At head of title: Survey of the northern and northwestern lakes. Made in obedience to acts of Congress and orders from the Headquarters of the Corps of Engineers, War Department.
Includes: Authorities -- Water table -- Light-houses -- Magnetic Variations.
Projected from a trigonometrical Survey executed under the orders of Major C.B. Comstock, Corps of Engineers, Brvt. Brigadier Gen. U.S.A., in 1875, '76 and '77.