278 YACHT EQUIPMENT 



wire ; diameter, T \- inch ; breaking-strain, 280 pounds ; 

 price 23s. per 300 fathoms. 



One of the present writers, after two years' experi- 

 ence, is able to speak highly of the following stranded 

 wire of German manufacture : 3x7 galvanized steel 

 wires of 0-4 millimetre gauge ; diameter, i\ inches ; 

 breaking-strain, 1,046 pounds ; price £6 7s. 6d. per 

 1,000 fathoms. 



The high, breaking-strain allows this wire to be 

 used for physical operations with water-bottles and 

 capsizing thermometers. 



The various types of deep-sea sounding machines 

 have each their own supporters. By the courtesy of 

 the manufacturers we are able to give here the following 

 prices of the Lucas machines as a guide : (1) For depths 

 to 5,000 fathoms, coupled to a Brotherhood three- 

 cylinder engine ; the whole fitted to an iron base, £131 ; 

 (2) the same, with rope-wheel for driving from deck- 

 engine, £52. The capacity is calculated for piano-wire 

 of 22 gauge. 



For really deep-sea sounding it is advisable to 

 use a heavy sinker of 50 pounds, which is detached 

 on striking bottom and left there ; this method enables 

 the wire to be hauled rapidly, and without danger 

 either of breaking the wire or of bursting the barrel 

 on which it is reeled up. The sinkers are made of 

 cast-iron. 



Several types of deep-sea sounding leads are in use, 

 their form being dictated by the fitting employed to 

 bring up a sample of the bottom (cf. Chapter VI., 

 " The Sea Floor "). For the latter purpose have been 

 employed a cup (not now in use) ; a heavy tube, which, 

 when being hauled, is closed below, either by a butter- 

 fly valve or a cock ; and a snapper, consisting of two 

 tightly fitting buckets which grip a bottom sample. 



