Astronomical reductions and observations, including an eclipse of 25 June 1767; the Sun's place and an eclipse at Greenwich, 3 June 1769; an extract from a letter by Captain Wallis, 20 June 1771; and an account of experiments carried out on board the vessel 'Carcass' on a voyage to the north pole with Captain Phipps. The observations were made on 3 June - 10 July 1772 for latitude and longitude as determined by Arnold's chronometer and Kendall's watch. Other experiments were performed on magnetic variation and dip, temperature at different depths in the oceans and lunar observations.