Sextant Appeal


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In discussions about the instruments promoted and developed by the Board of Longitude, an observation I have noticed reoccurring is one that suggests the development of the marine timekeeper and Nautical Almanac mirror the more recent development and use of satellite navigation systems. As far as the comparison goes, the suggestion is that both are about 'telling you where you are', and that satellite navigation systems do it better. While such a comparison can obviously be useful, I find it misleading. Firstly, and for reasons I won't dwell on here, the roles and uses of various technologies and instruments can often be very different according to task and purpose. Secondly, that it often leads to a discussion that accepts as a basic premise a triumphant ascendancy from the Board of Longitude-backed technologies (marine timekeepers, sextants etc.) to the innovation of satellite navigation systems. I find that such story of technological progression can be problematic for several reasons.

The first, is that these conversations tend to reduce the comparison of such objects to the instruments themselves, leaving little or no room for the agency of human action. Consequently, there is very little discussion of the quality and scale of the active role involved in the constant maintenance work that goes into making these very different systems perform. In the case of satellite navigation systems, this involves an incredible ensemble of human roles, working on and around a whole ensemble of different expensive technologies, often linked together by humans: a human using a navigation system in a car involves not only the extended system that makes a GPS system work, but also a working car, a serviced road and so on.

The second, and perhaps more important point is the effort to which humans actively seek to adapt to technologies, like GPS, or eighteenth and nineteenth century methods of finding longitude, so as to try and make them work. Adaption is rarely expansion, so that when it is claimed that GPS better helps people 'know where they are', it also entails 'knowing where you are in a particular way', to the detriment or exclusion of the myriad ways of understanding and communicating 'where you are'. This particular way can be a specific representation of time and space that is accepted by the user to be useful – either simply between the technology and them-self, or between the user and someone else they wish to communicate their location to.

The relationship between an instrument, its users, and the audience to whom to communicate the results relies on an incredible amount of labour and adjustment, the extent of which is generously demonstrated in the archives of the Board of Longitude.

One particular episode involves Captain Matthew Flinders and his brother and Lieutenant, Samuel Ward Flinders on their 1801-3 voyage to chart the eastern coast of New Holland (Australia) on board HMSInvestigator. For this voyage, they had been assigned by the Board of Longitude an astronomer called John Crosley who was tasked to take charge of the Board's many instruments for navigation and surveying and for the deployment and entry of their results. Unfortunately for Matthew Flinders, John Crosley had to leave at the Cape of Good hope owing to ill-health, and by the time the Board had sent out another astronomer to Port Jackson, the voyage had already ended as the Investigator had been too badly damaged to continue sailing.

Much of the attention this voyage has received has followed the subsequent imprisonment of Captain Matthew Flinders by a French garrison on the island of Mauritius, and Flinders' despairing letters to his family and to the Board of Longitude about getting back to England and having his observations published. However, the experience of his brother, Samuel Ward, and his relationship with the Board of Longitude is equally as interesting.

Following the departure of John Crosley from the voyage, it was decided that the duty for taking observations and testing the equipment to measure and record longitude would fall to Captain Flinders and his brother. However, due to the four timekeepers on board being deemed too faulty – they were, according to Captain Flinders, 'beyond repair' - and the fact that Matthew Flinders had too little time to make the required lunar observations, much of the work was left to Lieutenant Samuel Ward.

Midshipman, by Thomas Rowlandson [artist]; Merks [engraver]; R Ackermann [publisher], 15 February 1799. Repro ID: PW4970 ©National Maritime Museum, Greenwich, London.

Upon his return to England in 1804, Samuel Ward Flinders, upon instruction from his brother, presented his astronomical observations to the Board of Longitude in the hope that they would be used as the backbone for the official publication of the charts from the voyage, and in the hope that he would receive money for the work that had gone into their construction. But much to his despair, the Board of Longitude proved to be reluctant to accept the observations made by him as accurate. His skill as an astronomer and the trustworthiness of his claims were called to question, forcing him to write to several members of the ship's crew to testify to the quality of his character and to recall the nature of his work. Things were made harder for the Lieutenant, however, because of particular comments he had made in his 'Booklet of Observations', relating to his use of the Troughton Sextant No. 4 that he had used to make the astronomical observations which made up the rows of data communicating and tracing the ship's longitude. Flinders, making life much harder for himself, had mentioned the problems inherent in handling the Troughton sextant, stressing that the observations would only very nearly agree provided that great ‘pains are taken in the Observ g [sic]’. These ‘pains’ could only be remedied by ‘the Observer himself having no weight to sustain, that the arch of the sext t [sic] is not moved up to the eye to read off; & that the Obs ns [sic] are taken within 24 h of each other’. In other words, Samuel Flinders was admitting that to use the sextant according to its design was impossible.

This very physical experience of having to adapt the body to try and get the technology to perform is something that is demanded by all sorts of technologies. It should be remembered that the pains Samuel Flinders took in order to get a reading from the sextant was not the only way in which he could have understood and recorded 'where the ship was' – he could have, for example, described the flora and fauna encountered surrounding his ship. He could have also understood 'where he was' and communicated it in a very different way to a very different audience, as opposed to the abstracted set of lines and figures imposed from an imagined god-like vision of the globe. But it was the particular way in which the Board of Longitude wanted the position to be communicated, so as to present and construct this specific image of the globe, that meant that it was instruments like the sextant that became the things around which to adapt an understanding of 'where they were'. After his trials with the Board derived in part from a perceived ambiguous use of his sextant, Lieutenant Flinders was eventually paid, but only half the amount that was meant to be paid to an astronomer.

As an officer in the Royal Navy, Samuel Ward Flinders was exactly the kind of person the Board of Longitude and the Admiralty were targeting as potential consumers for the Nautical Almanac and the suite of precision instruments being developed through the Board of Longitude. When considering the relations between human experience and specific instruments and technologies that seek to represent and harness a specific image of time and space, a question worth asking is whether it is not actually a desirable thing that there was some room in which Samuel Ward Flinders could register his frustration in trying to make his experience correspond with that of the specificities of a sextant for the Board of Longitude

Many thanks go to my friend, Tom White, for help with the title.