DOI Page / Citation link:
https://doi.org/10.11588/diglit.62828#0443
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With refpeCi to the houfcs, we fee the fecond weaker in its *
parts, and its fhadow, partly on the water and on the ground,
fainter than that of the firft. The laft houfe being at a vaft
diftance, appears as one mafs without diftinCtion of parts; and
thus objects diminifh off till they and the horizon on which they
ftand mix with the fky.
Of the refected Images of Objects on Water.
To afcertain the reflected images of objects on water is ex-
ceeding eafy, and very effential to fome pictures. It is a law in
catoptrics #, that the angle of reflection is always equal to the
angle of incidence t.
The angle of incidence and reflection may be thus under-
ftood and diftinguifhed. The inclined poft, and its fhadow on
the water, form an angle with each other; and at the bottom of
the poft, where the line of reflection on the water and the line
* Catoptrics, from xaroTrlpoy, katoptron, a mirror or looking-glafs. Catoptrics teach
the fcience of reflex vifion, and optics that of direct vifion, though in the general and ex-
tensive meaning of the term optics, “ from owlo/zai, optomai, I fee,” it includes in it
<£ whatever relates to fight, or the dodtrine of vifion;” and therefore mult imply dioptrics
alfo, which teaches the properties of refracted vifion ; that is, when rays of light pafs through
one medium into another, as air and wafer.
t See fecond axiom of Sir Ifaac Newton’s Optics.
X X 2 of
With refpeCi to the houfcs, we fee the fecond weaker in its *
parts, and its fhadow, partly on the water and on the ground,
fainter than that of the firft. The laft houfe being at a vaft
diftance, appears as one mafs without diftinCtion of parts; and
thus objects diminifh off till they and the horizon on which they
ftand mix with the fky.
Of the refected Images of Objects on Water.
To afcertain the reflected images of objects on water is ex-
ceeding eafy, and very effential to fome pictures. It is a law in
catoptrics #, that the angle of reflection is always equal to the
angle of incidence t.
The angle of incidence and reflection may be thus under-
ftood and diftinguifhed. The inclined poft, and its fhadow on
the water, form an angle with each other; and at the bottom of
the poft, where the line of reflection on the water and the line
* Catoptrics, from xaroTrlpoy, katoptron, a mirror or looking-glafs. Catoptrics teach
the fcience of reflex vifion, and optics that of direct vifion, though in the general and ex-
tensive meaning of the term optics, “ from owlo/zai, optomai, I fee,” it includes in it
<£ whatever relates to fight, or the dodtrine of vifion;” and therefore mult imply dioptrics
alfo, which teaches the properties of refracted vifion ; that is, when rays of light pafs through
one medium into another, as air and wafer.
t See fecond axiom of Sir Ifaac Newton’s Optics.
X X 2 of