64 The National Geographic Magazine 



Map showing the Condition of the Coast Surveys of the World 



has been attained in the portrayal of the 

 forms and characteristics of the strip of 

 the sea bottom which borders the coast 

 than is yielded by measurements ob- 

 tained by dropping a sounding-plummet 

 at close intervals, and that nearly all 

 coasts and harbors, whatever may be the 

 initial completeness of the surveys, re- 

 quire reexamination in the course of 



time to disclose the altered conditions 

 that are produced by natural agencies 

 and artificial developments. 



It will not escape attention that while 

 there is a comparatively small total ex- 

 tent of completely surveyed coast which 

 bounds the world's seats of enlighten- 

 ment and wealth in the Northern Hemi- 

 sphere, the extent of coast that is unex- 



