International Gnomonic Bulletin - Gnomonica by Nicola Severino

ichly painted (they display biblical motifs) and moreover, they are gnomonically interesting.
Eg. the right Eastern dial on the Economic Court (Figure 2) indicates time from the most recent
sunset (so called Italian hours). Its calendar consists of 3 declination curves for solstices and
equinoxes. The Latin inscriptions read: "NON SOLO PANE VIVIT HOMO" ("A man does not live
of bread only") and "ET VERBUM CARO FACTUM EST" ("A word becomes a body").
Figure 2 - The Klementinum, the Economic Court, the right Eastern sundial. Photo Miroslav Brož (2003).
(5) Let us inspect the Astronomical Tower. It was built as a look-out tower in 1720s, when František
Retz (1730-1750) was the head of the monastery. Astronomical instruments were installed and
regular astronomical observations began much later - in 1750s. The observatory was firstly led by
Josef Stepling (1716-1778). 2
A complete sundial is visible on the Eastern wall (Figure 3), a style without a dial is on the opposite
side. In the past there was probably a sundial also on the Southern side and possibly even on the
Northern one. The decoration of the Eastern sundial, secession ornaments, differs from the other
sundials in the Klementinum.
Figure 3 - The Astronomical Tower in the Klementinum, the Eastern sundial. Photo Miroslav Brož (2002).
However, the most compelling sundial is hidden inside the tower: a noon aperture sundial, the most
precise in Bohemia. (If you would like to see it, you should note that the opening hours are from
March to September, Mon-Fri 14-19, Sat-Sun 10-19 and the entrance fee is 100 CZK, ie. 3 EUR.)
There is a small hole in the Southern wall of the tower, which serves as a camera obscura. The solar
disk is projected on the inner floor and wall. The disk is divided into the two halves by an iron wire