Temperature observations at sea, on a voyage from Madras [Chennai], India to Alderney, Channel Islands, by Robert Barker Daily temperature readings at sea, taken at 8am, midday, and 8pm, with remarks on the weather, particularly winds and rain, and [from 21 February] noon observations of latitude and longitude. On 21 May the [unnamed] vessel anchored off St. Helena, and Sir Robert Barker took the thermometer ashore. Observations ceased, to re-commence on board from 7 June. Commencing: 'Observations of the Thermometer taken in a Passage from Madras [Chennai] to England commencing the 13 of [March - deleted] February 1774'. 13 February-16 August 1774