TABLE 4O3 (continue^. 

 RESISTIVITIES AT HIGH AND LOW TEMPERATURES. 



(Ohms per cm. cube unless stated otherwise.) 



Pt. low, Nernst, 1. c. high, Pirrani, Ber. Dentsch. Phvs. Ges. 12, p. 305, Pb. low, Schimank, Nernst, 1. c. high. 

 Northrup, see Zn. Bi. low, means, high, Northrup, see Zn. Cd. low, Euchen, Gehlhoff, Verh. Deutsch. Phys. Ges. 14, 

 p. 169, 1912, high, Northrup, see Zn. Sn. low, Dewar, Fleming, high, Northrup, see Zn. Carbon, graphite, Metallurg. 

 Ch. F.ng. 13, p. 23, 1915. Silica, Campbell, Nat. Phys. Lab. n, p. 207, 1914. Alundum, Metallurg. Ch. Eng. 12, p. 

 125, 1914. 



* Diamond 1030 C, p >io 7 ; 1380, 7.5 X IC)5 v - Wartenberg, 1912. 



TABLE 404. Volume and Surface Resistivity of Solid Dielectrics. 



The resistance between two conductors insulated by a solid dielectric depends both upon the surface resistance and 

 the volume resistance of the insulator. The volume resistivity, p, is the resistance between two opposite faces of a cen- 

 timeter cube. The surface resistivity, <r, is the resistance between two opposite edges of a centimeter square of the 

 surface. The surface resistivity usually varies through a wide range with the humidity. (Curtis, Bui. Bur. Standards, 

 IT, 359, 1915, which see for discussion and data for many additional materials.) 



SMITHSONIAN TABLES. 



