Laputan Logic
Thursday, November 14, 2002
How did Prokudin-Gorskii take his pictures?
Sergei Mikhailovich Prokudin-Gorskii was a chemist turned photographer ahead of his time who undertook an ambitious photographic survey of the Russian Empire for Tsar Nicholas II. Between 1909 and 1915, he completed tours of eleven regions, traveling in a specially equipped train carriage which had been provided by the Ministry of Transportation.
What made this project remarkable was his use of an innovative technique for taking photographs in colour. He was able to capture colour by using a camera that exposed one oblong glass plate three times in rapid succession through three different colour filters: blue, green, and red. To view his images, he printed positive glass slides of his negatives and projected them through a triple lens magic lantern. The images were projected through the three lenses and, with the use of colour filters, superimposed in full colour on to a screen.
In 1918, Prokudin-Gorskii left Russia and the glass plates of his unique images of Russia on the eve of revolution were purchased from his heirs in 1948 by the U.S. Library of Congress. Many, but not all1, of the plates have been scanned and reconstituted through a process called digichromatography into vivid full colour images. An online exhibition of these images can be found on the Library of Congress web site as well as access to their collection of approximately 2,615 images, 110 of which have been made into full colour renderings.
Side note: The images have a striking quality about them but the colour renderings do contain some strange artifacts which come from the process that Prokudin-Gorskii used to take them. Because each of his three exposures probably took somewhere between 3 and 30 seconds, small changes in the scene can show up looking a bit like rainbows or even oil slicks. This is particularly noticeable in images of water or where shadows are moving about such as under trees being blown by the breeze. David Dyer-Bennet demonstrates on his web site the feasibility of Prokudin-Gorskii's method by using a garden variety digital camera and a copy of Photoshop and examines these artifacts.
1 You can find most of the remaining images of the collection (1,902 of them) as low quality colour images on Frank Dellaert's web site.
Sergei Mikhailovich Prokudin-Gorskii was a chemist turned photographer ahead of his time who undertook an ambitious photographic survey of the Russian Empire for Tsar Nicholas II. Between 1909 and 1915, he completed tours of eleven regions, traveling in a specially equipped train carriage which had been provided by the Ministry of Transportation.
What made this project remarkable was his use of an innovative technique for taking photographs in colour. He was able to capture colour by using a camera that exposed one oblong glass plate three times in rapid succession through three different colour filters: blue, green, and red. To view his images, he printed positive glass slides of his negatives and projected them through a triple lens magic lantern. The images were projected through the three lenses and, with the use of colour filters, superimposed in full colour on to a screen.
In 1918, Prokudin-Gorskii left Russia and the glass plates of his unique images of Russia on the eve of revolution were purchased from his heirs in 1948 by the U.S. Library of Congress. Many, but not all1, of the plates have been scanned and reconstituted through a process called digichromatography into vivid full colour images. An online exhibition of these images can be found on the Library of Congress web site as well as access to their collection of approximately 2,615 images, 110 of which have been made into full colour renderings.
Side note: The images have a striking quality about them but the colour renderings do contain some strange artifacts which come from the process that Prokudin-Gorskii used to take them. Because each of his three exposures probably took somewhere between 3 and 30 seconds, small changes in the scene can show up looking a bit like rainbows or even oil slicks. This is particularly noticeable in images of water or where shadows are moving about such as under trees being blown by the breeze. David Dyer-Bennet demonstrates on his web site the feasibility of Prokudin-Gorskii's method by using a garden variety digital camera and a copy of Photoshop and examines these artifacts.
1 You can find most of the remaining images of the collection (1,902 of them) as low quality colour images on Frank Dellaert's web site.
A. P. Kalganov poses with his son and granddaughter for a portrait in the industrial town of Zlatoust in the Ural Mountain region of Russia. The son and granddaughter are employed at the Zlatoust Arms Plant--a major supplier of armaments to the Russian military since the early 1800s. Kalganov displays traditional Russian dress and beard styles, while the two younger generations have more Westernized, modern dress and hair styles.
Photographed in 1910 by Sergei Mikhailovich Prokudin-Gorskii.
Borzhomi is a small town in the Caucasus Mountains in the interior of what is now the Republic of Georgia. Noted for its mineral waters, it was a fashionable spa at the end of the nineteenth century. Shown here are elegantly dressed visitors posing for a photograph by the Ekaterinin, ("Catherine's") Spring.
Photographed in c 1907-1915 by Sergei Mikhailovich Prokudin-Gorskii.
Samarkand: a group of Jewish boys, in traditional dress, studying with their teacher.
Photographed in 1911 by Sergei Mikhailovich Prokudin-Gorskii.
The Emir of Bukhara, Alim Khan (1880-1944), poses solemnly for his portrait, taken shortly after his accession. As ruler of an autonomous city-state in Islamic Central Asia, the Emir presided over the internal affairs of his emirate as absolute monarch, although since the mid-1800s Bukhara had been a vassal state of the Russian Empire. With the establishment of Soviet power in Bukhara in 1920, the Emir fled to Afghanistan where he died in 1944.
Photographed in 1911 by Sergei Mikhailovich Prokudin-Gorskii using his revolutionary colour technology.
Lost city found in jungles of Nicaragua
Archaeologists have found what they believe to be a lost city in the jungles of Nicaragua. The remnants are located near the town of Kukra Hill in the south of the country. Preliminary studies suggest it was a settlement dating back more than 2000 years. The place is only accessible by boat or plane. The archaeological expedition was sponsored by the National University of Nicaragua, the University of Barcelona, the Spanish Agency for International Cooperation and the Spanish Historical Heritage Institute. Professor Ermengol Gassiot from the University of Barcelona told El Nuevo Diario newspaper: "We found architectural sites with structures and platforms that are very high and very old." The first reports of the discovery came from Nicaraguan Nicolas Jarquin, who organized the expedition.
Tuesday, November 12, 2002
Travesty
I first read about Travesty in an issue of BYTE magazine way back in 1984. A travesty generator takes an original text and performs a statistical analysis of letter combination frequencies. It then randomly generates an output text which has the same letter-combination frequencies as the input text.
The result is, needless to say, a complete and utter travesty of the original text and yet it seems to have an eerie resemblance to the writing style of the original author. The travesty generator will also often make up nonsense words which are surprisingly realistic sounding.
Travesty creates a new text based on how often sequences of characters appear in the original text. Suppose we're doing an order 3 travesty. Travesty analyzes the original text to find all the combinations of two characters (one less than the order) that appear in the text. It also constructs a table of all of the letters that follow those two-letter combinations and how often those letters follow the combination. Travesty then takes the first two letters of the original text, looks up that character sequence in the table, and randomly selects the next letter according to the frequencies in the entry. It adds the new letter to the beginning string of two characters and uses the second and third characters in that string as the new two-letter combination to look up. This process continues until Travesty produces the requested number of characters of output. Thus, for an order 3 travesty, the result is a text in which all combinations of three characters appear at roughly the same frequency as all three-letter combinations in the original text. Notice that travesty uses all of the characters in the original text (letters, digits, dashes, etc.) and not just letters.Come on then, let's make a travesty of something:
More about this web implementation including Perl source code can be found at Poetry Links.
Monday, November 11, 2002
Red Slave
In 1729, the Englishman Robert Drury published an account of his captivity on Madagascar. For years it was dismissed as fiction but archaeology has now shown that it was true after all.Also more information on Mike Parker Pearson's field work in Southern Madagascar.How many people were fooled by Robinson Crusoe when it was first published? That book - one of the world's first novels - claimed in its preface to be 'a just Story of Fact' and was snapped up by an audience for whom the idea of fictional books was very novel indeed. Daniel Defoe published Robinson Crusoe in 1719 and, ten years later, the book-reading public were puzzling over another story of shipwreck on a tropical island - Madagascar: or Robert Drury's Journal during fifteen years captivity on that island. This book also purported to be 'a plain, honest Narrative of Matters of Fact' whilst admitting 'of no Doubt of its being taken for such another Romance as Robinson Cruso'. Was this story of warlike tribes, kings and slaves a novel, a true story or, like the adventures of Robinson Crusoe, a bit of both? For the last three hundred years, literary critics have argued over the book Drury wrote after his return to England. Was Robert Drury's Journal true? Or did Defoe write it? Many have judged it to be fiction or, at best, a merging of half-truths and seamen's tales cobbled into a good yarn. In 1962 a book published posthumously in America presented the results of a lifetime's investigation into Robert Drury. The author, Arthur Secord, had picked up his trail in London and found proof of his birth and death and information about his early life - strangely, we know more about Drury's youth than we know about Defoe's. Secord located the Degrave's muster-roll, where Robert Drury's name appears among the midshipmen, and also found a letter from Drury requesting the East India Company to employ him on another expedition to Madagascar - if they couldn't find him a job, he wrote, he would go and work for the Swedes. Until his death in 1735, Robert Drury could be found frequenting Old Tom's Coffee-House in Birchin Lane in central London. Here he was willing to 'confirm those Things which to some may seem doubtful' and 'gratify any Gentleman with a further account' of anything in the book. He was buried in the churchyard of St Clement Danes in the Strand. This evidence that Drury really had existed silenced many doubters - but not all. Some historians and literary specialists still argue that this story of life in Madagascar is a work of imagination. None of these critics, however, have ventured into the land of the Sakalava in the west or to the far south of Madagascar, the land of thorns. In 1991, by contrast, a small team of European and Malagasy archaeologists started on a journey of discovery - rather than searching through 18th century documents for more information on Drury, why not look for him in the Indian Ocean? I'd come across Drury's book during research for an earlier visit to Madagascar and was fascinated by the world he described. After many long evenings telling my colleagues strange tales of shipwrecks and pirates, we set off for the forests of Androy. The project's main aim was to study monumental tombs and funerary practices - a tough enough task on its own - and in the applications for funding we hadn't dared mention the hunt for a shipwrecked sailor. During our years of research in Androy we have learnt a lot about tombs, and about the history of southern Madagascar from its earliest settlement - the island, which is about the size of France, was uninhabited until its discovery by migrants from Indonesia and Africa in the 1st millennium AD. These colonists probably contributed to the extinction of the Elephant Bird, a flightless giant that survived in Madagascar for over 80 million years until shortly after the arrival of people. We have found the traces of a previously unknown civilisation, which rose and fell before the first Europeans reached Madagascar, and investigated the impact (or lack of it!) of the doomed attempts by Europeans to get a foothold on the island in the pre-colonial period - but this all belongs to another story. Our journey from the highland capital of Madagascar to the scorched south was a voyage across cultures, leaving the red soil and the quietly spoken rice-cultivators of the highlands to enter the world of the spear-carrying Tandroy cattle pastoralists. With our colleague Ramilisonina from Madagascar's national museum, we began to investigate the region's archaeology, working with Retsihisatse, a Tandroy pastoralist and archaeologist. Read more...
The ancient ‘manda’ civilisation The first part of this season's work was devoted to the study of manda and other large settlements of the 10th-13th centuries. Ever since the discovery of Andranosoa and Mandan d'Remananga in the 1970s, these large and formerly densely occupied sites have been central to archaeological investigations in the south of Madagascar. They bear witness to a vanished civilisation which once inhabited the river systems of the south and imported Islamic sgraffiato and Chinese ceramics but has left no clear traces in oral or written history.
