Secrets of David Livingstone鈥榮 experiences and thoughts from Africa are about to be revealed for the first time, thanks to multispectral imaging enhancement.
To date, historians have had to rely on a heavily edited version of the diaries called , compiled and published a year after Livingstone鈥檚 death in 1873 by his friend, Horace Waller, to whom all the letters were addressed. Now, historians will be able to see what Livingstone really said, experienced and thought in his final and doomed quest to find the source of the Nile.
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Most of the letters are virtually unreadable since Livingstone had run out of writing paper and reverted to newspaper and pages ripped out from journals and books, which meant scrawling in the margins and all over the existing newsprint or text. In the 140 years since the letters were written, Livingstone鈥檚 ink made from local berries has faded or soaked through the paper, obliterating his words. Now, a project is under way to rescue his words from the mush of paper and print.
The imaging technique accentuates the visibility of Livingstone鈥檚 ink while simultaneously suppressing the visibility of the underlying print (see picture). It does this by taking 12 separate images of each document, exposing it in turn to 12 different wavelengths of light, from blue ultraviolet, through the visible spectrum to infrared.
Eureka moment
By feeding the stack of 12 superimposed images through image analysis software, algorithms pick out and best highlight the Livingstone text. 鈥淲e get the 12 images that stack up in an image cube, and you can process this digitally,鈥� says Michael Toth, the programme manager, who has used the same technique to enhance other valuable ancient documents including the revealing Archimedes鈥檚 famous 鈥淓ureka鈥� theory, parts of the US Declaration of Independence and Abraham Lincoln鈥檚 Gettysburg Address condemning slavery.
Different light wavelengths bring out different parts of the text, Toth explains. So Livingstone鈥檚 ink disappears under infrared and becomes most distinct under blue.
The group鈥檚 first fully deciphered letter, written in 1871 from a remote village in what is now the Democratic Republic of the Congo, has been made public today in the first stage of the project. The aim is to decipher all the letters written between 1870 and early 1871, just months before Livingstone鈥檚 famous meeting with New York Herald reporter Henry Morton Stanley.
The letters amount to around 140 sides altogether, and the four sides comprising , dated 5 February 1871, showcase the potential of the technology. The letter reveals Livingstone鈥檚 despair over his failing health, feeling ravaged by heat and tropical diseases, his intense rivalry towards other African explorers, and his well-documented abhorrence of the slave trade.
鈥淭he letter is really just a test run for the much larger diary project,鈥� says of Birkbeck, University of London, the project director guiding the programme in collaboration with the in Edinburgh and the in Balantyre. 鈥淭his takes us back to the original text and Livingstone鈥檚 experiences as he went through this key period towards the end of his life.鈥�
Deciphered diary
Toth says that the next stage of the project is already under way, with all 140 diary pages already scanned and ready for deciphering. He expects the complete versions to be available within 18 months or so.
Like the Letter from Bambarre, they will all eventually be made publically available at , the leading British-based internet resource for Livingstone鈥檚 writings.
The project promises to reveal much about Livingstone that Waller鈥檚 editing concealed. He presented the explorer as a swashbuckling hero, an anti-slavery campaigner and martyr. The deciphered letter portrays a man in terrible health, wracked by fevers, weak from bleeding haemorrhoids, and virtually stranded at Bambarre by bone-deep wounds in his feet until his 鈥渞escue鈥� by Stanley. All of which Livingstone told Waller to conceal from the public with the words 鈥渇or your eyes only鈥�.
More true to form, he rails in the letter against the trafficking of slaves saying: 鈥淚t is awful traffic and can be congenial only to the Devil and his angels.鈥�
