[14] First published by O. Benndorf, E. Weiss, and A. Rehm, _Jahreshefte des österreichischen archäologischen Institut in Wien_, 1903, vol. 6, pp. 32-49. I have given further details of its construction in _A history of technology_, ed. Singer, Holmyard, and Hall, 1957, vol. 3, pp. 604-605. [15] L. Maxe-Werly, _Mémoires de la Société Nationale des Antiquaires de France_, 1887, vol. 48, pp. 170-178. [16] The first definitive account of the Antikythera machine was given by Perikles Rediadis in J. Svoronos, _Das Athener Nationalmuseum_, Athens, 1908, Textband I, pp. 43-51. Since then, other photographs (mostly very poor) have appeared, and an attempt at a reconstruction has been made by Rear Admiral Jean Theophanidis, _Praktika tes Akademias Athenon_, Athens, 1934, vol. 9, pp. 140-149 (in French). I am deeply grateful to the Director of the Athens National Museum, M. Karouzos, for providing me with an excellent new set of photos, from which figures 6-8 are now taken. [17] H. Diels Über die von Prokop beschriebene Kunstuhr von Gaza, _Abhandlungen, Akademie der Wissenschaften_, Berlin, Philos.-Hist. Klasse, 1917, No. 7. [18] L. A. Mayer, _Islamic astrolabists and their works_, Geneva, 1956, p. 62. [19] The translation which follows is quoted from J. Beckmann, _op. cit._ (footnote 1), p. 349. [20] E. Wiedemann, "Ein Instrument das die Bewegung von Sonne und Mond darstellt, nach al Biruni," _Der Islam_, 1913, vol. 4, p. 5. [21] I acknowledge with thanks to the Curator of that museum the permission to reproduce photographs of this instrument. It is item 5 in R. T. Gunther, _Astrolabes of the world_, Oxford, 1932. [22] Abulcacim Abnacahm, _Libros del saber_, edition by Rico y Sinobas, Madrid, 1866, vol. 3, pp. 241-271. The design of the instrument has been very fully discussed by A. Wegener, "Die astronomischen Werke Alfons X," _Bibliotheca Mathematica_, 1905, pp. 129-189. A more complete discussion of the historical evolution of the equatorium is given in Derek J. Price, _The equatorie of the planetis_, Cambridge (Eng.), 1955, pp. 119-133. [23] E. Wiedemann, and F. Hauser, "Über die Uhren im Bereich d. islamischen Kultur," _Nova Acta; Abhandlungen der königliche Leopoldinisch-Carolinische Deutsche Akademie der Naturforscher zu Halle_, 1915, vol. 100, no. 5. [24] E. Wiedemann, and F. Hauser, _Die Uhr des Archimedes und zwei andere Vorrichtungen_, Halle, 1918. [25] The manuscripts in question are as follows: Gotha, Kat. v. Pertsch. 3, 18, no. 1348; Oxford, Cod. 954; Leiden, Kat. 3, 288, no. 1414, Cod. 499 Warn; and another similar, Kat. 3, 291, no. 1415, Cod. 93 Gol. [26] H. Schmeller, Beiträge zur Geschichte der Technik in der Antike und bei den Arabern, Erlangen, 1922 (_Abhandlungen zur Geschichte der Naturwissenschaften und der Medizin_ no. 6).