The journey of dial development from the mid-late sixteenth-century multi-function dial to the standard format that emerged in 1770 was a multifaceted one that is explained in terms of four main themes. There was a fluid boundary between dials and printed paper sources. Dials were a conveyor of knowledge, comparable to texts and diagrams. They were used for astrological purposes until the decline of astrology during the mid-late seventeenth century, which led to the decline of certain indications, but notably the survival of others. Dials were effective communication devices, based on perceptions of knowledge acquisition in the period. Users’ emotions also influenced dial design throughout the period. Dial change rarely took place immediately and there were often periods of transition, rather than immediate change.