The Notebooks of Leonardo Da Vinci — Volume 1 eBook

This eBook from the Gutenberg Project consists of approximately 360 pages of information about The Notebooks of Leonardo Da Vinci — Volume 1.

The Notebooks of Leonardo Da Vinci — Volume 1 eBook

This eBook from the Gutenberg Project consists of approximately 360 pages of information about The Notebooks of Leonardo Da Vinci — Volume 1.

[Footnote:  A here stands for levante (East), B for ponente (West).]

140.

Every body in light and shade is situated between 2 pyramids one dark and the other luminous, one is visible the other is not.  But this only happens when the light enters by a window.  Supposing a b to be the window and r the body in light and shade, the light to the right hand z will pass the object to the left and go on to p; the light to the left at k will pass to the right of the object at i and go on to m and the two lines will intersect at c and form a pyramid.  Then again a b falls on the shaded body at i g and forms a pyramid f i g. f will be dark because the light a b can never fall there; i g c will be illuminated because the light falls upon it.

Light and shadow with regard to the position of the eye (141—­145).

141.

Every shaded body that is larger than the pupil and that interposes between the luminous body and the eye will be seen dark.

When the eye is placed between the luminous body and the objects illuminated by it, these objects will be seen without any shadow.

[Footnote:  The diagram which in the original stands above line 1 is given on Plate II, No 2.  Then, after a blank space of about eight lines, the diagram Plate II No 3 is placed in the original.  There is no explanation of it beyond the one line written under it.]

142.

Why the 2 lights one on each side of a body having two pyramidal sides of an obtuse apex leave it devoid of shadow.

[Footnote:  The sketch illustrating this is on Plate XLI No 1.]

143.

A body in shadow situated between the light and the eye can never display its illuminated portion unless the eye can see the whole of the primary light.

[Footnote:  A stands for corpo (body), B for lume (light).]

144.

The eye which looks (at a spot) half way between the shadow and the light which surrounds the body in shadow will see that the deepest shadows on that body will meet the eye at equal angles, that is at the same angle as that of sight.

[Footnote:  In both these diagrams A stands for lume (light) B for ombra (shadow).]

145.

OF THE DIFFERENT LIGHT AND SHADE IN VARIOUS ASPECTS AND OF OBJECTS
PLACED IN THEM.

If the sun is in the East and you look towards the West you will see every thing in full light and totally without shadow because you see them from the same side as the sun:  and if you look towards the South or North you will see all objects in light and shade, because you see both the side towards the sun and the side away from it; and if you look towards the coming of the sun all objects will show you their shaded side, because on that side the sun cannot fall upon them.

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The Notebooks of Leonardo Da Vinci — Volume 1 from Project Gutenberg. Public domain.