At http://phys.org/print339747040.html …. sketchbooks from the voyage of HMS Beagle have been digitised to produce a video of pencil drawings and watercolours by Conrad Martens, shipmate of Charles Darwion. These are available at Cambridge University Digital Library – go to http://cudl.lib.cam.ac.uk/
Some of them can be seen in a video slide show at the Phys Org link above, bringing to life views from nearly 200 years ago.