innercurtain: Leonhard Euler. Theoria Motuum Planetarum et Cometarum. 1744.
tags: Leonhard Euler,Theoria Motuum Planetarum et Cometarum,Illustration,art,
from: http://ocularorder.tumblr.com/post/84635476889
tags: Leonhard Euler,Theoria Motuum Planetarum et Cometarum,Illustration,art,
from: http://ocularorder.tumblr.com/post/84635476889