Article ID: CBB995065632

Time signals for mariners in South Africa (2021)


The aim of this paper is to establish the nature of visual time signals for mariners that used to exist in South Africa. It builds on earlier research concerning the Royal Observatory at the Cape of Good Hope, using Admiralty lists of time signals, notices to mariners and other sources to show how they evolved. South Africa used an extraordinary range of time signals, including the first shuttered lamp in 1823, one of the earliest time balls and a wide range of subsequent time ball types. Various contradictions between different records have been found and resolved as far as possible. Initial ideas for precise chronometer calibration signals have been attributed to Robert Wauchope during his naval service at the Cape of Good Hope from 1818. The 1836 time ball at the Cape Observatory was constructed locally and supplemented by a manually-operated repeater ball at Lion's Rump in 1853. The Observatory ball was replaced in 1863 using an apparatus supplied from London. The Observatory time balls were not included in Admiralty lists from 1880 onwards. A time ball at Simon's Bay was added in 1857, later replaced by a disc and then by another time ball in 1898. Additional time signals were provided at Alfred Docks, Port Elizabeth, Port Alfred and East London. All were ultimately controlled by electric telegraph from the Cape Observatory. The first 1870s time ball at the Docks was replaced in 1894 and had increased elevation after 1904. A time ball at Durban in Natal was established in 1883 and relocated in 1904. The last time ball service in South Africa was withdrawn in 1934 when wireless and telegraph signals had become almost universally available. The Docks time ball was restored in 1997.

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Authors & Contributors
Grijs, Richard de
Kinns, Roger
Orchiston, Wayne
Hilster, Nicolàs de
Morfouli, Meropi
Jacob, Andrew P.
Journal of Astronomical History and Heritage
Royal Historical Society. Transactions
Imago Mundi: A Review of Early Cartography
Histoire & Mesure
Archives Internationales d'Histoire des Sciences
Archive for History of Exact Sciences
IOP Publishing Ltd
Oxford University Press
Kluwer Academic
Antiquarian Horological Society
Vrije Universiteit te Amsterdam (Netherlands)
Nautical astronomy
Instruments, navigational
Time measuring instruments
Longitude and latitude
Time measurement
Galilei, Galileo
Bond, family
Col. Thomas L. Thurlow
Smyth, Charles Piazzi
Lacaille, Nicolas Louis de
Fallows, Fearon
Time Periods
17th century
19th century
16th century
18th century
20th century
New Zealand
United Kingdom
Greenwich (England)
Cape of Good Hope (South Africa)
United States
Royal Observatory, Cape of Good Hope
National Maritime Museum (Great Britain)
Greenwich Observatory

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