SURVEYING THE ROUTE. 



13 



showing number of fathoms. The curved arm carrying this 

 ■wheel moves in a vertical plane similarly to the lever F in the 

 type last described. There are two horizontal springs tending 

 to pull this arm inwards, and apply the brake to the wire 

 reel. While the wire with sinker and tube is running out over 

 the small wheel the weight keeps the wheel and arm down, in 

 which position the brake band is slack, but immediately the 

 weight is taken off by the sinker touching bottom, the springs 

 pull up the wheel and arm, thus applying the brake in the 

 manner described, and stopping the reel. When used for 

 taking flying soundings — that is those taken while the ship 

 is under way (generally at about half-speed) — a correction 

 has to be applied for the lead of the wire, but this is some- 

 times avoided by the simultaneous use of pressure tubes 

 or gauges, which indicate the depth by the sea pressure. 



Lock Screw. 



Hand Wheel for Setting Brake Spring. 



Fig. 10.— Steam Recovery Sounding Machine (Lucas). 



In the latest equipments for cable ships this machine is 

 constructed for sounding to the greatest depths, with steam 

 winding-in, as in Figs. 10 and 11. The machine is driven by a 

 three-cylinder Brotherhood engine through suitable gear-wheels 

 for reeling-in. When running out the wire the engine is 

 disconnected by shifting out of gear the pinion on engine shaft. 



