The Sun.
London, England, 1861-07-15 00:00:00

The close agreement of these elements with the
observed path of the comet up to this date proves
that its period of revolution must be one of consi-
derable length, though any attempt to determine
its duration at present -would be fruitless. Whether
we shall ever ascertain it with any degree of cer-
tainty will depend upon the time the comet can be
observed, and upon the amount of deviation from
parabolic motion which the later observations may
indicate. The small differences so far remarked
between the true and calculated places of the
nucleus are probably due to the earth's attraction
upon it, which will have slightly affected its geo-
centric position from day to day, particularly in the
early part of the month.
The following ephemeris will represent the track
of the comet during the ensuing fortnight, by the
expiration of which time its increasing distance
from us will most likely have carried it to the limit
of naked eye vision
AT GIMENWICII—MIDNIGHT.
Right North Distance from
Ascension. Declination. the Earth in
h. m. s. Deg. Alin. Miles.
July 12 .. 14 643 .. 57 5 37,800,000
13 .. 14 13 27 5G 10 ..
",
14 .. .. 14 19 7 55 20 .. 43,000,000
15 .. 14 23 55 .. 54 33
„ 16 14 28 6 .. 53 54 ..; 43,200,0,,0
17 .. 14 31 45 53 17
18 .. 14 34 58 .. 52 44 .. 53,400,000
„ 20 .. 14 40 26 .. 51 44 .. 58,600,000
„ 21 .. .. 14 42 4G 51 18
„ 19 .. 14 37 50 52 13

~ 22..
„ 23 ..
„ 24 ..
„ 25 ..

H 44 55 .. 50 53 63,700,000
.. 14 46 54 .. 50 30
14 48 44 .. 50 9 .. 68,800,000
.. 14 50 28 .. 49 49 ..

26 .. 14 52 5 49 30 .. 73,900;000 •
„ 27 .. 14 53 36 .. 49 12 ..
„ 28 .. .. 14 55 4 .. 4S 55 .. 78,900,000
The intensity of light this evening will be barely
1-10th of that on the 30th of, June, while on the
28th inst. it will be reduced to 1-60th.

Independently of a general prevalence of unfa-,
vourable weather in the last days of June, the
sudden appdarance of the comet in Europe is fully
accounted for by the course it was then following
among the stars. Its places calculated from the
above orbit would be at midnight, on June 27, right
ascension sh. 21m.; north declination, 15 deg. 8
min. ; on June 28, right ascension, sh. 40m. ; north
declination, 25 deg. 13 min. ; on June 29, right as-
cension, 6h. 6m. ; north declination, 36 deg. 11 min.
On the 27th it therefore set long before the sun;
it rose after him on the 28th, and again set before
him by three quarters of an hour or upwards is the
latitude of London. On the morning of the 29th
it would be above the horizon at daybreak, and
might possibly have been discovered so far as its
position was concerned, though clouds appear to
have prevented its being detected until the evening
of the same day, when it was remarked in several
places a few degrees above the N.N.W. horizon.
Since this date, on account of its increasing declina-
tion, it has never set, nor can it do so for at least a
month from the present time.
The circumstances attending the comet's appear-
ance at this return to perihelion are as favourable
as possible for the exhibition of its brilliancy ; had
the event occurred in December or January it would
probably have passed through these parts of space
unobserved from the earth.

By measures taken here on the night of the 11th,
the principal dimensions of the comet were as sub-
joined :

Miles.
Breadth of the cometic nebulosity at the nucleus 150,000
Depth from preceding edge to nucleus
Diameter of the nucleus

Length of the tail

It is still a beautiful object in the telescope, the
more condensed part shining with a pale yellow
light, and the luminous sector thrown out towards
the sun being yet discernible, though with a very
indefinite outline. A bright streamer proceeded
from the nucleus on the Bth inst., some distance up
the tail, quite changing its previous aspect ; it has
since faded away leaving the more usual dark or
hollow appearance in the centre..
I am, Sir, your obedient servant,
J. R. HIND.
Mr. Bishop's Observatory, Regent's Park,
Saturday.

The following are the elements of the new comet,
as calculated at Naples by the Director of the Ob-
servatory, M. Capocci. They differ in some respects
from those of Mr. Hind : Passage through the
perihelion, June, 4.719; longitude of perihelion,
231 deg. 46 min. 8 sec. ; longitude of ascending
node, 278 deg. 53 min. 24 sec.; inclination of the
orbit, 85 deg. 26 min. 30 sec. Perihelion distance,
0.71891. Motion, direct. M. Capocci adds that the
above elements bear a certain analogy to those of
the fine comets of 1684, 1742, 1807, and 1819; and
that the differences existing between these and the
present one may perhaps disappear when a helio-
centric arc shall have been obtained, of sufficient
length to ensure the greatest precision in the cal-
culation of the orbit. M. Donati, of Florence, it
will be remembered, has already adverted to the
similarity of the orbits of this comet and that of
1807.