section_path: Life/Work/Astronomical observations 1513–1516
section_name: Astronomical observations 1513–1516
paragraph_text: Astronomical observations 1513–1516
  
  In 1510 or 1512 Copernicus moved to Frombork, a town to the northwest at the Vistula Lagoon on the Baltic Sea coast. There, in April 1512, he participated in the election of Fabian of Lossainen as Prince-Bishop of Warmia. It was only in early June 1512 that the chapter gave Copernicus an "external curia"—a house outside the defensive walls of the cathedral mount. In 1514 he purchased the northwestern tower within the walls of the Frombork stronghold. He would maintain both these residences to the end of his life, despite the devastation of the chapter's buildings by a raid against Frauenburg carried out by the Teutonic Order in January 1520, during which Copernicus's astronomical instruments were probably destroyed. Copernicus conducted astronomical observations in 1513–1516 presumably from his external curia; and in 1522–1543, from an unidentified "small tower" (turricula), using primitive instruments modeled on ancient ones—the quadrant, triquetrum, armillary sphere. At Frombork Copernicus conducted over half of his more than 60 registered astronomical observations.