BARTON C HACKER is currently senior curator in armed forces history at the Smithsonian Institution's National Museum of American History, Washington, DC. His publications include Astride Two Worlds: Technology and the American Civil War (2016), A Companion to Women's Military History (2012), Science in Uniform, Uniforms in Science: Historical Studies of American Military and Scientific Interactions (2007), American Military Technology (2006, 2007), and Materializing the Military (2005). JENNIFER TUCKER is Associate Professor of History and Science in Society at Wesleyan University and a specialist on British technology, law, photography, and media. She is the author of Nature Exposed: Photography as Eyewitness in Victorian Science (Baltimore: Johns Hopkins University Press, 2005) and Photography and Law (forthcoming). MARGARET VINING is curator of armed forces history in the National Museum of American History, Smithsonian Institution, Washington, DC. and a specialist in American women's military history, military material culture, and the social sciences in the Great War. Her publications include A Companion to Women's Military History (2012), Science in Uniform, Uniforms in Science: Historical Studies of American Military and Scientific Interactions (2007). and American Military Technology (2006, 2007).