392 



HYDROGRAPHICAL SURVEYING [chap, xviii. 



The large machine now supphed holds over 5,000 fathoms 

 of 20-gauge wire, and is very compact. It is fitted with two 

 brakes : one a screw brake for holding the reel when required, 

 the other an automatic brake for stopping the reel when the 

 weights strike the bottom. A guider for the purpose of winding 

 the wire uniformly on to the reel is also attached, and is worked 

 by a small handle. 



After leaving the reel the wire passes over a registering 



Fig. 78. 



Automatic Sounding Machine to carry e,ooo Fatlioms of Wire. 



A Reel or drum. 



B Brake. 



C Braku lever. 



D Springs. 



E Regulating screw. 



F Hand wheel. 

 G Swivelling frame. 

 H Measuring wheel. 

 J Indicator. 

 K Stop. 



L Wire-guiding rol'er.':. 

 M Handle for working 



roller. 

 N Bolt. 

 O Screw brake. 



wheel, the dial of which indicates the amount of wire run out, 

 no matter how little or how much wire is on the reel . 



A machine of smaller size, but very similar in type, is sup- 

 plied for use in boats for soundings of, say, more than 15 

 fathoms, and is also useful from the ship for serial temperatures 

 and other purposes. 



Heaving in is accomplished by means of a hemp " swifter " 

 or driving-belt, which conveys the motion of the drum of a 

 donkey engine to the drum carrying the wire of the sounding 

 machine. 



