You may well think these are
sketches for abstract paintings, perhaps by a frontrunner like Maleavich, or even one of our own, McCahon maybe. But they are in fact margin drawings from the The Codex Arundel a
collection of papers assembled by Leonardo and now in the British Museum. If
you want to spend your day (ok, evening) going through the entire codex
(seriously, they have put every page up on line) this is the place to go.