THE LOCALISATION OF BREAKS AND FAULTS. 



543 



The use of these curves must not be understood to transform 

 a test into a purely mechanical operation. Some acquaintance 

 has necessarily to be gained with curves on localisations before 

 distances can be correctly taken off by inspection without the 

 check calculation. But light is thrown on a set of readings 

 when plotted in this way that is not possible to appreciate by 

 figures alone, and the graphic records are much more readily 

 understood than columns of figures. 



Mr. Raymond-Barker has developed this graphical treatment 

 for partial earth fault localisations, and the curve in Fig. 309 

 is one such taken on the French Atlantic between position of 

 ship's cut-in and the shore. On board the cable ship 

 " Buccaneer " readings with different currents were taken to 

 scale zero, the points on the curve marked with a cross being 

 for currents varied by battery power and those marked with 

 a circle by altering the bridge ratios. 



The observations were as follows : — 



Test for Partial Earth hetioeen SJiip^s Gut-in and Brest, 

 Balances to scale zero. Zinc to line. 



Series. 



II. 



III.. 



IV, 



V. 



