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