DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.18826#0121
ON PERSPECTIVE. [LECT. Ill,
LECTURE III.
IF the principles, which in the preceding Lec-
tures have been honoured with vour atten*
tion, Ladies and Gentlemen, have been fo
clearly dated as their importance deferves, I may
juftly flatter myfelf, that the remainder of our fubjeft
will be eafily difcuffed, and fully underftood; for,
when we have once acquired accurate ideas of ob-
jects as feen in perfpe&ive, and know how to re-
prefer t them juftly, and on genuine principles, we
fhall need very little exertion of genius, or of ftudy,
tp comprehend aright, the natural effects of their
Shadows, which, at this opportunity, are the fub-
jects to be inveftigated.
Shadows, are privations, or abfences, of light;
caufed by the interpofition of bodies fufficiently
denfe to prevent the paffage of luminous rays; and,
though it cannot, with exact propriety, be afTerted,
thatfhadows are the offspring of light, yet it mull
be granted, that, without light, there could be no
fliadow.
Darknefs was anterior to light, and feems more
intimately connected with this lower world; fince
fo foon as the great difpenfer, and caufe, of light,
withdraws his beams, obfcurity returns, and con-
tinues, till the activity of the folar rays again difpels
the gloom.
But,
LECTURE III.
IF the principles, which in the preceding Lec-
tures have been honoured with vour atten*
tion, Ladies and Gentlemen, have been fo
clearly dated as their importance deferves, I may
juftly flatter myfelf, that the remainder of our fubjeft
will be eafily difcuffed, and fully underftood; for,
when we have once acquired accurate ideas of ob-
jects as feen in perfpe&ive, and know how to re-
prefer t them juftly, and on genuine principles, we
fhall need very little exertion of genius, or of ftudy,
tp comprehend aright, the natural effects of their
Shadows, which, at this opportunity, are the fub-
jects to be inveftigated.
Shadows, are privations, or abfences, of light;
caufed by the interpofition of bodies fufficiently
denfe to prevent the paffage of luminous rays; and,
though it cannot, with exact propriety, be afTerted,
thatfhadows are the offspring of light, yet it mull
be granted, that, without light, there could be no
fliadow.
Darknefs was anterior to light, and feems more
intimately connected with this lower world; fince
fo foon as the great difpenfer, and caufe, of light,
withdraws his beams, obfcurity returns, and con-
tinues, till the activity of the folar rays again difpels
the gloom.
But,