In your dictionary: the language of longitude

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This appeared as a guest post by Katy for the OxfordWords blog run by Oxford Dictionaries ...

Words can be difficult and scary. Everyone has words that they can’t spell or can’t pronounce. I always say rhetoric wrong, and inevitably still get the ‘i’ and ‘e’ in receive the wrong way around. But words also scare us when they come with memories of difficult school lessons, or signify something that we only partially understand.

At the National Maritime Museum, we found that longitude is one such word, which can bewilder visitors. Should it be pronounced with a ‘g’ or a ‘dg’ sound in the middle? And do you spell it with a ‘d’ or not? It’s got something to do with geography – memories of hours spent colouring in maps for homework – and maybe something to do with time, but other than that it is somewhat of a mystery. In making our recent exhibition Ships, Clocks and Stars: the Quest for Longitude we had to think about how to minimize some of these concerns.

A hot topic

The exhibition was about the high-profile search to find a means of accurately measuring longitude at sea in the eighteenth century. My research into the visual and literary culture surrounding the problem showed, somewhat surprisingly, how much of a hot topic the problem became in the period. It cropped up in every conceivable type of play, poem, novel, pamphlet, treatise, joke, and print. It also appeared, of course, in dictionaries and what’s striking is how much the definition of the word longitude changed over the century. Even turning to that simple dictionary explanation of a tricky word, it seems, is not safe.

My favourite is Samuel Johnson. In the quotations that he chose to define longitude in hisDictionary of the English Language (1755-56), he beautifully crystallized a group of concerns and discussions that were floating around the idea of longitude in the period. Two of his quotations come from Dr John Arbuthnot, royal physician, man of science, and member of the group of satirical writers led by Jonathan Swift and Alexander Pope that are known as the ‘Scriblerians’. Johnson’s first quotation comes from Arbuthnot’s Essay on the Usefulness of Mathematical Learning published in 1701. It gives the basic definition of longitude as ‘the distance of any part of the earth to the east or west of any place,’ broadly what you will still find in

Finding longitude at sea

His second quotation, while attributed to Arbuthnot, comes from the Scriblerian groups’ greatest production The Memoirs of Martin Scriblerus, the absurd life of an obsessed and foolish man of letters who the group used to satirize and critique contemporary literature. They made him the author both of a series of ridiculous publications and schemes of their invention and, crucially, of those genuine contemporary writings that they thought absurd. Johnson quotes Martin’s proposal for finding longitude at sea, ‘his was the method of discovering the longitude by bomb vessels’, which was, in fact, a proposal made by the nonconformist scientist William Whiston for using rocket signals at sea.

The Scriblerians made Whiston a particular figure of fun because of his latitudinarian views (cue many witticisms on longitude and latitude) as well as his absurd longitude schemes. They saw his idea as just one of many ‘projects’ of the time, which were aimed naively or even maliciously at an investing public, to get money for ideas that could never work. The ‘South Sea Bubble’ of 1720 had been the most famous example of a ‘project’ in which thousands were reportedly ruined by unwise investment. Longitude became another example. Not only did Johnson make this an intrinsic part of his definition of what the word longitude meant, he also made longitude itself a definition of the word project. This he defined by a quotation from Joseph Addison’s Guardian in 1714, where Addison had opined that Whiston’s proposal ‘is discovering the longitude, and deserves a much higher name than that of a project.’ Johnson’s point, of course, was just the opposite.

Yet Johnson himself was not immune to hopeful longitude schemes. In the 1750s, while working on his Dictionary, he also became involved in helping the aging mathematician Zachariah Williams to write his own proposal for finding the longitude. So ubiquitous did such proposals become that  the word longitude was often confusedly used for the method of ascertaining longitude at sea: the meaning of the word became condensed to the contemporary problem. And which source provides a quotation to exemplify that very confusion? ‘Mr. Williams had made many ingenious advances towards a discovery of the longitude.’ (J. Boswell, The Life of Samuel Johnson).