Gears from the Byzantines: A portable sundial with calendrical gearing

Summary The Science Museum, London, has recently acquired four fragments of a portable sundial with associated calendrical gearing. All the fragments are made of low zinc brass of substantially the same composition. The sundial is of a type known in other examples, some the products of recent archaeological excavations and all dated to the Late Antique or Early Byzantine period. Dating by the place names included in the latitude table, by the style of the heads of the planetary gods used to identify the days of the week, and by the style of the script, all indicate that the instrument dates from the late fifth century of the Christian era or the first half of the sixth. The gearing, of which two arbors survive, carrying four toothed wheels and one ratchet, seems to have resembled that of a calendrical device described by al-Bīrūnī in about AD 1000. Like al-Bīrūnī's device and the geared calendar associated with a Persian astrolabe of AD 1221/2 now in the Museum of the History of Science, Oxford, the Byzan...

[1]  R. Gunther,et al.  Astrolabes of the World , 1933 .

[2]  Derek J. de Solla Price,et al.  Gears from the Greeks: The Antikythera Mechanism—a Calendar Computer from ca. 80 B.C. by Derek de Solla Price (review) , 1974 .

[3]  M. T. Wright,et al.  Early Gearing: Geared Mechanisms in the Ancient and Mediaeval World: , 1985 .

[4]  O NEUGEBAUER,et al.  The exact sciences in antiquity. , 1952, Acta historica scientiarum naturalium et medicinalium.

[5]  Donald R. Hill,et al.  Al-Bīrūnī's mechanical calendar , 1985 .

[6]  Robert S. Brumbaugh,et al.  Ancient Greek Gadgets and Machines , 1968 .

[7]  O. Pedersen.  A survey of the Almagest , 1974 .

[8]  J. Needham.  Science and civilisation in China , 1963 .

[9]  Georgios Gounaris.  ANNEAU ASTRONOMIQUE SOLAIRE PORTATIVE ANTIQUE, DCOUVERT PHILIPPES * , 1980 .

[10]  F. H. Colson.  The Week: an Essay on the Origin and Development of the Seven-day Cycle , 2015, Nature.

[11]  E. Zinner.  Deutsche und niederländische astronomische Instrumente des 11.-18. Jahrhunderts , 1956 .

[12]  Derek Price.  Portable Sundials in Antiquity, including an Account of a New Example from Aphrodisias , 1969 .

[13]  Derek J. de Solla Price,et al.  Automata and the Origins of Mechanism and Mechanistic Philosophy , 1964 .

[14]  Sharon L. Gibbs.  Greek and Roman Sundials , 1976 .

[15]  A. G. Drachmann.  THE PLANE ASTROLABE AND THE ANAPHORIC CLOCK , 1953 .

[16]  Otto Neugebauer,et al.  A History of Ancient Mathematical Astronomy , 1975 .

[17]  O. Neugebauer.  The Early History of the Astrolabe , 1983 .

[18]  O. Neugebauer,et al.  The Early History of the Astrolabe. Studies in Ancient Astronomy IX , 1949, Isis.

[19]  R. F. Tylecote,et al.  A History of Metallurgy , 1976 .

[20]  R. Gunther.  Early Science at Oxford , 2022, Nature.

[21]  Derek Price,et al.  Gears from the Greeks : the Antikythera mechanism, a calendar computer from ca. 80 B.C. , 1974 .

[22]  G. Brett.  The Automata in the Byzantine "Throne of Solomon" , 1954, Speculum.

[23]  H. Stern.  Le Calendrier de 354 , 1953 .