Posts Tagged ‘Matthew Flinders’

Great Australian Bight

Friday, August 7th, 2009

My post about the Round Australia Race and Rally reminded me about my own voyage across the Great Australian Bight some years ago.

Cliffs along the Great Australian Bight

This photo was taken on our way across the Nullabor Plain to Perth. I’m glad to say that our delivery trip, which included a stop-over in Esperance to replace a lost mast, kept us well clear of these terrifying cliffs. There is no break in them for hundreds of miles.

I must restate my admiration for the skill and courage of Captain Matthew Flinders, who charted this coastline in 1802.

Matthew Flinders and deviation

Wednesday, March 18th, 2009

We’ve just uploaded an article, Matthew Flinders – an unsung hero. It’s about his place in our maritime history for discovering deviation of the compass.

Why not read the article and then return here to post your comments?

Magnetism

Friday, January 23rd, 2009

I’ve just finished reading A Pirate of Exquisite Mind: The Life of William Dampier: Explorer, Naturalist, and Buccaneer by Diana and Michael Preston. I was very impressed to read of the meticulous observations that Dampier made. In fact, his writings were carried by Charles Darwin on his voyage on the Beagle and held in high esteem by sailors such as Cook and Nelson. I knew that Dampier had charted part of the Western Australian coast in the 1685 but not that he made three circumnavigations.

My only quibble with an otherwise excellent book was the authors’ confusion between variation and deviation. As Matthew Flinders observed and defined deviation in the early 19th century, it is unlikely that the crew onboard with Dampier would have moved iron objects away from the compass to avoid its effects.

To clarify the two terms I have extracted the definitions below from The Language of the Sea*.

Variation. The angle between magnetic north and true north, it varies in different parts of the world, and may be either easterly or westerly. It is caused by the magnetism of the Earth.

Deviation. The amount of deflection of a compass needle caused by the magnetism of the vessel itself. The deviation is different according to the vessel’s heading.

There is much greater detail about these two concepts in Navigation and Passage Planning.

*Found in Skipper and Crew, Knots and The Language of the Sea.