538 



SUBMARINE CABLE LAYING AND KEPAIRING. 



provided with a transparent sheet of celluloid having a 

 roughened surface for drawing upon. Underneath it is a 

 sheet of squared paper having certain curves permanently 

 indicated thereon. The sheets being clamped in position, 

 the squares can be seen through the transparent sheet 

 and points or curves marked with pencil on the prepared 

 surface. These can afterwards be traced and copies printed 



0'80 40 



0-60 



rt]-^0-40 



O'20 



:20 



10 



n 



B 

 A ^^1 



^_ Jc I 



^3: ^i; 1 1 1 



t. "I?*,,— 



I . T^:^^Jb^__ 



/ ~+ — .J. 



/. ^^ 

 — ^j 1 1 — , 1 



/ 



i I I I 1 1 1 \ \ 1 1 1 ! 1 L- — • — 



550 



60O 



€50 



500 

 Position of Brealc. Ohms. 



Fig. 304.— Break Localisation Curve to True Zero (E. Jona). 



70OR 



off, while the transparent surface can be cleaned for fur- 

 ther use, or a sheet of tracing paper may be used instead of 

 the celluloid sheet and the curve plotted directly upon it. In 

 any case the arrangement dispenses with the need of sepa- 

 rate sheets of squared paper for every curve or set of curves. 

 A pair of cursors are provided for assisting in plotting curves 

 or taking off quantities from them by inspection. 



The board is supplied with useful curves by which the 



