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.

Cutting a dash: men of science as ‘historical hotties’

I had a bit of fun this week tweeting links to portraits of some 19th-century men of science, suggesting that they were ’19thC scientific hotties’. Such a phrase is not, I should add, my usual vocabulary, and nor is a focus on people’s looks. And thus explanation is in order. My tweets brought a response from Vanessa Heggie – “trying to tell myself this ‘historical hotties’ thing is OK, as is clearly subversion of patriarchal power” – and linking to Bangable Dudes in History.  Was I making a feminist point? Or was I objectifying these men in a way that I would naturally find uncomfortable if it were living women? Was I, perhaps, attempting to claim that men of science can be attractive, in some sort of historical, masculine version of the (for me) dubious Cheerleaders for Science.

I was, in fact, playing with a few ideas that I didn’t want to develop in 140-character chunks on Twitter. One was exploring this as a hook for introducing less-well-known scientific figures to an unsuspecting public, another was thinking about how such men chose to be portrayed in their lifetimes, and the third was my own response to these portraits, and how they may have coloured views of these historical characters.

The whole thing started in response to this post by Beth Dunn on Thomas Say and the utopian project that had Robert Owen sending a ‘Boatload of Knowledge‘ – in the form of men of science, writers and artists – to New Harmony in the mid-West. It was not Beth’s contention, but someone had suggested that Say was a “19th century hottie”. I retweeted the post, but also suggested that I had another favourite portrait of a man of science and adventurer, the NMM’s portrait of James Clark Ross by John R. Wildman.

Ross, who travelled to both the Arctic and Antarctic, located the north magnetic pole and carried out a huge range of scientific observations, was reckoned by Jane Franklin “the handsomest man in the navy”. He was the “scientific serviceman” par excellance: a heroic naval figure who could cut a dash and demonstrate his manly devotion to nation in time of peace. He’s fascinating, but I don’t fancy him (he’s dead, for a start), I just love the portrait: a Romantic shock of dark hair, passionate glance, icebergs, polar bearskin, Pole Star and, beautifully delineated in the foreground, an instrument known as a dip circle, used to measure variation in magnetic inclination.

As my tweet got a reasonable response, I followed it up over the next couple of days with links to Thomas Phillips’ portrait of Michael Faraday and Thomas Lawrence’s portrait of Henry Brougham. Again, these are Romanticised images of men who, in very different ways, took on public roles that were undoubtedly enhanced by their intelligence and charismatic personalities. Faraday was, of course, a star public lecturer (the Brian Cox of his day, dare I say?) as well as a hugely important figure in the history of chemistry and physics. Although modest and discrete, he certainly knew – or learned – how to capture his audiences through look, voice and gesture as well as knowledge and dexterity. Brougham, in reality, was probably no looker but I was captured by his portrait when it was displayed in a NPG exhibition, The British Portrait 1660-1960, way back in 1991 (when I just about knew of the Great Reform Act, but had never heard of history of science). It is Lawrence at his best: capturing a light of fierce intelligence in the eye of this young, ambitious, passionate lawyer.

I think I would have to admit, if challenged, that my knowledge of these portraits probably pre-disposed me to some level of sympathy for the sitters. Quite probably it was more than I might have felt had I first seen their much later photographic portraits. It’s never nice to admit, but looks and first impressions inevitably colour our impressions of people and, I think, the same can be true of those we meet through paintings and archives, although better acquaintance can often override early opinions. Other times, an interest, familiarity or admiration can build up from knowledge of the archive, only to be challenged when finally seeing a portrait that misses by a country mile the mental image built up.

What interests me particularly about these portraits, and others of the period like Humphry Davy or William Whewell, is that they depict relatively young men, in a period when youth, imagination, intellect and genius were unabashedly romanticised and celebrated. Although there are plenty of exceptions to the rule, before this date portraits often appear more formal, and later the dominance of photography brings a distinctly unflattering stiffness or realism to our heroes. By and large, too, men of science tended not to have portraits done until they had reached rich or honoured old age, usually long after their best work was behind them. And how much do they affect our assumptions? Flamsteed, the first Astronomer Royal is usually thought of as dull, plodding, uptight and downright grumpy. There is certainly plenty of this in what his wrote in old age, and it is underlined by our best-known image of him, a frontispiece to a posthumous volume, but do we think a little more kindly of him when presented with his more youthful image?

John Flamsteed (1646–1719)

These themes are particularly pertinent in a museum setting. People and the personal are very often dominant in our displays, either reflecting the kind of material that has been collected (relics, provenances) or assumptions about how audiences best respond to the themes we are treating. If you want people to care about the bunch of stuff (scientific instruments, documents, tools, trinkets, whatever) we are showing, the usual tactic is to provide a name, some biography and a portrait. If those portraits evoke sympathy and interest, all the better. Thus, while I have concluded that my ’19thC scientific hotties’ are not the answer to eschewing anniversaries as a hook for introducing my historic characters, I nevertheless found it helpful to think about personal reactions to these images, with their ability – part of their original intention – to inspire the viewer with a whole range of emotions.