by John Gribbin
The English, Dutch and Austrians formally declared war in May 1702. Between them, the English and Dutch had powerful naval forces, but lacked a base in the Mediterranean and a way to link up by water with their Austrian allies at the head of the Adriatic Sea. George Stepney, the English Ambassador in Vienna, suggested that if an English, or Anglo-Dutch, squadron could be based in the Adriatic all year round it would be invaluable, and recommended that a suitable person be sent to find an appropriate port. The job description could have been written for Halley, who was the ideal man, both for his nautical experience and because he was a suitable Gentleman to be a representative of the Queen. His nautical rank of Captain was equivalent to Colonel in the army, which ensured that he would be well received by the protocol-conscious Imperial Court. And he was known to be discreet.fn13
Halley received his formal instructions in a letter from Queen Anne dated 4 November 1702; like his naval orders, the letter was clearly drafted by Halley himself:
You shall immediately upon receipt hereof repair to the Emperors Court at Vienna, or such other Place where he may be. and there apply your Selfe to Our tr. and Wellb. Stepney Esqr, Our Envoy Extrary or in his absence to his Secretary, whom We have directed to be assisting to You in obtaining such Commission or Orders [from the Emperor] as shall be sufficient to enable you to perform the Service, whereupon you are sent, and herein …
… you shall make what haste you can to the said severall Ports, and take exact Plans of each of them, making such Observations and Remarks as you think may any way conduce to Our Service.
You shall particularly sound the depth of water in each Port, what Rocks or Sands are in each Port, and in the Entrance into it, what number of Ships can ride there securely against Wind and Weather, what fortifications can be made for the defence of them against an enemy, and in what manner and with wheat charge the same can be made.
What conveniencys there are or may be made there for careening, cleaning and repairing Our Ships …
You are to go from hence to the Hague, and there communicate your instructions to the Earle of Marlborough …
You are to use all diligence in your journey to Vienna and thence to the Adriatick and returne and in the execution of these Our Instructions, since it is of great importance to Our Service, that we have as speedy an Account of these matters as is possible …
Halley, travelling with his servants, was in the Hague on 12 December, and moved on via Leipzig and Prague to Vienna, arriving on 10 January 1703. He could not travel more directly, through Bavaria, which was a French ally. In Vienna, Halley had to wait while the diplomatic niceties were observed until he could receive the formal documents allowing him passage to the Adriatic, and used his time to study the available maps and other information about the ports. He found only one that was likely to meet the requirements of a squadron of Her Majesty’s ships – Buccari, a little to the south of Fiume. From Vienna, Halley moved on to Trieste, arriving on 1 February, and carried out a brief survey of the port, reporting back to Stepney that it was not suitable for their needs. But Buccari, which Halley reached on 10 February, offered everything he had hoped for, with a narrow and easily defended entrance opening up to a sheltered bay with plenty of anchorage. The entrance is only about 400 metres wide, but the bay itself is about a kilometre wide and four-and-a-half kilometres long, running parallel to the coast. After surveying the harbour and taking depth soundings, identifying the best sites for gun batteries to defend the harbour, and taking a quick look round the nearby region, Halley was back in Vienna on 27 February, where he used his observations to draw up charts of the harbour, one set of which was presented to the Emperor on 10 March. In return, Emperor Leopold gave Halley a diamond ring worth £60 (taken, the story goes, from the Emperor’s own finger); a sensational sign of favour which is mentioned in all the accounts of Halley’s visit to Vienna.fn14 Just a week later, armed with his charts and data, he was on his way back to London (unfortunately, no copies of the charts survive).
Halley arrived home by the middle of April, carrying also a letter from Stepney reporting to the Secretary of State, the Earl of Nottingham, that:
he has performed what he was sent about entirely to the satisfaction of this Court and I hope that your Lordp will herein be satisfied with the discoveries he has made.
He had indeed carried out his duties with ‘all diligence’; but the same could not be said of the Austrians left to carry out the work at Buccari. In pite of Stepney’s prodding, very little work was carried out, and Halley was sent back to see what could be done to speed things up, leaving London on 22 June 1703 and arriving in Vienna on 23 July. On the way he passed through Hanover, and is reported to have met the Elector, who was Queen Anne’s designated successor, and already known as George I; the future King clearly had an interest in the activities Halley was now involved in.
In Vienna, Stepney was relieved to see him:
It will be an ease to me to have Capt. Halley in these parts to look after the Fortifications and Provisions which are things I do not understand and I should have been unwilling to rely on the assurances these Ministers can give me, that all is in readiness, wherein they are apt to deceive both themselves and others.
But even Halley was frustrated by the task in hand. The work, especially the key task of preparing batteries for the guns to defend the harbour, was proceeding slowly, both because those in charge believed (or pretended to believe) that no fleet would be coming that year, and because of a problem that has a familiar resonance today: the workers were, as Halley wrote to Nottingham, ‘being well paid by the day while the work is in hand’, so it was in their interest to carry it out slowly. When Halley did manage to get things moving on the construction of the batteries, another problem arose. Where were the cannon to go in them? The Austrians wanted the English to take some out of the ships and mount them in the batteries when the fleet arrived; the English wanted the Austrians to supply the guns. While the wrangling continued, a squadron under Sir Cloudsley Shovell did enter the Mediterranean in 1703, but stayed only briefly before returning home. Halley also returned to England in the autumn of 1703, having achieved less than he had hoped but probably more than anyone else could have done. The following year, the capture of Gibraltar by the English and the destruction of the French fleet at Toulon removed the immediate need for an Adriatic base, and the project was never completed.fn15
There is, however, an intriguing twist in the tail. Halley had arrived home in November 1703. A letter from the Earl of Nottingham dated 14 January 1704 instructs the Exchequer to pay to Stepney the sum of £36 ‘out of the secret fund’ as a reimbursement for money he had given to Halley for expenses he had incurred.fn16 Expenses doing what, we shall never know, but it seems that Halley’s travels around Europe also provided the cover for a little quiet spying.
Whatever he had been up to, as far as his career was concerned, Halley’s return to England had been perfectly timed. All thoughts of future voyaging seem to have disappeared with the news that John Wallis, the Savilian Professor of Geometry at Oxford, had died on 28 October 1703 (the day before Halley’s forty-seventh birthday). It opened up the possibility of settling down into the academic life Halley had long wanted.
CHAPTER ELEVEN
LEGACIES
Patronage was of key importance in deciding appointments to Oxford or Cambridge professorships, and at least one prospective candidate for the Savilian Chair moved quickly to call in a favour. On 6 November 1703 Viscount Hatton, of Kirby Hall in Northampton, wrote to the Earl of Nottingham, who was Secretary of State but a more junior member of the family which Hatton headed, mentioning that:
I am so much obliged to Dr Keith … for his care of me in my late sickness that I cannot but recommend his brother, at his request, for the ‘mathematique’ Professorship at Oxford, for which he is a candidate. He is, I know, very capable of it, ‘but if Mr Halley be thought of, or aim at it, he acquiesces and would by no means oppose it’.
Nottingha
m was obliged to let Dr Keith and his brother down gently, writing to Hatton on 20 November, with Halley not yet back in London, that:
I can’t say yt Mr Halley thinks of ye Mathematick professor’s place but everyone who has a vote in the election thinks of him; and [I] am very glad yr Lops recomendation of another is accompanyd with this condition, if Mr Halley does not pretend to it, for I have seen his zeal in the publick service (on which he is now abroad) the which added to his extraordinary skill above all his competitors obligd me to be very forward in promoting him to this place.
One person was not happy at the prospect of Halley’s appointment. In a letter to Abraham Sharp, dated 18 December 1703,fn1 Flamsteed grumbled ‘Dr Wallis is dead – Mr Halley expects his place – who now talks, swears and drinks brandy like a sea captain’. Halley was indeed a sea captain, and proud of it. After his election, on 8 January 1704, he still preferred to be known as ‘Captain’ Halley, rather than as ‘Professor’ Halley. He was formally appointed to the post of Savilian Professor of Geometry on 7 March, and gave his inaugural lecture on 24 May 1704. He was now forty-seven, and had been elected to the Council of the Royal Society on his return to England, the same day that Newton was elected as President.
Halley’s income as Professor was notionally about £150 a year, from rents on estates endowed by Sir Henry Savile back in 1619, but this seems to have been no more reliable than Hooke’s income from Cutler and the Royal, and by the time Halley became Astronomer Royal he was owed more than £1,000. But his duties were not onerous: he had to lecture once a week in term time and to be available for one hour each week to give tuition to anyone who might call on him at the house in New College Lane which went with the job. Like other professors, however, he was often away from Oxford, at his home in London.
As with Hooke, Halley worked on different projects at the same time, and we have to unpick the threads and tell each story in turn. One important theme of his day, but of less interest now, concerned his translation of Ancient Greek mathematical treatises, using Arabic copies of the original Greek texts. But it was Ancient Greek observations, not mathematics, that led Halley to a profound discovery, linked to an ongoing dispute between Flamsteed and the entire academic establishment of his day. Amazingly to modern eyes (and to most of his contemporaries), by the time Halley became a Professor in Oxford, Flamsteed had still not published his catalogue of the northern stars, nearly thirty years after Halley had published his (admittedly more limited) Catalogue of the Southern Skies. Some idea of what people felt about this can be gleaned from a letter written by James Gregory (David’s brother) in 1699:
Mr Flamsteed has rectified above 3,000 fixed stars; but is so perversely wicked that he will neither publish nor communicate his observations.
This was not a situation that Isaac Newton, the new President of the Royal Society, was willing to tolerate. He gained a formal promise from Prince George, the Consort of Queen Anne, that he would pay for the publication of the catalogue, which Flamsteed claimed was ready for the press, or would be once a fair copy was made. A Committee of Referees, headed by Newton (but not including Halley), was established to check the manuscripts and get them ready for publication, and Flamsteed handed over a rough copy of his observations on the understanding (as he saw it) that nothing would be printed until he provided a final fair copy. But that is not what the Referees understood, and they set the ball rolling, albeit somewhat sluggishly. David Gregory had the main responsibility for overseeing the project, and printing started in May 1706 but in a very desultory manner, and stopped entirely in 1708 when both Gregory and Prince George died. Nothing more happened until 1710, when Anne appointed a Board of Visitors (headed, of course, by Newton, and this time including Halley) to oversee the work of the Royal Observatory. As well as being empowered to demand from Flamsteed a ‘true and fair copy’ of his observations each year, the Visitors had the power to instruct him what observations to make, and to inspect his instruments to see that everything was being kept in good order. This was more than a mere slap on the wrist for Flamsteed, but the work they were particularly interested in was the catalogue; in December 1710 Halley was given the job of seeing the project through, adding his own observations and computed results to fill in gaps in the material supplied by Flamsteed. This was entirely within the remit of the Visitors, and Halley tried to keep Flamsteed in the loop, even sending him proofs for checking, with a conciliatory covering letter ending ‘if you signify what’s amiss, the errors shall be noted, or the sheet reprinted, if the case require it. Pray govern your passion, and when you have seen and considered what I have done for you, you may perhaps think I deserve at your hands a much better treatment than you for a long time have been pleased to bestow on Your quondam friend, and not yet profligate enemy (as you call me).’ But Flamsteed still refused to cooperate.
While the catalogue was going through the press, in October 1711 Flamsteed had a furious row with Newton at a meeting called to discuss the need for new instruments at the Greenwich Observatory, and ended up calling Newton an atheist – which we know, as Flamsteed did not, would have been particularly barbed. That was the end of any prospect of friendly relations between Newton and Flamsteed. Halley fared no better. Flamsteed continued to refuse all overtures of friendship, and after Halley visited him in June 1712, taking with him companions clearly carefully chosen to reduce the prospect of unpleasantness, Flamsteed recorded in his notes:
the impudent editor, with wife son and daughtersfn2 attending him, and a neighbouring clergyman in his company, came hither, I said little to him. He offered to burn his catalogue (so he called the corrupted and spoiled copy of mine, of which I had now a correct and enlarged edition in the press, and the second sheet printing off) if I would print mine. I am apt to think he knew it was so, and was endeavouring to prevent it. But to render his design ineffectual, I said little to him of it: so he went away not much wiser than he came.
The upshot of the unpleasantness was that the Gregory/Halley version of the catalogue appeared in 1712, but Flamsteed and his wife managed to buy up most of the copies and burn them. Flamsteed, now in his late sixties, was, however, at last moved to put his data in order for publication (the reference to it being already in the press in 1712 seems to have been an exaggeration), and it was eventually published in three volumes in 1725, giving three thousand star positions to an accuracy of 10 arc seconds, much better than earlier catalogues. By then, though, Flamsteed was dead, and Halley had succeeded him as Astronomer Royal.
Catalogues such as those of Flamsteed, Hevelius and Halley were intended as charts of the positions on the sky of the fixed stars, thought to be eternal and unchanging. But during his time as Savilian Professor, Halley realised that this is not always the case. ‘New’ stars, or novae, that had appeared from time to time, flaring up brightly then fading into obscurity, had already proved that the heavens were not entirely unchanging, but Halley seems to have been the first person to recognise that there are two kinds of nova. Writing in the Philosophical Transactions in 1715, he noted that the new star seen by Tycho Brake in 1574 and the one seen by Kepler in 1604 were particularly bright and faded very quickly, while other novae were less bright, and some of them seemed to flare up every few years. ‘These two,’ wrote Halley, ‘seem to be of a distinct Species from the rest’; his was the first recognition of what we now call supernovae. A couple of years later, when he was already over sixty years old, Halley reported the profound discovery we mentioned. He found that even the ‘permanent’ stars do not all stay in the same place.
Halley was interested in the way the pattern of the stars seen from Earth seems to drift in the long term, which is a result of the way the Earth wobbles as it orbits the Sun. In the course of this work, while preparing astronomical tables, Halley compared the latest catalogues he had available with a star catalogue that had originally been compiled by Hipparchus in the second century Bc and had been recorded in the works of Ptolemy. Most of the star positions in the old catalo
gue matched those of the same stars in the catalogues made in Halley’s day, but three stars were in significantly ‘wrong’ positions. Halley realised that the old observations were accurate – as shown by the positions of the other stars – but that a few stars had moved strikingly across the sky since the time of Hipparchus. The star Arcturus, for example, had moved across the sky by about twice the width of the full Moon in just under two thousand years, far too much to be explained as a mistake by the Greek astronomer. Halley pointed out (in the Philosophical Transactions) that the stars must be at different distances from us, and that the ones we see moving in this way must be the nearest ones; while more distant stars must be moving in the same way, we do not notice this because of the greater distances.
What shall we say then? It is scarce credible that the Antients could be deceived in so plain a matter … these Stars being the most conspicuous in Heaven, are in all probability nearest to the Earth, and if they have any particular Motion of their own, it is most likely to be perceived in them, which in so long a time as 1800 Years may shew itself by the alteration of their places, though it be utterly imperceptible in the space of a single Century of Years.
The discovery of stellar motion was one of the most important observational discoveries in the history of astronomy, and a completely new idea in the eighteenth century, but seems to have passed almost without comment at the time. Halley’s attention, though, was not solely fixed on the distant stars. Around the same time he was making this discovery, Halley was also demonstrating his impressive organisational skills and continuing intellectual power with observations of an event much closer to home, an eclipse of the Sun. These observations became part of a legacy that he would leave to future generations, in the same way that Hipparchus had provided a legacy of data for Halley.