Gregor Stemmrich and Dan Graham describe and discuss two video installation works of Grahams, Time Delay Room I (1974) and Yesterday/Today (1975) within the context of the CTRL[SPACE] conference Rhetorics of Surveillance from Bentham to Big Brother. Both of these installations engage the viewer and challenge perceptions of video surveillance and the relationships of memory, space and time in video documented events. Reprinted from Dan Graham. Video, Architecture, Television. Writings on Video and Video Works 1970-1978, edited by Benjamin h. D. Buchlow, The Press of the Nova Scotia College of Art & Design, New york University Press, Halifax and New York 1979, pp.41-46.