New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-10-09

star clusters; and the opinion gained grouhd
that, if sufficient optical power could be applied,
all the nebulD could thus be picked to pieces.
With greater improvements in telescopes, that
opinion was not justified. Then came the
spectroscope, with its astonishing train OF dis-
coveries These, so to speak, set the nebular
bypOthesis on its legs again. The light OF the
unresolved star-n,ists was analysed, and 1t was
found TO consist of glowing gases, such as
form large component in the outer atmos-
phere of the sun. On the other hand, these
nebuous masses exhibited no metallic or min
eral substances in state of incandescence, as
10 the sun and the fixed stars. The inference,
of course, was that the mineral constituents
had not been raised to the degree OF heat
necessary to give light, because the mass was
not sufficiently condensed that we had before
our eyes matter in process of being formed
into suns with attendant planets, but as yet a
primeval fire-mist in which the gases alone
were luminous.
But some of the astronomical discoveries of
the present year threaten the nebuar hypoth-
esis quite as much az did the earlier observa-
tons of Lord Roses telescope, while the re-
cent testimony OF the spectrosc0pe throws
doubt over the differences that were so service
able in supporting the great theory. To begin
with, it has always been accounted one OF the
strongest points in the argument, that all the
members of the solar system moved in the
same direction around the sun, or, in the case
of satellites, around their primaries; direction
which is also that of the rotation OF the sun
and planets. The chances against such uni
formity being accidental, are so many to one,
a. a. G 1liah
the proportion would be wearisome to the eye.
For while, however there was doubt as to
this uniformity in respect to the satellites of
Uranus. But closer observation showed that
those satelitessthough retrOgrade rs to the ecip-
tic, were direct as to the equator. To explain
this, it ought to be stated that their orbit is so
far out of the usual plane of the planetary
orbits as to be nearly at a right angle thereto.
The new difficulty is with the satellite of Nep-
tune. Professor Newcombs recent tables show
that it's motion is decidedly retrograde, both as
to equator and elliptic The fact is not at all
fatal to the nebular hypothesis, but it is GER
tany not favorable
The next of the recent objections lin the
order of time) is the strange aspect of the new
star in Cygnus, when latterly viewed through
the spectrOscOpe. When that star was first OBJ
served several months ago, it was exceedingly
brilliant. Its spectrum was like that OF some or
the fixed stars, and it was supposed to be one
of them that had been rapidly formed by the
condensation of its materials, causing 1T sud
denly to blaze out where all before had been
darkness. Here, then, was probably the quick
formation of sun from a previously invisi-
BILE nebula. But the new star soon began to
lose its light it is growing fainter, week by
week Now it can be shown by calculation
that if star of the size of our sun were sud-
denly heated to incandescence, it would take
several million years to COOL Therefore, this,
which appeared ike one of the fixed stars
when first observed with the spectroscOpe,
could scarcely have been one At present,
when it is fading, its light is again examined,
and strange to say. it has entirely the appear
ance Of being a planetary nebula. To meet
the expectations o. the friends of the great
theory, this apparitiOn ought to have begun as
n nebula and ended as a fixed star; it has
done precisely the reverse. True, Professor
Lockyer says, the nebular hypothesis,
:" in its grandeur and simplicity, remains
untouched by these observations :" but it
is not easy yet to bring the facts into line with
the theory.
Last, and more formidable than the rest
of these troublesome discoveries. come Pro-
fessor Asaph Halls new pets. the sat
elites of Mars of which the inner one
goes around that planet in seven hours
and thirty-eight minutes, while the plan
cts own rotation on its axis requires
more than thrice that length of time. Mani
fcsty, if the satellite was originally left
ont in the cold while Mars was cooling and
contracting into shape, the speed of that little
moon, in it's orbit, should have been less, not
more, than that of the rotation of the interior
mass which ultimately became the planet.
Professor Kirkwood says that something SINH
lar has been observed as to the interior ring of
Saturn-the third ring, with which sstrono
mers have only become acquainted in recent
years. 1t il suggested that the extra speed of
the Martial satellite may be explained by sup
posing that, when it was part of a rebulOus
ring il struck against some other portions OF
the ring, or was struck by them, 40 that it |
gained velocity at their expense. The pieces
that were thus knocked out of time would fall
inward, perhaps on the surface of Mars. Pro-
fcssor KirkwQod thinks that such a process is
taking place in Saturns rings. He adds these
WOTuS. OultSS ooiiC SuOn CADit'hbtoh 40 WHO
"can be given, the short period of the inner
satellite will doubtless be regarded as a con-
"clusive argument against the nebular hypoth
"ess.r Such words are the more startling,
since they come from mathematician and as
tronomer who has done good service for the
nebuar theory, by showing, among other
things, that the distribution of the groups of
asteroids ia in strict and remarkable accord