It traces to folio 812r of the Atlantic Codex, one of greatest collections of Leonardo da Vinci’s sketches and studies.

The Automobile is a sketch of a cart, complete with its inner workings. The sketch is of extreme importance considering it depicts the plan of the first ever self-propelled vehicle in the world, confirming Leonardo da Vinci as the inventor of the earliest form of automobile or robot.

The sketch ranks at the very top of Leonardo da Vinci’s several innovations related to transportation and locomotion.

Leonardo da Vinci's sketch is of an open top three-wheeler, capable of motion without being pushed. The sketch is scaled to a cart measuring 1.68 meters long and 1.49 meters wide (or 5 foot 6 inches by 4 foot 11 inches).

The dominating feature of the sketch is two big coiled leaf springs on either side of the cart, with its shape bearing a close resemblance to a crossbow’s arms.

The cart is depicted to run on clockwork, powered by the coiled springs. However, so complex and intricate is the drawing, that it remained an enigma for experts well into the 20th century.

The initial assumption was the motion of Leonardo’s cart being powered by the two big leafed coiled springs, with the springs to be wound up by rotating the wheels opposite to the intended direction.

However, later research reveals the springs apparently do not directly power the cart, but rather regulate the drive mechanism located on the underside of the cart and enclosed in drum-like casings.

The new knowledge was made explicit in the early 15th century copies of the automobile in the Uffizi archives, which contain some early Da Vinci sketches. These archives depict a different view of the automobile, from above the spring mechanism.

The Automobile nevertheless incorporates steering and brakes. Releasing the brakes propel the cart forward. The sketches show a hidden rope connecting the brakes, enabling an operator to release the brakes from a distance. The steering could be programmed to go straight or turn at pre-set angles to the right.

Historians deduced Leonardo da Vinci designing his automobile for theatrical use. The persistent question of whether the sketch would actually work if translated to real rendering was recently addressed by a team of engineers, computer designers, and joiners, working under the Institute and Museum of the History of Science, Florence.

The effort, completed in 2006, was a culmination of several attempts made in the previous century to construct the vehicle.

While the earlier efforts failed, the latest effort succeeded, and a successful prototype based on Leonardo da Vinci’s sketch was displayed at an exhibition in Florence.

The prototype actually moves, and is a very powerful machine! In fact, the Mars Rover takes inspiration from Leonardo da Vinci’s Automobile.