Biographical Memoir of Sir William Herschel. 225 
the Solar Motion In the first of these memoirs, he concludes 
that the direction of the solar motion is towards a point in the 
heavens, whose right ascension is 245° 52' 30", and whose north 
polar distance is 40° 22'. In the second memoir, he concludes 
that the quantity of the solar motion is such, that by an eye 
placed at right angles to its direction, and at the distance of 
Sirius from us, the sun would be seen to describe annually an 
arch of l".l 16992 of a degree. 
In the examination of the planet Saturn, Dr Herschel had con- 
sidered it as of a spheroidal figure, but more correct observations 
had indicated to him a considerable irregularity of form, and he 
has given a detailed account of them in two papers, one pub- 
lished in the Transactions for 1805, entitled “ Observations on 
the Singular Figure of the Planet Saturn ,” and the other, in 
the same work for 1808, entitled “ An Account of a New Irregu- 
larity lately perceived in the apparent figure of the Planet Sa- 
turn” In the first of these papers, he shews that the equatorial 
diameter is 35, and the polar diameter 32, but that the diame- 
ter of the greatest curvature is 36, which falls in the latitude of 
43° 20'. In the second paper, he states that the northern polar 
regions were flattened, as formerly, but that the southern polar 
regions were more curved, or bulged outwards. The same pecu- 
liarity was observed, at Dr HerscheFs request, by the late Profes- 
sor Wilson ; but both astronomers regarded it as an illusion, and 
our author ascribed it to the position of the ring between the 
eye and the southern pole, the rays of light being supposed to 
be acted upon by the atmosphere of the ring, of which he had 
previously observed the effects. 
The subject of the construction of the heavens, which Dr 
Herschel had made entirely his own, formed the principal topic of 
all the subsequent communications of importance, which he laid 
before the Royal Society. In 1814, he published in the Trans- 
actions his “ Astronomical Observations relating to the sidereal 
part of the Heavens , and its connexion with the nebulous part” 
He supposes, in this paper, that the various nebulosities which 
fill the heavens, are condensed by attraction, and converted into 
stars ; that stars previously formed sometimes attract nebulous 
matter, and increase in size, and that neighbouring stars gra- 
dually approach each other, and constitute globular clusters. 
