LIGHT ROPE 279 



The second of these is represented in Fig. 157, p. 202, 

 the third in Fig. 199. 



A full account of the Le Blanc sounding machine is 

 furnished in Lieutenant Tydeman's Siboga Report 

 already quoted, The Sigsbee machine is described in 

 the " Bulletin of the United States Fish Commission 

 for 1896," p. 312. 



The wire should be well greased. A mixture of 

 castor oil and tallow is recommended for stranded wire, 

 applied hot. For single-strand wire boiled oil is good. 

 Very great care should be exercised in spreading the 

 sounding wire evenly on the barrel, and the same pre- 

 cautions taken in paying it on to the barrel from the 

 manufacturer's reel, as in the case of wire rope. 



3. Other Work. 



It is not economical, either of time, labour, or the 

 life of a rope, to use a heavy rope where a lighter one 

 would do the work, and a i-inch rope is not well 

 adapted for other uses than trawling, dredging, and big 

 vertical nets. A lighter and cheaper type of rope can 

 be used for reversing thermometers, current meters, 

 water-bottles, open and closing tow nets — in fact, for 

 everything except bottom work.* A rope of this type 

 was spun to the order of one of the present writers for 

 mid-water work down to 2,500 fathoms; it consisted 

 of seven wires of 16 gauge plough-steel ; diameter, 

 fV inch ; breaking - strain, 2 tons ; weight (in air) 

 42 pounds per 100 fathoms ; price about 21s. per 

 100 fathoms. It should be stipulated with the makers 

 that a rope of this type be spun from continuous 



* It is not recommended to use Six thermometers with any 

 rope of so large diameter ; the vibration tends to jar their 

 indices down, and thus to give defective readings. 



