The Da Vinci Notebooks at sacred-texts.com
The painter who works from nature should have a window, which he can raise
and lower. The reason is that sometimes you will want to finish a thing you are drawing, close to the light.
Let a b c d be the chest on which the work may be raised or lowered, so that the work moves up and down and not the painter. And every evening you can let down the work and shut it up above so that in the evening it may be in the fashion of a chest which, when shut up, may serve the purpose of a bench.
257:244 : See Pl. XXXI, No. 2. In this plate the lines have unfortunately lost their sharpness, for the accidental loss of the negative has necessitated a reproduction from a positive. But having formerly published this sketch by another process, in VON LUTZOW'S Zeitschrift fur bildende Kunst (Vol. XVII, pg. 13) I have reproduced it here in the text. The sharpness of the outline in the original sketch is here preserved but it gives it from the reversed side.