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

CONST6'r,LATION1s. 273
M'ost per)sons uIlacquainld with tle actual 1number of the stars
whichl conmpose the visible firmlament, would suppose it to be
much g'Ceaterd' tan thtis; but it is found that the catalog:-ue of
Il.ipparchus embraces nearlly all thlat 1are easily seen in the sallme
latitudc, an1d that on the equator, wherlc the spectator has the
northern and southten hlemispllcres both ill view, the number
of stlars that cani be counted it oes not exceed 3000. A hasty
glance over the sky gives us tlie impres-sionl of a countleiss mnublltitude otf stars; but the greater partl vanishl as soon aS \we try
to nllnltb)(n' them. Thlis is owilng to t1he ivdlirect vision of
thousands of faitit; stars, vwhich are unseen as soon as we turn
tihe axes of the eyes directly 11poll them.:lBy the aid of tthe telescope, new fields of stars presentt tllemselves of boundless extent; the numbeCr continually auglenlting
as tie po\ierls of tlle telescope are increaset(. ItalandeR ill Ilis
]istoilr' (Cleste, ltas registered thll positions of 1no less thanll
500()0); and tlhe w]ole utlllnbr visible in the la'orgest telescopes
amount to mainy mlliollnIs.
41 3. it. is st.rongly recommended to the learner to acquaint
Ilimlself with thle leadintt constellations at least, and withl a fewv
of thle lnost rnemarkable individual stars. Thel task of learnling'
thel is Com})arativel'y eas, when they are taken up at suitlable
intervals tllroughlout tlhe year, tlte lloon being ablsent and the
sky clear. After becotuing famliliar with llsuch constellations
as are visible onl any given cvening (sup)posC the;1fist of JantIary), tihese may be carcefilly reviewed aftclr al interval of a
1mnorlm Ii, and tlhe several new ones ad(ledl wlicll have in t~he
(mean tilmne risen above ttc easterni lhoizon. "13S'y rel)atingl tllis
process near' the beginlilng of every monlth of the year, the
lcarner will acquire a competelnt knowledlge of the ~whole tlhat
Mare visiible i hllis ilatitudel, and with a small expenditure of timte.
JIt,ay at first st e advisable to obtain, for an evening or0 two,
the assistance of some one whlo is acquainted \ith thie constellatio,lls to l)oint out sucll as are then visible inl the evening sky.
11el 1), b tlhc aid of a celestial map, or, w\hlat is better, a celest;ial gltolc, thle lc:rner will pur1sue thle study \ithlout difficltty.
WVc tIttin byr re:. it'fying the globe for tlhe time, accortding to tilo
dilreetmi(ls (iveCll ill Article't".
Inl t;la fellowing sketch of the leading constellationis we will
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