[ 4‘ ]
esitdfc of one only it appears clearly, that na-
ture never intended any objedt, whose diame-
ter is too large to be comprised in the space
of that circle, Ihould be surveyed closer than
that station. In fact, the internal humours of
the eye are obliged to assume a form different
from their usual one, when they wish to accom-
modate themselves to the inspedtion of objedts
introduced within this distance j which, perhaps
after all, are usually seen with one eye (the
other becoming quiescent), or at leas! be# seen
with one eye only.
A similar mode of reasoning will greatly
enforce the importance of this article to sub-
jedls not so closely approximated, but of larger
dimensions, seen direftly forward and, if we ad-
vert to subjedfs seen laterally, we shall find, that
by a bad distance the confusion of rays admit-
ted sideways into the eye is very much in-
creased, and what 4C being remote from the
center, is naturally disordered and indetermi-
nate,” now becomes insufferable.
Permit me by a familiar example to elucidate
this matter. When two persons Hand converg-
ing close together, they naturally look at each
other about the height of the eye, and conse-
quently see very little more of each other than
the face ; as is evident from the necessity, if the
conversation sliould happen to have any refer-
26. G ence