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© John Stuart Clark Thanks to Jim McGurn, Hans-Erhard Lessing, Derek Roberts & Open Road for their help with this article.

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Forward to the Past by John Stuart Clark As we inexorably slide towards the new millennia, and the world gets ever higher on the technological fix, there is a satisfying irony about our hopes that an invention of the last century will help solve the traffic problems of the next. Acknowledged to be the last piece of design technology understood by the majority of the population, the bicycle has roots that can clearly be traced back to human powered invalid vehicles of the 17th Century and treadle-driven carriages of the 1700s. However there are many, particularly in Italy, who believe the genealogy of the vehicle of delights goes back another two hundred years. How come? In April 1974, literary historian Augusto Marinoni gave a lecture in Vinci at which he presented a drawing of a bicycle, ostensibly discovered in an album containing folios of sketches by Leonardo da Vinci and his students. According to Marinoni, when the monks who were restoring da Vinci's work peeled away the backing pages of the Codex Atlanticus, they discovered indisputable proof that Leonardo was the inventor of the bicycle, 325 years before Karl von Drais patented his 'running machine'. In the 16th century, when Pompeo Leoni acquired Leonardo's drawings, he also bought sheets from the maestro's studio used by apprentices. In order to save reams and reams of loose folios, Leon glued them into three albums, one of which became known as Codex Atlanticus. Sheets with Leonardo's drawings on both sides had a window cut in the supporting page. Those backed by the work of an apprentice were stuck down and apparently remained hidden for 400 years. In 1960, the monks at Grottaferrata near Rome removed the Codex from the Ambrosia Library, Milan, where it had remained since Leoni's death, and began work on restoring Leonardo's folios. In 1967, Jules Piccus, an American romanist, discovered the two other albums in the National Library of Madrid. Called the Codices Madrid, they contained folios that indicated the artist was much more of an inventive visionary than had previously been appreciated. Specifically, it was his chain and chain wheel sketches that created a stir. Folios 132 and 133 in the Atlanticus were evidently once a single sheet. On the reverse of a Leonardo sketch of military fortifications, next to a couple of obscene graffiti of walking penises and a crude caricature of a youth, there was a drawing of a two wheeled vehicle with all the mechanical characteristics of a pedal driven bicycle. The machine is drawn in two colours of pencil. The steering, transmission and wheel cladding are drawn in dark brown, possibly indicating metal, while the frame and wheels are in light brown and possibly of wood. The power transmission and steering mechanism are the most extraordinary features of the so-called Leonardo's Bicycle. As bicycle historian Jim McGurn observed, "The chain wheel, rear sprocket and rear wheel correspond remarkably in size and ratio to the transmission system on a modern bicycle, a system which developed slowly and tortuously from the many mistakes and cul-de-sacs of Victorian bicycle design". The steering is more of a puzzle, with two elements unexplained - the inverted T beneath the handlebar column and the wedge shape extending from the wheel hub. As depicted, it appears the bicycle was rigid and non-steerable. Antonio Calegari's axiometric reconstruction found in The Unknown Leonardo emphasises this, though clearly, if such a machine had ever been built, pedal power and a fixed front wheel would have proved impractical. Prof. Marinoni's accreditation of the sketch rests on the argument that it was produced by an apprentice of Leonardo's, who maybe saw a model, a prototype or a drawing in the great man's studio and quickly copied it. This could account for the crudity of the extended pedal. On the other hand, care was taken in using a compass to draw the wheels, in employing two colours and in the detail of the gearing. Quite probably the accompanying graffiti were drawn by one of Leonardo's boys. There is the name "salaj" inscribed on one sheet, and the cruel caricature is thought to be a destruction job on Salai, a handsome model, servant, pupil and possibly toy-boy of Leonardo's, known to be unpopular with the other apprentices. Of course, if the machine did exist, even as a sketch by the maestro, the most remarkable thing about it was the concept that a person could balance on two wheels, lined one in front of the other, and power the machine forward while remaining upright. The world had to wait four centuries before Kirkpatrick Macmillan produced his ingenious two-wheeled treadle machine, and that was forty years before its time. Leonardo da Vinci (1452-1519) was a prolific creative genius. He was an artist, architect, scientist, technologist, mechanic, inventor, physicist, anatomist, engineer and geologist. His ideas for enhancing the physical capabilities of human beings ranged from human-powered carriages, through military hardware to helicopters and ornithopters. Many of his concepts were highly imaginative and beyond the capabilities of Renaissance engineering, but almost all (the helicopter included) can be found to have a corollary in nature. The bicycle is an important exception. When Marinoni released the news, there was uproar. Carlo Pedretti, an art historian at UCLA, summed up the skeptics' view with the words, "Folios 132 and 133 hardly deserve the attention they have received". Vernard Foley of Purdue University, Indiana, dismissed Pedretti's dismissal as symptomatic of the culture surrounding the petrol crisis of the 1970s and the unwelcomed renaissance of the bicycle. Since then, the machine, the drawing, and its authenticity have occupied many a cycling historian, antiquarian, and academic. In the 1980s, Jim McGurn was in communication with a number of specialists around the world who furthered the believers' argument. Only one correspondent, Derek Roberts, a respected British bicycle historian, remained unmoved and deeply skeptical. Ten years on, the balance has tipped in Roberts' favour. It is difficult to establish what forensic tests, if any, have been performed on the pencil lines. Prof. Paolo Galluzzi, director of the Florence Science Museum, claims a 'nuclear-something' test detected two kinds of ink, one manufactured after 1880, the other after 1920. Unfortunately he can't find the source of this report - it was just something he read on an airplane. The director of the library that holds the Codex Atlanticus refuses to comment on anything relating to the drawing, even on whether the lines are in ink or pencil. Since lead pencils weren't around until 50 years after Leonardo's death, the information would be useful. All we know is that, in 400 years of contact, the lines did not rub off on the backing sheet of the Codex, though marks from the penises did. The folio is now encapsulated in plastic to preserve it, but even that should not be a barrier to further investigation. Pedretti claims he studied the folios in 1961, while they were still glued in the Codex. He held sheet 133 up to a strong light and saw no bicycle. What he did see (according to his notes) were two circles with curved lines bisecting them that later, mysteriously, became transformed into the famous bicycle. To add another twist, Pedretti's original notes were stolen with his car in 1965 so, to a degree, he is working from memory. The image first appeared worldwide in the three volume work, The Unknown Leonardo, edited by Ladislao Reti and published in 1974. It appears in the appendix to volume two, Leonardo the Scientist, which Marinoni contributed to. Reti was a skeptic, even accusing Marinoni of forging the drawing. Sadly he died in 1974 before the volumes saw the light of day, and it was Marinoni who took over the editorship. This might explain why there was such a delay in revealing this astounding discovery to the world. If the drawing is an imaginative hoax, the questions are who did it, when and why? The scenario that, prior to 1960, the album was taken from the Ambrosia Library, the sheet carefully removed, the drawing done, the folio glued back and the album returned is possible, but unlikely. However, it appears that just before the restoration of the Codex began, some sheets did go walkabout from the Ambrosia Library. Marinoni claims this was in 1966 and did not include folios 132 and 133, by then already in the restorers' hands. Despite the mechanical sophistication of the sketch, and its strong echo of Leonardo's work, it is not inconceivable that a mischievous monk drew the bicycle. Sample pages from the Codices Madrid featuring Leonardo's sketches of cogs and chains were published in numerous newspapers and popular magazines in 1967. Although these were specifically designed for lifting purposes, by February of that year Jules Piccus and his editor Ladislao Reti had popularised the idea that they were designed for transmitting power. Pedretti notes that the restoration process was chaotic and thoroughly unscientific, claiming that some drawings were totally destroyed by "restorers" (he always refers to the monks' profession in inverted commas) employing the wrong chemicals. In such an environment, a little creative vandalism wouldn't be amiss, though one has to wonder how any monk thought he could get away with such an obviously traceable fake that would have worldwide repercussions. As to why, Hans-Erhard Lessing from the University of Ulm offers up the motive of jingoism. Again, it is not inconceivable that the Italians could go to great lengths to snatch the credit for inventing the bicycle away from the German, Baron von Drais. The Brits tried it with the 1642 image of a land survey instrument depicted in the famous Stoke Poges church window. The French tried it with de Sivrac's non-steerable two-wheeler of 1791. It was Lessing's paper, presented to the Eighth International Conference of Cycling History in August 1997, that resurrected the controversy, triggering the headline "On yer bike, Leonardo" in New Scientist and a piece by John Humphries on the Today programme. Unfortunately, while illuminating many grey areas, his "Evidence against Leonardo's Bicycle" lacks the hard evidence needed to identify the perpetrator(s) of the hoax. Until that time, and in lieu of a death-bed confession by Marinoni, the jury remains out.

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