The Working-Volume may be moved through space and changed in size. To move it use the Hand tool and to change its size use the Zoom tool. Both these tool have keyboard accelerator key equivalents.
Pan by pressing the space bar and then click and drag.
Zoom In by holding the Space bar and Ctrl keys simultaneously then click to re-center window box and zoom. Click and drag to define region to be viewed in full window.
Zoom Out by holding the Space bar and Alt keys simultaneously then click to Zoom out and re-center.
Double-click on the Zoom Tool to enclose all parts of the model and its vertices in the WndowBox.