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

129'THE MiooN.
Iloonll, wVin full, t raversing that partt of ]ler orbit whic,11 lies
nort]t of the equator, and of coturse above the htorizon of the(
north pole, and traversing thte portioll thlat lies ssontll of I die
eqvuator, and beloew thel polar hlorizon, whetn ntw. I )ur-int' th Ie
)olat williter, thertefrel the t11oo1n, from tlle first to the la Ist
quartelCr is colnlllnl>ly abti)oveizon, While the sntt is tabsentt; whereas, durin sulinmer, while tht s8tl is prcsetnt, tile
lno00on is above thle horizon whjle describing ther first; and last
q l ad ranl t-its.
216. About tlle time of the autumnal eqluinox, tlhe mooll
wrtcl nletar the f,ell, l'is about; siiset ftor a nutllellr of niulits
ilt suessiSClti; l and as tlis is, i lln Favrland th period tof lharvcst:, tile pll 0llcolltlo is called the li/i.'rve.'t./brn.. itll(ltcrstandt the reason of tlhis, silce t}he -110011 is never farl fr'om
tlte ecliptic, w xe will suppose hleri Sio ss t)o be in til e ecliptie.
if the itnoo moved in thtc equator, tithen, since ttils great ciircle
is at rigltt anltes to tte axis of tlte etartlX, all p)at of it, as tlhe
eartl rctlvolvcs, would cut the liorizoil at tute sallte cotlstant t anglle.
ta11 the ]lltoon's lorblit, or t ile ecliptic, w\tich is here taken to
reIrX'eseilt it, l)ein-I oblique to thle eqllator, cuflts the hol)izon at
ditffterlnt aglcs i1 diffliereant parts', as will easily be sseen b)y
rcftitret ce to an artificial globe. V'hltct tte filrst. of A\Aries, ol'
ver.nal eqlinllox, is ill thle cIsterot horizoll, it will 1)e seell thlat
t:le celiptic (and colsequently tthe 1oo0s18 orblit) mtakes its
least aglle AwithI time orizoni. 2ow at tile autunltal equinox,
thie 1sun beillg in. I,iblia, tile 110oo11 t t tlte full is inll.Aic, atd
Irises \illcll thloe sun sets. O() thCe following Cvcittlilg, altlhola1gh
she afts atlvan lced iln 1cr orbit aboutt 1t 3 (Art. 213), yet hcer
progress l)cilgp ob)lique to tile horizon, adi at ia S11111 11atngle
wvitlt it, she \vill be found at tt l tlhs t ime hlut a little way below
tile ltrl'izoll, con(pltared with thIe point l\\Iere scie was \ t Stillset
thle preceding evening. Site therefore rises but a little later
eachl evea.lll tlanl s1he did o11 tite evening previous, but her
Jpldace of' risinog moves rapidly northward. It sthould )tet ohservedt, tihat in uitlking leir r'evolultio llt'Ot1(1d tlt)o earth, trhe
ilto011 ItluSt passl tlte first of Ariesi and therefore maltke tlhese,silliall diltter eces, ill the timle of risillg, every nonitll l. Btt as
the mtool is not tfull at tile samile time, except iln autulmnl tlhe
eircunsltaltee attracts 1no attenltiol.