Happy Pi Day! March 14 is a special day for nerds everywhere to pig out on pie and celebrate the world’s most endearing mathematical constant, π. The ratio of a circle’s circumference to its diameter, π (the Greek letter pi) rounds to 3.1415—earning this year’s date, 3.14.15, the designation of Ultimate Pi Day.
In honor of the day, we celebrate circularity with six beautiful manuscript pages selected by our curators as leading exemplars of roundness.
Astrological & Astronomical Circles
Volvelles are proto-cyber wheel charts, usually made of paper with moving or rotating pieces. This one is an astronomical table featuring concentric circles that was used as a medieval calculating device.
This many-circled chart features the earth (labeled Terra) at the center, with the signs of the Zodiac on the outer rim.
In a religious context, circles represent Earth and sometimes Heaven. This illumination shows the creation of the heavens, a red orb covered in what might be a wind, cloth, or a wave.
These four miniatures compress the seven days of the creation of the heavens and Earth. Take a closer look.
Around the dove at the center of this diagram is inscribed “fear and hope, love and desire.” Sometimes fear and love are known as “extremes,” while hope and love are qualities associated with doves. There’s a metaphor in there somewhere.
Here a music lesson takes place as the philosopher Boethius (in red) points out tonal intervals that hover in a gold circle above a grassy field. This alludes to music of the spheres, a philosophical concept that likens the harmonious movements of heavenly bodies to music.