From this fact it follows that we can shield any conductor entirely from external influence by other "charged conductors by enclosing it in a metal case.
Measurement of Capacity.-Numerous methods have been devised for the measurement of the electrical capacity of conductors in those cases in which it cannot be determined by calculation.
Some writers have supposed that the ultimate atoms are conductors, and that heat is transferred through them when they are in contact.
Weber's hypothesis of electric atoms, capable of diffusing through metallic bodies and conductors of electricity, but capable of vibration only in non-conductors, it is possible that the ultimate mechanism of conduction may be reduced in all cases to that of diffusion in metallic bodies or internal radiation in dielectrics.
In their simplest form, they are merely a row of slender stakes of larch or other wood driven into the ground, and connected by a slight rod or fillet at top. The use of iron rails has now been almost wholly discontinued on account of metallic substances acting as powerful conductors of both heat and cold in equal extremes.