Evening capital journal. (Salem, Or.) 1888-1893, 1889-05-06
NEBULE EXPLAINED.
Instructive Information for Stu
dents Of Astronomy.
According 10 Late Researches Ncbulse Arc
Neither Very Distant Clusters Of Stars
Nor Masses Of Gas, But Merelya
Cluster Of Meteorites.

Ptolemy was the first to point out, when
he was making his map of the stars, that
there were certain CLOUDY" stars, of which
he gave five on his map, writes j. Norman
Lockyer in Harper's Magazine; and Tycho
Brahe, whose work was done before the in
vention of the telescope, although he did
not notice any bodies which we now class
as nebula, was firmly convinced that that
nebulous luminosity which we call the
Milky-Way was something entirely differ
ent in its nature from the stars He
imagined it to be what he called an ethereal
essence, sort of fire-mist, so that when in
his time, in the year 1872, new star ap-
peared, he supposed it to be considerable
agglomeration of this ethereal fluid
Calico was able to show that the Milky
Way, the ethereal substance of Tycho,
was only an appearance due to enormous
numbers of stars lying in the same visual
ray; the stars of which it is composed can
indeed be seen with very small optical
power.
1t was not till 1912, few years after the
introduction Of the telescope, that we got
the first real definition of body which we
now call a nebula. The first observation
we owe to Simon Marius, who stated that
some of the bodies visible in his telescope
e4dCUly ICoCmOlCu tuO appearance pTOuuC6u
by the flame of a candle seen through horn.
twas not till 1856 that the nebula in Orion
was discovered, although now to the trained
eye it is very easily visible, so that it seems
rather wonderful that it was. not discov-
cred before. In 1714, in England, attention
began to be paid to these bodies, but 1t was
not until the time of Sir William Herschel
that the most magnificent revelations were
made. He was the first to construct very
large telescopes, by means of which objects
which appear to the eye as excessively dim,
or objects entirely invisible to the naked
eye, may be brought in to full visibility In
this way Sir William Herschel convinced
himself of the existence of a true nebulous
fluid differing from stars.
After not only Sir William Herschel, but
his son, Sir John Herschel, had ac-
cumulated vast stores of facts, Lord
Rosse took up the story, and made
telescope very much more powerful
than any which had been employed by the
Herschels. His telescope has hght-grasp-
ing power compared with the eye of 10000.
The chief result of Lord Rosse's work to
which we need here refer is the idea that in
great many bodies which had been classed
as nebuIe this enormous increase of optical
power suggested that we were only dealing
with very distant clusters of stars.
Lord Rose was able to get the sugges-
tion of ''resolvability' in so many bodies
which had been classed as nebulae by Sir
William Herschel and others that gradually
the idea came to be held that the most neb-
ulous nebula, il we could get sufficient op-
tical power to bear upon it, would be broken
up into stars just as certainly as the Milky
Way had been by Calico.
This would mean that the hebuas were
simply clusters of stars so infinitely remote
from our ken that even with the power of
Lord Rosse's instrument they retained the
appearance of an ethereal essence.
This was the general opinion in 1864, in
the early days of spectrum analysis, when DR..
Huggins turned his spectroscope one night
to one of the planetary nebule. Al nrst
he thought that something had gone wrong
in the apparatus, because he could only see
a bright line instead Of the usual sort OF
spectrum obtained from star. Further
work on other nebulB showed him, how
ever, that the spectroscope was doing
it's level best, and that the cause the anom-
ally, was really that the nebula gave out
light, while stars gave out
light of all colors.
In some cases another line was seen, easily
proved to be due tohydrogen, and in another
planetary pnebula other observers have
since shown that there is another hydrogen
line visible
1t became DR.. Huggins' duty to find out
the origin of the first line observed, ana ne
came to the conclusion, after considerable
labor, that this line was very nearly, II not
in the position of the chief line
seen in the spectrum OF nitrogen, and the
suggestion was therefore made that these
nebulB were masses of nitrogen and hydro
gen gasses mixed, or if not nitrogen, some
of nitrogen mixed with hydro
gen. That result made the idea OF Lord
Rosse concerning the possibility OF the re-
of nebule into stars untenable.
We had to consider from that time that the
light of the nebule came from gas or
vapor, ahd hence it was held that the nebule
were masses of gas.
Another explanation OF the origin OF the
green line has already been given. If we
study the spectrum of magnesium, we dnd
a very bright fluting with it's less refrangi-
BILE edge absolutely in the position OF the
green line; in the nebulR and in cometst the
same line appears, not nearly, as in the case
of the line Of nitrogen, but absolutely. But
not only SO, We find another line OF mag
nesium also visible in the planetary nebulae
Again, in the spectrum OF magnesium burn
ing IN the Bunsen burner can be photo
graphed line having the exact wave length |
of line also seen in the nebula OF Orion,
so that there is a considerable amount OF
cumulative evidence that magnesium is the
true origin Of this spectrum, the luminosity
being produced by meteorites, the CHIEF con-
stituent of which is a. compound OF mag
nesium with oxygen, silicon and iron.
We are therefore justified, until some
better explanation has been given, in hold
ing the view that nebulR, like COMETS con
sists of meteorites, and that they are neitn-
er very distant clusters of stars nor masses
of gas.