Conservator Paul Cook takes a closer look at Arctic artefacts
Conservator Paul Cook tells the improbable story of a small hydrogen balloon and its mission to find lost polar explorers.
Hi, I’m Lucinda Donnachie, and today I’ve come on a behind-the-scenes visit to the Museum’s conservation studio to meet paper conservator, Paul Cook. Paul’s been working on some of the objects going on display on the upcoming exhibition, The Northwest Passage: An Arctic Obsession.
So, Paul, it’s only a few weeks now before the exhibition opens to the public. What have you been up to?
Well, at the moment, we’re preparing a variety of items for the exhibition, including charts, prints and watercolours, some books and some manuscript letters. And there’s even an early jigsaw puzzle dated 1819.
But what you might find of particular interest, although it’s not actually destined for display, is part of a longer-term project to conserve a message-carrying balloon which is a part of the story surrounding the searches for Sir John Franklin’s expedition.
Can you tell us a little more about Franklin’s expeditions?
Yes. Sir John Franklin set out on 19 May 1845, in command of HMS Erebus, together with Captain Francis Crozier in HMS Terror, to try and discover a north-west passage – that’s a sea route connecting the Atlantic and Pacific across the top of Canada.
After being sighted on 26 July, at the head of Baffin Bay, Franklin’s expedition was never heard of again.
Now, towards the end of 1847, there were concerns about the expedition.
During 1848 there were three separate rescue attempts, made by the British Admiralty, but they returned without result.
In 1850 the Admiralty finally offered a reward of £20,000 for the rescue of Franklin and his group. And that’s where the story of the Museum’s message-carrying balloon comes in.
Now, the interest in ballooning and its possible applications was considerable during this same period, and many suggestions were made as to how the technique could be applied to an Arctic search.
Now a Lieutenant Gale came up with the idea to send up small balloons carrying hundreds of paper messages attached to a slow match – that’s like a gunpowder fuse – which would be released on the balloon reaching sufficient altitude, and to be scattered by the wind and perhaps fall under the notice of some member of the missing party.
Gale’s idea was copied by others, and he later complained that the Board of Admiralty had used his invention. He approached the Admiralty several times on this, but was ignored.
The credits, instead, went to Charles Green, who in 1850 supplied nine balloons to an expedition under the command of Captain Austin that was about to set out.
We don’t actually know who produced the balloon that we’ve got though.
Do you know how these balloons worked?
Yes. To publicise this event, posters were printed describing the function of the balloons. This said they could be inflated using hydrogen in just a few minutes, they would remain aloft for something like 12 hours, and with a fair wind, travel from 500 to 600 miles.
Now the signals or dispatches were connected to the balloon by a slow match of considerable length, and that’s lit and then the balloon is launched. Now, the suspended packages, or it even mentions parachutes possibly carrying messages, detach at intervals of one every five minutes, and the whole part of this is protected under the balloon from rain or night dew by a waterproof cone, without which the match would soon be extinguished.
Austin’s expedition returned a year later without any trace of Franklin, and it’s not known how many balloons were released, or if they functioned as planned.
Other expeditions were also supplied with balloons, and we have a printed leaflet dated April 1852 that tells us: ‘invented by George Shepherd’. And this also gives the details for the method for generating the hydrogen gas to inflate the balloon from the reaction between sulphuric acid and zinc metal granules in water, carried out in three interconnecting barrels, and describing the system for purging the equipment of air before filling the balloon itself with hydrogen gas to provide the lift for the balloon and its payload.
It looks like it has aged a little over the years.
Yes, indeed it has. The balloon is a little over a metre in diameter and was kept with its covering net, flattened and folded in a box for many years. Now, when newly made it must have been reasonably flexible and strong, but on ageing it has become very brittle, with very little strength, and certain heavy folds are fractured and many small pieces are now becoming detached.
What have you been doing to conserve it?
Well, considerable research went into investigating the balloon, and much thought into the process and procedures of conservation treatment, also into building a support structure to hold the balloon into what would have been close to its inflated shape.
The balloon had first to be humidified to make it supple enough to unfold, and this was done with an enlarged sort of polythene tent structure. Once that had been done, we were able to divide the balloon into two sections along an original seam.
The balloon is made of a laminate of thin wove paper and transparent animal-gut membrane – somewhat similar to what’s called goldbeater’s skin. The gut is on the outside and forms the gas-impermeable membrane, and the paper on the inside gives strength and rigidity to the very thin gut. The gut also, but the paper, certainly, has discoloured on ageing.
The original colouration would have appeared as alternate segments of creamy white and red; a typical kind of balloon colouration that we might think of. The off-white is the natural colour and the appearance of the paper and gut, and the deep red bands, interestingly, after analysis, were found to be most probably blackberry juice, which is interesting.
The repair treatment, at first carried out with the balloon sections on their support and affected from the outside, has been proving very problematic. So, latterly, a sort of deep hammock has been made to support the thin envelope so that the repair can be carried out first on the inside. And to do this, sections of very thin, high quality Japanese paper are being adhered over the weak and torn areas of the paper, using a thin methylcellulose water gel.
Once the inside has been sufficiently strengthened the envelope will then be returned to its supporting form, and any losses filled in on the outside.
Now, we could do this with a suitably tinted paper, but this doesn’t replicate the slight surface sheen that the original gut membrane possesses, so we’ve made an in-fill to replicate the original using a thin, again, Japanese paper that we’ve tinted to match the wove creamy colour of the paper balloon.
And then over this we’ve adhered a thin layer of reconstituted collagen. Now, this is an animal by-product, and it’s actually what sausages are put into. It’s the edible sausage casing. We cut this up into sheets, and this can be adhered onto the paper and it then gives a very similar surface to the appearance of the balloon itself, and we can crinkle it up to match the folded and fissured surface of the original.
So that’s cut into appropriate shapes to fill in the losses on the balloon and adhered to the outside surface with a wheat starch and gelatine adhesive, which forms a good bond between the repair and the gut. And then the deep red areas, we can colour in to match with an acrylic paint.
Now that you’ve conserved the balloon, what happens?
Well, one section of the balloon was completed some while ago and was put on display for a while, but it will now join the collections in store. Whereas before treatment it was too fragile to handle, in that sense, no one could look at it because it would literally crumble in your hands and parts would fall off. So now, after this treatment we’ve revealed the proper shape, and the construction can be seen and it can be properly appreciated. And it is, after all, probably a unique survivor itself.
Thank you, Paul.