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Not the Leonardo Bicycle?

© John Stuart Clark

On Thursday 16th October 1997, cyclists woke up to the dulcet tones of John Humphreys informing Today listeners to BBC Radio 4 of the earth shattering news that Leonardo's Bicycle wasn't Leonardo's bicycle, or even that of one of his assistants. It belonged to a monk who got bored in the Sixties. The 1960's, that is, not the 1460's.

The news item didn't expand further and the newspapers offered little more, except to quote from an article by Jonathan Knight in that week's New Scientist. Unfortunately, Mr Knight got a number of facts wrong, further muddying the waters of the controversy. So, what was it all about?

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 he committed them to paper anyway, possibly as problems for future exploration.

When Pompeo Leoni acquired Leonardo's drawings in the late 16th century, he also bought sheets from the maestro's studio used by apprentices. In order to save reams and reams of loose folios, Leoni 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 Ambrosian 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.

But the real bombshell was dropped by literary historian Augusto Marinoni in April 1974. According to Marinoni, when the monks peeled away the backing pages of the Codex Atlanticus containing folios 132 and 133, they discovered indisputable proof that Leonardo was the inventor of the bicycle, 325 years before Karl Drais patented his 'running machine'.

The two sheets were evidently originally one. 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 claddings are drawn in dark brown, possibly indicating metal, while the frame and wheels are in light brown and possibly of wood. It's proportions are strikingly close to those of a traditional bicycle and some features, like the flat chassis and arching seat, are elements seen in both Renaissance cart designs and modern bicycle styling.

The power transmission and steering mechanism are the most extraordinary features of the so-called LeonardoÕs Bicycle. As cycling historian Jim McGurn observed, "The chainwheel, 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 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 possibly 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 lads.

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 maintaining their balance. The world had to wait four centuries before Kirkpatrick Macmillan produced his ingenious treadle machine, and that was forty years before its time.

When Marinoni released the news, there was uproar in the academic world. Carlo Pedretti, an art historian at UCLA, summed up the sceptics' 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 embroiled in correspondence with a number of specialists around the world who furthered the believers' argument. Only one person, Derek Roberts, a respected British bicycle historian, remained unmoved and deeply sceptical. Ten years on, the balance has tipped in Roberts' favour.

Mechanically, a handful of solutions have been postulated for the steering mechanism, all within the capabilities of 15th century technology, including the idea of a T-screw and chain that rotated an Archimedes screw (the mysterious wedge) which slid an extended hub within two axle slots (quadrant steering). Likewise the problem of the chainwheel with square teeth, which theoretically wouldn't work, has been overcome, albeit not very satisfactorily. (Leonardo himself realised its limitations and went on to sketch chain wheels with rounded teeth.)

As to the drawing, it is difficult to establish what chemical tests, if any, have been performed on the pencil lines. Basic forensic analysis could provide some proof of authenticity, or otherwise, but nobody seems to have pursued that line of enquiry. All we know is that, in 400 years of contact, the crayon 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.

If the drawing is an imaginative hoax, the question is by whom and when. The scenario that, prior to 1960, the album was taken from the Ambrosian Library, the sheet carefully removed, the drawing done, the folio glued back and the album returned is possible, but highly unlikely. Imagine trying to perpetrate the same act of vandalism on one of the British Library's treasured folios in the now defunct Reading Room. Worse still, imagine dying without receiving any credit for the hoax!

Presuming that Prof. Marinoni's integrity is beyond question (which it isn't), that just leaves the monks at Grottaferrata, and it is they that stand accused in the news item on Today. Hans-Erhard Lessing, retired curator of the Museum of Technology and Labour in Mannheim, interviewed Carlo Pedretti who examined the folios back in 1961. Pedretti held them 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. Ipso facto, the monks did the dirty deed.

Or did they? It appears that just before the restoration of the Codex began, some sheets went walkabout from the Ambrosian Library. Marinoni claims this was in 1966 and did not include folios 132 and 133, by then already in the monks' hands. Marinoni is an ill man, not up to responding to Lessing's accusation, and there has been no rebuttal from the cloister, but the questions have to be asked of Pedretti, why wasn't he outraged when the vandalism first came to light and why didn't he kill the speculation stone dead at the outset?

It is not inconceivable that a mischievous monk did sketch the bicycle but, given the mechanics, he would have had to be well versed in Leonardo's gearing designs (possible) and in quadrant steering (unlikely). Though Pedretti notes that the restoration process was chaotic and thoroughly unscientific, we also have to wonder how any monk thought he could get away with such an obviously traceable fake.

To nail this issue once and for all, a thorough multi-disciplined investigation is needed, similar to that conducted into the Nazca Lines of Peru by Christopher Mann of BBC Manchester. Pulling together a wide range of research and researchers, Mann's TV programme, Flightpaths to the Gods, offered a new, credible and complete explanation for the mysterious tracks etched in the Nazca desert.

With resources and clout far beyond the means of the academic world, only the media can mount such a project. The question is whether the Italian authorities would endorse such an investigation given that, at present, despite Lessing's damp squid, Leonardo is still (speculatively) credited in his homeland with the invention of the bicycle.

END