The Royal Observatory, Greenwich: A Glance at Its History and Work

by E. Walter Maunder

THE OBSERVATORY BUILDINGS

Like a living organism, Greenwich Observatory bears the record of its life-history in its structure. It was not one of those favoured institutions that have sprung complete and fully equipped from the liberality of some great king or private millionaire. As we have seen, it was originally established on the most modest—not to say meagre—scale, and has been enlarged just as it has been absolutely necessary. To quote again from Professor Newcomb—

'Whenever any part of it was found insufficient for its purpose, new rooms were built for the special object in view, and thus it has been growing from the beginning by a process as natural and simple as that of the growth of a tree. Even now the very value of its structure is less than that of several other public observatories, though it eclipses them all in the results of its work.'

Entering the courtyard—an enclosure some eighty feet deep by ninety feet in extreme breadth—by the great gate, we see before us Flamsteed House, the original building of the Observatory. Flamsteed's little domain was only some twenty-seven yards wide by fifty deep, and for buildings comprised little beyond a small dwelling-house on the ground floor, and one fine room above it. This room—the original Greenwich Observatory—still remains, and is used as a council room by the official Board of Visitors, who come down to the Observatory on the first Saturday in June, to examine into its condition and to receive the Astronomer Royal's report. The room is called, from its shape, the Octagon Room, and is well known to Londoners from the great north window which looks out straight over the river between the twin domes of the Hospital.

In Bradley's time, about 1749, the first extension of the domains of the Observatory took place to the south and east of the original building, the direction in which, on the whole, all subsequent extensions have taken place, owing to the fact that the original building was constructed at the extremity of what Sir George Airy was accustomed to call a 'peninsula'—a projecting spur of the Blackheath plateau, from which the ground falls away very sharply on three sides and on part of the fourth.

The Observatory domain at present is fully two hundred yards in greatest length, with an average breadth of about sixty. Nearly the whole of this accession took place under the directorates of Pond and Airy. The present instruments are, therefore, as a rule, the more modern in direct proportion to their distance from the Octagon Room—the old original Observatory. There is one notable exception. The very first extension of the Observatory buildings, made in the time of Halley, the second Astronomer Royal, consisted in the setting up of a strong pier, to carry two quadrant telescopes. The pier still remains, but now forms the base of the support of the twin telescopes devoted to the photographic survey of the heavens for the International Chart.

Standing just within the gate of the courtyard, and looking westward, that is toward Flamsteed House, we have immediately on our right hand the porter's lodge; a little farther forward, also on the right, the Transit Pavilion, a small building sheltering a portable transit instrument; and farther forward, still on the right, the entrance to the Chronograph Room. Above the Chronograph Room is a little, inconveniently-placed dome, containing a small equatorially-mounted telescope, known as the Shuckburgh. Beyond the Chronograph Room a door opens on to the North Terrace, over which is seen the great north window of the Octagon Room. Close by the door of the Chronograph Room a great wooden staircase rises to the roof of the main building. It is not an attractive-looking ascent, as the steps overlap inconveniently. Still, there is no record of an accident upon them, and those who venture on the climb to the roof, where are placed the anemometers and the turret carrying the time-ball, which is dropped daily at 1 p.m., will be well repaid by the splendid view of the river which is there afforded to them.

Passing under this staircase, on the wall by its side is seen the following inscription:—

Carolus II^s Rex Optimus
Astronomiæ et Nauticæ artis
Patronus Maximus
Speculam hanc in utriusque commodum
fecit
Anno D^NI MDCLXXVI. Regni sui XXVIII.

Curante Iona Moore milite
R. T. S. G.

THE ASTRONOMER ROYAL'S HOUSE.
(From a photograph by Mr. Lacey.)

In the extreme angle of the courtyard is the entrance to the mean solar clock cupboard, and to the staircase leading up to the Octagon Room. At the head of this staircase in a small closet is the winch for winding up the time-ball.

Coming back into the courtyard, and crossing the face of the Astronomer Royal's private house, the range of buildings is reached which form the left hand or south side of the enclosure. Entering the first of these, we find ourselves in the Lower Computing Room, which is devoted to the 'Time Department.' The next room which opens out of it, as we turn eastwards, was Bradley's Transit Room, but is now used for the storage of chronometers. Passing through Bradley's Transit Room, we come to the present Transit Room, which brings us close to the great gate. The range of buildings is, however, continued somewhat farther, containing on the ground floor some small sitting-rooms and a fire-proof room for records.

THE COURTYARD.
(From a photograph by Mr. Lacey.)

Turning back to the Lower Computing Room, we notice in it the stone pier, already alluded to, which was set up by Halley, and formed the first addition to the original Observatory of Flamsteed. The Lower Computing Room itself and Bradley's Transit Room were due to the Astronomer after which the latter is named. An iron spiral staircase in the middle of the Lower Computing Room leads up to the Upper Computing Room, and above that to the Astrographic dome, so called because the twin telescope housed therein is devoted to the work of the Astrographic Chart—a chart of the entire sky to be made by eighteen co-operating observatories by means of photography. In this way it is intended to secure a record of the places of far more stars than could be done by the ordinary methods, and in this project Greenwich has necessarily taken a premier place. This is a work which, whilst it is the legitimate and natural outcome of the original purpose of the Observatory, is yet pushed beyond what is necessary for any mere utilitarian assistance to navigation. For the sailor it will always be sufficient to know the places of a mere handful of the brightest stars, and the vast majority of those in the great photographic map will never be visible in the little portable telescope of the sailor's sextant. But it will be freely admitted that in the case of an enterprise of this nature, in which the observatories of so many different nations were uniting, and which was so precisely on the lines of its original charter, though an extension of it, it was impossible for Greenwich to hold back on the plea that the work was not entirely utilitarian.

Descending again to the Lower Computing Room, and passing through it, not to the east, into Bradley's Transit Room, but through a little lobby to the south, we come upon an inconvenient wooden staircase winding round a great stone pillar with three rays. This pillar is the support of Airy's altazimuth, and very nearly marks the place where Flamsteed set up his original sextant.

Returning again to the Lower Computing Room, and passing out to the east, just in front of the Time Superintendent's desk, we enter a small passage running along the back of Bradley's Transit Room, and from this passage enter the present Transit Room near its south end. Just before reaching the Transit Room, however, we pass the Reflex Zenith Tube, a telescope of a very special kind.

Immediately outside the Transit Room is a staircase leading on the first floor to two rooms long used as libraries, and to the leads above them, on which is a small dome containing the Sheepshanks equatorial. These libraries are over the small sitting-rooms already referred to. The fire-proof Record Rooms, two stories in height, terminate this range of buildings.

Beyond the Record Rooms the boundary turns sharply south, where stands a large octagonal building surmounted by a dome of oriental appearance, a 'circular versatile roof,' as the Visitors would have called it a hundred years ago. This dome—which has been likened, according to the school of æsthetics in which its critics have been severally trained, to the Taj at Agra, a collapsed balloon, or a mammoth Spanish onion—houses the largest refractor in England, the 'South-east Equatorial' of twenty-eight inches aperture. But, though the largest that England possesses, it would appear but as a pigmy beside some of the great telescopes for which America is famous.

Beyond this dome the hollow devoted to the Astronomer Royal's private garden reduces the Observatory ground to a mere 'wasp's waist,' a narrow, inconvenient passage from the old and north observatory to the younger southern one.

The first building, as the grounds begin to widen out to the south, contains the New Altazimuth, a transit instrument which can be turned into any meridian. A library of white brick and a low wooden cruciform building—the Magnetic Observatory—follow it closely.

This latter building houses the Magnetic Department, a department which, though it lies aside from the original purposes of the Observatory, as defined in the warrant given to Flamsteed, is yet intimately connected with navigation, and was founded by Airy very early in his period of office. This deals with the observation of the changes in the force and direction of the earth's magnetism, an inquiry which the greater delicacy of modern compasses, and, in more recent times, the use of iron instead of wood in the construction of ships, has rendered imperative.

Closely associated with the Magnetic Department is the Meteorological. Weather forecasts, so necessary for the safety of shipping round our coasts, are not issued from Greenwich Observatory, any more than the Nautical Almanac is now issued from it. But just as the Observatory furnishes the astronomical data upon which the almanac is based, so also a considerable department is set apart for furnishing observations to be used by the Meteorological Office at Westminster for their daily predictions.

So far, the development of the Observatory had been along the central line of assistance to navigation. But the 'Magnetic Department' led on to a new one, which had but a secondary connection with it. It had been discovered that the extent of the daily range of the magnetic needle, and the amount of the disturbances to which it was subjected, were in close connection with the numbers and size of the spots on the sun's surface. This led to the institution of a daily photographic record of the state of the sun's surface, a record of which Greenwich has now the complete monopoly.

PLAN OF OBSERVATORY AT PRESENT TIME.
(For key to plan, see p. 135.)

Key to the Plan of the Observatory on Page 134.

1. Chronograph Room.
2. Old Altazimuth Dome.
3. Safe Room.
4. Computing Room.
5. Bradley's Transit Room.
6. Transit Circle Room.
7. Assistants' Room.
8. Chief Assistant's Room.
9. Computers' Room.
10. Record Rooms.
11. Chronometer Rooms and South-east Dome.
12. Greenhouse and Outbuildings.
14. New Library.
15. Magnetic Observatory.
16. Offices.
19. Sheds.
23. Winch Room for Time-ball.
24. Porter's Lodge.
25. New Transit Pavilion.
26. New Altazimuth Pavilion.
27. Museum: New Building.
28. South Wing "
29. North Wing "
30. West Wing "
31. East Wing "
F. Rooms built for Flamsteed.
H. Added by Halley.
B. " Bradley.
M. " Maskelyne.
A. " Airy.
F'F'. Flamsteed's boundaries.
M'M'. Maskelyne's " 1790.
P'P'. Pond's " 1814.
A'A'. Airy's " 1837.
A"A". Airy's " 1868.

Beyond the Magnetic Observatory the ground widens out into an area about equal to that of the northern part, and the new building just completed, and which is now emphatically 'The Observatory,' stands clear before us. The transfer to this stately building of the computing rooms, libraries, and store rooms has been aptly described as a shift in the latitude of Greenwich Observatory, which still preserves its longitude. It may be noted that the only two buildings of any architectural pretensions in the whole range are—Flamsteed's original observatory, built by Sir Christopher Wren, and containing little beyond the octagon room, in the extreme north; and this newest building in the extreme south.

This 'New Observatory,' like the old, and like the great South-eastern tower, is an octagon in its central portion. But whilst the two other great buildings are simply octagonal, here the octagon serves only as the centre from which radiate four great wings to the four points of the compass. The building is by far the largest on the ground, but in little accord with the popular idea of an astronomer as perpetually looking through a telescope, carries but a single dome; its best rooms being set apart as 'computing rooms,' for the use of those members of the staff who are employed in the calculations and other clerical work, which form, after all, much the greater portion of the Observatory routine.

An observer with the transit instrument, for instance, will take only three or four minutes to make a complete determination of the place of a single star. But that observation will furnish work to the computers for many hours afterwards. Or, to take a photograph of the sun will occupy about five minutes in setting the instrument, whilst the actual exposure will take but the one-thousandth part of a second. But the plate, once exposed, will have to be developed, fixed, and washed; then measured, and the measures reduced, and, on the average, will provide one person with work for four days before the final results have been printed and published.

It is easy to see, then, that observing, though the first duty of the Observatory, makes the smallest demand on its time. The visitor who comes to the Observatory by day (and none are permitted to do so by night) finds the official rooms not unlike those of Somerset House or Whitehall, and its occupants for the most part similarly engaged in what is, apparently, merely clerical work. An examination of the big folios would of course show that instead of being ledgers of sales of stamps, or income-tax schedules, they referred to stars, planets, and sun-spots; but for one person actively engaged at a telescope, the visitor would see a dozen writing or computing at a desk.

The staff, like the building, is the result of a gradual development, and bears traces of its life history in its composition. First comes the Astronomer Royal, the representative and successor of the original 'King's Astronomer,' the Rev. John Flamsteed. But the 'single surly and clumsy labourer,' which was all that the 'Merry Monarch' could grant for his assistance, is now represented by a large and complex body of workers; each varied class and rank of which is a relic of some stage in the progress of the Observatory to its present condition.

The following extract from the Annual Report of the Astronomer Royal to the Board of Visitors, June, 1900, describes the present personnel of the establishment:—

'The staff at the present time is thus constituted, the names in each class being arranged in alphabetical order:—

'Chief assistants—Mr. Cowell, Mr. Dyson.

'Assistants—Mr. Hollis, Mr. Lewis, Mr. Maunder, Mr. Nash, Mr. Thackeray.

'Second-class assistants—Mr. Bryant, Mr. Crommelin.

'Clerical assistant—Mr. Outhwaite.

'Established computers—Mr. Bowyer, Mr. Davidson, Mr. Edney, Mr. Furner, Mr. Rendell, and one vacancy.

'The two second-class assistants will be replaced by higher grade established computers as vacancies occur.

'Mr. Dyson and Mr. Cowell have the general superintendence of all the work of the Observatory. Mr. Maunder is charged with the heliographic photography and reductions, and with the preparation of the Library Catalogue. Mr. Lewis has charge of the time-signals and chronometers, and of the 28-inch equatorial. Mr. Thackeray superintends the miscellaneous astronomical computations, including the preparation of the new Ten-Year Catalogue. Mr. Hollis has charge of the photographic mapping of the heavens, the measurement of the plates, and the computations for the Astrographic Catalogue. Mr. Crommelin undertakes the altazimuth and Sheepshanks equatorial reductions, and Mr. Bryant the transit and meridian zenith distance reductions and time-determinations. In the magnetic and meteorological branch, Mr. Nash has charge of the whole of the work. Mr. Outhwaite acts as responsible accountant officer; has charge of the library, records, manuscripts, and stores, and conducts the official correspondence. As regards the established computers, Mr. Bowyer, Mr. Furner, Mr. Davidson, and Mr. Rendell assist Mr. Lewis, Mr. Thackeray, Mr. Hollis, and Mr. Bryant respectively, and Mr. Edney assists Mr. Nash.

'There are at the present time twenty-four supernumerary computers employed at the Observatory, ten being attached to the astronomical branch, two the chronometer branch, six to the astrographic, one to the heliographic, four to the magnetic and meteorological, and one to the clerical.

'A foreman of works, with two carpenters, and two labourers; a skilled mechanic with an assistant; a gate porter, two messengers, a watchman, a gardener, and a charwoman, are also attached to the Observatory.

'The whole number of persons regularly employed at the Observatory is fifty-three.'

The day work, as said before, is by far the greatest in amount, the 'office hours' being from nine till half-past four, with an hour's interval. The arrangements for the night watches present some complications.

For many years the instruments in regular use were two only, the transit circle and the altazimuth. The arrangements for observing were simple. Four assistants divided the work between them thus: an assistant was on duty with the transit circle one day, his watch beginning about six a.m. or a little later, and ending about three the following morning; a watch of twenty-one hours in maximum length. The second day his duties were entirely computational, and were only two or three hours in length. The third day he had a full day's work on the calculations, followed by a night duty with the altazimuth. The latter instrument might give him a very easy watch or a terribly severe one. If the moon were a young one it was easy, especially if the night was clear, as in that case an hour was enough to secure the observations required.

Very different was the case with a full moon, especially in the long, often cloudy, nights of winter. Then a vigilant watch had to be kept from sunset to sunrise, so that in case of a short break in the clouds the moon might yet be observed. Such a watch was the severest (with one exception) that an assistant had to undergo.

His fourth day would then resemble his second, and with the fifth day a second cycle of his quartan fever would commence, the symptoms following each other in the same sequence as before.

Such a routine carried on with iron inflexibility was exceedingly trying, as it was absolutely impossible for an observer to keep any regularity in his hours of rest or times for meals.

This routine has been considerably modified by the present Astronomer Royal, partly because the instruments now in regular daily use are five instead of two, and partly because a less stringent system has proved not merely far less wearing to the observers, but also much more prolific of results. It was impossible for a man to be at his best for long under the old régime, and from forty-six to forty-seven has been an ordinary age for an assistant to break down under the strain.

One point in which the observing work has been lightened has been in the discontinuance of the altazimuth observations at the full of the moon, another in the shortening of the hours of the transit circle watch; and a further and most important one in the arrangement that the observers with the larger instruments should have help at their work. The net result of these changes has been a most striking increase in the amount of work achieved. Thus, whilst in the year ending May 20, 1875, 3780 transits were taken with the transit circle, and 3636 determinations of north polar distance; in that ending May 10, 1895, the numbers had risen to 11,240 and 11,006 respectively, the telescope remaining precisely the same.

One principle of Airy's rule still remains. So far as possible no observer is on duty for two consecutive days, but a long day of desk work and observing is followed by a short day of desk work without observing.

It will be readily understood that with five principal telescopes in constant work and one or two minor ones, some demanding two observers, others only one, each telescope having its special programme and its special hours of work, whilst by no means every member of the staff is authorized to observe with all instruments indifferently, it becomes a somewhat intricate matter to arrange the weekly rota in strict accordance with the foregoing principle, and with the further one, that whilst a considerable amount of Sunday observing is inevitable, the average duty of an observer should be three days a week, not seven days a fortnight. There is a story, received with much reserve at Cambridge, that there was once a man at that university who had mastered all the colours and combinations of shades and colours of the various colleges and clubs. If so gifted a being ever existed, he may be paralleled by the Greenwich assistant who can predict for any future epoch the sequence of duties throughout the entire establishment. At any rate, one of the first items in the week's programme is the preparation of the rota for the week, or rather, to use an ecclesiastical term, for the 'octave,' i.e. from the Monday to the Monday following.

The special work to be carried out on any telescope is likewise a matter of programme. For the transit circle a list of the most important objects to be observed is supplied for the observer's use, and the general lines upon which the other stars are to be selected from a huge 'Working Catalogue' are well understood. With some of the other telescopes the principles upon which the objects are to be selected are laid down, but the actual choice is left to the discretion of the observer at the time. There is no time for the watcher to spend in what the outsider would regard as 'discovery'; such as sweeping for comets or asteroids, hunting for variable stars, sketching planets, and so forth. Indeed, there is a story current in the Observatory that some fifty years ago, when the tide of asteroid discovery first set in, Airy found an assistant, since famous, working with a telescope on his 'off-duty' night. That stern disciplinarian asked what business the assistant had to be there on his free night, and on being told he was 'searching for new planets,' he was severely reprimanded and ordered to discontinue at once. A similar energy would not meet so gruff a discouragement to-day; but the routine work so fully occupies both staff and telescopes that an assistant may be most thoroughly devoted to his science, and yet pass a decade at the Observatory without ever seeing those 'show places' of the sky which an amateur would have run over in the first week after receiving his telescope. For example, there is no refractor in the British Isles so competent to bring out the vivid green light of the great Orion nebula—that marvellous mass of glowing, curdling, emerald cloud—or the indescribable magnificence of the myriad suns that cluster like swarming bees or the grapes of Eshcol in the constellation of Hercules; yet probably most of the staff have never seen either spectacle through it. The professional astronomer who is worth his salt will find abundance of charm and interest in his work, but he will not,

'Like a girl,
Valuing the giddy pleasures of the eyes,'

consider the charm to lie mainly in the occasional sight of wonderful beauty which his work may bring to him, nor the interest in some chance phenomenon which may make his name known.

It is not every field of astronomy that is cultivated at Greenwich. The search for comets and for 'pocket planets' forms no part of its programme; and the occupation so fascinating to those who take it up, of drawing the details on the surfaces of the moon, Mars, Jupiter, or Saturn, has been but little followed. Such work is here incidental, not fundamental, and the same may be said of certain spectroscopic observations of new or variable stars, and of many similar subjects. Work such as this is most interesting to the general public, and is followed with much devotion by many amateur astronomers. For that very reason it does not form an integral part of the programme of our State observatory. But work which is necessary for the general good, or for the advancement of the science, and which demands observations carried on continuously for many years, and strict unity of instruments and methods, cannot possibly be left to chance individual zeal, and is therefore rightly made the first object at Greenwich.

Those striking discoveries which from time to time appeal strongly to the popular imagination, and which have rendered so justly famous some of the great observatories of the sister continent, have not often been made here.

Its work has, none the less, been not only useful but essential. A century ago, when we were engaged in the hand-to-hand struggle with Napoleon, by far the most brilliant part of that naval war which we waged against the French, and the most productive of prize-money, was carried on by our cruisers, who captured valuable prizes in every sea. But a much greater service, indeed an absolutely vital one, was rendered to the State by those line-of-battle ships which were told off to watch the harbours wherein the French fleet was taking refuge. This was a work void of the excitement, interest, and profit of cruising. It was monotonous, wearing, and almost inglorious, but absolutely necessary to the very existence of England. So the continuance for more than two centuries of daily observations of places of moon, stars, and planets is likewise 'monotonous, wearing, and almost inglorious;' the one compensation is that it is essential to the life of astronomy.

The eight Astronomers Royal have, as already said, kept the Observatory strictly on the lines originally laid down for it, subject, of course, to that enlargement which the growth of the science has inevitably brought. But had they been inclined to change its course, the Board of Visitors has been specially appointed to bring them back to the right way. As already mentioned in the account of Flamsteed, the Board dates from 1710, when it practically consisted of the President and Council of the Royal Society. Its Royal warrant lapsed on the death of Queen Anne, and was not renewed at the accession of the two following sovereigns; but in the reign of George III. a new warrant was issued under date February 22, 1765; and this was renewed at the accession of George IV. When William IV. came to the throne, the constitution of the Board was extended, so as to give a representation to the new Royal Astronomical Society, founded in 1820. The President of the Royal Society is still chairman of the Board, but the Admiralty, of which the Observatory is a department, the two Universities of Oxford and Cambridge, and the Royal Astronomical Society are all represented on it by ex officio members, and twelve other members are contributed by the Royal and Royal Astronomical Societies respectively, six by each. The first Saturday in June is the appointed day for the annual inspection by the Board, and for the presentation to it of the Astronomer Royal's Report. To this all-important business meeting has been added something of a social function, by the invitation of many well-known astronomers and the leading men of the allied sciences to inspect the results of the year, and to partake of the chocolate and cracknels, which have been the traditional refreshments offered on these occasions for a period 'whereof the memory of man runneth not to the contrary.'

---