https://plus.google.com/110098899518608988386/posts/4Za6eG8Ane9
Graphic design based on the sketch of a tree by Da Vinci in his notebooks:
“All the branches of a tree at every stage of its height when put together
are equal in thickness to the trunk”
達文西手稿原圖：
https://i.pinimg.com/originals/d7/31/1a/d7311a18b5c843378dc735a890e35b52.jpg