skip to content

Astronomical Images : Volvelle illustrating the Sun's daily motion through the year

Johannes Sacrobosco

Astronomical Images

<p style='text-align: justify;'>Very little is known about Johannes Sacrobosco, the author of the work from which this paper instrument is taken, except that he was probably British, taught astronomy at Paris University, and died there in the second quarter of the thirteenth century. <i>Sphaera mundi</i>, his major work, was an extraordinarily popular astronomical textbook for several generations. Manuscripts of it circulated through all the main European centres of learning. It was first published in 1472 in Ferrara, and went through dozens of editions up to the mid-seventeenth century. Volvelles with moving parts like this one were commonly included in order to illustrate the text of the <i>Sphere</i>. The <i>Calendarium</i> printed by Johannes Regiomontantus in 1470 was the first astronomical book to contain movable parts, including a volvelle. Many editions of Peter Apian's <i>Cosmographia</i> also carried volvelles as didactic devices. A volvelle was first incorporated into Sacrobosco's <i>Sphaera</i> in the octavo edition issued at Wittenberg in 1538. This volvelle from a Parisian edition of the <i>Sphaera</i> is based on that from the Wittenberg version, as the motto and the decoration underneath it (two figures with instruments) is almost identical. This volvelle can be used to demonstrate the Sun's daily motion through the year and the relation between the horizon and height of the pole. The motto reads: <i>Nulla dies sine linea</i> [no day without a line]. The saying is attested in medieval sources. The closest thing to a classical Latin source is this passage in Pliny: <i>Apelli fuit alioqui perpetua consuetudo numquam tam occupatum diem agendi, ut non lineam ducendo exerceret artem, quod ab eo in proverbium venit</i>: 'Apelles had in fact a regular custom that he never passed a day, no matter how busy, without practising his art by drawing something [<i>lineam ducendo</i>], which has thus become a proverb'. (Pliny, <i>Naturalis historia</i>, XXXV.36.84). Apelles (fourth century BC) was court painter to Alexander the Great.</p>


Want to know more?

Under the 'More' menu you can find , and information about sharing this image.

No Contents List Available
No Metadata Available

Share

If you want to share this page with others you can send them a link to this individual page:
Alternatively please share this page on social media

You can also embed the viewer into your own website or blog using the code below: