- Email: [email protected]
Silver, tin, lead: the ternary system
CURRENT ToPIcs.
97
scratch hardness, loss of weight in a I per cent. acid solution, the amount of carbide, and microscopically. It is concluded that hardened steel always tends to change into a-iron and free cementite. Although this change proceeds imperceptibly at ordinary temperatures, it takes only a few seconds at 65 °0 C. and some hours at IOO° C.
Silver, Tin, Lead: the Ternary System.
N. PARRAVANO.
(Ga~. Chim. Ital., xli, 813.)--This paper is a thermal and microscopic study of ternary alloys of silver, tin, and lead. All the ternary alloys are composed of the four solid phases, mixed crystals of silver and tin, mixed crystals of lead and tin, the compound Ag3Sn, and crystals of tin. The system contains two non-variant points, one of which, at about 3oo ° C., is a transformation point, while the other, at about 175 ° C., is an eutectic point. The ternary eutectic contains 63.4 per cent. of tin, 35.6 per cent. of lead, and I per cent. of silver. The transformation point is very near the binary lead-silver eutectic point, and the ternary eutectie point is very near the binary tin-lead eutectie point. This paper has 23 microphotographs.
Paper Pulp from Eucalyptus. ANon. (Paper Making, xxx, 376.)mSamples of pulp of excellent quality have been prepared from the eucalyptus (blue gum) which has been planted over large areas in Southern California. The pulp is strong, clean, and slightly reddish, owing to the action of the alkali. Experiments with this wood as a raw material for paper pulp have been carried out at Washington and leave no doubt that it is suitable for the purpose. A sufficient growth of blue gum may be obtained in four to six years; three years after cutting the stump yields a further good growth. Preservative Treatment of Poles. W . H . KEMPFER. (Forest Service Bull., 84, I 9 I I . ) - - A s the pressure method of treatmenl~ with creosote is comparatively costly, investigations were directed to simpler and cheaper methods, which could be employed locally. Special attention was given to the seasoning of the timber, and investigations were conducted with the object of ( I ) testing the efficiency of various wood preservatives and of the application of varying amounts; (2) developing a method for impregnating the butt, as the portion of the pole most subject to decay; (3) designing inexpensive apparatus for local use in application. The timbers used were chestnut, three kinds of cedar, and three kinds of pine; and six different commercial preservatives were tried. The conclusions reached were: The reduction in the weight of poles by seasoning is generally from 16 to 3° per cent., and thorough seasoning is an essential preliminary to preservative treatment. Poles cut during autumn and winter lose weight less rapidly but more
97
scratch hardness, loss of weight in a I per cent. acid solution, the amount of carbide, and microscopically. It is concluded that hardened steel always tends to change into a-iron and free cementite. Although this change proceeds imperceptibly at ordinary temperatures, it takes only a few seconds at 65 °0 C. and some hours at IOO° C.
Silver, Tin, Lead: the Ternary System.
N. PARRAVANO.
(Ga~. Chim. Ital., xli, 813.)--This paper is a thermal and microscopic study of ternary alloys of silver, tin, and lead. All the ternary alloys are composed of the four solid phases, mixed crystals of silver and tin, mixed crystals of lead and tin, the compound Ag3Sn, and crystals of tin. The system contains two non-variant points, one of which, at about 3oo ° C., is a transformation point, while the other, at about 175 ° C., is an eutectic point. The ternary eutectic contains 63.4 per cent. of tin, 35.6 per cent. of lead, and I per cent. of silver. The transformation point is very near the binary lead-silver eutectic point, and the ternary eutectie point is very near the binary tin-lead eutectie point. This paper has 23 microphotographs.
Paper Pulp from Eucalyptus. ANon. (Paper Making, xxx, 376.)mSamples of pulp of excellent quality have been prepared from the eucalyptus (blue gum) which has been planted over large areas in Southern California. The pulp is strong, clean, and slightly reddish, owing to the action of the alkali. Experiments with this wood as a raw material for paper pulp have been carried out at Washington and leave no doubt that it is suitable for the purpose. A sufficient growth of blue gum may be obtained in four to six years; three years after cutting the stump yields a further good growth. Preservative Treatment of Poles. W . H . KEMPFER. (Forest Service Bull., 84, I 9 I I . ) - - A s the pressure method of treatmenl~ with creosote is comparatively costly, investigations were directed to simpler and cheaper methods, which could be employed locally. Special attention was given to the seasoning of the timber, and investigations were conducted with the object of ( I ) testing the efficiency of various wood preservatives and of the application of varying amounts; (2) developing a method for impregnating the butt, as the portion of the pole most subject to decay; (3) designing inexpensive apparatus for local use in application. The timbers used were chestnut, three kinds of cedar, and three kinds of pine; and six different commercial preservatives were tried. The conclusions reached were: The reduction in the weight of poles by seasoning is generally from 16 to 3° per cent., and thorough seasoning is an essential preliminary to preservative treatment. Poles cut during autumn and winter lose weight less rapidly but more