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Absorption of hydrogen by tantalum and tungsten
CURRENT TOPICS.
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silica glass from melted quartz an artifice is required, because on reaching the temperature of 6oo ° C. the quartz splits and minute bubbles of air fill the mass. This can be prevented by first raising the temperature of the quartz to a point little under 6oo °, and then surrounding it with liquid silica at a temperature of 2'ooo° C. The liquid silica acts as a shield to prevent the entrance of air when the quartz splits, and thus the formation of bubbles is avoided. Artificial Leather. A~oN. (Sci. Amer., civ, 21,549.)--The price of leather is rising rapidly, and several inventors are endeavoring to produce satisfactory substitutes for this material. M. Louis Gevaert, of Beveren-les-Audenarde, has been so remarkably successful in his efforts that he was awarded a prize of 5,ooo francs by an Agricultural Committee of Terni. The process was patented in 19o7 and perfected by successive steps. It consists of the more or less intimate impregnation of stout cotton cloth with tannic albuminoid substances. Shoes made of this are said to possess not only the resistance and elasticity of natural leather, but also its durability of wear. They are much cheaper than leather, costing, including manufacture, only about four francs and selling for about six francs per pair. Electricity in Indian Mills. ANON. (Sci. Anwr., civ, I 4 , 365.)--The mills in Bombay are largely driven by steam power a t present, and this proves to be very costly. A scheme has been started to generate the power required from stored water. During the monsoon water is to be collected and stored in large reser~ voirs up in the ghats about forty miles from Bombay. The valleys which are being dammed are close to a fall of 1,74o feet, and it is the power of this fall which is to be utilized. The transmission line to Bombay is about forty-three miles long, and a voltage of 8o,ooo will be used in the line. In Bombay it will be transformed to varying voltages for distribution to consumers, which will be principally the cotton mills. These mills alone now use about Ioo,ooo horse-power.
Absorption of Hydrogen by Tantalum and Tungsten.
A.
SIEVERTS and E. BERGNER. (Ber. xliv, 2394.)--The solubility of hydrogen and nitrogen in tantalum up to I33 °0 C. has been measured. At constant pressure the solubility decreases as the temperature rises, and at constant temperature is proportional to the square root of the pressure. Heating in hydrogen causes a structural change in the metal, which becomes brittle and crystalline. The original condition is not restored by removing the hydrogen, but only by heating nearly to the melting point. Tantalum reacts slowly with nitrogen above 90o ° C., forming a nitride. Tungsten dissolves very little hydrogen and does not react with nitrogen at any temperature up to I5OO° C.
91
silica glass from melted quartz an artifice is required, because on reaching the temperature of 6oo ° C. the quartz splits and minute bubbles of air fill the mass. This can be prevented by first raising the temperature of the quartz to a point little under 6oo °, and then surrounding it with liquid silica at a temperature of 2'ooo° C. The liquid silica acts as a shield to prevent the entrance of air when the quartz splits, and thus the formation of bubbles is avoided. Artificial Leather. A~oN. (Sci. Amer., civ, 21,549.)--The price of leather is rising rapidly, and several inventors are endeavoring to produce satisfactory substitutes for this material. M. Louis Gevaert, of Beveren-les-Audenarde, has been so remarkably successful in his efforts that he was awarded a prize of 5,ooo francs by an Agricultural Committee of Terni. The process was patented in 19o7 and perfected by successive steps. It consists of the more or less intimate impregnation of stout cotton cloth with tannic albuminoid substances. Shoes made of this are said to possess not only the resistance and elasticity of natural leather, but also its durability of wear. They are much cheaper than leather, costing, including manufacture, only about four francs and selling for about six francs per pair. Electricity in Indian Mills. ANON. (Sci. Anwr., civ, I 4 , 365.)--The mills in Bombay are largely driven by steam power a t present, and this proves to be very costly. A scheme has been started to generate the power required from stored water. During the monsoon water is to be collected and stored in large reser~ voirs up in the ghats about forty miles from Bombay. The valleys which are being dammed are close to a fall of 1,74o feet, and it is the power of this fall which is to be utilized. The transmission line to Bombay is about forty-three miles long, and a voltage of 8o,ooo will be used in the line. In Bombay it will be transformed to varying voltages for distribution to consumers, which will be principally the cotton mills. These mills alone now use about Ioo,ooo horse-power.
Absorption of Hydrogen by Tantalum and Tungsten.
A.
SIEVERTS and E. BERGNER. (Ber. xliv, 2394.)--The solubility of hydrogen and nitrogen in tantalum up to I33 °0 C. has been measured. At constant pressure the solubility decreases as the temperature rises, and at constant temperature is proportional to the square root of the pressure. Heating in hydrogen causes a structural change in the metal, which becomes brittle and crystalline. The original condition is not restored by removing the hydrogen, but only by heating nearly to the melting point. Tantalum reacts slowly with nitrogen above 90o ° C., forming a nitride. Tungsten dissolves very little hydrogen and does not react with nitrogen at any temperature up to I5OO° C.