FIRST EMPLOYMENT OF THE CONDENSER IN CABLE TELEGRAPHY. 181 



with discharging contact as quickly as on land lines, 

 whilst by excluding translation stations it w r as only 

 possible to make oneself understood very slowly on 

 the line of 1400 nautical miles in length. 



During my stay in Aden, however, I succeeded 

 by a peculiar expedient in communicating quickly and 

 certainly by the direct line also, and in rendering the 

 intermediate translation stations superfluous. Through 

 the study of the electric properties of underground 

 conductors it had become clear to me that all the 

 secondary currents, which confuse the telegraph signals, 

 could best be avoided, if definite amounts of positive 

 and negative electricity in proportion to the capacity 

 of the cable were suddenly sent to the delivering end 

 of the cable, and likewise at the receiving station only 

 definite quantities of electricity were allowed to leave 

 the cable. At first I thought to be able to attain 

 this by the intercalation of a polarizing battery, 

 possessing so large a number of elements and so small 

 a surface of electrodes that the quantity of electricity 

 necessary for reversing the battery just siifficed for 

 moving the relay-bar. I had brought with me such a 

 polarizing battery of 150 platinum elements, but found 

 that the resistance of the battery did almost as much 

 harm as the polarizing action did good. The fortunate 

 circumstance however came to my assistance that the 

 remnant of the cable of 150 nautical miles, or so, had 

 been submerged from Aden, to be subsequently utilized 

 for the further extension of the line. This was an 

 electric condenser, which could not but accomplish, 



