For some time back I have felt the want, among Students of Drawing, of a
written code of accurate Perspective Law; the modes of construction in
common use being various, and, for some problems, insufficient. It would
have been desirable to draw up such a code in popular language, so as to
do away with the most repulsive difficulties of the subject; but finding
this popularization would be impossible, without elaborate figures and
long explanations, such as I had no leisure to prepare, I have arranged
the necessary rules in a short mathematical form, which any schoolboy
may read through in a few days, after he has mastered the first three
and the sixth books of Euclid.
Some awkward compromises have been admitted between the first-attempted
popular explanation, and the severer arrangement, involving irregular
lettering and redundant phraseology; but I cannot for the present do
more, and leave the book therefore to its trial, hoping that, if it be
found by masters of schools to answer its purpose, I may hereafter bring
it into better form.[1]
An account of practical methods, sufficient for general purposes of
sketching, might indeed have been set down in much less space: but if
the student reads the following pages carefully, he will not only find
himself able, on occasion, to solve perspective problems of a complexity
greater than the ordinary rules will reach, but obtain a clue to many
important laws of pictorial effect, no less than of outline. The subject
thus examined becomes, at least to my mind, very curious and
interesting; but, for students who are unable or unwilling to take it up
in this abstract form, I believe good help will be soon furnished, in a
series of illustrations of practical perspective now in preparation by
Mr. Le Vengeur. I have not seen this essay in an advanced state, but the
illustrations shown to me were very clear and good; and, as the author
has devoted much thought to their arrangement, I hope that his work will
be precisely what is wanted by the general learner.
Students wishing to pursue the subject into its more extended branches
will find, I believe, Cloquet’s treatise the best hitherto published.[2]
[1] Some irregularities of arrangement have been admitted merely for
the sake of convenient reference; the eighth problem, for
instance, ought to have been given as a case of the seventh, but
is separately enunciated on account of its importance.
Several constructions, which ought to have been given as problems,
are on the contrary given as corollaries, in order to keep the
more directly connected problems in closer sequence; thus the
construction of rectangles and polygons in vertical planes would
appear by the Table of Contents to have been omitted, being given
in the corollary to Problem IX.
[2] Nouveau Traité Élémentaire de Perspective. Bachelier, 1823.