The artists repository and drawing magazine: exhibiting the principles of the polite arts in their various branches (3.1789)

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and expressions, that I possibly could, and have
endeavoured to familiarize the whole : if I have
succeeded according to my^ desire, we have
done very well without abstruse terms, and hard
names j without axiom,] theorem, corol-
lary, or even CE E. D.
Now as you go home. Ladies and Gentle-
men, you will look down the first regular and
strait street you pass ; and you will observe
the planes around you : the pavement is unde-
niably the ground plane ; in that part of ano-
ther street which crostes the end of what you
are in, will be the center of the horizontal
line : and the fronts of the houses on each side
of the street, are vertical planes; which to-
gether with the ground plane, seem by their
diminution perpetually tending to the center.
1 conceive you have now, Ladies and Gen-
tlemen, the whole science and secret of Per-
spedtive in your possession whatever variations
may happen, or indeed can possibly be contriv-
ed, may be reduced ultimately to these prin-
ciples. I shall detain you but little longer,
while I notice what, perhaps, may to some
person of my auditory, at some time or other,
prove serviceable.
From the nature of the visual rays, I infer
that the misfortune of a cast in the eye,
4 arises