Meridional section of Atlantic Ocean at ca. 25°-30° W longitude. Specific gravity of ocean waters shown by isolines. Depth shown in fathoms [vertical scale ca. 1:42,700]. Dates of voyage along meridian are shown. Includes diagram "representing the distribution of surface-saltness along the same meridian." From: The Journal of the Royal Geographical Society of London. Vol. 47, (1877), pp. 72-86; held in Firestone Library. Call number: G7 .J687 v.47 1877