# Magic Circle of Circles

## Description

The magic circle of circles, first developed by Benjamin Franklin, consists of eight annular rings and a central circle, each ring being divided into eight cells by radii drawn from the centre; there are therefore 65 cells. The number 12 is placed in he center and the consecutive numbers 13 to 75 are placed in the other cells. The properties are: 1) sum of eight numbers in any ring with 2 equals 360, 2) sum of eight numbers in any set of radial rings with 12 is 360, 3) sum of numbers in any four adjoining cells is 180.

## Galleries

## Source:

*Encyclopaedia Britannica (New York: The Encyclopaedia Britannica Company, 1910) 17:310*

Courtesy the private collection of Roy Winkelman