Place a sheet of not too transparent paper between the relievo and
the light and you can draw thus very well.
[Footnote: Bodies thus illuminated will show on the surface of the
paper how the copyist has to distribute light and shade.]
525.
If you want to represent a figure on a wall, the wall being
foreshortened, while the figure is to appear in its proper form, and
as standing free from the wall, you must proceed thus: have a thin
plate of iron and make a small hole in the centre; this hole must be
round. Set a light close to it in such a position as that it shines
through the central hole, then place any object or figure you please
so close to the wall that it touches it and draw the outline of the
shadow on the wall; then fill in the shade and add the lights; place
the person who is to see it so that he looks through that same hole
where at first the light was; and you will never be able to persuade
yourself that the image is not detached from the wall.
[Footnote: _uno piccolo spiracelo nel mezzo_. M. RAVAISSON, in his
edition of MS. A (Paris), p. 52, reads _nel muro_--evidently a
mistake for _nel mezzo_ which is quite plainly written; and he
translates it _"fait lui une petite ouverture dans le mur,"_ adding
in a note: _"les mots 'dans le mur' paraissent etre de trop.
Leonardo a du les ecrire par distraction"_ But _'nel mezzo'_ is
clearly legible even on the photograph facsimile given by Ravaisson
himself, and the objection he raises disappears at once. It is not
always wise or safe to try to prove our author's absence of mind or
inadvertence by apparent difficulties in the sense or connection of
the text.]
526.
TO DRAW A FIGURE ON A WALL 12 BRACCIA HIGH WHICH SHALL LOOK 24
BRACCIA HIGH.
If you wish to draw a figure or any other object to look 24 braccia
high you must do it in this way. First, on the surface _m r_ draw
half the man you wish to represent; then the other half; then put on
the vault _m n_ [the rest of] the figure spoken of above; first set
out the vertical plane on the floor of a room of the same shape as
the wall with the coved part on which you are to paint your figure.
Then, behind it, draw a figure set out in profile of whatever size
you please, and draw lines from it to the point _f_ and, as these
lines cut _m n_ on the vertical plane, so will the figure come on
the wall, of which the vertical plane gives a likeness, and you will
have all the [relative] heights and prominences of the figure. And
the breadth or thickness which are on the upright wall _m n_ are to
be drawn in their proper form, since, as the wall recedes the figure
will be foreshortened by itself; but [that part of] the figure which
goes into the cove you must foreshorten, as if it were standing
upright; this diminution you must set out on a flat floor and there
must stand the figure which is to be transferred from the vertical
plane _r n_[Footnote 17: _che leverai dalla pariete r n_. The
letters refer to the larger sketch, No. 3 on Pl. XXXI.] in its real
size and reduce it once more on a vertical plane; and this will be a
good method [Footnote 18: Leonardo here says nothing as to how the
image foreshortened by perspective and thus produced on the vertical
plane is to be transferred to the wall; but from what is said in
Nos. 525 and 523 we may conclude that he was familiar with the
process of casting the enlarged shadow of a squaring net on the
surface of a wall to guide him in drawing the figure.
_Pariete di rilieuo; "sur une parai en relief"_ (RAVAISSON). _"Auf
einer Schnittlinie zum Aufrichten"_ (LUDWIG). The explanation of
this puzzling expression must be sought in No. 545, lines 15-17.].
[Footnote: See Pl. XXXI. 3. The second sketch, which in the plate is
incomplete, is here reproduced and completed from the original to
illustrate the text. In the original the larger diagram is placed
between lines 5 and 6.
1. 2. C. A. 157a; 463a has the similar heading: '_del cressciere
della figura_', and the text begins: "_Se voli fare 1a figura
grande_ b c" but here it breaks off. The translation here given
renders the meaning of the passage as I think it must be understood.
The MS. is perfectly legible and the construction of the sentence is
simple and clear; difficulties can only arise from the very fullness
of the meaning, particularly towards the end of the passage.]
527.
If you would to draw a cube in an angle of a wall, first draw the
object in its own proper shape and raise it onto a vertical plane
until it resembles the angle in which the said object is to be
represented.
528.
Why are paintings seen more correctly in a mirror than out of it?
529.