The Codex Atlanticus is a collection of more than a thousand sheets of the scientific and technical drawings of Leonardo da Vinci, put together at the end of the sixteenth century by Pompeo Leoni, a sculptor. Leoni was trying to organize Leonardo's work into categories, cutting and pasting drawings from original notebooks on to the atlas-sized pages that give the Codex Atlanticus its name. Some drawings were damaged in the process and others lost.

History continued to be unkind to the drawings. The codex was appropriated by Napoleon at the end of the eighteenth century, before being returned from Paris to Milan in the mid-nineteenth century. Early photographers, most fortunately as it turned out, captured images of the sheets on huge glass plates, and these formed the basis of a luxurious reproduction in 1906 of the entire codex. The original sheets were poorly restored in the 1950s and the early photographs are more valuable to historians than the original sheets.

Copies of the 1906 edition — a collaboration between the Accademia dei Lincei, Italy's national academy, and the publisher Anthelios — are now rare. But one forms the centrepiece of an exhibition currently on view in the austere, baroque rooms of the Accademia dei Lincei in Rome. The sheets are displayed alongside modern interpretations, or counterparts, of the drawings: there is a reconstruction of Leonardo's helicopter in wood and a Ferrari engine, for example.

In mid-March the exhibition begins an extensive European tour, taking in Budapest, Bratislava, Warsaw, Bolzano and other European cities in 2006, before moving to the United States and Japan in 2007.

A.A.