The Nuttall Encyclopedia
A marshy, well-wooded island at the mouth of the Gulf of Riga, in the Baltic, 45 m. long and 25 m. of average breadth; has some low hills and precipitous coasts; Arensburg, on the SE. shore, is the only town; Danish from 1559, the island passed to Sweden in 1645 and to Russia in 1721; the wealthier classes are of German descent.
Wood, James, ed. Entry for 'Oesel'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/o/oesel.html. Frederick Warne & Co Ltd. London. 1900.