00891cam a22002411 4500 gs 19000004 DLC 20260227111323.0 850329r1918uuuudcuf f000 0 eng c gs 19000004 (OCoLC)11865267 Library, U.S. Geological Survey NRU NRU DLC premarc n-us-pa QE75 .B9 no. 515 Marshall, R. B. (Robert Bradford), 1867-1949. Results of spirit leveling in Pennsylvania, 1899 to 1911, inclusive. R.B. Marshall, chief geographer. Work done in cooperation with the state. Reprinted with corrections. Washington, Govt. Print. Off., 1918. 164 p. pl. 24 cm. Geological Survey bulletin, 515 Pennsylvania Altitudes. Pennsylvania. Bureau of Topographic and Geologic Survey. 25896 25896