Lunar Eclipses, Longitude and the New World

  title={Lunar Eclipses, Longitude and the New World},
  author={M. Portuondo},
  journal={Journal for the History of Astronomy},
  pages={249 - 276}
  • M. Portuondo
  • Published 1 August 2009
  • Geography
  • Journal for the History of Astronomy
Throughout the first hundred years after the discovery of the New World late in the fifteenth century, determining the location and extent of their overseas domains was a principal preoccupation of the Spanish empire. Not only were terrestrial coordinates vital for navigation, but following the 1494 Treaty of Tordesillas, knowing with certainty the location of newly discovered territories carried significant geo-political implications as well. Further complicating the matter were the technical… 
5 Citations

Figures and Tables from this paper

O astrolábio, o mar e o Império
Based on certain texts written by Portugal’s cosmographers of the kingdom between the sixteenth and eighteenth centuries, we bring to light the technical and scientific foundations for the European
Recent publications
Alexanderson, G L, ‘About the cover: Christopher Clavius, astronomer and mathematician’, Bulletin of the American Mathematical Society, 46 (2009), 669–672. Almira, J M, and Romero, A E, ‘A note about
La medición de un imperio: reconstrucción de los instrumentos utilizados en el proyecto de López de Velasco para la determinación de la longitud
The article discusses the graphical reconstruction of the instruments to determine longitude by observing lunar eclipses, described in Lopez de Velasco’s project to map the New World. Finally, a
La sélénographie au XVIIe siècle : support des interrogations géographiques et espace de projection des enjeux politiques, intellectuels et institutionnels
Developpee dans la premiere moitie du dix-septieme siecle, la cartographie lunaire, dite selenographie, a ete concue comme un instrument pour l’augmentation du savoir des longitudes par des methodes
Darkness and Din
Abstract This contribution is part of a special issue on History and Human Nature, comprising an essay by G.E.R. Lloyd and fifteen invited responses.


Observations and Predictions of Eclipse Times by Early Astronomers
Preface. I: Introductory Orientations. 1. Introduction. II: The Western Heritage. 2. Mesopotamia. 3. The Greco-Roman World. 4. The Islamic Near East. 5. Late Medieval and Renaissance Europe. III: The
Gemma Frisius, His Method of Determining Differences of Longitude by Transporting Timepieces (1530), and His Treatise on Triangulation (1533)
Comments on and text of: 1. De novo modo inveniendi longitudinem (chapter XVIII of De usu globi, in Gemma's De principiis astronomiae et cosmographiae, Antwerp, 1530); 2. the first treatise on
Alfonsine Meridians: Tradition versus Experience in Astronomical Practice c. 1500
Angelus publia en 1510 un almanach qu'il declara etre fonde sur de nouvelles tables planetaires qui modifierent les algorithmes des tables alphonsines et permirent d'ameliorer la prediction des
I discuss a number of additional observations and reports, as well the historical context of the eclipse project
  • chaps. 6 and 7 of my Secret science: Spanish cosmography and the New World
  • 2009
For more on the reform see M. I. Vicente Maroto and Mariano Esteban Piñeiro, Aspectos de la ciencia aplicada en la España del Siglo de Oro
  • 2006
Regiomontanus preferred to calculate eclipse local contact times from altitude observations made during the eclipse and to determine times using spherical trigonometry
  • Cosmographicus liber Petri Apiani mathematici studiose collectus (Landshut, 1524)
  • 1998
Edwards’s opinion is echoed
  • 1996
Steele cites only seven astronomers known to have systematically observed eclipses during the period 1200-1600
  • Observations and predictions of eclipse times by early astronomers (Dordrecht and
  • 1996
Los cosmógrafos al servicio de Felipe II
  • 1995
Astronomers throughout the sixteenth century routinely complained about the predictive accuracy
  • Tycho expressed his concern in his correspondence. Victor E. Thoren, The Lord of Uraniborg (Cambridge,
  • 1990