Apple Numbers '09 - Manual (Page 37)

Chapter 2 Creating, Saving, and Organizing a Numbers Spreadsheet 37
The view changes to show snapshots of all saved versions of the spreadsheet receding
against a star field. A timeline along the right side of the screen indicates when the
frontmost version on the left was saved.
Past spreadsheet versions Current spreadsheet version
Click to restore the version currently
viewable on the right side of the screen.
Click to leave this view without
restoring an older version.
Drag along the timeline to see
versions saved at different times
in the past.
3 Drag the handle along the timeline to move back through time and look at older
versions of the spreadsheet.
4 When you find a version that you want to inspect more closely, click its image.
The version moves to the foreground, where you can view different sheets or
resize the view, select objects on a sheet, open the inspectors, and copy objects or
inspector settings.
5 Do any of the following:
To completely restore the older version, click Restore when the version you want Â
is in the foreground. The restored spreadsheet appears on your regular desktop,
replacing the last version you were working on prior to viewing the older versions.
(That version is then saved in the timeline, if you want to retrieve it.)