Here is Charles Bouleau’s analysis of a miniature from the Tres Riches Heures of Jean de Berry, made by the Limbourg Brothers early in the fifteenth century.
Here Adam and Eve are shown in the Garden of Eden, whose circular perimeter was surely drawn with a compass.
More interestingly, Bouleau showed that the height of the Gothic fountain of life in the image could be found by unfolding the diagonal of the square framing the garden’s circular border.
Bouleau also demonstrated that the width of the fountain was set by the intersection of two pentagons inscribed within that circle. In the lower-left of the image, moreover, Adam’s foot locates the corner of the pentagon with the horizontal base.
Bouleau extends that baseline to the right, as shown in green, and then connects it back to the tip of the fountain.
The intersection of this green diagonal with the circle’s equator, he claims, sets the width of the Gothic portal through which the first couple exit, while the blue diagonal to its top sets the sloping pose of the expelled Eve.
This page is folio 25v of the Très Riches Heures du Duc de Berry, which is MS 65 from the Musée Condé in Chantilly, France.
This particular image is from: