A Timeless History
The Codex Atlanticus is the largest set of Leonardo's papers: over a thousand sheets at the Biblioteca Ambrosiana in Milan. It was restored in 1966–69; in 1974 a chain-driven two-wheeler on the back of folio 133 was announced as his. In 1997 the historian Hans-Erhard Lessing showed it was almost certainly drawn during the restoration. The real story starts in 1817, with Drais's running machine.
SourceVeneranda Biblioteca Ambrosiana, Milan — ambrosiana.it · H.-E. Lessing, 8th International Cycle History Conference, Glasgow, 1997 · New Scientist, 18 October 1997 · Hadland & Lessing, Bicycle Design (MIT Press, 2014) · Rijksmuseum, Amsterdam
Science In Action
Two equal wheels, pedals on cranks and a chain to the rear wheel — the layout of the 1880s “safety” bicycle • Chain drive reached bicycles between 1879 and 1885; the sketch has it four centuries early, hence the doubt • No steering at all: the front fork is drawn fixed. A bicycle that cannot steer cannot stay upright • Balance is steering: a bike stays up by steering into its lean — no gyroscope or caster needed (Delft, 2011)
SourceScience Museum Group, cycling collection — collection.sciencemuseumgroup.org.uk · Kooijman, Meijaard, Papadopoulos, Ruina & Schwab, “A bicycle can be self-stable without gyroscopic or caster effects”, Science 332 (2011), 339–342 · Wellcome Collection, London
Arts
Deciding who drew something is a discipline of its own. Ink, paper fibres, the slope of the hatching: Leonardo was left-handed and shaded from upper left to lower right, a habit forgers rarely get right. His sketches for the Virgin adoring the Child, in the Met, are genuine — every stroke slopes his way — the first thing an examiner checks on any sheet that carries his name.
SourceThe Metropolitan Museum of Art, 17.142.1 — metmuseum.org · Royal Collection Trust, Leonardo drawings — rct.uk · C. Pedretti, The Codex Atlanticus: A Catalogue of its Newly Restored Sheets (1978) · New Scientist, 18 October 1997
Applications Today
Museums now authenticate with X-ray fluorescence, infrared reflectography and fibre analysis, reading a sheet's materials rather than its style. The technology keeps improving, so attributions keep changing — including some that had been settled for a century. The Ambrosiana has photographed every sheet of the Codex Atlanticus, front and back, and put it online: anyone can now look at folio 133 for themselves.
SourceThe National Gallery, London, scientific department — nationalgallery.org.uk · Veneranda Biblioteca Ambrosiana, Codex Atlanticus online — codex-atlanticus.ambrosiana.it · Library of Congress, Carol M. Highsmith Archive
The first bicycle ever built, in 1817, was pushed along with the feet. Pedals came fifty years later.
Man op een draisine (Man on a draisine) — 'Draisine', hand-coloured aquatint and engraving — Anonymous printmaker; published by Rudolph Ackermann, London — February 1819 — Rijksmuseum, Amsterdam — on loan from the Koninklijk Oudheidkundig Genootschap (KOG) — KOG-ZG-1-10-162 (id.rijksmuseum.nl/200715662; handle RM0001.COLLECT.848495)
