Unpublished paper, 'Observations on magnetism' by John Macdonald Macdonald offers his explanation of the variation of the magnetic needle in view of the recent discovery of the northwest magnetic pole, which he suggests could be the sole point of magnetic attraction on earth, the North Pole being merely a point of reference. An ink inscription top left of first page reads '(Not to be printed)'. Minor corrections appear throughout in ink. Subject: Geodesy Written by Macdonald in Putney [London]. Read to the Royal Society on 23 January 1823. November 1822