An introduction to astronomy: designed as a text-book for the use of students in college. By Denison Olmsted ...

U1RANU 8 —-NPTUNWl. 21 1.
to astronomers of other countries, the planet was called Nl1rschel
il A.lcricra, after tihe name of tile discovllerer, and U/'afwnS'* oni
the continenlt of lri'1l0op, whlich last appellation is now unlivcrsally adopted. Thle diametel of'Uranusl is altout 35,000
milels, alid consequently its volume more than 80 times that of
thle cart,1.l Its revolution around the sun occupies nearly ISt:
years, so that its position among the stars vlaries but little fior
severatl yetars in successiot, since it s]hifts its l)lace only a little
more1 tlhan four dleglrccs in a year, and of colurlsewould remtai
in the same sign of tie Zodiac seven years. Its pathll lies veiry
ntar the ecliptic, being inclined to it, less than 00 47'.'Th: e sun
himself, wh'en 1 seen from Uralius, (\winlles almost to a star,
subttending, as it (oes, aln angle of onlly' 40"; so thaitt tlhe
surfac of the sunll would appeal there nearly 400 times less
than it does to us.
3;50. The n'daellites of Uranus are exceedingly liniute cbjects, and viSible only to tle most powcirftul telescopes. Althloulgh Sir Willialn 1eIrschell assigned si:e satellites to thlis
planet, yet onlly two of tfhe lnunl)le (the secoItnd and foubrthl ilt
the order of dcistances) hlave, until quite recenltly, been seeen by)
otherl astrlonolners. \Two othllers have of late been added, and
all increasing confidence is be gilding, to be felt tlhat th]e cntire
lnutmbe announced by Helschel Nwill be identified. The o-rbits
of th.lese satellites, says Sir J'ohll e I sehhelcl, ofier r1mcarkalble,
and inldeed quite unexi)eCtel land unexamnled peculiarities.
Contrary to the unbrolken analogy of tlhe whlole p1latiet ary
System, whether of primlaries or secondaries, the planes of their
orbits atre nearly.eilqealdiculal tlo Ite ec/iptic, becin:g inclined
no less tlhan 78~ 58': to that plane, and in tlheso orbits their
motions aroe retrograde. Instead of atClvaneing, fiom )l:est to
east, as is the case with every othler plalnet and satellite, tlhey
move in the opposite directionI, or fr'om east to west. WVith.
thllis exception, all thel motions of the plancts, whlethertl aroultd
their own axes or around tlhe sun, and thlat of tihe siun hinumscelf
on Ihis axis, are fiom wvest to east.
3 5 11. NE'ITUNE: is (so far as is known) the last planet of the
o From ovpa'os, tOld fat her of Saturn.