C. H. HITCHCOCK'S 1878 GEOLOGIC MAP OF NEW HAMPSHIRE AND ENVIRONS: RESTORATION IN PROGRESS

During the work on his monumental three volume "Geology of New Hampshire" (1874, 1877, 1878), it's first State Geologist (1868-1878) Dartmouth Professor Charles H. Hitchcock prepared four inch to the mile wood laminate relief maps with vertical exaggerations of ~2.5 and ~5X. Between 1984 and 1990 the late Dartmouth Physics Professor Emeritus Allen L. King published four historical accounts of Hitchcock's efforts and of the fate of his maps. The first map was of the White Mountains for the 1876 Philadelphia Centennial Exposition and was likely later incorporated in the large relief map covering NH, VT and westernmost ME, now preserved at Dartmouth College. Another is housed at UNH and the one of just NH is at the State Library in Concord, both with the greater vertical exaggeration. Only the map at Dartmouth preserves Hitchcock's original painted interpretation of the late 19th century (King, 1985).

The UNH Hitchcock map was transferred from Hanover in 1894 and installed in Thompson Hall; moved to Conant Hall in 1933, repaired and updated by Professor T. R. Meyers to show only the geology of Hampshire as then understood; and in 1966 moved again to James Hall. Renovation of James Hall offers the opportunity to restore Hitchcock's map to the state of geologic knowledge depicted in his 1878 NH atlas and to include his geology of adjacent Vermont and Maine omitted in the 1933 effort. Where necessary, parts of his 1877 VT - NH and 1885 Maine compilations will complete the coverage.

Although in 1878 Hitchcock is said to have considered this work sufficiently complete to recommend “discontinuance of the New Hampshire Geological Survey .... [because] geologically all was known of New Hampshire that could be known” (Tuttle, 1938), his relief maps were still “works in progress” through 1893 (King, 1985). He set a stage for the later state and regional maps that followed. Each illustrates new observations (e.g., central magmatic complexes) and interpretations based on new theories (e.g., plate tectonics) and analytical techniques (e.g., radiometric dating). To the extent that the history of scientific inquiry inspires present and future generations, nearby displays of the 1933 (Meyers, ms), 1955 (Billings), and 1997 (Lyons et al.) geologic maps of New Hampshire in the “new” James Hall (January 2010) will illustrate an evolution of geologic thought and serve as springboards for future work.