MANCHESTER EXPERIMENTS 99 



in so far as the receiving machine was concerned. 

 The " line " terminals were connected to the spring 

 tongues of the reverser (see Chapter III.), which 

 was in contact with two upper platinum pins 

 during nearly the whole revolution, these pins lead- 

 ing one to the stylus and the other to the drum, 

 i.e., the back of the sensitive paper. At synchro- 

 nism the check which stopped the drum revolving 

 temporarily automatically lowered the tongues into 

 contact with two other pins which led directly to 

 the polarised relay, the latter switching in the 

 mechanism for withdrawing the check. 



The machines worked so satisfactorily over the 

 artificial line that in July, 1909, I was tempted to 

 place a similar instrument in Manchester, where an 

 installation of Professor Korn's apparatus was in 

 full swing, as already described. The first expe- 

 riments over this line, some 200 miles in length, 

 were very disappointing. The attempts were made 

 with line sketches, not half-tone photographs, and 

 the lines appeared on the paper as so many 

 smudges ; each mark had a long tail, and it was 

 evident that secondary discharges were coming 

 from the line into the paper. These discharges 

 were much more noticeable some days than others . 



It thus became obvious that the capacity and 

 induction effects would have to be counterbalanced, 

 and after a series of experiments the means already 

 described were adopted, with what success has been 



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