National Maritime Museum collections blog
An extraordinary day when time and a pig flew…
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December 6th, 2012

To mark the centenary of the sinking of the Titanic on 12 April 1912, the National Maritime Museum put on an exhibition, entitled, Titanic Remembered, which highlighted some of the stories told by survivors of the disaster to Walter Lord, who wrote the book,  A Night to Remember on which the 1957 film of the same name was based.  When the exhibition closed at the end of September, there was a brief opportunity to research two of the Museum’s most emotionally evocative Titanic-related items before they are re-displayed in the ‘Voyagers’ gallery. Both are mechanical objects: an 18-carat gold pocket watch and a child’s musical pig.

Robert Douglas Norman and his 18-carat gold pocket watch (ZBA0004)

The owner of the watch, 27-year old Robert Douglas Norman, had joined the Titanic at Cherbourg, intending to visit his brother in Vancouver and from there continue to travel the world. As a male passenger, Norman’s chances of surviving the disaster were poor at best and his body was one of over 300 recovered by the cable ship, Mackay-Bennett. The watch was returned to his brother and passed down through the family until it was donated to the Museum in 1995.

The musical pig belonged to Edith Rosenbaum (1879–1975), who, like Norman, boarded the ship at Cherbourg. Edith, a 32-year old American, was a successful player in the fashion world and could afford to travel first-class. However, despite her professional success, her personal life was in pieces after she narrowly survived a road traffic accident, which claimed the life of her fiancé, Ludwig Loewe, in 1911.

The 'lucky pig' (ZBA2989)

Edith changed her surname to Russell in 1918, owing to political sensitivities following the First World War. In a televised interview, about 1970, she described how, when was asked to evacuate, she locked all 19 of her trunks before heading for the lifeboats. ‘I never would have left the ship,’  she recalled, ‘but a sailor came along and he said “say you;  you don’t want to be saved, well I’ll save your baby” and he grabbed this pig from under my arm and he tossed it in the lifeboat … when they threw that pig, I knew it was my mother calling me.’ (British Pathé 347801)

Edith followed the musical pig into the crowded Lifeboat 11 and, during the seven hours before being picked up by the passenger liner Carpathia, she comforted children on board with the tune, thought to be the Maxixe, from her lucky pig. Played by Theresa Thorne, Edith and the pig appear briefly in William MacQuitty’s film of Lord’s book, which shows her leaving her jewellery behind in favour of her lucky toy.

Edith Russell meets Theresa Thorne during filming of 'A Night to Remember'

The pig came to the Museum as part of the Lord-MacQuitty collection in 2003.

So did the pig really fly?

Well, dear reader, I am afraid that I may have over-egged the flying bit; it was more like travelling at sensible speed up the M1 in a van en route to the Nikon Metrology factory in Hertfordshire. But it was to be an extraordinary day, and as is the case with extraordinary days, relativity comes into effect and they are over all too soon. Even if the pig didn’t literally fly the time certainly did!

Nikon Metrology produces high resolution X-ray equipment that is normally used for doing failure analysis on, and checking the internal quality and precision of components such as electronic chips, automotive parts and aircraft turbine blades: objects with complex internal structure that have to be made exactly to specification. The systems can also be used to examine material properties in materials research, soil science and geology. We were met by computed tomography (CT) specialist, Andrew Ramsey, who is incidentally the first person in over 2000 years to have seen inside the Antikythera Mechanism, an ancient Greek astronomical calculator, and had very kindly agreed to set a couple of days aside to examine our two Titanic relics using state-of-the-art CT scanning equipment.

A common factor of both of these objects is that neither can be opened without causing irreparable damage. The pig’s body is constructed from organic material, wood and papier maché are identifiable where the legs have broken and the outermost layer is of pig skin moulded around the carcass and pinned in places. Externally there is no evidence to suggest that the toy was designed so that the musical movement could be extracted for servicing and also no clue as to what sort of movement it contains. The watch, with its rust-stained glass and dial, is an extraordinarily poignant object with the hands – which read 3.07 – apparently frozen at the time of entering the water. Because of the watch’s condition and the nature of its history, we could never justify opening its case, let alone dismantling the movement.

Ready for the first scan, the watch safe inside its travel box on the turntable and the lucky pig packed in plastazote and acid-free tissue

We hope that the CT scan will eventually help us to answer the big question surrounding the watch, which is raised by the discrepancy between the time it shows and the officially recorded time of sinking of 2.20 a.m. It has always been believed that watch stopped when it entered the sea and that the time disparity highlights the issue of the changing local time as one travels westwards. Put another way, passengers would probably have had to adjust their watches daily to keep in step with local time, and so Norman would have been due to set his back the following day. But, of course, there was always a slim chance that the watch had stopped some time before entering the water and we hope the CT scan will help clarify this. We also hoped to learn what sort of watch movement was hidden within the case and who might have made it.

When it comes to x-rays, gold has similar properties to lead in that it tends to act as a shield. For this reason the watch went into the scanner first, in case we needed to use a more powerful machine. In this day and age, the x-ray image is not an unusual phenomenon, but the first view of its inside was thrilling: despite the 18-carat gold inner case back, known as the cuvette, we were going to get a really good look.

Each scan took just under half an hour to complete and, during scanning, the object is rotated through 360 degrees. The data is sent to a computer and converted into tiny building blocks called voxels, each representing a cube measuring 32.6 µm across (approximately 0.03mm) which are then put together to create the 3-D model. Once created it is possible to slice through any specified area to have a look inside the object.

One of the first dramatic shots of the mechanism shows it to be an English fusee watch with full-plate movement and bi-metallic balance.

A first view of the watch movement through the cuvette and cap

A maker/retailer’s signature can just be made out but the gold has rather fogged the image. Because of this lack of clarity there is still a lot of sifting to do through the vast quantities of data, approximately 80 gigabytes in total, before we can be certain that we have the answers we are looking for.

By contrast, the lucky pig was far more scanner-friendly and we were very quickly able to see some spectacular results. It required two scans, the first to pick out the details of the main body and a second to obtain good images of the musical movement. To scan the movement, the lower energy radiation had to be filtered out and this is achieved by placing a small copper sheet in the path of the x-rays before they met the object.

The 3-D model of the pig assembled and ready for dissection

Dissecting the digital model down the middle gave us our first view of the pig’s interior and, as can be seen, it is made from moulded papier maché, with a transversely mounted wood soundboard to which the musical movement is mounted.

The rendered dissection showing the inner surface of the carcass, perhaps reminiscent of Damien Hirst’s ‘Mother and Child Divided’

From this scan we learn that the tail is simply a knotted piece of vellum that was never connected to the music box. Prior to scanning it seemed likely that this was spring-driven and activated by pulling the tail but the scans show us that it was a hand-powered type of movement, known as a manivelle (French for crank-handle). By slicing across the width of the model the cause of a rattling noise was identified as a hairpin, probably used in attempt to reconnect to the music box after the crank had broken away. The S-shaped object in the centre appears to be the original crank-handle and tail. Detailed examination of this object shows it to be a skin-covered metal tube, which is an unexpected and very exciting find, perhaps a case for key-hole surgery…

The model bisected horizontally, showing the shell construction of the carcass and the loose hairpin and what is possibly the original tail/crank-handle. The bright spots down the belly centreline are the pins securing the outer skin

The second scan of the lucky pig produced some brilliant images of the musical movement, showing it is quite simple in construction. It has a toothed wheel attached to the pin barrel, which is driven by a worm gear on the end of the crank shaft. The comb is marked with a distinctive star logo, which may in due course help us identify the maker.

Two views of the musical movement

The movement showing the star logo, by the screw on the near corner of the comb

What has been shown here is only the beginning of the study; these 3-D models provide invaluable information that will assist with our curatorial questions as well as the long-term care and conservation of these extraordinary objects.

Adjusting after a ‘long’ weekend at the Royal Observatory – Precision clocks and the leap second
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July 6th, 2012

It is unlikely that anyone came into work feeling more refreshed than usual following the insertion of an extra second into Saturday 30 June. While this event did not affect our body clocks, it did have an effect on the National Maritime Museum’s collection. At the Royal Observatory two clocks, in particular, needed adjustment: the Shepherd gate clock (ZAA0533) and the Hewlett Packard atomic clock (ZBA2599).

The Shepherd gate clock was installed at the Observatory in 1852 under the direction of the seventh Astronomer Royal, George Biddell Airy, and is named after its maker, Charles Shepherd. The clock’s installation marks the beginning of the Royal Observatory’s role as a provider of accurate time for the nation. Today it can be relied upon to show Greenwich Mean Time (GMT) accurate to half a second. The second clock was originally used at the National Physical Laboratory in the 1990s for its contribution to the international time-scale, known as Coordinated Universal Time (UTC).

Why do we need a leap second?

Believe it or not, the Earth is not as reliable a timekeeper as our atomic clock and the leap second is a fine-tuning that keeps UTC synchronized with the motion of the Earth. The speed of our planet’s rotation is variable for a number of reasons. Generally speaking, the Earth’s rotation is slowing down because the Moon is gradually moving away from us: there is no need for alarm as it is only moving away at about the same speed our fingernails grow, but as it does so its gravitational influence is lessened. This and other unpredictable influences, such as seismic activity, are monitored by the International Earth Rotation and Reference Systems Service (IERS), who decide whether or not a leap second is necessary.

The leap second has caused us to adjust the two clocks already mentioned and make a basic equivalent calculation when comparing the rates of precision pendulum clocks against a radio-controlled clock. But for those responsible for managing computer networks that handle large volumes of digital traffic the leap second poses a tricky problem. Networks depend on accurate timekeeping: every data transfer is time-stamped and any data logged during the leap second will be outside of the computer’s logic. This could potentially cause the system to fail. Indeed, there are reports indicating that some systems did stop working after last Saturday’s leap second and, as a result, some popular websites were inaccessible. Among various ways of overcoming this problem, there is one that bears an interesting parallel to operational principles used by Airy in the mid-1800s. Google, in preparation for the 2005 leap second, opted to add it, in advance and over a set period across their system, in tiny increments that did not upset communication with any other systems that they were connected to. They named their method the ‘leap smear’.

The same principle was applied to the system that drove the gate clock at the Royal Observatory. Most people do not realize that this is a slave clock, not a timekeeper in its own right: it was originally one of several slave dials on the site, all of which followed the instruction of Shepherd’s master clock (ZAA0531). The beauty of Shepherd’s master clock was not that it was an exceptional timekeeper but that it could be corrected electrically by means of electro-magnetic adjusters working on the pendulum. Small and precise adjustments to the hands could be made by causing the pendulum to move faster or slower over a fixed period of time; and because the master clock was continuously sending out pulses to all of the slave clocks, the slaves were automatically corrected. Today, the gate clock is driven by a radio-controlled Quartz clock and the hands are corrected manually.

Of course, the leap second was unheard of in Airy’s time; the first leap second was implemented in 1972 and, since then, a total of 35 have been inserted into UTC. The IERS gives six months’ notice of forthcoming leap seconds in their Bulletin C, so we will have at least another year before we can look forward to a ‘long’ weekend like that of 30 June – 1 July 2012.

Conserving the H3 Timekeeper
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June 28th, 2011

H3 has returned to public display after a thorough cleaning and cataloguing. This video captures Jonathan’s feeling about the project as well as the timekeepers move back into its showcase.

Conserving the H3 Timekeeper part 6 from Royal Observatory Greenwich on Vimeo.

Conserving the H3 Timekeeper
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May 20th, 2011

Conserving the H3 Timekeeper part 4 from Royal Observatory Greenwich on Vimeo.

The timekeeper is now completely dismantled, but the job is not over yet for Jonathan. The case is keeping him busy and presenting surprises as well.

The H3 case
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April 20th, 2011

As part of a large cataloguing project to research all the NMM’s marine chronometers, I am currenmtly undertaking a close study of Harrison‘s third marine timekeeper, H3 (made during the 1740s). It is proving hugely interesting and revealing as can be seen in the videos which have been tracking my progress.
H3.jpgMarine timekeeper, H3 (ZAA0036)
The aspect I’m studying at the moment is the extraordinary (at least to me) glazed brass case of the instrument, and I’m wondering about 18th century ‘instrumental’ practice where glazed cases are concerned?
The case (which the timekeeper fits in very closely indeed and which stands just over 60cms high) has a ‘top’, a middle band (attached to the timekeeper) and a ‘bottom’, the three parts held together round the middle with 32 screws. The whole thing is incredibly beautifully made, using cabinet-making techniques, and consists of precisely 501 parts, all fitted together mechanically, with no solder anywhere.
The brass panels are just 2mm thick and the four main vertical edges are dovetailed (yes!) all the way from top to bottom with a total of 174 tiny dovetails rather in the way that coppersmiths tie plates together before soldering, but much finer and without solder. The dovetails are so well cut the vast majority cannot be seen, but I show a patch where corrosion and stress has revealed some of them (I have temporarily marked the lacquered surface with felt-tip pen to identify them).
H3 rivets.jpgThe brass panels with dovetails
The structure inside forming the frames for the glazed panels are all pinned and riveted with 425 rivets, and the glass is then puttied in.
The decorative moulded cornice is also ‘invisibly’ attached all round with pins, disclosed at one corner where the case was damaged in the past and was apparently heated to repair it, not very successfully.
H3 cornice.jpgThe decorative moulded cornice
I wonder whether such large cases are unusual at this period, or are other instruments made in the mid-18th century that are housed in such cases? If so, how are they constructed? I am familiar with the 18th century grand orreries (e.g. those by Wright etc) in the lovely ‘cold-frame’ type wooden glazed covers, but can’t think of anything in metal at this period. If anyone knows of any examples please do get in touch below.