The Great Divider is a decoration tool to get patterns and geometries with high accuracy and precision on to your pottery. With a vertical ruler, a 360 degree protractor ring, a rotating set of pointers that work with the polygons of the TC Dividing Pattern, you get all the support you can get to create the most wonderful geometries.
The Doubling scale is a series of pointers with numbers on the foot of the Great Divider, these are the double values of the numbers of the polygons on the disc. When you point pointer 18 for instance to a corner of the 9-polygon on the disc, the scriber stands exactly on half the distance to the next corner. So now you can divide a circle in 18 equal pieces.