Magnetic and navigational observations made at Simon's Bay, South Africa, and at sea aboard by HMS Erebus [?], by [James Clark Ross?] Various tables made at the Cape of Good Hope, South Africa, the Simon's Bay locations variously noted as Admiral's Jetty, the Block House, and H.M.S. Erebus and H.M.S. Melville [pp.1-7]. These include 'Sights for time', 'Circumeridian altitudes', and rates of chronometers. Afterwards, there are a series of magneric and temperature observations at sea, by latitude and longitude. The paper cover is inscribed in ink: 'Cape'. There are two inserted sheets: one with a note initialled 'JCR' [James Clark Ross]; another headed 'Private notes' on natural history and minerals. 19 March-11 August 1840