That portion of a tree which is farthest from the force which
strikes it is the most injured by the blow because it bears most
strain; thus nature has foreseen this case by thickening them in
that part where they can be most hurt; and most in such trees as
grow to great heights, as pines and the like. [Footnote: Compare the
sketch drawn with a pen and washed with Indian ink on Pl. XL, No. 1.
In the Vatican copy we find, under a section entitled '_del fumo_',
the following remark: _Era sotto di questo capitulo un rompimento di
montagna, per dentro delle quali roture scherzaua fiame di fuoco,
disegnate di penna et ombrate d'acquarella, da uedere cosa mirabile
et uiua (Ed. MANZI, p. 235. Ed. LUDWIG, Vol. I, 460). This appears
to refer to the left hand portion of the drawing here given from the
Windsor collection, and from this it must be inferred, that the leaf
as it now exists in the library of the Queen of England, was already
separated from the original MS. at the time when the Vatican copy
was made.]

Light and shade on clouds (474-477).