Copy observations with the pendulum clock and dipping needle, by Edward Sabine Copy records of observations with Browne's dipping needle on the Isle of Brassa, Shetland, with magnetic force observations; and records of the running of the No.2 pendulum clock against Earnshaw's chronometers, with barometer and hygrometer readings, also on Brassa Island. Observations compiled during the Arctic North-West Passage expedition led by Sir John Ross (1777-1856) aboard HMS 'Isabella' and accompanied by HMS 'Alexander' under Lieutenant William Edward Parry. The expedition reached Lancaster Sound at the north end of Baffin Island and entered Lancaster Sound. April-May 1818