Thomas Romney Robinson
Romney Robinson - no relation to the Primate - was born on 23 April 1792 in the parish of St. Anne's, Dublin. When he was still a small boy his family moved first to Dromore, then to Lisburn and then to Belfast. He was the son of the artist Thomas Robinson, and godson of Romney the portrait painter, after whom he was given the second of his Christian names. (Romney had, incidentally, been his father's tutor.).
From all accounts he was a most remarkable child. There is some fascinating information about him in a book of poems from his pen, printed in Belfast by J. Smyth and D. Lyons in 1806 which makes its author then a mere thirteen years old. According to the Foreword to this booklet, "While yet in his nurse's arms there appeared to be something extraordinary in the tone of the infant's feelings and the structure of his nerves; this appeared particularly in the effect of music on his animal frame; the notes of an ill-tuned instrument raising in him sensations of sickness and disgust, while harmonious sounds affected him with evident delight".
Music was not his only joy. At the age of two he listened with pleasure to Wordsworth's poems, and before long he was an avid reader, his choice ranging from the Arabian Nights to textbooks on chemistry. He also started to write poems on his own account. When his family moved to Belfast in 1801, the Rev. Dr. Bruce, Principal of the Academy, "as soon as he discovered the talents of the young poet, made him a voluntary offer of gratuitous education", which was promptly accepted.12 And indeed he had poetic talent. When aged seven, he was asked to make up some spontaneous verse about a calender he had been looking at, and immediately produced:
Four rollers here of polished wood we view,
This may not be great poetry, but for a seven-year-old it is somewhat unusual, and there is no reason to doubt that Robinson could have earned himself a reputation as a poet had he felt so inclined. In fact, he took Holy Orders, and became Rector of Enniskillen. When appointed Astronomer at Armagh, he was only just over thirty years of age; he remained at the Observatory, in full control, until his death in 1882 at the age of almost ninety.
Robinson was a man of great character and determination and, it must be added, a healthy (and justified) faith in his own ability. He kept large numbers of irons in large numbers of fires, and he was never afraid to speak his mind. There can be few people now living who remember him, but his reputation as an administrator and an astronomer of the first rank will be long-enduring. In religious matters it is said that he tended to be narrow-minded, but this was hardly surprising in view of the time and place in which he lived. It was an excellent thing that he assumed the Directorship when he did. Without him, Armagh Observatory might not have survived.
He was twice married, first to Elizabeth Rambaut - a relative of whom, W. H. Rambaut, was assistant at Armagh between 1850 and 1864 - and secondly to Lucy Jane Edgeworth, of whom it was said that she "loved astronomy, but only as impersonated in the astronomer"13. Lucy was thirty-eight at the time of the marriage, and it was said that "never was a marriage hailed with more family acclaim of universal joy"14. She was a step-sister of Maria Edgeworth, the famous nineteenth-century authoress, to whose style Sir Walter Scott owed so much. Apparently, Maria visited the Observatory several times. Their father, Richard Lovell Edgeworth, a man of many talents, had married four times, and Lucy was one of a total of 22 children! .
Robinson's first duty was to find out the state of the Observatory's instruments. The results were not very encouraging. No equipment of note had been added since 1795, and the equipment was virtually limited to the Troughton equatorial, three astronomical clocks, and the watchmaker's transit instrument, which was simply not good enough to be of real use. The Troughton, of course, was excellent of its type, but its aperture was smaller than that of the kind of telescope used to-day by a schoolboy enthusiast, and its massive pillar, around which wound the staircase of the main dwelling-house, made it look much more imposing than it really was. Robinson wrote15 that it was "supposed by its maker, with the somewhat overweening confidence in his own powers which was his great defect, to be capable of fully supplying the place of meridian instruments. Its performance was really very good; but I need scarcely say that it fell short of his promise";. Neither had there been left any detailed instructions about its use, and Robinson himself produced two papers in the Transactions of the Royal Irish Academy dealing with the corrections of observations made with equatorials.16 17
There was another problem to be faced. Hamilton had been of independent means, and so presumably had Davenport; in any case, a more or less inactive Observatory is less expensive than a flourishing one! Robinson was not so well placed. He was not penniless, but neither was he affluent, and he certainly did not have enough money to buy astronomical instruments; he could hardly have afforded even to pay for the cost of publishing observations. Luckily the new Primate, Archbishop Lord John George Beresford, was generous and farsighted, with an attitude similar to that of the Founder. Accordingly, Robinson's appeal for funds did not fall upon deaf ears. Beresford promised to provide a transit instrument which would be somewhat better than the watchmaker's, together with a mural circle and a large reflector, as well as financing repairs and extensions to the Observatory buildings.
Jones Mural Circle
He more than made good his promises. The transit instrument and mural circle were ordered from Jones of London, whose reputation was second to none; the transit room was extended eastward by another meridian room designed for the mural circle, and again eastward a new tower was built, on the top of which was a revolving dome. In this dome, Robinson erected a Herschel reflector of focal length 10 feet and aperture 9 inches. The mirror, incidentally, is still at the Observatory, and is in good repair; with it are some handwritten instructions by Caroline Herschel. However, the telescope was not used at Armagh for long, since in 1835 it was replaced by a 15in. reflector made by Grubb; apparently no serious work was done with the Herschel, since it was from the outset meant only to be a temporary installation.*
The new instruments proved to be most successful. The Jones transit was installed in 1827; it had a 3.8in. object-glass and it focal length of 63 inches, with a power of 120 diameters (changed, in 1840, to 195 diameters). It was set up in the special room built for it, supported by piers of Armagh marble, secured by cement and bronze dowels to a block of the same marble - a truly impressive construction.2 The Earnshaw clock retained its excellence; originally it had had a grid-iron pendulum, but this was replaced, in 1830, by a mercurial pendulum by Sharp of Dublin.18 The mural circle followed in 1831; it was 56 inches in diameter, and its telescope, which remained in use for thirty years, was an exact duplicate of that of the transit instrument. Finally, there was the Grubb reflector, which was mounted under the East Dome, and was fitted with a clock drive. The mirror was of course made of speculum metal - glass mirrors of any size were then almost unknown - and the next Director, Dreyer, had some hard things to say about it many years later; but at the time it seemed to be a wise choice, and it performed well. In 1843 the Earl of Rosse made a duplicate mirror for it.
Robinson set himself a hard task, though with confidence that he would be able to carry it through. He aimed to compile a catalogue of star positions which would be better than anything previously published. This would mean many years of observational work with the transit instrument and mural circle, but it would be well worth while. As a basis, he took the catalogue made during the middle of the previous century by James Bradley, the third Astronomer Royal, and set out to re-determine the positions with the greatest accuracy possible. The long-serving assistant, Hogg, had died in 1830 following a lengthy illness, and for a time there were no funds to pay a replacement, so that Robinson had to do all the work himself; but in 1837 it became possible to appoint a new assistant, Neil M'Neil Edmondson, who took over the transit instrument. Robinson continued with the mural circle until mid-1850, when he handed over to his other assistant, Rambaut. The final result of all this labour was the
Armagh Catalogue of 5345 stars, which represented a marked advance, and caused the Oservatory to be recognized as a major scientific establishment. The Catalogue was published in 1859, but there had been many additional developments before then.
Even when observations are made, they are of little use unless they are printed and made available - which costs money. The Observatory's endowment was too small to defray the costs of publication, but the generosity of Primate Beresford allowed the observations for the period 1828-30 to be produced. For some years afterwards the situation was difficult, but gradually there came an improvement. Writing in 1859, Robinson recorded2 that following 1830 "the Established Church of Ireland became the object of a systematic attack, in consequence of which the majority of its clergy were for some years reduced to extreme distress. . . Considering the almost total ignorance of everything connected with science, which was then normal in our statesmen, this result was not surprising". By 1859, however, the Royal Society had obtained an annual grant, and some of this money found its way to Armagh.
Robinson was undaunted by these troubles, and regular observing work for the star-catalogue was continued on every clear night. Also, attention was paid to weather study; the first meteorological records had been begun as long ago as 1793. An early paper of Robinson's shows how to correct the rate of a clock by the use of a syphon barometer attached to the pendulum19, and it is clear that the Armagh results were as careful as they were valuable. More spectacular, perhaps, was his attempt to determine the longitude difference between Armagh and Dublin by means of rockets. This idea has a decidedly modern flavour about it, but Robinson was not concerned with sending rockets into space; at that time - and, indeed, until well into the present century - the idea of practical space-research was regarded as nothing more than a fantastic dream; The rockets used for the longitude experiment were modest fireworks, but the story is worth relating, partly because it shows Robinson's ingenuity and partly because it marked the real start of active co-operation with the other famous Irish observatory, Dunsink.**
Dunsink, which lies not far from Dublin, was founded slightly earlier than Armagh. It began when, in 1774, Francis Andrews, the Provost of Trinity College, bequeathed £3000 for it, with a further £250 per year to pay staff salaries. By 1788 the Observatory was functioning; the first director was the Rev. Henry Ussher, a friend of Hamilton's, who died in 1790 at about the time when Hamilton was being installed at Armagh. Ussher was succeeded by John Brinkley, who remained director until 1826. Brinkley was in turn succeeded by a young man aged only 21; William (afterwards Sir William) Rowan Hamilton, who is one of the most famous of all Irish scientists, and whose mathematical researches will never be forgotten. Incidentally, he was no connection of Hamilton of Armagh. It is pure coincidence that the story of the Observatory features two unrelated Hamiltons and two unrelated Robinsons.
The determination of longitude is a matter of vital importance, and only in recent times has it been satisfactorily carried out to the degree of accuracy needed. There was, therefore, sound logic behind Robinson's proposed use of rockets; as he stated20, "The time of one place is transported to another, not by any machine, imperfect in its performance. . . the chronometer in it is light." As a matter of fact, the idea was not new. It seems to have been first used by Picart in Denmark, who wanted to measure the position of Uraniborg - the observatory on the island of Hven where Tycho Brahe had carried out his long series of observations in pre-telescopic days. A fire had been lit in the tower of the Copenhagen Observatory; this fire was periodically covered by a screen, and the time of its disappearance noted both there and at Uraniborg, seventeen miles away. The results were reasonable, but the fire was some three feet in diameter, so that nothing really precise could be expected. Then, in 1735, de la Condamine had suggested measuring an arc of longitude by means of the flash from a cannon, and four years later Cassini and Lacaille put this into practice when they observed the flash of ten pounds of powder fired from a point intermediate between them.
Balloons were also suggested, apparently by the well-known astronomer Baron F. X. von Zach, who realized that so far as flash-powder was concerned there would be difficulties in finding a firing-point sufficiently high. However, Von Zach was suitably cautious, and recorded that "the fates of Pilâtre de Rozier and Madame Blanchard" (two of the early balloonists who met with fatal accidents) "are strong arguments against the union of aerostation and pyrotechny".
Robinson certainly had no intention of going up in a balloon for any purpose whatsoever, but he was attracted by the idea of firework rockets. This had been proposed by Robins in 1749, and had been tried out by the elder Wollaston, near London, in 1775; it had been successfully used by an Anglo-French team in 1824 to measure an arc between Greenwich and Paris, despite defective rockets which had the annoying habit of exploding at the wrong moment.21 22
The results were encouraging enough to persuade the British Association to form a committee, in 1834, to investigate the chances of measuring the longitudes of Cambridge, Oxford, Edinburgh, Dublin and Armagh by what they called "the method of signals and chronometers". Both Hamilton and Robinson were members of the committee, and they decided to put its recommendations into practice.
Alignment of Armagh, Slieve Gullion
The distance between Dunsink and Armagh is about 68 miles, and there is no intermediate point visible from both, but the top of Slieve Gullion, at the southern extremity of County Armagh, has an altitude of 1893 feet, and is occasionally visible from Dublin. Measures were made, and from the peak it was found that the distance to Dublin was 50.9 miles, while Armagh was 18.2 miles away. This was evidently as good a site as could be found, and accordingly Robinson applied to the Board of Ordnance for a supply of rockets. He obtained them without difficulty, and was even given tents to accommodate the firing party.
On 13 May 1838, Robinson and his party set out for the mountain, where the Rector of Forkhill, Dr. Campbell, had made arrangements for the tents "with the hospitality for which he is remarkable, even in Ireland", as Robinson wrote in his account. The weather was typically perverse. The wind blew furiously from the north-west, and on the following day there was a snowstorm. Robinson himself decided to go back to the Observatory, so he left his son, T. A. Robinson, in charge of the party, with instructions to begin firing at 10 p.m. and continue signalling every five minutes provided that conditions did not become absolutely impossible.
Everything went as well as could be expected. From Armagh, Edmondson used the 3.2in. Tulley achromatic refractor, with a magnification of 30, from the southern window of the transit room. Robinson had meant to use the large reflector, but found this impracticable because the rockets moved so quickly across the field of view; therefore he changed to the 2.75in. finder, which gave a magnification of 18 and an adequate field of 1.5 degrees. The Sharp clock was certainly reliable. A third observer, R. Finlay, used the Troughton equatorial. At Dublin, the signals were seen with Sharp's 5.2in. equatorial and a power of 54; the time was taken with an accurate clock made by the famous Arnold.
The flashes were pleasingly clear from Dublin, and from Armagh each rocket showed a trail and an explosion visible with the naked eye. Thirteen firings were made on May 16, but the rain increased, so that most of the flashes were missed. Steadily the weather grew worse, and the party on Slieve Gullion had to move to a more sheltered spot; even so, twenty more rockets were fired on May 20, and a further twenty on the following night.
The night of May 22 was perfectly fine, but an annoying hitch, dismissed tersely by Robinson as "the miscarriage of a letter", meant that no rockets were let off. Predictably, the gale then returned, and of the nine rockets fired on May 23 only six were seen from Armagh, while Dublin's total score was nil. By now the waxing Moon was starting to cause grave trouble, and Robinson decided that the experiment should be stopped. The final results of the longitude-difference between Armagh and Dunsink were:
By chronometer: 1m. 14s.220.
By rocket signals: 1m. 14s.258.
Robinson was not displeased, and commented that the method might well be extended; for instance, a rocket sent off from Plinlimmon, at a height of 1500 feet, should be visible from both Dublin and Oxford. He seems to have expected a long series of such experiments, but for one reason or another they were never carried out, and modern techniques naturally make them unnecessary. At any rate, it seems that the Slieve Gullion episode of 1838 marks one of the first uses of rockets for purely scientific purposes, and for this alone it deserves to be remembered. Luckily, Robinson has left a very full account of it.23
William Rowan Hamilton had co-operated fully in the experiment, and had taken part personally. His relations with Robinson were always good, though it is on record that when visiting Armagh, Hamilton dropped and broke a particularly delicate micrometer made from specially-treated platinum wire - a cherished invention of Robinson's, and probably the only one of its kind ever constructed13. And at this point, it may be as well to refer to two further episodes involving Dunsink, even though both occurred some time after the Slieve Gullion firings.
Hamilton was primarily a mathematician, not an astronomer, and in the early 1840's it was suggested by Lord Adare that Robinson might move from Armagh to Dunsink, assuming the Directorship there and releasing Hamilton to become Professor of Mathematics at Trinity College.24 In this way Hamilton would have full mathematical scope, while Robinson might, "by his peculiar qualifications as a practical astronomer, increase the efficiency of the latter observatory, and by his general scientific accomplishments and ability become an invaluable acquisition to the scientific society of the metropolis", to use Adare's somewhat flowery phrasing. Robinson seems to have been in favour. In a letter to the Rev. Humphrey Lloyd, Senior Fellow of Trinity, written on 30 October 1843, he said that he was" in favour of the plan", and continued: "I would certainly have a great deal of uphill work, besides the annoyance of leaving this Observatory after I have got it appointed as I think no other is. But I think I would have means of being more useful with you." Actually, the plan never came to fruition, since in spite of many negotiations there were insuperable difficulties so far as Trinity College was concerned - and Robinson remained at Armagh, which, all things considered, was probably just as well.
Some years later, in 1851, Lloyd was due to retire from the Presidency of the Royal Irish Academy, which he had held for five years. Robinson's name was put forward as his successor, and, rather surprisingly, Hamilton opposed it on the grounds that it would be awkward to have a President who lived as far away from Dublin as Armagh. Instead, he nominated Professor Graves, the next member in seniority, who had the advantage of being resident in Dublin; However, Robinson was the obvious choice, despite geographical considerations; Graves knew this, and Hamilton agreed that the alternative nomination should be withdrawn. We may suppose that if there was a certain feeling of embarrassment, this was remedied on the day of the election itself, when Hamilton proposed Robinson as President; there were no other nominations, and everything went smoothly. In a letter to Lord Dunraven, written on 11 February 1851, Hamilton said that "it was not in any spirit of hostility to Robinson, who is one of the persons that I know longest in the world, that I took some steps towards proposing Graves. My grand point was, that I thought the President ought to be on the spot."25
The only other hint of irritation was contained in a letter from Hamilton to Aubrey de Vere, written on 12 February 1856. Apparently Hamilton had spent some trifling sum of money on Robinson's behalf, and the scrupulous Doctor sent him four stamps in repayment. Hamilton wrote: "I am rather vexed by receiving these stamps, but suppose that the civil thing is to retain them … He is a very pleasant person, to love or quarrel with."26
Actually, it seems that Robinson was in some ways a hard man to cross, as is shown by his dealings with the Irish and English railways - to which reference will be made later. He was also extremely meticulous, which is why he was so successful as an observer and administrator. For example, he spent some time in investigating the very slow, small annual movements of Armagh Observatory, which he thought to be upward in summer and downward in winter, and attributed them to temperature changes causing alternate expansion and contraction of the Earth's crust27. Few astronomers of his time would have gone to such lengths.
Another man with whom Robinson was on excellent terms was the third Earl of Rosse, the gifted amateur who set up an observatory at Birr Castle and constructed the largest reflector ever made up to that time, using it to discover the spiral nature of the objects we now know as external galaxies. The story of Birr would need a book to itself; for the moment, suffice to say that in 1843 Rosse presented a second mirror which he had made for the Armagh reflector, and in 1850 he induced the Royal Society to divert part of a Government grant towards the cost of printing Armagh observations.13 It was his son, Laurence, who later supported a House of Lords motion to help the Observatory financially.
Birr Castle remained an astronomical centre for many years, but the last observations made there date back to the middle of the 1914-18 war, when the final holder of the post of Astronomer had to return home - simply because he was a German. Nowadays one can see the remains of the great 72-inch reflector, lying rather forlornly between its two stone walls, and there are numerous historical relics; but the mirror has been taken away to the Science Museum in Kensington (one feels that it really should have stayed in Ireland) and the story has come to an end.
In 1853 Rosse, Robinson and Professor Phillips made up a Committee appointed by the British Association to draw up a report on the physical character of the Moon's surface. The report duly appeared,28 and stressed the need for surveying parts of the lunar disk so as to draw up more detailed maps than those of Beer and Mädler, which were the best of the time. Actually, the project was never completed; but this was not the fault of the three-man Committee, which did all that it had been asked to do.
Short 6 inch Reflector
Armagh had connections, too, with another institution of historical interest: Kew. In 1840 Primate Beresford induced Queen Victoria to donate to Armagh several instruments from King George Ill's old observatory in Kew Gardens, and some of them, including the telescope with which the King observed the Venus transit of 1769, are still on display. This telescope has an aperture of 6 inches and a focal length of 2 feet; it was made by the celebrated instrument expert Short, and can be adapted to either the Newtonian, Gregorian or Cassegrain systems. It still gives excellent results. Recently I observed the Moon and Jupiter through it, and was surprised at the quality of the definition.
The Observatory's Minute-book contains an entry for 1851 stating that Robinson was authorized to transfer some of the Kew instruments to Professor Wilson for the use of Queen's, Belfast; a clock, a small achromatic refractor and a night-glass were sent, plus a transit instrument "with the exception of the object-glass". It seems strange that the objective was removed from the transit instrument before dispatch, but in any case Queen's guaranteed to return the instruments when they were no longer needed there.
On a different plane, there was the long correspondence about the great Melbourne telescope, in which Robinson was closely involved. The complete story has been told recently by A. R. Hogg29, but Robinson's part seems well worth describing here.
Lord Rosse's great reflector caused some radical re-thinking among astronomers as a class; this also applied to Robinson, who had actually been present at the original trials of the telescope in 1845, though the clouds had prevented any observation during the period of his stay at Birr30. Clearly, it was desirable to erect a comparable instrument in the southern hemisphere, and in 1852 the Royal Society set up a Telescope Committee to express an opinion as to the most suitable form of telescope for southern nebulae. The Committee consisted of the Royal Society officers plus Robinson, Lord Wrottesley, John Couch Adams, James Nasmyth, William Lassell, Sir David Brewster, Sir John Herschel, Sir John Lubbock, the Dean of Ely, and the Astronomer Royal (Airy); John Phillips joined later.
Various optical arrangements were considered. For instance, Nasmyth, who is remembered nowadays both as a leading lunar observer and as the inventor of the steam-hammer, wanted to make provision for the observer to be suspended at the telescope's eyepiece, but this was generally regarded as too dangerous - no doubt with justification! Robinson stressed that the telescope should be equatorial and clock-driven, and preferred the German type of mount to the English. Evidently Rosse agreed with him, and equally clearly some other members of the Committee did not, since on 28 December 1852 we find Robinson writing to Rosse in the following terms:31 "I think none can gainsay your remarks as to the advantage of an equatorial mount. Work such as we contemplate is facilitated almost beyond estimation, when the object to be drawn is kept immovable in a given part of the field; and the fatigue of signalling or shouting to the assistants when the movement is by hand, absorbs no small portion of the observer's powers." Yet strangely enough, he had no faith in observatory domes, and preferred his telescopes to be in the open. Here he differed from Lassell, one of the best observers of the time, and it is interesting to quote a letter written by Robinson to Thomas Bell in 1853:32 "Mr. Lassell's opinion is certainly of great weight, yet I continue to think that large telescopes should be worked in the open air; I have tried a 15in. reflector and a 12in. achromatic thus, and also under domes, and very much prefer their action in the first case. Nor need there be much apprehension from wind."
This view seems strange to-day, but Robinson did at least urge the need for large aperture. Some members of the Committee had expressed doubts as to the feasibility of making a reflector with a focal length of what would be needed for an aperture of 48 inches, but Robinson dismissed these fears as "exaggerated ", and continued:33 "And were the difficulty and the uncertainty even as great as those gentlemen suppose, that is the strongest reason for pursuing this our purpose. It is only by the reflecting telescope that we shall reach the remotest parts of the visible universe." With these sentiments, at least, no modem astronomer will quarrel.
After six months of discussion, the Committee settled for a 48in. reflector, to be made by Grubb. It was to be erected in Australia, despite Lubbock's contention that the political situation there was too unstable. (Cooper suggested Tasmania, then a major convict settlement, and the Governor, Sir W. Dennison, wrote saying in suitably delicate terms that he could provide "the means of erecting cheaply all the buildings"!34) Robinson, Lassell and Warren de la Rue were appointed as a sub-committee to supervise the Grubb undertaking. Wrottesley wanted to obtain a 72in. reflector, which would cost some £15,000 as against the $pound;5,000 for the 48in. instrument; Robinson, while entirely agreeing that the larger aperture would be preferable, doubted whether the necessary sum would be forthcoming35. He was right. Even the smaller sum was rejected by the Government, due partly to the aftermath of the Crimean War, and for a time the whole project was in abeyance.
In 1862 the matter was re-opened by the State of Victoria, who were backed by funds from the Legislature, and who wanted a reflector of not less than 48in. aperture for Melbourne. Lassen offered to present his 24in, reflector, then set up at Malta, but the Melbourne Board of Visitors declined the offer, no doubt unwisely. Instead, they came to the Royal Society for advice, and the upshot was that Grubb made the telescope known as the Great Melbourne Reflector, with a 48in. mirror.
There were long delays, due partly to the discussions about the design for the mounting; indeed, in 1862 Robinson wrote to Major-General (later Sir Edward) Sabine, President of the Royal Society, that "if it were a question between an altazimuth mounting and no southern telescope, I would of course accept the former; but I think that to adopt it without absolute necessity is a real retrogression which would be bitterly repented ... Let us not raise up difficulties".36 Certainly he was anxious to press on: "The days that pass before this survey of the southern heavens begins are each an irretrievable loss to Astronomy".
At last, in 1867, the telescope was ready, and was examined in Dublin by Robinson, Lassell and de la Rue. Lassell had some reservations about it, but his colleagues pronounced it a masterpiece of engineering, and optically good. By 1870 the telescope was in use at Melbourne.
Unfortunately, it never came up to expectations. The speculum-metal mirrors were liable to tarnish, and the focal length was too great; the fact that there was no dome, but only a run-off shed (as Robinson had wanted) made any appreciable breeze into an observational hazard. When first set up, the telescope was the largest equatorial reflector in the world, but its indifferent performance almost certainly held back the development of other reflectors of comparable aperture.29 Robinson, however, continued to have faith in it. When H. A. Severn, of the Union Bank of Australia in Melbourne, described the telescope as "a grievous failure",31 Robinson retorted38 that this opinion "will have far less weight with the public than the good work that the telescope has already done, and is doing".
To bring the story up to date, let us note that when the Melbourne Observatory was closed, in 1945, the telescope was purchased for Mount Stromlo. The 48in. speculum-metal mirror was replaced by a 50in. aluminized glass mirror; the focal length was reduced, and electric drive added, so that at long last the telescope began to fulfil its proper role in astronomical science.
After this rather lengthy digression, let us return to the Armagh of the mid-19th century, and turn to the famous Catalogue of Stars which was so dear to the Director's heart.
Work on the Catalogue had been carried on without respite. There were irritating delays, of course; for instance, in 1854 there was a mishap which destroyed the spider's lines of the main instrument, and many fine nights had to be spent in tedious observation to work out the calibrations for the new system of wires. There were also Robinson's battles with the railway authorities, to be described below. And for a time both the Director and his assistant, Edmondson, were in poor health, so that in 1849 William Hautenville Rambaut joined the staff as an extra assistant. Rambaut was a good observer, and carried out excellent work with the mural circle.
Finally, in 1859, the catalogue appeared.39 Its full title was "Places of 5,345 stars observed from 1828 to 1854, at the Armagh Observatory"; it was under Robinson's authorship, and was dedicated to "His Grace Lord John George Beresford, Archbishop of Armagh and Primate of All Ireland".
As a basis, Robinson took the famous star-catalogue of Bradley, the third Astronomer Royal, who was noted for the accuracy of his observations. The star places were re-measured with the greater precision made possible by the Jones transit instrument and mural circle; as the stars in Bradley's catalogue were disposed of, others were selected from the catalogues of Stephen Groombridge and Piazzi. Each star was measured on many occasions; Robinson believed, in leaving nothing to chance. The catalogue, for the epoch 1840.0, contained for each star the right ascension; north polar distance; number in the Catalogue; usual designation; magnitude. annual precession, and secular variation in precession. Notes were also given with regard to the right-ascension differences between the measures at Armagh on the one hand, and those of some other observer (Bradley, Groombridge or Piazzi) on the other.
The Catalogue was warmly welcomed; for instance, the reviewer appointed by the Royal Astronomical Society commented that40 "all readers . . . will cordially congratulate the author on having brought his arduous and important labours to so satisfactory a close". In 1862, Robinson was awarded the Royal Medal from the Royal Society. Of course, one could not hope for complete accuracy, and nobody realized this better than Robinson; but he was glad to accept corrections, as is shown by his note published in 1882, amending the places of three stars in the Catalogue after slight inaccuracies had been pointed out by M. L. Schulhof of Paris.41
One must not over-stress the importance of the Armagh Catalogue, but in the pre-photographic era it was a notable achievement, particularly in view of the conditions under which it was drawn up. Certainly Robinson was entitled to be well satisfied with his efforts.
It was not only in astronomy that Robinson was a pioneer. He wrote, for instance, on topics such as the properties of metallic conductors42 and the lifting powers of electromagnets43. Yet possibly his best-known legacy to science is in meteorology, since the Cup Anemometer is due to him. He developed it after many years of theoretical and practical experimentation, and his anemometer still stands on its original site atop the Observatory roof.
On a much more down-to-earth level, there was the vexed question of the Ulster Railway.
In his Foreword to the Armagh Catalogue2, Robinson had some hard things to say about the general siting. The prevailing west to south-east winds, he complained, were apt to "drive smoke from thousands of chimneys from the town over the Observatory, and interfere, by heated air, for nine months out of twelve". A similar but still more serious mistake had been the placing of the instruments to the east of the dwelling-house, from which the streams of warm air drifted across. More serious again was the fact that the terminus of the Ulster Railroad was a mere 700 yards away, and the tremors produced by trains affected the delicate instruments. The worst result was the motion of the mural circle if a train happened to pass by after a star's transit had been observed, but before the microscopes had been read. The errors could arise to as much as four seconds of arc, which was intolerable. He placed great (and justifiable) reliance upon the ability of the observer to record such transits accurately, and had indeed written at length about it - notably in 1853, when he published a paper about possible causes of human error in taking observations.44
So far as the Observatory was concerned, the Newry and Armagh Railway Corporation was an unmitigated nuisance, though it is probably fair to say that the Corporation must have felt the same about Dr. Robinson. Nothing much could be done about the existing line, but at least it could be prevented from encroaching further, and in 1856 the Governors and Guardians of Armagh Observatory - at Robinson's instigation - petitioned the House "against the Newry-Enniskillen railway". The petition was completely successful,4 and resulted in an Act prohibiting "the transit of locomotive engines or carriages" within 700 yards of the Observatory without the consent of the Governors, which, presumably, would on no account be given! Robinson was ever vigilent; and when, in 1858, the Newry Railway Company gave notice of a Bill authorizing them to "make a branch to a terminus near Dean's Bridge, in Armagh, the Doctor made a sinister entry in the Observatory's Minute-book: "It will not come within the limit, I believe, but I shall watch them carefully."
This was not his first clash with the transport authorities. As he recorded in the Minute-book, in 1846 he attended a Parliamentary Committee in England in connection with a railway which had been scheduled to run "in dangerous proximity" to Greenwich Observatory, and, in his own words, "had some share in inducing the Lords of the Admiralty to retract the consent which they had previously signed". The same sort of thing happened at Oxford Observatory in 1853;4 again Robinson went to England to appear at the committee of investigation, and again his intervention led to the rejection of the plan. Much later, in 1873, the Newry and Armagh Railway was given permission to encroach within the limit by some 32 yards, but it was laid down that no engine or carriage travelling on that sector should move at more than 5 m.p.h. The Observatory was paid £26. 10. 3. for the land acquired.
Robinson, then, was largely responsible for preventing the development of several railway lines; Dr. Beeching would have approved of him!
By 1859, when the Armagh Catalogue was published, Romney Robinson was well in his sixties. His main life's work had been triumphantly carried through, but his intellect and enthusiasm were as keen as ever, and he had no intention of resting on his laurels. He continued to publish papers on all sorts of topics; he dealt, for instance, with the transits of Venus due in 1874 and 1882, and in 1869 published an interesting note about the production of an "imitation transit".45
At that time, a transit of Venus gave the most reliable means of measuring the length of the astronomical unit, or Earth-Sun distance, but everything depended upon an accurate timing of the moment when Venus passed wholly on to the Sun's disk. At the previous transits, those of 1761 and 1769 (the latter observed by King George III with the small Kew reflector which had been sent to Armagh in 1840), the measures had been ruined by the so-called Black Drop. As Venus passed on to the Sun; it appeared to draw a strip of blackness after it, and when this effect vanished the transit was already in progress. The Black Drop is, of course, purely optical, but it was more than annoying at the time. Robinson suggested placing a small opaque disk in the frame of a micrometer in the observing telescope, so that the disk would appear as a black spot against the Sun, and could be moved around at will. If it were possible to study a simulated Black Drop, the effect could be allowed for. So far as is known, the experiment was never actually tried, but nowadays there are much more accurate means of measuring the astronomical unit - by radar, for instance - and the next transits of Venus, those of 2004 and 2012, will not be regarded as of real importance.
At Armagh, observations of star places were still the main work, and were continued assiduously, but Robinson had become acutely aware of the need for more powerful instruments. In particular, he was anxious to obtain a large, high-quality reflector. There had been much discussion about the relative merits of reflectors and refractors; the truth is, of course, that each type of instrument is suited to its own special branches of research, but Robinson, at least in the latter part of his career, emerged as a reflector enthusiast, and wrote that only a reflector could attain "the ultimate practical limit of telescopic research"46 47. Without spending a great deal of money, no such reflector could be installed, but, as Robinson pointed out in 1860,4 even the refractors at Armagh were very small - less than 4in. aperture, and so much less powerful than a telescope of the sort used by a modern amateur. Robinson regretted that he could not, for instance, observe many of the minor planets or asteroids, of which 62 were then known. Had the telescopes been of 7 inches aperture, he wrote, they would "certainly be adequate for the demands of astronomy for a century to come". In this, the Doctor was wrong; in the 1960's, even a 7in. telescope is hopelessly small for almost any type of professional research, but in Victorian times nobody could have foreseen the immense strides which would be made in a relatively few decades.
There was also the question of the West Dome, which had been useless ever since 1838 simply because it could not be rotated. Troughton's equatorial was therefore out of action. Apparently there was no record of how the dome had been built, and Robinson wrote in 18614 that even the Rev. Robert Hogg, the long-serving assistant of the Hamilton-Davenport era who had died in 1830, knew nothing about it; all he said was that according to general practice, the dome was periodically loosened by pouring pints of oil into "certain pipes secured in the woodwork". Even then, the dome was always stiff, and by no means easy to turn. Robinson decided to investigate. He raised the dome, and exposed what he called "an arrangement which was very remarkable both for its costliness and its want of mechanical foresight". There were copper and bronze rollers, covered and immovably fixed by a green mass as hard as stone - formed by the action on the bronze of the oil which had been so liberally poured in. This would not do at all, and Robinson replaced the moving parts with new ones made of cheaper but more suitable material. To prevent further pouring-in of oil, he also wisely removed the offending pipes.
Of the other instruments, the 4.5in. aperture, 12-foot zenith sector obtained from Kew in 1840 had proved a great disappointment; Primate Beresford had had it placed in a square tower, built over the eastern part of the transit-room, and it was installed by 1841, but unfortunately it was made of wood and metal, and never worked properly. It needed complete reconstruction, and was never used; it was dismantled in 1882.48 The Jones mural circle was, of course, good, but was inconveniently small. Again Primate Beresford came to the rescue. He provided the money for a new telescope, which was made by Thomas Grubb of Dublin and attached to the Circle without adding a second pier; the focal length was much the same as before, but this time the aperture was 7 inches. Two small collimators were mounted in the same room, on iron pillars north and south of the Circle. The improvements were completed in 1862, but in the same year the generous Primate died. He had been a great benefactor of the Observatory, and had spent over £2000 on it; £300 on the transit equipment, £850 for the new telescope made by Grubb, £250 for the 15in. reflector, £220 for the Circle Room, £633 for the tower and dome, and £150 for the sector tower and mounting. Without his help, the observing programme would have been severely restricted.
There was another blow in 1864. Neil M'Neil Edmondson, who had been assistant for 27 years, died following a long illness, and before he had been able to carry out much work with the new mural circle. He was a painstaking and skillful observer, of whom Robinson spoke very highly - and the Doctor was not a man to distribute praise lightly. Rambaut succeeded him as senior assistant, and in 1868 the Rev. Charles Faris, M.A., L.C.E., was appointed as second assistant. Faris, too, had a long association with the Observatory, and did not finally give up until after the end of the first world war.
Automatic Weather Station
Weather records were continued, and in 1867 the new meteorological station was completed under the supervision of a Kew meteorologist named Stillman. The Board of Trade had decided to set up seven first-class stations distributed over the British Isles, where complete sets of self-recording instruments were to be in action day and night. Armagh was one of the stations selected; a small house was built to the east of the Tower, at the expense of the Board, and in May 1868 regular observations were commenced under the supervision of S. Call, who had been appointed by Robinson. The self-recording station remained in action until discontinued in 1883, after the end of Robinson's regime.
For some years all went well. A new series of observations of star positions was under way, the stars this time being selected from those in Lalande's catalogue; a list of 1000 positions appeared in the Transactions of the Royal Dublin Society for 1879.49 Accuracy had been still further improved when, in 1865, Robinson had purchased an electric chronograph at his own expense, and presented it to the Observatory; three years later the clock movement had been altered and improved by Thomas Grubb. Faris, with whom Robinson expressed his "complete satisfaction", undertook much of the actual observation. Unfortunately there were ominous clouds on the horizon, and these became heavy in 1869, with the Disestablishment of the Church of Ireland. The troubles arising from this development plagued Robinson for the rest of his life, and the effects were both unpleasant and far-reaching.
The Act for Disestablishment was passed on 26th July, 1869. So far as the Observatory was concerned, the worst effect of it was that the various leases held from the Primate could not be renewed - and, incidentally, the Primate's own income was very much reduced, so that in future it would be less likely that there would be gifts on the scale of those given earlier. Robinson, as might be expected, felt most strongly about the whole matter. The loss of more than £60 of the Observatory's small income was almost disastrous, and in any case it must be admitted that religious toleration was not one of the Director's strongest points. His attitude was summed up in his entry in the Observatory's Minute-book for 1869: "The Observatory has not escaped unscathed from the destructive legislation of last summer, which has confiscated at least half its annual income. The income is derived partly from Lands in Tyrone and Carlingford, and partly from the Rectorial Tithes of Carlingford, both held under lease from the Primate."
As a matter of fact, the situation was not so immediately pressing as might appear; Robinson himself was comparatively well off, he had the income of a valuable benefice, and could deal with any imminent crises. Yet the long-term outlook was depressing, and it was obvious that firm action was called for. Robinson felt that "even the present Government" would be forced, by pressure of public opinion, to make some compensation to the Observatory, but this view was somewhat optimistic; Governments in general are reticent about making grants for pure science. Moreover, Gladstone was in power, and to say that he and Robinson saw eye to eye would be stretching the truth dangerously.
Meanwhile, the only course was to wait and see what the final result of the Disestablishment would be. It was found that the Observatory's income, (from which the salary for any assistants was paid, was cut from £216 to about £155, which, even in those days, was not a princely sum. The Church Temporalities Commissioners offered to purchase the surrender of the lease of the tithes of Carlingford for £1328. 17. 9., and the Governors of the Observatory had no choice but to agree,4 but Robinson pointed out that this would leave an income well short of the minimum necessary to keep the Observatory functioning properly.
What were the hopes of a Government grant? Robinson's friend and colleague R. S. Ball, afterwards Sir Robert Ball, Director of Dunsink and perhaps the best of all " popularizers" of astronomy, was not hopeful. However, even if Gladstone seemed likely to prove un-cooperative, there was always his great political opponent, Disraeli, and accordingly a long memorandum to Disraeli was prepared. As was very correctly pointed out,4 Armagh Observatory was a national institution which had "not cost the nation one shilling", but whose very existence was now threatened.
Disraeli may or may not have been sympathetic, but he had many other matters to attend to, most of which were no doubt more important from his point of view. In any case, the final decision rested with Gladstone, and the memorandum was answered by nothing more than a stiff note saying that the time had not come to consider such questions. If Armagh were favourably treated, then other institutions would have every right to claim similar grants, and a dangerous precedent would have been set.
The whole position was most unsatisfactory, and Robinson, now well in his eighties, was naturally both irritated and depressed. There were other troubles, too. In 1875 his assistant, the painstaking Faris, had a long illness, and the Director himself had now reached the age when observing on cold nights was beyond his physical powers. He was not idle, and hated losing good evenings, as happened several times in 1875 when the gas supply failed because of a blockage in the street main, and the circles of the telescope could not be illuminated. In 1877 the weather was even worse than usual, and Robinson was inclined to associate the prevailing gloom with "the present minimum of sunspots, which meteorologists are beginning to connect with atmospheric phenomena of storms and rain",4 a view not nowadays held, it must be added.
Financially, the Observatory had not been without its supporters in Parliament. Even when the Irish Church Act had been before the House of Commons, the member for Dublin University, J.T. Ball, who was also one of the Governors of Armagh Observatory, had made an unsuccessful effort to obtain compensation. In the House of Lords, Earl Stanhope had put forward a similar motion, but had withdrawn it when Lord Dufferin, for the Government, had promised that a claim would certainly be considered "at the proper time".50 But by the end of Robinson's regime nothing had been done.
Robinson kept up his efforts. He even suggested that a full statement of Armagh's case should be printed and circulated to all M.P.s and the scientific bodies of the Old and New World, which would "at least make known the gross injustice with which this Observatory has been treated, and the indifference of Mr. Gladstone in anything that does not forward the interests of Revolution".51 And there was certainly trouble ahead, since when all expenses had been paid the Observatory's net reserves amounted to only £18!
All this was summarized by the Director in a letter written to the Dean of Armagh on 11 April 1879. As Robinson stated, it was as well "to try and get some compensation out of the plunder of our Church, for what we have lost by Mr. Gladstone's doing". The income for the past year had amounted to £156. 17.2., and the necessary expenditure, after the strictest possible economies had been practised, was £138. 7. 2. Which left the balance of £18 - hardly enough to buy new equipment or even to renovate some of the buildings, which were by now in urgent need of attention.
The plain fact was that the instruments at Armagh were inadequate for further researches. A proper equatorial was needed, since that in use was only of 2.5in. aperture; this would cost at least £600. A spectroscope was also called for (approximate cost, £50) and there was also the matter of the publication of results, together with the income for the resident astronomer and a salary for an assistant. Under the circumstances, Robinson's requests were modest, and he considered that an annual grant of £200 would be sufficient to maintain the Observatory in a state of permanent efficiency.
Then, on 28 February 1882, Romney Robinson died. He was almost ninety years old, and for some time his health had been frail, but his mental powers were unimpaired to the last, and his final papers, published in two memoirs of the Philosophical Transactions in 1878 and 1880, were as clear and concise as ever. His career had been a great one in every way. When he came to Armagh, after the Davenport tragedy, he had found the Observatory badly equipped, inactive, and virtually unknown even in Ireland. On his death, the work carried on there was famous all over the world; as well as the star-catalogue, there had been numerous publications of all kinds, many of them of great value - and despite the troubles caused by the Irish Church Act, there was little real danger that the Observatory would be closed down. Its reputation was too great.
* Surprisingly enough, it seems that of all the many mirrors made by William Herschel, only those used by himself and the German observer Johann Schröter ever made real contributions to astronomy.
** The Directors at Dunsink have been: Henry Ussher (1785-90), J. Brinkley (1790-1826), W. R. Hamilton (1826-65), F. Brünnow (1865-74), R. S. Ball (1874-92), A. R. Rambaut (1892-7), C. J. Joly (1897-1906), E. T. W,Whittaker (1906-12), H. C. Plummer (1912-21), H. A. Brück (1947-57), M. A. Ellison (1958-63) and P. A. Wayman (1964 to the present time). Between the directorships of Plummer and Brück, Dunsink was more or less in a state of abeyance. M. A. Ellison was the son of the Rev. W. F. A. Ellison, sixth Director at Armagh.
Last Revised: 2009 November 16th