These two “paper tool” sundial broadsides, present readymade, wall-mounted sundials based on the Crucifixion of Christ. The large central engraving was meant to be affixed to a plank of wood and needles inserted into Christ’s nail wounds to serve as the gnomons for the dials, marking time as the sun passes across the sky.

The text opens with a nod to the giants of celestial horology and then discusses how to use the broadside to build the sundial and provides details about how to use it. Users who followed the instructions would have had to destroy or damage the broadside—which likely was produced in small numbers to begin with—and so it is little surprise that so few examples survive today. These particular examples appear to be completely unknown to the scholarly literature on celestial horology.

The letterpress text was printed in Bologna, followed by a second run of the sheet through a roller press to add the engraving.

Bologna: Jacopo Monti, 1675. One other copy known, at the Biblioteca Nazionale Centrale di Roma.

The sundial was designed by a certain Milanese Barnabite cleric Virmundo Corio, and the copperplate was engraved by the Bolognese printmaker Francesco Corti. The Latin text was written by jurist Francesco Maria Bordocchi, who dedicated the piece to the jurist Vincenzo Butari of Osimo. The Latin poem at the foot of the sheet was composed by a cleric using the initials R. P. D. S. G.

Milan: Francisci Vigoni, 1675. No other copies are known.

The design of the engraving is spectacular, with the Crucifix set within a fictive niche flanked by Solomonic columns thought to have been in the original Temple of Jerusalem. Above is a cupid with his own sundial, whose quiver contains Christ’s three nails. On the steps leading up to the scene sit lions as putti display both Solomonic and Christological mottos. The dial furniture is shown as if it were woven into tapestries.

Using the Crucifix as a central design for sundials was already well established in celestial horology, perhaps most notably by Georg Hartmann (1489-1564), who created a cut-out “paper tool” of such a device; and also by Christopher Clavius, who provided a similar design in the last pages of his 1581 Gnomonices. The layouts of these predecessors, however, function differently than the dials presented in this broadside.

Far from losing market share to mechanical clockmakers, early modern creators of sundials in fact saw prospects for their devices improve: “This was primarily due to the need to periodically readjust mechanical clocks, bringing them into correspondence with the local solar time, as well as to the increasing awareness of the utility of public and private timekeeping” (Lloyd, 14).

Interestingly, the other known copy of the Bologna broadside is folded and was tipped into an autograph manuscript by the Jesuit polymath Athanasius Kircher (1602-80), himself a celestial horologist of considerable importance as author of the Ars magna lucis et umbrae [1646].

Sources:

  • S. Karr Schmidt, Interactive and Sculptural Printmaking in the Renaissance, Brill, 2018, pp. 205-40.
  • S. A. Lloyd, Ivory Diptych Sundials, 1570-1750: A Catalogue of the Collection of Historical Scientific Instruments, Harvard University Press, 1992.
  • H. Maué, et al., Quasi Centrum Europae: Europa Kauft in Nürnberg 1400-1800, Verlag des Germanischen Nationalmuseums, 2002, p. 367-71.