Coming your way, 19 June… Finding Longitude

Yes, this is one big advert – but hey, this is my blog and you all know that I’ve been going on about longitude for long enough…

19 June 2014 sees the publication of Finding Longitude: How Clocks and Stars Helped Solve the Longitude Problem, written by me and my former National Maritime Museum colleague, Richard Dunn. It accompanies the exhibition Ships, Clocks & Stars: The Quest for Longitude, on at the NMM from 11 July 2014 – 4 January 2015.


Finding Longitude

I will admit that the front cover’s stormy seas, echoed in the exhibition publicity, is a little off the mark for longitude (stormy seas will get you whether or not you know where you are), but evidently drama and peril sell. We authors did, however, have (mostly) full control over the contents and many images that are inside. You can get a flavour of this from the “See Inside” feature on a well-known book-selling website that you will otherwise undoubtedly eschew.

Finding Longitude 2

The book largely follows the flow of the exhibition, but gives us a chance to go into more depth, provide additional stories and name more names : longitude was a very collective endeavour. It’s a story that starts well before the Longitude Act of 1714 and goes on until the middle of the 19th century: the voyages of HMS Beagle, which girded the Earth with a series of accurately determined locations, are our symbolic stopping point. We have space to be a little more international, although this is still certainly the story from the British perspective, and we have the luxury of being able to illustrate objects that could not fit in the exhibition or travel overseas.
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It’s available as a hardback (RRP £25), as a paperback special edition available at the Museum for the exhibition (titled Ships, Clocks & Stars: The Quest for Longitude) and as an eBook (RRP £9.99).
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Longitude Season has started…

There has already been plenty of longitude on this blog, The H Word and the Longitude Project blog, so apologies that there is more to come. This has all been leading up to 2014, the tercentenary of the first Longitude Act, and the start of Longitude Season at Royal Museums Greenwich. It seems like a good idea to put in one place where we’ve been and some of what’s happening this year.

The Board of Longitude Project logo.
The Board of Longitude Project logo.

First came the Board of Longitude Project. A five year, AHRC-funded research collaboration between the National Maritime Museum and the Department of History and Philosophy of Science at the University of Cambridge. The team is/was: Principal Investigator Simon Schaffer, Co-Investigators Richard Dunn (Senior Curator and Head of Science and Technology at NMM) and me; two postdocs (Alexi Baker and Nicky Reeves) and three PhD students (Katy Barrett, Eoin Phillps and Sophie Waring). Very shortly joining us as engagement officer is Katherine McAlpine.

Then came the brilliant digitisation project, a JISC-funded digitisation of the Board of Longitude archive, together with related papers from Cambridge University Library and the NMM. Because of its association with the research project and the Museum, this came with lots of add-ons beyond the scanning and listing, and you can read more on the site and at my Guardian post here.

This year is about delivery and public engagement: four exhibitions, two books and a conference (although there’ll be more scholarly books, collections and articles to come out of the project in following years).

Exhibitions

Already open at the Royal Observatory is Longitude Punk’d, which is a steampunk intervention (invasion?) into the courtyard and Flamsteed House that plays with existing spaces and displays, the themes of travel and longitude and with art/science, fact/fiction, real/fabricated. You can read more about it in this post by curator Heloise Finch-Boyer. It is inventive, playful and very funny, but can also confuse and is not necessarily to everyone’s taste. As a response to the problem of denuding the existing galleries in order to put on the main longitude exhibition (see below), it is really brilliant. Once the two exhibitions exist together I hope everyone will be happy! Hashtag is #LongitudePunk’d

Also at the Observatory is a small image and text display, Start to Satellites, about the development of satellite navigation, which takes the story of navigation well beyond the 18th and 19th one about longitude.

Next up will be the main event: Ships, Clocks & Stars: the Quest for Longitude, opening to the public on 11 July. It is an object-rich, historical telling of the story, supported by AV and interactives, with Richard Dunn as the lead curator, me (though my involvement has somewhat diminished since I left the museum) and an NMM team involving Kris Martin, Claire Warrior and Matt Lawrence. I hope it will be fab, and you will hear more anon! Hashtag is #ShipsClocksStars

Last to open will be Art and Science of Exploration, a rehang in The Queen’s House that focuses on the art surrounding the voyages of James Cook. It will be the first opportunity to have Stubbs’s kangaroo and dingo properly on show, alongside paintings by Hodges and Webber. In many ways it will be a natural extension of the main exhibition, which features a section on Cook’s voyages, a key testing ground for new longitude techniques. Hashtag is #ArtSciEx

There will be lots of events on during the run of the exhibitions, so keen an eye on the website. The hashtag for the season as a whole is #WhereOnEarth.

Books

The official book accompanying the exhibition has been written by Richard Dunn and me, and is published by Collins. Called Finding Longitude, it is already available on Amazon for pre-order. It’s available on Kindle and a paperback edition will be sold in the exhibition shop (with luck the hardback trade edition will also make it to paperback?). This follows the same narrative as the exhibition, taking the story well beyond Sobel’s John Harrison focus, and is beautifully illustrated with historical painting and objects. It is out on 19 June.

Out in the autumn is a collection of essays on Nevil Maskelyne, published by Hale Books, called Maskelyne: Astronomer Royal. I have edited it and there are chapters and sections by me, plus chapters by Jim Bennett, Mary Croarken, Nicky Reeves, Rory McEvoy, Alexi Baker, Caitlin Homes and Amy Miller, largely coming out of the symposium we held back in 2011. This should also be well-illustrated with images from the NMM’s collections and, although not in any way replacing Derek’s Howse’s biography of Maskelyne, adds some interesting different angles.

Conference 

The big conference for the project, and the exhibition, is Longitudes Examined: Tercentenary Conference on the History of the Board of Longitude and the Determination of Longitude at Sea. The programme is now available online and looks brilliant (I’m not speaking, although will be part of the final discussion panel, so I’m allowed to say that)! 

Navigating 18th-century science: Board of Longitude archive digitised

Cross-posted from The H Word blog.

Today [18 July 2013] the complete archive of the Board of Longitude is being launched online, with stories of innovation, exploration and endeavour – and much more than just John Harrison

Design for a marine chair

Design for a marine chair submitted to the Board of Longitude. Source: Cambridge University Library

 

Today Lord Rees will be launching the digitised archive of the Board of Longitude at Cambridge University Library. Stuffed full of the correspondence and work of those who preceded him as Astronomer Royal, it also contains letters and papers of artisans, inventors, expeditionary astronomers and maritime explorers.

For those not familiar with the story of the 18th-century search for a means to determine longitude at sea, this video, gives an introduction to the project and the story.

The digitisation project is a collaboration between CUL and the National Maritime Museum, funded by JISC, and is closely allied to an AHRC-funded project on the history of the Board of Longitude that brings together researchers from the NMM and History and Philosophy of Science department in Cambridge.

This association has meant that as well as digitising 48,596 pages from the archives and libraries at Cambridge and NMM, the content is supported by links to relevant object records at the Museum, summaries of all and transcriptions of some of the files and essays on key figures, places, institutions, objects and events.

Written by the project researchers, there is enough text there for a couple of PhDs (at least) and a really useful resource for users of the site. I was the laggard who has only contributed one essay so far, on Astronomer Royal Nevil Maskelyne. He was, though, an extremely significant figure both for the longitude story and in this project, which also includes selections from Maskelyne’s archive from the Royal Observatory and his personal papers held now at the NMM.

While historical researchers will undoubtedly find many ways to start digging into the archive, for those newer to the game there are, on top of the summaries and essays, resources for schools and some selected stories lifted from the archive. The content can take the reader to the observatory at Greenwich, meetings at the Admiralty, artisan workshops of London and the South Seas.

William Wales' map of Easter Island, from Cook's Second Voyage

William Wales’ map of Easter Island, from Cook’s Second Voyage. Source: Cambridge University Library

Key Stage 2 pupils will, we hope, learn about Captain Cook’s voyagesand Key Stage 3 will be able to think about inventors and enterprise.

For those who feel they are familiar with the story of longitude, having read about John Harrison and his sea clocks in Dava Sobel’s Longitude, they will find there is much more to explore. As my NMM colleague, Richard Dunn says,

The archive places the familiar story of Harrison in its richer context. He was a crucial figure but the story is much broader. It takes in the development of astronomy, exploration and technological innovation and creativity during the period of the Industrial Revolution, the work of the first government body devoted to scientific matters, and public reactions to a challenge many considered hopeless.

Simon Schaffer, who leads the research project, adds that

The longitude story is a spectacular example of expert disagreement and public participation. As well as attracting the greatest scientific minds of the day, the board enticed people who belong to one of the most important traditions in British society; the extreme eccentric.

Thus while there may be interest in reading the full story of the Board’s dealings with Harrison, eyes are likely to be caught by what were damned by the archive’s 19th-century compilers as “Impractical schemes”. Some of these are real green ink stuff, with perpetual motion and squaring the circle bound into the seemingly intractable problem of finding longitude.

Scheme for dead reckoning

Proposal for finding longitude by determining the ship’s rate of sailing. Source: Cambridge University Library

However, there are many other schemes that, while they did not come to fruition, were based on sound ideas. These included improvements todead reckoning – the educated estimate of position that was not displaced by chronometers until the 20th century – or ways to steady an observer sufficiently to allow them to use Jupiter’s satellites as a celestial timekeeper (the standard means of determining longitude on land).

In its later life, the Board supported the two successful methods of finding longitude at sea – chronometer and lunar distance – and broadened its remit into other fields. Thus those who explore the digital archive will also land on geomagnetic researchpendulum experiments measuring gravity, the search for the North-West Passage and a young Michael Faraday pulled in to investigate ways to improve optical glass.

And much more besides – go on, dive in!

Picturing science: Mapping the moon

A reproduction of a lunar map by H. Percy Wilkins, a “proto-Patrick Moore”, is on display at the National Maritime Museum. It makes an interesting side-show to the new major exhibition, Visions of the Universe. [Cross-posted from The H Word blog.]

Map of the Moon by H. Percy Wilkins
Sheet from 1951 ed. of Wilkins’ Map of the Moon. Source: National Maritime Museum

Given my recurring Picturing Science posts in this blog, I can’t avoid mentioning the new exhibition that has opened at the National Maritime Museum, Visions of the Universe. (Full disclosure: I have not been involved with this exhibition at all.) It has been getting some really nice reviews and previews, and anyone with an interest in astronomy or photography should make the trip.

Visions of the Universe exhibition at the National Maritime Museum

In this post, though, I want to highlight something else that is currently on view, within the main (free) museum. While the exhibition showcases what the space age has brought us, with extraordinary Hubble-type images and – the real hit, I think – a 13-metre long Mars Window, this other display offers the clearest possible reminder of how recently it is that any of this became possible.

In the NMM’s Compass Lounge (at the rear left of the Museum’s new entrance foyer), the several sheets of a 1951 map of the moon have been photographed and reproduced to show the complete 300-inch chart. It shows an extraordinary level of hand-drawn detail, achieved by its maker, H. Percy Wilkins (1896-1960), with the aid of distinctly earth-bound telescopes.

This map, versions of which he had been working on since the 1920s, was the largest-scale and most detailed of its time, combining Wilkins’ personal observations with data from the drawings, photographs and measurements of other astronomers. As his Wikipedia entry says, it was “considered by some as the culmination of the art of selenography prior to the space age”. Wilkins himself described it as “the World’s greatest Moon Map”.

The map was also, perhaps, one of the last productions of its kind. Not only was it published just on the cusp of the space age, but it was also the project of an amateur, working from his home near Bexleyheath with a 12½-inch, and later a 15½-inch, reflector. Wilkins did the work in his spare time, being employed first as a mechanical engineer and then a civil servant at the Ministry of Supply.

Title page of Wilkins' Map of the Moon
The title page of Wilkins’ Map of the Moon. Source: National Maritime Museum

Wilkins nevertheless found time to make telescopes, publish several works on popular astronomy and act as director of the British Astronomical Association’s Lunar Section. As well as founding the Section’s periodical The Moon, he was also, late in life, the first president of the International Lunar Society.

Two of Wilkins’ books were co-authored with another selenographic authority, Patrick Moore, to whom the Visions of the Universe exhibition is dedicated. I found online a reminiscence of Wilkins by an acquaintance describing him as a “proto-Patrick Moore”, but he was perhaps also a direct inspiration. In an obituary of his colleague, Moore wrote of the “prodigious amount of work” that went into the mapping project but, also, that “his personal enthusiasm was inspiring”. Moore felt a “deep sense of personal loss”.

Wilkins did not quite become the media star that Moore did, but he made “numerous broadcasts and television appearances”. You can, for example, see him (his telescope, his map, and his daughter) here in a 1953 Pathé newsreel. Somewhat more infamously, he made the news in 1954 when he announced his observation of “the most extraordinary feature known on the moon today”.

This was a curved shadow, already spotted and described as bridge-like by an American astronomer, John J. O’Neill. It was reported as a 20-mile arch, which can be seen clearly in the photographs reproduced in one of the newspaper reports, viewable at the bottom of the page here. It was, however, no more than a trick of the light, rather like the Face on Mars.

The episode seems to have damaged his credibility considerable and may be one of the reasons that he is less than well-remembered today. Part of the problem was that Wilkins spoke to the press and on the radio before submitting his, rather more cautious, observations to peer scrutiny, His case was not aided by his initially appearing to hint that the structure could be evidence of life on the moon: phrases like “looks artificial” and “almost like an engineering job” led some to leap to such conclusions, even if they were simply descriptive.

The “bridge” was not included in Wilkins’ map, although it did incorporate some other erroneous details. Nevertheless, NASA purchased at least one, and possibly several, copies of the reduced reproduction of his lunar chart when preparing for the Apollo moon landings. His map was also used to help match up the first photographs of the far side of the moon, produced by a Lunar 3 in 1959, with features visible from Earth.

As well as the originals of three editions of the maps themselves, the Museum also received a number of notebooks, all kindly donated by Wilkins’ daughter. The notebooks include formulae, photographs, newspaper cuttings, original drawings and observational notes, from Wilkins’ Kentish observatory and visits to professional observatories in France and the US. They are testament to his years of dedicated work.

When you go (as you must) to see the images, the ingenuity and the leaps that have been made in professional and amateur astronomical imaging on display in the major exhibition, do also remember to pop over to see “the World’s greatest Moon Map”.

Picturing science: inside a Georgian observatory

Cross-posted from The H Word blog.

Detail of Shirburn Castle Observatory

Detail of engraving of the observers at Shirburn Castle Observatory. Source: National Maritime Museum

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I only recently, and by accident came across this rather delightful 1778 mezzotint by James Watson among the collections of the National Maritime Museum. It was a somewhat hidden gem, having not been fully catalogued, although there are copies to be found elsewhere.

I have now updated the description, having realised that the full imageshows two servants-cum astronomical assistants of George Parker, 2nd Earl of Macclesfield (c.1696-1764). They are depicted in his private and exemplary observatory at Shirburn Castle, erected in about 1739.

In the detail at the top of this post is Thomas Phelps, then aged 82, and with him (see below) is John Bartlett, then aged 54. Most of what we know about them is what appears in the text given within this engraving. It is a tale of common men made good, thanks to natural ability, hard work, access to books and recognition by their superiors.

Detail of Shirburn Castle Observatory

Phelps, “who from being a stable-boy in the year 1718, to the then Lord Chief Justice Parker, afterwards Earl of Macclesfield, rose by his merit to the upper employments in that family, and at last, for his uncommon genius, was promoted to be observer, in their Observatory”. John Bartlett was “originally a shepherd, in which station he by books and observation acquired such a knowledge in computation, and of the heavenly bodies, as induced the late George, Earl of Macclesfield, to appoint him assistant observer in his Observatory”.

Phelps and Bartlett are shown in the observatory’s transit room, with Phelps at the eye-piece of the 5-foot transit telescope, made byJonathan Sisson. This instrument is fixed to supporting pillars and aligned to the meridian in order ensure the accuracy of repeated positional measurements of the heavenly bodies.

Behind Bartlett is an astronomical regulator, an accurate observatory clock, by George Graham. To the left is an equatorially-mounted telescope, probably by John Dollond, These were tip-top London instrument makers. Macclesfield spared no expense to create an observatory that, with a salaried observer and assistant, rivalled or, indeed, trumped the establishment at the Royal Observatory in Greenwich.

Macclesfield was a remarkable individual. He was instructed in mathematics by Abraham De Moivre and William Jones, and the sciences became his passion. Under Jones’s influence he formed an exceptionallyimportant collection of 17th-century mathematical manuscripts andbooks. He erected his observatory with the assistance of James Bradley, then Savilian Professor of astronomy at Oxford and later Astronomer Royal. He also built a chemical laboratory, in which his observer, Thomas Phelps also assisted.

Macclesfield was, as well as being an MP, President of the Royal Society for 12 years, from 1752 until his death. From both positions he was a principal proponent of the adoption of the Gregorian calendar. His son, Thomas Parker, 3rd Earl of Macclesfield, was also elected FRS, and evidently kept the observatory going, under Phelps and Bartlett, joined in about 1776 by someone called Redding. Regular observations seem to have ceased in the 1790s.

This engraving is a remarkable celebration of two relatively unknown individuals who, otherwise, survive only in the manuscript observations. It is relatively rare, before the advent of photography, that we see images of people engaged in the activity of astronomical observation. It is also rare to see the assistants, rather than the owner of such fine instruments.

The engraving is, of course, also a celebration of those instruments, which were still impressive in the 1770s. In addition to the telescopes and clock, core tools of the well-quipped working observatory, is a celestial globe. This plays a iconographic rather than a practical function, and is unlikely to have been placed in the observatory itself.

Detail of Shirburn Castle Observatory

However, perhaps my favourite part of the image depicts some rather more humble, but no less essential, aspects of observatory equipment. They are a ratcheted, adjustable observing chair, against which Phelps leans, and the pen and paper with which Bartlett notes the time on the clock at the moment that Phelps calls a star as crossing the meridian of the telescope.

Detail of observing chair in Shirburn Castle observatory

These ordinary things – a chair and writing materials – remind us that the work of these observers was not simple star-gazing but, even in this private observatory, something precise, regular, regulated and tiring. It was the hard work of making and recording observations with an eye to posterity.

Drawing Mars in Greenwich: recreating an experiment for Stargazing Live

Cross-posted from The H Word blog.

Recreating Mars drawing experiment in Greenwich
Filming for Stargazing Live at Queen’s House in Greenwich. Photograph: Marek Kukula

This week [NB This post was first published on 7 January 2013] sees the return of the BBC’s highly successful Stargazing Live. It starts on Tuesday, in an episode that follows last year’s biggest astronomy story by focusing on Mars.

In thinking about the search for possible life on Mars, the programme will include some of the historical observations and debates that I discussed in a previous post. I’m delighted that the programme gave us at theRoyal Observatory a chance to recreate a key Greenwich contribution to the story.

This was the 1903 experiment carried out by E. Walter Maunder, an assistant at the Observatory, exploring perception at the limits of vision. It was one element in his campaign against the then-dominant view that the Martian surface was covered with immensely long, wide and straight “canals”, thought by many to the work of an advanced civilisation.

Maunder was not alone, being joined by Eugène Michel Antoniadi andWilliam Campbell, together described in Michael J. Crowe’s The Extraterrestrial Life Debate as “the leaders of a wrecking crew” that demolished the Martian canals.

Maunder, with the assistance of the headmaster of the Royal Hospital School in Greenwich, asked a number of the school’s pupils to draw from different depictions of Mars, placed on a board at the front of the room.His results suggested that, particularly at certain distances, the eye tended to resolve indistinct waves and dots into straight lines, suggesting that the “canals” were an optical illusion rather than real surface features.

Ever since I heard about this experiment, I have wanted to recreate it. Asking people to undertake an exercise like this is a wonderful way to understand the problems and contingencies surrounding astronomical observation and recording (imagine not only peering at this small image, but it flickering in an unsteady atmosphere, and having to keep taking your eyes away in order to represent it on paper). I also wondered if it really worked as Maunder described.

Maunder claimed in his paper that the boys, aged around 12 to 14, were all “wholly and entirely ignorant of the appearance of Mars in the telescope, and of the discussions which have taken place as to the markings on his surface.” I have always wondered if this was true, given the widespread popularity of the Martian canal idea at this period.

Our guinea pigs were probably familiar with what Mars looks like when photographed today, but less likely than the 1903 schoolboys to think of drawings or canals. An interesting difference was their age and the fact that most of them were art students. This probably produced different results than had we picked people off the street but might compare interestingly with the naval cadets. The latter were encouraged by Maunder, and probably by their education, simply to draw what they could see. Our art students may have been more likely, despite my instructions, to attempt to interpret the image and to consider different graphic approaches to its re-depiction.

It is likely that the experiment took place in the school’s old gymnasium. This no longer exists, so the BBC team opted for another of the school’s former buildings – the beautiful Queen’s House. They set up the experiment pretty faithfully, with distances and scales as specified in Maunder’s paper. Told to draw, our students obliged, and demonstrated that their eyesight and drawing ability was a good deal keener than mine.

Did our results back Maunder’s? Sort of. I didn’t see the generation of any “canals” where little or nothing appeared on the original image, but there were certainly more straight lines. In our small sample, it also appeared that the middle rows were more likely to see these lines than those nearest (who saw more detail) or those furthest away (who saw little distinctly). It could be argued that these distances mimicked the experience of observing with particular-sized telescopes, creating the conditions where the eye tends to resolve indistinct detail into non-existent straight lines.

Maunder’s report of this experiment apparently brought a key ally to the campaign against Martian canals – the veteran Canadian-American astronomer Simon Newcomb. It was, however, just one of the arguments brought – one of the simplest being the point that if straight canals like those reported by Percival Lowell did exist on the curved surface of Mars, they ought to appear curved to the observer on Earth.

In his writings, Maunder focused on scientific evidence and his own experiences as an astronomical observer. He chose to stay clear of the philosophical and religious dimension of the debate, despite the fact that his popular writings in astronomy were usually framed with natural theology and Biblical references.

Religious beliefs could support either position in the debate about the existence of life on other planets. However, it was clear that Maunder, an active member of a small pentecostal, adventist sect, believed man’s relationship with God and place in the universe were unique. He could not countenance intelligent, canal-building Martians – and thus his scientific arguments were motivated by religious belief.

Watch on Tuesday to see how the experiment went and how it fits into the long history of observing Mars and the search for extra-terrestrial life. Also visit Alien Revolution a small, free exhibition at the Royal Observatory, opening in March.

In the end the section of the film that included the experiment wasn’t run live on Stargazing, due to lack of time. Happily, the whole thing was made available online and you can see it here.

A mystery astronomer?

The National Maritime Museum owns a painting that is something of a mystery, so I thought I would open the question up to readers of the blog. It was in the Museum’s foundational collection, donated by its major benefactor, Sir James Caird, and was at that time believed to be a portrait of Nevil Maskelyne. This explains why I have come across it again recently, for it is included in both the Oxford Dictionary of National Biography entry and Derek’s Howse’s 1989 biography, The Seaman’s Astronomer. Howse, however, had his doubts about the attribution, for the sensible reason that it does not look all that much like the other known portraits. It now appears in the NMM’s online catalogue as “Formerly called Nevil Maskelyne“. If you do a Google image search you will find both attributions – you will also, bizarrely, find that you can buy a Photo Mug of Formerly Called Nevil Maskelyne from Amazon. [Read more…]

Longitude Project and Blog

My blogging loyalties are now divided (or perhaps cross-fertilised) as I am also blogging at the new Longitude Blog, set up for all the researchers involved with an AHRC-funded project on the history of the Board of Longitude at the National Maritime Museum and Department of History and Philosophy of Science at the University of Cambridge.

[I was about to link in that sentence to the Wikipedia page on the Board, but see that this needs a health warning and would benefit from the input of some of the team!Read More »