Tag: History

Apr 07 2012

Board of Longitude

It’s been a while since I did a data driven blog post, so here I am with one on the “Board of Longitude”. The board was established by act of parliament in 1714 with a headline prize of £20,000 to anyone who discovered a method to determine the longitude at sea to within 30 nautical miles. The members of the Board also had discretion to make smaller awards of up to £2,000 in support of proposals which they thought had merit. The Board was finally wound up in 1828, 114 years after its formation.

The latitude is your location in the North-South direction between the equator and either of the earth’s poles, it is easily determined by the position of the sun or stars above the horizon, and we shall speak no more of it here.

The longitude is the second piece of information required to specify ones position on the surface of the earth and is a measure your location East-West relative to the Greenwich meridian. The earth turns at a fixed rate and as it does the sun appears to move through the sky. You can use this behaviour to fix a local noon time: the time at which the sun reaches the highest point in the sky. If, when you measure your local noon, you can also determine what time it is at some reference point Greenwich, for example, then you can find your longitude from the difference between the two times.

The threshold for the highest Longitude award amounts to knowing the time at Greenwich to within 2 minutes, wherever you are in the world, and however you got there. This was a serious restriction at the time, because a journey to anywhere in the world could have taken months of voyaging at sea with its concomitant vibrations and extremes of temperature, pressure and humidity all of which have serious implications for precision timekeeping devices.

The Board of Longitude intertwines with various of the people whose biographies I’ve read, and surveying efforts taking place during the 18th and 19th centuries. It made a walk on appearance in Tim Harford’s Adapt, which I’ve just read, as an early example of prizes being offered to solve scientific problems.

Below I present data on the awards made by the Board during its existence from 1714 to 1828. The data I have used is from “Britain’s Board of Longitude: The Finances, 1714-1828” By Derek Howse1 which I reached via The Board of Longitude Project based at the Royal Museums at Greenwich. The chart below shows the cumulative total of the awards made by the Board (blue diamonds), awards made to John Harrison who won the central prize of the original Board (black triangles) and the dates of Acts of Parliament relating to the Board (red squares). Values are presented as at the time they were awarded, the modern equivalent values are debatable but the original £20,000 award is said to have been worth between £1million and £3.5million in modern terms, so a rule of thumb would be to multiple by 100 to get approximate modern values.

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Although established in 1714, the Board made no reward until 1737 and until 1765 made the great majority of awards to John Harrison for his work on clocks; clockmakers Thomas Earnshaw (1800, 1805), Thomas Mudge (1777,1793) and John Arnold (father and son 1771-1805) also received significant sums from the Board.

A second area of awards was in the “lunar” method of determining the longitude which uses the positions of stars relative to the moon to determine time and hence longitude. The widow of Tobias Mayer received the largest award, £3,000, for work in this area. The list of awardees contains a number of famous European mathematicians including Leonhard Euler, Friedrich Bessel, and Johann Bernoulli.

After 1763 the Board started to branch out, having been mandated by parliament to prepare and print almanacs containing astronomical information. In the twilight of its years the Board gained responsibility for awards relating to the discovery of the North-West passage (a sea route from the Atlantic to the Pacific via the north of Canada), the second largest recipient of awards for the whole period were the crews of the Hecla and Griper of £5000 in 1820 for reaching 110oW within the Arctic Circle, pursuing this goal.

The story of the Board of Longitude is often presented as a battle between the Board and John Harrison for the “big prize” but these data highlight a longer and more subtle existence with Harrison receiving support over an extended period and the Board going on to undertake a range of other activities.

References

1. “Britain’s Board of Longitude: The Finances, 1714-1828” By Derek Howse, The Mariner’s Mirror, Vol. 84(4), November 1998, 400-417. (pdf) Sadly the article notes that Derek Howse died after the preparation of this article.

2. Data from (1) can be found in this Google Docs spreadsheet

Mar 25 2012

Book Review: The Great Arc by John Keay

TheGreatArcThis is a review of “The Great Arc: The Dramatic Tale of How India Was Mapped and Everest Was Named” by John Keay. This book does exactly what it says in the lengthy subtitle: describe the Great Triangulation Survey of India which was conducted in the first half of the 19th century.

It fits together with “Map of a Nation” by Rachel Hewitt and “The Measure of All Things” By Ken Alder. The former describes the detailed mapping of the United Kingdom by the Ordnance Survey, whilst the later describes the measurement of the Paris meridian by Méchain and Delambre. Of the three surveys the French one had been completed first at the beginning of the 19th century whilst the mapping of the UK was going on at the same time as the Indian survey.

The book is centred around the Great Arc survey originally proposed by William Lambton at the beginning of the 19th Century. Lambton’s aim was primarily to measure a meridian (a line of longitude), in the same manner as the Paris meridian in order to gain more information on the shape of the earth (geodesy). For his sponsors in England and the administration of India the survey served as a military and commercial exercise. Military action is often a spur to survey, since getting your troops and their equipment from point A to point B and ensuring they prevail over any forces they come across on the way is a high-value activity which is greatly assisted by the provision of accurate maps. Surveying is also invaluable when you are planning infrastructure such as roads, canals and railways.

The survey came a time when the British relationship with the area now known as India was changing from a trading one based on outposts to one in which the British took territory militarily. The Triangulation Survey was not exhaustive, it comprised a central spine (The Great Arc) running along the 78th meridian up through the tip of the Indian peninsular to the edge of the Himalayas with regular “cross-bars” running from West to East, towards the north an array of parallel meridians were also measure. (You can see a map here). The aim was to use this survey to constrain further local surveys.

The Great Arc survey was a great endeavour, taking 40 or so years in total, after Lambton died in 1823 George Everest took on the job of leading the project. Lambton seems to have been a pleasant sort of chap who went a little native, disappearing from the view of his sponsors. Everest, on the other hand, appeared to be a complete git – being abusive to most of his subordinates and apparently also winding up his superiors.

Much of the activity in the book is in common with that which took place during the surveys of France and the United Kingdom. Laying out base-lines: distances measured directly on the ground by means of rods or chains used to pin down the distances in the “triangulation” which is a collection of angular measurements at the vertices of an array of triangles. Once again the precision is impressive, two 7 mile baselines measured out 200 miles apart agree with the triangulation measurement to within a few inches. Angular measurements were made using a theodolite, Keay labels the one used in India as the “Great Theodolite”, which I thought was a term reserved for the Ramsden device used in the UK (we can’t all have a Great Theodolite!).

The Indian survey presented different challenges in the form of the wildlife (tigers, scorpions etc) but also disease. The rate of attrition amongst the surveyors, particularly as they traversed jungle was terrible. The book is not explicit about figures but in the later stages of the survey something like a thousand men were involved and a couple of hundred of those died of disease. Lambton and later Everest both suffered from recurring bouts of malaria.

The “discovery” of Mount Everest and the tallest peaks in the Himalayas was somewhat incidental to the main thrust of the survey. It had become clear in the first decade or so of the 19th century that the Himalayas were the tallest mountains in the world but their precise height was uncertain. Political difficulties with Nepal, their location far from the sea and their immense size meant determinations were poor. Indeed at the time of the beginning of the survey the height of Mont Blanc in Europe was only know to within a thousand feet or so of its currently accepted value. It wasn’t until 1856, after the Great Arc had been completed and Andrew Scott Waugh had taken over the survey that Mount Everest (known at the time as Peak XV) was measured and Waugh proposed Everest be its name. (Everest is apparently pronounced Eve-rest rather than Ever-est, and the man himself was very particular about this).

Put beside “Map of a Nation” and “The Measure of All Things”, “The Great Arc” is a nice, brief introduction to the theme of triangulation surveys and geodesy which covers measuring the height of mountains in a bit more detail than the other two.

The Great Arc survey, along with the French meridian survey fit together with the earlier French Geodesic Mission to Peru by Condamine and Bouger around 1735, which is described in “Measure of the Earth” by Larrie G. Ferreiro – I’ve added this to my wish list.

Footnotes

You can see my Evernotes on The Great Arc here.

Mar 18 2012

Book Review: Decoding the Heavens by Jo Marchant

DecodingtheHeavens“Decoding the Heavens” by Jo Marchant is the story of the Antikythera Mechanism, a mechanical astronomical calculator dating from around 100BC which predicts the motions of heavenly bodies including the sun, moon and various planets. The best way to understand how the device worked is through videos relating to this book (here) and, rather more slickly (here).

The Antikythera Mechanism was recovered off the coast of the island which provides its name in 1900. The wreck from which it was recovered was also carrying a large number of impressive bronze and marble statues, for example the Antikythera Ephebe. It is believed it was sailing from the Asia Minor coast to Rome, carrying the spoils of war. The wreck lies at a depth of 60 metres which is deep for the technology available at the time, the distinctive metal-helmeted diving suit. It was discovered by the crew of Captain Krontos, who were sponge-divers. As such they did a very risky job, Marchant reports that between 1886 and 1910 around 10,000 divers died from the bends and a further 20,000 were paralysed.

Once they had discovered the wreck they reported it to the Greek government who organised the salvage operation, at the time it was one of the first marine archaeological salvages – it was preceded  in 1884 by a speculative operation in the straits of Salamis which had recovered little. By the 1950s hundreds of wrecks were known in the Mediterranean. Marchant states that this is the first ever attempt to salvage artefacts from a sunken ship, I’m sceptical of this claim – it’s only true for very narrow definitions of each word – Edmond Halley, for example, had a company offering to salvage treasure from sunken ships in the 1690s.

It is curious how little regarded the Anthikythera Mechanism has been over the hundred or so years since its discovery. A measure of this is that the Athens National Museum, where it is kept, were still finding bits of it in 2005! This re-discovery is in some sense understandable, the Mechanism presents a rather unassuming appearance when compared to the statues with which it was found furthermore curating appears to have sharpened its act up over the years. A second reason is that it almost has the air of a fake about it, no other mechanism of comparable complexity was known until around 1000AD, and there was little written evidence for the existence of such devices.

The book works through the interpretation of the mechanism chronologically by researcher, starting with the initial interpretations made by John Svoronos and Pericles Rediadis (1903), Konstantin Rados (1905), Albert Rehm (1907) and John Theophanidis (1934). These are covered quite briefly. These initial studies were based on an exterior view of the fragments and small amounts of visible text, of which more became visible as cleaning attempts were made. It’s worth highlighting here that the mechanism was covered in text, both labels and operating instructions although originally little of this text was discernable. From these studies the mechanism was related to astronomical equipment such as the astrolabe, but was clearly different since it had a more complex clockwork-like mechanism. This chronological approach means that the reader gets a fragmented view of the device (with reverses in interpretation), as the story unfolds. There is also a degree of dramatisation of the story (e.g. “Shit,” said Roger Hadland) scattered through the book, I must admit to finding these rather grating but they are relatively sparse.

After the initial investigations there was a hiatus, with interest appearing to restart in the 1950s possibly spurred by a visit by Jacque Cousteau to the wreck in 1953. Derek De Solla Price was the next to attempt an analysis aided by x-ray imaging of the mechanism which was not available in earlier times. Price was Professor of the History of Science at Yale, in addition to his work on the Antikythera Mechanism he also did early work on scientometrics and the Japanese atomic bomb effort. He finally published his analysis in “Gears from the Greeks” in 1974, this included a detailed description of how the mechanism might have operated based on the gearing made visible by x-ray imaging.

The next attempt at a reconstruction was made by Michael Wright, originally curator of the engineering collection at the Science Museum in work starting in the early 1980s. He was joined by Allan G Bromley, a computer scientist and historian who was also involved in the reconstruction of the the Babbage. They quickly realised that Price’s theoretical reconstruction was in places somewhat creative. Wright ultimately produced a physical reconstruction of the mechanism over a period of 20 or so years.

Most recently, commencing in around 1998) there has been a collaboration led by Mike Edmunds at Cardiff University (The Antikythera Mechanism Research Project). They were able to bring to bear better x-ray tomography which was even able to reveal the details of inscriptions inside the accreted masses of the mechanism fragments, alongside Polynomial Texture Mapping, a photographic technique utilising multiple lighting angles and reconstruction to provide maximum information from surface markings. With collaborators at the Athens Nation Museum they also had access to an additional major fragment which had recently been discovered. Their work was published in the journal Nature (here in 2006 and here in 2008).

The comparison between the Wright and Edmunds collaborations is intriguing, in terms of scientific prestige the Edmunds collaboration have published on the mechanism in Nature the premier general science journal. They are a large collaboration with the best equipment, and fit well within the conventional scientific context. Wright, and to a lesser extent Bromley, were different. Wright in particular comes over has being very hard done by in the process, working in his spare time on the mechanism, always apparently “junior” to Bromley (the formal academic) and ultimately being pipped to glory by the Edmunds collaboration. His story comes through because Marchant has clearly interviewed many of the participants, rather than relying on the published literature. From the point of view of the published literature, all that is really visible to the scientific world, Wright’s efforts were virtually invisible until long after he had started work on the Mechanism.

The “problem” for the earliest interpreters of the mechanism is that it was so utterly different from anything else available from the period. There were no other clockwork like devices and few mentions of them, indeed the next instances were thought to be around 1000AD – it looks like the Antikythera Mechanism was dropped into the past from elsewhere. Nowadays it can be seen that this isn’t true. Archimedes and Ctesibius had been making complex mechanical devices in the 3rd century BC, although there are no physical remnants and the written records are sparse. On the other side, mechanisms of this type were in existence through to 1000AD and from then clocks appeared very rapidly suggesting a pre-existing store of knowledge.

In ancient Greece it is believed there were hundreds of thousands of bronze statues, the number left today are in the hundreds, at most. What chance even a few hundred rather unassuming objects to survive? As for the written record, what survives from the period has been repeatedly transcribed to suit the prevailing conditions, and they did not seek detailed descriptions of recondite mechanics. Can you lay your hands on the blue prints for an NMR machine?

The Antikythera Mechanism would have been made on the basis of the astronomical observations of the Babylonians who preceded its Greek makers. They had no “mechanical” model of the motions of the stars but they had a long, deep observational record of their movements. I’m interested in the night sky, and I can’t tell you but the details of the phases of the moon, even where it rises and sets let alone the motions of other planets are a mystery to me in the intuitive sense (I know I can look them up). The ancients had little to do at night, other than look at the sky – I feel I’ve lost something through having so many distractions and a night sky obscured by light pollution.

Footnotes

My Evernote on the book contains page by page comments, and also some links to related material

Jan 04 2012

Book Review: The First American by H.W. Brands

first_americanBenjamin Franklin (1706-1790) is someone who has crossed the paths of a number of protagonists in books I have read on the history of science, including Antoine  Lavoiser, Joseph Banks and the Lunar Society. I thought I should read something on the man himself: “The First American: The Life and Times of Benjamin Franklin” by H.W. Brands.

Franklin trained as a printer, as an apprentice to his brother. This was a route into learning since he got to read a lot, interacted with learned men and also started writing, when his brother launched a newspaper in their hometown of Boston – one of the early campaigns of this newspaper was against vaccination for smallpox. In the later years of his life he set up a printing press at his residence at the edge of Paris. Franklin ran away to Philadelphia before his apprenticeship finished, making his first trip to England to learn more of his trade with the (moral if not financial) support of the governor of Pennsylvania. This is another example, like Edmond Halley, of rather precocious responsibility which was not so unusual at the time. It turns out the publication of almanacs was lucrative, as was his printing work for the Pennsylvania Assembly. By the 1750s, only in his forties, he was able to step back from his business and carry on earning a good income from it. His trade as a printer seems to me important in honing his writing skills and getting his opinions out in the public domain.

I picked upon Benjamin Franklin primarily for his work as a “scientist”. The first substantial mentions of science in this book come around 1743, it is at this point he founds the American Philosophical Society and does work on a more efficient stove (which he refuses to patent), although in 1726 he is found making observations of a lunar eclipse on his return trip from England. This suggests a scientific turn of mind from a relatively young age. A few years later he is doing original and well-regarded work on electricity, as well as recommending the use of pointy lightning conductors (of great practical importance). He did some work relating a little to my own field: the spreading of oil and water as well as evaporative cooling, the Gulf Stream and some earlier thoughts on meteorology (this seems to strike a cord with some later proposals by Erasmus Darwin).

When Franklin was born Pennsylvania was in the hands of the Penn family, known as the proprietors – other states were controlled directly by the Crown via Royal governors. For much of his life Franklin considered himself to be British but by the end, the United States of America had become a newly minted nation with Franklin a pivotal figure in its creation. I suspect the causes of the War of Independence are the subject of many books. The battle cry of “no taxation without representation” has taken popular hold as a motivation, although at the time the British living in Britain were taxed with not very much representation, this taxation cause is certainly the theme that Brands follows. Also relevant was colonial support for the British in battles against the French, for which they felt little gratitude and that the British gave up in diplomacy much of that which they had paid for in blood. Ineptness on the part of the British political establishment and George III also plays a large part. Franklin’s part in the War of Independence is played politically in London in the run-up to the war, in France during the war – to garner their support, and finally in Philadelphia where he is heavily involved in the creation of the United States of America.

Throughout his life Franklin was a civic activist, a community politician, setting up the Junto (something of the character of the Lunar Society) and the American Philosophical Society (more like the Royal Society). He also founded fire brigades, a Library Company, an academy and a militia. In a sense the United States of America were the culmination of this civic activity.

For much of the last 25 or so years of his life, from 1757,  Franklin was resident in either London or Paris. In London as a representative of the Pennsylvania assembly to the British state, and in Paris similar when their help was sought in the war against the British. He appears to have fitted well into high society, and been exceptionally highly regarded in both countries. No doubt this is in part due to the formal position he held but prior to his arrival he was known in both cities via his interactions with learned societies (the Royal Society and the Académie des Sciences). He strongly considered staying the rest of his life in London, which is odd since his wife was unwilling to join him there.

In the same way that Poirier’s biography of Lavoisier introduced me to the French Revolution, this book on Franklin has introduced me to the American War of Independence. It’s like sneaking vegetables into a child by hiding them in something they like!

Footnotes

My Evernotes on this book can be found here.

Nov 17 2011

Book Review: The Illustrated Pepys edited by Robert Latham

41dJ gYoaLL._SL500_AA300_In this post I review “The Illustrated Pepys”, extracts from Samuel Pepys’ diaries edited by Robert Latham and enhanced with illustrations from the period. You can download the full Pepys diaries from Project Gutenberg (here) in the earlier 1893 edition and the www.pepysdiary.com website has loads of additional information, it is working it’s way through the diary and will reach the end in May next year.

I feel somewhat ashamed for going for the “illustrated” and edited version which contains approximately one twelfth of the complete diaries, it feels like dumbing down but to be honest I struggle with 17th century English. However, I did enjoy the illustrations.

Samuel Pepys was born in 1633, his family appears to have been relatively well-connected, he attended grammar school, St Paul’s School the Magdalene college at Cambridge funded by two exhibitions and a grant from the Mercers Company (his father was a tailor). In 1649 he was present at the execution of Charles I.

Prior to the start of the diary in 1660 he had married Elisabeth de St Michel, a 15 year old Hugenot, in 1655. On 26th March 1658 he was “cut for the stone” that’s to say had a lithotomy to remove stones from his bladder, this was a painful and dangerous operation at the time. He celebrates the anniversary of this day in each year through the diary – under the circumstances I think I would too!

After university he starts work as clerk to Sir George Downing at the Exchequer and he was also a secretary to Sir Edward Montagu, a relative of his father’s who was later to become 1st Earl of Sandwich. The diary begins in 1660 when Pepys is 27 years old, on the eve of the Restoration, in which he is involved as a member of the fleet which travels to Holland to bring back Charles II as part of Montagu’s retenue. On his return he becomes Clerk of the Acts to the Navy Board, this seems to have been a relatively senior, but not top, position. Later in the diary he describes giving evidence to a committee of parliament on the conduct of the navy in the Second Anglo-Dutch War.

The diaries are an interesting mishmash of the mundane and high politics. Pepys was living in interesting times, he lived in London during the coronation of Charles II, the plague and the Great Fire – all events covered in his diaries.

Pepys has regular sexual encounters with women who are not his wife, he often drops in to an argot of foreign languages (French, Spanish and latin) to describe these encounters. Late in the book his wife catches him fondling their maid, Deb Willet and the repercussions of this last for several months. Interestingly he describes a later, non-sexual meeting with Deb in his argot. The diaries were written in shorthand and were clearly not intended for general readership, he expresses a degree of remorse and guilt over his affairs, so to me it seems this use of language is to separate him from his disreputable acts.

Aside from the womanising Pepys entertained himself with music making with his wife and friends, going to plays and trips into the countryside. Servants seemed like more of the family for Pepys than I imagined, he and his wife give two of their servants who marry a substantial wedding gift for their departure, he also talks of working with labourers such as carpenters who come to his house to work.

I wrote a diary for a period between 2000 and 2005, looking back at them the similarities with Pepys diaries are striking. The little domestic details, the meetings with friends, the extended descriptions of current events, the hints of the work he is currently engaged in, the brief formulaic entries for those days when you just don’t feel like writing, his joy at new clothes and gadgets (like a carriage). I should hasten to add for the benefit of Mrs Somebeans that no sexual encounters with anyone are described in my diary!

The details of his relationship with his wife are touching and domestic, he talks of them laying long and talking, of returning to share a bed with her after she has had a cold. He also describes accidently elbowing her in the face as he wakes with a start and grumbles about her leaving her belongings in a coach, grudgingly admitting at the end of the entry that she had given the items into his care.

I come to the diaries having read Alan Cook’s biography of Edmond Halley (reviewed here), a contemporary of Pepys. Cook’s biography of Halley is very dry, you can almost feel the transition between different sets of formal records. The personality of Halley can only be imagined. The life and character come from the diaries of associates such as Samuel Pepys, Robert Hooke and John Evelyn. Looking more widely biographies of Charles and Erasmus Darwin are both given character by their extensive surviving personal letters and diaries.

“British diaries : an annotated bibliography of British diaries written between 1442 and 1942” compiled by William Matthews lists the diaries known from the period in which Pepys lived, they are sparse: a handful in each year from people in a range occupations. Pepys diaries are well-known because they are preserved, along with his large library, they cover a very active period of history in which Pepys plays a small role close to the centre of action. They are readable and cover both the professional and personal.

He finishes the diary in May 1669, fearing for his eyesight which subsequently improves. Elisabeth, his wife, dies shortly after the end of the diary; over the succeeding years he takes up more senior roles in the navy, becomes and MP and serves briefly as President of the Royal Society. He dies in 1703.

Foot notes

You can see my rather incomplete Evernotes on the diaries here, I recommend www.pepysdiary.com for more detailed exploratory with added details and explanations.