(278.) 
(279.) 
Division 
Crap. III., § 5.] 
though the perturbations of Jupiter were, as usual, 
large. 
Biela’s Comet has been ‘since recognised in 1846 
and 1852, but it was not seen in 1839. It does not 
appear to be admitted that it shows any acceleration 
due to a resisting medium. Its perihelion distance 
is, however, considerable. 
At the apparition of 1846 an extraordinary cir- 
cumstance occurred. When discovered in the end 
of the body of November 1845 it appeared round and single. 
of the co- 
met in 
1846. 
(280.) 
Other 
periodical 
comets, 
(281.) 
Great 
comets of 
1811 and 
1843. 
On the 19th December it was observed by Mr Hind 
to be elongated, and ten days later was seen in Ame- 
rica (and soon after at Cambridge and elsewhere) to 
have divided into two seemingly distinct nebulous 
parts! These continued to subsist and move inde- 
pendently throughout the remainder of the appari- 
tion: the real distance of the centres being about 
150,000 English miles. In 1852 the comet was 
rediscovered at Rome; the division into two still 
subsisting, but the interval of separation being in- 
creased about eight-fold. 
Besides the comets of Encke and Biela, there are 
several others which are suspected on good grounds 
to have periods of from 5} to 74 years, their aphelia 
all lying in tolerable proximity to the orbit of Ju- 
piter. But among these the return of only one has 
yet been verified by observation ; namely, the comet 
of Faye, which, after passing its perihelion 17th 
October 1843, returned to it 3d April 1851, within 
an hour of the time predicted by M. Leverrier. The 
motion of comets of short period seems to be inva- 
riably direct or conformable to that of the planets. 
The inclination of their orbits to the Neliptic is 
usually moderate. 
Great Comets of 1811 and 1843.—The finest 
comets of the last hundred years were those of 1811 
and 1843. The former was observed for a length of 
time altogether unusual, having been visible from 
March 1811 to August 1812. There is pretty good 
reason to think that its period is not much less than 
8000 years. The comet of 1843 was even more 
splendid, but its flight was more rapid, and it was 
not favourably seen in northern latitudes. It was 
visible at many places in broad daylight when less 
than 4° from the Sun, and at one time a tail 65° in 
length could be traced. The circumstance which 
distinguishes this comet from all others which have 
been computed is the smallness of its perihelion dis- 
tance, which was only +, of the radius of the Earth’s 
orbit, or the comet approached the Sun’s body within 
one-seventh of his radius, The solar disk then sub- 
tended an angle at the comet of 121}°, or the glare 
was equal to that of 47,000 suns as seen by us! 
The heat to which the comet was exposed is supposed 
ASTRONOMY.—MR HIND—MR LASSELL. 
859 
to have exceeded 24 times that concentrated by our 
most powerful burning-glasses by which even rock 
crystal has been fused.,? 
Mr Hinv.— Discovery of New Planets.—We have 
spoken in a former section (161), of the discovery of 
four small planets or asteroids between the orbits of 
Mars and Jupiter. They were found between the years 
1801 and 1807. An interval of nearly forty years 
elapsed without any addition to the members of our 
system. In 1845 anew asteroid, Astrea, was found 
by M. Hencke; the following year was distinguished 
by the discovery of Neptune under unparalleled cir- 
cumstances; and since 1847 every year, down to the 
present time (1855), has added to our knowledge of 
the group of asteroids. 
Among the discoverers of these planetary bodies 
Mr Hind has been distinguished by frequent success, 
under circumstances which appeared by no means 
peculiarly advantageous. This indefatigable obser- 
ver and computer commenced (I believe) his astrono- 
mical career as one of the assistants at Greenwich, 
and afterwards had the sole charge of the private ob- 
servatory of Mr Bishop, \a wealthy citizen of London, 
together with the use of a fine refractor equatoreally 
mounted, It is within the Regent’s Park, close to 
the smoke of the metropolis, that Mr Hind has dis- 
covered a larger number of planetary bodies than 
any other person living. Next to him M. de Gas- 
paris of Naples has been most successful. Unques- 
tionably the impulse towards these new discoveries 
has been given by the indefatigable industry of astro- 
nomers (principally those of Germany), in constructing 
minutely accurate star-maps. Mr Hind is also advan- 
tageously known by the discovery of several.comets, 
and by his ingenious observations in sidereal astro- 
nomy, especially on variable stars. I shall here 
give a table of the asteroids in the order of discovery 
as at present known (July 1855). 
1 Ceres 1801 Jan, 1 Piazzi. 
2 Pallas 1802 March 28 Olbers. 
3 Juno 1804 Sept. 1 Harding. 
4 Vesta 1807 March 29 Olbers. 
5 Astrea 1845 Dec. 8 Hencke. 
6 Hebe 1847 July 1 Hencke. 
7 Iris Aug. 13 Hind. 
8 Flora Oct. 18 Hind. 
9 Metis 1848 April 26 Graham. 
10 Hygeia 1849 April 12 De Gasparis. 
11. Parthenope 1850 May 11 De Gasparis, 
12 Victoria Sept. 13 Hind. 
13 Egeria Nov. 2 De Gasparis. 
14 Irene 1851 May 19 Hind. 
15 Eunomia July 29 De Gasparis. 
16 Psyche 1852 March 17 De Gasparis. 
17 Thetis April 17 Luther, 
18 Melpomene June 24 Hind. 
19 Fortuna Aug, 22 Hind. 
1 A similar phenomenon is related by Seneca. See Grant’s History of Astronomy, p. 302. 
2 See many other interesting particulars of this comet in Sir J. Herschel’s Outlines of Astronomy, arts. 589, &c. See also in- 
teresting details on the subject of comets generally in Mr Hind’s and Mr Milne’s works on comets, and in Mr Grant’s excellent 
History of Physical Astronomy. 
(282.) 
Discovery 
of new 
Planets or 
Asteroids. 
(283.) 
Mr Hind. 
M. de Gas- 
paris. 
List of the 
Asteroids, 
