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

D)ISTAN}V5CS OF T1ile FIX IT) STAIRS. 30
we can form no adequatte oneptio is, and attenpt to tleatsltie
it ol1lty by the time that lighlt (which moves more than 92) 00)(0
miles per secolnd) would take to traverse it. Now,)
192,000 () 1.s.: 1 9,000,000,000,000 3.:1 ycars.
4-35. After many fit'it;less and delusory efforts to mtleasurel'
the imnlllse interval that, separates 1us fromil the fixed stars, the
great }Irussian astrololtn cr,.cssci"l il t ye} ar 1.838, dcetermined
tlhis intcresting andt imtlportat cl(mcntl, b)y observatiotns on a:
double star;in thlle San (61. C ni). I.lis star wal s selecterd
for the fowlIc16illo g reasonls: first, it wa ns known to have a great?g'(~{ia iofgob (Ar t. 4-33), indicatie ng an' comparlatively great;
-'oxi~itm to otr system; scondlyt; ssitulated as it is (atllO0ig tlhe
circntpo)lar stars, ol)sc.rvations co(uld be mnaile upon it nearly
\ievery niltt itn tlte year'; and thlidly, the great nuttmber of stnall
starns ii tthe itilnmed iate itcigollbo hlood, furnislhed tle oplporttnitfy of sclccGting favoralle stationlary points fiom wtltich (iinas_tmuch}l as tJlcse titore remote obljects migtft,be eotfsitdetlrd as eitirly ldevoid of Iparall ax) atnyw cltanlces of place in tile licarer,
ill col1lnse1ttence of all annual iarallax ighs, tn t 1)e rea dily estimnatcal. lI:,v observations of the last dlt%"rec of rciinmnlelmtt,) coitducted i 1br a eI m'io(l of several years, a parallax was (Iccisively
itldlicated, andiountitin9 to about one-tllird of a second; or, mtioe
exacstly, to 0".3t-4S3, implying a distance of 592,20() times thle
mIeantil distatlce of th-e earthl fio tie sutlnos, or a space w\liclh it
woutld take liglt, ttovuiglt att tte1 rate of tweltve millionI s of miles
per I' inullttc, winie (t"(/ vt qn utc{iid i/Zei tO to' tei Pe.h'aps tle
best, way to c(ncecive of this distance, is to collpal'e it with thlt
dlicnsio n.is of the solar system, ast represenlted l)y thit dicngrani
(note, p). 178).'Thel (disitance from thle sun to Nepttne ieilng
30 fect, 61 (lytni sloul d el pl)aced I 10 i./ites off.'Thus isolated
are tei systeims of thle luiverlse firom each otlher.
Tl' lc oblservations of Biesse1 ienalled him to estimatC also thre
plrtiod( of revolutiont of the t\\o stars comlposing tle binary system of G (Jg'ni, alltld thle dimenlsions of tile orbit, aild lie fo)und
ite periodi(c tilnc about 540( years, and the Iclotht of tlie orbit
aliout two (and a ihalf times tlhat of Urantus. (nowhing the (listance antd l)roper motionl ot' tle starl, \e catll ow obtain its
JvdloctC/, so far as it is perpendicullal to our lille of vision.'hlis
is found to be about forty-fbur milcs pcr. sccot.dll- more t-hlan