SURVEILLANCE OF THE LINES. SYSTEM OF CONTROL. 157 



lines, he would pay us for the service the hundred 

 roubles per verst. which he had hitherto given to the 

 road contractors. In reality a successful watch could 

 not be carried out by us, it could only be done by 

 natives, who would certainly not have kept a better 

 look out on our behalf than for the Government, 

 Nevertheless we accepted the count's offer on the 

 condition, that we might carry out the surveillance and 

 the necessary repairs entirely in our own fashion. 



As this was accorded, we gave up altogether 

 keeping a guard properly so called, contrived instead 

 a mechanical system of control, which was relatively 

 cheap and yet fully answered the purpose. At every 

 fifty versts we erected a guard -hut. into which the 

 wires were conducted. In the hut was placed an 

 alarum and a galvanometer, which were intercalated 

 into the course of the current in such a way, that the 

 watcher of the movement of the galvanometer-needle 

 could always see if an electric current was traversing 

 the wire. If the needle stood still for half an hour, 

 he had with the help of a simple mechanism to tele- 

 graph the number of his hut by repeatedly connecting 

 to earth. The telegraph stations, between which the 

 connection was interrupted, had orders to insert their 

 battery between the conductor and the earth, and 

 received accordingly the reports of all the guard-huts 

 on the hither side of the place of interruption, thus 

 learning its situation. To every telegraph station was 

 assigned a mechanician, whose duty it was, immediately 

 on the report of an interruption, to take post-horses 



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