When we acquired this watercolour in 2019 from the estate of the Dowager Lady Normanby, we were particularly delighted to have another work by William Ellis (1751-1785), Surgeon’s Mate and talented artist on Cook’s third voyage. The painting of Matavai Bay provides a particularly good image of the place in Tahiti to which Cook returned on all his voyages. The tents erected on shore and people going to and fro give a nice sense of everyday activity.
However, looking closer, the scene depicts not only tents for some of the ship’s company who needed to work on shore, such as the coopers who had to repair the barrels for refilling with fresh water, but also two round astronomers’ tents. These were quite different to the tents which were standard issue for the army or navy. Two such tents can be seen behind the astronomers’ tents, and were made in different sizes, consisting of a large piece of linen or other fabric slung over a ridge pole supported at either end by two standard poles, and secured by guy ropes to the ground. They could be erected or dismantled quickly and transported easily.
The astronomers’ tents were very different, and this was an item of specialised equipment which was first used on Cook’s voyages. Large and expensive pieces of equipment such as the astronomical clock, transit instrument or large quadrant needed protection from the weather and a flat, firm place on which to stand. They might also need protection from curious residents – note the marine standing on guard outside one of the tents in Ellis’s picture.
The tent taken by Cook on the voyage to observe the Transit of Venus was a rather cumbersome affair though certainly very sturdy and solid. It was designed by John Smeaton (1724-1792), the renowned civil engineer and builder of the Eddystone lighthouse. It is not altogether surprising that Smeaton was commissioned to design a tent as he was in any case a skilled scientific instrument maker and extremely interested in astronomy, presenting papers on the subject to the Royal Society of which he was a Fellow. His tent was circular but supported on 16 posts which carried a circular ring to support the panelled roof, from which a section could be removed to allow the operation of the telescope.
The only surviving depiction of Smeaton’s design is in the Alexander Turnbull Library in New Zealand and has annotations in Dutch, which suggests that it might have been done at the instigation of the Dutch astronomer, Johann Maurits Mohr (1716-1775), whom Cook visited in Batavia (modern Jakarta) in 1770. Cook was impressed by Mohr’s magnificent observatory, and Mohr himself wrote an account of the Transit which was published in the Philosophical Transactions of the Royal Society in London.
The astronomers’ tent developed considerably during Cook’s second voyage, where the astronomer was William Bayly (1738-1810) on Adventure, together with his fellow astronomer, William Wales (1734-1798) on Resolution. Wales would have been familiar with the Smeaton design as one had also been provided for the expedition to Hudson’s Bay in 1769 to observe the Transit of Venus simultaneously with the Cook observations on Tahiti in the South Seas. Bayly produced a tent of greatly improved design.
Here the tent was suspended from a tripod with just eight supports and a similar ring from which to suspend the cloth panels. The hook from which the whole was suspended held the roof panels taut and enabled one to be rolled aside when the big telescope was in use. A key consideration was making sure the astronomical clock was firm and level, hence the supports around it. The design indeed seems to owe something to the Royal Navy’s ability to make repairs wherever they were, for instance, by using spars rigged in an A shape to act as sheers when needing to lift a heavy object, such as a mast, out for repairs. A rope passed from the hook at the apex of the timber supports and down to the rather strangely shaped fixture on the right-hand pole. This was a lever to help hoist the tent up and keep the structure taut without the need for guy ropes, and to enable the structure to be rotated so that the opening faced the right area of the sky. As Bayly noted, the whole thing could be packed into a large box (2.06m x 50.8 cm), with the poles stored separately among the “spare booms” of the ship. Such poles could if needed be cut from trees or purchased “for a trifle at any place where they are wanted”. This was very much in the tradition of naval self-sufficiency and the need to create equipment that could travel, not take up too much room and be reasonably robust. William Wales gave Bayly high praise for contriving ‘one of the most convenient portable Observatories that has yet been made’. Perhaps Wales had struggled a bit with the Smeaton tent at Hudson’s Bay! The tents could be reused, and Bayly’s tent was repaired in 1776 after Cook’s second voyage, costing the princely sum of £36.15s.8d. (a little over £3000 in today’s money) though this included the cost and carriage of some small instruments as well (Papers of the Board of Longitude, RGO 14/17 345r). Perhaps the repaired tent was one of those depicted in Ellis’ sketch of Matavai Bay shown above.
The ground was carefully levelled for the tent, and inside the instruments were mounted on a barrel filled with sand to ensure stability. Was there a chair for the astronomer to sit on, either while waiting for the right conditions or during the observation?
The drawing of the Smeaton tent shows a chair and what appears to be a couch. Astronomers often needed a reclining type of chair during long hours observing at night. But the duration of observations during Cook’s voyages was less likely to be very extended, and more than likely the astronomer would take one of the standard issue naval chairs such as that owned by Joseph Banks (see Blog on Joseph Banks chair from Kew). This folded flat and was easy to carry.
The flatpack naval chair and Bayly’s astronomers’ tent were both in the tradition of campaign furniture, which became a significant part of the furniture market in the 19th century and could be obtained from the Army & Navy Stores and numerous other dealers. Campaign furniture tends to be thought of more in connection with the army or people working in the colonies, but the Navy had long designed furniture and instruments adapted to its needs on board ship or when landing ashore in unknown places. Naval men, and certainly some of the astronomers who worked with them, were practised at coping with running repairs and stormy circumstances.
Astronomers’ tents of this design continued to be used during the 18th century and were last employed by Matthew Flinders during his circumnavigation of Australia. Flinders was of course trained by William Bligh, who had been master of Resolution on Cook’s third voyage and heavily involved in the cartographic work. They are depicted in several of Webber’s pictures of the voyage, as for instance at Charlotte Sound in New Zealand.
Webber seems to have omitted the large poles of the tripod supporting the tents or drawn them so faintly that they look like guy ropes, perhaps a matter of artistic licence when preparing the later print. The original pencil drawing of the scene (displayed in the Museum) clearly shows the poles and the armed marines standing by together with a barrel ready to be rolled in for the instruments.
Portable tents of course continued to be used for a multitude of different scientific tasks, but this example neatly encompasses developments during Cook’s voyages at the particular moment when longitude and new cartographic information had to be checked and verified by astronomical observation on land. The way in which the basic equipment for this operation, the tent, was designed, has a nice resonance with a naval culture of the time of neat stowage and self-sufficiency.
With thanks to Richard Dunn for his comments and information
SF January 2025
Kommentare