Dr. Rosemary Firman, librarian of Hereford Cathedral, finishes cleaning a 12th century manuscript of The Old Testament in the cathedral's Chained Library after it's annual spring clean on January 24, 2012 in Hereford, England. The famous Chained Library contains 1,500 books including 227 medieval manuscripts. Once a year specialists and trained volunteers take six days to clean the rows of historic historic writings. The cathedral's oldest and most important book is the eighth-century Hereford Gospels. Chaining books for security was widespread in libraries from the middle ages to the eighteenth century and Hereford Cathedral's seventeenth-century Chained Library is the largest to survive with all its chains, rods and locks intact. (Photo by Christopher Furlong/Getty Images)