Copy of draft letter, from Sir John Herschel to George Biddell Airy, dated at Collingwood Copy of draft letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Has read the syllabus of George Biddell Airy's lectures on magnetism; it reminds John Frederick William Herschel of his attempt to solve the problem of 'Mahomet's coffin', which John Frederick William Herschel still believes would work. 8 May 1869