After following the 'Search Box' link described in the last post the page whiich opens presents a second link 'The Elements of Drawing' which gives access to Ruskin's teaching collection. The opening page has a slide show with a beautiful drawing of the head of a Golden Eagle.
It'a a lovely example of a graphite drawing developed by adding a watercolour wash - a classic technique. The initial 'search lines' which Ruskin used to arrive at the final form are still there. It's worth making a careful copy of it. By halting the slideshow - right click the image - choose the 'View Image' option in the drop down window.
Alternatively take this link: 'John Ruskin: Head of a Golden Eagle From Life' Click the 'Zoom Button' for a large image.
Enjoy a browse of the whole site there is a lot of material to choose from. The best way to learn is to copy a great master - it's a practice all studio apprentice artists followed.