This is a MapHist list message (when you hit 'reply' you're replying to the whole list) o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o +
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I don't know (and doubt that anyone knows, in fact, doubt that it is KNOWABLE) exactly what induced Melish to draw Indiana the way he did on his various maps. The general answer, of which I am entirely confident, is that before the completion of the General Land Office surveys in the upper Midwest in the 1840s, no one knew, with any degree of accuracy, how far it was between the western border of Pennsylvania and the Mississippi River. Cartographers in the 1810s, 20s and 30s had a pretty accurate fix on the western border of Pennsylvania, thanks to the surveys of Mason and Dixon. What they had for the Mississippi river were a few scattered longitude observations and the river as platted on maps by Ross (1772), Hutchins (1778), or King (1810). So, between western Pennsylvania and the Mississippi, cartographers had to fit in the states of Ohio (1803), Indiana (1812) and Illinois (1816). They had some fairly accurate ideas about how wide each of these new states was, but when they tried to fit them in between what they knew about the longitudinal positions about the western border of Pennsylvania and the Mississippi, there simply wasn't enough room! They had to make adjustments, compressing each of the three states a little or a lot, to make them fit. If there were no Great Lakes, these distortions would not be so obvious to us, but the Great Lakes, and especially the great southward protrusion of Lake Michigan, serves as a strongly iconic feature. From our perspective (and from the perspective of anyone who's looked at a map of the upper Midwest since the 1850s) we KNOW how lake Michigan is supposed to look in relationship to the surrounding states. Problem was, before the General Land Office surveys defined the shape of Lake Michigan by filling in the lower peninsula of Michigan with a grid of one-mile squares, the lake swung from east to west like a pendulum. Here are two maps that illustrate the extremes of that pendulum shift: Bellin, 1764: http://www.newberry.org/renaissance/images/Great%20Lakes.jpg Burr, 1831: http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~3309~400126:Michigan-Drawn-&-Published-by-David The English cartographer John Cary, in this 1825 map, has a reasonably accurate orientation for the lake, but the state borders get all messed up for the reasons given above, resulting in Illinois completely losing its Lake Michigan shoreline.  (From my iPhone; not sure if this image will be viewable on all servers) The GLO gridding of Michigan (and concomitant accurate mapping of the eastern shore of lake Michigan) was pretty well completed between 1837 and 1841, as you can see by comparing the GLO maps for those years: http://alabamamaps.ua.edu/historicalmaps/us_states/michigan/index.html Interestingly, the English cartographer John Hutchins had made an extraordinarily accurate map of Michigan's lower peninsula way back in 1762, but it remained in manuscript, and so had no influence on the work of later cartographers: http://www.historycooperative.org/journals/mihr/34.1/images/widder_fig01b.jpg The reason he was able to capture so accurately the Lake Michigan shoreline is that he literally walked the perimeter of the peninsula (or circumnavigated it in a small boat), taking frequent compass bearings and carefully estimating distances covered. Not until the GLO surveyors got on the ground with compasses and measuring chains was a more accurate shape possible. Howell, Monique wrote: This is a MapHist list message (when you hit 'reply' you're replying to the whole list) o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + -- Robert W. Karrow, Jr. Curator of Special Collections and Curator of Maps The Newberry Library 60 West Walton Street Chicago, Illinois 60610-7324 [email protected] Phone: 312-255-3554 Fax: 312-255-3646 Search our map catalog at www.biblioserver.com/newberry |
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