Near-blank verso with faint charcoal traces

This verso is almost entirely blank: it was invisible before restoration and now preserves only a few lines of a charcoal drawing largely lost when the sheet was mutilated, together with the fragment of a single line and a faint drawing brought to light by cleaning; one section bears neither writing nor drawing. Nothing of the design is securely legible. The Ambrosiana catalogue associates the leaf with studies in natural philosophy and mechanics.