rather bold in describing the case he
does as a "very common error;" and I cannot agree with him that the facade
of Sennacherib's Palace (Layard's 2nd book on _Nineveh_) is an instance of
the kind. The theory that horizontal lines in the plane of the picture
should converge to a point on the horizontal line right and left of the
visual ray, is by no means new; in truth, every line according to this view
must form the segment of a circle more or less, according to circumstances.
Apply this principle to the vertical lines of a tower or lofty building,
and every such structure must be represented diminished at the top, the
vertical lines converging to a vanishing point in the sky.

Some years since, this theory was brought forward by Mr. Parsey, and the
subject fully discussed at scientific meetings. There was much ingenuity in
the arguments employed, but the illustrations were so unsatisfactory that
the system has never gained ground. The principles of perspective are most
ably exemplified in many well-known works, as they set forth very
satisfactory modes of delineation. The limits of your periodical prevent a
fuller correspondence on this subject, or I think it would not be difficult
to {379} satisfy MR. HOARE that there are great difficulties attending his
proposition.

No recent discoveries in the art of perspective have tended to more
truthful representations than those produced by the recognised systems
usually adopted. The method of showing the internal courts, &c. of large
groups of buildings by isometrical perspective, although very useful for
developing architects' and engineers' projects, is not a system that will
bear the test of close examination.

BENJ. FERREY.

G. T. HOARE is quite right in saying "that every line above or below the
line of the horizon, though _really_ parallel to it, _apparently_
approaches it, as it is produced to the right or left." But he seems to
forget that the same holds good in the picture as in the original
landscape, the part opposite the eye being nearer to it than the margin of
the paper. To produce the same effect with _converging lines_, the drawing
must be made to assume the form of a segment of a circle, the eye being
placed in the centre.

JOHN P. STILWELL.

Dorking.

I must beg leave to differ most decidedly with MR. G. T. HOARE on this
point. If it is in accordance with the principles of perspective that,
supposing the eye and the picture in their true positions i