SAFEGUARDS OF THE SEA 91 



each of which covers only a small portion of 

 the sea and land. On these charts the vari- 

 ous channels are marked with innumerable 

 figures showing the depths; letters designate 

 the character of the bottom at various points, 

 and all rocks, reefs and other obstacles, as well 

 as all the various buoys, beacons and lights are 

 shown. Moreover these charts illustrate 

 prominent landmarks, such as hills, mountains, 

 tall trees and buildings, etc., which serve as 

 bearings and minute detailed sailing directions 

 are also included. 



With such a chart a mariner may readily 

 find his way into a strange harbour or may 

 navigate his ship through strange waters, even 

 though there are no buoys, lights or similar 

 guides. By frequent soundings with the lead, 

 and by comparing the depths and the samples 

 of bottom with the chart, the captain or pilot 

 of the ship may locate the position of his ves- 

 sel with great accuracy and by proceeding 

 slowly, and sounding as he proceeds, and 

 watching landmarks and bearings he may 

 wend his way into most difBcult and danger- 

 ous spots in safety. This may seem very mys- 



