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

CLUSTE'RS AN) ) N E U i,' 293.1The telescope only canll, however, display the real magnificenco
of the -IPleiades. (Sce Plate lLt., Fig. 1.) Colma ierelnices has
fewcer stars, but they are of a larger class thall tllose whicll conpose the P-'lciades. The Beehive, or ~Nebula of Cancer, is oltC
of the finest oAbjects of this kind for a small telescope, bleilng, ib,
its aid, convcrted into a rich congeries of sllining points. A.
cluster in the sword-handlle of I'clrsus, below Cassiopeia's chair,
thoughl but a (dim speck to the naked eye, is a vlery clganlt
objcct to a large telescope, being separatedl into bright and
beautiful stars, emlbracing several distinct subordinate clusters
of exceedingly minute. stellar points.'.Tle chead of Orion affords anll example of another cluster, though less remlarkable
thtan tlhe others.
425. iN4:;juLA,i: are faint misty olbjects seen in various parts
of ttche firmament., always maintaining a fixed position, which
resemllble comets, olr patches of fog.'Thel Gralaxy, olr Milky
\\Wly, lpresents a constant succession of large neblulat. Of the
individual nebuhl, seen by the nlaked eye, the most conspicluous is that near, the girdle of Andromeda. lIt is the oldest
known tnebula, Iraving attracted the attention of star-gazers
as (early as the beginning of the tenth centuryl,':x althloug]h it is
commonly slaid to hlave been liscovered by Simon Marntius, ill:G1,1. ]No Ipowe rs of thle telescope have bccn able to resolve
thiis into separate stars, althouglt the great Cambridge tclescopel reveals a vast number of stalrs, more thlan 1,500, of varlious
degrees of brightness, scattered over its surflace; but these appear' not to belong to the nebula itself, which thas hitherto af-t
forded n1o evidlene of resolution.t Its (limnllsions are astonislingly great, since it covers a space of a quarter of a deCgree
in ditIameter; tanld we lust'bear in mind that., at such a (distance as the fixed stars, a space of 15' impllies an imnmense extent. Its figure is oval, and ettllical neCbul constitute a com-l
mon val'riety 11among tleC figures which these bodies exhibit.
(Sce l'lato lit., Fig;. 2, for a represeltation of the great nebula
of Andromeda.) Another very commolln figure are thle ilob/niar
ntcbula'. A. grand specimen of this variety may bte easily
* Snmyth's Cycle, ii., i. 16.' Memoirs of the Atler. Acad., vol. iil.