Trees with Straight Branches, and Trees at Sunrise
Pollarded willows, relief in shadow, and western trees dimmed by murky air
A page of the Treatise on Painting turning from single leaves to whole trees. It notes that a leaf's transparent reverse glows bright green when lit from m through leaf s, and that many leaf-masses lack shadow, showing a transparent reverse and a glossy face. Chapter [897] describes pollarded willows and similar trees whose cut branches grow straight, casting shade at the middle and little at the tips, so that the sky-turned branches show little relief while the downward branches brighten from dark to their tips against a shadowy ground. Chapter [898], marked b, observes that at sunrise the western trees show almost no relief because the intervening air is very murky.
On this page
The bright green reverse of a lit leaf (m, s)
If m is the illuminator of leaf s, every eye that sees the leaf's reverse sees it a most beautiful bright green, because it is transparent. Often leaf-masses have no shadow at all, showing a transparent reverse and a glossy, sheening face.
Pollarded willows and their relief [897]
Willows and like plants cut every three or four years put out very straight branches, with shade toward the middle where the branches spring and little shade at the tips. The sky-turned branches show little shadow and little relief, while the downward branches are born in shadow and brighten gradually to their tips, giving good relief against a shadowy ground; the sparser the branchwork and leaves, the less shaded the plant.
Western trees at sunrise show little relief [898]
With the sun in the east, the western trees appear to the eye with very little relief and an almost imperceptible presence, because the air between eye and trees is very murky, as proved by the seventh proposition of this book.