Flamsteed Astronomy Society

Huygens, Halley & Harrison

— Anniversaries 2006

1656 : November 8th (n.s.)  350 years ago, Edmond Halley was born in ‘Ackney (well, ‘Aggerston really) — a good London lad (mind you, Hackney was then a quiet rural village 3 miles from London).  His father was a prosperous business man, owner of soap and salting factories (smelly!) and property.  Edmond himself gives his birthday as October 29th, but this is ‘old style’ (o.s.) according to the Julian calendar used in England until 1752, and equates to November 8th ‘new style’ in the Gregorian calendar used since then.  He had a very comfortable upbringing and was educated at St Paul’s School and Queen’s College, Oxford.  He’d already developed a keen interest in astronomy and arrived at Oxford with a full set of instruments the envy of many a professional.  But enough of this.  The story of Halley’s life has filled several books.  Here we must be content with a very brief overview of his legion accomplishments.   Edmond was much more than ’just’ a brilliant astronomer  —

Early ‘astro-brat’ — at the age of 18, before he graduated from Oxford, Edmond was in correspondence with the Astronomer Royal, John Flamsteed, who gave him help and encouragement.   Edmond was truly pushy for quick success and with Flamsteed’s help and the king’s backing, took passage in 1676 on an East Indiaman to the Island of St Helena, in order to map the southern stars not visible from Britain.  When he returned in 1678 his Catalogue of the Southern Stars brought him instant recognition from the scientific community.  Flamsteed called him ‘our southern Tycho’.  It didn’t hurt that Halley devised a new constellation which he called Robur Carolinum (Charles’ Oak) after the tree which had hidden the king, Charles II, following defeat at the battle of Worcester.  Robur Carolinum failed to catch-on, but the boot-lick got Halley granted his degree by royal mandate.  He was also deservedly elected to the Royal Society in November 1678.

All-round ‘good egg’ — Not like some other grumpy old men associated with the Greenwich story (notably Flamsteed and Harrison), Halley enjoyed the society of the coffee house and was comfortable in the company of kings and princes.  It is rumoured that he amused himself by pushing Tsar Peter the Great about in a wheelbarrow, during Peter’s visit to London in 1698.  Peter and his entourage trashed John Evelyn’s mansion in Deptford.

Midwife to Principia — In 1682 Edmond cut short a Grand Tour of Europe, returned to London, married and set-up house in Islington.  There follows a period of hard work on behalf of the Royal Society — in 1685 he was appointed Clerk to the Royal and editor of Phil. Trans.  Around 1684 he got involved in a debate with Wren and Hooke on why the planets follow the orbits they do (elliptical ‘Keplerian’ orbits).  Hooke felt the Sun was generating an attractive force which obeyed an inverse square law (double the distance, and the force drops to one-fourth), but he failed to come up with a mathematical proof.   Halley visited Isaac Newton in Cambridge and was delighted to discover that Newton had already prepared a proof (although he couldn’t find the paper at once).  Newton was reluctant to make his work public however, and Edmond had to coax him along.  He virtually became Newton’s agent at the Royal Society, culminating in 1687 when Halley personally paid for the publication of Newton’s Principia, which sets-out the law of universal gravitation.  Halley was god-parent and midwife to Newton’s great masterwork.  If it hadn’t been for Halley it may never have seen the light of day.

Intrepid Mariner : Halley and the Paramore — Halley had been very interested in navigation and matters maritime since his voyage to St Helena.  In the late 1680s he designed a diving bell system and in 1691 was involved in using it at Pagham in Sussex.  In 1698, despite him having no previous formal experience, the Royal Navy gave him a commission and appointed him Captain of HMS Paramore to sail on surveys of the Atlantic and study the variation of the magnetic field.  Halley hoped that the magnetic variation (now called ‘declination’ — how much a compass needle deviates from true north) might be used as a way to find longitude.  His lack of experience initially brought him into conflict with his First Lieutenant, and Edmond then personally commanded and navigated the return voyage to have the man court-martialled (!!).  His two Atlantic voyages on the Paramore failed to find a lasting longitude technique (magnetic variation alters over time) but to report his findings Halley devised the first chart to use ‘isogonic lines’ — lines drawn to connect places of equal magnetic variation, but now used for all kinds of measurements: eg barometric pressure (isobars); and equal heights (contour lines).     Queen Anne was so impressed that Edmond was sent on two diplomatic (spying?) missions to the court of Emperor Leopold in Vienna to advise on fortifications in the Adriatic.  On one of his return journeys, he popped into Hanover to meet the Elector, soon to become King George I of England.  In later life, in 1729, his voyages also brought him a pension when Queen Caroline, wife of King George II, discovered this episode of his past and granted him retired Captain’s half-pay.

Professor Halley — Amazingly Edmond had not yet held a leading academic post.  In 1691 he’d applied for the Savilian chair of astronomy at Oxford but been refused (of which more later).  By 1704 his track record and contacts were such that he couldn’t be refused again and was appointed to the Savilian chair of geometry.  Then in 1710 Oxford conferred the degree of D.C.L. — ‘Dr Halley’ at last.  He published on endless subjects including meteors, novae, nebulae, aurorae, mortality, and the great age of the Earth, but particularly —

 

How to pronounce ‘Halley’

 

Today we mostly say it ‘Hal-lee’.  Many, especially in the USA, say ‘Hay-lee’.  Edmond himself probably said ‘Haw-lee’

Edmond Halley 1656-1742

(Royal Society)

Edmond Halley — On Christmas Day 1758 a German amateur astronomer and farmer called Georg Palitzsch was apparently the first to witness the return of the great comet later called Halley’s Comet.  Its return in 1758 had been predicted in Halley’s book

A Synopsis of the Astronomy of Comets published in 1705.  Halley knew he wouldn’t be around to see it for himself — in fact he died in 1742.   The prediction of the return of a great comet, the first such based on Newton’s law of universal gravitation, was how Halley is mostly remembered, but it was almost the least of his many, many accomplishments ...

Turn over for more on Halley

Halley’s Atlantic chart showing ‘isogons’ — lines connecting equal measurement of magnetic variation

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