A very interesting and somewhat unusual map of the US mostly East of the Mississippi, showing magnetic declination or variation between magnetic North and true North. This is helpful to account the error in a compass reading vs. true North. This map was published in the American Journal of Science, the longest running US scientific journal -- 1818 to present.
1838 Loomis Magnetic Chart of the US
Magnetic Chart of the United Statesa
Map Maker Specifics
E Loomis / Am. Jour. Sci., 1838, New Haven
7.5 x 7.5 in. plus margins
Very good. Sharp image on bankers note quality paper. Light 'shadow' ink trasfer from previous adjoining page. Slight toning. Narrow margins.