Manuscript map by Arnold Henry Guyot drawn on [Karte der Schweiz]. Scale 1:380.000 by Jakob Melchior Ziegler. Winterthur : Eigenthum d. top. Anstalt von John. Wurster. [1846]. Map shows by color coded the distribution of errratics and drift by basin name. Coloured lines illustrate the glacial erratic flow transport path of relocated boulders by rock type. Principal meridian: Ferro. Relief shown by hachures. Depth shown by soundings.