102 SUBMARINE CABLE LAYING AND REPAIRING. 



arrested, and damage to the core prevented. Formerly, the 

 stream was independent of the driving power, and the insula- 

 tion of the core was sometimes damaged through the com- 

 pound not being stopped in time. There are usually a pair of 

 sleeking tongs to remove superfluous compound from the cable 

 before it leaves the tank. These tongs are, of course, hot, and 

 it is essential that upon any stoppage of the machine they 

 should be promptly removed. In the machines made and used 

 by the Telegraph Construction and Maintenance Co. this is 

 done by a lever close to the starting valve, and is worked by a 

 hydraulic cylinder, so that no time is lost. 



Sir Charles Bright first introduced and patented in 1862 the 

 application of preservative substances in a warm or plastic 

 state to the outside of submarine cables by a wheel, roller, or 

 circular brush, one part of which moved through the sub- 

 stance, while the cable travelled on the upper side, and was 

 coated without passing through the substance, whereby all 

 danger of injuring the cable by heat on the stoppage of the 

 closing machine was avoided. The cable so covered was after- 

 wards passed between rollers with grooved surfaces to com- 

 press the preservative substance into the interstices of the 

 cable, making the exterior coating smooth and regular. The 

 rollers had adjustable springs to regulate the pressure as 

 required, and a stream of water played over them while cable 

 passed through. 



The cable next passes through the hollow axle of the first 

 yarn-serving disc and receives a serving of prepared canvas tape 

 or yarn. This is followed by another coat of compound, then a 

 second serving of canvas tape or yarn, and finally, a third coat 

 of compound. The belt driving one of the discs is crossed so 

 that the two revolve in opposite directions and serve the yarn 

 in diS"erent lays. For the outer serving prepared canvas tape 

 costs less than jute yarn, but it is also not so durable and the 

 yarn forms a better vehicle for the preservative compound. 

 Hence a return has of late been made to the use of jute yarn 

 for this purpose. 



The cable is now finished, a stream of water plays on it as it 

 issues from the machine to cool and harden the compound, and 

 it is then drawn away by a hauling-ofFdrum to the tank. This 

 drum is driven by gear from the machine at a little greater speed 



