A Collection of Maritime Coastal Charts of Indian Ocean, Including Madagascar.

A Collection of 23 Maritime Charts of Indian Ocean, including Madagascar, The Seychelles and the Malacca Strait, copper engraved, mostly double-page, many with coastal profiles, vignettes, inset charts, former working maps, cancelled stamp from the Admiralty on some charts, some wear and position markings, London, published by the Admiralty, [1822- 1935] Updated c.1930s

These surveys are by some prominent officers and hydrographers. Some ships that took part in the surveying include H.M.S. Leven, H.M.S. Barracouta, H.M.S. Alert, H.M.S. Waterwitch, H.M.S. Magpie and H.M.S. Clio

Comprising of: Sokotra, 1835; Sokotra, 1835; The Seychelles Group with the Amirante and Other Outlying Islands, 1882; Cape St. Andrew to Antongil Bay, 1822-6; Penang Harbour, 1884; Achin Head to Diamond Head, 1872-74; Cape St. Andrew to Bevato I, 1873; Delagoa Bay to Cape Guardafui including Mozambique Channel and Madagascar I…, 1881; Pulo Berhala to Cape Rachado, 1895; Klang Strait and Approaches, 1908; North Approach to Klang Strait, 1909; Indian Ocean, Northern Portion, 1912; Butang Group to Pulo Berhala, 1913; Diamond Point to Pulo Berhala, 1913; Indian Ocean - Northern Portion, 1923; Pulo Berhala to Cape Rachado, 1923; North West Part of Sumatra and the Off-Lying Islands, 1928; Ujong Porola to Ujong Raja, 1929; Malacca Strait with Part of the East Coast of the Malay Penninsula, 1929; Penang Harbour, 1930; Cape Rachado to Singapore, 1932; Indian Ocean - Northern Portion, 1937.

These Admiralty charts or hydrographic charts were produced by the British Admiralty. The Hydrographic Office was established as a sub-department of the Admiralty in 1795 and issued its first officially published Admiralty chart in November 1800.

Most Admiralty charts delineate the coastline and high and low water marks, and record the depth of water as established from soundings. They record navigational hazards such as reefs and wrecks, and navigational aids, such as lights, buoys and beacons. Most charts have a compass indicator, often an elaborate compass rose. They also have some indication of scale, either a scale bar or representative fraction, or a border showing degrees of latitude and longitude.

One of the characteristics of an Admiralty chart is that it is continually updated and corrected. Obsolete charts were regarded as dangerous and were to be destroyed because they presented a potential navigational hazard. Dates of survey and compilation are minutely recorded, as are those of the corrections continually made to maintain the accuracy and utility of the chart. These corrections were often made by amending the existing copper plates on which the chart was engraved and re-publishing it as a new edition; in other instances, the chart was completely re-drawn. However, in the early years of the Hydrographic Office, published Admiralty charts were drawn on earlier surveys. In extreme cases this means that some charts may be based on surveys made more than a century earlier. For example, Admiralty chart 751, the chart of Maculla Bay which was listed in the first published catalogue of 1825, bears a survey date of 1703. They are also numbered in manuscript to record when they were updated.

Some Admiralty charts contain little information on areas inland of the foreshore other than that required to assist in making a landfall. Others include extensive representations of land features and may also have coastal elevations and topographic views as insets. Nineteenth-century charts in particular may include ground plans of sites of archaeological interest, or details of coastal forts and other defences, as well as pictures of natural features. Some insets contain detailed charts of harbours. Admiralty charts record names given to coastal features and include many names no longer in use today. In many instances they also provide the best and most easily accessible maps of small oceanic islands. Some charts record surveys of navigable rivers.