Magnetic variation observations at Padre's House, Fernando de Noronha, [Atlantic Ocean, Brazil], by Henry Foster and others Daily magnetic observations, in three columns, recording hourly position of the north end of the dip needle [degrees, minutes, seconds] at appointed observation times, with temperature [in Fahrenheit]. With a title page: 'Horary Variation of a Magnetic Needle Padre's House Island of Fernando Noronha'. Each page is headed: 'Observations on the Horary Changes of a Magnetic Needle, at Fernando de Noronha'. 23 June-15 July 1830