96 ELECTROSTATIC CHARGE OF UNDERGROUND WIRES. 



sufficient. But meanwhile I had become convinced 

 that the peculiar behaviour of the underground wires 

 could only be ascribed to the electrostatic charge 

 already observed at the testings in the factory, the wire 

 namely forming the inner, the damp soil the outer 

 coating of a Leyden jar. Conclusive was the circum- 

 stance, that the quantity of electricity contained in a 

 perfectly insulated conductor, measured by the deflec- 

 tion of a freely oscillating magnetic needle, was defini- 

 tely related both to the electro -motive force of the 

 interposed galvanic battery and to the length of the 

 wire; further that the electric tension of the charge in 

 a closed conductor corresponded to the electric tension 

 occuring at every point of the circuit according to the 

 law of Ohm. Having perceived this, the impediments 

 to signalling on long underground lines, could, if not 

 be removed entirely, yet be rendered innocuous Im- 

 practical purposes by suitable contrivances. These were 

 the application of by -passes in the form of metallic 

 resistances without self-induction, and automatic trans- 

 lation by which several closed pieces of line were 

 united into a single large line. 



My theory of the electrostatic charge of closed 

 as well as of open circuits found however even in 

 scientific circles at first but little acceptance, since it 

 was opposed to the ideas prevailing at the time. 

 Altogether it is not easy at the present day. when 

 one can hardly conceive how a civilized man can live 

 without railroads arid telegraphs, to carry oneself back 

 in imagination to that time, with the view of under- 



