The Bibliographical Description of Astronomical Volvelles and Other Moveable Diagrams

olvelle diagrams are those woodcut illustrations part of which the reader can physically move, usually by rotating a circular paper disc attached to the page, and their inclusion was one of the most recognisable features of astronomical books published in the sixteenth century. This article proposes, and gives examples of, a three stage methodology for their bibliographical description: 1. the use of lambda λ in the book collation formula to indicate that a book contains cut-out volvelles and where known how many uncut leaves containing volvelle pieces were printed 2. a volvelle collation formula for each volvelle diagram, indicating how many pieces there are in total at each location within the book and how they should be assembled; 3. a rigorous description of each individual volvelle diagram in sufficient detail to construe its precise appearance and use. Finally it is considered how the methodology might be applied to a wider range of printed materials including paper instruments, globe gores and 'pop-up' books.