566 abstracts: technology 



TECHNOLOGY. — Combined table of sizes in the principal wire gages. 

 Bur. Stand. Cir. No. 67. Pp. 5. Jan. 17, 1918. 

 This table combines in one series the sizes in the American (B. & S.) 

 Steel, Birmingham (Stubs'), British Standard, and Metric Wire Gages, 

 arranged in order of sizes (diameters) of wires. It gives the diameter of 

 all the gage numbers in these five systems in mils, millimeters, and 

 inches, also the cross-sections in square mils, circular mils, square milli- 

 meters, and square inches. The table is especially useful to manufac- 

 turers who wish to determine the nearest equivalent in American or 

 British gage sizes of wires specified in millimeters or square millimeters, 

 or vice versa. R. Y. F. 



TECHNOLOGY. — Determination of permeability of balloon fabrics. 



Junius David Edwards. Bur. Stand. Tech. Paper No. 113. 



Pp. 31. 1918. 

 This paper describes the various methods which may be employed 

 for determining the permeability of balloon fabrics to hydrogen. The 

 precise and rapid method used at the Bureau of Standards measures 

 the hydrogen penetrating a given area of fabric by means of a gas 

 interferometer. Data are given to show the effect upon the apparent 

 permeability of different experimental conditions such as temperature, 

 pressure, humidity of the gas, etc. A knowledge of the effect of these 

 factors enables one to compare results of tests made under different 

 conditions. The test adopted as standard by the Bureau is described. 



J. D. E. 



