El Paso herald. (El Paso, Tex.) 1901-1931, 1911-11-25
By Prof. David TOdd.

BY Prof. David Todd.
Director Amherst College Observatory
n VEN 40 years ago. when astrOu-
omers were busy with the
probleus Of the old astronomy
which tells where the heavenly bodies
are. it was quite usual for them TO
speak slightingly OF the devotees OF
astrophysics, or tie new astronomy
which tells what these bodies are.
since then, however, the speeuoscope
has completely rev u.lolll@e0 49,
outlook upon the universe htsIs
large observatory has become a pay
steal laboratory as Wei, ana 1ut4y mai
the work Of astronomers TO-DAY appef-
tains to the spectropscope- rms pow
srful instrument OF research mas IN
vaded the especial field NO1 precise as
trOnomy, ascerua1ning anew the az
lance OF the sun; and II has not only
verified the drift OF the solar sys-
tenn I,vra-ward but told US the speed
(something over u miles per seconQ3
Of our own jOurneying thltheri while
its latest achievement. unoer the ustt
manipulation OF Campbell (1s62- },
has By Joining hands with the old as
tronomv. assigned 80 light years as
the average distance OF hundreds OF
stars.
the prismatic cOloTS OF sunlight trans
mitted through glass; but the Ilrst
close observer was sir Isaac New
ton. who, by passing rouno,
slender beam through prism, not only
bent Cor refracted) it from It's OIL
ginal course but expanded cor as
DersedO it into band or rtDDOn OF
multi-colOred light, which he named
a sDectrum. Violet. indigo, blue, green,
yellow. orange, Ted-these were the
simple cOlOrs, each blending into us
neighbor. FraunhOfer ill6l-l626)s by
sending the sunbeam through mar
ca1 sraa q q
the spectrum crossed here ana Inere
by fine dark lines, whose poslIlon ne
first mapped in the suns spectrum
but the riddle Of these lines Inelr
number and position was unsOlVed TIL
Kirchoff (1824-S), the first 10 rormu-
late the principles Of spectrum ana1y 70
sis in 1858, and who may, there1Qre5
be called the inventor OF the spectre
scope
These principles are that ID glow
ing gases under high pressure, lqulos
and solids. yield a thoroughly blended
or continuous spectrum, Cd low pres
sure gases Weld q discCntnuOus spec
trum, that is, one crossed by bright
lines Indicating what substance the
vaDors come from. and 80 any gas
through which white light shines
ouenches its radiatiOns (and therefore
makes dark lines), In exactly the POSI-
ton in the spectrum where It's own
bright lines are. Every line Of the
thousands in the suns spectrum It's
shade its position, its intensity, is
highly significant in spectrum analy-
ciples are the key that unlocks the
secrets Of solar and stellar cOnsIlIu-
ffon So we know there are iron, cali
cfum hydrogen, nickel, sodium ana
dozens OF othef elStsS- 81 s 49, - -
the sun. Draper tiS5f-6z) round oAy-
gen also. The moon ana an lne pan
efs shining only by sunlight yield the
same spectrum, though greatly en-
The spectroseOpe.
T,oclver 1886 and Jansen
dS2s-1s07) first showed how to see
the suns hydrogen protuperances py
the spectroscope without an eclipse.
Young C1S34-190S) first photographed
a prominence, and he observed one
eruptinE to an extreme height or 4vg'-
900 miles. Also he first observed the
suns reversing or absorption layer;
and Hale il86S- ana DesIaHdres
G853- ) by inventing and applying
the speCtrOheliOg graph, are enaDIed 10
photograph the prOminences and Iacu-
lac or Whitish spots on any cloudless
day Also Hale has proved the dis
tributfon of iron and calcium cloud cts
or fIoccuH all over the sun, and has
demonstrated that sun spots often eI-
hfbit a magnetic field. His design of
q huge spectrOscOpe in connection with
a tower telescope 100 feet high at
Mount Wilson, California, affords un-
surpassed facilities. For solar WORK
the spectrum is formed by reflection
from a finely ruled glass or metal
lie grating. often called a attraction
spectroscOpe. Beyond the red Of the
visible spectrum is the invisible or
heat spectrum, which Langley (lS34-
1900 was the first to investigate
with his spectre bOlOmeter, using lens
IS and prims OF rOcksalt.
The Violet Light
Doppler (1803-53 proved that If a
source Of light were moving swiftly
toward us. the lines in its spectrum
would shift toward the violet; if trav-
cling away. toward the red. So the
suns speed Of axial rotation in diff
ferent solar ATTITUDES has been found:
likewise its gaseous constitution is
demonstrated; because the higher the