Chicago, Newberry Library, VAULT Case MS 3A 26
Sundial Manual
Italy, between 1600 to 1699
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Legibly and attractively written on paper in Italian in a seventeenth-century notarial hand, these two contiguous pamphlets include fifteen practical exercises on the construction of wall and platform sundials. Taken directly from Bartolomeo Scanavacca’s 1688 Novissima inventione per dissegnare con grandissima facilità, e prestezza horologi solari, italiani, babilonici, e francesi, (New Inventions to Design Italian, Babylonian and French Sundials with the Greatest Ease and Speed), these exercises build up from the most basic calculations novices would need to know, to demonstrating complete sundials for permanent installation. The most common way to tell time in the early modern period had long been clocks in church towers and associated hourly bells, but there was a growing secular need for broader horary options. While pocket sundials had been in common use throughout Europe since the sixteenth century, as were pocket watches, industrious noblemen sometimes also wanted to know how to design (or commission) a vertical sundial for the wall of their family home or a horizontal sundial for a plinth in their gardens. For instance, Frederick the Wise of Saxony demanded a local mathematician install several for his territories in the early sixteenth century. Artists could also be involved, to decorate the area around the functional and diagrammatic part of the sundial, although these Italian sundial pamphlets only discuss sundial schematics.
Case MS 3A 27 opens by describing parallel lines (1) and ways to divide the 360 degrees of a circle (2); next it details making hand-held time telling devices called quadrants (3); then it covers creating several types of angles (4-7); followed by establishing the meridian line (8-9); continues by building an astrological wall sundial (10); and finally, describes the way to use a horizontal astronomical clock to locate the Tropic of Cancer and of Capricorn (11). The second part, Case MS 3A 26, opens with the construction of another horizontal sundial using astronomy, this using Italian hours (developed in Italy, these were used to calculate time in 24 equal hour segments, starting from sunset), and described in two extensive, separate exercises offering alternate construction techniques (12-13). A horizontal sundial for Babylonian hours follows (14). (Like Italian hours, Babylonian hours were used to calculate time in 24 hour segments, but starting from sunrise). The final exercise explains the mounting of vertical sundials with care taken to achieve the correct declination so the device will function properly (15).
The pamphlets, still enclosed in their original, matching paper wrappers with hand-painted blue and black geometric borders with slight tonal variations, are sewn separately, but only signed at the end of the second pamphlet with a notarial symbol. There are minimal corrections (primarily in exercise 10), suggesting the booklets comprise a direct copy of the exercises extracted from the much lengthier, printed edition of Scanavacca’s Novissima inventione, which consists of 136 pages and four engraved plates. That 1688 book is known in some dozen copies recorded. Small-scale pamphlets on scientific instruments were more common in Northern Europe in the sixteenth century, but Jesuit sundial maker Christopher Clavis, Nicolo Tartaglia, and Galileo Galilei were some of the prolific Italian scholars publishing on this subject in the seventeenth century.
Corsiva usuale e aggrazziata, dal tracciato rotondo e sottile, ricca di elementi ornamentali.
Da notare: il ricciolo che conclude l’asta della d (r. 5: frigida); la s raddoppiata che lega a destra e sinistra (r. 14: distanza); l’abbreviazione per per in un sol tratto (r. 4: per).
Item fully digitized here.
