490 



SUBMAHINE CABLE LAYING AND REPAIRING. 



charge can be taken immediately after the condenser is earthed, 

 as recommended by Dr. Muirhead. Thia is done by closing the 

 discharge key which automatically at the same instant raises 

 the charge key. But if a longer earthing period is required the 

 <3harge key can first be raised by hand and then the discharge 

 key closed after a given iaterval. A small galvanometer key 

 marked "balance" is incladed. The permanent connections 



Fig. 274. — Gott's Capacity Test with Saunder's Key. 



between the key parts and external connections for the test are 

 given in Fig. 274 in "which for clearness the three keys are 

 represented as ordinary front and back stop keys. 



In taking the test with this key the line and condenser are 

 first cleared of any residual charge by closing the discharge 

 key "which earths the middle point between them through the 

 galvanometer. The charge key is then put down and the slides 

 balanced as already described (using the small balance key pro- 

 vided). The absorption discharge d is then obtained by closing 

 the discharge key. As already explained, this will give the 

 immediate discharge after earthing the condenser by automati- 



