Hybride Temporalitäten

When the astronomical clock of the Strasbourg Cathedral was inaugurated in 1574, Nicodemus Frischlin, humanist and professor of poetics in Tübingen, responded to this monumental, ‘time-defining event’ with a didactic poem – in Latin, and profoundly informed by the great models of Classical Antiquity – in which he embedded the stages of human life in an encompassing horizon of both secular and religious temporality. With his ‘carmen’, Frischlin aimed to complement the ambitious technological construction with an equally ambitious literary account, gradually tracing the building’s multiple and hybrid conceptions and semantics of ‘time’ in versified description. This article examines how Frischlin’s didactic poetry organizes knowledge of anthropological, historical, and eschatological times; moreover, illuminating the motifs of the moon disc, the ‘Lebensalterautomat’, and the mechanical figure of Death, it sheds light on the emulating adaptation of Classical tradition (Lucretius; Ovid). Frischlin portrays the Strasbourg clock as a technological masterpiece without equal in Classical Antiquity.

Reconstruction designs of an early Chinese astronomical clock with a waterwheel steelyard clepsydra

During the 8th century, ancient China began to use a steelyard clepsydra to control the waterwheel, giving it a time-keeping function for use in hydromechanical astronomical clocks. In the Tang Dynasty, the monk I-Hsing (683–723 CE) and Liang Lingzan jointly built a water-powered celestial globe (shuiyun huntian), which, according to historical records, was China's first hydromechanical astronomical clock with a waterwheel steelyard clepsydra. However, the original device has since been lost. The objective of this study is to use the design methodology for the reconstruction of lost ancient machinery to systematically reconstruct this lost clock. The methodology included the study of ancient literature to formulate reconstruction design specifications. Through the process of generalization and specialization, the target device was analyzed to determine its function, and different mechanical configurations that achieved the same function were developed. Thereafter, an atlas of possible mechanical sketches that were consistent with the technological level of ancient times was built. A computer 3D reconstruction of the waterwheel steelyard clepsydra, time-reporting device, and astronomical device was carried out, and 50 possible configurations were developed. One was selected to build a physical model.

Günther Oestmann, The Astronomical Clock of Strasbourg Cathedral: Function and Significance. Trans. Bruce W. Irwin

Günther Oestmann, The Astronomical Clock of Strasbourg Cathedral: Function and Significance. Trans. Bruce W. Irwin Leiden and Boston: Brill, 2020. Hardback xvi, 348 pp. ISBN: 978-90-04-42346-6. $179.00.

The Design and Simulation of an Astronomical Clock

This paper describes and explains the synthesis of an astronomical clock mechanism which displays the mean position of the Sun, the Moon, the lunar node and zodiac circle as well as the Moon phases and their motion during the year as seen from the Earth. The clock face represents the stereographic projection of the celestial equator, celestial tropics, zodiac circle (ecliptic) and horizon for the latitude of Belgrade from the north celestial pole to the equator plane. The observed motions of celestial objects are realized by a set of clock gear trains with properly calculated gear ratios. The method of continued fraction is applied in the computation of proper and practically applicable gear ratios of the clock gear trains. The fully operational 3D model of the astronomical clock is created and the motion study of its operation is accomplished by using the SolidWorks 2016 application. The simulation results are compared with the ephemeris data and the detected differences are used to evaluate the long-term accuracy of the astronomical clock operation. The presented methods of the clock mechanism synthesis can be useful for the design, maintenance and conservation of large-scale city astronomical clocks since these clocks represent a precious historical and cultural heritage of European civilization.

The Wheel of Fortune

Chapter 4 looks at the early development of the mechanical clock. The fully mechanical clock may have been invented in southern England around 1280, possibly at Dunstable Priory in Bedfordshire. One line of evidence derives from a commentary on Sacrobosco’s De Sphaera Mundi by Robertus Anglicus, written in 1271. The chapter discusses subsequent developments and, in particular, the life and work of Richard of Wallingford, who rose from humble beginnings to become Abbot of St Albans. In 1327 he wrote Tractatus Horologii Astronomici (Treatise on the Astronomical Clock). The manuscript was rediscovered by John North in 1965, and it has been used to reconstruct Wallingford’s clock, which is now on display in St Albans Cathedral.