A la rencontre de Sindbad; La route maritime de la soie (Paris: Musée de la marine, 1994), p.147 for similar example by Ferreira dated 1744.
Bennett, J. The Divided Circle: A history of instruments for astronomy, navigation and surveying (Oxford: Christie's, 1987), fig. 97.
Hitchins, H. & May, W. From Lodestone to Gyro-Compass (London, 1955).
May, E. A History of Marine Navigation (Henley, 1973).
Knight, G. 'A description of a Mariner's Compass Contrived by Gowin Knight M.B. F.R.S.', Phil. Trans., Vol. 46 (1749), pp.505-512.
Knight, G. 'An Account of Some Improvements of the Marniners Compass, in Order to Render the Card and Needle, Proposed by Doctor Knight, of General Use, by John Smeaton, Instrumen-Maker', Phil. Trans., Vol. 46 (1749), pp.513-517.
Lisbon, Salão de Antiguidades, 1964