Two notebooks that document the thoughts of Leonardo da Vinci's scientific investigations are now available online following a landmark collaboration between the British Library (BL) and Microsoft founder and chairman Bill Gates.

Codex Leicester, owned by Gates, the world's richest man, and Codex Arundel, a British Library treasure, have been reunited online as part the famed BL Turning the Pages digital books service.

"I am amazed by da Vinci, he personally worked out how light worked," said Bill Gates of his Codex Leicester, "Every one of those notebooks is an amazing document." The Codex Arundel and Codex Leicester were dispersed in the 16^th Century.

The notebooks contain da Vinci's notes, diagrams and sketches of his studies of mechanics, optics and the moon. "Nobody used visual material so brilliantly," said Professor Martin Kemp the world's leading da Vinci authority. "The way da Vinci combined incomparable genius with the human determination to strive for knowledge and practical improvement is an incredible inspiration," Gates said. 

Kemp, talking to an audience at the BL where Gates was launching the Windows Vista operating system, said; "It is incredibly important to have it available digitally as a scholar."

Windows Vista technology is at the centre of the second generation Turning the Pages application. Users can browse high resolution images of the texts and now compare two volumes side by side. "The historian of science will be able to exchange ideas with the historian of art, the Leonardo biographer with the structural engineer, the aeronautics expert with the mathematician," said Lynne Brindley, BL chief executive of the ability to add and share notes and annotations online via

Vista

Brindley added that Microsoft's involvement will speed up the addition of research material to Turning the Pages, "Putting a book on used to take weeks, now can be done in a few hours."

As Gates launched

Vista

www.bl.uk/ttp2/ttp2.html