A 200-year-old maritime navigation instrument, thought to have come from the wreck of the Amsterdam, has been discovered on the beach at Bluewater Bay. The strange device was spotted sticking out the sand by a party of Zwartkops Conservancy members who were cleaning up the beach recently after a storm.
Conservancy spokesman Jenny Rump, a former Herald Citizen of the Year, said (speaking May 15 2013) they thought at first it was just a piece of black plastic. When they examined it, they realised it was much older and more interesting.
Conservancy member and amateur maritime archaeologist Emile Hallaby got onto the internet, and identified it as an “octant” — a navigation instrument used in the 18th and 19th centuries before the advent of the sextant.
The find was referred to eminent maritime archaeologist Dr Jennie Bennie — who confirmed Hallaby’s identification.
“There was great excitement,” Rump said.
“It was particularly special for us because it was found right where the wreck of the Amsterdam was discovered.
“We cannot prove it – but our conclusion is that the octant comes from the Amsterdam.”
The wreck of the Amsterdam was discovered in 1985 after a period of very high seas, which exposed its position in the beach sand, 2kms north-east of the Swartkops River mouth.
Amsterdamhoek, the Port Elizabeth suburb running along the north side of the Swartkops estuary, was named after the ship. She was originally built in Holland as a man ‘o war, then converted to transport troops, and she ran aground in Algoa Bay in December 1817 while sailing home from Dutch territory in Southeast Asia.
Dutch ships of that era would have been carrying a range of exotic navigational equipment from compasses and slide rules to celestial globes, azimuths, astrolabes – and octants. The octant was invented by English mathematician John Hadley and the one found by Rump’s party was probably manufactured about 1800, Bennie said.
The instrument was used to measure the angle between a celestial body – usually a star but sometimes the sun or moon – and the horizon. The angle was then used to plot the position of the ship.
The device consisted of a frame with a 45° arc, graduated to show degrees and fractions of a degree; three mirrors; shades to allow the mariner to view a bright object; and a sighting
The one discovered on Bluewaterbay Beach is made of ebony, a very hard wood, which is probably the reason it survived two centuries, rough seas and harsh
Bennie has done an online survey of the octants in the Greenwich National Museum and has found four matchers. This research showed her that our octant would, in its original state, have included an ivory-topped pencil to allow the captain to jot down readings. This part is missing, together with brass fittings and an ivory plate with the maker’s name, which would also have been part of it.
But it is still a wonderful find, Bennie said.
“It’s great — amazing that an early 19th century octant can have survived our rough southern African seas.”
The Suez Canal was only opened in 1869 so, when the Amsterdam set sail from Holland in late 1815, she took what was considered to be the best route for the trade winds – south-west to Brazil, back across the Atlantic to the Cape of Good Hope, and then up to the Dutch East Indies. She arrived in the port of Batavia, in Java, six months later.
Having offloaded her 600 troops, and loaded up with sugar, coffee and arrack, a rum-like liquor, she took the same route home. Off the Eastern Cape coast, she encountered heavy seas and severe winds.
As Capt Hermanus Hofmeijer recorded in his journal, which Bennie had translated for her 1998 Rhodes doctorate – the wind ripped apart their sails, masts snapped and they began to take on water. After 11 hours of pumping, with the crew weak with exhaustion and the water still rising, he took the decision to purposely run aground, in order to save the lives of his men. The ship grounded on December 16 1817 “between the mouths of the Zwartkops and Coega rivers”. Three of the 220 crewmen drowned but the rest were saved.
Timber and some of the supplies were recovered together with several cannon. The biggest canon was installed outside the Uitenhage Court House.
Bennie is busy with further research on the octant and she has been in correspondence with various institutions around the world including the Scheepvaartmuseum in Amsterdam. Among the points of discussion has been the best method to preserve the instrument. This will probably involve soaking it in fresh water to get rid of the salt.
Once it has been fully researched, the octant will be installed either at Bayworld or in the Scheepvaartmuseum, she said.