They are the thinking of a genius, the 500-year-old notes and drawings that reveal the extraordinary creative imagination of Leonardo da Vinci.
But these are not preparatory works for his famous paintings such as the Mona Lisa or the Last Supper.
They are the notebooks that demonstrate the great Renaissance master's other life as an inventor, engineer and scientist centuries ahead of his time.
A new exhibition at the Victoria and Albert Museum, in London, is to show more than 60 precious leaves of da Vinci drawings, including works from the British Library, the Royal Collection and the V&A itself. Visitors to the show will be able to puzzle over sheets so fragile they rarely see the light of day.
Martin Kemp, a professor of the history of art at Oxford University who has curated the exhibition, admitted many were "difficult" in comparison with da Vinci's better known works. But if the artist's explorations in geometry, anatomy and engineering prove daunting, highlights have been brought to life with animations commissioned from Cosgrove Hall, the company better known for creating Dangermouse.
Professor Kemp hopes the combination will explain elements of his work that are often overlooked. "Most people have some sense that he was a universal man, but I think these should give reality to the idea," he said. "I'm confident that people will go away and think, 'Wow, there's even more to this person than I thought.'"
Leonardo da Vinci was born the illegitimate son of a Florentine notary in 1452 and had a good grounding in literacy and numeracy. But it is impossible to understand how he became the prolific and dynamic figure we know today. "To assemble Leonardo, you would probably need a bit of half a dozen or a dozen people, all inventive in different areas," Professor Kemp said.
The artist-scientist was often way ahead of his time, but this does not mean he was always right. As drawn, his prototype tank would have had wheels going in different directions. And he was ultimately doomed in his investigations into "squaring the circle", a classic problem of ancient Greek mathematics.
Professor Kemp said da Vinci's basic thinking on problems from blood vessels to theories of force was usually correct. "Where he differed from earlier science was that he was saying, 'We need the book learning - the maths - but we also the experience, the grit of experiment.'"
Several sequences of drawings, such as a man hammering, worked exactly like an animator's key frames and showed da Vinci's accurate understanding of movement.
In addition to the animations, the entrance hall to the V&A has several giant models based on da Vinci's designs. They include a glider created for a Channel 4 programme on da Vinci and a parachute produced by Adrian Nicholas, a flight enthusiast who died in a skydiving accident.The professor said: "In his mind, they [his art and inventions ] weren't very separate. If you were painting the Mona Lisa or making a flying machine, they're both great recreations of nature."
Leonardo da Vinci: Experience, Experiment and Design, sponsored by Deloitte, is at the V&A, London, from Thursday until 7 JanuaryReuse content