The discovery of this drawing among Leonardo’s papers has raised much controversy.

Between 1966 and 1969, the monks of the "Laboratorio di Restauro" of the Abbey of Grottaferrata, near Rome, were entrusted with the restoration of the Codex Atlanticus. A binding contract was drawn up with the fundamental clause of this contract being that absolutely no person was to be admitted to see the folios of the Codex during the years of the restoration. 

During the process of the restoration, the monks separated two sheets that a sixteenth-century conservator, Pompeo Leoni, had folded in half and glued together. The separation of these two sheets revealed some scurrilous scribbles and the rough sketch of a vehicle resembling a bicycle. Some scholars believe that it might have been drawn by one of Leonardo’s young pupils, Salai. The style is certainly in keeping with many of Leonardo’s sketches, and Leonardo did draw a transmission system with a chain with square shaped teeth, which is familiar to bicycle users today. 

Da Vinci - Inventions
  1. Welcome and Introduction
  2. Life and Times
  3. About Leonardo
  4. Codices - Notebooks
  5. Anatomical Studies
  6. Alphabet and Introduction to Leonardo's Inventions
  7. Civil Machines
  8. Autotraction Car
  9. The Ideal City
  10. Father of Flight
  11. Aerial Screw
  12. Flying Machine
  13. Glider
  14. Parachute
  15. Introduction and Overview of Aquatic and Hydraulic Machines
  16. Emergency Bridge
  17. Scuba and Breathing Equipment
  18. Submarine
  19. Paddle Boat
  20. Instruments of Optics, Music, and Time
  21. Mechanical Drum
  22. Spot Light
  23. Mirror Room
  24. Physics and Mechanical Principals
  25. The Last Supper
  26. Bicycle
  27. Military Engineering
  28. Ogival Bullet
  29. Three-Registered Machine Gun
  30. Steam Canon
  31. The Battle of Anghiara Drawings
  32. Renaissance Art
  33. The Mona Lisa
  34. Self Portrait
  35. The Lady with an Ermine
  36. Annunciation
  37. Virgin of the Rocks
  38. The Madonna Litta
  39. The Benois Madonna
  40. Portrait of a Musician
  41. St. Jerome
  42. The Vitruvian Man
  43. Sforza Horse Sculpture
  44. Conclusion and Thank You