Flamsteed AS Anniversaries 2006 Halley

Read more at —

Books —

John Gribbin ‘The Fellowship — The story of a revolution’ Allen Lane, 2005

Lisa Jardine ‘Ingenious Pursuits — Building the scientific revolution’ Little, Brown & Co 1999

Michael Hoskins (Ed) ‘The Cambridge Concise History of Astronomy’ Cambridge University Press 1999

Alan Cook ‘Edmond Halley — Charting the Heavens and the Seas’ OUP 1998

Colin Ronan ‘Edmond Halley — Genius in Eclipse’ Macdonald & Co 1970

Colin Ronan ‘The Astronomers’ Evans Brothers 1964

Flamsteed Astronomy Society

Huygens, Halley & Harrison

— Anniversaries 2006

The Transit of Venus — When on St Helena, Halley had observed a transit of Mercury (when the planet can be seen from Earth crossing in front of the face of the Sun). He realised observations of a transit from two different places on Earth could be used to calculate the distance from the Earth to the Sun (called the astronomical unit A.U.) Once the A.U. was known, the distances to all the other planets could be calculated using Kepler’s laws. He saw that a transit of Venus would be better for this (Venus is nearer Earth). He published a series of papers on the subject, and finally in 1716 he published his ‘ admonitions’ that the scientific community should organise itself to send expeditions to observe the very rare transits next due in 1761 and 1769, when he would be long dead. Read what happened next in our Transit of Venus report.

The motions of the ‘fixed’ stars — Since antiquity the stars had been known as the ‘fixed’ stars because their patterns (constellations) didn’t seem to change over centuries of observation. In 1710 Halley found that some stars, though, weren’t where they were placed in early catalogues eg Hipparchos and Ptolemy. Rather than assume the ancient positions were inaccurate, Halley dug deeper and concluded that the differences for particular stars were so big that it was more likely they had really moved. In 1717 he published his conclusions that the stars studied (Arcturus, Procyon & Sirius) did show ‘proper motion’ — they were changing position. The ‘sphere of the fixed stars’ was no longer.

Halley and the comets — Edmond had long been interested in comets and had observed the great comets of 1680 and 1682. In fact, he had exchanged correspondence with both Flamsteed and Newton on the subject — the shape of a comet’s trajectory or orbit, was unclear and controversial. After the publication of Newton’s laws, Halley did more work on comets including studying historical records. He was inclined to the view that comets follow elliptical orbits around the Sun and therefore would return. By comparing old observations he concluded that the comets observed in 1531, 1607, & 1682 were one and the same, and that it would probably return ‘about the year 1758’. He published the prediction from Oxford in 1705.

Flamsteed and Halley — Although Flamsteed had encouraged the 19-year old Halley at the beginning of his career, it didn’t seem to take long before he cooled-off towards him. Their personalities were very different and Flamsteed apparently disapproved of Halley’s life-style, manner, and closeness to Newton. A whispering campaign by Flamsteed in 1691 may have been partly responsible for Halley’s failure to get the Savilian chair of astronomy, and by 1703 Flamsteed was whinging that Halley “talks, swears, and drinks brandy like a sea captain” (which indeed he was by then!). This time it didn’t stop Halley getting the chair of geometry. The final rift came after 1710. Flamsteed was refusing to release the bulk of his years of observations at Greenwich, and Newton, who wanted the numbers to test his theories of lunar motion, lost patience. Newton got Queen Anne to appoint him as Chair of a Board of Visitors to the Observatory and proceeded to seize Flamsteed’s work. He asked Halley to edit the work for publication and Halley spent a great deal of time arranging and ‘correcting’ the observations. In 1712 it was printed as the Historia Coelestis now known as the ‘pirate’ catalogue. Flamsteed was furious and never spoke to Halley again. In 1714 he got a court order to have the undistributed copies returned to him (300 of 400 printed) and burned them in Greenwich Park. His own catalogue was eventually published posthumously by his widow, Margaret, as the Historia Coelestis Britannica in 1725. That wasn’t quite the end for Halley and the Flamsteed family —

Second Astronomer Royal — John Flamsteed died on December 31, 1719 after 44 years at Greenwich. On February 9, 1720 Edmond Halley was appointed to succeed him as Astronomer Royal. He was 64 years old. There is a story that he gave Margaret Flamsteed three days to vacate the Observatory. What is certain is that Margaret sold everything in it that wasn’t bolted down, and much that was — the furniture, the instruments, and the clocks. She needed the money to proceed with engraving and printing Flamsteed’s life’s work. Halley had to start again from scratch, and got government money to do it. He developed a great collaboration with London’s best clock and instrument maker, George Graham. Many examples of Graham’s work for Greenwich are there to this day. The Halley-Graham relationship delivered again in 1730 when an uneducated carpenter from Lincolnshire came to London claiming to be able to build an accurate sea-clock and solve the longitude problem. ’Good-egg’ Halley sent him off to meet ’Honest’ George Graham and their encouragement and support got John ‘Longitude’ Harrison well launched on a brilliant career that delivered the first marine timekeeper good enough to claim the £20,000 longitude prize in 1761— ‘H4’. But Edmond Halley was now past his best. He too, pursued the longitude problem through an 18-year programme of observation of the Moon, an entire ‘Saros’ cycle (Halley coined the name ‘Saros’), but he was over 70 and the results were disappointing.

Edmond Halley died on January 14, 1742 aged 86. His wife Mary had passed away already, in January 1736. They are buried in the churchyard of St Margaret’s Lee, just two miles south of the Observatory. The original tombstone was moved for safekeeping and can be seen set in the wall of what is now the Camera Obscura at Flamsteed House, Wren’s Observatory building at Greenwich. What a life. Rather than the ‘Flamsteed Society’ maybe we should have been the ‘Halley Society’ ... ? Brandy anyone?

Edmond Halley 1656-1742

Edmond Halley — continued

Turn over for John Harrison

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