Orleans County monitor. [volume] (Barton, Vt.) 1872-1953, 1875-03-22
From thu Vermont Journal
HEAT AND LIGHT.

lalhlIldr pneHoHiehd WIN WHICH my read
ers are acquainted. aud yet how few,
comparatively, understand the philoso-
ply aud chemistry of the sunbeam. The
old Ncwtonian theory Of heat and light
made them material particles emanatiug
from the sun. darting out into space like
shot from the gun; but this theory has
been discarded, and one more sensible
accepted III its place.
As now understood, the phenomena of
heat and light result from successive
waves OF luminous ether starting from
the sun and striking upon the organs of
sense. as the vibrations of air strike up
on the ear. To illustrate. drop a pcbble
into the water. and a number OF wave
lets will spread themselves in concentric
circles; drop another pebble. and the
wavelets of the one will cross the wave
lets of the other, and if it 50 happens
that the crest of one wave occupies the
trough of the other, all motion ceases
and the water becomes still but if the
crest of the one rides over the crest of
the other, the wave is increased to dou-
bic its former height Just so it is with
sound. Let two waves of air be sent
ont Of two ,,,,s;a,l ;,,.+,.,,~,u,4 :. II
a way that the crest of the one fits into
the trough of the other, and perfect ST.
lence is produced ; but if crest sweep
over crest, the sound is increased in loud
ness. So with light and heat; when one
wave of light interferes with another,
there is darkness otherwise, the light
Is increased and perpetuated When one
wave of heat interferes with another
there is cold; if wave succeeds wave in
the natural order, the heat is intensified.
Heat, light and sound are. then, all
transmitted through space in waves, and
are impressed upon our senses by vibra.
tlons and they all are said to have We
locity. Sound travels LOO feet per
second but in the time that sound ac-
complishes journey of one foot, light
and heat have travelled a distance of
seventeen miles. Hence, light travels
at the rate of l85, 900 miles per second.
Light is the source Of color. and the vi
brations of different breadth and rapidi-
ty produce the seven colors as seen in
the rainbow. or the solar spectrum The
light that comes from the sun is white.
and is composed of violet, blue green,
yellow, orange and red. and in this or
der, according to their refrangibility and
rapidity of vibration
When these colors are all reblended,
white is again produced if all are alb
sorbed by any substance, black is the
result. Hence white is all colors, and
black is no color at all. The different
objects around US are of different colors
simply because they have different
power to absorb and reflect the different
colors that fall upon them. Grass is
green, as it appears to the eye, because
that particular substance absorbs all the
cOlors but this one So it is with all
the tints that meet the eye gazing upon
flower garden. In the dark everybody
alike is entirely destitute of color.
The noh-luminous rays of the sun, as
well as the luminous, produce heat.
There are also chemical rays, and each
is found connected with its own color.
The heat is most apparent at the red
end Of the ray; light Is the most intense
in the yellow, and the chemical. or de.
composing rays, are at the violet end.
And how useful and important are these
little vibrations in the physical econO-
my. Highly important Offices have been
assigned them. They print our photo
graphs build up the woody fibre of the
forests; paint the flowers elaborate the
juices which nourish the vegetable world,
and give life and animation to man and
beast. Heat is sometimes latent and
sometimes sensible, but it is ever ready
to perform its part as one of the repro
ductiYe forces of natnre Rrr,