The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1901-12-01


long result of time" there had been already |
many discovery melting minds hardened |
by fact or duled by tradition 10 renew |
their youth and revisit its wonderland. in |
the domain of the oldest Of the sciences |
the Hersches, father, sister and son, had /
swept the heavens with the telescope re- |
solving a cloudlike cluster ;nto what Will |
liam Herschel described as "a shining fluid |
of nature totally unknown to u.s." But
in thus confessng Ignorance he, unlike |
Auguste Comte, put no limits to the field of
possible knowledge. In 1856 the French |
philosopher declared that the distances of
the stars could never be measured and that
the matter of which they" composed
could never be known. Three years after
this prophecy Bessel, then dir ector of the
observatory at konigsberg,; measured the
distance of a star in the constellation of the
Swan, numbered 81 Cygni, which was
chosen by him in virtue of its large proper
motion. that is, its real as opposed TO its
apparent motion. He found that this star
is about 100000 times the distance of the
sun, and therefore that it's light, travelling
at the rate of $4,000 miles per second of
time, takes rather more than six years
to reach US. Up TO the present the "paraI-
lax" or distance of some fifty stars has
| been approximately ascertained, the nearest
known example being Alpha Centauri, the
light from which takes about four years to !
| reach us. In 1865, the year of the great
plague in London, Newton then in retire
ment at Woolsthorpe, formulated the theory
| of gravitation, the teaching of which more
| than a century afterwards was prohibited
| by the University of Salamanca as dis
| cordant with revealed religion. But the
| movements of thought, like those of the
| stars in their courses, cannot be arrested,
| and the observations of Bessel and his sue
| cessors increased the volume of evidence
| proving that if gravtation operates any
| where 1t operates everywhere, the remotest
| star and the stone that falls to the ground
when hurled being alike within the uni
| versal order. The browning triumph OF
| Newton's discovery was effected three years
after "Locksey Hail. was published, when
certain irregularities in the movements Of
Uranus led two astronomers, Adams in
England and Leverrier in France, to esti-
mate the place of the disturbing body.
Hence the discovery of the planet Neptune.
A MODERN MIRACLE.
Only few years were to elapse after this
memorable success before Comte's second
prophecy, that the matter OF which the sun
and stars are built up can never be known,
was to be refuted. Newton had discovered
that when a ray of sunlight is refracted,
or broken upon prism, it is resolved into
different colors, red, which is the least re-
fracted, being at one end. and violet, which
is the most refracted, being at the other
end of the spectrum" or appearance"
The colors between these two are orange,
yellow, green, blue and indigo, each one
passing into the other by insensible grada-
tions. Newton conceived light to be due to
the emission of luminous particles which
affected the eye and caused the sensation
of vision. This ''corpuscuar'' theory, as it
is called, was displaced in the beginning of
the ninteenth century by the ''undulatory'
or wave theory, which explains light as
due to energy radiated from luminous
bodies through the ethereal medium which
fills all space and interspace. Each color
has it's own wave length of refrangibility
and speed The wave-lengths vary between
about thirty-two millonths of an inch
which is the measurement of the extreme
red, to observation-disclosures of an inch,
which is the measurement of the extreme
violet. Their speed equally defies grasp by
the imagination, ranging from twenty bill
lions to four hundred billions per second
But as the shorter waves, so to speak take
quicker steps than the longer waves, they
all arrive together, combining to affect the
eye as white light.
AS observed by Newton, the suns spec
trum appeared to be an unbroken band of
colors, and it was not until $50 years after
his observations published that VOL
laston, an eminent chemist. noticed seven
dark lines or gaps appearing at intervals
marking the boundaries between the seven
colors. But in 1914, Fraunhofer, a German
optician, using improved apparatus, ex-
amined the spectrum more infinitely, and
detected the presence of no less than SIC
dark lines; the position of more than one
half of which he mapped out, naming the
few very conspicuous among them after
the letters A to H. These are known as
''Fraunhofer's lines" but such is the
enormous number discovered since his day,
that their wave-lengths are now expressed
in figures 1t was Fraunhofer's fate to die
without having determined their signifi-
canoe, and the secret of the stars lay hid
den for another generation. The year 1859 is
forever memorable in the history of science
through the publication of Darwin's
Origin of Species" the far-reaching in
+. / o.
cerned by the many. That year has further
distinction through Kirchhoff's discovery
Of the meaning of the dark, and also the
light lines of spectra both in terrestrial ele-
lyments and in the light-waves from sun.
star nebula and comet. For, in the sew
eral attempts 70 interpret these lines, ex-
periments were made by passing light
through various colored substances, when
both classes of lines were produced
Kirchof proved that every element in an
incandescent state gives out rays, or, as
; they appear in its spectrum, lines peculiar
to itself and when these rays pass through
a gaseous substance of lower temperature,
they are absorbed by their fellow element.
1t is as If we sounded a note near piano
when, as is we'll known the piano at
once responds with the same note. Now,
by watching these absorbed dark lines, the
relative positions of which to one another
are constant with the bright lines of ter
, restrial elements, burnt, let us say, in the
electric arc, so as to insure the highest
state Of incandescence, the positions of the
, dark and light lines are found to be coinci-
dent For example, the lines caused by