396 



TABLE 404.— RESISTIVITY OF SOILS AND SEA WATER MEASURED WITH 

 HIGH-FREQUENCY ALTERNATING CURRENT* 



* For reference, see footnote 45, p. 136. 



TABLE 405.— ELECTRICAL RESISTIVITY OF NATURAL WATERS* 



Resistivity 

 Material ohm-cm 



Very fresh distilled waters 2X10 7 



Mine waters 500 



Material 

 Potable ground waters 

 Surface waters 



Resistivity 

 ohm-cm 



. 10 8 -10 B 

 . . 10 B 



* For reference, see footnote 45, p. 136. 



TABLE 406. 



-RESISTIVITY OF SOME GLASSES AT THREE 

 TEMPERATURES 147 



Log 10 



Glass Principal use 



Potash soda lead Lamp tubing 



Soda lime Lamp bulbs 



Potash soda lead Lamp tubing 



Hard Lime Cooking utensils 



Borosilicate Kovar sealing 



Borosilicate Low loss electrical 



Borosilicate Baking ware 



Pyrex General 



Vycor Low expansion ultra- 

 violet transmission 



Fused quartz 



147 Corning Glass Co. publication, Properties of selected commercial glasses, 1949. General Electric 

 Co. publication, Fused quartz, 1947. 



SMITHSONIAN PHYSICAL TABLES 



