Stuart Malin was the society’s president from 1898 to 1991. Here he recalls his earlier years as a professional astronomer working initially at the Royal Greenwich Observatory.
World War 2 is not generally considered to have been a Good Thing, but it wasn’t all negative. I grew up during the blackout that was imposed during the Blitz and which effectively continued for several years after the war ended until streetlights began to blossom again. Thus, starlit nights were the norm (cloud permitting) and the star patterns were familiar friends.
My first observation through a telescope was at a Scout camp c. 1950, to which one of the organisers had brought his 3-inch, tripod-mounted, brass refractor. He pointed it at Saturn and we took it in turns to look. I had seen pictures and photographs of Saturn, all much better than the small, unsteady image through the telescope, but to actually see the rings ‘in the flesh’ was a magic moment that I have never forgotten. I was hooked!
As an undergraduate in the mid-1950s I saw a note on the Physics Department noticeboard inviting applications to enrol for a summer vacation course at the Royal Greenwich Observatory (RGO), Herstmonceux, where the observatory was in the process of being reestablished after being dispersed from Greenwich during the war. ‘Why not?’ I thought, and became one of six students who attended the first of these courses, which were initiated by the new Astronomer Royal, Sir Richard Woolley. The courses went on to become an institution and were the introduction of a generation of astronomers to their future careers.
So it proved for me. I had previously thought of astronomy as a hobby pursued by old men in dressing gowns and smoking-caps, and it came as a revelation to find that it could be a career with a proper pay-structure and a pension, just like the Civil Service. (At the time the Royal Observatory came under the Admiralty and the staff were classified as Scientific Civil Servants.) A second ‘That’s for me’ moment.
On the course, after the evening meal the AR, as the Astronomer Royal was universally known, would come into the dining room and chat with the students. On one such occasion, someone burst in and announced a bright star-like object in the sky to the south-west. A naked-eye supernova! The AR cursed because here was the event of a lifetime and the only workable telescope (the transit telescopes were operative, but their field of view was restricted to the meridian) was the 6-inch Solar telescope. We all dropped everything and headed that way – just like the Magi, except that there were eight of us, including the AR and the messenger. Then it went out! Just a high-altitude weather balloon moving into the Earth’s shadow.
You get the same effect with satellites, though nothing like so bright, but artificial satellites did not exist then. The first one, Sputnik, appeared on the scene during a later vacation course in 1957 (I attended three of them). Unspectacular visually, but what a dramatic moment and in the ideal place to experience it. We speculated wildly on what it might portend, but all predictions fell pathetically short of what would so rapidly become reality.
The AR asserted that three years at the RGO would be every bit as valuable as a PhD, so I joined the staff there – as an Assistant Experimental Officer – straight after graduation in 1958. It is true that after three years I was at the same grade and receiving the same salary as a newly-recruited PhD, but I still fancied being a doctor so I eventually acquired both PhD and DSc.
Every able-bodied male was eligible for night observing duties. The ladies had to wait years before it was considered safe to expose them to such hazards, the most serious of which was the male observers. Not only was this a chance to get to grips with real telescopes and serious sky-watching, it was also a nice little earner. For every scheduled night, clear or cloudy, you earned 2/6d (12½p) and half a day off if you actually had to attend.
Another source of supplementary income was the running of evening classes for local authorities or for the Workers’ Educational Association, preferably jointly with a colleague so that one could swap with the other to comply with the observing rota. This was my introduction to the world of amateur astronomy and what a fascinating variety of people the amateurs proved to be. Some signed up for the course as a dating agency; others because ‘pottery’ was fully subscribed. Those for whom astronomy was the main reason for attending fell broadly into two groups: those who were interested in techniques (telescope and instrument building) and those who were interested in the observations and what they revealed. There was surprisingly little overlap.
Many of them were fearsomely expert and, until I discovered The Technique, I would dread the tea-break for which we would have to traipse to another building. If the sky was clear, someone was bound to ask me ‘What star is that?’ The Technique was to throw the question to the rest of the class. Once I was sure that no one else knew either, I could make up a plausible star name and everyone was happy.
An important factor was to choose a venue remote from Herstmonceux. Not for fear of retribution for mis-naming stars, but because the real profit from these courses was in the mileage allowance. Some authorities would pay as much as 10d (about 4p) a mile.
I count myself very fortunate to have worked in the days when one actually looked at real starlight through a telescope, rather than watching it all on a monitor in an adjacent room. It had its downside, of course. To avoid fuzzy images due to convection currents, the dome and its contents, including the observer, had to be at the same temperature as the air outside. In winter we used to dress like Arctic explorers. One concession to the cold was the issue of 12 volt electrically-heated observing suits which incorporated electrically heated socks and gloves, though the gloves were seldom used because it was not possible to operate sensitive equipment with muffled fingers. The suits were designed for deep-sea divers who went down in those tin-can things with claws sticking out, and were designed to be worn while standing up. (Being an Admiralty establishment, the RGO had access to the suits.) Roy Wallis successfully claimed for a new pair of trousers after constant bending of the knees frayed the heating wires, which set fire to the trousers he was wearing. (He exaggerated a little: the damage was merely a scorch behind one knee, but he could always tell a good story.)
Most of my observing was done on three telescopes of the six that comprised the Equatorial Group. As the name implies, they were all equatorially mounted so that they could point to anywhere in the sky and be kept directed at a chosen star by a motor that counteracted the rotation of the Earth by rotating the telescope at the same constant rate, but in the opposite direction, about an axis parallel to that of the Earth. Following objections from locals on aesthetic grounds to the eminently functional solar telescope dome, the design for the Equatorial Group was put out to competition. The winner was a famous Irish architect who produced a design that was elegant and pleasing in daylight, but was wildly impractical for night work when even the light from dimmed torches had to be limited. A few examples will give the idea. The site was originally flat, so no steps would have been needed, but was landscaped to incorporate ‘interesting’ features such as a bridge, many steps and – the ultimate idiocy – an un-fenced lily pond right in the middle! Fences and railings were considered unsightly, so the outer boundary was a sheer 12-foot drop into a ha-ha. A subtle touch: the bridge over which one had to pass to get from one of the telescopes to the darkroom, was made of York stone, which retains enough water to produce a sheet of ice on its surface when there is a frost. Naturally, there was no railing on the side over another 12-foot drop onto concrete. I could go on, but you get the idea. I was working as a student in the AR’s office when he got a courtesy call from the architect to say that he wished to show some friends over his new construction. The AR refused permission on the grounds of safety!
The 1950s and 1960s saw the final flowering of the chemical photography era in astronomy. People are not at their best at three in the morning, so that is no time for intellectual activity or judgement. Far better to obtain a permanent record for careful consideration in the cold light of day. The last outpost of serious on-the-spot measurement was double stars where one had to wait for that brief moment when the two stars appeared as separate objects from the fuzzy mess, remember where they were, and make the measurement. And electronic imaging was not yet good enough for astronomical use. So dark room skills were an important part of the job; cutting, sensitising, loading and processing glass photographic plates in total darkness. It was obviously important to know which side the emulsion was on and this was done by the merest touch of a slightly moistened lip. At the telescope the observer’s job was to keep the telescope pointing accurately in the right direction by making fine adjustments via buttons on a handset to keep a star (viewed through a guiding telescope rigidly attached to the main telescope) at the centre of a pair of crosswires. Details of the night’s programme were worked out in some detail the day before, but obviously had to be modified, or abandoned, according to circumstances; rain or cloud didn’t help.
One of the observing programmes in which I was involved was on the 13-inch Astrographic telescope. Essentially it was a camera with a 13-inch diameter lens at the top end of an 11-foot-long cylinder with a photographic plate holder at the bottom end. (Telescopes are usually specified by the diameter of their main lens or mirror, as this is a measure of their light-collecting power – the main purpose of a large telescope is to be a light-bucket.) The Astrographic had originally been used at Greenwich in the late 19th century to photograph the whole of the sky north of 65º as Greenwich’s contribution to the international Carte du Ciel project. The Herstmonceux programme was to repeat this survey, using un-backed plates of optically flat glass so that the starlight passed through the glass before being recorded on the emulsion. Then the new plates could be placed emulsion-to-emulsion on the old ones and the Proper Motions (movements of stars across the line-of-sight) could be established for stars too faint and numerous to have their positions measured on a transit circle. A good idea, but it was overtaken by measurements made above the atmosphere by the satellite Hipparcos. Though the first set of plates still provided the necessary earlier positions.
The telescope was a delight to use, with accurately engraved silver circles that obviated the need for a finder telescope to locate the guide-star. Auto-guiding was just coming in, but was spurned by serious observers who had more, though probably unjustified, faith in their eyesight. It is difficult to abandon the old skills, one of which was the ability to scoot the observing bed – two hinged, padded boards on a frame with casters – around the dome and under the eyepiece using just heel and buttock power. Anything that got in the way, frequently my glasses, was mercilessly crushed.
The next dome along – watch out for the pond, bridge and steps on the way – housed the big brother of the Astrographic: the 26-inch refractor, twice the length and diameter, four times the light-gathering power and occupying eight times the space of the Astrographic. Again, essentially an f-10.4 camera with a rigidly attached 12.8-inch guide telescope that dated from 1860 and was formerly known as The Great Equatorial when housed in its own dome in Greenwich, but was now doing sterling work in semi-retirement as an appendage to the 26-inch. The programme on this telescope was the measurement of distance of stars by their parallax – the angle they subtended when viewed from opposite ends of the Earth’s orbit. The idea was to take a photograph of a star against a background of distant stars on, say, March 1, wait six months until the Earth had moved to the other side of its orbit around September 1, take a second photograph and measure the miniscule amount the star had moved relative to the background stars. The catch being that, if the first photograph was taken at around midnight on March 1, by the time September came around, it would be broad daylight when the star was above the horizon. The way around this was to wait a couple of months, take the first photograph as soon as possible after sunset when our star was still high in the sky, and the second one just before sunrise just a bit more than six months later. For this reason, the useful observing was restricted to a few hours after sunset and a few hours before dawn, getting as many photographs of programme stars as possible in those two intervals.
To speed things up, the dome had a rising floor to take the observer to the business end of the telescope, which, being on the end of a 22-foot, centrally pivoted tube, could move over an alarming range of distances between one star-setting and the next. Great fun, but it could be a bit nauseating looking up at the rotating dome while also raising the floor. Also, it was really tough on the neck to stand looking up at an overhead star for anything up to 20 minutes while carefully guiding during an exposure. My way around this was to lie on my back on the floor with my head on a cushion, and gently approach the eyepiece by pressing the ‘slow – up’ button. Then one day, while the engineer was doing maintenance, the button failed to spring back and the floor continued upwards. Harm was done neither to man nor telescope, but I decided to abandon my cushion and put up with a crick in my neck, dramatic though it would have been to have ended my life impaled on a telescope.
The middle of the night was available for other observing, but was seldom used except by me renewing my acquaintance with Saturn, or other wonders. One night in 1958 there was a strange red glow in the sky when looking South through the slit in the dome. I went outside to see what was up and was rewarded with the most spectacular auroral display to the North that I had ever seen up to that date (Alaska trumped it, but not until years later). This was at the peak of the biggest sunspot maximum ever and it was accompanied by a massive magnetic storm.
The post-sunset shift was a doddle, but the pre-dawn one was much more of a chore. I was living in a bachelor flat in Herstmonceux Castle at the time (posh address; modest quarters) only three minutes by Austin Seven from the Equatorial Group, so I could sleep normally until just before observing time. When the alarm went off, I would pause for a bit in the hope that I could hear rain. If not, I would totter to the window and stick my head out. Cloud? bliss! Stars? damn! But on with the gear and sally forth. Once I had properly woken up all was well. I might even stay on until Civil Twilight, when it was too light for Astro-photography, but still dark enough to seek, for example, Mercury. Then back to the flat for the traditional brown-ale omelette breakfast. Just a dash of ale in the omelette made it fluff-up beautifully, and the rest of the bottle washed it down.
The third telescope I observed on at Herstmonceux was the Yapp 36-inch reflector, the biggest one there until the Isaac Newton 98-inch was installed in 1967. Yapp was the name of the industrialist who paid for it. It was an ugly brute compared to the elegant Victorian 13- and 26-inch telescopes (and the 28-inch, though I had only slight acquaintance with that until it became my responsibility after its return to the onion dome in Greenwich), which looked as telescopes should with a lens at the top end and the observer down at the sharp end. But, with its centre of gravity much nearer the bottom end and a length much shorter than the focal length because the light was reflected up and back down the tube using a secondary mirror, the 1930’s 36-inch had a much sounder engineering design. The only disadvantages of reflecting telescopes compared to refracting telescopes is that the reflecting surface needs to be re-aluminised at intervals, and it needs to be figured to a higher precision than a lens, but this is readily achieved nowadays and it is usually the quality of the ‘seeing’ that affects the sharpness of the image more than the quality of the optics.
In any case, since the 36-inch was used for spectroscopy, which involved trailing the star image up and down a slit so that all parts of the slit eventually received nearly the same amount of light (rather like painting a tiny barn door), a slightly fuzzy image was an advantage. At the beginning and end of each exposure, an M-shaped mask was moved to cover the part of the slit where the starlight went and expose the two ends of the slit, into which light from an iron-arc was shone for a few seconds. Thus, the resulting photograph has a star spectrum spread along the middle, with an iron spectrum above and below. By measuring the small displacement (due to Döppler effect) between the spectral lines from the star and the corresponding lines from the stationary iron arc, the star’s radial velocity, i.e., the line-of-sight velocity, can be deduced. When combined with its proper motion, this gives a full description of the star’s motion relative to the Solar System. More interestingly, regular variations in its the radial velocity show that a star is part of a binary system and provide useful information about the binary orbit. The orbital details together with the distance of the star (from its parallax) provide the only direct way of measuring the mass of a star.
An interesting alternative use of the 36-inch was discovered and exploited by Derek Jones – distinguished astronomer, good friend and inventor of the brown-ale omelette. At the end of a morning observing session, he would point the telescope as nearly as possible due east, leave the dome, climb onto the roof of the adjacent aluminising laboratory, look at his enlarged reflection in the concave mirror, and have a shave.
In late 1962 the AR summoned me to his office, introduced me to Dr Stoy, Her Majesty’s Astronomer at the Cape, and ‘invited’ me to take the post of Cape Observer at the Radcliffe Observatory for three years, taking over from George Harding in April. ‘I am planning to get married in June’ was countered by ‘Then you will have to get married earlier.’ ‘How long do I have to think about it?’ ‘Dr Stoy leaves in five days, the longer you take, the less time there will be for the next candidate.’ The AR was not a man to beat about the bush. Of course, I accepted.
The Radcliffe Observatory was originally founded in 1773 in Oxford, using the remnants of Dr John Radcliffe’s will, after founding the Radcliffe Infirmary and the Radcliffe Camera. By 1934 the city-centre site was useless for astronomy, but very valuable as real-estate, so the trustees cashed it in and built a new, one-telescope observatory in Pretoria, South Africa. Unfortunately, while the money was sufficient for the building and the telescope, not enough was left over to pay the staff. The solution was provided by the UK-Government-funded Royal Observatory at the Cape of Good Hope, who rented one third of the telescope time. So there was me, seconded to the Cape Observatory, but living a thousand miles away in Pretoria, with 10 nights a month on the biggest telescope in the Southern Hemisphere; whoopie! Actually, it was the biggest equal, as there was a twin brother of the Radcliffe telescope in Canberra, Australia, but the site there, in terms of clear nights per year, was much inferior. Most of my observing was on behalf of astronomers in Herstmonceux and The Cape, but there was still plenty of time for my own interests (seeing Saturn upside down, for instance). My new wife was also seconded to Pretoria, as a Scientific Assistant, and we shared an office.
The telescope was a double-sized version of the 36-inch at Herstmonceux – both the 36-inch and 74-inch Grubb Parsons telescopes were very successful and many observatories around the world had one or other of them. The ‘dome’ was actually much more like a gas-holder, with vertical sides and just enough curvature on the top for the rain to run off. Pretoria was notable for the number of its clear nights (in comparison, the Canberra Observatory report one year noted that they had had more than twice as many clear nights as the previous year – that would never have been possible in Pretoria). But it was also noted for its ‘Businessman’s Shower’. At about 4 pm the sky would cloud over and at 5 the heavens would open, accompanied by thunder, lightning and hail, with stones up to the size of golf-balls. On return to UK, I was proud to display the hailstone-dents in my trusty Morris Minor. The storm typically lasted for only a quarter of an hour, but it was spectacular when viewed from the balcony of our flat with a glass of cold beer to hand. Less so if one was caught in it: both the lightning and the hailstones could literally be lethal. It was also pretty frightening, at least the first few times, to experience it from inside the dome. Being metal and the highest point for miles around, it was frequently struck by lightning, accompanied by a mighty bang that made normal thunder sound like a whimper. I knew in theory that the metal structure formed a Faraday cage inside which was the safest place to be, but my gut was not good at theory.
Observing was influenced by the phase of the Moon. At full Moon, when it was less practical to observe fainter stars, observing was done at the coudé focus, where mirrors directed the starlight into a room-sized camera at the downward extension of the polar axis. In theory very comfortable, as the light was brought to the observer, rather than the observer having to follow the telescope around the dome, but the coudé focus was designed as an afterthought and the observing position was cramped; very uncomfortable when sat there for a long exposure. Because of the long focal length and the high-dispersion spectrograph, it was suitable only for brighter stars, and even then, long exposure times were needed, occasionally extending over more than one night.
When the Moon had waned a bit, the mirror configuration was changed to Cassegrain, involving the removal of one mirror and its replacement with a convex one, which reflected the light back down the tube, through a hole at the centre of the massive main mirror (nearly two tons of glass), below which it came to a focus. This mirror-changing occurred weekly and involved ‘all hands’, one to work the crane, others to do the delicate locating of precision optical parts, and the Director (Dr David Thackeray) to bite his fingernails and pray. But it was as nothing compared to the palaver of re-aluminising the main mirror, which had to be lowered through the floor, cleaned, and manoeuvred into a vacuum chamber for the fresh coating; fortunately, less frequently than once a year.
The Cassegrain focus was used for spectroscopy (radial velocities and investigation of stellar chemistry) and photometry (temperatures and colour-magnitude studies). The eyepiece was approached using high steps fitted with a moveable chair, which could be cranked up and down by the occupant, but as the telescope followed a star, the eyepiece moved steadily away from the observer who had to climb down, move the steps and climb back up again. At least it kept him awake – mostly.
One observer (not me) woke up to find the Sun shining into the dome and the telescope nearly horizontal. He must have dozed off after 3 am, as that was the time when Simon, the nightwatchman, made his visit. Simon had been told not to use his torch and, on his own initiative, or out of mischief, chose also to make no noise. The first one knew of his presence was ‘Morning, baas’ from just behind you. Jump-out-of-skin time. I tried to be ready for him, but seldom was, so I took to working with the door locked. Better to bleed to death unattended than to die of a Simon-induced heart attack. If he came across any snakes during his rounds, he would kill them with his knobkerry and put them on the office steps, as the Director liked to keep a tally. Rather than just dump them there, he would arrange them in lifelike threatening poses for the benefit of arriving staff. Other than that, he was a lovely bloke.
During the dark of the Moon, the focus was switched to Newtonian, with the Cassegrain mirror swapped for a 45º flat mirror near the top of the tube, directing the light out to the side. This was my favourite focus where one could observe the faintest objects and take direct photographs. It was also used for taking galactic spectra and sometimes used with an objective grating. Reaching the focus, some 40 feet above the floor, involved climbing a vertical steel ladder to reach a narrow platform above the crane, at the far end of which was a control box to swing the platform out towards the centre of the dome, raise and lower it, rotate the dome and trundle the whole crane structure, including the ladder, around the dome. Quite a lot to get wrong in total darkness.
For this reason, Newtonian observing was usually done with a colleague sent up from the Cape Observatory, who stayed in the Cape Cottage in the observatory grounds. One such was a heavy drinker. Though I was younger than him, I was – at least in principle – his boss, so I summoned up the courage one night to point out the incompatibility of drink and high-altitude observing. He took it well, but asked if he could return to the Cape Cottage for a bit. Had I ‘laid it on’ too thickly and upset him? When he returned, he brought with him a flask of brandy and two mugs. What could I do but join him? Come the dawn we closed down and left the dome together, the door locking itself behind us. It was only then that we discovered that our departure was blocked by a puff-adder on the steps. Unlike most snakes, the slow, but deadly, puff-adder would rather strike than flee, so it was a frightening moment, but my colleague calmly drew a revolver from his pocket and shot the snake dead. What was more frightening was the thought that I had spent the night working alongside an armed drunk!
Derek Jones was my successor as Cape Observer at the Radcliffe Observatory and we had a few weeks overlap before I departed. There was a newly discovered comet around at the time (Ikeya-Seki) and Derek and I were keen to get the first photograph of it as a suitable end to my term and start to his. It was expected to rise in the East just before the Sun, but the coordinates were not precise. I was at the Newtonian focus looking out for the comet while Derek turned the setting wheel very slowly, as the telescope was almost horizontal. The sky was brightening and we were on the point of giving up when I saw a promising glimmer at the edge of the field of view – ‘Just a touch more’ I asked; Derek obliged and for a brief moment the glimmer revealed itself as a streetlamp before there was a clonk and the image disappeared. ‘Back Back’ I shouted and back Derek turned – just in time to prevent the two-ton mirror, which was held in its cell purely by gravity, from rolling down the tube and ruining itself, two careers, and goodness knows what else.
We retired to our beds (mirror, Derek and me), shaken but unharmed. We got the comet photograph the next night.
Stuart Malin
June 2023