Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1883-09-07
THE sPECTROsCOPE.
whatItIs and How II Is Used.


There is no scientific instrument sine
the days of Calico, who invented th,
telescope, which has revealed so man.
wonders and amazed and startled til
world by its revelations, as the spectre
cope.
The discovery which led to the inven
ton of the spectroscopc was made b,
Fraunhoffer in Munich in 1926. Th
most celebrated optcian of modern times
he devoted his ,tireless energies to tn
fabrication of telescope which woul,
yield chromatic alteration, in the con
struction of an achromatic teles
cope. The object to be achieved is t,
form the lenses so as to escape the dis
persion of the rays of light by bringing
together two prisms of different kinds o
glass, with equal powers of dispersion
but with unequal refractical qualities.
1t was ascertained by series of expert
ments that the Idispersial powers of dens,
flint glass are about double that of crow
glass, while their fractional powers ar,
nearly the same. Hence it was fount
that two prisms, having two opposite dis
persions, neutralized each other, and the
rays passed through unbroken and, with.
Out hSOtiu5 tht ONC, utCoHipOsths
hotter discovered while conducting his
experiments that different substances re-
duced to a gaseous condition threw differ
ent colored lines upon n screen, each line
representing an individual element. Thus
the light of iron at white heat gave Q
dark line, potassa violet line, sodium a
yellow line, etc. and these lines are call.
ed Fraunhoffcr's lines. But the great
genius who made this wonderful discov-
ers died young, without ever dreaming OF
his invaluable gift to science.
Kirchoff, Bessel & Bunsen at once saw
the immense value of the discovery and
the spectroscope was the speedy result,
and is now in the laboratory of every
scientist.
To give an idea of the refinement of the
powers of the spectroscope and its accu-
racy in investigation Take one pound
of salt divided into 100000 parts, each
part is millegramme, which any chem
list can detect by reagents and analysis
but divide n millegramme of the salt into
3,000,0 900 parts-there is probably no
chemical test which would show the pres
ence of chloride of sodium in the infin-
itesimal subdivision of the salt, vet
take any part of this mixture, however
small, and convert it into gas, and the
spectroscope will promptly detect the
presence of sodium common salt being
the chloride of sodium).
The spectroscope is now brought into
by astronomers in daily OBJ
1t has revealed the constitu-
ton of the Philosophers and chron os-
phere of the sun in part, demonstrating
the presence of hydrogen i'll glowing
and also other elements equal
ly clear and satisfactory. These discoy-
cries produced complete revolution in
solar physics. Lockyer Of England and
Jannsen of India made these discoveries
in 1868. The spectroscope was then lii
rected to the star Sirius and to other
bright stars with marvellous and amazing
results. Sirius is at least 2O0, 900 times
as far from us rs the sun, which 1893, ,0O0,-
900 of miles away, yet the spectroscope
has shown that it possesses the same ele-
ments that have been found in the clro-
of the sun. What wonderful
achievement Of the human mind When
Leverrier discovered the planet Neptune
in 1916, it was universally regarded as
the proudest and the most brilliant dis
covery in science, and it crowned him
with imperishable laurels. But here is
an instrument which reaches far ont into
boundless space, hundreds of millions of
miles away, and with unerring fidelity
places upon the screen before you the
lines that tell of the elements entertain
ing into the composition of the distant
orb. The sun is $780, miles in diane
ter, and the star Sirius is fourteen times
larger than our .luminary, and is suppos-
ed to be the center of another system sim
liar to our own. 1t is impossible for any
one to form the vaguest idea or the re-
motest conception of the distance to the
sun, yet Sirius is 200, times as dis
tant. Thus the spectroscope revels i'll
the vast labyrinth and azure depths of the
star-gemmed heavens, jeweled with a
thousand worlds, blazing with suns be-
longing to other systems, set in diamond
dust nebule of mysterious light, studded
with luminous points and hung with
pearls dim and cleaning still more re-
mote, which battles the intrusive scrutiny
Of the most powerful telescopes. Every
star that wrinkles in its calm and spark
ling beauty is legitlmately within the do
main of spectroscopic research, and every
subject i'll nature resolvable into gas is
to yield the secrets of its COM
position to the searching inquiry of the
spectfoscope.