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CHAPTER II.
Optics or Vision -At what Distance Objects appear largest -Axis
of Vision -Quantity or Field of Vision- Ground apparently
altered by Situation ofthe Spectator- Reections from the Sur-
face of Water explained and applied- Different Eflects of
Light on different Objects- Example.
LANDSCAPE GARDEMING being connected with optics or vision,
or rather with the. application of their rules to practical improve-
ment, it may not be :improper to devote a chapter to the follow-
ing observations.
I There is-a certain point of distance from whence every ob-
ject appears at its greatest magnitude.  This subject was origi-
nally discussed in consequence of observing that a particular
rock at PORT ELIOT appeared higher or lower, at different dis-
tances. The inquiry into the cause of this difference led m6
to propose a question to several ingenious friends.
Query, At what distance does any object appear at its greatest
height?
'The general optical distinction of the magnitude of objects,
is into ,real and apparent; the real being what its name imports,
and the apparent not that which may ultimately result to the
mind, but that which is immediately impressed on the eye.
This is measured by a plain and certain rule, namely, the angle
which is formed. at the eye by lines drawn from the extremities