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

P)oilt out a few of the marks by wlichl thely mnay be severallyT
recoglize(, alddincg' occaisionally a few )particulars, and leavinJg
it to the learlner to fill 1up tlhe outline by the aid of his 1map) or
glol)e, one of whiclh, in(leed, is lp).esumed to be before lhim.*'
Let u1 begilli withI tlhe constellations of the Zodiac, whlich,
suceeedlinc) each other as tlely do int a known or(ler, arel most
easily found. 1:
Autwtls (thle Rx),,ithe first constellation of the Zodiac) is
knlown by two bright stars, Alp/ ta (a.) on the nortllheast, and
il)a (03) onl tlhe siouthwest,'1: apart., forming thle head. South
of Beta, at t distance of 2~, is a smaller star, Gaomua (y).
thPe next brigihtest star of thie Rtan, Delta (d), is in the tail,
15~ southeast of Alphla. Tlle feet of tlhe figure rest onl tlhe
llcad of the Whale.:It has been alreadl intimatel (Art. 19d),
that the vernal equinox was near the lhead of Arilc.s, when the
si)gns of tlhe Zodiac received their present namnes, but tlhat the
equinox is now fobld 30~ wvestward of cc Arictis, in consequence
of the precession of the equinoxes.
Txuvts (tlhe ]vuIL) will be rea(fily found by tlhe seven stars,
or Plci./ades, whichl lie inl thle lneck, 2.-0 castward of c. Arietis.
T'hle largest star in Tauru'- s is il./d:be'aIn eOf the first magnitu(e,
inll thellt 11111's eye, 1.~ southetast of the Pleiades. It hlas a reddish color, and resembl es tle plan1et Mars. The other eye of.......... _ __..+................................................................
* A celestial gltobe. sufficient for' stludying, thle constellations, may be purc)hased
for a smnall sum, anli1d is, inl other rspects, a valuable possessionl to the astronomical stiudctit; but even cheap m1aps of the stars, lidke those of lhurcitt or Kendal,
~ vill ansvwrt for beginners; and the Celestial Atlas, publl.ished by the Society for
the Diffusionl of Useful Knowledge, which is suitable for the more advanced
tiudent., lmay be procured at a moderate expense.? It. will he expedient, where it, is practicable, for the learne r to study thle constellations in.-separate portieos, at. ditlferent scasons of thle year, as at tihe. cquinoxes aud at thle solstices, according to the direc-tions given inll the closing article
of this chaIpter.
These measi'ures are not. intended to be stated with minute accuracy, butt only
witlh suchll a (degree of exactness as may serve for a general guide. The learner
will tild it gre'atly for his a(valnitage to accustoem himself to make anl accurate estillmate withl thile eye of distaclles iln degrecs on the celestial sphere and he 1may,
at. the outset, fix on the distance b)et.welen Alpha and Beta Arictis as a stadlard
tmeIls;L11e (Vt) l.W whilich to estimate other angular listances among the stars.'thus. 1hlf this length applied from Beta to Gammall{h, indlicates that tlhe.two latter
stars arIe 2~ apart; and two andl a.half times the samne measure (100) will reach
fromn the Pleiadcs to Aldebaran. Or the Pointers in the Gireat Hcapr wi furnish
a mellstleO of 60.