230 THE ELECTRIC TELEGRAPH. 



observable more or less with every kind of element when a 

 great number are connected up in series. 



12. The Earth-element, or Terra- Voltaism. Steinheil says, 

 speaking of this method of telegraphing, " On the repetition 

 of the experiment of using the earth as conductor, M. Gauss 

 provided the ends of the line wire at one station with a 

 copper, at the other with a zinc plate. When these came 

 into contact with the earth a powerful galvanic current 

 traversed the circuit. The place of the acidulated cloth in 

 the common voltaic pile was in this case taken by a thickness 

 of 3,000 feet of earth." 



Bain, in 1844, arranged a similar system in the hope of 

 being able to work his telegraph with it ; but the success 

 attained was only moderate. He, as well as Robert Weare, 

 however, succeeded better with the earth battery for working 

 their electric clocks. 



Two years later Steinheil employed an earth-pair for 

 working his instruments on the serial line between Munich 

 and Nanhofen a distance of more than twenty English 

 miles for both railway and general service. A copper 

 plate of 120 square feet surface was buried in the earth at 

 Munich, and in Nanhofen a plate of sheet zinc of the same 

 dimensions. The current of this earth-pair was found to be 

 amply sufficient to give the necessary signals by deflecting 

 the magnet needles. 



In later years, Mr. Septimus Beardmore, of London, has 

 taken up the advocacy of this system, which he has christened 

 " terra- voltaism," and although he has not pushed it much 

 farther than it was when it left the hands of Steinheil, he has 

 expended much time in its study and made some interesting 

 experiments. 



A very excellent suggestion of this gentleman to increase 

 the electro-motive force of the pair, which he has found 

 insufficient to overcome the resistance of a long line, is by 

 the employment of an amalgam of potassium, moistened with 

 diluted sulphuric acid, for the positive metal, and platinised 

 graphite for the negative element, immersed in a solution of 

 bi-chromate of potassium and sulphuric acid. The great 



