Elements of Design
The Golden Mean - Proportion /2
To test people's feeling for ratio, let us ask a number of people to divide a line so that a pleasing relationship exists between the two parts. Here you can see how some of them will do it.
To halve anything exactly is not very interesting; to have one very large and one very small piece is too unbalanced and therefore also unsatisfactory;
most people will compromise between these two extremes and divide the line as shown below. If you took a very large number of samples and averaged them out you would get the result shown.
Most people find this a particularly happy division, in which neither part is too small or too large. We can say that the two parts of the line harmonise; that their relationship is satisfactory.
Notes Taken from "Looking and Seeing 3 - THE SHAPES WE NEED"
by Kurt Rowland ©1965 (out of publication)