Posts Tagged ‘lunar tables’


Tuesday, August 15th, 2017

‘The grim roll-call broke his [Cook’s) heart…the death of the astronomer Charles Green marked a wave of those who ‘departed this life’….By the end of January [1771] they had barely enough men to man the ship [HMS Endeavour]’. Vanesssa Collingridge, Captain Cook, The Life, Death and Legacy of History’s Greatest Explorer, Ebury Press, 2002

Charles Green son of ‘a prosperous’ free-hold Yorkshire farmer born in Swinton towards the end of 1734 received a broad education with a strong emphasis on science.

John his elder brother took Holy Orders and established a school in Soho, London where Charles found his ‘heavenly passion’ astronomy. After graduating he stayed on for a time teaching mathematics.

In 1760 Charles Green applied successfully for the position of Assistant Astronomer at Greenwich Observatory going on to serve as Chief Assistant to three (3) Astronomer Royals, James Bradley, Nathenial Bliss and briefly Nevil Maskelyne.

In 1675 King Charles II engaged Sir Christopher Wren to design a National Observatory. Wren considereid the ruins of Greenwich Castle a perfect site. Although Oliver Cromwell’s Roundhead Model Army had destroyed its buildings during The Protectorate Interregnum (1653-59) the foundation were intact.

In 1676, Rev. John Flamsteed, England’s inaugural Astronomer Royal, took up residence in the newly minted Observatory and remained in the role until his death in 1720.

Edmond Halley of comet fame succeeded Flamsteed and held the post for twenty-two (22) years until his death in 1742.

Rev. James Bradley followed Halley. His tenure too was lengthy 1742-1762. Bradley is celebrated principally for his work on the speed of light. In 1728 he estimated light moved at the speed of 295,000 km (183,000 miles) per second. Three (3) centuries later Bradley’s calculations were amended to 299,790 km (186,290 miles) per second

‘John Harrison, the man who solved the problem of longitude in 1759’. Peter Ackroyd, Revolution, Macmillan, London, 2016

Had Bradley stuck to light and left longitude to Mr. John Harrison inventor of an accurate marine chronometer – a sea-going ‘pocket-watch’ – many a sea-farer would not have met a watery end.

In 1762 James Bradley died and Rev. Nathaniel Bliss succeeded but owing to ill-health Bliss did not take up residence at Greenwich. He remained in Oxford and died there in September 1764.

In Bliss’ absence Charles Green faithfully fulfilled the onerous role of principal astronomer at the Observatory and, for more than six (6) months following Bliss’ death.

On 8 February 1765 King George III appointed Reverend Nevil Maskelyne Britain’s fifth Astronomer Royal. Maskelyne held the position in a strangle-hold for just on half a century, until his death in 1811. See: Malicious Maskelyne


‘On the day before reliable time-keeping, the skies were used as a giant clock’. Collingridge. ibid. Random House, 2003

John Flamsteed, James Bradley, Nathaniel Bliss and Nevil Maskelyne, consecrated men of the Church had a lot in common, all were wedded to old technology the lunars’.

Luna Tables and Star Catalog listing three thousand (3000) stars were the work of Rev. John Flamsteed the first Astronomer Royal appointed by King Charles II in 1675.

Why then in 1765, did Nevil Maskelyne publish as the only reliable solution to the problem of longitude, the first edition of his Nautical Almanac , extolling celestial navigation.

‘The Almanac represents Maskelyne’s enduring contribution to navigation – and the perfect task for him, too, as it embodied an abundance of excruciating detail’. Dava Sobel. ibid.

‘Maskelyne’s Method’ of determining longitude depended on measuring with a sextant the angular distance between moon, sun and seven (7) selected stars. On a moonless night on a pitching weather deck ‘much too difficult’ many said ‘for ordinary sailors’.

‘John Harrison, the man who solved the problem of longitude in 1759’. Ackroyd. ibid.

Charles Green walked away from Greenwich Observatory a few weeks after Nevil Maskelyne’s appointment as Astronomer Royal.

Maskelyne and Green had history

‘The board [had] concluded in its final report in August 1762 “the Experiments already made of the Watch have not been sufficient to determine the Longitude at Sea”. H- 4 must needs submit to a new trial, under stricter scrutiny’. Sobel. ibid.

In 1764, with Bliss too ill to travel, Green had been tasked to team up with Maskelyne and sail to Barbados to represent the Board of Longitude and oversee yet another assessment of John Harrison’s H-4 marine chronometer.

Maskelyne and Green were to shadow William, John Harrison’s son and Thomas Wyatt, who were making for Barbados aboard HMS Tartar with his now elderly father’s ‘pocket watch’.

For the Board of Longitude this was to be it – failure or success for H-4. Maskelyne’s Almanac versus John Harrison’s chronometer. The sacred versus the secular and a king’s ransom £20,000, in 2019 roughly £400 millions.

As Dava Sobel says; ‘The Board of Longitude was top-heavy with astronomers’ and, one Nevil Maskelyne was determined to scuttle Harrison and his ‘watch‘ once and for all.

Maskelyne in 1761 had began intensive work on his Nautical Almanac. If Harrison’s invention was discredited, with the Almanac on the cusp of publication, fame and fortune would be his.

To put all doubt to rest Sir John Lindsay, Tartar’s captain, was tasked to supply the required ‘stricter scrutiny’.

When Lindsay and William Harrison with H-4 reached Barbados aboard Tarter  in May 1764 they found Green and Maskelyne, who had sailed to Barbados in the Princess Louise, were already ensconced in the local Observatory.

However for Maskelyne his early arrival proved to be counter-productive. He had aired to anyone who would listen unwavering allegiance to ‘his lunar distance method…boast[ing]’ that, with his soon to be published ‘Nautical Almanac (1767), ‘he was sure he’d clinched the case and secured the prize’. Sobel. ibid.

Sir John Lindsay quietly gathered evidence. The Harrison team supported by Lindsay; ‘challenged Maskelyne’s fitness to judge H-4 impartially [Maskelyne] was outraged by their  accusations…in his disquieted condition, he botched the astronomical observations – even though all those present recalled there wasn’t a cloud in the sky’. Sobel. ibid.

H-4 performed flawlessly. There could be not doubt it would supply accurate time-keeping, the essential ingredient required for determining longitude at sea. Charles Green’s epiphany was complete.

‘The Watch proved to tell the longitude within ten miles – three times more accurately than the terms of the Longitude Act demanded! [however] the Board of Longitude allowed months to pass without saying a word…[finally] they were “unanimously of the opinion that the said time-keeper has kept its time with sufficient correctness”. Sobel .ibid.

From then on it should have been plain sailing for John Harrison and his ‘pocketwatch’ but that was not to be.

1765 – 15 March: Charles Green logged his final official Observations on 15 of March 1765 and left Greenwich not long afterwards. It is reasonable to speculate irreconcilable differences, centred on the H-4,  was responsible for Green’s departure.

1765 – 25 March: Rev. Nevil Maskelyne appointed by King George III in February 1765 assumed the role of Britain’s fifth Astronomer Royal in March 1765. He immediately opened up a second front in the fight against John Harrison and H-4. See: Three Yorkshire-men – James Cook, John Harrison, Charles Green  Walked Into A Bar – Maskelyne

Due in large part to Maskelyne’s obstinate scientific pride and avarice, his long tenure at Greenwich was characterised by the unnecessary loss of thousands upon thousands of Royal Naval men in both offensive and defensive mode, as well as a multitude of merchant seamen who sank without trace along with cargo and booty worth untold billions. See: Lotto and Longitude

‘Shortly before Cook sailed [for Tahiti] Maskelyne published his Nautical Almanac’. Dava Sobel. ibid.

Maskelyne was not yet finished with John Harrison and Charles Green.

‘Compared with that of (Joseph) Banks, Mr Green’s equipment was comparatively modest’. H.C. Cameron, Sir Joseph Banks, Angus and Robertson, Sydney, 1966.

Although Cook was supplied a ‘nautical clock’ it was not Harrison’s H-4 ‘pocket watch’. See: Captain Cook Caught Short

1769: In April 1769 Lieutenant James Cook RN sailed HMS Endeavour from England to Tahiti in order to observe the Transit of Venus. The Transit had been predicted by Edmond Halley of comet fame, to occur on 3 June 1769. Charles Green was engaged of the Royal Society to act as Assistant Observer to Cook.

Having recorded the Transit of Venus at Tahiti Lieutenant Cook RN then opened ‘secret Admiralty Instructions’ ordering him sail deep into the southern oceans in search of the fabled Great South Land.

‘John Harrison had perfected the chronometer some years before but it is the character that authorities who for a great many years had withheld half of the prize for his achievement should also decline to make an instrument available to Cook’. A.W. Beazley, Fellowship of Three – John Hunter Surgeon, James Cook Navigator, Joseph Banks Naturalist, Kangaroo Press, Sydney, 1987

James Cook had not been Maskeyne first choice to lead the Transit expedition he had recommended Alexander Dalrymple to the Admiralty. A wealthy Fellow of the Royal Society Dalrymple was held by that august body as Cameron has it; ‘a proper person to be sent to the South Seas’.

Dalrymple had never forgiven Cook for replacing him in the command of he expedition….Of the many charges which he made against Cook perhaps the most ridiculous was that the grounding of the Endeavour on the coral reef was due to the Captain’s misconduct in not anchoring’. Cameron. ibid.

And Maskelyne the scientist who persecuted John Harrison the carpenter-artisan ‘had never forgiven’ the Admiralty for choosing lowly James Cook, a mere warrant officer over Dalrymple.

Maskelyne withheld H – 4 from the newly commissioned Lieutenant James Cook RN. It is highly likely if Cook had known with greater certainty HMS Endeavour’s position while in uncharted waters he may not have spent three (3) months getting to New Zealand.

‘The great Captain Cook observed and calculated more than six hundred lunar distances to obtain the longitude of Strip Cove in New Zealand’. Gavin Menzies, 1421, Harper Collins Publishers, London, 2008

Strip Cove: Consider then the time taken to observe and calculate New Zealand’s North and South Islands. Captain Cook did not leave the area until February 1770. In April 1770 HMS Endeavour anchored in Botany Bay.

Time: Although much is rightly made of Cook’s success in warding off scurvy nevertheless, home-ward bound at Batavia, one-half of Endeavour’s starving debilitated crew succumbed to malaria and dysentery.

Of Joseph Banks’ party of ten (10) only four (4) survived including Banks himself. Earlier two (2) were lost when they froze to death on Terra del Fuego. Alexander Buchan an artist died at Tahiti following an epileptic fit.

Charles Green died not long after Endeavour left Batavia for the return to England via Cape Town of what, from his symptoms may not have been drunkenness as an Australian author of a recent ‘Cook’ book so glibly assigns for Green’s bizarre behaviour, but cerebral malaria.

1771 – 13 July – Spithead: Cook, once on home soil began to; ‘write to the families of all those who had died in his care [including] the loved ones of Mr Green [and] George Monkhouse of Cumberland who had entrusted his sons with Cook’. Collingridge. ibid.

William Monkhouse was Endeavour’s surgeon and his brother Jonothan the young sailor who saved Endeavour from complete destruction after she ran aground on the Great Barrier Reef by ‘fothering‘ the ship a tricky manoeuvre Jonothan had picked up on a previous voyage.


John Harrison’s marine chronometer H-1 had shown, as early as 1736-37 on a timed voyage London, England to Lisbon, Portugal in HMS Centurian, to be capable of when ships were at sea beyond sight of land, giving accurate time-keeping sufficient to establish longitude.

In 1763 Ferdinand Berthoud the Swiss born clockmaker, whose interests also included the marine chronometer had, at the behest of the French King, visited John Harrison in London.

In early October of 1764 Berthoud took his own chronometer to sea for a timed trial but no results of that trial have been discovered. In 1766 Berthoud tried, again without success, to have Harrison divulge the essential elements of H-4.

However Thomas Mudge a prominent London watchmaker who, from time to time serviced H-4, did discuss its intricacies with Berthoad.

‘As it turned out, Berthoud and the other continental clock-makers did not steal Harrison’s designs in the construction of their own marine timekeepers’. Sobel. ibid.

While it is not known for certain if Antoine de Bougainville, a mathematician of note and member of Britain’s Royal Society, took a chronometer with him on France’s first successful voyage of circumnavigation, November 1766 to March 1769, the intriguing question remains open to speculation.

‘Joseph-Jerome Lalande; self-styled most famous astronomer in the universe…visited the Greenwich Observatory, exchanged pleasantries with King George III and helped smuggle out the first description of Harrison’s famous chronometer designed to determine longitude at sea’. Ken Alder, The Measure of All Things, The Free Press, Simon and Schuster, 2002


Harrison’s chronometer was useful but not essential in mapping the world’. Gavin Menzies. ibid.

John Harrison’s chronometer was ‘essential’ in saving sailors’ lives and their widows and children grief and destitution.

‘From the publication of Regiomantanus ephemis tables in 1474 Europeans for the first time calculated Latitude and Longitude…Regiomantanus’s tables were improved by Nevil Maskelyne. They were published in 1767 and remained in use by Royal Navy captains and navigators well after Harrison’s chronometer was introduced. Menzies. op.cit.

Not only did English seamen suffer and die due to Maskelyne’s intransigence in sabotaging and actively discouraging the use of Harrison chronometers the damage spread across the maritime world with thousands upon thousands lives lost. See: Malicious Maskelyne








Monday, August 14th, 2017

‘The Transit [of Venus] was more than just an astronomical curio, it was the key to a wealth of information about the universe, information that would be seized upon by the intensely curious men of science who characterised the age’. Vanessa Collingridge, Captain Cook, The Life, Death and Legacy of History’s Greatest Explorer, Random House, 2003

1663 – England: In 1663 during the reign of King Charles II (1660-1685) a collection of ‘intensely curious men of science’ – the ‘Invisible College’ – morphed into the Royal Society.

A century later, during King George III’s long reign 1760-1820, the Society flowered under his patronage to become one of the world’s most celebrated scientific institutions.

In 1767 with the Transit of Venus in the offing – 3 June 1769 – its second appearance that decade – the Society petitioned King George III for financial support to send observers to report on the phenomenon.

‘That the passage of the Planet Venus over the Disc of the Sun, which will happen on the 3rd of June in the year 1769, is a Phaenomenon (sic) that must, if the same be accurately observed in proper places, contribute greatly to the improvement of Astronomy on which Navigation so much depends.

 As the [Fellows] are in no condition to defray this Expense about £4,000 pounds, exclusive of the Expense of the Ships…with all humility and submit the same to your Majesty’s Royal consideration’. Cited, H.C. Cameron, Sir Joseph Banks, Angus and Robertson, Sydney, 1968

1768 – February: To that end James Douglas 14th Earl of Morton, then President of the Royal Society, penned on 15 February 1768 a Memorial requesting the Monarch’s financial support.

Royal money was forthcoming for it was clear accurate and reliable navigation could equate with domination over the seas. Domination would expedite expansion of territory and trade and strategically more likely assure victory in a naval war.

‘And the sum of £4,000 pounds clear of fees, [was] to be placed at the disposal of the Society…On March 5th of the next year, 1768, the Navy Board was instructed by the Admiralty to purchase a suitable vessel for the great voyage to the South Seas’. Cameron, Sir Joseph Banks, Angus and Robertson, 1968



Wednesday, August 9th, 2017

‘But by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made”. And not likely to be, either, he implied’.  Isaac Newton cited, Dava Sobel, Longitude, Fourth Estate, London, 1998

‘Not likely’ however in 1736-7 on a timed voyage, England to Lisbon aboard HMS Centurian, H-1 an early model of John Harrison’s  marine watch – proved to be a reliable time-keeper.

‘He [Harrison] succeeded, against all odds, in using the fourth – temporal – dimension to link points on the three-dimensional globe’. Sobel. ibid.

Accurate time-keeping was essential for the calculation of longitude at sea and John Harrison a Yorkshire carpenter solved that problem  with his sea-going ‘pocket watch’ that gave a ship’s precise position when beyond sight of land.

‘John Harrison, the man who solved longitude in 1759’. Peter Ackroyd, Revolution, Macmillan, London, 2016

Maritime disasters were common-place throughout the centuries. One of England’s worst recorded disasters occurred during the reign of Queen Anne in the middle of the War of Spanish Succession (1701-1714) .

1707 – 29 September: At the end of September 1707 a fleet of twenty-one (21) English ships led by HMS Association flagship of Admiral Cloudesley Shovell, overall Commander of British fleets set sail from Gibraltar, captured in 1704 from Spain, for Portsmouth England their home base.

Shovell’s vessels were battered by fierce gales. As they neared England dense sea-mist thrown up by recurring storms proved a nightmare for ships’ navigators making it all but impossible to plot a safe course.

1707 – 22 October: To add to their woes, when off the coast of Cornwall heavy cloud obscured moon and stars, celestial navigation became impossible. In the darkness some sailing masters lost their bearings and failed to recognise their proximity to the Isles of Scilly.

Four (4) vessels including HMS Association crashed onto rocks and sank with all hands including Admiral Shovell. Two (2) more ships capsized, overall mortality was reckoned at 1500 souls.

 ‘The 1707 incident, so close to the shipping centres of England, catapulted the longitude question into the forefront of national affairs [and] underscored the folly of ocean navigation without a means for finding longitude’. Dava Sobel. ibid.

A lengthy investigation into the Cloudesley Shovell disaster concluded, due to prevailing weather conditions, ships’ navigators had been unable to determine their true position in relation to the Cornish coast.

‘The souls of Sir Cloudesley’s lost sailors – another thousand martyrs to the cause precipitated the famed Longitude Act of 1714, in which Parliament promised a prize of £20,000 for a solution to the longitude problem’. Sobel. ibid.

So why then by 1740, nearly a half-century after Parliament passed the Longitude Act,  did a second naval disaster of similar magnitude occur yet  its prize, £20,000 reckoned now at more than £400 millions, had not been awarded?

Worse still; ‘ when John Harrison arrived in London in the summer of 1730, the Board of Longitude was nowhere to be found. Although that august body had been in existence for more than fifteen years, it occupied no official headquarters in fact, it had never met’. Sobel. ibid.

By 1740 Harrison had built three (3) versions of his mechanical ‘watch’ but persistent hounding by the commissars – Astronomer Royals – of Greenwich Observatory meant that when disaster overtook Admiral Anson;‘the longitude clock stood on terra firma in Harrison’s home at Red Lion Square’. Sobel. ibid.

On the days before reliable time-keeping, the skies were used as a giant clock’.Vanessa Collingridge, Captain Cook, The Life, Death and Legacy of History Greatest Explorer, Random House, London, 2003

1740 – September: Although H-2 and H-3, improved models of Harrison’s chronometer, were available Commodore George Anson in HMS Centurion, took a squadron of six (6) warships to sea ‘the old fashioned way’.

‘Anson’s squadron took the Atlantic the old-fashioned way, on the strength of latitude readings, dead reckoning and good seamanship’. Sobel. ibid.

1741 – March: Anson’s ships rounded Cape Horn in early March 1741 only to be caught by gales so intense navigators had no idea where the squadron stood in relation to the land. As Dava Sobel has it; ‘a grand tragedy unfolded, founded on the loss of their longitude at sea’.

The squadron had been at sea longer than intended. Many crew developed scurvy ‘killing 6 to 10 men every day’. As time went on, there was never enough man-power to repair sails shredded by ‘winds [that] carried rain, sleet and snow’. 

Finally, the ship’s reached Juan Fernandez where Admiral ‘Anson helped carry the hammocks of sick sailors ashore, then watched helplessly as the scourge picked off his men one by one…until more than half of the original five hundred were dead and gone’.  Sobel. ibid.

‘The old fashioned way’ celestial navigation used complex Lunar Tables devised a century earlier by Rev. John Flamsteed during his tenure as Britain’s first Astronomer Royal. Appointed by King Charles II in 1675 he held the post until his death in 1719.

Flamsteed’s Luna Tables and Star Catalogues may have been well suited to static land-based platforms. But much less so on a pitching deck in churning seas when dense cloud and black starless nights magnified a navigator’s problems.

In such circumstances ‘tedious’ complicated ‘difficult to execute’ calculations required four  (4) men with hand-held instruments, the reason many a seaman lost an eye.

Flamsteed himself had, like Harrison, felt the cruel lash of duplicity.

With the connivance of Isaac Newton, Edmond Halley of comet fame,  purloined, plagiarised and, during the Flamsteed’s lifetime, published his work without permission or attribution. In 1720, following Flamsteed’s death, Halley was appointed Astronomer Royal.

Meantime in 1740 Admiral Anson’s martyrs were added to Sir Cloudesley’s lost souls and this, in part at least, because £20,000 up for grabs, had unintended consequences.

‘The Board of Longitude was top-heavy with astronomers, mathematicians and navigators’. Sobel. ibid.

The vast sum proved a heady brew when thrown amidst the warlocks of Greenwich Observatory whose intransigence was without doubt responsible for the loss of countless lives.

‘John Harrison, the man who solved longitude in 1759’. Peter Ackroyd, Revolution, Macmillan, 2016

In the mid 1760s battle-lines were drawn between moon and machine. The Observatory’s Rev. Nevil Maskelyne, Britain’s fifth Astronomer Royal, clung to outmoded 17th century thinking and old technology – Luna Tables versus the mechanical sea-going clock. ‘See: Moon Versus Machine 

1765:  Maskelyne published the first edition of his major work The Nautical Almanac’ one hundred (100) years after King Charles II founded Greenwich Observatory.

Maskelyne was certain theNautical Almanac’, based on the relationship between Sun, Moon and Stars as a means of calculating longitude on the high seas, would deliver him the ‘king’s ransom’ £20,000.

John Harrison died in March 1776 aged ‘exactly eighty-three years’. Dava Sobel covers fully the extraordinary story of the Yorkshire carpenter whose invention of the marine chronometer solved the problem of longitude at sea. See: Cook, Harrison, Green – Three Yorkshire Men Walked Into A Bar – Maskelyne

‘A true-life thriller, jam-packed with political intrigue, international warfare, personal feuds and financial skullduggery’. Francis Wheen, Daily Mail.

Longitude tells of Harrison’s painstaking efforts to perfect his ‘watch’ and of unending frustrations as he butted heads with the dictators of the Longitude Board.

Sobel catalogues the merciless persecution of Harrison by a succession of Astronomer Royals, James Bradley, Nathaniel Bliss and finally Rev. Nevil Maskelyne who held the position from 1765 to 1811. See: Malicious Maskelyne

‘Rarely have I enjoyed a book as much as Dava Sobel’s Longitude. She has an extraordinary gift of making difficult ideas clear’. Patrick O’Brien, Daily Telegraph (London).

For more details on Dava Sobel’s book, Longitude see:


‘In January 1772 William [Harrison] wrote the king [George III] a poignant letter covering the history of his father’s hardships with the Board of Longitude and the Royal Observatory…the king is reported to have muttered under his breath “These people have been cruelly treated”. Sobel. ibid.

And where a mere three (3) years earlier, in 1769, was Harrison’s chronometer when Lieutenant James Cook RN sailed HMS Endeavour deep into the South Seas in search of the fabled Great South Land?

‘[H-4 [was] bolted to a window seat in the [Greenwich] Observatory’. Sobel. ibid. See: Captain Cook Caught Short