270 DISCOVERY CH. 



instruments which had been in daily use by thousands 

 of practical men from early times without one of them 

 suggesting any substantial improvement. 



All sailors are grateful to Lord Kelvin for his inven- 

 tions for the preservation of life at sea, notably by means 

 of his compass and sounding machine. With these two 

 aids to navigation a safe course can be followed with 

 confidence in fog or darkness ; and every sailorman 

 can tell of disasters from which he was saved by them. 

 A characteristic tribute to Kelvin from a sailor's point 

 of view has been given by Admiral Sir W. R. Kennedy. 



" Some years ago," he says, " I left a port on the coast of 

 Patagonia in the Ruby. We shaped a course for Golfo Nuevo 

 for the night. At 8 p.m. the navigating officer came into my 

 cabin and showed me the position of the ship, well clear of the 

 land, and 100 fathoms no bottom, marked on the chart. * All 

 right,' I said. ' Get a cast of the lead.' ' Throw Thomson 

 overboard,' was the way I put it. The navigator looked at me 

 to see if I was joking. ' Why, there's no bottom at 100 fathoms, 

 sir.' ' Well, heave Thomson over.' He left the cabin, and 

 presently I heard the whirr of the wire suddenly stop. I rushed 

 on deck. Fifteen fathoms ! Stop her, hard-a-port, leadsmen 

 in both chains ! Sure enough, 15 fathoms. I hove to all night, 

 head off shore, and next morning steered for the gulf, which we 

 reached without further adventure, but had we continued on 

 our course we should have been ashore before daylight. The 

 navigating officer was not at fault, but the coast-line was not 

 correctly charted. No wonder that we sailors bless the name of 

 Lord Kelvin." 



By his improvements of the two oldest aids to naviga- 

 tion the compass and the sounding line Lord Kelvin 

 earned profound gratitude from all who go to sea. He 

 has been called the best friend the sailor ever had ; 

 and it is said that a blue- jacket was once overheard to 

 remark, " I don't know who this Thomson may be, but 

 every sailor ought to pray for him every night." 



