Minutes of Board of Longitude meetings regarding, among other matters, tables devised by José Mendoza de Ríos; correspondence with John Crosley (the astronomer with the expedition to New South Wales); a claim for a reward for Charles Mason's work on lunar tables; a report on the Arnold and Earnshaw chronometers going on the voyage of Captain Matthew Flinders; grants and awards to chronometer-makers; the observations of Nathaniel Bliss when he was Astronomer Royal; models of watch escapements produced by John Arnold and Thomas Earnshaw; methods of calculating refraction and parallax; observations made by Captain and Lieutenant Flinders; Edward Massey's patent log and sounding machine; a method of observing the eclipses of Jupiter's satellites at sea invented by John Playfair; the appointment of Thomas Young as Secretary to the Board of Longitude; the establishment of an observatory at the Cape of Good Hope; Rowland's pendulum quadrant; the voyages of HMS 'Hecla' and HMS 'Griper' to the north of America, including questions asked of the officers of these vessels on their return; questions asked of various chronometer-makers about their inventions, with answers; a joint proposal with the Académie des Sciences, Paris, to measure the exact distance between Dover and Calais; the first years of the Cape Observatory under Fearon Fallows; the re-measurement of Lacaille's arc of the meridian; observations of a biennial comet in 1823; the trials of various chronometers and other timepieces; and matters relating to computers and comparers.