Perspective at the
Royal Academy in 1807--over a hundred years ago--and took great pains
with the diagrams he prepared to illustrate his lectures, they seemed to
the students to be full of confusion and obscurity; nor am I aware that
any record of them remains, although they must have contained some
valuable teaching, had their author possessed the art of conveying it.

However, we are here chiefly concerned with the necessity of this study,
and of the necessity of starting our work with it.

Before undertaking a large composition of figures, such as the
'Wedding-feast at Cana', by Paul Veronese, or 'The School of Athens',
by Raphael, the artist should set out his floors, his walls, his
colonnades, his balconies, his steps, &c., so that he may know where to
place his personages, and to measure their different sizes according to
their distances; indeed, he must make his stage and his scenery before
he introduces his actors. He can then proceed with his composition,
arrange his groups and the accessories with ease, and above all with
correctness. But I have noticed that some of our cleverest painters will
arrange their figures to please the eye, and when fairly advanced with
their work will call in an expert, to (as they call it) put in their
perspective for them, but as it does not form part of their original
composition, it involves all sorts of difficulties and vexatious
alterings and rubbings out, and even then is not always satisfactory.
For the expert may not be an artist, nor in sympathy with the picture,
hence there will be a want of unity in it; whereas the whole thing, to
be in harmony, should be the conception of one mind, and the perspective
as much a part of the composition as the figures.

If a ceiling has to be painted with figures floating or flying in the
air, or sitting high above us, then our perspective must take a
different form, and the point of sight will be above our heads instead
of on the horizon; nor can these difficulties be overcome without an
adequate knowledge of the science, which will enable us to work out for
ourselves any new problems of this kind that we may have to solve.

Then again, with a view to giving different effects or impressions in
this decorative work, we must know where to place the horizon and the
points of sight, for several of the latter are sometimes required when
dealing with large surfaces such as the painting of walls, or stage
scenery, or panoramas depicted on a