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Protecting iron and steel from corrosion
582
W. W. COBLENTZ.
was being removed after some years’ usage. In the same manner the granolith was a piece of pavement. The latter sample, however, was washed and free from dust. Of the other building materials the slate used in roofing is of interest, for it reflects only about 6.7 per cent. of the solar rays. For convenien,ce in tabalating, the data on “ bluestone ” (the dark-colored sandstone extensively used in buildings) are given in Table IV. This material cleaves into thin, flat laminae. The reflecting power at 8.8 p and 24 p is very high, owing ‘to the bands of selective reflection (silica,) and the presence of fine crystal surfaces. The reflecting power of powdered feldspar and of quartz (“ French flint “) is also given in Table IV. Black velvet has a very low reflecting power. The reflecting power of the sample of black felt recorded in Table V was examined several times on different days. The values were always high. In comparison, visually, with the black velvet the sample appeared much lighter in color. WASHINGTON,D. C., Oct. 5, 1912.
Lignite in Tuscany. (Mon. Sci. Mewwe, ii, 84.8, 61.) ANON. -The deposits of lignite in Tuscany are of great importance to the whole of Italy, for the beds at San Giovanni, 45 kilometres (28 miles) from Florence, furnish two-thirds of the total supply. The content o’f these beds is estimated at S,ooo,ooo tons. The product contains 40 to 45 per cent. of water and has a caloritic power of 3,400 calories in the dry condition. It is marketed in the form of briquettes. In agog there were 176,490 tons sold. Protecting Iron and Steel from Corrosion. ANON. (Brass World, viii, 8, 272.)-Gilbert Rigg, of the New Jersey Zinc Company, has discovered that sodium tungstate prevents the rusting of iron and steel. A solution of I part of sodium tungstate in 2,000 parts of water is efficient. This is applied to zinc oxide paints, and zinc tungstate is ground with the paint and protects iron and steel. ‘Colloid Phenomena in Coneretiorrs. E. GEINITZ. (Cetitr. Igm, 282.)-The concentric structure of clay-stone concretions, and the striated cylindrical masses observed in flint and usually regarded as problematical organisms, are most readily explained as the result of diffusion in colloid substances, such as has been shown by Liesegang to be the origin of agate structures.
Mis,
W. W. COBLENTZ.
was being removed after some years’ usage. In the same manner the granolith was a piece of pavement. The latter sample, however, was washed and free from dust. Of the other building materials the slate used in roofing is of interest, for it reflects only about 6.7 per cent. of the solar rays. For convenien,ce in tabalating, the data on “ bluestone ” (the dark-colored sandstone extensively used in buildings) are given in Table IV. This material cleaves into thin, flat laminae. The reflecting power at 8.8 p and 24 p is very high, owing ‘to the bands of selective reflection (silica,) and the presence of fine crystal surfaces. The reflecting power of powdered feldspar and of quartz (“ French flint “) is also given in Table IV. Black velvet has a very low reflecting power. The reflecting power of the sample of black felt recorded in Table V was examined several times on different days. The values were always high. In comparison, visually, with the black velvet the sample appeared much lighter in color. WASHINGTON,D. C., Oct. 5, 1912.
Lignite in Tuscany. (Mon. Sci. Mewwe, ii, 84.8, 61.) ANON. -The deposits of lignite in Tuscany are of great importance to the whole of Italy, for the beds at San Giovanni, 45 kilometres (28 miles) from Florence, furnish two-thirds of the total supply. The content o’f these beds is estimated at S,ooo,ooo tons. The product contains 40 to 45 per cent. of water and has a caloritic power of 3,400 calories in the dry condition. It is marketed in the form of briquettes. In agog there were 176,490 tons sold. Protecting Iron and Steel from Corrosion. ANON. (Brass World, viii, 8, 272.)-Gilbert Rigg, of the New Jersey Zinc Company, has discovered that sodium tungstate prevents the rusting of iron and steel. A solution of I part of sodium tungstate in 2,000 parts of water is efficient. This is applied to zinc oxide paints, and zinc tungstate is ground with the paint and protects iron and steel. ‘Colloid Phenomena in Coneretiorrs. E. GEINITZ. (Cetitr. Igm, 282.)-The concentric structure of clay-stone concretions, and the striated cylindrical masses observed in flint and usually regarded as problematical organisms, are most readily explained as the result of diffusion in colloid substances, such as has been shown by Liesegang to be the origin of agate structures.
Mis,