Edited by W. Valentine Ball 1915

PARSONSTOWN: 1865-1867

After my father left Trinity College, the next few years of his life were spent at Parsonstown, where he was tutor to Lord Rosse's sons. His experiences during this period are thus recorded by himself:

I do not think it had ever occurred to me to embark upon an astronomical career until November 8th, 1865, when I received a letter from Dr. Johnstone Stoney. It conveyed the following message: "Would it be agreeable to you to act as tutor to Lord Rosse's Sons at Parsonstown?" I was by no means sure of my qualifications for the post. I had never paid much attention to classics, beyond the small minimum necessary to pass examinations. In' those days classics were generally regarded as the primary part of a tutor's duties. Up to that time it had never at any moment entered into my thoughts to become a tutor or a schoolmaster. I may, parenthetically, remark that when Clifton College was founded, I was offered, through Dr. Lloyd, the Provost of Trinity College, the position of chief science master.

Dr. Stoney's letter, however, presented great attractions. When it reached me, Lord Rosse, who had been President of the Royal Society, was one of the most prominent men of science in the kingdom. His great telescope was then, as indeed it still is, unrivalled in dimensions. I saw in this letter an opportunity for studying astronomy under the very best auspices. I also realized that acceptance of this post would enable me to become acquainted with scientific things and with leading men of science. In framing my reply I explained that my classics, to put the thing very mildly, were very shaky, but that I would do my best. I added that with regard to the other matters necessary for the education of three youths of ages varying from eleven to sixteen, I had no grave doubts as to my competence, and that I would accept the post, provided that I was allowed to use the great telescope. A favourable reply was soon forthcoming, in which it was stated that Lord Rosse would be delighted to give me the free run of his Observatory. This decided my course in life, and I have never since regretted for a moment that I failed to become a Fellow of Trinity.

I hasten to say, however, that I did not sever my connection with college without a considerable wrench. I was bound to my Alma Mater by many ties, and the acceptance of the new post involved separation from many excellent friends. I did not foresee that nine years later I was to return again to my dear old university - this time in the capacity of professor.

Let me describe the scenes and conditions amongst which my life for the next two interesting years was to be passed. The residence of the Earl of Rosse is at Birr Castle, in King's County, about eighty miles from Dublin. Birr Castle is situated at the little town, which was then officially known as "Parsonstown," but to the inhabitants as "Birr." Quite recently I believe the official designation has been abandoned, and the Post Office only recognizes "Birr." Birr Castle is a noble building of modern erection, surrounded by a moat. It is situated in a beautiful park, through which two pretty rivers flow, and these unite in a single stream before they leave. The park has also a large artificial lake, ingeniously constructed by Lord Rosse himself, which is the perennial home of innumerable wild duck. Several instances of Lord Rosse's consummate mechanical skill are to be found about the grounds. Visitors used to stand gazing in wonder on a water-wheel which, being turned by the waters from the lake, raised water from a drainage system connected with low-lying lands around. A suspension bridge was thrown across the river close to the castle. The outstanding feature of Birr Castle, by which it will be forever famous in the annals of science, is the mighty telescope. Between the lake and the castle are two great walls, which are now somewhat overgrown with ivy. I have been told that Visitors entering the gates of the park for the first time have driven up to these walls 'In the belief that they were approaching the castle itself, which is not visible from the park gates. Between these two walls there swings a tube sixty feet long and six feet in diameter - a tube large enough to be the funnel of a good size steamship. At the lower end of this tube is the mighty mirror or speculum Lord Rosse's telescope is what is known as a "reflecting telescope " - a reflecting telescope of the Newtonian type. The instrument is raised by means of a winch, which is place towards the north, and the observers who are to use the telescope have to make their way to the galleries. It is characteristic of this type of telescope that the eye-piece is at the top of the tube, not, as in the refracting instruments; at the bottom four men had to be summoned to assist the observer. One stood at the winch to raise or lower, another at the lower end of the instrument to give it an eastward or westward motion as directed by the astronomer, while the third had to be read' to move the gallery in and out, in order to keep the observer conveniently placed with regard to the eye-piece. It was the duty of the fourth to look after the lamps and attend to minor matters.

Lord Rosse not only designed the great instrument, but actually constructed it. At the back of the castle he had extensive workshops, where a capable smith named Coghlan and numerous assistants carried out the work under the direction of the Earl himself. It was he who devised methods for getting over the innumerable difficulties involved in casting, grinding, and polishing the great speculum, which weighed over three tons¹. He had many failures before he achieved success; and the precepts which he laid down have been followed by all who have since made great reflecting telescopes. To illustrate the thoroughness of his methods, let me recall one detail which I heard from his own lips. In the final polishing of the mirror, rouge was the material employed. When he commenced operations he found that the rouge of commerce was not satisfactory. He therefore investigated the subject, and eventually discovered the way to make good rouge. His method was afterwards adopted in the manufacture of the rouge which is used by the great silversmiths in London.

When I went to Parsonstown, in 1865, Lord Rosse was advanced in years. He no longer took an active part in the work of observation, but he evinced a lively interest in all. Lord Oxmantown, Lord Rosse's eldest son, was not one of my pupils. They were his three younger brothers, who are now the Hon. and Rev. Randal Parsons, the Hon. R. C. Parsons - a well-known engineer - while the youngest is the Hon. Sir C. A. Parsons. It has always been a great satisfaction to me to remember that I had the great honour of instilling the elements of algebra and Euclid into the mind of the famous man who has revolutionized the use of steam by his invention of the steam turbine. It would seem that he inherited his father's brilliant mechanical genius, with an enormous increase in its effect on the world.

The two years I spent at Parsonstown were full of interest. Ever since the erection of the great telescope, Lord Rosse had had an astronomer in charge of it. They were five in number, but I only propose to mention three. The first of these was my friend, Dr. George Johnstone Stoney, whom I have already mentioned. He was in Lord Rosse's Observatory in the early days of the great telescope. He did much excellent work, and laid the foundation of a scientific reputation, which was greatly enhanced by his subsequent labours. He left Lord Rosse to become Professor of Natural Philosophy at Queen's College, and was subsequently appointed to succeed my father in Dublin as secretary of the Queen's University. It was then that my friendship with him began, and it lasted until his lamented death in 1911. Although he retired from every official position some time before his death, he devoted his well-earned leisure to strenuous labour in many branches of science. He often found the hours of the day too short for all he wanted to do. Of the many scientific people who work at electricity, physics, acoustics, spectroscopy, and microscopy, there are few who would not gladly acknowledge that Dr. Stoney had often been their teacher.

It was he who began the great work of observing nebulae with the big telescope. Nebula was at that time objects of special interest. At the beginning of the century, Sir William Herschel had completed his famous survey of such nebulous objects as were visible in the northern sky, while Sir John Herschel in his expedition to the Cape of Good Hope, had completed the work which had been begun by his father. It was left to the Earl of Rosse to start from the point which these investigators had already reached. His telescope was much more powerful than those which the Herschels had used. Indeed its optical and mechanical arrangements were as perfect as was possible in an instrument of this description. On the other hand, it must be remembered that Birr Castle is not an ideal place for an observatory. It is near to the Bog of Allen. Consequently, the skies were frequently overhung with clouds, to the distraction of the astronomer. Even Herschel himself, in his observatory near Windsor, had found that not more than a hundred hours in the whole year were adapted for the purposes of the highest class of astronomical investigation.

It was fortunate that Lord Rosse had as his associate in those early days one who combined in such a high degree the essential qualities of accuracy and scientific enthusiasm which were found in Dr. Stoney. Dr. Stoney was succeeded at Parsonstown for a short time by his brother, Mr. Bindon Stoney, the eminent engineer, whose great services to the Port of Dublin will be gratefully remembered by every citizen. The Rev. T. Gray, now a distinguished Senior Fellow of Trinity College, was there also, in the capacity of tutor, as was also the late Professor Purser, who was afterwards Professor of Mathematics in Belfast for many years. Purser had left his mark on the science of the time not so much by his own original writings-though even these are noteworthy - as by his great success as a teacher. I think my friend, Professor Sir Joseph Larmor, Secretary of the Royal Society, would gladly admit how much he owed in his early years to the remarkable mathematical teaching which was given in Purser's classes in Belfast.

Such were a few of my predecessors at Parsonstown. I ought here to say that in one respect the position I occupied was somewhat different. For, as already explained, I was both tutor and astronomer. And I certainly had a busy time of it during the two years. The morning was spent with my pupils in the castle. Hours of study over, we indulged in certain rather strenuous forms of relaxation. Felling trees was a favourite amusement of Lord Rosse, and we frequently spent an afternoon so employed. If one desired to fish, there were great pike to be caught in the lake. But the large workshops were my chief resort during the hours of leisure. I managed to construct a six-inch reflector, having learnt under Lord Rosse's guidance the uses of the screw-cutting lathe and other metalworking tools. Nor did my young pupils confine their energies to the work of the classroom. In those days there was a small workshop just off the library at Birr Castle. This was the constant resort of my youngest pupil, the Hon. Charles Parsons. In this little den he was always making all sorts of machines. I remember two of his early contrivances. One of them was an air cane, and the other a sounding machine, which he afterwards used with success in his father's lake. The depth of water was ascertained by measuring pressure as recorded in a barometric tube, this being, of course, the principle now so well known in Lord Kelvin's sounding machine. With the assistance of his brothers, the future inventor of the steam turbine also made a steam engine, and I well remember the delight they took in grinding the reflector of a telescope in a machine which was driven by the home-made engine.

I asked Lord Rosse for permission to use the telescopes for some private experiments on the moon which I had in contemplation. He warmly entered into the subject. I also got from him carte blanche to borrow any books from his library.

On fine evenings I would go to the observatory as soon as it was dark. The observatory proper was a little building containing two small instruments, close under the shadow of the two great instruments outside. One of these was the great reflector already mentioned. The other was the "three-foot instrument"- is to say, an instrument having a mirror three feet in diameter, the tube of the telescope being ten times as long as the width of the mirror. The great six-foot instrument was, however the one which we employed for important observations I shall suppose that we are ready to commence a night's work. The assistants above referred to are already at their posts. Up we climb to the lofty gallery, taking with us a chronometer, our observing book, various eye-pieces, and a lamp. The "working list" as it is called, contains a list of the nebulae, which we want to observe. A glance at the book and at the chronometer shows which of these is coming into the best position at the time. The necessary instructions are immediately given to the attendants. The observer, standing at the eye-piece, awaits the appointed moment, and the object comes before him. He carefully scrutinizes it to see whether the great telescope can reveal anything which was not discovered by instruments of inferior capacity. A hasty sketch is made in order to record the distinctive features as accurately as possible. One beautiful object having been observed, the telescope is moved back to the meridian to be ready for the next vision of delight. When I first began this work, nothing amazed me so much as the extraordinary speed with which the hours passed. A look at my watch might show it was half-past eight. When I next drew it from my pocket, at what seemed no great interval of time, it would show half-past eleven! On a third occasion I would find it ten minutes to two! I sometimes followed Herschel's strenuous example and remained observing from dusk to dawn. I would have kept this lengthy vigil more frequently had it not been that the faithful and uncomplaining attendants, who could have but little interest in the work, were freezing gradually through the night. Personally I did not mind the cold². I was young then; indeed, it frequently happened that, after a dinner-party at the castle, I went out with a light coat over my evening clothes to pass the night at the telescope. I should add that work was occasionally interrupted by little visits to the castle, where, by the kindness of Lord Rosse, tea and other refreshments were always available.

At the first glimmer of dawn the order would come for the telescope to be closed up. This operation, which took some little time, having been duly performed, the little party broke up for a well-earned repose.

Lord Oxmantown was also an assiduous observer. Many a night did we spend together at the great telescope. Astronomy was just then beginning to quicken with new life under the great impulse that had been given to it by recent spectroscopic discoveries. A spectroscope (then regarded as of colossal dimensions, for it weighed about seventy pounds, though that itself would be nothing in comparison with the spectroscopes now used at the Yerkes Observatory) had been built from Lord Rosse's design. By means of it we saw that superb spectacle, certain lines in the spectrum which announced the gaseous character of the Nebula in Orion. With infinite patience Lord Rosse devoted years to making a drawing of the Great Nebula. Those were not the days of astronomical photography. That great advance only became possible when the dry plate was introduced. Lord Rosse's beautiful drawing was engraved on steel by Basire, and copies of it are now to be seen in all the principal observatories. It is an exquisite piece of work. It was repeatedly compared with the actual object in the heavens, and corrected altered until accuracy was attained. In some respects we may say it is unique. Never before was so much pains bestowed on the drawing of a celestial object, and never again will equal pains be devoted to the same purpose. In an hour or two the photgraphic plate will now record much more than the most accomplished astronomer can observe, even though his repeated observations cover a period of several years.

The visitors' book at the Parsonstown Observatory contains the names of many great astronomers, both native and foreign. Amongst them I can recall those of Dr. Romney Robinson, who had been intimately associated with Lord Rosse from the first, the late Sir George Stokes, the Astronomer Royal, Sir George Airy, Sir John Herschel, General Sabine, and many more too numerous to mention. I should add that these visitors had been there before my time, for by 1865, when I was in charge, the novelty of the great instrument had to some extent died away.

I would point out that the work of observing in the manner above described is extremely trying and fatiguing. It should be remembered, however, that the nights on which the nicer observations can be made are few and far between. In the first place, all moonlight nights may be ruled out, for the nebulae, hard enough to see under the, most favourable conditions, become altogether invisible when there is moonlight in the sky. Diligence at the telescope was, therefore, not incompatible with tutorial duties in the day.

I have said that the years I spent at Parsonstown stand out as being of exceptional interest and importance in my life. I may go yet farther and say that the most remarkable scene I have ever witnessed took place during my sojourn there. Anyone who has apprehended that I was at Parsonstown in 1866 may at once infer that I am now alluding to the great shower of shooting stars.

I have described this phenomenon at various times and in many places, but I am always glad to talk about it and think about it, for I wish to preserve as clearly as I can the impression of one of the most wonderful sights that can possibly be seen by mortal man. The conditions were exceptionally favourable, for on the night of November 13th, 1866, the weather was clear and the moon was nowhere to be seen. On that memorable night I had in mind what took place at the British Association earlier in the year. I had then attended a meeting of that body for the first time. For some years a committee of the Association had been diligently collecting information about luminous meteors and kindred phenomena. The annual reports for many years before and after this date are full of information about shooting stars, fire-balls, meteors, and meteorites.

At one meeting some years before, Mr Glaisher, who divided his interest between meteoric studies and ballooning, had made the startling announcement that, although he was not absolutely certain, there was reason to expect that on November 13th, 1866, there would be a notable shower of shooting stars. His opinion was based upon the fact that such showers had appeared more or less regularly at intervals of thirty-three years. As there had been a display in 1833, it was reasonable to suppose that there would be another in 1866. He made his prediction, as I have said, with some reserve. It was not and could not possibly be made with the confidence which astronomers feel in predicting an eclipse of the sun or moon. Mr. Glaisher's utterance, however, had often been the subject of conversation at Birr Castle, and when we went out to the observatory on the momentous night we had some expectation that the shower would appear. I ought to mention, in passing, that Lord Rosse's great instrument could have been of no use in the observation of a shower of shooting stars. Its movements were too limited and the field was too small. Indeed, with this instrument it was impossible to see as much of the heavens as is occupied by a full moon. A meteoric shower can best be observed either "with your hands in your pockets," or with a pair of ordinary binoculars, which combine a moderate magnifying power with a very large field of view.

On this memorable evening I had repaired, as usual, to carry on my work at the big telescope. I had observed one nebula. The attendants were occupied in winding the gallery back towards the wall. This operation was necessary to enable the telescope to be moved in order to follow an object which was passing from the meridian by the diurnal motion. I suddenly heard a shout. Looking up, I was just in time to see a brilliant streak of light overhead. It was all that was left of the meteor which had attracted the notice of the attendant and had caused him to shout. Shortly afterwards another appeared, and though they were both brighter than the kind of meteor usually seen, we thought they were only casual visitors. But presently they began to come in twos and threes. It was now about ten o'clock, and Lord Oxmantown had come over from the castle to join me in the gallery. As the shooting stars were every minute increasing in number, we desisted from attempting any further work on the nebulae, and went up a few feet higher to the summit of one of the great meridian walls from which the telescope was suspended. From a height of sixty feet above the ground I saw a spectacle which, even after an interval of forty years, was the grandest I ever remember having seen. It was a beautifully clear winter's night, with the canopy of heaven above us, and not a cloud to obstruct the vision in any direction. At first, as I have said, the great meteors flashed across the sky in twos and threes. Each of them was bright enough and sufficiently conspicuous to arrest attention. But when they came in dozens, in scores, in uncounted hundreds, and finally in myriads, the scene was unspeakably sublime. Not a sound was heard. It was in the dead silence of dark night that the heavens were scored in every direction by these wonderful streaks of light. As a rule the duration of each was very short - perhaps it lasted a second or two. They were moving, as we afterwards ascertained approximately forty miles per second.

Individually they were small objects - probably not so large as the pebbles on a. gravel walk - but it was the immense speed at which they were hurrying along which warmed them and converted them into streaks of golden fire. Occasionally the "streak" did not disappear immediately. In some cases the meteor appeared to leave a sort of phosphorescent haze along its track, which endured for some time. I took note of some streaks, which lasted for a quarter of an hour or twenty minutes, becoming gradually twisted and deformed by air currents in the higher atmosphere. This went on until at last the material was dissipated. We were all struck by the fact that the meteors moved in a certain direction. They appeared to radiate from the east. Occasionally they swept round by the north, or by the south; sometimes they streamed right overhead in magnificent arrows of fire; but the point of rising of each one of them was in the east. As the night wore on the eastern sky gradually ascended. In due course the constellation Leo - well known as one of the signs of the Zodiac - attained an altitude at which it could be clearly seen. We then observed that all the meteors had a special relation to the constellation Leo; in fact, they started from that group. Closer examination revealed the fact that there was a certain point in that remarkable sickle-shaped arrangement of stars from which all the meteors appeared to radiate. This point could be determined quite accurately. It is this relation of the shooting stars to Leo, which has given them the name of the Leonids.

Lord Rosse, who had come out to the observatory, watched this superb display with me for a couple of hours. In the actual vicinity of Leo itself the track of the shooting star was often very much foreshortened, suggesting a resemblance to a comma on the surface of the heavens. Sometimes the meteor appeared to be end on to us, and then what we saw appeared like a Star gradually rising to brilliance, and then again fading to extinction. The explanation is that all these objects were really moving in parallel lines, and that the vanishing point of the parallel lines was the constellation Leo. The Stars that appeared to come straight towards us came actually from the vanishing point. There could be no better demonstration of the doctrine of parallel lines than the shooting stars which we saw that night.

Lord Rosse always went to London for the season, and as he took me with him I had opportunities of becoming acquainted with many distinguished men of science. On one occasion we paid a visit to Wheatstone, who was famous not only in relation to the electric telegraph, but also as the inventor of the concertina and the stereoscope. Wheatstone showed us the original apparatus, which he had used in perfecting these inventions. Amongst other curious things he showed us what, for want of a better phrase, I will describe as a negative stereoscope. If one looked at a face through this instrument, instead of appearing to stand out in relief, it appeared to be hollow - just as if one were looking into a mould which had been taken from the face. On another occasion Lord Oxmantown and I went to spend a day with Mr. Babbage, the inventor of the calculating machine.

Other scientific men to whom I was introduced by Lord Rosse were Mr. Warren De Ia Rue, who had just succeeded in taking photographs of the moon, and Mr. J. P. Gassiot. In his house at Clapham Mr. Gassiot had an immense battery of many thousand cells, by which he could show electrical phenomena in exhausted tubes, which were then novelties in the scientific world.

Lord Rosse also took rue to see Sir William Huggins, K.C.B. the late President of the Royal Society. The circumstances under which this visit was paid were of considerable interest, inasmuch as it occurred at a time which was to be memorable in the history of astronomy. Mr. Huggins, as he then was, had recently made his discovery of the gaseous composition of many nebulae. This was one of the first results of the application of the spectroscope to the study of the heavenly bodies.

Let me attempt to describe the nature and significance of the discovery in a few words. In earlier days the view generally held was that nebulae - those little patches of light in the sky -were only clusters of stars at a distance so great as to render it impossible to distinguish the individual stars. No doubt many of the so-called star clusters can be thus explained; and it frequently happens that objects which look like nebulae when viewed through a small telescope are found to be star clusters when telescopes of great power are directed towards them. The spectrum of a star, properly so called has a general resemblance to the solar spectrum. It exhibits all the colours of the rainbow, and forms a brilliantly coloured streak of light. But it is well known that when a gaseous object is examined through a spectroscope the light instead of being drawn out into a long, variously coloured streak, is concentrated into one or more bright lines, with intervening dark spaces.

One evening Huggins turned his spectroscope, which he had already wielded with such admirable effect upon the stars, towards one of these nebulae. He has stated that he himself was astonished at the result. At first he thought that the instrument must have become deranged, because he failed to find the streak of light which a star ought to show. Instead of a streak, he saw nothing but a line in which the light seemed all concentrated. Closer examination showed that the light coming from the nebula was entirely contained in two or three lines, from which, knowing the properties revealed by ordinary gases when examined by the spectroscope, he drew the inference that the celestial body under observation was of a gaseous nature. It is impossible to overestimate the significance of this discovery. The theory then accepted with regard to nebulae had taught the world that the sun and the planets had all been evolved from a nebula in some form. But this theory had theretofore been open to the objection that, so far as we knew, no such nebulae existed in the universe. The discovery made by Huggins that night silenced this objection forever. It showed that gaseous nebulae were of common occurrence in the heavens. This was the commencement of a most remarkable series of investigations, prosecuted with great vigour by Huggins himself, and afterwards carried on by other astronomers in various parts of the world.

I visited this renowned astronomer shortly after he had made his great discovery, and the occasion was made still more interesting by another circumstance which I shall now relate. Tuam, in the west of Ireland, is a place remote from the ordinary scientific centres, but in that town there dwelt a very acute observer of the skies, the late Mr. Birmingham. I do not think he ever used a telescope of high power. No doubt he had a fairly good instrument, but he had something else, without which the most admirable instruments are of little use-he had genuine interest in his subject. He also possessed that accuracy and care which are so necessary in faithfully recording observations. One evening Mr. Birmingham noticed a bright star in a place where he did not remember having seen any point of light before. He immediately consulted a map of the heavens. This confirmed his recollection. There was no star marked in the place indicated. He knew that it could not be a planet, as the whereabouts of every planet is regularly set forth in our almanacs. They are always to be found in their proper places. It seemed that the Tuam astronomer had discovered the birth of an entirely new celestial object. He wrote two letters, one to the Times, and the other to Mr. Huggins. As he had not been heard of before in scientific circles, those who were first told of his discovery came to the conclusion that he was mistaken. It did not seem likely that an event of this kind should have passed unnoticed at recognised observatories by all the well-known astronomers, only to be detected by a comparatively unknown astronomer in a rather remote part of the country. Mr. Huggins, however, thought that there could be no harm in looking towards the spot in the heavens which Mr. Birmingham's letter had clearly defined. There he found the star blazing brilliantly. He then remembered his spectroscope, and, turning this instrument upon the star, he made a startling discovery. I have already pointed out that the spectrum of an ordinary star is a long streak of light, coloured from one end to the other with the hues of the rainbow. In the spectrum of this new star, which astronomers now known as Coronae because it is, in the constellation of Corona, the streak was not, indeed, wanting; but superimposed upon it there were certain brilliant lines. Even if Mr. Huggins had known nothing of the wonderful history of the object he was studying, he immediately pronounced it to be a celestial body of unusual character. He had been led to this conclusion solely by his spectroscopic observations, for there was nothing in the appearance of the star to attract special attention as distinguished from other stars. Indeed, if it had presented any unusual appearance, it could scarcely have escaped the vigilance of astronomers and observers other than Mr. Birmingham. It was fortunate that Huggins had so far been able to deal with the new object. Indeed it could not have arrived more opportunely if the highest interest of science had to be served.

His spectroscope taught Huggins that there were in the new star great volume of gas. The gas consisted to a large extent of hydrogen, which was at the, moment in a state of blazing incandescence. The discovery of this fact threw a flood threw a flood of light on the remarkable suddenness with which the star had appeared. It is generally thought that there had been a collision of two stars hurrying along through space with a stupendous velocity. The effect of the impact was to generate heat sufficient to vaporize the solid constituents of both stars.

It was shortly after these startling discoveries that I paid my visit to Mr. Huggins. The evening was bright and clear. The great astronomer lived then in Upper Tulse Hill, and those who say that the climate of England is unsuitable for delicate astronomical work should bear in mind that at least one great modern astronomer made some immortal discoveries in a sky which is often obscured by the fog and smoke of the great metropolis. Huggins had a dome at the back of his house, which contained his telescope. On the occasion of my visit I met Dr. Miller, the distinguished chemist, who had been closely associated with Huggiris in his spectroscopic work. Miller had helped to measure the dark lines in the spectra of other stars, which work he had carried on with the utmost delicacy of skill and completeness. So admirable was the work as done by the astronomer and chemist in association, that each received the gold medal of the Astronomical Society for his share in the work.

On the night we visited Mr. Huggins, Mr. Birmingham's new star had lost something of its pristine splendour. It had sunk to the sixth magnitude, and was no longer visible to the naked eye. But when we entered the dome we found both the telescope and the spectroscope turned upon it. Huggins first took us outside, where, by means of a pair of binoculars, we could see the wonderful object which had declined so much in lustre in the course of a few days. He then showed it to us through the spectroscope. The bright lines were quite unmistakable, although no doubt they were fainter than they had formerly been. It was thus that we saw in all its grandeur this wonderful light which was kindled in the depths of the heavens. I have since seen other phenomena of a similar nature, but nothing can ever displace from my memory the evening at Tulse Hill to which I now refer. The delight of making the acquaintance of Mr. Huggins himself, the novelty of the spectroscope-that little instrument which, attached to the eye-piece of the telescope, is so potent an agent for analysing the wonders of the heavens-the beauty of the subject, and, last but not least, the reflection that this was probably the beginning of a new era in celestial investigations; all these made the visit an incident in my life never to be forgotten.

Among the visitors at Birr I should have mentioned Dr. Brunnow, who was appointed Astronomer Royal of Ireland in succession to Sir William Rowan Hamilton, who died in 1865. I little thought when I first met Dr. Brünnow at Parsonstown that I was to take his place at Dunsink a few years later.

I will conclude what I have to say about my sojourn with Lord Rosse by stating that shortly after I went to the Royal College of Science, Lord Rosse fell into bad health, and after a severe operation, from which he never rallied, he died on October 30th, 1867.

Dr. Dreyer, of the Armagh Observatory, has been kind enough to supplement my father's own account of his work at Parsonstown with the following:

"Ball went to Parsonstown, probably in January, 1866, to prepare Lord Rosse's three younger sons for Trinity College, Dublin, and also to observe with the great telescope. Though the teaching was considered his principal work, he was chiefly induced to accept the post (as he said in after years) by the prospect of studying the heavens by means of the six-foot and three-foot reflectors, of which the former was at that time still facile princeps among telescopes. Erected in 1845, it had been used more or less continuously since 1848 for observations of nebulae, the great discovery of spiral nebulae having been made with it, as soon as it was first pointed to the sky. When Ball began to use it in February, 1866, nearly all the large and interesting objects had been carefully drawn, and there was very little left to be done in that direction. But the micrometer had - been very little used, and he found there a field worth cultivating. As the telescope was not yet provided with a clock motion to counteract the earth's rotation, it had to be moved along by hand by a workman, while the observer took the distance and position angle between nebulae near each other, or a nebula and several stars close to it. Obviously measures taken in this way could not be very accurate; still they might be of use in various ways, and it was desirable to make them as carefully as possible. The telescope was not mounted equatorially, but was supported at the lower end on a universal joint, with its primary axis directed east and west. As soon as the telescope was moved away from the meridian its optical axis therefore began to describe an arc of a great circle through the east and west points of the horizon, while an equatorial moves along a circle parallel to the equator. The zero-point of the position circle of the micrometer was therefore continually altering, and a correction ought to be applied to the angles measured. This had never yet been done, and as the correction depends partly on the distance of the telescope from the meridian, and the time had never been noted when the measures made by the earlier observers were taken, it had not been possible to apply the correction to them. It was an easy matter for Ball to find a formula by which this correction could be worked out, and from that time it was always applied.

"Another improvement which Ball tried to introduce in the work of the observatory was the collation of the observations already made, with a view to finding which objects did not require any further attention, as a great deal of time had been wasted for some years previous to his arrival by indiscriminate observing. But he did not remain long enough at Birr Castle to effect much in this way.

"He was an indefatigable observer, and was remembered for years after his departure by the workmen who helped to work the telescope as the man who kept them up 'terrible late' at night. And yet Lord Rosse said that no matter how late he observed, he turned up at the castle the next morning to attend to his work as tutor with almost his usual punctuality. He lived in rooms in Cumberland Square, Parsonstown, about eight or ten minutes' walk from the castle and the telescope.

"His last recorded observations were made in August, 1867, just before he was appointed a professor in the Royal College of Science, Dublin. His observations were published in 1879-80, with the rest of the long series of observations of nebuae made with the great telescope from 1848 to 1878."

My father never forgot his pupils at Parsonstown. He retained their friendship to the end, and they frequently consulted him on scientific matters. Sir Charles Parsons wrote to him on October 9th, 1899:
"I have on hand an address to the Senior Engineers next month on heat engines, and should be very much obliged if you can tell me if I am right in taking approximately 2,000,000,000 as the fraction of the sun's total heat radiated that is caught by the earth. Is one right in taking it as the ratio of the solid angle subtended at the sun to the whole spherical angle? Also what depth of ice is it calculated that the sun's direct heat would thaw in twelve months, say in Egypt? Pray excuse my ignorance, but one gets so very rusty when immersed in ordinary engineering surroundings."

My father's reply is not recorded, but Sir Charles wrote again on October 21st.

"It is exceedingly kind of you to write me so fully, and it is just what I wanted.
"My address is on heat engines, and I wanted to show that with mirrors it would be quite possible (I think financially) to generate steam power in Egypt or the Sahara, allowing 50 per cent. loss to cover absorption and loss in reflection. A 13-foot diameter mirror ought to generate i h.p. for twelve hours a day on the average. I will send you a copy, if it gets printed, as they usually are, but possibly it may be too bad for this privilege. Very many thanks, and with best wishes.
"P. S.-A 24-inch diameter short-focus mirror, as used for searchlights, will work a toy engine very well.
"P.P.S.-Mr. T. Lipton has got his yacht too short and full-bodied for the speeds they go. They seem to design by rule of thumb in England - they should rely on model experiments, which would put them right."

Notes:
  1. Since these lines were written this great mirror has been removed from the telescope and placed in the Victoria and Albert Museum, South Kensington. The work of removal and transportation involved no small difficulty owing to its weigh and fragility.
  2. In later years when he was at Dunsink, he had a buffalo coat with cap and gaiters which baffled the cold during the night in the dome of the South Equatorial. He had purchased the coat, which was made of a genuine skin, in the United States. He used to say that future astronomers would be deprived of such comforts owing to the extinction of the buffalo, and that, notwithstanding the benefits he had derived from the coat, he regretted his small contribution towards the obliteration of this noble animal.