Patent for a screen-operating mechanism for window-screens. It is meant to hide the mechanism from view and to improve the way the screen is raised and lowered. It also moves the "upper sash in one direction moves the screen in the reverse direction, the construction being such that the motion-transmitting gearing does not in any manner interfere with the use of ordinary window-sashes balanced by weights or springs, or the use of sashes of which the upper one only is movable" (lines 24-30).