National Republican., 1876-11-09

q planet. The evidence on this point is pos.-
tive. Senior Ventosa, of the Observatory at
Madrid, has written two letters describing his
own studies of the suns surface at the time
named by Herr Weber. A small sun spot-de-
termined as such by characteristics beyond
doubt-was seen at Madrid just where (on the
disc of the sun) Herr Weber thought he
deserted planet. A similar view of o sun
spot was obtained at the Royal Observatory at
Greenwich. Sir George B. Airy, in note
published IN Nature, gives full details OF the
Greenwich observations Of April 4, which in
clude two photographs Of the suspicious OBJ
ject, and he says there can be no question that
it was sun spot, not planet
Now this particular observation at Peckeloh
was the one which seemed especially to arouse
the activity of II. Le Verrier. He evidently
regarded It as confirming his own inferences
concerning an inner plsnet-inferences drawn
from the irregularities Of the orbit of Mer-
curry. He, announced this supposed observa-
tion several months after its dstes giving 1t In
direct connection with calculations concerning
this matter, and with his request to distant
astronomers to keep lookout for the planet
on certain DAYS in October. It Is true that NJ.
Le Verrier has taken pains to disclaim
any prediction that Vulcan would be found
on the sun at any of the dates when he
asked for special observations. But on the
other hand he has declared that there must
be an intra-M -Mercurial body; that the analysis
which he has made of the adjoining orbit
"puts US heneeforth In possession Of data to
find the planet He has again selected sew
eral of the alleged transit observations, and
from Eve of them which he regards as authen-
tic he calculates an orbit for Vulcan Of little
over thirty three days. Some of our readers
may recollect that the orbit for this mythical
planet calculated BY Prof. Krkwood and pub
1E-la l.. ~. aF Ax,~f rro-a
nearly thirty five days for the revolution.
Professor Pliny z. Chase has brought forward
an harmonic series for the orbits of the solar
system. This he deduces from mathematical
data; the assumption being that the planets
were originally formed from meteoric rings.
By such means he finds place for Vulcan In
the series; curiously enough giving an orbit
which Is Just between the estimate of NJ. LIE
Verrier and that of Professor Kirkwood.
In his most recent communications to the
French Academy, NJ. LIE Yerrier gives reasons
for believing that the opportunities for seeing
Vulcan on the sun must Of necessity be rare.
He assigns as the next favorable occasion
March %, 1877. After this the nearest chances
will be In the fall of 1851 and the spring of
1885. In the interim the planet must be
looked for near the sun, but not on IL. With
present means of investigation the question
whether there is or is not such planet should
not long remain open. The practice of taking
photographs Of the sun regularly, day by day,
at different obseryatcries, will add materially
to the means for assigning their true value to
the spparitions of Vulcan in the future. DR..
Jansen, the distinguished French astronomer,
thinks photographs are more to be depended
upon for this purpose than eye OBJ
servations; but that if the latter are made
with sufficient care and attention to detail,
sun-spot will never again be mistaken for a
planet. OF course, the apparatus for taking
photographs of the sun could easily be made
automatic so that they would be obtained
continuously at regular intervals on fair days.
There are new appliances by which the sky
close to the sun could also be photographed
separately from the luminous disk. If such
pictures were delicate enough, they would be
more trustworthy than the more direct modes
of vision. 1t only remains to organize such
system throughout the observatories of the
world. This would soon settle the matter.
As It now stands, the discrepancies of obser-
yation cannot be wholly accounted for, un-
less we suppose that Vulcan has. the ring of
Gyges and can be at times invisible to mortal
eyes -...- 90 o. 'E1g - ~. EEss1a