Public Sub TestCollection()
    Dim lngRevisions As Long
    lngRevisions = 0
    Count = 0
    Dim myRevision As Revision
    For Each myRevision In ActiveDocument.Revisions
        myRevision.Range.Select
        lngRevisions = lngRevisions + Len(Selection.Text)
        Count = Count + 1
    Next
    MsgBox "There were" & Str(Count) & " revisions for a total length of " & Str(lngRevisions)
End Sub