92 THE OCEAN 



terious to a landsman, for it is very difficult to 

 understand how mere depths of water and the 

 tiny samples of bottom, brought up on the 

 grease at the end of the sounding-lead, can 

 tell a sailor where he is. As a matter of 

 fact there are seldom two spots in any locality 

 where the depths and bottom are alike or 

 where the water shoals in exactly the same 

 manner. Thus if the lead indicates ten 

 fathoms and muddy bottom and at the 

 next sounding shows eight fathoms and 

 muddy bottom, the sailor, by referring to the 

 chart, may be sure he is on or near the spot 

 where the soundings and bottom agree 

 with those designated on the chart. If, by 

 a study of the chart, the officer finds that the 

 proper course lies to the north and has a depth 

 of nine fathoms and a sandy bottom he has 

 but to steer in that direction and sound and if 

 the stated depth and sandy bottom is found he 

 knows he is right, whereas if a different depth 

 or bottom is encountered he can still locate 

 his position by the chart. Many times bear- 

 ings on shore are almost as useful as buoys 

 or lights and by keeping certain prominent 



