Sheffields Millenium Gallery has a display of several of his sketches from the royal archives (they were originally purchased by Charles II). One chilly February afternoon, I went along to see them with Jill.
There were a number of his anatomical sketches, including a dissection of the blood vessels of the liver, and this rather fine study of leg muscles. It was also covered in his miniscule handwriting (paper was very expensive in the fifteenth century). He wrote from right to left as he was left handed and it avoided smudging the ink.
There were other examples of 'natural philosophy' including some studies of water flows. Again, this one is heavily annotated.
He was also very interested in humans and animals in motion. This is a series of studies of horses rolling, which were used to sketch St George and the Dragon (in the centre right of the sketches) as well as some of the horses in The Battle of Anghiari.
This was another study of a horse, this time with a rider (and intended as the design for a monument which was never built).
There were several portrait sketches, this is one of the head of St Phillip, which later appeared in The Last Supper.
Another portrait worthy of Rembrandt, albeit drawn almost 200 years earlier.
This was an amazing exhibition and I feel privileged to have gone to it. The thing that was really astonishing was that he was drawing like this in the fifteenth century, when most European art was still firmly rooted in the medieval.
There are similar exhibitions all over the country, but if you are in Sheffield, the details are here: Leonardo da Vinci. A life in drawing The only slight let down was that there weren't any war machines!