We have received, at the last moment before making up for press, the
following letter from Sir John Herschel,[793] {384} in reference to the
matter referred to in the communication from Mr. Hind[794] given below:
"Collingwood, Oct. 1.
"In my address to the British Association assembled at Southampton, on the
occasion of my resigning the chair to Sir R. Murchison,[795] I stated,
among the remarkable astronomical events of the last twelvemonth, that it
had added a new planet to our list,--adding, 'it has done more,--it has
given us the probable prospect of the discovery of another. We see it as
Columbus saw America from the shores of Spain. Its movements have been
felt, trembling along the far-reaching line of our analysis, with a
certainty hardly inferior to that of ocular demonstration.'--These
expressions are not reported in any of the papers which profess to give an
account of the proceedings, but I appeal to all present whether they were
not used.
"Give me leave to state my reasons for this confidence; and, in so doing,
to call attention to some facts which deserve to be put on record in the
history of this noble discovery. On July 12, 1842, the late illustrious
astronomer, Bessel,[796] honored me with a visit at my present residence.
On the evening of that day, conversing on the great work of the planetary
reductions undertaken by the Astronomer Royal[797]--then in progress, and
since published,[798]--M. Bessel remarked that the motions of Uranus, as he
had satisfied {385} himself by careful examination of the recorded
observations, could not be accounted for by the perturbations of the known
planets; and that the deviations far exceeded any possible limits of error
of observation. In reply to the question, Whether the deviations in
question might not be due to the action of an unknown planet?--he stated
that he considered it highly probable that such was the case,--being
systematic, and such as might be produced by an exterior planet. I then
inquired whether he had attempted, from the indications afforded by these
perturbations, to discover the position of the unknown body,--in order that
'a hue and cry' might be raised for it. From his reply, the words of which
I do not call to mind, I collected that he had not then gone into that
inquiry; but proposed to do so, having now completed certain works which
had occupied too much of his time. And, accordingly, in a letter which I
received from him after his return to Koenigsberg, dated November 14, 1842,
he says,--'In reference to our conversation at Collingwood, I _announce_ to
you (_melde_ ich Ihnen) that Uranus is not forgotten.' Doubtless,
therefore, among his papers will be found some researches on the subject.
"The remarkable calculations of M. Le Verrier--which have pointed out, as
now appears, nearly the true situation of the new planet, by resolving the
inverse problem of the perturbations--if uncorroborated by repetition of
the numerical calculations by another hand, or by independent investigation
from another quarter, would hardly justify so strong an assurance as that
conveyed by my expressions above alluded to. But it was known to me, at
that time, (I will take the liberty to cite the Astronomer Royal as my
authority) that a similar investigation had been independently entered
into, and a conclusion as to the situation of the new planet very nearly
coincident with M. Le Verrier's arrived at (in entire ignorance of his
conclusions), by a young Cambridge mathematician, Mr. Adams;[799]--who
will, I hope, {386} pardon this mention of his name (the matter being one
of great historical moment),--and who will, doubtless, in his own good time
and manner, place his calculations before the public.
"J. F. W. HERSCHEL."
_Discovery of Le Verrier's Planet._
Mr. Hind announces to the _Times_ that he has received a letter from Dr.
Bruennow, of the Royal Observatory at Berlin, giving the very important
information that Le Verrier's planet was found by M. Galle, on the night of
September 23. "In announcing this grand discovery," he says, "I think it
better to copy Dr. Bruennow's[800] letter."
"Berlin, Sept. 25.
"My dear Sir--M. Le Verrier's planet was discovered here the 23d of
September, by M. Galle.[801] It is a star of the 8th magnitude, but with a
diameter of two or three seconds. Here are its places:
h. m. s. R. A. Declination.
Sept. 23, 12 0 14.6 M.T. 328 deg. 19' 16.0" -13 deg. 24' 8.2"
Sept. 24, 8 54 40.9 M.T. 328 deg. 18' 14.3" -13 deg. 24' 29.7"
The planet is now retrograde, its motion amounting daily to four seconds of
time.
"Yours most respectfully, BRUeNNOW."
"This discovery," Mr. Hind says, "may be justly considered one of the
greatest triumphs of theoretical astronomy;" and he adds, in a postscript,
that the planet was observed at Mr. Bishop's[802] Observatory, in the
Regent's Park, {387} on Wednesday night, notwithstanding the moonlight and
hazy sky. "It appears bright," he says, "and with a power of 320 I can see
the disc. The following position is the result of instrumental comparisons
with 33 Aquarii:
Sept. 30, at 8h. 16m. 21s. Greenwich mean time--
Right ascension of planet 21h. 52m. 47.15s.
South declination 13 deg. 27' 20"."