Moon and Tide: A New Interpretation of Exeter Riddle 22 Based on the Medieval Science of Computus

Abstract

Exeter Riddle 22 tells the story of how 60 riders and 15 horses are unable to cross a body of water until a 'wægn' ('wagon') miraculously transports them to the other shore. Several solutions have been proposed, but none are entirely satisfactory. This article uses medieval scientific lore, as well as the medieval coastal landscape and comparative readings of Old English, Latin and Old Norse texts, to propose a new solution explaining all aspects of the riddle-the full moon. Riddle 22 requires not only an awareness of the relationship between the lunar and tidal cycles, but also a knowledge of the computistical formulae that were taught in monastic schools. The horses and the riders represent the hours of moonlight and the 'wægn' represents the moon itself. Additionally, the riddle draws upon images of the coastal landscape, as the riddle also depicts the crossing of a tidal causeway. Solving the riddle in this way is a transformative experience for the scientifically literate reader, who comes to recognize-as per Augustine-that prosaic, repeatable events in nature are everyday miracles.