Example image of eyePlorer eyePlorer map for 'A. E. Douglass': 1867 1962 Astronomer July 5 March 20 Tucson, Arizona United States Windsor, Vermont Dendrochronology Solar cycle Sequoia Herschel Solar variation Lowell Observatory Douglass (lunar crater) Impact crater Mars Percival Lowell Venus William Henry Pickering American Museum of Natural History Clark Wissler National Geographic Society Laboratory of Tree-Ring Research University of Arizona 1920 in science 1928 in archaeology Emil Haury Florence Hawley Flagstaff, Arizona Douglass Timeline of Chacoan history Timeline of United States inventions