176 BULLETIN OF THE 



in making each one hundred turns during soundings, — noting the state 

 of the sea, etc., — as the best way to gain a knowledge of the rate at 

 which it is safe to let the wire pay out under different circumstances. 

 In a smooth sea there will be very little trouble, and probably with the 

 new machine there will be none in the heaviest sea in which soundings 

 can be taken ; but sounding with wire having a tensile sti'ength of 240 

 lbs. is a delicate operation even with the best apparatus, and the person 

 in charge, should he lack experience in sounding with wire, would do 

 well to keep, at first, well within the bounds of safety, and then to 

 approach gradually the limit of theoretical possibilities. If everything 

 is working well and the wire keeping taut at all times, it is of course 

 safe if the correct amount of resistance has been applied to the reel 

 according to the rule. 



Sounding- Rod, composed of Sigshee's Detacher 7(sed in connection vnth a 

 modification of Captaiii JjeUcnaji's Cylinder No. 2. 



Description op Parts, 



A cylinder, a, with screw-joint at B. 



A casting composed of the cylindrical guides C, C and the perforated 

 plate J. 



The valve seat E. 



The popper-valve F, connected rigidly to the pipe G, which slides freely 

 on the lower guide C. 



The weak spiral spring II. 



The hollow cone /, to the bottom of which is soldered the smooth cylin- 

 drical plate D. 



A detacher composed of the swivel K, the pawl L, the tumbler M, and 

 the spring N (No. 1 4 American-gauge brass spring wire). 



The perforations P, P, etc., for the escape of water. 



In connection with the above is used the iron shot-sinker Q, fitted with 

 the iron wire bail R. 



Working. 



During the descent the cone / is kept up by the 'shot as shown in 

 Figs. I. and II., and on striking bottom the bail is prevented from get- 

 ting over the top of the detacher by the bearing which the sinker has 

 against the tmdcr part of the cone. 



When the sinker strikes bottom the slacking of the sounding lino or 

 wire trips the tumbler, and the sinker is free to slide off the cylinder. 



