"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 | | | | | | ||