[ i°4 ]
even some of our own streets, would be near-
ly invisible at their further ends. Neither, in
my opinion, are they always so evanescent; for
not only in dimensions, but also in effetft,
many objedts evade the rules of geometry, as
it does not always happen that their force de-
creasesaccording to their geometrical distances,
but, by a variety of accidents, arising from the
vivacity of the light, or from the rarity or den-
sity of the circumambient air, they vary consi-
derably from their prescribed essedts. Nor
indeed is perspective itself infallible here; for,
is you suppose yourselves. Ladies and Gentle-
men, to have taken the most accurate view (of
a distant town for instance) while the sun has
been obscured by clouds, should they be sud-
denly dissipated, and the sun shine full on that
particular spot, it would scarce seem the same
place it did before: or, some gilded weathercock,
just moved by a little shift of wind, may gleam
irregularity into the keeping of the piece. I have
osten noticed housesat a distance, perhaps bare-
ly sufficient to distinguish them, when suddenly,
by the parting of the clouds, the sun-beams have
been reftedted with great splendor, from windows
which besore were imperceptible. This often
happens in the evening, to houses built on hills,
and