Matthew Flinders - an unsung hero
by Jim Murrant

Each year on 16 March Annie and I celebrate the anniversary of the birth of Matthew Flinders by raising a glass in his name. Why? Because he discovered and 'cured' deviation. I consider him to be a sailing and scientific genius, who was also the first man to sail around Australia.

Flinders was one of that remarkable group of Royal Navy navigators - Cook, Bligh, Vancouver, Furneaux etc. - who were the space travellers of their day. They were not simply great and daring sailors. They were also great practitioners of the complex mathematics that went into knowing where they were. Accurate chronometers, essential for calculating longitude, had only just been designed. Their development was so rapid that by the time Flinders was retracing some of Cook's courses along Australia's east coast he was able to correct some of the master's observations.

A thing to bear in mind is the smallness and tightness of this group, even across several decades. Bligh was sailing master to Cook and so learned from him. Flinders was sailing master to Bligh. Furneaux commanded the Adventure, which was the second vessel in Cook's second voyage. And so it went on.

In my view, as well as being one of the great navigators and explorers, Flinders was a scientific genius. He discovered deviation of the compass (although he did not name it) and he could not have done so unless he possessed the kind of mind that scientists use when they collect data in an orderly fashion, correlate it and come to a conclusion from it.

In his book, A Voyage to Terra Australis, Flinders records how his observations, and the unexplained movements of the Investigator's compasses, made him realise there were movements - apart from variation - which deflected the needles according to a pattern.

His attention to detail, his meticulous recording of all that he did and his obsession with accuracy were what allowed him to compare the observations of one day with those of the next and to see whether they had changed. So he was able to see that when metal objects were placed near the compass the needle moved. This led him to move the nearby guns. What surprised him was that this did affect the compass, but not to the extent that he had expected.

After more, similar, experiments he realised that it was the magnetic field of the entire vessel that affected the compass. This discovery alone meant that compass errors of anything up to 30 degrees could be avoided, a fantastic improvement in accuracy.

But the explorer's work did not finish there. By taking observations when his ship was at anchor he was able to observe that the deviation of the compass changed according to the ship's heading. So then he devised a system close to the modern method of swinging the compass to enable a navigator to know what deviation to allow for on any particular heading on any particular ship.

As if it were not enough, 200 years ago, to have brought the accuracy of the steering compass to its present level, Flinders discovered a method of counteracting any ship's internal magnetic field. He worked out that small adjustable magnets built into the binnacle could, in the hands of a skilled adjuster, correct the compass to be accurate at all times.

These magnets are installed on any vessel - sail or steam - large enough to have the steering compass in a binnacle. This includes the USS Constitution and all its sister ships, the QM2 and all similar liners, every large ferry in the world and all the world's commercial and military vessels.

In recognition of his work these correcting magnets are called Flinders Bars. It is impossible to calculate how many lives, how many cargoes, how much grief Flinders has saved. This is why I say he is underestimated. He has not been given his true place in history.