NavList:

Maybe this Russian divider is also for the same purpose, although I can't read the Russian explanation on the cover. Best regards Juergen 

The table in picture 2 is simple ratios. Left is for lines, middle is for areas, right is for volumes.  E.g.  1:1 is the same for all three.  With the pivot in the middle the marker ought to be found against 130.  For 1:2 for lines the pivot should be 1/3 from one end.  The points at the long end will be twice the distance apart than those at the short end.  For areas the pivot will be nearer the centre, because the longer end points only need to be 1.42 (root 2) times the distance apart of the smaller end points.  For volumes, the pivot would be even nearer the centre because the wider points would only need to be 1.26 (cube root 2) times the distance apart of the smaller end points.  E.g.  If you want to double the volume of a square cube, you only need to increase the length each edge by 1.26.  Understanding the table in photo 4 is beyond my pay grade, except to say n=6 corresponds to pivot in the middle.  DaveP