New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1897-05-02

carbon for comparison with the stellar spectrum
But that WAS a laborious undertaking. Now the
astrophysicst can make his measurements OF po-
sition from a photograph at his convenience. ana
then with the aid of carefully prepared tables can
determine the significance of the lines The table
Of Professor H. A. Rowland Of Johns Hopkins
University is now almost universally accepted IN
Europe as we'll America as the standard or fel-
erence In this IN some OF the earlier lists, the
lines are designated by the wave length OF light at
the particular place they occupy in the spectrum
for II must be remembered that the undulations
which produce one color are shorter and more IRE
ouent than those which produce another. The So
called tx line" at the point Of visibility at the
violet end OF the spectrum, is situated where the
light waves have a length OF 1894 tenth meters
"A tenth meter IL ten-millionth part OF MILL
metre) But the "A line" at the other extreme or
the visible spectrum Is a wave length 1900 tenth
meters Another advantage OF photographihs
spectra Is that the record may be mace at Some
distant spot in the Southern hemisphere anu
then sent home for subsequent examination. Har-
Yard has done some famous work Of this sort al It's
are usually sent the director AT Cambridge Will Min
special scrutiny mhIf it ths home stationj
was able to discover the existence OF s,enc ~ wss
not even suspected by the astrononrrs at Areaulpa
who took the picture Mrs fiem,ng pra on ona
Owe detected an unusual type OF spectrum on one
Mate while inspecting and cataloeung a numoer
If snectra and then she instituted further invest-
ga
ora T hout Quarter OF the visible spectrum is
ranressented i'm the photographs shown here. They
he gin at the violet and reach only lnto me
blue Pit b the SIX lines are placed
one another for comparison one reason LOT apoIe'
vstonb Is Than the Yellow and red part Another
is that by cutting the spectIa on tney can n1 IA IA
III" are produced by hydrogen The one furtne s
n the left is the epsilon line or that gas ana lies
Very close to position occupied In some speGtr
is the delta line Of hydrogen and me one 10 tne
RICH, Is u sn9 as the alpha and beta lines
which however. lie too far away toward the req
end to hke is o1s Of the newly
covered lines of hsM% lines ness off IN phe ye
low Region, and not shown in any Of these photo
graphs. ...,oo,,,o, =, tho stars has been
based on their differences of hue and speeroscopic
examination shows that the distinctions mus h nno
are by no superficial Pure WI ,te o. os s
white stars usually show spectrum IKE the II, 81
In This known sSse as Gamma orions This like Vega
and sirius, shows the hydrogen lines strongly.
Alpha Cygn resembles II rather closely. ai!hougn
,,asph"droeen lines are not strong and II lacks
he heiium line and shows suggestion OF calcium
at * All OF these stars belong 10 the rsi d
Arietis the fourth in the series. also resembles
those Just mentioned al'hougn Ewes nors sur ~
difference Arcturus whose spectrum IL shown as IN
hS mich includes the yellow like sun
and Capea. These exhibit great many meta am,
lines notably those OF ron ana we Z, a"h IN -
itnss NJ calcium are broadened out so as TO be the
most conspicuous OF all Secchi finds In red stars
tendencv to exhibit broad bands shading or IN one
dirertion or the other There is hint of this sort
Of shading In the fourth picture OF our series; But
Secchi observed that In ight-re stars me edse OF
sharply dchned whereas In the dark,red stars II
,ras the other edge which was sharp. The dark-red
stars too showed broader bands than the light.red
ones Rice the northcrnmost bright star IN orion:
Uercus belong to the light-red stars. The dark
red stars are mostly very faint ores.
4 linn on
70 auspect that these differences In spectra and
color are due In a large measure to the differences