Odhner, Willgodt Theophil, 79
Office of Naval Research (ONR), 198, 204
Office of Scientific Research and Development (OSRD), 139
Ohl, Russell, 226
Olsen, Kenneth, 202, 256–58
Oppenheimer, J. Robert, 136
Oscillator, phase-shift, 233, 236–37
Oughtred, William, inventions of, 11–12
Output unit, 65