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.
Marine 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).
The 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.
The 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.

Many passengers love to be entertained on board their ship, and with excursions at ports of call.

A Tunisian tour guide posing with his official P & O sign, Bizerte, Tunisia (P90849)
In the Exhibition there is a picture of a man holding a sign on the quay beside Viceroyof India in 1935, advertising a P&O Official Excursion at Bizerte, Tunisia; there is the rickshaw man beside a ship in 1935 in Durban, South Africa; the Waterline book includes pictures from many ports of call, including Blue Star Line’s Arandora Star at Valletta, Malta, about 1937.

A local rickshaw driver in ‘traditional’ costume, with a Union-Castle Line ship in the background (P91550)
My Father was a Junior Engineer on that ship as a young man in the early 1930s, so I have similar pictures from his photo album, and often think I am ‘following in Father’s footsteps’ when I look at his pictures and mine nowadays. Of course I don’t have a picture, like one of his, of Amundsen’s sleigh dog ‘Jacob’ in Kings Bay, Spitzbergen, about 1932!
The Exhibition shows us passenger children in the 1960s on the deck of Windsor Castle following a Children’s Hostess, or trying to catch an apple (suspended on a string) in their mouth, without using hands, on board Chusan about 1960; the book shows us children’s parties and children with Father Christmas.

Three children in the “Apple Eating” contest, possibly in the ballroom of the Chusan (P85787)
In the Exhibition I like the pictures of passengers with a splendidly-moustachioed barman on board Transvaal Castle, of Father Christmas apparently climbing down to the deck from a ship’s funnel, of lightly-clad passengers playing deck games, others enjoying a daytime deck buffet (obviously on a Union-Castle ship, to judge by the stewards’ lavender-coloured collar and cuffs), and dancing a Conga at night in a ship’s lounge in obviously sunny climes, according to the clothing. Passengers could enjoy dog racing (not real ones) or frog racing (again, not real ones) which were very popular when I was at sea. Wooden ‘frogs’ with a long string through their middle could be flapped along a course with perhaps six contestants, with bets being placed on the winner.
Passengers could be as inactive or as busy as they chose, as shown in all these Waterline photographs, and that is just the way it should be.

Conserving the H3 Timekeeper part 3 from Royal Observatory Greenwich on Vimeo.

With H3 almost completely dismantled, Jonathan Betts reflects on his progress so far and how the project affected the last man to undertake the task.

I liked the Waterline picture of passengers on board Kungsholm about 1967 taking part in Lifeboat Drill. That certainly brought back some memories for me. Union-Castle ships’ staff always had to take part in the Drill, whether the snow was lying around our feet, or we were being baked by the tropical sun, and of course it was very reassuring to know that all the equipment was working properly.
A group of passengers with lifejackets aboard ‘Kungsholm’, undergoing life boat drill (P88247)
I remember an occasion in Cape Town when I was on the 1962-built Transvaal Castle (32,697 tons, to carry 729 passengers). I was on duty that morning in December 1965 and had to go in one of the lifeboats down into the harbour. My diary records that I was in full uniform and clutching a passenger list, a crew list, my little tricorne hat and a small towel (to sit on). One empty lifeboat was then sent round to collect in all 147 people, the absolute total one lifeboat could take. We had to clamber from one boat to the other, but of course we did it and then chugged round the harbour just to prove the point. The boats were uncovered, with very basic provisions, but could be a lifesaver if required.
I remember on a 2004 visit to the 1914-built Doulos that the printed lifeboat instructions included a first instruction to ‘insert plug’.
On some Japanese-built little ships I’ve looked down into lifeboats and noticed rows of horseshoe-shaped painted lines on the seating, to signify where to sit. I suspect these sizes would be totally inadequate in some other countries where there is said to be a growing obesity problem.
In complete contrast, the 2009-built Oasis of the Seas at 220,000 tons, and carrying up to 5,400 passengers (and up to 6,296 when 3rd and 4th berths are used), has lifeboats designed differently, giving direct access from the promenade deck, and hung underneath a cantilevered upper deck when not in use. Lifeboat Drill is still held but life belts are no longer stored in cabins/staterooms but at the various assembly points. Each lifeboat can carry 370 people and even includes a bathroom. The whole purpose is that any large ship can be evacuated within the 30 minutes that the law stipulates.