Relief shown by hachures.
Depths shown by shading and soundings.
"Soundings expressed in fathoms and show the depth at mean low water."
Includes table of abbreviations.
Discovered in October, 1854, by the hydrographic party under the command of Lieut. H.S. Stellwagen, U.S.N, Assist ; A.D. Bache, Supdt. ; drng. by E. Cordall, engg by App. S.W. Bradley.