You can click a point in the map to zoom in on that point.
The map zooms in on the point you clicked to display the map at twice the previous magnification.
You can continue to zoom in by clicking another point in the map. When you finish zooming, press Esc, click the SELECT button on the toolbar, or choose SELECT > SELECT from the Map Window popup menu. Note that pressing Esc does not work if you are using the Java edition of the Viewer on an Apple Macintosh computer.