On the development of the equatorium see PriceDerek J. (ed.), The Equatorie of the Planetis (with linguistic analysis by WilsonR. M.) (Cambridge, 1955); PoulleEmmanuel, “L'Equatoire de Guillaume Gilliszoon de Wissekerke”, Physis, iii (1961), 223–51; PoulleEmmanuel and MaddisonFrancis, “Un Equatoire de Franciscus Sarzosius”, Physis, v (1963), 43–64; NorthJohn, “A post-Copernican equatorium”, Physis, xi (1969), 418–57. For a preliminary survey of the development and cultural context of mechanized equatoria and celestial models, see TurnerA. J., The clockwork of the heavens … (London, 1973).
2.
For a full survey of the fortunes of the astrarium, together with a brief life of de' Dondi, an appreciation of the significance of the instrument, and a copious bibliography, see BediniSilvio A. and MaddisonFrancis R., “Mechanical Universe, the astrarium of Giovanni de' Dondi”, Transactions of the American Philosophical Society, ns, lvi, 5 (1966).
3.
The details and relevant documents for this episode are given in Bedini and Maddison, op. cit., 37–41.
4.
The myth that the clock collection of Charles v, including the astrarium, remained at San Yuste and perished there when the convent was burnt during the peninsula wars on the orders of Marshal Soult was finally buried by Bedini and Maddison (op. cit., 39–40). It has unfortunately been recently exhumed in The Dondi clock, modern reconstruction of Dondi's astronomical clock of 1364, Science Museum take-away leaflet (London, 1975). For Charles v at San Yuste with a brief account of Torriano, see StirlingWilliam, The cloister life of the Emperor Charles the fifth (London, 1852), especially 51–52, 88–89, and 228.
5.
The failure of direct references does not necessarily mean that de' Dondi's instrument ceased to have influence. There are several references in sixteenth and seventeenth century writings to elaborate mechanized astronomical models which, although ascribed elsewhere, do, in fact, refer to de' Dondi's instrument. A common mistake was to credit a repairer as the maker of the device which he had restored. Gulielmus Zelandinus was thus credited by Girolamo Cardano as the maker of the astrarium (Bedini and Maddison, op. cit., 37–38) and Torriano was similarly believed by later writers to have designed the whole machine himself. The passing reference by William Derham (The artificial clockmaker (London, 1696), ch. ii, sect. 5) to astronomical models by William of Zeland and Janellus Turrianus may therefore be interpreted as referring to Dondi's original astrarium which William of Zeland (= Gulielmus Zelandinus = Willem Gilliszoon) had repaired, and to Torriano's copy. The survival of this kind of intellectual ‘folk-memory’ may have been of some importance in stimulating sixteenth and seventeenth century clockmakers to emulation.
6.
“Giovanni de' Dondi and his planetarium clock, 1364”, Horological journal, April and May 1934, 1–12.
7.
BaillieG. H., Clocks and watches, an historical bibliography (London, 1951).
8.
de Solla PriceDerek J., “On the origin of clockwork, perpetual motion devices and the compass”, Contributions from the Museum of Science and Technology (U.S. National Museum bulletin no 218), vi (1959), 81–112.
9.
Baillie, Clocks and watches, 1. Since Baillie speaks of the Turin manuscript as existing when, in fact, it had been destroyed by fire in 1904, it is likely that he may not have seen some of the other manuscripts which he mentions.
10.
The most important of these are “Giovanni de Dondi's horological masterpiece, 1364”, La Suisse horlogere (international edition), 49–71; Some outstanding clocks over seven hundred years, 1250–1950 (London, 1958); “Il Capolavoro d'Orologeria di Giovanni de' Dondi”, La Clessidra, xvii (1961), 9–11; Old clocks, fourth edition, revised and enlarged (London, 1970), 171–201.
11.
The reconstruction was completed in 1961 and is now in the Smithsonian Institution, Washington. Three other reconstructions like the first built by Mr HawardP. N. exist. They are now in The Time Museum, Rockford, Illinois; The Bayer Collection, Zurich; and The Science Museum, London. A fourth reconstruction was built for the I.B.M. Exhibition, New York, by Mr TrickiJ. J. under Mr Haward's direction. At present it may be seen at the Hayden Planetarium, New York. In addition a small number of copies of the dial of Mercury only have been made.
12.
Giovanni Dondi dall' Orologio, tractatus astrarii …, Biblioteca capitolare de Padova Cod D. 39. Introduzioni, transcrizione e glossario a cura di Antonio Barzon, Enrico Morpurgo, Armando Petrucci, Giuseppe Francescato, con la riproduzione fotografica del codice (Codices ex ecclesiasticus Italiae bibliotechis selectis phototypice expressi …, ix) (Vatican City, 1960).
13.
Pippa's reconstruction, which followed the Padua manuscript and differs in detail from that produced by Thwaites & Reed, is now in the Museum of the History of Science and Technology, Milan.