5. Armagh Observatory between the Wars

The Directorship was again vacant, and there was an urgent need to fill it. Meteorological records were still kept, and Faris remained in nominal charge; in April 1918, for instance, we find that he was authorized to place four telescopes at the disposal of the Lady Roberts Glass Fund for the duration of the war, and in a letter dated 29 April Lady Roberts wrote saying that the instruments would be returned after the end of the war "should circumstances permit".

In March 1918 the Primate stated that several applications for the Directorship had been received. Only one name has been preserved: that of the Rev. W. F. A. Ellison, who was the successful candidate. He was officially appointed on 2 September 1918, and took up residence in the following month.

W.F.A. Ellison

William Frederick Archdall Ellison, born in 1864, had been classed as an amateur astronomer, but a highly distinguished one. Originally he had no thought of a scientific career. He came of a clerical family; his father, the Ven. Humphrey Eakins Ellison, had been Dean of Ferns, and was also a first-class scholar who personally undertook the early education of his six sons. (As all six subsequently won scholarships to Trinity College, the Ven. Humphrey must have been a good teacher.) William gained a sizarship in classics at Trinity in 1883, became a Scholar of the House in 1886, and graduated with junior moderatorships in classics and experimental science in 1837. He took Holy Orders in 1890, and went to England, where he became curate of Tudhoe and Monkwearmouth. Monkwearmouth to-day is far from being the centre of learning that it used to be in the Dark Ages, when the Venerable Bede lived and worked there, but Ellison was able to continue his studies; he took his M.A. and B.D. degrees in 1894, and won the Elrington Theological Prize in the following year.

So far his career had been quite conventional, and the pattern was continued when in 1899 he returned to Ireland to become secretary of the Sunday School Society. He held the post for only three years, after which he accepted the incumbency of Monart, Enniscorthy, shifting in 1908 to become Rector of Fethard-on-Sea with Tintern in Wexford. But by now he had developed a keen interest in astronomy, and it was at Wexford that he set up his first observatory. His most marked ability was in telescope-making; he had been introduced to practical optics by Dr. N. Alcock of Dublin (afterwards Professor of Physics at McGill University, Montreal), and before long Ellison was grinding lenses and making mirrors. He became highly skilled, and contributed to many optical journals and publications, notably the famous book Amateur Telescope Making - which remains a standard for telescope-makers the world over84.

He also wrote a book, The Amateur's Telescope, which achieved tremendous success. At the time there was nothing quite like it, and even to-day it is still thought to be as good an introduction to telescope-making as has ever been written. Incidentally, it proved to be rewarding from a financial point of view, since it ran to many editions and was translated into various foreign languages.

When Ellison arrived at Armagh, in October 1918, he found that the Observatory was, in his own words, "practically derelict".85 Apart from the meteorological recording, nothing had been done since Dreyer's departure two years earlier, and the first essential was to get the instruments back into working order. Here Ellison scored heavily, because he could do the work himself - and do it extremely well. The 10in. Grubb refractor presented no real problems, and was soon cleaned and renovated, but the dome was by no means satisfactory. It leaked, as it had always done, and Ellison proceeded to cover it with rubberoid.

By good fortune, it became possible to add a fine 18 in. Calver reflector to the Observatory equipment. It was Ellison's property, and he generously handed it over by a deed of gift made on 3 January, 1919. The 18in. is still in use today, though not in its original form. The devious route by which it came to the Observatory is worth recounting.

The telescope was made by the famous George Calver, in 1883, for a Colonel Tupman, of Harrow, who was a wealthy amateur; he had taken part in eclipse expeditions between 1870 and 1875, and made observations of the transits of Venus in 1874 and 1882. Tupman spent £800 on the telescope, and a further sum on a, suitable dome. When the work was finished, officialdom stepped in. The story is best told in Ellison's own words:4

"Those enlightened and progressive patrons of science, the local British Bumbles, raised his rates, on the pretext of the new building. Colonel Tupman was so disgusted that he dismantled the telescope and pulled down the dome. After some time Mr. John Pierce, of the Wexford Engineering Works, bought it for £200 to replace his 8in. Wray refractor. Mr. Pierce had been persuaded to acquire the instrument by an engineer in his employment, who promised to oversee the erection of both telescope and dome, but when the work was half done the engineer was tempted away by the offer of a lucrative post in Australia, leaving Mr. Pierce with the instrument on his hands. Mr. Pierce sent for me, and consulted me … He entreated me to take the thing away as a gift. I replied that even to transport it would cost more than I could afford. "Never mind that," he replied. "I will send the steam lorry and deliver it at your door." In this way I came into possession of the largest telescope in Ireland … Before re-erecting the telescope here I lightly re-figured the mirror, which was rather under-corrected, to its very great benefit."

Calver Telescope reconfigured as a Schmidt

During 1919 the new reflector came into operation, and in the following year Ellison completed a 6.25in. object-glass for a new refractor, which was set up in the East Tower. The equatorial and clock were those of the old 15in. reflector which had been there ever since Robinson's day. The speculum-metal mirror had become more or less useless, and Ellison wrote that in his view, Robinson had made a miscalculation in ordering it in the first place; had he preferred a refractor, there would have been no need for a replacement at all. (This seems rather harsh. Robinson could not have been expected to see into the future, and at the time when he had to make the decision it seemed as though a large reflector would be the best choice.) Troughton's old telescope in the West Dome was still as good as it had been when first set up in 1793, and Ellison used it once or twice, though it was of course of historical interest only.

Actually, Ellison had difficulties with the 6.25in. lens, but the fault was not his. The first blank of flint, which he obtained from the manufacturers, Chance Brothers of Birmingham, was so defective that he sent it back. Three more were sent, but these too were poor in quality. Ellison was not a man to tolerate shoddy workmanship, and he spoke his mind so plainly that the firm dispatched him a fourth blank at half price. With this Ellison was satisfied, though, as he wrote, it "did not give back the weeks of wasted labour". He went on to say4 that "the completed lens is as fine a lens of its size as any optician ever turned out. Except in size, the 10in. Grubb object-glass has no advantage over it". Clearly, Ellison had a high opinion of his own skill - but he had good reason, since he was a very fine optical worker indeed.

By the end of 1924 the overhauling of the equipment at the Observatory was complete. Observations had been carried out during the renovation period, and a few of them seem to be worth noting here. Unlike his predecessors, Ellison was interested in physical observations of planets, and he paid considerable attention to Mars; his drawings will be found scattered fairly liberally through the Reports of the Mars Section of the British Astronomical Association during the period, and in 1918, on 28 February, he made an interesting observation with regard to Saturn. This involved the eclipse of the eighth satellite, Iapetus, by the shadow of the rings.

Iapetus is a curious little body. Its diameter is uncertain, and estimates range between 900 and almost 2000 miles; it is much brighter when west of Saturn than when to the east of the planet, so that its surface may be unequally reflective. It is more than two million miles from its primary, and has a revolution period of 79 days. A moderate telescope will show it, and with the 10in. Grubb refractor it is an easy object.

Only twice before had an eclipse of Iapetus by the ring-shadow been observed, each time by Bond. Notice was sent to all European observatories before the event, but only at Armagh were observations secured; bad weather prevailed everywhere else. When first seen, Iapetus was illuminated by the sunlight passing through the Cassini Division; the satellite faded, though it did not vanish, on entering the shadow of Ring A, and then, following a twenty minutes' interruption from clouds, was picked up again, though its brightness seemed to be showing short-term variations of two to three minutes. This confirmed the translucency of Ring A, which had already been indicated by the visibility of the globe through it and also by studies of the occultation of the faint star B.D. 21o1714 by the rings on 9 February 1917, observed by M. A. Ainslie and J. Knight.

In 1921 Saturn's ring was edge-on, and was followed with the 10in. refractor and 18in. reflector "except for one or two days. At other times the ring could be seen as an indescribably fine line of light - a spider's thread reflecting the sunlight"4.*

Double stars also came under scrutiny, and in this work Ellison was helped by his son Mervyn, who later became Director of the Dunsink Observatory. First, the pairs in Holmes' catalogue were re-measured, and later on the doubles contained in the Scheiner catalogue drawn up at Potsdam were examined. The 10in. refractor was used for all this work; the 6.25in. was not quite large enough, though in 1921 it was mounted on the equatorial in the East Dome in place of the old 15in. speculum-metal Cassegrain, as has been noted. The results of this double-star work appeared in the Monthly Notices of the Royal Astronomical Society between 1925 and 1928. 86 87 88 In the course of the observations, Ellison discovered a new double star near Delta Lyrae. It was far from striking, since the magnitudes of the components were only 11 and 13, but, as he recorded in the Minute-book4, it was "the first discovery made at Armagh for many years".

The occultations of various stars in the Pleiades and Hyades by the Moon, on 2 February 1926, were carefully observed, and the results sent by request to the Johannesburg Observatory90. Eclipses were also of interest to Ellison. He went to North Wales in 1927 and Canada in 1932 to observe total eclipses of the Sun, though on each occasion he was baulked by clouds (he had been luckier at Waterloo, in Belgium, in 1912).

From an observer's point of view, it is worth noting that Ellison was strongly opposed to Summer Time! In the Minute-Book4, he even wrote that because of this tampering with the clock, "no observation at all is possible during the summer months. I believe all scientific men heartily detest this freak of the House of Commons. It is difficult now to be sure of the time when anything happened."

The famous Robinson Cup Anemometer, which had been on loan to Kew, was returned in 1927 and restored to its original position91. The assistant meteorologist, W. H. Espley, departed in 1921, and for financial reasons was not replaced; Mrs. Ellison undertook some of the duties, but in 1929 we find the Director writing92 that "the climatological work to some extent crowds out astronomy". The Air Ministry made an annual payment of £50 for the records, and this sum was too great to be given up, as other sources of income provided only a yearly £276. This was patently inadequate. For instance. the classic First Armagh Catalogue of Stars was out of print; requests for copies came in regularly, but there were no available funds for reprinting and binding. The library also was in a poor condition, and was not up to date, while even the older periodicals remained unbound.

Money was always the problem, and Ellison had to do his best to eke out his meagre salary. He retained the incumbency of Kildarton, and in 1934 he became Canon and Prebendary of Ballymore, Armagh Cathedral. The royalties from his book on telescope-making continued to come in, and he also made and sold mirrors and lenses, which were in great demand. Nevertheless, things were most unsatisfactory, and scientific research was badly held up.

The Astronomer Royal, Sir Frank Dyson, had written an encouraging letter to Ellison, dated 11 December 1924, in which he said that since the Observatory had so long and honourable a history it must not be allowed to perish gradually because of lack of funds; it was, as he put it, much more than "an interesting monument of Northern Ireland". But moral support is one thing, while hard cash is quite another - and cash was what Armagh needed.

In 1928 the Northern Ireland Parliament did provide an annual grant of £100, which was just sufficient to avert actual decay93, and was used to make urgent repairs to the East Wing. However, further economy cuts were made in 1931, and the grant was reduced by £10 until restored to its former level five years later. It is not surprising that it became essential to sell some of the Observatory land. Actually, this sale was effected in 1928, before the grant came through, and raised £1000. The decision was taken with reluctance, but in the event it led to no trouble. The Armstrong School now stands upon the plots given up at that time.

Ellison was, of course, highly skilled in all practical matters, and went so far as to install a wireless room in the old Zenith Sector Tower as early as 1921; the Paris time signals were, he wrote, clearly audible - and in 1932 he was officially authorized to erect wireless equipment and an aerial. But he could not do everything by himself, and to have an assistant was out of the question. The shutters of the transit room were out of order for nearly two years from 1929, and later the dome of the 18in. reflector gave such trouble that the instrument was unusable. Previously Ellison had made some studies of stellar spectra with it, but had found that his equipment was hopelessly inadequate94. From about 1929 Ellison's published reports became more and more brief and routine. He died on 31st December; 1936, having held office for almost twenty years.

Ellison was a man of many talents. As well as his skill in practical astronomy, he was a noted Hebrew scholar capable of translating psalms from their original sources. He had a remarkably good memory, and became widely known as a "character", largely because of his forthright letters to the Press; he was an expert organist who often played at Armagh Cathedral, and he had a gift for humorous poetry. The fact that the Observatory was in poor shape when he died was due mainly to the lack of funds, and not to deficiencies on the part of its Director.

* The 10in. is particularly suitable for planetary work. During 1965 I made a series of observations of Saturn with it89, and found it much more effective than the 12.5in. reflector in my own observatory. In 1966 the Earth again passed through the ring-plane, and a long series of observations was made with the 10in. refractor by two Armagh amateurs - T. J. C. A. Moseley and P. G. Corvan - and myself. Like Ellison so long before, we found that the rings were not lost to view even when edge-on to the Earth.


Last Revised: 2013 July 18th