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  1. Elly Dekker (2011). The Provenance of the Stars in the Leiden Aratea Picture Book. Journal of the Warburg and Courtauld Institutes 73 (1):1-37.
     
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  2. Elly Dekker (2008). Ordering the Heavens: Roman Astronomy and Cosmology in the Carolingian Renaissance. Early Science and Medicine 13 (5):514-515.
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  3. Elly Dekker (2008). 'With His Sharp Lok Perseth the Sonne': A New Quadrant From Canterbury. Annals of Science 65 (2):201-220.
    Summary This paper describes a medieval instrument, a quadrans novus, which turned up during archaeological works in England. The invention of the instrument by Profacius in 1288 is discussed in terms of two other medieval instruments, the quadrans vetus and the common astrolabe. The characteristics of the present instrument are compared with those of the seven other known medieval quadrants. It is shown that the new quadrant was made in England for explicit use with the Sun.
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  4. Elly Dekker (2006). An Unrecorded Medieval Astrolabe Quadrant From C. 1300. Annals of Science 52 (1):1-47.
    A detailed description of an as yet unrecorded astrolabe quadrant in a private collection is presented. A date between 1291 and 1310 is deduced from the calendrical data engraved on it. The characteristics of the newly recorded instrument have been compared with those of six other medieval astrolabe quadrants. The newly recorded instrument appears to present an early, if not the earliest, stage of development in the history of the astrolabe quadrant. In the comparison the newly recorded instrument is also (...)
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  5. Elly Dekker (2006). The Copernican Globe: A Delayed Conception. Annals of Science 53 (6):541-566.
    The impact on globe making of the change from a Ptolemaic to a Copernican world-view is examined. As well as showing a map of the Earth and the Heavens, the main use of globes originally was to demonstrate the natural phenomena as these are observed from a geocentric perspective. In the second half of the eighteenth century some belated attempts were made to construct so-called Copernican globes for this purpose. This late response did not stop the production and use of (...)
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  6. Elly Dekker & Kristen Lippincott (1999). The Scientific Instruments in Holbein's Ambassadors: A Re-Examination. Journal of the Warburg and Courtauld Institutes 62:93-125.
  7. Elly Dekker (1993). Epact Tables on Instruments: Their Definition and Use. Annals of Science 50 (4):303-324.
    This paper examines the purport of epact tables encountered on scientific instruments, and explains their use. The epact is a valuable chronological aid for calculating the age of the moon. In handbooks of chronology, usually two types of epacts are distinguished: the epact used in medieval times, and the so-called Lilian epact used after 1582 in the Gregorian perpetual calendar. By examining the rules for calculating the age of the moon, it turns out that the Julian and Gregorian epacts encountered (...)
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  8. Gerard L'E. Turner & Elly Dekker (1993). An Astrolabe Attributed to Gerard Mercator,C.1570. Annals of Science 50 (5):403-443.
    The Istituto e Museo di Storia della Scienza, Florence, Italy, possesses an astrolabe with five latitude plates that is now attributed to the Duisburg workshop of Gerard Mercator. Although it is known that Mercator made instruments, this is the first surviving example to be identified. Another latitude plate is shown to come from the workshop of the Florentine, Giovan Battista Giusti. A seventh plate, possibly engraved by Rumold Mercator, provides the only known Mercatorian polar stereographic projection. The role of Egnazio (...)
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  9. Elly Dekker (1990). The Light and the Dark: A Reassessment of the Discovery of the Coalsack Nebula, the Magellanic Clouds and the Southern Cross. Annals of Science 47 (6):529-560.
    Early observations of the southern celestial sky were reported in many sixteenth-century books and compilations of voyages of discovery. Here we analyse these accounts in order to find out what was really seen and reported by the first navigators. Our analysis had resulted in new interpretations of the phenomena reported by Amerigo Vespucci and Andreas Corsali. Thus, a reassessment of the discovery of the Coalsack Nebula, the Magellanic Clouds, and the Southern Cross can be made. From a comparative review of (...)
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