,,astronomy      ,,for ,,young ,,folks  
,illustration3 ,,northern ,,portion ,,of
 ,,the ,,moon ,,at ,,last ,,quarter     
,taken with #ajj-;inch ,hooker          
,telescope of the ,mt4 ,wilson          
,observatory    7,see ,chapter ,,xxi7   
,,astronomy                             
for                        ,,young      
,,folks                            ,,by 
,,isabel ,,martin ,,lewis1 ,a4 ,m4      
7,connected with the ,nautical ,almanac 
,office            of the ,u4 ,s4 ,naval
 ,observatory7                          
,,new ,,york                 ,,duffield 
,,and ,,company                         
#aibb                     ,copyright1   
#aiba1 by                 ,,the         
,,century ,,company                     
,copyright1 #aibb1 by                   
,,duffield ,,and ,,company              
,printed in ,u4 ,s4 ,a4                 
,,contents          ,,chapter           
,,page                ,preface          
xiii             ,i4 ,the               
,constellations                         

#c            ,,ii4 ,january            
#ae           ,,iii4 ,february          
#ba            ,,iv4 ,march             
#bh             ,v4 ,april              
#ce            ,,vi4 ,may               
#da           ,,vii4 ,june              
#di          ,,viii4 ,july              
#ef            ,,ix4 ,august            
#fd             ,x4 ,september          
#ga            ,,xi4 ,october           
#gh           ,,xii4 ,november          
#hd          ,,xiii4 ,december          
#ij           ,,xiv4 ,stars of the      
,southern ,hemisphere                   
#if            ,,xv4 ,the ,milky ,way or
 ,galaxy                          #ajg  
,,xvi4 ,the ,surface of the ,sun        
#aac          ,,xvii4 ,the ,solar       
,system                                 
#aai         ,,xviii4 ,the ,origin of   
the ,earth                          #abg
           ,,xix4 ,jupiter and ,his     
,nine ,moons                       #aci 
,,xx4 ,the ,rings and ,moons of ,saturn 
#adh           ,,xxi4 ,is the ,moon a   

,dead ,world                            
#aef          ,,xxii4 ,comets           
#afe         ,,xxiii4 ,meteorites       
#agc          ,,xxiv4 ,the ,earth ,as a 
,magnet                            #ahc 
,,xxv4 ,some ,effects of the ,earth's   
,atmosphere ,upon                       
,sunlight                               
#aic          ,,xxvi4 ,keeping ,track of
 the ,moon                        #bjg  
,,xxvii4 ,the ,motions of the ,heavenly 
,bodies               #baf              
,,xxviii4 ,the ,evolution of the        
,stars--,from ,red ,giants              
to ,red ,dwarfs                         
#bbe          ,,xxix4 ,double and       
,multiple ,stars                        
#bcj           ,,xxx4 ,astronomical     
,distances                              
#bda          ,,xxxi4 ,some             
,astronomical ,facts ,worth ,remembering
        #bej          ,,illustrations   
,,page        ,northern ,portion of the 
,moon at ,last ,quarter                 
,frontispiece        ,the ,great        

,hercules ,cluster--,a ,universe of     
,suns     facing page  #ef        ,a    
,dark ,nebula3 ,the ,dark ,bay or ,dark 
,horse        ,nebula in ,orion         
facing page #aaj        ,a4 ,venus4     
,b4 ,mars4   ,c4 ,jupiter4   ,d4 ,saturn
     facing page #abb        ,spiral    
,nebula in ,canes ,venatici             
facing page #baf        ,spiral ,nebula 
in ,andromeda ,viewed ,edgewise         
facing page #bbb          ,,list ,,of   
,,tables                                
,,page          ,i4 ,the ,principal     
,elements of the ,solar ,system         
#bfa         ,,ii4 ,the ,satellites of  
the ,solar ,system                  #bfb
        ,,iii4 ,the ,twenty ,brightest  
,stars in the ,heavens           #bfc   
,,iv4 ,a ,list of the ,principal        
,constellations          #bfd-bfe       
,v4 ,pronunciations and ,meanings of    
,names of             ,stars and        
,constellations                         
#bff-bfg          ,,preface             
,astronomy1 it has been said1 is the    

oldest and the noblest of  the sciences4
 ,yet it is one of the few sciences for 
which most  present-day educators seem  
to find little1 if any1 room in their   
curriculum of study for the young1 in   
spite of its high cultural  value4 ,it  
is1 we are told1 too abstruse a subject 
for the youthful  student4 ,this is     
doubtless true of theoretical or        
mathematical  astronomy and the         
practical astronomy of the navigator1   
surveyor and  engineer1 but it is not   
true of general1 descriptive astronomy4 
,there  are many different aspects of   
this many-sided science1 and some of    
the simplest and grandest truths of     
astronomy can be grasped by the         
intelligent child of twelve or fourteen 
years of age4    ,merely as a branch of 
nature study the child should have some 
knowledge of the sun1 moon1 stars and   
planets1 their motions and  their       
physical features1 for they are as truly
 a part of nature as  are the birds1    
trees and flowers1 and the man1 woman or

 child who  goes forth beneath the      
star-lit heavens at night absolutely    
blind to  the wonders and beauties of   
the universe of which he is a part1     
loses  as much as the one who walks     
through field or forest with no thought 
of the beauties of nature that surround 
him4    ,the astronomer is the pioneer  
and explorer of today in realms  unknown
 just as the pioneers and explorers of  
several centuries ago  were to some     
extent astronomers as they sailed       
unknown seas and  traversed unexplored  
regions4 ,as the years pass by the      
astronomer  extends more and more his   
explorations of the universe and brings 
back among the fruits of discovery      
measures of giant suns and  estimates of
 the form and extent of the universe1   
views of whirling1  seething nebul1     
mysterious dark clouds drifting through 
space1  tremendous solar upheavals or   
glimpses of strangely marked surfaces   
of nearby planets4    ,in the following 
pages the author has endeavored to tell 

in words  not beyond the comprehension  
of the average fourteen-year-old child  
something of the nature of the heavenly 
bodies4 ,in ,part ,i an effort  is made 
to make the child familiar with the     
stars by indicating when  and where they
 can be found in the early evening      
hours4 ,in addition  to identifying the 
principal constellations and their      
brightest stars  by means of diagrams an
 attempt has been made to acquaint the  
child  with the most interesting recent 
discoveries that have been made         
concerning the principal stars or       
objects in each group as well as  with  
some of the stories and legends that    
have been associated with  these groups 
of stars for centuries1 and that have   
been handed down  in the folk-lore of   
all nations4    ,chapters #b-ac1        
inclusive1 appeared originally with     
diagrams similar  to those shown here1  
under the department of ,nature and     
,science  for ,young ,folk in ,st4      
,nicholas from ,may1 #aiba1 to ,april1  

#aibb1  inclusive4 ,the ,introductory   
,chapter and ,chapters #ad and #ae1 on  
the  ,milky ,way and ,stars of the      
,southern ,hemisphere1 respectively1 are
  published here for the first time1 as 
is also the chapter in ,part ,,ii  on   
the ,evolution of the ,stars from ,red  
,giants to ,red ,dwarfs1 which  gives   
the order of the evolution of the stars 
as now accepted as a  result of the     
brilliant astronomical researches of    
,dr4 ,henry ,norris  ,russell of the    
,united ,states and ,prof4 ,a4 ,s4      
,eddington1 of ,england4    ,the        
remaining chapters in ,part ,,ii have   
been chosen from a series of  articles  
that have appeared in ,science and      
,invention1 formerly  ,the ,electrical  
,experimenter1 in the past four years1  
and have been  considerably revised and 
in some parts rewritten to adapt them to
 the  understanding of more youthful    
readers4 ,these chapters deal with a    
variety of astronomical subjects of     
general popular interest and an  effort 

has been made to select subjects that   
would cover as wide an  astronomical    
field as possible in a limited space4   
,the author's aim has not been to write 
a text-book of astronomy or  to treat in
 detail of any one aspect of this       
extensive science1 but  simply to give  
the average child some general knowledge
 of the nature  of the heavenly bodies1 
both those that form a part of our own  
solar  system and those that lie in the 
depths of space beyond4    ,it has been 
necessary to write very briefly1 and we 
feel  inadequately1 of many topics of   
special interest such as the sun and    
moon4 ,books have been written on these 
two subjects alone as well as  upon such
 subjects as ,mars1 eclipses1 comets1   
meteors1 etc41 but the  object has been 
to acquaint the child with the          
outstanding features  of a variety of   
celestial objects rather than to treat  
of a few in  detail4    ,if the writer  
succeeds in arousing the child's        
interest in the stars  so that he may   

look forth with intelligence at the     
heavens and  greet the stars as friends 
and at the same time grasps some of the 
simplest and most fundamental of        
astronomical truths such as the         
distinction between stars and planets1  
the motions of the heavenly  bodies and 
their relative distances from us and the
 place of our own  planet-world in the  
universe1 this book will have served its
 purpose4                               
,,astronomy            ,,for ,,young    
,,folks      ,the heavens declare the   
glory of ,god1 and the firmament showeth
    ,his handiwork4                     
,psalm ,,xix4      ,i    ,,the          
,,constellations        ,canst thou bind
 the sweet influences of the ,pleiades  
,or loose the bands of ,orion8          
,canst thou bring forth ,mazzaroth in   
his season      ,or canst thou guide    
,arcturus with his sons8                
--,,book ,,of ,,job4      ,who would not
 like to know the stars and             
constellations by their  names and in   

their seasons as we know the birds and  
the trees and  the flowers1 to recognize
 at their return1 year by year1 ,sirius 
and  ,spica1 ,arcturus and ,antares1    
,vega and ,altair1 to know when ,ursa   
,major  swings high overhead and ,orion 
sinks to rest beneath the western       
horizon1 when ,leo comes into view in   
the east or the ,northern ,crown  lies  
overhead8    ,often we deprive ourselves
 of the pleasure of making friends with 
the  stars and shut our eyes to the     
glories of the heavens above because  we
 do not realize how simple a matter it  
is to become acquainted with  the       
various groups of stars as they cross   
our meridian1 one by one1  day after day
 and month after month in the same      
orderly sequence4  ,when the robin      
returns once more to nest in the same   
orchard in the  spring time1 ,leo and   
,virgo may be seen rising above the     
eastern  horizon in the early evening   
hours4 ,when the first snow flies in    
the late fall and the birds have all    

gone southward the belt of  ,orion      
appears in the east and ,cygnus dips low
 in the west4 ,when we  once come to    
know brilliant blue-white ,vega1 ruddy  
,arcturus1 golden  ,capella and         
sparkling ,sirius we watch for them to  
return each in its  proper season and   
greet them as old friends4    ,in the   
following pages we give for each month  
the constellations  or star-groups that 
are nearest to our meridian1 that is1   
that lie  either due north or due south 
or exactly overhead in the early part   
of the month and the early part of the  
evening4    ,we do not need to start our
 study of the constellations in         
,january4  ,we may start at any month in
 the year and we will find the          
constellations given for that month on  
or near the meridian at the  time       
indicated4    ,in using the charts or   
diagrams of the constellations1 we      
should hold  them in an inverted        
position with the top of the page toward
 the  north or else remember that the   

left-hand side of the page is toward    
the east and the right-hand side of the 
page toward the west1  which is the     
opposite of the arrangement for charts  
and maps of the  earth's surface4    ,we
 should also bear in mind that the      
constellations are all  continually     
shifting westward for the stars and the 
moon and the  planets as well as the sun
 rise daily in the east and set in the  
west4 ,this is due to the fact that the 
earth is turning in the  opposite       
direction on its axis1 that is from west
 to east4 ,in  twenty-four hours the    
earth turns completely around with      
respect to  the heavens or through an   
angle of #cfj1 so in one hour it turns  
through an angle of #cfj  #bd or #ae4   
,as a result the stars appear  to shift 
westward #ae every hour4 ,this is a     
distance about equal in  length to the  
handle of the ,big ,dipper1 which ,i am 
sure we all know1  even if we do not    
know another constellation in the       
heavens4    ,if1 then1 we look at the   

heavens at a later hour than that for   
which  the constellations are given we  
will find them farther westward and  if 
our time of observation is earlier in   
the evening than the hour  mentioned we 
will find them farther eastward4    ,in 
the course of a year the earth makes one
 trip around the sun and  faces in turn 
all parts of the heavens4 ,that is1 it  
turns through  an angle of #cfj with    
respect to the heavens in a year or     
through  an angle of #cfj  #ab or #cj in
 one month4 ,so as a result of our      
revolution around the sun1 which is also
 in a west to east direction1  we see   
that all the constellations are         
gradually shifting westward at  the rate
 of #cj a month4 ,it is for this reason 
that we see different  constellations in
 different months1 and it is because of 
the turning  of the earth on its axis   
that we see different constellations at 
different hours of the night4    ,if we 
should sit up from sunset to sunrise and
 watch the stars rise  in the east1 pass

 the meridian and set in the west--as   
the sun does  by day--we should see in  
turn the same constellations that are to
  pass across the heavens in the next   
six months4 ,this is because in  twelve 
hours' time we are carried through the  
same angle with respect  to the heavens 
by the earth's rotation on its axis that
 we are in the  next six months by the  
motion of the earth around the sun4     
,let us suppose then that the time we   
choose for our observation of  the      
heavens is the last of the month while  
our charts are given  for the first of  
the month4 ,we must look then farther   
westward  for our constellations just as
 we must look farther westward if  we   
chose a later hour in the evening for   
our observations4 ,let us  suppose that 
we choose for our time of observation   
half-past eight  in the early part of   
,december4 ,on or close to the meridian 
we will  find the constellations        
outlined in the charts for ,december4   
,to  the east of the meridian we will   

find the constellations that are  given 
for ,january and ,february1 and to the  
west of the meridian  the constellations
 that are given for ,november and       
,october4 ,so if  we are particularly   
ambitious or wish to become acquainted  
with  the constellations more rapidly we
 may study at the same time the         
constellations for the preceding months 
now west of the meridian and  the       
constellations for the following months 
now east of the meridian  as well as the
 constellations for the month which will
 be due north  or south or directly     
overhead as the case may be4    ,if we  
were able to see the stars by day as    
well as by night we  would observe that 
as the days go by the sun is apparently 
moving  continuously eastward among     
certain constellations4 ,this is a      
result  of the earth's actual motion    
around the sun in the same direction4   
,the apparent path of the sun among the 
stars is called the ecliptic  and the   
belt of the heavens eight degrees wide  

on either side of the  ecliptic is      
called the zodiac4 ,the constellations  
that lie within  this belt of the zodiac
 are called zodiacal constellations4    
,the  zodiac was divided by the         
astronomer ,hipparchus1 who lived       
#afa-abf  ,b4,c41 into twelve signs #cj 
wide1 and the signs were named for the  
constellations lying at that time within
 each of these divisions4  ,these       
zodiacal constellations are ,aries1     
,taurus1 ,gemini1 ,cancer1 ,leo1        
,virgo1 ,libra1 ,scorpio1 ,sagittarius1 
,capricornus1 ,aquarius and ,pisces4    
,with the exception of ,libra1 the      
,scales1 all of these constellations    
are named for people or animals and the 
word zodiac is derived from  the ,greek 
word meaning of animals4    ,each month 
the sun moves eastward #cj through one  
of these zodiacal  constellations4 ,in  
the days of ,hipparchus the sun was in  
,aries at  the beginning of spring1 at  
the point where the ecliptic crosses the
  celestial equator--which lies directly

 above the earth's equator4  ,this point
 where the ecliptic crosses the equator 
was then known  as the ,first ,point in 
,aries4 ,the autumnal equinox was #ahj  
distant  in ,aquarius and the two points
 were called the equinoxes because  when
 the sun is at either equinox the day   
and night are equal in  length all over 
the world4 ,now for certain reasons     
which we will not  explain here the     
equinoctial points are not fixed in     
position but  shift gradually westward  
at the rate of #a in #gj years4 ,it is  
as if  the equinoxes were advancing each
 year to meet the sun on its return  and
 their westward motion is therefore     
called ,the ,precession of the          
,equinoxes4    ,since the days of       
,hipparchus this motion has amounted to 
about #cj so  that the constellations no
 longer occupy the signs of the zodiac  
that  bear their names4    ,the sun is  
now in ,pisces instead of ,aries at the 
beginning of spring  and in ,virgo      
instead of ,aquarius at the beginning of

 fall4    ,not only the sun but the moon
 and planets as well move through the   
zodiacal constellations4 ,in fact a     
limit for the zodiac of #h on  either   
side of the ecliptic was chosen because 
it marks the extent  of the excursions  
of the moon and planets from the        
ecliptic4 ,neither  moon nor planets    
will be found at a greater distance than
 #h on  either side of the ecliptic4    
,for convenience in determining the     
positions of the heavenly bodies  the   
astronomer assumes that they lie upon   
the surface of a celestial  sphere that 
has its center at the center of the     
earth4    ,the north pole of the        
celestial sphere lies directly above the
 north  pole of the earth and the south 
pole of the celestial sphere directly   
above the south pole of the earth4 ,the 
celestial equator is the  great circle  
of the celestial sphere that lies midway
 between its  north and south poles and 
directly above the earth's equator4 ,the
  ecliptic is also a great circle of the

 celestial sphere and cuts the          
celestial equator at an angle of        
#bc-a_/b in the two points #ahj apart   
known as the equinoctial points1 of     
which we have already spoken4    ,the   
zodiacal constellations lie nearly      
overhead within the tropics  and can be 
seen to advantage all over the world    
except in polar  regions4    ,for every 
position of the earth's surface except  
at the equator we  have also our        
circumpolar constellations which are the
 ones that  never pass below the horizon
 for the place of observation4    ,in   
#dj ,n4 ,latitude the ,big ,dipper is a 
circumpolar constellation for  it is    
above the horizon at all hours of the   
day and night and all  times of the     
year4 ,if our latitude is #dj ,n41 all  
stars within #dj of  the north pole of  
the heavens are circumpolar and never   
set1 while  stars within #dj of the     
south pole of the heavens never rise4   
,all  other stars rise and set daily4   
,if we were at the north pole all stars 

within #ij of the north pole  of the    
heavens would be circumpolar and would  
describe daily circuits  of the pole    
parallel to the horizon remaining always
 above it4    ,if we were at the equator
 all stars within zero degrees of either
  pole would be circumpolar1 that is no 
stars would be circumpolar1  all stars  
rising and setting daily4    ,as a      
general rule1 then1 we may say that     
stars within an angular  distance of the
 nearest pole of the heavens equal to   
the latitude  never set and stars within
 an equal distance of the opposite pole 
never rise while all stars outside of   
these limits rise and set daily4    ,the
 beginner who attempts to make the      
acquaintance of the principal  stars and
 constellations occasionally may find a 
bright star in a  constellation that is 
not noted in the diagrams4 ,in this case
 he has  probably happened upon one of  
the bright planets4    ,it is not       
possible to include the planets in our  
diagrams for the  reason that they are  

not fixed in position but apparently    
wander  among the stars4 ,the name      
planet is1 in fact1 derived from a      
,greek  word meaning wanderer4 ,the     
stars shine by their own light but the  
planets shine only by reflected light   
from the sun4 ,of the seven  planets in 
the solar system additional to our own  
planet earth1  there are two1 ,uranus   
and ,neptune that we need not consider  
for  ,neptune is not visible without the
 aid of a telescope and ,uranus is      
fainter than any of the stars included  
in our diagrams4    ,mercury will never 
appear except in the morning or evening 
twilight1  when none but the very       
brightest stars are visible1 since it   
never  departs far from the sun4 ,it    
will only be seen under certain         
favorable conditions1 and usually it    
will escape our notice  altogether      
unless we know exactly where to look for
 it although  there are but two or three
 stars in the heavens that surpass it in
  brightness4    ,venus1 we will        

probably never mistake for any star in  
the heavens for  it far surpasses all   
stars in brightness4 ,it will always be 
seen in  the west after sunset or in the
 east before sunrise and it is never    
seen more than three hours before or    
after the sun4    ,this leaves us but   
three planets1 ,jupiter1 ,saturn and    
,mars that we  may mistake for bright   
stars4 ,there is little chance that     
,jupiter  will be thus mistaken for it  
also is far brighter than all of the    
stars except ,sirius which differs      
greatly from ,jupiter in color4  ,sirius
 is a brilliant white and ,jupiter is a 
golden yellow4 ,the  planets do not     
twinkle as the stars do and this is     
particularly true  of ,jupiter which is 
remarkable for the quiet steadiness of  
its yellow  light4 ,this alone would    
serve to identify it4    ,saturn is     
probably mistaken for a star oftener    
than any of the other  planets4 ,it     
moves so slowly among the stars that we 
would have to  watch it for a number of 

successive evenings before we could     
discover  that it is moving with respect
 to the stars4 ,saturn is yellowish in  
color and we can probably best          
distinguish it by the steadiness of  its
 light4 ,if we find in one of the       
zodiacal groups of stars--for  the      
planets appear among no other           
constellations--a bright yellowish  star
 where no bright star is indicated on   
the diagram we may be  reasonably       
certain that we have found the planet   
,saturn4    ,mars is the only planet    
that is reddish in color4 ,once in      
fifteen  or seventeen years1 when it is 
particularly near to the earth1 it      
surpasses even ,jupiter in brightness1  
but ordinarily it appears  no more      
brilliant than one of the brighter      
stars4 ,there are only  two stars with  
which we are likely to confuse          
,mars1--,aldebaran and  ,antares--which 
are very similar to it in color1 and1 at
 times1 in  brightness4 ,moreover1 both 
of these stars are zodiacal stars and   

,mars  frequently passes through the    
constellations to which they belong4    
,there should be no trouble about       
identifying ,aldebaran and ,antares1    
however1 from their distinctive         
positions in the diagrams so that any   
other reddish star appearing in any of  
the zodiacal groups we may  feel certain
 is the planet ,mars4    ,in the        
following diagrams of the constellations
 the brightest  and most conspicuous    
stars1 called first-magnitude stars1 are
  represented by white stars4 ,these are
 the stars we should all be  able to    
recognize and call by name and in every 
instance the name of  a first-magnitude 
star is given on the diagram4 ,all other
 stars are  represented by circles1 and 
the size of the circle is an indication 
of the brightness of the star4    ,stars
 visible without the aid of a telescope 
are referred to usually  as naked-eye   
stars4 ,they are classed as first1      
second1 third1  four1 fifth or sixth    
magnitude stars1 according to their     

relative  brightness4 ,a star of the    
first magnitude is about two and        
one-half  times brighter than a star of 
the second magnitude1 which in turn is  
two and one-half times brighter than a  
star of the third magnitude  and so on4 
,a first-magnitude star is1 then1 one   
hundred times  brighter than a sixth    
magnitude star which is the faintest    
star that  can be seen without the aid  
of the telescope4    ,this ratio between
 successive magnitudes continues among  
the  telescopic stars4 ,a star of the   
sixth magnitude is one hundred times    
brighter than a star of the eleventh    
magnitude which in turn is one  hundred 
times brighter than a star of the       
sixteenth magnitude4    ,the faintest   
stars that can be seen visually in the  
greatest  telescopes are of the         
seventeenth or eighteenth magnitude1    
though  stars two or three magnitudes   
fainter can be photographed4    ,the    
faintest stars shown in the diagrams are
 fifth-magnitude stars  and stars of    

this magnitude as well as stars of the  
fourth magnitude  are only given when   
needed to fill out the distinctive      
outlines of  the constellations which   
have been formed by connecting the      
principal  stars in each group by dotted
 lines4    ,all stars of first1 second  
and third magnitude are given in the    
diagrams without exceptions as such     
stars are visible to everyone on  clear 
nights4    ,the constellations given in 
the following pages include practically 
all of the constellations that can be   
seen in #dj ,n4 ,latitude4 ,a  diagram  
is given for each constellation4    ,in 
this latitude it is impossible to see   
the constellations of the  southern     
hemisphere that lie within #dj of the   
south pole of the  heavens4 ,a brief    
chapter with diagram treats of these    
constellations  that are invisible in   
mid-latitudes of the northern           
hemisphere4          ,,ii    ,,january  
,one of the most easily recognized      
constellations in the heavens is        

,taurus1 ,the ,bull1 a zodiacal group   
which lies just south of the  zenith in 
our latitudes in the early evening hours
 about the first of  ,january4          
,taurus is distinguished by the         
,v-shaped group of ,the ,hyades1  which 
contains the bright1 red1               
first-magnitude star ,aldebaran1        
representing the fiery eye of the bull4 
,it also contains the famous  cluster of
 faint stars known as ,the ,pleiades1   
lying a short distance  northwest of    
,the ,hyades4    ,no group of stars is  
more universally known than ,the        
,pleiades4  ,all tribes and nations of  
the world1 from the remotest days of    
recorded history up to the present time1
 have sung the praises of  ,the         
,pleiades4 ,they were ,the ,many ,little
 ,ones of the ,babylonians1  ,the ,seven
 ,sisters of the ,greeks1 ,the ,seven   
,brothers of the  ,american ,indians1   
,the ,hen and ,chickens of many nations 
of ,europe1  ,the ,little ,eyes of the  
,south ,sea ,islanders4 ,they were      

honored in  the religious ceremonies of 
the ,aztecs1 and the savage tribes of   
,australia danced in their honor4 ,many 
early tribes of men began their  year   
with ,november1 the ,pleiad month2 and  
on ,november #agth1 when  ,the ,pleiades
 crossed the meridian at midnight1 it   
was said that no  petition was ever     
presented in vain to the kings of       
ancient ,persia4      ,illustration3    
,,january--,,taurus    ,poets of all    
ages have felt the charm of ,the        
,pleiades4 ,tennyson gives  the         
following beautiful description of ,the 
,pleiades in ,locksley  ,hall3          
,many a night ,i saw the ,pleiades1     
rising through the mellow shade1        
,glitter like a swarm of fireflies      
tangled in a silver braid4    ,a        
well-known astronomer1 not so many years
 ago1 also felt the  mysterious charm of
 ,the ,pleiades and seriously expressed 
the belief  that ,alcyone1 the brightest
 star of ,the ,pleiades1 was a central  
sun  about which all other suns were    

moving4 ,but we know that there is no   
foundation whatever for such a belief4  
,a fairly good eye1 when the night is   
clear and dark1 will make out  six stars
 in this group arranged in the form of a
 small dipper4 ,a  seventh star lies    
close to the star at the end of the     
handle and is  more difficult to find4  
,it is called ,pleione1 and is referred 
to in  many legends as the lost ,pleiad4
 ,persons gifted with exceptionally     
fine eyesight have made out as many as  
eleven stars in the group2  and with the
 aid of an ordinary opera-glass1 anyone 
can see fully  one hundred stars in this
 cluster4 ,astronomers have found that  
,the  ,pleiades cluster contains at     
least two hundred and fifty stars1 all  
drifting slowly in the same general     
direction through space1 and that  the  
entire group is enveloped in a fiery1   
nebulous mist which is  most dense      
around the brightest stars4 ,it is not  
known whether the  stars are being      
formed from the nebula or whether the   

nebula is being  puffed off from the    
stars4 ,the brightest star1 ,alcyone1 is
 at least  two hundred times more       
brilliant than our own sun1 and all of  
the  brighter stars in the group surpass
 the sun many times in brightness4  ,it 
is believed that this cluster is so     
large that light takes many  years to   
cross from one end of it to the other1  
and that it is so far  from the earth   
that its light takes over three         
centuries to reach  us1 traveling at the
 rate of #ahf1jjj miles a second4       
,the ,hyades is a group of stars        
scarcely less famous than ,the          
,pleiades1 and the stars in the group   
also form a moving cluster of  enormous 
extent at a distance of #adj light-years
 from the earth4    ,among the ancients1
 ,the ,hyades were called the           
rain-stars1 and the  word ,hyades is    
supposed to come from the ,greek word   
for rain4 ,among  the many superstitions
 of the past was the belief that the    
rising or  setting of a group of stars  

with the sun had some special influence 
over human affairs4 ,since ,the ,hyades 
set just after the sun in the  showery  
springtime and just before sunrise in   
the stormy days of late  fall1 they were
 always associated with rain4 ,in       
,tennyson's ,ulysses  we read3          
,through scudding drifts the rainy      
,hyades      ,vex'd the dim sea4    ,the
 ,hyades outline the forehead of        
,taurus1 while two bright stars  some   
distance to the northeast of the ,v form
 the tips of the  horns4 ,only the head 
and forequarters of the bull are shown  
in the  star-atlases that give the      
mythological groups1 for1 according to  
one  legend1 he is swimming through the 
sea and the rest of his body is         
submerged4 ,according to another legend1
 ,taurus is charging down upon  ,orion1 
,the ,warrior1 represented by the       
magnificent constellation just  to the  
southeast of ,taurus1 of which we shall 
have more to say next  month4           
,aldebaran is the ,arabic word for ,the 

,hindmost1 and the star is so  called   
because it follows ,the ,pleiades across
 the sky4 ,it is one of  the most       
beautiful of all the many brilliant     
stars visible at this  time and we might
 profit by following the advice of ,mrs4
 ,sigourney in  ,the ,stars3            
,go forth at night      ,and talk with  
,aldebaran1 where he flames      ,in the
 cold forehead of the wintry sky4       
,next to ,aldebaran in the ,v is the    
interesting double star ,theta1  which  
we can see as two distinct stars without
 a telescope4    ,directly south of     
,taurus is ,eridanus1 sometimes called  
,fluvius  ,eridanus1 or ,the ,river     
,eridanus4 ,starting a little to the    
southeast  of ,taurus1 close to the     
brilliant blue-white star ,rigel in     
,orion1 it  runs to the westward for a  
considerable distance in a long curving 
line of rather faint stars1 bends       
sharply southward for a short  distance1
 then curves backward toward the east   
once more1 and1 after  running for some 

distance1 makes another sharp curve to  
the southwest  and disappears below the 
southern horizon4 ,its course is        
continued  far into the southern        
hemisphere4 ,its brightest star1        
,achernar1 is  a star of the first      
magnitude1 but it lies below the horizon
 in our  latitudes4      ,illustration3 
,,january--,,eridanus    ,eridanus      
contains no star of particular interest 
to us4 ,most of the  numerous stars that
 mark its course are of the fourth and  
fifth  magnitude4 ,it contains but two  
stars of the third magnitude1 one  at   
the beginning of its course and one     
close to the southwestern  horizon4 ,the
 beautiful constellation of ,perseus    
lies just to the  north of ,taurus and  
should rightfully be considered among   
the  constellations lying nearest to the
 meridian in ,january1 but we give  this
 constellation among the star groups for
 ,december because of  its close        
association with the nearby             
constellations ,andromeda and  ,pegasus 

in legend and story4          ,,iii     
,,february      ,across the meridian1   
due south1 between eight and nine       
o'clock in  the evening in the early    
part of ,february1 lies ,orion1 ,the    
,warrior1  generally considered to be   
the finest constellation in the heavens4
  ,orion is directly overhead at the    
equator1 and so is seen to  advantage   
from all parts of the world except the  
extreme northern and  southern polar    
regions4    ,a group of three faint     
stars outlines the head of ,orion4 ,his 
right  shoulder is marked by the        
deep-red1 first-magnitude star          
,betelgeuze  7meaning armpit71 and his  
left shoulder by the bright white star  
,bellatrix1 ,the ,amazon4 ,orion stands 
facing ,taurus1 ,the ,bull1 and         
brandishes in his right hand a club1    
outlined by a number of faint  stars    
extending from ,betelgeuze toward the   
northeast4 ,the top of the  club lies   
near the tips of the horns of ,taurus4  
,in his left hand he  holds up a lion's 

skin1 which we can trace in another     
curving line of  faint stars to the west
 and northwest of ,bellatrix4 ,the      
brilliant1  blue-white1 first-magnitude 
star ,rigel lies in the left foot1 and  
the  second-magnitude star ,saiph1 a    
little to the east of ,rigel1 is in  the
 right knee4 ,three evenly spaced stars 
lying in a straight line  that is       
exactly three degrees in length form the
 ,belt of ,orion1  and from the ,belt   
hangs the ,sword of ,orion1 outlined by 
three faint  stars4 ,the central star in
 the ,sword appears somewhat blurred and
 is  the multiple star ,theta1 in the   
midst of the great ,orion nebula1 the   
finest object of its kind in the        
heavens4 ,entangled in the meshes of    
this glowing nebula are a number of     
brilliant suns1 appearing to us  as     
faint stars because of their great      
distance4 ,the star ,theta1 in  the     
heart of the nebula1 is seen with a     
powerful telescope to consist  of six   
stars2 that is1 it is a sextuple star4  

,even with a small  telescope1 four of  
these stars can readily be seen1        
arranged in the  form of a small        
trapezium4 ,the lowest star in the      
,sword is a triple  star1 and the entire
 constellation abounds in double1       
triple1 and  multiple stars4    ,from   
the central portion of the nebula extend
 many branches and  streamers of        
nebulous light1 and it is known that the
 entire  constellation of ,orion is     
enwrapped in the folds of this          
nebulosity1  which forms a glowing1     
whirling mass of fiery gases in rapid   
rotation4 ,this constellation is        
remarkable for the fact that all of  its
 brighter stars1 with the exception of  
the deep-red ,betelgeuze1  form one     
enormous1 connected group of stars4     
,they are all more or  less associated  
with the great nebula and its branches1 
and are all  extremely hot1 white or    
bluish-white stars1 known as helium     
stars1  because the gas helium is so    
conspicuous in their atmospheres4 ,the  

,orion stars are the hottest and        
brightest of all the stars4    ,blazing 
,rigel1 ,bellatrix1 and ,saiph1 marking 
three corners of the  great             
quadrilateral1 of which ,betelgeuze     
marks the fourth corner1 are  all       
brilliant helium stars4 ,so are the     
three stars in the ,belt and  the       
fainter stars in the ,sword and the     
great nebula4      ,illustration3       
,,february--,,orion    ,it has been     
estimated that the great ,orion group of
 stars is over  six hundred light-years 
from the earth1 or about forty million  
times  more distant than the sun4 ,for  
more than six centuries the rays of     
light that now enter our eyes from these
 stars have been traveling  through     
space with the speed of lightning4 ,so  
we see ,orion not as it  exists today1  
but as it was six centuries ago4 ,the   
extent of the  ,orion group of stars is 
also inconceivably great4 ,even the     
central  part of the great nebula1 which
 appears to our unaided eyes only as a  

somewhat fuzzy star1 would extend from  
here to the nearest star and  beyond1   
while our entire solar system would be  
the merest speck in  its midst4         
,betelgeuze1 the red star that marks the
 right shoulder of ,orion1  is1 as we   
have said1 not a member of the ,orion   
group4 ,it has been  estimated that it  
is about two hundred light-years from   
the earth1  or only about one-third as  
far away as the other stars of the      
constellation4    ,betelgeuze very      
recently has attracted universal        
attention1 and will  probably be        
considered an object of historic        
interest in the future1  because it is  
the first star to have its diameter     
measured with the  new ,michelson       
interferometer1 which is now being used 
so successfully  to measure the         
diameters of the largest stars4 ,the    
truly sensational  discovery has been   
made that ,betelgeuze is a supergiant of
 the  universe1 with a diameter of about
 #bge1jjj1jjj miles4 ,our own sun1      

which is known as a dwarf star1 has a   
diameter of #hfd1jjj miles4  ,that is1  
,betelgeuze would make about thirty     
million suns the size of  our own4 ,if  
placed at the center of the solar       
system1 it would fill  all of the space 
within the orbit of ,mars2 and the      
planets ,mercury1  ,venus1 and the      
,earth would lie far beneath its        
surface4 ,measurements  of the diameters
 of other giant stars which are now     
being made with  the interferometer give
 results quite as startling as have been
  obtained in the case of ,betelgeuze2  
and it has been found that  several of  
these stars may even exceed ,betelgeuze 
in size4 ,such a  star is ,antares1 the 
fiery-red star in the heart of ,scorpio1
 which  is such a conspicuous object in 
the summer evening skies4 ,all these    
huge stars are deep red in color1 and   
some of them vary irregularly  in       
brightness4 ,betelgeuze is one of the   
stars that changes in  brightness in a  
peculiar manner from time to time4 ,when

 shining with  its greatest brilliancy  
it is a brighter object than the nearby 
star  ,aldebaran1 in ,taurus2 but a few 
months or a year later it may lose  so  
much of its light as to be decidedly    
inferior to ,aldebaran4 ,we  may note   
for ourselves this remarkable change in 
the brightness of  ,betelgeuze by       
comparing the two stars from time to    
time4    ,directly south of ,orion lies 
the small constellation of ,lepus1 ,the 
,hare1 which is made up of              
third-magnitude and fourth-magnitude    
stars4  ,the four brighter stars are    
arranged in the form of a small1 but    
distinct1 quadrilateral1 or four-sided  
figure1 which may be easily  seen in our
 latitudes4 ,the small constellation of 
,columba1 ,the ,dove1  which lies just  
south of ,lepus1 is so close to the     
horizon that it  can not be seen to     
advantage in the mid-latitudes of the   
northern  hemisphere4 ,neither ,lepus   
nor ,columba contain any object of      
unusual  interest4      ,illustration3  

,,february--,,auriga    ,due north of   
,orion1 and lying in the zenith at this 
time1 is ,auriga1  ,the ,charioteer1    
represented1 strange to say1 with       
,capella1 a goat1 in  his arms4 ,the    
beautiful first-magnitude star ,capella1
 golden-yellow  in color1 serves us in  
identifying the constellation4 ,close at
 hand  are ,the ,kids1 represented by a 
group of three faint stars4 ,capella  is
 one of the most brilliant stars of the 
northern hemisphere4 ,it  is almost     
exactly equal in brightness to ,arcturus
 and ,vega1 stars  conspicuous in the   
summer months1 and it is a shade        
brighter than  magnificent blue-white   
,rigel in ,orion4 ,capella is about     
fifty  light-years distant from the     
earth and is fully two hundred times    
more brilliant than our own sun4 ,at the
 distance of ,capella1 the sun  would   
appear to be considerably fainter than  
any one of the three  stars in the      
nearby group of ,the ,kids4    ,capella 
is attended by a companion star so close

 to its brilliant  ruler that it can not
 be seen as a separate star save with   
the aid of  the most powerful           
telescopes4 ,its distance from ,capella 
has been very  accurately measured1     
however1 by means of the interferometer1
 which  is giving us the measurements of
 the diameters of the giant stars4 ,it  
is known that this companion sun is     
closer to ,capella than our planet      
earth is to the sun4    ,at no time of  
the year shall we find near the meridian
 so many  brilliant and beautiful stars 
as appear in the month of ,february at  
this time in the evening4 ,in addition  
to ,capella1 which is one of  the three 
most brilliant stars in the northern    
hemisphere of the  heavens1 we have1 in 
,orion alone1 two stars of the first    
magnitude1  ,betelgeuze and ,rigel1 and 
five stars of the second magnitude1     
,bellatrix and ,saiph and the three     
stars in the ,belt4 ,in addition1 we    
have not far distant in the western sky1
 fiery ,aldebaran in ,taurus1  and close

 on the heel of ,orion in the east1     
,sirius1 the brightest  star in the     
heavens1 in the constellation of ,canis 
,major1 ,the ,greater  ,dog1 as well as 
the first-magnitude star ,procyon in    
,canis ,minor1 ,the  ,lesser ,dog4 ,of  
these two groups we shall have more to  
say under the  constellations for       
,march4          ,,iv    ,,march        
,to the southeast of ,orion and almost  
due south at eight o'clock in  the      
evening on the first of ,march lies the 
constellation of ,canis  ,major1 ,the   
,greater ,dog1 containing ,sirius1 the  
,dog-star1 which far  surpasses all     
other stars in the heavens in           
brilliancy4    ,sirius lies almost in   
line with the three stars that form the 
,belt  of ,orion4 ,we shall not have the
 slightest difficulty in recognizing    
it1 owing to its surpassing brilliancy  
as well as to the fact that it  follows 
so closely upon the heels of ,orion4    
,sirius is the ,greek for scorching or  
sparkling1 and the ancients  attributed 

the scorching heat of summer to the fact
 that ,sirius  then rose with the sun4  
,the torrid days of midsummer they      
called  the dog-days for this reason1   
and we have retained the expression  to 
the present time4 ,since ,sirius was    
always associated with the  discomforts 
of the torrid season1 it did not have an
 enviable  reputation among the ,greeks4
 ,we find in ,pope's translation of the 
,iliad this reference to ,sirius3       
,terrific glory6 for his burning breath 
,taints the red air with fever1 plagues1
 and death4    ,in ,egypt1 however1 many
 temples were dedicated to the worship  
of  ,sirius1 for the reason that some   
five thousand years ago it rose  with   
the sun at the time of the summer       
solstice1 which marks the  beginning of 
summer1 and heralded the approaching    
inundation of the  ,nile1 which was an  
occasion for great rejoicing among the  
,egyptians4  ,it was1 therefore1 called 
the ,nile ,star and regarded by them    
with the  greatest reverence4    ,sirius

 is an intensely white hydrogen star2   
but owing to its great  brilliancy and  
to the fact that it does not attain a   
great height  above the horizon in our  
latitudes1 its rays are greatly         
refracted  or broken up by the          
atmosphere1 which is most dense near the
 horizon1  and as a result1 it twinkles 
or scintillates more noticeably than    
other stars and flashes the spectrum    
colors--chiefly red and  green--like a  
true diamond in the sky--a magnificent  
object in the  telescope4    ,sirius is 
one of our nearest neighbors among the  
stars4 ,only two  stars are known to be 
nearer to the solar system4 ,yet its    
light takes  about eight and a half     
years to flash with lightning speed     
across the  great intervening chasm4 ,it
 is attended also by a very faint star  
that is so lost in the rays of its      
brilliant companion that it can  only be
 found with the aid of a powerful       
telescope4 ,the two stars  are separated
 by a distance of #a1hjj1jjj1jjj miles2 

that is they are  about as far apart as 
,neptune and the sun4 ,they swing slowly
 and  majestically about a common       
center1 called their center of gravity1 
in a period of about forty-nine years4  
,so faint is the companion of  ,sirius  
that it is estimated that twenty        
thousand such stars would be  needed to 
give forth as much light as ,sirius4    
,the two stars together1  ,sirius and   
its companion1 give forth twenty-six    
times as much light  as our own sun4    
,they weigh only about three times as   
much1 however4  ,the companion of       
,sirius1 in spite of its extreme        
faintness1 weighs  fully half as much as
 the brilliant star4      ,illustration3
 ,,march--,,canis ,,major    ,there are 
a number of bright stars in the         
constellation of ,canis  ,major4 ,a     
fairly bright star a little to the west 
of ,sirius marks the  uplifted paw of   
the dog1 and to the southeast1 in the   
tail and hind  quarters1 are several    
conspicuous stars of the second         

magnitude4    ,a little to the east and 
much farther to the north1 we find      
,canis  ,minor1 ,the ,lesser ,dog1      
containing the beautiful first-magnitude
  star ,procyon1 ,precursor of the      
,dog--that is1 of ,sirius4 ,since       
,procyon is so much farther north than  
,sirius and very little to the  east1 we
 see its brilliant rays in the eastern  
sky some time before  ,sirius appears   
above the southeastern horizon1 hence   
its name4 ,long  after ,sirius has      
disappeared from view beneath the       
western horizon  in the late spring1    
,procyon may still be seen low in the   
western  sky4 ,procyon1 also is one of  
our nearer neighbors among the stars1   
being only about ten light-years distant
 from the solar system4 ,like  ,sirius1 
it is a double star with a much fainter 
companion1 that by  its attraction sways
 the motion of ,procyon to such an      
extent that  we should know of its      
existence1 even if it were not visible1 
by  the disturbances it produces in the 

motion of ,procyon4 ,the period  of     
revolution of ,procyon and its companion
 about a common center is  about forty  
years1 and the two stars combined weigh 
about a third  more than our own sun and
 give forth six times as much light4    
,canis  ,minor contains only one other  
bright star1 ,beta1 a short distance to 
the northwest of ,procyon4 ,originally1 
the name ,procyon was given to  the     
entire constellation1 but it was later  
used only with reference  to the one    
star4 ,procyon1 ,sirius1 and ,betelgeuze
 in ,orion form a huge  equal-sided     
triangle that lies across the meridian  
at this time and  is a most conspicuous 
configuration in the evening sky4       
,illustration3 ,,march--,,gemini ,,and  
,,canis ,,minor    ,directly south of   
the zenith we find ,gemini1 ,the ,twins1
 one of the  zodiacal constellations4   
,it is in ,gemini that the sun is to be 
found  at the beginning of summer4 ,the 
two bright stars ,castor and ,pollux    
mark the heads of the twins1 and the two

 stars in the opposite  corners of the  
four-sided figure shown in the chart    
mark their feet4    ,castor and ,pollux1
 according to the legend1 were the twin 
brothers of  ,helen of ,troy who went on
 the ,argonautic expedition4 ,when a    
storm  overtook the vessel on its return
 voyage1 ,orpheus invoked the aid of    
,apollo1 who caused two stars to shine  
above the heads of the twins1  and the  
storm immediately ceased4 ,it was for   
this reason that ,castor  and ,pollux   
became the special deities of seamen1   
and it was customary  to place their    
effigies upon the prows of vessels4 ,the
 ,by ,jimini6  of today is but a        
corruption of the ,by ,gemini6 heard so 
frequently  among the sailors of the    
ancient world4    ,the astronomical name
 for ,castor1 the fainter star1 is      
,alpha  ,geminorum1 meaning ,alpha of   
,gemini4 ,as it was customary to call   
the  brightest star in a constellation  
by the first letter in the ,greek       
alphabet1 it is believed that ,castor   

has decreased considerably in           
brightness since the days of the        
ancients1 for it is now decidedly       
inferior to ,pollux in brightness1 which
 is called ,beta ,geminorum4  ,of the   
two stars1 ,castor is the more          
interesting because it is a  double star
 that is readily separated into two     
stars with the aid of  a small          
telescope4 ,the two principal stars are 
known to be1 in turn1  extremely close  
double stars revolving almost in contact
 in periods  of a few days4 ,where we   
see but one star with the unaided eye1  
there  is1 then a system of four suns1  
the two close pairs revolving slowly    
about a common center of gravity in a   
period of several centuries and  at a   
great distance apart4    ,the star      
,pollux1 which we can easily distinguish
 by its superior  brightness1 is the    
more southerly of the twin stars and    
lies due  north of ,procyon and about as
 far from ,procyon as ,procyon is from  
,sirius4    ,the appearance of ,gemini  

on the meridian in the early evening and
  of the huge triangle1 with its corners
 marked by the brilliants1  ,procyon1   
,sirius1 and ,betelgeuze1 due south1    
with ,great ,orion sloping  slowly to   
the west1 is as truly a sign of         
approaching spring as  the gradual      
lengthening of the days1 the appearance 
of crocuses and  daffodils1 and the     
first robin4 ,it is only a few weeks    
later--as  pictured by ,tennyson in     
,maud--        ,when the face of the    
night is fair on the dewy downs1        
,and the shining daffodil dies1 and the 
,charioteer      ,and starry ,gemini    
hang like glorious crowns      ,over    
,orion's grave low down in the west4    
,v    ,,april      ,in the early evening
 hours of ,april the western sky is     
still adorned  with the brilliant jewels
 with which we became familiar on the   
clear frosty evenings of winter4 ,orion 
is now sinking fast to his  rest beneath
 the western horizon4 ,beautiful1 golden
 ,capella in  ,auriga glows in the      

northwest4 ,sirius sparkles and         
scintillates1 a  magnificent diamond of 
the sky1 just above the southwestern    
horizon1  while ,procyon in ,canis      
,minor1 ,the ,lesser ,dog1 and ,castor  
and ,pollux1  ,the ,twins1 in the       
constellation of ,gemini1 are still high
 in the  western part of the heavens4   
,in the northeast and east may be seen  
the constellations that will  be close  
to the meridian at this time next month4
 ,ursa ,major1 ,the  ,greater ,bear1    
with its familiar ,big ,dipper1 is now  
in a favorable  position for            
observation4 ,the ,sickle in ,leo is    
high in the eastern  sky1 and ,spica1   
the brilliant white diamond of the      
evening skies of  spring1 is low in the 
southeast in ,virgo4    ,near the       
meridian this month we find between     
,auriga and ,ursa ,major1  and east of  
,gemini1 the inconspicuous constellation
 of ,lynx1 which  contains not a single 
bright star and is a modern             
constellation  devised simply to fill   

the otherwise vacant space in           
circumpolar  regions between ,ursa      
,major and ,auriga4      ,illustration3 
,,april--,,cancer    ,just south of the 
zenith at this time1 and lying between  
,gemini and  ,leo1 is ,cancer1 ,the     
,crab1 the most inconspicuous of all the
 zodiacal  constellations4 ,there are no
 bright stars in this group1 and there  
is also nothing distinctive about the   
grouping of its faint stars1  though we 
can readily find it1 from its position  
between the two  neighboring            
constellations of ,gemini and ,leo by   
reference to the  chart4    ,in the     
position indicated there we will see on 
clear evenings a  faint1 nebulous cloud 
of light1 which is known as ,praesepe1  
,the  ,beehive1 or as ,the ,manger1 the 
two faint stars flanking it on either   
side being called ,aselli1 ,the ,asses4 
,this faint cloud can be easily         
resolved by an opera-glass into a coarse
 cluster of stars that lie  just beyond 
the range of the unaided human vision4  

,to the ancients1 ,praesepe served as an
 indicator of weather  conditions1 and  
,aratus1 an ancient astronomer1 wrote of
 this cluster3        ,a murky manger1  
with both stars      ,shining unaltered1
 is a sign of rain4      ,if while the  
northern ass is dimmed      ,by vaporous
 shroud1 he of the south gleam radiant1 
,expect a south wind2 the vaporous      
shroud and radiance      ,exchanging    
stars1 harbinger ,boreas4    ,this was  
not entirely a matter of superstition1  
as we might possibly  imagine1 for the  
dimness of the cluster is simply an     
indication  that vapor is gathering and 
condensing in the atmosphere1 just as  a
 ring around the moon is an indication  
of the same gathering and  condensation 
of vapor that precedes a storm4    ,some
 centuries ago the sun reached its      
greatest distance north of the          
equator--which occurs each year at the  
beginning of summer--at the  time when  
it was passing through the constellation
 of ,cancer4 ,our  tropic of ,cancer1   

which marks the northern limit of the   
torrid zone1  received its name from    
this fact4 ,at the time when the sun    
reaches  the point farthest north1 its  
height above the horizon changes very   
little from day to day1 and for a short 
time it appears to be slowly  crawling  
sideways through the heavens1 as a crab 
walks1 and for this  reason1 possibly1  
the constellation was called ,cancer1   
,the ,crab4  ,at the present time the   
,precession of the ,equinoxes1 or       
westward  shifting of the vernal        
equinox--the point where the sun crosses
  the equator going north in the        
spring--brings the sun1 when it is      
farthest north1 in ,gemini instead of in
 ,cancer4 ,at the present time1  then it
 would be more accurate to speak of the 
tropic of ,gemini1  though this in turn 
would be inaccurate after a lapse of    
centuries1  as the sun passed into      
another constellation at the beginning  
of  summer4 ,the tropic of ,capricorn1  
which marks the farthest southern       

excursions of the sun in its yearly     
circuit of the heavens1 should  also    
more appropriately be called the tropic 
of ,sagittarius1 as the  sun is now in  
,sagittarius instead of ,capricornus at 
the time when it  is farthest south1    
though the point is slowly shifting     
westward into  ,scorpio4    ,mythology  
tells us that ,cancer was sent by ,juno 
to distract ,hercules  by pinching his  
toes while he was contending with the   
many-headed  serpent in the ,lernean    
swamp4 ,hercules1 the legend says1      
crushed the  crab with a single blow1   
and ,juno by way of reward placed it in 
the  heavens4    ,in ,cancer1 according 
to the belief of the ,chaldeans1 was    
located the  gate of men1 by which souls
 descended into human bodies1 while in  
,capricornus was the gate of the gods1  
through which the freed souls  of men   
returned to heaven4      ,illustration3 
,,april--,,hydra    ,hydra1 the         
many-headed serpent with which ,hercules
 contended1 is  represented by a        

constellation of great length4 ,it      
extends from a  point just south of     
,cancer1 where a group of faint stars   
marks the  heads1 to the south and      
southeast in a long line of faint stars4
  ,it passes in its course just south of
 ,crater and ,corvus1 the two  small    
star-groups below ,leo 7see             
constellations for ,may71 which  are    
sometimes called its riders1 and it also
 stretches below the  entire length of  
the long1 straggling constellation of   
,virgo4 ,at  this time we can trace it  
only to the point where it disappears   
below the horizon in the southeast4 ,it 
contains but one bright star1  ,alphard1
 or ,cor ,hydrae as it is also called1  
standing quite alone and  almost due    
south at this time4 ,hydra1 as well as  
,lynx and ,cancer1  contains no         
noteworthy or remarkable object and     
consists chiefly of  faint stars4       
,alphard is1 in fact1 the only bright   
star that we have  in the constellations
 for this month4 ,it chances that these 

three  inconspicuous star-groups1 ,lynx1
 ,crater1 and ,hydra1 lie nearest to    
the meridian at this time1 separating   
the brilliant groups of winter  from    
those of the summer months4             
,illustration3 ,,april--,,lynx          
,,vi    ,,may      ,ursa ,major1 the    
,great ,bear1 and ,ursa ,minor1 the     
,lesser ,bear1 or1  as they are more    
familiarly called1 the ,big ,dipper and 
the ,little  ,dipper1 are the best known
 of all the constellations visible in   
northern latitudes4 ,they are called    
circumpolar constellations1 which  means
 around the pole4 ,for those who live   
north of #dj ,n4 ,lat4 they  never set1 
but can be seen at all hours of the     
night and at all times  of the year4 ,in
 fall and winter evenings ,ursa ,major  
lies below the  pole and near the       
horizon1 and so is usually hidden more  
or less from  view by trees or          
buildings4 ,it is during the early      
evening hours of  late spring and summer
 that this constellation is seen to the 

best  advantage high in the sky above   
the pole4 ,if one looks due north at    
the time mentioned1 it will be          
impossible to miss either of these      
constellations4    ,to complete the     
outline of the ,great ,bear1 it is      
necessary to include  faint stars to the
 east1 which form the head of the ,bear1
 and other  faint stars to the south1   
which form the feet1 but these are all  
inconspicuous and of little general     
interest4    ,the two stars in the bowl 
of the ,big ,dipper through which an    
arrow is  drawn in the chart1 are called
 the ,pointers1 because an imaginary    
line drawn through these two stars and  
continued a distance about  equal to the
 length of the ,big ,dipper1 brings us  
to the star  ,polaris1 or the ,north    
,star1 at the end of the handle of the  
,little  ,dipper1 which is very close to
 the north pole of the heavens1 the     
direction in which the earth's axis     
points4 ,the pole lies on the line      
connecting the star at the bend in the  

handle of the ,big ,dipper with         
,polaris1 and is only one degree distant
 from the pole-star4      ,illustration3
 ,,may--,,ursa ,,major ,,and ,,ursa     
,,minor    ,the distance between the    
,pointers is five degrees of arc1 and   
the  distance from the more northerly of
 these two stars to ,polaris is  nearly 
thirty degrees4 ,we may find it useful  
to remember this in  estimating         
distances between objects in the        
heavens1 which are always  given in     
angular measure4    ,a small two and    
one-half inch telescope will separate   
,polaris into  two stars eighteen       
seconds of arc apart4 ,the companion    
star is a  faint white star of the ninth
 magnitude4    ,twenty years or so ago  
it was discovered with the aid of the   
spectroscope that the brighter of the   
two stars was also a double  star1 but  
the two stars were so close together    
that they could not  be seen as separate
 stars in any telescope4 ,later it was  
found that  the brighter star was in    

reality triple1 that is1 it consists of 
three suns close together4 ,the faint   
white companion star formed  with these 
three suns a system of four suns        
revolving about a common  center of     
gravity4 ,still more recently it has    
been discovered that  the brightest of  
these four suns varies regularly in     
brightness in a  period of a little less
 than four days4 ,it belongs to the     
important  class of stars known as      
,cepheid variable stars1 whose changes  
of light1 it is believed1 are produced  
by some periodic form of  disturbance   
taking place within the stars           
themselves4    ,with one exception1     
,polaris is the nearest to the earth of 
all these  ,cepheid variable stars1     
which are in most instances at very     
great  distances from the solar system4 
,the latest measurements of the         
distance of ,polaris show that its light
 takes about two centuries  to travel to
 the earth1 or1 in other words1 that it 
is distant two  hundred light-years4    

,like all ,cepheid variables1 ,polaris  
is a giant star4 ,it gives forth  about 
five hundred and twenty-five times as   
much light as our own  sun4 ,if ,polaris
 and the sun were placed side by side at
 a distance of  thirty-three            
light-years1 the sun would appear as a  
star of the fifth  magnitude1 just well 
within the range of visibility of the   
human  eye1 while ,polaris would        
outshine ,sirius1 the brightest star in 
the  heavens4    ,as a practical aid to 
navigators1 ,polaris is unsurpassed in  
importance by any star of the northern  
hemisphere of the heavens4 ,at  the     
equator the pole-star lies in the       
horizon2 at the north pole of  the earth
 it is in the zenith or directly        
overhead4 ,its altitude or  height above
 the horizon is always equal to the     
latitude of the place  of observation4  
,as we travel northward from the equator
 toward the  pole we see ,polaris rise  
higher and higher in the sky4 ,in ,new  
,york  the elevation of ,polaris above  

the horizon is forty degrees1 which is  
the latitude of the city4    ,the       
,pointers indicate the direction of     
,polaris and the true north1  while the 
height of ,polaris above the horizon    
tells us our latitude4  ,these kindly   
stars direct us by night when we are    
uncertain of our  bearings1 whether we  
travel by land or sea or air4 ,they are 
the  friends and aids of explorers1     
navigators and aviators1 who often  turn
 to them for guidance4    ,bryant writes
 thus beautifully of ,polaris in his    
,hymn to the ,north  ,star3             
,constellations come and climb the      
heavens1 and go4      ,star of the      
,pole6 and thou dost see them set4      
,alone in thy cold skies1      ,thou    
keep'st thy old unmoving station yet1   
,nor join'st the dances of that         
glittering train1      ,nor dipp'st thy 
virgin orb in the blue western main4    
,on thy unaltering blaze      ,the half 
wrecked mariner1 his compass lost1      
,fixes his steady gaze1      ,and       

steers1 undoubting1 to the friendly     
coast2      ,and they who stray in      
perilous wastes by night1      ,are glad
 when thou dost shine to guide their    
footsteps right4    ,the star at the    
bend in the handle of the ,big ,dipper1 
called ,mizar1  is of special interest4 
,if one has good eyesight1 he will see  
close  to it a faint star4 ,this is     
,alcor1 which is ,arabic for ,the ,test4
 ,the  two stars are also called the    
,horse and the ,rider4    ,mizar forms  
with ,alcor what is known as a wide     
double star4 ,it is1 in  fact1 the      
widest of all double stars4 ,many stars 
in the heavens that  appear single to us
 are separated by the telescope into    
double or  triple or multiple stars4    
,they consist of two or more suns       
revolving  about a common center1 known 
as their center of gravity4 ,sometimes  
the suns are so close together that even
 the most powerful telescope  will not  
separate them4 ,then a most wonderful   
little instrument1  called the          

spectroscope1 steps in and analyzes the 
light of the stars  and shows which are 
double and which are single4 ,a star    
shown to be  double by the spectroscope1
 but not by the telescope1 is called a  
spectroscopic binary star4    ,mizar is 
of historic interest1 as being the first
 double star to  be detected with the   
aid of the telescope4 ,a very small     
telescope  will split ,mizar up into two
 stars4 ,the brighter of the two is a   
spectroscopic binary star beside1 so    
that it really consists of two  suns    
instead of one1 with the distance       
between the two so small that  even the 
telescope cannot separate them4 ,about  
this system of three  suns which we know
 as the star ,mizar1 the faint star     
,alcor revolves  at a distance equal to 
sixteen thousand times the distance of  
the  earth from the sun4                
,illustration3 ,,may--,,leo    ,if we   
follow the imaginary line drawn through 
the ,pointers in a  southerly direction 
about forty-five degrees1 we come to    

,leo1  ,the ,lion1 one of the zodiacal  
constellations4 ,there should be  no    
difficulty in finding the constellation 
,leo1 as its peculiar  sickle-shaped    
group of bright stars makes it          
distinctive from all  other             
constellations4 ,at the time we have    
mentioned1 that is1 the  early evening  
hours1 it will lie a little to the      
southwest of the  zenith4 ,leo is one of
 the finest constellations and is always
  associated with the spring months     
because it is then high in the sky  in  
the evening4 ,regulus is the beautiful  
white star which marks  the handle of   
,the ,sickle1 and the heart of ,leo2 and
 ,denebola is the  second-magnitude star
 in the tail of ,leo4                   
,illustration3 ,,may--,,corvus ,,and    
,,crater    ,due south of ,denebola1    
about thirty degrees1 we find the small 
star-group known as ,crater1 ,the ,cup1 
which is composed of rather  faint and  
inconspicuous stars4 ,just east of      
,crater is the group  known as ,corvus1 

,the ,crow1 which forms a very          
characteristic little  four-sided figure
 of stars differing very little from one
 another  in brightness4 ,these two star
 groups lie far to the south in our     
latitudes2 but if we lived twenty       
degrees south of the equator1 we  would 
find them nearly overhead1 at this time 
of the year4 ,just south  of ,corvus and
 ,crater we find ,hydra1 one of the     
constellations for  ,april which extends
 beneath these constellations and also  
beneath  ,virgo1 one of the ,june       
constellations4          ,,vii    ,,june
      ,the star-groups that occupy the  
center of the celestial stage in        
mid-latitudes of the northern hemisphere
 during the early evening  hours of     
,june are ,botes1 often called ,the     
,hunter1 7although the word  means      
,herdsman or ,shouter71 which will be   
found overhead at this  time2 ,virgo1   
,the ,maiden1 largest of the zodiacal   
constellations1  lying nearly due south2
 ,canes ,venatici1 ,the ,hunting ,dogs2 

,corona  ,borealis1 ,the ,northern      
,crown1 and ,coma ,berenices4    ,the   
gorgeous orange-hued ,arcturus in ,botes
 and the beautiful  bluish-white ,spica 
in ,virgo1 like a diamond in its        
sparkling  radiance1 form with ,denebola
 in ,leo1 which we identified in ,may1 a
  huge equal-sided triangle that is     
always associated with the spring  and  
early summer months4    ,to the west of 
,botes1 below the handle of the ,big    
,dipper1 is a  region where there are   
few conspicuous stars4 ,here will be    
found  ,canes ,venatici 7,the ,hunting  
,dogs with which ,botes is supposed to  
be  pursuing the ,great ,bear around the
 north pole71 and1 further south1  ,coma
 ,berenices 7,bernice's ,hair74    ,the 
brighter of the two ,hunting ,dogs1     
which is also the brightest  star in the
 entire region covered by these two     
constellations1  appears as a beautiful 
blue-and-yellow double star in the      
telescope4  ,it was named ,cor ,caroli  
7,heart of ,charles7 by the astronomer  

,halley  in honor of ,charles ,,ii of   
,england1 at the suggestion of the court
  physician1 who imagined it shone more 
brightly than usual the  night before   
the return of ,charles to ,london4 ,of  
more interest to  astronomers is the    
magnificent spiral nebula in this       
constellation1  known as the ,whirlpool 
,nebula1 appearing as a faint1 luminous 
patch  in the sky1 of which many        
photographs have been taken with the    
great  telescopes4 ,this entire region1 
from ,canes ,venatici to ,virgo1 abounds
  in faint spiral nebul that for some   
reason not yet understood by            
astronomers are crowded together in this
 part of the heavens where  stars are   
comparatively few4 ,it is believed that 
there are between  five hundred thousand
 and a million of these spiral nebul in 
the  entire heavens1 and the problem of 
their nature and origin and  distance is
 one that the astronomers are very      
anxious to solve4 ,many  wonderful facts
 are now being learned concerning these 

faint nebulous  wisps of light which1   
with a few exceptions1 are observable   
only with  great telescopes4 ,they      
reveal their spiral structure more      
clearly to  the photographic plate than 
to the human eye1 and some magnificent  
photographs of them have been taken with
 powerful telescopes4    ,coma          
,berenices1 south of ,canes ,venatici   
and southwest of ,botes1 is  a          
constellation that consists of a great  
number of stars closely  crowded        
together1 and just barely visible to the
 unaided eye4 ,as  a result1 it has the 
appearance of filmy threads of light1   
which  doubtless suggested its name to  
the imaginative ancients1 who loved  to 
fill the heavens with fanciful creations
 associated with their  myths and       
legends4 ,these stars form a moving     
cluster of stars  estimated to be at a  
distance of about #bgj light-years from 
the solar  systems4      ,illustration3 
,,june--,,bo,,tes1 ,,canes ,,venatici   
,,and ,,coma ,,berenicis    ,this       

region1 so lacking in interesting       
objects for the naked-eye  observer1 is 
a mine of riches to the fortunate       
possessors of  telescopes2 and the great
 telescopes of the world are frequently 
pointed in this direction1 exploring the
 mysteries of space that  abound here4  
,just to the east of ,botes is the      
exquisite little circlet of stars  known
 as ,corona ,borealis1 the ,northern    
,crown4 ,it consists of six  stars      
arranged in a nearly perfect semicircle1
 and one will have no  difficulty in    
recognizing it4 ,its brightest star1    
,alpha1 known also  by the name of      
,alphacca1 is a star of the second      
magnitude4    ,botes is one of the      
largest and finest of the northern      
constellations4 ,it can be easily       
distinguished by its peculiar           
kite-shaped grouping of stars or by the 
conspicuous pentagon  7five-sided       
figure7 of stars which it contains4 ,the
 most southerly  star in this pentagon  
is known as ,epsilon ,botes and is one  

of  the finest double stars in the      
heavens4 ,the two stars of which it     
consists are respectively orange and    
greenish-blue in color4    ,by far the  
finest object in ,botes1 however1 is the
 magnificent  ,arcturus1 which is the   
brightest star in the northern          
hemisphere  of the heavens4 ,this star  
will be conspicuous in the evening hours
  throughout the summer months1 as will 
also the less brilliant ,spica  in      
,virgo4    ,some recent measurements    
show that ,arcturus is one of our nearer
  neighbors among the stars4 ,its       
distance is now estimated to be about   
twenty-one light-years4 ,that is1 a ray 
of light from this star takes           
twenty-one years to reach the earth1    
traveling at the rate of one  hundred   
and eighty-six thousand miles per       
second4 ,it would seem as  if we should 
hardly speak of ,arcturus1 twenty-one   
light-years away1  as a near neighbor1  
yet there are millions of stars that are
 far  more distant from the earth1 and  

very few that are nearer to us than     
,arcturus4    ,the brightness of        
,arcturus is estimated to be about forty
 times that  of the sun4 ,that is1 if   
the two bodies were side by side1       
,arcturus  would give forth forty times 
as much light and heat as the sun4      
,arcturus is also one of the most       
rapidly moving stars in the heavens4    
,in the past sixteen centuries it has   
traveled so far as to have  changed its 
position among the other stars by as    
much as the apparent  width of the moon4
 ,most of the stars1 in spite of their  
motions  through the heavens in various 
directions1 appear today in the same    
relative positions in which they were   
several thousand years ago4 ,it  is for 
this reason that the constellations of  
the ,egyptians and of  the ,greeks and  
,romans are the same constellations that
 we see in the  heavens today4 ,were all
 the stars as rapidly moving as         
,arcturus1 the  distinctive forms of the
 constellations would be preserved for  

only a  very few centuries4             
,illustration3 ,,june--,,virgo          
,virgo1 which lies south and southwest  
of ,botes1 is a large1  straggling      
constellation1 consisting of a ,y-shaped
 configuration of  rather inconspicuous 
stars4 ,it lies in the path of our sun1 
moon and  planets1 and so is one of the 
zodiacal constellations4 ,the cross in  
the diagram indicates the present       
position of the autumnal equinox1  the  
point where the sun crosses the equator 
going south1 and the  position the sun  
now occupies at the beginning of fall4  
,spica1 the brightest star in ,virgo1 is
 a bluish-white1  first-magnitude star1 
standing very much alone in the sky4 ,in
 fact1  the ,arabs referred to this star
 as ,the ,solitary ,one4 ,its distance  
from the earth is not known1 but must be
 very great as it cannot be  found by   
the usual methods4 ,the spectroscope    
shows that it consists  of two suns very
 close together1 revolving about a      
common center in a  period of only four 

days4    ,within the branches of the ,y 
in ,virgo1 and just to the north of it1 
is the wonderful nebulous region of this
 constellation1 but it takes  a powerful
 telescope to show the faint spiral     
nebul that exist here  in great         
profusion4 ,all of these spirals are    
receding from the plane  of the ,milky  
,way with enormous velocities4 ,the     
spiral nebul are1 in  fact1 the most    
rapidly moving objects in the heavens4  
,,viii    ,,july      ,due east of the  
little circlet of stars known as ,corona
 ,borealis1 and  almost directly        
overhead in our latitude 7#dj ,n47 about
 nine o'clock  in the evening in the    
early part of ,july1 is the large       
constellation  of ,hercules1 named for  
the famous hero of ,grecian mythology4  
,there  are no stars of great brilliancy
 in this group1 but it contains a  large
 number of fairly bright stars arranged 
in the form outlined in  the chart4 ,the
 hero is standing with his head1 marked 
by the star  ,alpha ,herculis1 toward   

the south1 and his foot resting on the  
head of  ,draco1 ,the ,dragon1 a        
far-northern constellation with which we
 become  acquainted in ,august4         
,illustration3 ,,july--,,hercules       
,alpha ,herculis1 the best known star in
 this constellation1 is of  unusual     
interest4 ,not only is it a most        
beautiful double star1 the  brighter of 
the two stars of which it is composed   
being orange1 and  the fainter          
greenish-blue1 but it is also a star    
that changes in  brightness irregularly4
 ,both the orange and the blue star     
share in  this change of brightness4    
,there are a number of stars in the     
heavens  that vary in brightness1 some  
in very regular periods1 and others1    
like ,alpha ,herculis1 irregularly4     
,these latter stars are nearly  always  
deep orange or reddish in color4 ,one   
may note this variation  in the         
brightness of ,alpha ,herculis by       
comparing it from time to time  with    
some nearby star that does not vary in  

brightness4      ,illustration3 ,,the   
,,great ,,hercules ,,cluster--,a        
,,universe ,,of ,,suns    ,taken with   
#fj-;inch ,reflector of the ,mt4 ,wilson
 ,observatory    ,the constellation of  
,hercules is a very rich field for the  
possessor  of even a small telescope4   
,here are to be found beautifully       
colored  double stars in profusion1 and1
 in addition1 two remarkable clusters   
of stars4 ,the brighter of the two is   
known as the ,great ,hercules  ,cluster4
 ,its position is shown on the chart1   
and1 under favorable  conditions--that  
is1 on a clear1 dark night1 when there  
is no  moonlight--it may be seen without
 the aid of a telescope as a small1     
faint patch of light4 ,one would never  
suspect from such a view what  a        
wonderful object this cluster becomes   
when seen with the aid of a  powerful   
telescope4 ,photographs taken with the  
great telescopes show  this faint wisp  
of light as a magnificent assemblage of 
thousands of  stars1 each a sun many    

times more brilliant than our own sun4  
,the  crowded appearance of the stars in
 the cluster is due partly to the  fact 
that it is very distant from the earth1 
though neighboring stars  in the cluster
 are indeed much nearer to one another  
than are the  stars in the vicinity of  
our solar system4 ,it has been found    
that  this cluster is so far away that  
its light takes over thirty-six         
thousand years to reach the earth4 ,at  
the distance of this cluster1  a sun    
equal in brightness to our own sun would
 be so faint that the  most powerful    
telescope in the world would not show   
it4 ,so we know  that the stars that are
 visible in the ,hercules cluster are   
far more  brilliant than our sun4 ,a    
fair-sized telescope will show about    
four  thousand stars in this cluster1   
but the greatest telescopes show over   
one hundred thousand in it1 and there   
are without doubt many more too  faint  
to be seen at all4 ,the ,hercules       
cluster is called a globular            

star-cluster1 because the stars in it   
are arranged nearly in the form  of a   
sphere4 ,there are in the heavens about 
ninety such clusters  whose distances   
have been found1 and they are among the 
most distant  of all objects4 ,most of  
them are very faint1 and a few are over 
two  hundred thousand light-years       
distant from the earth4 ,the ,hercules  
cluster is one of the nearest and is the
 most noted of all of these  globular   
clusters4 ,it is considered to be one of
 the finest objects  in the heavens4    
,the other cluster in ,hercules is also 
very fine1 but  not to be compared with 
this one4      ,illustration3           
,,july--,,ophiuchus ,,and ,,serpens     
,just to the south of ,hercules are two 
constellations1 ,ophiuchus1 ,the        
,serpent-,bearer1 and ,serpens1 ,the    
,serpent1 which are so intermingled     
that it is difficult to distinguish     
them4 ,there are in these two           
constellations1 as in ,hercules1 no     
stars of unusual brilliancy1  but a     

large number of fairly bright stars4    
,the brightest star in  ,ophiuchus is   
known as ,alpha ,ophiuchi and it marks  
the head of the  ,serpent-,bearer4 ,the 
two stars1 ,alpha ,ophiuchi and ,alpha  
,herculis1  are close together1 being   
separated by a distance about equal to  
that between the ,pointers of the ,big  
,dipper4 ,alpha ,ophiuchi is the        
brighter of the two1 and it is farther  
east4    ,ophiuchus1 according to one   
legend1 was once a physician on earth1  
and was so successful as a healer that  
he could raise the dead4  ,pluto1 the   
god of the lower world1 became alarmed  
for fear his  kingdom would become      
depopulated1 and persuaded ,jupiter to  
remove  ,ophiuchus to a heavenly abode1 
where he would be less troublesome4     
,the serpent is supposed to be a symbol 
of his healing powers4 ,the  head of    
,serpens is marked by a group of faint  
stars just south of  ,corona ,borealis  
and southwest of ,hercules4 ,from here a
 line of fairly  bright stars marks the 

course of ,serpens southward to the hand
 of  ,ophiuchus4 ,two stars close       
together and nearly equal in brightness 
mark the hand with which the hero grasps
 the body of the serpent4 ,the  other   
hand is marked by an equally bright     
single star some distance  to the       
eastward where the two constellations   
again meet4 ,ophiuchus  is thus         
represented as holding the serpent with 
both hands4 ,it is  not an easy matter  
to make out the outlines of these       
straggling  groups1 but there are in    
them several pairs of stars nearly equal
 in  brightness and about as evenly     
spaced as the two stars in the one  hand
 of ,ophiuchus1 and these1 as well as   
the diagram1 will be of aid  in tracing 
the two groups4    ,just south of       
,serpens and ,ophiuchus lies one of the 
most beautiful  and easily recognized   
constellations in the heavens4 ,this is 
the  constellation of ,scorpio1 ,the    
,scorpion1 which will be found not far  
above the southern horizon at this time4

 ,the small constellation  of ,libra1   
,the ,scales1 which lies just to the    
northwest of ,scorpio1  was at one time 
a part of this constellation and        
represented the  creature's claws1 but  
some centuries ago its name was changed 
to  ,libra4 ,both ,scorpio and ,libra   
are numbered among the twelve zodiacal  
constellations--that is1 they lie along 
the ecliptic1 or apparent  yearly path  
of the sun among the stars4 ,scorpio is 
the most brilliant  and interesting of  
all the zodiacal groups4 ,the heart of  
the ,scorpion  is marked by the         
magnificent first-magnitude star        
,antares1 which is  of a deep reddish   
color4 ,the name signifies ,rival of    
,ares 7,mars74  ,it is so called because
 it is the one star in the heavens that 
most  closely resembles ,mars1 and it   
might be mistaken for the ruddy planet  
if one were not familiar with the       
constellations4 ,at times1 when ,mars   
is at a considerable distance from the  
earth1 it is almost equal  in brightness

 and general appearance to this glowing 
red star in  the heart of the ,scorpion4
 ,in its trips around the sun1 ,mars    
passes  occasionally very close to      
,antares1 and the two then present a    
very  striking appearance4              
,illustration3 ,,july--,,libra ,,and    
,,scorpio    ,with a telescope of medium
 size1 one will find an exquisite little
  green companion-star close to         
,antares4 ,the little companion is so   
close to ,antares that it is difficult  
to find it in the glare of  light from  
its more brilliant neighbor4 ,antares is
 one of the giant  stars of the         
universe4 ,in fact it is1 so far as we  
know1 the greatest  of all the giants4  
,its diameter is more than five hundred 
times that  of our own sun and nearly   
twice that of the giant star ,betelgeuze
 in  ,orion4 ,if placed at the center of
 the solar system its surface would  lie
 far beyond the orbit of ,mars4    ,both
 ,ophiuchus and ,scorpio are crossed by 
the ,milky ,way1 that broad  belt of    

numberless faint stars that encircles   
the heavens4 ,some of  the most         
wonderful and beautiful regions of the  
,milky ,way are to be  found in these   
two constellations4    ,at various times
 in the past1 there have suddenly       
flashed forth  brilliant stars in the   
,milky ,way which are known as temporary
  stars1 or nov4 ,these outbursts       
signify that some celestial  catastrophe
 has taken place1 the nature or cause of
 which is not  clearly understood4 ,some
 of the most brilliant of these         
outbursts  have occurred in these two   
constellations4 ,the life of a nova is  
very  short1 a matter of a few months1  
and it rapidly sinks into oblivion1  so 
nothing is to be seen of some of the    
most brilliant of all these  stars that 
have appeared in this region in the     
past4 ,a few are still  faintly visible 
in large telescopes4          ,,ix      
,,august      ,it was one of the twelve 
labors of ,hercules1 the hero of        
,grecian  mythology1 to vanquish the    

dragon that guarded the golden apples in
  the garden of the ,hesperides4 ,among 
the constellations for ,july we  found  
the large group of stars that represents
 the hero himself1  and this month we   
find just to the north of ,hercules the 
head of  ,draco1 ,the ,dragon4 ,the foot
 of the hero rests upon the dragon's    
head1  which is outlined by a group of  
four fairly bright stars forming a      
quadrilateral or four-sided figure4 ,the
 brightest star in this group  passes in
 its daily circuit of the pole almost   
through the zenith  of ,london4 ,that   
is1 as it crosses the meridian of       
,london1 it is  almost exactly overhead4
 ,from the head of ,draco1 the          
creature's body  can be traced in a long
 line of stars curving first eastward1  
then  northward1 toward the pole-star to
 a point above ,hercules1 where it      
bends sharply westward4 ,the body of the
 monster lies chiefly between  its head 
and the bowl of the ,little ,dipper4    
,the tail extends in a  long line of    

faint stars midway between the two      
,dippers1 or the  constellations of     
,ursa ,major and ,ursa ,minor1 the tip  
of the tail  lying on the line          
connecting the ,pointers of the ,big    
,dipper with the  pole-star ,polaris4   
,draco1 as well as ,ursa ,major and     
,ursa ,minor1 is a circumpolar          
constellation in our latitude2 that is1 
it makes its circuit of the  pole       
without at any time dipping below the   
horizon in latitudes  north of #dj4 ,it 
is1 therefore1 visible at all hours of  
the night in  mid-latitudes of the      
northern hemisphere1 but is seen to the 
best  advantage during the early evening
 hours in the summer months4 ,there  are
 no remarkable stars in this            
constellation with the exception of     
,alpha1 which lies halfway between the  
bowl of the ,little ,dipper and  ,mizar1
 the star at the bend in the handle of  
the ,big ,dipper4      ,illustration3   
,,august--,,draco ,,and ,,lyra    ,about
 four thousand seven hundred years ago1 

this star was the  pole-star--lying even
 nearer to what was then the north pole 
of the  heavens than ,polaris does to   
the present position of the pole4 ,the  
sun and moon exert a pull on the bulging
 equatorial regions of the  earth1 which
 tends to draw the plane of the earth's 
equator down  into the plane of the     
ecliptic4 ,this causes the ,precession  
of the  ,equinoxes and at the same time 
a slow revolution of the earth's axis   
of rotation about the pole of the       
ecliptic4 ,the north pole of the        
heavens as a result describes a circle  
about the pole of the ecliptic  of      
radius #bc-a_/b in a period of #be1hjj  
years4    ,each bright star that lies   
near the circumference of this circle   
becomes in turn the pole-star sometime  
within this period4 ,the star  ,alpha1  
in ,draco1 had its turn at being        
pole-star some forty-seven  centuries   
ago4 ,polaris is now a little over a    
degree from the north  pole of the      
heavens4 ,during the next two centuries 

it will continue  to approach the pole  
until it comes within a quarter of a    
degree  of it1 when its distance from   
the pole will begin to increase  again4 
,about twelve thousand years hence the  
magnificent ,vega1  whose acquaintance  
we will now make1 will be the most      
brilliant and  beautiful of all         
pole-stars4    ,vega 7,arabic for       
,falling ,eagle7 is the resplendent1    
bluish-white1  first-magnitude star that
 lies in the constellation of ,lyra1    
,the ,lyre  or ,harp1 a small1 but      
important1 constellation just east of   
,hercules  and a little to the southeast
 of the head of ,draco4 ,vega is almost 
exactly equal in brightness to          
,arcturus1 the orange-colored star in   
,botes1 now lying west of the meridian  
in the early evening hours4  ,it is also
 a near neighbor of the solar system1   
its light taking  something like forty  
years to travel to the earth4 ,vega is  
carried  nearly through the zenith of   
,washington and all places in the same  

latitude by the apparent daily rotation 
of the heavens4 ,it is a star  that we  
have no difficulty in recognizing1 owing
 to the presence of  two nearby stars   
that form1 with it1 a small equal-sided 
triangle  with sides only two degrees in
 extent4 ,if our own sun were at the    
distance of ,vega1 it would not appear  
as bright as one of these faint  stars1 
so much more brilliant is this          
magnificent sun than our own4  ,the two 
faint stars that follow so closely after
 ,vega and form the  little triangle    
with it are also of particular interest4
 ,epsilon  ,lyr1 which is the northern  
one of these two stars1 may be used as a
  test of keen eyesight4 ,it is the     
finest example in the heavens of a      
quadruple star--that is1 a double-double
 star4 ,a keen eye can just  separate   
this star into two without a telescope1 
and with the aid of  a telescope1 each  
of the two splits up into two stars1    
making four  stars in place of the one  
visible to the average eye4 ,zeta1 the  

other  of the two stars that form the   
little triangle with ,vega1 is also a   
fine double star4 ,the star that lies   
almost in a straight line with  ,epsilon
 and ,zeta and a short distance to the  
south of them is a very  interesting    
variable star known as ,beta ,lyr4 ,its 
brightness changes  very considerably in
 a period of twelve days and twenty-two 
hours4  ,this change of brightness is   
due to the presence of a companion      
star4 ,the two stars are in mutual      
revolution1 and their motion is  viewed 
at such an angle from the earth that1 in
 each revolution1 one  star is eclipsed 
by the other1 producing a variation in  
the amount  of light that reaches our   
eyes4 ,by comparing this star from day  
to  day with the star just a short      
distance to the southeast of it1 which  
does not vary in brightness1 we can     
observe for ourselves this change  in   
the light of ,beta ,lyr4 ,there are a   
number of stars in the heavens  that    
vary in brightness in the same manner as

 ,beta ,lyr1 and they are  called       
eclipsing-variable stars4    ,on the    
line connecting ,beta ,lyr with the star
 southeast of it and  one-third of the  
distance from ,beta to this star1 lies  
the noted  ,ring ,nebula in ,lyra1 which
 is a beautiful object even in a small  
telescope4 ,it consists of a ring of    
luminous gas surrounding a  central     
star4 ,the star shines with a brilliant1
 bluish-white light  and is visible only
 in powerful telescopes though it is    
easily  photographed since it gives     
forth rays to which the photographic    
plate is particularly sensitive4 ,in    
small telescopes the central part  of   
this nebula appears dark but with a     
powerful telescope a faint  light may be
 seen even in the central portion of the
 nebula4 ,this is  one of the most      
interesting and beautiful telescopic    
objects in the  heavens4    ,it is in   
the general direction of the            
constellation of ,lyra that our  solar  
system is speeding at the rate of more  

than a million miles a  day4 ,this point
 toward which we are moving at such     
tremendous speed  lies a little to the  
southwest of ,vega1 on the border       
between the  constellations of ,lyra and
 ,hercules1 and is spoken of as ,the    
,apex of  the ,sun's ,way4              
,illustration3 ,,august--,,sagittarius  
,in the southern sky we have this month 
the constellation of  ,sagittarius1 ,the
 ,archer1 which is just to the east of  
,scorpio and  a considerable distance   
south of ,lyra4 ,it can be recognized by
 its  peculiar form1 which is that of a 
short-handled milk dipper1 with  the    
bowl turned toward the south and a trail
 of bright stars running  from the end  
of the handle toward the southwest4     
,this is one of  the zodiacal groups    
which contain no first-magnitude stars1 
but a  number of the second and third   
magnitude4 ,it is crossed by the ,milky 
,way1 which is very wonderful in its    
structure at this point4 ,some          
astronomers believe that here--among the

 star-clouds and mists of  nebulous     
light which are intermingled with dark  
lanes and holes1 in  reality dark       
nebul--lies the center of the vast      
system of stars and  nebul in which our 
entire solar system is but the merest   
speck4 ,some  of the grandest views     
through the telescope are also to be    
obtained  in this beautiful             
constellation of ,sagittarius1 which is 
so far  south that it is seen to better 
advantage in the tropics than in the    
mid-latitudes of the northern           
hemispheres4          ,x    ,,september 
,one of the most beautiful              
constellations of the northern          
hemisphere  is ,cygnus1 ,the ,swan1     
which is in the zenith in mid-latitudes 
about  nine o'clock in the evening the  
middle of ,september4 ,it lies directly 
in the path of the ,milky ,way which    
stretches diagonally across  the heavens
 from the northeast to the southwest at 
this time4 ,in  ,cygnus1 the ,milky ,way
 divides into two branches1 one passing 

through  ,ophiuchus and ,serpens to     
,scorpio1 and the other through ,sagitta
 and  ,aquila to ,sagittarius1 to meet  
again in the southern constellation of  
,ara1 just south of ,scorpio and        
,sagittarius4 ,on clear1 dark evenings1 
when there is no moonlight1 this long1  
dark rift in the ,milky ,way  can be    
seen very clearly4 ,in ,cygnus1 as in   
,ophiuchus1 ,scorpio1 and  ,sagittarius 
we find wonderful star-clouds1          
consisting of numberless  stars so      
distant from us and1 therefore1 so faint
 that they do not  appear as distinct   
points of light except in the greatest  
telescopes4  ,it is the combined light  
from these numberless stars that cannot 
be seen separately that produces the    
impression of stars massed in  clouds of
 nebulous light and gives to this girdle
 of the heavens  its name of the ,milky 
,way4 ,in ,cygnus1 as in a number of    
other  constellations of both           
hemispheres1 the ,milky ,way is crossed 
by dark  rifts and bars and is very     

complicated in its structure4 ,it is in 
,cygnus1 also1 that one may see with the
 aid of powerful telescopes  the vast1  
irregular1 luminous nebul1 that are like
 great clouds of  fiery mist4 ,these    
nebul are of enormous extent1 for they  
cover space  that could be occupied by  
hundreds of stars4      ,illustration3  
,,september--,,cygnus    ,cygnus is a   
constellation that is filled with the   
wonders and  mysteries of space and that
 abounds in beautiful objects of varied 
kinds4 ,it is a region one never tires  
of exploring with the  telescope4 ,the  
principal stars in ,cygnus form the     
well-known ,northern  ,cross1 with the  
beautiful1 white1 first-magnitude star  
,deneb1 or  ,arided1 as it is sometimes 
called1 at the top of the cross1 and    
,albireo1 the orange-and-blue double    
star at the foot4 ,albireo1  among all  
the pairs of contrasting hues1 has the  
distinction of  being considered the    
finest double star in the heavens for   
small  telescopes4 ,this star marks the 

head of ,the ,swan1 as well as the foot 
of the ,northern ,cross1 and ,deneb     
marks the tail of ,the ,swan4 ,a short  
distance to the southeast of ,deneb1 on 
the right wing of ,the ,swan1  is a     
famous little star1 #fa ,cygni1 barely  
visible to the naked eye  and forming a 
little triangle with two brighter stars 
to the east4  ,this star has the        
distinction of being the first one to   
have its  distance from the solar system
 determined4 ,the famous mathematician  
and astronomer ,bessel accomplished this
 difficult feat in the year  #ahch4     
,since that day1 the distances of many  
stars have been found  by various       
methods1 but of all these stars only    
four or five are  known to be nearer to 
us than #fa ,cygni4 ,its distance is    
about eight  light-years1 so its light  
takes about eight years to travel the   
distance that separates it from the     
solar system4 ,as a result1 we see  it  
not as it is tonight1 but as it was at  
the time when the light  now entering   

our eyes first started on its journey   
eight years ago4  #fa ,cygni is also a  
double star1 and the combined light of  
the two  stars gives forth only         
one-tenth as much light as our own sun4 
,most  of the brilliant first-magnitude 
stars give forth many times as much     
light as the sun2 but among the fainter 
stars1 we find some that  appear faint  
because they are very distant1 and some 
that are faint  because they are dwarf  
stars and have little light to give     
forth4 ,to  the class of nearby1        
feebly-shining dwarf stars #fa ,cygni   
belongs4  ,deneb1 on the other hand1 is 
one of the giant stars1 and is at an    
immeasurably great distance from the    
solar system4    ,just south of ,cygnus 
in the eastern branch of the ,milky ,way
 lie  ,sagitta1 ,the ,arrow1 and        
,aquila1 ,the ,eagle4 ,not far to the   
northeast  of ,aquila is the odd little 
constellation of ,delphinus1 ,the       
,dolphin1  popularly referred to as     
,job's ,coffin4 ,there will be no       

difficulty in  finding this small       
star-group1 owing to its peculiar       
diamond-shaped  configuration4 ,its five
 principal stars are of the fourth      
magnitude4  ,it is in the constellation 
of ,delphinus that the most distant     
known  object in the heavens is located4
 ,this is the globular star cluster     
known only by its catalogue number of   
,n4,g4,c4 #gjjf4 ,it is estimated to  be
 at a distance of #bbj1jjj light-years  
from the earth4    ,sagitta1 ,the       
,arrow1 lies midway between ,albireo and
 the brilliant  ,altair in ,aquila4 ,the
 point of the arrow is indicated by the 
star  that is farthest east2 and the    
feather1 by the two faint stars to the  
west4 ,like ,delphinus1 this            
constellation is very small and contains
  no objects of particular interest4    
,altair 7,flying ,eagle7 is the         
brilliant white star of the first       
magnitude in ,aquila and is attended by 
two fainter stars1 one on  either side1 
at nearly equal distances from it4      

,these two stars serve  readily to      
distinguish this star1 all three stars  
being nearly in a  straight line4       
,altair is one of the nearer stars1 its 
distance from  the earth being about    
sixteen light-years4 ,it gives forth    
about ten  times as much light as the   
sun4      ,illustration3                
,,september--,,delphinus1 ,,aquila ,,and
 ,,sagitta    ,we cannot leave the      
constellation of ,aquila without        
referring to  the wonderful temporary   
star or nova1 known as ,nova ,aquil ,no4
 #c  7because it was the third nova to  
appear in this constellation71  which   
appeared in the position indicated on   
the chart upon the  eighth of ,june1    
#aiah4 ,a few days previous to this     
date1 there was  in this position an    
extremely faint star1 invisible to the  
naked  eye and in small telescopes4     
,this fact became known from later      
examinations of old photographs of this 
region that had been taken  at the      
,harvard ,college ,observatory1 where   

the photographing of the  heavens is    
carried on regularly for the purpose of 
having a record  of celestial changes   
and happenings4 ,clouds prevented the   
obtaining  of any photographs of this   
part of the heavens on the four nights  
preceding the eighth of ,june1 but on   
this evening there shone in the  place  
of the faint telescopic star1 a         
wonderful temporary star1 or  nova1     
which was destined on the next evening  
to outshine all stars  in the heavens1  
with the exception of the brightest of  
all1 ,sirius1  which it closely rivaled 
in brilliancy at the height of its      
outburst4  ,within less than a week's   
time1 this faint star in the ,milky ,way
 for  some mysterious reason increased  
in brightness many thousandfold4  ,such 
outbursts have been recorded before1 but
 on rare occasions1  however4 ,no star  
since the appearance of the nova known  
as ,kepler's  ,star1 in the year #afjd1 
which at its greatest brilliancy rivaled
  ,jupiter1 shone with such splendor or 

attracted so much attention as  ,nova   
,aquil4 ,in the year #aija1 there       
appeared in the constellation of        
,perseus a star known as ,nova ,persei  
which at its brightest surpassed  ,vega1
 but its splendor was not as great as   
that of the wonderful nova  of #aiah4   
,it speaks well for the zeal and        
interest of amateur astronomers1 as     
well as for their acquaintance with the 
stars1 that ,nova ,persei was           
discovered by an amateur astronomer1    
,dr4 ,anderson1 and that among  the     
deluge of telephone calls and telegrams 
received at the ,harvard  ,college      
,observatory on the night of ,june #hth1
 announcing independent  discoveries of 
the new star1 were many from            
non-professional  astronomers4    ,like 
all stars of this class1 ,nova ,aquil   
,no4 #c sank rapidly into  oblivion4 ,in
 a few weeks it was only a              
third-magnitude star2 a few  weeks more 
and it was invisible without a          
telescope4 ,many wonderful  and         

interesting changes have been recorded  
in the appearance of this  star1        
however1 even after it became visible   
only in the telescope4  ,soon after its 
outburst it appeared to develop a       
nebulous envelope1  as have other novas 
before it4 ,it showed in addition many  
of the  peculiarities of the nebul1     
though the central star remained visible
  as before the outburst4               
,astronomers are still in doubt as to   
the cause of these outbursts1  which    
certainly indicate celestial            
catastrophies of some form on a         
gigantic scale4 ,all novas possess one  
characteristic in common--that  of      
appearing exclusively in the ,milky     
,way2 and another characteristic  is the
 development of a nebular envelope after
 the outburst of  greatest brightness4  
,in some cases temporary stars have been
 known to  be variable in brightness for
 years before the great outburst4 ,such 
a star was ,nova ,aquila1 for the       
examination of photographs of this      

region taken some years previous showed 
variations in its brightness  for a     
period of thirty years at least4    ,up 
to the beginning of this century only   
about thirty novas had  been discovered4
 ,since that date1 thanks to the        
vigilance of the  astronomers of today  
and to the aid of photography1 more have
 been  discovered than in all the       
preceding centuries4 ,these outbursts   
of new stars appear to be not so rare as
 the earlier astronomers  believed1     
though great outbursts as brilliant as  
that of ,nova ,aquila  are very         
uncommon4          ,,xi    ,,october    
,the constellations that will be found  
nearest the meridian in early  ,october 
evenings are the circumpolar            
constellations ,cepheus and             
,cassiopeia1 and in the southern sky1   
,capricornus and ,aquarius4    ,cepheus1
 ,the ,king1 and ,cassiopeia1 his       
,queen1 of whom we shall have  more to  
say later in connection with the        
constellations of ,andromeda  and       

,perseus1 sit facing the north pole of  
the heavens opposite  ,ursa ,major1 ,the
 ,great ,bear1 familiar to us under the 
name of ,the  ,big ,dipper4 ,the foot of
 ,cepheus rests upon the tail of the    
,little  ,bear1 and the star farthest   
north in the diagram is in the left     
knee4 ,the head is marked by a small    
triangle of faint stars1 shown  in the  
diagram4 ,one of these three faint      
stars--the one farthest  east--known as 
,delta ,cephei1 is a very remarkable    
variable star1  changing periodically in
 brightness every five and one-third    
days4  ,its name has been given to a    
large class of variable stars--the      
,cepheid variables--that resemble ,delta
 ,cephei in being giant suns1  faint    
only because they are at very great     
distances from the earth1  and varying  
in brightness with the greatest         
regularity in periods  that range from a
 few hours to several weeks4 ,it has    
been found that  the longer the period  
of light change the greater is the star 

in  size and brightness4 ,the ,cepheids 
of longest period are #aj1jjj times     
more brilliant than our own sun4        
,cepheus contains no very bright or     
conspicuous stars4 ,alpha ,cephei1 the  
brightest star in the group1  marks ,the
 ,king's right shoulder4 ,it is the star
 farthest to the west  in the diagram1  
and is only a third-magnitude star4     
,illustration3 ,,october--,,cassiopeia  
,,and ,,cepheus    ,cassiopeia is a     
constellation with which every one in   
the northern  hemisphere should be      
familiar1 owing to its very distinctive 
,w-shape  and its far northern position1
 which brings it conspicuously into     
view throughout the clear fall and      
winter evenings4 ,cassiopeia is         
pictured in all star atlases that show  
the mythological figures1  with her face
 toward the north pole4 ,the stars in   
the ,w outline the  body4 ,alpha1 the   
star farthest south in the diagram marks
 the breast  of ,cassiopeia4 ,her head  
and uplifted hands are represented by   

faint  stars south of ,alpha4 ,this star
 is occasionally referred to by its     
,arabic name of ,schedir4 ,beta1 the    
leader of all the stars in the ,w in    
their daily westward motion1 is also    
known by an ,arabic name1 ,caph4    ,in 
the constellation of ,cassiopeia there  
appeared in the year #aegb  ,a4,d41 a   
wonderful temporary star which suddenly1
 within a few days'  time1 became as    
brilliant as the planet ,venus and was  
clearly visible  in broad daylight4     
,this star is often referred to as      
,tycho's ,star1  because it was         
observed1 and its position very         
accurately determined1  by ,tycho       
,brahe1 one of the most famous of the   
old astronomers4 ,this  star remained   
visible to every one for about sixteen  
months1 but it  finally faded completely
 from view1 and it is believed that a   
faint1  nebulous red star1 visible only 
in the telescope and close to the       
position recorded by ,tycho1 represents 
the smoldering embers of the  star that 

once struck terror to the hearts of the 
superstitious and  ignorant among all   
the nations of ,europe1 who took it to  
be a sign  that the end of the world was
 at hand4    ,both ,cassiopeia and      
,cepheus lie in the path of the ,milky  
,way1 which  reaches its farthest       
northern point in ,cassiopeia and passes
 from  ,cepheus in a southerly direction
 into the constellation of ,cygnus4     
,illustration3 ,,october--,,aquarius    
,,and ,,capricornus    ,turning now to  
southern skies1 we find on and to the   
west of the  meridian at this time the  
rather inconspicuous zodiacal           
constellation  of ,capricornus1 ,the    
,goat4 ,it contains no stars of great   
brightness  and is chiefly remarkable   
for the fact that it contains one of the
  few double stars that can be seen     
without the aid of a telescope4  ,the   
least distance in the heavens that the  
unaided human eye can  separate is about
 four minutes of arc4 ,the star ,alpha  
in ,capricornus  is made up of two stars

 separated by a distance of six minutes 
of arc1 so that any one can readily see 
that it consists of two  stars very     
close together4 ,this star1 ,alpha1 will
 be found in the  extreme western part  
of the constellation1 and can best be   
located  in conjunction with the star   
,beta1 which is slightly brighter and   
lies but a short distance almost due    
south of ,alpha1 the two stars  standing
 somewhat alone in this part of the     
heavens4    ,to the north and east of   
,capricornus we find ,aquarius1 which is
 also  a zodiacal constellation4        
,aquarius is the ,water-,bearer1 and the
 water  jar which he carries is         
represented by a small1 but distinct1 ,y
 of  stars from which flows a stream of 
faint stars toward the southeast  and   
south4 ,aquarius1 like ,capricornus1 is 
a rather uninteresting  constellation1  
as it is made up of inconspicuous third-
 and  fourth-magnitude stars4 ,the      
entire region covered by these two      
groups  of stars is remarkably barren1  

since it contains not a single first-   
or even second-magnitude star and little
 to attract the observer's  eye4    ,to 
relieve the barrenness of this region1  
there appears just to the  south of     
,aquarius and southeast of ,capricornus1
 sparkling low in the  southern sky on  
crisp ,october evenings1 the beautiful  
first-magnitude  star ,fomalhaut in the 
small southern constellation of ,piscis 
,australis1 ,the ,southern ,fish4 ,this 
star is the farthest south of  all the  
brilliant first-magnitude stars that can
 be seen from the  middle latitudes of  
the ,northern ,hemisphere4 ,the         
constellation in  which it lies is so   
close to the southern horizon in our    
latitudes  that it cannot be seen to any
 advantage1 and it is at best very      
inconspicuous1 containing no other      
objects of interest4 ,fomalhaut  cannot 
be mistaken for any other star visible  
at this time of year  in the evening1   
since it stands in such a solitary      
position far to  the south4 ,at the time

 of which we are writing it will be     
found a few  degrees east of the        
meridian4          ,,xii    ,,november  
,directly south of ,cassiopeia and      
,cepheus1 the circumpolar               
constellations with which we became     
acquainted last month1 and almost       
overhead in our latitudes in the early  
evening hours of ,november1 lie         
,pegasus1 ,the ,winged ,horse1 and      
,andromeda1 ,the ,woman ,chained4       
,according to the legend1 ,cepheus was  
king of ,ethiopia1 and ,cassiopeia  was 
the beautiful1 but vain1 queen who dared
 to compare herself in  beauty with the 
sea-nymphs4 ,this so enraged the nymphs 
that1 as a  punishment for her          
presumption1 they decided to send a     
terrible  sea-monster to ravage the     
coast of the kingdom4 ,the king and     
queen1  upon consulting the oracle1     
found that the only way to avert this   
calamity would be to chain their        
daughter ,andromeda to the rocks and    
permit the monster to devour her4       

,illustration3 ,,november--,,andromeda  
,,and ,,pegasus    ,as the story goes1  
the valiant hero1 ,perseus1 chanced to  
be riding  through the air on his winged
 horse and saw1 far beneath him the     
beautiful maiden chained to the rocks   
and the frightful monster  approaching  
to devour her4 ,he immediately went to  
the rescue1 and1  after a terrible      
struggle with the monster1 succeeded in 
overpowering  him and thus saved the    
maiden from a dreadful fate4 ,perseus   
and the  fair ,andromeda were married   
shortly afterward1 and at the end of a  
happy life the pair were transferred to 
the heavens4 ,cassiopeia1 the  vain     
queen1 was ordered to be bound to a     
chair and1 with the king  ,cepheus at   
her side1 to be swung continually around
 the north pole of  the heavens that she
 might be taught a lesson in humility4  
,the constellation ,cetus1 representing 
the sea-monster1 will be found  to the  
southeast and south of ,pisces1 ,the    
,fishes1 which lie south of  ,andromeda 

and ,pegasus4    ,the ,great ,square in 
,pegasus is the most conspicuous        
configuration  of stars to be seen in   
the heavens in autumn evenings4 ,the    
star  that marks the northeastern corner
 of ,the ,great ,square belongs to  the 
constellation of ,andromeda and marks   
the head of the maiden1  who is resting 
upon the shoulders of ,pegasus1 ,the    
,winged ,horse4 ,the  three bright stars
 nearly in a straight line outline the  
maiden's  body1 ,alpha1 or ,alpheratz1  
as it is called1 being the star in the  
head1 ,beta or ,mirach in the waist1 and
 ,gamma or ,almach in the left  foot4   
,the last-named star1 which is farthest 
to the northeast in  the diagram1 was1  
in the opinion of the noted astronomer  
,herschel1  the finest double star in   
the heavens4 ,the two stars into which  
the  telescope splits it are of the     
beautifully contrasted shades of  orange
 and sea green4    ,a second most       
interesting object in ,andromeda and one
 of the finest  in the entire heavens is

 ,the ,great ,andromeda ,nebula1 which  
is faintly  visible without the aid of a
 telescope as a hazy patch of light4 ,it
  is believed that in reality this      
nebula is a great universe composed  of 
many thousands of stars so distant that 
no telescope can show the  individual   
members and that the light from it takes
 many thousands  of years to span the   
abyss that separates it from the solar  
system4  ,some magnificent photographs  
of ,the ,great ,andromeda ,nebula have  
been  taken with powerful telescopes4   
,it is through the use of photography   
that the nebul can best be studied1 for 
a photographic plate after  long        
exposure1 reveals a wonderful detail in 
the structure of these  objects that the
 human eye fails to see4 ,on a clear1   
dark evening  one may find ,the ,great  
,andromeda ,nebula by the aid of two    
faint stars  with which it makes a small
 triangle1 as shown in the chart4 ,this 
nebula is the only one of the spiral    
nebula that can be seen in these        

latitudes without the aid of a          
telescope1 though there are several     
spiral nebul in the southern heavens    
that can be thus seen4    ,lying to the 
northwest of ,the ,great ,square in     
,pegasus are a number of  faint stars   
that outline the shoulders and head of  
the winged steed1  while the stars to   
the southwest of the square outline his 
forelegs4  ,the creature is represented 
without hind quarters in all star       
atlases4 ,the space within ,the ,great  
,square contains no bright stars1  and  
as a result1 the outline of the square  
stands out with great  distinctness4    
,there are1 in fact1 no stars of the    
first magnitude in  either ,pegasus or  
,andromeda1 though there are a number of
 the second  and third magnitude which  
very clearly show the distinctive forms 
of  these two star-groups4    ,pisces1  
,the ,fishes1 the constellation just    
south of ,andromeda and  ,pegasus1 is   
the first of the twelve zodiacal        
constellations4 ,it  consists of the    

southern fish1 lying in an east-to-west 
direction1  and the northern fish1 lying
 nearly north and south1 the two        
touching  at the southeastern extremity 
of the constellation4                   
,illustration3 ,,november--,,pisces     
,there is in ,pisces not a single bright
 star1 and its only point of  interest  
is to be found in the fact that it      
contains the point1  marked by the cross
 and letter ,v in the diagram1 that is  
known  variously as the vernal equinox1 
the equinoctial point and ,the  ,first  
,point in ,aries4 ,this is a very       
important point of reference  in the    
heavens1 just as the meridian of        
,greenwich is for the earth1  and it    
marks the point where the sun crosses   
the equator going north  in the spring4 
,owing to the ,precession of the        
,equinoxes1 as it is  called1 this point
 is gradually shifting its position     
westward  through the zodiacal          
constellations at a rate that will carry
 it  completely around the heavens      

through the twelve zodiacal groups in  a
 period of #be1hjj years4 ,since the    
beginning of the ,christian era1  this  
point has backed from the constellation 
of ,aries1 which lies  just east of     
,pisces1 into ,pisces1 though it still  
retains its name of  ,the ,first ,point 
in ,aries4          ,,xiii    ,,december
      ,the eastern half of the sky on   
early ,december evenings is adorned     
with some of the finest star-groups in  
the heavens2 but as we are  considering 
for each month only the constellations  
that lie on or  near the meridian in the
 early evening hours1 we must turn our  
eyes for the present from the sparkling 
brilliants in the east to  the stars in 
the less conspicuous groups of ,aries1  
,the ,ram1 and  ,cetus1 ,the ,whale4 ,we
 will also become acquainted this month 
with  the beautiful and interesting     
constellation of ,perseus1 the hero of  
mythical fame to whom we referred last  
month in connection with the  legend of 
,cepheus and ,cassiopeia4 ,cetus1 you   

will recall1 represents  the sea-monster
 sent to devour ,andromeda1 the daughter
 of ,cepheus and  ,cassiopeia4 ,we have 
included the constellation of ,andromeda
 in our  diagram for this month1 since  
it is so closely associated in legend   
with the constellations of ,perseus and 
,cetus1 though we also showed  it last  
month4    ,the brightest star in        
,perseus1 known as ,alpha ,persei1 is at
 the  center of a curved line of stars  
that is concave or hollow toward  the   
northeast4 ,this line of stars is called
 the ,segment of ,perseus1  and it lies 
along the path of the ,milky ,way1 which
 passes from this  point in a           
northwesterly direction into            
,cassiopeia4 ,according to the  legend1 
,perseus1 in his great haste to rescue  
the maiden from ,cetus1  the monster1   
stirred up a great dust1 which is       
represented by the  numberless faint    
stars in the ,milky ,way at this point4 
,the star ,alpha  is in the midst of one
 of the finest regions of the heavens   

for the  possessor of a good field-glass
 or small telescope4    ,a short        
distance to the southwest of ,alpha is  
one of the most  interesting objects in 
the heavens4 ,to the ancients1 it       
represented  the baleful1 winking       
demon-eye in the head of the            
snaky-locked  ,gorgon1 ,medusa1 whom    
,perseus vanquished in one of his       
earliest  exploits and whose head he    
carried in his hand at the time of the  
rescue of ,andromeda4 ,to the           
astronomers1 however1 ,algol is known   
as ,beta ,persei1 a star that has been  
found to consist of two stars  revolving
 about each other and separated by a    
distance not much  greater than their   
own diameters4 ,one of the stars is so  
faint that  we speak of it as a dark    
star1 though it does emit a faint light4
  ,once in every revolution the faint   
star passes directly between us  and the
 bright star and partly eclipses it1    
shutting off five-sixths  of its light4 
,this happens with great regularity once

 in a little  less than three days4 ,it 
is for this reason that ,algol varies in
  brightness in this period4 ,there are 
a number of stars that vary in          
brightness in a similar manner4 ,their  
periods of light-change are all  very   
short1 and the astronomers call them    
eclipsing variables4 ,at  its brightest1
 ,algol is slightly brighter than the   
star nearest to  it in ,andromeda1 which
 is an excellent star with which to     
compare it4      ,illustration3         
,,december--,,perseus1 ,,aries ,,and    
,,cetus    ,perseus is another one of   
the constellations lying in the ,milky  
,way  in which temporary stars or novas 
have suddenly flashed forth4 ,at the    
point indicated by a cross in the       
diagram1 ,dr4 ,anderson1 an amateur     
astronomer of ,scotland1 found on       
,february #ba1 #aija1 a new star as     
brilliant as the pole-star4 ,on the     
following day it became brighter  than a
 star of the first magnitude4 ,a day    
later it had lost a third  of its light1

 and in a few weeks it was invisible    
without the aid  of a telescope4 ,in a  
year it was invisible in all except the 
most  powerful telescopes4 ,with such   
telescopes1 it may still be seen as a   
very faint nebulous light4              
,triangulum and ,aries are two rather   
inconspicuous constellations that  lie  
on1 or close to1 the meridian at this   
time4 ,there is nothing  remarkable     
about either of these groups1 except    
that ,aries is one of  the twelve       
zodiacal constellations4 ,some centuries
 ago1 the sun was  to be found in ,aries
 at the beginning of spring and the     
position it  occupies in the sky at that
 time was called the ,first ,point in   
,aries4  ,as this point is slowly       
shifting westward1 as we have explained 
elsewhere1 the sun is now to be found in
 ,pisces1 instead of ,aries at  the     
beginning of spring and does not enter  
,aries until a month later4  ,pisces was
 one of the constellations for ,november
 and we showed in  that constellation   

the present position of the sun at the  
beginning  of spring4    ,two stars in  
,aries--,alpha and ,beta--are fairly    
bright1 ,alpha being  fully as bright as
 the brightest star in ,andromeda4 ,beta
 lies a short  distance to the southwest
 of ,alpha1 and a little to the         
southwest  of ,beta is ,gamma1 the three
 stars forming a short curved line of   
stars that distinguishes this           
constellation from other groups4 ,the   
remaining stars in ,aries are all faint4
    ,just south of ,aries lies the head 
of ,cetus1 ,the ,whale4 ,this is an     
enormous constellation that extends far 
to the southwest1 below  a part of      
,pisces1 which runs in between          
,andromeda and ,cetus4 ,its  brightest  
star1 ,beta1 ,diphda1 or ,deneb ,kaitos1
 as it is severally  called1 stands     
quite alone not far above the           
southwestern horizon4  ,it is almost due
 south of ,alpha ,andromed1 the star in 
,andromeda  farthest to the west1 which 
it exactly equals in brightness4 ,the   

head  of ,cetus is marked by a          
five-sided figure composed of stars that
 are  all faint with the single         
exception of ,alpha1 which is fairly    
bright1  though inferior to ,beta or    
,diphda4    ,cetus1 though made up      
chiefly of faint stars1 and on the whole
  uninteresting1 contains one of the    
most peculiar objects in the  heavens1  
the star known as ,omicron ,ceti or     
,mira 7,the ,wonderful74 ,this  star    
suddenly rises from invisibility nearly 
to the brightness of a  first-magnitude 
star for a short period once every      
eleven months4  ,mira was the first     
known variable star4 ,its remarkable    
periodic  change in brightness was      
discovered by ,fabricius in the year    
#aeif1 so  its peculiar behavior has    
been under observation for three hundred
  and twenty-five years4 ,it is called a
 long-period variable star1  because its
 variations of light take place in a    
period of months  instead of a few hours
 or days1 as is the case with stars such

 as  ,algol4 ,mira is not only a        
wonderful star1 it is a mysterious star 
as well1 for the cause of its           
light-changes are not known1 as in  the 
case of ,algol where the loss of light  
is produced by a dark  star passing in  
front of a brighter star4 ,mira is a    
deep-red star1  as are all long-period  
variable stars that change irregularly  
in  brightness4 ,it is visible without a
 telescope for only one month or  six   
weeks out of the eleven months4 ,during 
the remainder of this  time1 it         
sometimes loses so much of its light    
that it cannot be found  with telescopes
 of considerable size4 ,its periods of  
light-change are  quite variable as is  
also the amount of light it gains at    
different  appearances4    ,it is       
believed that the cause of the          
light-changes of ,mira is to be  found  
within the star itself4 ,it has been    
thought that dense clouds  of vapors may
 surround these comparatively cool1 red 
stars and that  the imprisoned heat     

finally bursts through these vapors and 
we see  for a short time the glowing    
gases below2 then the vapors once more  
collect for a long period1 to be        
followed by another sudden outburst  of 
heat and light4    ,it is interesting to
 remember in this connection that our   
own sun has  been found to be slightly  
variable in the amount of light and heat
  that it gives forth at different      
times1 and the cause of its changes  in 
light and heat are believed to lie      
within the sun itself4          ,,xiv   
,,stars ,,of ,,the ,,southern           
,,hemisphere      ,as one travels       
southward from the mid-latitudes of the 
northern  hemisphere into the tropics   
our familiar circumpolar constellations 
sink lower and lower in the northern    
heavens and strange and  unfamiliar     
star-groups rise gradually above the    
southern horizon4  ,if we make our      
southward journey in the winter months  
the first of  the southern              
constellations to come fully into view  

is the small  star-group just south of  
,lepus known as ,columba 7,the ,dove71  
whose  brightest star ,phact is of the  
second magnitude4 ,a line drawn from    
,procyon to ,sirius and extended as far 
again brings us to this star  and a line
 from ,betelgeuze to ,sirius extended an
 equal distance  brings us to ,zeta     
,argus which is equal to ,phact in      
brightness4 ,the  two lines intersecting
 at ,sirius make the ,egyptian ,x as it 
is  called4    ,magnificent1 blue-white 
,canopus1 the most brilliant star in the
  heavens next to ,sirius1 a veritable  
diamond sparkling low in the  southern  
sky1 now commands our unqualified       
admiration4 ,canopus lies  about #ce    
south of ,sirius and is invisible north 
of the #cgth parallel  of latitude4 ,at 
nine o'clock in the evening of ,february
 #fth it can be  seen just above the    
southern horizon in that latitude and is
 then a  conspicuous object in ,georgia1
 ,florida and the ,gulf ,states4        
,the star of ,egypt whose proud light   

,never hath beamed on those who rest    
,in the ,white ,islands of the ,west4   
writes ,moore of ,canopus in ,lalla     
,rookh4    ,along the ,nile ,canopus was
 an object of worship as the god of     
waters4  ,at the time of their erection1
 #fdjj ,b4,c41 a number of temples in   
,upper ,egypt were oriented so as to    
show ,canopus at sunrise at the         
autumnal equinox1 and other temples     
erected many centuries later were       
oriented in a similar manner4 ,in       
,china1 as late as #ajj ,b4,c41 and in  
,india also ,canopus was an object of   
worship4    ,the astronomer tells us    
that ,canopus is immeasurably distant   
from the  earth4 ,it has been estimated 
to be forty thousand times more luminous
  than our sun4    ,canopus is located  
in the constellation of ,argo ,navis    
which is  the largest and most          
conspicuous constellation in the        
heavens4  ,in addition to ,canopus it   
contains a number of second- and        
third-magnitude stars and is subdivided 

for convenience into ,puppis1  ,the     
,prow2 ,carina1 ,the ,keel2 and ,vela1  
,the ,sails4 ,huge as it is1  ,argo     
,navis represents only half of a ship   
for the stern is lacking4  ,according to
 the legend this ship was built by      
,argos1 aided by  ,pallas ,athene1 for  
,jason1 the leader of the expedition of 
the fifty  ,argonauts who sailed from   
,greece to ,colchis in search of the    
golden  fleece4 ,pallas ,athene placed  
in the bow of the ship a piece of       
timber from the speaking oak of ,dodona 
to guide the crew and warn  them of     
dangers and after the voyage the ship   
was supposed to have  been placed in the
 heavens4      ,illustration3 ,,southern
 ,,constellations--#a4 ,,in ,,february  
,in ,argo ,navis is one of the finest   
telescopic objects in the heavens1  the 
,keyhole ,nebula1 as it is usually      
called1 from a peculiar-shaped  dark    
patch in its brightest part4 ,on the    
border of this nebula is the  deep-red  
,wonder ,star of the southern           

hemisphere1 ,eta ,argus1 which  varies  
suddenly and unexpectedly in brightness 
between the seventh  and first          
magnitudes4 ,in #ahdc it burst forth    
with a splendor rivaling  ,sirius and   
maintained this brilliancy for nearly   
ten years and then  slowly waned in     
brilliancy until it disappeared to the  
unaided eye  in #ahhf4 ,the surrounding 
nebula also seems to share in its       
peculiar  fluctuations of brightness4   
,eta ,argus is now a star of the seventh
  magnitude and since it is still       
varying fitfully in brightness it is    
believed that the history of its        
light-changes is not complete4    ,among
 the constellations of the southern     
heavens near the meridian  in ,february 
we see in addition to ,argo ,navis the  
constellations  of ,dorado1 ,the        
,goldfish2 ,hydrus1 ,the ,serpent1 and  
,tucana1 ,the  ,toucan4 ,though         
insignificant in appearance ,dorado     
contains what was  described by ,sir    
,john ,herschel as one of the most      

extraordinary  objects in the heavens1 a
 worthy rival of ,the ,great ,orion     
,nebula and  in some respects very      
similar to it1 ,the ,great ,looped      
,nebula1 the  center of a great spiral4 
,in ,dorado also is located ,the        
,greater  ,magellanic ,cloud which looks
 like a detached portion of the ,milky  
,way though it is far removed from it4  
,to the naked eye it resembles  a small 
white cloud about #d in extent4 ,in the 
telescope it bears a  close resemblance 
to a typical portion of the ,milky ,way4
 ,a similar  formation known as ,the    
,lesser ,magellanic ,cloud is located in
 ,hydrus4  ,it has been estimated that  
the distance of ,the ,lesser ,cloud is  
#hj1jjj  light-years and that it is     
receding from us4    ,in ,tucana is     
located one of the finest globular star 
clusters in  the heavens1 known as #dg  
,tucan4 ,this cluster and ,omega        
,centauri1  a globular star cluster in  
,centaurus1 are the two nearest of all  
the globular clusters4 ,they are distant

 from the earth about #bb1jjj           
light-years and it is known that the    
combined light of the thousands  of     
stars of which each cluster is composed 
is about one million times  that of our 
own sun4    ,in the western sky in the  
southern hemisphere in ,february may be 
seen  the brilliant1 white1             
first-magnitude star ,achernar in the   
river  ,eridanus1 the long1 winding     
constellation that1 we recall1 starts   
near the brilliant ,rigel in ,orion and 
disappears from the view of  northern   
observers below the southern horizon1   
extending its course  far into the      
southern hemisphere4 ,achernar means    
,the ,end of the  ,river and this is    
nearly its position in the              
constellation4    ,though ,argo ,navis  
is the largest and most important       
constellation of  the southern          
hemisphere1 ,crux1 ,the ,southern       
,cross1 far-famed in story  and legend  
as well as for its historical           
associations1 is beyond a  doubt the    

most popular4    ,the best time to view 
the ,southern ,cross is in ,june or     
,july when  it is near the meridian4 ,it
 is not seen to advantage in the months 
of ,january or ,february4 ,it then lies 
on its side and close to the  horizon   
and therefore is dimmed by atmospheric  
haze so that it almost  invariably is a 
disappointing object to the tourist from
 the north  who usually views it for the
 first time in one of these months4 ,the
  ,cross is viewed to advantage in the  
latitude of ,rio or ,valparaiso  and it 
is best seen from the ,straits where it 
rides high overhead4  ,it is not seen to
 advantage from the latitudes of ,cuba  
or ,jamaica4  ,it is small1 only #f in  
extent from north to south and less in  
width  and it lies in the most brilliant
 portion of the ,milky ,way which is    
here a narrow stream only three or four 
degrees wide4 ,directly below  the      
,cross is the noted ,coal ,sack1        
apparently a yawning chasm in the  midst
 of its brilliant surroundings though   

probably in reality a dark  nebula4     
,viewed with the telescopes a number of 
stars are to be seen  projected on this 
dark background4    ,the ,southern      
,cross is to the inhabitants of the     
southern hemisphere  what the ,big      
,dipper is to those who dwell in the    
northern  hemisphere--an infallible     
timepiece4 ,the upright of the ,cross   
points  toward the south pole of the    
heavens which lies in a region where    
there is a singular dearth of bright    
stars1 the nearest star to the  south   
pole being a faint fifth-magnitude star 
called ,sigma ,octantis4  ,when seen in 
the southeast or southwest the ,cross   
lies on its side1  but when passing the 
meridian it stands nearly upright4      
,humboldt1  referring to this fact1     
says3      ,how often have we heard our 
guides exclaim in the savannahs of      
,venezuela and in the desert extending  
from ,lima to ,truxillo1    ',midnight  
is past1 the ,cross begins to bend4'    
,by the explorers of the sixteenth      

century the ,cross was taken as  a sign 
of heaven's approval of their attempt to
 establish the  ,christian religion in  
the wilds of the ,new ,world4 ,this     
thought is  beautifully expressed in    
,mrs4 ,hemans' lines in ,the ,cross of  
the  ,south4        ,but to thee1 as thy
 lode-stars resplendently burn      ,in 
their clear depths of blue1 with        
devotion ,i turn      ,bright ,cross of 
the ,south6 and beholding thee shine1   
,scarce regret the loved land of the    
olive and vine4      ,thou recallest the
 ages when first o'er the main      ,my 
fathers unfolded the ensign of ,spain1  
,and planted their faith in the regions 
that see      ,its imperishing symbol   
ever blazoned in thee4    ,alpha        
,crucis1 the brightest star in ,crux1 is
 at the foot of the  ,cross4 ,it        
consists in reality of two              
second-magnitude stars forming a        
beautiful double while a third          
fifth-magnitude star one and one-half   
minutes of arc distant makes with this  

pair a combination similar to  our      
,mizar and ,alcor of the ,big ,dipper   
though the separation is not  great     
enough to be visible to the naked eye4  
,the second-magnitude  star at the head 
of the ,cross is a deep orange in color 
and the two  stars that mark the ends of
 the cross-arm are white third-magnitude
  stars4      ,illustration3 ,,southern 
,,constellations--#b4 ,,in ,,july       
,one of the finest constellations of the
 southern hemisphere is  ,centaurus1    
,the ,centaur1 which surrounds ,crux on 
the north and is more  than #fj in      
length4 ,its center lies about #ej south
 of ,spica in ,virgo  and below the tail
 of ,hydra4 ,alpha ,centauri1 its       
brightest star and  the nearest star to 
the solar system1 four and one-third    
light-years  away1 is a golden-yellow   
double star that forms with the star    
,beta  ,centauri on the west a          
configuration similar to that of ,castor
 and  ,pollux in ,gemini1 only one that 
is far more striking because of the     

superior brilliancy of the stars4 ,alpha
 ,centauri lies in the ,milky  ,way and 
transits the meridian at the same time  
with ,arcturus though  it cannot be seen
 north of the #bith parallel4 ,alpha    
,centauri1 like  ,canopus1 was an object
 of worship in ,egypt and a number of   
temples in  northern ,egypt were        
oriented to its emergence from the sun's
 rays in  the morning at the autumnal   
equinox1 between #cjjj and #bege ,b4,c4 
,north of ,centaurus is the             
constellation ,lupus1 ,the ,wolf1 which 
is  also crossed by the ,milky ,way4    
,according to one myth ,lupus is held   
in the right hand of the ,centaur as an 
offering upon the altar which  is       
represented by the constellation of ,ara
 next to ,centaurus on the  east4 ,ara  
also is crossed by the ,milky ,way4     
,neither ,lupus nor ,ara  contain any   
objects that are worthy of special      
attention4    ,triangulum ,australe1    
,the ,southern ,triangle1 a little to   
the southeast  of ,alpha ,centauri1 is  

far more conspicuous than the           
,triangulum of the  northern hemisphere4
    ,the accompanying charts give two   
views of these principal southern       
constellations that lie within #dj of   
the south pole of the heavens  and that 
are below the horizon in #dj north      
latitude4 ,the first of  these charts   
shows the constellations that are       
nearest the meridian  in the early      
evening hours in ,february4 ,canopus in 
,argo ,navis and the  ,greater          
,magellanic ,cloud then lie close to the
 meridian4 ,argo ,navis  with its       
subdivisions ,puppis1 ,vela and ,carina 
are found east of the  meridian lying   
directly in the path of the ,milky ,way1
 which stretches  diagonally across the 
sky from the northwest to the southeast4
 ,far  over in the southeast appears    
,crux1 the ,southern ,cross1 also       
directly  in the path of the ,milky     
,way4 ,in the western heavens may be    
seen the  ,lesser ,magellanic ,cloud in 
,hydrus1 brilliant ,achernar in         

,eridanus  and the inconspicuous        
star-group of ,tucana4    ,in the early 
evening hours of ,july we find as shown 
on the second  chart1 ,alpha and ,beta  
,centauri in ,centaurus close to the    
meridian1  ,lupus due north of          
,centaurus1 ,ara and ,triangulum        
,australe in the  southeast and ,crux in
 fine position for observation just west
 of the  meridian4 ,carina of ,argo     
,navis lies to the southwest of ,crux4  
,the  ,milky ,way now arches            
magnificently across the heavens from   
,carina  through ,crux1 ,centaurus and  
,lupus and ,ara to the zodiacal groups  
of  ,scorpio and ,sagittarius in the    
northeast4    ,in the northern part of  
the heavens1 as seen from the southern  
hemisphere1 appear the familiar zodiacal
 constellations that we of  the northern
 hemisphere find south of the zenith1 as
 well as the  constellations of ,orion1 
,lepus and ,canis ,major1 ,hydra1       
,corvus and  ,crater1 ,ophiuchus and    
,serpens and ,aquila1 all finely in view

 in their  appropriate seasons4    ,it  
is only our familiar circumpolar        
constellations of the north--,the  ,two 
,bears1 ,draco1 ,cassiopeia1 and        
,cepheus1 ,andromeda and ,perseus and   
,auriga that are invisible in           
mid-latitudes of the southern hemisphere
  just as the constellations shown in   
the diagrams1 and a few  additional     
groups such as ,pavo1 ,grus1 ,phoenix1  
,apus1 ,mensa and ,volans  which we have
 not shown1 lie hidden from view beneath
 the southern  horizon in mid-latitudes 
of the northern hemisphere4    ,the     
northern visitor to the southern        
hemisphere familiar with the            
constellations of his own land is filled
 with a queer sensation of  being in    
topsy-turvydom as he sees familiar      
,orion standing on his  head and all of 
the zodiacal constellations passing in  
their daily  motions to the north       
instead of to the south of his zenith   
while  by day the sun passes across the 
northern part of the heavens and        

culminates north instead of south of his
 zenith4 ,he misses the  familiar       
,dippers of his own land and searches in
 vain for a pole-star  in the unfamiliar
 circumpolar regions of the south4      
,,xv    ,,the ,,milky ,,way ,,or        
,,galaxy        ,broad and ample road   
whose dust is gold1      ,and pavement  
stars1 as stars to thee appear          
,seen in the galaxy1 that milky way     
,which nightly as a circling zone thou  
seest      ,powder'd with stars4        
--,,milton1 ,paradise ,lost4      ,on   
clear1 winter evenings one may see a    
portion of the zone of  the ,milky ,way1
 which encircles the heavens1 arching   
magnificently  across the heavens as it 
passes from ,cassiopeia and ,cepheus in 
the  northwest1 through ,perseus and    
,auriga and the eastern part of ,taurus1
  across the feet of ,gemini1 between   
,canis ,minor and ,orion and through    
the eastern part of ,canis ,major to the
 southern horizon4    ,at this point it 
passes beyond our range of vision into  

the  star-groups of ,puppis1 ,vela and  
,carina1 subdivisions of the huge       
southern constellation of ,argo ,navis4 
,it reaches its greatest  distance south
 of the celestial equator and also      
attains its greatest  brilliancy in     
,crux1 the far-famed ,southern ,cross4  
,from here it turns  northward once     
more1 passing into ,centaurus1 ,musca1  
,circinus ,ara and  ,lupus              
constellations of the southern          
hemisphere and comes within our  range  
of vision again in ,sagittarius and     
,scorpio4 ,here the ,milky ,way  divides
 into two branches1 though some         
astronomers now believe that  this      
apparent division into two branches is  
due to the presence of an  enormous     
cloud of non-luminous matter lying along
 the course of the  ,milky ,way at this 
point1 similar in its nature to the dark
 holes  and caves and streaks that      
appear in all portions of the ,milky    
,way  and most noticeably athwart its   
course in ,argo and ,centaurus4    ,one 

of these branches of the ,milky ,way    
passes from ,sagittarius  through       
,aquila to ,cygnus and the other through
 ,scorpio1 ,ophiuchus and  ,serpens to  
,cygnus1 the two extending diagonally   
across the heavens  in the late summer  
and early fall evenings from the        
northeast to  the southwest4 ,from      
,cygnus1 the ,milky ,way passes into    
,cepheus and  ,cassiopeia and thus      
completes its circuit of the heavens4   
,it is not seen to advantage in spring  
or early summer evenings  because it    
then rests nearly on the horizon4 ,its  
plane is inclined  about #fc to the     
celestial equator and its poles lie in  
the  constellations of ,coma ,berenicis 
and ,cetus4 ,these are the two points   
that lie farthest from the ,milky ,way4 
,the ,milky ,way has been called the    
groundwork of the universe4 ,by far  the
 greater number of all the stars are    
crowded towards its plane in  the form  
of an enormous flattened disk or lens4  
,our solar system1 it has been          

estimated1 lies close to the plane of   
the ,milky ,way and at a distance of    
some #ej1jjj or #fj1jjj light-years     
from its center4 ,the diameter of the   
,milky ,way as deduced from ,dr4        
,harlow ,shapley's work on globular star
 clusters is about #cjj1jjj  light-years
 in extent1 or ten times greater than   
the limit set some  years ago4    ,the  
apparent crowding together of the stars 
into dense clouds in the  ,milky ,way is
 partly an effect due to our position in
 the ,milky ,way4  ,when we look at the 
heavens in a direction at right angles  
to this  plane we find comparatively few
 stars lying along our line of vision   
because the stars are actually fewer in 
number in this direction4  ,if we look  
along the plane of the ,milky ,way1     
however1 we see  to a greater distance  
through an enormous depth of stars4     
,though  individual stars may not be    
much closer together in the ,milky ,way 
than they are outside of it1 there are  
on the whole more of them and  the      

effect of greater density is produced4  
,father ,hagen of the ,vatican          
,observatory1 who has for years made a  
study of the dark clouds of obscuring   
matter and dark nebul that  abound in   
space1 has found evidence of the        
existence of many vast  clouds of dark  
obscuring matter over the entire heavens
 above and  below the plane of the      
,milky ,way as well as surrounding the  
,milky  ,way in its own plane4 ,the     
existence of such clouds of non-luminous
  matter would account partly for the   
comparative fewness of stars in  space  
outside of the plane of the ,milky ,way 
since many stars would be  concealed    
from our eyes by these obscuring clouds4
 ,there is1 however1  in addition1 an   
actual crowding of all the visible stars
 toward this  plane4    ,the peoples of 
all ages have honored the ,milky ,way in
 story and  legend4 ,it has been        
universally referred to as ,the ,sky    
,river and ,the  ,pathway of ,souls4 ,to
 the little ,hiawatha1 we remember1 the 

wrinkled  old ,nakomis        ,showed   
the broad white road in heaven          
,pathway of the ghosts1 the shadows1    
,running straight across the heavens1   
,crowded with the ghosts1 the shadows4  
,to the ,kingdom of ,ponemah      ,to   
the land of the hereafter4    ,in ,the  
,galaxy1 ,longfellow thus describes the 
,milky ,way3        ,torrent of light   
and river of the air      ,along whose  
bed the glimmering stars are seen       
,like gold and silver sands in some     
ravine      ,where mountain streams have
 left their channels bare6    ,in       
,sweden1 where the ,milky ,way arches   
high through the zenith in  winter1 it  
is called the ,winter ,street1 and ,miss
 ,edith ,thomas writes  thus beautifully
 of it in her poem entitled1 ,the       
,winter ,street3        ,silent with    
star dust1 yonder it lies--        ,the 
,winter ,street1 so fair and so white2  
,winding along through the boundless    
skies1        ,down heavenly vale1 up   
heavenly height4        ,faintly it     

gleams1 like a summer road        ,when 
the light in the west is sinking low1   
,silent with star dust6 ,by whose abode 
,does the ,winter ,street in its        
windings go8        ,and who are they1  
all unheard and unseen--        ,o who  
are they1 whose blessd feet      ,pass  
over that highway smooth and sheen8     
,what pilgrims travel the ,winter       
,street8        ,are they not those whom
 here we miss        ,in the ways and   
the days that are vacant below8      ,as
 the dust of that ,street their         
footfalls kiss        ,does it not      
brighter and brighter grow8             
,beautiful indeed are these poetic      
fancies but none of them picture  even  
remotely the awe-inspiring grandeur of  
the ,milky ,way as it  actually exists4 
,illustration3 ,a ,,dark ,,nebula3 ,,the
 ,,dark ,,bay ,,or ,,dark ,,horse       
,,nebula ,,in    ,,orion    ,taken with 
#ajj-;inch ,hooker ,telescope of the    
,mt4 ,wilson ,observatory    ,millions  
upon millions of far distant suns equal 

to or surpassing  our own sun in        
brilliancy are gathered within this vast
 encircling  zone of the heavens1 their 
combined light giving to the naked eye  
the  impression of a milky band of      
light4 ,nine-tenths of all the stars1 it
  has been estimated1 lie close to the  
plane of the ,galaxy1 as well as  all   
the vast expanses of luminous gaseous   
nebul and clouds of dark  obscuring     
matter all seemingly intermingled in    
chaotic confusion2  yet law and order   
govern the motions of all4 ,here also   
are the great  moving star clusters such
 as the ,pleiades and the ,hyades and   
all of  the brilliant ,orion stars4     
,the structure of the ,milky ,way is not
 clearly understood but many            
astronomers believe there is evidence   
that it takes the form of a  vast spiral
 nebula along whose arms the stars pass 
to and fro4    ,beyond the ,milky ,way  
at enormous distances of many thousands 
of  light-years1 but apparently         
influenced by it1 lie the globular      

star-clusters and the spiral nebul4 ,the
 spirals appear to avoid the  plane of  
the ,milky ,way for they are receding in
 the direction of its  poles at high    
velocities2 the globular clusters on the
 other hand  are drawing in toward the  
,milky ,way on either side1 and in time 
will  cross it4    ,whether these       
objects external to the ,milky ,way form
 with it one  enormous universe or      
whether the spiral nebul are in turn    
galaxies  or island universes1 as the   
astronomer calls them1 similar in form  
and structure to our own galaxy and at  
inconceivably great distances  of       
millions of light-years from it1 is     
still one of the riddles of  the        
universe which the astronomers are      
attempting to solve4          ,,xvi     
,,the ,,surface ,,of ,,the ,,sun        
,the visible surface of the sun is      
called the photosphere4 ,even the       
smallest telescopes will show its       
peculiar rice-grain structure1          
consisting of intensely brilliant flecks

 or nodules about #ejj miles  in        
diameter1 which can be resolved by the  
more powerful telescopes  into smaller  
particles about #ajj miles in diameter1 
against a darker  background4 ,it has   
been estimated that these bright nodules
 or  rice-grains occupy only one-fifth  
of the total surface of the sun1  yet   
radiate three-fourths of the total      
light4    ,it is generally believed that
 the rice grains are the summits of     
highly heated columns of gas1 arising   
from the sun's interior1 and  that the  
darker portions between are cooler      
descending currents4    ,it is well     
known that the photosphere or visible   
surface of the sun  appears to be much  
brighter in the center of the disk than 
near its  circumference4 ,this is due   
entirely to its gaseous nature and to   
the fact that it is surrounded by an    
atmosphere of dense enveloping  cooler  
gases4 ,rays from the center of the disk
 travel a shorter  distance through this
 atmosphere than the rays from the rim  

and  therefore are absorbed less by     
surrounding gases4 ,we look further     
down into the sun's interior near the   
center of the disk than in the          
direction of its circumference and so   
the light appears more intense  there4  
,the photosphere is the region where    
sun-spots appear and they are  found in 
zones extending from #h to #ce on either
 side of the solar  equator1 never      
appearing exactly at the equator or near
 the poles4    ,the disturbances that   
produce sun-spots and many allied       
phenomena  occur cyclically in periods  
of eleven years on the average4 ,the    
first outburst of the disturbance is    
manifested by the appearance  of        
sun-spots in high solar latitudes4      
,these break out and disappear  and     
break out again with increased vigor1   
working gradually downward  toward the  
solar equator1 the maximum spottedness  
for a given period  occurring in solar  
latitude about #af4 ,the disturbance    
finally dies  out within #h or #aj of   

the equator1 but even before one cycle  
of  disturbance has entirely passed away
 a new cycle has broken forth in  high  
latitudes4 ,so during the period of     
minimum spottedness there  are four     
distinct belts1 two in low latitudes1   
due to the dying  disturbance1 and two  
in high latitudes1 due to the new       
disturbance4  ,at sun-spot maximums     
there are two well-marked zones of great
  intensity1 approximately #af north and
 south of the sun's equator4            
,sun-spots are solar cyclones1 occurring
 usually in groups1 though  large single
 spots appear less frequently4 ,each    
spot is quite sharply  divided into an  
umbra and a penumbra4 ,the umbra is the 
darker central  portion1 the funnel of  
the whirling cyclone1 and the penumbra  
is  composed of the outspreading gases1 
and is less dark than the umbra4  ,the  
peculiar thatch-straw structure of the  
penumbra is due1 it  is believed1 to the
 fact that the columns of gases that    
usually  rise vertically from the sun's 

interior and from the rice grains  of   
the photosphere are drawn into a        
horizontal position by the  whirling    
motion that exists in the penumbra      
regions of a sun-spot and  therefore we 
get a longitudinal rather than a cross  
sectional view of  them4    ,the umbra  
of a sun-spot is anywhere from a few    
hundred miles to fifty  thousand miles  
in diameter1 frequently exceeding the   
earth in size1  while the penumbra      
occasionally reaches a diameter of two  
hundred  thousand miles4 ,sun-spots of  
exceptional size can be seen even       
without the aid of a telescope4    ,the 
darkness of sun-spots is only by        
comparison with their more  brilliant   
background4 ,owing to the rapid         
expansion and cooling of  gases the     
temperature in sun-spot regions is far  
below the normal  solar temperature of  
#f1jjj ,centigrade1 lying between #c1jjj
 and  #d1jjj ,centigrade4 ,at this      
temperature it is possible for the more 
refractory chemical compounds to form1  

the oxides and the hydrides1  and the   
spectra of sun-spots reveal the presence
 of titanium oxide  and magnesium and   
calcium hydride4 ,at the higher solar   
temperatures  that exist elsewhere in   
the photosphere and in its overlying    
gaseous  envelopes all chemical elements
 occur in a free state1 intermingling   
as incandescent vapors without the      
formation of any chemical  compounds4   
,strong magnetic fields exist in        
sun-spot regions and magnetic  storms in
 our own atmosphere frequently accompany
 the appearance of  exceptionally large 
sun-spots4    ,directly above the       
photosphere of the sun lies the         
reversing layer1  which is about five   
hundred miles in depth and is composed  
of the  incandescent vapors of all the  
chemical elements that exist on the     
sun1 which are also the same familiar   
elements that exist on the  earth1 with 
the exception of coronium1 the unknown  
element in the  solar corona1 there is  
no element in the sun that has not been 

found  on our own planet4    ,the       
reversing layer receives its name from  
the fact that it  reverses the solar    
spectrum4 ,it produces by its absorption
 of the  rays of light from gases below 
the dark absorption lines found in the  
spectrum that serve to identify all the 
elements existing in the sun4  ,during  
the time immediately preceding and      
following a total eclipse  of the sun   
this reversing layer produces what is   
known as the flash  spectrum4 ,when the 
photosphere1 which gives the bright     
continuous  background of the solar     
spectrum1 is concealed by the moon1 the 
normally dark lines of the reversing    
layer--dark only by contrast  with the  
bright background--become momentarily   
intensely bright lines  against a dark  
background4 ,the flash spectrum only    
lasts a second or  so1 as the reversing 
layer itself is soon covered by the     
moon4    ,just above the reversing layer
 lies the chromosphere1 which is        
between five thousand and ten thousand  

miles in depth4 ,many of the  gaseous   
vapors of the reversing layer are found 
in the chromosphere1  thrown there      
continually by the vast upheavals of    
gases that are  constantly disturbing   
the surface of the sun4 ,the greater the
 solar  activity the more is the        
chromosphere charged with the vapors of 
the lower strata of the sun's           
atmosphere4 ,the gases that are most    
characteristic of the chromosphere1     
however1 are the incandescent  gases of 
hydrogen and calcium1 which give it the 
pink or reddish  tinge so noticeable    
during total solar eclipse4 ,helium is  
also found  in great abundance in the   
solar chromosphere4    ,shooting upward 
from the photosphere with the tremendous
 velocity of  one hundred or more miles 
per second1 can be seen at all times1 by
  properly screening off the light from 
the photosphere1 the vast solar         
eruptions known as the prominences4     
,these are composed chiefly  of hydrogen
 and calcium gas1 though other elements 

also appear1  especially near the bases 
of the prominences4 ,prominences are of 
two  varieties1 the quiescent1 or       
cloud-like prominences1 that float high 
above the solar surface for days at a   
time in some instances and  resemble    
terrestrial clouds in form1 and the     
eruptive1 or metallic  prominences1 that
 dart up from the surface of the sun in 
an infinite  variety of forms that may  
be entirely changed in the short        
interval  of fifteen or twenty minutes4 
,these eruptive prominences usually     
attain heights of thirty or forty       
thousand miles on the average1 but      
exceptional prominences reach  heights  
of more than one hundred thousand miles 
and in a few rare  cases have reached   
elevations of over five hundred thousand
 miles1  or more than one-half of the   
solar diameter4    ,prominences are the 
most spectacular and beautiful of all   
solar  phenomena1 with the possible     
exception of the solar corona1 which is 
the outermost of all the solar envelopes

 and also the most tenuous4  ,the extent
 of the corona is enormous4 ,its outer  
streamers extend  usually to distances  
of several million miles from the center
 of the  sun4 ,measurements of the      
coronal light during total eclipses of  
the  sun have shown that its intensity  
is only about one-half that of  full    
moonlight1 and it seems almost          
impossible to devise methods for        
detecting it1 except during total       
eclipses1 on account of the extreme     
faintness of its light4    ,the sun1 it 
is now known1 is surrounded by a strong 
magnetic field in  addition to the      
magnetic fields that exist in sun-spots4
 ,the cycle  of sun-spot change is      
attended by marked changes in many forms
 of  solar activity4 ,the frequency of  
outbursts of eruptive prominences1  the 
brightness and form of the corona1      
magnetic storms and weather  changes on 
the earth are all closely associated    
with the sun-spot  cycle4    ,the cause 
of this sun-spot cycle1 with all the    

attendant changes  in the general solar 
activity1 and the source of the         
apparently  limitless supply of solar   
energy still remain the two chief       
unsolved  secrets of the sun4           
,,xvii    ,,the ,,solar ,,system        
,our sun is but a star traveling through
 the universe4 ,it is  accompanied in   
its journey to unknown parts of space1  
that lie in  the general direction of   
the constellation ,hercules1 by an      
extensive  family of minor bodies       
consisting of the eight planets and     
their  encircling moons1 one thousand or
 more asteroids1 numerous comets1  and  
meteors without number1 all moving in   
prescribed paths around  their ruler4   
,the most important members of the sun's
 family are the planets1  ,mercury1     
,venus1 ,earth1 ,mars1 ,jupiter1        
,saturn1 ,uranus and ,neptune1  named in
 the order of their position outward    
from the sun4 ,we hear  occasionally of 
the possibility of the existence of     
intra-,mercurial  and trans-,neptunian  

planets and it is possible that some day
 an  additional planet may be discovered
 within the orbit of ,mercury or  beyond
 the orbit of ,neptune4 ,the            
gravitational control of the sun        
extends far beyond the orbit of ,neptune
 and there are reasons for  believing in
 the existence of at least one or two   
additional planets  on the outskirts of 
the solar system4 ,the existence of a   
planet  within the orbit of ,mercury is 
now1 after long continued and diligent  
search1 believed to be very doubtful4   
,were it possible to view the sun from  
the distance of the nearest  star with  
the aid of the greatest telescope on    
earth all the members  of his family    
would be hopelessly invisible4 ,so1     
also1 we cannot  tell as we point our   
powerful telescopes at the stars whether
 these  other suns are attended by      
planet families4 ,we may only argue that
 it  is very unlikely that there should 
be only one star among hundreds  of     
millions that is attended by a group of 

comparatively small dark  bodies that   
shine by the reflected light from the   
star they encircle4    ,with the        
exception of the two planets1 ,mercury  
and ,venus1 which are  known as the     
inferior planets1 since their paths lie 
between the  earth and the sun1 all the 
planets have moons or satellites of     
their  own that encircle the planet just
 as the planet encircles the sun4       
,our planet earth has one satellite1 the
 moon1 that has the  distinction of     
being the largest of all the moons in   
proportion to  the size of the planet it
 encircles4 ,jupiter and ,saturn have   
moons  that surpass our moon in actual  
size2 in fact1 two of the moons  of the 
outer planets are actually larger than  
the smallest planet  ,mercury1 but they 
are very small in proportion to the size
 of the  planets around which they      
revolve4 ,mars1 the next planet beyond  
the  earth1 the nearest of the superior 
or outer planets1 has two tiny  moons   
that bear the names of ,deimos and      

,phobos1 respectively4 ,they  are both  
less than twenty miles in diameter and  
revolve very near  to the surface of    
,mars4 ,they can only be seen with the  
aid of very  powerful telescopes4 ,the  
inner moon1 ,phobos1 is unique in the   
solar  system for it makes three trips  
around ,mars while the planet is        
turning once on its axis4    ,jupiter1  
the next planet outward from the sun1 is
 almost a sun itself  to its extensive  
family of nine moons4 ,four of these    
moons were first  seen about three      
hundred years ago when ,galileo pointed 
his first  crude telescope at the       
heavens and any one can now see them    
with the  aid of an opera glass4 ,one of
 the four is equal in size to our own   
moon2 the others surpass it in size4    
,these moons are most interesting       
little bodies to observe4 ,their        
eclipses in the shadow of ,jupiter1     
occultations or disappearances behind   
his disk1 and the transits of  the      
shadows as well as the moons themselves 

across the face of the  planet can be   
easily seen even with the smallest      
telescope4 ,the five  remaining moons   
have all been discovered in modern      
times4 ,they are  extremely small bodies
 visible only in large telescopes4      
,satellite  ,v is the nearest of all the
 moons to ,jupiter4 ,the other four are 
at  great distances from the planet4    
,the planet ,saturn has nine moons4     
,titan1 the largest1 is nearly  equal in
 size to ,jupiter's largest moon1 and is
 larger than ,mercury2  four of the     
other moons have diameters between one  
thousand and two  thousand miles in     
length4 ,since ,saturn is nearly twice  
as far from  the sun as ,jupiter his    
moons are more difficult to observe1    
though  the two largest are visible in  
small telescopes4    ,saturn is unique  
in the solar system in possessing in    
addition to  his nine satellites a most 
wonderful ring system1 composed of      
swarms  of minute moonlets1 each        
pursuing its individual path around the 

planet4 ,it is this unusual ring system 
that makes ,saturn the most  interesting
 to observe telescopically of all the   
planets4    ,the planet ,uranus has four
 satellites and ,neptune one4 ,these    
planets  and their satellites cannot be 
well observed on account of their  great
 distances from the earth4 ,the         
indistinctness of surface  markings     
makes it impossible to determine the    
period of rotation of  these two outer  
planets on their axes4 ,it is believed  
that their  rotation is very rapid1     
however1 as is the case with the other  
planets ,jupiter and ,saturn4    ,all   
the planets in the solar system fall    
naturally into two groups4  ,jupiter1   
,saturn1 ,uranus1 and ,neptune1 the     
members of the outer group1  have on the
 average1 diameters ten times as great  
and1 therefore1  volumes one thousand   
times as great as ,mercury1 ,venus1     
,earth and  ,mars1 the members of the   
inner or terrestrial group4             
,illustration3 ,a4 ,,venus4 ,b4 ,,mars4 

,c4 ,,jupiter4 ,d4 ,,saturn4    ,taken  
by ,prof4 ,e4 ,e4 ,barnard with the     
#dj-;inch telescope of the ,yerkes      
,observatory1 with exception of ,saturn1
 which was taken by ,prof4    ,barnard  
on ,mt4 ,wilson4      ,,note3 ,the      
reader must bear in mind that the       
telescopic views of    the four planets 
have not been reduced to the same scale 
and so    are not to be compared in     
size4    ,the terrestrial planets are   
the pigmies of the solar system1 the    
outer planets are the giants4 ,the      
densities of the planets ,mercury1      
,venus1 ,earth and ,mars are several    
times greater than the density  of      
water4 ,they are all extremely heavy    
bodies for their size1 and  probably    
have rigid interiors with surface       
crusts4    ,the existence of life on    
,mercury is made impossible by the      
absence  of an atmosphere4 ,venus and   
,mars both have atmospheres and it is   
possible that both of these planets may 
support life4 ,mars has  probably been  

the most discussed of all the planets1  
though ,venus is  the ,earth's twin     
planet in size1 mass1 density and       
surface gravity1  just as ,uranus and   
,neptune are the twins of the outer     
group4 ,it  is now believed that water  
and vegetation exist on ,mars4 ,the     
reddish  color of this planet is        
supposed to be due to its extensive     
desert  tracts4 ,the nature of certain  
peculiar markings on this planet1 known 
as canals1 still continues to be a      
matter of dispute4 ,it is generally     
believed since air1 water and vegetation
 exist on ,mars1 that some  form of     
animal life also exists there4    ,the  
length of the day on ,mars is known very
 accurately1 for the  rareness of its   
atmosphere permits us to see readily    
many of its  surface markings4 ,the     
length of the day is about twenty-four  
and  one-half hours1 and the seasonal   
changes on ,mars strongly resemble  our 
own1 though the seasons on ,mars are    
twice as long as they are  on our own   

planet since the ,martian year is twice 
as long as the  terrestrial year4       
,the question of life on ,venus depends 
largely upon the length of the  planet's
 rotation period4 ,this is still        
uncertain since no definite  surface    
markings can be found on the planet by  
which the period of  its rotation can be
 determined4 ,so dense is the atmosphere
 of ,venus  that its surface is1        
apparently1 always hidden from view     
beneath a  canopy of clouds4 ,it is the 
more general belief that ,venus1 as well
  as ,mercury1 rotates on its axis in   
the same time that it takes to  make a  
revolution around the sun4 ,in this case
 the same side of the  planet is always 
turned toward the sun and1 as a result1 
the surface  is divided into two        
hemispheres--one of perpetual day1 the  
other of  perpetual night4    ,this     
peculiar form of rotation in which the  
period of rotation and  revolution are  
equal is by no means unknown in the     
solar system4 ,our  own moon always     

keeps the same face turned toward the   
earth and there  are reasons for        
believing that some of the satellites of
 ,jupiter and  ,saturn rotate in the    
same manner4    ,life on any one of the 
outer planets is impossible4 ,the       
density of  these planets averages about
 the same as the density of the sun1    
which is a little higher than the       
density of water4 ,the density of       
,saturn is even less than water4 ,in    
other words1 ,saturn would float  in    
water and it is the lightest of all the 
planets4 ,it is assumed  from these     
facts that the four outer planets are   
largely in a gaseous  condition4 ,they  
all possess dense atmospheres and1 in   
spite of their  huge size1 rotate on    
their axis with great rapidity4 ,the two
 whose  rotation periods are known1     
,jupiter and ,saturn1 turn on their axis
 in  about ten hours4 ,on account of    
this rapid rotation and their gaseous   
condition both ,jupiter and ,saturn are 
noticeably flattened at the  poles4     

,the terrestrial planets are separated  
from the outer group by a wide  gap4    
,within this space are to be found the  
asteroid or planetoid  group4 ,there are
 known to be over nine hundred and fifty
 of these  minor bodies whose diameters 
range from five hundred miles for the   
largest to three or four miles for the  
smallest4 ,there are only four          
asteroids whose diameters exceed one    
hundred miles and the majority  have    
diameters of less than twenty miles4    
,the total mass of the  asteroids is    
much less than that of the smallest of  
the planets4 ,it  was believed at one   
time that these small bodies were       
fragments of a  shattered planet1 but   
this view is no longer held4 ,the       
asteroids as  well as the comets and    
meteors probably represent the material 
of the  primitive solar nebula that was 
not swept up when the larger planets    
were formed4    ,with few exceptions the
 asteroids are only to be seen in large 
telescopes and then only as star-like   

points of light4 ,most of them  are     
simply huge rocks and all are           
necessarily devoid of life since  such  
small bodies have not sufficient        
gravitational force to hold an          
atmosphere4    ,the revolution of the   
planets around the sun and of the       
satellites  of the planets around the   
primary planets are performed according 
to  known laws of motion that make it   
possible to foretell the positions  of  
these bodies years in advance4          
,asteroids and comets also obey  these  
same laws1 and after three observations 
of the positions of  one of these bodies
 have been obtained its future movements
 can be  predicted4 ,all the planets and
 their satellites are nearly perfect    
spheres4 ,they all1 with few exceptions1
 rotate on their axes and  revolve      
around the sun1 or1 in the case of      
moons1 around their  primaries1 in the  
same direction1 from west to east4 ,only
 the two  outermost satellites of       
,jupiter1 the outermost satellites of   

,saturn  and the satellites of ,uranus  
and ,neptune retrograde or travel in    
their orbits from east to west1 which is
 opposite to the direction of  motion of
 all the other planets and satellites4  
,the paths of all the planets around the
 sun are ellipses that are  nearly      
circular1 and they all lie nearly in the
 same plane4 ,the  asteroids have orbits
 that are more flattened or elliptical  
and these  orbits are in some instances 
highly inclined to the planetary orbits4
  ,the comets have orbits that are      
usually very elongated ellipses or      
parabolas4 ,some of the comets may be   
only chance visitors to our  solar      
system1 though astronomers generally    
believe that they are all  permanent    
members4 ,paths of comets pass around   
the sun at all angles  and some comets  
move in their orbits from west to east1 
while others  move in the opposite      
direction or retrograde4 ,the behavior  
of the  asteroids and comets is not at  
all in accord with the theory that  was1

 until recently1 universally advanced to
 explain the origin of  the solar       
system4    ,some astronomers have made  
attempts to modify the nebular          
hypothesis  that has held sway for so   
many years1 in order to make it fit in  
with  more recent discoveries1 but      
others feel that a new theory is now    
required to explain the origin of the   
solar system4 ,several theories  have   
been advanced but no new theory has yet 
definitely replaced the  famous nebular 
hypothesis of the noted ,french         
astronomer ,la ,place4          ,,xviii 
,,the ,,origin ,,of ,,the ,,earth       
,it is not possible to consider the     
question of the origin of the  earth    
apart from the question of the origin of
 the solar system4  ,that all the       
planets1 as well as the asteroids1      
originated from a  common parent-mass   
has never been seriously questioned4    
,all of these  bodies revolve about the 
sun1 and rotate upon their axes in the  
same  direction--from west to east4     

,moreover1 all of the planetary orbits  
lie very nearly in the same plane and   
are nearly circular in form4    ,the    
orbits of the asteroids are more        
elliptical and more highly  inclined to 
one another than are the orbits of the  
planets1 but on  the average they are   
neither very elliptical nor very highly 
inclined  to the planetary orbits4      
,the sun rotates upon its axis in the   
same direction in which the  planets    
rotate and perform their revolutions1   
and the orbits of  the planets are      
inclined at small angles to the plane of
 the sun's  equator4    ,these facts are
 all significant and cannot be          
overlooked in  formulating a theory to  
explain the origin of the planetary     
system in  general and of the earth in  
particular4 ,presumably the planets and 
asteroids formed at one time a part of a
 central body which rotated  on its axis
 in the direction in which they now     
revolve about the sun4    ,when and by  
the operation of what force1 external or

 internal1 they  were separated from    
this central body is the question4      
,in #agif ,la ,place advanced his       
celebrated nebular hypothesis to        
explain the origin of the solar system4 
,it was received with favor  both by    
scientists and laymen1 and in a short   
time was almost  universally accepted as
 closely approximating to the truth4    
,according to the nebular hypothesis the
 solar nebula from which the  planetary 
system was formed1 originally extended  
at least as far as  the orbit of        
,neptune and rotated slowly in the      
direction in which  the planets now     
revolve4 ,as it lost heat by radiation  
and contracted  under the gravitation of
 its parts its rate of rotation         
increased4  ,when the centrifugal       
7center-fleeing7 force at the equator   
equalled  the gravitational force       
directed toward the center1 a ring would
  be left behind by the contracting     
nebula4 ,such a ring would not be       
absolutely uniform and would break at   

some point and gather into a  planetary 
mass under the gravitation of its parts4
 ,this planetary  mass would abandon    
rings in turn and these would break up  
to form  satellites4 ,successive rings  
were supposed to have been abandoned at 
intervals by the solar nebula at the    
present distances of the planets  from  
the sun in the manner described above   
until the original solar  nebula had    
contracted to its present size4    ,the 
rings of ,saturn were supposed to be the
 single example remaining  of this      
process of forming planets and          
satellites from a contracting  nebulous 
mass4    ,the ,la ,placian hypothesis   
attempted to explain why all the planets
  and their satellites revolve in the   
same direction in which the sun  turns  
on its axis1 in nearly circular orbits  
and nearly in the same  plane4 ,at the  
time it was advanced it appeared to be  
in accord with  all the facts then known
 regarding the solar system4    ,the    
planetoids with their interlacing and in

 some instances highly  inclined and    
elliptical orbits were then             
undiscovered4 ,it would have  been      
impossible for them to have been formed 
by the abandonment of  successive rings 
from a central1 rotating mass4    ,the  
constitution of ,saturn's rings was     
unknown at this time2 also  the fact    
that the moonlets of the inner ring     
revolve about ,saturn in  half the time 
required for the planet to turn on its  
axis--another  impossibility under the  
nebular hypothesis1 for1 according to   
the  assumptions of the nebular         
hypothesis it would be impossible for a 
satellite to revolve about a central    
body in a shorter time than that  body  
turns on its axis4    ,the satellites of
 ,mars were not discovered until many   
years later1  as well as the            
retrograding satellites of ,jupiter and 
,saturn1  all presenting difficulties in
 the way of accepting the nebular       
hypothesis without radical changes4     
,attempts1 mostly unsuccessful1  have   

been made from time to time to make     
these exceptional cases fit  in with the
 requirements of the nebular hypothesis4
    ,the theory that the sun's heat was 
maintained by the contraction of  the   
original solar nebula1 which would cause
 its temperature to rise1  appeared to  
give considerable support to the theory 
of ,la ,place1 but  the mathematicians  
got to work and showed that the amount  
of heat  that would be furnished by the 
contraction of the sun from beyond  the 
orbit of ,neptune to its present        
dimensions would be sufficient  to      
supply heat to the earth at the present 
rate for only twenty-five  million      
years1 a period far too brief1 the      
geologists and biologists  said1 to     
cover all the vast cyclical changes that
 are known to have  taken place upon the
 surface of this planet since its       
surface crust  was formed4 ,evidently   
gravitational contraction is by no means
 the  only or even the chief source of  
the sun's heat4    ,it was also shown   

indisputably1 that it would have been   
impossible  for successive rings to have
 been abandoned at certain definite     
intervals by a contracting nebula1 and  
granted a ring could have  been formed  
it would have been impossible for it to 
condense into a  planet1 since forces   
residing in the sun would offset the    
gravitation  of its parts4    ,when ,la 
,place advanced his famous theory it    
was1 to use his own  words1 with that   
distrust which everything ought to      
inspire that is  not a result of        
observation or of calculation4    ,were 
,la ,place living today he would be1 we 
believe1 the first to  abandon a theory 
that is now known to be in accord       
neither with  observation nor           
calculation4    ,deprived of a theory   
that has served to explain the          
outstanding  features of the solar      
system more or less adequately for one  
hundred  and twenty-five years1         
astronomers are seeking in the light of 
recent  observations and discoveries to 

formulate a satisfactory theory of  the 
origin of the solar system4    ,in the  
planetesimal theory of ,chamberlin and  
,moulton and the recently  suggested    
theory of the well-known ,english       
mathematician1 ,jeans1 a  second sun    
passing close to our own sun is assumed 
to have been the  cause of the origin of
 the planetary system4    ,the effect of
 the close approach of such a sun would 
be the  ejection of a stream of matter  
from our sun1 as we term it1 in the     
direction of the passing body and also  
in a diametrically opposite  direction4 
,this ejection would be continuous as   
long as the stars  remained near one    
another1 the height attained by the     
ejected stream  decreasing as the       
passing star receded4 ,the result would 
be the  formation of a spiral nebula in 
which the motion of the ejected         
particles--planetesimals--would be      
across the spiral arms1 toward  and away
 from the passing star4 ,after the sun  
had receded so far as  to have no       

further effect upon these ejected       
particles they would  revolve about the 
sun in more or less elliptical orbits   
which would  gradually be reduced to    
nearly circular forms by repeated       
collisions  between planetesimals4      
,larger nuclei would be formed and these
 would  gradually sweep up smaller      
fragments and become the planets of the 
present system4 ,smaller nuclei in the  
vicinity of larger ones would  become   
their satellites and in the course of   
many millions of years  all of the      
larger fragments would be swept up by   
the planetary nuclei  and their         
satellites--leaving only the asteroids1 
comets and meteors  as survivors of the 
original spiral system4    ,it must be  
borne in mind that a spiral nebula      
formed by the close  approach of two    
suns would resemble in form only the    
great spiral  nebul that are known to   
exist by hundreds of thousands in the   
heavens4 ,these are far too extensive to
 form anything so small as a  single    

solar system1 but might condense into   
systems composed of many  suns--either  
galaxies or star clusters4    ,jean's   
suggested theory of the origin of the   
planetary system differs  in its details
 from the above1 though a passing sun is
 assumed to  be the disturbing force    
that causes the ejection of a stream of 
matter which condenses to form the      
planets and their satellites4 ,the      
origin of the inner planets is left     
greatly in doubt by this theory1        
however1 and the system which interests 
us chiefly--the earth-moon  system--is  
the one about which it is most difficult
 to arrive at any  definite conclusion4 
,our own sun1 it is assumed1 was dark   
and cold1  of low density and with a    
diameter about equal to that of         
,neptune's  orbit at the time of the    
catastrophe which is placed at some     
#cjj1jjj1jjj years ago4 ,in ,jean's     
words1 444 ,the time for arriving  at   
conclusions in cosmogony has not yet    
come--and it must be left to  future    

investigators armed with more           
mathematical and observational          
knowledge than we at present possess to 
pronounce a final decision4    ,however1
 since ,la ,place advanced his          
celebrated nebular hypothesis1  great   
advances in astronomy have been made1   
and man is in a better  position to     
theorize on this fascinating problem    
today than he was  one hundred and      
twenty-five years ago4    ,all such     
theories must necessarily be regarded as
 working hypotheses  only1 to be        
discarded or modified as our knowledge  
and understanding  of the laws of the   
universe increase4 ,no theory can ever  
be regarded  as final or perfect4       
,the discovery of radio-activity        
furnishes us with new material  for new 
theories4 ,the sun and the planets may  
be and probably are  far older than we  
ever dreamed could be possible4 ,it is  
no longer  necessary or reasonable to   
assume that a greatly extended solar    
nebula once existed and supplied the    

planets with heat through  gravitational
 contraction or to place a time limit   
upon the period  required for the       
formation of the planets and their      
satellites that  is not in accord with  
the requirements of other sciences4     
,we know today that there exist within  
the sun powerful repulsive  forces1     
which even under present conditions     
occasionally eject  gaseous matter to   
heights of five hundred thousand miles  
or more with  a velocity of over two    
hundred miles per second4 ,small changes
 in the  velocity of ejection produce   
great differences in the height of the  
ejected columns4    ,with an initial    
velocity of three hundred and eighty    
miles per  second1 matter would be      
thrown from the solar surface to a      
height  of fifty million miles4 ,were   
the velocity of ejection three hundred  
and eighty-three miles per second the   
height of the column would be  five     
hundred million miles1 while a further  
increase in the initial  velocity would 

send matter away from the sun1 never to 
return4    ,instead of suns and solar   
systems evolved from nebul we are now   
more familiar with the idea of nebul    
evolved from stars through some         
terrific cataclysm as in the case of    
novas or temporary stars4    ,it is now 
known that there exist in certain parts 
of space a number  of sharply defined   
stars surrounded by extensive nebulous  
envelopes4  ,are these possibly suns    
that are going through the process of   
forming  their planetary systems8    ,it
 is now known that pressure of light and
 electrical repulsion are  forces to be 
reckoned with in the evolution of stars 
and nebul as  well as gravitational     
contraction4 ,it has long been felt that
 the  peculiar formations existing among
 the vast irregular gaseous nebul  could
 not be explained as gravitational      
effects alone4    ,light-pressure and   
electrical repulsion1 as well as        
gravitation  are at work within the     
solar system and the sun is the seat of 

powerful disturbances which produce     
periodic outbursts of exceptional       
activity and which may have produced in 
the distant past more  startling effects
 than any with which we are familiar at 
present4    ,the earth and moon form a  
system that is in a way unique4 ,no     
satellite in the solar system is so     
large in proportion to its  primary as  
is our own moon4 ,seen from the distance
 of ,venus or ,mars1  the two bodies    
would apparently form a double star4    
,the diameter of  the moon is one-fourth
 that of the earth4 ,satellite ,,iii of 
,jupiter  far exceeds our own moon in   
actual size but its diameter is only    
about four-hundredths of the diameter of
 the planet about which  it revolves4   
,the diameter of ,titan1 the largest    
satellite of the  ,saturnian system1    
bears the same ratio to the diameter of 
,saturn4  ,moreover1 all the nearer     
satellites of ,jupiter and ,saturn lie  
nearly  in the equatorial planes of     
these planets1 but the orbit of the moon

  is inclined at a high angle to the    
plane of the earth's equator4    ,it is 
not difficult to believe that the       
satellites of ,jupiter or  ,saturn were 
at some time thrown off from the        
equatorial belts of  their primaries1   
just as the planets themselves may have 
been ejected  from the equatorial belt  
of the sun1 but we cannot so readily    
believe  that our own satellite was     
formed from the earth in a similar      
manner4    ,the moon's orbit lies nearly
 in the plane of the sun's equator1     
however1 and it is conceivable that both
 earth and moon were  simultaneously    
ejected from the equatorial zone of the 
sun1 the two  nuclei being so close     
together that the smaller one remained  
under  the gravitational control of the 
larger4    ,the difficulties in the way 
of believing that the moon once formed  
a part of the earth are very great4 ,it 
can be shown mathematically  that if the
 two bodies at one time formed a single 
mass it would have  been impossible for 

the moon to break away from the earth1  
unless the  force that caused the       
separation were sufficient to hurl the  
moon to  a greater distance than two and
 a half times the earth's radius4 ,the  
mathematician1 ,roche1 found out by     
computation that a satellite could  not 
remain intact within this distance of   
the planet1 but would be  broken up into
 small fragments under the effects of   
the tides raised  by the larger body4   
,if1 then1 the moon had originally been 
ejected  from the earth to a less       
distance than two and one-half radii of 
the  earth 7#b4dd to be exact7 it would 
have been disintegrated into small      
particles1 or moonlets1 under the tidal 
strains exerted upon it by  the earth   
and would have been gradually           
distributed about the earth  in the form
 of a meteoric ring which1 in the course
 of ages1 would be  absorbed by the     
earth1 just as ,saturn is now gradually 
absorbing its  rings4    ,the planets   
differ greatly in density4 ,the more    

distant and larger  planets--,jupiter1  
,saturn1 ,uranus and ,neptune--have     
densities  equal to or less than that of
 the sun4 ,the densities of the inner   
planets--,mercury1 ,venus1 ,earth and   
,mars--are1 relatively1 extremely  high1
 the density of the ,earth's core being 
about that of meteoric  iron4 ,the      
densities of ,mercury and ,venus are    
slightly less than that  of the earth   
and the densities of ,mars and the moon 
about equal to  that of the earth's     
crust4    ,if a stream of matter were   
ejected from the sun under the influence
  of some external force1 such as that  
exerted by a passing star1 the  outlying
 parts of the stream would consist of   
the lighter elements  and the lower     
parts of the heavier elements1 since the
 lighter solar  elements lie at or near 
the surface of the sun and the heavier  
elements at greater depths4 ,at the time
 of ejection the lighter  elements would
 be thrown to great distances and would 
go to form the  less dense outer        

planets2 the heavier elements would go  
to form the  inner planets of high      
density4    ,it is conceivable that     
ejection of solar material might have   
taken  place under the influence of     
certain forces at work within the sun   
itself1 such as electrical repulsion or 
pressure of light which might  become   
powerful enough under certain conditions
 to overcome the  effect of gravitation4
    ,next to nothing is known about the 
physical state of matter at great  solar
 depths1 where abnormal conditions of   
temperature and pressure  must exist1   
and where great physical changes and    
disturbances may  have taken place in   
the past4 ,even today solar activity    
goes through  a cycle of change during  
the sun-spot period1 and many millions  
of  years ago the sun-spot cycle of     
solar activity may have been far        
different from what it is today and a   
far more powerful factor in  producing  
changes in the solar system4            
,outbursts of novas indicate that       

agencies making for peace and  order are
 not the only ones at work among the    
stars4 ,the cause of  such outbursts has
 never been satisfactorily explained4   
,the theory  that they are caused by the
 close approach of two suns or by the   
encounter of a star with a dark nebula  
does not account for all of  the        
circumstances of such outbursts4 ,the   
nebulous matter seen about  a nova after
 the outburst is now generally believed 
to have been  expelled from the star    
itself at the time of the catastrophe   
and may  conceivably be the stuff of    
which planetary systems are made4    ,at
 some epoch in the past1 probably at    
least one thousand million  years ago1  
our own sun may have undergone some     
cataclysmic change  and this may1       
conceivably1 have been brought about by 
disturbances  within the sun itself4    
,elements may have been so formed and   
distributed within the interior of the  
sun that friction and internal          
instability resulted and in time        

produced an upheaval of solar  elements 
with initial velocities so great that1  
possibly1 through  electrical repulsion 
and light-pressure1 portions of the     
ejected  streams were permanently       
detached from the sun and became the    
nuclei  of future planets4 ,in some such
 way1 it is conceivable1 our own  planet
 ,earth and the other members of our    
solar system may have been  brought into
 existence in the dim and distant       
past--many hundred  million years ago4  
,,xix    ,,jupiter ,,and ,,his ,,nine   
,,moons      ,jupiter shines by         
reflected sunlight with a brilliancy    
that usually  exceeds that of the       
brightest of the stars1 ,sirius4 ,when  
seen during  the midnight hours the     
remarkable unflickering brightness of   
this  largest and most distinguished    
member of the solar system at once      
serves to set it apart from the         
scintillating stars far beyond4         
,there is but one planet1 ,venus1 that  
always surpasses ,jupiter in            

brilliancy1 though ,mars on the         
occasions of its close approaches  to   
the earth may equal or slightly surpass 
,jupiter in brightness4  ,as ,venus     
never departs more than forty-eight     
degrees from the sun1  and so is never  
seen in the midnight hours1 ,jupiter    
usually shines  without a rival when    
visible at midnight4 ,to one who has    
observed the  two planets together the  
silvery radiance and surpassing         
brilliancy  of ,venus1 due not to its   
size1 but to its comparative nearness to
  the earth1 at once serves to          
distinguish it from the golden glow of  
,jupiter4    ,even the smallest         
telescopes of two- or three-inch        
aperture will show  the four historic   
moons of ,jupiter which were the first  
celestial  objects to be discovered when
 ,galileo turned his crude telescope to 
the heavens in the year #afaj4    ,the  
fact that these tiny points of light    
were actually revolving  around the     
great planet was soon detected by the   

famous astronomer  and we can imagine   
with what breathless interest he        
observed these  satellites of another   
world whose discovery dealt such a      
severe blow  to the old ,ptolemaic      
theory that the earth was the center of 
the  universe4 ,it was not until the    
great telescopes of modern times were   
invented that the five additional moons 
of ,jupiter were discovered4  ,the four 
satellites first observed by ,galileo   
were fancifully named  ,io1 ,europa1    
,ganymede and ,callisto1 in the order of
 their positions  outward from the      
planet1 but these names are rarely used 
now1 the  satellites being designated   
for convenience ,i1 ,,ii1 ,,iii and     
,,iv1  respectively4 ,the first of the  
new satellites to be discovered was     
,satellite ,v1 which is the nearest to  
,jupiter of all the nine moons4  ,it is 
an extremely small body1 not more than  
one hundred miles in  diameter1 and to  
discover this tiny body as it skirted   
rapidly around  the great planet within 

sixty-seven thousand miles of its       
surface1  nearly lost in the glaring    
rays1 was a difficult feat even for an  
experienced observer4 ,it was           
accomplished1 however1 by ,prof4 ,e4    
,e4 ,barnard with the great ,lick       
refractor in #ahib4 ,satellite ,v is    
hopelessly beyond the reach of any but  
the greatest telescopes1 as  are also   
the four satellites discovered since    
that date4 ,in fact1  most of these tiny
 moons are observed photographically4   
,satellites ,,vi  and ,,vii were        
discovered photographically in #aije4   
,they are both about  seven million     
miles from the planet and their paths   
loop through  one another2 they are1    
moreover1 highly inclined to each other 
at  an angle of nearly thirty degrees4  
,when nearest together they are         
separated by a distance of two million  
miles4 ,two more extremely  small       
bodies1 known as ,satellites ,,viii and 
,,ix1 have been discovered  since then1 
one at ,greenwich1 ,england1 in #aijh1  

the other at the ,lick  ,observatory in 
#aiad4 ,these excessively faint bodies  
are the most  remote satellites of      
,jupiter and they are of particular     
interest  because they travel around the
 planet in a retrograde direction1 or   
from east to west1 which is opposite to 
the direction of revolution  prevailing 
in the solar system4 ,the ninth and most
 distant satellite  of ,saturn also     
retrogrades1 or revolves in a clockwise 
rather than  a counter-clockwise        
direction around the planet4 ,one       
explanation  given for this peculiarity 
of the outermost satellites of ,jupiter 
and ,saturn is that this backward       
revolution around the planet is  more   
stable when the satellites are at great 
distances from the  primary1 and the    
gravitational control that the planet   
exerts is  therefore weak4 ,the moons of
 the planets are1 of course1 subject  to
 the attraction of the sun as well as to
 the attraction of the  controlling     
planet1 and the greater the distance of 

the satellite  from the planet the      
stronger the pull exerted by the sun and
 the  weaker the bonds that bind the    
moon to the planet4 ,beyond a certain   
limit it would be impossible for the    
planet to hold the satellite  against   
the sun's greater attraction and the    
satellite would leave  the planet to    
revolve directly around the sun1 thereby
 becoming a  planet4 ,it appears that as
 this danger limit is neared it is safer
  for the satellite to back around the  
planet than to follow the  usual west to
 east direction of revolution4 ,the     
eighth satellite  of ,jupiter is more   
than fourteen million and the ninth more
 than  fifteen million miles from the   
parent planet and they require about    
two years and three years1 respectively1
 to complete one trip around  ,jupiter4 
,when we consider that ,satellite ,v    
darts around the planet  in less than   
twelve hours at a distance of only      
sixty-seven thousand  miles from its    
surface we realise what tremendous      

differences exist  in the distances and 
periods of revolution of the nine moons4
 ,there  is also great disparity in the 
sizes of the various moons4 ,the five   
moons discovered in modern times are all
 excessively faint and  extremely small4
 ,the diameter of the largest of these1 
,satellite  ,v1 is less than one hundred
 miles4 ,on the other hand1 the four    
historic moons of ,jupiter are of       
planetary dimensions4 ,the smallest1    
,satellite ,,ii1 is slightly larger than
 our own moon1 while the  largest1      
,satellite ,,iii1 has a diameter1       
according to measurements  made with the
 #dj-;inch ,yerkes refractor in #aiaf1  
of three thousand  nine hundred and     
eight miles1 which is only four hundred 
miles less  than the diameter of ,mars4 
,the periods of revolution of these four
  satellites range from one day and     
eighteen hours for the nearest1  which  
is about two hundred and sixty-one      
thousand miles from the  center of      
,jupiter1 to sixteen days and sixteen   

and one-half hours for  the most        
distant1 which is more than one million 
one hundred and  sixty thousand miles   
from the planet4 ,these four moons are  
so near  to the great planet that they  
are continually dipping into his huge   
shadow and experiencing an eclipse of   
the sun which1 owing to the  nearness   
and great size of ,jupiter1 lasts for   
two or three hours4 ,at  times of       
eclipse the moon suddenly disappears    
from the observer's  view1 though it may
 be considerably to one side of the     
planet4 ,its  reappearance later on is  
just as sudden1 or it may pass out of   
the  shadow while hidden from us behind 
the disk of the planet1 in which  case  
its reappearance is invisible from the  
earth4 ,the occultations  of the        
satellites1 or1 in other words1 their   
disappearance behind  the planet's disk1
 are also interesting phenomena to      
observe1 as  are their transits across  
the disk of the planet as the satellite 
passes in front of it4 ,not only the    

satellite itself but its shadow  as well
 can be seen1 a small black dot passing 
over the surface of  ,jupiter4 ,the     
satellite is totally eclipsing the sun  
for this small  dark portion of the     
planet's disk4 ,two satellites and their
 shadows  are frequently seen crossing  
the face of the planet at the same      
time4 ,it is possible to observe all the
 phenomena of the satellite's  transits 
and shadows1 eclipses and occultations  
with very small  telescopes4 ,from      
observations of the eclipses of         
,jupiter's satellites  the important    
discovery of the finite velocity of     
light was first  made as far back as the
 year #afge4    ,faint surface markings 
have been made out at certain times on  
the  largest of the four satellites1    
,satellite ,,iii1 and also on ,satellite
  ,i4 ,observations of the markings on  
the former seem to indicate that  it    
always keeps the same face turned toward
 ,jupiter as does our own  moon toward  
the earth4    ,there are also reasons   

for believing that the equatorial       
regions of  ,satellite ,i are light     
colored and the polar regions dark4     
,there is  the possibility that forms of
 life may exist on these satellites of  
,jupiter1 though they are more likely   
barren1 lifeless worlds1 such as        
,mercury and the moon4 ,their great     
distance from the earth1 never less     
than three hundred and sixty-eight      
million miles1 makes observations  of   
their surface markings very difficult4  
,how beautiful beyond description must  
the heavens appear as viewed  from the  
satellites of ,jupiter6 ,viewed from the
 distance of ,io1 or  ,satellite ,i1 the
 mighty planet ,jupiter presents a      
spectacle such  as the eye of man has   
never been privileged to behold4 ,the   
huge  flattened globe1 ninety thousand  
miles in equatorial diameter1 equal  in 
mass to three hundred planets such as   
our own and in volume to  nearly        
fourteen hundred1 fills a space in the  
heavens nearly twenty  degrees in extent

 as viewed from this satellite4 ,fifteen
 hundred of  our own full moons would   
hardly fill the same space4 ,whirling on
 its  axis with frightful speed in a    
period of less than ten hours1 the  huge
 ball glides rapidly but majestically   
onward through the sky4 ,a  far distant 
sun shrunk to but one-fifth the diameter
 of the full moon  throws light and     
shade across the rapidly changing       
surface of the  planet1 rich in the     
reds1 browns and yellows and all the    
gorgeous  shades and tints of its dense1
 seething1 gaseous envelope4 ,the phases
  of the moon on a greatly enlarged     
scale rapidly succeed each other  on    
,jupiter as it is viewed from the       
satellite in all positions with         
reference to the sun4 ,the cause of the 
belts of ,jupiter1 that lie  parallel to
 the planet's equator and are constantly
 changing in  number1 width and shade1  
as well as the nature of all the        
peculiar  splashes of color and         
intensely white flecks that come and go 

in  the dense atmosphere of the planet  
would not be such a mystery to  us were 
it possible to view the great planet    
from the distance of  ,satellite ,i1    
which is about as far from the surface  
of ,jupiter as  the moon is from the    
earth4 ,it is uncertain whether the     
planet is  entirely gaseous throughout  
or has a central core of solid or liquid
  matter4 ,its density is only one and  
one-quarter times that of water  and    
slightly less than that of the sun1     
showing that it is composed  largely1 if
 not entirely1 of matter in a gaseous   
state4 ,jupiter is a  world as different
 from our own as it is possible to      
imagine4 ,there  is no visible surface  
crust and there are no permanent        
markings4  ,different spots on the      
planet's disk give different periods of 
rotation showing that it is atmospheric 
phenomena that we observe4  ,all is     
constant flux and change on ,jupiter4   
,dense vapors arise  from a highly      
heated interior and spread out into     

belts parallel  to the equator in the   
direction of the planet's rotation4     
,from its  nearest satellite all the    
interesting changes of color and form   
that  constantly take place in the      
atmosphere of this great globe could be 
observed in great detail4 ,the high     
percentage of light and heat that       
,jupiter reflects from the sun to its   
nearer satellites makes it a  secondary 
sun to them of tremendous size though   
feeble strength4    ,as seen from       
,satellite ,i the other three major     
moons of ,jupiter  present all the      
phases of our own moon in rapid         
succession1 due to  their constantly    
changing positions with reference to the
 sun4 ,the  five small moons1 discovered
 in modern times1 are so minute that    
they  are simply star-like points of    
light even when viewed from the other   
moons of ,jupiter4    ,to keep track of 
the rapidly changing positions and      
various phases  of the moons of ,jupiter
 as seen from any one of them1 as well  

as  the rapid apparent motion of the    
planet through the sky due to  the      
revolutions of the satellite around the 
planet1 would be a  troublesome task for
 an astronomer stationed on one of these
 far  distant worlds4 ,it would be a    
common sight to see in the sky at one   
time the huge planet1 the far-distant1  
shrunken sun1 and one1 two  or three    
moons4 ,seen from the moons of ,jupiter 
the constellations  would appear as they
 do to us on earth1 for such a slight   
change in  position as five hundred     
million miles1 more or less1 is trivial 
when one is looking at the stars4       
,observations of the stars from the     
nearest moon of ,jupiter would be       
attended with great difficulties at     
times1 since reflected sunlight from a  
body nearly twenty degrees in  diameter 
would be extremely troublesome1         
especially were the phases  of the      
planets near that of the full moon4 ,we 
know how the presence  of our own moon  
in the heavens at the full dims the     

brightness of  the stars so that only   
the brightest stars are seen4 ,even as  
viewed  from the fourth or most distant 
of the major satellites the planet      
subtends an angle of nearly five        
degrees4 ,occultations of the stars  are
 many and frequent as the huge planet   
globe glides swiftly through  the       
heavens4 ,many a moonlight night appears
 almost as day owing to  the presence of
 the enormous1 brilliantly reflecting   
ball of light  and at times two or three
 moons in addition4 ,only the brightest 
stars  could possibly be seen under such
 circumstances4 ,when1 however1 the     
small worlds pass into the shadow of the
 great mother planet and not  only the  
light of the sun but also the reflected 
light of ,jupiter  disappears for many  
minutes1 the stars shine forth in all   
their glory  there as here4 ,at such    
times some of the larger moons would    
usually  be seen shining by the         
reflected light of the far distant sun4 
,saturn  also would be visible as a     

magnificent star1 but beautiful ,venus  
and  ruddy ,mars would fail to appear4  
,tiny bodies1 mere specks of light at   
this distance1 they would be lost to    
view in the glare of the sun4           
,,xx    ,,the ,,rings ,,and ,,moons ,,of
 ,,saturn      ,nearly everyone has felt
 at some time or other a strong desire  
to  gaze at some of the beauties and    
wonders of the heavens through  a       
telescope and the one object that all of
 us wish to see1 if1  perchance1 this   
desire is to be gratified is ,saturn1   
whose unusual  ring system has1 so far  
as we know1 no counterpart in the sky4  
,all the planets in the solar system    
with the exception of the two           
innermost1 ,mercury and ,venus1 are     
attended by satellites1 but ,saturn1    
alone1 has in addition to a family of   
nine moons1 three distinct  rings of    
great dimensions which are composed of  
swarms of minute  particles revolving   
around the planet4    ,why ,saturn      
should be the only planet to possess    

such a system of  rings has never been  
explained in an entirely satisfactory   
manner4  ,there is an interesting law   
known as ,roche's ,law1 however1 named  
from its investigator1 that states that 
no satellite of a planet can  exist     
intact with #b4dd times the radius of   
the planet4 ,this limit is  spoken of as
 ,roche's ,limit and applying it to the 
planet ,saturn we  find that the rings  
of ,saturn fall within this limit4 ,it  
does not  necessarily follow from this  
that the minute particles of which the  
rings are composed are the shattered    
remains of one small satellite1  but    
rather that they are the material from  
which a satellite might  have been      
formed were it not so close to the      
planet4 ,within ,roche's  ,limit the    
mutual attraction of the various        
particles for each other  that would    
tend eventually to gather them into one 
body is overcome  by tidal forces that  
arise from such close proximity to the  
huge  planet4 ,the stress and strain of 

such forces is so great that no         
grouping of particles can take place4   
,this explains1 possibly1 why  the rings
 continue to exist in their present     
condition4 ,the total  quantity of      
matter in the rings is known to be very 
small1 for  it does not disturb the     
motions of any of the nearer and smaller
  satellites1 though tiny ,mimas1 six   
hundred miles in diameter1 is only      
thirty-one thousand miles beyond the    
outer edge of the outer ring4    ,an    
interesting observation was made a few  
years ago of the passage  of the rings  
of the planet between us and a star4    
,though the light  of the star was      
diminished to one-fourth of its normal  
brightness  when the rings passed before
 it1 at no time was its light entirely  
eclipsed by any of the particles4 ,it   
was computed that if the  diameters of  
any of the individual particles had     
amounted to as much  as three or four   
miles the star would have been          
temporarily eclipsed4  ,an upper limit  

for the size of the moonlets was thus   
obtained4 ,the  average diameter of the 
particles is probably much less than    
three  miles4    ,the thickness of the  
ring system is not over fifty or one    
hundred  miles1 but its total diameter  
is one hundred and seventy-two thousand 
miles4 ,there are1 in all1 three        
concentric rings4 ,the faint inner      
ring1 known as the crape ring1 is       
invisible in a telescope under  four    
inches in aperture4 ,the width of this  
inner ring is eleven  thousand miles4   
,just beyond the crape ring is the      
chief1 bright  ring1 eighteen thousand  
miles in width4 ,it shades gradually in 
brightness from its juncture with the   
crape ring to its most luminous  portion
 at its outer edge1 which is separated  
from the third or  outer ring by a gap  
two thousand two hundred miles in width1
 known  as ,cassini's ,division4 ,the   
third or outer ring is eleven thousand  
miles wide and is less bright than the  
central ring4 ,the inner edge  of the   

inner ring is but six thousand miles    
above the surface of the  planet4 ,on   
account of the curvature of the planet  
the ring system  is invisible from the  
north and south poles of ,saturn4 ,as in
 the  case of the satellites of a planet
 the inner particles of the rings       
revolve around the planet more rapidly  
than the outer particles4 ,the          
innermost particles of the crape ring   
require but five hours for one  journey 
around ,saturn while the outermost      
particles of the outer ring  require one
 hundred and thirty-seven hours1 or     
nearly six days to  complete one        
revolution4    ,in addition to the gap  
in the rings known as ,cassini's        
,division  several other fainter        
divisions exist4 ,if a group of moonlets
 were  to revolve around the planet in  
the positions marked by these gaps      
their periods of revolution would be    
commensurable with the periods  of      
several of the satellites of ,saturn4   
,as a result the attraction  exerted on 

such particles by these satellites would
 gradually disturb  their motion in such
 a way as to draw them away from these  
positions4  ,it is owing1 therefore1 to 
the attraction of the satellites of     
,saturn  for the moonlets that these    
gaps in the rings exist4    ,as a result
 of the disturbances produced in the    
motion of the  moonlets by the          
satellites of ,saturn collisions are    
bound to occur  occasionally among the  
various particles4 ,when two particles  
collide  the period of revolution of one
 or both of them is reduced and as a    
result collisions tend to bring the     
moonlets gradually closer and  closer to
 the surface of the planet4 ,the dusky  
inner ring1 it is  believed1 may consist
 largely of particles whose periods have
 been  continually shortened by         
collisions4    ,saturn may1 therefore1  
lose its ring system in the course of   
time  through its gradually being drawn 
down upon the planet by collisions  of  
the various particles until all of the  

material is finally swept  up by the    
planet4 ,such a change would probably   
require millions of  years1 however1 as 
collisions are probably1 on the whole1  
infrequent4  ,it is possible that the   
ring system of ,saturn may have been    
much more  extensive in the past than it
 is now and other members of our solar  
system may have had such appendages in  
the far distant past4    ,the appearance
 of the rings of ,saturn as viewed from 
our planet  changes periodically as a   
result of the revolution of the earth   
and ,saturn around the sun1 which places
 them in constantly changing  positions 
with reference to each other4 ,the rings
 lie in the plane of  ,saturn's equator1
 which is inclined twenty-seven degrees 
to its orbit  and twenty-eight degrees  
to the ,earth's orbit4    ,since the    
position of the equator remains parallel
 to itself while  the planet is         
journeying around the sun it happens    
that half the time  the earth is        
elevated above the plane of the rings   

and the remainder  of the time it lies  
below the plane of the rings4 ,twice in 
the period  of ,saturn's revolution     
around the sun1 which occupies nearly   
thirty  years1 the earth lies directly  
in the plane of the rings and at this   
time the rings entirely disappear from  
view for a short time4 ,mid-way  between
 the two dates of disappearance the     
rings are tilted at their  widest angle 
with reference to the earth and they are
 then seen to  the best advantage4 ,as  
the date of their disappearance         
approaches  they appear more and more   
like a line of light extending to either
  side of the planet's equator4 ,even in
 the most powerful telescope  the rings 
entirely disappear from view for a few  
hours at the time  the earth lies       
exactly in the same plane4 ,it is at    
this time that  the ball of the planet  
is best seen4 ,its flattening at the    
poles1  which is nearly ten per cent4 of
 its equatorial diameter then gives  it 
a decidedly oval appearance4 ,ordinarily

 one of the hemispheres  of ,saturn is  
partly or entirely concealed by the     
rings so that the  oblate form is not so
 noticeable4 ,it was the change in the  
tilt and  visibility of the rings that  
so perplexed ,galileo when he attempted 
to make out the nature of these         
appendages of ,saturn with his  crude   
telescope of insufficient magnifying    
power4 ,so great was his  bewilderment  
when the rings finally disappeared that 
he cried out in  despair that ,saturn   
must have swallowed his children1       
according to  the legend4 ,he finally   
became so exasperated with the results  
of his  observations that he gave up    
observing the planet4 ,the true nature  
of  these appendages of ,saturn remained
 a mystery until ,huygens solved  the   
problem in #afee1 some time after the   
death of ,galileo4    ,in addition to   
the rings1 ,saturn has nine satellites  
named1 in the  order of their distance  
outward from the planet1 ,mimas1        
,enceladus1  ,tethys1 ,dione1 ,rhea1    

,titan1 ,hyperion1 ,iapetus and ,phoebe4
 ,the  last-mentioned satellite was     
discovered by ,w4 ,h4 ,pickering in     
#ahii4  ,it aroused great interest at   
the time because it was the first       
satellite to be discovered with         
retrograde motion in its orbit4 ,two    
satellites of ,jupiter since discovered 
revolve in the same direction  around   
their primary4    ,the satellites of    
,saturn are approximate to those of     
,jupiter in  size and exactly equal them
 in number4 ,the largest1 ,titan1 is    
three  thousand miles in diameter and   
can be easily seen with the smallest    
telescopes4 ,with a four-inch telescope 
five of the satellites can  be readily  
found1 though they are not as           
interesting to observe as  the          
satellites of ,jupiter because they are 
far more distant from  the earth4 ,the  
time they require to make one journey   
around ,saturn  varies from nearly      
twenty-three hours for ,mimas1 the      
nearest1 to  approximately five hundred 

and twenty-four days for ,phoebe1 the   
most  distant4    ,saturn as well as    
,jupiter is marked by belts parallel to 
the ,equator  though they appear more   
indistinct than those of ,jupiter on    
account  of the greater distance of     
,saturn4 ,saturn also resembles ,jupiter
  in its physical composition which is  
largely1 if not entirely1  gaseous1 and 
in the extremely short period of        
rotation on its axis  which is          
approximately ten hours4 ,in more ways  
than one ,saturn is  a very unusual     
planet4 ,in addition to possessing an   
enormous ring  system it is the lightest
 of all the planets1 its density being  
only  sixty-three hundredths that of    
water1 and it is the most oblate1  its  
flattening at the poles amounting nearly
 to one-tenth of its  diameter4 ,its    
equator is more highly inclined to its  
orbit than is  the case with any other  
planet1 not even excepting the earth and
  ,mars4 ,for this reason its seasonal  
changes are very great1 in marked       

contrast to ,jupiter whose equator lies 
very nearly in the plane of  its orbit4 
,since ,saturn is so far away from the  
sun that it receives  only one ninetieth
 as much light and heat per unit area as
 the earth1  its outer gaseous surface  
must be extremely cold unless           
considerable  heat is conveyed to the   
surface from within its hot interior4   
,the late ,prof4 ,lowell concluded from 
certain observations made at            
,flagstaff1 ,ariz41 that ,saturn is     
composed of layers of different         
densities and that the inner layers are 
more flattened at the poles  and rotate 
faster than the outer layers4 ,marked   
variations in the  color and brightness 
of the ball of the planet have been     
noted from  time to time4 ,in #aiaf     
observers of ,saturn described the      
planet as  pinkish-brown and            
conspicuously darker than the brighter  
portions of  the rings4    ,it is       
believed that these very noticeable     
changes in the color and  brightness of 

,saturn are due to slight1 irregular    
changes in the  intensity of the        
radiations of the sun which set up      
certain secondary  effects in the       
atmosphere of the planets4 ,similar     
changes in color  and brightness have   
been observed also in the case of       
,jupiter4          ,,xxi    ,,is ,,the  
,,moon ,a ,,dead ,,world8      ,it has  
been a generally accepted belief among  
astronomers for years  that the moon is 
a dead world devoid of air and water and
 so1  necessarily1 lifeless4 ,it is     
certain that the moon has no extensive  
atmosphere such as envelops our own     
planet4 ,there is abundant proof  of    
this fact4 ,the edge of the lunar disk  
is clear-cut4 ,whenever1  as happens    
frequently1 the moon passes between us  
and a star the  disappearance of the    
star is instantaneous4 ,there is no     
gradual  dimming or refraction of the   
star's light by atmospheric vapors4     
,moreover1 lunar shadows are harsh and  
black4 ,there is no evidence of         

diffusion of light on the moon by       
atmospheric gases4    ,the absence of   
water or water vapor on the visible     
surface of the  moon1 at least in any   
appreciable quantity1 is plainly evident
 to  anyone who observes the moon       
through the telescope4 ,even with small 
telescopes1 objects five miles or so in 
diameter can be readily  detected and   
clouds drifting over the surface could  
not possibly  escape our observation if 
they existed4    ,bodies of water1 great
 or small1 would be plainly visible and 
would  besides give rise to water vapor 
and clouds1 which we would not fail  to 
detect4    ,since the surface of the    
moon is unscreened by air and water     
vapor to  absorb the incoming rays from 
the sun1 and the outgoing radiations    
from the surface1 the extremes of       
temperature between day and night  are  
very great1 and are augmented by the    
fact that the lunar day  equals the     
lunar month in length1 so that fourteen 
days of untempered  heat are followed by

 fourteen days of frigid darkness4      
,observations  of the rate of radiation 
from the moon's surface during total    
eclipses of the moon indicate that the  
moon's radiation is very  rapid1 and    
that its temperature during the height  
of the lunar day  probably approaches   
#bjj ,f41 while at the lunar midnight it
 may have  fallen to #ajj below zero    
,f41 or even lower4    ,with air and    
water both lacking and such extremes of 
temperature  existing why should we     
seriously consider the question of life 
on the  moon8    ,this is the point of  
view of the majority of astronomers and 
it seems  well taken4 ,yet many         
astronomers who have made a special     
study of  the lunar surface for years   
under all conditions of illumination and
  phase1 and have most carefully        
observed and mapped and photographed    
its characteristic markings1 are agreed 
that there are evidences  that changes  
are taking place on the moon1 and       
recently ,prof4 ,w4 ,h4  ,pickering has 

expressed the belief1 substantiated by  
drawings1 that  there is a progressive  
change of color or darkening within     
certain  lunar craters with the advance 
of the lunar day1 indicating1 in his    
opinion1 a rapid vegetational growth    
that springs up in the height  of the   
lunar day and dies out as the lunar     
night approaches4    ,some years ago    
certain selenographers suggested that   
there might  exist in the numberless    
crater-pits and craters1 in the         
deep-lying  maria or seas1 and in the   
clefts and rills and cracks that form   
intricate systems all over the lunar    
surface1 certain exhalations  from the  
surface and heavy vapors including      
possibly carbon dioxide  and water vapor
 to temper the extremes of the long     
lunar days and  night and furnish the   
necessary medium for the support of     
certain  forms of animal and vegetable  
life4    ,many astronomers1 including a 
number who are not in sympathy with  the
 above view1 believe that snow and ice  

exist on the moon1 even  though water in
 the form of liquid and vapor is not    
observable4 ,all  the extremely         
brilliant portions of the surface1      
according to some  astronomers1 are     
covered with snow and ice4 ,certainly1  
some portions  of the moon's surface    
reflect sunlight as brilliantly as if   
they  were covered with freshly fallen  
snow1 while other portions appear  to be
 black by contrast4 ,there also appears 
to be evidence that  certain small      
markings1 described as crater-cones and 
resembling our  terrestrial volcanoes   
more than any other lunar feature1 are  
at times  temporarily obscured from view
 by a veil of vapors4 ,many observers   
believe that these crater-cones are     
active volcanic vents1 and that  there  
is considerable volcanic activity still 
taking place upon the  moon4    ,these  
small crater-cones resemble1 we are     
told1 parasitic cones found  on the     
sides of terrestrial volcanoes1 and they
 are frequently seen  on the floors of  

craters closely associated with light   
streaks4  ,these crater-cones appear    
under a high sun as minute white spots  
and can be studied to advantage only    
with powerful instruments4  ,the        
,italian astronomer1 ,maggini1 observing
 the floor of the lunar  crater1 ,plato1
 in #aiaf noted that one of the small   
crater-cones that  exist there in great 
numbers1 was temporarily obscured from  
view by  a cloud of reddish vapors1 and 
,prof4 ,w4 ,h4 ,pickering1 at ,arequipa1
  ,peru1 observing the same region some 
years ago1 believed that he  saw        
evidence of change in some of these     
small markings4 ,the crater1  ,plato1   
has probably been more carefully studied
 than any other  portion of the lunar   
surface4 ,it is sixty miles in diameter 
and may  be seen even without a         
telescope as a dark eye not far from the
  northern edge of the moon4 ,its floor 
is one of the darkest objects in  the   
moon--a dark steel-grey in color--and   
there is no doubt that for  some unknown

 reason its dark hue deepens from the   
time the sun has an  altitude of twenty 
degrees until after full moon4 ,it has a
 brilliant  white wall rising from      
#c1jjj to #d1jjj feet above its floor1  
crowned  with several lofty peaks and   
intersected by a number of valleys and  
passes4 ,the spots and faint light      
markings on the floor have been the     
object of much study with small or      
moderate sized instruments1 and  at     
least six of them are known to be       
crater-cones4 ,since they can  only be  
studied to advantage with powerful      
instruments and as such  instruments are
 rarely used for a systematic study of  
lunar markings1  it is difficult to     
settle the controversy as to whether    
they have  changed in appearance or have
 been at any time obscured by vapors4   
,most lunar observing is                
done--necessarily--with smaller         
instruments  because the majority of    
astronomers appear to have accepted the 
view that the moon is a dead world1 and 

those who are engaged in  astronomical  
work with our greatest telescopes seem  
to feel that  other fields of research  
will prove more fruitful4 ,possibly it  
is  for this reason that we know so     
little about our nearest neighbor in    
space6 ,there are at least as many      
unsolved problems confronting us on  the
 moon as there are among the distant    
stars4    ,geologists tell us that more 
oxygen is to be found in the first six  
feet of the earth's crust than in all of
 the atmosphere above4 ,does  oxygen not
 exist in the surface rocks of the moon 
as well8    ,volcanic action1 we are    
told1 is primarily an escape of gases   
from  the interior1 chiefly hydrogen1   
nitrogen1 hydrocarbons1 sulphur1 and    
various compounds1 as well as vast      
quantities of steam4 ,beneath the       
surface chemical change is continually  
taking place which results  in the      
release of an enormous amount of heat4  
,some of the gases  mentioned above     
combine with the oxygen in the surface  

rocks and heat  is evolved4 ,it is a    
known fact that there is great inherent 
heat in  the earth's surface crust4 ,why
 not in the moon's surface crust as     
well8    ,the water that would be       
expelled in the form of steam from      
volcanic  vents on the moon would be    
transformed immediately into hoar-frost1
  snow and ice and would settle down    
upon the flanks of the  crater-cones or 
vents4    ,it should be borne in mind   
that only volcanic activity on an       
enormous scale would be plainly visible 
to us even with the powerful  telescopes
 at our command4 ,ordinary eruptions    
such as occur on our  own planet would  
be very difficult to detect4 ,since the 
escaping  vapors would rapidly pass into
 the solid state and settle down  upon  
the flanks of the crater-cones or vents1
 we would observe in  general little if 
any change in an object unless we       
chanced to be  looking at it at the time
 of the eruption1 when it might appear  
to be  temporarily obscured by a veil of

 vapors4 ,what are the chances that  we 
would be carefully observing at the     
precise time of an eruption1 a  minute  
marking1 two or three miles in diameter1
 on a surface as large  as all of ,north
 ,america1 a surface that is covered    
with some #cj1jjj  charted craters1     
numberless crater-pits1 streaks1 rays1  
spots1 clefts  and rills in intricate   
systems1 mountain chains and valleys and
 a  mass of intricate detail8    ,if we 
were looking at the earth from the moon 
with the aid of a  powerful telescope   
would we be apt to notice an eruption of
 ,vesuvius  or ,katmai or ,mauna ,loa8  
,objects four or five miles in diameter 
would appear as hazy spots with nothing 
distinctive or remarkable  in their     
appearance4 ,yet vapor and steam arising
 from terrestrial  volcanoes would be   
carried by our atmosphere over an area  
of many  square miles1 while there is no
 atmosphere on the moon to spread the   
vapors that may arise from similar      
volcanic vents4 ,it would have  to be a 

cataclysmic change indeed to be accepted
 as indisputable  evidence that change  
is taking place on the moon1 and the    
days of  gigantic upheavals are probably
 over on our satellite as well as on    
the earth4 ,if volcanic activity is     
still taking place on the moon it  is   
probably in a mild form such as a       
comparatively quiet emission  of gases  
from volcanic vents and fumaroles4 ,such
 forms of activity  would not be plainly
 visible at this distance1 even with the
 aid of  powerful telescopes4 ,the      
problem of detecting changes on the moon
 is  complicated by the fact that a     
change of illumination greatly alters   
the appearance of all lunar markings4   
,such a change is continually  taking   
place in the course of the month4 ,a    
marking that stands out  in bold relief 
at lunar sunrise or sunset will change  
entirely in  appearance a few days later
 under a high sun or even disappear from
  view entirely4 ,these changes in phase
 or illumination have to be  taken      

account of in the search for evidence of
 actual change4 ,to  decide whether or  
not change has actually taken place the 
object must  be viewed under similar    
conditions1 so far as they can be       
obtained4  ,even when special care is   
taken in this respect the suspected     
evidence of change is usually explained 
away as due to differences  in          
illumination or seeing1 by those who    
have not observed the object  themselves
 and are not in sympathy with the view  
that the moon is  anything but a dead   
world4    ,as regards the question of   
life on the moon1 it is interesting to  
consider the facts brought out by       
investigations made by scientists       
connected with the ,geophysical         
,laboratory of the ,carnegie ,institute 
in the ,valley of ,ten ,thousand        
,smokes4 ,the volcanic activity there   
takes the form of eruptions from        
numerous small vents or fumaroles  and  
ninety-nine per cent4 of the emanations 
are water vapor4 ,it was  observed that 

blue-green algae were living at the edge
 of active  vents emitting ammonia      
compounds at a temperature of #bab ,f4  
,they  were not found1 however1 near    
vents from which ammonia compounds  were
 not being emitted4 ,if life exists     
under such conditions it is  conceivable
 that suitable conditions for the       
support of certain forms  of life1      
animal as well as vegetable1 may be     
found in low-lying  valleys and crevices
 and upon the floors of craters1 where  
certain  gases essential to the support 
of life might be evolved from many      
small volcanic vents and fumaroles4     
,many theories have been advanced to    
explain the origin of the lunar  craters
 which have no counterpart on our own   
planet4 ,they are  saucer-like          
depressions in the surface of the moon1 
frequently of  such great size that an  
observer standing in the center would   
not  be able to see either side of the  
crater owing to the curvature of  the   
moon's surface4 ,craters fifty1 sixty or

 one hundred miles in  diameter are by  
no means uncommon1 while there are      
thousands between  five and fifty miles 
in diameter4 ,a characteristic feature  
of many  craters is a central peak1 and 
the surrounding walls are often a  mile 
or more high and in some instances are  
symmetrically terraced4  ,new craters   
have been formed on the sides or floors 
of old craters1  and these are always   
more clear-cut and sharper in outlines  
than the  old formations1 and generally 
much smaller4 ,a number of craters are  
surrounded by a system of light streaks 
or rays of unknown origin  that extend  
in some instances to enormous distances 
on all sides  of the crater4 ,the most  
conspicuous system is the one           
surrounding  the lunar crater ,tycho    
near the south pole of the moon4 ,the   
rays  originating in this crater extend 
in all directions for hundreds  of miles
 without turning aside for any          
obstructions1 passing over  mountains1  
craters and plains in their course in   

practically straight  lines like spokes 
in a wheel4 ,this ray system of ,tycho  
is the most  noticeable marking on the  
moon's surface at the time of full moon4
  ,as these streaks cast no shadow they 
are apparently cracks in the  surface   
that have filled up with some           
light-colored material from  below4     
,their origin has never been            
satisfactorily explained4    ,as to the 
origin of the lunar craters1 some       
believe that they were  produced in past
 ages by a bombardment of the lunar     
surface by huge  meteoric masses2 but   
there are many objections to this theory
 that we  will not take up here4 ,it is 
more generally believed that the lunar  
craters are a result of volcanic        
activity on an enormous scale which     
took place on the moon many ages ago and
 which has now practically  ceased1 its 
only manifestations now taking the form 
of a quiet  emission of gases from small
 volcanic vents or fumaroles which exist
  all over the lunar surface but which  

are to be found in greatest  numbers on 
the floors and sides of craters4        
,,xxii    ,,comets      ,the orbits of  
comets are inclined at all angles to    
each other and to  the orbits of the    
planets which1 on the other hand1 lie   
very nearly  in the same plane4    ,the 
larger members of the sun's family1 the 
planets and their  satellites1 revolve  
from west to east around the sun4       
,comets on the  contrary frequently     
retrograde or back around the sun in the
 opposite  direction--from east to west4
    ,the paths that these erratic       
visitors follow in their journeys around
  the sun bear not the slightest        
resemblance to the paths of the         
planets1 which are almost perfect       
circles4 ,the orbits of comets are      
ellipses that are greatly elongated or  
parabolas4 ,if the orbit is a  parabola 
the comet makes one and only one visit  
to the sun1 coming  from interstellar   
space and returning thereto after a     
brief sojourn  within our solar system4 

,donati's comet of #aheh1 one of the    
greatest comets of the nineteenth       
century1 had a period of more than two  
thousand years and its  aphelion 7the   
point in its orbit farthest away from   
the sun7 was five  times more distant   
than the orbit of ,neptune4    ,there   
is1 however1 a class of comets known as 
periodic comets  that have extremely    
short periods of revolution around the  
sun4  ,to this class belongs ,halley's  
comet whose period of seventy-five      
years exceeds that of any other short   
period comet4 ,encke's comet1  on the   
other hand1 has a period of three and a 
third years which is  the shortest      
cometary period known4 ,most of the     
periodic comets are  inconspicuous and  
only visible telescopically even when   
comparatively  near to the earth4       
,halley's comet is the only one of this 
class that  lays any pretensions to     
remarkable size or brilliancy and it    
also is  showing the effects of         
disintegration resulting from too       

frequent  visits to the sun4    ,comets 
are bodies of great bulk or volume and  
small total mass4 ,their  tails1 which  
only develop in the vicinity of the sun1
 are formed of  the rarest gases1 and   
the best vacuum that man can produce    
would not  be in as tenuous a state as  
the material existing in the tails of   
comets4 ,there are many proofs of the   
extreme tenuity of comets4 ,the  earth  
has on a number of occasions passed     
directly through the tails  of comets   
without experiencing the slightest      
visible effects4 ,stars  shine undimmed 
in luster even through the heads of     
comets4 ,if the  earth should encounter 
a comet head on it is doubtful if it    
would  experience anything more serious 
than a shower of meteors which would  be
 consumed by friction with the earth's  
atmosphere1 or a fall of  meteorites    
over a small area of a few square miles4
 ,it is possible1  however1 that matter 
in the nucleus1 the star-like           
condensation in  the head of a comet1   

may consist of individual particles     
weighing in  some instances a number of 
tons1 surrounded by a gaseous envelope  
and held together by the loose bonds of 
their mutual attraction4 ,if  the earth 
should encounter the nucleus of a comet 
considerable damage  might be done over 
a portion of the earth's surface1 but   
the chances  of such an occurrence are  
less than one in a million4    ,since   
the total mass of a comet is so small1 a
 close approach to one  of the planets1 
especially ,jupiter1 produces great     
changes in the  form of the comet's     
orbit1 though the motion of the planet  
is not  disturbed in the slightest      
degree by the encounter4    ,the        
majority of all the short-period comets 
have been captured  by ,jupiter1 that   
is1 the original orbits have been so    
changed by  the perturbations produced  
by close approaches to the giant planet 
that their aphelia1 or the points in    
their orbits farthest from the  sun1 lie
 in the vicinity of ,jupiter's orbit4   

,several of the other  planets have also
 captured comets in this sense1 and the 
fact that  the aphelia of a number of   
comets are grouped at certain definite  
intervals beyond the orbit of ,neptune  
has been considered by some  astronomers
 to be an indication that there are two 
or more additional  planets in the solar
 system revolving around the sun at     
these  distances4    ,the most          
interesting feature of a comet is its   
characteristic tail  which develops and 
increases in size and brilliancy as the 
comet  approaches the sun4 ,as the tail 
is always turned away from the sun  it  
follows the comet as it draws near the  
sun and precedes it as  it departs4 ,its
 origin is due1 it is believed1 both to 
electrical  repulsion and light-pressure
 acting upon minute particles of matter 
in the coma or head of the comet4       
,the curvature of the tail depends upon 
the nature of the gases  of which it is 
composed4 ,long1 straight tails consist 
chiefly of  hydrogen1 it has been found1

 curved tails of hydrocarbons and short1
  bushy tails of mixtures of iron1      
sodium and other metallic vapors4 ,at   
times the same comet will have two or   
more tails of different types4    ,since
 the material driven off from the       
nucleus or head of a comet by           
electrical repulsion and light-pressure 
is never recovered1 it is  evident that 
comets are continually disintegrating4  
,also1 comets that  have passed close to
 the sun at perihelion have frequently  
been so  disrupted by tidal forces that 
one nucleus has separated into several  
parts and the newly formed nuclei have  
pursued paths parallel to the  original 
orbit1 each nucleus developing a tail of
 its own4    ,many periodic comets1 it  
is now known1 have gradually been broken
 up  and dissipated into periodic swarms
 of meteors as a result of the          
disruptive effect produced by too       
frequent returns to the vicinity of  the
 sun4    ,these swarms of meteors       
continue to travel around the sun in the

  orbits of the former comets4 ,the     
earth encounters a number of such       
swarms every year at certain definite   
times4    ,the largest and best known of
 these swarms or showers are the        
,leonids1 which appear about ,november  
#ae2 the ,andromedas 7or ,bielids71     
which appear later in the same month and
 the ,perseids1 which appear  early in  
,august4 ,these swarms are named for the
 constellations in  which their radiant 
lies1 that is1 the point in the heavens 
from  which they appear to radiate4 ,the
 position of the radiant depends  upon  
the direction from which the swarm is   
coming4 ,it is simply a  matter of      
perspective that the individual         
particles appear to radiate  from the   
one point1 for they are actually        
travelling in parallel  lines4    ,the  
luminosity of these meteoric particles  
is caused by the friction  produced by  
their passage through the atmosphere4   
,they always appear  noiselessly because
 they are mere particles of meteoric    

dust weighing  at the most scarcely a   
grain4 ,they differ greatly in this     
respect  from their large and noisy     
relatives1 the meteorites1 bolides and  
fireballs4    ,numberless small meteoric
 particles are entrapped by the earth's 
atmosphere every day4 ,they are referred
 to as shooting stars or  falling stars 
though1 of course1 they are not in any  
sense stars4  ,it is only when these    
meteoric particles travel in            
well-defined  cometary orbits and appear
 at certain definite times every year   
that  they are referred to as swarms or 
showers of meteors4    ,the luminosity  
of comets is due not only to reflected  
sunlight1 but  to certain unknown causes
 that produce sudden and erratic        
increases  or decreases of brilliancy4  
,the causes of these sudden changes in  
luminosity are unknown2 possibly        
electrical discharges or chance         
collisions between fragments of         
considerable size may account for  some 
of them4    ,the peculiar behavior of   

the tails of comets at certain times has
  frequently been noted and suggests the
 existence of quantities of             
finely-divided meteoric or gaseous      
matter within the solar system  that has
 no appreciable effect upon the huge    
planetary masses1 but  offers sensible  
resistance to the passage of the tenuous
 gases of  which the tails of comets are
 composed4 ,the fact that the earth     
daily  encounters meteoric dust1        
meteorites and fireballs also indicates 
that meteoric matter exists in          
considerable quantities within our      
solar system4 ,tails of comets appear at
 times to be twisted or  brushed aside  
as if they had encountered some unknown 
force or some  resisting medium4    ,up 
to the present time several hundred     
comets have been discovered4  ,nearly   
three-fourths of this number travel in  
orbits that appear to  be parabolas4 ,of
 the remaining number there are about   
forty that  have been captured by the   
major planets1 ,jupiter1 ,saturn1       

,uranus  and ,neptune1 though ,jupiter  
possesses the lion's share of these     
captured comets4 ,scarcely a year passes
 by that several comets are  not        
discovered4 ,most of these are          
telescopic1 however1 even when they  are
 near the sun and at their greatest     
brilliancy4 ,naked-eye comets  of great 
splendor and brilliancy are             
comparatively rare and there  has been a
 particular dearth of such unusual      
comets during the past  thirty years or 
so4    ,the last spectacular comet1     
unless we make an exception of ,halley's
  periodic comet1 which made its return 
according to prediction in  #aiaj1 was  
the great comet of #ahhb which was      
visible in broad  daylight close to the 
sun and at its perihelion passage swept 
through  the solar corona with a        
velocity that exceeded two hundred and  
fifty  miles a second and carried it    
through one hundred and eighty degrees  
of its orbit in less than three hours4  
,some comets approach much closer to the

 sun than others4 ,the majority  of all 
comets observed have come within the    
earth's orbit and no  known comet has   
its perihelion beyond the orbit of      
,jupiter4 ,it is1 of  course1 possible  
that there may be a number of comets    
that never come  within the orbit of    
,jupiter1 but it is very unlikely that  
any such  comet would ever be           
discovered4 ,the majority of comets are 
simply  small1 fuzzy points of light    
that are only visible telescopically and
  the greater the perihelion distance of
 the comet the less likely is  it to be 
seen with the naked eye4    ,since      
comets as well as planets obey ,kepler's
 first law1 known as  the law of areas1 
and sweep over equal areas in equal     
times1 it is  evident that when a comet 
is at perihelion1 or nearest to the sun1
 it  is moving at maximum speed and when
 it is at aphelion1 or farthest  from   
the sun1 it is moving at minimum speed4 
,moreover1 its speed at  these two      
points in its orbit varies tremendously 

since the orbits of  comets are ellipses
 of very high eccentricity4 ,the speed  
with which  the planets are traveling   
is1 on the other hand1 remarkably       
uniform  since their orbits are nearly  
circular4    ,the leisurely speed with  
which a comet travels through the frigid
  outer regions of the solar system is  
gradually accelerated as the  comet     
draws nearer and nearer to the sun until
 it has acquired near  the time of      
perihelion passage a velocity that      
occasionally exceeds  two hundred miles 
a second4 ,here1 also1 the great        
increase in light  and heat and the     
strong magnetic field of the sun produce
 complex  changes in the gaseous and    
meteoric substances of which the comet  
is  composed until the characteristic   
tail and peculiar cometary features  are
 fully developed4 ,as the comet again   
recedes from the sun after  perihelion  
passage its speed slackens once more4   
,it soon parts with  its tail and other 
spectacular features and fades rapidly  

from view  even in the largest          
telescopes4          ,,xxiii            
,,meteorites      ,meteorites1 bolides  
or fireballs1 as they are variously     
called1 are  stones that fall to the    
earth from the heavens4 ,they furnish   
the one  tangible evidence that we      
possess1 aside from that furnished by   
the  spectroscope1 as to the composition
 of other bodies in space and  it is a  
significant fact that no unknown        
elements have ever been  found in       
meteorites1 though the forms in which   
they appear are so  characteristic that 
they make these stones readily          
distinguishable  from stones of         
terrestrial origin4    ,the origin of   
meteorites is not definitely known1 but 
the evidence is  very strong in favor of
 the theory that they are the larger    
fragments  of disintegrated comets of   
which meteors and shooting stars are the
  smaller2 the distinction between the  
two being simply that the latter  class 
includes all bodies that are completely 

consumed by friction  with the earth's  
atmosphere and1 therefore1 only reach   
the surface in  the form of meteoric    
dust4    ,according to other theories   
meteorites may be fragments of shattered
  worlds that have chanced to come too  
near to a larger body and have  been    
disrupted1 or they may possibly be the  
larger fragments of the  disintegrated  
comets of which the meteoric swarms are 
the smaller4    ,interplanetary space is
 not altogether a void4 ,our own planet 
sweeps up in the course of a single day1
 it has been estimated1  approximately  
twenty million shooting stars or meteors
 of sufficient  size to be visible to   
the naked eye1 while the estimate for   
the  telescopic particles runs up to    
four hundred million4    ,meteorites on 
the other hand are comparatively rare4  
,on the average  it has been estimated  
about one hundred meteorites strike the 
earth  in the course of a year1 of which
 number only two or three are  actually 
seen4 ,according to ,bulletin #id1 ,u4  

,s4 ,national ,museum1  approximately   
six hundred and fifty falls and finds of
 meteorites  have been reported1        
representatives of which appear in      
museums and  private collections4       
,meteorites1 as well as shooting stars  
and meteors1 frequently appear  in      
showers4 ,in such instances the fall    
usually consists of several  hundred or 
thousand individual stones and the area 
over which they  fall is several square 
miles in extent and roughly ellipsoidal 
in shape4 ,one of the most remarkable of
 such falls 444 hundred  thousand       
stones1 varying in weight from fifteen  
pounds to a small  fraction of an ounce1
 fell near ,pultusk1 ,poland4 ,another  
remarkable  fall of meteorites occurred 
at ,l',aigle1 ,france1 in #ahjc4        
,between two  thousand and three        
thousand stones fell over an ellipsoidal
 area of  six and two-tenths miles in   
greatest diameter1 the aggregate weight 
of the stones being not less than       
seventy-five pounds4    ,this fall of   

stones is of particular interest since  
it took place at  a time when men were  
still very doubtful as to whether or not
 stones  actually fell to earth from the
 heavens4    ,after this fall had       
occurred in a most populous district of 
,france  in broad daylight and attended 
by violent explosions that lasted for   
five or six minutes and were heard for a
 distance of seventy-five  miles1 no    
reasonable doubt could longer be held as
 to the actuality  of such phenomena4   
,meteorites are without exception of an 
igneous nature1 that is1  they are rocks
 that have solidified from a molten     
condition4 ,they  can be classified into
 three groups1 ,aerolites or ,stony     
,meteorites1  ,siderolites or           
,stony-iron ,meteorites1 and ,siderites 
or ,iron  ,meteorites4    ,more iron    
meteorites seem to have fallen in       
,mexico and ,greenland than  in any     
other part of the world--at least of its
 land surface4    ,yet strange to say1  
of all the meteorites that have been    

seen to  fall only nine belong to the   
group of ,siderites or ,iron            
,meteorites1  though the three largest  
meteorites known1 ,peary's meteorite    
from  ,cape ,york1 ,greenland1 weighing 
#cg-a_/b tons1 the meteorite lying on   
the plain near ,bacubirito1 ,mexico1    
weighing about #bj tons1 and the        
,willamette1 ,oregon1 meteorite1        
weighing #ae-a_/b tons all belong to    
this group4 ,moreover1 all the ,canyon  
,diablo meteorites1 which are  strewn   
concentrically around ,coon ,mountain   
crater in northern ,arizona  to a       
distance of about five miles1 are       
members of this same group4  ,coon      
,mountain or ,meteor crater itself is a 
perfectly round hole1  about six hundred
 feet deep and over four thousand feet  
in diameter  and was formed1 it is      
believed1 by the impact of a huge       
meteorite  which has never been found4  
,it is believed that the ,canyon ,diablo
  meteorites1 of which there are nearly 
four hundred individuals in  the ,u4 ,s4

 ,national ,museum alone1 were all      
members of this same fall4  ,it is      
possible that these meteorites of the   
,canyon ,diablo district1  with the huge
 meteorite that produced the crater     
itself1 formed the  nucleus of a comet  
that struck the earth not more than five
 thousand  years ago1 according to the  
geological evidence4    ,all iron       
meteorites or siderites 7from the ,greek
 sideros1 iron7 are  composed chiefly of
 alloys of nickel and iron4 ,the        
percentage of  nickel in these iron     
meteorites is very small1 usually from  
five to  ten per cent41 while the iron  
forms about ninety or ninety-five per   
cent4 of the whole4 ,cobalt is also     
present in practically all iron         
meteorites in small quantities of #a per
 cent4 or less4 ,usually small          
quantities of iron sulphide and         
phosphide as well as graphite or  some  
other form of carbon appear in the iron 
meteorites and in some  instances black 
and white diamonds have been found1 as  

in some of the  ,canyon ,diablo irons4  
,a very interesting and beautiful       
feature of many iron meteorites  is the 
,widmansttten figures which appear when 
a section of such a  stone is polished  
and treated by means of a weak acid4    
,these figures  are due to the unequal  
solubility of the three different alloys
 of  nickel and iron of which the stones
 are composed4 ,the irons giving  the   
,widmansttten figures are known as      
octahedral irons4 ,other irons  known as
 hexahedral irons give figures of a     
different type known as  ,neumann       
figures when the polished section is    
treated with weak acid1  while other    
irons are so homogeneous in their       
composition that they  show no figures  
at all4    ,aerolites or ,stony         
,meteorites occur more abundantly than  
iron or  stony-iron types1 and they are 
classified into many divisions and      
subdivisions according to their         
composition4 ,in these stones appear    
certain compounds that are commonly met 

with in terrestrial igneous  rocks4 ,the
 mineral that is most abundant in the   
stony meteorites1  composing sometimes  
nearly seventy-five per cent4 of the    
stone1  is a magnesium and iron silicate
 known as olivine1 which is also        
usually present in terrestrial rocks of 
an igneous nature4 ,certain  compounds  
found in the stony meteorites are rarely
 if ever found in  terrestrial rocks1   
however1 and these serve to distinguish 
the stony  meteorites readily from      
stones of terrestrial origin4 ,the      
alloys of  iron and nickel1 for         
instance1 that occur in minor quantities
 in the  stony meteorites and make up   
usually about ninety-five per cent4  of 
the mass of the iron meteorites1 are    
never found in terrestrial  rocks4      
,although about thirty of the           
terrestrial elements are to be  found in
 meteorites1 the forms and compounds in 
which they appear  are so characteristic
 and on the whole so different from     
those  occurring in terrestrial rocks1  

that the analyst has no difficulty  in  
distinguishing between the two4 ,there  
are1 for instance certain  formations   
known as chondrules1 peculiar spherical 
and oval shapes1  varying in size from  
minute particles to objects the size of 
walnuts1  appearing in many varieties of
 stony meteorites that are never found  
in terrestrial rocks1 and that are one  
of the most puzzling features           
associated with the origin and nature of
 these stones4 ,sometimes  the          
chondrules are so loosely embedded in   
the stone that they fall  away when it  
is broken4 ,in some instances almost the
 entire stone is  made up of these      
chondrules4 ,according to one theory the
 chondrules  were originally molten     
drops1 like fiery rain1 and their       
internal  structure1 which is greatly   
varied1 depends upon their conditions of
  cooling4    ,stony meteorites1 in     
which these chondrules are to be found1 
are spoken of as chondrites4 ,there are 
white and gray and black  chondrites and

 crystalline and carbonaceous           
chondrites1 according to  the nature of 
the chondrules found in the stones4     
,stony meteorites also contain minute   
quantities of iron and nickel  alloys in
 the form of drops or stringers4        
,upon entering the earth's atmosphere   
stony meteorites become coated  with a  
thin black crust which is a glass formed
 by the fusion of its  surface materials
 by the heat generated during its       
passage through  the atmosphere4    ,in 
many of the stony meteorites there also 
appear fine thread-like  veins which are
 due to the fracturing of the stone     
prior to its  entrance into the         
atmosphere4 ,the material filling these 
veins is  coal black in color1 opaque   
and of an unknown composition4    ,many 
meteorites show signs of collisions and 
encounters with other  meteorites       
outside of the atmosphere as would be   
expected as they  travel in swarms and  
groups4 ,sometimes the entire meteorite 
is  composed of fragments of two or more

 distinct stones cemented  together4    
,such a stone is spoken of as a breccia4
    ,in the third class of meteorites to
 which we now come1 known as the        
stony-iron meteorites1 there is a       
network or sponge of nickel-iron  alloy1
 the interstices of which are filled    
with stony material4    ,when this      
network or sponge is continuous the     
meteorite is spoken of  as a stony-iron 
pallasite4 ,when the network of metal is
 more or less  disconnected the         
meteorite is a meso-siderite4    ,if    
meteorites are heated in a vacuum1 the  
conditions existing in  interplanetary  
space being thus produced to a certain  
extent1 they  give forth their occluded 
gases and it has been found that these  
gases give spectra identical with the   
spectra of certain comets4  ,meteoric   
irons give forth hydrogen as their      
characteristic gas while  the gases     
occluded in the stony meteorites are    
chiefly the oxides  of carbon1 carbon   
monoxide and carbon dioxide4 ,it has    

been found  that the amount of gases    
contained in a large meteorite or shower
 of  meteorites is sufficient to form   
the tail of a comet4 ,these facts all   
tend to strengthen the belief that      
meteorites are indeed cometary          
fragments4    ,in view of the fact that 
some geologists believe meteorites may  
be  fragments of other worlds1 it is of 
interest to know that so far no         
fossil-bearing meteorites have been     
found1 and if meteorites are  fragments 
of a shattered world1 such worlds must  
have been reduced to  a molten condition
 at the time of the catastrophe4    ,the
 rapid passage of the meteorite through 
the air leaves a partial  vacuum in its 
trail into which rush the molecules of  
air from all  sides1 producing the      
characteristic noises that accompany the
 passage  of a meteorite1 which have    
been variously compared to the rattle of
  artillery1 the distant booming of     
cannons or the rumble of thunder4       
,there may be1 also1 explosions of      

inflammable gases occluded in the       
crevices of the meteorite which will    
shatter it into fragments or  the       
meteorite may be shattered by the       
resistance and pressure of the          
atmosphere or as a result of the        
extremes of temperature existing        
between the interior and its surface4   
,many meteorites have actually  been    
seen to burst into fragments in the air 
with a loud report4    ,there is        
practically no foundation for the belief
 that germs of life  have been brought  
to our planet on such igneous rocks4 ,no
 microscopic  examinations of meteorites
 have yielded any results that could be 
interpreted in favor of such a view4    
,falls of meteorites are accompanied in 
nearly every instance by  terrific      
explosions and sharp reports that can be
 heard for many  miles around1 often    
causing the ground to shake as in an    
earthquake4  ,the meteorite itself has  
been described as resembling a ball of  
fire or the headlight of a locomotive1  

and is followed frequently  by a trail  
of light or a cloud of smoke4 ,at the   
time it enters our  atmosphere a        
meteorite is moving with planetary      
velocity ranging from  two to forty-five
 miles per second4 ,its interior is     
intensely cold1  approaching in         
temperature the absolute zero of        
interplanetary space1  and it is1       
therefore1 far more brittle than it     
would be at ordinary  temperatures4 ,as 
it ploughs its way into the earth's     
atmosphere its  surface temperature is  
soon raised by friction to at least     
#c1jjj or  #d1jjj ,c41 which is         
sufficient to fuse all surface materials
 into the  characteristic black crust1  
with which stony meteorites are coated4 
,meteorites are usually first seen at an
 altitude of fifty or sixty  miles4     
,although they are moving with a        
velocity comparable to that of  the     
planets1 when they enter the earth's    
atmosphere1 this velocity is  so rapidly
 reduced by friction with the atmosphere

 that they usually  drop to the surface 
of the earth with a velocity about equal
 to that  of ordinary falling objects4  
,the flight of a meteorite often extends
 over a path several hundred  miles in  
length and the meteorite may be seen by 
many observers in  several different    
,states and yet finally fall in some    
unknown spot  and never be found4       
,the evidence gathered regarding the    
actual fall of meteorites is  often     
contradictory4 ,some stones are too hot 
to handle for hours  after they fall1   
others are merely warm1 while still     
others have been  picked up cool or even
 intensely cold4 ,meteorites have been  
seen to  fall upon dried grass and upon 
straw without producing even charring   
effects4 ,the evidence regarding the    
depths to which meteorites  penetrate   
the ground is quite as conflicting4 ,the
 largest of all  the stony meteorites   
which fell at ,krnyahinya1 ,hungary1    
weighed #fdg  pounds and buried itself  
to a depth of eleven feet4 ,yet ,peary's

 ,cape  ,york iron meteorite1 weighing  
#cg-a_/b tons1 was only partially       
covered  and showed no signs of         
abrasions of surface resulting from the 
fall4    ,the ,willamette iron          
meteorite1 weighing #af-a_/b tons1 lay  
in a forest  when found and was not     
deeply buried4 ,the ,bacubirito iron    
meteorite1  weighing #bj tons1 lay in   
soft soil1 barely beneath the level of  
the  surface4 ,on the other hand a      
fragment of a stony-iron meteorite1     
weighing #dcg pounds1 that fell at      
,estherville1 ,iowa1 buried itself      
eight feet in stiff clay4    ,geologists
 in charge of the meteoric collections  
of various museums  quite frequently    
have stones sent to them for analysis   
that are  reputed to be of celestial    
origin4 ,more often than not such stones
  are found to be purely terrestrial in 
their origin4 ,the composition  of a    
meteorite is so characteristic and      
unique that such a stone can  never be  
mistaken4 ,finds of bona-fide meteorites

 are on the whole  extremely rare4      
,it is also a peculiar fact that        
meteorites are usually observed in  the 
months when ordinary meteors or periodic
 swarms of meteors are  least prevalent1
 that is in the months of ,may1 ,june   
and ,july4          ,,xxiv    ,,the     
,,earth ,,as ,a ,,magnet      ,if a     
small1 freely suspended compass needle  
is moved over a highly  magnetized steel
 sphere1 it will be seen that it        
constantly changes  its position both   
horizontally and vertically so as to lie
 always  along the lines of force of the
 sphere4    ,there will be one point on 
the sphere which we will call the ,north
  ,magnetic ,pole1 where the            
north-seeking end of the needle will    
point vertically downward or make a dip 
of #ij with the tangent  plane4 ,at the 
diametrically opposite point on the     
sphere1 called  the ,south ,magnetic    
,pole1 the opposite end of the compass1 
the  south-seeking end1 will point      
vertically downward2 while at a point   

midway between the magnetic poles of the
 sphere the needle will lie  parallel to
 the diameter connecting the two poles  
and there will be  no dip4    ,the total
 intensity of the magnetic field        
surrounding the sphere will  be found to
 be greatest in the vicinity of the     
magnetic poles and  least1 midway       
between the poles4    ,now1 a freely    
suspended compass needle carried to all 
parts of the  earth will behave very    
much in the same manner as the needle   
moved  over the magnetized steel sphere4
 ,there are two points on the earth's   
surface1 known as the ,north and ,south 
,magnetic ,poles1 where the  needle     
points vertically downward and          
approximately midway between is  the    
,magnetic ,equator where the compass    
needle places itself in a  perfectly    
horizontal position and the dip of the  
needle is zero4 ,in  other words1 the   
earth acts as a huge magnet and         
possesses a magnetic  field with lines  
of force converging towards its poles   

similar to the  lines of force of the   
steel sphere4    ,there are1 however1   
some very important differences between 
the  sphere of steel and our earth4 ,the
 matter of which the earth is  composed 
is not homogeneous4 ,it is believed to  
possess an iron core  of considerable   
size1 it is true1 but its outer shell is
 composed of  heterogeneous masses that 
in certain regions cause very           
appreciable  local deflections of the   
needle4 ,it is surrounded1 moreover1 by 
an  atmosphere permeated by electrified 
particles of matter shot forth  from the
 sun1 which we now know is a still      
greater magnet surrounded  by a magnetic
 field that is of the order of #ej      
gausses at the poles  and about eighty  
times more powerful than that of the    
earth4    ,it is now a well-established 
fact that the sun's magnetic field      
exerts a powerful influence over the    
condition of the earth's  magnetic      
field1 and that vast solar disturbances 
affect very  materially the direction   

and intensity of the lines of force4    
,it is thus little wonder that this     
non-homogeneous and rapidly  rotating   
terrestrial globe1 surrounded by an     
electrified atmosphere  and subject to  
the action of a still more powerful     
magnet1 the sun1  should not behave in a
 manner exactly analogous to a uniformly
  magnetized steel sphere4    ,the      
earth's magnetic poles are neither      
symmetrically placed nor  absolutely    
fixed in position4 ,there is every      
reason to suspect  that they shift about
 from year to year1 and possibly        
fluctuate  irregularly in position in   
the course of a few days or hours under 
the influence of disturbing forces4 ,the
 position of the earth's  ,north        
,magnetic ,pole1 last visited by        
,amundsen in #aijc1 now lies            
approximately in ,latitude #gj ,n4      
,longitude #ig ,w4 ,the position of  the
 ,south ,magnetic ,pole1 according to   
the latest determinations1  is1 in round
 numbers1 in ,latitude #gc ,s4 and      

,longitude #aef ,e4 of  ,greenwich4 ,it 
is evident1 therefore1 that the magnetic
 poles of the  earth are not            
symmetrically placed and that they lie  
fully #cj from  the geographical poles4 
,the chord connecting the magnetic poles
  passes #gej miles from the earth's    
center1 and it is about #a1bjj miles    
from the geographic pole to the nearest 
magnetic pole4 ,there exist1  moreover1 
in high latitudes local magnetic poles1 
due possibly to  heavy local deposits of
 ore4 ,one such pole was discovered at  
,cape  ,treadwell1 near ,juneau1        
,alaska1 during ,dr4 ,l4 ,a4 ,bauer's   
observations  there in #aijj and #aijg4 
,in the center of the observing tent at 
this point the needle pointed vertically
 downward and the compass  reversed its 
direction when carried from one side of 
the tent to  the other4    ,it is a     
well-known fact that there are very few 
points on the  earth's surface where the
 compass needle points either to the    
true  geographical pole or to the       

magnetic pole1 and if it does chance to 
do so1 it is a transient happening4 ,the
 variation of the compass  or the       
declination of the needle1 as it is     
called1 is the angle that  the compass  
needle makes with the true north and    
south line or the  meridian4 ,it is an  
angle of greatest importance to         
navigators and  explorers1 for it gives 
them their bearings1 yet it is          
unfortunately  subject to ceaseless     
variations of a most complicated nature1
 since  it depends on the constantly    
pulsating and never ceasing magnetic    
changes that sweep over the surface of  
the earth and through its  crust4 ,it is
 affected by long period or secular     
changes1 as they  are called1           
progressing more or less regularly in   
obscure cycles of  unknown period4 ,it  
is subject to a diurnal change that     
depends on the  position of the sun     
relative to the meridian1 and that      
varies with  the seasons and with the   
hour of the day4 ,it is affected by the 

sun  spot cycle of #aa4c years which has
 a direct effect upon the intensity  of 
the earth's magnetic field4 ,the        
intensity of the magnetic field in  sun 
spots is1 according to ,abbot1 sometimes
 as high as #d1ejj gausses  or #i1jjj   
times the intensity of the earth's      
field4 ,at times of  maximum spottedness
 of the sun the intensity of the earth's
 magnetic  field is reduced4            
,moreover1 when great and rapidly       
changing spots appear upon the  sun1    
electrified particles are shot forth    
from the sun with great  velocity and in
 great numbers1 and are drawn in towards
 the magnetic  poles of the earth4      
,meeting the rarefied gases of the      
earth's upper  atmosphere1 they         
illuminate them as electric discharges  
illuminate  a vacuum tube4 ,some of     
these electrons are absorbed by gases at
  high elevations1 other descend to     
lower levels4 ,the most penetrating     
rays have been known to descend to an   
altitude of twenty-five miles  which is 

about the lowest limit yet found for    
auroral displays4 ,it  is the passage of
 these rays through the atmosphere that 
cause the  magnetic disturbances known  
as magnetic storms1 that are associated 
with the appearance of great sun spots  
and auroral displays4 ,at such  times   
sudden changes take place in the        
intensity of the earth's  magnetic field
 that cause the compass needle to shiver
 and tremble  and temporarily lose its  
directive value4 ,these magnetic storms 
have been known to produce great        
temporal changes in the intensity  of   
the earth's field4 ,according to ,dr4   
,l4 ,a4 ,bauer1 ,director of the        
,department of ,terrestrial ,magnetism  
of the ,carnegie ,institute of          
,washington1 the earth's intensity of   
magnetization was altered by  about     
one-twentieth or one-thirtieth part by  
the magnetic storm of  ,september #be1  
#aiji1 which was one of the most        
remarkable on record1  and the earth's  
magnetic condition was below par for    

fully three  months afterwards as a     
result4    ,in addition to these various
 regular and irregular changes in the   
variation of the compass1 or declination
 of the needle1 due to  changes in the  
earth's magnetic field as a whole1 there
 are local  effects due to restricted   
regional disturbances of the earth's    
magnetic field or to local deposits of  
ore1 or to volcanoes or  other local    
causes4 ,the effect of all these        
disturbances upon the  declination of   
the needle must be determined by        
continual magnetic  surveys of all      
portions of the earth's surface4    ,as 
a whole the earth's magnetic field is   
more uniform over the oceans  than over 
the land1 with all its disturbing       
topographical features4  ,yet this      
advantage is offset largely in          
navigation by the fact that  every steel
 ship that sails the seas is a magnet1  
with its two  magnetic poles and its    
neutral line where the two opposite     
magnetic  forces are neutralized1 as is 

the case with every magnet4 ,the        
direction in which a steel ship lies    
with reference to the earth's  magnetic 
field while it is being built determines
 the position of  the magnetic poles in 
its hull and the position of its neutral
 line  and this distribution of         
magnetism over a ship's hull must be    
taken  account of in the installation of
 its standard compass4 ,every piece  of 
horizontal and vertical iron aboard ship
 has an effect upon the  variation of   
the compass and compensation must be    
made for such  disturbing forces4 ,the  
direction of sailing1 the position in   
which a  ship lies at dock1 storms      
encountered at sea1 the firing of       
batteries  7on warships7 are some of the
 factors that are operative in producing
  changes in the variation of the       
magnetic compass aboard a ship4         
,every ship must undergo at frequent    
intervals magnetic surveys for  the     
purpose of determining its magnetic     
constants and its ,table of  ,deviations

 of the ,compass4    ,the direction in  
which the compass needle points aboard  
ship is the  resultant of the effect of 
the earth's magnetic field and the      
magnetic field of the ship1 and both    
fields are subject to continual  and    
complicated variations from year to     
year1 from day to day1 and  even from   
hour to hour6    ,the elements of the   
earth's magnetic field are determined   
for any one  epoch by long-continued    
magnetic surveys carried on to a greater
 or  less extent by the various nations 
of the world1 and the results are       
published in the form of magnetic charts
 for land and sea1 showing  the values  
of the three magnetic elements1         
declination of the needle1  dip or      
inclination1 and horizontal intensity of
 the earth's field  for a definite      
period4 ,so rapid are even the          
long-period changes in  the earth's     
magnetic field that a magnetic chart can
 be relied upon  for only a very few    
years and fresh data for the            

construction of  these charts that are  
so valuable to navigators and explorers 
must be  gathered continually4    ,the  
,department of ,terrestrial ,magnetism  
of the ,carnegie ,institute  of         
,washington is engaged in continual     
magnetic surveys of the earth  by land  
and sea that are of the highest value   
not only to navigators  but also to     
scientists interested in solving the    
great and mysterious  problem of the    
underlying causes of the earth's        
magnetism4    ,to give an idea of the   
extent and scope of the work of this    
department it may be mentioned that its 
non-magnetic ship ,carnegie  made in the
 period #aiji-aiah a total run of       
#ahi1agf nautical miles1  nearly nine   
times the earth's circumference1 with an
 average  day's run of #aai nautical    
miles4 ,magnetic observations were made 
practically every day at a distance of  
#ajj to #aej miles apart4 ,in  this     
nine-year period five cruises were made4
 ,on her first cruise  the ,carnegie    

sailed from ,st4 ,john's1 ,newfoundland1
 to ,falmouth1  ,england1 over          
practically the same course followed by 
the famous  astronomer1 ,halley1 in the 
,paramour ,pink two centuries earlier to
  determine the variation of the        
compass4 ,in her fourth voyage the      
,carnegie circumnavigated the world in  
sub-antarctic regions in #aah  days--a  
record time4 ,she has traversed all     
oceans from #hj ,north to  the parallel 
of #fj ,south and has crossed and       
recrossed her own path  and the path of 
her predecessor1 the ,galilee1 many     
times1 thus  making it possible to      
determine for the points of intersection
 the  secular changes in the magnetic   
elements4    ,after a thorough          
overhauling in #aiai and the            
installation of a  four-cylinder        
gasoline engine1 made of bronze         
throughout1 to take  the place of the   
producer-gas engine used on earlier     
cruises1 the  ,carnegie started on her  
sixth cruise with a crew of twenty-three

  officers and men on ,october #i1      
#aiai4 ,a cruise of #fa1ejj miles was   
planned in the ,south ,atlantic1 ,indian
 and ,pacific ,oceans to last           
approximately two years4 ,unsurveyed    
regions in the ,south ,atlantic and     
,indian ,ocean were to be covered and   
the route was planned so as to  obtain a
 large number of observations of the    
progressive changes that  have taken    
place in the magnetic elements4 ,this is
 accomplished as  stated above by       
intersecting former routes and obtaining
 new values  of the element at the      
points of intersection4    ,in addition 
to its ocean magnetic surveys the       
,department of  ,terrestrial ,magnetism 
also carries on extensive land surveys  
in all  parts of the globe4 ,in #aiai   
special expeditions were sent out by the
  ,department to observe the total solar
 eclipse of ,may #bith at stations      
distributed over the entire zone of     
visibility of the eclipse and           
immediately outside4 ,at ,dr4 ,bauer's  

station in ,liberia the total  phase was
 visible in a cloudless sky for more    
than six minutes1 which  is very close  
to the maximum length of phase that can 
possibly be  observed4 ,unmistakable    
evidence was gathered at all stations of
 an  appreciable variation in the       
earth's magnetic field during a solar   
eclipse1 which variation is the reverse 
of that causing the daylight  portion of
 the solar diurnal variation of the     
needle4    ,in addition to the magnetic 
survey work on land and sea which  is   
the chief work of the ,department of    
,terrestrial ,magnetism1                
atmospheric-electric observations are   
carried on continually on land  and sea 
and experiments have been carried on at 
,langley ,field1 ,va41  lately1 in the  
development of methods and instruments  
for determining  the geographical       
position of airplanes by astronomical   
observations4  ,there has also been     
recently formed under this department a 
,section  of ,terrestrial ,electricity4 

,the cause of the earth's magnetic field
 is still one of the greatest  unsolved 
problems of astro-physics4 ,the theory  
that has been  advanced by ,schuster    
that all large rotating masses are      
magnets as  a result of their rotation  
has received considerable attention     
from astrophysicists1 and attempts have 
been made to prove this  experimentally4
 ,it has been found that iron globes    
spun at high  velocities in the         
laboratory do not exhibit magnetic      
properties4  ,this may mean simply that 
the magnetic field is too weak to be    
detected in the case of a comparatively 
small iron sphere spun for  a limited   
period under laboratory conditions4 ,it 
must be remembered  that the earth has  
been rotating rapidly on its axis for   
millions  of years and is1 compared to  
terrestrial objects1 an extremely  large
 mass4 ,yet it has been shown that as a 
whole our earth is an  extremely weak   
magnet1 and that if it were made        
entirely of steel and  magnetized as    

highly as an ordinary steel-bar magnet1 
the magnetic  forces at its surface     
would be a thousand times greater than  
they  actually are4    ,if it is true   
that all rotating bodies are magnets1   
then all the  heavenly bodies1 planets1 
suns and nebul are surrounded by        
magnetic  fields4 ,we know nothing to   
the contrary4 ,in fact1 we know this to 
be  true for the earth and sun1 and     
strongly suspect that it is so in the   
case of the planets ,jupiter and        
,saturn4    ,when we understand more    
about the properties of matter1 the     
nature of  magnetism1 as well as of     
gravity1 may be revealed to us4         
,,xxv    ,,some ,,effects ,,of ,,the    
,,earth',s ,,atmosphere ,,upon          
,,sunlight      ,it is impossible to    
exaggerate the importance of the        
atmosphere to  all forms of life upon   
the surface of the earth4 ,if there were
 no  atmosphere there would be no life1 
because it is through the agency  of the
 water-vapor1 carbon-dioxide and oxygen 

in the atmosphere that  all             
life-processes are maintained4    ,if   
there were no atmosphere there would not
 only be no life upon  the earth2 there 
would be also none of the beautiful     
color effects  produced by the passage  
of sunlight through the atmosphere4     
,there  would be no blue skies1 no      
beautiful sunrise and sunset effects1 no
  twilight1 no rainbows1 no halos1 no   
auroral displays1 no clouds1 no  rains1 
no rivers nor seas1 no winds nor storms4
 ,the heavens would be  perfectly black 
except in the direction of the heavenly 
bodies which  would shine as brilliantly
 by day as by night4    ,to understand  
how the atmosphere produces color       
effects such as blue  skies1 sunrise and
 sunset tints1 rainbows and halos1 as   
well as the  twinkling of the stars1 and
 numerous other phenomena1 we must know 
something of the nature of light itself4
    ,light moves outward from any       
source1 such as the sun1 in all         
directions radially1 or along straight  

lines 7so long as it does not  encounter
 a gravitational field7 with the        
unimaginable velocity of  #ahf1jjj miles
 per second4 ,as it advances it vibrates
 or oscillates  back and forth across   
its path in all directions at right     
angles to  this path1 unless it is plane
 polarized light1 in which case its     
vibrations are confined to one plane    
only4    ,these vibrations or           
oscillations of light take the form of a
 wavelike  motion1 one wave-length being
 the distance passed over in the time of
  one vibration1 measured from crest to 
crest or from trough to trough  of      
adjacent waves4    ,we may consider that
 a beam or ray of sunlight is made up of
 a great  number of individual rays of  
different wave-lengths and different    
colors4 ,the average wave-length of     
light1 the wave-length of the  green ray
 in sunlight1 is about                  
one-fifty-thousandth part of an  inch1  
that is1 it would take about            
fifty-thousand wave-lengths of  green   

light to cover a space of one inch4     
,now1 since light makes one  vibration  
in passing over a distance of one       
wave-length1 it makes  fifty thousand   
vibrations1 while advancing one inch1   
and since it  advances one hundred and  
eighty-six thousand miles in one second 
we  can easily figure out that a ray of 
sunlight of average wave-length  makes  
about six hundred trillion vibrations   
7#fjj1jjj1jjj1jjj1jjj7 in  a single     
second6    ,the chief colors of which   
sunlight or white light is composed  are
 red1 orange1 yellow1 green1 blue1      
indigo and violet1 though  there are an 
infinite number of gradations of color  
which blend  into one another1 gradually
 producing the intermediate tints and   
shades4 ,the colors just mentioned are  
called the primary colors  of the solar 
spectrum1 which can be produced as a    
band of light  of variegated colors1    
arranged in the order named by passing a
  ray of ordinary sunlight through a    
glass prism4 ,the individual  rays of   

different color and wave-length that    
make up a beam of  sunlight1 or white   
light1 then separate out in the order of
 the  wave-lengths4 ,the red rays       
vibrate the most slowly and have the    
longest wave-length of all the rays of  
the visible spectrum4 ,about  four      
hundred trillion vibrations of red light
 reach the eye in one  second4 ,violet  
rays1 on the other hand1 vibrate the    
most rapidly  of all the visible rays   
and have the shortest wave-length4      
,about  eight hundred trillion          
vibrations of violet light reach the eye
  every second4 ,the wave-lengths of the
 intermediate colors decrease  in length
 progressively from the red to the      
violet and1 of course1  the frequencies 
of their vibrations increase in the same
 order4 ,all  sunlight is made up of    
these rays of different colors and      
different  vibration frequencies1 and of
 other rays as well1 to which the human 
eye is not sensitive1 and which1        
therefore1 do not appear in the  visible

 spectrum4 ,among these invisible rays  
are the infra-red rays  which come just 
below the red of the visible spectrum1  
and which are  of longer wave-length    
than the red rays1 and the ultra-violet 
rays1  which lie beyond the violet rays 
of the visible spectrum1 and are of     
shorter wave-length than the violet     
rays4    ,now a ray of ordinary sunlight
 is separated into the rays of various  
colors1 which form the solar spectrum   
when it passes from a medium  of one    
density obliquely to a medium of another
 density1 as when it  passes from air to
 glass1 or from air to water1 or from   
outer space  into the earth's           
atmosphere4 ,under such circumstances   
its velocity  is slowed down when it    
passes from a rare to a denser medium1  
and  the waves of different wave-lengths
 are bent from their former  course1 or 
refracted1 by different amounts4 ,the   
red rays1 of longest  wave-length1 are  
bent from their former course the least1
 and the  violet rays1 of shortest      

wave-length1 are bent the most upon     
passing  from a rare to a denser medium4
 ,as a result the ray of sunlight  is   
spread out or dispersed into its rays of
 different wave-length  and color upon  
entering a medium of different density4 
,it is this  refraction and dispersion  
of sunlight that produces many color    
effects in the earth's atmosphere4      
,the atmosphere is not of uniform       
density throughout4 ,at high  altitudes 
it is extremely rare4 ,that is1 there is
 little of it  in a given volume4 ,close
 to the earth's surface1 however1 it is 
comparatively dense4 ,half of all the   
atmosphere is within three and  one-half
 miles of the surface and half of the   
remainder lies within  the next three   
and a half miles4 ,we may consider it as
 made up1 on  the whole1 of layers of   
different densities1 strongly compressed
 near  the surface4    ,imagine a ray of
 sunlight entering the earth's          
atmosphere from  without4 ,if it comes  
from a point in the zenith its course is

 not  changed upon entering the         
atmosphere1 because light passing from a
  certain medium--as space--into a      
medium of different density1 is  not    
bent from its course1 or refracted1     
provided it enters the new  medium in a 
direction perpendicular to the surface4 
,if it enters the  atmosphere 7which is 
the new medium of greater density7      
obliquely1  refraction1 or bending of   
the ray1 takes place1 and as the ray    
advances toward the earth1 through      
layers of increasing densities1  it is  
bent from its former course more and    
more4 ,as the advancing  rays of        
different colors and wave-lengths in the
 beam of sunlight  are slowed down in   
the new medium1 the red rays are turned 
from  their course the least and the    
violet rays the most and the entire     
advancing wave-front of the beam of     
sunlight is bent down more and  more    
toward the horizon1 as it proceeds      
through the atmosphere4 ,as we  on the  
earth's surface see the ray not along   

its bent course through  the atmosphere1
 but in the direction in which it       
finally enters our  eyes1 the effect of 
refraction upon a ray of light passing  
through  the atmosphere is to displace  
the object in the direction of the      
zenith or increase its distance above   
the horizon4 ,as a result of  refraction
 we see the sun--or moon--above the     
western horizon after  it has really    
set1 and above the eastern horizon      
before it has really  risen4 ,the oval  
shape that the sun1 or moon1 often      
presents on  rising or setting1 is due  
to the fact that the light from the     
lower  limb is passing through denser   
air than the light from the upper  limb1
 and so is refracted more4 ,as a result 
the lower limb is lifted                
proportionately more than the upper     
limb4 ,this distorts the form of  the   
solar or lunar disk1 making it appear   
oval instead of circular4    ,the       
familiar twinkling or scintillation of  
stars and1 more rarely1  of the planets1

 is a result of interference of light   
waves due to  irregular and variable    
refraction in air that is not uniform in
  density1 owing to the presence of     
constantly rising and descending        
atmospheric currents of different       
densities4 ,this also produces  the     
shimmering or unsteadiness of star      
images in the telescope1  that          
interferes so greatly with accurate     
measurements of angles or  observations 
of planetary markings4    ,one may ask  
why it is1 if light from an object1 say 
a star1 is bent  from its course and    
separated into rays of various colors   
upon  entering the earth's atmosphere1  
that we do not see the object  drawn out
 into a band of spectral colors4 ,it is 
because the angular  separation of the  
various colors is so slight under       
ordinary  circumstances that light from 
one point is blended with light from  a 
neighboring point of complementary color
 to produce white light  again4 ,under  
certain circumstances1 however1         

beautiful color effects  may be seen in 
the earth's atmosphere as a result of   
the refraction  of sunlight4    ,the    
blue color of the sky and its brightness
 is caused by the  scattering of the    
rays of shortest wave-length1 the violet
 and  blue rays1 by the oxygen and      
nitrogen in the upper atmosphere4 ,the  
molecules of these gases interfere with 
the passage of these rays1  powerfully  
scattering and dispersing them1 and thus
 increasing the  length of their path   
through the air and diffusing their     
color and  brightness in the upper      
atmosphere1 while permitting rays of    
longer  wave-length1 the red and orange1
 to pass on practically undisturbed4    
,when an object in the heavens lies     
close to the horizon1 the rays of  light
 from it have to travel a longer path   
through the atmosphere  than when the   
object is overhead1 and that too through
 the densest  part of the atmosphere1   
which lies close to the earth's surface1
  and in which are floating many dust   

particles and impurities from  the      
earth's surface4 ,all these particles1  
as well as the increased  density of the
 atmosphere1 interfere with the free    
passage of the  rays1 especially of     
shorter wave-lengths4 ,the violet and   
blue rays  are sifted out and scattered 
in their long journey through the lower 
strata of air1 far more than when they  
come to us from an object  high in the  
sky4 ,even the red and yellow rays are  
more or less  scattered and bent        
aside--diffracted--by these             
comparatively large  particles near the 
surface4 ,the reddish color of the sun1 
moon and  even of the stars and planets1
 when seen near the horizon1 as well  as
 the beautiful sunset tints1 in which   
reds and pinks and yellows  predominate1
 are due to the fact that the rays of   
longer wave-length  are more successful 
in penetrating the dense1 dust-laden    
layers of  the lower atmosphere4 ,it is 
to be free of the dust and impurities as
  well as the unsteadiness of the lower 

atmosphere1 that observatories  are     
built at high altitudes whenever        
possible4    ,when there have been      
unusually violent volcanic eruptions1   
and great  quantities of finely divided 
dust have been thrown into the upper    
atmosphere1 the effect upon the blue and
 violet rays from the sun is  very      
great4 ,the volcanic dust particles are 
so large that instead of  scattering    
these rays of shorter wave-length1 as do
 the oxygen and  nitrogen in our        
atmosphere1 they reflect them back into 
space and so  decrease the amount of    
light and heat received from the sun4   
,for this  reason the general           
temperature of the earth is lowered by  
violent  volcanic eruptions4 ,unusually 
cold periods1 that lasted for months1   
followed the terrible eruption of       
,krakatoa in #ahhc and of ,katmai in    
#aiab4    ,at times when much dust is   
present in the atmosphere1 the sky  is a
 milky white color by day as a result of
 the reflection of  sunlight from the   

dust particles4 ,sunrise and sunset     
colors are then  particularly gorgeous1 
with reds predominating4 ,at such times 
the  blue and violet rays are almost    
completely shut out1 and the red1       
orange and yellow rays are powerfully   
diffracted and scattered by the  dust   
particles in the air4    ,the twilight  
glow that is visible for some time      
before sunrise or  after sunset is1 of  
course1 entirely an atmospheric effect  
caused by  the reflection of sunlight to
 our eyes from the upper atmosphere1    
upon which the sun shines1 while it is1 
itself1 concealed from  our view below  
the horizon4 ,the atmosphere extends in 
quantities  sufficient to produce       
twilight to an elevation of about sixty 
miles4    ,when all the rays of which   
sunlight is composed are reflected in   
equal proportions we get the impression 
of white light4 ,dust and haze  in the  
air reflect all rays strongly and give a
 whitish color to an  otherwise blue    
sky4 ,brilliant white clouds appear     

white1 because they  are reflecting all 
rays equally4 ,clouds or portions of    
clouds appear  black when they are in   
shade or1 at times1 by contrast with    
portions  that are more strongly        
illuminated1 or when they are           
moisture-laden  and near the point of   
saturation1 when they are absorbing more
 light  than they reflect4 ,at sunrise  
and sunset1 when the light that falls   
upon the clouds is richest in red and   
orange and yellow1 clouds  reflect these
 colors to our eyes1 and we see the     
brilliant sunset  hues which are more   
intense the more the air is filled with 
dust and  impurities4    ,the familiar  
and beautiful phenomenon of the rainbow 
is produced  by refraction1 reflection  
and interference of sunlight by drops of
  falling water1 such as rain or spray4 
,as the ray of sunlight enters  the drop
 of water1 which acts as a tiny glass   
prism1 it is refracted  or bent from its
 course and spread out into its spectral
 colors4  ,reflection of these rays next

 takes place 7once or twice1 as the     
case may be7 from the inside of the drop
 and a second refraction of  the        
reflected ray takes place as it leaves  
the drop4 ,the smaller the  drops the   
more brilliant is the rainbow and the   
richer in color4  ,the most brilliant   
rainbows are produced by drops between  
#j4b and  #j4d millimeters in diameter4 
,in addition to the primary bow1 which  
has a red outer border with a radius of 
#db1 there is the secondary  bow with a 
radius of about #ea and with colors     
reversed1 the red  being on the inner   
border2 the supernumerary bows which are
 narrow  bands of red1 or green and red1
 appear parallel to the primary and     
secondary bows along the inner side of  
the primary bow and the outer  side of  
the secondary bow4 ,no rainbow arches   
ever appear between the  primary and    
secondary bows1 and it can be shown in  
fact1 that the  illumination between    
these two bows is at a minimum4    ,the 
primary1 secondary and supernumerary    

bows all lie opposite the  sun in the   
direction of the observer's shadow and  
the observer must  stand with his back  
to the sun in order to see them4 ,the   
primary and  secondary rainbow arches   
take the form of arcs of circles that   
have  their common center on the line   
connecting the sun with the observer  at
 a point as far below the horizon in    
angular distance as the sun is  above   
the horizon4 ,it is1 therefore1 never   
possible to see a rainbow  arch of more 
than a semicircle in extent unless the  
observer is at an  elevation above the  
surrounding country1 under which        
circumstances  it might be possible to  
see a complete circle formed by the     
rainbow4    ,the highest and longest    
arch appears when the sun is on the     
horizon1  and the greater the altitude  
of the sun the smaller and lower the    
visible arch4 ,as the angular radius of 
the primary bow is #db and of  the      
secondary bow #ea and as the common     
center of the two circles  is always as 

far below the horizon as the sun is     
above1 it is never  possible to see     
either primary or secondary rainbow when
 the altitude  of the sun is over #ea1  
or the primary bow when the altitude is 
over  #db4 ,for this reason rainbows are
 rarely seen at or near noon in         
mid-latitudes1 since the sun is usually 
at an elevation of more than  #db at    
noon1 especially in the summer season1  
which is also the most  favorable season
 for rainbows1 owing to the great       
likelihood of rain  and sunshine        
occurring at the same time4    ,the     
light which comes to an observer from   
the primary bow is once  reflected      
within the drop1 and that which comes   
from the secondary  bow is twice        
reflected within the drop4 ,the sharper 
and brighter  light therefore comes from
 the primary bow of #db radius4 ,the    
space  between the two bows is          
particularly dark1 because it can be    
shown  that the drops there do not      
reflect any light at all4    ,the       

rainbow colors are rarely pure or       
arranged in spectral order1  owing to   
interference of light waves4 ,it is the 
interference of light  waves from       
different parts of the same drop that   
produces the bands  of alternate maximum
 and minimum brightness1 that lie below 
the  primary bow and beyond the         
secondary bow4 ,the red or green and red
  bands of maximum brightness produced  
thus by interference1 are called  the   
supernumerary bows1 and they are always 
found parallel to the  primary and      
secondary bow within the former and     
above the latter4    ,the distance of   
the rainbow from the observer is the    
distance of  the drops that form it4 ,a 
rainbow may be formed by clouds several 
miles distant or by the aid of the      
garden hose on our lawn4 ,no two        
observers can see exactly the same      
rainbow because the rainbow arch        
encircles the surface of a cone whose   
vertex is at the observer's  eye and no 
two such vertices can exactly coincide4 

,two observers see  rainbows formed by  
different drops4    ,refraction of light
 by ice-crystals in clouds produces many
  beautiful color effects1 such as halos
 of various types around  sun or moon1  
vertical light pillars1 circumzenithal  
arcs1 and  parhelia--sun-dogs--or       
paraselen--moon-dogs--which are luminous
  spots at equal altitudes with sun or  
moon--one to the left the other  to the 
right1 at an angular distance of #bb4   
,the most usual form of halo is that of 
#bb radius4 ,this is a luminous  ring of
 light surrounding sun or moon1 with the
 inner edge red and  sharply defined and
 the spectral colors proceeding outward 
in order2  red is frequently the only   
color visible1 the remainder of the ring
  appearing whitish4 ,since the halo is 
produced by refraction of light  by     
ice-crystals1 which exist in clouds of a
 certain type gathering at  high        
altitudes1 it is always a very good     
indicator of an approaching  storm4     
,coronas are luminous rings showing the 

spectral colors in the  reverse order1  
that is1 with the inner edge blue       
instead of red4  ,they are usually of   
very small radius1 scarcely two degrees1
 closely  surrounding sun or moon and   
are produced--not by refraction--but  by
 diffraction or a bending aside of the  
rays as they pass  between--without     
entering--very small drops of water in  
clouds4 ,as in  the case of refraction1 
the red rays are turned from their      
course the  least and the violet rays   
the most4    ,many of these             
phenomena--halos1 luminous spots1       
vertical pillars and  arcs of light may1
 at times1 be seen simultaneously1 when 
clouds of  ice-crystals are forming     
around the sun or moon4 ,they then      
present a  very complex and beautiful   
outline of luminous circles1 arches and 
pillars that have a mysterious and      
almost startling appearance when  the   
cause is not clearly understood4    ,we 
have found then that sunlight is made up
 of rays of many  different wave-lengths

 and colors and that the atmosphere acts
 upon  these rays in various ways4 ,it  
reflects them or turns them back  on    
their course2 it refracts them as they  
pass through the gases  of which the    
atmosphere consists1 or through the     
water-vapor and  ice-crystals suspended 
in it1 thus sifting out and dispersing  
the  rays of different colors and       
wave-lengths and producing beautiful    
color effects2 it diffracts them or     
bends them aside as they pass  between  
the fine dust particles and small drops 
of water in the air1  again sifting out 
the rays of different colors and        
producing color  effects similar to     
those produced by refraction2 it also   
scatters  and disperses1 through the    
action of the molecules of oxygen and   
nitrogen in the upper strata1 the blue  
and violet rays of shorter  wave-length 
and thus produces the blue color and    
brightness of the  sky2 it produces     
beautifully colored auroral streamers   
and curtains  and rays of light through 

the electrical discharges resulting when
  the rarefied gases in the upper air   
are bombarded by electrified  particles 
shot forth from the sun4    ,it is our  
atmosphere1 then1 that we have to thank 
for all these  beautiful displays of    
color that delight our eyes and give    
pleasure  to our existence1 as well as  
for the very fact of our existence upon 
a planet that without its presence would
 be an uninhabitable waste1  covered    
only with barren rocks4          ,,xxvi 
,,keeping ,,track ,,of ,,the ,,moon     
,of all celestial objects the nearest   
and most familiar is our  satellite1 the
 moon4 ,yet the mistakes and blunders   
that otherwise  intelligent persons     
frequently make when they refer to the  
various  aspects of the moon are quite  
unbelievable4    ,who has not read in   
classics or in popular fiction of       
crescent moons  riding high in midnight 
skies1 of full moons rising above       
western  cliffs or setting beyond       
eastern lakes8 ,who has not seen the    

moon  drawn in impossible positions with
 horns pointing toward the horizon1  or 
a twinkling star shining through an     
apparently transparent moon8    ,careful
 observation of the moon in all its     
various phases and at  different seasons
 is the best method to be used in       
acquiring a  knowledge of the elementary
 facts regarding the motion of the moon 
through the heavens from day to day1 but
 that requires that one be up  often    
after midnight and in the early hours   
preceding dawn and so it  is that we    
feel so hazy in regard to what happens  
to the moon after  it has passed the    
full4    ,a few fundamental rules can be
 easily acquired1 however1 and these    
will enable us to locate the moon in the
 right quarter of the  heavens at any   
time of the day or night when we know   
its phase and  the approximate position 
of the sun at the same instant1 and thus
 we  may avoid some of the most obvious 
blunders that are made in dealing  with 
the general aspect of the moon at any   

given time4    ,as can be verified by   
direct observation1 the moon is always  
moving  continually eastward4 ,since it 
makes a complete revolution around  the 
earth from new moon back to new moon    
again in a little less than  thirty     
days1 it passes over about twelve       
degrees a day 7#cfj divided  by #cj71 on
 the average1 or one-half a degree an   
hour1 which is about  the angular extent
 of its own diameter4 ,therefore every  
hour the  moon moves eastward a distance
 equal to its own diameter4 ,this is of 
course only approximate as the moon     
moves more rapidly in some parts  of its
 orbit than in others4    ,in addition  
to its real eastward motion the moon    
shares the apparent  daily westward     
motion of all celestial objects which is
 due to the  daily rotation of the earth
 on its axis in the opposite direction4 
,that is1 the moon1 as well as the sun1 
stars and planets1 rises in  the east   
and sets in the west daily4 ,on account 
of its continuous  eastward motion1     

however1 the moon rises later every     
night1 on  the average about fifty      
minutes1 though the amount of this daily
  retardation of moon-rise varies from  
less than half an hour to  considerably 
over an hour at different seasons of the
 year and in  different latitudes4 ,in  
the course of a month then the moon has 
risen  at all hours of the day and night
 and set at all hours of the day  and   
night4    ,it might seem unnecessary to 
emphasize the fact that the moon always 
rises in the east were it not that the  
astronomer occasionally meets  the man  
who insists that he has at times seen   
the moon rise in the  west4    ,to be   
sure the new crescent moon first becomes
 visible above the  western horizon     
shortly after sunset though it rises in 
the east  the morning of the same day   
shortly after sunrise4 ,as is also true 
of the sun the exact point on the       
horizon where the moon rises or  sets   
varies from day to day and from season  
to season4 ,in one month  the moon      

passes over very nearly the same path   
through the heavens  that the sun does  
in one year1 for the moon's path is     
inclined only  five degrees to the      
ecliptic or apparent path of the sun    
through the  heavens4 ,it can never pass
 more than #bh-a_/b 7#bc-a_/b  #e7 south
 of  the celestial equator1 nor more    
than #bh-a_/b north of it4 ,it has a    
slightly greater range in altitude than 
the sun1 therefore4 ,north of  #bh-a_/b 
north latitude it always crosses the    
meridian south of the  zenith and below 
#bh-a_/b south latitude it crosses the  
meridian north  of the zenith4 ,in      
tropical regions the moon sometimes     
passes north of  the zenith1 sometimes  
south1 or again directly through the    
zenith4    ,since the full moon is      
always diametrically opposite to the sun
 it  passes over nearly the same part of
 the heavens that the sun did six       
months before4 ,in winter then when the 
sun is south of the equator  the moon   
rides high at night north of the equator

 and1 vice versa1  in summer when the   
sun is north of the equator the full    
moon rides  low south of the equator4   
,in winter then we have more hours of   
moonlight than we have in summer4 ,this 
may be of no great advantage  in        
mid-latitudes but we may imagine what a 
boon it is to the  inhabitants of the   
,arctic and ,antarctic regions to have  
the friendly  moon above the horizon    
during the long winter months when the  
sun is  never seen for days at a time4  
,at time of new moon the moon lies      
directly between us and the  sun1 but   
ordinarily passes just to the north or  
south of the  sun since its orbit is    
inclined five degrees to the ecliptic or
  plane of the earth's orbit4 ,if the   
moon's path lay exactly in the  ecliptic
 we would have an eclipse of the sun    
every month at new  moon and an eclipse 
of the moon two weeks later at full     
moon4 ,now  the moon crosses the        
ecliptic twice a month1 the points of   
crossing  being called the nodes of its 

orbit1 but only twice a year is the     
moon nearly enough in line with the sun 
at the time it crosses to  cause        
eclipses4 ,every year1 then1 there are  
two eclipse seasons1  separated by      
intervals of six months1 when the moon  
is in line with  the sun at or close to 
the point where it crosses the ecliptic2
 then  and only then can solar and lunar
 eclipses occur4 ,the solar eclipses1   
of course1 will occur when the moon is  
new1 that is1 when the moon  passes     
directly between the earth and the sun  
and throws its shadow  over the earth2  
and the lunar eclipses two weeks later  
when the earth  passes between the sun  
and moon and throws its shadow over the 
face  of the moon4    ,probably there is
 no astronomical subject that has been  
more  generally misunderstood than that 
of solar and lunar eclipses4 ,it  is    
well to remember that solar eclipses can
 only occur at time of  new moon and    
lunar eclipses only at the time of full 
moon2 and at  the time of eclipses1     

whether lunar or solar1 the moon is at  
or near  its nodes1 the points where its
 orbit crosses the ecliptic4 ,there  are
 always at least two solar eclipses     
every year and there may be  as many as 
five4 ,there are years when there are no
 lunar eclipses1  though ordinarily both
 solar and lunar eclipses occur every   
year1  some partial others total4       
,the moon shines only by reflected      
sunlight4 ,it is of itself a solid1     
dark body with its day surface intensely
 hot and its night surface  intensely   
cold1 a world of extreme temperatures4  
,at new moon all of the night side of   
the moon is turned toward us1 at  full  
moon all of the day side4 ,at other     
phases we see part of the day  side and 
part of the night side and the          
illuminated side of the moon  is always 
the side that is towards the sun4       
,failure to observe this  simple rule   
leads to many grievous blunders in      
depicting the moon4    ,at the time of  
new moon the moon1 moving continually   

eastward1 passes  north or south of the 
sun from west to east except when it    
passes  directly in front of the sun1   
causing eclipses4 ,a day or so later    
the waxing crescent moon or the new     
moon1 as it is popularly  called1       
becomes visible low in the west         
immediately after sunset4 ,the  moon is 
now east of the sun and will remain east
 of the sun until the  time of full     
moon4 ,during the period from new moon  
to full moon it  will1 therefore1 rise  
after the sun and set after the sun4    
,the waxing  crescent moon will not be  
visible in the morning hours because1   
inasmuch as it rises after the sun1 it  
is lost to view in the sun's  brilliant 
rays4 ,nevertheless1 it follows the sun 
across the sky and  becomes visible in  
the west as soon as the sun has         
disappeared below  the western horizon4 
,the thin illuminated crescent has its  
horns  or cusps turned away from the    
point where the sun has set4 ,the  horns
 of the crescent can never point toward 

the horizon since the  illuminated side 
of the moon is always turned toward the 
sun whether  the sun is above or below  
our horizon4    ,as hour by hour and day
 by day the moon draws farther eastward 
and  increases its angular distance from
 the sun1 more and more of the          
illuminated side becomes visible2 the   
crescent increases in width and  area   
and the moon appears higher in the      
western sky each night at  sunset4      
,usually about seven and a fraction days
 after the date of new moon  the moon   
completes the first quarter of its      
revolution around  the earth4 ,the      
period from one phase to the next is    
variable and  irregular1 being sometimes
 less than seven days and at other times
  more than eight days1 since the moon  
does not move at a uniform rate  in     
different parts of its orbit4    ,when  
the moon has completed the first quarter
 of a revolution it  is ninety degrees  
east of the sun and presents the phase  
known as  half-moon since half of the   

surface that is turned toward the earth 
is illuminated and half is in darkness4 
,it is said to be at the  first quarter4
 ,the illuminated half is of course the 
western half  because the sun is to the 
west of the moon4 ,the half moon is near
 the  meridian at sunset and sets near  
midnight4 ,up to the first quarter1     
then1 the moon is a crescent in the     
western sky during the first part  of   
the night and should never be           
represented as east of the meridian  or 
near the meridian at midnight4    ,after
 the moon has passed the first quarter  
and before it is full  more than half of
 the side turned toward the earth is    
illuminated and  it is in the gibbous   
phase4 ,it is still the western limb    
that is  fully illuminated4 ,the moon is
 now east of the meridian at sunset and 
it crosses the meridian before midnight 
and sets before sunrise4 ,all  who are  
abroad during the first half of the     
night find this phase of  the moon more 
favorable to them than the gibbous phase

 following full  moon4    ,the moon now 
being above the horizon at sunset is    
visible  continuously from sunset to    
midnight but sets some time during the  
second half of the night1 while the full
 moon shines throughout  the night1     
rising in the east at sunset and setting
 in the west at  sunrise4    ,when the  
moon is full it is #ahj east1 or west1  
of the sun and so  both its eastern and 
western limbs are perfectly illuminated4
 ,after  the full the moon goes through 
its phases in reverse order1 being      
first gibbous1 then a half-moon once    
more1 and lastly a waning  crescent4    
,it is now west instead of east of the  
sun and so it is the eastern  limb that 
is fully illuminated by the sun4 ,being 
west of the sun it  will now rise before
 the sun and set before the sun1 the    
interval  decreasing each day as the    
moon draws in toward the sun once more4 
,the gibbous phase preceding full moon  
is favorable to all abroad  before      
midnight but the gibbous phase following

 full moon is more  favorable to those  
who are abroad after midnight1 for from 
full moon  to last quarter the moon is  
below the horizon at sunset1 and of     
course1 is rising later and later each  
night1 while at sunrise it is  still    
above the horizon1 appearing each day   
higher and higher above  the western    
horizon at sunrise as it approaches the 
third or last  quarter4    ,when it has 
reached this point it is once more a    
half-moon1 though  now it is the eastern
 half instead of the western half of the
 disk  that is fully illuminated4 ,the  
moon is #ij west of the sun at third    
quarter and from this phase to the phase
 of new moon it is a crescent  once     
more1 but now a waning instead of a     
waxing crescent4 ,it appears  east of   
the meridian before sunrise and as the  
crescent grows thinner  it draws nearer 
and nearer to the eastern horizon and   
the rising sun4  ,as with the waxing    
crescent moon the horns are turned away 
from the  horizon4 ,the waning crescent 

moon is always to be looked for east  of
 the meridian and to be associated with 
the rising sun1 while the  waxing       
crescent moon is to be looked for west  
of the meridian and  associated with the
 setting sun4 ,neither the waxing nor   
the waning  crescent moon will be       
visible during the midnight hours4      
,as the waning crescent moon grows      
thinner and draws in closer to  the sun 
each successive night1 its time of      
rising precedes that of  the sun by an  
ever-decreasing interval until finally  
the crescent  disappears from view in   
the eastern sky2 the next day we see no 
crescent either in the eastern or       
western skies--the moon is once  more in
 conjunction with the sun and new4 ,one 
revolution of the  moon about the earth 
with respect to the sun has been        
completed and  a day or so later we may 
look for a new crescent moon in the     
western  sky after sunset4              
,,xxvii    ,,the ,,motions ,,of ,,the   
,,heavenly ,,bodies      ,about three   

hundred and twenty years ago ,giordano  
,bruno was burned  at the stake for his 
audacity in believing in the existence  
of other  worlds4 ,a few decades later  
the famous astronomer ,galileo was      
forced  to publicly recant his belief   
that the earth moved4 ,yet the truth    
could not long be suppressed by such    
means1 and since those dark  days man's 
advance in knowledge has been so rapid  
that it seems  to us today in this      
wonderful age of scientific discovery   
almost  inconceivable that man ever     
believed that the earth1 a tiny planet  
of a vast solar system1 was the hub of  
the universe1 the fixed and  immovable  
center about which revolved all the     
heavenly bodies4 ,very  reluctantly1    
however1 and with bitter feeling1 but in
 the light of  overwhelming evidence man
 finally gave up his long-cherished idea
 of  terrestrial importance1 and when   
finally forced to move his fixed  center
 of the universe1 he moved it only so   
far as the comparatively  nearby sun4   

,this center he then regarded as fixed  
in space and also held to  his belief   
that the stars1 set in an imaginary     
celestial sphere1  were immovable in    
space as well1 and all at the same      
distance from  the sun4 ,so1 scarcely   
two hundred years ago we find that the  
astronomer ,bradley was endeavoring to  
measure this common distance  of the    
fixed stars4 ,though he failed in this  
attempt he made the  important discovery
 that the observed positions of the     
stars are not  their true positions1    
owing to the fact that the velocity of  
light is  not infinite but takes a      
definite finite interval of time to     
travel  a given distance4 ,as a result  
the stars always appear displaced in    
the direction of the earth's motion     
around the sun1 the amount of  the      
displacement depending upon the velocity
 of the earth in its  orbit and the     
velocity of light4 ,this aberration of  
light1 as it is  called1 furnished      
additional proof that the earth revolves

 about the  sun and was one more nail   
driven into the coffin of the old       
,ptolemaic  theory that the earth was   
the center of the universe4 ,bradley    
also  discovered that the positions of  
the stars were affected by the  wabbling
 of the earth's axis1 called its        
nutation4    ,although in the days of   
,bradley neither the methods of         
observation  nor the instruments were   
sufficiently accurate to show the minute
  shifts in the positions of the stars  
that reveal the individual  motions of  
the stars and the distances of those    
nearest to us1 yet  the discovery of the
 two large displacements in the         
positions of all  the stars1 due to the 
aberration of light and the nodding of  
the  earth's axis were of the greatest  
value1 for they were a necessary  step  
in the direction of the precise         
measurements of modern times4 ,it  is   
only through measurements of the        
greatest refinement and accuracy  that  
it is possible to detect the motions and

 distances of the stars  and to discover
 the wonderful truths about the nature  
and structure  of the universe that they
 are revealing to us today4    ,after   
unsuccessful attempts extending over    
several centuries the  distance of one  
of the nearest stars1 the faint #fa     
,cygni1 as it is  catalogued1 was       
finally determined by the astronomer    
,bessel in the  year #ahch4    ,this    
star is about ten light-years distant   
from the earth1 which  places it about  
six hundred and thirty thousand times   
farther away  from us than the sun2 that
 is1 we would have to travel six hundred
  and thirty thousand times the distance
 from the earth to the sun  to reach    
this very close stellar neighbor1 #fa   
,cygni4 ,the nearest  of all the stars1 
,alpha ,centauri1 is over two hundred   
and seventy  thousand times the distance
 from the earth to the sun4 ,it is1     
therefore1 little wonder that the early 
astronomers believed that the  stars    
were fixed in space since even the      

nearest is so far away that1  viewed    
from opposite points in the earth's     
orbit1 its apparent change  in position 
due to our actual change in position of 
#ahf1jjj1jjj  miles1 amounts to only one
 and a half seconds of arc4 ,two stars  
separated by one hundred and sixty times
 this angular distance  might possibly  
be glimpsed as two distinct stars by a  
person with  good eyesight1 though to   
most of us they would appear as one     
star4  ,upon the measurement of such    
minute angles depended a knowledge of   
the distances of the nearest stars4     
,it is to ,sir ,william ,herschel that  
we owe the discovery1 more than a       
hundred years ago1 of the motion of the 
sun through the universe4  ,from the    
consideration of a long series of       
observations of the  positions of the   
stars this famous astronomer discovered 
that the  stars in the direction of the 
constellation ,hercules were separated  
by much greater angular distances than  
the stars diametrically  opposite in the

 heavens4 ,in other words1 the stars    
were spreading  apart in one portion of 
the heavens and crowding together in the
  opposite direction and he rightly     
interpreted this to mean that the  sun  
was moving in the direction of the      
constellation of ,hercules4  ,it was not
 until the spectroscope was applied to  
the study of the  heavens in the latter 
part of the nineteenth century that the 
amount  of this motion of the sun was   
found to be about twelve and a half     
miles per second1 or four times the     
distance from the earth to the  sun in a
 year4    ,it is to ,sir ,william       
,herschel that we owe also the discovery
 of  binary systems of stars in which   
two stars swing around a point  between 
them called their center of gravity4    
,illustration3 ,,spiral ,,nebula ,,in   
,,canes ,,venatici    ,taken with       
#fj-;inch ,reflector of the ,mt4 ,wilson
 ,observatory    ,our first conception  
of the immensity and grandeur of the    
universe  dates from the time of the    

older ,herschel only a century or so    
ago4 ,the mysterious nebul and star     
clusters were then discovered1  the     
wonders of the ,milky ,way were         
explored1 and a new planet and          
satellites in our own solar system were 
discovered4 ,it was found that  the sun 
and the stars as well as the planets    
were in motion4 ,neither  sun nor earth 
could be regarded any longer as a fixed 
point in the  universe4    ,with the    
application of the spectroscope to the  
study of the heavens  toward the end of 
the nineteenth century the key to a     
treasure-house  of knowledge was placed 
in the hands of the astronomers of      
modern  times and as a result we are now
 learning more1 in a few decades1  about
 the wonders and mysteries of the       
heavens than was granted to  man to     
learn in centuries of earlier endeavor4 
,yet it is the feeling  of the          
astronomer of today that he is only     
standing on the threshold  of knowledge 
and that the greatest of all            

discoveries1 that of the  nature of     
matter and of time and space is yet to  
be made4    ,it is the spectroscope that
 tells us so many wonderful facts about 
the motions of the stars1 nebul and star
 clusters4 ,it tells us also            
practically all we know about the       
physical condition of our own sun  and  
of the other suns of the universe1 their
 temperature and age1 and  the          
peculiarities of their atmospheres4     
,some of the most important astronomical
 discoveries that have been  made in the
 past few years have to do with the     
distribution and  velocities of the     
heavenly bodies as revealed by the      
spectroscope4    ,it has been found1    
with the aid of the spectroscope1 that  
the most  slowly moving of all stars are
 the extremely hot bluish ,orion stars  
with an average velocity of eight miles 
per second1 while the  most rapidly     
moving stars are the deep-red stars with
 an average  velocity of twenty-one     
miles per second1 and there is in all   

cases a  relationship existing between  
the color1 or spectrum1 of a star and   
its velocity4 ,the reason for this      
connection between the two still        
remains undiscovered4    ,the           
spectroscope has also told us some      
astonishing facts in recent  years about
 the velocities of the spiral nebul4    
,it is now known that these mysterious  
objects are moving with the  tremendous 
average velocity of four hundred and    
eighty miles per  second1 which exceeds 
the average velocity of the stars fully 
twenty-five fold4 ,they possess1        
moreover1 internal motions of  rotation 
that are almost as high as their        
velocities through space4  ,it is now   
generally believed that spiral nebul are
 far distant  objects of enormous size  
and mass1 exterior to our own system of 
stars and similar to it in form4    ,in 
place of the universe of the fixed stars
 and the immovable sun  or earth of a   
few centuries ago we find that modern   
astronomical  discovery is substituting 

a universe of inconceivable grandeur and
  immensity in a state of ceaseless flux
 and change4    ,our earth--an atom     
spinning about on its axis and revolving
 rapidly  around a huge sun that is     
equal in volume to more than a million  
earths--is carried onward with this sun 
through a vast universe of  suns4       
,only an average-sized star among       
several hundred million other stars  is 
this huge sun of ours1 moving with its  
planet family through the  regions of   
the ,milky ,way1 where are to be found  
not only moving  clusters and groups of 
stars1 speeding along their way in      
obedience  to the laws of motion of the 
system to which they belong1 but also   
strangely formed nebul covering vast    
stretches of space1 whirling  and       
seething internally and shining with    
mysterious light1 and still  other      
stretches of dark obscuring matter      
shutting off the rays of  suns beyond4  
,the extent and form of this enormous   
system of stars and nebul and  the laws 

that govern the motions of its          
individual members are among  the       
problems that the astronomers of today  
are attempting to solve4  ,on both sides
 of these regions of the ,milky ,way1   
wherein lies our  own solar system1 lie 
other vast systems1 such as the globular
 star  clusters1 composed of thousands1 
possibly hundreds of thousands1 of      
suns2 the ,magellanic clouds1 which     
resemble detached portions of the       
,milky ,way1 and1 probably1 the much    
discussed spiral nebul1 possible  island
 universes similar to our own4    ,we   
have come far in the past three hundred 
years from the conception  of an        
immovable earth at the center of the    
universe to this  awe-inspiring         
conception of the universe that we have 
today1 which is  based upon modern      
astronomical discoveries4    ,whatever  
may be discovered in the future in      
regard to the form and  extent of the   
universe the idea of a fixed and        
immovable center  either within the     

solar system or among the stars beyond  
has gone  from the minds of men at last4
      ,illustration3 ,,spiral ,,nebula  
,,in ,,andromeda ,,viewed ,,edgewise    
,taken with #fj-;inch ,reflector of the 
,mt4 ,wilson ,observatory    ,not more  
than a generation ago a survival of the 
old idea of a  fixed center was seen in 
the belief that ,alcyone1 in the        
,pleiades  was a central sun about which
 all the stars revolved4 ,it is now     
well known that the ,pleiades form a    
moving star cluster4 ,alcyone is        
therefore drifting slowly onward through
 the universe and the idea  of a fixed  
and immovable center to which man may   
anchor his ideas is  drifting away also4
 ,there are1 it is true1 local centers  
of systems1  such1 for instance1 as the 
sun occupies in the solar system or some
  group of stars may occupy in the      
stellar system to which our sun         
belongs1 yet as a whole these systems   
move on and their centers  with them4   
,there is no evidence today that any    

absolutely immovable  point exists in   
the heavens4    ,no celestial object has
 been found to be without the attribute 
of  motion1 not only motion onward      
through the universe1 but also          
rotational motion about an axis of the  
body4 ,the planets rotate on  their axes
 as well as revolve about the sun1 and  
the sun also turns  on its axis as it   
moves onward through space4 ,this       
rotational motion  is also found in the 
nebul and star clusters as well as in   
the stars  and planets4 ,no object in   
the heavens is known to be without it4  
,even  the slowly drifting ,orion nebula
 possesses a rapid internal velocity  of
 rotation4 ,there is no such thing as a 
body absolutely at rest in  the         
universe4      ,,table      ,showing the
 number and relative size1 velocity and 
distribution of the various types    of 
celestial objects4                      
,velocities         ,object             
,number             ,diameter           
miles       ,distribution               

per sec4                                
----------------------------------------
----------------------------------------
---------    #a4 ,solar ,system         
a4 ,planets      ,eight                 
#c1jjj to #hh1jjj mi4  #c to #ce        
,revolving in nearly                    
miles      circular orbits              
per sec4   about the sun4    b4 ,sun    
#hfd1jjj mi4          #ab-a_/b mi4      
,travelling through                     
galactic systems of    #b4 ,stars       
stars 7,milky ,way74                    
a4 ,helium                              
#h mi4              7bluish7            
b4 ,hydrogen     ,approx4               
,dwarfs           #ad mi4     ,all types
 of stars are        7white7            
#b1jjj1jjj1jjj 7,two  #ejj1jjj to       
more or less crowded    c4 ,solar       
thousand million7    #a1jjj1jjj mi4     
#ah-ai mi4   toward plane of ,milky     
7yellow7                                
,way in lens shaped    d4 ,type ,m      
,including all types     ,giants        

#ba mi4      formation4 7,milky         
7red7                                   
#aj1jjj1jjj to                   ,way   
possibly a spiral                       
#djj1jjj1jjj mi4                nebula47
    #c4 ,nebul                          
a4 ,diffuse or    ,numerous             
,very extensive1 many ,very low   ,in or
 close to ,milky        ,gaseous        
light years4                    ,way4   
b4 ,spiral       ,approx4 #gjj1jjj      
,size and distance    ,average    ,far  
external to ,milky                      
7seven hundred      doubtful but        
#dhj mi4    ,way and numerous           
thousand7           very great4         
near its poles4                         
c4 ,planetary    ,one hundred and       
,several times that   ,average    ,in or
 close to ,milky                        
fifty 7#aej7         of the solar system
  #dh mi4     ,way4                     
on the average4                         
#d4 ,globular ,star,about one hundred   
#bb1jjj-bbj1jjj       ,very high        

,external to ,milky ,way                
,clusters     known                     
light-years4                    and     
spherically                             
distributed about it4                   
#e4 ,magellanic   ,two 7,greater and    
,thousands of         ,very high  ,far  
beyond ,milky ,way4        ,clouds      
,lesser7             light-years4       
,,xxviii    ,,the ,,evolution ,,of ,,the
 ,,stars--,,from ,,red ,,giants ,,to    
,,red ,,dwarfs      ,the most casual of 
star-gazers is aware that the stars     
differ one  from another in color and in
 brightness4 ,there are red stars1      
yellow  stars1 white stars and          
bluish-white stars4 ,there are the      
brilliant  stars of first magnitude such
 as ,vega1 ,capella and ,antares1 and   
there are1 on the other hand1 stars so  
faint that they can barely be  glimpsed 
with the most powerful telescopes4      
,in general the most brilliant stars are
 the nearest and the faintest  stars are
 the most distant1 but there are many   

exceptions to the  rule1 since there are
 stars that appear faint even when      
comparatively  near because they are    
small and shine with a feeble light4    
,such a  star is the faint1             
sixth-magnitude star1 #fa ,cygni1 one of
 the nearest  of all the stars4 ,again1 
there are stars in far-distant clusters 
visible only in powerful telescopes that
 in actual brightness exceed  our own   
sun several thousand times and in volume
 several million  times4 ,a star the    
size of the sun would be invisible in   
the most  powerful telescope in         
existence if it were at the distance of 
many  stars in the ,milky ,way or       
globular star clusters4    ,stars differ
 in color because they differ in        
temperature4 ,we are  all aware of the  
fact that a piece of iron when heated   
first glows  a deep red1 then appears   
yellowish in color and finally attains  
to  white heat4 ,it is the same among   
the stars4 ,the red stars are the       
coolest of all the stars and the        

bluish-white stars are the hottest  of  
all the stars1 while intermediate       
between them in temperature come  the   
yellow and the white stars4    ,now as  
the biologist and the geologist see in  
this world of ours  signs of evolution1 
or gradual development and change from  
the simple  to the more complex forms1  
and of growth and decay1 so the         
astronomer  sees among the stars signs  
of a continuous1 progressive development
  from one type of star to another4     
,stars share in the general  evolution  
that is the law of the universe1 and are
 born1 reach the  height of their       
development1 decline to old age and die4
    ,within the past few years important
 astronomical discoveries have  been    
made that show the true order of this   
evolution of the stars4 ,it  was        
believed not so long ago that the       
blue-white helium stars--the  type ,b   
stars the astronomers called them1 or   
the ,orion stars1  since there are so   
many stars of this type in the          

constellation of  ,orion--were not only 
the hottest but also the youngest of the
 stars  and that they represented the   
first stage in the development of a     
star from a primitive gaseous nebula    
such as the ,great ,orion ,nebula4  ,it 
is now known that these brilliant1 hot  
helium stars represent the  peak of     
development of the most massive of all  
the stars and not the  first stages in  
the development4    ,a star1 it is now  
known1 comes into existence as a giant1 
reddish  star of enormous size and of a 
density only about one-thousandth that  
of the earth's atmosphere at sea-level4 
,it is inconceivably tenuous  or rare1  
and its temperature is comparatively    
low1 about #c1jjj  ,centigrade or less4 
,it is not evolved from the luminous1   
gaseous  nebul because red stars are    
never found associated with the gaseous 
nebul1 as are the blue-white stars4 ,the
 origin of these red giant  stars is    
uncertain1 but it is possible that they 
may be gradually  evolved in some manner

 from the dark clouds of obscuring      
matter or  dark nebul that exists so    
abundantly in the heavens4    ,in the   
next stage of its development the       
deep-red giant star  increases in       
temperature as it contracts under the   
action of  gravitation and its color    
gradually changes from red to yellow4   
,its  density increases slightly and its
 volume decreases4 ,it is now a  yellow 
giant star4 ,as the evolution progresses
 in the course of ages  the star        
continues to contract1 its temperature  
increases greatly as  does also its     
density and it continues to decrease in 
volume4 ,it is  now a brilliant white   
star1 a hydrogen star1 so called because
 its  spectrum is chiefly characterized 
by the lines of hydrogen4    ,as the    
star contracts under the gravitation of 
its parts and  increases in temperature 
and density there comes more and more   
into  play an important factor that has 
a great effect upon its future          
development4 ,this is light-pressure or 

radiation pressure which acts  in       
opposition to gravity and exerts a      
strong outward pressure upon  matter    
within the depths of the star1 tending  
to push it outward from  the center     
where the temperature is greatest and   
the light is most  intense4 ,it is a    
most interesting fact that if the mass  
of a star1  that is the quantity of     
matter that it contains1 exceeds a      
certain  value the pressure of light or 
radiation within it overbalances the    
gravitational attraction that draws     
matter towards its center and  the star 
disintegrates or ceases to exist as a   
star4 ,this accounts  for the fact that 
the stars differ very little among      
themselves in  the quantity of matter   
that they contain1 that is1 in their    
masses1  though they may differ         
enormously in size4 ,stars that exceed a
  certain mass will become unstable and 
this may account for the  association of
 luminous nebul with the hottest of all 
stars1 the  nebul possibly being puffed 

off from the surfaces of these stars    
under the action of radiation pressure4 
,after a star has reached the height of 
its development as a  bluish-white      
helium star with a temperature of       
something like #aj1jjj  ,centigrade and 
a density about one-tenth that of the   
sun1 it begins  to lose heat and to cool
 gradually though it continues to       
contract  and increase in density4      
,it is now on the descending scale of   
evolution and is to be counted  among   
the dwarfs instead of the giants4 ,a    
brilliant blue-white helium  or ,orion  
star is about one hundred times more    
luminous than the sun1  and its diameter
 is about ten times that of the sun4    
,our own sun1 we find1 is on the        
descending scale of stellar  evolution4 
,it is a yellow dwarf star of           
temperature about #f1jjj  ,centigrade   
and density one and one-fourth that of  
water1 which is  probably about as great
 a density as is attained by any star   
since  even the non-luminous planets    

,jupiter and ,saturn have lower         
densities  than the sun4    ,the last   
stage in the development of a star is   
represented by the  dwarf red star of   
high density and low temperature4 ,the  
diameter of  the dwarf red star probably
 averages about five hundred thousand   
miles and its temperature is #c1jjj     
,centigrade or less4 ,after this  we    
have the extinct stars1 similar possibly
 to our planet ,jupiter1  though        
considerably larger1 with a dense       
gaseous atmosphere and a  certain degree
 of internal heat4    ,we have traced   
the evolution of a star from a red giant
 to a red  dwarf through the            
intermediate stages from yellow giant to
 a giant  helium star with increasing   
temperature and thence to yellow dwarf  
and red dwarf as the temperature        
decreases4 ,only the most massive  stars
 pass through this entire chain of      
evolution4 ,stars of small  mass never  
attain to the splendor of brilliant     
blue-white helium  stars1 but begin to  

decrease in temperature and brightness  
before  this stage is reached4    ,the  
time required for the evolution of a    
star from red giant to red  dwarf is not
 known1 but it must be very great4 ,the 
age of the earth1  which is probably    
equal to that of the solar system1 is   
estimated as  something like one        
thousand million years4 ,it is probable 
that the  average life of a star far    
exceeds this limit4          ,,xxix     
,,double ,,and ,,multiple ,,stars       
,the plan of the solar system which     
consists of a central sun  encircled by 
satellites that are far inferior to     
their luminary  in size1 and that move  
about it in orbits that are almost      
perfect  circles1 is not the only1 nor  
possibly1 even the most general one in  
the universe4    ,sweeping the heavens  
with powerful telescopes one is         
astonished  to find that myriads of     
stars can be separated into two or more 
physically connected suns that are      
often1 moreover1 of exquisitely  tinted 

and contrasting shades4 ,green and red1 
orange and blue1 white  and golden or   
white and blue pairs exist in profusion1
 and strange to  say there are          
well-authenticated instances of color   
changes taking  place temporarily within
 the same system4 ,a pair of white stars
 has  been known to change within a few 
decades1 first to golden yellow and     
bluish green and then to orange and     
green4 ,the famous pair catalogued  as  
#ie ,herculis was noted to change from  
green and red to a palish  yellow and   
back to the original strongly           
contrasting hues within  the course of a
 single year1 while at another time they
 appeared to  be a perfectly white pair4
 ,at the present time both of these     
stars  are decidedly yellowish in color4
 ,such changes in hue are probably  due 
to temporary disturbances in the        
atmospheres of the stars1  possibly of  
an electrical nature or to sudden or    
unusual outbursts of  activity1         
concerning the origin of which we are as

 much in doubt as  we are of the cause  
of the sun-spot cycle and periodic      
variation in  the intensity of radiation
 of our own sun4 ,temporary changes in  
the  color of the components of double  
star systems sometimes take place  when 
the two stars approach their periastron 
or point of nearest  approach4 ,owing to
 the great eccentricity of the orbits of
 double  stars1 such stars are anywhere 
from twice to nineteen times as near  to
 each other at periastron as they are at
 apastron1 or point of  greatest        
departure4 ,such great changes in the   
relative distances  of two physically   
connected suns would produce marked     
changes in  the intensity of the tides  
raised upon each of them by their mutual
  gravitational attraction and unusual  
outbursts of gases or electrical        
excitement in the atmospheres of the    
stars might cause very  noticeable      
changes in the color of these stars as  
they drew nearer to  each other1 which  
would subside as they receded toward    

apastron4    ,in addition to visual     
double or multiple stars1 there exists a
 very  extensive class of stars known as
 spectroscopic binaries1 in which  the  
two components are so close to each     
other that even the most  powerful      
telescopes cannot divide them4 ,it is   
only from the shifting  of the lines of 
their overlapping spectra1 caused by    
their alternate  motion toward and from 
the earth as they revolve about their   
common  center of gravity1 that their   
duplex nature is revealed to us4    ,in 
some instances one member of the system 
is so faint that its  spectrum is not   
visible and its presence is disclosed   
only by the  shifting of the lines of   
the bright star4    ,according to       
,doppler's ,law1 when a star is         
approaching the earth the  lines of its 
spectrum shift toward the blue end of   
the spectrum1  and when the star is     
receding from the earth the lines are   
shifted  toward the red end of the      
spectrum4 ,the amount of this shift can 

be very accurately measured1 and gives  
the relative velocities of  the stars in
 their orbits directly in miles per     
second4 ,knowing in  addition1 by       
observation1 the period of mutual       
revolution of the  stars1 it is possible
 to find the dimensions of these        
spectroscopic  binary systems compared  
to our own solar system1 and also the   
masses  of the stars compared to the    
mass of our own sun4 ,if the spectrum of
  the fainter star is not visible1 only 
the velocity of the brighter  star with 
respect to the center of gravity of the 
system can be  found and the mass found 
for the system comes out too small4 ,in 
such  cases we can obtain only a lower  
limit for the mass of the system4       
,then1 too1 it must be remembered that  
these systems of stars lie at  all      
angles with reference to our line of    
sight1 and so we rarely  see the orbits 
in their true form4 ,the measured       
velocities are as a  result smaller than
 the true velocities1 and on the average

 amount to  only sixty per cent4 of the 
true orbital velocities4 ,the calculated
  masses of spectroscopic binary stars  
are1 therefore1 in general only  about  
sixty per cent4 of the true masses4 ,it 
has been found from  calculating the    
masses of a number of binary systems1   
that the  combined masses of the stars  
in these systems do not differ very     
greatly among themselves1 nor as        
compared to our own sun1 though in      
light-giving power these stars may      
differ hundreds1 thousands1 even        
millions of times4 ,for instance1 there 
are stars that give only one            
ten-thousandth part of the light of our 
own sun1 and other stars that  give ten 
thousand times as much light as the sun4
 ,moreover1 there  are many instances of
 physically connected stars differing   
thousands  of times in luminosity1      
though in mass1 or quantity of matter   
found  in the stars1 they differ only   
two or three times4 ,why this is so     
remains one of the great mysteries of   

the heavens1 and makes it  extremely    
difficult to give any satisfactory      
theory of the origin  of double-star    
systems4 ,it has never been explained   
satisfactorily  why of two suns         
physically connected and1 therefore1    
presumably  originating at the same     
time1 one should be radiating with the  
greatest intensity1 while the other is  
practically an extinct sun1  in spite of
 the fact that the quantity of matter in
 the two bodies  differs but slightly4  
,in a few systems the plane in which the
 stars revolve passes so  nearly through
 the earth that the two stars           
temporarily eclipse one  another during 
each revolution4 ,such systems are      
called eclipsing  binaries4 ,to such a  
system belongs the famous ,algol4 ,its  
light  waxes and wanes periodically with
 the greatest punctuality in a  period  
of #b;d #bj;h #dh4im1 owing to its      
temporary eclipse by a very  large but  
extremely faint attendant sun4 ,the     
diameter of the faint  star is slightly 

greater than the diameter of the bright 
star  which is about one million miles  
in extent4 ,the distance between  the   
centers of the stars is only about three
 million miles1 which  brings their     
surfaces within two million miles of    
each other4 ,the  masses of the two     
stars are in the ratio of two to one1   
the brighter  and more massive star     
being about half as heavy as our own    
sun1  though its density is only about  
two-tenths that of the sun4 ,the        
density of the fainter star is still    
less1 being only about half  that of the
 brighter star4 ,very low density of    
both components and  extreme faintness  
of one member compared to the other1    
appears to be  a very general           
characteristic of closely associated    
eclipsing and  spectroscopic binary     
stars4 ,among the extremely hot and     
brilliant  helium and hydrogen stars1   
spectroscopic binaries exist in great   
numbers4 ,in fact1 among these types    
there appear to be as many binary  and  

multiple systems as there are systems of
 isolated suns4 ,sometimes  these close 
binary stars are egg-shaped or oval and 
revolve rapidly  almost in contact about
 their common center of gravity4        
,inhabitants  of satellites of such a   
system would see in their heavens the1  
to us1  strange and startling phenomenon
 of two suns1 each equal to our  own or 
even greater in size1 whirling rapidly  
about each other and  separated by a    
space comparable in extent to their own 
diameters4  ,eclipses in such a system  
would be of daily occurrence1 and1 if   
one star were dark1 would produce for   
the satellite world the same  effect of 
alternate day and night that results    
from axial rotation  of a satellite4    
,the two hemispheres of the faint       
companion sun  would be very unequally  
illuminated owing to the fact that the  
side  turned toward the brilliant sun   
would always reflect its neighbor's     
brightness in addition to shining with  
its own comparatively feeble  inherent  

light1 while the opposite hemisphere    
would shine only by its  own dim light1 
and would1 therefore1 be in comparative 
darkness4    ,the spectroscopic binaries
 generally revolve closely and rapidly  
about their common center of gravity2   
there are to be found1 on the  other    
hand1 among the wider visual doubles1   
many systems wherein the  components are
 separated by distances comparable to   
the distances of  the outer planets1    
,saturn1 ,uranus and ,neptune1 from the 
sun4 ,it is  evident that the individual
 stars of such binary systems could not 
possibly be encircled by any such       
extensive system of satellites as       
attends our own sun1 though satellites  
such as our own planet ,earth1  or the  
inferior planets ,mercury and ,venus1   
might conceivably encircle  the         
individual components of such binary    
systems at distances not  greater than  
that of the earth from the sun4 ,no     
planet could safely  exist at a much    
greater distance from one of these suns 

without being  subject to most dangerous
 perturbations and disruptive tidal     
forces  arising from the vicinity of the
 second sun4 ,granted that planets      
might encircle one of these suns at a   
distance approximating that of  ,venus  
or our own planet from the sun1 the     
inhabitants of such worlds  would behold
 the strange phenomenon of two suns in  
the heavens1  not almost in contact as  
in spectroscopic binary systems1 but at 
one time comparatively near and again in
 opposite portions of the  heavens as is
 the case with the sun and moon in our  
own heavens4 ,as  the planet advanced in
 its orbit about the ruling sun1 the    
secondary  sun would be visible at first
 by day and again by night4 ,if the two 
suns were of contrasting hues1 as1 for  
instance1 green and red1 there  might   
appear in the nearby heavens at a       
distance of one hundred  million miles  
or so a magnificent sun of deep reddish 
hue1 equal to  or surpassing our own in 
splendor1 while in a far distant part of

  the sky1 at a distance as great as    
that which separates us from the  planet
 ,saturn1 might appear a rival sun of   
greenish hue1 smaller and  fainter1 but 
nevertheless1 hot and extremely         
brilliant and capable of  exerting      
through its great gravitational         
attraction a most disturbing  effect    
upon the motion of the planet of its    
neighbor4 ,at times the  rays of the two
 suns1 red and green1 would combine to  
produce a day  characterized by terrific
 heat and intense illumination4 ,again  
the  green orb would rise in the east as
 the red sun set in the west and  night 
would be turned into a weird1           
dimly-lighted day by the greenish  rays 
of the secondary sun4 ,compared to the  
wonders and beauties of  the heavens in 
such a system1 our own well-regulated   
and orderly  planet family1 undisturbed 
by the exciting proximity of a rival    
sun1  seems to pale into insignificance4
 ,yet we have every good reason to  be  
content with the ordering of affairs    

within our own solar system1  and to    
feel relief rather than regret at the   
absence of a secondary  sun4 ,in a      
planet world revolving about one member 
of a double star  system1 we may imagine
 the dread rather than pleasure with    
which the  periodic near-approach of a  
rival sun would be hailed1 and even the 
possible hurried migration from exposed 
to sheltered portions of the  planetary 
world to escape the rapidly increasing  
heat and intensity  of light from the   
approaching sun4 ,in such systems the   
coming and  going of the seasons might  
indeed be a matter of life and death to 
the inhabitants of satellite worlds6    
,within our solar system the masses of  
the planets are practically  negligible 
compared to the mass of the sun1 and it 
is for this reason  that they appear to 
revolve about the center of the sun4 ,as
 a  matter of fact1 no body in the      
universe revolves about the exact       
geometrical center of another body1 but 
two mutually attracting  bodies revolve 

in orbits about their common center of  
gravity1 which  always lies between the 
two bodies on the line connecting them  
and  at a distance from each of them    
that is in inverse proportion to the    
mass of the body4 ,the moon does not    
revolve about the center of the  earth1 
but about the center of gravity of the  
earth and moon1  which lies on the line 
connecting the two bodies and at a      
distance  from the earth's center that  
is one eighty-first of the distance     
from the center of the earth to the     
center of the moon1 since this          
represents the ratio of the masses of   
the two bodies4 ,this center  of gravity
 of the earth and moon1 lies1 then1     
about two thousand  miles from the      
earth's center1 and about this point    
both earth and  moon trace out orbits of
 revolution that are identical in form  
and  differ only in size4 ,in the same  
way each of the planets of the  solar   
system revolves about the center of     
gravity of itself and the  sun1 but the 

mass of the sun is so far in excess of  
the combined  masses of all the planets 
that we may consider1 for all practical 
purposes1 that the planets revolve about
 the sun's center1 the center  of       
gravity of the system being within the  
sun1 just as the center of  gravity of  
the earth and moon is within the earth4 
,prof4 ,t4 ,j4 ,j4 ,see found from the  
investigation of forty binary star      
orbits that the average eccentricity of 
double star orbits is twelve  times as  
great as the average eccentricity of a  
planetary orbit1 and  that the masses of
 the component suns never differ very   
greatly4 ,the  center of gravity of a   
binary system1 therefore1 lies at a     
great  distance from the centers of the 
stars1 and about this point1 as a       
focus1 the stars move in orbits that are
 exactly similar in form but  differ in 
size in inverse proportion to the ratio 
of the masses4  ,since the orbits of    
binaries are1 moreover1 very highly     
eccentric1  the two suns are1 as we have

 said1 anywhere from two to nineteen    
times nearer to each other at periastron
 than they are at apastron4    ,we have 
spoken so far only of systems of two    
associated suns1 but  many systems exist
 in which three or more sun-like bodies 
are in  revolution about a common center
 of gravity4 ,frequently two fairly     
close suns are in revolution about a    
common center of gravity1 in a  period1 
say1 of fifty or sixty years1 while a   
third sun revolves at  a comparatively  
great distance about the center of      
gravity of itself  and the first pair in
 a period of several hundred years4 ,or 
possibly  the third sun also possesses a
 close attendant and the two pairs      
revolve in a period of great length     
about a common center of gravity4       
,such1 for instance1 are the systems of 
,zeta ,cancri and ,epsilon  ,lyr4 ,in   
the former system the closer components 
revolve rapidly  about their center of  
gravity in a period of about sixty      
years1 while  the remote companion shows

 irregularities in its motion that      
indicate  that it is revolving about a  
dark body in a period of seventeen and  
a half years1 while the two together are
 revolving very slowly in a  period of  
six or seven centuries1 about a common  
center of gravity  with the first pair  
in a retrograde direction4    ,the wider
 pair of ,epsilon ,lyr is a naked-eye   
double for it can  be seen as a double  
star by a keen eye1 while even a        
three-inch  telescope will separate each
 of the components into a double star4  
,so  extensive is this system that the  
periods of revolution of the closer     
components occupy several centuries1 one
 pair appearing to revolve  about twice 
as rapidly as the other1 while the      
period of revolution  of the two pairs  
about a common center is probably a     
matter of  thousands of years4 ,the gap 
that separates the two pairs may be so  
great that light requires months to     
cross it4    ,these multiple systems are
 by no means exceptional4 ,they are to  

be  found in profusion among the        
brilliant ,orion stars4 ,they have been 
referred to as knots of stars and it has
 been suggested that they  may have     
originated as local condensations in one
 vast nebulous  tract4 ,a system of only
 two components appears to be the       
exception  rather than the rule1 groups 
of several connected suns being more    
numerous than single pairs4    ,in all  
of these double and multiple systems    
there exists the  possibility of minute 
satellites1 such as our own earth1 in   
attendance upon some one component of   
the system4 ,such tiny bodies  shining  
only by reflected light from a nearby   
brilliant sun would be  hopelessly      
invisible in the most powerful          
telescope4    ,we can only assume that  
it is far more reasonable to believe in 
than  to disprove the existence of such 
satellites4    ,our own solar system1   
then1 represents neither in its         
mechanical nor  physical features1 the  
only possibilities for the maintenance  

of  life2 it can neither be considered a
 unique form1 nor even the most         
generally prevalent form in the         
universe4          ,,xxx                
,,astronomical ,,distances      ,the    
grandeur of the scale upon which the    
visible universe is  fashioned lies     
almost beyond human comprehension4 ,in  
measuring the  vast extent of our own   
solar system1 which is but a single unit
  in the system of the stars1 we may    
have recourse to some earthly  standard 
of measurement1 such as the mile4 ,but  
when we desire to  express in terms of  
units that can be grasped by our        
imagination1 the  distances of the stars
 that lie far1 far beyond1 we find that 
all  ordinary standards of measurement  
become utterly inadequate for our       
purpose4 ,in the measurement of         
celestial distances within the solar    
system the unit employed is either the  
familiar mile or kilometer or  the      
astronomical unit1 which is the mean    
distance from the earth  to the sun     

7ninety-two million nine hundred        
thousand miles in round  numbers74      
,in the measurement of distances beyond 
the solar system the unit  employed is  
either the light-year or more recently  
the parsec1  which is rapidly replacing 
the light-year among astronomers4 ,a    
light-year is the distance that light1  
with its finite but almost  unimaginable
 velocity of one hundred and eighty-six 
thousand miles  per second1 travels in a
 year4 ,it is equal in round numbers to 
sixty-three thousand times the distance 
from the earth to the sun or            
approximately six thousand billions of  
miles4 ,the parsec is equal  to three   
and twenty-six hundredths 7#c4bf7       
light-years1 and it is  approximately   
two hundred thousand times the distance 
from the earth  to the sun4 ,it is the  
distance of a star with the parallax of 
a second1 a fact which its name1 parsec1
 conveys to us4 ,in other  words1 at the
 distance of one parsec the distance    
from the earth to  the sun1 the         

astronomical unit1 would subtend an     
angle equal to  one second of an arc4   
,this angle is spoken of as the parallax
 of the  star4 ,the larger the parallax1
 that is1 the larger the angle the      
astronomical unit or radius of the      
earth's orbit subtends1 viewed  from the
 star1 the nearer the star is to us4    
,the fact that there is  no known star  
within one parsec1 or three and         
twenty-six hundredths  light-years1 of  
the sun shows the immensity of the scale
 of the  universe of stars4    ,before  
considering the distances of the stars  
and the extent of the  sidereal system  
of which our sun and his satellites form
 a part1 let  us undertake to express   
the distance of the sun1 moon and       
planets  from the earth and the extent  
of the solar system in terms with which 
we are familiar4    ,the nearest to the 
earth of all celestial bodies is its    
satellite1  the moon4 ,so near is the   
moon that if we should make on some     
great  plain a model of the solar system

 in which the astronomical unit1 the    
distance from earth to sun1 would be    
four hundred feet1 the distance  between
 the earth and moon would be only one   
foot4 ,on the same scale  the most      
distant planet ,neptune would be two and
 one-quarter miles  away4    ,granted   
that it were possible to escape the     
earth's gravitational  bonds and to     
travel by our swiftest means of         
conveyance1 the  airplane1 through      
interplanetary space1 let us consider   
how long  it would take us to reach the 
moon1 sun and planets if our speed  were
 maintained at a uniform rate of two    
hundred miles an hour4 ,an  airplane    
traveling at this rate would            
circumnavigate the earth in a  little   
over five days and would reach the moon 
in seven weeks4 ,a trip  to the sun1    
however1 would take fifty-three years4  
,after traveling for fourteen and a     
fraction years we would pass  the orbit 
of ,venus and eighteen years later the  
orbit of ,mercury4  ,if we preferred to 

travel outward from the earth in the    
direction  of ,mars and the outer       
planets instead of toward the sun1 more 
than  twenty-seven years would elapse   
before we would reach the orbit of      
,mars4 ,an airplane journey to ,jupiter 
would be a matter of more than  two     
hundred years1 to ,saturn four hundred  
and fifty years1 to ,uranus  nearly one 
thousand years1 and to ,neptune1 about  
one thousand five  hundred years4 ,to   
cross the solar system on the diameter  
of ,neptune's  orbit in an airplane1    
traveling day and night without stopping
 at the  rate of #bjj miles per hour    
would take more than three thousand     
years4  ,the sun's attraction reaches   
far beyond ,neptune's orbit1 however4   
,there are comets belonging to the solar
 system compelled by the sun's          
attraction to accompany him on his      
travels through space that return       
periodically to the immediate vicinity  
of the sun from regions far  beyond the 
orbit of ,neptune and there is also the 

possibility that  one or more           
undiscovered planets may travel around  
the sun in orbits  far exterior to      
,neptune's orbit4    ,measured in terms 
of familiar units1 such as are employed 
for the  measurement of distances on our
 own planet1 the extent of the solar    
system is tremendously great4 ,viewed   
from ,neptune1 the sun is so  far away  
that it presents no appreciable disk4   
,it is in this sense  star-like to the  
,neptunians1 but at the distance of     
,neptune the stars  appear no more      
brilliant and no nearer than they do to 
us4    ,to ,neptune the sun1 though     
star-like in form1 supplies a very      
appreciable quantity of light and heat  
7one nine-hundredth of the  amount the  
earth receives7 while the amount of     
light and heat that  ,neptune receives  
from the nearest stars is entirely      
inappreciable4  ,when our airplane      
reaches ,neptune after a journey of one 
thousand  five hundred years1 it is1 as 
it were1 just clearing the ground  for  

its flight to the stars4 ,to cover the  
intervening space to  the nearest star1 
traveled by light in four and a third   
years1 an  airplane would need fourteen 
and a half million years4 ,in that time 
the solar system itself would be in some
 far distant part of the  universe1     
since it is speeding onward through     
space at the rate of  twelve miles a    
second or about four astronomical units 
a year4    ,changing now our unit of    
measurement that we may express         
interstellar  distances in              
comprehensible numbers1 we prepare to   
travel from the  earth to the stars with
 the velocity of light4    ,with this   
velocity1 one hundred and eighty-six    
thousand miles per  second1 we          
circumnavigate our globe in one-seventh 
of a second1 reach  the moon in one and 
a fourth seconds and the sun in eight   
minutes4  ,in a little over four hours  
we pass the orbit of ,neptune and are   
started on our journey to the stars1    
penetrating further and further  into   

interstellar space4 ,for a year we      
travel and reach not a single  star     
though we are speeding ever onward with 
the velocity of light4  ,we have now    
covered the distance of one light-year1 
which means that  the waves of light    
from the sun we have left behind must   
travel for a  year before they reach us4
 ,we continue our journey and find      
ourselves  next at a distance of one    
parsec from the sun4 ,we have traveled a
  distance of approximately three and a 
quarter light-years1 and were  it       
possible to see the earth as well as the
 sun at this distance1  the two would   
appear to be but one second of arc      
apart1 a distance  that requires the    
most careful adjustment and manipulation
 of the  telescope to measure           
accurately4 ,we are still one light-year
 distant  from ,alpha ,centauri1 the    
nearest of the bright stars4 ,a few of  
the  stars will now appear somewhat     
brighter than they appeared to us on    
earth1 but the majority of the stars    

appear just as we see them here  and the
 forms of the constellations remain     
practically unchanged  in appearance1   
for we are only beginning our journey   
through the  sidereal universe and our  
position in it has only shifted by a    
very  slight amount4 ,if we should      
continue our journey to the immediate   
vicinity of ,alpha ,centauri1 we would  
find that it is not like our  own sun1 a
 single star1 but is a binary star      
consisting of two suns  in revolution   
around their common center of gravity4  
,the distance  of this binary system    
from the solar system has been measured 
with considerable accuracy and is known 
to be four and a third  light-years4    
,though there may be a few faint stars  
or non-luminous  stars nearer to us than
 ,alpha ,centauri1 this star has long   
held the  distinction of being the      
nearest of the stars4 ,as the sun       
continues  his journey through the      
universe the two stars1 ,alpha ,centauri
 and  our sun1 will finally draw away   

from each other after many ages have    
passed and some other sun of space will 
be our nearest star4 ,the  distances    
that separate the stars from each other 
probably average as  great as the       
distance from the sun to ,alpha         
,centauri4 ,within a sphere  whose      
center is at the earth and whose radius 
is five parsecs1 or  about sixteen      
light-years1 there are only about twenty
 known stars4  ,there is1 therefore1    
small chance of collision among bodies  
that are  so small in proportion to the 
tremendous intervals of space that      
separate them from each other4 ,there is
 ample room for the individual  stars to
 pursue their journey through space     
without interfering with  each other's  
motion so long as they are as widely    
scattered as they  appear to be in this 
portion of the universe4 ,the fact that 
our own  sun has continued its journey  
through the universe for some hundreds  
of millions of years without any        
catastrophe such as would result  from  

closely approaching or colliding with   
another sun of space shows  how enormous
 is the scale upon which our sidereal   
system is fashioned4    ,stars that are 
ten1 fifty or even one hundred          
light-years from the  earth are our     
nearest neighbors in space4 ,they are   
the stars that  show a slight           
displacement in the heavens or          
measurable parallax1  viewed from       
opposite sides of the earth's orbit4    
,there are probably a  thousand stars   
among the hundreds of millions of stars 
within reach  of the greatest telescopes
 whose distances have been determined   
in light-years by direct measurement of 
their displacement in the  heavens      
resulting from the change of position of
 the earth in its  orbit4 ,the most     
distant of the stars are apparently     
immovable in  the heavens showing       
neither the effect of the sun's motion  
or their  own motion through space4     
,methods for finding the distances of   
many  far remote stars and star-clusters

 have been devised1 however1 and  some  
comparatively recent investigations have
 given results for the  distances of    
these objects indicating that the       
diameter of the system  of stars to     
which our sun belongs is approximately  
three hundred  thousand light-years4 ,it
 is difficult to grasp the full         
significance  of this fact4 ,it means   
that hundreds of millions of the suns of
 space  throng the visible universe at  
distances from us and from each other   
running into hundreds1 thousands and    
even hundreds of thousands of           
light-years4 ,the light waves from some 
tiny object that we view  today in one  
of our great reflectors may have started
 on their  journey through space over   
one hundred thousand years ago when men 
of  the ,old ,stone ,age inhabited our  
planet earth6    ,astronomers have found
 as a result of their investigations    
that the  sidereal system to which our  
solar system belongs is in the form of  
a flattened spheroid with its longest   

axis in the plane of the ,milky  ,way4  
,the extent of this star system composed
 of hundreds of millions  of individual 
suns in addition to nebul and clusters  
is probably  something like three       
hundred thousand light-years along its  
longest  axis1 while globular star      
clusters lying above and below its      
central  plane are estimated to be at   
distances from it ranging from ten      
thousand to two hundred thousand        
light-years4 ,this entire organized     
system is our sidereal universe4 ,space 
beyond is unexplored4 ,the  globular    
star clusters are among the most distant
 celestial objects  so far discovered4  
,the spiral nebul may be entirely within
 the  limits of this system or they may 
be even more distant than the  globular 
clusters for their distances are not    
known as yet4    ,there is a possibility
 that our sidereal universe1 vast as it 
is  known to be1 may be but a unit in   
some still greater unit and that  other 
similar systems lie beyond the reach of 

existing telescopes at  unimaginable    
distances4    ,the mind of man is       
overwhelmed by the thought of sidereal  
systems  as vast as our own lying far   
beyond his ken4 ,whether or not such    
external systems do exist and are with  
our own sidereal system units  in some  
still vaster creation we cannot know4   
,so vast1 indeed1 is this one visible   
universe of ours that the  mind of man1 
accustomed to earthly standards1 cannot 
comprehend  its magnitude or the        
infinitesimal size of our whole solar   
system  compared to it4          ,,xxxi 
,,some ,,astronomical ,,facts ,,worth   
,,remembering      ,kepler's ,three     
,laws of ,planetary ,motion3    ,i4 ,the
 planets move in ellipses with the sun  
at one focus4    ,,ii4 ,the radius      
vector of a planet 7line adjoining sun  
and planet7  sweeps over equal areas in 
equal times4    ,,iii4 ,the square of   
the time of revolution 7the year7 of    
each planet  is proportional to the cube
 of its mean distance from the sun4     

99       99       99       99       99  
,sir ,isaac ,newton discovered that the 
law of gravitation extends to  the      
stars4 ,that is1 every mass in the      
universe attracts every other  mass with
 an attraction directly proportional to 
the product of the  masses and inversely
 proportional to the square of the      
distances  between them4           99   
99       99       99       99    ,ocean 
tides are caused by the difference      
between the attraction of  the sun and  
moon for the main body of the earth and 
their attraction  for different         
particles of the earth's surface4 ,the  
tide-raising  force of the disturbing   
body is proportional to its mass and    
inversely proportional to the cube of   
its distance4 ,the tides  produced by   
the sun are1 therefore1 only two-fifths 
as great as the  tides produced by the  
moon4           99       99       99    
99       99    ,the celestial sphere is 
an imaginary sphere of infinite radius1 
with the earth at its center1 upon which

 the celestial bodies are  considered to
 be projected for convenience in        
determining their  positions with       
respect to fixed points of reference in 
the heavens4    ,the north and south    
poles of the heavens are the points on  
the  celestial sphere directly above the
 north and south poles of the  earth4   
,the celestial equator is the great     
circle in which the plane of the        
earth's equator intersects the celestial
 sphere4 ,it passes through  the east   
and west points of the horizon and      
through the zenith--or  point directly  
overhead--at the earth's equator4       
,the ecliptic is the great circle in    
which the plane of the earth's  orbit   
intersects the celestial sphere4 ,the   
celestial equator and the  ecliptic are 
inclined to each other at an angle of   
#bc-a_/b1 which is  called the obliquity
 of the ecliptic4 ,the two points in    
which the  celestial equator and the    
ecliptic intersect are called           
respectively  the vernal equinox and the

 autumnal equinox4    ,the vernal       
equinox is an important point of        
reference on the  celestial sphere4     
,as the position of a point on the      
earth's surface is determined  by its   
longitude and latitude so the position  
of an object on the  celestial          
sphere--star1 sun1 planet--is determined
 by its ,right  ,ascension and          
,declination4    ,the ,declination of a 
celestial object is its distance north  
or  south of the celestial equator1     
measured in degrees1 minutes and        
seconds of arc1 on a great circle of the
 celestial sphere passing  through the  
object and north and south poles of the 
heavens4 ,these  great circles are      
called hour circles and they correspond 
to the  meridians or circles of         
longitude on the earth's surface4 ,the  
declination of an object in the heavens 
corresponds to the latitude  of a point 
on the earth's surface4 ,the ,right     
,ascension of a point  on the celestial 
sphere corresponds to the longitude of a

 point on  the earth's surface4 ,it is  
measured--as longitude is measured--in  
degrees1 minutes and seconds of arc or  
in hours1 minutes and seconds  of       
time--eastward along the celestial      
equator from the hour circle  passing   
through the vernal equinox to the foot  
of the hour circle  passing through the 
object4 ,the hour circle passing through
 the  vernal equinox is the zero        
meridian for the celestial sphere just  
as  the meridian of ,greenwich is the   
zero meridian on the earth's surface4   
99       99       99       99       99  
,the mean distance of the earth from the
 sun is #ib1ijj1jjj miles and  is called
 the astronomical unit4    ,the sun with
 its satellites advances through the    
universe at the rate  of #d astronomical
 units in a year or approximately one   
million miles  a day4    ,the parallax  
of a star is the angle at the star      
subtended by the  radius of the earth's 
orbit1 #ib1ijj1jjj miles1 or the        
astronomical  unit4 ,it is1 in other    

words1 the angular distance between the 
earth  and sun as viewed from the star4 
,the larger the parallax the nearer  the
 star4 ,the largest known stellar       
parallax is that of ,alpha  ,centauri   
and its value is #j4ge4    ,the         
light-year is the distance that light   
travels in one year4 ,it  is equal to   
about #fc1jjj astronomical units or     
nearly six trillion                     
7#f1jjj1jjj1jjj1jjj7 miles4 ,the        
velocity of light is #ahf1jjj miles per 
second4    ,the parsec is equal to #c4bf
 light-years4 ,it is the distance of a  
star  that has a parallax of one second 
of arc4    ,the apparent magnitude of a 
star is its apparent brightness         
estimated  on a scale in which a        
difference of one magnitude corresponds 
to a  difference in brightness of #b4ea1
 or the fifth root of one hundred4  ,a  
difference of five magnitudes           
corresponds to a difference one one     
hundredfold in brightness1 of ten       
magnitudes to ten thousandfold  in      

brightness4 ,in exact measurements on   
this scale magnitudes are  estimated to 
tenths4    ,stars that are one magnitude
 brighter than stars of the standard    
first magnitude are of the zero         
magnitude and stars still brighter  are 
of negative magnitudes4    ,sirius is a 
star of the -#a4f magnitude4 ,jupiter at
 opposition is of  -#b4j magnitude and  
,venus at greatest brilliancy of -#d4j  
magnitude4  ,the sun on this scale of   
comparative brightness is of the -#bf4g 
apparent magnitude4 ,the faintest stars 
visible in the most powerful  telescope 
in the world--the #aja-;inch ,mt4       
,wilson ,hooker telescope--are  of the  
twentieth magnitude4    ,the absolute   
magnitude of a star is its apparent     
magnitude at  the standard distance of  
ten parsecs or #cb4f light years4 ,the  
absolute magnitude of the sun is five4  
,that is1 the sun would be a            
fifth-magnitude star at the standard    
distance of #cb4f light-years4  ,the    
absolute magnitudes of stars indicate   

how bright they would be  relatively if 
they were all at the same standard      
distance4 ,apparent  magnitudes indicate
 how bright the stars appear to be at   
their true  distances4           99     
99       99       99       99    ,the   
mean distance of the moon from the earth
 is approximately #bdj1jjj  miles or    
sixty times the earth's radius4    ,the 
sun is four hundred times farther away  
than the moon and its  diameter is about
 four hundred times greater than the    
moon's diameter4    ,the nearest star is
 about #bge1jjj times more distant than 
the sun1  and the most distant known    
object1 the globular star cluster1      
,n4,g4,c4  #gajf1 is about fourteen     
billion times more distant than the sun4
    ,the earth is a spheroid flattened  
at the poles and its polar diameter  is 
about twenty-seven miles shorter than   
its equatorial diameter4 ,an  object    
weighs less at the poles than at the    
equator4    ,the earth's interior is as 
rigid as steel and probably consists of 

a  core of magnetic iron surrounded by  
an outer stony shell4    ,eclipses of   
the sun occur when the moon passes      
between the earth and  sun4 ,they can   
only occur at the time of new moon4     
,there must be at  least two solar      
eclipses every year separated by an     
interval of six  months and there may be
 as many as five solar eclipses in a    
year4  ,eclipses of the moon occur when 
the earth comes between the sun and     
moon1 and the moon passes into the      
earth's shadow4 ,eclipses of the  moon  
can only occur at full moon4 ,there may 
or may not be eclipses of  the moon     
every year4 ,the greatest number of     
eclipses than can occur  in any one     
year1 solar and lunar combined1 is seven
 and the least  number is two and in    
that case they are both solar eclipses4 
,the sun is a yellow1 dwarf star of a   
density of one and one-fourth  that of  
water and with a surface temperature of 
about #ab1jjj ,f4  except in sun-spot   
regions where the temperature is about  

#f1jjj ,f4  ,it is probably gaseous     
throughout4    ,the sun1 as well as the 
planets1 rotates on its axis and        
different  portions of the surface      
rotate at slightly different rates4 ,the
  average period of the rotation of the 
sun on its axis is about  twenty-six    
days4    ,the sun is a variable star    
with a twofold variation4 ,one is of    
long  period during the eleven-year     
sun-spot cycle with a range of from     
three to five per cent4 ,the other is a 
short irregular variation with  a period
 of a few days1 weeks or months and a   
range of from three to  ten per cent4   
,sun-spots are solar cyclones and appear
 black only by contrast with  their     
hotter and brighter surroundings4 ,they 
come in eleven-year  cycles             
7approximately7 with periods of maximum 
and minimum appearance4    ,the         
brightness and blue color of the sky is 
due to the scattering  of sunlight by   
the molecules of oxygen and nitrogen in 
the earth's  upper atmosphere4 ,if there

 were no atmosphere the skies would     
appear  black except in the direction of
 the heavenly bodies1 which would be    
visible by day as well as by night4     
,the solar corona is the rare outer     
envelope of the sun and it is  visible  
only during a total eclipse of the sun4 
,it is partly of an  electrical nature  
and it varies in form during the        
sun-spot cycle4 ,it  often extends to a 
distance of several solar diameters on  
either side  of the sun4    ,the warmth 
and the habitability of the earth's     
surface is due to the  presence of      
water-vapor and carbon-dioxide in the   
atmosphere4 ,without  these substances  
in the atmosphere life on the earth's   
surface would  be impossible4    ,half  
of the earth's atmosphere and all clouds
 lie within seven miles  of the earth's 
surface1 and at high elevations above   
the earth the  temperature is many      
degrees below zero4    ,the temperature 
of space approaches the absolute zero of
 -#dei ,f4    ,the only planets in the  

solar system with the exception of the  
earth  that might possibly support life 
are ,venus and ,mars4    ,stars shine by
 their own light but planets shine only 
by reflected  light from the sun4       
99       99       99       99       99  
,if the earth were represented by a     
six-inch school globe the sun  would be 
on the same scale a globe fifty-four    
feet in diameter4  ,mercury would be a  
small ball two and a third inches in    
diameter4  ,venus would be another      
six-inch globe4 ,mars would be a ball   
about  the size of a baseball1 three and
 a fifth inches in diameter4 ,the  moon 
would be about the size of a golf ball1 
one and a half inches  in diameter4 ,the
 largest asteroids would be the size of 
marbles4  ,average-sized asteroids would
 be the size of shot and the smallest   
would be merely grains of sand4         
,jupiter would be a huge globe standing 
as tall as a man five feet  six inches  
in height4 ,saturn would be a smaller   
globe four and a  half feet in diameter 

and its ring system would extend to a   
distance  of five and a half feet on    
either side of the globe4 ,uranus would 
be represented by a globe almost exactly
 two feet in diameter and  ,neptune     
would be a slightly larger globe with a 
diameter of two feet  two and a half    
inches4    ,the satellites of the outer 
planets would range in size from tennis 
and golf balls for the largest1 to      
marbles for the smaller and grains  of  
sand for the smallest4    ,on the same  
scale of measurement the distance of the
 six-inch globe  of the earth from the  
fifty-four foot globe representing the  
sun  would be one and one-tenth miles4  
,the moon would be placed fifteen  feet 
from the earth-globe and the diameter of
 the solar system on the  same scale    
measured across the orbit of ,neptune   
would be sixty-six  miles4 ,the nearest 
star on this scale would be three       
hundred thousand  miles away4           
99       99       99       99       99  
,if the distance from the earth to the  

sun is taken as one inch so  that the   
scale of the universe is reduced six    
trillion times1 the  diameter of the    
solar system across ,neptune's orbit is 
five feet and  the distance of one      
light-year comes out almost exactly     
equal to one  mile4 ,the nearest star to
 the five-foot solar system would be    
four  and a third miles away2 the most  
distant known object would be two       
hundred and twenty thousand miles away1 
and the extent of the visible  universe 
would be three hundred thousand miles4  
,on the same scale the  diameter of our 
sun would be about one hundredth of an  
inch and the  diameters of the giant    
stars ,antares and ,betelgeuze would be 
four  inches and two and three-fourth   
inches respectively4 ,to see the earth  
we would need a microscope4             
,,tables      ,,table ,i    ,,the       
,,principal ,,elements ,,of ,,the       
,,solar ,,system                        
,mean ,distance from ,sun               
,velocity                               

---------------------               in  
,inclination                            
,relative   ,period    ,orbit           
,eccentricity    of    ,planet          
,in ,miles      to        of     7,miles
      of       ,orbit to                
,earth's  ,revolution   per      ,orbit 
,ecliptic                               
,distance            ,second 7          
----------------------------------------
------------------------------------    
,mercury        #cf1jjj1jjj  #j4ci      
#hg4ig days #bc to #ce    4#bjef    #g  
#j'    ,venus          #fg1bjj1jjj      
#j4gb  #bbd4gj days   #ba4i      4#jjfh 
#c     #bc    ,earth                    
#ib1ijj1jjj  #a4jj  #cfe4be days   #ah4e
      4#jafg    #j      #j    ,mars     
#ada1ejj1jjj  #a4eb    #a4hh years      
#ae4j      4#jicc    #a     #ea         
,asteroids#a  44444444444#b4j-e4b       
444444444  444444  4#jj to 4#dj  #j to  
#ce    ,jupiter       #dhc1cjj1jjj      
#e4bj   #aa4hf years   #h4a      4#jdhd 
#a     #ah    ,saturn                   

#hhf1jjj1jjj  #i4ed   #bi4df years      
#f4j      4#jeeh    #b     #bi          
,uranus      #a1gha1ijj1jjj #ai4ai      
#hd4jb years   #d4b      4#jdga    #j   
#df    ,neptune     #b1iga1fjj1jjj      
#cj4jg  #afd4gi years   #c4d      4#jjhe
    #a     #dg        ,,footnote3    #a 
,about #idj have been discovered up to  
the present time4    ,,the ,,principal  
,,elements ,,of ,,the ,,solar ,,system  
7,continued7                     ,mean  
,density   ,surface   ,velocity         
,reflecting  ,period    ,inclination    
,name   ,diameter   ,mass     ,volume   
,relative  ,gravity   of ,escape        
,power       of           of            
in   --------------------to that        
7,relative  7,miles per   in            
,axial      ,equator                    
,miles  ,relative to ,earth's of ,water 
to ,earth's7 ,second7   ,per ,cent      
,rotation     to ,orbit                 
----------------------------------------
----------------------------------------
--------------------    ,sun            

#hfd1cib  #cbi1cij  #a1cjj1jjj  #a4dj   
#bg4fd      #chc       44444   #be d4 #h
   h4  #g #ae'    ,moon        #b1afj   
4#jab     4#jb     #c4cd      #j4af     
#a4e        #g    #bg d4 #g4g h4  #f    
#da    ,mercury     #c1jji     4#jde    
4#jf     #d4dh8     #j4ca8       #b4b   
#g    #hh d4  8        8    ,venus      
#g1ege     4#hjg     4#ib     #d4he8    
#j4he        #f4f       #ei           8 
8    ,earth       #g1iah    #a4jjj      
#a4jj     #e4ec      #a4jj         #g   
#dd    #bc h4 #ef m4  #bc  #bg    ,mars 
#d1baf     4#ajf     4#ae     #c4eh     
#j4ce        #a4e       #ae    #bd      
#cg     #bc  #ei                        
,asteroids#e-dhebvery smallvery small   
#c4c   4#jjjh to 4#jd4cc to 4#ja     #g 
44444        44444    ,jupiter          
#hh1cib  #cad4ej     #acji     #a4be    
#b4eb        #cg        #ef     #i      
#ee     #c    ,saturn     #gd1afc       
#id4jg      #gfj     #j4fc      #a4jg   
#bb        #fc    #aj    #ad    #bg     
,uranus     #cj1hgh   #ad4dj       #fe  

#a4dd      #j4ii        #ac        #fc  
#aj    #de       8    ,neptune          
#cb1icb   #af4gb       #he     #a4ji    
#j4hg        #ad        #gc           8 
8        ,,footnote3    #b ,extreme     
values4      ,,table ,,ii    ,,the      
,,satellites ,,of ,,the ,,solar ,,system
                                        
,mean ,distance                         
,apparent from ,planet's,diameter       
,period of                   ,year of   
,name     ,magnitude   ,center1   in    
miles     ,revolution       ,discoverer 
,discovery                            in
 miles                                  
----------------------------------------
----------------------------------------
-----                                   
,,the ,,earth                           
,moon                   #bch1heg        
#bafj    #bg days1  #g hours1           
#dc minutes                       ,,mars
                                        
#a4 ,phobos       #ad          #e1hej   
#aj8     #j days1  #g hours1  ,asaph    

,hall    #ahgg                          
#ci minutes                     #b4     
,deimos       #ac         #ad1fej       
#aj8     #a day1   #f hours1  ,asaph    
,hall    #ahgg                          
#ag minutes                             
,,jupiter                               
v4           #ac         #aab1ejj       
#ajj8     #j day1  #aa hours1  ,barnard 
#ahib                                   
#eg minutes                        i4   
#f4e         #bfa1jjj   #bdeb     #a    
day1  #ah hours1  ,galileo       #afaj  
#bh minutes                       ii4   
#f4e         #dae1jjj   #bjde     #c    
days1 #ac hours1  ,galileo       #afaj  
#ad minutes                      iii4   
#f         #ffd1jjj   #ceeh     #g days1
  #c hours1  ,galileo       #afaj       
#dc minutes                       iv4   
#g       #a1afg1jjj   #ccde    #af days1
 #af hours1  ,galileo       #afaj       
#cb minutes                       vi4   
#ad       #g1cgb1jjj   small  #bff days1
  #j hours1  ,perrine       #aijd       

#j minutes                       vii4   
#af       #g1efg1ijj very     #bgf days1
 #af hours1  ,perrine       #aije       
small       #e minutes                  
viii4           #ag      #ae1fjj1jjj    
very     #ghi days1  #j hours1  ,melotte
       #aijh                            
small       #j minutes                  
ix4           #ai      #ah1ijj1jjj      
#bj8    #c years            ,nicholson  
#aiad                                   
,,saturn                                
#a4 ,meimas       #ae         #aag1jjj  
#fjj     #j days1 #bb hours1  ,herschel 
#aghi                                   
#cg minutes                     #b4     
,enceladus    #ad         #aeg1jjj      
#hjj     #a day1   #h hours1  ,herschel 
#aghi                                   
#ec minutes                     #c4     
,tethys       #aa         #ahf1jjj      
#abjj     #a day1  #ba hours1  ,cassini 
#afhd                                   
#ah minutes                     #d4     
,dione        #aa         #bch1jjj      

#aajj     #b days1 #ag hours1  ,cassini 
#afhd                                   
#da minutes                     #e4     
,rhea         #aj         #ccb1jjj      
#aejj     #d days1 #ab hours1  ,cassini 
#afgb                                   
#be minutes                     #f4     
,titan         #i         #gga1jjj      
#cjjj    #ae days1 #bb hours1  ,huygens 
#afee                                   
#da minutes                     #g4     
,hyperion     #af         #icd1jjj      
#ejj    #ba days1  #f hours1  ,bond     
#ahdh                                   
#ci minutes                     #h4     
,japetus      #aa       #b1bbe1jjj      
#bjjj    #gi days1  #g hours1  ,cassini 
#afga                                   
#ed minutes                     #i4     
,phoebe       #ag       #h1jjj1jjj      
#bjj8  #edf days1 #ab hours1  ,w4,h4    
#ahih                                   
#j minutes        ,pickering    #aj4    
,themis       #ag         #ijf1jjj    8 
#bj days1 #bj hours1  ,w4,h4            

#aije                                   
#bd minutes       ,pickering            
,,uranus                                
#a4 ,ariel        #ae         #abj1jjj  
#ejj     #b days1 #ab hours1  ,lassell  
#ahea                                   
#bi minutes                     #b4     
,umbriel      #af         #afg1jjj      
#djj     #d days1  #c hours1  ,lassell  
#ahea                                   
#bh minutes                     #c4     
,titania      #ac         #bgc1jjj      
#ajjj     #h days1 #af hours1  ,herschel
      #aghg                             
#ef minutes                     #d4     
,oberon       #ad         #cfe1jjj      
#hjj    #ac days1 #aa hours1  ,herschel 
#aghg                                   
#g minutes                              
,,neptune                               
#a4 ,nameless     #ac         #bba1ejj  
#bjjj     #e days1 #ba hours1  ,lassell 
#ahdf                                   
#c minutes                              
,,rings ,,of ,,saturn                   

,distance of        ,distance of        
,diameter of ,ring                      
,inner ,edge from    ,outer ,edge from  
,system from outer           ,name      
,width1   ,surface of ,saturn1 ,surface 
of ,saturn1 edge to outer edge1         
in miles      in miles           in     
miles       #agb1ejj miles4             
----------------------------------------
---------------------------,thickness of
 ,ring                                  
,system1 about one    ,dark or ,crape   
,ring   #aj1ijj         #e1ijj          
#af1hjj        hundred miles4    ,bright
 ,ring          #ah1jjj        #af1hjj  
#cd1hjj       ,size of ,individual      
,cassini's ,division    #b1bjj          
#cd1hjj             #cg1jjj             
,moonlets1 probably    ,outer ,ring     
#aa1jjj        #cg1jjj                  
#dh1jjj        less than three          
miles in diameter4          ,,table     
,,iii    ,,the ,,twenty ,,brightest     
,,stars ,,in ,,the ,,heavens            
,passes                                 

,on       through    ,distance          
,name                    ,magnitude     
,color      ,meridian   the ,zenith     
in                                      
#i ,p4 ,m4   in ,latitude,light-,years  
----------------------------------------
----------------------------------------
-----    ,sirius1 ,alpha ,canis ,majoris
     -#a4f   ,white       ,february  #ab
   #ag ,s4      #h4h    ,canopus1#c     
,alpha ,argus         -#j4i   ,white    
,february   #h   #ec ,s4       8        
,alpha ,centauri#c                #j4a  
,yellow      ,june      #ae   #fa ,s4   
#d4c    ,vega1 ,alpha ,lyr              
#j4a   ,white       ,august    #ae   #ci
 ,n4       #dj    ,capella1 ,alpha      
,aurig            #j4b   ,yellow        
,january   #bj   #df ,n4       #ch      
,arcturus1 ,alpha ,botis           #j4b 
,orange      ,june      #aj   #bj ,n4   
#ba    ,rigel1 ,beta ,orionis           
#j4h   ,bluish-,white,january   #bj     
#h ,s4        8    ,procyon1 ,alpha     
,canis ,minoris     #j4e   ,white       

,february  #bf    #e ,n4       #ab      
,achernar1#c ,alpha ,eridani       #j4f 
,bluish-,white,december   #b   #eh ,s4  
#hj    ,beta ,centauri                  
#j4i   ,bluish-,white,june       #g     
#fj ,s4      #ajj    ,betelgeuze1 ,alpha
 ,orionis     ,var4     ,red            
,january   #ca    #g ,n4    #aej-bgj8   
#a4j-a4d                                
,altair1 ,alpha ,aquil             #j4i 
,white       ,september  #d    #i ,n4   
#af    ,alpha ,crucis#c 7,double ,star7 
#a4f-b4a ,bluish-,white,may       #ad   
#fc ,s4      #bbj    ,aldebaran1 ,alpha 
,tauri           #a4a   ,red            
,january   #aa   #af ,n4       #bg      
,pollux1 ,beta ,geminorum           #a4b
   ,yellow      ,february  #bh   #bh ,n4
       #ce    ,spica1 ,alpha ,virginis  
#a4b   ,bluish-,white,may       #bi     
#aa ,s4       8    ,antares1 ,alpha     
,scorpii           #a4b   ,red          
,july      #ab   #bf ,s4      #hej      
,fomalhaut1 ,alpha ,piscis          #a4c
   ,white       ,october   #bd   #cj ,s4

       #be      ,australis              
,deneb1 ,alpha ,cygni               #a4c
   ,white       ,september #ai   #de ,n4
       8    ,regulus1 ,alpha ,leonis    
#a4c   ,white       ,april      #h   #ab
 ,n4       #cb        ,,footnote3    #c 
,invisible north of #ce ,n4 ,lat4       
7approximate74      ,,table ,,iv    ,a  
,,list ,,of ,,the ,,principal           
,,constellations    #a4 ,,visible ,,in  
#dj ,,north ,,latitude                  
,passes            ,name         ,chief 
,star    ,on ,meridian   ,overhead      
or          #i ,p4 ,m4    in ,latitude#d
                        ,noted ,object  
7,degrees7                              
----------------------------------------
--------------------      ,andromeda    
,great ,nebula   ,november         #ce  
,n4      ,aquarius                      
,october           #e ,s4      ,aquila  
,altair         ,september         #j   
,aries                                  
,december         #bj ,n4      ,auriga  
,capella        ,february         #dj   

,n4      ,botes            ,arcturus    
,june             #cj ,n4      ,cancer  
,praesepe       ,march            #bj   
,n4      ,canes ,venatici    ,cor       
,caroli     ,june             #dj ,n4   
,canis ,major       ,sirius             
,march            #bj ,s4      ,canis   
,minor       ,procyon        ,march     
#aj ,n4      ,capricornus               
,october          #ae ,s4               
,cassiopeia                             
,november         #fj ,n4      ,cepheus 
,november         #gj ,n4      ,cetus   
,mira           ,december          #e   
,s4      ,columba                       
,february         #ce ,s4      ,coma    
,berenices                   ,may       
#be ,n4      ,corona ,borealis          
,alphecca       ,july             #cj   
,n4      ,corvus                        
,may              #bj ,s4      ,crater  
,may              #ae ,s4      ,cygnus4 
,deneb          ,september        #dj   
,n4      ,delphinus         ,most       
distant   ,september        #ae ,n4     

globular                                
cluster                        ,draco   
,alpha          ,august           #fe   
,n4      ,eridanus          ,achernar   
,january      #aj ,n4 to #fj ,s4        
,gemini            ,pollux              
,march            #be ,n4      ,hercules
          ,great ,cluster  ,july        
#cj ,n4      ,hydra                     
,april            #bj ,s4      ,leo     
,regulus        ,april            #ae   
,n4      ,lepus                         
,february         #bj ,s4      ,libra   
,june             #ae ,s4      ,lynx    
,april            #de ,n4      ,lyra    
,vega           ,august           #dj   
,n4      ,ophiuchus                     
,july             #aj ,s4      ,orion   
,great ,nebula   ,february          #j  
,piscis ,australis  ,fomalhaut          
,october          #cj ,s4      ,pegasus 
,november         #bj ,n4      ,perseus 
,algol          ,january          #ej   
,n4      ,pisces                        
,december          #e ,n4      ,sagitta 

,september        #bj ,n4               
,sagittarius                            
,august           #cj ,s4      ,scorpio 
,antares        ,july            #cj ,s4
      ,serpens                          
,july        #bj ,n4 to #ae ,s4         
,taurus            ,pleiades            
,january         #bj ,n4                
,triangulum                             
,december        #ce ,n4      ,ursa     
,major        ,mizar          ,may      
#fe ,n4      ,ursa ,minor               
,polaris                        #he ,n4 
,virgo             ,spica          ,june
             #j          ,,footnote3    
#d ,the approximate position of the     
center of the constellation4    #b4     
,,invisible ,,in #dj ,,north ,,latitude 
,on        ,passes       ,name          
,chief ,star    ,meridian    ,overhead  
or         #i ,p4 ,m4   in ,latitude#d  
,noted ,object               7,degrees7 
----------------------------------------
-----------    ,apus                    
,july          #ge ,s4    ,ara          

,july          #ee ,s4    ,argo ,navis  
,canopus        ,march         #ej ,s4  
#a4 ,carina                 ,march      
#fj ,s4     #b4 ,puppis                 
,march         #de ,s4     #c4 ,vela    
,march         #ej ,s4    ,centaurus    
,alpha ,centauri ,june          #ej ,s4 
,crux                                   
7,southern                              
,cross7    ,alpha ,crucis   ,june       
#fj ,s4    ,dorado      ,gt4 ,magellanic
                             ,cloud     
,february      #eh ,s4    ,grus         
,october       #de ,s4    ,hydrus       
,lesser ,mag4                           
,cloud                      #gj ,s4     
,indus                      ,september  
#ee ,s4    ,lupus                       
,june          #dj ,s4    ,musca        
,june          #gj ,s4    ,octans       
#he ,s4    ,pavo                        
,october       #fe ,s4    ,phoenix      
,november      #de ,s4    ,telescopium  
,july          #dh ,s4    ,triangulum   
,australe                 ,july         

#fe ,s4    ,tucana      ,great ,cluster 
,november      #fj ,s4    ,volans       
,march         #ge ,s4          ,,table 
,v    ,,pronunciations ,,and ,,meanings 
,,of ,,names ,,of ,,stars ,,and         
,,constellations    #a4 ,,stars         
,name       ,pronunciation              
,meaning                                
----------------------------------------
-------------    ,achernar      a-ker-nr
          ,end-of-the-,river            
,aldebaran     al-deb-ar-an       ,the  
,hindmost    ,altair        al-tar      
,antares       an-ta-rez          ,rival
 of ,ares 7,mars7    ,arcturus          
rk-tu-rus            ,bellatrix         
bel-latrix         ,the ,female ,warrior
    ,betelgeuze    bet-el-gerz          
or bet-el-gez    ,the ,arm-,pit         
,canopus       cn-o-pus                 
,capella       ca-pel-la                
,little ,she-,goat    ,deneb            
den-eb                ,denebola         
de-neb-o-la        ,the ,lion's ,tail   
,fomalhaut     fo-mal-o           ,the  

,fish's ,mouth    ,hyades               
hi-a-dez            ,the ,rainy ,ones   
,pleiades      ple-ad-ez                
,pollux        pol-lux                  
,praesepe      pre-se-pe          ,the  
,beehive    ,procyon       pro-si-on    
,precursor of the ,dog    ,regulus      
reg-u-lus          ,the ,ruler    ,rigel
         ri-gel or ri-jel      ,sirius  
sir-i-us           ,the ,sparkling ,one 
,spica         spi-ka             ,the  
,ear of ,wheat    ,vega          ve-ga  
#b4 ,,constellations               ,name
          ,pronunciation                
,meaning                                
----------------------------------------
-----------------    ,andromeda         
an-drom-e-da          ,the ,woman       
,chained    ,aquarius                   
a-kwa-ri-us           ,the ,water-bearer
    ,aquila           ak-wi-la          
,the ,eagle    ,ara              a-ra   
,the ,altar    ,argo ,navis             
r-go-na-vis         ,the ,ship ,argo    
,aries            a-res                 

,the ,ram    ,auriga           w-ri-ga  
,the ,charioteer    ,botes              
bo-o-tez              ,the ,herdsman    
,cancer           can-ser               
,the ,crab    ,canes ,venatici   ca-nez 
ven-at-i-si   ,the ,hunting ,dogs       
,canis ,major      ca-nis major         
,the ,greater ,dog    ,canis ,minor     
ca-nis minor         ,the ,lesser ,dog  
,capricornus      cap-ri-kr-nus         
,the ,goat    ,cassiopeia               
cas-si-o-pe-ya          ,centaurus      
cen-tw-rus           ,the ,centaur      
,cepheus          se-fe-us              
,cetus            se-tus                
,the ,whale    ,columba                 
col-um-ba             ,the ,dove        
,coma ,berenices   coma ber-e-ni-ses    
,berenice's ,hair    ,corona ,borealis  
co-ro-na bo-re-a-lis ,the ,northern     
,crown    ,corvus           cr-vus      
,the ,crow    ,crater           cra-ter 
,the ,cup    ,crux             krux     
,the ,cross    ,cygnus           sig-nus
               ,the ,swan    ,delphinus 

del-fi-nus            ,the ,dolphin     
,dorado           dr-a-do               
,the ,goldfish    ,draco                
dra-co                ,the ,dragon      
,eridanus         e-rid-a-nus           
,the ,river ,eridanus    ,gemini        
jem-i-ni              ,the ,twins       
,grus             grus                  
,the ,crane    ,hercules                
her-ku-lez                ,hydra        
hi-dra                ,the ,water-snake 
,hydrus           hi-drus               
,the ,serpent    ,indus                 
ind-us                ,the ,indian      
,leo              le-o                  
,the ,lion    ,lepus            le-pus  
,the ,hare    ,libra            li-bra  
,the ,scales    ,lupus            lu-pus
                ,the ,wolf    ,lynx     
,the ,fox    ,lyra             li-ra    
,the ,lyre    ,musca            mus-ca  
,the ,fly    ,octans           oct-ans  
,the ,octant    ,ophiuchus              
o-fi-u-kus           ,the               
,serpent-holder    ,orion               

o-ri-on               ,the ,warrior     
,pavo             p-vo                  
,the ,peacock    ,phoenix               
fe-nix                   ,piscis        
,australis pis-sis aus-tra-lis  ,the    
,southern ,fish    ,pegasus             
peg-a-sus             ,the ,winged      
,horse    ,perseus          per-se-us or
 per-sus     ,pisces           pis-sez  
,the ,fishes    ,sagitta                
sa-jit-ta             ,the ,arrow       
,sagittarius      sa-jit-ta-ri-us       
,the ,archer    ,scorpio                
skr-pi-o             ,the ,scorpion     
,serpens          ser-pens              
,the ,serpent    ,taurus                
tu-rus                ,the ,bull        
,telescopium      tel-es-cop-i-um       
,the ,telescope    ,triangulum          
tri-an-gu-lum         ,the ,triangle    
,tucana           tuc-an-a              
,the ,toucan    ,ursa ,major       ur-sa
 ma-jor         ,the ,greater ,bear     
,ursa ,minor       ur-sa mi-nor         
,the ,lesser ,bear    ,virgo            

ver-go                ,the ,maiden      
,volans           vol-ans               
,the ,flying ,fish                 99   
99       99       99       99           
,transcriber's ,note3    ,obvious       
typographical errors have been repaired4
    ,underscores surround italicized    
content4    ,mid-paragraph illustrations
 were moved near to the text describing 
the illustrated material4    ,redundant 
title--,astronomy for ,young ,folks--on 
p4 #c was deleted4    ,p4 #c3 ,canst    
thou bring forth ,mazzaroth--,canst is  
assumed in blank  space4    ,p4 #be3    
brighter object than the nearby star    
,aldebaran--star is  assumed in blank   
space4    ,p4 #abb3 ,illustration       
originally stated ,see note page #abf4  
,that  statement was removed1 and the   
actual note from page #abf was moved to 
its place with the illustration4    ,p4 
#agd3 444--duplicate of later line      
occurred at ,l',aigle1 ,france1  in     
#ahjc4 ,between two appeared at this    
spot4 ,possible missing text  where the 

line occurred4    p4 #bcc3 period of    
#b;d #bj;h #dh4im--carat 77 indicates   
that the  letter immediately following  
appears as a superscript4    ,data in   
tables retained as in original1 but may 
be incorrect--for  example1 the escape  
velocity of ,mars1 represented as #a4e  
miles per  second in ,table ,i1 is      
closer to #c4a4