Astronomy and the Bible;

CELESTIALMAGNITUDES 107

reachhimuntilone minuteafterthecreationofthe
object; andshould itsuddenlybe struckfrom exist-
ence,theobserverwouldbeholditforoneminuteafter
theextinction."
Andnowjustafewwordsastotheparallaxofthe
fixed stars. 'If itwere possibleto measure onthe
earth's surface a base line of a thousand miles in
length,bylocatinganobserver ateachextremityof
thisbasewith instrumentssuitable tofixthemoon's
place amongthe fixedstars, thetelescopes of these
two observers, directed to the moon's centerat the
same instant, would incline toward each other, and
thevisualrayfromeachoftheseinstrumentswould
meet atthemoon'scenter, and forman anglewith
eachother."
Thisgives atrianglewhose anglesaremarkedby
themoonattheapex,anobserverateachendofthe
base line. One observer sees the moon from one
direction,andtheotherobserverseesitfromanother
direction. Thatis,toeachobserver,themoonseems
tobe ina different spot inthesky. Thisdisplace-
ment,ordifferenceindirection,owingtothedifferent
positionoftheeyethatviewsit,iscalledtheparallax.
Averysimpleexperimentwillhelpyoutoseethat
achangeinthe viewpointwill produce anapparent
change of position in the object under observation.
Forexample,looktowardthewallofonesideofyour
room; hold theindex finger of yourhand erectin
frontof you,atsome distance from your face, and
closethelefteye. Youwillnowseethatyourfinger
covers acertain spoton thewall,as atA. Donot