Abstract: A window mirror is disclosed as comprising a frame, at least two transparent panes, and means for holding the panes in a juxtaposed position such that a liquid-tight cavity is defined therebetween. A quantity of mercury is inserted from a reservoir below the cavity, creating a mirror, and removed, leaving a window, from this cavity. In an alternative embodiment the transparent panes have certain portions held in juxtaposed position, while other portions are held in a releasably contacting position, such that when the liquid is inserted between the panes, the panes separate allowing the liquid to fill therebetween.