Science and Health: Doctor Livingstone, not as one presumed – spectral imaging illuminates details


By Steve Elliott our Science and Health correspondent

Legendary explorer, Dr David Livingstone’s first-person account of a 19th-century massacre in Nyangwe, Africa helped to close one of the continent’s most notorious slave markets.

Using spectral imaging, scientists have managed to decode his long-illegible African field diary from 1871 and Livingstone’s record of events suggests that his own men may have participated in the Nyangwe atrocity.

Researchers have rescued a 19th-century field diary by the Scottish missionary and explorer David Livingstone from literal obscurity, using 21st-century imaging and processing technology to make his writing legible after the ink had nearly vanished from the page.

Dr Adrian S. Wisnicki helped uncover the diary in 2009 while working on a book about Victorian-era travel in Africa.  The document was in archives at Livingstone’s birthplace in Blantyre, Scotland (now a museum), but it was in bits and pieces. “Eventually we had the whole diary but you couldn’t read it.” he said

By 1871 Livingstone, in ill health and struggling through difficult terrain, had been long delayed in his explorations. Isolated for months in a Congolese village on the Lualaba River as he tried in vain to buy a canoe to continue his search for the source of the Nile, he ran out of writing paper.

While he was stranded in the Congo in 1871, Livingstone was low on supplies and had run out of notebooks and iron gall ink by this point.  Abed, an Arab trader of slaves and sundries and Livingstone’s right hand man, made him some ink from the seeds of a plant called Zingifure, a brick-red dye the locals used as face paint and cloth dye.  Livingstone created a field diary out of a single eight-page copy of the London Standard newspaper and wrote in it using the berry seed ink.  He turned it into two 32-page notebooks and wrote the diary across the pages, perpendicular to the printed text.

The oppressively hot and humid conditions, the delicate natural dye and the forceful news type made the original journal entries fade over time until they became entirely unreadable. When New York Herald reporter Henry Stanley found the long-missing explorer in October of 1871, he supplied him with fresh paper so Livingstone was able to rewrite his journal entries over the next year.

His rewrites weren’t transcriptions, though – Livingstone left out uncomfortable facts and opinions he had written in his original diary.  When Horace Waller published the Last Journals of David Livingstone in 1874, a year after Livingstone’s death, he did a little clean-up of his own to ensure his friend’s reputation as an abolitionist hero and intrepid explorer would remain unsullied by reality.

Livingstone used his field diary as notes to produce a more reader-friendly journal, which he finished in 1872 and which Stanley, who had been retained by a New York newspaper to find Livingstone, brought to Britain.

Livingstone died in 1873 in what is now Zambia, the revised reader-friendly journal was used, again with modifications, in an 1874 book that cemented his reputation as a heroic explorer.

However, a quite different picture from the reader-friendly David Livingstone’s story is revealed by the newly revealed field diary.

Dr Wisnicki said that in the field diary, Livingstone recorded events as they were happening, the account of the massacre: “is very rough, very chaotic”, at one point Livingstone writes that he suggested catching “the people who started the massacre and put their heads on poles.”

Tim Jeal, a biographer of Livingstone who was not involved in the project: “Scholars had known that in the later rewriting, things that had been taken out were pretty bad – he was no saint already.”

The resulting document, published for the first time, helps flesh out the life of Livingstone, who in his day in Britain was revered as an adventurer and antislavery activist but who has become more broadly, and shallowly, known as the object of Henry M. Stanley’s greeting: “Dr. Livingstone, I presume?”

Recovering David Livingstone’s original African Field Diary:
The aim was to separate the London Standard background newsprint from Livingstone’s handwriting.

How was the imaging of the diary accomplished?

In June 2010, the scientific team brought the imaging equipment from the U.S. to Scotland to image the diary.  Over the course of a week and a half, both sides of the many pages of the diary were imaged one at a time and viewed using the following technique:

Photographed in a dark room, each page was illuminated with LEDs (Light Emitting Diodes).  Each LED emits light of a very specific color and the set of LEDs covers the visible range of light from blue to red – extending a little beyond the visible region into the ultraviolet and the near infrared.  The advantage of LEDs is twofold: LEDs don’t generate heat, which can damage the fragile pages, nor do the low levels of UV light produced during imaging harm the paper or ink.

Each leaf of Livingstone’s Field Diary was illuminated sequentially with sixteen different wavelengths of light a separate digital image for each wavelength of light (i.e. color) was captured using a 39 megapixel camera, stored on external drives and taken back to the U.S. for post-processing.

How does the post-processing reveal Livingstone’s handwriting?
David Livingstone’s handwriting could be recovered from the diary, because the inks on the paper respond differently to different colors of light. The ink of the handwriting is much darker against the paper when illuminated under blue light, than it is under red.  This difference in the ink response was exploited to separate the handwriting from the printed text, which was obscuring Livingstone’s written words.

Usefully, in the color region beyond red light – the infrared region – much of the handwriting disappears completely leaving the London Standard newspaper printed text which remained unchanged at all across the whole color range.  

Thus, the team was then able, using a computer algorithm, to eliminate the printed text in the background leaving only Livingston’s handwriting.

Livingstone’s 1871 Field Diary

Livingstone Spectral Image Archive

It’s only now, after 18 months of painstaking spectral imaging work that we can see the unvarnished words of David Livingstone in the moment.  The truth is the intrepid explorer was sick, frustrated, depressed.  You know conditions are rough when you look forward to your hemorrhoids bleeding.

Researchers claim that discrepancies between Dr Livingstone’s original account of the massacre and the field diary suggests he has something to hide about the atrocity.

Tim Jeal said the publication of the diary “gives a fuller impression of the sheer horror that Livingstone was up against.”

The field diary makes clear that Livingstone – an ardent abolitionist – was horrified by the moral character of the freed slaves sent to reinforce his expedition. He describes them as “senseless slaves with no honor.”

In Livingstone’s account, they emerge as rebellious and violent – at one point he confides that “if they go anywhere I must go with them or murder is certain.” In another passage, dated May 18, Livingstone says the slaves have mutinied and bought guns with his money.
Those passages were either sanitized or excised from Livingstone’s 1872 journal. 

Wisnicki claims that the edits, combined with discrepancies between the field diary and the journal’s descriptions of the massacre, suggest Livingstone may have had something to hide about the bloody Nyangwe incident.

That’s not to say that Livingstone was involved in any killings personally, but at best he had little control over his employees.  There is more than one entry in which he describes his men coming back from a trip talking about all the murders they’d committed.

Dr Wisnicki concludes: “Livingstone’s party might have been involved in the massacre” but he advises caution, ‘We’re only beginning to analyse the evidence.’

Spencer Tracy : Stanley and Livingston