- Email: [email protected]
Johann and Elizabeth Hevelius, astronomers of Danzig
Johann and Elizabeth Hevelius, astronomers of Danzig Sir Alan Cook FRS Elizabeth Hevelius (1647–1693) was the second wife of Johann Hevelius, the renowned astronomer of Danzig, and assisted with his observations from the first years of her marriage. Hevelius wrote of her in his books as an able collaborator and she is portrayed in one of them observing with him. She brought out his final, posthumous work. With Johann, she received many notable visitors (including Edmond Halley) and observed with some of them at Danzig. She is the first woman astronomer of whom we have any record.
Elizabeth Hevelius, the second wife of the renowned astronomer, Johann Hevelius of Danzig (1611–1687), may or may not have been the first woman astronomer but she was certainly the first woman to appear in a picture as actually engaged in observing (Figure 1). Elizabeth was one of three daughters of a Danzig merchant, Nicholas Koopman. She married Hevelius on the third or fourth of February 1663, when he was 52 and she 16, following the death of his first wife. Within two years or less, she was helping with his observations. Johann Hevelius himself was the son of a wealthy brewer of Danzig; the brewery still exists under the name of Hevelius, and the labels on its bottles carry his picture. Danzig, one of the cities of the Hanseatic League, was part of the Kingdom of Poland but enjoyed considerable independence. It was a splendid place (Figure 2), with rich merchants and a famous great harbour crane, now reconstructed. Much of its trade was with the farms and forests of Poland. The city councillors, of whom Hevelius became one, were very grand people. Hevelius became interested in astronomy as a young man and travelled to London, Leyden, Paris and Avignon, where he met a number of prominent savants with whom he continued to correspond for many years. He intended to go to Italy to meet Galileo but was called back to Danzig to look after the family interests because his father’s health was failing. He became a senator (a member of the Rathscollegium, of which he was twice president) and he was also a city judge. He devoted himself to astronomy from shortly after his return to Danzig; after his father’s death in 1649, he constructed many instruments and installed them in an observatory that he built upon his house. He resolved to improve upon the catalogue of star positions that Tycho Brahe had made and he acquired the manuscripts of Kepler. In 1635, he married Katrina Rebeschke, the daughter of a city councillor of Danzig. They had no children and she died in 1662.
Hevelius first studied the Moon, making the first map of her surface and discovering the libration (rocking motion) of the Moon, although he could not explain it1. He made systematic studies of the planets and of the fixed stars, he observed comets and detected variable stars. By the time he married Elizabeth, after the death of Katrina, he had already accumulated a very large number of observations; these are recorded together with his later ones in the second volume of his Machina Coelestis of 16792. Hevelius had a licence to print from the king of Poland,
Sir Alan Cook FRS Is Jacksonian Professor of Natural Philosophy Emeritus and former Master of Selwyn College, Cambridge. His new biography of Edmond Halley appeared in 1998. He edits the Notes and Records of the Royal Society.
8
Endeavour Vol. 24(1) 2000
Figure 1 Hevelius and Elizabeth observing with the great sextant3. Reproduced by permission of the University Librarian, Cambridge.
0160-9327/00/$ – see front matter © 2000 Elsevier Science Ltd. All rights reserved. PII: S0160-9327(99)01263-6
Johann II Sobieski, and he employed a printer, Simon Reiniger (Typographus), for his astronomical works. He distributed them widely in Europe and there are presentation copies in the British Library, the Bodleian Library in Oxford and the University Library in Cambridge. They are handsomely printed and bound, and record something of the astronomical activities of Elizabeth. Elizabeth was unusually well educated for a young woman, for Hevelius said that she was a good mathematician. She and Hevelius had four children: a son born in 1664, who died when a year old, and three daughters. Katerina Elizabeth was born in 1666 and married a councillor of Danzig, Ernst Lange; Julia Renata was born in 1668 and married Dietrich Mathis d’Heinrichson who was the Grand Veneur of the King of Poland; Flora Constantine was born in 1668 and married Charles Adolph Ferber, another councillor of Danzig. Elizabeth seems to have begun to take Figure 2 Hevelius’s instruments on the roof of his house, with the river Vistula in the background3. part in observations from the first years Reproduced by permission of the University Librarian, Cambridge. of her marriage. In the first volume of the Machina Coelestis of 16733, in which Hevelius described had been using Brahe’s methods for some 30 years and had great confidence in them. Figure 2 shows the observatory his instruments, he says that he had a number of assistants that Hevelius built on his house, with some of the but that his wife (Elizabeth) became a valuable collaborator instruments set up there and a view over the river Vistula. and a most exact observer, and he came to rely entirely on Hevelius’s principal instrument was a large brass her and his printer. His comment on her mathematical sextant six feet in radius (‘Sextant Magno Orichalcico’) ability suggests that she also helped with computations. (Figure 1). Its characteristics had a great influence on Elizabeth’s observations and on the relationships of Hevelius The observatory at Danzig and Elizabeth with English astronomers, so it is worth Hevelius constructed his instruments and began his obserdescribing them in some detail. There were two sets of vations of the stars some 30 years before Flamsteed had open sights, one fixed to the frame of the sextant and the his up-to-date telescopic instruments at Greenwich. other movable, rotating around the Hevelius saw himself as the succentre of the arc of the sextant. The cessor of Tycho Brahe and, like Halley arrived on 26 May angle between them was read from Tycho, he used open sights (essenand immediately began the graduated arc of the sextant. The tially a rod with slits at the two ends) to watch Hevelius, and no sextant was mounted on a vertical to point on stars, for he distrusted the doubt Elizabeth, at the axis and supported by ropes so that it then-still-novel telescope for such could be tilted about a horizontal measurements4. He measured the great sextant. axis. Evidently, such a large instruangular distances between two stars ment that was adjustable about both the vertical and the with a sextant, which is a frame carrying a 608 arc with horizontal axes would have been very cumbersome. two sets of sights, one usually fixed to the frame and the When John Flamsteed set up the new Royal Observatory other rotating about the centre of the arc (Figure 1). at Greenwich, he had to use a sextant in his first years until Thirty years later, Flamsteed and his French contemhis mural arc was ready. However, he mounted it on an axis poraries used telescopic sights with micrometers in the eyedirected to the North Pole so that one person could rotate pieces. They mounted their principal instrument, a quadit about that axis to keep the fixed (telescopic) sight on a rant carrying a telescope, vertically in the meridian on a particular star while adjusting the movable sight to another. wall. They measured the time and altitude at which a star Edmond Halley seems to have used a similar mount for crossed the meridian, from which they calculated its absothe telescopic sextant he used for his observations of southlute position in right ascension and declination. Hevelius had ern stars from St Helena in 1677. In Danzig, there had to to calculate the individual positions from the angular disbe two observers: one to make the horizontal and vertical tances between stars, a much less satisfactory procedure. adjustments to keep the fixed sight on one of the stars, and However, by the time English and French astronomers the other to point the movable sight at the other star. were devising these new instruments and methods, Hevelius Endeavour Vol. 24(1) 2000
9
years younger than Hevelius and about nine years Elizabeth the observer younger than Elizabeth. He had just spent a year in In Figure 1, Elizabeth is at the fixed sight and is making St Helena observing the positions of southern stars, a fine adjustment of the frame of the sextant with a screw which had given him a European reputation. He had used while Hevelius himself is setting the movable arm on the the most advanced instruments – telescopic sights, second star with another screw adjustment. In his account micrometer eyepieces and clocks of the best English of the sextant in the Machina Coelestis, Hevelius says that workmanship. He constructed a catalogue of star poshis wife assisted him diligently in his observations and itions that was the first made with the new instruments, was a valuable collaborator. He explained the need for not just of southern stars but of any part of the heavens. two observers to use the great sextant and that, for many He had written to Hevelius about his work and Hevelius years, his dearest wife (‘conjugam meam charissimam’), was looking forward to receiving who was a keen student of mathAs Hevelius made clear, the the southern catalogue. Now Halley ematics, had assisted him in his obwas proposing to visit Danzig, servations with it3. Thus, he wrote, observations after about men and women are equally well 1664 are predominantly the but not to talk about his southern stars. suited to observing (‘Quippe ad work of three people – Hevelius, who had been elected to observationis Mulieres aeque at Viri Hevelius himself, the Royal Society in 1664, had for idoneae’3). He set out Elizabeth’s abilities more fully than he did those Typographus and Elizabeth. some while been in correspondence with English astronomers about his of the printer and his words imply preference for open as against that, as well as observing with the telescopic sights, and he had been greatly offended by the great sextant, Elizabeth assisted in other activities of the way that Robert Hooke had dismissed his work. observatory, possibly with computations. Flamsteed was more emollient but still considered that The names of the observers are rarely given for the telescopic sights gave better results. In an attempt to stellar observations recorded in Machina Coelestis but the placate Hevelius, the Royal Society welcomed an offer by description of the great sextant implies that Hevelius Halley that he should go to Danzig and take with him one usually observed with either the printer or Elizabeth. If of his own instruments with telescopic sights7. So he did, Figure 1 is typical then Elizabeth or the printer would have set the sextant on one star with the fixed sight and and Hevelius described his visit in detail in his book Hevelius would have set the movable sight on the second Annus Climactericus of 16857. Hevelius gave the book its star. There are, however, occasions when observations title because 1679 was 49 years (i.e. 7 3 7) since he by Elizabeth or the printer are particularly noted and began to observe, because he considered Halley’s visit the they seem to be when there were visitors to the Obserclimax of his life. Also, vatory who also observed. She is also mentioned on a in the autumn of 1679 (two months after Halley left), a few occasions with a student or a novice. Did she perdisastrous fire broke out that destroyed his observatory. It haps instruct people unfamiliar with the sextant in its seems that it was also a memorable year for Elizabeth. use? Halley arrived on 26 May and immediately began to Elizabeth first appears in the Machina Coelestis2 on watch Hevelius, and no doubt Elizabeth, at the great sextant. Later, he used the great sextant himself, at first 2 July 1665, not long after the death of her son. Hevelius with Hevelius, then with the printer, with Buthner (an and Flamsteed exchanged observations from time to time5 associate of Hevelius) and with Elizabeth. He also oband, in a letter to Flamsteed of 24 June 1676, Hevelius served with his own quadrant, which was, however, too gives the results of some repeated observations of the small for the highest accuracy. He did not observe stars angular distances between pairs of stars. Elizabeth obonly but, for example, he and Hevelius measured the served one distance on 1 August 1674 with a visitor, diameter of the Moon. Their joint observations during Bernhard Fullenius, and on 2 July 1665 with Hevelius. Halley’s visit are recorded in the Annus Climactericus8. Fullenius observed another pair on 18 September 1674, first with Hevelius and then with Elizabeth, and Hevelius Halley did not spend all his time observing. He wrote and Elizabeth observed the same distance on 3 September to Flamsteed on 7 June with an account of Hevelius’ 1665. With one exception, all those measurements were instruments and some observations that he himself had within 5 arc seconds. Hevelius wanted to demonstrate to made with Hevelius and with the printer, but began by Flamsteed the accuracy of his instruments and he eviexcusing his delay in writing, saying that he was ‘wholly dently gave details of the observers to support his claims. taken up with the Curiosityes of this Place’ so that he had He would hardly have mentioned Elizabeth if she were sent no more than two letters5. Elizabeth, as the daughter not already an able observer. In a letter of 1675, Fullenius of one prominent citizen and the wife of another, was sends salutations to ‘dulcissimam conjugam’6. used to entertaining the distinguished visitors who came to pay their respects to Hevelius and to see his instruments, as some seem to be doing in Figure 3. In that milieu, Edmond Halley at the observatory Halley spent what were evidently two very interesting and Of all the visitors to the Observatory, the most notable agreeable months; he made good friends with Hevelius’ and the one whom Hevelius most appreciated was colleagues the Buthners, father and son, and with Johann Edmond Halley. Halley was there for two months in the Olhoff, the City Secretary, who later published a selection early summer of 1679, when he was about 23, which is 45
10
Endeavour Vol. 24(1) 2000
of Hevelius’s correspondence6. Halley left Danzig with an important commission from Elizabeth. He was to have made for her in London, in the highest fashion, a gown and petticoat each of ten yards of rich silk. When he was ready to send it to Danzig, news came to London of the fire that had destroyed Hevelius’ observatory. There were rumours that Hevelius himself had perished in the fire, although he had not. Halley wondered if he should send the gown. Would Elizabeth be constrained to wear black for many months? He confided his doubts to Olhoff9 but decided to send the gown, for perhaps Hevelius was not dead and, even if he were, perhaps in time Elizabeth would feel inclined to wear the dress. So off it went, with the price (it was not a gift from Halley), which Halley explained on account of the considerable lengths of very rich material5. Later, when he was in Rome at the end of 1681, Halley heard from London that Hevelius was not dead and he wrote to him with some brief remarks on Rome and his respects to Figure 3 The great telescope at Danzig, with the reception of a distinguished visitor in the foreground3. Reproduced by permission of the University Librarian, Cambridge. Elizabeth. Eventually, he asked that his outstanding expenses for the gown should be settled with some of Hevelius’ books9. hostile to Halley at the time Hearne heard the story. Although the fire had destroyed all his instruments, his printing press and many of his books and records, Hevelius Posthumous works was nonetheless able to prepare an account of the events of Halley figures in Hevelius’ last work, which appeared posthumously, brought out by Elizabeth as Prodromus Astro1679 as Annus Climactericus and he sent a presentation copy to Halley with a warm inscription. That copy was found in the nomiae11. The Prodromus is, in effect, the final account of Library of the Signet in Edinburgh and is now in the Library Hevelius’s work in the years of his marriage to Elizabeth. of the University of Chicago. Hevelius and Halley must Perhaps because his young wife had now become an able surely have corresponded about that book but no letter about collaborator, he devoted himself more consistently to preit seems to survive from either of them. Neither is there any paring a new catalogue of the positions of stars. The first known correspondence between Halley and Elizabeth. part of the Machina Coelestis describes the instruments of In November 1713, Thomas Hearne, the Oxford diarist, his observatory; the second part (Books II, III and IV) recounted a scurrilous tale about Halley and Elizabeth. contains all the observations made up to 1678, both before Halley’s picture by Thomas Murray had just been presented and after he married Elizabeth. Their observations of to the Bodleian Library and had been hung beside that of 1679 are in Annus Climactericus of 1685. Hevelius, presented by him to the University in 1679 – As Hevelius made clear, the observations after about 1664 Halley might have brought it back from Danzig. Accordare predominantly the work of three people – Hevelius ing to Hearne, Halley’s picture himself, Typographus and Elizabeth. After the fire of September 1679, he made few observations. He always inhangs by Hevelius whom Dr Halley, when he was young, had tended to construct a catalogue of positions of fixed stars visited at Dantzick, and for that reason, as well as his skill in from his observations, seeing himself as the successor of Astronomy, Hevelius hath mentioned him in one of his books. Tycho. He may have gone a long way towards this goal by And some Persons say that he is very justly placed by Hevelius, the time of the fire, for he explains in the introduction to the because he made him (as they give out) a Cuckold, by lying with his wife when he was at Dantzick, the said Hevelius Prodromus how the catalogue and his manuscripts of Kepler, having a very pretty Woman to his Wife, who had a very great almost alone of his possessions, were saved. The catalogue, Kindness for Mr Halley and was (it seemed) observed often to the principal part of the Prodromus, is accompanied by a debe familiar with him. But this story I am apt to think is false.10 scription and analysis of it, and by a set of diagrams of the constellations, some of which he named and delineated for Hearne often appeared to be gullible and to think the the first time. It was probably after the fire that he wrote the worst of people, and so a story that he was apt to think description and analysis, and drew and had engraved the diafalse was most probably groundless. It might well have grams of the constellations. He also included comparisons of come from Flamsteed, who had corresponded with Halley his positions with those in earlier catalogues, those of Tycho when Halley was in Danzig and who was particularly Endeavour Vol. 24(1) 2000
11
Brahe, Ulagh Beg and the Prince of Hass. He also revised and printed Halley’s catalogue of the southern stars. Halley published his own southern catalogue as a supplement to that of Tycho Brahe, which was confined to stars that could be seen from Denmark. He recognized that some constants and star positions that he took from Tycho might be improved later and so he published his observations as well as the catalogue that others might revise the positions of stars when better values of the constants became available. Hevelius’ work provided such improved values and, in recalculating Halley’s catalogue, he surely paid a tribute to Halley. The Prodromus reads as though it had been prepared by Hevelius and, at one point, he writes that he is in his 76th year; that is, he was writing in 1687, immediately before his death. The book was not printed until three years later, in 1690. It has a fulsome dedication by Elizabeth to the King of Poland, John III Sobieski. The king wrote very gracious letters to Elizabeth and continued to her a pension of 1000 florins that he had allowed to Hevelius. Elizabeth writes that the book has been produced by a substitute author (herself) and prays that the king will support it. She says that she has been left desolate but rejoices to present the book to the king. It seems that she prepared the Prodromus for the press and may possibly have completed the catalogue. The Prodromus is however not just a work of final piety: it is a record of her own life as an astronomer. Concealed for the most part as it may be, the catalogue is nonetheless certainly a record of her life as a co-observer, and perhaps as a computer also. Hevelius distributed his works widely and Elizabeth may also have done so with the Prodromus. Although the Royal Society and the University Library in Cambridge lack copies, there is one in the British Library and two in the Bodleian Library in Oxford, one of which belonged to John Wallis, the Savilian Professor of Geometry in 1690. Halley himself had two copies, to judge by the catalogue of the sale of his books after his death. I do not know where those copies may be now, whether they carried any inscription nor if there were any correspondence with Elizabeth about them. Last years
12
Endeavour Vol. 24(1) 2000
As the wife of a prominent citizen and an astronomer of a European reputation, Elizabeth must have had many guests and other visitors to entertain. Elizabeth and Hevelius seem to have gathered a friendly company around them, to judge by Halley’s references to his time in Danzig, and he and Fullenius clearly remembered Elizabeth with pleasure. Hearne’s story, however exaggerated and embroidered, reflects Elizabeth as an attractive woman and a charming hostess. It is sad that we do not know more about such an interesting lady. Elizabeth did not long survive the publication of the Prodromus, for she died in 1693. For some 25 years, from when she first began to observe with Hevelius at the age of 18 until the publication of the Prodromus when she was 43, she supported her husband as his preferred and valued collaborator in astronomy. Hevelius’ catalogue had been made obsolete by new methods by the time the Prodromus appeared and was eventually replaced by Flamsteed’s but for some 20 years it was the best available and remains a monument to the skill and care of the last astronomers of the older times, Johann and Elizabeth Hevelius. Notes and references 1 2 3 4
5
6 7 8 9 10 11
Hevelius, J. (1647) Selenographia, Danzig Hevelius, J. (1679) Machina Coelestis (Part II), Danzig Hevelius, J. (1673) Machina Coelestis (Part I), Danzig Hevelius did, however, have a number of telescopes, some very long, that he used for other sorts of observation Forbes, E.G., Murdin, L. and Willmuth, F. (eds) (1995) The correspondence of John Flamsteed (vol. 1), Bristol and Philadelphia Olhof, J.H. (1683) Excerpta ex literis … ad J. Hevelium, Danzig Cook, A. (1998) Edmond Halley: charting the heavens and the seas, Clarendon Press Hevelius, J. (1685) Annus Climactericus, Danzig MacPike, E.F. (ed.) (1932) The correspondence and papers of Edmond Halley, Clarendon Press Hearne, T. (1884…) Remains and collections, (vol. 4), Oxford Historical Society Hevelius, J. (1690) Prodromus Astronomiae, Danzig
Further reading • • •
Cook, A. (1997) Ladies in the scientific revolution. Notes Rec. R. Soc. London 51, 1–12 Béziat, L.C. (1875) La vie et les travaux de Jean Hévélius. Bulletino Bibliografia e Storia Scienze Mathematica e Physica 8, 497–558 Béziat, L.C. (1875) La vie et les travaux de Jean Hévélius.
Elizabeth Hevelius, the second wife of the renowned astronomer, Johann Hevelius of Danzig (1611–1687), may or may not have been the first woman astronomer but she was certainly the first woman to appear in a picture as actually engaged in observing (Figure 1). Elizabeth was one of three daughters of a Danzig merchant, Nicholas Koopman. She married Hevelius on the third or fourth of February 1663, when he was 52 and she 16, following the death of his first wife. Within two years or less, she was helping with his observations. Johann Hevelius himself was the son of a wealthy brewer of Danzig; the brewery still exists under the name of Hevelius, and the labels on its bottles carry his picture. Danzig, one of the cities of the Hanseatic League, was part of the Kingdom of Poland but enjoyed considerable independence. It was a splendid place (Figure 2), with rich merchants and a famous great harbour crane, now reconstructed. Much of its trade was with the farms and forests of Poland. The city councillors, of whom Hevelius became one, were very grand people. Hevelius became interested in astronomy as a young man and travelled to London, Leyden, Paris and Avignon, where he met a number of prominent savants with whom he continued to correspond for many years. He intended to go to Italy to meet Galileo but was called back to Danzig to look after the family interests because his father’s health was failing. He became a senator (a member of the Rathscollegium, of which he was twice president) and he was also a city judge. He devoted himself to astronomy from shortly after his return to Danzig; after his father’s death in 1649, he constructed many instruments and installed them in an observatory that he built upon his house. He resolved to improve upon the catalogue of star positions that Tycho Brahe had made and he acquired the manuscripts of Kepler. In 1635, he married Katrina Rebeschke, the daughter of a city councillor of Danzig. They had no children and she died in 1662.
Hevelius first studied the Moon, making the first map of her surface and discovering the libration (rocking motion) of the Moon, although he could not explain it1. He made systematic studies of the planets and of the fixed stars, he observed comets and detected variable stars. By the time he married Elizabeth, after the death of Katrina, he had already accumulated a very large number of observations; these are recorded together with his later ones in the second volume of his Machina Coelestis of 16792. Hevelius had a licence to print from the king of Poland,
Sir Alan Cook FRS Is Jacksonian Professor of Natural Philosophy Emeritus and former Master of Selwyn College, Cambridge. His new biography of Edmond Halley appeared in 1998. He edits the Notes and Records of the Royal Society.
8
Endeavour Vol. 24(1) 2000
Figure 1 Hevelius and Elizabeth observing with the great sextant3. Reproduced by permission of the University Librarian, Cambridge.
0160-9327/00/$ – see front matter © 2000 Elsevier Science Ltd. All rights reserved. PII: S0160-9327(99)01263-6
Johann II Sobieski, and he employed a printer, Simon Reiniger (Typographus), for his astronomical works. He distributed them widely in Europe and there are presentation copies in the British Library, the Bodleian Library in Oxford and the University Library in Cambridge. They are handsomely printed and bound, and record something of the astronomical activities of Elizabeth. Elizabeth was unusually well educated for a young woman, for Hevelius said that she was a good mathematician. She and Hevelius had four children: a son born in 1664, who died when a year old, and three daughters. Katerina Elizabeth was born in 1666 and married a councillor of Danzig, Ernst Lange; Julia Renata was born in 1668 and married Dietrich Mathis d’Heinrichson who was the Grand Veneur of the King of Poland; Flora Constantine was born in 1668 and married Charles Adolph Ferber, another councillor of Danzig. Elizabeth seems to have begun to take Figure 2 Hevelius’s instruments on the roof of his house, with the river Vistula in the background3. part in observations from the first years Reproduced by permission of the University Librarian, Cambridge. of her marriage. In the first volume of the Machina Coelestis of 16733, in which Hevelius described had been using Brahe’s methods for some 30 years and had great confidence in them. Figure 2 shows the observatory his instruments, he says that he had a number of assistants that Hevelius built on his house, with some of the but that his wife (Elizabeth) became a valuable collaborator instruments set up there and a view over the river Vistula. and a most exact observer, and he came to rely entirely on Hevelius’s principal instrument was a large brass her and his printer. His comment on her mathematical sextant six feet in radius (‘Sextant Magno Orichalcico’) ability suggests that she also helped with computations. (Figure 1). Its characteristics had a great influence on Elizabeth’s observations and on the relationships of Hevelius The observatory at Danzig and Elizabeth with English astronomers, so it is worth Hevelius constructed his instruments and began his obserdescribing them in some detail. There were two sets of vations of the stars some 30 years before Flamsteed had open sights, one fixed to the frame of the sextant and the his up-to-date telescopic instruments at Greenwich. other movable, rotating around the Hevelius saw himself as the succentre of the arc of the sextant. The cessor of Tycho Brahe and, like Halley arrived on 26 May angle between them was read from Tycho, he used open sights (essenand immediately began the graduated arc of the sextant. The tially a rod with slits at the two ends) to watch Hevelius, and no sextant was mounted on a vertical to point on stars, for he distrusted the doubt Elizabeth, at the axis and supported by ropes so that it then-still-novel telescope for such could be tilted about a horizontal measurements4. He measured the great sextant. axis. Evidently, such a large instruangular distances between two stars ment that was adjustable about both the vertical and the with a sextant, which is a frame carrying a 608 arc with horizontal axes would have been very cumbersome. two sets of sights, one usually fixed to the frame and the When John Flamsteed set up the new Royal Observatory other rotating about the centre of the arc (Figure 1). at Greenwich, he had to use a sextant in his first years until Thirty years later, Flamsteed and his French contemhis mural arc was ready. However, he mounted it on an axis poraries used telescopic sights with micrometers in the eyedirected to the North Pole so that one person could rotate pieces. They mounted their principal instrument, a quadit about that axis to keep the fixed (telescopic) sight on a rant carrying a telescope, vertically in the meridian on a particular star while adjusting the movable sight to another. wall. They measured the time and altitude at which a star Edmond Halley seems to have used a similar mount for crossed the meridian, from which they calculated its absothe telescopic sextant he used for his observations of southlute position in right ascension and declination. Hevelius had ern stars from St Helena in 1677. In Danzig, there had to to calculate the individual positions from the angular disbe two observers: one to make the horizontal and vertical tances between stars, a much less satisfactory procedure. adjustments to keep the fixed sight on one of the stars, and However, by the time English and French astronomers the other to point the movable sight at the other star. were devising these new instruments and methods, Hevelius Endeavour Vol. 24(1) 2000
9
years younger than Hevelius and about nine years Elizabeth the observer younger than Elizabeth. He had just spent a year in In Figure 1, Elizabeth is at the fixed sight and is making St Helena observing the positions of southern stars, a fine adjustment of the frame of the sextant with a screw which had given him a European reputation. He had used while Hevelius himself is setting the movable arm on the the most advanced instruments – telescopic sights, second star with another screw adjustment. In his account micrometer eyepieces and clocks of the best English of the sextant in the Machina Coelestis, Hevelius says that workmanship. He constructed a catalogue of star poshis wife assisted him diligently in his observations and itions that was the first made with the new instruments, was a valuable collaborator. He explained the need for not just of southern stars but of any part of the heavens. two observers to use the great sextant and that, for many He had written to Hevelius about his work and Hevelius years, his dearest wife (‘conjugam meam charissimam’), was looking forward to receiving who was a keen student of mathAs Hevelius made clear, the the southern catalogue. Now Halley ematics, had assisted him in his obwas proposing to visit Danzig, servations with it3. Thus, he wrote, observations after about men and women are equally well 1664 are predominantly the but not to talk about his southern stars. suited to observing (‘Quippe ad work of three people – Hevelius, who had been elected to observationis Mulieres aeque at Viri Hevelius himself, the Royal Society in 1664, had for idoneae’3). He set out Elizabeth’s abilities more fully than he did those Typographus and Elizabeth. some while been in correspondence with English astronomers about his of the printer and his words imply preference for open as against that, as well as observing with the telescopic sights, and he had been greatly offended by the great sextant, Elizabeth assisted in other activities of the way that Robert Hooke had dismissed his work. observatory, possibly with computations. Flamsteed was more emollient but still considered that The names of the observers are rarely given for the telescopic sights gave better results. In an attempt to stellar observations recorded in Machina Coelestis but the placate Hevelius, the Royal Society welcomed an offer by description of the great sextant implies that Hevelius Halley that he should go to Danzig and take with him one usually observed with either the printer or Elizabeth. If of his own instruments with telescopic sights7. So he did, Figure 1 is typical then Elizabeth or the printer would have set the sextant on one star with the fixed sight and and Hevelius described his visit in detail in his book Hevelius would have set the movable sight on the second Annus Climactericus of 16857. Hevelius gave the book its star. There are, however, occasions when observations title because 1679 was 49 years (i.e. 7 3 7) since he by Elizabeth or the printer are particularly noted and began to observe, because he considered Halley’s visit the they seem to be when there were visitors to the Obserclimax of his life. Also, vatory who also observed. She is also mentioned on a in the autumn of 1679 (two months after Halley left), a few occasions with a student or a novice. Did she perdisastrous fire broke out that destroyed his observatory. It haps instruct people unfamiliar with the sextant in its seems that it was also a memorable year for Elizabeth. use? Halley arrived on 26 May and immediately began to Elizabeth first appears in the Machina Coelestis2 on watch Hevelius, and no doubt Elizabeth, at the great sextant. Later, he used the great sextant himself, at first 2 July 1665, not long after the death of her son. Hevelius with Hevelius, then with the printer, with Buthner (an and Flamsteed exchanged observations from time to time5 associate of Hevelius) and with Elizabeth. He also oband, in a letter to Flamsteed of 24 June 1676, Hevelius served with his own quadrant, which was, however, too gives the results of some repeated observations of the small for the highest accuracy. He did not observe stars angular distances between pairs of stars. Elizabeth obonly but, for example, he and Hevelius measured the served one distance on 1 August 1674 with a visitor, diameter of the Moon. Their joint observations during Bernhard Fullenius, and on 2 July 1665 with Hevelius. Halley’s visit are recorded in the Annus Climactericus8. Fullenius observed another pair on 18 September 1674, first with Hevelius and then with Elizabeth, and Hevelius Halley did not spend all his time observing. He wrote and Elizabeth observed the same distance on 3 September to Flamsteed on 7 June with an account of Hevelius’ 1665. With one exception, all those measurements were instruments and some observations that he himself had within 5 arc seconds. Hevelius wanted to demonstrate to made with Hevelius and with the printer, but began by Flamsteed the accuracy of his instruments and he eviexcusing his delay in writing, saying that he was ‘wholly dently gave details of the observers to support his claims. taken up with the Curiosityes of this Place’ so that he had He would hardly have mentioned Elizabeth if she were sent no more than two letters5. Elizabeth, as the daughter not already an able observer. In a letter of 1675, Fullenius of one prominent citizen and the wife of another, was sends salutations to ‘dulcissimam conjugam’6. used to entertaining the distinguished visitors who came to pay their respects to Hevelius and to see his instruments, as some seem to be doing in Figure 3. In that milieu, Edmond Halley at the observatory Halley spent what were evidently two very interesting and Of all the visitors to the Observatory, the most notable agreeable months; he made good friends with Hevelius’ and the one whom Hevelius most appreciated was colleagues the Buthners, father and son, and with Johann Edmond Halley. Halley was there for two months in the Olhoff, the City Secretary, who later published a selection early summer of 1679, when he was about 23, which is 45
10
Endeavour Vol. 24(1) 2000
of Hevelius’s correspondence6. Halley left Danzig with an important commission from Elizabeth. He was to have made for her in London, in the highest fashion, a gown and petticoat each of ten yards of rich silk. When he was ready to send it to Danzig, news came to London of the fire that had destroyed Hevelius’ observatory. There were rumours that Hevelius himself had perished in the fire, although he had not. Halley wondered if he should send the gown. Would Elizabeth be constrained to wear black for many months? He confided his doubts to Olhoff9 but decided to send the gown, for perhaps Hevelius was not dead and, even if he were, perhaps in time Elizabeth would feel inclined to wear the dress. So off it went, with the price (it was not a gift from Halley), which Halley explained on account of the considerable lengths of very rich material5. Later, when he was in Rome at the end of 1681, Halley heard from London that Hevelius was not dead and he wrote to him with some brief remarks on Rome and his respects to Figure 3 The great telescope at Danzig, with the reception of a distinguished visitor in the foreground3. Reproduced by permission of the University Librarian, Cambridge. Elizabeth. Eventually, he asked that his outstanding expenses for the gown should be settled with some of Hevelius’ books9. hostile to Halley at the time Hearne heard the story. Although the fire had destroyed all his instruments, his printing press and many of his books and records, Hevelius Posthumous works was nonetheless able to prepare an account of the events of Halley figures in Hevelius’ last work, which appeared posthumously, brought out by Elizabeth as Prodromus Astro1679 as Annus Climactericus and he sent a presentation copy to Halley with a warm inscription. That copy was found in the nomiae11. The Prodromus is, in effect, the final account of Library of the Signet in Edinburgh and is now in the Library Hevelius’s work in the years of his marriage to Elizabeth. of the University of Chicago. Hevelius and Halley must Perhaps because his young wife had now become an able surely have corresponded about that book but no letter about collaborator, he devoted himself more consistently to preit seems to survive from either of them. Neither is there any paring a new catalogue of the positions of stars. The first known correspondence between Halley and Elizabeth. part of the Machina Coelestis describes the instruments of In November 1713, Thomas Hearne, the Oxford diarist, his observatory; the second part (Books II, III and IV) recounted a scurrilous tale about Halley and Elizabeth. contains all the observations made up to 1678, both before Halley’s picture by Thomas Murray had just been presented and after he married Elizabeth. Their observations of to the Bodleian Library and had been hung beside that of 1679 are in Annus Climactericus of 1685. Hevelius, presented by him to the University in 1679 – As Hevelius made clear, the observations after about 1664 Halley might have brought it back from Danzig. Accordare predominantly the work of three people – Hevelius ing to Hearne, Halley’s picture himself, Typographus and Elizabeth. After the fire of September 1679, he made few observations. He always inhangs by Hevelius whom Dr Halley, when he was young, had tended to construct a catalogue of positions of fixed stars visited at Dantzick, and for that reason, as well as his skill in from his observations, seeing himself as the successor of Astronomy, Hevelius hath mentioned him in one of his books. Tycho. He may have gone a long way towards this goal by And some Persons say that he is very justly placed by Hevelius, the time of the fire, for he explains in the introduction to the because he made him (as they give out) a Cuckold, by lying with his wife when he was at Dantzick, the said Hevelius Prodromus how the catalogue and his manuscripts of Kepler, having a very pretty Woman to his Wife, who had a very great almost alone of his possessions, were saved. The catalogue, Kindness for Mr Halley and was (it seemed) observed often to the principal part of the Prodromus, is accompanied by a debe familiar with him. But this story I am apt to think is false.10 scription and analysis of it, and by a set of diagrams of the constellations, some of which he named and delineated for Hearne often appeared to be gullible and to think the the first time. It was probably after the fire that he wrote the worst of people, and so a story that he was apt to think description and analysis, and drew and had engraved the diafalse was most probably groundless. It might well have grams of the constellations. He also included comparisons of come from Flamsteed, who had corresponded with Halley his positions with those in earlier catalogues, those of Tycho when Halley was in Danzig and who was particularly Endeavour Vol. 24(1) 2000
11
Brahe, Ulagh Beg and the Prince of Hass. He also revised and printed Halley’s catalogue of the southern stars. Halley published his own southern catalogue as a supplement to that of Tycho Brahe, which was confined to stars that could be seen from Denmark. He recognized that some constants and star positions that he took from Tycho might be improved later and so he published his observations as well as the catalogue that others might revise the positions of stars when better values of the constants became available. Hevelius’ work provided such improved values and, in recalculating Halley’s catalogue, he surely paid a tribute to Halley. The Prodromus reads as though it had been prepared by Hevelius and, at one point, he writes that he is in his 76th year; that is, he was writing in 1687, immediately before his death. The book was not printed until three years later, in 1690. It has a fulsome dedication by Elizabeth to the King of Poland, John III Sobieski. The king wrote very gracious letters to Elizabeth and continued to her a pension of 1000 florins that he had allowed to Hevelius. Elizabeth writes that the book has been produced by a substitute author (herself) and prays that the king will support it. She says that she has been left desolate but rejoices to present the book to the king. It seems that she prepared the Prodromus for the press and may possibly have completed the catalogue. The Prodromus is however not just a work of final piety: it is a record of her own life as an astronomer. Concealed for the most part as it may be, the catalogue is nonetheless certainly a record of her life as a co-observer, and perhaps as a computer also. Hevelius distributed his works widely and Elizabeth may also have done so with the Prodromus. Although the Royal Society and the University Library in Cambridge lack copies, there is one in the British Library and two in the Bodleian Library in Oxford, one of which belonged to John Wallis, the Savilian Professor of Geometry in 1690. Halley himself had two copies, to judge by the catalogue of the sale of his books after his death. I do not know where those copies may be now, whether they carried any inscription nor if there were any correspondence with Elizabeth about them. Last years
12
Endeavour Vol. 24(1) 2000
As the wife of a prominent citizen and an astronomer of a European reputation, Elizabeth must have had many guests and other visitors to entertain. Elizabeth and Hevelius seem to have gathered a friendly company around them, to judge by Halley’s references to his time in Danzig, and he and Fullenius clearly remembered Elizabeth with pleasure. Hearne’s story, however exaggerated and embroidered, reflects Elizabeth as an attractive woman and a charming hostess. It is sad that we do not know more about such an interesting lady. Elizabeth did not long survive the publication of the Prodromus, for she died in 1693. For some 25 years, from when she first began to observe with Hevelius at the age of 18 until the publication of the Prodromus when she was 43, she supported her husband as his preferred and valued collaborator in astronomy. Hevelius’ catalogue had been made obsolete by new methods by the time the Prodromus appeared and was eventually replaced by Flamsteed’s but for some 20 years it was the best available and remains a monument to the skill and care of the last astronomers of the older times, Johann and Elizabeth Hevelius. Notes and references 1 2 3 4
5
6 7 8 9 10 11
Hevelius, J. (1647) Selenographia, Danzig Hevelius, J. (1679) Machina Coelestis (Part II), Danzig Hevelius, J. (1673) Machina Coelestis (Part I), Danzig Hevelius did, however, have a number of telescopes, some very long, that he used for other sorts of observation Forbes, E.G., Murdin, L. and Willmuth, F. (eds) (1995) The correspondence of John Flamsteed (vol. 1), Bristol and Philadelphia Olhof, J.H. (1683) Excerpta ex literis … ad J. Hevelium, Danzig Cook, A. (1998) Edmond Halley: charting the heavens and the seas, Clarendon Press Hevelius, J. (1685) Annus Climactericus, Danzig MacPike, E.F. (ed.) (1932) The correspondence and papers of Edmond Halley, Clarendon Press Hearne, T. (1884…) Remains and collections, (vol. 4), Oxford Historical Society Hevelius, J. (1690) Prodromus Astronomiae, Danzig
Further reading • • •
Cook, A. (1997) Ladies in the scientific revolution. Notes Rec. R. Soc. London 51, 1–12 Béziat, L.C. (1875) La vie et les travaux de Jean Hévélius. Bulletino Bibliografia e Storia Scienze Mathematica e Physica 8, 497–558 Béziat, L.C. (1875) La vie et les travaux de Jean Hévélius.