To change view, select desired zoom level and window size from the options below the Zoom View window and then click on the image. The display will be centered where you click. To move up, down, left, or right within a zoom level, click near the edge of the image in the Zoom View or select an area in the Navigator View. The red box on the Navigator View indicates the area of the image being viewed in the Zoom View.

CREDIT: Ruger, Albert. "Springfield, Illinois 1867. Drawn from nature by A. Ruger." Chicago Lithographing Co. 1867. Map Collections: 1544-1999, Library of Congress.