Grimoire Horologique

a spell preparation clock, after Jack Vance's Dying Earth

In Vance's Dying Earth a spell is learned from a book, held in the mind only by effort, and gone from memory the instant it is spoken. This clock's magician can hold four. Its grimoire keeps twelve spells, one to each hour of the dial. Through every hour the next is committed to memory, and as the hour turns the eldest is cast to make room.

Held in mindcast at

Cast today

The spell names are Vance's. Their order in the book, the four-spell mind and the hourly casting are this clock's own conceit.