Relief shown by hachures; depths shown by contours and soundings. "Aids to navigation corrected to November 1, 1886." "Reduction for engraving by Edw. Molitor." "Engraved by W.H. Dougal." At head of title: Survey of the northern and north western lakes made in obedience to acts of Congress and orders from the headquarters of the Corps of Engineers, War Department. Includes "sailing directions," "harbors and anchorages," "magnetic declinations," "water table," and notes. Insets: Chart of Todd's Harbor -- Chart of part of Rock Harbor -- Chart of Washington and Grace Harbors. 1 map; 71 x 109 cm.