Maskelyne: Astronomer Royal – book now available

Now available from the publisher, Robert Hale Books currently cheaper than AmazonMaskelyne: Astronomer Royal has been edited and partly written by me, with contributions from seven other curators and historians of science.



Stemming from a public symposium at the National Maritime Museum in 2011, marking the bicentenary of Maskelyne’s death, the book aims to be readable. It is also very well illustrated, particularly with photographs of objects, drawings and papers from the Museum’s Maskelyne collection. The full contents are as follows:

Introduction (Rebekah Higgitt)

Chapter 1: Revisiting and Revising Maskelyne’s Reputation (RH)

Case study A: The longitude problem (RH)

Chapter 2: ‘The Rev. Mr. Nevil Maskelyne, F.R.S. and Myself’: The Story of Robert Waddington (Jim Bennett)

Case study B: The projects of eighteenth-century astronomy (RH)

Chapter 3: Maskelyne the Manager (Nicky Reeves)

Case study C: The Astronomer Royal at Greenwich (RH)

Chapter 4: Nevil Maskelyne and his Human Computers (Mary Croarken)

Case study D: Maskelyne and the marine timekeeper (RH)

Chapter 5: Maskelyne’s Time (Rory McEvoy)

Case study E: Instruments of exploration (RH)

Chapter 6: ‘Humble servants’, ‘loving friends’, and Nevil Maskelyne’s Invention of the Board of Longitude (Alexi Baker)

Case study F: The Royal Society and Georgian science (RH)

Chapter 7: Friend and foe: The Tempestuous Relationship Between Nevil Maskelyne and Joseph Banks (Caitlin Homes)

Case study G: Visualizing and collecting the Maskelynes (RH) 

Chapter 8: The Maskelynes at Home (Amy Miller)

Coda: A life well lived (RH)

The Longitude Prize Committee: a new Board of Longitude?

Cross-posted from The H Word blog.

The Board of Longitude brought to life at Greenwich Theatre in 2005.
The Board of Longitude brought to life at Greenwich Theatre in 2005. Photograph: Tristram Kenton

The new Longitude Prize has nothing to do with longitude: that particular problem is long since solved. Yet it has a Longitude Committee that, like the original Board of Longitude, includes the Astronomer Royal. Lord Rees has borrowed the tercentenary of the first Longitude Act and the idea of an incentive prize in the hope of turning money and talent toward a new challenge.

But, apart from the Astronomer Royal, what are the connections between the new committee and the old? And what do the differences tell us about the two schemes?

The Commissioners

The 1714 Act appointed a number of Commissioners of Longitude, either by name or by position, from political, maritime and scientific worlds. By making several positions ex officio, the authors of the Act ensured – by accident or design – that the Commission could continue in perpetuity. It also marked a first by bringing key scientific positions directly into government decision-making.

The political positions were: the Speaker of the House of Commons, the First Commissioner of Trade and, in 1714, ten named Members of Parliament. The maritime and Admiralty representation was: the First Lord of the Admiralty; the First Commissioner of the Navy; the Admirals of the Red, White and Blue Squadrons; and the Master of Trinity House.

The scientific men were: the President of the Royal Society; the Astronomer Royal; and the SavilianLucasian and Plumian Professors at Oxford and Cambridge Universities. Later the Lowndean Professorship, founded in 1749, was also added.

The Commissioners do not seem to have met before 1737, when they deliberated John Harrison’s first reward, by which time many of the named MPs had died. The left the ex officios, the best-known of which attending in 1737 were Edmond Halley and James Bradley. Halley was Astronomer Royal, although he had previously been a Commissioner as Savilian Professor. Bradley was there as Savilian Professor, but was to remain a Commissioner when he succeeded Halley as Astronomer Royal. It was a small world.

The Board

The Commissioners of Longitude were not known as the Board of Longitude until around the 1760s. By then business was considerably more bureaucratic and regular and the core team had settled down as the Astronomer Royal, President of the Royal Society, the professors, the first Lord of the Admiralty and the secretaries to the Board and the Admiralty.

Things changed again when, under the influence of Joseph Banks, the Board was reorganized. It had already become concerned with all navigational issues, not just longitude, and now the ambition was to become a scientific advisory board to the Admiralty. The 1818 Longitude Act appointed three Fellows of the Royal Society and three salaried Resident Commissioners on top of the professors. This was, apart from packing the Board with Banksian sympathisers, a way to include other scientific fields.

The Committee

I can’t comment on the internal politics but, despite obvious differences, there are some interesting similarities between the Board and the Longitude Committee. Firstly, of course, there is Lord Rees, who as Astronomer Royal links the two groups. (A few years ago, Rees had positions that would have earned him a seat on the Board of Longitude three times over: Astronomer Royal, President of the Royal Society and Plumian Professor).

Oxbridgian scientific gravitas remains, with Athene Donald, Professor of Experimental Physics at Cambridge, and Kay Davies, Dr Lee’s Professor of Anatomy at Oxford. Also present is is Wendy Hall, Professor of Computer Science at Southampton. The range of disciplines shows that, while longitude was seen as a mathematical and astronomical matter, the breadth of potential challenges this time around requires a broader mix. The presence of women also reveals social change, although at 4/18 of the Committee, perhaps less than we’d like.

Engineering had no academic or institutional presence in the early 18th century, but in the 21st it is clearly a field relevant to solving technical problems. Thus, rather than the President of the Royal Society, we haveMartyn Thomas, Vice-President of the Royal Academy of Engineering.

A novelty of the last century is the appointment of scientists directly to government. On the Committee are Chief Scientific Advisor Mark Walport, Chief Medical Officer Sally Davies and David Mackay, Regius Professor in Engineering at Cambridge and Chief Scientific Advisor to the DECC. Otherwise, the connection to government is down to John O’Reilly, Director General of Knowledge and Innovation (there’s a title!) at BIS.

From here the differences are significant, starting with those linking business, charity and government. In 1714, men who made their living through trade would not, unlike the propertied gentlemen MPs, have been seen as disinterested enough to guarantee their trustworthiness. In 2014, however, we have David Gibson, Head of Innovation at GlaxoSmithKline; Andrew Dunnett, Director of the Vodafone Foundation;Iain Gray of the Technology Strategy Board; and Geoff Mulgan, Chief Executive of the prize organisers Nesta.

Also included are individuals known for championing and communicating science. There is Imran Khan, Chief Executive of the British Science Association; Roger Highfield, journalist and Director of External Affairs at the Science Museum; and Andrew Cohen, Head of the BBC Science Unit. Spanning different ends of science and technology publishing arePhil Campbell, Editor in Chief of Nature, and David Rowan, editor of Wired Magazine.

The public

While 18th-century Britain had many significant popularisers of science, they would not have been Board members. Plenty was said about providing something of public utility, not to mention saving lives at sea, but there was no interest in consulting more widely. Indeed, it seems that the call for longitude rewards came from the scientific community – potential winners of money – rather than from mariners.

The role of the public has, therefore, changed. While in 1714 an interested public was the source of potential solutions, with the large reward of £20,000 designed to spread the word and catch the eye, in 2014 there is little sense that answers will come from outside a trained and professional group of scientists or engineers. Thus the public is brought on board to help (a little) with a choice from the six potential challenges.

What the result of the public choice is, and the response to the challenge, time will tell. Given that, unlike the original Commissioners of Longitude, the Longitude Committee has not been appointed ex officio, we might assume they hope it will all take less than half a century.


Farewell Greenwich Mean Time (see you in October)

Cross-posted from The H Word blog, where this was first published on 30 March 2014.

The 24-hour Shepherd Gate Clock outside the Royal Observatory, Greenwich, displaying Greenwich Mean Time to the public.
The 24-hour Shepherd Gate Clock outside the Royal Observatory, Greenwich, displaying Greenwich Mean Time to the public.

It has become something of a tradition on this blog to mark the biannual change of the clocks and, although I no longer work at the Royal Observatory Greenwich, it’s a habit that sticks. This time, as we say farewell to it until the autumn, it seems a good opportunity to reminisce about Greenwich Mean Time.*

Why Greenwich time? And what’s mean about it?

Mean time is clock time. It is a regularised, idealised version of solar time that is tracked not by the apparent motions of the Sun, observed by shadows on sundials, but by a mechanical device that splits the solar day into equal parts. Mean time ticks away at the same pace no matter the season. The difference between the two is described by the equation of time.

Establishing the relationship between mean solar time and apparent solar time only really became possible, or useful, with the arrival of the pendulum clock in the 1650s. This made the mechanical clock, for the first time, a scientific instrument. Christiaan Huygens, who developed the first prototype pendulum clock in 1656, was able to produce reasonably accurate tables of the equation of time in 1665.

However, it fell to John Flamsteed to publish tables in 1672-3 that tackled the problem in what became the standard way. He provided the formula by which apparent solar time could be converted into Mean Time.

Just a couple of years later, Flamsteed was appointed the first Astronomer Royal and moved into the newly built observatory in Greenwich. There, he and his patrons had installed state-of-the-art pendulum clocks by the best clockmaker available, Thomas Tompion. With observations of the Sun and the help of his tables, Flamsteed set these clocks to the local time: Greenwich Mean Time.

Greenwich time became important because there were people measuring it and because other people made use of astronomical observations based on it. Flamsteed’s catalogue of stars, which was to become a standard reference work for the following decades, listed their positions based on Greenwich time.

It was one of Flamsteed’s successors, Nevil Maskelyne, Astronomer Royal from 1765 to 1811, who did most to ensure that GMT mattered to more than just astronomers. Under his initiative, observations made at Greenwich were processed into tables that could be used by navigators and cartographers to establish positions at sea or on land. This was the Nautical Almanac, first published for the year 1767.

Surveyors of the Royal Navy and the Ordnance Survey relied on data that was based on observations made at Greenwich, meaning that their charts and maps used Greenwich as a reference point. More precisely, this was the meridian (north-south line) on which the chief telescope at Greenwich was mounted. The Greenwich meridian thus became a prime meridian for British mapping, and east-west position was measured from there. To establish longitudes it was necessary to know the difference between local time and GMT. This could be worked out with astronomical observations and the tables of the Nautical Almanac and, increasingly, with chronometers set to GMT.

The move of GMT from the specialist worlds of astronomy, navigation and surveying into civilian life was down to the increasing role of technologies and cultures that demanded standardization. The arrival of railways made timetabling a necessity. Telegraph systems made it both desirable and possible to know what time it was elsewhere. Factory work made production and payment dependent on timekeeping.

GMT became “Railway Time” in the 1840s, and Britain’s legal standard time in 1880. Despite what you’ll often read, it did not become an international standard in 1884. In that year an international conferencedid recommend the adoption of the Greenwich meridian as the world’s reference point for time and longitude, but it was just a recommendation.

What actually happened as a result of the International Meridian Conference, and what did not, is a story for another post. See you back here on 26 October.

* Our standard time is now in fact Coordinated Universal Time (UTC), derived from International Atomic Time but as close as darn it to GMT.

Astronomers Royal, scientific advice and engineering

Cross-posted from The H Word blog, where this post first appeared on 12 September 2013.

The collapsed Tay Bridge

This evening, the Astronomer Royal, Lord Rees, will weigh into the debate about climate change and geoengineering in an address at the British Science Festival.

Finding such fixes, as well as more efficient forms of alternative energy, may well be problems focused on by the new challenge prize that Rees has helped set up. That he, as Astronomer Royal, will be judging what has been called a new ‘Longitude Prize’, seems appropriate, but the innovations under consideration may be a long way from his own field of astronomy and cosmology.

Today the post of Astronomer Royal is honorary. It means simply, as Alok Jha’s article on Rees’s speech suggests, that he is “one of Britain’s most senior scientists”. Like a Chief Scientific Advisor, or the head of a scientific society, the Astronomer Royal can be expected to give all sorts of opinions about science and science policy, straying at least occasionally, if they wish, well beyond their area of research.

Was it always like this? Yes and no. Until the 1970s the post of Astronomer Royal was synonymous with director of the Greenwich Observatory (at GreenwichHerstmonceux and then Cambridge). Before the 19th century, the AR was also an active observer, in fact only one of two observers in the institution.

Nevertheless, Astronomers Royal were often called upon to make judgements and offer advice in areas that did not relate to making observations or managing an observatory. Because the Royal Observatory was funded by government, being under the administration of first the Board of Ordnance and then the Admiralty, there was potential for them to be asked to consider a whole range of technical and scientific issues.

For much of the AR’s history, the most obvious place in which this happened was the Board of Longitude. While many of the ideas under consideration were astronomical (involving knowledge of astronomical theory, mathematics, optics and instrumentation), others were based on geomagnetism or, of course, horology. Understanding clocks and timekeeping was essential to astronomy, but the specifics of horological theory and manufacture would have been beyond the AR’s experience.

ARs also advised on areas like cartography, instrument design and weights and measures, that involved techniques closely allied to astronomy. But they were also asked to consider a wide range of fields of interest to the Admiralty and other branches of government, simply because they ended up being their available scientific expert.

One of the ARs who most obviously became the government’s go-to scientific and technical guy was George Airy, who was in position from 1835 to 1881. Airy covered a great deal of ground, intellectually and practically. Unlike all his predecessors he was not much involved with daily observations and he had a significantly larger workforce at the Observatory, onto which observation, calculation and even management could be delegated.

Airy, for example, did a considerable amount of work on the effect of iron ships’ hulls on compass use and design. He also advised, like many other ARs, on education and he was involved in the organisation of the Great Exhibition. He was, perhaps most intriguingly, called in to advise the Great Western Railway on track gauges and the engineer Thomas Bouch about the pressures that might be exerted by wind on the planned rail bridge crossing the Forth.

That latter advice got him into trouble. It was first applied by Bouch to the Tay Bridge and, when that collapsed in 1879 [see image above], Airy was called in by the enquiry. He claimed that his advice had been specific to the circumstances of the Forth and the design for that bridge (which was now speedily discarded). The enquiry agreed, suggesting that Bouch had “must have misunderstood the nature of [Airy’s] report”.

Airy did know quite a lot about engineering. He was, apart from anything else, closely involved with the design of large instruments and their mounts at Greenwich. Times and the nature and range of expertise have changed considerably since the 19th century, however. Lord Rees is not an Astronomer Royal who can offer specific or technical engineering expertise, rather he is calling for research and funding. Whether or not you agree with his statements is a different matter.