | --|33  |-- |--|34| -- |--|-- |--| -- |90  | -- |10| -- |--|--|--|--
+   17|100 |(Type A)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|--
+   18|100 |(  "  B)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|--
+   19|100 |(  "  C)|-- |--|--| -- |--|-- |--| -- |   10 gal. oil   |--|--|--|--
+     |    |        |   |  |  |    |  |   |  |    |    reduction    |  |  |  |
+   20| -- |100| -- |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|--
+   21| -- | --|100 |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|--
+   22| -- | --| -- |-- |--|--| -- |--|-- |--|100 | -- | -- |--| -- |--|--|--|--
+   23|100 |(Type C)|-- |--|--| -- |--|-- |--| -- | 5-1/2 gal. oil reduction for
+     |    |   |    |   |  |  |    |  |   |  |    |           priming
+   24| 37.|7. |25. |20.|--|--|8.42|  (Michigan Seal   | -- |--| -- |--|--|--|--
+     | 51 |84 |87  |36 |  |  |    |   White Lead)     |    |  |    |  |  |  |
+   25| 38.|4. |33. |19.|--|--|3.18|(Railway White| -- | -- |--| -- |--|--|--|--
+     | 95 |81 |58  |48 |  |  |    |     Lead)    |    |    |  |    |  |  |  |
+  200|15. | --|--  | 1.|--|--| -- |--| 1.|--|43. |32. | 4. |--| 1. |--|--|--|--
+     |625 |   |    |875|  |  |    |  |250|  |750 |250 |000 |  |250 |  |  |  |
+  ===+====+===+====+===+==+==+====+==+===+==+===+====+=====+==+====+==+==+==+===
+
+  [B] = Benzine
+
+  ===+=========+=========================================
+   T |         |           REPORT OF CONDITION
+   e |         +------------+------+------+--------------
+   s |         |            |      |      |
+   t |         |            |      |      |
+     |         |            |      |      |
+   N |         |            |      |      |
+   o |         |            |      |      |
+   . |         |            |      |      |
+     |CHALKING |CHECKING    |HIDING|COLOR |CONDITION FOR
+     |         |            |POWER |      |REPAINTING
+  ---+---------+------------+------+------+--------------
+    1|Medium   |Considerable|Fair  |Fair  |Poor surface;
+     |         |with lateral|      |      |too hard
+     |         |cracking    |      |      |
+    2|Medium   |Considerable|Good  |Fair  |Rather poor
+     |         |with lateral|      |      |
+     |         |cracking    |      |      |
+    3|Bad      |Medium--    |Good  |Good  |Fair
+     |         |scaling some|      |      |
+    4|Medium   |Considerable|Good  |Good  |Medium
+     |         |with lateral|      |      |
+     |         |cracking    |      |      |
+    5|Slight   |Slight      |Good  |Good  |Good
+    6|Medium   |Considerable|Medium|Medium|Fair
+    7|Consider-|Present;    |Fair  |Fair  |Poor
+     |able     |long cracks |      |      |
+    8|Slight   |Surface     |Good  |Good  |Fair
+     |         |checking    |      |      |
+    9|Not      |Considerable|Medium|Good  |Medium
+     |evident  |with lateral|      |      |
+     |         |cracking    |      |      |
+   10|Medium   |Very slight |Good  |Good  |Good
+   11|Slight   |Lateral     |Fair  |Fair  |Fair
+     |         |cracking    |      |      |
+   12|Consider-|Present with|Fair  |Fair  |Not very good
+     |able     |slight      |      |      |
+     |         |cracking and|      |      |
+     |         |scaling     |      |      |
+   13|Medium   |Surface     |Good  |Good  |Good
+     |         |checking    |      |      |
+     |         |only        |      |      |
+   14|Consider-|Considerable|Medium|Fair  |Medium; some
+     |able     |with lateral|      |      |washing shown
+     |         |cracking    |      |      |
+   15|Medium   |Medium      |Good  |Good  |Medium
+   16|Medium   |Slight; some|Fair  |Good  |Medium
+     |         |shelling    |      |      |
+   17|Bad      |Alligator-  |Good  |Fair  |Poor
+     |         |ing; deep   |      |      |
+     |         |checking    |      |      |
+   18|Bad      |Alligator-  |Fair  |Fair  |Poor
+     |         |ing; deep   |      |      |
+     |         |checking    |      |      |
+   19|Bad      |Deep        |Good  |Fair  |Poor
+   20|Consider-|Slight      |Good  |Fair  |Fair
+     |able     |            |      |      |
+   21|Not      |Consider-   |Fair  |Good  |Poor
+     |evident  |able; slight|      |      |
+     |         |cracking;   |      |      |
+     |         |scaling     |      |      |
+   22|Medium   |Lateral     |Good  |Good  |Fair
+     |         |cracking;   |      |      |
+     |         |split       |      |      |
+   23|Bad      |Medium deep |Good  |Good  |Fair
+   24|Consider-|Slight;     |Fair  |Good  |Good
+     |able     |lateral     |      |      |
+     |         |cracking    |      |      |
+   25|Consider-|Some;       |Fair  |Good  |Excellent
+     |able     |lateral     |      |      |
+     |         |cracking    |      |      |
+  200|Medium   |Bad cracking|Good  |Good  |Fair
+  ===+=========+============+======+======+==============
+
+"As before stated, the committee believes that a serious mistake was
+made on the test fence in painting out the leads and other formulas on
+the various woods without any special attention to reduction to suit the
+nature of the wood, thus accounting largely for the difference of the
+wearing of the paints on the different woods.
+
+"The reduction of the white leads especially was to be criticised in
+these tests, in many cases too much oil and not sufficient turpentine
+being present to cause penetration.
+
+"The application of paint to cedar was satisfactory in most all cases,
+and this wood showed much better results than the other woods upon the
+fences. The exudation of resinous pitch on the hard pine was extremely
+serious, in some cases coming through the paint in large streaks,
+causing bad results.
+
+"It is to be regretted that the house repainting tests which were
+conducted are of no special value, inasmuch as no information is on file
+as to the composition of the old paints originally on the houses before
+the application of the test paints. Imperfections in the old coating,
+such as excessive chalking, deep checking, scaling, rosin exudations,
+etc., affected the subsequent coats in such a manner as to prevent any
+knowledge of where the new and old paint troubles began. The committee,
+therefore, omitted a detailed inspection of such tests.
+
+"Examination of the three houses which were painted over new wood showed
+results which correspond with the results obtained from the fence tests.
+That is, they showed the ultimate value of high type mixtures of several
+pigments over one pigment alone. These tests seem to indicate that very
+good results can be secured from most of the paints sold in North
+Dakota. If the consumer or householder would exercise more care in the
+selection of wood and preparation of surfaces, with due regard to the
+proper reduction for various coats, more satisfactory results would be
+obtained.
+
+"From an examination of certain paints on the 1908 fence containing
+petroleum spirits, it would appear that this paint thinner is of value,
+and in the face of conditions such as are presented by the present
+scarcity of turpentine, the use of petroleum spirits in moderate
+quantity would be justified."
+
+NORTH DAKOTA TESTS
+
+[Illustration: 1. Formula No. 21, Section 31, on 1907 Fence]
+
+[Illustration: 2. Section 80, on 1908 Fence]
+
+[Illustration: 3. Formula No. 6, Section 9, on 1907 Fence]
+
+[Illustration: 4. Formula No. 2, Section 3, on 1907 Fence]
+
+[Illustration: 5. Formula No. 1, Section 1, on 1907 Fence]
+
+[Illustration: 6. Formula No. 14, Section 21, on 1907 Fence]
+
+[Illustration: 7. Formula No. 13, Panel 19, on 1907 Fence]
+
+[Illustration: 8. Formula No. 19, Panel 28. Broad, Deep Checking on
+Corroded White Lead on 1907 Fence]
+
+[Illustration: 9. Formula No. 24, Panel 36, on 1907 Fence. Good
+Condition. Surface Checking Only]
+
+[Illustration: 10. Formula No. 25, Section 37, on 1907 Fence. Good
+Condition. Surface Checking Only]
+
+[Illustration: 11. Formula No. 8, Panel 12, on 1907 Fence]
+
+[Illustration: 12. Formula No. 10, Panel 15, on 1907 Fence]
+
+[Illustration: 13. Panel No. 34, Formula 23, on 1907 Fence. Deep
+Checking on Corroded White Lead]
+
+[Illustration: 14. Test No. 13 on 1906 Fence. White Spots Show Paint
+Left on Wood. Balance of Paint Split and Disintegrated from Surface]
+
+[Illustration: 15. Test No. 6 on 1906 Fence. Surface Checking Only]
+
+[Illustration: 16. Test No. 2, 1906 Fence. Sublimed White Lead]
+
+[Illustration: 17. Cracks in Test No. 15 on 1906 Fence]
+
+[Illustration: 18. Effect of Cracking on Hard Pine, Causing Splitting of
+Painting Coating]
+
+[Illustration: 19. Formula No. 22, Section 23, 1907 Fence. Cracks in
+Paint Coating, Caused by Cracks in Wood; Coating Otherwise in Good
+Condition]
+
+[Illustration: 20. Test No. 8, on 1906 Fence. Surface Checking Only]
+
+[Illustration: 21. Combination Cracking and Checking on Section 69, on
+1908 Fence]
+
+[Illustration: 22. Cracks in Paint Coating, Caused by Cracking of Hard
+Pine Wood]
+
+[Illustration: 23. Section 65 on 1908 Fence. Showing Early Breakdown of
+Corroded White Lead]
+
+
+
+
+CHAPTER XIII
+
+TENNESSEE PAINT TESTS
+
+
+=Location and Object of Tests.= On September 15, 1910, the erection of a
+wooden test fence was completed on the State Fair Grounds at Nashville,
+Tenn. Upon this fence were exposed forty-two samples of white paint, the
+object of the test being to determine whether the combination type of
+formula is superior to the single pigment type in the southern plateau,
+of which Nashville is the centre.
+
+=Construction of Tests.= The construction and outline of these tests
+differ somewhat from those conducted at Atlantic City and elsewhere by
+the Scientific Section. The fence frame is 150 feet long, being made of
+6-inch bevelled girders supported three feet from the ground by 4-inch
+posts set six feet apart. Upon this girder were placed a series of
+forty-two test panels supported at top and bottom with weather strips
+and braces. The test panels used were 40 inches high, 30 inches wide,
+and one inch thick, being made of the highest grade white pine, tongued
+and grooved together, and protected on the edges by weather strips
+projecting from the surface of the panels. Each panel was painted on
+both sides with the same paint, thus giving an eastern and western
+exposure, the fence running north and south. The formulas used in the
+test vary in their percentage composition, being made up in some cases
+of single pigments, and again with combinations of the opaque white
+pigments, with and without certain percentages of the crystalline or
+inert pigments. The paints were applied under the supervision of
+prominent master painters and a committee representing the Scientific
+Section and other technical organizations.
+
+Other field tests have shown that the sap and knots in hard-grained
+woods, such as yellow pine, cypress, etc., have been the cause of the
+failure of even the best paints, and that all tests should be conducted
+upon soft woods, such as white pine and poplar, if definite results are
+to be obtained. Paints tinted with ochre, chrome yellow, lampblack,
+iron oxide, etc., have shown on the other field tests which have been
+conducted at Atlantic City, Pittsburg, and Fargo the value of these
+pigments in giving to the paints increased wearing properties. On the
+Southern Test Fence, therefore, all the formulas were ground in white
+only and placed upon white pine so as to make the test primarily one to
+determine the value of the various white pigments upon good wood.
+
+[Illustration: Tennessee Test Fences]
+
+=Oil and Thinner Tests.= Upon one series of panels on the fence was
+placed one of the formulas which had given universal satisfaction on the
+various test fences in the past, and this formula was made up with
+various oils other than linseed oil, in order to determine the value of
+these oils as painting materials. For instance, the vehicle part of the
+one formula referred to is made up of 50% linseed oil and 50% soya bean
+oil, and again 50% linseed oil and 50% rosin oil, etc., an effort being
+made to test out a few of the available semi-drying oils.
+
+The same formula referred to was ground in pure linseed oil and
+subjected to a series of tests where it has been thinned for application
+as priming and second coats with a series of wood turpentines obtained
+from the United States Forest Products Laboratory at Madison, Wis. These
+turpentines were made from southern pine stumps and sawdust, and they
+vary greatly in their properties. Some were objectionable in odor, while
+others were of excellent quality, having an odor almost equal to that of
+pure gum spirits.
+
+[Illustration: Views of Fence]
+
+One product under test on the Southern Test Fence is pine oil, a high
+boiling point product obtained from the manufacture of wood turpentine
+from sawdust. This oil has a boiling point of over 210 degrees
+Centigrade as against the 150 degrees of ordinary gum spirits. It is
+almost water white and has the same penetrating qualities as the pure
+gum spirits; when mixed with 50% linseed oil forming a paint oil of
+extremely light color, that produces a semi-flat paint of great
+whiteness.
+
+=Reductions and Application.= Formulas No. 1 to No. 37 were all ground
+in pure refined linseed oil. They were made in the form of semi-paste
+and then thinned down with sufficient refined linseed oil so that each
+would have a relative viscosity. To each formula was then added a
+sufficient amount of pure lead and manganese linoleate drier to give
+proper drying qualities. On thinning for the priming coat, one pint of
+turpentine was added to each gallon of paint. For the second coat,
+one-half pint turpentine and one-half pint refined linseed oil were
+added to each gallon. For the third coat work, reduction was made with
+one pint of refined linseed oil.
+
+In the case of formulas 31 to 37, reductions were the same, except that
+a series of specially prepared wood turpentines were used in place of
+the pure gum spirits used in formulas 1 to 31.
+
+Formulas 38 to 41, as will be shown, were ground in equal parts of the
+oils tested. These formulas, however, were all thinned for application
+with pure gum spirits of turpentine, and the respective vehicle in which
+they were ground.
+
+No inspection of the Tennessee Test Fence has yet been made. The
+formulas tested are as follows:
+
+FORMULAS FOR SOUTHERN TEST FENCE
+
+VEHICLE: _Bleached Linseed Oil with Lead and Manganese Linoleate Drier_.
+
+  Formula
+  No.
+
+  1 [30]Corroded white lead                100%
+  2 [30]Sublimed white lead                100%
+  3 Zinc oxide XX                          100%
+  4 Zinc lead white                        100%
+  5 Leaded zinc 65%, corroded white lead   35%
+  6 [30]Corroded white lead                100%
+  7 [30]Corroded white lead                100%
+
+  [30] Corroded White Lead is the Basic Carbonate of Lead. Sublimed
+       White Lead is the Basic Sulphate of Lead.
+
+No. 8
+
+  Corroded white lead   85%
+  Zinc oxide            15%
+                       ----
+                       100%
+
+No. 9
+
+  Corroded white lead   65%
+  Zinc oxide            35%
+                       ----
+                       100%
+
+No. 10
+
+  Corroded white lead   50%
+  Zinc oxide            50%
+                       ----
+                       100%
+
+No. 11
+
+  Corroded white lead   40%
+  Zinc oxide            60%
+                       ----
+                       100%
+
+No. 12
+
+  Corroded white lead   30%
+  Zinc oxide            70%
+                       ----
+                       100%
+
+No. 13
+
+  Corroded white lead   45%
+  Zinc oxide            45%
+  Silica                10%
+                       ----
+                       100%
+
+No. 14
+
+  Corroded white lead   45%
+  Zinc oxide            45%
+  Asbestine             10%
+                       ----
+                       100%
+
+No. 15
+
+  Corroded white lead   45%
+  Zinc oxide            45%
+  China clay            10%
+                       ----
+                       100%
+
+No. 16
+
+  Corroded white lead   45%
+  Zinc oxide            45%
+  Barytes               10%
+                       ----
+                       100%
+
+No. 17
+
+  Corroded white lead   45%
+  Zinc oxide            40%
+  Silica                15%
+                       ----
+                       100%
+
+No. 18
+
+  Corroded white lead   45%
+  Zinc oxide            40%
+  Asbestine             15%
+                       ----
+                       100%
+
+No. 19
+
+  Corroded white lead   45%
+  Zinc oxide            40%
+  Barytes               15%
+                       ----
+                       100%
+
+No. 20
+
+  Sublimed white lead   45%
+  Zinc oxide            40%
+  Silica                15%
+                       ----
+                       100%
+
+No. 21
+
+  Sublimed white lead   45%
+  Zinc oxide            40%
+  Asbestine             15%
+                       ----
+                       100%
+
+No. 22
+
+  Sublimed white lead   45%
+  Zinc oxide            40%
+  Barytes               15%
+                       ----
+                       100%
+
+No. 23
+
+  Zinc oxide            90%
+  Calcium carbonate     10%
+                       ----
+                       100%
+
+No. 24
+
+  Sublimed white lead   40%
+  Zinc oxide            45%
+  Calcium carbonate     15%
+                       ----
+                       100%
+
+No. 25
+
+  Corroded white lead   35%
+  Zinc oxide            50%
+  Silica                15%
+                       ----
+                       100%
+
+No. 26
+
+  Corroded white lead   20%
+  Sublimed white lead   30%
+  Zinc oxide            40%
+  Asbestine             10%
+                       ----
+                       100%
+
+No. 27
+
+  Corroded white lead   20%
+  Sublimed white lead   20%
+  Zinc oxide            40%
+  Barytes               10%
+  Asbestine             10%
+                       ----
+                       100%
+
+No. 28
+
+  Corroded white lead   20%
+  Sublimed white lead   20%
+  Zinc oxide            40%
+  Calcium carbonate     10%
+  Silica                10%
+                       ----
+                       100%
+
+No. 29
+
+  Sublimed white lead   20%
+  Corroded white lead   20%
+  Zinc oxide            30%
+  Barytes               10%
+  Asbestine             10%
+  Calcium carbonate     10%
+                       ----
+                       100%
+
+No. 30
+
+  Corroded white lead   33%
+  Zinc oxide            33%
+  Barytes               33%
+                       ----
+                        99%
+
+No. 31
+
+  Corroded white lead   45%
+  Zinc oxide            45%
+  Asbestine              5%
+  Calcium carbonate      5%
+                       ----
+                       100%
+
+Formula No.
+
+32. Same as No. 31 but thinned with wood turpentine No. 1.
+
+33. Same as No. 31 but thinned with wood turpentine No. 2.
+
+34. Same as No. 31 but thinned with wood turpentine No. 3.
+
+35. Same as No. 31 but thinned with wood turpentine No. 4.
+
+36. Same as No. 31 but thinned with wood turpentine No. 5.
+
+37. Same as No. 31 but thinned with high-boiling-point petroleum spirits
+(turpentine substitute).
+
+38. Same as No. 31 but ground in 50% raw linseed oil, 50% soya bean oil.
+
+39. Same as No. 31 but ground in 50% raw linseed oil, 50% corn oil.
+
+40. Same as No. 31 but ground in 50% raw linseed oil, 50% cotton seed
+oil.
+
+41. Same as No. 31 but ground in 50% raw linseed oil, 50% rosin oil.
+
+42. Same as No. 31 but ground in 50% raw linseed oil, 50% pine oil.
+
+
+
+
+CHAPTER XIV
+
+WASHINGTON PAINT TESTS
+
+
+The new vehicle test fence at Washington is fully described in the
+writer's paper[31] as presented before the American Society for Testing
+Materials, as follows:
+
+  [31] The Practical Testing of Drying and Semi-Drying Paint Oils, by
+       Henry A. Gardner. Paper presented at Fourteenth Annual Meeting,
+       Amer. Soc. for Test. Mater., Atlantic City, N.J., June, 1911.
+
+"The high price attained by linseed oil during the past two years of
+over a dollar a gallon, together with the unusual scarcity of this
+valuable oil, has led many investigators into the field of research,
+with a view of discovering some mixture of other oils to partly replace
+linseed oil. Many valuable contributions to oil technology have
+resulted, but the makers and users of paints have wisely demanded
+specific and authoritative information as to the practical value of
+proposed mixtures before adopting them. The Institute of Industrial
+Research, at the request of the Paint Manufacturers' Association of the
+United States, has recently started a series of practical paint vehicle
+tests designed to decide the question at issue.
+
+"Forty-eight white-pine panels have been placed upon a test frame on the
+grounds of the new laboratory building of the Institute, at Washington,
+D. C. They are painted with a standard white pigment formula reduced
+with a different oil formula for every panel. White-pine panels were
+selected for the test on account of the good painting surface which this
+type of lumber presents; the grade selected was free from knots or pitch
+pockets--defects which often ruin a paint test. Each panel was
+constructed of four tongued-and-grooved planed boards, 22 inches long, 1
+inch thick, and 9 inches wide. The boards were leaded together and
+capped at the sides with weather strips, making the finished panels
+about 2 feet wide and 3 feet high. The fence upon which the panels were
+placed was constructed of 4-inch squared yellow pine with open
+framework, allowing the panels a resting place upon which they were
+finally secured with sherardized screws.
+
+"Before erecting the panels, they were carefully painted in a paint
+laboratory especially fitted out for the tests. The work was done during
+the months of April and May, the temperature averaging from 60 degrees
+to 90 degrees Fahrenheit. This precaution was taken in order that the
+paint in each case might become thoroughly dry and hard before exposure,
+so that there would be no accumulation of dust or effect from exposure
+during the drying period. The actual painting of each panel was done
+personally by Mr. Charles Macnichol, master painter, of Washington, D.
+C., who has had a wide experience in the practical application and
+testing of paints.
+
+[Illustration: View of Panels on Washington Test Fence]
+
+"The viscous nature of several of the oils tested precluded the
+possibility of grinding each oil formula with the white pigment base
+selected; great heating of the paint mills and a paste of insufficient
+fineness was the result of an early attempt at this method. It was
+decided, therefore, to grind the standard pigment formula to a thick
+paste in the minimum amount of raw linseed oil. Subsequently a weighed
+amount of the white pigment base was thinned with the oil formula to be
+tested, to a standard viscosity, judged by the experienced master
+painter in charge of the practical application of the formulas as
+sufficiently heavy for third-coat work. When making the reductions with
+oil mixtures, an allowance was made for the amount of linseed oil
+already contained in the ground white pigment base.
+
+"During the application of the first coat an equal amount of turpentine
+was added to each formula, in the proportion of one-half pint to a
+gallon of paint; in the application of the second coat there was added
+to each formula a like amount of an equal mixture of turpentine and the
+oil formula under test. The third coat was applied without the addition
+of thinners of any kind.
+
+"It is well known that the time of drying and the condition of the dried
+film of any oil or mixture of drying or semi-drying oils will vary
+widely. It is for the purpose of causing oils to set up to a hard film
+in a short time that metallic driers in the form of salts of manganese
+and lead, soluble in oil, are added to a paint. Some oils require a
+large amount of drier, while others require only a very small amount.
+Those which require a large amount are apt, upon exposure, to be burned
+up by the drier, resulting in the formation of a powdered and
+disintegrated film. To add various types of drier or even differing
+amounts of a drier to the oils under test, seemed very unfair from every
+standpoint, and it was therefore decided to eliminate the drier question
+entirely, so as not to vitiate the results by bringing in a factor of
+this nature. The plan of omitting driers proved successful in the
+Atlantic City steel-panel paint tests, erected three years ago by the
+writer under the supervision of Committee A-5 of this Society.
+
+"The systematic methods which are necessary when making paint tests were
+carefully followed. A standard weighed amount of white pigment paste was
+placed in a clean paint cup and thinned to the proper consistency with a
+weighed amount of the oil under test. Proper reductions were made, as
+before stated. Weighings of the paint, cup, and brush were made before
+and after application to the panel, in order to determine the quantity
+of paint used and the spreading power. A period of fifteen days was
+allowed between the application of successive coats, in order to give
+each formula sufficient time to dry thoroughly. Although several of the
+formulas remained tacky for over a week, all dried thoroughly in the
+time allotted. (Oils which when used alone have slow drying properties,
+have been found to yield good firm films when used with drying pigments
+such as lead and zinc.) The backs and edges of each panel were painted
+with two coats of the paint used on the face of the panel, so as to
+prevent the admission of moisture. After erection, the panels were
+numbered with aluminum figures pressed into the surface. Frequent
+inspections will be made, and at the proper time reports will be issued
+giving the results of the tests.
+
+"During the painting of the panels considerable interesting data were
+collected, of which the following is a brief résumé:
+
+"The hiding power of a paint is one of its most important requisites. It
+was found in the tests that some oils had the effect of lessening, while
+others had the effect of increasing the hiding power of the standard
+pigment formula. This may be due in part to the varying refractive
+indices of the oils used, as well as to the difference in the quantity
+of oil required in each test. Some oils were very viscous, while others
+were very light.
+
+"The stiff working of heavy-bodied, blown, or heat-oxidized oils,
+produced films which in some cases gave a very glossy surface, even on
+the priming coat. Some of these resembled varnished work when finished.
+It will be of importance to watch these tests carefully for any signs of
+early breakdown, which might come from too thick a film. The treated
+Chinese wood oil paints worked rather stiff but produced very smooth
+films. The rosin oil paints became slightly lumpy on standing, but
+worked out to a smooth finish somewhat yellowish in color. The marine
+animal oils, especially the menhaden oil mixtures, dried to a film
+slightly flatter than straight linseed oil. Any odor which was present
+in the paints made from the animal oils seemed to disappear a few hours
+after application. The cotton seed and corn oil mixtures made the
+slowest drying paints, but at the end of the second week of the drying
+period they set up rapidly to firm films. Soya bean and perilla oils
+behaved like straight linseed oil, the former being a little slower and
+the latter slightly more rapid in drying properties. The perilla oil was
+made from one of the first importations into this country, and was dark
+in appearance. It made, however, a very easy-working and hard-drying
+paint.
+
+"The oils used in the tests were obtained from reliable sources. After
+they were received, they were carefully analyzed. The results of the
+analyses appear in Table 1.
+
+TABLE 1. ANALYSES OF OILS USED IN THE VEHICLE TESTS
+
+  ===================================+=========+=========+========+========
+                                     |Specific |Saponifi-|Iodine  | Acid
+                                     |Gravity  | cation  |Number  |Number
+                                     |         | Number  |        |
+  -----------------------------------+---------+---------+--------+--------
+  Raw linseed oil                    |0.931    |  188    | 186    | 2.0
+  Boiled linseed oil (linoleate type)|0.941    |  187    | 172    | 2.7
+  Boiled linseed oil (resinate type) |0.930    |  186    | 176    | 2.2
+  Blown linseed oil                  |0.968    |  189    | 133    | 2.8
+  Lithographic linseed oil           |0.970    |  199    | 102    | 2.7
+  Soya bean oil                      |0.924    |  189    | 129    | 2.3
+  Menhaden oil                       |0.932    |  187    | 158    | 3.9
+  Perilla oil                        |0.94     |  188    | 180    | 2.0
+  Chinese wood oil (raw)             |0.944    |  183    | 166    | 3.8
+  Chinese wood oil (treated)[32]     |0.898[32]|  128[32]| 104[32]| 6.8[32]
+  Corn oil                           |0.925    |  191    | 118    | 9.5
+  Cottonseed oil                     |0.921    |  193    | 105    | 3.6
+  Rosin oil                          |0.966    |   27    |  41    |16.7
+  Whale oil                          |0.924    |  191    | 148    | --
+  Neutral petroleum oil[33]          |0.916    |    6    |  12    | --
+  ===================================+=========+=========+========+========
+
+  [32] Low constants due to presence of over 40% of volatile matter,
+       largely petroleum spirits.
+
+  [33] This oil contained over 20% of petroleum spirits.
+
+"The pigment formula selected for the tests had the following
+composition:
+
+  Basic carbonate-white lead    20%
+  Sublimed white lead           30%
+  Zinc oxide                    35%
+  Magnesium silicate            10%
+  Barytes                        5%
+
+100 lbs. of pigment base ground to a stiff paste in 16 lbs. of linseed
+oil.
+
+"While this pigment formula was not selected as being superior to
+certain other formulas, it is of a type that has given very fair service
+in paint tests throughout the country, and will no doubt serve admirably
+for the purpose designed in these tests.
+
+"The vehicle formulas in the finished paints are as follows:
+
+  No. 1
+  Raw linseed oil                 100%
+
+  No. 2[34]
+  Soya bean oil                   100%
+
+  [34] Dry pigment formula in soya bean oil.
+
+  No. 3[35]
+  Menhaden oil                    100%
+
+  [35] Dry pigment formula in menhaden oil.
+
+  No. 4
+  Raw linseed oil                  25%
+  Boiled linseed oil (resinate)    75%
+
+  No. 5
+  Raw linseed oil                  25%
+  Boiled linseed oil (linoleate)   75%
+
+  No. 6
+  Raw linseed oil                  50%
+  Boiled linseed oil (resinate)    50%
+
+  No. 7
+  Raw linseed oil                  50%
+  Boiled linseed oil (linoleate)   50%
+
+  No. 8
+  Raw linseed oil                  50%
+  Blown linseed oil                50%
+
+  No. 9
+  Raw linseed oil                  50%
+  Litho. linseed oil               50%
+
+  No. 10
+  Raw linseed oil                  50%
+  Soya bean oil                    50%
+
+  No. 11
+  Raw linseed oil                  50%
+  Menhaden oil                     50%
+
+  No. 12
+  Raw linseed oil                  50%
+  Perilla oil                      50%
+
+  No. 13
+  Raw linseed oil                  50%
+  Treated wood oil                 50%
+
+  No. 14
+  Raw linseed oil                  50%
+  Corn oil                         50%
+
+  No. 15
+  Raw linseed oil                  50%
+  Cottonseed oil                   50%
+
+  No. 16
+  Raw linseed oil                  50%
+  Rosin oil                        50%
+
+  No. 17
+  Raw linseed oil                  50%
+  Whale oil                        50%
+
+  No. 18
+  Raw linseed oil                  75%
+  Soya bean oil                    25%
+
+  No. 19
+  Raw linseed oil                  75%
+  Menhaden oil                     25%
+
+  No. 20
+  Raw linseed oil                  75%
+  Perilla oil                      25%
+
+  No. 21
+  Raw linseed oil                  75%
+  Treated wood oil                 25%
+
+  No. 22
+  Raw linseed oil                  75%
+  Corn oil                         25%
+
+  No. 23
+  Raw linseed oil                  75%
+  Cottonseed oil                   25%
+
+  No. 24
+  Raw linseed oil                  75%
+  Rosin oil                        25%
+
+  No. 25
+  Raw linseed oil                  50%
+  Soya bean oil                    25%
+  Menhaden oil                     25%
+
+  No. 26
+  Raw linseed oil                  50%
+  Soya bean oil                    25%
+  Treated wood oil                 25%
+
+  No. 27
+  Blown linseed oil                50%
+  Soya bean oil                    50%
+
+  No. 28
+  Raw linseed oil                  25%
+  Soya bean oil                    25%
+  Menhaden oil                     25%
+  Treated wood oil                 25%
+
+  No. 29
+  Raw linseed oil                  25%
+  Soya bean oil                    25%
+  Menhaden oil                     25%
+  Corn oil                         25%
+
+  No. 30
+  Raw linseed oil                  25%
+  Soya bean oil                    25%
+  Menhaden oil                     25%
+  Cottonseed oil                   25%
+
+  No. 31
+  Raw linseed oil                  25%
+  Soya bean oil                    25%
+  Menhaden oil                     25%
+  Rosin oil                        25%
+
+  No. 32
+  Raw linseed oil                  25%
+  Soya bean oil                    25%
+  Treated wood oil                 25%
+  Rosin oil                        25%
+
+  No. 33
+  Raw linseed oil                  20%
+  Soya bean oil                    20%
+  Treated wood oil                 20%
+  Menhaden oil                     20%
+  Cottonseed oil                   20%
+
+  No. 34
+  Raw linseed oil                  20%
+  Soya bean oil                    20%
+  Treated wood oil                 20%
+  Menhaden oil                     20%
+  Rosin oil                        20%
+
+  No. 35
+  Raw linseed oil                  40%
+  Soya bean oil                    20%
+  Corn oil                         20%
+  Cottonseed oil                   20%
+
+  No. 36
+  Whale oil                        33%
+  Treated wood oil                 33%
+  Raw linseed oil                  33%
+
+  No. 37
+  Raw linseed oil                  25%
+  L. O.[36]                        75%
+
+  No. 38
+  Raw linseed oil                  50%
+  Raw Chinese wood oil             50%
+
+  No. 39
+  Raw linseed oil                  75%
+  Reducing oil[37]                 25%
+
+  No. 40
+  Raw linseed oil                  50%
+  Soya bean oil                    35%
+  Neutral petroleum oil            15%
+
+  No. 41
+  Raw linseed oil                  50%
+  Soya bean oil                    25%
+  Neutral petroleum oil            15%
+  Tungate drier                    10%
+
+  No. 42
+  Linseed oil                      25%
+  Soya bean oil                    37%
+  Neutral petroleum oil            23%
+  Tungate drier                    15%
+
+  No. 43
+  Raw linseed oil                  25%
+  Soya bean oil                    37%
+  Whale oil                        19%
+  Tungate drier                    19%
+
+  [36] Mixture of boiled tung and soya bean oil, thinned with petroleum
+       and turpentine.
+
+  [37] 25% raw linseed oil. 73% petroleum oil. 2% drier--lead and
+       manganese linoleate."
+
+No. 44
+
+Special test on white base of the following composition, in pure linseed
+oil:
+
+  Asbestine                        10%
+  Corroded white lead              20%
+  Sublimed white lead              30%
+  Zinc oxide                       40%
+
+Upper board of panel reduced with straight turpentine on priming coat.
+Second board of panel reduced with wood turpentine on priming coat.
+Third board of panel reduced with pine oil on priming coat. Bottom board
+of panel reduced with petroleum spirits on priming coat.
+
+No. 45
+
+Same pigment formula as No. 44, reduced with:
+
+  Pine oil                         50%
+  Linseed oil                      50%
+
+No. 46
+
+Special test of white base of the following composition, in pure linseed
+oil:
+
+  Corroded white lead              20%
+  Sublimed white lead              30%
+  Zinc oxide                       35%
+  Asbestine                        15%
+
+No. 47
+
+Cypress panel unpainted.
+
+No. 48
+
+Cypress panel painted with formula No. 1, thinned with benzol on the
+priming coat.
+
+
+
+
+CHAPTER XV
+
+CEMENT AND CONCRETE PAINT TESTS
+
+
+=Damp-proofing and Waterproofing.= The decoration and preservation of
+cement and concrete is a subject which is being given the careful
+consideration of many technologists on account of the wide usage of
+cement for structural purposes, and the necessity of properly guarding
+it against the destructive effects of moisture.
+
+To obtain with various paints decorative effects, and, at the same time,
+provide a high degree of damp-proofing, is a process quite distinct from
+that of water-proofing cement and concrete superstructures. The use, in
+small percentage, of stearic acid solutions, aluminum stearate, marine
+animal soaps, and other lime-reacting materials, as a component of
+concrete while it is being mixed, has been in practice for some time,
+the resulting mixture being used largely upon base-work subjected to
+water under high pressure. Although some of the materials used for such
+purposes actually do give to the concrete a high power of water
+resistance, the degree of waterproofing to be obtained through the use
+of many such compounds varies to a wide extent, often interfering with
+the lime-silica reactions, and ultimately affecting the strength of the
+finished concrete.
+
+=Decorative and Preservative Coatings.= The necessity of obtaining
+suitable paint coatings for cement and concrete surfaces suggested to
+the writer a series of tests on paints designed to prevent the
+destructive action of the lime which, by seepage and other physical
+action, is brought to the surface, causing saponification of some oil
+coatings, as well as destruction of color. The tests referred to were
+carried out during 1908, and although great advances have been made
+since that time in the preparation of concrete paints, the tests have,
+nevertheless, afforded information of a valuable nature as indicating
+the proper methods to follow in the painting of cement, as well as
+suitable materials to use in the manufacture of cement paints. The
+tests, moreover, show the comparative durability of a number of paints
+typical of those prominent in the market at the time the tests were
+started.
+
+[Illustration: View of Concrete Paint Test Panels]
+
+=Acid Reacting Compounds.= A series of acid reacting washes were
+included in the tests, having been designed as prime coaters for use
+previous to the application of oil paints. The application of many of
+these washes has the effect of neutralizing the lime within cement and
+concrete surfaces, and often precipitate insoluble lime compounds which
+aid in filling up the outer voids, thus presenting a surface more
+suitable to receive oil coatings. To the writer who has since made a
+careful study of the painting of concrete, it would seem advisable for
+painters to avoid, when possible, the use of these lime neutralizing
+washes, as some of them have more or less disintegrating and weakening
+influences upon concrete. Recent laboratory experiments, however, have
+indicated that zinc sulphate, an acid reacting material used for many
+years as a wash for concrete surfaces by Macnichol, actually has a
+strengthening effect upon cement and concrete surfaces. The more
+successful coatings of to-day, however, are those which may be placed
+directly upon the cement and concrete surfaces without the aid of such
+washes. Several fairly successful paints of this type have recently
+appeared in the market; some of them being made of acid rosins
+compounded with vegetable oils. Probably one of the first mixtures of
+this sort was the so-called suction varnish which the master painter has
+for years used as a prime coating on plastered walls previous to
+painting. These suction varnishes generally contain a high percentage of
+rosin, a material having an exceptionally high acid value and thus
+lending itself successfully to the neutralization of free lime. It has
+been claimed, however, by certain practical painters that the lime-rosin
+compounds formed when such paints are applied to the exterior of
+buildings, are of a brittle nature and subject to early failure. If this
+is true, it would seem advisable to use in a concrete paint an oil of a
+relatively unsaponifiable nature, which would withstand successfully the
+action of the lime, and, at the same time, prevent disruption of the
+coating and failure of the color used in the paint.
+
+=Outline of Tests.= The tests referred to as carried out by the writer
+were made on a brick wall forty feet long, surface-coated with a
+four-inch coating of Portland cement mortar made of one part of Portland
+cement and three parts of sharp, clean sand. After the cement had
+hardened for three days, the solutions under test were applied.
+
+In many of the tests outlined above, one-coat, as well as two-coat work,
+was used on different sections of the test surfaces. It was shown that
+the two-coat work gave far better results than with the one-coat work,
+and the writer would recommend for the painting of concrete at least
+two-coat work. Whenever paints containing Prussian blue or chrome green
+are applied to concrete surfaces, immediate whitening in the case of the
+blue, and yellowing in the case of the green, will take place, if any
+degree of action has been exerted by the lime within the concrete. For
+this reason, green is an especially delicate color to test and should be
+utilized for this purpose.
+
+The materials used, and the results shown at an inspection made after
+two years' exposure, are given herewith.
+
+=Test No. 1.= Concrete primed with a 25% solution of zinc sulphate
+crystals dissolved in water. A wide brush was used for the application,
+and the spreading rate was approximately 200 square feet per gallon.
+Second and third coated on the second day with No. 119 blue paint of the
+following composition:
+
+NO. 119 BLUE PAINT
+
+  Sublimed white lead      50%
+  Zinc oxide               35%
+  Silica and barytes       12%
+  Prussian blue             3%
+
+Ground in linseed oil, turpentine and drier.
+
+This panel, after three years' exposure, is in good condition. Slight
+checking observed.
+
+=Test No. 2.= Concrete primed with a 20% solution of (alum) (aluminum
+sulphate). Second and third coated with No. 119 blue.
+
+In similar condition to Test No. 1.
+
+=Test No. 3.= Concrete primed with zinc sulphate followed by two coats
+of para red.
+
+PARA RED FORMULA
+
+  Blanc fixe               60%
+  Whiting                  25%
+  Zinc oxide                3%
+  Paranitraniline lake     12%
+
+Ground in linseed oil, turpentine and drier.
+
+Panel in fair condition with exception of slight crazing. Characteristic
+dullness of color after exposure shown. Bright red color restored upon
+washing.
+
+=Test No. 4.= Concrete primed with an 8% solution of stearic acid and
+rosin dissolved in benzine. Second and third coated with No. 119 blue.
+
+This panel is not in as good condition as Tests Nos. 1 and 2, and would
+indicate the inferiority of the priming liquid used. Color failing in
+spots and checking observed.
+
+=Test No. 5.= Concrete primed with mixture used in Test No. 4, and then
+given two coats of para red.
+
+Test is in about the same condition as No. 4.
+
+=Test No. 6.= Concrete primed with a 10% mixture of acid calcium
+phosphate, followed with two coats of No. 119 blue.
+
+The acid phosphate solution evidently had a neutralizing effect upon the
+lime in the concrete, as the paint is in fair condition.
+
+=Test No. 7.= Concrete primed with one coat of a soap emulsion of the
+following composition, then painted with two coats of No. 119 blue.
+
+  Water                    85%
+  Linseed oil              12%
+  Alkali                    3%
+
+Very poor results obtained. Destruction of color and peeling resulted.
+
+=Test No. 8.= Concrete primed with one coat of white paint of the
+following composition:
+
+PRIMER
+
+  Zinc oxide               25%
+  Silica                   35%
+  Corroded white lead      20%
+  Gypsum                   15%
+  Whiting, etc.             5%
+
+Ground in a vehicle of linseed oil and containing 35% of volatile
+hydrocarbon spirits and drier.
+
+This coat was followed by one of the following composition, tinted blue:
+
+  Zinc oxide               60%
+  Gypsum                   20%
+  Silica                   20%
+
+Ground in linseed oil with 12% of turpentine and drier.
+
+Fair results shown during first year, but a breakdown occurred during
+the second year, and cracking and scaling resulted.
+
+=Test No. 9.= This test was a duplicate of No. 8 with the addition of 5%
+of zinc sulphate solution emulsified into the primer.
+
+Slightly superior to Test No. 8.
+
+=Test No. 10.= Primed with a white paste paint thinned with turpentine.
+Second coated with same paint tinted blue.
+
+FORMULA OF PASTE
+
+  Zinc oxide              40%
+  Whiting                 30%
+  Silica                  20%
+  Alumina and gypsum      10%
+
+Ground in 16% of linseed oil vehicle.
+
+Scaling and peeling due to lack of binder and use of saponifiable oil
+resulted during the first six months' exposure. Entire destruction of
+coating at end of two years.
+
+=Test No. 11.= Primed with a white mixture, and second coated with the
+same mixture tinted blue.
+
+FORMULA OF MIXTURE
+
+  Whiting                  30%
+  Silica                   30%
+  Zinc oxide               40%
+
+Stirred into a 5% solution of glue in water, until a fairly thick paste
+was obtained.
+
+Much chalking was shown, and a bleaching of color. It is evident that
+this mixture would not serve to keep moisture out.
+
+=Test No. 12 A.= Primed with a 5% solution of soluble nitrated cotton
+and paraffin dissolved in equal parts of amyl acetate and benzine.
+Second coated with No. 119 blue.
+
+Not very good results were obtained, chalking and slight scaling
+resulting.
+
+=Test No. 12 B.= Primed with a heavy varnish containing Chinese wood oil
+and kauri gum. Second coated with No. 119 blue.
+
+Fair results obtained.
+
+=Tests Nos. 13, 14, 15, and 16.= Primed with a solution made by
+dissolving 10 parts of sodium oxalate in 100 parts of water. Second and
+third coated with linseed oil paints in red, brown, blue, and green.
+
+Very good results shown at end of test.
+
+=Test No. 20, Special.= Primed and second coated with a green paint
+containing zinc oxide and barytes, ground in an oil having a low
+saponification value. Very slow drying was shown. Excellent results. No
+failure of color. Extremely glossy, waterproof surface presented.
+
+
+
+
+CHAPTER XVI
+
+STRUCTURAL STEEL PAINT TESTS
+
+
+=The Necessity of Protective Coatings.= Most painters have in the past
+considered of minor importance the painting of iron and steel; any paint
+that would properly hide the surface of the metal being accepted without
+much question. The demand, however, for structural steel for office
+buildings, factories, steel cars, railroad equipment, etc., has doubled
+the output of structural paints, and created a demand for painters
+having a knowledge of the proper materials to use in the painting of
+steel, so that its life may be preserved, and its strength maintained.
+Such knowledge is as important to the painter as a knowledge of how to
+properly select materials for the painting of wood, and how to temper
+these materials to suit the various conditions met with.
+
+=The Cause of Rust.= Everyone is familiar with the appearance of rust,
+but few actually understand what causes rust. No attempt will be made
+here to present even an outline of the many theories advanced to explain
+the phenomenon of the rusting of iron, for the subject is as diverse as
+it is interesting. A brief résumé, however, will be given of the now
+generally accepted theory that explains the subject. This theory is
+called the electrolytic theory. "Auto-electrolysis" is the term used to
+define the peculiar tendency of iron to be transformed from a metal
+possessing a hard lustrous surface, high tensile strength, and other
+useful properties, to a crumbling oxide that falls to the ground and
+again becomes part of the earth from which it was originally taken by
+man.
+
+[Illustration: A Side View of Steel Test Fences]
+
+This "going back to nature" is more readily accomplished by most of the
+steel produced to-day than by the old hand-made irons produced many
+years ago. It seems to be a curious fact that the more quickly a product
+or an article is fashioned by man, the more quickly it tends to return
+again to its original oxidized condition. Some manufacturers of steel,
+however, through an understanding of the causes of rust, have progressed
+in the manufacture of slow rusting materials, either by the elimination,
+or by the proper distribution of impurities.
+
+When iron is brought into contact with moisture, currents of electricity
+flow over the surface of the iron between points that are relatively
+pure and points that contain impurities. These currents stimulate the
+natural tendency of the iron to go into solution, and the solution
+proceeds with vigor at the positive points. The air which the water
+contains oxidizes the iron which has gone into solution, and
+precipitates the familiar brown iron rust. Thus water, which acts as an
+acid, and air, which acts as an oxidizer, have combined together to
+accomplish the downfall of the metal.
+
+[Illustration: Three Photomicrographs of Corroding Steel]
+
+=Inhibition and Stimulation of Rust.= It is obvious that if means could
+be devised to stop the solution pressure of iron and make it resistant
+to the flow of surface electric currents, rust could be prevented. Such
+methods have been devised, and to better illustrate how they operate, an
+analogy may be drawn between iron in water and shellac in alcohol.
+
+It is common knowledge that when shellac is placed in alcohol, the
+shellac will force itself into solution in the alcohol, and form a
+clear, transparent lacquer. If, however, there should be mixed with the
+alcohol a quantity of water, it would be found that the shellac could no
+longer go into solution, and it would remain in its original condition.
+In the same way, if there be placed in water a small quantity of
+material, such as soluble chromates, or an alkaline substance like
+caustic soda or lime, it will be found that iron will no longer have a
+tendency to go into solution in this treated water, but will stay bright
+and clean. These materials which prevent the rusting of iron have been
+called by Cushman, who first advanced these explanations, "rust
+inhibitors," or materials which inhibit rusting. The paint maker,
+realizing the importance of these rust inhibitors, is incorporating them
+into paints designed for the protection of iron and steel, and the
+success which paints of this type have met with from a practical
+standpoint is a justification of what was first called the "electrolytic
+theory," which suggested their use.
+
+By placing small, brightly polished steel plates into a mush of paint
+pigment and water, a determination may be made of the pigment's effect
+upon the metal. Some pigments, under such conditions, cause rapid
+corrosion of the steel plates. Such pigments are stimulators of
+corrosion, on account of acid impurities which they contain, or because
+of their effect in stimulating galvanic currents. Many carbonaceous
+pigments are of this type. Other pigments have the effect of keeping
+bright the steel plates and preventing rust. Such pigments are of the
+inhibitive type, and their action is to check or retard the solution
+pressure of the iron.
+
+=The Effects of Moisture.= It might occur to the reader that although
+paint pigments, when mixed up with water and brought into contact with
+the surface of steel, might show either an inhibitive or stimulative
+action, that it is by no means certain that the same tendency will be
+exhibited by pigments when they are properly mixed with linseed oil and
+laid out as a film upon the surface of steel. In answer to this, it may
+be well to state that almost no material used by mankind is absolutely
+dry. Linseed oil, as it is pressed from the seed, comes from the cells,
+carrying with it a certain small definite percentage of water, and it is
+quite certain that even the best linseed oil that goes into use is not
+theoretically dry. Everyone knows, of course, that oil and water do not
+readily mix and are, in fact, more or less repellent to each other. It
+is, however, true that, in spite of this, oils can carry quite a
+percentage of water, without the admixture being apparent to the eye. In
+addition to this, careful experiments have proved very conclusively that
+linseed oil films, even after they have oxidized and hardened, have the
+power to a certain extent of absorbing water from the atmosphere. It is,
+therefore, safe to say that no linseed oil film in a paint coating is
+dry all the time. As a matter of fact, there is abundant evidence to
+show that in rainy weather, and, in fact, when the humidity in the air
+is high, paint films have absorbed water. As the sun comes out and warms
+the paint coating, and the humidity content of the atmosphere falls,
+this water to a large extent evaporates out of the film, only to be
+taken up again when the weather conditions change. This action may be
+likened to a breathing of the paint film, that is to say, an indrawing
+of water under humid conditions, followed by an exhaling of water under
+dry conditions. With these facts in mind, it must be apparent that
+pigments laid out in intimate contact with the surface of steel are
+subjected at all times either more or less to the reactions produced by
+water contact. Furthermore, as it is a property of water to become
+saturated with the gases of the atmosphere, such as oxygen, carbonic and
+sulphurous acids, and other impurities, there is present in a protective
+paint film at all times the elements necessary to carry on the corrosive
+process and reactions.
+
+An outline of Cushman's original research work, upon which has been
+based the classification of pigments as inhibitors, stimulators, and
+inerts, is clearly presented in his report[38] as Chairman of Committee
+U of the American Society for Testing Materials, of which the following
+is an excerpt:
+
+  [38] Page 73, 1910 Proceedings of the American Society for Testing
+       Materials.
+
+[Illustration: Ferroxyl Tests on Painted Steel Surfaces. Upper Row
+Painted with Stimulative Paints--Lower Row with Inhibitive Paints.]
+
+[Illustration: Water Test on Plates Painted--Except in Center Spot. Left
+Hand Plates Painted with Stimulative Paints, Right Hand Plates Painted
+with Inhibitive Paints.]
+
+[Illustration: View of Steel Plates Painted with Stimulative Paints,
+after Immersion in Ferroxyl Jelly.]
+
+"Three years ago the suggestion was made in a paper presented before the
+Tenth Annual Meeting of this Society that the various types of
+substances used as pigments in protective coatings might exert a
+stimulative or an inhibitive action on the rate and tendency to
+corrosion of the underlying metal. It was further suggested on a
+theoretical ground that slightly soluble chromates should exert a
+protective action when employed as pigments by maintaining the surface
+of the iron in a passive condition in case water and oxygen penetrated
+the paint film. In view also of the well-known fact that alkalies
+inhibit while acids stimulate the corrosion of iron, it was suggested
+that the action of more or less pure pigments on iron in the presence of
+water should be thoroughly investigated. Two years ago this Committee
+invited the co-operation of Committee D-1 (then known as Committee E) in
+the investigation, and a special sub-committee representing the two main
+committees was appointed.
+
+"The methods and results of the water-pigment tests have previously been
+reported and published, and need not be given in detail. Briefly, the
+method consisted in immersing samples of steel in water suspensions of
+the various pigments and blowing air through the containers for definite
+periods of time, the corrosion being measured by the loss in weight
+sustained by the test pieces. About fifty pigments which are in more or
+less common use for painting steel were purchased in the open market and
+distributed among a number of the members of the Committee, who agreed
+to carry out the work. Each investigator worked independently of the
+others, except that the same general method was followed; the time of
+exposure to the corroding action, however, varied in the different
+experiments. When the results were compared and analyzed by the
+sub-committee, it was felt that the general agreement of the results
+obtained by the several investigators was striking and merited further
+and more systematic work. As a result of these tests the sub-committee
+tentatively divided the pigments into inhibitors, stimulators, and
+indeterminates. The word 'indeterminate' was selected after considerable
+discussion, because the words 'neutral' or 'inert' already possess a
+special meaning as applied to paint technology. The Committee takes this
+occasion to emphatically state that in adopting this tentative
+classification, the words 'inhibitive' and 'stimulative' as used by them
+up to the present time apply only to the results obtained in the water
+tests, and the inference that the results obtained have decided which
+class the pigment will fall into when made into a paint with the usual
+vehicles and used as a protective coating on iron and steel, is not
+justified. In order to make this point quite clear, it has been agreed
+by the Committee to qualify the classification so as to speak of the
+various materials tested as 'water stimulative' or 'water inhibitive.'"
+
+[Illustration: Apparatus for Testing the Inhibitive Value of Pigments]
+
+=Importance of Field Tests.= Although the laboratory accelerated tests
+for the determination of the relative value of structural steel paints
+afford information of some import, there seems to be a general opinion
+that the best method to follow, if information of a reliable character
+is to be obtained, is to make actual field exposure tests upon large
+surfaces. The results of the above described water-pigment tests
+suggested the erection of a series of steel panels on which to test out
+the same pigments under practical service conditions. The Paint
+Manufacturers' Association of the United States erected and painted the
+panels, the work being under the constant supervision of the writer, and
+the inspection of the work under Committee U of the American Society for
+Testing Materials. A brief résumé of the work[39] is herewith presented.
+
+  [39] Page 181, "Corrosion and Preservation of Iron and Steel"--Cushman
+       and Gardner--McGraw-Hill Book Co., New York City.
+
+=Pickling and Preparation of Plates.= The three types of metal[40]
+selected for the test were rolled to billets, the middle of which were
+selected, and worked up into plates 24 inches wide, 36 inches high, and
+1/8 inch in diameter--approximately 11 gauge. A number of plates of each
+of the metals selected, in all 450, were pickled in 10% sulphuric acid,
+kept at 180 to 200 degrees Fahrenheit, in order to remove the
+mill-scale. The plates were then washed in water, and later in 10%
+solution of caustic soda. Finally the plates were again washed in water
+and wiped dry. They were then packed in boxes containing dry lime, in
+order to prevent superficial corrosion. By this method the plates were
+secured in perfect condition, the surfaces being smooth and free from
+scale. Upon these pickled plates paints were applied with a definite
+spreading rate of 900 square feet per gallon. The unpickled plates,
+coated with mill-scale, were painted with the same paints, but without
+adopting any special spreading rate, thus following more closely the
+ordinary method of painting structural steel. A few extra plates of
+special Bessemer steel and Swedish charcoal iron were also included in
+the test, some of which were painted, while others were exposed without
+any protective coating. Plates of the three types of metal already
+mentioned were also exposed unpainted, both in the black and pickled
+condition.
+
+  [40] Bessemer Steel, Open Hearth Steel, and Pure Iron.
+
+[Illustration: Front View of Steel Test Fences]
+
+=Fence Erection and Preparation for Work.= The fences which were erected
+for the holding of the plates were constructed of yellow pine, the posts
+being set deeply in the ground and properly braced. The framework of the
+fence was open, with a ledge upon the lateral girders, upon which the
+plates might rest, and to which the plates were secured by the use of
+steel buttons. After the framework had been erected, painted, and made
+ready for the placement of the panels, a small shed was built upon the
+ground, and the materials for the field test placed therein. The steel
+plates were unpacked from the boxes in which they were shipped, brushed
+off, and stacked up ready for painting. Small benches were erected, and
+the accessories of the work, such as cans, brushes, pots, balances,
+etc., were placed in position.
+
+=Methods Followed in Painting Plates.= A frame resting upon the
+workbench served to hold the plates in a lateral position while being
+painted, room being allowed beneath the plate for the operator to place
+his hands in order to lift the plates from the under surface after the
+painting had been finished.
+
+A pickled plate having been placed upon the framework everything was in
+readiness for the work. The specific gravity and weight per gallon of
+the paint to be applied was determined, and the amount, in grams, to be
+applied to each individual panel was calculated according to the
+following formula:
+
+  Spreading rate       Sq. ft. in plate      Grams paint in gal.
+   900 sq. ft.     :          6          ::         5400           :  x
+
+The reciprocal of _x_ being the number of grams of paint to be applied
+to the panels.
+
+An enamel cup was then filled with the paint and a brush well stirred
+within. The cup, paint, and brush were placed upon the balances and
+accurately weighed in grams. After most of the paint had been applied to
+the panel, cross-brushing of the panel was continued until the pot with
+brush and paint exactly counterbalanced the deducted weight. The painted
+panel was then set in a rack, in a horizontal position to dry.
+
+A period of eight days elapsed between the drying of each coat. The
+greatest care was taken in the painting of the edges of the plates, and
+the racks for containing the plates after they were painted were so
+constructed that the paint would not be abraded while sliding the plates
+back and forth. The working properties of each paint, and the appearance
+of the surface of each plate after painting, were carefully noted and
+included in the report. No reductions were made to any of the paints
+applied except in three cases, where the viscosity was so great that it
+was necessary to add a small amount of pure spirits of turpentine. The
+amount of paint was proportionately increased in such cases, so that the
+evaporation of the turpentine would leave upon the plate the amount of
+paint originally intended.
+
+The appearance of the completed series of test panels is shown on page
+221.
+
+=Vehicles Used and Reasons for Avoidance of Japan Driers.= The pigments
+used were selected with the view to securing as nearly as possible
+purity and strength, and as already noted, were out of the same lots
+used in making the preliminary laboratory tests on inhibitives. They
+were ground in a vehicle composed of two parts of raw linseed oil and
+one part of pure boiled oil. Paint is generally caused to dry rapidly by
+the use of japan or driers. These materials contain a large amount of
+metallic oxides which might have some effect in either exciting or
+retarding corrosion. To prevent the introduction of such a factor, these
+materials were not used in the test. The boiled oil, with its small
+percentages of metallic oxides, was sufficient, however, to cause the
+paints to dry in a short time after they were spread.
+
+=Testing Effect of Various Prime Coats.= Some of the special tests made
+included a series of plates prime-coated with different inhibitive
+pigments, and these tests were designed to determine which pigments
+offer the best results for such work. These plates were all
+second-coated with the same paint. It is the opinion of the authors that
+any good excluding paint may be used whether it be inhibitive in action
+or not, provided the contact coat is inhibitive. If, however, both coats
+can be designed so as to have the maximum possible value from both these
+points of view, the best results would, of course, accrue. The only way
+such data can be obtained is by careful observation of the results of
+exposure tests.
+
+=Combination Formulas Tested.= By selecting a series of pigments which
+in the water tests showed inhibitive tendencies, and properly combining
+these pigments into a paint, it was thought possible that a more or less
+inhibitive paint would be produced. If this proved to be the case, it
+would follow that the selection and introduction into a paint of the
+stimulative pigments would inevitably produce a paint unfit for use on
+iron or steel.
+
+=Data on Application of Paints.= The recorded data on the application of
+the paint to the panels is voluminous. There is presented herewith,
+however, the data on two of the paints.
+
+  NO. 2, QUICK PROCESS WHITE LEAD:
+
+  Sp. Gr. of pigment                        6.78
+  Lbs. to gallon oil                       20.34
+  Sp. Gr. of paint as received              2.47
+  Wt. of paint per gallon                  20.56
+  Grams to panel                              62
+  Condition of paint                        Good
+  Working properties                  Works easy
+  Drying                       24 hrs. all coats
+
+  1 coat   Oct. 26   T 60   B 29.94   W. fair
+  2 coat   Nov.  3   T 54   B 30.23   W. clear
+  3 coat   Nov.  7   T 52   B 29.66   W. cloudy
+
+  NO. 9, ORANGE MINERAL (AMERICAN):
+
+  Sp. Gr. of pigment                        8.97
+  Lbs. to gallon oil                       26.91
+  Sp. Gr. of paint as received              2.97
+  Wt. of paint per gallon                  24.74
+  Grams to panel                            74.7
+  Condition of paint                        Good
+  Working properties      Smooth--no brush marks
+  Drying                                    Good
+
+  1 coat   Oct. 28   T 58   B 30.01   W. cloudy
+  2 coat   Nov.  4   T 65   B 29.61   W. cloudy
+  3 coat   Nov.  9   T 58   B 29.91   W. clear
+
+=Composition of Paints.= The following table gives data regarding the
+composition, etc., of paints applied to the steel panels.
+
+=Results of Inspection.= The results of an inspection of the steel test
+plates, made by Sub-committee D representing Committee D-1 of the
+American Society for Testing Materials, is herewith presented:
+
+"On Wednesday, June 28, 1911, the second inspection of the Atlantic City
+Steel Test Panels, erected in October, 1908, was made by Sub-committee D
+of Committee D-1, this Committee having agreed to report upon the
+condition of the painted surfaces, leaving any report on the comparative
+corrosion of the various types of metal used in the test to Committee
+A-5 on the corrosion of iron.
+
+  ===+=========================+=======+=======+======+=======+=========
+     |                         |       |       |      |       |Grams
+     |                         |       |       |      |       |Paint
+     |                         |       |Wt. of | Sp.  |Wt. of |to Panel
+     |           Name          |  Sp.  |Pigment| Gr.  | Paint |at 900
+     |                         |  Gr.  |to Gal.| of   |  per  |Sq. ft.
+  Pigment                      |of Pig-|of oil |Paint |  Gal. |spreading
+  No.|                         | ment  | Lbs.  |Rec'd |  Lbs. |rate
+  ---+-------------------------+-------+-------+------+-------+---------
+    1|Dutch process white lead | 6.83  | 20.49 | 2.45 | 20.49 |  61.0
+    2|Quick process white lead | 6.78  | 20.34 | 2.47 | 20.34 |  62.0
+    3|Zinc oxide               | 5.56  | 16.68 | 2.12 | 16.68 |  59.0
+    4|Sublimed white lead      | 6.45  | 19.17 | 2.36 | 19.17 |  59.0
+    5|Sublimed blue lead       | 6.39  | 19.17 | 2.42 | 19.17 |  61.0
+    6|Lithopone                | 4.26  | 12.78 | 1.80 | 12.78 |  45.3
+    7|Zinc lead white          | 4.42  | 13.26 | 1.96 | 13.26 |  49.4
+    9|American orange mineral  | 8.97  | 26.91 | 2.97 | 26.91 |  74.7
+   10|Red lead                 | 8.70  | 26.10 | 2.93 | 26.10 |  73.6
+   12|Bright red oxide         | 5.26  | 15.78 | 2.05 | 15.78 |  60.0
+   14|Venetian red             | 3.1   |  9.30 | 1.52 |  9.30 |  38.0
+   15|Prince's metallic brown  | 3.17  |  9.51 | 1.50 |  9.51 |  37.7
+   16|Natural graphite         | 2.60  |  7.80 | 1.37 |  7.80 |  34.4
+   17|Acheson graphite         | 2.21  |  6.63 | 1.22 |  6.63 |  30.8
+   19| {Lampblack              |       |  1.82}|      |  1.82 |
+     | {Barytes                | 1.82  |  8.92}| 1.60 |  8.92 |  40.2
+   20|Willow charcoal          | 1.49  |  4.47 | 1.08 |  4.47 |  27.0
+   21| {Gas carbon black       | 1.85  |  1.39}| 1.67 |  1.39 |
+     | {Natural barytes        |       | 10.03}|      | 10.03 |  50.7
+   24|French yellow ochre      | 2.94  |  8.82 | 1.46 |  8.82 |  37.0
+   27|Natural barytes          | 4.46  | 13.38 | 1.83 | 13.38 |  46.0
+   28|Precipitated barytes     | 4.23  | 12.69 | 1.84 | 12.69 |  46.0
+     |(blanc fixe)             |       |       |      |       |
+   29|Calcium carbonate        | 5.48  |  8.22 | 1.37 |  8.22 |  34.5
+     |(whiting)                |       |       |      |       |
+   30|Calcium carbonate        | 2.56  |  7.68 | 1.35 |  7.68 |  34.0
+     |precipitated             |       |       |      |       |
+   31|Calcium sulphate (gypsum)| 2.33  |  6.99 | 1.25 |  6.99 |  31.4
+   32|China clay (kaolin)      | 2.67  |  8.01 | 1.34 |  8.01 |  34.0
+   33|Asbestine (silicate of   | 2.75  |  8.25 | 1.38 |  8.25 |  34.7
+     |magnesium)               |       |       |      |       |
+   34|American vermilion       | 6.83  | 20.49 |      | 20.49 |  64.5
+     |(chrome scarlet)         |       |       |      |       |
+   36|Medium chrome yellow     | 5.88  | 17.64 |      | 17.64 |  67.1
+   39|Zinc chromate            | 3.57  | 10.71 | 1.57 | 10.71 |  39.2
+   40|Zinc and barium chromate | 3.45  | 10.35 | 1.58 | 10.35 |  40.0
+   41|Chrome green (blue tone) | 4.44  | 13.32 | 1.94 | 13.32 |  49.0
+   44|Prussian blue            | 1.96  |  5.88 |      |  5.88 |  30.0
+   45|Prussian blue            | 1.93  |  5.79 |      |  5.79 |  34.5
+   48|Ultramarine blue         | 2.40  |  7.20 | 1.29 |  7.20 |  32.5
+   49|Zinc and lead chromate   | 4.76  | 14.28 | 1.92 | 14.28 |  48.3
+   51|Magnetic black oxide     |       | 15.00 | 1.92 | 15    |  48.3
+     |                         |       |       |      |       |
+     |   _Composite Paints_    |       |       |      |       |
+     |                         |       |       |      |       |
+  111|Brown } Made from pig-   |       | 10.82 | 1.30 | 10.82 |  32.7
+  222|Black } ments that were  |       | 10.86 | 1.30 | 10.86 |  32.8
+  333|White } inhibitive in the|       | 14.52 | 1.74 | 14.52 |  43.8
+  444|Green } water test       |       | 12.77 | 1.53 | 12.77 |  38.6
+     |                         |       |       |      |       |
+  555|Black } Made from pig-   |       |  9.37 | 1.125|  9.37 |  28.
+  666|Brown } ments that were  |       | 11.74 | 1.41 | 11.74 |  35.5
+  777|White } stimulative in   |       | 14.55 | 1.75 | 14.55 |  44.
+  888|Green } the water test   |       | 14.57 | 1.75 | 14.57 |  14.57
+  ===+=========================+=======+=======+======+=======+=========
+
+"According to the amount of rust apparent on the painted surfaces of the
+panels, as well as the degree of checking, chalking, scaling, cracking,
+peeling, loss of color, and other signs of paint failure shown, ratings
+were given each panel. The system of rating which took into
+consideration all the above conditions, was similar to the system used
+at the first inspection during 1910, when 0 (zero) recorded the worst
+results and 10 (ten) the best results.
+
+"In Table No. 1 there is shown the rating accorded by each inspector to
+each panel, as well as an average for each panel.
+
+TABLE NO. 1.--SECOND INSPECTION OF STEEL PAINT TEST PANELS AT ATLANTIC
+CITY, N. J., BY SUB-COMMITTEE D OF COMMITTEE D-1
+
+  =======+========================+======+======+=======+=======+=======
+         |                        |      |      | H. A. |       |
+   Panel |                        |W. H. |P. H. |Gardner|  C.   |
+    No.  |         Pigment        |Walker|Walker|Chair- |Chapman|Average
+         |                        |      |      |  man  |       |
+  -------+------------------------+------+------+-------+-------+-------
+       1 |Dutch process white lead| 2    | 3    |  3    |  5    |  3.7
+       2 |Quick process white lead| 4    | 4    |  3    |  6    |  4.2
+       3 |Zinc oxide (XX)         | 1    | 1-1/2|  1    |  2-1/2|  1.5
+       4 |Sublimed white lead     | 9    | 9-1/2|  9    |  8-1/2|  9.0
+       5 |Sublimed blue lead      | 9    | 9-1/2|  9-1/2|  7-1/2|  8.8
+       6 |Lithopone               | 2    | 1-1/2|  2    |  3-1/2|  2.2
+       7 |Zinc lead white         | 3    | 4    |  5    |  7    |  4.7
+       9 |Orange mineral          | 9    | 9    |  9    |  6-1/2|  8.3
+      10 |Red lead                | 9    | 9    |  9    |  6-1/2|  8.3
+      12 |Bright red oxide        | 8-1/2| 9    |  8    |  7    |  8.1
+      14 |Venetian red            | 7    | 9    |  7    |  9    |  8.0
+      15 |Prince's metallic brown | 5    | 7-1/2|  6    |  8    |  6.3
+      16 |Natural graphite        | 6    | 8    |  4    |  9-1/2|  6.8
+      17 |Artificial graphite     | 5    | 7-1/2|  4    |  7    |  5.9
+      19 |Lampblack               | 5    | 7-1/2|  5    |  8    |  6.3
+      20 |Willow charcoal         | 9    | 8-1/2|  9    |  9    |  8.8
+      21 |Carbon black            | 7    | 8-1/2|  5    |  8-1/2|  7.2
+      24 |Yellow ochre (French)   | 5    | 7    |  2    |  8    |  5.5
+      27 |Barytes (natural)       | 1    | 1    |  1    |  0    |  0.7
+      28 |Barytes (precipitated)  | 2    | 1-1/2|  2    |  2    |  1.8
+      29 |Calcium carbonate       | 0    | 0    |  0    |  0    |  0.0
+         |(whiting)               |      |      |       |       |
+      30 |Calcium carbonate (pre- | 0    | 0    |  0    |  0    |  0.0
+         |cipitated)              |      |      |       |       |
+      31 |Calcium sulphate        | 1    | 1    |  1    |  3    |  1.7
+         |(gypsum)                |      |      |       |       |
+      32 |China clay (kaolin)     | 6    | 6    |  7    |  6-1/2|  6.3
+      33 |Asbestine (magnes. sili-| 5    | 4-1/2|  6    |  5    |  5.1
+         |cate)                   |      |      |       |       |
+      34 |American vermilion      |10    |10    | 10    | 10    | 10.0
+      36 |Lead chromate           | 7    | 7-1/2|  8-1/2|  8    |  7.7
+      39 |Zinc chromate           | 9    | 9    | 10    |  9-1/2|  9.5
+      40 |Zinc and barium chromate| 9    | 9-1/2| 10    |  9-1/2|  9.5
+      41 |Chrome green (blue tone)|10    |10    | 10    |  9-1/2|  9.8
+      44 |Prussian blue, W. S     | 9    | 9-1/2|  9-1/2|  9    |  9.0
+      45 |Prussian blue, W. I     | 8    | 9-1/2|  8-1/2|  8-1/2|  8.5
+      48 |Ultramarine blue        | 0    | 0    |  0    |  0    |  0.0
+      49 |Zinc and lead chromate  |10    | 9-1/2| 10    |  9-1/2|  9.7
+      51 |Magnetic black oxide    | 9    | 9-1/2| 10    |  9-1/2|  9.5
+     111 |Brown composite paint   | 7    | 9    |  9    |  9    |  8.5
+     222 |Black composite paint   | 9    | 9    |  9    |  8-1/2|  8.8
+    3333 |White composite paint   | 4    | 4    |  7    |  3    |  4.5
+     444 |Green composite paint   | 5    | 7    |  7    |  8    |  6.7
+     555 |Black composite paint   | 9    | 9    |  6    |  9    |  8.2
+     666 |Brown composite paint   | 8    | 8    |  6    |  9    |  7.7
+     777 |White composite paint   | 7    |10    |  5    |  7    |  7.2
+     888 |Green composite paint   | 7    | 8    |  8    |  9    |  8.0
+    2000 |1 coat zinc chromate   }| 8    | 8-1/2|  8    |  8    |  8.1
+         |1 coat iron oxide ex-  }|      |      |       |       |
+         |cluder                 }|      |      |       |       |
+    3000 |1 coat lead chromate    | 7    | 8    |  7    |  7-1/2|  7.3
+    4000 |1 coat red lead        }| 7    | 8-1/2|  8    |  7-1/2|  7.7
+         |1 coat iron oxide ex-  }|      |      |       |       |
+         |cluder                 }|      |      |       |       |
+     100 |Straight carbon black   | 5    | 8-1/2|  4    |  8-1/2|  6.5
+         |paint with turps and    |      |      |       |       |
+         |drier                   |      |      |       |       |
+      90 |Straight lampblack paint| 5    | 7    |  3    |  8    |  5.7
+         |with turps and drier    |      |      |       |       |
+    5555 |Coal tar paint over red | 4    | 8    |  2    |  7    |  5.2
+         |lead                    |      |      |       |       |
+    1000 |Chrome resinate in oil  | 1    | 0    |  0    |  2    |  0.7
+         |(1 coat)                |      |      |       |       |
+  1 plate|3 coats boiled linseed  | 1    | 0    |  1    |  4    |  1.5
+         |oil                     |      |      |       |       |
+  =======+========================+======+======+=======+=======+=======
+
+"In Table No. 2 there is shown the rating obtained by those panels which
+were considered by the committee as meriting from 8 to 10, and having
+given the best all-round service.
+
+TABLE NO. 2.--ANALYSIS OF AVERAGES. GRADE OF EXCELLENCE FROM 8 TO 10
+
+  =====+=============================================+=======
+  Plate| Pigment                                     |Average
+  -----+---------------------------------------------+-------
+    34 | American vermilion (basic chromate of lead) |  10.0
+    41 | Chrome green                                |   9.8
+    49 | Lead and zinc chromate                      |   9.7
+    39 | Zinc chromate                               |   9.5
+    40 | Zinc and barium chromate                    |   9.5
+    51 | Black oxide of iron                         |   9.5
+     4 | Sublimed white lead                         |   9.0
+    44 | Prussian blue                               |   9.0
+     5 | Sublimed blue lead                          |   8.8
+    20 | Willow charcoal                             |   8.8
+   222 | Composite paint                             |   8.8
+    45 |  Prussian blue                              |   8.5
+   111 | Composite formula                           |   8.5
+     9 | Orange mineral                              |   8.3
+    10 | Red lead                                    |   8.3
+   555 | Composite paint                             |   8.2
+    12 | Bright red oxide of iron                    |   8.1
+  2000 | 1 coat zinc chromate; 1 coat iron oxide     |   8.1
+    14 | Venetian red                                |   8.0
+   888 | Composite paint                             |   8.0
+  =====+=============================================+=======
+
+=Comparison of Results.= It is of interest to compare with Table 2 of
+the above report, Table 2 of the 1910 report of Committee U of the
+American Society for Testing Materials. Both charts show the highly
+inhibitive pigments to be in the lead.
+
+
+COMMITTEE U REPORT 1910
+
+TABLE II.--ANALYSIS OF AVERAGES. GRADE OF EXCELLENCE FROM 8 TO 10
+
+(_Only resistance to corrosion was considered, and only pigments which
+were common to both tests are included_)
+
+  ===+====================================+=======
+  No.| Pigment                            |Average
+  ---+------------------------------------+-------
+  34 | American vermilion (chrome scarlet)|  9.8
+  41 | Chrome green (blue tone)           |  9.7
+  40 | Zinc and barium chromate           |  9.7
+   5 | Sublimed blue lead                 |  9.6
+   4 | Sublimed white lead                |  9.5
+  49 | Zinc and lead chromate             |  9.5
+  39 | Zinc chromate                      |  9.4
+  12 | Bright red oxide                   |  9.3
+  44 | Prussian blue (water stimulative)  |  9.2
+  16 | Natural graphite                   |  9.1
+   9 | Orange mineral (American)          |  9.0
+  36 | Medium chrome yellow               |  9.0
+   2 | White lead (quick process)         |  8.9
+  20 | Willow charcoal                    |  8.8
+  45 | Prussian blue (water inhibitive)   |  8.8
+   1 | White lead (Dutch process)         |  8.7
+  10 | Red lead                           |  8.7
+  7  | Zinc lead white                    |  8.0
+  ===+====================================+=======
+
+The writer has recently made a careful inspection of the panels painted
+with single pigment paints, and has made the following brief summary of
+the characteristic appearance of each.
+
+=Panel No. 1--Dutch Process White Lead.= The excessive chalking which
+took place began to disappear at the end of a year, being washed away by
+the rains and carried away by the winds, so that there was left upon the
+surface but a thin coating of pigment, insufficient to give good
+protection. Slight corrosion was apparent beneath the film.
+
+=Panel No. 2--Quick Process White Lead.= In the same condition as Panel
+No. 1.
+
+=Panel No. 3--Zinc Oxide.= Panel covered with thin lateral streaks of
+rust, due to the admittance of moisture in cracks caused by brittleness
+of film. Result doubtless due to insufficient amount of oil used with
+pigment. Removal of film shows steel very bright except where cracks
+have formed.
+
+=Panel No. 4--Sublimed White Lead.= Although sublimed white lead chalked
+very heavily, the chalked pigment seemed to be tenacious and adhered to
+the plate, presenting an excellent surface with absence of rust. Film of
+good color and quite elastic.
+
+=Panel No. 5--Sublimed Blue Lead.= In same condition as Panel No. 4, but
+color has slightly faded.
+
+=Panel No. 6--Lithopones.= Lithopone was early destroyed, as is usual
+with this pigment when used alone on exterior surfaces. It became rough
+and discolored, presenting a very blotchy appearance and disclosed the
+formation of rust working through the film.
+
+=Panel No. 7--Zinc Lead White.= In general good condition with the
+exception of the color, which is slightly dark. Medium chalking was
+apparent but only very slight corrosion appeared.
+
+=Panel No. 9--Orange Mineral.= In excellent condition, showing a good
+firm surface with no checking or corrosion apparent. Shortly after
+exposure the film became covered with a white coating of carbonate of
+lead, which indicates action of the red lead with the carbonic acid of
+the atmosphere. Removal of this white coating with water discloses the
+brilliant color of the unaffected portion of the red lead.
+
+=Panel No. 10--Red Lead.= In same condition as Panel No. 9.
+
+=Panel No. 12--Bright Red Iron Oxide.= In general good condition. Film
+intact and unfading in color.
+
+=Panel No. 14--Venetian Red.= Similar to Panel No. 12, but slight
+corrosion apparent beneath, in localized spots, and film showing slight
+wart-like formations.
+
+=Panel No. 15--Prince's Metallic Brown.= Similar to Panel No. 14.
+
+=Panel No. 16--Natural Graphite.= Deeply pitted in spots, showing
+bulbous eruptions, indicating the stimulative nature of this pigment.
+
+=Panel No. 17--Artificial Graphite.= In same condition as Panel No. 16.
+
+=Panel No. 19--Lampblack and Barytes.= Although the film seems to be
+intact, there are apparent abrasions of the surface showing stimulative
+corrosion effects of a pronounced nature.
+
+=Panel No. 21--Carbon Black and Barytes.= In same condition as Panel No.
+19.
+
+[Illustration: Corrosion Pits on Graphite Panel]
+
+[Illustration: Rust on Stripped Graphite Film]
+
+[Illustration: Section of Wire Painted with a Stimulative Carbonaceous
+Paint]
+
+[Illustration: Corroded and Pitted Surface of Plate Painted with
+Stimulative Paint]
+
+The longevity of lampblack and carbon black paint films when applied to
+wood has been attributed to the slow drying nature of these pigments
+when mixed with oil. It is assumed that they have the property of
+keeping the oil in a semi-drying condition, which will not disintegrate
+as early as when the oil is thoroughly dried to linoxyn. If this is
+true, it would seem advisable to use with hard-drying pigments, a
+proportion of some oil that is semi-drying in nature or one which will
+leave a film not too hard. Soya bean oil, wood oil, and fish oil present
+themselves as candidates for such use. How they will work in practice,
+however, is a question not yet determined. On the other hand, it is well
+known that these pigments require enormous quantities of oil in order to
+grind to a working consistency, and it is possible that the life of
+such coatings is due rather to the property of these pigments, of taking
+up large quantities of oil, than to their effect upon the slow drying of
+oil. Excessive oil carrying, however, should be avoided, as shown by the
+early failure and pitting of those carbon black and lampblack paints
+ground with very large quantities of oil, as is the usual practice. When
+these carbon and lampblack pigments were ground with barytes (which is a
+heavy pigment and requires only about 9 pounds of oil to 100 pounds of
+pigment, as against 175 pounds of oil to 100 pounds of lampblack), it
+was found that the lampblack and carbon black paints were reinforced and
+made more suitable for actual practice. The stimulative nature of these
+black pigments, however, asserted itself in both cases, and large
+pittings and eruptions were evident at the end of a year. Carbon black,
+lampblack, graphite, or any other good conductor of electricity should
+never be placed next to the surface of iron. They are good as
+top-coatings, but not as prime-coaters. Some pigments are stimulators of
+corrosion, because they contain water-soluble impurities that hasten the
+rusting, while others, like graphite, hasten it simply because, being
+good conductors, they stimulate surface electrolysis.
+
+=Panel No. 20--Willow Charcoal.= In excellent condition throughout.
+Presence of small quantities of potash may be responsible for the
+inhibitive nature of this black pigment.
+
+=Panel No. 24--Ochre.= While the film seems intact, it has a very
+mottled appearance and examination shows eruptions of rust through the
+film, in several places.
+
+=Panel No. 27--Natural Barytes.= Within a year the film became
+pin-holed, and corrosion was apparent. At the end of three years very
+little of the pigment was left upon the plate, having chalked and scaled
+off. Barytes has proved its usefulness as a constituent of a combination
+type of paint, but it should not be used alone.
+
+=Panel No. 28--Blanc Fixe.= In the same condition as Panel No. 27, but
+slightly more chalking and disintegration was shown.
+
+[Illustration: Panel Painted with Blanc Fixe. Right Side Stripped of
+Paint to Show Corrosion]
+
+[Illustration: Scaled Whiting Films
+
+Chemically Active Pigments and Their Effect After Eighteen Months'
+Wear]
+
+[Illustration: Plate Showing Effect of Chemically Active Pigments on Oil
+after One Year's Wear]
+
+=Panel No. 29--Whiting.= Plates coated with calcium carbonate or whiting
+in oil presented a very fair appearance at the start of the test, but
+they soon began to chalk and disintegrate. It is well known that
+whiting, being alkaline, has the property of acting on oil and causing
+its early disintegration by saponification. As a matter of fact, six
+months after the whiting plates were exposed, crumbling of the surface
+appeared, and twelve months was sufficient for the total destruction of
+the paint. At this time the rusted surface of the plates which had been
+painted with calcium carbonate, seemed not to rust as fast as those
+plates which were exposed without paint coatings, and the rust which had
+formed appeared to be of an even, fine texture. On the lower left-hand
+corner of these plates had been lettered the figures "29" and "30,"
+using lampblack in oil. One of the most remarkable things which appears
+on the fence to-day is the perfect condition of these lampblack letters
+over their priming coat of calcium carbonate, standing out in clear
+relief against the rusted metal. This test would suggest, therefore,
+that if the surface of metal is properly protected with a pigment which
+is slightly alkaline or inhibitive in nature, and then topped with a
+good weather-resisting material, such as lampblack, graphite or carbon
+black, good results would be obtained. Further tests will be made to
+determine the value of this suggestion.
+
+=Panel No. 30--Precipitated Calcium Carbonate.= Showed more rapid
+destruction than Panel No. 29.
+
+[Illustration: Corrosion Adhering to Film Stripped from Panel Painted
+with Gypsum (Calcium Sulphate)]
+
+=Panel No. 31--Calcium Sulphate.= Under the paint film of gypsum, rust
+soon appeared, showing that the film was not a good excluder of
+moisture. Although the film remained intact, rusting progressed
+throughout the test and considerably darkened the color of the paint.
+
+=Panel No. 32--China Clay.= This pigment gave excellent service for
+eighteen months. Afterwards indications of corrosion were shown, and
+apparent breakdown of the film was indicated.
+
+[Illustration: China Clay
+
+Asbestine
+
+Gypsum]
+
+=Panel No. 33--Asbestine.= In the same condition as Panel No. 32.
+
+[Illustration: Excellent Surface shown by American Vermilion after
+nearly Four Years' Exposure]
+
+=Panel No. 34--American Vermilion.= This pigment has given perfect
+protection to the plates. The film is strong and elastic, and upon
+removal reveals the bright steel. No chalking, checking, discoloration,
+or other signs of paint failure are shown. It would appear that the
+inhibitive characteristics of this pigment are pronounced, and it
+promises to give efficient service for several years more.
+
+=Panel No. 36--Lead Chromate.= This panel is in generally fair
+condition, but slight checking is shown.
+
+[Illustration: Perfect Condition of Plate Painted with Zinc Chromate;
+One Half Stripped. (_Negative cracked_)]
+
+=Panel No. 39--Zinc Chromate.= This panel is in condition similar to
+Panel No. 34, presenting a perfect appearance, with decided maintenance
+of color, elasticity of film, and freedom from any bad characteristics.
+It has proved to be one of the highest type rust inhibitive pigments.
+
+=Panel No. 40--Zinc-and-Barium-Chromate.= Although the color of this
+pigment is not very pleasing, it has proved itself to be the equal of
+zinc chromate in its protective value.
+
+=Panel No. 41--Chrome Green.= In excellent condition. Presents an
+appearance similar to Panels Nos. 34 and 39. Its surface is perfect and
+will doubtless give service for many years.
+
+=Panel No. 44--Prussian Blue.= This panel stands forth as the most
+wonderful moisture-excluder in the whole test, its surface presenting an
+appearance similar to a varnished plate, even after three years'
+exposure. Action between the pigment and the oil, resulting in the
+formation of iron linoleate, may account for this property.
+
+=Panel No. 45--Prussian Blue.= In same condition as Panel No. 44.
+
+=Panel No. 48--Ultramarine Blue.= Soon after this test was exposed,
+early vehicle decay and excessive chalking were observed. The admittance
+of moisture may have caused the formation of acid with the sulphur
+content of the pigment, which would account for the rapid corrosion
+which followed. It is of a pronounced stimulative type. The effect of
+stimulative under-coatings is well shown on some special plates on the
+fence, which when received were not pickled before painting, but had
+upon their surfaces the ordinary coating of mill scale. Over this had
+been stencilled in a triangular form the trade mark of the manufacturer.
+The stencilling material was made of ultramarine blue. When these plates
+were painted with some of the special paints, and exposed, the
+stimulative nature of the ultramarine blue began to assert itself, and
+within a short time, wherever the stencil marks were located, signs of
+rust began to appear through the coatings of top paint which had been
+applied. Corrosion under these stencil marks became so great that the
+trade mark was plainly outlined in letters of rust. This would seem to
+be final proof that pigments of a stimulative nature should never be
+used for the priming of iron and steel.
+
+=Panel No. 49--Zinc-Lead Chromate.= In excellent condition throughout,
+with a smooth surface and showing no corrosion. Stands in the same class
+as Panels Nos. 34 and 39.
+
+[Illustration: Effect of Stimulative Paint. Manufacturer's Trade Mark
+Stencilled on Bare Metal in Triangular Form, showing Through Subsequent
+Paint Coating]
+
+=Panel No. 51--Black Magnetic Oxide of Iron.= In excellent condition.
+
+
+
+
+CHAPTER XVII
+
+THE SANITARY VALUE OF WALL PAINTS
+
+
+=Decoration and Sanitation.= The proper decoration of the interior of
+dwellings and public buildings has become of even greater importance
+than the protection and decoration of exteriors. There is, moreover, an
+increasing demand for harmonious effects and the production of more
+sanitary conditions than have prevailed in the past. Up until a few
+years ago a great variety of wall papers of more or less pleasing
+appearance were almost exclusively used for the decoration of walls in
+the interior of buildings, and their application was commonly considered
+the most effective means of wall decoration. There seems to be no
+question, however, that the use of wall paper is steadily decreasing,
+and that the art of interior decoration is undergoing a transition to
+the almost universal use of paint.
+
+Modern progress demands the maintenance of sanitary conditions for the
+benefit of the public welfare, and there is no doubt that from the
+standpoint of sanitation and hygiene, properly painted wall surfaces are
+far superior to papered walls. There is an abundance of evidence which
+shows that dust germs may easily be harbored, and thus disease
+transmitted from wall paper. In the tenement houses, which are common to
+the larger cities, and to a lesser extent in the dwellings found in
+smaller communities, where tenants are more or less transient, the
+continued maintenance of sanitary conditions presents a difficult
+problem. Infectious and epidemic illnesses generally leave behind
+bacilli of different types, which may find a culture medium in the
+fibrous and porous surfaces presented by wall paper, backed up as they
+invariably must be by starch, casein, or other organic pastes.
+Occasionally the restrictions of local boards of health provide in such
+events for proper fumigation, but too often no precautions are taken to
+destroy the disease germs which are caught in the dust which collects on
+wall paper. As a rule, both tenant and landlord are oblivious to all
+conditions which cannot be readily seen or detected. Burning sulphur,
+one of the most effective means of fumigation, will generally cause
+bleaching and consequent fading of the delicate colors used in printing
+the designs upon wall paper. Washing of the paper with antiseptic
+solutions will destroy its adhesiveness to the plaster and often cause
+bulging and general destruction.
+
+[Illustration: Heavy Colonies of Bacteria Developing in Agar Jelly
+Treated with Washings from Wall Paper
+
+Practically no Development of Bacterial Colonies in Agar Jelly Treated
+with Washings from Sanitary Wall Paint]
+
+=Hospital Practice.= In hospitals, where it is necessary to maintain
+sanitary conditions, the walls are invariably painted, and requirements
+should demand the use of paints which can be washed frequently, so that
+there will be no possibility of uncleanliness. Inquiry made of a
+prominent surgeon[41] connected with one of the large metropolitan
+hospitals substantiated the writer's findings regarding the greater
+sanitary value of wall paints, and brought forth the information that in
+hospitals under construction provision had been made for the finishing
+of walls so that a hard, non-absorbent, and washable surface might be
+obtained. The same authority stated that the common practice, in
+apartments and tenements, of covering the old wall paper over with a
+layer of new each time a tenant moved in, should be condemned, and that
+from a hygienic standpoint the use of sanitary wall paints should be
+advocated in all dwellings as well as public buildings.
+
+  [41] Dr. F. F. Gwyer, Cornell Uni. Med. Col., New York City.
+
+If such conditions are maintained in hospitals, where special attention
+is paid to sanitation, it would appear that similar precautions should
+be equally as necessary in public buildings and in dwellings--wherever,
+in fact, people congregate or live.
+
+=Sanitary Wall Paints.= There have recently appeared in trade a number
+of wall paints composed of non-poisonous pigments ground in paint
+vehicles having valuable waterproofing and binding properties, and of a
+nature to produce the flat or semi-flat finish that has become so
+popular. Such paints produce a sanitary, waterproof surface, which
+permits of frequent washing. By their use it is possible to secure a
+more permanent and a wider range of tints than can be obtained with wall
+paper, as they are produced in a myriad of shades, tints and solid
+colors, from which any desired combination may be selected. On the
+border or on the body of walls decorated with such paints, attractive
+stencil designs, which bring out in relief the color combinations, may
+be applied.
+
+For the decoration of chambers and living rooms, delicate French grays,
+light buffs, cream tints and ivory whites may be used, while in the
+library and other rooms richer and more solid colors, such as greens,
+reds, and blues, may be harmoniously combined.
+
+=Defects of Wall Paper.= It recently occurred to the writer to
+investigate the conditions which obtain in many apartment houses in the
+larger cities. Inspection of a number of such places, in which wall
+paper had been exclusively used on the walls, showed generally bad
+conditions; bulging of the surfaces, caused by dampness in the walls,
+which had loosened up the binder, as well as peeling and dropping of the
+paper from the ceilings, were frequently observed. In many cases a
+shabby appearance was shown, accompanied by an odor which suggested
+decomposition of the paste binder used on the paper. The writer was
+impressed with the fact that such conditions could easily be avoided by
+the very simple expedient of using properly manufactured wall paints,
+which are so easily made dustproof and waterproof.
+
+Samples of wall paper, which had been applied to plastered walls for a
+year or more, were obtained, and examination under the microscope showed
+a most uncleanly surface. Cultures were made of these samples, and
+bacilli of different types were developed in the culture medium in a
+short time.
+
+=Experimental Evidence.= That the above conditions could not have
+existed, had proper wall paints been used, seemed doubtless, and
+suggested a carefully conducted experiment to prove the relative
+sanitary values of wall paper and wall paints. A large sheet of fibre
+board, such as is occasionally used to replace plastered walls, was
+painted on one side with a high-grade wall paint, three-coat work. A
+similar sheet was papered on one side with a clean, new wall paper.
+These test panels were placed where unsanitary conditions, such as
+dampness, foul odors, and a scarcity of air were present. After a short
+period of exposure, the panels were taken to the bacteriological
+laboratory and a small section of the painted surface, about two inches
+square, as well as a small section of the papered surface of similar
+size, were removed and used for making cultures. In each case the
+surface of the section under test was washed with 100 c.c. of distilled,
+sterilized water. The washings which dripped from the surface were
+collected in a graduated flask. One c.c. of the washings was used in
+each case, admixed with bouillon and again with agar-agar. The enormous
+development of bacteria in the bouillon, treated with the washings from
+the wall-papered surface, was sufficient evidence to convince one of the
+greater sanitary value of the wall paint, the washings from which gave a
+culture practically free from bacteria. The colonies of bacteria shown
+in the petri-dish test made of the washings from wall paper further
+supports these findings. It will be noticed that the tests made from the
+washings of the wall paint show practical absence of bacteria, and was
+clear, as was the bouillon-solution test of the paint. The washings from
+the wall paper showed active development of bacteria, both in the
+bouillon and agar tests.
+
+[Illustration: DEVELOPMENT OF BACTERIA IN BOUILLON SOLUTIONS
+
+Note Practical Freedom of Bacteria in Clear Bouillon Solution Treated
+with Washings from Sanitary Wall Paint
+
+Note Milky Appearance of Solution Due to Heavy Development of Bacteria
+in Bouillon Treated with Washings from Wall Paper]
+
+_From the Conservation Standpoint_: It would be of interest to sum up in
+figures the acreage and cordage of wood that annually is transformed
+into pulp for the manufacture of wall paper. Unfortunately, there are no
+available statistics on this subject. It is clear, however, that from
+the standpoint of conservation the use of wall paints should take
+precedence over the use of wall paper.
+
+
+
+
+INDEX
+
+
+                                                               PAGE
+
+  Abrasion, apparatus for determining resistance to,            153
+  Acid reacting compounds,                                      215
+  Actinic light tests,                                          112
+  Adhesive power of Paint Coating,                              104
+  Aluminum Silicate,                                             62
+  American Vermilion,                                            64
+  Analogies of Paint and Concrete manufacture,                   94
+  Analyses of Averages in Atlantic City steel paint test,  235, 236
+    Corn Oil,                                                    16
+    Cottonseed Oil,                                              15
+    Debloomed Mineral Paint Oil,                                 18
+    Iron Oxide Pigments, table,                                  63
+    Linseed Oil,                                                  7
+    Menhaden Oil,                                                14
+    Oils used in Washington tests,                              211
+    Petroleum Spirits,                                           20
+    Rosin Oil,                                                   16
+    Soya Bean Oil,                                                8
+    Sunflower Oil,                                               15
+    Tung Oil,                                                    12
+    Whale Oil,                                                   14
+    Wood Turpentine,                                             19
+  Asbestine,                                                     55
+  Atlantic City fence tests,                                    107
+    steel paint tests,                                      228-235
+    Checking,                                                   122
+    Gloss,                                                      122
+    Hiding power,                                               122
+    inspection of,                                              114
+    Methods used,                                               114
+    Results,                                                    124
+  Auto-electrolysis,                                            220
+
+  Bacteria in wall paper,                                       256
+  Barium Sulphate,                                               55
+  Barytes,                                                       55
+    and Silica Paints in Pittsburg tests,                       172
+  Basic Carbonate-White Lead,                                    42
+  Benzine,                                                       20
+  Benzol,                                                        20
+  Blanc Fixe,                                                    60
+  Blue Lead, Sublimed,                                           47
+  Blue Paint for concrete wall, formula,                        215
+  Blue paints in Pittsburg tests,                               142
+  Boiled Linseed Oil,                                             2
+    Driers in,                                                   28
+  Bone Black,                                                    66
+
+  Calcium Carbonate,                                             60
+  Calcium Sulphate,                                              60
+  Carbon Black,                                                  66
+  Cause of rust in steel work,                                  220
+  Chalking test for laboratory,                                 149
+  Checking and cracking in Pittsburg tests,                     166
+  Checking, in Atlantic City tests,                             122
+  China Clay,                                                    62
+  Chrome Green,                                                  66
+  Chrome Yellow,                                                 64
+  Coatings for cement and concrete,                             214
+  Colored formulas in North Dakota tests,                       190
+  Colors, report of, in Pittsburg tests,                        139
+  Combination formulas in inhibitive paints,                    231
+  Composite formulas in North Dakota tests,                     190
+    in Pittsburg tests,                                         142
+  Composition of paints, in steel test,                         232
+  Conclusion from Pittsburg tests,                              144
+  Concrete primer formula,                                      218
+  Constants of Pine Oil,                                         18
+    Pure Gum Turpentine,                                         19
+  Co-operative tests of Driers,                               29-41
+  Corn Oil,                                                      16
+  Cottonseed Oil,                                                15
+
+  Damp-proofing and Waterproofing,                              214
+  Decay of Lithopone paints,                                    124
+  Decomposition of Paint,                                       122
+  Driers, Co-operative tests of,                              29-41
+    in Boiled Oil,                                               28
+    Tests of Manganese, Lead and Combination, tables,         24-25
+  Drying Properties of Oil,                               1, 26, 27
+
+  Elasticity and Strength of Paint Coating,                     102
+
+  Fence tests of paints,                                        105
+    Supervision of,                                             112
+  Film sectioning,                                               87
+  Film testing results, table,                                   80
+  Filmometers,                                                74-79
+  Formula for Blue Paint for concrete wall,                     215
+    Concrete primer,                                            218
+    Para Red Paint for concrete wall,                           217
+  Formulas of Atlantic City fence test,                         108
+    Tennessee tests,                                       202, 204
+    Washington tests,                                      208, 211
+  Fume Pigments Paints in Pittsburg tests,                      173
+
+  General results of Atlantic City tests,                       128
+  Gloss, in Atlantic City tests,                                122
+  Graphite,                                                      66
+  Green paints in Pittsburg tests,                              142
+  Grinding Pigments,                                             87
+  Gums as moisture resisters,                                    84
+  Gypsum,                                                        60
+
+  Hailstorm, effects of in North Dakota tests,                  185
+  Hospital, painting practice,                                  254
+  House paint tests in North Dakota,                            196
+  Hydrocarbon Oils,                                              16
+
+  Imperviousness of paint coating,                              100
+  Indian Red,                                                    62
+  Inert Pigments, use of,                                        99
+  Inhibition of rust,                                           222
+  Iodine Values of Linseed and Mixed Oils, table,                 8
+  Iron Oxide Paints,                                             64
+
+  Japan driers in tests on steel,                               231
+
+  Laboratory tests, panels for,                                 149
+  Lampblack,                                                     66
+  Laws of Paint Making,                                          93
+  Lime action on paint,                                         214
+  Linoxyn,                                                       21
+  Linseed Oil, boiled,                                            2
+    Chemical action of pigments upon,                            91
+    Table of Analyses of Various Types of,                        7
+    tests of Driers with,                                    24, 25
+  Lithopone,                                                     53
+    paint in Pittsburg tests,                                   136
+    tests at Atlantic City,                                     124
+  Lumbang Oil,                                                   12
+
+  Magnesium Silicate,                                            55
+  Manufacturing Barytes,                                         55
+    Blue Lead,                                                   47
+    Bone Black,                                                  66
+    Paint Pigments,                                           42-68
+    White Lead,                                                  42
+  Menhaden Oil,                                                  12
+    Constants of, table,                                         14
+  Metallic Brown,                                                62
+  Microscope, use of in paint laboratory,                        86
+  Microscopic examination of paint, preparation for,             86
+    measurements of paint sections,                              89
+  Mineral Black,                                                 68
+    Oils,                                                        17
+  Moisture Absorption, tests in,                                 84
+    experiments with various Pigments,                           83
+
+  North Dakota Paints tests,                                    182
+    test fence,                                                 105
+    report of, table,                                       193-195
+
+  Ochre,                                                         62
+  Oil and Thinner tests,                                        202
+  Oil, Corn,                                                     16
+    Cottonseed,                                                  15
+    Effects of Pigments on,                                      90
+    Linseed,                                                      1
+    Linseed, Analyses of Various Types of, table,                 7
+    Linseed, Iodine Values of, table,                             8
+    Linseed, Tests of Driers with,                           24, 25
+    Lumbang,                                                     12
+    Menhaden,                                                    12
+    Menhaden, Constants of, table,                               14
+    Perilla,                                                     21
+    Pine,                                                        18
+    Rosin,                                                       16
+    Soya Bean, and Driers, table,                                 9
+    Soya Bean,                                                    7
+    Chemical Characteristics of, table,                           8
+    Sunflower,                                                   14
+    Tung,                                                         9
+    Whale,                                                       14
+  Oils, Constants and Characteristics of,                         1
+    Drying properties of,                                     1, 26
+    Hydrocarbon,                                                 16
+    In Washington paint tests,                                  210
+    Iodine Value of Linseed and Mixed, table,                     8
+    Mineral,                                                     17
+    Moisture resistance of,                                      84
+    Oxygen Absorbing qualities,                                  21
+    Outline of tests of paints on concrete walls,               216
+  Oxygen Absorption in Oils,                                     21
+
+  Paint Coating, Adhesive power of,                             104
+    Elasticity and Strength of,                                 102
+    imperviousness of,                                          100
+    decomposition of,                                           122
+    films, action of water upon,                                223
+    permeability of,                                             71
+    Testing machine,                                             74
+    preparation of,                                              70
+    in Hospitals,                                               254
+    making, Laws of,                                             93
+    Perry's Principles of,                                      100
+    pigments,                                                 42-69
+    pigments, properties of,                                     42
+    preparation for microscopic examination of,                  86
+    tests at North Dakota Experiment Station,                   105
+    at Washington,                                          207-213
+    supervisors of,                                             113
+    woods used on,                                         124, 135
+  Painting steel plates for tests,                              230
+  Paints for cement and concrete surfaces,                      214
+    composition of in steel test,                               233
+    hiding power of,                                            111
+    sanitary value of,                                          252
+  Panels for laboratory tests,                                  149
+  Para Red formula for concrete wall,                           217
+  Paranitraniline paints in Pittsburg tests,                    140
+  Paranitraniline Red,                                           64
+  Perilla Oil,                                                   21
+  Perry's analogies of paint and concrete manufacture,           99
+    principles of Paint Making,                                 100
+  Petroleum Spirits,                                             20
+  Photomicrographs,                                         89, 165
+  Pigment contention, the,                                      105
+    grinding,                                                    87
+  Pigments,                                                   42-69
+    as stimulators of rust,                                     223
+    Chemical action of upon Linseed Oil, table,                  91
+    Effects of on Oil,                                           90
+    inert, use of,                                               99
+    moisture experiments with, table,                            83
+    percentages of Oil required for grinding,                    68
+    re-enforcing,                                                89
+    report of results of steel paint tests,                 236-251
+    Water resistance of,                                         81
+  Pine Oil,                                                      18
+  Pittsburg fence tests,                                        107
+  Polar Micro-Examinations and Photomicrographs,                 89
+  Primer for concrete,                                          218
+  Properties of Paint Pigments,                                  42
+  Prussian Blue,                                                 66
+
+  Red Lead,                                                      64
+  Reductions used in fence tests,                               111
+  Re-enforcing Pigments,                                         89
+  Results of new test at Atlantic City test fence in 1910,
+    table,                                                  178-181
+    Pittsburg tests,                                            135
+    steel test plates,                                          232
+  Rosin Oil,                                                     16
+  Rust, cause of in steel work,                                 220
+    inhibition of,                                              222
+    stimulation of,                                             223
+
+  Sanitary value of paints,                                     252
+    wall paints,                                                254
+  Sienna,                                                        62
+  Silex,                                                         60
+  Silica,                                                        60
+  Silica and Barytes Paints in Pittsburg tests,                 172
+  Solvent Naphtha,                                               20
+  Soya Bean Oil and Driers, table,                                9
+    Chemical Characteristics of, table,                           8
+  Steel Paint test, rating report,                              234
+    reports on pigments used,                               236-251
+  Steel paint, result of tests at Atlantic City,           234, 235
+  Steel, preparation of for paint tests,                        228
+    water contact and paint,                                    224
+  Structural steel paint tests,                                 220
+  Sublimed Blue Lead,                                            47
+  Sublimated White Lead,                                         46
+  Suction varnish,                                              215
+  Sunflower Oil,                                                 14
+    Constants of, table,                                         15
+  Supervisors of paint tests,                                   113
+
+  Table Analysis of Averages in Atlantic City Steel Paint
+    test,                                                  235, 236
+    Analyses of Corn Oil,                                        16
+    Analyses of Debloomed Mineral Paint Oil,                     18
+    Analysis of Iron Oxide Pigments,                             63
+    Analyses of Oils used in Washington tests,                  211
+    Analyses of Petroleum Spirits,                               20
+    Analyses of Rosin Oil,                                       16
+    Analyses of various types of Linseed Oil,                     7
+    Analyses of wood Turpentine,                                 19
+    Atlantic City test fence formula,                           108
+    Chemical Characteristics of Soya Bean Oil,                    8
+    Comparative spreading rates of White Paint in Pittsburg
+      tests,                                                    148
+    Composition of Blue Lead,                                    49
+    Composition of paints in Atlantic City Steel test,          233
+    Constants of Cottonseed Oil, table,                          15
+    Constants of Menhaden Oil,                                   14
+    Constants of Pine Oil,                                       18
+    Constants of Sunflower Oil,                                  15
+    Constants of Whale Oil,                                      14
+    Co-operative drying tests,                                32-41
+    Excluding tests for moisture absorbed,                       84
+    Fineness for grinding pigments,                              87
+    Formulas in Tennessee tests,                                204
+    Iodine Value of Linseed Oil and Mixed Oils,                  84
+    Moisture experiments with various pigments,                  83
+    Paint section measurements under microscope,                 89
+    Percentages of Oil required for grinding various dry
+      pigments,                                                  68
+    Permeability of Paints,                                      72
+    Ratings of Atlantic City Steel Paint test,                  234
+    Report of North Dakota test fence,                      193-195
+    Results of Atlantic City test fence,                   130, 131
+    Results of new tests at Atlantic City test fence in
+      1910,                                                 178-181
+    Results of second annual inspection Atlantic City test
+      fence,                                                    133
+    Results of second annual inspection in Pittsburg tests,     145
+    Showing action of various pigments upon Linseed Oil,         91
+    Soya Bean Oil and Driers,                                     9
+    Tests of Linseed Oil and Manganese, Lead and Combination
+      Driers,                                                24, 25
+  Talcose,                                                       55
+  Tennessee Paint tests,                                    201-206
+  Test Fences in Paint Experiments,                             105
+    at Atlantic City,                                       114-134
+    at Pittsburg,                                           135-148
+    at Washington,                                          207-213
+    Cement and concrete,                                        214
+    in Tennessee,                                           201-206
+    laboratory, chalking,                                       149
+    North Dakota,                                               182
+    of Oil and Thinners,                                        202
+    of various pigments in steel paint,                     236-251
+    panel sections for,                                         149
+    Structural steel paints,                                    220
+    Water pigment,                                              226
+  Thinner, Wood Turpentine as a,                                202
+  Tung Oil,                                                       9
+  Tung Varnishes,                                                11
+  Turpentine,                                                    18
+
+  Ultramarine Blue,                                              66
+  Umber,                                                         62
+
+  Varnishes from Tung Oil,                                       11
+  Vermilion, American,                                           64
+
+  Wall paints,                                                  252
+  Wall paper, defects of,                                       255
+  Washington Paint tests,                                   207-213
+  Water, action of upon paint films,                            223
+    contact with steel and paint,                               224
+    resistance of Pigments,                                      81
+    tests,                                                      226
+  Water-pigment tests,                                          226
+  Waterproofing and damp-proofing,                              214
+  Whale Oil,                                                     14
+  White Lead, Basic Carbonate,                                   42
+    Basic Sulphate,                                              46
+    Mild Process,                                                46
+    Quick Process,                                               45
+    in Pittsburg tests,                                         139
+    in North Dakota tests,                                      190
+    Paints, checking in Pittsburg tests,                        172
+    processes of manufacture of,                              43-46
+  Whiting,                                                       60
+  Wood Turpentine,                                               19
+    experiments with as a thinner,                              202
+  Woods used in paint tests,                               124, 135
+
+  Zinc Chromate,                                                 64
+  Zinc Lead White,                                               51
+  Zinc Oxide,                                                    51
+
+
+
+
+  +------------------------------------------------------------------+
+  |                     TRANSCRIBER'S NOTES:                         |
+  |                                                                  |
+  | * Page 25, Table VIII: the table header row contains duplicate   |
+  |   values which may be a typographical error.                     |
+  | * Pages 86 and 87: two section titles are followed by numbers    |
+  |   without any obvious reason. These have not been deleted.       |
+  | * The original spelling (including hyphenation) has been         |
+  |   preserved, except as indicated below. Some minor inconsisten-  |
+  |   cies and typographical errors have been corrected silently.    |
+  | * Changes made to the text:                                      |
+  |   * Page 26: 'as discolored and turned brown' changed to 'was    |
+  |     discolored and turned brown'.                                |
+  |   * Page 87, table 3rd row: '0.00067--' changed to '0.00067'.    |
+  |   * Page 94, exposition: some elements re-arranged for better    |
+  |     readability.                                                 |
+  |   * Page 124: the note at the bottom of the page has been moved  |
+  |     to directly underneath the first paragraph.                  |
+  |   * Page 130: 'MacNichol' changed to 'Macnichol' as elsewhere.   |
+  |   * Page 137 (caption): 'Pittsburgh' changed to 'Pittsburg' as   |
+  |     elsewhere in text (and in illustration itself).              |
+  |   * Page 142: 'prussian blues' changed to 'Prussian blues'.      |
+  |   * Page 177: 'pages 174 to 177' changed to 'pages 178 to 181'.  |
+  |   * Page 211: one footnote anchor changed from '*' to '[32]' as  |
+  |     others in row.                                               |
+  |   * Page 230, formula: '4500' changed to '5400'.                 |
+  |   * Page 234, table: row for Panel No. 2000: '}' inserted for    |
+  |     combined rows.                                               |
+  |   * Index: changed to agree with text: 'determinating' to        |
+  |     'determining', 'Derbloomed' to 'Debloomed', 'Filometers' to  |
+  |     'Filmometers', 'Parilla Oil' to 'Perilla Oil'. 'Grinding     |
+  |     Pigments' moved to proper alphabetic location.               |
+  |                                                                  |
+  +------------------------------------------------------------------+
+
+
+
+
+
+End of Project Gutenberg's Paint Technology and Tests, by Henry A. Gardner
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