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fyxmll Wimmxi^ Jibatg 



THE GIFT OF ^ Til . 

Hetirg 119. Sage 


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Cornell University Library 

3 1924 031 323 797 

Cornell University 

The original of tiiis bool< is in 
tine Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 



























The present book, which stands in the joint names of 
my wife and myself, is almost wholly the work of my 
wife, cis circumstances prevented my taking any further 
part in it soon after it was commenced. 

It is not intended as a text-book to teach astronomy ; 
it has rather been written with the hope that the reader 
may be drawn by it to study astronomy for himself. 
The old story tells us that King Alfred was first stirred 
up to a desire to learn to read by his rpother showing 
him the pictures in a beautifully illuminated book. And 
so it has been our desire to point our readers to some 
of the pictures presented to us by the heavens, in the 
hope that they may desire to spell out their meaning for 

For ' the heavens are telling ' stories of interest, 
stories of wonder, if we but have the eyes to see and 
the ears to hear. It is not necessary to be a rich man, 
and to build a great observatory, in order to become 



an astronomer. There were great astronomers before 
ever the telescope was invented ; there have been 
astronomers even in our own days, there are some still 
Hving, whose work needs no other instrument than their 

In the first book we have dealt with some of the 
lessons — only with some of them — which the open 
heavens can teach us, if we watch them with attention 
and thought. With no telescope, with no apparatus, 
there is still much that we can learn. It is true that the 
particular lessons treated of in this book were all learned 
by our forefathers long ago. But it will be a real benefit 
to ourselves if we work them out afresh, and to any one 
who has a soul capable of appreciating the wonder and 
beauty of Nature in her sublimest aspect, it cannot fail 
to be the source of real pleasure. 

In the second book, a few — only a very few — of 
the lessons which we have learned concerning the sun, 
by means of the telescope, the spectroscope, and photo- 
graphy, are touched upon ; particularly with regard to 
the question so often asked nowadays whether sun- 
spots have any influence on the earth. The third book 
is devoted to a few particulars respecting the planets 
and other members of the solar system ; the design 
being to point out wherein they differ from the world 


whereon we live. The concluding book touches lightly 
on the structure of the stellar universe, and is intended 
to suggest, rather than to describe, the vastness and 
mystery of that great starry system of which our sun 
and his family occupy a small and insignificant corner. 
We start, therefore, with a little plot of ground upon this 
earth of ours, and watching from thence the sun, moon, 
and stars circling round it, we learn that our earth is a 
vast globe floating unsupported in space. Next, we 
study the sun — that other vaster globe that lights and 
warms us. Then we look round on our companion 
worlds, also like ourselves dependent on the sun for 
light and heat, and find that there is not one that is 
probably the home of intelligent life. So far, we learn 
of the greatness of the earth and of its importance ; 
last of all we go into the depths of space to learn how 
small it is, how insignificant. 

Our grateful acknowledgements are due to the many 
friends who have helped us in the matter of the illustra- 
tions : to the Astronomer-Royal, Sir W. H. M. Christie, 
K.C.B., for Plates XL, XVII., XIX., XXV., XXVI., 
to the Royal Astronomical Society, for permission to use 
Plate XLIV., the reproduction of four of the late Mr. 
N. E. Green's drawings of Mars, also Plates XXIV. 


and LX.; to M. E. M. Antoniadi, for Plates XL I. and 
XLIII. ; to Miss Gertrude Bacon, for Plate XLII. ; to 
Professor E. E. Barnard, for Plates LXVI. to LXXI. 
inclusive ; to Mr. Franklin Adams, for Plate LIV, ; to 
Lord Hampton and the Hon. Miss Edith Pakington, 
for Plate XX VH.; to Mr. F. W. Longbottom, for the 
photograph of the Plough stars in Plate LV. ; to 
Miss L. Martin- Leake, for Plate XXVHL; to Professor 
£:. C. Pickering, for Plates XIL and XXIX. ; to the 
Rev. T. E. R. Phillips, for Plates XXXVHL, XXXIX., 
and XL., ; to M. Puiseux, for Plates XLVL, XLVII., 
XLVIII., and XLIX.; to Professor Ritchey, for Plates 
L., LIX., and LXXI I. ; and to Professor Max Wolf, 
for Plates LVII. and LXIV. 


St. John's, 

London, S.E., 

September, igo8. 




I. The Story told by the Sun 19 

II. The Story told by the Moon .... 42 

III. The Story told by the Stars .... 58 

IV. The Story told by the Planets .... 74 


V. The Story told by the Sun's Surface . . .103 

VI. The Story told by the Sun and Planets together 119 

VII, The Story told by Sun-spots . . . .131 

VIII. The Story told by the Sun and Moon together 144 

IX. The Story told by the Sun's Broken Light . 164 

X. The Story told by the Sun and Earth together 178 


XI. The Story told by the Planet Jupiter . . 197 
XII. The Story told by the Planet Saturn . .212 




XIII. The Story of Vknus and Mars .... 225 

XIV. The Story told by the Moon .... 246 
XV. The Story told by Comets 263 


XVI. The Story told by the Star in the Centaur . 277 

XVII. The Story told by the Stars in the Plough . 292 

XVIII. The Story told by the Nebulae .... 305 

XIX. The Story told by the Milky Way . . .327 

Index .353 




XXXIV. Solar and Stellar spectra Frontispiece 

XXVII. Total solar eclipse in Lapland, August 9, 1896 .... 148 

XXVIII. Telescopic view of Corona, May 28, igoo 151 

XXIX. Eruptive and quiescent prominences 156 

XXXIX. Jupiter, February 2, 190S, by the Rev. T. E. R. Phillips . . 205 

XL. Jupiter, February 10, 1908, by the Rev. T, E. R. Phillips . . 209 

XLIII. Mars, by M. E. M. Antoniadi 232 

XLIV. Mars. Four drawings by the late Mr. N. E. Green . . .238 


An open-air Observatory 25 

The divisions of the clock-face, the compass, and the circle .... 26 

Rising points of the Sun on the Eastern horizon 31 

Varying lengths of the shadow at noon 31 

Apparent daily paths of the Sun at different seasons of the year ... 32 

Proof that the Earth is round 39 


The bow of the crescent Moon points to the Sun 40 

Photograph of the Full Moon 47 

Progress of the Moon during the month 48 


The Constellation of Cassiopeia 63 

The Constellation of Taurus 64 

Photograph of Trails of Stars near the North Pole 69 

Photograph of the Constellation of the Southern Cross 70 





Path of Mars amongst the stars in 1907 83 

Path of Jupiter amongst the stars in 1907 . , 83 

Elongations and conjunctions of an inner planet ...... 84 

Oppositions and quadratures of an outer planet ...... 84 

Which ran : The man or the tree ? • 97 

The Sun's atmosphere is deeper at its rim than at its centre .... 98 

The forward motion of an outer planet ....... 98 

The stationary points of an outer planet ....... 98 

The retrogression of an outer planet ........ 98 

The annual parallax of a star . 98 


Flamsteed's method of observing the sun ....... 109 

Dallmeyer photo-heliograph of Greenwich Observatory 109 

Passage of a Sun-spot across the Sun's disc . . . . . . . I lo 

Photograph of the Sun, July 14, 1905 113 

Granulation of the Sun's surface 114 

Granulation of the Sun's surface, showing blurring . . . . .121 


Sun setting behind St. Paul's .122 

Binocular vision ........... 122 

Determining the distance of the Moon . 122 

The relative distances of Mars and the Earth from the Sun . . . .122 

The diurnal parallax of Mars 122 

The diurnal parallax of Eros . 122 

Plan of the Solar S3rstem 133 


Distribution of Sun-spots in solar latitude 13^ 

Photographof a group of Sun-spots, July 31, 1906 130 

Photograph of a group of Sun-spots, August 3, 1906 140 


The Corona of May 18, 1901 (southern region) leo 

The Corona of May 18, 1901 (eastern region) 160 




Path of rays throngh a prism . 169 

Simple spectroscope ........... 169 

Flan of simple spectroscope 169 

Coincidence of D lines with sodium lines 170 

Reversal of D lines in spectram of limelight 170 


Carves of Snn-spot Areas and Annual Rainfall 181 

Corves of Sun-spot Areas and Magnetic Daily Ranges 181 

Fhotc^raphic trace of magnetic storm, February 13, 1892 . . . .182 

Corona of January 22, 1898, showing long rays 199 


Jupiter and his satellites 200 


Saturn 223 


Photograph of Douglas, Isle of Man, from balloon 224 

Photograph of the Medway, Kent, from balloon 224 

Drawings of Venus in 1871 247 


Photograph of the Moon, April 5, 1900 24S 

Photograph of the Moon, September 12, 1903 253 

Phob^raph of the Sea of Clouds 254 

Photc^raphof the Moon's chief mountain ranges 257 

Photograph of the lunar crater Copernicus 258 


Photograph of Daniel's comet, August 10, 1907 267 

Donati's comet, October S, 1858 268 

Forms of cometary orbits .......••• 285 

Halley's comet, from the Bayeuz tapestry 285 




Photograph of the Milky Way around Alpha Centauri 



Photograph of the stars of the Plough 301 

Drift of the stars of the Plough 301 


Photograph of the great nebula in Orion ....... 302 

Photographs of the nebulosities in Orion . 309 

Photograph of the great nebula in Andromeda . . . . . .310 

Photograph of the nebula about Nova Persei, September 20, 1901 . . . 315 
Photograph of the nebula about Nova Persei, November 13, igoi . . . 315 

Photograph of the comet of 1882 .316 

Astrographic telescope of Greenwich Observatory ..... 321 

Photograph of the stars of the Pleiades . . . . . . .322 

Photograph of the nebulosities of the Pleiades ...... 325 

Photograph of the exterior nebulosities of the Pleiades ..... 326 


Photograph of the Milky Way in Cygnus 
Photograph of the region of Rho Ophiuchi . 
Photograph of the region of Theta Ophiuchi 
Photograph of the great rift near Theta Ophiuchi 
Photograph of the great star cloud in Sagittarius . 
Photograph of the small star cloud in Sagittarius . 
Photograph of the region of cluster. Messier 1 1 
Photograph of the Veil nebula in Cygnus 





' T^HE sweet singer of Israel' long ago proclaimed 
-■■ that the heavens had a message for us, some- 
thing to say : 

The heavens declare the glory of God ; 
And the firmament showeth His handywork. 
Day unto day uttereth speech, 
Night unto night showeth knowledge. 

Yet David was well aware that though the heavens had 
this testimony to offer, it was not expressed in sounds, 
He was not dreaming of any fancied 'music of the 
spheres,' such as Shakespeare makes Lorenzo refer to in 
The Merchant of Venice : 

Look, how the floor of heaven. 
Is thick inlaid with patines of bright gold ; 
There 's not the smallest orb, which thou behold'st, 
But in his motion like an angel sings. 
Still quiring to the young-eyed cherubins : 
Such harmony is in immortal souls ; 
But, whilst this muddy vesture of decay 
Doth grossly close it in, we cannot hear it. 

David, on the contrary, knew 

There is no speech nor language ; 
Their voice cannot be heard. 

19 B 2 


And yet, in a very real sense, they were speaking to 
those who cared to listen : 

Their line is gone out through all the earth, 
And their words to the end of the world. 

This message of the glory of God, this testimony to 
' His everlasting power and divinity,' is the first, the 
most important, word which the heavenly bodies have to 
make known to us. But they have also many other 
' words,' much other ' knowledge,' to declare ; equally 
without speech or language, or voice that can be heard, 
and yet not hard to be understood if we listen for them 
in the right way. 

And men began so to listen from the very begin- 
ning ; and astronomy, the study of the heavenly bodies, 
began when there was first a reasoning human being to 
look upon them. For there are two great lights in the 
sky which it is impossible to overlook : the sun and the 
moon. The first discoverer of the sun and of the moon 
must have been none other than the first man, the first 
living creature possessing intelligence, the first being 
' made in the image of God.' 

And he must have made this discovery in the begin- 
ning of time. For the first use which man made of his 
discovery of the sun and moon was to measure time. 
Until he had noticed the sun, and that he seemed to 
move, and was sometimes present and sometimes absent, 
it was not possible to measure the lapse of time at all. 


So far as men were concerned, there was no time before 
that. Astronomy therefore began with the first man, 
and at the beginning of time ; for without the sun and 
moon there is no means of dating, of reckoning time. 
Our time is given us by the two great lights. It was for 
this purpose that they had been originally made, for the 
command had gone forth : 

' Let there be lights in the firmament of the heaven 
to divide the day from the night; and let them be for 
signs, and for seasons, and for days, and years.' 

But how is the sun ' for signs and for seasons' ? It 
is quite clear how he is ' for days ' ; for when he is 
present it is light, it is day ; and when he is absent, it is 
darkness and night. 

At first sight it is not easy to see what the sun can 
tell us more than this, the difference between day and 
night. The sun himself does not change in appearance. 
He looks to-day exactly as he did yesterday, and one 
part of the sky across which he seems to move looks 
exactly like another. Since no voice is heard in his 
story, it must be spelled out as from a writing. But 
how can we spell out a story where all the letters from 
A to Z are alike in shape ; where all the letters, words, 
and sentences are joined together in a chapter con- 
sisting of one unbroken, unswerving line ; where one 
chapter is very like another ? 

This was the difficulty which the first beginners in 


astronomy had to encounter when they tried to spell 
out the story that the sun had to tell. But little by 
little they were able to do it, and we may, if we will, 
put ourselves in their place, and watching the sun, as 
with their eyes, read for ourselves what it was that the 
sun had to tell them. 

The book in which the story told by the sun is 
written is the open sky, and the writing is simply the 
apparent place in the sky where we see the sun at this 
time or at that. The writing, therefore, is not all over 
the page, the margins are broader than the text, and the 
chapters are not all exactly alike. The sky, too, seems 
to rest on the earth at its lower edge, and to rise from it 
like a dome. The lower edge of the sky, therefore, is 
marked out by objects on the earth ; and though one 
part of the sky overhead looks, during the daytime, just 
like another, the earth itself distinguishes one part of 
the skyline from another. 

Our first forefathers, then, when they tried to spell 
out the story which the sun had to tell them, must have 
taken their stand in the open, where they could see the 
sky from horizon to horizon, and their first measuring 
instrument must have been the apparent circle of the 
earth. Let us do the same, and see what the sun can 
tell us under such conditions. 

For myself, a dweller in the smoke-laden air of 
London, shut in by houses, the nearest spot from whence 


I can watch the whole open page upon which the story 
told by the sun is written, is afforded by the ' Hilly 
Fields,' a pleasant little park close at hand, on the top of 
a rounded hill, that rises, like a miniature Ararat, above 
the flood of bricks and mortar which has submerged all 
the region round. Let us take our stand there, and see 
what it is that the sun has to tell ; what the story that 
he writes for us on the face of the sky. (See Pirate I.) 

Towards the east the Hilly Fields look down rather 
sharply on the valley of the Ravensbourne, the little 
river that separates Surrey from Kent, flowing due 
north to enter the Thames at Deptford Creek. The 
tower of the town hall at Catford — the ford so shallow 
that a cat would not object to cross it — rises almost due 
south of us. We can trace the course of the stream by 
the green spaces of the Recreation Ground, through 
which it winds, until its course is broken by a tiny fall, 
just at the foot of the venerable tower of St. Mary's 
Church, Lewisham, nearly south-east of our position. 
Further north, the course of the stream is hidden, but the 
hills on the opposite side of the little valley are clearly 
seen, and many good landmarks present themselves. 

Starting from the north, there is, first of all, almost 
due north, the spire of St. John's Church, in the Lewis- 
ham High Road. Passing round to the east, Trinity 
Church, Blackheath Hill, is 29° from the north point; 
the spire of the Roman Catholic Church in Croom's 


Hill lies 4° nearer the east. A little north of Trinity 
Church rise the four tall chimneys of the generating 
station which the London County Council so thought- 
fully erected exactly on the meridian of Greenwich 
Observatory. From 37° to 40° stretch the roofs of 
Lansdowne Place. The trees of Greenwich Park hold 
the horizon line next, and no special landmark can be 
discerned until we come to the spire of St. John's 
Church, St. John's Park, at 58°. All Saints' Church, 
Blackheath, comes next at 66°; and St. James's, Kid- 
brook, at 70°. The great line of Shooter's Hill forms a 
background to these spires, and carries the tall chimney 
of the Brook fever hospital on its western slope at 
74°. St. Michael's, Blackheath Park, stands at 77°, 
and the delicate spire of St. Margaret's, Lee, at 78°; 
the Wesleyan Church, Albion Road, at 82°; Christ 
Church, Lee, stands at 86°; Trinity Church, Lee, at 
91°. Farther south, the Congregational Church in the 
Lewisham High Street is at 111°, whilst St. Mary's, 
Lewisham, is at 130°, and St. Mildred's, Burnt Ash Hill, 
lies almost midway between the two at 123°; the 
Catford Town Hall stands at 174°, and the Board 
School at Rushey Green is precisely due south. 

These spires and towers and houses stand up 
against the eastern sky as marks to which we can refer 
the sun when he comes up from the underworld at the 
break of day. Each day, then, is a separate chapter in 

I'LATI-: I. 


J,^-i.^..>.^../,^.aa?. ^,.",J, .i/&t...,^W. ,.t. 



The 'Hilly Fields' Park, London, S.E. Looking towards {<!) the north-east, and 
(b) the south-east. 




Relation of ihe Divisions of the Clock-face, the Compass, and the Circle 



the sun's story, each rising point is the heading and 
opening of the chapter, and there are 365 chapters 
in all. 

We may begin to read our book where we will, and, 
for the greater convenience in the reading, we will begin 
in spring-time. It is March 21, and the sun rises at six 
o'clock. We see it first appear over the high ground to 
the east, midway between Trinity Church, Lee, and St. 
Mark's ; in a word, almost due east of us. He does not 
climb up straight into the sky, but obliquely, with an 
ascent of 4 in 5, or at an angle of 38^°, equal to the 
angle between the figure XII on a clock and a point 
nearly 6^ minutes from it. {See Plate II.) 

When the sun rises the next morning, his rising point 
is not quite the same, but is shifted slightly towards the 
north. Morning by morning his rising point shifts, and 
in less than a week the sun rises over Christ Church, 
Lee. A fortnight later, and St. Margaret's, Lee, marks 
his point of first appearance, and two mornings later still, 
St. Michael's, Blackheath, Every succeeding morning 
shows a slight movement northward of the rising point, 
until, a month after the first observation, the spire of St. 
James's, Kidbrook, gives the signal for the sun's first 
appearance, and we see that the paths followed by the 
sun, in his daily travel from east to west, are not the 
same on succeeding days, but lie close to each other, 
much as cotton is wound upon a reel. 


But, as the summer draws on, this northerly move- 
ment becomes less marked. The movement amounted 
to nearly 20° in the first month of observation ; it is 
only a little over 14° in the second month, and after that 
it becomes very slow. The Colfe Grammar School is 
reached in the middle of June, when the sun rises 40° 
north of due east, only 5° short of the north-east point. 
And now we seem to have come to the end of the reel, 
and one turn of the cotton is piled on the top of the 
preceding one, so as to start another layer, for in ten 
days in June there is less movement than was observed 
from one morning to the next in March, and in the last 
ten days of June this movement, small as it is, is not 
northward, but back again towards the south. But 
though the sun rises now so far from the point of the 
horizon where he rose in March, his daily path, as he 
moves upward in the sky, still slants as it did then, at an 
incline of 4 in 5, that is, at an angle of 38^° to the 
horizon. {See Plate III., fig. i.) 

Day by day, during these three months, March 21 
to June 21, the sun has risen earlier. It rose at six 
o'clock on March 21, it rose before five on April 21, and 
at four o'clock on May 21. After this there was little 
change in the time of its rising, and it was a quarter to 
four when it rose on June 21. 

Day by day, during these three months, the setting 
points of the sun have moved northward along the 


western horizon, to correspond with the movement of 
the rising points along the eastern, and the sun has 
set later each day. On March 2^1 he set soon after 
six o'clock, and very nearly due west. On April 2 1 he 
did not set until after seven, and he went down 19° 
north of the west point. On May 2 1 it was nearly eight 
o'clock before he set, at 33^° north of west. On June 21 
he did not go down until eighteen minutes past eight, 
and his setting point was 40° north of west. Thus the 
days were longer as the time went by, lengthening out 
from twelve hours in March to fourteen in April, to 
almost sixteen in May, and to sixteen and a half hours 
on June 21. 

But, throughout, the inclination to the horizon of the 
sun's path was the same at rising, the same at setting : 
an inclination of 4 in 5, or of 38^°. 

At midday, when the sun was highest in the sky, 
and the shadows cast were shortest, he was always due 
south, straight over the Board School at Rushey Green. 
And on March 21, when he rose almost due east 
and set almost due west, he reached just this same 
elevation of 38^° from the horizon when he was due 
south ; an upright stick four feet long would cast a 
shadow five feet in length ; the sun's elevation was four 
in five. 

But his noon-tide elevation on April 21 was very 
different. Then it was necessary to look up much 


higher in order to see him, and the shadow cast by a 
stick four feet in length, instead of being five feet long, 
was only three feet four inches. By May 21, the sun's 
elevation at noon was greater still, and the shadows 
were shorter : two feet five inches instead of five feet. 
On June 21 he was higher still, and the four-foot staff 
would throw a shadow only very little more than two 
feet long. {See Plate III., fig. 2.) 

After June 21 the sun begins to turn back over his 
old course ; a second layer of cotton is being wound over 
the first. Each morning his rising place is a little farther 
to the south ; each midday his height is a little less, and 
the shadows are a little longer ; each evening his setting 
place is a little farther south. His path on July 23 is 
the same as it was on May 21 ; on August 22 as on 
April 21 ; on September 23 as on March 21. He then 
again rises about due east, attains a height of 38^° at 
midday, and sets again about due west after a twelve- 
hour day. 

But as autumn fades into winter he still continues 
his southerly course. He rises above the Congregational 
Church in the Lewisham High Street on October 28 ; 
the day is only ten hours long, and his setting point 
is 21° south of west. So, day by day, his rising point 
moves southward, his daily path is shorter, his midday 
height less, his setting point closer to the south-west; 
until, by December 22, he has reached his limit, and 
















rises over St. Mary's Church, Lewisham, at six minutes 
past eight; he is' only 15° high at noon, a four-foot 
staff casting a shadow close on fifteen feet in length, 
and he sets, after a day of seven hours and three- 
quarters, 40° south of the west point. Then again he 
turns back, winding his coil northwards, until the 
book of his year is finished in March, and a new year 
is begun. 

Shakespeare refers to this change in the sun's place 
of rising when' he describes the meeting of the con- 
spirators in the orchard of Brutus, before the dawning 
of that fatal day whereon great Caesar fell. The time 
is supposed to be not yet three o'clock in the morning, 
and the date is the Ides of March, when the sun should 
not begin to rise until about three hours later; but 
Decius says : 

Here lies the east : doth not the day break here ? 

Casca says, ' No,' and Cinna replies : 

O, pardon, sir, it doth ; and yon grey lines 
That fret the clouds are messengers of day. 

Casca rejoins : 

You shall confess that you are both deceived : 
Here, as I point my sword, the sun arises ; 
Which is a great way growing on the south. 
Weighing the youthful season of the year. 
Some two months hence up higher towards the north 
He first presents his fire ; and the high east 
Stands, as the Capitol, directly here. 


But long before the day of either Shakespeare or 
Caesar, men were wont, both in this land and in others, 
to ' weigh the season of the year ' by the place of the 
sun's rising behind the landmarks of the horizon. What 
we have been doing on the Hilly Fields, and using 
the church spires of St. Margaret and St. Mary, the 
chimneys of the London County Council, or the water 
tower at Catford, in the doing, so men did long ago 
on Salisbury Plain, though we do not know whether the 
men were the Britons whom Caesar fought, or another 
and unknown race. For this they reared up the great 
circle of stones called Stonehenge. Just as they used 
the horizon as their measuring instrument, and the 
great stones as a graduation on it, so we use the 
horizon, with the spires and chimneys and towers out- 
lined on it, as our measuring instrument. And the sun 
repeats to us the story that he told long ago to them. 

This, then, is the first story which the sun tells to 
men ; namely, that he has his appointed paths in the 
sky. He does not cross it at haphazard, rising any- 
where, setting anywhere ; but for each day in the year 
he has a definite rising point, a definite setting point, a 
definite path between the two. For each day in the year 
there are definite points of the compass at which the sun 
rises and sets, and these points are the same for that day 
year after year. There is a defined region on the 
eastern horizon along which the sun's rising shifts in 


regular order, and beyond which it never strays. In the 
words of Job, ' the dayspring is made to know its 
place.' The path of the sun up the sky, or down it, 
slants each day to the horizon in exactly the same way. 
The daily paths of the sun through the sky in the year 
form an unshifting, unchanging band of even width, 
the same band from year to year ; and the width of this 
band is 47°, or like the arc between two clock-hands 
pointing nearly eight minutes apart. {See Plate IV.) 

If we leave the Hilly Fields and go northward 
towards the pole, or southwards towards the equator, 
we find that each * dayspring' throughout the year has its 
appointed 'place,' just as it had at the Hilly Fields. The 
slant of the sun's path has altered, sloping still more 
as we go north, and becoming more erect as we go 
south. The sun's band is unaltered ; the difference 
between the heights of the sun at noon in midwinter 
and midsummer is always the same : 47°, or nearly 
eight minutes between the hands on our clock. • The 
band of the sun's daily paths is unchanged in breadth ; 
it is merely swerving down or up in the sky. 

These daily paths of the sun tell our directions on 
the earth. For he rises in the east, — on March 2 1 and 
September 21 due east. When he has reached his 
greatest height for the day, no matter what the season 
of the year, he is due south. He sets in the west, — on 
March 21 and September 21 due west. 


The sun also marks out for us two great circles in 
the sky, the equator and ecliptic. The first is the 
central line of the sun's band, which, passing through 
the east and west points, is to the celestial vault 
what the terrestrial equator is on the earth. The one 
is, indeed, a projection of the other, and their poles 
point in the same direction. The ecliptic is another 
circle intersecting the celestial equator and so inclined 
to it that the angle between the two circles is half 
the width of the sun's band ; that is to say, the 
angle between them is 23^°, or the angle that there 
is between two clock-hands pointing nearly four minutes 

And the sun tells us what is the shape of the earth. 
If the earth were flat, then the sun's path, as he rose 
in the east, would be inclined to the horizon line at 
the same angle wherever we were. It would also be 
inclined at a constant angle to the vertical, the direction 
given by a plumb-line, which is, of course, at right 
angles to the horizon line. But we find that as we 
move northward or southward the inclination of this 
path varies. As we go north, the sun mounts the sky 
more gradually ; as we go south, the slant of his path 
becomes steeper. 

But as it is the same sun that we see, whether 
we watch him from Cape Wrath, or from Land's End, 
or from Gibraltar, and the path that he follows is the 


same in each case, it must be the plumb-line, and by 
similar reasoning the horizon also, that changes its 
inclination. The earth, therefore, is not a level plane, 
but its surface at one place is inclined at an angle to 
its surface at another. And this is true of the surface 
of the water as well as of the land, for the sun's path 
shows this change of inclination to different parts of 
the sea just as clearly. The surface both of land and 
sea is thus gently bent into a great and regular curve, 
showing the earth to be a globe, just as the vault of 
heaven above us appears to be a hollow sphere. {See 
Plate V., figs, i and 2.) 

The sun also tells us our latitude on the earth. For 
just so far as the path that the sun traces out in the sky 
on March 21 or September 21 lies above the horizon, 
just so high as is the sun at noon on one of these days, 
just so many degrees of latitude lie between our stand- 
point and the north pole of the earth. In much the 
same way the sun tells us the size of the earth. The 
problem was actually worked out more than two 
thousand years ago by Eratosthenes, who noticed that 
the sun was exactly overhead at noonday at midsummer 
at Syene, now Assuan, where the first cataract of the 
Nile occurs. At the same time the sun was 7 degrees 
and one-fifth of a degree from the zenith, i.e. the overhead 
point, at Alexandria, due north of Syene. The distance 
between the two places in a north and south line had 



been measured as 5,000 stadia. Since 7^° is the fiftieth 
part of 360° the entire circumference of the earth must 
be 250,000 stadia. Our present measures give this 
circumference as nearly 25,000 miles ; whence 10 stadia 
should equal one mile. The sun therefore told men not 
only the shape of the earth, but also its size, 

A question that men very early asked was, ' Where 
does the sun go to when he sets ? whence does he come 
when he rises ? ' The answer is soon given : he comes 
from the ' under world ' ; he passes below the earth. His 
path during the twenty-four hours is a complete circle, of 
which we see only the part that he traverses during the 
day. In winter time, when he is up for less than eight 
hours, two-thirds of that circle is below the earth ; in 
summer time, when the day is sixteen hours long, only 
one-third of that circle is below. ' His going forth is 
from the end of the heaven, and his circuit unto the ends 
of it.' 

The sun therefore tells us that there is a clear way 
under the earth. Does that clear way extend every- 
where, right from the north to the south ? That 
question the sun cannot answer for us. Watching him 
from the Hilly Fields, it would be possible to imagine 
that, far to the north, the earth rested on some great 
pillar, or support, and far to the south upon another. 
This was the very idea which the Babylonians held of 
old: they thought the earth stood upon two great 


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mountains, and that the sun passed every night through 
a vast tunnel or valley that lay between them. Two 
great scorpion men — so they imagined to themselves — 
stood on either side of this tunnel, or valley, at the gate 
of the west, and guarded the entrance to the under 
world, the abode of the dead. 

So the sun has a full story to tell, a story told merely 
by the path which he follows day after day across the 
unmarked heavens. He tellS men that the ea,rth on 
which they dwell is a round globe, some 25,000 piiles in 
circuit; he tells them that, for the most part at least, 
the earth is unsupported in space ; there is a clear way 
under it. The sun, too, is not free to wander anywhere 
in the sky ; he has a rigidly appointed path, a path 
which differs indeed from one day to the next, but is 
definitely fixed for each day throughout the year. For 
these changes of path run through a definite cycle which 
is completed in a year ; after which they recur again in 
their former order. The movements of the sun are all 
in obedience to an unswerving law. He is set 'f6r 
signs and for seasons, and for days and for years.' 


How like a queen comes forth the lovely moon, 
Walking in beauty to her midnight throne ! 


WE do not need the help of the telescope to demon- 
strate to us the difference in appearance between 
the sun and the moon. They are the ' two great lights ' 
set in the heavens ; but whilst the ' greater light ' is 
overpoweringly bright, we can look without flinching at 
the gentler radiance of the ' lesser.' From the earliest 
time that there have been men upon the earth, they have 
recognized two things about the moon. Her face was 
marked with spots or stains, showing like a map — marks 
that never changed. But whilst these marks or spots 
did not change, the moon herself changed. Sometimes 
she presented a broad, shining face, as round as the 
sun himself. Sometimes she showed only a narrow arch 
of light, the thin outline of a semi-circle. 

These changes, or ' phases,' of the moon are obvious, 
and it is impossible to overlook them ; they were as 



manifest to our forefathers before the Flood as to our- 
selves to-day. They are the letters by which the moon 
spells out her story to us ; and the reading of that story, 
the intelligent watching of the phases of the nioon, is 
astronomy — a small department of astronomy indeed, 
but quite a real one. The unintelligent watching of the 
phases of the moon produces myth and fable — very 
beautiful myths and fables, it may be, but unreal and 

One of the most beautiful of these lunar myths was 
told by the Babylonians in the song of the Descent of 
Istar. Istar is described as the daughter of the Moon 
god, and among the Phoenician nations was called 
Ashtoreth, sometimes even Ashtoreth Karnaim, or 
' Ashtoreth of the Horns.' The legend runs that Istar 
fixed her mind to go down 

To the House of Eternity, 
To the House men enter — but cannot depart from ; 
To the Road men go — ^but cannot return. 
The abode of darkness and famine, 
Where earth is their food : their nourishment clay, 
Light is not seen: in darkness they dwell. 
Ghosts like birds flutter their wings there, 
On the door and gateposts the dust lies undisturbed. 

Bright Istar descended through seven portals, but as 
she passed through each the porter made her shed, bit 
by bit, her jewels and her shining raiment, until when 
she reached the abode of darkness, she was bereft of 


everything. Then in the full assembly of the gods, 
the Sun came along with the Moon, his father, and 
weeping, spoke unto Hea, the king of the under world, 
and he bade that I star should be allowed to come forth 
again. Again she passed back through the seven 
portals, and as she passed, the porters readorned her, 
bit by bit, with her jewels and her shining raiment, 
until at last she stood forth again, ' walking in beauty 
to her midnight throne,' in all her brightness and 

The story is beautiful, but it is the story of fancy, 
not of knowledge ; it is not the story that the moon is 
writing for us to read. What she really tells us is that 
her changes of brightness depend absolutely upon the 
changes in her seeming distance from the sun. He it is 
who is responsible for her growth in breadth and bright- 
ness, from the thin arch of light which she shows at one 
time, to the full round shield we see a fortnight later ; 
and then to her decrease again from that full circle to 
the thin curve in the fortnight which follows. 

We shall see this plainly if we watch the moon night 
after night. It may be that some evening, soon after 
the sun has set, we see the moon as a narrow crescent 
in the western sky. If we think of the bright arch as a 
bow stretched for the shooting, then the point of the 
unseen arrow would be directed towards the place 
where the sun, now below the horizon, must be. The 


middle of the arch of the bow looks towards the sun. 
{See Plate VI.) 

The next evening, when the moon is first seen, she 
is higher above the western horizon than she was on the 
first evening, and she sets later. At the same time, her 
arch of light is not quite so narrow. The third evening 
she sets later still, and her bow is broader. Now she is 
still above the horizon when the stars begin to appear, 
and we can see her position with respect to them. 

The same change continues to progress on the 
following evenings : each succeeding night we see that 
the moon has moved towards the east quite a long way 
amongst the stars — fully twenty times her own diameter. 
Each succeeding night we see that she is higher in 
the sky at the time of sunset, she sets later, and 
fuller and rounder does her disc become. At length the 
time comes when she is the entire breadth of the sky 
away from the sun ; she rises as he sets, and does not 
set until he is about to rise on the following morning. 
She rides the sky the whole night through, and her circle 
is complete; she is 'full.' Then is she truly the queen 
of night. Sometimes the sun and the full moon are 
seen together, the one resting on the western horizon 
and the other on the eastern. 

After this the moon rises later night after night, and 
does not set until after the sun has risen on the next 
morning. She still moves eastward amongst the stars, 


but she begins to shrink in her seeming size. When 
seen earlier in the month it was her western edge that 
was rounded, and the eastern dark; now it is the 
western edge that begins to shrink, whilst the eastern 
keeps its full curve. 

Most people looking at the full moon think that it 
looks like a rather sad face. Two large, dark eyes are 
seen above a large and somewhat distorted mouth, 
twisted with a rather pained expression, towards the 
right of the face. Over the left eye, and quite near the 
side of the face, is seen a small, round, dark spot. This 
small spot was observed when the moon was only a 
few days old, but it is not seen long after the moon 
has become full. As the light passes from the more 
westerly edge, it withdraws from this spot, which is 
not seen again until the early days of another month. 
{See Plate VII.) 

During the mornings of the later part of the month 
the moon rises later and later, appearing to come 
closer and closer towards the sun, and at the same 
time the narrower becomes the arch of light which she 
displays, until she is seen, just before daybreak, a mere 
thin, semi-circular line of light, slanted towards the 
eastern horizon, where the sun is about to appear. The 
next three or four nights no moon is seen at all ; morning 
and evening the sun rides the sky alone. Then comes 
an evening when once again a narrow crescent is seen in 


Photograph of Full Moon (erect as seen in the sky) 



o 5 





S to T 

I a 










the sky, with its bow bent towards the western horizon 
where the sun has just gone down. It is by the associa- 
tion together of these several things that the moon tells 
us her story — tells us that she shines by no light of her 
own, but by reflecting to us the light of the sun. 

We know these things by seeing that in every month 
there is a continual change in the position of the moon 
in the sky relative to the sun and to the stars, and in 
the shape of the illuminated figure which she shows us. 
In the first part of the month she is seen in the sky 
when the sun sets, or before, and day by day she sets 
later, thus getting farther and farther away from the 
sun. Day by day she also gets fuller and fuller. Then 
comes the time when she is exactly opposite the sun, 
rising as he sets and setting as he rises ; and at this 
time of the month she is full, because she is turning the 
same face to the sun as she turns to the earth. After 
this she rises later and later every evening, and appears 
to come closer and closer to the sun on the other side, 
and at the same time her illuminated face begins to 
diminish. There is no way of accounting for this 
invariable association between the apparent place, relative 
to the sun, of the moon in the sky, and the change in 
her light, except by supposing that she is herself dark, 
and reflects his light. {See Plate VIII.) 

The moon also tells us that she is a round globe, not 
a mere flat disc, like a plate. For the change in her 


seeming shape is exactly the change which takes place 
when a dark globe is placed in different positions with 
respect to a strong light ; the curves shown by the 
moon's defective edge are the curves which would be 
shown by the illuminated part of such a globe as seen 
from different directions. 

Yet again, the moon tells us that she moves round 
the earth ; not merely as the sun and the stars seem to 
do — once every day; but she moves past the sun and 
the stars, her seeming motion in the sky day by day 
being slower than that of either star or sun. And as the 
moon moves round the earth she always turns the same 
face towards us ; the markings on her surface do not 
change their shape or, perceptibly, their position ; more 
or less may be visible of them as the moon is more or 
less fully lighted up, but the markings themselves do 
not change. 

This is a wonderful thing to have learned from the 
moon : that she is, of herself, a dark body, and not a 
' light ' at all. If we could imagine that the sun had 
become cold and dark we should never know of the 
existence of the moon, unless we guessed it by noting, 
after very careful watching, that the stars here and there 
were blotted out for a few minutes at a time. We could 
not talk with Croly of the lovely moon walking as a queen 
in beauty to her midnight throne; we should rather 
think that the starry heavens were haunted by a lurking 


thief who was continually pocketing the diamonds of the 
celestial treasure-house, and then dropping them again 
through the holes of his ragged pouch. 

In the legend of the Descent of Istar, seven times 
did she go through the portals of the east, each time 
shedding a portion of her glory ; seven times was she 
seen at the portals of the west in ever-increasing splen- 
dour. So the Babylonians conceived that the moon 
ruled as queen of the night, from her midnight throne in 
the upper world, during the fortnight from half-moon, 
through full, to half-moon again. Then for seven days, 
gradually discarding her glory from day to day, she 
descended towards the abode of darkness, where she 
remained unseen and lost until summoned forth by the 
sun. For seven days more, day by day, her glory was 
gradually restored to her, until, half-full again, she lit 
up the darkest hours of the night. 

For it is the full moon that rules the night : when 
she fully reflects the light of the sun, she gives that light 
to the earth from sun setting to sun rising. In the city 
of the New Jerusalem we are told that 'the city had no 
need of the sun, neither of the moon, to shine in it.* In 
our cities to-day we certainly need the light of the sun, 
but we seem not to need the light of the moon ; in the 
houses and in the streets there are artificial lights 
enough to make us indifferent as to whether the moon 
is shining or not, to make us even unaware of its 


presence. But in the country it is not so : men cannot 
work on the nights when sun and moon have gone down 
together ; men will stumble when they even walk abroad. 
A writer, telling recently of his travels in Russia, 
mentions what seemed to him to be a crowning hardship 
of the poverty-stricken peasants. For, being too poor 
to afford even a rushlight on the long, dark, winter, 
moonless nights, there was nothing possible for them 
to do but to stay in bed from the early setting of the 
sun until the late break of day, even though the hours 
of daylight were too short for all that needed to be done 
in them. 

The full moon is opposite to the sun : she sets as he 
rises, she rises as he sets ; at midnight we may, then. 

Behold the wandering moon 
Riding near her highest noon. 

Through the heaven's wide pathless way. 

When the moon is full she not only gives most light, but 
she gives it for the greatest length of time ; and in the 
night time, when there is no sunlight. Moreover, she is 
up the longest and rides nearest her highest noon in the 
winter time. For then the sun dips lowest below the 
horizon at midnight, and the full moon, being opposite 
to him, climbs to her highest, most nearly to the zenith. 
Within the Arctic Circle, during the long night which 
lasts through the whole winter, though the days are 


unmarked, the months are divided into two fortnights — 
the one when it is always Hght, and the other when it is 
always dark. In the one : — 

Mark, what radiant state she spreads. 
In circle round her shining throne, 
Shooting her beams like silver threads ; 
This, this is she alone, 
Sitting like a goddess bright. 
In the centre of her light. 

She is then Istar, queen of Heaven, reigning in the 
upper world, continuously clad in her shining robes of 
state. In the other, she is Istar of the Descent, shorn 
of her beams, abiding in darkness, and leaving the world 
in darkness. 

Speaking precisely, the moon is ' new ' when she is 
in conjunction, that is, when she is between the sun 
and the earth, and — turning her dark side towards us — 
is invisible. But, generally, the young moon that is first 
visible after conjunction with the sun is termed the 
' new moon,' and such will be the meaning that we will 
ascribe to it. 

The ' new moon ' is, then, a very slender crescent 
of light, so slender that it cannot be seen in sunlight. 
It lies to the east of the sun, and, therefore, is seen over 
the western horizon, a little above the point where the 
sun has very lately gone down. If the conjunction of 
sun and moon occurred eighteen hours before sunset, 
it might be possible to perceive for a few minutes 


before it sets the thin crescent of the moon, in the 
twilight of the same evening ; but if the time between 
conjunction and sunset were less than eighteen hours, 
then the moon's bow could not be seen until the follow- 
ing evening. Thus the interval of time between one 
new moon and another is uncertain by a day. 

Many of the ancient nations — the Jews, Babylonians, 
and Assyrians — used true lunar months ; not months of 
arbitrary lengths, as we do to-day. To these ancient 
nations the month began in the evening : it began with 
the observation of the first thin crescent of the young 
moon. The month contained a number of complete 
days ; but this number was sometimes twenty-nine days 
and sometimes thirty, and they could not tell for long 
beforehand which months would have the one number 
of days, and which the other. 

Our rule for telling the number of days in our 
months runs thus — 

Thirty days hath September, 
April, June, and November, 
All the rest have thirty-one, 
February has twenty-eight alone ; 
But Leap Year coming once in four — 
February's days are one day more. 

No such simple and general rule was possible for the 
Babylonian months, but yet these had several advan- 
tages of their own. There was then no need, with 


Bottom, in A Midsummer Night's Dream, to cry 
out — 

A calendar, a calendar ! look in the almanac, 
Find out moonshine, find out moonshine ! 

For the calendar was based on moonshine, and the day 
was dated according to the amount of moonshine, and by 
the time when the moon rose or set. When the moon 
was growing, and set before the middle of the night, 
those were the early days of the month. When the 
moon was full, and set as the sun rose, or rose as the 
sun set, that was the fourteenth or fifteenth day of 
the month, and then only could an eclipse of the moon 
take place. When the waning moon rode in the 
morning hours of the night, this was a sign that the 
month was drawing to a close, and when it had wholly 
vanished, on the twenty-eighth or twenty-ninth days of 
the month, then only could an eclipse of the sun occur. 
Moreover, from observing on the fourteenth or fifteenth 
days of the month whether the moon set or not before 
the sun rose, it could be judged whether or no that 
month would contain thirty days. We have a report to 
this effect from Balasi, an ancient Assyrian astronomer, 
which runs : ' When the moon is not seen with the sun 
on the fourteenth day of Adar, the day will complete 
Nisan.' And this is interpreted to mean that that 
month of Adar would contain thirty days. 


If we frequently measure the time from one obser- 
vation of the new moon until the next, we find that the 
number of days is either twenty-nine or thirty, so we 
cannot from this find out the true length of the month, or 
learn whether the months are all equally long, since there 
is an uncertainty of a full day in the observation itself. 
But if we try to measure the time of the other phases ; 
if, for instance, we take the time from the waxing moon 
being exactly half full, until the waning moon is exactly 
half full again, we shall find that this ' fortnight ' is not the 
same length in every month. In other words, the moon 
moves more quickly round the earth at some points of her 
path than at others, and she passes through her phases 
at a varying pace ; and being at some times nearer to 
the earth than at others, she sometimes looks larger. 

We do not know if the romantic writers of old 
Assyria treated the moon, upon whom all true lovers 
call, as erratically as do some novelists of the present 
day. Probably not, for they could not have failed to 
know that the young crescent moon is never seen to rise, 
or the thin arch of the old moon to set, and neither 
are ever seen high in the sky. If, in the morning dawn, 
before daybreak, we glimpse in the east a pale arc of 
light, we are sure that it is not the crescent, the young 
moon, but the decrescent, the old moon, soon to be lost in 
the rays of the pursuing sun. And since the moon is 
always the same solid globe, whether it is wholly lighted 


up, or only just touched with a thread of sunlight, it is 
impossible that we should ever see a star through its 
bulk, as the Ancient Mariner declared he had done, 
when he described 

The hornM moon, with one bright star 
Within the nether tip. 

The story told by the moon, therefore, is that the 
heavens contain dark bodies, as well as bright, and that 
she is one of the former, shining not by her own light, 
but by the light shed upon her by the sun. So, lighted 
by him, she travels through space unceasingly, a great 
round ball, unsupported by any pillars ; travels round 
the earth, but always turns the same face towards it, 
though she does not turn the same face always to 
the sun. 


THE day sky is the page on which the sun writes his 
story. His writing does not cover all the page, 
but is kept within an even band of closely inscribed 
text. The margins of his page are very broad and fair 
and clean. 

But if we turn to the night sky, we find that this 
page is written over also, but the handwritings here are 
by other writers than the sun, and the page has no 
margins. We have learnt to understand a little the 
language of the sun's book ; with this knowledge we 
can also begin 

To read the page 
Where every letter is a glittering world. 

The sun has just gone down behind the western bar, 
but his light is left behind. North, east, south, and 
overhead the sky is a deep blue, but in the west there 
is a rosy glow. Nothing else is to be seen. The blue 
deepens and the rosy glow fades ; and, first here, then 



there, perhaps in the darkest east, or the clear zenith, or 
even in the light from the sun long set, there seems to 
be set a pin-point spark of light, fighting for its light to 
shine out even in the overpowering light left by the sun. 
And, as the straggling sunbeams are summoned below 
the western steep, hundreds of other stars spring out, as 
if from ambush, to harass and hustle away the rearguard 
of a retreating force. 

Where do the stars of twilight spring from ? Have 
they been there in ambush all the time, whilst the sun 
was marching across the day sky ? or are they merely his 
camp-followers, keeping to his rear, but straggling over 
the whole region in the midst of which his road lies ? 
We are under no doubt as to whether or not the sun 
is present. He ascends in pomp above the eastern 
bar ; he marches in solitary state across the sky ; none 
but the moon is ever seen to make any approach to him. 
But what about the stars ? Can we tell if they are there, 
in hiding, in the sunlight? Can we tell if these are 
forming an invisible escort to the sun ? If they, too, 
like the sun, write a history of their daily travel, how 
can we tell the different histories, and the different stars, 
from each other ? 

As the daylight fades, the stars are seen not near the 
low east only, but overhead, or in the north, or south, or 
even in the west. They have not, then, rushed up from 
the under world as the sun goes down, but they are there 


already. They have been there, but hidden in the 
sunlight. As we watch them, and the daylight fades, 
we see that they are moving ; whether they are overhead 
or in the east, or south, or west, they are all moving 
towards the western skyline. Above the eastern skyline 
we see new stars climb ; below the western horizon we 
see the stars, that we have been watching, descend. 
Not so in the north. Here all the stars indeed move ; 
but some are moving west, some north, some south, 
and some east. 

We began to read the story of the sun by watching 
his rising in the east. Let us begin to read the stories 
of the stars in the same way. And the first thing that 
we note is a difference between the two. The day-dawn 
is the messenger of the sun : he sends his beams to 
herald his approach. So great is his pomp and 
splendour that, silent as it is, there seems appropriate- 
ness in the expression of one writer that — 

The dawn comes up like thunder. 

But with the stars there is none of this. Just above the 
eastern skyline, one moment there is no star ; the next, 
there is a star. It was not, and it is. And as we watch 
the east, from the extremest south, even to the farthest 
north, we see them thus rising at its every point, a 
single scoiit there, a company here, all coming from 
below and mounting into the sky. 


If we keep our watch on the east through all the 
long hours of the night, we see the silent ascent of 
the stars go on, until the horizon begins to pale, and 
the glitter of the stars seems swallowed up in the 
brightness of the dawn. One or two of the most 
brilliant we can hold steadily until they, too, are lost 
in the rays of the rising sun. 

Are they all different, these stars that we have been 
watching rise through the long night ? Have many of 
them, have any of them, risen for us a second time as 
we watched? How are we to tell one star from another? 
How are we to recognize a star when we see it ? The 
sun needs no label, but how are we to name the stars ? 
We can see no difference between one star and another, 
except in brightness. Can we tell whether the stars, 
like the moon, wax and wane ? 

Then follow one up from the east. Like the sun, 
it climbs the ascent of heaven obliquely; its path is 
slanted to the horizon at the same angle of 38^°, at 
the same inclination of 4 in 5, if we are watching from 
the Hilly Fields, or anywhere in the latitude of London. 
It mounts the sky until it hangs due south, then it 
descends and drops slantingly below the western horizon 
at the same angle that it mounted. If we follow the 
course of another star, it rises, perhaps, from a very 
different point of the eastern skyline, but it slants 
upwards at the same angle as did the sun or the other 


star ; it reaches the highest point of its path when due 
south, and it sinks down below the west by the same 
inclined path. The stars may be of very different 
brightness, they may rise and set at different points of 
the skyline, they may mount to different heights; but 
they all mount and fall at the same steady, even pace, 
by the same slant of path. 

Here, then, are the means by which we may 
distinguish the stars. They do not jostle or hurry 
each other, they keep an even pace, at unchanging 
distance from each other. In the north are many stars 
that do not rise or set, but move round in an unending 
circle ; yet the stars that rise and set never alter their 
distances from these, whilst we see them above the 

The stars never alter their distances from each other, 
and the stars differ in brightness. We can, then, fancy 
patterns or pictures nailed by the stars to the sky, and 
recognize the pattern again by the way the nails are 
driven in. Look, for instance, at the stars in the north. 
There are seven very brilliant stars swinging round in 
the sky every night ; four of them are in a rough oblong 
like a country cart, three others curve like the shaft of 
the cart. These never change in brightness ; we can 
recognize the seven again and again, and call them by 
the name of the Plough, or the Wain, or the Ladle, or 
the Dipper, as the fancy takes us. {See Plate LV.) 









In the same circle swings another set of five stars, not 
so bright, in the shape of a sprawling W. This we may 
fancy marks the Chair of a Lady enthroned in it. {See 
Plate IX.) Farther to the south, amongst the stars 
that rise and set, we see a very little V-shaped group, 
of which none of the stars, except a yellow one at the 
end of one of the prongs, is very bright ; following it is 
another little cluster of six stars, so close together that, 
as Tennyson sings of them, they seem 

Like a swarm of fireflies tangled in a silver braid. 

We may imagine that we have a bull's head, outlined by 
the V-shaped group, and that its brightest/ star is the 
eye of the bull. The little cluster of brilliants we may 
fancy as a cluster of doves, or of maidens, or of grapes, 
sheltering on the shoulder of the bull. A bull's head 
is not really pictured here, any more than a man 
whose name is Smith is therefore an artificer in 
metals, but that is the name that has been given to the 
constellation, or grouping, of the stars. The reason 
why this name was given has a history of its own. {See 
Plate X.) 

So the stars scattered oyer the sky are constellated 
or divided out into groups ; and names, fanciful names 
they seem, are given to the different groups. The 
individual stars are recognized by their positions in or 
near the groups. 


As the stars rise in the east we can recognize them 
by their places in the star groupings, and we can 
definitely tell that they do not rise oftener than once in 
the twenty-four hours. Night after night, as we watch 
them, we see that though, like the sun, they always rise 
with the same slant to the skyline, yet, unlike the sun, 
they do not shift their points of rising. At whatever 
point of the compass a star rises on one night, on every 
other night, and through the whole year round, it rises 
at that same. It makes the same slant in its path as 
does the sun, and makes its round in nearly the same 
time. Nearly, but not quite ; for, as we watch the stars, 
dawn by dawn, that are last seen in the morning twilight 
near the sun, we notice at each break of day they are 
seen for a longer time, until they lose their pre-eminence, 
and other stars, nearer the rising sun, are seen. And 
evening by evening, the stars near the west, where the 
sun has set, are ever becoming less clearly seen, ever 
drawing into the sunlight, until they are glimpsed no 
longer. As the seasons pass, new stars occupy these 
positions, until as the year comes round we recognize 
again the stars we first saw. Each season, each time of 
the year, is marked by the setting and rising together of 
the sun and certain stars. For the stars gain on the 
sun, just as the sun gained on the moon ; as the moon 
made one round of the sky in each month fewer than the 
sun did, so the sun makes one round of the sky in each 


year fewer than the stars do. The sun moves amongst 
the stars. 

The stars last seen in morning twilight, those rising 
just before sunrise, are said to be rising heliacally. The 
stars just seen in the evening twilight, setting where the 
sun has set, are said to be setting heliacally. The stars 
that rise as the sun sets, and set as he rises, are said to 
rise and set acronychally. 

By means of the stars that rise and set heliacally, we 
can trace those amongst which the sun's path seems to 
be laid, and the belt of constellations through which his 
path, which is called the ecliptic, seems to lie is known 
as the Zodiac. These constellations are twelve in 
number, and form a complete band round the sky. 
Their names are preserved in the old rhyme — 

The Ram, the Bull, the Heavenly Twins, 
And next the Crab, the Lion, shines, 

The Virgin and the Scales ; ' 

The Scorpion, Archer, and Sea-goat, 
The Man that pours the water out, 

And Fish with gUttering tails. 

If we watch a star rising at the point on the horizon 
which is due east, and take its height when it souths, 
we find, at the Hilly Fields, that it is 38^° the same 
height as the sun had at noon when he moved in the 
equator on March 21 or September 21. This star, then, 
marks out the equator in the night sky, as the sun 
marked it in the day sky. We have thus the two great 


circles of the ecliptic and the equator marked out both 
for daylight and for night ; and, as we have seen, they 
are inclined to each other at an angle such as is made 
by the hands of a clock pointing four minutes apart. 

If we draw a line from the south point through the 
sky to the north point, through the zenith, it will pass 
near a bright star, to which the front stars of the 
Plough, swinging round the northern sky, also point. 
This bright star wheels in a smaller circle than any 
other in the sky, and is nearly 90° from the equator, i.e. 
is close to its pole, just as the north pole of the earth is 
90° of latitude from the earth's equator. It is near to 
this star that the axis of the earth is pointing, and if 
we measure its average height above the north point of 
the horizon at the Hilly Fields, we find that it is 51^°, 
the 'complement' of the angle of 38 J° given by the 
slant of the paths of the sun and the stars ; that is, the 
angle required to make it up to 90°. Round this star, 
known as ' the Pole Star,' all the others seem to circle. 

If we tilt a photographic camera so as to point to 
this region of the sky, and keeping it rigidly fixed, 
expose the plate to the starlight, we shall find on 
development that the stars have tracied out parts of 
circles, more or less nearly complete, according to the 
length of time that the plate has been exposed. The 
diameters of these circles depend on the distances from 
the pole of the stars that drew them ; the distinctness 


Photograph of Trails of Stars near the North Pole, taken at the Royal Observatory, 





Photograph of the Constellation of the Southern Cross. From the Annals of the Harvard 
College Observatory, Vol. xxvi. Part 2. 



and breadth of the curving lines so drawn depend on 
the brightness of the stars. {See Plate XI.) 

If we leave the Hilly Fields and go northward, the 
Pole Star rises higher in the sky, and more and more 
stars wheel clear of the horizon, and are never lost to 
view. If we go southward, the Pole Star sinks lower, 
and fewer stars never set. But if we now look at the 
stars in the extreme south, we see that some have risen 
there that we never saw when standing on the Hilly 
Fields. Stars, then, there are, that never rise ; there 
are constellations which on the Hilly Fields we can 
never see. 

One of the most famous of the constellations that 
we, in England, never see, is the star group of the 
Southern Cross. {See Plate XII.) It is not until we 
get near the tropics, — ^go down the Red Sea, or travel 
up the Nile — that it climbs over the southern horizon. 
And then it is only seen at seasons of the year when 
the sun is in the region of the zodiac that is remote 
from it. 

Therefore, it would be impossible for Colonel Trench 
to say — as Mr. Mason represents him saying in The 
Four Feathers, on the night of his release from the 
Stone House in Omdurman — that for three years he 
had watched it every night. 

If we go northward we find that the stars — and the 
sun likewise — rise in paths less inclined to the horizon. 


at a smaller slant. If we go southward we find they 
rise at a greater slant. And, as with the sun, this tells 
us that the earth is a round globe. If it were a level 
flat plain, the inclination of the axis of the sky to that 
plain would be everywhere the same, and so also would 
be the inclination of the apparent paths of the Istars, for 
the whole of the starry heavens move as in one piece. 
So, like the sun, the stars enable us to measure the 
earth. If we measure the height of the Pole Star, — or 
rather of the Pole itself, which is the centre of the 
little circle round which that star appears to revolve, — 
and then travel southward until the Pole has sunken 
one degree lower, we shall find that we have travelled 
nearly seventy miles, or more nearly, sixty-nine miles, 
and that therefore the entire 360°, the whole circum- 
ference of the earth, must be about twenty-five thousand 

He that is dizzy thinks the world goes round. 

Do all these myriad stars move round the earth, or 
does the earth turn round upon herself ? The appear- 
ances, so far as we have described them, would be the 
same vvhichever happened, but surely it is simpler to 
suppose that it is the earth that turns. 

The daily course of the sun told us that there is 
a clear way under the earth, but we could not learn 
from it — at least, not in England — that the earth was 


everywhere unsupported, that everywhere the way is 
clear. This the stars can tell. At every point of the 
western horizon, at all times, stars go down, and pass 
round through the under world to the eastern horizon, 
from every point of which they arise. At no point, 
even in the farthest north or most extreme south, is 
there a blank space in the sky where no stars wheel ; 
nowhere in the under world can there be a support 
through which a star cannot pass. The Babylonians 
held that the earth is supported on two great mountains. 
The Hebrews had better read the story of the stars, 
for they wrote : ' He ' (God) ' stretcheth out the north ' 
(i.e. the northern circumpolar constellations) ' over empty 
space, and hangeth the earth upon nothing.' 


Like as a star. 
Without haste, without rest. 

THIS is the characteristic of a star. It keeps its 
own appointed path unswervingly, moving at an 
unchanging pace. Its path is a circle, complete for 
those stars that wheel in the north, broken by the sky- 
line for the others. But no star retraces backwards its 
way, no star overtakes or lags behind its neighbour; 
there are no stragglers in the ranks of this great army. 

Are we sure of this ? The stars are very many ; we 
cannot keep a continual watch on each one to see if ever 
it should err and stray aside. For the stars in the 
north, that wheel round the pole unceasingly, we can 
look upon them night after night, the whole year 
through ; we can be certain that the Seven Stars keep 
the form of the Plough ; that the W which forms the 
Lady's Chair never ceases to sprawl. But the more 
southern stars, those that for some part of every year 
are swallowed up in sunlight, can we be very sure that 



these always keep the same pattern ; especially when we 
see but a little of the pattern ? 

During the short nights of May and June, a bright 
constellation is seen very low down in the southern sky. 
Its principal features are a curved line of bright stars, 
upright to our horizon, followed by a longer curve of 
yet brighter stars that lie along the horizon. In 
particular, three bright stars are seen close together, of 
which the middle is much the brightest, and is of an 
orange-red colour. There are very few stars in the sky 
that are of so pronounced a colour to the naked eye as 
this one is. 

The ancients considered these stars as forming a 
g^ant scorpion, with his tail curled up to sting the foot 
of a man who was trampling upon him, and the bright 
reddish star iS known as the Scorpion's Heart. 

The star of the Scorpion's Heart rises year after year 
about three o'clock in the morning in the middle of 
February. But if we had been looking at Scorpio about 
the middle of February, 1907, we should have seen the 
pattern of the constellation quite altered. For north of 
the Scorpion's Heart was another star, very like it in 
brightness and in colour. And as the constellation 
reached the meridian, a little before the dawn blotted 
out the stars, these two stood out, the one above the 
other, like a couple of danger signals. 

This star above the Scorpion's Heart had certainly 


not been always there. If we had looked out a little 
before daybreak on the first morning of the year, and 
watched the Scorpion's Heart rise in the south-east, we 
should not have seen its red companion near it then. 
But if we had looked farther to the south, we should 
have seen a reddish star, not nearly so bright as the 
Scorpioa's Heart, already fairly high up in the sky, in 
a constellation known as 'the Virgin,' just about the 
place where her left foot is supposed to be resting 
upon one of the Scales, which the constellation between 
the Virgin and the Scorpion is considered to represent, 
and not far from its brightest star. 

If, morning by morning, we had watched the Scor- 
pion through the last fortnight in February, we could 
not help noticing that the new red star was moving 
relatively to the stars of the Scorpion. On February 14 
it rose before the Scorpion's Heart ; by the end of the 
month the two stars rose together ; by the end of March, 
Antares, as the Scorpion's Heart is called, rose at 
midnight, but the stranger star not until an hour and 
twenty minutes later. It had now passed clear out of 
the Scorpion and was in the constellation of the Archer ; 
it was passing amongst the stars in the same direction as 
the moon does ; and it moved in the course of a single 
night over a space equal to the apparent diameter of the 
full moon. All through April, all through May, this 
movement of the stranger went on. By the end of 


April, it had reached the middle of the constellation of 
the Archer, and was close to his brightest star, the 
one that marks his right shoulder. 

And now the stranger star was one that it was not 
possible to overlook. Rising about midnight, and pass- 
ing the meridian a little before dawn, it shone brightly 
low down in the southern sky ; brightly, for it was now 
quite four or five times as bright as when it was close 
to Antares. No other star in all that region of the 
sky could rival it in brightness ; none could compare 
with it in vividness of colour. 

And so the red star went its way, across the con- 
stellation of the Archer ; but as the month of May drew 
to a close, it became clear that it was moving much 
more slowly. It then took four or five days to move 
a distance equal to the moon's diameter, a distance for 
which a single day had been equal before. Night after 
night its rate of motion declined, until, early in June, 
it seemed to change the direction of its course, and 
instead of moving eastward among the stars, it began 
to turn southward ; and before June had come to its 
close, it was hurrying westward, as if to overtake the 
stars that it had recently passed. By July 15 it 
had got back as far as the bright star in the shoulder 
of the Archer, a star which it had first passed on the 
north side on April 28 ; now it passed it well to the 
south, travelling almost with its original pace. Its' 



speed toward the west soon slackened, and, as August 
began, the red star for several days remained almost 
motionless in the sky. But what a splendid object it 
was throughout July ! — rising before sunset, on the 
meridian at midnight, setting at sunrise ; visible, there- 
fore, all the short night through, it shone with a lustre 
ten times as great as when it was noticed in February. 
No star in the whole sky, not even Sirius, the brightest 
of them all, could compare with it. It caught the notice 
of many, even of the dull, unobservant dwellers in cities, 
who asked with a tepid curiosity what that big red star 
might be. It was noticed, it could not fail to be noticed, 
by peasants and desert wanderers and savages the world 
over ; and, no doubt, to many of them it seemed to 
shine with a baleful ill-omened light, and to threaten 
some undefined evil. 

It is possible that there were some who formed a 
vague idea from the rapid motion of the star, and its 
increase in brightness, that it was some fiery enemy 
approaching the earth and destined to overwhelm it. 
If so, its movements during August and September 
would have reassured the timid watcher, though they 
added an element of fresh mystery. For, at the end 
of the first week in August, the red star came to a 
dead stop, and then, after a few evenings, recommenced 
again its progress towards the east. On September 2, 
it passed the star in the Archer's shoulder for the third 


time, still to the south of it, but much nearer than it 
had been before. As September went on, the pace of 
the red star quickened, until by the end of the month 
the original pace of about a moon's diameter in twenty- 
four hours had been fully regained ; and early in October 
it had passed from the constellation of the Archer, in 
which it had followed so erratic a course, into that of 
the Seagoat. And thenceforward throughout the year, 
there was no break in the steadiness of its eastward 
progress. Evening by evening it set earlier, until by 
the end of the year it had gone down an hour before 
midnight. But during all this time its brightness had 
been fading, at first slowly, later more quickly, until as 
the old year expired, it was no brighter than it had been 
when it stood just above the Scorpion's Heart. It had 
come far enough since then, having passed through the 
whole of the constellations of the Scorpion, the Archer, 
the Seagoat, and the Waterpourer, or very nearly a third 
of the entire sky. {See Plate XI IL, fig. i.) 

Here was a star that obeyed a law quite different 
from that of the general starry host. 

Is this the only one, or are there others ? There are 
certainly others. For if we had been watching atten- 
tively the part of the heavens which the red star had 
reached in its wanderings as the year 1907 came to a 
close, we should have seen that there was another 
stranger star here. This is rather a dull region of the 


heavens : the neighbourhood of the more westerly of the 
two Fishes, where the constellations of the Fishes, the 
Waterpourer, and the Sea-monster meet. This region 
comes into view at about five o'clock in the morning at 
the end of March. It is up all night in September, and 
it is lost again in the sunset about the beginning of 
March. When the stars of the Western Fish begin to 
draw away from the sun, in the early mornings of April, 
1907, a star much brighter than any of those which 
make up this constellation was seen in a void region of 
the sky somewhat to the south of them. Through April 
and through May it followed a steady course eastward, 
taking five or six days to travel over a space equal to 
the diameter of the full moon. Towards the middle of 
July, however, it came to a full stop, and then through 
August, September, and October, drifted westward until 
very nearly the end of November, when again it stopped 
in order to resume, in December, its eastward drift. The 
entire range of its wanderings, during these eight 
months, was only over a small part of a constellation, 
perhaps one-fiftieth part of the circle of the sky ; but the 
movement amongst the stars, though much slighter than 
that of the red stranger, was quite evident. It moved 
more slowly, and it changed little in brightness. There 
was a dull leaden quality about its light, though it shone 
steadily ; it was much brighter than all the stars near to 
it, but neither sparkled nor twinkled. 


The midnight sky is in its greatest glory in winter. 
If we look out at eleven o'clock in the evening on 
the first of January, we see, due south before us, the 
beautiful constellation of Orion, the brightest in the sky. 
Lower down to the south-east, the great Dog, with 
flashing Sirius as its chief jewel, is shining ; above Orion 
and Sirius, the rich stream of the Milky Way flows down 
from north-west to south-east ; on the further border 
is the bright constellation of the Twins, Castor and 
Pollux ; whilst Procyon, the lesser Dog, attends at their 
feet. Nearly overhead is Capella, one of the three 
brightest stars of the northern hemisphere, and the chief 
brilliant of the constellation, Auriga, Holder of the Reins ; 
a little further west along the Milky Way is the long 
stream of stars that mark out Perseus ; and below the 
feet of both, bending his head to repel the attack of 
Orion, is the Bull, with the bright star of .Aldebaran 
shining as his eye. Nowhere else in our northern lati- 
tudes do we see such a glorious collection of stars. 

But on the first day of 1907, this glorious collection 
of stars was rendered yet more brilliant by the presence 
in its midst of a star that far outshone them all. It 
shone with a serene and steady silver light, very unlike 
the quick twinkling of the chief stars around it. It lay 
nearly midway between the five bright stars, Capella, 
Aldebaran, Betelgeuse, Procyon, and Pollux ; and was 
thus just within the constellation of the Twins, near the 


feet of Castor, the northern Twin. It was an object not 
possible to overlook. {See Plate XIII., %. 2,) 

This serene star was no more stationary in the sky 
than the red one. It was moving throughout the whole 
of January, westward amongst the stars, but it never 
quite succeeded in escaping from the constellation of the 
Twins. It reached the border line between the Twins 
and the Bull about the end of February, and then it 
turned back and pursued an eastward course through 
March, April, and May, crossing the space equal to the 
moon's diameter in about three days. It was lost in the 
sunlight early in June, at which time it was drawing near 
to the Twin stars. Castor and Pollux. It was seen again 
at the beginning of August, early in the morning, when 
the Twin stars emerged again from neighbourhood to 
the sun. Then, for the rest of the year, it moved steadily 
eastward till the beginning of December, when it stood 
still for a second time, and then again retraced its steps. 
The whole of the last month of 1907, and the first three 
months of 1908, it was travelling westward, and it came 
to a for a third time at the end of March, 1908, in 
the middle of the constellation of the Crab, just as it had 
come to a stop the first time at the end of February, 
1907, near the feet of the Twins. It had thus measured 
off in a year the whole of a constellation ; and for 
a third of a year it had been travelling backwards 
amongst the stars over a third of a constellation, a 


• ''. 













• 1 






, 1 


the 1 

5(M Goat ' 














Fig. I. — Apparent Path of Mars amongst the Stars during the year 1907. 


Ural IfKHciiv 


_• Twins 






Fig. 2.— Apparent Path of Jupiter amongst the Stars during the year 1907. 



Fig. I. — Elongations and Conjunctions of an Inner Planet. 

ouADRA rum 



Fig. 2. — Quadratures, Opposition, and Conjunction of an Outer Planets 


thirty-sixth part of the circumference of the sky, or 10° 
of arc. 

These three stars, the red star, the leaden star, and 
the serene star, are evidently quite unlike the rank and 
file of the heavenly host We know them to-day, as the 
ancients knew them of old, as planets, that is to say, 
wanderers ; and it was a very slow and tedious process 
by which men reached an understanding of their 

The names by which we know them to-day are 
those of three of the gods of ancient Rome. The red 
star is Mars; the serene, Jupiter; and the leaden 
star, Saturn. Their movements are like the movements 
of the moon, with one remarkable difference. The 
moon moves always eastward amongst the stars — 
moves rapidly eastward, more than twenty times its 
own diameter in a single day. Jupiter, Saturn, and 
Mars move eastward too, but each of them has a 
time when their eastward motion becomes very slow, 
then ceases, and is converted into a westward motion. 
This lasts for a considerable time, and then, in its turn, 
diminishes, comes to a stop, and is reversed. The 
great difference, then, between the movements of these 
three planets and that of the moon, is that the former 
pass through stationary points and a period of retro- 
gression ; that is, of westward, of backward motion. 

This period of retrogression takes place at the 


time when the planet is opposite the sun, and is 
therefore visible all night. For Mars, it begins about 
six weeks before the planet is exactly opposite the 
sun, and lasts for about six weeks after. For Jupiter, 
it begins about two months before opposition, and lasts 
about the same time after. For Saturn, the half-period 
of retrogression is ten weeks. Then the rate of motion 
across the sky of the three planets is very different 
from that of the moon ; for, while she traverses more 
than twenty times her own diameter in a day, Mars, 
at his quickest motion, takes an entire day to traverse 
a space equal to a single diameter of the moon ; 
Jupiter takes three days, and Saturn five. 

When we watch the ' morning stars ' escaping from 
the rays of the rising sun, or the ' evening stars ' being 
enmeshed in the rays of the setting sun, do we find 
that all of the former escape from the rising sun and 
all the latter are imprisoned by the setting sun ; or 
is it sometimes the other way about ? It is worth 
while to devote our mornings and our evenings for 
a time to making certain. 

Let us suppose that we are beginning our watch in 
the February of 1906. It is more than a month before 
the spring equinox, and as we look, evening by evening, 
first the stars in the stream that the man pours from 
his watering-pot, then the stars in the Fishes, fade into 
the setting sun ; morning by morning, the stars in the 


Archer — half man, half horse — then the stars in the Sea- 
goat and the Waterpourer are earlier and earlier seen. 
Everything is as we expected : the stars keep on their 
steady march westward, there are no stragglers in 
their ranks, and the sun shifts steadily in the one 
direction past them. We have watched for a month 
and seen nothing out of rule; is there any need to 
watch longer ? 

It still wants a week until the equinox, and the sun 
has set nearly half an hour. The stars of the twin 
Fishes are lost in the twilight, but surely there is a 
star just over the west point of the horizon that has 
no place in the constellation of the Fishes. It shines 
with a silvery light, but more steadily than the other 
stars of the sky. And a little farther from the sun, 
a little farther to the north of the silvery star, there 
is another. It is fainter than the silvery star, but it 
twinkles like a real star. Then both set. Are these 
two stars new creations ? How else should we not 
have seen them before when the other ' evening stars ' 
were clearly seen ? They are both set amongst the 
stars of the Fishes, but they are both much brighter 
than any of these. 

But on the next evening, when they should have 
disappeared, both stars are yet more clearly seen. The 
•evening stars* have shifted westward as regards the 
setting sun ; the silver star and the twinkler have moved 


eastward, a little more into the dark and the open — 
they have moved eastward amongst the westering army 
of stars. For a day or two the twinkling star is seen, 
and then drifts back into the sunset glow, but the silver 
star takes a steady eastward path backwards through 
the stars, away from the sun. 

During the summer months it travels backwards 
through the Twins, the Crab, the Lion, and the Virgin, 
its easterly motion just sufficient to keep it out of the 
sunset glow, but it has been growing brighter as it 
recedes ; until, by September 20, it can be seen in the 
sky even as the sun is setting, and the distance between 
the two is as the distance between two hands of a 
clock pointing eight minutes apart. 

But no farther does the silver star recede from the 
sun. After September 20, the sunlight begins to draw 
it back again ; yet still it brightens, until, by October 26, 
there is no star in all the heavens can compare with it. 
Still it moves more slowly eastward, and yet more 
slowly, until, by November 9, it has ceased its easterly 
motion and is a brilliant star, fixed amongst the other 
stars, far outshining its neighbour, Antares, the jewel 
of the Scorpion. Then it begins its westerly movement, 
rushing more quickly than the other stars to be im- 
prisoned in the rays of the setting sun, lost to sight 
before the third week of November is out. 

But not for long. The first week of December is 


not over before a new star has arisen as herald of the 

Hesperus, that leads 
The starry host, rides brightest. 

But Hesperus, the silver evening star, is seen no more, 
and a silver morning star, Phosphorus, has risen. Phos- 
phorus is moving westward, as Hesperus was moving 
when last we saw it. But Phosphorus ceases to move 
west by December 19; remains fixed, and again begins 
its eastward movement. By January 4, 1907, it has 
attained to all the brightness that Hesperus held on 
October 25, shining now in the head of the Scorpion, 
but giving it a jewel far surpassing all the other living 
sapphires of the sky. To the eastward it continues its 
road, gaining on the rising sun, and straying further 
from him. Phosphorus can be seen high in the morn- 
ing sky even when the sun is lifting above the eastern 
horizon, and if we measure its distance from the sun 
on some morning near the end of the first week of 
February, we find it is very nearly that between the 
two hands of a clock pointing eight minutes apart. 
This would tell us that the western 'elongation' of 
Phosphorus was 48° very nearly, the same as the 
eastern 'elongation' of Hesperus. It is also its 
greatest elongation, for, after February 9, Phosphorus 
begins to sink back into the rays of the rising stin, 
unlike the stars of the Archer's bow amongst which 


it is shining low down in the eastern sky, much lower 
than was Hesperus when it shone amongst the stars of 
the Virgin in the west. 

Phosphorus sinks back very slowly into the sun's 
rising during the long summer months of 1907. We see 
it threading its way through the stars of the Archer, the 
Sea Goat, the Waterpourer, the Fishes, the Ram, the 
Bull, and the Twins, until, at the end of July, we find it 
lying below the great Twin stars, Castor and Pollux. But 
the Twin stars are escaping from the sun's rising light, 
whilst Phosphorus is sinking into it, to be seen no more 
in the morning; though Hesperus reappears in the stars 
of the Scales when the long nights of November have 
come in. 

In our watch, morning by morning, and evening by 
evening, we have come on no other stars than these 
that do not obey the Law of the Stars. We have 
discovered Saturn the leaden star, Jupiter the serene 
star, and Mars the red star. Also, we have discovered 
Phosphorus and Hesperus, and the twinkling star. 
Phosphorus and Hesperus, we are almost sure, are one 
and the same star ; for the story of Phosphorus, of its 
movements in one direction or another, its stationary 
points amongst the stars, and its changes of brightness, 
is but the story of Hesperus as seen in a looking-glass. 
The star, Hesperus or Phosphorus, we call Venus. 

The twinkling star is far harder to watch, and, 


indeed, here in England, it can only be seen occasionally. 
But if watched for, year after year, on every possible 
opportunity, its movements are seen to be just of the 
same character as those of Venus, The ancients had 
discovered this thousands of years ago, and we inherit 
from them the name Mercury, which we give to it. 

These five wandering stars, or planets, do not obey 
wholly, though they seem to obey in part, the Law of 
the Sun. Like the sun, they shift their rising and their 
setting places, within limits, on the eastern and western 
skylines. But their change of rising and setting bears 
no relation to the seasons, and their pace across the sky 
is not steady and unswerving. They do not obey 
wholly, though they seem to obey in part, or at times, 
the Law of the Stars, for the latter have their places 
of rising and setting unalterable, and wheel continually 
without haste and without rest. They do not obey 
wholly, though they seem to obey in part, the Law of 
the Moon, for this never retraces its path nor stands still. 
They do not all even seem to obey the same law. The 
law that governs Saturn, Jupiter, and Mars seems 
different from the law of Venus and Mercury. 

Let us take Jupiter and Venus, the two greatest and 
brightest stars in all the sky, and contrast them. In 
brilliancy and silver light they are rivals. But there is 
one great difference between them. Jupiter, like the 
moon, after emerging from the sun's setting rays, recedes 


farther and farther from him in the sky, until, when he 
is brightest, he rises, as does the full moon, in the east 
at sunset, rides his highest in the south at midnight, 
and sets in the west at sunrise, thus being opposite to 
the sun the whole night long. It was for this reason 
that the ancient Babylonians called Jupiter by the name 
' Nibur ' — ' he who crosses over ' — because he crossed the 
midnight meridian. And they also called him by the 
name of their chief god, Merodach, who represented the 
sun in his strength. For just as the sun passes through 
one of the twelve signs in a month, Jupiter passes 
through one of them in a year. 

But Venus, so like Jupiter in lustre and brightness, 
is never opposite to the sun. The moon's movements 
would resemble hers, if we could suppose the moon to 
be stayed in the evening sky, when four days old, and 
sent back on her path ; or, to use the Babylonian . myth, 
if I star had been stopped at the fourth portal and 
been sent back through the gates into the under world. 
So, therefore, as the Babylonians gave the name 
Merodach to Jupiter, they gave the name Istar to 
Venus, as well as to the moon. For she, like the moon, 
was an attendant on the sun — his handmaid and his 

It is worth while to step out under the open sky, 
and to watch the coming and going of these five planets, 
so seemingly capricious in their movements, so different 


from the unswerving, ordered march of the stars. It is 
also worth while to remember that long before men had 
telescopes, or any means for delicate measurement, they 
had not only detected these five wanderers, but they 
had mastered part of the secret of their movements, 
and had learned to predict long beforehand when they 
would appear, when they would seem to stand still in 
the sky, and when reverse their paths. 

It is quite clear that the moon travels round the 
earth ; is it not possible that Mercury and Venus travel 
round the sun ? The interval between the time when 
Mercury is farthest from the sun as an evening star, 
to the east of him, and again to the time when he is 
farthest as a morning star to the west, is a little over 
six weeks. The interval from his greatest distance as a 
morning star to his next greatest distance as an even- 
ing star is a little over ten weeks. In all, the interval 
from one elongation to the same elongation again is 
about 1 1 6 days, or i6^ weeks. If, therefore, we suppose 
that Mercury is travelling round the sun in a period of 
this length of time, as viewed from our earth, his 
apparent movements amongst the stars might be ex- 
plained ; and it is quite clear that we should have to 
suppose that Mercury was between us and the sun, 
midway in his passage from evening star to morning 
star ; and beyond the sun, midway in his passage from 
morning star to evening star. (See Plate XIV., fig. i.) 


Venus moves in a similar fashion to Mercury, but she 
swings through a wider arc and moves more slowly. 
She takes 143 days to fulfil her entire passage from her 
greatest distance in the east as evening star, to her 
greatest in the west as morning star ; whilst she 
requires 441 days to pass behind the sun in her reverse 
course. Her entire period, as judged from the earth, is 
584 days. 

It is evident that Venus never recedes from the sun 
so far as the earth is. But suppose the sun had another 
attendant, that could move further from him than the 
earth. Clearly, instead of coming between the earth 
and the sun, it would pass behind the earth, and thus be 
seen opposite to the sun, just as the full moon is seen. 
Necessarily, it would then make its nearest approach to 
the earth, and would look large and bright. The sun 
appears to go round the earth once in a year. If this 
attendant on the sun took considerably more than a year 
to go round him, then we should have just exactly what 
we notice in the case of Mars, which takes seven weeks 
more than two full years between one * opposition ' and 
the next. If the attendant took several years to go 
round the sun, then it would be brought by the sun, at 
the end of a year, nearly to * opposition,' but there would 
be a small distance still to be made up, because of the 
planet's own movement round the sun. Now, Jupiter 
travels from one opposition to the next in a year and 


thirty-four days, Saturn in a year and thirteen days. 
Hence, they take nearly twelve years, and nearly thirty 
years respectively, to travel round the sun, since thirty- 
four days is nearly the twelfth part of this apparent 
period of Jupiter, and thirteen days nearly the thirtieth 
part of this apparent period of Saturn. {See Plate 
XIV., fig. 2.) 

But does the sun travel round the earth, carrying all 

these planets with him, or is it the earth that travels 

round the sun, just as the other planets do ? It would 

make no difference in the appearance of things, so far as 

observations made by the naked eye are concerned, 

which was the fact. But surely it is better to take the 

simpler explanation, and just as, when the stars had told 

us that the earth was a globe unsupported in space, it 

was easier to account for the apparent circuit of the stars 

round the earth by supposing that it was the earth that 

turned, so it is simpler to suppose that the earth travels 

round the sun, just as we see that the planets do, rather 

than that he travels round the earth, carrying all the 

planets, with their various motions round him. We know 

how difficult it is if we are sitting in a train in a railway 

station, side by side with another train, and we are 

watching the latter, to say which is moving, this train or 

that. The probability is that if the other train moves, 

we think it is ours ; if it is our train, we think it is the 

other one, if our motion be smooth enough. But there 



is no motion so smooth and so swift as that of the 
heavenly bodies ; they move without haste and without 
rest, and they jar over no stones in the road that they 
travel. So, as when we are in an express train, horses 
and hedges and trees seem to fly past us, whereas it is 
we that are flying past them, the sun seems to be 
circling round us in the course of a year whilst we are 
really circling round him. So in the pair of little 
sketches {see Plate XV.), it is the tree that seems to 
have moved, not the man. 

This gives us the clue to the meaning of those 
strange backward movements of Mars, Jupiter, and 
Saturn. The earth is nearer to the sun than they are, 
and moves round him in a shorter time. Hence there is 
one part of our path in which we pass them, and whilst 
we are passing them, since we are not conscious of 
our own movement, they seem to be going back- 
wards in the sky. There is a further point. We 
have seen that Mercury and Venus appear only to 
wander from the sun to a restricted degree: Mercury 
is never more than about 30° from the sun, nor Venus 
much more than 45°. That means to say that 30° is 
the apparent size of half the orbit of Mercury as seen 
from the earth, and 46° of the orbit of Venus. This 
does not tell us how big those orbits actually are in 
miles, but it gives us the relative size of the two orbits, 
so that if we knew the scale of the one we should know 








Fig. I. — The light from the edge of the 
Sun's disc has passed through a much 
greater depth of his atmosphere than 
that from the centre. 

Fig. 2. — Illustrating the apparent forward 
motion (eastward) of an outer Planet. 

Fig. 3.— Illustrating the ' .stationary points ' 
of an outer Planet. 

Fig. 4. — Illustrating the ' retrogression ' 
(westward motion) of an outer Planet. 

Fig. 5. — Illustrating the determination of Stellar Parallax. 



the scale of the other, and also the scale of the 
earth's orbit. {See Plate XVI., figs. 2, 3, and 4.) 

Just in the same way the apparent swing backwards 
of Mars, Jupiter, or Saturn, whilst they are going back- 
ward in the sky between their two stationary points, is 
an indication of the apparent size of the orbit of the 
earth as seen from these three planets, and consequently 
of their relative distances. We could therefore draw a 
map of the Solar system to scale, but we could not tell 
the value of the scale, whether an inch represented 
hundreds, or thousands, or millions of miles. 

This, then, is the story that the planets have to tell, 
namely, that they are moving round the sun at very 
different distances from him, and at very different speeds, 
and that the earth is one of their number. 

So much the movements of the heavenly bodies — 
Sun, Moon, Stars, and Planets — have been able to tell 
us without the need for our using telescope or observa- 
tory. So much, and much more, men had read from 
those movements two thousand years ago. Is there 
any good, then, in our learning again what has been 
known so long ? 

There is every good. Those who wish to learn 
something of other sciences than astronomy, such as 
botany and geology, are never content merely to read 
about them in books. They go to the fields and rocks 
to see with their own eyes that which the masters in 


these sciences have known and taught long before. 
And they do rightly. It is by our own observation 
that we learn to know ; it is by this that our perceptions 
become keener, and our interpretations more certain. 

If we would begin our study of astronomy aright, let 
us go out, under the open sky ; and what beauty, sub- 
limity, and wonder greet us as we turn our eyes to the 
heavens! The movements of the machinery of men 
are with noise, dirt, and shaking ; but this machine, 
infinitely greater than any man has ever produced, 
moves as easily as a thought. For the movements that 
we watch are those of the machine of God's own 
making, and how swift, smooth, silent, and inscrutable 
those movements are ! 





T N February, 1 866, as I ^ was returning home from 
-*■ school one evening, I saw the sun, low down in the 
west, shining red through the mist. The sun was dim 
and red enough for me to look at him without blink- 
ing, and I saw plainly on him a round black spot, just 
as if a nail had been driven into him up to the head. 
It was the first time that I had ever seen anything on 
the surface of the sun. 

If we are to see anything on the sun's face, we must 
be able to look at him. If the day is very clear, we 
are too dazzled by his light to see him. The im- 
pression that we get is that he has a round, glowing 
golden disc, all so overpoweringly brilliant that we 
cannot say that one part of it is any brighter than 
another part. For aught we could tell, it is a perfectly 
flat disc, as flat as a golden sovereign, or as our fore- 
fathers thought the earth to be. 

We now know that the earth is not flat, but rounded 

' E. Walter Maunder. 


as a sphere or globe ; the stories of the sun and stars 
told us that. But the atmosphere surrounds the earth 
and fits it like a skin, like a skin that, for the size of the 
earth, is not so thick as the skin of an apple is for the 
fruit. We know that the earth's skin of air is not 
thick, for the sky is much clearer overhead than 
towards the horizon, and if we could ascend high 
above the ground we should see that, of the circle of 
the earth beneath our feet, the region in the centre is 
the clearest, and the land lying near the borders in 
all directions is blurred and dim. 

We cannot gaze at the sun when he is in the clear 
sky overhead ; we can look steadily only at the low 
sun when his brightness is diminished by the thicker 
air of the horizon. Then we see that the golden 
disc is not equally bright, equally golden, all over. The 
centre is brightest and still of a golden yellow, but 
everywhere towards the border of the circle the bright- 
ness dims and the gold deepens into orange or red. 
It is not our atmosphere that causes this diversity, 
else the gold and orange would be in layers above 
our skyline ; the difference must be in the sun himself : 
his dim border must be at a greater distance from us 
than his bright centre, and he must have an atmosphere 
of his own, lying thicker over his border than his 
middle, as we found our air lying thick on our hori- 
zon. The sun, then, is not a flat disc like a golden 


sovereign, but a globe, a sphere, rounded as the earth 
is round. {See Plate XVI., fig. i.) 

The next time that I saw the sun lying low and red 
in the west, I saw the black spot like the head of a nail 
again, but it had changed its place, and was now much 
further from the centre of the sun. Two or three days 
later it had gone. 

I have seen similar spots with the naked eye on 
many occasions since. On November 18, 1882, Queen 
Victoria was holding a review in Hyde Park. The 
morning was somewhat foggy, and the sun shone dull 
and red through the thick air, so that it was easy to 
look at him. On this occasion there was a great spot 
on the sun; so big that it caught the attention of the 
soldiers who were marching across Blackheath, to go 
to the review, and they pointed it out to each other. 
Eleven years later, in August, 1893, I was on a voyage 
and watched the smoke from the steamer pass across 
the sun ; every time that it did so, and I was able for 
the moment to look at the sun, I saw two great spots 
upon him. And so on other occasions. On one day in 
February, 1907, no fewer than four spots could be seen 
separately on the sun at the same time. 

So the face of the sun changes, even to the naked 
eye. There are sometimes blemishes on it, and some- 
times there are not. It is not possible to go much 
further than this in the study of the sun's surface without 


the aid of a telescope — we can see that the sun is a 
globe, that he has an atmosphere, and that spots come 
and go upon his face. We cannot tell whether it is 
always the same, or a different, face that he turns to us. 

Every now and then we can see spots on the 
sun with the naked eye, and several such were seen 
in the centuries before the telescope was invented, yet 
the people who saw them did not recognize that the 
black blemishes were really spots on the sun's face. 
In the days of Charlemagne, one was recorded as 
lasting for eight days, but those in the Middle Ages, 
who read the record, thought that it was Mercury that 
was seen, passing straight between the earth and the 
sun. But Mercury it could not have been, for two 
reasons. The little planet takes only six weeks to pass 
from its east elongation to its west, over a space in the 
sky nearly two-thirds of a right-angle ; it could not, 
when it seemed to be moving at its quickest pace, loiter 
for eight days of that time, over barely the one hundred 
and seventieth part of that space. Besides, the planet 
is so little that we can only see it with the naked eye 
when it is a bright point of light, not when it is but a 
black dot on the bright sun. 

To study the features of the sun's face we must have 
a telescope, and we can use it in one of three ways. 
We can look at the sun directly through it — though in 
this case we must use a very dark glass to dim the glare 


of his light, which would blind us utterly. Or we can 
let the magnified image of the sun made by the lenses 
of the telescope fall upon a white card, and study the 
features that we see there. Or we can place, instead 
of the card, a photographic plate, and let the sun imprint 
his own image. In this last case, since the sun is very 
bright, the very brightest object we know, we must give 
very short exposures, perhaps but the one thousandth 
part of a second. Plate XVII., fig. i, shows the second 
of these methods as used at the Royal Observatory, 
Greenwich, by Flamsteed, the first Astronomer- Royal ; 
and Plate XVIL, fig. 2, shows one of the 'photo- 
heliographs,' or photographic telescopes for solar work, 
now in use at the same observatory. 

The spot that was seen in the days of Charlemagne 
lasted for eight days. It lay on the sun's face, when 
first it was seen, nearly a quarter of the sun's breadth 
away from the left-hand edge. But day by day it 
shifted its place, creeping right across its middle, until, 
on the last day that it was seen, it lay about a quarter 
of the sun's breadth from the right-hand edge. Either, 
then, the spot was moving on the sun, or the spot was 
fixed in its place and the sun was turning with it round 
in the same direction that we ourselves seem to move. 

It is only rarely that we notice naked-eye spots, 
but very soon after the invention of the telescope 
Galileo turned his new instrument upon the sun, and 


in April, 1611, announced that he had discovered dark 
spots on the body of the sun. For in the telescope 
spots are frequently to be seen, and these may remain 
visible not for eight days only, but perhaps for thirteen 
or fourteen, appearing first at the very eastern edge 
of the sun, and crossing his face to disappear at his 
western edge. And these show that the sun himself 
is carrying the spots. They are not merely transit- 
ing over his face, as Venus or Mercury transit, passing 
between the earth and the sun. For when the spots 
appear at the sun's eastern edge they are like a thin 
line along it; they seem but stains on him, much 
foreshortened as they lie on a part of his globe that 
is turned much away from us. As day by day passes, 
the spot group comes more clearly into view, until it 
is fully presented in the centre of the sun's disc. Then, 
day by day, as it creeps on towards the west, it fore- 
shortens again, showing clearly that the sun is a globe, 
and that he is turning round upon his axis. From these 
same spots we can tell how fast he is turning. For, since 
the sun is a globe, we can only see half of it at any time, 
the hemisphere that is turned to us. But it seems to us 
to take the sun thirteen or fourteen days to carry a spot 
from one boundary of that hemisphere to its other, and 
it takes, therefore, just so long to carry it again across 
the hemisphere that we do not see round into sight 
again at the eastern edge. Thus the sun appears to 


2 c 


















Diagram showing the Track of a Sun-spot across the Sun's Disc. 

{From a drawing made in September and October, 1850, by the late Father Sestini at the 
Georgetown College Observatory.) 


us to turn round in about twenty-seven days. In reality 
he turns round in less time by a couple of days, for, 
as the earth is travelling round the sun in the same 
direction as the spots do, we keep the spots longer in 
view than if we remained still ; just as we might follow 
down the platform a train that is moving out of the 
station, to keep a departing friend a few seconds longer 
in sight. {See Plate XVIII.) 

The spots go at the sun's western edge into the 
hemisphere that we do not see. Shall we ever see 
these spots again ? How shall we recognize them if 
they are the same spots ? How can we tell one spot 
from another ? Do they always come up at the same 
point of the sun's eastern rim as the stars do on the 
earth's horizon, or do they shift their rising places like 
the moon and the planets ? Do they wax and wane like 
the moon ; do they wander to the east or to the west 
like the planets ; or, like the stars, do they move without 
haste and without rest ? or do none of these laws have 
anything to do with sun-spots ? 

A spot, when seen with the naked eye, is round and 
black, like a nail's head ; and one nail is very like 
another. But that is because the naked eye is not 
powerful enough to see its details. Magnified by the 
telescope, and projected on the white card, or imprinted 
on the photographic plate, a spot is seen to have defined 
form and characteristics enough for it to be recognized 


again. But so has a cloud in the sky characteristics 
and a defined form, and just as clouds change so do 
sun-spots. The sun-spot of one day may have altered 
or lost every peculiarity by which we thought to 
remember it, ere the next has passed. A single spot 
may have broken up and become scattered into many ; 
a group of spots may have coalesced into one. 

Spots differ much in their shape and size, and in the 
length of time that they last. The most stable spots, 
those that change least and last the longest, are very 
nearly round. They appear black in the centre, which 
is not quite half as broad as the entire spot. In this 
black region, the nucleus, or umbra, of the spot, as it is 
called, there are sometimes points of intenser blackness, 
as if pits were sunk in the floor of a great cavity. 
Round the umbra is a lighter region, which surrounds 
it as the iris surrounds the pupil of an eye. This is 
called \}ae. penumbra, and is marked throughout by wavy 
lines flowing inwards, making the penumbra look as if it 
were built up of thatch straws. Where the penumbra 
borders on the umbra, it is ravelled out into a narrow 
fringe. Round the spot, outside the penumbra, the 
surface of the sun is brighter than usual, and seems to 
be heaped up ; and every now and then, some of this 
intensely bright white stuff will, as it were, boil over, 
and either flow right across the spot, forming what is 
known as ' a bridge,' or else flow into it. 

Photograph ok the Sun taken at the Royal Observatory, Greenwich, 

on July 14, 1905. 

(Two streams of sun-spots of different types are seen.) 



TiiK Solar Surface, showing tpee Granulations. Diameter of Solar image = 3 feet. 

(From a pIiotoi;raph taken Scpteinbcr, 1883, ad. 8/i. ^or/i. 20s. Paris Rlcan Tivn; at the McnJon 
Observatory, by the late Professor Jansseti.) 



But spots are not generally seen singly ; they are 
seen in groups. A very ordinary occurrence is for two 
very small spots to appear near each other. Then they 
grow very quickly and move apart as they grow. This 
movement is usually one of astonishing rapidity, since 
they travel away from each other at the rate of about 
8,000 miles a day, five or six times as fast as an express 
train. The spot that leads is usually nearly round, and is 
dark and well defined. The spot that follows is often the 
larger of the two, but is not so dark, and not so regular 
in shape. Between the two a number of smaller spots 
generally appear, but these are not seen for long, as the 
bright surface of the sun seems to swell up in this 
region and to flow over these smaller spots, hiding them 
from view. The irregular spot in the rear dis- 
appears next, and the round leader remains alone and 
may sometimes last for several weeks, or even months, 
after the rest of the group has gone. {See Plate 

Spots, therefore, change their form ; they increase 
and diminish, they are born and die. Some never 
become more than a faint, tiny smirch, which may last 
only a few minutes and then melt again into the general 
brightness of the sun's surface. Others grow and 
spread and darken, and may last for days, weeks, or 
even months, crossing the sun's disc again and again. 
Some may develop slowly, and decay in the same 


fashion. Others may break out almost full grown, 
or may die down whilst apparently in full vigour. 

But the spots are not the only markings upon the 
sun. As already noted, round the spots, and in the 
middle of their groups, we often see masses of material 
much more brilliant even than the general surface ; as 
if the substance of the sun were here boiling over and 
eddying round and across the gaps made by the spots. 
Masses of similar shining matter are also seen by 
themselves near the rim of the sun, more generally 
near the east or west ; in form they look like branches 
of gleaming coral. They are in the centre of the sun's 
disc also, but there their lustre is lost in the general 
brightness. They rise high into the sun's atmosphere 
like mountains, and its greater depth near the rim of 
the disc shades down the brilliancy of his surface, so 
that these bright masses— /acwlae they are called — shine 
out by contrast. These great groups of faculae, like 
the spots, come round into our sight over the eastern 
rim of the sun ; we lose them in the brightness of the 
centre, and we see them again near the western rim 
befpre they disappear into the hidden hemisphere. 

We have seen sun-spots and faculae on the surface 
of the sun ; but what is that surface itself like ? Its 
texture is not even ; it has its pattern, a wonderful and 
ever-changing pattern. On what seems to be a dark, 
or at least less brilliant, background, there float minute 


grains of intense brightness, and of irregular form. 
If we do not magnify it much, the general effect is 
like the roughness of drawing-paper, or like the curdling 
of milk that is turning sour. But, greatly magnified, 
it seems to be formed of tiny granules which run 
together here and there into grains, which rriay be 
round in shape, or drawn out into pointed filaments, 
and these grains aggregate, and separate out to form 
the changing pattern on the sun's face. One observer 
describes them as being like snowflakes sparsely 
scattered over a greyish cloth, another likens them to 
' willow-leaves,' figuring the sun over like basket-work ; 
another sees them as simple rice grains in shape. Over 
the edges of the umbra of spots, they form the fringe 
of the penumbra, hanging over the blackness like 
thatch straw. 

On some very beautiful photographs that Professor 
Janssen took of the sun, this pattern came up, at one 
time coarsely, at another time finely textured. At places 
the texture, whether coarse or fine, seems smeared and 
ill-defined, as if the pattern had been outKned in lumin- 
ous ink, and ere it dried, a careless sleeve had brushed 
across it. What causes this smearing, or how long it 
lasts, we do not yet know. It might be supposed that 
it was due to small but very rapid currents in our own 
atmosphere which make the parts of the sun seen 
through them ill-defined, as landscape shimmers in 


extreme heat. But it seems clear that it arises from 
some cause in the sun itself, from some motion or 
whirling of the grains themselves, or of the sun's 
atmosphere above them, so rapid that the small fraction 
of a second for which the photograph was exposed was 
all too long for them to seem at rest. {See Plates 
XX. and XXI.) 

The story told by the sun's surface, as we see it or 
photograph it by means of a telescope, is one that we 
should not have been likely to guess from anything that 
we can see of it with the naked eye. The whole of 
that surface is in commotion and change. Bright as it 
is on the whole, there are parts which are much brighter 
than the rest ; there are parts, too, which, though really 
bright, appear to be dark, appear even to be absolutely 
black, as compared with the general radiance. Yet 
even the blackest part of the darkest sun-spot is probably, 
surface for surface, thousands of times as bright as the 
full moon. 

And these spots change, change rapidly, in a way 
that hints at the action of mighty forces below the 

Finally, the sun is a globe, turning upon his axis 
once in twenty-five days, and so presenting in turn 
every face towards us. 



SOME years ago my study window faced north-west 
and looked over London. One evening in August 
it was very clear as I * watched the sun go down, and I 
hoped to see him set behind the houses, and not lose 
him in the smoke of the chimneys before he reached 
them. He was very close to the skyline, when I saw in 
his lower right-hand edge a black piece bitten out : a 
bite which grew larger and larger, just as the moon, in 
a solar eclipse, seems to eat the sun. Yet I knew that 
there was no eclipse of the sun possible on that evening. 
Farther and farther did the round black body encroach, 
until, when the sun was nearly hidden, an upright tower, 
surmounted by a cross, was outlined on the reddened 
disc. It was St. Paul's that was eclipsing the sun ; 
dome and tower together exactly fitting into the sun's 
round shield. {See Plate XXI L, fig. i.) 

We can cover up the sun's whole face more easily 
than by getting him to set behind St. Paul's to us at 

' E. Walter Maunder. 


Blackheath. If a halfpenny is held at a distance of nine 
feet from one of our eyes, exactly between the eye and 
the sun, no whit of the sun will be seen ; or if a three- 
penny-bit is held about five feet away, again the sun 
will be exactly hidden. So a threepenny-bit at five feet 
distance, a halfpenny at nine feet, the dome and cross of 
St. Paul's as seen from Blackheath, and the sun, if all in 
a straight line from the eye, will all appear exactly the 
same size. Now we can measure the distance to the 
threepenny-bit, and its size ; to the halfpenny, and its 
size ; to the dome and cross of St. Paul's, and their size ; 
but how are we to measure the distance to the sun to get 
his size ? We cannot pace the distance, or measure it 
with a chain. 

Suppose that we are looking at a candle with both 
our eyes, and that the candle is not far off. If, whilst 
we are looking at it, we shut our right eye, the candle 
seems as if it had shifted a little to the right ; if we 
shut the left eye instead, it seems to. shift a little to the 
left. Yet the candle has not moved at all ; it is simply 
that our eyes are two and a half inches apart, and we 
look first with one, and then with the other. The 
direction from the right eye to the candle is not quite the 
direction of the left eye to the candle. The whole shift 
that it appears to us to make is the width between the 
pupils of our two eyes, as this would appear to a person 
in the place of the candle. Now the width between our 




The Solar Surface, showing the Blurring of the Granulations. 

Diameter of the Solar image = 3 feet. 

(From a photograph taken July 10, 1887, 7/;. 35'«. 55^'., Paris Mean Time, at tlie Meudon 
Obsen'atory, by the late Professor Jatissen.) 








eyes to that person will seem greater or less according 
as he is near or far from us ; the farther he goes away 
the closer together will our eyes appear to him. If 
we measure the distance between our eyes, and measure 
the shift that the candle seems to make, we can tell the 
distance that it is from us, even though we do not 
measure the distance to it. {See Plate XXII. , fig. 2.) 

It is in exactly the same way that we can measure 
the distance to the moon, and so tell her real size. We 
do not do it by shutting first one eye and then the other, 
and measuring the shift of the moon in the sky, because 
the moon is so very far away, that her shift — the distance 
between our eyes as seen from the moon — is too small 
for us to perceive it. The moon is so far away that we 
must look at her direction from two points that are 
thousands of miles apart, instead of a few inches, in 
order to get a sufficient change in the place she seems 
to have. 

.But here are two difficulties. When we measured 
the distance of the candle by observing its apparent 
change of place as seen with the one eye and the other, 
we watched it shift with respect to something much 
more distant. But what is more distant than the moon ? 
The stars, and to them we can refer the moon's place. 

Instead of our two eyes we can take two very distant 
observatories. The Royal Observatory, Greenwich, 
was built largely in order to observe the moon ; and 


in order to co-operate with it — to be, as it were, the 
second eye — the Royal Observatory at the Cape of Good 
Hope was built. Now these two observatories are 6,000 
miles apart, and the moon, as seen from Greenwich, 
does not seem to be in precisely the same part of the 
sky as it is when seen from the Cape ; indeed, the 
apparent change' of place is two and a half times 
the apparent diameter of the moon, or nearly so. Now 
this is the apparent distance apart of two objects which 
are really a foot apart if viewed from a distance of forty 
feet, or a yard apart if viewed from forty yards. In 
other words, the moon is forty times the distance between 
the two observatories at Greenwich and the Cape, that 
is, nearly 240,000 miles ; more exactly (for we have only 
dealt in round figures hitherto), 238,400 miles. (See 
PlateXXII., fig. 3.)- 

But we have a far more difficult problem when we 
try to measure the distance of the sun. First of all, we 
cannot measure his position with reference to the stars, 
as they are not visible by daylight. Next, the sun is 
not an easy body to observe. He is large, with his 
rim ill-defined, and is so bright and hot that we cannot 
get his centre with precision. We should need to get 
his centre exact to the one eighth-thousandth part of a 
hair that we are holding about a foot distant, where we 
can see it best. Yet we could not tell where is the real 
rim of the sun by the breadth of many hairs. 


The third difficulty is, as before, to get a ' base-line ' ; 
that is, to get two places sufficiently far apart from whence 
to make our measurements. 

The first two difficulties we can get over together by 
measuring the distance — that is, getting its shift with 
respect to the stars — of one of the sun's planets instead 
of the sun himself. We can always draw a map of the 
solar system, accurate to any degree we like to name, at 
any given moment, but we do not know the scale on 
which that map is .drawn ; we cannot say how many 
millions of miles should go to the inch. 

Let us select the planet Mars, Let S be the sun, 
MiMa be the orbit of Mars, E1E2 be the orbit of the 
earth. Then Mars makes one complete revolution in his 
orbit in 687 days, and the earth in hers in 365^. We 
know both of these times by observing when Mars 
and the sun return to the same place amongst the stars. 
Note the date when Mars is in opposition ; that is to 
say, when he lies in the same straight line from the 
earth to the sun. After a certain number of days, say 
four months, when the earth has reached Eg, note his 
elongation or apparent distance from the sun. This is the 
angle MgEgS. We know the length of time that it takes 
Mars to travel right round his orbit, and therefore we 
can tell how much of it he describes in 1 20 days ; we 
can tell the angle MjSMj. Therefore we know the pro- 
portion that the distance SMj bears to the distance E^S, 


though we do not know the actual measure of either. 
If we can measure the distance to Mars, therefore, we 
can tell the distance to the sun. {See Plate XXII., 

fig. 4-) 

We can get over the difficulty about the length of 
the base line, from whose ends we should measure, 
without leaving the spot on which we are standing. 
The earth is a great spinning globe, and we who stand 
on its surface are some 8,000 miles away in the morning 
from where we were in space twelve hours before, 
even if the earth were not moving in her orbit round 
the sun. Suppose, now, that Mars is at opposition, and 
that we fix both Mars and the earth for a while in their 
places, preventing them from moving round the sun, 
but not preventing the earth from spinning on her axis, 
Mars, being on the other side from the sun, seems to 
rise as the sun sets, and sets as he rises. But the 
direction of Mars should seem to us to shift, as the 
earth turns round, from EM^ as we saw him when 
rising, to WMzy as we saw him when setting. We 
know the distance ECW, for it is the diameter of the 
earth, and we have just measured the angle EMW, so 
we can tell the distance EM. This is the principle of 
the method, but, of course, as neither Mars nor the 
earth have remained fixed in their places during the 
twelve hours or so that have elapsed between two 
observations, corrections have to be made for the 


distances that they have travelled. (See Plate XXII., 

fig. 5-) 

Mars is the best of all the major planets, as it is 

outside the earth's orbit, and it is the nearest of those 
outside, but some of the minor planets are better than 
Mars for this purpose. One in particular, Eros, some- 
times comes nearer to the earth than any other heavenly 
body except the moon, and it is also such a small point 
of light that there is no difficulty in deciding its centre. 
Figure 6 in Plate XXII. will indicate how the shift 
is measured. Suppose that Si, S2, and S3 are stars, and 
Ee is the position of Eros in the evening shortly after 
rising ; Ew the position in the morning shortly before 
setting. The distances of Re and Ew from these stars 
are measured, and the differences between the measures 
when corrected for the motion of the little planet and of 
the earth, gives the shift in the interval of time between 
the two observations. {See Plate XXII., fig. 6.) 

By this method, or by some method like it, it has been 
found that the average distance of the earth from the 
sun is 92,892,000 miles, but this value may perhaps be 
too great or too small by about 1 20,000 miles. This is 
the average distance, for as the earth does not move 
round the sun in a circle, they are nearer to each other 
at one time of the year than at another ; in winter they 
come as close as ninety-one millions of miles ; in summer 
they are as far away as ninety-four millions. 


It is hard to picture such a distance to one's self, or 
even to conceive of it. There are about ninety-four 
millions of seconds in three years, so that if we travelled 
a mile in a second and went straight from the earth to 
the sun, we should not reach him in less than three years. 

And if the sun is so far away, how big must he be .-* 
As nine feet is to the size of the halfpenny, so is ninety- 
three millions of miles to the size of the sun. This sum 
in proportion works out at 866,400 miles for the diameter 
of the sun ; the diameter of the earth being only 7,920 
miles, not the one-hundredth part. The sun's great 
globe would contain 1,300,000 of the quantity of matter 
in the earth. 

Sir John Herschel long ago gave directions for 
making a model of the solar system to scale which will 
give an idea of how vast are the distances which separate 
its members. On a wide level common, place a globe 
two feet in diameter to represent the sun. At a distance 
of 82 feet from it put a mustard seed to represent 
Mercury ; a pea at 142 feet would stand for Venus, and 
another pea at 215 feet for the earth; whilst Mars 
would be indicated by a peppercorn at 327 feet. A 
fair-sized orange nearly a quarter of a mile from the 
central globe would stand for Jupiter, whilst the minor 
planets would be represented by minute grains of sand, 
mostly from 500 to 600 yards from the centre, though 
some would be as near as Mars, others as far as Jupiter. 


Saturn would be a small orange at two-fifths of a mile, 
Uranus a large cherry at three-quarters of a mile, and 
Neptune a plum at a mile and a quarter. 

If these little models of the planets were set in 
motion, then, in a day, the mustard seed for Mercury 
would have to travel a yard ; the peas representing 
Venus and the earth 24 inches and 22 inches respec- 
tively. Mars would move 18 inches, Jupiter 10 J, 
Saturn 7^, Uranus 5, and Neptune 4 inches. The 
further off from the sun a planet is, the more slowly it 
moves in its orbit. The moon, on the same scale, 
would be a smaller seed than Mercury, moving with 
the earth, but at a distance of about 6f inches from it. 
Its daily motion round the earth would only amount to ' 
about two-thirds of an inch. (See Plate XXIII.) 

When we looked at the sun and saw a spot on it 
with the naked eye, it looked no bigger than the head 
of a small nail driven into it. But what must have 
been the size of that spot to be seen at all ? If we 
placed a globe the size of the earth on the face of the 
sun, it would look no larger than a halfpenny at three 
hundred yards ; but a halfpenny at three hundred yards' 
distance from us we could not see at all. A naked- 
eye spot cannot be smaller than 25,000 miles across, 
more than three times the diameter of the earth. 

And many of the spots cover an area of a thousand 
million square miles or more. Cavities, they seem to 


yawn, so vast that they might swallow up Earths as 
peas might be poured into a saucer. If then the grains 
and granules on the sun are the flecks of foam, the 
faculae are the billows, and the spots are the eddies on 
this sea of flame, what vast powers and forces do we see 
here in action ! 


SIN BAD the Sailor relates in one of his adventures 
that he and his companions once encamped on what 
they took to be a desert island. Just as they were 
settling down to their evening meal, the supposed island 
began to sink, for it was a whale that had been wakened 
out of sleep by the inconvenience of having a fire lit on 
his back. There are certain points of resemblance that 
we may note between islands and whales, and certain 
points of difference. Both are situated in the oceans of 
our globe ; both partake, of the earth's daily rotation on 
its axis. But islands are fixed in their places; we define 
their position by their longitude and latitude on the 
earth; if we go, and return to them, we are sure of 
finding them in the same place as we left them. Not so 
with whales. They migrate, and where we have seen 
one once, we cannot expect to see it again. But, though 
whales do not obey the laws of islands, they are not 
wholly lawless. They may not remain fixed in the 
same spot, but they are constant to certain haunts. 



Whalers must sail to their peculiar localities, must seek 
them in their own seas to find them. 

With sun-spots it is as with whales rather than with 
islands. They are not to be found everywhere on the 
sun's great sea of flame ; they have their own peculiar 
haunts, beyond which they rarely stray ; nor are they 
always to be seen upon the surface even in these. 

Unlike islands they are not fixed, but they migrate, 
wandering to and fro. Our earth turns on her axis as a 
whole, and one part does not pass or lag behind another. 
Not so with sun-spots. If we were watching the spots 
on the sun's equator in order to determine the rate at 
which he turned, we should decide that he took about 
twenty- four and a half days to complete a rotation. If 
we watched the spots of latitude 35°, he would seem to 
take nearly twenty-seven days. This would be very 
much as if islands on the equator of our earth, like 
Sumatra and Borneo, had a day of twenty-three hours ; 
whilst islands in the position of Japan would have a day 
of twenty-five hours. It is quite clear in such a case 
as this, that Japan would lag behind Sumatra and 
Borneo, which would gain about 2,000 miles upon it in 
every rotation of the earth. Such a state of things 
of course could not take place on any solid globe, 
and we know, therefore, that we are watching on the 
sun no solid structure, but rather the upper surface 
of a shell of glowing clouds — clouds that move far 




Plan or the Solar System 





more freely, far more quickly, than any clouds in our 

Next, as to the peculiar haunts of sun-spots on the 
sun, we have seen in the Story told by the Sun's 
Surface that he turns on his axis in about twenty- 
five days, as the earth turns on h^rs in twenty-four 
hours ; so that he, too, like the earth, has his poles and 
an equator. It is very rarely that any spots are found 
outside the parallels of the sun's latitude that are 35° 
north or south of the equator. A very few have been 
found in a latitude so far from the equator as 40° ; one 
spot has been seen in 50° ; but all of these were very 
small, and lasted for no longer than two or three days. 
The seas in which we find the solar whales are ' tropical ' 
or 'sub-tropical.' Should we compare the spot -zones 
with those of our geography, we should include the whole 
of the inhabited region of the southern hemisphere ; 
but we should exclude, in the northern hemisphere, all 
Europe, Canada, and all the northern confederacy of 
the United States, and all Siberia. 

Nor do the solar spots migrate freely between these 
limits of 40° north and south of the solar equator. 
Rather there seem to be narrower zones within which 
the spots that arise there may move, but beyond which 
they may not transgress. This seems the first law laid 
upon them. 

The next law seems to be that in any particular 



zone on the sun's surface spots do not arise at all times, 
but only at particular times do spots seem to be formed. 
There are long intervals when the zone breeds no spots 
at all. (5^^ Plate XXIV.) 

The third law seems to be that though spots do 
not stray from one zone to another, there is a bond of 
connexion between the different spot-breeding zones, 
for there is an order observed in the times of breaking 
out of spots in neighbouring zones. 

Let us take an example from the southern' hemi- 
sphere, and divide it into zones 5° wide. 

Southern Hemisphere. 

5° zone in 

Period when 

Period when 

Period when 

Period when 


spots were 

no spots 

spots were 

no spots 



were visible. 


were visible. 


1880 July U 

1881 Apr./^ ^^■ 

9 yrs. 

1890 MayUi vrs 
1893 Nov.P^ yrs- 

-9 years. 


i88oFeb.\, „,^ 

sf „ 

1889 Dec.l 1 
1^95 Max.P^ " 

7 „ 

1880 July \ 
1885 Aug./5 » 

1889 Aug.1, 
1896 Aug./' " 

4 ,, 


4 )) 


1887 Nov./** " 

If » 

1889 Aug.Uo 
1898 Apx.n " 

3* » 


1888 Dec./" " 

2i „ 

1891 Junelgs 
1900 Apr. / » 

2i „ 


1881 May\„i 
i89oAug./9* " 

2 ,, 

1892 July ^ 2 
1902 Feb./'^ " 

i| ., 


1882 Mar.\ 1 
1889 Aug./'* » 

3i „ 

1893 Decj J 
1903 June/^^ >' 

2} ,, 

There are several interesting points to note about 
this table. In the first place there is quite a long 
interval of time between two outbreaks of spots in any 


of the zones ; always a year or two, perhaps many 
years ; so that there is no doubt as to when an epidemic 
of spots begins and ends in any particular zone. Next, 
the time during which the outbreaks last is shorter, and 
the interval between the outbreaks is longer, for the zones 
which are farther from the equator, than for those nearer 
to it. It is as if our solar whales belonged to different 
species in the different zones, and sought the solar 
depths for periods of time that varied with their distance 
from the solar equator ; and then brought the young 
schools to the surface to sport for lengths of time that 
again varied with their distance from the solar equator. 
Third, the whole time from the beginning or end of one 
outbreak of spots until the beginning or end of the next 
does not greatly differ for the different zones. If a 
school of solar whales stay long upon the surface, it 
must stay the shorter time below ; and the two times 
together make up about eleven years. Fourth, the 
outbreak of spots in the zones far from the solar equator 
begins earlier, and therefore ends much earlier, than those 
outbreaks that are near the equator. This is so marked, 
that we have a new outbreak starting in the highest 
latitudes before the old outbreak in the lowest latitudes 
has subsided. During a period, then, of about eleven 
years we seem to have an outbreak of spots on the sun 
beginning in the regions farthest from his equator, and 
spreading to the lower zones, increasing for a while as it 



spreads. Finally it dies out at the equator, when a new 
outbreak of spots has already started in high latitudes. 
This period of change is called the sun-spot cycle. 

The first spots of a cycle are few and small. During 
the next three, four, and five years they increase rapidly 
in number, and many of them in size, and they occur 
most frequently in latitudes that lie between io° and 25° 
from the sun's equator. Their number, and the spots 
of large size, are fewer and fewer during the next six 
years or so, and the spots that appear are frequently in 
the lower latitudes. The last spots of a cycle, again 
are few and small. 

What do we mean by small spots or large spots? 
We measure whitings by inches, whales by feet, and 
islands by miles. What is the measure that we should 
apply to sun-spots ? We measure them in terms of the 
space on the sun's disc that they occupy : in millionths 
of the sun's visible surface. The smallest spot that we 
measure would occupy about the one millionth of the sun's 
disc, and the biggest might occupy as much as three 
thousand millionths. To know how big any sun-spot 
is, we must therefore know how big the sun is. This 
we found in the last chapter has a diameter of nearly a 
million miles, so that the surface of its hemisphere 
visible to us is more than a million million of square 
miles; therefore, the smallest spot we can measure 
covers an extent of ground of at least a million square 


•-0 A 
O z 

— o 
O 2 

l1 ^ 



O 5 

» ^SP* •**" 

o Z ° 






miles, the bigger spots hundreds or thousands of times 
this area. The smallest spot we measure would be 
about half the size of Russia, Poland, and Finland 
together; into the larger spots there might be poured 
worlds like ours as peas are poured into a saucer. (See 
Plate XXV.) 

As a general rule, the bigger a sun-spot the longer 
it lives ; but the life of any sun-spot, huge though it is, 
is but short, as we reckon time. Very many spots do 
not last through the twenty-four hours of our day ; 
the area that an average spot of this longevity would 
occupy is about twelve millions of square miles. The 
average area of a group of spots lasting for eight days 
is about twenty-two millions. The longest time that any 
group of spots has lasted, during the last quarter of a 
century, has not been as much as seven months. The 
disturbances of the sun's surface are stupendous and on 
a vast scale, but they do not last for long. 

The sun-spots do not stray from their peculiar zones, 
but in the zones they move with considerable freedom. 
The Law of the Stars is that they neither haste nor rest, 
they do not jostle each other nor lag behind. Not so 
with sun-spots. They move more quickly or more 
slowly, they may jostle each other or move apart ; the 
same spot does not move always at the same pace. 
The very zones seem to move at different rates, the 
low latitude spots moving as a rule more rapidly than 


the high latitude. The rate at which the sun, as a 
whole, appears to turn round may not be the rate at 
which any spot travels ; it is but the average rate of all 
the spots, taken at all times. 

What causes the spots we do not yet know. We 
may never know, for their cause seems to lie deep down 
in the sun itself, and we can but see the sun's surface ; 
we do not know how to probe beneath it. We cannot 
tell if it is the same cause that gives rise to the outbreak 
of spots in each zone, eleven years after eleven years. 
If the spots are the same, cycle after cycle, we have no 
means of recognizing them. We can recognize again a 
star by its place in the pattern of stars ; we can do the 
same with a planet by its colour and its movements ; we 
can know again an island on the earth, for it does not 
change its place ; we can even know again a whale if it 
has had a harpoon driven into it ; but how are we to 
know a sun-spot when it emerges again from the solar 
depths ? 

We do not know what makes the sun-spots, or what 
brings about their changes. We have learnt, neverthe- 
less, some of the laws that seem to govern their changes, 
some of the fixed rules that they obey. Of the laws of 
faculae we know less than of sun-spots ; we cannot see 
them except near the sun's edge. (See Plate XXVI.) 
We know that they too lie in zones of latitude, and these 
zones extend farther from the sun's equator than do the 


sun-spot zones ; that they diminish and increase in a 
cycle of years as do the sun-spots ; that they move at 
a different rate from the sun-spots. We know that 
they change, but their forms are not defined as are the 
spots, and we do not know their manner of change, or 
their lengths of life. Of the grains and granules that 
cover the sun's whole face we know still less. We can 
see that they change continually and rapidly, but how 
they change, or if their changes run through a cycle, 
we do not know. 



WE cannot see the stars in the daytime. This is not 
because the stars are not there, or have lost any 
of their brightness, but because the sun is himself so 
bright that he lights up the atmosphere, and we cannot 
distinguish the brightness of the stars from the bright- 
ness of the sky. We have to wait until the sun is 
gone down below the earth, and no longer lights up the 
night sky, to see the shining of the stars. We do not 
see the sun's bright faculae in the middle of his disc. 
That is not because there are no faculae in the middle 
of the sun's round disc, nor because the faculae there 
have lost their brightness. It is because the middle of 
the sun is as bright as the faculae that we cannot see 
the one for the other. We can only see the brightness 
of the faculae near the sun's edge where the sun's atmo- 
sphere has dimmed its brightness. We do not see the 
light of a candle if we hold it up between us and 

the sun. It is not that the candle flame has lost its 



light, but it is because the flame is not brighter than the 
sun. To see the shining of the lighted candle we must 
hold it away from the sunlight, or else we must put 
something, a book or some screen, between the flame 
and the sun. 

How can we tell, then, that we see everything that 
there is on the sun, or near the sun ? The sun has an 
atmosphere, we know, for it dims the sun's light near 
his edge. Can we see this atmosphere extending 
beyond the sun ? Can we tell if there is anything but 
atmosphere surrounding the sun ? Heliography is so 
different from geography that we cannot be certain 
unless we know; sun-spots, for instance, behave more 
like whales than like continents or islands. 

It is no use to hold a screen up to shut off the sun's 
direct light. The sun still lights up the air in the sky 
so greatly that we could not distinguish any other light. 
We would need to hold the screen right outside the 
atmosphere, far away in the airless space that lies 
between us and the sun, where it would prevent the 
sunlight falling on the earth's air. We have no pole 
long and steady enough to hold up such a screen. 

There is one object that might act as such a screen. 
The moon appears to us to be of very nearly the same 
size as the sun, and we know that she is in herself a 
dark globe. If, then, the moon were exactly in a line 
with the sun and earth, she would blot out a part or the 


whole of the sun. Here, then, is the screen that may 
allow us to see the sun's surroundings by covering up 
the sun itself. But to do so, the moon must cover the 
whole of the sun ; if she only partially covers him, his 
uneclipsed part is brilliant enough, be it never so small 
an arc of sunshine, to drown the sky and all near him 
in a sea of light. When the moon completely covers 
up the sun's disc, she does so only for a short time ; it 
may be for a few seconds, or at the very longest, eight 
minutes. She does so rarely ; on an average there may 
be once in two or three years a total eclipse of the sun 
where it is possible to observe it. The whole amount 
of time available in half a century of eclipses may not 
exceed an hour. 

One of the most impressive sights that the heavens 
afford us is an eclipse of the sun. When the sky is 
clear and the sun unclouded, then there is little time to 
spare for anything terrestrial. One observer, at Algiers, 
of the eclipse of 1900, describes it thus : * The sky was 
deep purple, while over the sea was a strange light on 
the horizon ; a compromise between a thunderstorm 
and a sunset. The colour faded from the sea and trees, 
a shouting and wailing arose from the square below, the 
light was fading; suddenly the moon slipped over the 
sun and the eclipse was total. A deep purple sky, a 
black globe, surrounded by a crimson glow, and above 
and below it a milk-like flame, stretching its long 




streamers away into the purple.' But when clouds hide 
the eclipsed sun, then the weird effects, upon landscape 
and seascape, of the sun darkened whilst it is yet day, 
are the only observations that can be made. An 
astronomer writes of the cloudy eclipse in Lapland of 
1896: 'I observed that the clouds, which had been 
lightish grey, had suddenly assumed a very deep 
blackish-purple colour, while the whitish spaces between 
the clouds were glowing with a vivid amber-yellow tint. 
It seemed that the whole scene was illuminated by this 
amber light ; the colours of objects around were quite 
perceptible, but much subdued. The distant hills were 
dark indigo, and the sea very dark, except where 
it reflected the streaks of amber light. The whole 
effect was lurid and impressive in a high degree.' And 
yet another observer of the same eclipse likened the 
cloud-covered sky to a purple pall with a golden fringe, 
canopied over the earth. Lord Hampton, also an 
observer of this same eclipse, painted the scene, and his 
painting is here reproduced by the kind permission of 
his son and daughter. {See Plate XX VH.) 

There is not much time then for us to study the 
sun's surroundings. And when the moon has completely 
covered the sun, we see that there is so much in his 
surroundings that is novel and unlooked-for, that we 
have a good deal to study. 

The moon has completely covered up the sun's disc ; 


and as the sun and moon appear to be just about the 
same size, the moon can only just cover the sun, with 
but little, if any, to spare. Instead of the brilliant orange- 
coloured sun, we see blackness, for the moon gets no 
light now except from the sunlit earth. But round this 
blackness, fringing it, is a bright, red, ragged rim. This 
does certainly not belong to the moon — whether we see 
her waxing, or full, or waning, we see her outline hard 
and sharp, either sharp moonshine or sharp blackness. 
This red, ragged rim belongs, then, to the sun — it looks 
as if he were covered with a fiery red Turkey carpet, 
whose burning pile was pulled and torn. Everywhere 
round the moon's edge is seen this red rim; everywhere, 
then, on the sun does it lie. {See Plate XXVIII.) 

But this red rim is not all. Here and there are 
tongues of flame. Not the peaceful, steady flame of a 
bat's-wing gas burner, but twisting, turning serpents' 
tongues. They are not always most like flaming tongues ; 
sometimes they are tree-like : trees spreading as do 
the cedars in Turner's pictures, or burning, bent and 
bowing under a strong wind, and shedding their fiery 
leaves in the blast like a flaming shower. There are 
tongues of silver flame sometimes, as well as tongues or 
trees of red fire. And enveloping both in a wonderful, 
pure, cold radiance, stretching out far beyond them, 
is a silver glory : not a halo only, but a crown, a 
glory like nothing else that we see on earth or in 


'SI '~~ 

o 0) 



the heavens. We must compare it to many things, for 
no one comparison can convey what it is like. It is like 
a silver mist, it is like ivory gauze, it is like the wings 
of an angel, it is like the petals of the lilies of heaven. 
Its form takes on here and there the shape of a flower- 
leaf, and when I saw the sun's eclipse in 1898 it seemed 
to me as if a child had been playing the game of ' Loves 
me, loves me not,' until but three or four of the sun- 
flower's petals had been left on the red-rimmed, black- 
hearted stalk. {See Plate XXXVII.) 

Red rim, fiery flames, and silver radiance — * chro- 
mosphere,' ' prominences,' and ' corona ' — are there 
whether or not we can see them, whether or not the sun 
is eclipsed. In every eclipse we see them at the edge 
of the sun. But though we can only see them at the 
edge of the sun when it is undergoing eclipse, since the 
sun turns round, all must be everywhere on the sun's 
surface, no matter in what direction it is presented. On 
the sun's disc turned towards us there must be, not only 
the granules, spots, and faculae that we can see, but also 
the chromosphere, prominences, and corona that we do 
not see or recognize. 

All these belong to the sun. What connexion have 
they with each other ? What effect have they on each 
other } 

These questions we can only answer in part as 
yet, for they are some of the problems that we are 


still trying to solve, and for the answer we go to the 
ends of the earth to see an eclipse of the sun. The 
corona we can, as yet, only see during a total solar 
eclipse. The spots, faculae, and granules we cannot see 
during an eclipse, for then they are covered by the 
moon. Prominences and chromosphere we see during 
an eclipse ; but, by means of the spectroscope {see 
Chapter IX.), we can see the chromosphere and some 
of the prominences when the sun is not in eclipse ; some 
of the prominences only — the scarlet ones, but not the 
white. Here, then, is a connecting-link, by which we 
may perhaps learn if sun-spots have aught to, do with 
the corona. 

As we have said, red rim, fiery flames, and silver 
corona are there whether we can see them or not ; but 
they are not always the same. They are different in 
form and shape and place from one eclipse to another. Is 
this because they turn with the sun, and we see a different 
edge in each eclipse ? or do all change continually, and 
in cycles of years, as do the spots, the faculae, and the 
granules on the sun's surface ? 

The prominences rotate with the sun. Whether 
the sun is eclipsed or not, whether we observe them 
without the spectroscope or with it, we see their form 
and their changes when they are on the edge of the sun. 
But we see them coming out of the visible hemisphere 
upon the eastern edge, and we can see them disappear 


Eruptive and Quiescent Prominences. 

The upper group of prominences was observed on April 29, 1873,, at iqIi 5"^ a.m. It changed its form 

very rapidly. Its extreme height at the time of observation was 90,000 miles. The lower group was 

observed on April 15, 1872, at 10'' o^ a.m. Extreme height, 70,000 miles. Observer, L. Trouvelot. 

F7-oin '■Astronomical Engravings' published by the Harvard College Ohseri'atory. 



at the western into the sun's hemisphere that is turned 
away from us. In this way they behave just as do the 
sun-spots. Therefore, the differences in the prominences 
that we note at different times is due in part to different 
regions of the sun being presented edgewise to us. 
But only in part, for even as we watch the prominences 
stretching beyond the sun's edge, we note that they are 
changing, continually changing, as do sun-spots, and even 
more rapidly. We may watch a prominence spring 
actually into existence, flame up to a height of thousands 
of miles, and die out again ; and all this within the space 
of time of two or three minutes. Or the prominence 
that we have watched on the eastern edge may last so 
long, as still to exist when it has traversed the sun's 
breadth and reached the western edge. Sun-spots 
change, and so do prominences. (See Plate XXIX.) 

Both change in cycles. Sun-spots and faculae 
increase, multiply, diminish, and increase again, in cycles 
of about eleven years. So do prominences ; though 
the three may not coincide, even within a year or two, 
in their epoch of greatest or least display. Sun-spots 
have their zones of latitude beyond which they are not 
found ; so have faculae, but their zones extend further 
from the equator. So, too, prominences have their 
favourite zones, and their zones extend farther still, 
almost up to the sun's poles. 

There are points of closer connexion still between 


sun-spots and prominences. There must be prominences 
where there are no spots, for we find those near the 
poles where these never break out. But if we observe 
with a spectroscope the place on the sun's edge where a 
great and changing spot is just coming or passing away, 
there we are sure, or almost sure, to find great and 
rapidly changing prominences. Sun-spots seem to 
spout forth prominences. 

The corona seen during one eclipse is not the corona 
seen during another. Is this because the corona rotates 
with the sun, or because it changes in itself? 

^ We cannot say that the cc zona rotates as do 
the prominences, spots, and faculae ; we cannot say 
that it rotates as one with the sun, or not as one 
with the sun. We have failed to make any successful 
observations of the rotation of the corona on the sun 

But we do know that it changes its form, and we 
know that it does so in some sort of sympathy with the 
changing prominences arid sun-spots. When there are 
many sun-spots, and they are scattered widely over the 
zones in which they may appear, then the silver petals 
of the great sunflower are many, and surround the 
whole of the stalk. The child has not begun to play 
the game of * Loves me, loves me not,' has not plucked 
out any of the silver petals, but has only ruffled them, 
broken them, cramping one behind another in a bunch 


Southern Region of the Corona of JIay iS, igpi, showing the polar 'phimes.' 
(From a photograph by Mrs. ll^iltcr Maunder, taken in Mauritius.) 



Eastekn Region of the Corona of May iS, 1901. 
(From a fhotogrttpli by Mrs. Walter Maunder, taken in Mauritius.] 



here, or spreading them out thin there. But he plays 
his game as the spots diminish and creep downward to 
the sun's equator ; the petals are ruthlessly pulled out, 
and if we look upon the eclipsed sun at such a time, we 
see but the short protecting leaves, and here or there a 
long petal remaining, looking longer by its solitariness ; 
and when the cycle has reached its time of minimum 
activity, and the sun-spots lie only in two narrow zones 
to the north and to the south of the sun's equator, then 
the resemblance to the silver sunflower has departed^ 
and the sun's corona has become like four great wings : 
angels' wings, folded wings ; one pair stretched along to 
the east of the sun, the other pair to the west. Whilst 
round the north and south poles of the sun a beautiful 
row of fine plume-like rays is seen, each plume bending 
more or less away from the pole. The corona, like the 
prominences, the spots, and the faculae, has its cycle of 
changes, which it runs through in about eleven years. 
{See Plate XXX.) 

Bufthere is a closer connexion still between the 
changes of spots, prominences, and the petals of the 
corona. Spots give forth or spout prominences, and the 
base of the corona petal seems to envelop or stand upon 
the spot group, though stretching out far beyond it on 
all sides. Directly above the prominence the material 
of the petal seems forced up to form a dome, or rather, a 
series of domes or groined arches. The prominence 


looks as if it were sheltered beneath a number of glass 
cases. {See Plate XXXI.) 

As the prominences and spots change, so they seem 
to change the form of the corona lying round and just 
above them. Nowadays, astronomers strive to observe 
an eclipse at places very far apart, because it takes time 
for the shadow of the moon to travel along its path on 
the earth. So the observers who watched the eclipse 
of 1 90 1 in Mauritius watched it an hour and a half 
earlier than the observers who saw it in Sumatra. And 
it was thus found that, in such an interval of time, the 
shape of the corona near the chief spot and prominence 
underwent a distinct alteration. 

What is the shape of the silver petals of the great 
sunflower ? At the broad base of it we often find a 
spot or prominence, or both. Spots and prominences 
rise, live their life, which may be but a very short one, 
and die. And there rise again — in the same zone, it 
may be from the very same region — other spots. From 
these zones, from these very regions, perhaps, the great 
silver petals spring. If the active regions are in the high 
latitudes and in many zones, then many petals arise ; if 
the sun is quiet and the few spots that break out lie 
near his equator, then the petals are few and lie folded 
along the equator. 

But the petals do not have a round or pointed tip ; 
the outermost groined arch that covers the place where 


the prominence is, or has been, is not complete, but 
seems to taper out indefinitely into a long, rod-like ray. 
How long the rod-like ray extends we cannot see. One 
that was photographed in the eclipse of 1898 was seen 
to stretch out from the sun for at least eleven millions 
of miles. In the Story told by the Sun and Earth 
together (Chapter X.), we shall see that such a length 
is probably but a small fraction, but a tithe, of its extent. 




THE earliest astronomy was learned by the exercise 
of the unaided sight. Men watched where the sun 
appeared to rise and set, they noticed the changing 
phases of the moon, and how different constellations of 
stars were seen on different nights of the year, and from 
these, and many other such observations, they formed 
their first ideas of the relation of the earth to the rest of 
the universe. Three hundred years ago the telescope 
was invented, and ' astronomy ' took on a much wider 
meaning. Men were able to read far more in sun, moon, 
planets, and stars than they had ever dreamed of before. 
But just as the astronomy of the telescope had advanced 
far beyond what was possible to the astronomy of the 
unassisted sight, so, fifty years ago, a new instrument 
extended men's powers of research far beyond anything 
which the telescope could have done, and gave birth to 
a yet newer and more searching astronomy still. 

This newer astronomy might well be called the 



'Story told by the Rainbow,* for the many-coloured 
arch of light ' seen in the cloud in the day of rain ' is 
at once the type and an example of the principle of 
the new science. 

We know that if sunlight is allowed to fall upon a 
triangTilar piece of glass, a rainbow-coloured strip of 
light emerges from it. At one time it was much the 
custom to have chandeliers and gasaliers of glass hung 
with a number of long, triangular glass pendants. The 
light falling on such a chandelier would pass through it 
to form a great number of beautifully coloured images 
on the wall behind. The light fell upon these prisms, as 
the triangular pieces of glass are called, as white light ; 
it came forth as coloured light. 

The explanation of this is simple. Light is made 
up of an infinite number of very small vibrations, or 
waves, and these waves are of different lengths, the 
longest giving us the impression which we call red ; 
the shortest the impression which we call violet. Now, 
light moves forward in straight lines, but when it 
passes from one medium, like air, to another medium 
of a different density, like glass, it is bent out of its 
course and travels in a different straight line through the 
second medium. Passing out of that second medium 
again into the first, the course is again changed, and 
the amount by which it is changed on each occasion 
depends partly on the relative density of the two 


media, and partly on the angle at which it meets the 
new surface. 

Here it is that the principle of the prism, of the 
triangle, comes in. A ray of light passing through a 
sheet of glass with parallel sides would be turned 
out of its course indeed, but its final course would be 
parallel to its original course, because its change of 
direction on leaving the glass would be just the reverse 
of that on entering it. But if the two sides of the piece 
of glass are greatly inclined to one another, in other 
words, if the glass is a prism, then the direction of the 
light after leaving the prism is quite different from that 
which it had before entering it. 

This is what is called the refraction of light, but 
there is another effect. The very short waves of light 
are turned more out of their course than the very long. 
Consequently, the many different waves which entered 
the glass all in company leave it separately. If we had 
a company of men advancing at the double over smooth 
ground they would keep together, but if they came on a 
piece of difficult ground, irregular broken ground, with 
long grass or brushwood, wedged into the smooth plain, 
the stronger, bigger men would work their way through 
most quickly, and with least change of their direction ; 
the smaller, weaker men would be most hindered, and 
the company would emerge no longer together, but 


In like manner, light falling upon a prism enters it 
as a full company, compact and close, of all the different 
coloured rays, and when all the rays thus reach our eyes 
together, they produce upon us that sensation which we 
call white. But such white light leaving the prism, 
leaves it straggling, each colour following a different 
path, each colour therefore seen more or less separately, so 
that, instead of white light, we get a rainbow-tinted band. 

Now let us make this experiment more carefully. 
We will take a western room on which the sun is shin- 
ing as it nears its setting ; we will close the shutters, but 
in one of the shutters we will bore a small round hole 
(A), so that the sunlight falls on the opposite wall and 
makes a round bright spot (?'), there. If we place a 
triangular piece of glass (P), just inside the hole, we find 
that the spot of light has greatly changed its position on 
the wall and instead of being round it is about five times 
as long as it is broad — red at one end and violet at the 
other (V to R), and with the other colours of the rain- 
bow somewhat less clearly seen in the middle. {See 
Plate XXXII., fig. i.) 

Now, it is clear if there are only seven colours, and 
therefore seven different little coloured spots of sun- 
light, that these must overlap, since the whole image is 
only five times as long as it is broad. None of the 
colours therefore are quite pure, and in the centre of the 
band they are still a good deal mixed. 


Can we get over this ? The simplest way to do so 
would be to have a very narrow slit instead of a round 
hole in the shutter. In that case, we should find that 
the colours were far purer than they were before, and we 
should find also, as did Professor WoUaston, the great 
chemist of more than a century ago, that the rainbow- 
tinted band was not complete ; there were certain narrow 
dark spaces in it. In other words, the sun sends us 
a great number of different colours, but not every colour 
possible. This we can test by substituting a very bright 
artificial light, like the limelight, for the light of the sun ; 
no matter how narrow and sharp we make the slit, we 
get no dark lines amongst the colours coming from the 

It is not always convenient to set apart an entire 
room for the purpose of such an experiment, and a little 
instrument was devised for the study of the sun's 
spectrum, as the strip of rainbow light was called, which 
was at once much more convenient and more powerful. 
This instrument was called a spectroscope. A metal 
slit (S) was provided, the breadth of which could be 
regulated by a screw, and this admitted the light into 
a tube (A), carrying a lens, called a collimator, at the 
other end. The tube was of such a length that the 
slit was exactly in the focus of the lens, so that the rays 
of light diverging from the slit were rendered parallel by 
it ; then came a box containing a prism (P), and the 


Fig. I. — Path of Kays through a Prism. 

Fig, 2. — Simple .Spectroscope. 


Fig. 3, — Plan of Simple Spectroscope. 


^^^E A ''^^?^^%i^'i^^^l 
^^B,^^^^'^'^^^-^ ^^H 



:: V -I. 

3 :^ C : 

■uinjiogdi^ J^'|C'S i" l-'^J 

■LU[i4]D3dg mnipoc; jo S3ui';[ ii.|Siig 



rays, after they had passed through the prism, were 
examined by a small telescope (B). 

Such is the form of a simple spectroscope. Spectro- 
scopes of great size and very complex form are now 
common, but such a simple spectroscope as that just 
described exemplifies the fundamental principle of all. 
{See Plate XXXII., figs. 2 and 3.) 

Turning such a spectroscope upon the sun, it was 
seen that its 'spectrum,' that is to say, the long coloured 
band into which the sun's light was spread out, was not a 
perfectly continuous one, but was interrupted by dark 
lines to the number of many hundreds, or, indeed, if a 
very powerful spectroscope be used, of many thousands ; 
and that these lines were distributed irregularly through- 
out all the colours, making up a definite pattern which 
was the same from day to day. {See Plate XXXIV.) 

These lines of the spectrum are the characters in 
which ' the sun's broken light ' tells its story, and at 
first they proved very hard to read. Some of the lines 
were evidently due to the influence of the earth's atmos- 
phere, for they were seen when the spectroscope was 
turned upon the sun near his rising or setting, that is to 
say, when he was looked at through a great thickness of 
our atmosphere ; but they got thinner, fewer, and fainter 
as the sun rose higher in the sky. Many more, obviously, 
belonged to the sun himself, since certain of the stars 
showed different sets of lines. The spectrum of Arcturus 


is very like that of the sun, but the spectra of Sirius and 
Vega, though very like each other, are quite different 
from that of the sun, or of Arcturus. The spectrum of 
Antares, again, is different from both. In short, many 
varieties were found amongst the spectra of stars ; one 
star differed from another, not merely in its glory — in the 
amount of the light it gave — but in the quality of its 
light, and five principal types of star spectra were 
recognized. The white stars gave one type, like that 
of Sirius, some of the slightly greenish stars in the 
constellation of Orion giving a modified form of the same 
type ; the yellowish stars quite another type, like that of 
Arcturus, or Alpha Centauri, or of the sun ; the deeper 
coloured stars like Antares, the chief of the Scorpion, 
gave a third ; and the red stars, of which there is no 
bright specimen, gave a fourth. {See Frontispiece, Plate 

These dark lines in sun or star therefore are due to 
something in sun or star itself, sun and stars each 
sending us a message in their broken light. 

It was a very common substance that gave the key 
to the interpretation of these strange gaps in the 
spectrum. If a candle or spirit-lamp be fed with a 
little common salt or carbonate of soda, a yellow tinge 
is given to the flame. When a spectroscope is turned 
upon such a flame a spectrum is seen which has a very 
bright line in the yellow, and, if the slit is made very 


narrow, it is seen that this bright line is really a 
very close pair of bright lines. These two lines are 
simply images of the slit, through which the light from 
the spirit lamp comes into the spectroscope ; and we 
learn from it that the yellow light of the spirit lamp is 
due to two kinds of yellow light that differ very slightly 
the one from the other. In like manner the dark lines 
in the spectrum of the sun are negative images of the 
slit ; the sun sends us light of many shades, but not of 
all, and the gaps or dark lines in the spectrum are in 
the places corresponding to the missing shades. 

Now, if we look at the sun's spectrum we see, in the 
yellow, a close pair of very dark lines, corresponding in 
position to those given us by the carbonate of soda in 
the spirit lamp. They correspond so closely that if we 
allow sunlight to come through part of the slit of a 
spectroscope, and light from a sodium flame to come 
through another part of the same slit, we shall find that 
the bright lines from the flame are an exact prolongation 
of the dark lines in the sun. {See Plate XXXIII., fig. i.) 

We can go a step further. The limelight, as we 
have seen, gives us a complete spectrum — all the colours 
of the rainbow. A sodium flame gives us the two close 
bright lines. If, then, we look at a limelight through 
the spectroscope, and place a flame plentifully supplied 
with sodium between the spectroscope and the lime- 
light, what shall we see .-* A bright spectrum of all the 


colours with two lines specially bright in the yellow ? 
No. We see a spectrum with the full succession of 
colours, except in the yellow, where there are two dark 
lines. Remove the sodium flame and the spectrum is 
complete. Remove the limelight, and have the sodium 
flame alone, and we have the two bright lines. View 
the limelight through the sodium flame, and in the place 
of two bright lines we have two dark ones. To the 
extent of these two dark lines we have built up an 
artificial solar spectrum. The sodium flame, which had 
the power of sending out light of these two particular 
shades, has also the power of stopping light of these 
two shades ; and the lines which it gives look dark 
because they are so much fainter than the corresponding 
portion of the bright limelight spectrum. {See Plate 
XXXIII., fig. 2.) 

This is the reading of one set of characters written 
for us by the sun in his broken light. His bright 
surface sends out light of every shade — white light — 
but round him, enveloping him, are highly heated, 
glowing gases, themselves giving forth light of certain 
particular shades or colours, and therefore opaque to 
those same colours. These gases, if we could see them 
by themselves, would give us spectra of bright lines; 
but when we look at the body of the sun through them, 
they stop out the light corresponding to those lines and 
give us dark lines. In this way we have been able to 


recognize the presence round the sun of a number of 
elements with which we are familiar here, but in a 
different state. Hydrogen, here one of the two con- 
stituents of water, is there a free gas. Iron, nickel, 
cobalt, magnesium, and many other metals here always 
solids, are there always gases, glowing with intensity of 
heat. The same elements have been recognized also in 
the stars, but in apparently different proportions in 
different stars ; at least, the evidence for their presence 
is given in different manner. 

There are times and seasons when we can see these 
gases by themselves, apart from the sun's light. Some 
of them, as, for instance, hydrogen and calcium, surround 
the sun to such a depth that we can put the slit of 
the spectroscope pointing some distance away from the 
edge of the sun, and yet have some of these gases 
within its field of view. In this way we are able to 
recognize the presence round the sun of a shell three 
thousand miles deep, largely composed of hydrogen 
gas, from which great flames — prominences or protu- 
berances, as they have been called — shoot up from 
time to time to a distance, in some cases, of more 
than 100,000 miles. 

Of these prominences or red flames we first learnt 
during, total eclipses of the sun, when the dark body of 
the moon had cut off the direct light of the sun from 
us, and a great number of the elements more closely 


surrounding the sun show their bright lines to us, for 
a couple of seconds, at the beginning and end of such a 
total eclipse. 

The stories which have been told by the broken 
light of sun and stars would require an entire volume as 
large as this to summarize even in the briefest fashion. 
But there is one further fact told by them that must 
be mentioned here. They have not only told us that 
the sun is made up of elements known to us on the 
earth, and that those elements are there in an extremely 
highly heated condition, but they have been able to tell 
us of movements of those elements, or of sun and stars 
themselves. It sometimes happens that a vast quantity 
of glowing hydrogen gas is shot forth from the part of 
the sun that appears to us as its edge, and we then see 
it travelling away from the sun, for it is moving across 
our field of view ; it seems to be moving on the vault of 
the sky. But it may happen that such a stream of 
hydrogen may rise from the very centre of the sun's disc 
and come straight towards us. Or it may be that we 
are watching a star, and that from some cause or 
another, the star is moving with great rapidity in a 
straight line either towards or away from the earth. 
These motions are what we call ' motion in the line of 
sight,' or ' radial motion,' because it is motion along a 
radius having the earth for its centre. Now, if the star 
or the hydrogen gas is coming towards us, then the fact 


of it so approaching us will make the waves of light 
appear little shorter than they really are ; we shall meet 
more of them in a second of time than we should other- 
wise have done. Any particular line, whether bright or 
dark, in the spectrum of the body thus approaching us, 
would therefore seem to be shifted just a little towards 
the violet end of the spectrum, the end of the short 
waves. If the body were moving away from us, the 
shift would seem to be towards the red, the end of 
the longer waves. In this way we have been told 
of movements towards us or away from us, whether of 
gas streams in the sun, or of stars far in the depths of 
space — movements which formerly it seemed hopeless 
that we should ever detect. 



WE have already seen how great are some of the 
spots that form upon the sun. Thus on February 
13, 1892, there was a great group on the sun, the 
principal member of which was 92,000 English miles in 
extreme length, and 62,000 in extreme breadth. Smaller 
spots accompanying the chief disturbance were seen 
round it on every side, so that the entire group was 
162,000 miles in extreme length, and 75,000 in extreme 
breadth. . The area covered by the chief spot was close 
upon 3,000 millions of square miles, or, including the 
smaller spots that clustered so thickly round the central 
one, the area covered by the whole group was upwards 
of 3,500 millions of square miles. Such an area is more 
than seventeen times that of the entire surface of the 
terrestrial globe ; or, to put the matter in another way, 
some seventy worlds as large as our own could have 
lain side by side in that immense hollow. 

Even larger spots than this have occasionally been 



seen. In February, 1905, another great outbreak 
attained an area of very nearly 4,000 millions of square 
miles, and groups of half that size are not very infrequent 

Now, at first sight, it would seem as if a spot of such 
dimensions could not fail to produce a great effect upon 
the earth. If there was an object as bright as the sun, 
surface for surface, and of the same apparent size as the 
great spot of 1892, shining in the;nidnight sky, it would 
give us more light than 3,500 full moons, and 130,000 
times as much as all the stars in the heavens put 
together. Now as the spot appears to us to be dark, it 
might seem that whilst it was marring the sun we were 
losing this enormous amount of sunlight. Indeed, when 
we compare the position of the earth with that of the 
other planets dependent on the sun for their light, it 
seems manifest that the spots represent a most im- 
portant loss ; for the entire sun does not look nearly 
as large from Uranus as this great spot appeared to us. 
Even Saturn, bright and readily seen as that planet is, 
does not receive much more than twice the light from 
the sun that we receive from a part of the sun equal in 
area to the sun-spot. 

These figures have led many people to expect an 
immediate and striking change upon the earth in answer 
to the formation of a great spot upon the sun. The 
spot is so really vast, so much greater in size than the 


little world on which we live, that it seems quite natural 
at first sight to ascribe a great influence to it. 

So, from time to time, we hear it said, if we have a 
hot season, that it is due to there being many spots 
upon the sun, or else to the sun being free from spots. 
And in just the same way we find the same said if we 
have cold seasons, or rainy seasons, or dry seasons. 
Any weather that is at all irregular is at once ascribed 
to the presence of spots on the sun, or to their absence. 
Now, the amount of rain that we get in England varies 
from one year to another. Let us take the rainfall as 
registered at Greenwich, and compare it with the area of 
the spots observed on the sun. It is only necessary to 
look at the two curves to see that they have no connexion 
with each other. There is a sort of regular swing about 
the changes in the sun-spot area in eleven years or so ; 
there is no such regular swing in the changes of the 
rainfall. Sometimes a very dry year, sometimes a very 
wet year, falls when there are most spots on the sun ; 
and exactly the same thing happens when the spots are 
very few. {See Plate XXXV., fig. i.) 

But England may not be a fair example, and a much 
more hopeful and important inquiry has been set on foot 
as to whether the famines in India may not in some 
way correspond to the variations on the sun. So far, no 
connexion has been definitely established ; the nearest 
approach to such a connexion being a possible greater 


Fig. I. — Curves of Son-spot Areas and Annual Rainfall. 

The dotted line shows the numbers of Sun-spots, year by year ; the continuous line the Annual Rainfall 
at Greenwich (expressed in inches) for the same years. 

Qj 4879. 












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Fig. 2.— Curves of Sun-spot Areas and Magnetic Daily Ranges. 


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Photographic Trace of Magnetic Storm of February 13, 1892. 
{From the photographic registers taken at the Royal Observatory, Greenwich, from noon 
February 12 to noon February 14.) 

The upper register shows the abrupt beginning of the storm and the contrast between the normal and 

the disturbed traces. 


frequency of famines or scarcities iif one province of 
India — the Madras Presidency — when spots are rela- 
tively few. 

And if we think over it, there is no reason for 
surprise that we should find it very difficult to make 
out any connexion of the kind. A spot like that of 
February, 1892, is enormous of itself, but it is a very 
small object compared with the sun ; and spots of such 
size do not occur frequently, and last but a very short 
time. We have no right to expect, therefore, that a time 
of many sun-spots should mean any appreciable falling off 
in the light and heat we have from the sun. Indeed, 
since the surface round the spots is generally bright 
beyond the ordinary, it may very well be that a time of 
many spots means no falling off, but rather the reverse. 

Is there no connexion, then, between these great 
changes on the sun and any kind of change on this 
earth of ours? The sun has upon him spots, faculae, 
prominences, and corona, that change and move, wax 
and wane, in sympathy, and according to some law. 
The sun turns round upon his axis and carries with him 
the spots, faculae, and prominences. Has that motion of 
his any effect upon us ? Would it matter to us if he could 
not turn ? Would it make any difference to us here 
if he were blank and unchanging, as, for the most part, 
he seems to be to the naked eye ? Are any of the laws 
of the sun laid upon the earth ? The corona is always 



surrounding the sun ; the prominences may be there, 
though we cannot see them. Can they affect us here on 
the earth whether we should ever see them or not? 
Could they affect us here on the earth even if we hid 
ourselves in her depths, shut off by many feet of cold 
ground from the sight of the sun, from the knowledge 
of day and night, of summer heat or winter cold ? 

In a deep, windowless cellar, guarded from all light 
or heat or knowledge of the sun, there hangs a long 
steel bar, poised level by a silken thread fastened to its 
middle. It is balanced true, so that it moves neither up 
nor down, but the silk thread that suspends it allows it 
to move, as it will, to right or left. The room is not 
quite dark, for there is a lamp, and a ray of light from 
this falls on a little mirror on the steel bar, and is by it 
reflected to a sheet of photographic paper. The paper 
is wrapped round a drum which revolves, so that, if 
the steel bar remains steady, the ray of light reflected 
from the mirror upon it leaves a straight black trace 
on the moving paper. But if the bar swings to 
left or right, quickly or slowly, then the ray reflected 
from the mirror fastened to it dances to and fro upon 
the paper on the drum, and leaves behind it a wavy or 
a jagged line. 

But why should the steel bar swing or quiver ? It 
is hanging deep down in an underground cellar, where 
no breath of wind can ever come to stir it, where no 


overhead traffic can shake the earth and send it quiver- 
ing. It is in the still depths, far from the madding 
crowd's ignoble strife. What disturbing message can 
make it quiver ? 

But the sun has other messengers than his rays of 
light and heat : messengers that do not heed bolts and 
thick doors or walls ; that care not for darkness and cold. 
To such messages as these bring the steel bar responds 
day by day, year by year, cycle by cycle ; answering 
back not only to the movement of the sun as he runs his 
daily and his yearly course in our sky, but quivering 
in sympathy with the very state of the sun himself, 
whether he is suffering from a great outbreak of spots, 
prominences, and faculae, or whether he seems to have 
sunk back into quiescence. 

The steel bar — a magnetic needle it is called — is 
balanced so that it will point nearly due north and south 
if undisturbed. But it does not remain undisturbed for 
long. From about nine in the morning till about two in 
the afternoon there is a feeble swing of the magnet to 
the west, and during the remaining hours it creeps back. 

Day by day the magnetic needle swings to and fro, 
but the extent of the swing is not always the same. If 
we plot down the extreme distance of its pulse for each 
day, month by month, and year by year, we see that the 
swing is greater in the summer months, when the sun is 
long visible and high above the horizon, than in the winter 


months. But the average swing in the summer months 
for one year is not the same as for another, nor yet do 
the winter months give always the same swing. If we 
take the average of all the swings, year by year, we still 
find a steady progression. There is a pulse, too, in the 
years — a cycle — and the extent of the cycle is about 
eleven years, the same as the cycle of the sun-spots, the 
faculae, the prominences, and the corona. 

Is this a coincidence merely, or is there any con- 
nexion between the sun's surroundings and the mag- 
netized bar, swinging in the cold and dark ? It cannot be 
a mere coincidence, for not only are the lengths of the 
cycles the same, but one can superpose them. The 
greater the number of spots and faculae, the greater the 
swing of the magnetic needle ; when the sun sinks into 
a quiet state the swing of the needle is short and feeble. 
Thus in Plate XXXV., fig. 2, in which the areas of 
sun-spots and faculae are exhibited diagrammatically 
year by year in comparison with the daily variation 
shown by the magnetic needles, it will be seen at once 
that the maxima of the solar curves correspond always 
with the maxima of the magnetic curves, and the minima 
with the minima. There is, then, a connexion between 
the state of the sun and the swing of the needle. But 
how close is it ? 

Every now and then — we cannot foretell when — a 
monster spot breaks out upon the sun. It passes across 


the sun's disc into his unseen hemisphere, and may come 
again round his eastern rim a second, even a third, fourth, 
and fifth time. We know it to be the same spot by its 
place upon the sun — its solar longitude and latitude. 

Every now and then, without warning, the magnetic 
needle, swinging gently to and fro in the stillness, 
becomes violently agitated. It quivers and starts as 
if it were transmitting a panic-stricken messag'e, uttered 
so hastily that light is not a writer quick enough 
to transcribe it. The quivering and the agitation may 
last for hours or days ; then it ceases, and weeks may 
pass before the quiet swing is disturbed again. Who 
sent this message ? Where does he stay ? What does 
it mean ? 

In the November of 1882, a monster sun-spot, 
easily visible to the naked eye, crossed the sun, and 
when it was about halfway across, on November 1 7, a 
very violent magnetic storm, as these agitations of the 
magnetic needle are called, occurred. It began very 
sharply at ten o'clock in the evening. Ten years later, 
in February, 1892, a still greater spot, the one already 
referred to, appeared upon the sun, and when it had 
passed a little to the west of the sun's centre, on February 
13, at five o'clock in the evening, a still, more violent 
magnetic storm occurred than in 1882. It also began 
very suddenly. This great spot passed off the sun, and 
returning to the eastern edge, again crossed the sun's disc. 


When it arrived at the same distance from the centre 
of the sun, there suddenly broke out again upon the 
earth a great magnetic storm. This was at ten-thirty 
on the morning of, March 12, 1892. Eleven years later, 
in October, 1903, yet another giant sun-spot appeared, 
and when it had got a little more than halfway across 
the sun, there was a magnetic storm, but not a violent 
one. But a fortnight later, when an important, but 
smaller, spot had got into a central position on the sun's 
disc, a magnetic storm burst suddenly, at six o'clock in 
the afternoon of October 31, the most violent that has 
been experienced in the memory of man ; so violent that 
it disturbed the submarine cables all over the world, and 
stopped the sending of any telegraphic messages. {See 
Plate XXXVI.) 

Had the spots and the storms anything to do with 
each other ? They happened together, but though some 
monstrous spots came at the same time as monstrous 
storms, yet the biggest spot we have ever known of 
came with quite a feeble storm ; and a spot of moderate 
size accompanied the most violent of all storms. Yet 
further, there are many spots and many storms, but we 
cannot link them all. Many great spots are accompanied 
by no storms at all ; many storms occur when we cannot 
see a spot on the sun at all. Why does the law which 
connects them only seem to work sometimes ? What is 
the association between them .■* 


It is the great spot of 1892 that supplies the clue to 
the mystery. The time between the return of the spot 
to the same place is the apparent time that it takes the 
sun to turn on his axis, and that is the time that occurs 
over and over again as the interval between successive 
magnetic storms. On a particular region of the sun 
some commotion occurs : sun-spots, faculae, prominences, 
are formed ; above the disturbed area a great petal-like 
streamer of corona arises, its apex drawn out into a rod- 
like ray, which extends from the sun to distances which 
may be expressed in scores or hundreds of millions 
of miles. Indeed, in the eclipse of 1898 such rays were 
photographed, and they have been photographed in 
other eclipses, though not to quite the same great 
extent. {See Plate XXXVII.) In these rays the par- 
ticles, whatever their nature, are not now connected with 
the sun, though they once were ; each still keeps the 
direction and motion which it had when it left the sun. 
If, then, we could look down on the sun, we should 
see him spouting forth, from one region or another, 
as smoke issues from the funnel of a steamer, long rays, 
which remain as spirals behind him as he turns con- 
tinually on his axis. The sun may go on spouting a 
coronal stream from the same region for months at a 
time, and in this region spots may break out and die, 
and again break out ; for sun-spots are but one symptom 
of the sun's activity, and, perhaps, not even the most 


important symptom. As the earth moves round the 
sun, which is himself turning on his axis, the same long 
stream may strike and pass it, may strike and pass 
again, month after month, for many months at a time ; 
or perhaps it may sometimes strike and sometimes miss. 
There is no reason for surprise, then, that sometimes 
a great sun-spot is not answered by a magnetic storm 
on earth, for the ray from it may have missed our little 
world. So, too, we may have a storm when there is no 
spot visible, for the coronal ray may have been shot 
forth before the spot has formed or may be still in 
action after the spot has been covered over or filled up. 

The law that governs the changes of the sun, his 
waxing and waning cycles in spots and faculae and 
prominences, has its answer in the earth. It is under 
the influence of this law that the magnetic needle writes 
in the darkness and stillness of the cellar ; it writes of 
great changes, great commotions, that are going on in 
the sun ; and of the sending forth of these stupendous 
coronal rays, which we can only see at rare intervals, 
and by the accident, as it would seem, of the moon's 
dark body shutting off the sun's light, and allowing us 
to look upon the lesser brilliance of his surroundings. 

It does not seem strange that such stupendous com- 
motions on the sun should have an effect upon the 
earth. The spots are but a minor symptom in the great 
solar outbreak, and these spots, very many of them, 


could engulf the earth entirely. The wheel can certainly 
affect the fly upon it. 

But can the fly affect the wheel ? Can the earth 
exert any influence on the sun, or on the monstrous 
commotions upon it ? The question seems to stand 
self-condemned as an utterly foolish one. But — does 
the earth influence the sun or the sun-spots ? 

The sun's equator and his poles are definite regions 
on him ; they are fundamental positions on his surface, 
due to his turning on his axis. But the eastern rim, 
the western rim, and the central line of the sun, as we 
see them, are not definite and unaltering regions on him ; 
each region of the sun takes up all these positions in 
turn. East on the sun is east and west is west only to 
us on the earth ; they would not hold these same positions 
to another planet; an observer on the sun could not 
recognize them at all. The sun's visible hemisphere 
only differs from the sun's invisible hemisphere in the fact 
of the earth's relation to the two. If, then, the eastern 
half of the sun differs systematically from the western 
half, or the visible hemisphere in any way from the 
invisible hemisphere, those differences must be due to 
the earth. 

We do not see the sun's invisible hemisphere, and 
therefore we cannot measure the spots that are there, 
or count them. But the sun is continually turning 
round, and we can count the spots that come into view 


round the eastern rim, and we can count the spots that 
disappear round the western rim. If the earth had no 
influence on sun-spots, the numbers that came on should 
be, in the long run, just about equal to the numbers that 
go off. If more spots in the long run come round than 
go off, then the earth's influence must tend to kill the 
spots. If more go off than come on, then the earth's 
influence must tend to develop them. We find that the 
earth tends to kill the spots, and that to a degree which 
is out of proportion to its size. In a period of eleven 
years, though 947 spots came round the east, only ']']^ 
went round the west. The earth put out 1 70 spots in 
eleven years. 

If we measure the areas of all the spots when they 
were seen in the eastern half of the sun, and also in the 
western half, we find, similarly, that, in the long run, the 
eastern areas are greater than the western, for the earth 
tends to diminish the spots and to quiet down the 
commotions on the sun. 

And if the earth tends to subdue the sun's agitation, 
so probably do the other planets — Mercury, Venus, 
Mars, Jupiter, and the rest — though their influences we 
can only suspect ; we cannot yet measure. 

We have seen how the sun influences the earth — by 
his heat, his light, and the changes in himself which pro- 
duces magnetic storms on the earth. In how many 
other ways he dominates the earth we have yet to learn 


— whether his changes cause our blizzards and our heat- 
waves, our hurricanes or earthquakes. We may know 
some time, definitely, that with his changes these things 
do come or do not come ; but we do not yet know. 

Nor do we know by what means the earth influences 
the sun. We have seen that it tends to quiet some of 
his disturbances, but how we do not know. Nor do 
we know if sometimes, or by some means, it or any 
of the other members of his family may tend to rouse 
him to greater activity. 





TUTE may think of a nation as a collection of families 
^ bound together by common laws. The head of 
a family is its representative in the nation ; and in each 
family, laws special to it also hold good, though these 
laws must not run counter to the laws of the nation, else 
both nation and family will suffer. 

We may think of the universe of stars as a collection 
of solar systems. We classify these suns by their re- 
semblances to our sun, or by their differences from him. 
We may well believe that all, or many, of these suns 
have systems dependent on their control, but of only 
one such system have we any knowledge — that belong- 
ing to our sun. And, just as we may study the cha:- 
racters of the members of a family, so may we study 
the characteristics of the members of the solar system. 
Their individualities are distinct; they differ much 
amongst themselves and from the sun; yet some of 
them have traits that are distinctly sun-like. 



The one planet that is more eminently sun-like than 
any of the others is the planet Jupiter. He is more 
than equal in size to all the other planets put together ; 
he controls a numerous minor system of his own ; like 
the sun, he has a spotty globe ; he is a semi-sun. 

But the sun has a diameter of 866,400 miles ; the 
diameter of Jupiter is but a tithe of this. The sun is 
distant only some ninety-two millions of miles ; Jupiter 
is more than four times as far even when at his nearest 
to us. We cannot see that Jupiter is not a mere point 
of light with the naked eye ; we should have to magnify 
him at least fifty times to make him seem as big as the 
sun looks without the aid of a telescope. 

If we look at Jupiter through a telescope which 
magnifies his actual size fifty times or even two hundred 
times, he seems to have a very different appearance from 
that of drawings of him in astronomical books. The 
picture of Jupiter in the book is perhaps drawn to a 
scale of two or three inches to the planet's diameter, and 
so if we held it at the distance from our eyes that we 
usually hold a book, it would cover up a space in the 
sky twenty or thirty times the breadth of the sun. 
When we are looking at the sun low down in the sky 
we are looking at him over trees, or houses, or hills. 
We know that these last are really larger than they 
may appear to us to be ; we unconsciously compare the 
sun with them, knowing that the great light is vastly 

















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Jupiter and his Satellites. 
As seen in a 12-inch reflector with a magnifying power of about 300. 


more distant ; so we unconsciously magnify his apparent 
size ; we seem to see him covering a greater space than 
he really does. 

But when we look at Jupiter in a telescope that 
magnifies him fifty times, we see him alone, cut off by 
the telescope tube from any houses, or trees, or hills with 
which to compare him ; there is nothing to make us 
unconsciously magnify his appearance ; he looks as he 
really is, a very small object ; no bigger than a sixpence 
looks seven feet away. The drawing by the Rev. T. E. R. 
Phillips in Plate XXXVIII. gives a good idea of the 
actual appearance of Jupiter and his moons in the field 
of a telescope when a magnifying power of about 306 
is employed. 

To the naked eye, the sun looks but a glowing disc 
of light. It is only rarely that the unassisted sight can 
see speck or flaw on his bright surface ; and when the 
eye can see a spot, it looks like a round black nail's head 
driven into the sun. But Jupiter, when he is magnified 
to the same apparent size as the sun, does not look like 
this. His is no flawless disc of light, but one barred by 
parallel bands, bright and dark. Nor are the bands, 
whether bright or dark, quite uniform : the brightness 
seems coagulated here, the darkness knotted there. 

If we enlarge the apparent size of both the sun and 
Jupiter, the differences in their appearances become 
more marked still. There is no colour on the face of 


the sun ; there is but light and varying degrees of shade. 
We can trace out the direction and place of the sun's 
equator by diligent watching, for the spots and the 
faculae seem to move in parallels of latitude as the sun 
turns round. The spots and faculae themselves seem 
often to lengthen out along these parallels, but the 
length of the longest stream is short compared with the 
circle of the sun on which it lies. Spots and faculae 
seem to break out again and again along points in the 
same parallel. If the sun-spots and the sun's faculae 
remained permanently there and did not break out and 
disappear again completely, we should expect to find 
them, from what we know of them, to lie in dark and 
light bands parallel to the sun's equator. 

If the spots and faculae were not evanescent, but 
permanent, or very long-lived, features on the sun, and 
were greatly increased in size and number, we should 
expect them to lie in bands parallel to his equator and 
to look very much like the appearance that Jupiter 
actually presents, but with the difference that we could 
not have expected that these bright and dark spots 
should show more than light and shade, and that some 
of them should become tinted with various colours. 

In Plates XXXIX. and XL. there are two paint- 
ings of Jupiter by the Rev. T. E. R. Phillips ; the first 
made on February 2, 1908, the other eight days later. 
In both of these pictures it is perfectly easy to pick 


out the position of Jupiter's equator : it is across the 
thickest part of the disc and parallel to all the light and 
dark bars. 

But there are several other things to note about 
these pictures of Jupiter. There are many different 
colours on them, but the background seems to be a dull 
yellow which deepens and smears all round the border 
of the disc. In or under this yellow all the other 
markings seem to lie ; it is the colour of Jupiter's atmo- 
sphere, and we see that it is an atmosphere, for it 
deepens near the horizons, where it seems to us to lie 
thicker on the rounded body of the planet. But on 
the sun we remember that we could see his bright mark- 
ings, the faculae only, when near his rim, for only there 
was the bright body of the sun dimmed enough for us to 
distinguish the brightness of the faculae. We could not 
see the sun's faculae in the centre. But here, on Jupiter, 
it is in the centre that we see best all the markings, 
whether dark or light ; towards his rim they fade into 
the yellow. This shows us two things about Jupiter : 
first, that the body of the planet is not very bright, and 
is nowhere as bright as the white spots ; and second, 
that all the markings, lig^t as well as dark, lie low down 
in the atmosphere of Jupiter, and can therefore be most 
clearly seen where Jupiter's atmosphere seems to us 
to be shallowest, namely, at his centre. 

The next feature to be remarked is that round either 


the north or the south pole of Jupiter, there is nothing 
to be seen but greyness or yellowness, forming a broad 
cap. So in the sun we found that the spots ceased when 
they were about forty degrees north or south of the 
equator ; the faculae were to be found a little farther to 
the north or south, and the prominences yet farther. 
But it would seem that the regions near the poles, on 
both the sun and Jupiter, are undisturbed, inactive, and 

There is nothing on the sun that we can recognize 
as corresponding to the blue or crimson stripes in the 
northern hemisphere of Jupiter ; nothing even that we can 
compare with his even straight dark and light bands. 
And if we compare the shapes and appearance of the 
other white and dark markings with faculae and sun-spots, 
we find very striking differences. The faculae seem 
like mackerel clouds, or they sometimes mass together 
like cumuli ; the spots are irregular, ragged, and torn, 
with points of deeper blackness in the darkness of their 
centres, and thatches of brightness projecting over them. 
The white spots on Jupiter are smooth and round like 
drops of milk, or eggs. The dark markings are also 
smooth edged, with never a suspicion of shading towards 
central pits, or of overhanging thatch. And both 
light and dark are often tinted to a rosy or a purple 

The picture of February lo is not the same as the 


JUPITER, 1908 February 2" 9" 40"' G.M.T., 
by Ihe Rev. T. E. R. Pliillips. 



picture of February 2. We can recognize the yellowness 
of the northern cap, and the greyness of the southern, 
in both. We can see where one has a blue and a 
crimson stripe, that the other has too ; we can find the 
same style of marking at the same parallel of latitude 
in both. But we cannot recognize the same marking 
unchanged in the same surroundings on the two paint- 
ings. Are we looking at different hemispheres of 
Jupiter, or has his surface changed ? Both. 

It takes about twenty-seven days for a marking on 
the sun's eastern edge to come a second time to the 
same position. The sun appears to us to turn round 
in about twenty-seven days, that is, in about twenty-five 
days in reality. We are in no uncertainty as to how 
long it takes the earth to turn round ; it rotates in 
twenty-four hours, never faster or slower, and everything 
upon it rotates in the same piece, in the same time, 
land and sea, hill and valley, at the equator or at the 
tropics or at the poles. But as regards the sun we 
cannot give the time of its rotation with any such pre- 
cision, and this because faculae and spots seem to rotate 
at different speeds. Not only are spots moving at 
different rates from faculae, but all differ according to 
their latitude ; and they differ in their own latitude for 
some reason that we do not understand. According to 
the spots we choose, the sun may appear to turn round 
in any period between twenty-three and thirty-one days. 


Jupiter turns round also on his axis, but his turning 
is shorter than the sun's, much shorter even than the 
earth's, though he is so much larger. But his method 
of turning is like that of the sun, rather than of the 
earth. We can only say that he turns round in about 
9 hours 55 minutes. White spots give a different 
time of revolution from dark spots; the distance of 
a spot from Jupiter's equator also seems to affect its 
rate of moving ; and the same spot — white, dark, or 
coloured — may move with different speeds at different 

There are always spots and belts on Jupiter ; he is 
never free from them, as the sun may be for perhaps 
years at a time. The spots of Jupiter are longer lived, 
too, than those on the sun ; but they do change, it may 
be in colour, or size, or shape, or brightness ; they may 
even disappear altogether for a time, and leave, as it 
were, the impress of where they have been. 

The most remarkable of all the spots on Jupiter is 
shown on the first painting by Mr. Phillips, in the 
southern hemisphere of the planet. It is called the 
' Great Red Spot,' and is the large grey oblong, lying 
in a white cup, which seems to have hollowed a broad 
dark band, lying to its north, as an Q.g^ might indent a 
cushion. Another dark, smooth band arches over it to 
the south. This great red spot owes its name, not to the 
colour that it now has, but to that which it has had once 

I'LATI-: XI., 

JUPITER, 190S Feb. 10" 13" 35'" G.M.T., 
by the Rev. T. E. R. Phillips. 



in the past. It has had a long history, if not a continuous 
one. The ingenious Mr. Hooke observed it in the days 
of Charles II. It appeared and vanished eight times 
between the years 1665 and 1708, and then it remained 
invisible until 1713. It became very conspicuous in 
1878, and had then a brilliant colour. Since that date 
it has always been visible in large telescopes, though 
sometimes in small ones it has seemed as if it were 
itself gone, and had left only its impress in the south 
equatorial belt. Its impress remains clear whether itself 
be visible or not, and it drifts through the dark belt, 
or it may be the belt drifts past it ; or both move at 
different and at changing rates. 

Now, whatever the spot or the belt may be, they 
are not rigidly attached to the planet's crust. We do 
not see Jupiter's crust at all ; we cannot even tell if he 
has a solid crust like our own earth. All the belts and 
spots that we see on him must hang suspended in his 
atmosphere. They are clouds in fact, clouds moving 
under the influence of his winds and air currents. Our 
clouds and fogs are made up of water-vapour, and of 
dust. We think that the clouds that form the sun's 
bright surface are made of carbon. Whether the clouds 
of Jupiter are made of water- vapour or of carbon, or of 
some other substance, we have as yet no means of 
finding out. 



T T is always the unexpected that happens in astronomy. 
^ If there is one thing of which we can feel sure, it is 
that when we come to study some new object, or some 
object in a new way, it will present to us some feature 
so unexpected, so bizarre, that, until we had witnessed 
its actuality there, we should have declared that such a 
feature was not only unnatural, but impossible. We have 
noticed that the sun's corona is one such feature ; it is 
utterly unlike what we might expect in the sun's sur- 
roundings. We know of it, so to speak, by accident — ^by 
the accident that the moon sometimes hides, and only 
just hides, the sun; otherwise, though it exists, we 
could not know of its existence. We have pointed out 
that it is the vehicle to convey a disturbing power from 
the sun to the earth. It has been proved many a time 
and oft, proved without a flaw in the reasoning, that 
the sun, or its spots, could not, by any means, by any 
possibility, cause the magnetic storms on the earth. 



But the fact remains that he does. We can never 
know ; we can always learn. 

But the commonplace planet Saturn is the planet 
that 'surprises by himself.' Turn back to the Story 
told by the Planets. The other four had special stories 
to tell for themselves. Mercury was the twinkler, 
glancing out for a moment, now to the east, now to 
the west, of the sun. Venus was the brightest jewel 
in all the heavens ; the bright and morning star, the 
chief brilliant in the crown of the evening. Mars was 
the ruddy star, the blood-red star of war that alternately 
threatened and retreated with the years. Jupiter was the 
steady, bright-shining * Hebrew,' who crossed over the 
meridian and paced out the heavens from end to end. 
But Saturn had nothing special to say for himself. He 
was only the yellowish star, duller than the rest, slow 
moving in his westward course, slower moving in his 
eastward; so slow and sluggish that the astrologers 
gave him as his metal, lead : heavy, dull, inert — of little 
use and less ornament. 

He preserved this character through all the centuries 
until Galileo turned his newly invented telescope upon 
him, in the year 1610. What he saw is best given in 
his own words — ■ 

' I have observed with great admiration that Saturn 
is not a single star, but three together, which, as it were, 
touch each other. They have no relative motion, and 


are constituted in this form, the middle being much 
larger than the lateral ones. If we examine them with 
a glass of inferior power, the three stars do riot appear 
very distinctly. Saturn has an oblong appearance 
somewhat like an olive, but by employing a glass which 
multiplies the superficies more than one thousand times, 
the three globes will be seen very distinctly and almost 
touching, with only a small dark space between them. 
I have already discovered a court for Jupiter, and now 
there are two attendants for this old man, who aid his 
steps and never leave his side.' 

This observation was not generally accepted by the 
other scientists of Galileo's day, because they argued 
that they knew, and that, therefore, there could be no 
more room to learn. And Galileo himself received a 
great shock in perceiving that, during the next couple of 
years, the lateral bodies were diminishing, though they 
appeared to be immovable, both with respect to each 
other and to the central body. Toward the close of 
1612 they vanished altogether, and his opponents were 
triumphant, whilst Galileo mourned — 

' Are, perhaps, the two smaller stars consumed like 
spots on the sun ? Have they suddenly vanished and 
fled ? or has Saturn devoured his own children ? or was 
the appearance indeed fraud and illusion, with which 
the glasses have for so long mocked me and many 
others who have observed with me ? . . . The shortness 


of time, the unexampled occurrence, the weakness of 
my intellect, the terror of being mistaken, have greatly 
confounded me.' 

But Galileo was not mistaken, and by the middle of 
161 3 he was able to announce that the lateral stars were 
reappearing. They enlarged more and more until, in 
16 16, he writes — 

• Its two companions are no longer two small and 
perfectly round globes, as they have hitherto appeared 
to be, but are now bodies much larger, and of a form no 
longer round, but, as shown in the annexed figure, with 
the two middle parts obscured, that is to say, two very 
dark triangular-like spaces in the middle of the figure 
and contiguous to the middle of Saturn's globe, which 
later is seen, as always, perfectly round.' 

It was not until forty years later that Huygens saw 
and described these strange lateral bodies as really parts 
of a ring which girdles the equator of Saturn. 

We have finer and more powerful telescopes than 
Galileo made for himself; we are not so apt as he to be 
confounded by the terror of being mistaken ; we ought 
not to be, like his opponents, inclined to know more than 
we learn. We may therefore study this beautiful drawing 
of the planet Saturn for the sake of that which it can 
teach us, (See Plate XL I.) 

First, then, Saturn itself is a globe. We do not see 
in this picture the entire hemisphere that is turned 


towards us, for the northern pole is hidden by his ring. 
We cannot see the curve of the planet through the 
bright ring; therefore that part of the ring is thick 
enough, or opaque enough, to prevent us seeing through 
it. The southern part of Saturn throws a shadow on 
the far side of the bright ring ; therefore the planet is 
opaque to the sun's rays, and does not shine of himself, 
or not to any appreciable degree. The globe Saturn 
has dark belts and bright bands, dark spots and light 
spots, unmarked uniform polar caps ; liker the sun than 
the earth, liker Jupiter than the sun. He is coloured, 
too, like Jupiter ; unlike the sun, his poles are sometimes 
blue or olive-green ; his spots show brown and purple 
and ruddy tints ; his equatorial band is often of a 
delicate pinkish tinge. He turns, too, on his axis in 
about lo hours 14 minutes, but various regions move at 
varying rates. He is so much more distant from us than 
Jupiter, and so much smaller than the giant semi-sun, 
that his belts and spots seem to us to have their irregular 
edges smoothed off and rounded. In all this he is but a 
lesser and more distant Jupiter. 

But he has that which Jupiter has not. Girdling 
his bright equatorial band, his thickest diameter, there 
is poised a series of concentric flat rings ; not attached 
to him, not touching him anywhere, but all hanging 
even and level with his equator, and the nearest edge 
fully nine or ten thousand miles from his surface. 


The innermost ring is dusky, transparent, crape-like ; 
we can see the curve and body of Saturn distinctly 
through it : it lies before his brighter surface like a veil. 
This ring, then, is not solid or opaque. 

The crape ring has a sharp line of demarcation from 
the next ring, though there seems to be no space 
between the two. And the next ring is bright and 
very broad ; but it is brighter at its outer border than 
at its inner ; it is a little dusky at its inner edge, 
especially where we seem to see it spread out most at 
the two ends of the oblong — for, though the ring itself 
is truly circular, we are looking at it in perspective and 
see it as if elongated. Here* it seems thin, almost 
as if we could see through it ; here, too, it is not 
solid, at least, nor is the substance of which it is com- 
posed very closely woven together. Here and there, 
too, especially on the right-hand wing, there seems 
to be a darker line drawn, as if a cleavage was 
beginning which might separate the broad band into 
narrow rings. 

Where this band is at its brightest, it ends, and a 
broad line of cleavage separates it from a duller band. 
Or it may be from a double band, for on the right-hand 
wing of this there is to be traced for a space a distinct 
tear, but one which does not seem to be continued all 
round into the left-hand wing. This wing is not uniform 
either, but appears gored, as are the seams of a dress ; 


it looks puckered and snipped as if to form a straight 
strip of material into a circular band. 

Saturn's ring girds Saturn's equator, and his pole 
points, as ours does, at an angle to his path round the 
sun. As he pursues his journey, and we pursue ours, we 
see his equator and rings tilted at various angles ; we 
look upon his northern pole and the northern face of the 
rings, or upon his southern pole and their southern 
face, or equator and rings are presented level to our 
eyes. This last is when we cannot see the rings at all, 
because, though the band in which they lie is nearly 
40,000 miles broad, it is so thin that we cannot 
see it edgewise. It cannot be thicker than a hundred 
miles or so. It was at a time that the rings were so 
turned to us that Galileo njade his horrifying observation 
that Saturn had become a solitary and single globe. 

The rings do not shine of themselves ; like Saturn, 
they receive their light from the sun. Sometimes, then, 
the sun is shining on their southern face whilst we are 
looking on their northern, or vice versa, and we again 
cannot see the rings, except where, at the cleavages near 
the elongations, we can, through them, see part of their 
sunlit face. 

We can see through parts of the rings, so they 
are not solid or liquid, since it would be impossible 
to do so were they but a mile or so thick. But 
they must have something material in them, since they 


intercept the sunlight and cast a shadow on the globe 
where they come between him and the sun, just as a 
wreath of smoke or a cloud of dust will cast a shadow. 
Saturn's girdle is, in truth, a dust girdle; it is a ring, 
not solid, or liquid, or vaporous, but made up of solid 
particles which are 'free,' or move independently of 
each other, each in its own orbit, like a true satellitoid 
of Saturn. How big these bands of free satellitoids 
are we do not know ; they may be rocks of many 
tons mass ; they may be no more than pebbles in size ; 
they may be true dust, such as the wind whirls down 
our streets ; they may be no larger than those particles 
which form the substance of the corona's great petals, 
particles smaller than we can conceive. Saturn's rings 
may, indeed, be his corona — a corona which does not 
depart from the parent semi-sun in ever more widely 
extending spirals as does the sun's, but a corona whose 
particles are compelled to circle endlessly round the body 
that gave them forth. But this, too, we do not know. 

Besides these rings of satellitoids, Saturn has true 
satellites, and we know of ten of them. Here we come 
upon another of the unexpected happenings ; nay, more, 
on an happening that was ' impossible.' 

The sun, Mercury, Venus, the earth, the moon, Mars, 
Jupiter, and Saturn, all turn upon their axes, and their 
turning is alf in the same sense; some do not turn 
from right to left, and others from left to right. Mercury, 


Venus, the earth, Mars, Jupiter, Saturn, all revolve 
round the sun, and they all move in the same direction, 
and it is the same sense in which all the bodies rotate. 
Laplace, the great mathematician, was greatly struck by 
this unanimity in the motion of the sun and his planets. 
It could not be simply a chance, he argued, that all these 
bodies, great and small, should all move in the one 
direction. His argument was greatly strengthened by 
the fact that all the moons of which he knew, the moons 
revolving round the earth, or Jupiter, or Saturn, all 
moved in the same direction round their planets, as 
these moved round the sun. The overwhelming proba- 
bility was that all the planets and satellites in the solar 
system must move in this one direction. It seemed an 
inconceivable thing, almost an impossible thing, that any 
satellite or planet should pursue its course in a direction 
the opposite of its companions. 

Nevertheless, this inconceivable thing has occurred ; 
this thing that was considered wellnigh impossible has 
come to pass. Saturn, the planet of the unexpected, 
furnished the example. 

It was but a few years ago that Professor W. H. 
Pickering discovered a small object on a photograph of 
Saturn, which he believed was a satellite, but which he 
could not find again for some years. Then, when at 
last such an object was again picked up and kept in 
view, its motions were so peculiar, and so puzzling, that 


' confounded ' by ' the terror of being mistaken/ he 
hesitated for long to announce that this little satellite, so 
distant from Saturn, so helpless and so small, was yet a 
rebel to the universal law that the great sun and the 
great Saturn obeyed ; that little Phoebe, as the new 
satellite has been called, had struck out a new career for 
herself, and was revolving round Saturn in a direction 
contrary to all his other moons. It is better to learn 
than to know. 

And yet a second example has chanced. For, 
within the last few months, Mr. Melotte at Greenwich 
Observatory has discovered a new satellite to Jupiter, 
an eighth in the 'court for Jupiter,' that Galileo 
discovered. This satellite of Jupiter, as yet unnamed, 
lies very far away from him, and like Saturn's Phoebe, 
pursues a course round him contrary to all his other 

There is one more instance that Saturn offers that 
learning is oftentimes the enemy of knowledge. The 
astrologers of times past, and of to-day, gave to Saturn 
as his metal, lead : the dull, inert, heavy. But we can 
weigh the earth, and the sun, and the planets, and of 
them all we find that Saturn's globe is made up of the 
lightest materials. He is seven hundred times the bulk 
of the earth, yet he only contains in all that huge bulk 
but ninety times the earth's mass. If Saturn could be 
thrown into our ocean, he would not sink but float, for 



his density is but three-quarters that of water, lighter 
than the substance of the sun, lighter than the substance 
of Jupiter, as light as wood. There seems an irony in 
this, which, were it possible, should teach astrologers 
that it is better to learn than to invent sham knowledge. 





Photographs from a Balloon, 

(i) The Parade, Douglas, Isle of Man. Good photographic conditions. Air 
moisture-laden ; little sunlight. i p.m. on November afternoon. (2) Over the 
Ri\'er Medwaj', Kent. Bad photographic conditions. Air dry and hazy. Bright 
sunlight ; summer afternoon. 



Oh wad some power the giftie gie us 
To see ourselves as ithers see us ! 

BURNS might have added that this one gift is not 
enough ; we should need a second to enable us to 
recognize ourselves when thus seen. 

Is there any other of the sun's planets like the earth ? 
What do we look like from outside ? Should we know 
ourselves to be what we are if we could look upon the 
earth from some other planet ? 

We can answer the first question partly if we put it 
in another way. We can say what members of the solar 
system are not earth-like. We can say at once that the 
sun, Jupiter, Saturn, Uranus, and Neptune are not as 
the earth is. Ours is a solid earth ; these are not ; they 
are globes of vapour, or at most fluid, current riddled, 
and without even a backwater of encrusted scum. 

But of Mercury and the moons of other planets we 
know too little to guess at any likeness to ourselves. 



There remain but three bodies amongst which we may 
seek our kin — our own moon, Venus, and Mars. 

We look out over our earth and find on it bare 
mountains and deep valleys, craters and canons, wide 
clefts and vast plains. On the moon we see all these 
things unmistakably. Good ! The moon, then, is bone 
of our bone. But on the earth we also see flowing 
rivers and great tidal seas ; snow, cloud, and mists, 
verdure and forest, follow upon these. On the moon 
there is nothing of all this ; the moon is not flesh of our 
flesh. On the earth the hard rigid skeleton is covered 
above by living flesh ; that is to say, by fertile soil and 
trees and verdure, of which the moon has nothing. 

Suppose we then ascend above the earth, and, stage 
by stage, as we ascend, examine the prospect that lies 
beneath us. We ascend by daylight into a clear sky, so 
that the higher we go, nothing but an increasing thick- 
ness of unclouded atmosphere intervenes between us 
and the earth's surface. 

What is the atmosphere ? It is filled with exceed- 
ingly small particles, capable of reflecting or scattering 
light. Now, under the rays of the sun, these tiny par- 
ticles have their sunward faces lit up, their earthward 
faces in shadow. At any height above the earth we 
can see skyward clearly, for we are looking at the 
sheltered faces of the little atmospheric particles, but 
when we are looking earthward the sunlit faces dazzle 


us and confuse the outlines of the objects on the 
earth. The higher we go the greater is the number of 
sunlit particles between us and the earth, and the more 
pronounced the haziness of her appearance, no matter 
how clear the atmosphere may be. With such an 
atmosphere as ours we can well believe that were we 
to look at the earth from but the distance of a hundred 
miles or so, which is yet well within the outermost 
confines of our air, we should see nothing below us 
but a dazzlingly white and uniform disc of light, with 
never a marking or shade to indicate which was land or 
water, ice or forest, and that although no cloud floated 
beneath us. 

The amount of dust in the air varies astonishingly 
from time to time, and the difference of the appearance of 
the earth as seen from a balloon when the atmosphere is 
charged with dust particles and when it has been cleaned 
of them by heavy rain, is well illustrated by the two 
photographs in Plate XLII. We are indebted for 
these photographs, taken from a balloon, to the kindness 
of Miss Gertrude Bacon, daughter of the well-known 
aeronaut, the late Rev, J. M. Bacon. The upper photo- 
graph shows the Parade at Douglas, Isle of Man, on a 
November day when the air was laden with moisture. 
The lower photograph shows the Medway, in Kent, on 
a very bright day, but when the atmosphere was full 
of haze and dust. 


Which of the two planets, Venus or Mars, that we 
have left for comparison with the earth, shows such an 
appearance ? Without doubt, Venus. We never see 
her surface ; she presents but a dazzling disc, with never 
a marking that we can be certain is not the result of 
eyes tired with too much brightness. Whether her 
atmosphere is clear or cloudy, or what lies behind that 
dazzling light, we do not know. (See Plate XLV.) 
Mars shows us markings in plenty, some well defined, 
some ill defined. We can trace upon his face permanent 
configurations of all shapes and sizes, of all tints and 
shades. Certainly in his atmosphere, in his clouds and 
vapours, the planet Mars differs importantly from the 
planet earth. 

Can we then say that, of all the planets, Venus is 
nearest in kin to the earth ? If we could look upon 
them from a common distance, we might see no 
difference in their uniform brightness. But we know 
what is beneath the earth's atmosphere ; we do not 
know what is beneath that of Venus. The lesson that 
the planet Saturn has taught us, we must not forget 
here : We cannot know what we are not able to karn. 
So far we have not learned, even yet, how long it takes 
Venus to turn upon her axis. This is because there is 
no marking on her that we can recognize again. We 
can only tell the time more or less that it takes the sun, 
Jupiter, or Saturn to turn round, not because there are 


no markings that we cannot recognize again, but because 
the time given by one marlcing differs more or less 
from the time given by another, and the pace, at which 
any given marking moves, varies from time to time. 
But Mars is in a different case from all these. He has 
markings that can be recognized, no matter by whom or 
where they are observed. These markings all move 
together, all in a piece, as the planet turns ; each and 
all turn round in the same time, and as the turning has 
been watched for more than two hundred years, we can 
say with certainty and precision that Mars rotates on his 
axis in 24 hours 37 minutes 22*67 seconds, and that this 
time is certainly not more than the one-fiftieth of a 
second out from the true length of his ' day.' 

So a ' day ' of Mars is only a few minutes longer 
than a day on the earth. Let us examine the beautiful 
painting (Plate XLIII.) that M. Eugene Antoniadi has 
made of one of the sides that he presents to us every 
twenty-four or more hours. 

The whole is round and yellowish, but the deeper 
yellow is near the centre of the disc where the least 
thickness of his atmosphere comes between us and his 
actual surface. Towards his rim, his horizons to us, 
the yellow pales into white, so, like the sun and the 
earth. Mars has an atmosphere, and we see more of 
Mars himself at the centre of the disc, and more of his 
atmosphere at his horizons. On the sun, the centre is 


brighter than the horizons, because it, is the sun himself 
that is shining, not merely reflecting the light from 
elsewhere, and his atmosphere tends to dim his light. 
Mars is brightest^ near the rim, for he shines only by 
light reflected from the sun, his atmosphere being a 
better reflector than his surface, and in this he is like 
the earth. 

In the north of Mars we see a small round dazzlingly 
white patch, as if marking out his north pole. So 
brilliantly white it is we can only liken it to snow, and 
we have such a snow-white patch round the north pole 
of the earth, so that we readily connect this polar cap of 
Mars with our polar ice and snow. We see the whole 
of the Martian polar cap, because when this picture was 
painted, it was the north pole of Mars that was turned 
to us, his south cap was not then visible. Mars, like 
the earth, has his summer and winter, and another point 
of similarity between the polar caps of the earth and of 
Mars is that in the summer of the Martian northern 
hemisphere, his north polar cap diminishes, just as ours 
does under like conditions. We think it probable, then, 
that the polar caps of Mars are made up of ice and 
snow ; but we do not actually know, and we do not yet 
see how to find it out for certain. 

But if the caps are made up of ice and snow, then 
we naturally think that the dark ring, which spreads as 
the cap diminishes, surrounding the north polar cap, is 


MARS, Ijy E. M. Antoniadi. 


melting ice — is water. And if this darkness round the 
cap is water, so perhaps are the other dark markings 
that we see. Perhaps, then, the dark areas on Mars are 
seas and lakes, and the light are continents and islands. 
Where the two border on each other we may see inlets 
and bays, promontories and capes. According to this 
assumption, the markings on Mars have been named. 
The large dark triangle, not unlike the northern conti- 
nent of America in shape, is called the 'Hour-glass 
Sea ' or ' Syrtis Major.' ' Dawes Forked Bay,' like the 
opened beak of a bird, lies in the south and nearly as 
far to the right as the Kaiser Sea is to the left ; a great 
continent lies between these, and to their north, its 
northern portion being called 'Arabia,' along whose 
border a long inlet, the ' Protonilus,' lies; and at the 
end of this inlet is ' Lake Ismenius ' ; whilst ' Lake 
Arethusa ' comes between ' Lake Ismenius ' and the 
north polar cap. The continent ' Libya ' lies to the 
extreme left-hand of the ' Syrtis Major,' and ' Thymia- 
mata ' and ' Edom ' are on either side of ' Dawes 
Forked Bay.' 

The four drawings given in Plate XLI V. are by the 
late Mr. N. E. Green, F.R.A.S., drawing-master to 
Queen Victoria, and the truest astronomical artist of his 
day. They are taken from a superb series of twelve, 
published in Vol. XLIV. of the ' Memoirs of the Royal 
Astronomical Society.' The entire series presents a 


complete rotation of the planet, so that all its varying 
aspects can be easily followed. The four selected from 
that series give a view of about three-fourths of the 
planet's rotation. 

The first of the above drawings shows the end of a 
long, dark, straight marking, which used at one time to 
be called by astronomers the ' Maraldi Sea ' ; it is now 
known by two names — the ' Mare Sirenum ' and the 
' Mare Cimmerium.' It is the latter half oi this marking 
which forms the chief feature of the drawing. The dark 
marking sloping from above the centre towards the 
right is the ' Mare Tyrrhenum.' In the next drawing 
the ' Mare Cimmerium ' has passed out of view, and the 
' Mare Tyrrhenum ' has moved over to the left of the 
picture ; whilst ' The Hour-Glass Sea * or ' Syrtis Major ' 
has come into view on the right. The * Syrtis Major ' is 
seen fully presented in the third design, and the little 
double triangle of ' Dawes Forked Bay ' has just come 
into view on the extreme right. The last picture shows 
a still further rotation of the planet on its axis. 

It all looks very like another earth, an earth whose 
continents and seas are differently distributed, with more 
land than water, instead of more water than land, as 
with us. 

We can see the 'continents' and 'seas' on Mars 
quite easily, though they are slightly hazy and ill- 
defined. We see them just as distinctly as we should 


see the seas and continents of the earth if we looked 
down on it, on a perfectly clear sunshiny day, from a 
height of a dozen miles or so. And this is where the 
difficulty comes in. For we are looking at the surface 
of Mars not only through the whole thickness of our 
atmosphere, but also through the whole thickness of his. 
Ours is trouble enough to us, though we are observing at 
night with no sun to light it up and dazzle us, even if 
we choose the best and clearest climates we can for the 
observation — it may be the desert of Arizona with 
Professor Lowell^ or the clear equatorial skies of Ceylon 
with Major Molesworth, where neither cloud nor haze 
nor unsteady air may greatly trouble us. But the sun 
is shining full on Mars, else we could not see him at 
all. Changing our station on the earth, and securing 
the best climate it affords, will not affect one whit the 
conditions on Mars itself; we can avoid our cloud or 
haze to some extent, but we cannot get away from his 
bad weather conditions ; from haze or cloud on him ; 
from the lighting up of his air particles even when his 
atmosphere is at its clearest ; from the reflection of their 
dazzling light which should prevent us seeing clearly, 
or seeing at all, down to his surface. 

But we do see down to his surface, and we see it 
not so very indistinctly. So the atmosphere of Mars 
must be very different from that of the earth ; it must 
be very much less dense, and very much more 


transparent, even when scattering and reflecting the 
sun's rays. 

Now there are two ways in which we can speak of 
the atmosphere of Mars as being less than ours ; it 
may be shallower, or it may be less dense, less closely 
packed. And here we are able to speak with certain 
knowledge. We know that as we climb a mountain 
on the earth, or go up in a balloon, the air becomes 
rarer and rarer as we ascend. If, on the other hand, 
we go down into a deep mine, it becomes denser and 
denser the farther we descend, and the reason of this 
is obvious. At any level the air is compressed by the 
total weight of all the air above it. On the earth, 
therefore, we find that when we have climbed three 
and a half miles, that is to sa,y, a little higher than the 
top of Mont Blanc, we have passed through half the 
atmosphere as to weight ; the pressure upon us is only 
one-half what it was at the sea-level. Another three 
and a half miles would take us through half the 
remainder, and the pressure would be reduced to one- 
quarter ; and so on, every additional three and a half 
miles upward would reduce the pressure by one-half. 
The mercury in a barometer which stood at thirty inches 
at the sea-level, would stand fifteen inches high at three 
and a half miles, seven and a half inches high at seven 
miles, three and three-quarters at ten and a half miles, 
and so on. 


1S77 Sept. 18'' 11'' 45"' 
r.niiLjimde, 232'' 

1877 "Sept. 15'' 11'' 10'" 
Longitude, 2c;o^ 

1S77 Sept. 10'' u'' 20'" iS77,Sept. 8'' 12'' 30'" 

Longitude, 297" I,i5ngi(ude, 332" 

MARS, by the late N. E. liieeii. 


Now, on the planet Venus, which is very nearly as 
large, and very nearly as heavy a planet as the earth, 
this rate of decline of the mercury would be very 
nearly the same. It would take an ascent of four 
miles to reduce the atmospheric pressure by one-half. 
There would be no very great difference, therefore, 
in the distribution of an atmosphere on Venus and 
on the earth. 

But the case is very different when we come to 
Mars. He is a much lighter planet and a much smaller 
planet than the earth, and the ' pull ' which its attraction 
exercises at his surface is much less than it is with the 
earth. His atmosphere, therefore, is piled much more 
loosely above his surface ; the weight of a given amount 
of air is much less on Mars than it is here. We should 
have to ascend nine miles above Mars to pass through 
half his atmosphere by weight ; eighteen miles to pass 
through three-quarters ; and twenty-seven miles to pass 
through seven-eighths. At twenty-seven or twenty-eight 
miles above Mars we have, therefore, passed through 
only seven-eighths of his atmosphere ; at the same height 
above the earth we have passed through about |5| of 
ours. If, therefore, the air at the surface With us was 
thirty-two times as dense as that at the surface of Mars, at 
twenty -seven or twenty-eight miles the density would be 
about the same in both cases. If the total atmosphere of 
Mars bears the same proportion to the total weight of 


the planet as it does with us, then the aneroid barometer 
would give the pressure at the surface as about one- 
eighth the pressure here. In other words, the atmospheric 
density would be about equal to that which we should 
get could we mount in a balloon ten miles above the 
surface of the earth, a height at which nothing that 
we know of could live. On Venus there would be no 
very perceptible difference from the condition of things 

Our atmosphere is necessary for our life and vegeta- 
tion ; the atmosphere of Mars is both deeper and much 
less closely packed than our own, and we have no reason 
to suppose that it is sufficiently dense even close to the 
surface to support any form of life with which we are 
acquainted here. 

It must differ from our atmosphere in another feature. 
The attraction of Mars being so much less powerful than 
of the earth, the winds of Mars must be far gentler 
than ours. A stone dropped on the earth will fall, in 
obedience to the earth's pull, sixteen feet in a second ; 
on Venus it would fall fourteen feet ; on Mars six feet. 
So if, from some cause or another, the air in one region 
of the earth should become heavier than in the region 
round about, the heavier air tends to move to regions 
where the pressure is less, and a wind is set up. A 
similar wind on Venus would be not quite so violent; 
on Mars it would be quite feeble. On Jupiter, on the 


other hand, where the stone would fall forty-one feet 
in a second, the same difference of atmospheric pressure 
would set up a terrible hurricane. 

We can now realize to some extent the atmospheric 
conditions of Mars ; it is very rare, rarer than we have 
any experience of here on earth ; it is slow moving and 
stagnant, which again is not favourable for life; and 
there is little difference between the density of different 
layers. This last means that clouds do not form readily, 
nor rain. 

From our point of view, the atmosphere of Mars, 
though thin, is deep. We see the markings on his 
surface, his ' seas ' and ' continents,' but we see them 
somewhat hazily and indistinctly; the extraordinary 
thing is not that we see them so, but that they are 
visible at all. Mars has an atmosphere — we can see it 
thickening towards his horizons — ^and it would be im- 
possible for us to see any object on his surface except 
indistinctly, hazily, and ill-defined. 

But there are some objects on him that have been 
seen with much distinctness, without any haziness or 
want of definition. There is no doubt about them ; 
any one can see them who has good eyes, a good 
telescope, and clear enough atmosphere. The same 
objects are so recognized again and again ; they have 
been seen for many years; they are long and straight 
and narrow — lines in fact. The better the telescope, the 


clearer our air, the narrower and more distinctly they 
are seen. The man who first drew attention to them, 
SchiaparelH, the greatest living Continental astronomer, 
called them, in his native Italian tongue, ' canali,' which 
has been literally rendered ' canals,' though ' channels * 
would have been the better word. For they have been 
seen not only as dark lines intersecting the continents, 
but as darker lines running through the dark seas, and 
sometimes as bright lines bridging the lakes. 

We have said it is impossible ; and yet these 
strange markings on Mars have been seen — some have 
actually been photographed by Professor Lowell's 
assistant, Mr. Lampland, But are these markings on 
Mars actually as we see them, or do we only see them 
like that ? In other words, does the explanation of the 
impossibility which has occurred lie in our being unable 
to see rightly ? 

We know that we cannot always see rightly. If we 
look at a big spot on the sun with the naked eye, it 
appears like a round black nail driven to its head into a 
golden plate. But that round dark nail is not the real 
shape of the spot as we see it magnified in the telescope. 
The jagged surrounding thatch, the bright bridges, the 
great number of smaller outlying spots, are not suggested 
by the sharp black dot which is all we see with the 
naked eye. 

If there were another spot upon the sun large 


enough to be seen by the naked eye, it would also seem 
to us like a black round dot ; and if it were so near to 
the first spot that the space (though in reality it might 
be very great) was not large enough for the naked eye 
to see it, these two spots would seem to us merged into 
one elongated one. If, beyond the second, a third spot 
lay, and then a fourth, and many more in a straggling 
and uneven row across the sun, we should not see these 
as separate dots, but all merged into one even line, as 
sharp and defined in its edges as the black dots have 
already been. This string of spots across the sun would 
look to us like a sharp black line, without indentations 
or gaps. Yet if we did not look at it with the naked 
eye, but magnified it in the telescope, we should not 
see it thus, but as an irregular and detached series of 
spots, themselves irregular and broken. The apparent 
sharpness would have been due, not to the actual 
sharpness and definiteness of the object, but to the 
inability of our eyes to detect the small gaps and 

So we have no right to conclude that the straight, 
sharp, even ' canals ' we see on the surface of Mars are 
really as artificial as they seem to us. Markings there 
are certainly, small, irregular, unevenly distributed ; and 
since Mars is a very small and very distant object, our 
small telescopes cannot make these separately visible at 
all, our greater telescopes can only show them as merged 



into even sharp lines, as do our eyes with sun-spots 
lying near together. But our greatest telescopes begin 
to show some of these lines as losing their sharpness, 
as varying their regularity with nodules, curves, and 
gaps ; they are beginning to get at the actual mark- 
ings which, by their seeming junction, give rise to 
the hard, straight lines that have been called the 
' canals.' 

We are not sure that we should not see 'canals,' 
somewhat like the Martian ones, if we ascended high 
above the earth. The Gulf of California and the Red 
Sea would look like perfect ' canals ' ; the Aleutian 
Islands, or the Japanese, might well seem to be bright 
bridges in the Yellow Sea, when looked at from a 
height of fifty or a hundred thousand miles; or the 
North American lakes unite into a narrowish, dark 
streak under the same conditions — that is if we could 
see these features on the earth at all. 

We must therefore leave the question as to what 
planet is nearest in kin to us without a final answer. 
We know that in many important particulars Mars 
differs from the earth. We know very little about 
Venus, but what we do know of her size and atmosphere 
and weight is all in favour of her being a true sister 
planet to the earth. There remains the yet unsolved 
problem as to the time in which she rotates on her axis. 
If her day is about the same length as ours, she may 


well be the abode of life and of intelligence ; if her day 
is the same length as her year, so that she always turns 
one and the same face to the sun, then one half her 
surface must be burned to a cinder, the other half 
chained in eternal ice. 



' I 'HE sun is shining on a house. It is a house 
-'■ furnished and inhabited, and muslin curtains hang 
before the windows. The house is light within, for the 
muslin curtains do not keep out the sun ; but from out- 
side no one can see through them to the people or 
furnishing within. Such a house is the Earth, lighted 
up by the sun, but screened from the impertinent 
scrutiny of those outside by her curtains of the air. 
Such a house may Venus be, but she, too, is screened 
from our prying by her veil, and we have no oppor- 
tunity of looking behind it. {See Plate XLV.) 

The sun is shining on a house. There are no 
curtains veiling its windows, so we can see through 
them into it, and we find no furnishing there. The 
house is not inhabited, though it may have been once, 
or may perhaps be again. Such a house is Mars. Men 
such as we are can scarcely live there now, though in 
the past or in the future the planet may provide a fitting 
home for them. 



M;- \ 

Mai 9 

Mm 21 

Drawings of Venus in 1871, made at the Bothlcanip Observatory. 



Photograph of the Moon, taken by M. Puiseux, April 5, 1900. Moon's Age, 6 days 

(Tlie Moon is shiown as seen in an in\erting telescope.) 



The sun is shining on a house. He can shine in 
where he will, for it is but the shell of a house. Any- 
one can look in from outside and see that it is not 
in fit state to be furnished for the habitation of man. 
Such a house is the Moon ; a house where life can find 
no place to dwell in. Because the moon is a dead 
world, a mere world-shell, there is offered no bar to our 
prying where we will. Where the sun holds the candle 
to guide us, there we may look. The moon neither 
assists nor resists. 

There are two bodies in the heaven which appear 
to us to be of the same size. These two bodies are the 
only ones that we can find exercising any real influence 
on the earth. They are the sun and the moon. The 
sun has already told his story ; how he turns round and 
bears with him the spots, faculae, and prominences which, 
from time to time, break out on him, and how this 
turning has consequences upon our earth. The sun's 
disc can be easily seen by the naked eye, and usually 
is unblemished. But sometimes one or more round 
black spots mar his fair surface, and then we see that 
from day to day they seem to move across his face ; in 
truth, the ' sun is turning and the spots turn with 

The moon's disc can as easily be seen by the naked 
eye, but it is never unblemished ; great grey stains 
curve in a chain along her upper part, and the brightness 


of the rest of her is not uniform : some parts are 
almost dull, and at other points she glitters as if she 
were set with diamonds. There are always the same 
grey stains, the same gleaming points of light when the 
moon is full. (See Plates VII., XLVL, and XLVII.) 

And when the moon is not full ? When the moon 
is still young and the silver bow of the evening has 
widened enough for us to see any markings on it, in 
the upper half we trace a dark oval stain like a sun-spot, 
that has just come over the eastern edge. But as the 
sunlight creeps over the moon, the stain does not move 
as does the sun spot — it always keeps its oval shape ; it 
never comes to the centre of the moon's disc, presenting 
the full round ; it never shifts its place, though the sun- 
light passes over it and leaves it ag^in in darkness. 
And so with the other bright points of light or dark 
stains ; they are in the sunshine or they are in darkness, 
but they do not alter or move. The moon has been 
taken by poets and philosophers in all ages as the 
emblem of fickleness and change. But she is no true 
emblem ; the dead cannot be fickle ; it is the sunlight 
on her, not she, that changes. She does not suffer 
change in herself; she does not alter her face, for she 
does not seem to us to turn upon her axis. The moon 
is but a 

batter'd caravanserai 
Whose doorways are alternate night and day. 


The moon is an interesting body to the naked eye 
because we can, even unassisted, study some of her 
features. But she gains beyond measure in beauty and 
interest when seen in the telescope, unlike many other 
astronomical objects, such as the planets Venus and 
Mercury for instance. Her bright parts shine like the 
purest silver, her parts in shadow are in blackest con- 
trast, her grey stains are not dull greyness, but give 
evidences of innumerable shades and inexhaustible 
details. The moon is herself so black, so dependent on 
the sun's light to make her visible, that as the sun 
begins to rise on any part of her, little points of bright- 
ness, like constellations, spring up where they seem quite 
detached from her, for they are the protruding tips of 
her mountains that themselves catch the first rays, but 
shelter their sloping sides and valleys from the sunlight. 
The rays creep down towards the hollows, and the con- 
stellated points of light increase and run together, 
forming here a round ringed wall, there a straight ridge, 
or again, a solitary central peak within a crater. The 
call for the month-long day has come : 

Awake ! for Morning in the Bowl of Night 
Has flung the Stone that puts the stars to flight : 
And Lo ! the Hunter of the East has caught 
The Sultan's Turret in a noose of Light, 
Dreaming when Dawn's Left Hand was in the Sky. 

Like many another fair lady, the moon's photographs 


cannot be made to do her full justice. Other heavenly 
bodies there are that we fail to see completely, or 
perhaps at all, with the eye, either aided or not by a 
telescope. Such bodies are comets and nebulae, and to 
study ^these fully we must photograph them. But parts 
of the moon are so bright, and parts so dull, that a 
photograph, timed not to over expose the first, will fail 
to show the second ; and exposed sufficiently to photo- 
graph the fainter parts, will show the brighter lost in a 
confused glare. So we must photograph her under 
many conditions of sunlight, and with varying times 
of exposure. 

The photograph given in Plate VII. was taken when 
the moon was nearly at the full. It is usual with repre- 
sentations of the heavenly bodies to place the south pole 
at the top, the east being at the right hand, but in this 
instance the moon is shown as seen in the sky. 

In the first place, it will be noted that the edges of 
the moon which are in full sunlight are perfectly sharp. 
Neither are the moon's features near her borders any 
less clearly defined, any more misty, than at her centre. 
There is /no atmosphere on the moon ; none, at least, 
that we can detect by even the most delicate method. 
Therefore, there is no cloud, no rain, no vapour even. 
And if there is no vapour-laden atmosphere on the 
moon, neither are there oceans or rivers, snow or dew. 
The earlier observers of the moon through the newly 


Photograph of the Moon, taken by M. Puiseux, September 12, 1903. Moon's age, 19 da\'s. 
(The Moon is shown as seen in an inverting telescope.) 




The 'Sea of Clouds,' showing the settling down of the Lunar Surface. 
(From the Photographic Atlas of the Moon of the Paris Observatory, by MM. Lorcuy and Puiseux.) 



discovered telescope did not realize this. When they 
saw craters and mountains similar to those on the earth 
they jumped to the conclusion that the low, level, grey 
markings were the lunar seas, and named them thus, 
and so we call them to this day. Milton, in his Paradise 
Lost, makes Galileo discover 

Rivers or mountains on her spotty globe. 

But Galileo himself denies this, and on February 28, 
1 616, he wrote: 'I do not believe that the body of the 
moon is composed of earth and water ; and, wanting these 
two elements, we must necessarily conclude that it wants 
all the other things which, without these elements, cannot 
exist or subsist,' 

There is no doubt that some time or other the great 
grey lunar ' seas ' were filled with a flowing tide, but that 
tide was probably of molten lava, and not water, as our 
oceans are. Most of the lunar seas form a chain curving 
through the northern hemisphere, not along the moon's 
equator. So marked is the divergence of this 'sea- 
band' from the moon's equator, that some have urged 
that the moon's axis of rotation has shifted since the 
' seas ' were formed. Somewhere Mark Twain says that 
' there is not a parallel of latitude but thinks it should 
have been the equator if it had had its rights,' and on 
the moon it certainly looks as if one of these rebellious 
circles had brought about a successful treason. The belt 


of seas are named thus, from left to right : the Seas of 
Fruitfulness, of Peace, of Serenity, of Showers, and 
of Storms. The Sea of Nectar lies to the south of 
the Sea of Fruitfulness, and the Sea of Crises, the 
oblong sea like a sun-spot, lies to its north. And the 
Sea of Clouds lies to the south and east again of 
the Sea of Storms. 

Plate XLVIII., which shows part of the Sea of 
Clouds and the little neighbouring Sea of Dews, exhibits 
very clearly the evidence of the ' settling down ' of the 
moon's surface at some period. The centre of the 
photograph shows a number of long, curved, concentric 
cracks, concave to the east, and cutting through both 
plain and highland. A great but partly ruined walled- 
plain lies on one of these cracks, just above the middle 
of the picture, and looks as if it had partly sunk or 
partly dissolved under the rising of the tide of molten 
lava. Nearer the east of the picture a number of 
curving ridges are seen practically concentric with these 
cracks, and are due, no doubt, to the same disturbance 
at a later stage of its action. 

The chief mountain ranges on the moon are gathered 
together and separate the Sea of Serenity from the Sea 
of Showers. The Apennines form the most southerly 
ridge. A broad pass cuts through their northern end, 
and the Caucasus range trends to the west, whilst the 
Alps trend to the east, forming the northern boundary 



The Chief Mountain Ranges of the Moon. 
(From the Photographic Atlas of the Moon of the Paris Observatory, by MM. Loewy and Piiiseux.) 





of the Showery Sea. The Carpathians form its southern. 
{See Plate XLIX.) 

The full moon looks rather like a badly peeled silver 
orange, the seas being the portions where the skin has 
been torn off. The resemblance is increased by a 
brilliant round crater in the southern hemisphere named 
Tycho, which marks the place where the orange stalk had 
joined, and from this place a great number of bright rays 
radiate, as if to show the divisions of the fruit. These 
lunar ' rays ' are only seen when the moon is near her 
full, and we do not know to what they are due. They 
extend into the hemisphere of the moon that we never 
see, as well as in some cases right across the hemisphere 
which is always turned to us. One such ray can be seen 
surmounting every obstacle and radiating from Tycho 
through the Sea of Serenity, and continuing almost to 
the northern edge. There are other systems of rays 
besides those from Tycho. Another system radiates 
from the great ring-plain Copernicus, which lies between 
the Seas of Showers, of Storms, and of Clouds. {See 
Plate L.) 

But the most remarkable features of the moon are its 
craters and walled plains of all sizes, and in all states of 
preservation or decay. Craters and craterlets are seen 
everywhere : on the beds of the great solid * seas,' 
aligning the 'rays,' on the slopes and summits of the 
mountain ranges, in the valleys, on the crater walls of 


other volcanic peaks ; in the depths of their hollows ; 
obliterating other craters. The very 'seas' seem but 
the giant remnants of some earlier and still more 
stupendous volcanic outburst ; while the mountain 
ranges appear as half-broken-down crater walls to the 
' seas,' 

It is in the south, however, near the moon's pole, 
that the craters are seen in greatest numbers. The 
whole surface in this region is pock-marked, riddled 
with pits and holes. 

These pits have usually ring-like walls about them, 
which slope very steeply to a central cavity, and more 
gently towards the surrounding country. They vary 
greatly in size ; the largest are more than a hundred 
miles in diameter, while the smallest discernible are less 
than a half-mile across. The number increases as the 
size diminishes; there are many thousands of them, 
so small that they are revealed only when sought for 
with the most powerful telescopes and with the best 

In all these pits, except those of the smallest size, and 
possibly in these also, there is within the ring wall, and 
at a considerable, though variable, depth below its 
summit, a nearly flat floor, which often has a central pit 
of small size or, in its place, a steep rude cone. On the 
floors of the larger craters, numerous small pits, or 
craterlets, are found. The lunar pits certainly suggest 


that these features are volcanoes, and probably they are 
in some way nearly analogous to the volcanic vents on 
the earth. At some time in the moon's history these 
allowed her pent-up energies to burst forth, and are 
evidence of the violence of her activity at such a 

But whatever may have been the violence of the 
moon's activity in the past, it is all spent now. No new 
pits are now formed, no old ones are being defaced. We 
mark no sure change on any part of the moon, and the 
few instances of a slight suspected change are due to the 
crumbling of a crater wall, perhaps from sheer force of 
gravity, perhaps to the impact of a meteorite which has 
upset its unstable equilibrium. One of the best known 
instances of suspected change is the little crater Linne, 
seen as a white spot in the great plain, the ' Sea of 
Serenity,' on the west side of Plate XLIX. 

The moon is the heavenly body which we know most 
intimately ; we have mapped its surface more fully than 
we have explored many parts of our own globe. Yet 
all our scrutiny fails to yield us any evidence of forms of 
life upon her such as we know here; or even of the 
power to live. So far as we know there is no home for 
life in the solar system, other than on our own world. 
Saturn and Jupiter are not yet sufficiently condensed. 
The moon is condensed and solid, but she has no 
atmosphere. Mars is solid and with an atmosphere, 


but that atmosphere is insufficient for the sustenance of 
life in the forms in which we know it, and the planet 
does not receive sufficient light and heat from the 
sun. Venus alone is a possible sister world, and we 
deem her possible, simply because we know so little 
about her. 


'"T'HERE is a strong family likeness between all the 
■'■ members of the solar system that we have just 
described. They are all globes revolving round the 
sun in orbits that are very nearly circles, and all in the 
same direction ; all the orbits lie in a thin slice of space ; 
to all of them the sun rises in the east, and sets in the 
west. They have their individual characteristics, it is 
true — thus our moon is without any atmosphere that we 
can perceive, and Saturn is distinguished from all other 
planets by his wonderful ring — but their resemblances 
are more pronounced than their differences. 

The sun is, without doubt, also of the same family. 
He, too, is a globe, revolving on his axis in the same 
direction as his dependants, and some of the character- 
istics of his surface have analogies upon several of 
them ; on Jupiter, for instance, and on Saturn. 

Though the sun belongs to the same family as the 
planets, he differs from them in two very important 
particulars. The first is in his stupendous bulk and 



mass ; in both he is greater than all his family put 
together by many hundred times. The second is in 
his possession of a corona, in the long, rod-like rays, 
the fingers he stretches out as if to touch his family. 
We know of nothing upon the earth to correspond; 
we know of nothing like it, even on the giant planet 
Jupiter. What are the conditions for a corona ? Does 
the sun possess it because of his great size, or because 
he is a highly heated body ? 

If we look elsewhere for a corona, we do not find one 
on the ponderous planet Jupiter, the largest, heaviest, and 
probably the most highly heated of all the planets, but 
we find what resembles it very closely in those members 
of the solar system that seem of least weight and feeblest 
influence. These members are called comets, and are 
of all degrees of brilliancy, from the most faintly shining 
mist which is only photographed in a powerful telescope 
by long exposure, to objects so bright that they can 
even be distinguished in the glare of the noonday sun. 
There are, on an average, some twenty or thirty bright 
comets to be seen in a century, that is to say, comets 
that are conspicuous to the naked eye. During the last 
quarter of a century, however, we seem to have fallen 
into a blank space, for only one bright comet has been 
seen since 1882, and this one was not visible to dwellers 
in northern latitudes. 

Comets, whether they are faint telescopic ones, or 


bright and visible to the naked eye, have three features, 
not indeed separate and distinct, but merging into each 
other. The nucleus and coma together form the head ; 
the nucleus in a naked-eye comet appearing like a star, 
shining through a patch of mist or fog, which is the 
coma. Stretching away from the comet is the tail, or 
perhaps the tails. These narrow in near the head, and 
not only diverge from each other as they recede, but 
themselves grow wider and more diffuse, so that they 
are always more or less fan shaped. {See Plate LI.) 

The most brilliant of all the comets in the memory 
of living men was that of 1858, known by the name of 
its discoverer, Donati. It was first seen on June 2, but 
was then only visible through a telescope, and as a 
faint, white mist, without tail or nucleus. In the middle 
of August a little tail began to be seen, and the comet 
became visible to the naked eye early in September. 
From this time it increased enormously in its pro- 
portions and splendour, and for a whole month it 
could be seen night after night. After October 10 it 
began to fade away, and as it was then also travelling 
towards the south, it was lost to observers in the 
northern hemisphere. To watchers in the south it 
remained visible in the telescope until the March of 
1859. When at its brightest, the nucleus was equal in 
lustre to Arcturus, which indeed appeared involved 
in its tail on October 5, and the tail itself stretched out 



like a scimitar whose curving blade was over fifty 
millions of miles in length. (See Plate LIT.) 

But this great blade was not the only tail. On 
September i6 an observer at the Strasburg Observatory 
saw a faint outer envelope, like the thinnest of veils, 
flung over and away from the comet's head, and on the 
next evening a narrow straight ray, a secondary tail, 
that seemed like a strand that had sprung to the straight 
from the curved edge of the blade. This secondary tail 
was visible for nearly three weeks, and during part of 
the time a third tail was to be seen, straight like the 
second, and lying between it and the curved blade-like 
tail. This great blade was not evenly bright, but its 
outer edges were more illuminated than its centre, as if 
the nucleus cast a curving shadow. The tail seemed 
formed by the envelopes thrown off one after another 
from the nucleus towards the sun, and then cast back- 
wards right and left to form the great branches of the 
blade-like tail. 

The coma, or the envelopes, seem drawn out of the 
nucleus towards the sun, but the matter which thus 
seems to be drawn out is soon swept away, as fast as it 
is formed, in a contrary direction. Mr. R. A. Proctor 
likened it to the steam from the funnel of an engine, 
a funnel directed forwards, not upwards, and rushing 
against a hurricane ; for the tail, which seems made up 
of the matter drawn to him by the sun from the nucleus. 


Daniel's Comet, 1907, d. 
(From a photo^ra^h taken at the Royal Observatory, Greenwich, August 10, 1907.) 



DoNATi's Comet, October 5, 1858, seen near Arcturus. 
{From Cuil/emin's 'Lis Cometis.') 



is continually swept away from the sun. Thus, in the 
comet observed by Sir Isaac Newton in 1680-81, as it 
approached the sun, its tail, which was some ninety 
millions of miles in length, pointed back almost along 
the orbit. But when, a few days later, the comet had 
made its nearest approach to the sun, and was receding 
from him, its tail, still of huge length, was pointing 
forward, almost straight before the comet in the direction 
in which it was moving, and in the opposite direction to 
that which it had a few days previously. Now, we 
cannot imagine that a comet's tail can be brandished like 
a stick, so that we must believe that these were two 
different tails, and that the matter of which they were 
composed comes from the comet's head, just as the 
matter of which the coronal rays are made comes from 
the sun. Both sun and comet give of their substance 
continually to form their tails. The sun's bulk is so 
stupendous that he can afford to throw off his long 
coronal rays ; the loss would make no appreciable differ- 
ence to him even if the ray contained a quantity of matter. 
But the head of a comet is but a small thing : it cannot 
continue for a length of time to supply a tail that may 
stretch into hundreds of millions of miles, if there is 
much in the tail; each time that a comet approaches 
near to the sun, it develops a coma and a tail, and 
thereby expends itself; the tail must therefore be 
almost inconceivably attenuated, or else each time 


it returned the comet would become smaller, until it 
had become too faint and small to be seen at all. 

For comets resemble the other members of the solar 
system in this one respect : they all obey the law of 
gravity. As all the planets move in orbits of which the 
sun occupies a focus, so do all comets, but the paths 
they follow may greatly differ from the orbits of the 
planets or from each other. For sometimes we see a 
comet that travels in a path of moderate extent ; some- 
times one whose nearest point to the sun lies within 
the corona, but whose farthest is many thousands of 
millions of miles away from him, and whose 'year* of 
travelling round it must be measured in millenniums. 
So, too, comets do not confine their paths within the thin 
slice of space wherein the orbits of the planets lie ; their 
paths may be inclined to this at any angle that may be 
named. Some may pursue a path in the same direction 
that the planets move, others, many others, revolve 
round the sun in a contrary direction. 

Sir Isaac Newton was the first to show that a body 
moving under the influence of the sun's attraction, must 
follow one of three paths, either an ellipse, a parabola, or 
an hyperbola. The ellipse is a closed curve, of which 
the circle is a particular example ; but an hyperbola 
or parabola is not closed, each of them extends without 
end in two branches. In the case of the hyperbola 
these branches continually diverge from each other, but 


in a parabola they become ultimately two parallel 
straight lines. {See Plate LIII., fig. i.) 

Suppose that we have a beam of light coming 
through the lens of a magic-lantern and falling on the 
white sheet. If the lantern is fair and square to the 
sheet, there is a circular disc of light upon it. But if 
we twist the lantern a little askew, the circular disc of 
light on the screen becomes oval-shaped; it is an 
ellipse, and the more askew we twist the lantern the 
more elongated the ellipse becomes, the long sides of the 
oyal tend to open out, until, when the sheet is parallel to 
the far side of the beam, or cone of light that we see 
issuing from the lens, these two sides to the oval do not 
close in again to each other, but become parallel 
straight lines; the ellipse of light has become a 
parabola. If we turn the lantern still farther askew to 
the sheet, the sides of the parabola diverge instead of 
being parallel, and the parabola of light has become an 

If, then, a comet were moving round the sun in an 
ellipse, however long stretched out that ellipse might be, 
the comet would return at last to the neighbourhood of 
the sun. Its ' year ' might be a long one, but it would 
have its limits. But if a comet were moving in a 
parabola or an hyperbola, then, when once it had passed 
away from the sun, it would never return, but would 
retreat slowly, and yet more slowly, farther and farther 


from him. In most cases all that we can say of a comet 
is that its path is probably a very long ellipse, almost a 
parabola, so that the comet flies out to an immense 
distance, not returning for hundreds, or, it may be, 
thousands or tens of thousands of years. Yet even 
when they lie in space many millions of miles beyond 
the farthest planet, they still seem to have a part in that 
motion through space that the whole solar system has. 
All the comets of which we have knowledge form a 
genuine part of the solar family ; and they are not, so 
far as we can tell, visitors to us from other suns. 

If, as these comets return to the sun from the region 
where they have been moving far beyond the planets, 
they should chance to pass near where a great planet is 
circling, two things may happen : the comet may get 
either a pull from the planet which will increase its 
speed and send it out from the sun even farther than 
before, or one that may diminish its speed, so that the 
comet moves in a smaller orbit, where we can see it 
swinging again and again past the sun. These last are 
called periodic comets. Jupiter has been the most 
powerful of the planets in forming a family of them, but 
the greatest of all the periodic comets probably owes its 
present orbit to a 'pull' by Neptune many hundreds 
of years ago. 

This is Halley's comet, which we expect to return to 
a near approach to the sun in the year 1910. It is the 


first comet whose return was predicted, for it was seen 
during the time of the first Astronomer- Royal at Green- 
wich Observatory and from his observations, H alley, the 
second Astronomer- Royal, found its orbit, identified it 
with a comet seen by Kepler in 1607, ^^^ foretold that 
it would again return about 1758. It did actually 
return in 1759, a little later than Halley had predicted, 
for the pull of Jupiter and Saturn was sufficient to keep 
it back a little. It was again seen in 1835, ^^'^ we hope 
that it is still in existence to return again within the 
next year or two. But we cannot predict with certainty 
that a comet will return, especially a comet that goes 
so far beyond the confines of the solar system as Halley's 
does. There may be planets out there, of which we 
know nothing, that may pull it into a new and unknown 
orbit, or it may have split up as other comets have been 
known to do ; or it may have expended all its substance 
in its tail. For it would seem to have been diminishing 
in brightness at each return to the sun, at each display 
of its splendid tail. An early record of its appearance 
was in the days of the conquest of England by William 
the Norman, when it was a fear-inspiring sight. 
William's Queen ^Matilda worked into her Bayeux 
tapestry the appearance that it presented to them. So, 
too, when it appeared in the thirteenth and fourteenth 
centuries, it struck terror into all the nations. But it 
was not to be compared to some other comets of the 


first half of the nineteenth century, when it appeared in 
1835, and if it comes again in 1910, it may seem but as 
a spendthrift noble at a Court: dull, lustreless, and 
bereft of all its former shining train. (See Plate LI 1 1., 
fig. 2.) 





Star Distances 

"TNOES the sun go round the earth, or does the earth 
'^ go round the sun ? Which is the right doctrine 
to hold, the first or the second? When we ask the 
question to-day, certainly nine hundred and ninety-nine 
persons out of every thousand would affirm the second. 
But if it had been asked three or four centuries ago, the 
majority would have been as great in affirming the first. 
So it is no proof that a given assertion is true, that 
every one believes it. 

Three hundred years ago the gates of the sky were 
thrown wide. A young Italian professor of mathe- 
matics, Galileo Galilei by name, heard a rumour that 
a Dutch optician had made someglasses that appeared 
to bring far things near. This rumour set Galileo 
thinking, and he said : 'It appeared to me that it 
depended upon the laws of perspective. I reflected on 
the manner of constructing it, and was at length so 



entirely successful that I made a spy-glass which far 
surpasses the report of the Flanders one.' The principle 
on which Galileo constructed his telescope was that 
which we to-day use in an opera-glass. When he had 
constructed one powerful enough to magnify an object 
about twenty times, Galileo turned it on the heavens, 
and, without leaving Italy, became the Columbus of a 
new and greater world. He discovered four moons to 
Jupiter ; he observed the mountains on the moon, and 
measured the height of some of them ; he discovered 
the phases of Venus ; he observed a curious triple 
appearance of Saturn, which we have since learned to 
be due to its rings ; he found innumerable new stars and 
nebulae, and he also found spots on the sun. Like the 
Ancient Mariner, he was 

... the first that ever burst 
Into that silent sea; 

and where everything was new, everything was to be 
discovered. Of all astronomers, surely he was the most 
fortunate, the one most to be envied. 

But there was another side to the shield. His dis- 
coveries made the name of Galileo famous throughout 
the length and breadth of Europe, and brought him 
many friends. But they also brought him enemies, and 
these were the more powerful. The scientific writers 
held most in esteem in those days were the old Greek 


philosophers, who taught that the universe was con- 
structed as they conceived it ought to be, not as they 
might have observed it to be ; and the ideas of these 
philosophers were held by the world of Galileo's day, 
but were weighed and found false by Galileo. He 
became an old man, weighed down by family griefs and 
afflicted with many diseases. He was a devout Catholic, 
and he was accused of teaching that which led his pupils 
to err from the Catholic faith. He was called upon to 
abjure this teaching, and this he did on June 22, 1633, in 
the following words — 

' Because I have been enjoined, by this Holy Office, 
altogether to abandon the false opinion which maintains 
that the sun is the centre and immovable, and forbidden 
to hold, defend, or teach, the said false doctrine in any 
manner ; and because ... I held and believed that the 
sun is the centre of the world and immovable, and that 
the earth is not the centre and movable. . . . Therefore 
with a sincere heart and unfeigned faith, I abjure, 
curse, and detest the said errors and heresies, and, 
generally, every other error and sect contrary to the 
said Holy Church.' 

Galileo had based his belief that the earth went 
round the sun, and was therefore merely a planet like 
other planets, on the resemblances between the earth 
and the moon, and the more distant heavenly bodies. 
Venus, he showed, had her phases like the moon, so that 


both earth and planets got their light from the sun, and 
were dark when turned away from him. He brought 
forward the resemblance between Jupiter, with his family 
of small bodies, and the sun, with his family of planets. 
All these, however, were analogies only, and, however 
convincing they might be, they were not proofs. 

But Galileo also showed that it was more probable 
that the earth went round the sun, instead of the other 
way about, since the motions of the planets were thus 
seen to be less complex. Further, if the stars were all 
distinct and independent bodies, and not immovably 
fixed in a crystal sphere, he urged that it was improbable 
that the laws controlling their motion about a fixed 
earth should result in revolutions timed uniformly for all, 
and at the same time of enormous rapidity. The pre- 
cession of the equinoxes, too, in virtue of which the 
direction of the earth's axis in space moves slowly, com- 
pleting a revolution in about 26,000 years, would make 
the motions of the different stars inconceivably complex. 
Above all, Galileo relied on the ebb and flow of the 
tides as showing the motion of the earth both on her 
axis and round the sun. These, however, we know are 
really unconnected, and Galileo was relying here on a 
false argument. 

But there was a difficulty which was as fatal to the 
doctrine of the earth going round the sun — unless the 
stars were all immovably fixed in a crystal sphere — as 


the precession of the equinoxes was fatal to the doctrine 
that both sun and stars went round the earth. Galileo 
recognized this difficulty, and to the end of his life 
hoped against hope that evidence would be forthcoming 
to clear it away. But all his efforts, and those of other 
astronomers, were worse than unavailing ; the more 
powerful their instruments, the more exact and care- 
ful their observations, this fatal difficulty to the truth 
of the doctrine that the earth went round the sun only 
became the more pronounced. There are those who 
consider that Galileo sinned against the light when 
he abjured the doctrine 'that the sun is the centre 
of the world and immovable, and that the earth is not 
the centre and movable.' 'There are those,' as Sir 
Oliver Lodge says, 'who lament that he did not hold 
out, and accept the crown of martyrdom.' But instead of 
sinning against the light when he abjured, Galileo knew 
that he had failed to procure essential evidence for the 
truth of the doctrine that the earth moves. Until he 
could procure that evidence, he could not be sure of 
the truth of that doctrine ; he ought not to be sure of 
it. That evidence was not procured until wellnigh two 
hundred years after Galileo's death. 

The difficulty in the way of accepting the doctrine 
that the earth moves round the sun may be explained 
thus. If we are looking at the picture of a landscape, 
with trees, streams, men, and animals in it, we cannot 


get any of these objects to shift their positions with 
regard to any of the other objects, no matter from what 
point of view we regard the picture, no matter how 
perfectly they are represented in perspective. We may 
shut first the right eye and then the left, we may regard 
the picture from above or from below, we may look at it 
from any angle to the incident light; but the picture 
simply shifts to us as a whole, with its trees, streams, 
men, and animals. We cannot by any means superpose 
one of the objects on another, or separate between two 
that touch. This is because they are all on the canvas, 
all at the same distance from us ; their perspective effect 
is but make believe. 

But it is different if we are looking at the real 
landscape, no matter how still and fixed the objects 
may remain. Then, the looking with the right eye or 
the left, the shifting from one point of view to another, 
will bring some of the objects more into line, will tend 
to throw others apart. This is because they are at 
different distances from us. Though the objects re- 
main immovable, and it is ourselves who shift about, 
all the objects will seem to move, and the nearer 
objects will seem to move more than the more distant 

Now, the distance of the sun from the earth is about 
93,000,000 miles ; so that if the earth goes round the 
sun, the sun and the stars really remaining fixed, the 


earth is in June fully 186,000,000 miles away from 
the spot where she is in December; and 186,000,000 
miles is no small distance. Such a. shift of the earth 
ought to make the stars, if they are at different distances 
away, appear to shift among themselves. Now the stars 
look as if they are at different distances ; the bright 
stars certainly seem to stand out well in front of the 
starry background of the Milky Way. As the earth 
gives her half-yearly swing of 186,000,000 miles, these 
bright jewels in the foreground should swing out towards 
the opposite direction, across the fainter star-set back- 
ground. They ought to swing as the earth swings; 
they must swing as the earth swings. 

But they did not, let Galileo test each and every 
star with his most perfect telescopes. They did not 
shift to and fro, no single one of them, as Galileo's great 
astronomical successors tested them with telescopes 
incomparably more powerful and more accurate than 
his. The Astronomers- Royal of Greenwich, one after 
another, searched for a swing to and fro in star after 
star, for a swing corresponding to the earth's swing 
round the sun, and no star gave it. The ingenious 
Mr. Hooke, the incomparable Sir William Herschel,_ 
whose telescope seemed able to peer even to the very 
outermost confines of 'the stars, all these searched for 
the swing of even a single star, and failed to find it. 
And now it was nigh two centuries since Galileo had 



expressed his belief that the earth did move and not 
the sun, and had abjured it. 

Are the stars all, then, like the men and trees of the 
picture we described, some painted in small so as to 
look far off, some painted in large as if they were near, 
but all at the same distance from us so that they cannot 
seem to shift to each other as we shift our position ? 
Are the stars really set like jewels on a crystal globe, as 
men used to believe very long ago, so that they cannot 
move from their setting ? 

Not so. During the two hundred years since Galileo 
died, evidence was continually accumulating that the 
stars did move from their setting, each with its own 
* proper motion.* Flamsteed, the first Astronomer- Royal, 
and Bradley, the third, each made catalogues of stars, 
giving their exact places in the sky; but the stars in 
the two catalogues had not quite the same places ; the 
stars had moved slightly, not all in the same way, not 
all in the same direction, but indiscriminately, one a 
good distance that way, another but a small distance 
this way. It was not that either Flamsteed or Bradley 
were careless and inexact in marking down the place 
where they saw the stars, for in the catalogues that have 
been since made the same movements are emphasized. 
Each star has its own motion, its ' proper motion,' as it 
is called; but it is a steady motion, straight on, year 
after year, not the swing to and fro in a year, which 








Photograph of the Milky Way around Alpha Centauri, taken by Mr. Franklin- Adams. 



the earth's revolution round the sun should make it 
seem to have. And later still, when the spectroscope 
has been used on the light of the stars, it has been 
found that they have their ' proper motions ' towards 
us, or from us, as well as their ' proper motions ' along 
the face of the sky. And these proper motions in the 
direction of a line joining the star to us are very great 
and rapid motions, amounting, it may be, to scores of 
miles in each second of time. So the stars truly move 
from their places. 

At last, a little more than two centuries after Galileo 
had abjured his belief in the movability of the earth, 
evidence was forthcoming that the earth did swing to 
and fro, by the little corresponding swing that was 
observed in the case of two stars. The evidence for 
both was forthcoming almost at the same time, in the 
winter of the year 1838-39, by two observers, for one 
of the stars could only be seen by those in the southern 
hemisphere, and the other by those in the northern. 

The southern star is the brightest in the constella- 
tion of the Centaur, the third brightest star in the whole 
heavens. It has a large ' proper motion ' of about three 
and a half seconds of arc annually; that is to say, in 
about six. hundred years it would move from its place 
among the stars by a distance equal to the apparent size 
of the moon. A Royal Observatory had been lately com- 
pleted at the Cape of Good Hope in order to supplement 


for the southern hemisphere the observations made at the 
Royal Observatory at Greenwich ; and it was by Hender- 
son, Director of the Cape Observatory, that the obser- 
vations were made which showed that Alpha Centauri 
had a swing in a year of about a second of arc. Such 
a swing would be about the width that a sixpence would 
seem to have, if it were held up at Charing Cross for 
an observer at Millbank to measure. But such a swing 
would mean that the star Alpha Centauri is distant from 
us about 206,265 times 93 millions of miles, a distance 
that we cannot conceive of in our own mind. {See 
Plate LIV.) 

And yet Alpha Centauri is not even so near to us as 

that, for Henderson's measures made the swing too large, 

and later observers have reduced the shift to and fro to 

only three-fourths of a second of arc, which means that 

the star is 206,265 times | times 93 millions of miles away 

from us. This shift of the star in a year is only just 

about as much as the apparent shift in the sky that the 

cross on the top of St. Paul's would appear to us to 

have, if we looked at it first with the right eye, and 

then with the left, from a distance about two miles 

away, say from the roof of the Tate Gallery. The 

shift is due to the swing of the earth in her huge orbit, 

round the sun, of 186,000,000 miles in span; the star 

appears to describe in fact a miniature copy in the sky 

of the earth's orbit, but this copy, so minute, is the 


exact representation in size and shape of the orbit 
described by the earth, as it would be seen by an 
inhabitant of Alpha Centauri, — if he could perceive 
the earth at all. 

Is it any wonder that Galileo failed to detect or 
measure a shift so small ? Besides, no star in the 
northern hemisphere has so great a one. For Alpha 
Centauri is the nearest neighbour that we know of 
amongst the stars, and Galileo never saw a star that 
lies so far to the south. The number of miles that this 
nearest star is distant is so great that the recital of their 
number conveys no meaning to us. We prefer to 
express his distance by the time that it takes the light 
from him to reach us, and that time we do not measure 
in seconds or in liours, but in years. It takes over four 
years for the light from the nearest star to travel to us ; 
if Alpha Centauri was extinguished to-day and became 
darkness, then more than four years would elapse before 
we should know it. 

The star whose shift was measured at the same time 
as Alpha Centauri is not so near ; it takes eight years 
for its light to travel to us. This star is an insignificant 
one in the Swan. It is only faintly visible to the naked 
eye, for it is but of the sixth magnitude, and is not 
dignified by a letter, a name, or a Greek letter, but only 
by a number. It is No. 61 in the constellation of the 
Swan. Its shift in the sky is about as much as the 


shift of the cross of St. Paul's would appear to be when 
viewed first with one eye and then with the other from 
a distance of four miles. 

No doubt, by this time, you do not wonder so much 
that such a shift cannot be measured with extreme 
exactness, as that such a shift can be even conceived 
of, much less measured at all. How can a measure be 
made of a displacement so small that the keenest eye 
could not see it? 

Practically, what is done is this. A star which is 
either very bright, or has a large 'proper motion,' is 
supposed to be much nearer in actuality than the 
surrounding stars, which are fainter, or do not seem to 
move so quickly across the sky. Throughout the year 
a great number of measures are made of the distance of 
this star from as many other stars as possible, and these 
measures are repeated year after year. The measures 
may be made either directly with a measuring machine 
— a micrometer — at the telescope, or with the micro- 
meter on photographs of the region in which the star 
lies. The neighbouring stars are supposed to be so far 
off that they do not shift at all, so that if the measures 
seem to show that the bright or quickly moving star 
has swung ever so little as regards the other stars, 
this swing is supposed to be all its own, and due to its 
nearness. {See Plate XVI., fig. 5.) 

In all the myriads of stars, there are only about 


thirty whose distances we have measured at all, and of 
none of these can we be sure that we know the real 
distance within several hundreds of thousands of millions 
of miles. Alpha Centauri is our nearest neighbour as far 
as we know, and is distant over four light years. The 
next nearest is a little star too faint to be seen without a 
telescope, and light takes seven years to come from this 
star to us. Next comes No. 61 in the Swan, distant 
eight light years ; and then Sirius, the brightest star in 
the whole sky, but its light, that we now see, left it 
more than eight and a half years ago. No other star 
that we know of as yet, is nearer to us than a distance 
that it takes ten years to cross ; from the Pole star the 
light we see to-night left it forty-four years ago. 

So, though we know now for a certainty that the 
earth does move, and swings round the sun, we have 
not been able to send our fathoming line very far into 
space. We cannot measure out the depths of the stars, 
for we can barely and uncertainly touch their nearest 



Star Drift 

'T~'HERE are seven stars that every one knows, for 
-■■ year in and year out they are always present in 
our skies, shining in the north. The Romans called 
them the Seven Plough Oxen, ever treading the 
same unseen furrow in the sky. Dante, the poet, named 
them the Lords of Cold, as hanging continually over the 
frozen regions of the north ; we ourselves call them the 
Plough, or Charles' Wain, that is, the waggon of the churl 
or peasant. These seven stars are part of a larger 
constellation, the Great Bear ; the Plough itself being 
the hindquarters of the beast, and its Handle the tail 
possessed by the heavenly bear, unlike his curtailed 
brothers on the earth. 

Each of the seven stars had a special name given to 
it by the Arabs, and we, to-day, either use these names 
or one of the first seven letters of the Greek alphabet. 

The stars are named Dubhe, Merak, Phecda, and 



Megrez in the ploughshare, the line from Merak to 
Dubhe passing through the Pole star, so that these are 
sometimes called the Pointers ; and Alioth, Mizar, and 
Benatnasch in the plough handle. Megrez is the faintest 
star of the seven, and Mizar has a fainter star very close 
to it called Alcor. Mizar and Alcor can be seen as two 
stars by those with average good sight. 

Long ago, men thought that the heavens moved 
round the earth and that they were built up of a series 
of transparent crystal spheres. Seven inner spheres 
carried the ' seven planets,' that is, the sun, the moon, 
Mercury, Venus, Mars, Jupiter, and Saturn. An eighth 
sphere carried all the stars, so that these were placed all 
at the same distance from us, like lights in the roof of a 
vast dome, and the shape of any group of stars, as we 
saw it, was its true shape. But the star in the Centaur 
told us that all the stars are not at the same distance 
from us, not even all the stars that look to us of the 
same brightness. We have measured the distances 
roughly of only thirty or forty stars, and these lie at 
very different distances. For all the rest their annual 
shift, or ' parallax,' is too small to be measured, but we 
cannot believe that, though immeasurably small, it is the 
same for all. They, too, are at vastly different distances 
from us and from each other. Are they all then discon- 
nected ? Do any of the stars form groups ? Have 
we been foolish in calling all these stars in the 


Plough by one name, as if they were members of one 
family ? 

If the old idea were true that the stars were fixed in 
a crystal sphere, then they could not alter their places 
with regard to each other. But just as we have been 
able within the last seventy years to measure 'annual 
parallax,' that is, the yearly shift in the position of a 
star, so, too, we have been able to measure 'proper 
motion,' the motion across the sky peculiar to each star. 
In most cases this is a very small amount indeed, but it 
can be found more easily than parallax, because its effect 
accumulates year after year. If, then, we are able to 
observe a star over a period of fifty, a hundred, or a 
hundred and fifty years, a very minute annual movement 
will have brought the star over a distance that is quite 
easy to see and to measure. It so happens that for 
something like three thousand stars we have really 
accurate observations, which go back nearly one hundred 
and fifty years. These were the observations of the places 
of stars, made by Bradley, the third Astronomer- Royal. 
These observations we compare with those made quite 
recently, and so get the ' proper motions ' of these stars. 

Some years ago the late Mr. R. A. Proctor drew 
out a chart of the sky, in which he indicated for some 
sixteen hundred stars the rates and directions of their 
' proper motions ' ; and it became evident from this chart 
that there were companies amongst the stars, groups of 


stars moving in fellowship together through space, 
having the same direction, and moving at the same 
rate. Of these companies, the most striking was found 
in the constellation of the Plough. 

It is not all the seven stars that move thus together ; 
the foremost, Dubhe, and the hindermost, Benatnasch (at 
the extremity of the handle), have a different direction. 
But the other five show a striking similarity in their paths. 

This, of itself, would make us think that the five 
stars form a true brotherhood; but there is in their 
spectra another indication of family likeness. The five 
middle stars of the Plough are made of the same 
materials, which are combined in the same way, but 
they differ in this respect from the first and last. The 
spectroscope gives still further evidence that these five 
are a travelling company, for it shows that they are 
coming in our direction, and all with the same rapid 
speed, or very nearly the same, of about eighteen miles 
a second. 

So these five great suns form one company, making 
a common pilgrimage through space, just as the sun and 
his family of planets travel together. But only ninety- 
three millions of miles separate the earth from the sun ; 
not quite three thousand millions separate Neptune, the 
furthest planet, from him. What can be the distance 
that separates Merak from Mizar ? Of what nature can 
be the bond between them ? 


We can point one leg of a compass to Merak and 
the other to Mizar, and measure on a protractor the 
angle that they make as about 19°. So, too, we can 
measure with the compass the diameter of the sun or 
of the moon, and find that they each cover about half a 
degree. But we cannot say how many miles go to the 
degree, the minute, or the second, until we know the 
distances of Merak and Mizar from us, just as, until 
we learned that the sun is distant about ninety-three 
millions of miles, and the moon about 238,400, we could 
not tell that, in the one case, about half a degree meant 
866,400 miles, and in the other 2,163 miles. How are 
we to find the distances of Merak and Mizar so as to 
know how many miles, or light years, go to the 19° 
or more that separate them ? If they were as near 
as Alpha, the bright star in the Centaur, which is 
our nearest neighbour amongst the suns, then each 
second would mean | multiplied by 206,265 multiplied 
by ninety-three millions of miles ; and there are 3,600 
seconds in each degree ; or, in all, 1,750,000 millions of 
millions of miles between Merak and Mizar, But they 
are at an untold distance further than Alpha in the 
Centaur, therefore each second of arc means an untold 
number of millions of miles more with them than it does 
at the nearer star. 

The yearly shift of any of these five stars is too 
small for us to see or to measure, but it is possible 


to gauge their distance from us — of course, only very 
inaccurately — from the manner in which the five stars lie, 
and the direction in which they are all travelling. In the 
diagram of the Plough (Plate LV. fig. 2a) given here- 
with, we see that four out of the five stars lie very 
nearly on a straight line, and the directions in which the 
proper motions of the five stars carry them lie very 
nearly in this line, or else parallel to it. Mizar seems 
to lead the procession of five, and Merak brings up the 
rear, whilst Phecda marches a little on one side, like 
a sergeant bringing out his policemen to their beats. 
If it were a celestial globe on which we were looking, 
and not a flat sheet of paper, the four stars would seem 
to lie very closely to a circle that passes through the 
centre of the globe, and the motions of all the five 
stars would seem to lie very nearly, but not quite, 
parallel to this circle. This means that we on the earth 
and these four stars lie in one plane, in a thin slice of 
space; that Phecda lies so as to make that thin slice 
somewhat thicker ; and that all the stars are moving so 
as not to leave it. They all move in one plane, just as 
the earth and the other planets do in the ecliptic plane. 

Now the proper motions of all these stars are very 
nearly indeed in the same direction, but not quite. It 
seems quite reasonable to suppose that all five are really 
moving at the same actual pace and in the same actual 
direction, but that the small differences in these paces 


and directions that we see are due to the five stars 
being at different distances from us. We see them 
moving with a perspective effect; and if we compare 
the motions together we find that the perspective point, 
'the vanishing point,' as it is called in drawing, is 
situated just about the place in the sky where the fore- 
foot of the Seagoat nearly touches the hindquarters of 
the man-horse, who is called the Archer. It is towards 
this point that they are actually moving in space, and 
we see this motion partly projected on the sky as 
* proper motion,' partly as motion directly towards us as 
measured in the spectroscope. The actual motion of 
the star company through space is compounded of these 
two motions, and, since we know the direction of the 
whole, we can find a proportion between the two. But 
the motion towards us is measured in miles per second, 
and the ' proper motion ' is measured in seconds of arc. 
We have, therefore, got what we wanted in this par- 
ticular case, and find that, at Mizar, a second of arc 
is equal to about 60 times 206,265 times 93 millions of 
miles. Light takes about four years to reach us from 
the star in the Centaur ; it takes, on this estimate, one 
hundred and eighty years to travel from the Plough stars. 
As observed above, if we point the two legs of a 
compass, one towards Mizar, and the other towards 
Merak, we find the angle between them is about 19°. If 
these stars are at about the same distance — more or 


less — from us, then the distance of Merak from Mizar 
must be about one-third the distance of Mizar from us. 
If Merak is more distant than Mizar, as is probable, 
then the distance between them is greater than a third 
of the distance to us. But this implies that it must take 
sixty years at least for light to travel from the van to 
the rearmost of this great company. To bridge the 
distance even from Mizar to its near neighbour, Alioth, 
light must take at least fourteen years. 

We look upon our sun as being isolated in space, for 
light which travels faster than we can conceive cannot 
cover the distance between our nearest neighbour and 
ourselves in less than four years. Yet we can count 
several stars nearer to us than Alioth is to Mizar. Both 
Altair and Sirius are, for instance ; but they are not of 
our kin, they are not made of the same stuff and they 
do not travel in our company. All the stars whose 
yearly shift we have measured are closer to us than 
Mizar is to Merak, for Polaris, the farthest from us; is 
but distant forty-four light years, whilst these great twin 
suns of the Plough are separated by sixty light years. 
Were our earth a planet of Mizar's, then, even with our 
most delicate instruments, we could not see or measure 
the yearly shift of Merak. 

These five stars are amongst the brightest in our 
northern heavens, and yet they are enormously distant 
from us. In just the same proportion, they must be 


enormously great. Most of them are fully of the second 
magnitude of brightness, yet if we circled round Mizar, 
and looked from that distance upon our sun, we would 
account him but of the eighth magnitude. 

Mizar is itself a double star ; this has been told us 
by the spectroscope, and also that the twin stars lie 140 
millions of miles apart, though this vast space is so 
dwarfed to us by distance that we can never distinguish 
them separately. But this twin Mizar has also another 
star, a faint one of the fourth magnitude, circling in ten 
thousand years, at a seeming distance from it of fourteen 
seconds; and yet a third, Alcor, far from it, but yet 
moving with it, as bound in the same chains. 

The picture presented to us of these five suns, so 
vastly superior to our own in brightness and size, and, in 
the case of Mizar, consisting itself of so complex a system 
of suns, the whole five separated by infinitudes of space, 
but subject to the same impulse and travelling on the 
same journey — this picture gives us a hint of manners 
and systems in the star depths far transcending our own. 
We may liken our ruling sun and his little dependants 
to some small, isolated, country village, remote from 
telegraph or rail, where the movement of the great 
world is hardly felt. Its great man is the local squire, 
and the villagers hardly dream that a more important 
personage exists. His word is their simple law, his de- 
cision final ; round him, as its centre, their life revolves. 











Beta ■ 


Fig. I. — The Stars of the Plough. 
(From a photograph by F. IV. Longbottom.) 

Fig. 2. — Drift of the Stars of the Plough. 

i(rt) Showing amount and direction of drift, {b) Appearance of the Plough 100,000 years ago. (c) Appearance 
of the Plough at the present time, (a") Appearance of the Plough 100,000 years hence. 


The Great Nebula of Orion. 
(Pliotografhcd at the Royal Observatory, Greemuieh.) 



Yet, perchance, there filters down to them, from time 
to time, some hint or rumour of a greater world without, 
of greater, more important, persons than their squire. 
They hear of the five great powers of Europe, of their 
rulers, of the great statesmen who guide them. They 
hear of arbitrations and conferences, of intricate diplomacy, 
whose course they find it hard to follow. In something 
like their perplexity we watch this vast star-system of 
suns, so much greater than our own, of motions on a 
scale for which the law of gravity seems hopelessly 
inadequate. And we are like the villagers in another 
respect. Their news from afar reaches them much after 
date. The latest European crisis is known to them it 
may be a week, it may be two, after the event. Our 
news from the five great suns of the Plough is older still. 
It has come to us on the wings of light, without hindrance 
or delay, one hundred and eighty-five thousand miles in 
every second of time, but it has been a hundred and 
eighty years in the coming. We see these five suns, 
not as they are, nor where they are, but as they were, 
and where they were when the first Hanoverian George 
was come to the throne of England. 

As far as we know, our sun is a solitary one, bound 
to no others by invisible bonds, nor travelling with any 
others to the same goal. He has neighbours nearer to 
him than any two of the great Plough stars are to each 
other ; but these neighbours of his are not made of his 



stuff, they are not flesh of his flesh, or they are travelling 
in divergent ways. But the Plough stars are five great 
suns — Mizar and his family we may count as one, even 
as Jupiter and his moons count for one in the planets 
of the sun — moved by the same impulse, and carved 
out, we must believe, from the same great block of 
world-stuff, though they lie so far apart. The five 
great confederates lie in a wilderness, a void ; for though 
there are many other stars, faint or bright, that seem to 
lie near them, yet none of them partakes of their motion ; 
they all lie nearer us, or else in the far depths of space 
beyond. For we cannot conceive that any alien force 
could dare to intrude within the spheres controlled by 
the vast confederacy, -or, if intruding, could resist, for a 
moment, their sway. 

We see, then, that the great block of space occupied 
and controlled by the five confederate suns is not a 
crowded one; not nearly so crowded as the space in 
which our sun moves. The stars are, then, not dis- 
tributed evenly throughout the universe. Are there 
regions more crowded than where the sun is ? 


A MONGST the stories told by the sun was the one 
■^*- he told in concert with the moon, when the latter, 
in a total eclipse, screens our atmosphere for a short 
time from the sun's bright illumination, and shows us 
that he is surrounded by a wonderful halo, the corona. 
Again, in the solar system we have seen that there are 
sundry strange, filmy bodies, erratic in movement and 
weird in form, that we know as comets ; like the corona 
in their peculiar filmy appearances. And far out in the 
star depths we meet again, faint diffused objects, weird 
in shape and shining with much the same sort of filmy 
light that we have already recognized in corona and 

These are the nebulae. Many thousands of these 
are known, and a volume could easily be written simply 
to describe the chief classes into which they may be 
divided. But there is one nebula which stands out as 
by far the most beautiful and mysterious of them all : 
the great nebula in the constellation Orion. 



The great nebula is easily found if we know the 
constellation of Orion, the brightest in the entire sky. 
Three bright stars mark the giant's girdle, and below 
them shines 

A single misty star 
Which is the second in a line of stars 
That seem a sword beneath a belt of three. 

The misty star grows in a powerful telescope into 
a vast filmy cloud of glowing emerald light. It is not 
a regular diffused glow ; in one place it is, as it were, 
curdled into greater brilliance, and close at hand faint 
arches are flung out into space. Elsewhere, it is carded 
and combed like wool or tangled hair. But, most 
striking of all, some of its brightest portions have edges 
sharp as in an engraving and border regions of intense 
blackness. {See Plate LVI.) 

The first mystery about the nebulae, in particular 
about such a nebula as that in Orion, is that we can 
see any form in it. None of the stars are so near, 
or so large, as to offer any visible size even in the 
most powerful telescope ; indeed, the greater and more 
powerful the telescope, the sharper and smaller becomes 
the point of light which is all we see of a star. We 
can quite understand why this is, for if Sirius even, the 
brightest of all the stars, were so huge as to fill the 
entire space between the earth and the sun — 93,000,000 
of miles — that is to say, if it were more than one 


hundred times the diameter of our sun, and more than 
a million times its volume, it would still only be one- 
third of a second of arc in diameter, or about the 
apparent size of a halfpenny seen nine miles away. 

But the great nebula in Orion, and nebulae in 
general, are not mere points of light ; they are objects. 
The central, most brilliant, part of the Orion nebula 
appears very considerably larger than the full moon, 
and its outer extensions are several degrees in 

One of two things then. Either the nebula is very 
near us ; or it is enormously large. But it is not near 
us ; it is no nearer us than the stars are. Hitherto, all 
attempts to discover a 'parallax' for a nebula have 
failed ; there is no difference, that we can see, in the 
place of a nebula when observed from one end of the 
earth's orbit, and when observed from the other, 
1 86,000,000 of miles away. Of course a large, diffused, 
filmy object like a nebula, often very irregular in shape> 
is not at all an easy object to measure, and the argu- 
ment for their great distance is, therefore, not quite so 
direct as in the case of stars. But in not a few cases 
stars are found which at least appear to be enmeshed 
in a nebula, and such stars show no shift that we can 
detect as the earth swings round in her orbit. 

Suppose that this nebula in Orion is as near to us 
as the five stars of the Plough — and we have no reason 


to suppose that it is such a close neighbour to us — 
suppose, in other words, that it takes light at least one 
hundred and eighty years to cross the space between 
us and the nebula, then the central and most brilliant 
part of the nebula must be so enormous that it would 
more than half fill the space between us and our neigh- 
bouring star, Alpha Centauri. But the greater its dis- 
tance the greater its real size must be, and we have 
made a very modest estimate of its distance; it is 
probably even farther away. In this case, both our 
sun and his twin. Alpha Centauri, distant from him 
more than four light years, might both be deeply en- 
gulfed in the densest central meshes of such a nebula. 
But the bright central portion is but a small part of 
the whole, for the nebula sends its spirals and branches 
far and wide. Were our sun in such a nebula, its 
tentacles would reach out to and enfold not only Alpha 
Centauri, but the star in the Swan, Sirius, and every 
star whose shift we can measure as the earth swings 
round in her orbit; even Polaris itself, from whom it 
takes forty-four years at least for light to come. 

Light is the swiftest messenger we know, but it 
takes at least sixty years for it to speed between Merak 
and Mizar, and it certainly cannot traverse the distance 
between the most outlying parts of the great nebula in 
Orion in much less time. But, as far as we can see, 
Merak and Mizar and the other stars of the Plough 



Neeulosities in the Constellation of Orion. 

(F7-om photographs by Dr. Max Wolf.) 

The two photographs overlap by nearly an inch in the N.-S. direction ; but the sonthern photograph is 
displaced two-thirds of an inch towards the East as compared with the northern. 


TjiE Great Neuui.a in Andromeda. 
{P/iofogra/Iii'd at tJie Royal Obscrvaioiy^ C/ra/^o/t-//.) 


are isolated; no visible connexion stretches between 
them, no filmy cloud or tentacle enfolds them. The 
Plough stars travel to a common goal, under a common 
law ; but we cannot see what binds them all together. 
In the nebula we seem to see such a bond. The space 
between the stars is filled up with star mist, mist that 
seems infinitely rarer than even the shining veil that we 
see in coronal ray or in comet's tail. Both these shine, 
in part at least, by reflection fi-om the sun ; but the star 
mist shines of itself. It must, therefore, be a luminous 
gas, a gas that is less dense than any vacuum that we 
can make. It passes our comprehension how such a rare 
gas can assume and retain the definite forms such as 
we see in Professor Max Wolf's beautiful photographs 
of the Orion nebula. It looks as if the gas was in 
violent motion under the influence of some powerful 
force, but how or when or where the force is impressed 
we cannot see. {See Plate LVII.) 

The Orion nebula is the greatest in the heavens ; it 
is an ' irregular ' nebula, but with outlying spiral branches. 
But it has a rival, running it near in beauty and size. 
This is the great nebula in Andromeda, one of the 
' regular,' or spiral^ nebulae. This nebula can really be 
seen by the naked eye, and the old Arabic astronomers 
were familiar with the ' little cloud ' near the most 
northern of the three stars in the girdle of Andromeda; 
but this ' little cloud ' in the first telescope took on the 


appearance of a ' candle shining at night through a semi- 
transparent horn/ and in the more powerful telescopes of 
the later centuries it showed as a steady luminous cloud, 
gradually brightening from the circumference to the 
centre, where it abruptly condensed to a small nucleus of 
indistinct outline under high magnifying powers, but 
containing no star. The telescope, too, extended its 
borders to a great distance, and showed strange dark 
rifts, or ' canals,' whose connexion with the nebula it was 
very hard to understand. 

For the eye at the telescope is not very capable of 
seeing nebulae ; a nebula such as Andromeda's extends 
over a large space in the sky, and the more powerful 
the telescope, the more confined the space that can be 
seen at a time ; it is like surveying a glacier through a 
pinhole. It was not until the photographic plate was 
substituted for the eye and eye-piece of a telescope that 
we could learn what is the true form of the nebula, and 
the meaning of the dark 'canals.' {See Plate LVIII.) 

Then the nebula was seen to be of a form that 
distinctly recalls the appearance of the ringed planet 
Saturn. But Saturn, though the lightest of the planets, 
is still a globe with defined edges. In the nebula the 
central glowing nucleus is not globular, but is undefined 
and merges into the rings. For rings are there, incon- 
ceivably more huge, and not so regular, as the rings of 
Saturn, but showing divisions — for the dark ' canals ' 


are, in the photographs, seen to be but divisions — with 
blotches and differences in brightness, such as that 
between Saturn's crape ring and the others. 

Saturn's rings are neither solid, liquid, nor gaseous, 
but seem made up of a number of solid particles which 
revolve independently and freely round the planet, like 
so many little satellitoids. We do not know how big 
these particles may be ; they may be mere fog or mist 
particles, they may be of the size of dust, or of pebbles, 
or even of great boulders. So, too, as far as we can 
tell, the nucleus and the rings of the nebula in Andro- 
meda are not gaseous, but are composed of solid 
particles. But here the particles cannot be of the size 
even of those in fog or smoke ; they must be smaller 
than anything that we can conceive of, and they cannot 
lie close together. For we cannot consider nebulae as 
being merely painted in the sky, having length and 
breadth, but no thickness. Through many of them we 
must be looking through their greatest thickness, a 
thickness as great as that of the length or breadth as 
we see it in the sky. This thickness must amount to 
millions of millions of miles, and yet we can see through 
it. The matter in such a huge volume must be incon- 
ceivably attenuated, inconceivably light ; else it would be 
as opaque as a wall, and the attraction of its mass would 
perturb the universe. The most empty vacuum that 
we can make is crowded as compared with the emptiness 


in any part of the nebula. Yet it shines by its own 

There are very many nebulae in the sky, some com- 
posed of diffused particles, very sparsely scattered, but 
self-luminous like the one in Andromeda, some com- 
posed in whole or in part of glowing gas like the one in 
Orion. Most of them assume the spiral form ; even the 
' irregular ' nebula of Orion has been shown by Dr. Max 
Wolf to have outlying, far-extending, spiral branches. 
Whence comes such a spiral form ? Is it always there, 
or can we ever watch it forming ? 

It is only within the last decade that an event 
happened which gives some sort of answer to these 
questions. In the early part of the year 1901, a ' new 
star' burst out in the constellation Perseus. In a few 
days it sprang from invisibility to the first magnitude. 
After February 24 it slowly faded, but with many 
fluctuations in light, until, in August, it was but of the 
sixth or seventh magnitude. By this time its spectrum 
had become more like that of a gaseous nebula than 
like that of a true star; but when Professor Barnard 
examined it with the great telescope of the Yerkes 
Observatory, the most powerful in the world, in early 
September, he could detect no trace of nebulosity. 
But on the night of September 20, Professor G. W. 
Ritchey, also of the Yerkes Observatory, photographed 
the 'new star' with a reflecting telescope of two feet 


Nebula about A'uva Persei, September 20, 1901. 


^^\\ . ' ■ 


" ii^^^M 


Me . 


Es'K"' '• ' 








Fig. 2. — Nebula about Nova Persei, November 13, 1901. 
[Photiigraphid by Professor G. W. Ritchey at the Yerkes Observatory.) 




aperture, giving an exposure of four hours, and on this 
photograph were seen two wisps of nebulosity, extending 
from the new star to the west, then curving toward the 
north. The new star had given off a nebula of complex 
form, whose interlacing branches seemed to be of a spiral 
form. In the middle of November, at two American 
observatories — at the Yerkes and at the Lick — photo- 
graphs with long exposure were again taken ; and it 
was seen that not only was the spiral nebula round the 
star more pronounced and distinct, but that parts of it 
had moved, as it were, along the spiral branches, extend- 
ing, outwards, and at a rate that would have carried the 
moving parts over about eleven minutes of arc in a year. 
On September 20 the nebula almost fitted into a square 
on the sky of about fifteen minutes (just under half the 
apparent diameter of the moon); on November 13 it 
fitted into a rectangle of about seventeen minutes by 
sixteen. (See Plate LIX.) 

Now, is it probable that the nebula was actually 
spreading out in space in this rapid and peculiar way ? 
Might it not be possible that the spiral nebula was 
always there, though dark, and when the star in its 
centre burst out, its light illuminated the dark nebula 
travelling from the star out to the outlying branches? 
On this assumption, it would take light a year to travel 
across a distance which to us appears eleven minutes of 
arc in size. If this is so, then the new star and nebula 


in Perseus must be distant from us at least three hundred 
light years ; that is to say, the outburst of the star and 
the lighting up of the nebula actually took place about 
the time that Galileo first turned his telescope upon the 
heavens, and the news of this great stellar catastrophe, 
though speeding to us on the wings of light, only reached 
us in the year 1901. It also means that seven months 
after the first outburst of the ' new star ' the nebula was 
lighted up to a length and breadth of eight and a half 
millions of millions of miles, or about a third of the 
distance from the sun to Alpha Centauri. 

Now, whether the outbursting new star shot forth 
the spirals, or whether it simply lighted up the nebula, 
it is quite certain that the two are in closest connexion. 
The nebula is an appendage of the star ; the star is 
involved in the nebula. In this case, at least, it is 
evident that the phenomena are not distinct. 

But there are other cases where the connexion of 
stars with nebulae, where the evidence of stars being 
bound together by nebulous bonds is even more 
distinct. The most notable of all these is to be found 
in the cluster of the Pleiades. 

This little group was happily described by Tennyson 
as — 

. . . like a swarm of fireflies tangled in a silver braid. 

For they seem so close together that the eye connects 


them up by chains of light. When seen through a 
telescope the light chains are broken ; and the more 
powerful the telescope, the more stars come into view ; 
but each star stands out distinctly, unsheathed in nebulous 

But it is not the eye at the telescope that teaches 
us most about the cluster of the Pleiades, but the 
photographic plate. ■ For the eye sees all that it can see 
at once ; prolonged gazing will strain the sight without 
increasing knowledge. But the sensitive plate does not 
tire, and, unlike the eye, it sums up the sensations it 
receives during its whole length of exposure. A very 
faint, dim light, if falling on the plate for a long time, 
will be as effectual in its impression as a bright light in 
a short time. Photographs of different exposures will 
give information of different kinds. 

If we look at the starry heavens we cannot fail to 
notice — as in the words of the Apostle — that ' one star 
differeth from another star in glory.' Men have there- 
fore divided them into six classes, according to their 
brightness — classes which are commonly spoken of now 
as magnitudes. The ordinary 6th-magnitude star is one 
which can be clearly seen by average sight on a good 
night, and it gives us about one-hundredth the light of 
an average 1st magnitude star. Sirius, the brightest of 
all the fixed stars, would require some two and a half 
million stars of the 14th magnitude to equal it in light. 


Several years ago, some observatories began to make 
a census of the stars which would embrace all those 
from the brightest down to the 14th magnitude. The 
work went on steadily until the observers entered on the 
region of the Milky Way ; but here the numbers of the 
stars presented to them were so great as to baffle all 
ordinary means of observation ; and the census threat- 
ened to come to a complete standstill for lack of power 
to deal with the wealth of material. 

Just at this time immense interest was caused in the 
astronomical world by the appearance of the great comet 
of 1882. It was watched and observed and sketched by 
countless admirers, but more important still, it was 
photographed, and some of its photographs (Plate 
LX.), taken at the Royal Observatory, Cape of Good 
Hope, showed not only the comet with marvellous 
beauty of detail, but also thousands of stars ; and the 
success of these photographs suggested to Sir David 
Gill, then Director of the Cape Observatory, that in 
photography, more or less prolonged, we possessed the 
means for making a complete sky census, even to the 
14th magnitude. This project was thought over in 
all its bearings, and in 1887, a great conference of 
astronomers at Paris resolved upon an international 
scheme for photographing the entire heavens. The 
form of telescope by which the scheme has been carried 
out is represented in Plate LXI. 


The ' Astrographic Telescope' of the Royal Observatoiy, Greenwich, i.e. the Photographic 
Telescope in use for the International Photographic Chart of the Heavens. 



Q D 
< -S 

o c< 

« 5 
1^ a 




A telescopic camera turned on the Pleiades, then, 
will succeed only in getting those stars visible to the 
naked eye if the exposure is but for a few seconds ; but 
as the seconds are prolonged to minutes, more and more 
stars appear on the plate, just as more were seen with 
the increase in power of the telescope. The accompany- 
ing photograph (PlAte LXII.) had an exposure of forty 
minutes, the standard time for those taken to form part of 
the great International Chart of the Heavens. For this, 
eighteen observatories, scattered over the face of the 
earth, are federated to photograph the entire sky in two 
series, one with but half a dozen minutes' exposure in 
order to form a great catalogue of the brighter stars, the 
other with an exposure of forty minutes, so that all stars 
down to the fourteenth magnitude may be charted. On 
this photograph there is a ' reseau,' or cross-scale, printed, 
in order to give the positions of the stars with reference 
to these cross-lines. But if the minutes of exposure be 
prolonged to hours, then the form of the great stars is 
lost in patches and clouds of filmy mist; patches and 
clouds that are shredded and combed into wisps and 
threads, as flax on a distaff. Not only is the star mist 
that shrouds the great stars combed out into these 
curious straight lines, but straight wisps of nebulosity 
join star to star. {See Plate LXII I.) 

On the short exposure photographs, the stars stand 
out sharp, clear, distinct, and unveiled. On the long 


exposure photographs in the places where should be the 
stars, there are dense patches of nebulosity ; to each of 
the greater stars its own nebulous veil. And with the 
increase of exposure, the nebulous veil deepens and 
extends, but centres still round the places of the stars, 
until, as in the wonderful photograph (Plate LXIV.), 
by Dr. Max Wolf, the entire group of the stars of the 
Pleiades is masked by a vast nebula which stretches its 
arms far beyond it into space. In a total eclipse of our 
sun, when his brightness is screened, we see and can 
photograph a nebulous veil surrounding him ; and the 
longer the exposure, the more extended seems his nebula. 
So in the Pleiades, with greater exposure we find these 
stars shrouded in nebulae — in veils which we might 
speak of as their coronae, but coronae on an immeasur- 
ably greater scale than that which surrounds our sun. 


o O 

A it 


I'LATl'; LX1\'. 















'T^HE earth is very differently populated in different 
-■■ parts. There, in the Australian bush, a man 
may need to ride for a day in order to visit his nearest 
neighbour; here, in London, millions of persons are 
crowded into a plot of ground fifteen miles square. 

So, in the universe of stars. In the story by the 
five great brothers of the Plough, it was told that they 
held sway over a vast space, so long that it extended 
over the eighteenth of the whole heavens' span ; a sway 
so unchallenged that, for aught we could see, the five 
confederates were there alone, their domain swept bare 
of rivals. This quarter of the universe is certainly not 
a crowded one. 

But there are parts of the sky which certainly appear 
to be crowded. There is that 

Broad and ample road whose dust is gold 
And pavement stars, as stars to thee appear, 
Seen in the Galaxy, that Milky Way, 
Which nightly as a circling zone thou seest 
Powdered with stars. 

327 R 


and in this description, Milton has touched on the two 
wonderful characteristics of the Milky Way. It is a 
starry zone, a visible belt, spanning the vault of heaven, 
just as the equator and ecliptic are imaginary belts. It 
is strewn with powdered stars ; stars so small and faint 
that the naked eye cannot perceive them singly, yet set 
so closely together that they form a golden road by the 
shining of their numbers, for the eye confuses their 
innumerable points of light into a continuous star surface. 
But the telescope shows them to be separate stars, and 
the more powerful the telescope the more widely does it 
separate them, the more of star-points does it bring into 
view. The five stars of the Plough are moving together 
to a common goal, under a common impulse ; but in the 
vast spaces between them, the most powerful telescope, 
the most prolonged exposure, brings out but few stars, 
and has not hitherto given evidence of any nebulous 
bonds linking them together. In the family of the 
Pleiades, on the other hand, the photographic plate 
shows that the great stars are bound together by 
straight nebulous ribbons, and on these ribbons are 
strung fainter stars, as beads might be threaded on a 
string. But the Plough stars and the Pleiades each 
form a single community ; does the Milky Way form 
one also ? The Milky Way spans the heavens in a 
complete and great circle ; the Plough stars stretch 
over but the eighteenth of this, and the Pleiades 


might almost be covered by the full moon. If the 
Milky Way is a unity, does it take after the vast 
emptinesses of the Plough, or the vast crowdedness 
of the Pleiades ? 

Since the Milky Way is a girdle to the sky, inclined 
to both equator and ecliptic, some part of it can be seen 
on any night of the year ; but in spring time it lies at 
night close to the northern horizon, and is too low in 
the sky to be well observed. Its sweep at midnight in 
mid-July, in this country, is from the north-eastern 
horizon, where the constellation Auriga is just rising, 
through Perseus and Cassiopeia on to Cygnus in the 
zenith ; descending again on the other side through 
Aquila, Serpens, Sagittarius, and Scorpio to the horizon 
in the south-west. It continues to cross the zenith at 
midnight until mid-December, when it sweeps upward 
from the south-eastern horizon in Argo between Orion 
and Gemini to the zenith now marked by the constella- 
tion Auriga ; from whence it passes downwards through 
Perseus and Cassiopeia to the north-west horizon, where 
the constellation Cygnus is setting. It makes its nearest 
approach to the north pole of the heavens in the con- 
stellation Cassiopeia, where it is broad and rather faint. 
This part is always visible to dwellers in this country, at 
all times of the year, and at any time of the night. It 
makes its nearest approach to the south pole of the 
heavens in the constellation of the Southern Cross, 


where it is rather narrow, and exceedingly brilliant. 
This part, being always below our horizon, is never 
visible to us, but it is always to be seen by the dwellers 
in the southern hemisphere, and it helps very greatly to 
make their starry heavens more brilliant than ours. It 
crosses the equator in the constellations of the Unicorn 
and of the Eagle. In the first it is at its broadest and 
faintest, indeed, the whole section of the Milky Way, 
from the Unicorn to Cassiopeia, is wide and dim. But 
in the Eagle it is divided into two great branches which 
have sprung up in the Swan, both of them narrow and 
very brilliant. 

There are two ways by which we can read, at least 
in part, the story told by the Milky Way. We can 
study it and draw it as the naked eye sees it, or we 
can photograph it, or parts of it, with different sorts of 
telescopes and different lengths of exposure. By the 
first way, we draw its form or outline, marking in the 
hollows, and tracing out the spurs and branches ; giving 
due value to the different grades of brightness. This is 
the method pursued by many astronomers, but it is not 
the one that we will now adopt ; so that we will only 
quote here the opinion of Dr. Easton, one of the most 
thorough of these students of the Milky Way. He 
judges that the Milky Way is one system as a whole, 
but a system with perhaps two or more long spirals, 
certainly with many small spurs and branches. This 


spiral girdle of the Millcy Way, lie says, completely 
surrounds the solar system, but though we lie in its 
plane, we do not lie at tl^e centre of the ring, but are 
nearer to those parts that are broad and faint, and 
further from those that are narrow and bright. He 
argues this last on the supposition that the Milky Way 
is just about as thick as it is broad, and does not extend 
to an indefinitely great distance ; as it were, our sun is 
situated inside a ring, not inside a hole in a board. 
The nearer we are to one side of the ring the larger 
does it there appear to be, but also the larger appear 
the spaces between the stars, and the greyer is the 
whole. The farther we are from one side of the ring 
the narrower does it appear, the spaces between the 
stars seem to close up, and the stars coming closer 
together give a more brilliant effect. So a flock of 
crows at a distance seems a small black cloud, but the 
nearer they come the larger and greyer does the cloud 
appear, until it seems no longer a cloud, but we see the 
several birds. 

But we are going to examine the Milky Way from 
another point of view ; we will not consider its form and 
constitution as a whole, but examine samples of it, as it 
were ; studying only small portions of it, photographed in 
this region or in that. First we will study a photo- 
graph of the region of the Swan, where the Milky 
Way divides into two great branches. The photograph 


(Plate LXV.) was taken ^ in the second week of 
August, in 1900, with an exposure of six and a half 
hours. The scale of the photograph is very small, so 
that it covers a very wide area — about one thousand 
degrees in all. The moon on this photograph would 
have a diameter of about the one-thirteenth of an inch, 
and the whole breadth of the Milky Way in both its 
branches is comprised well within the borders of the 
plate. The brightest star near the centre of the photo- 
graph is Alpha Cygni, the most brilliant in the constella- 
tion of the Swan. No. 61 Cygni, our nearest neighbour 
but two, is one of the small stars about one-fifth of the 
way from Alpha to the south-east corner of the plate. 

This photograph shows that the Milky Way in 
Cygnus is not merely double, but is divided into five 
fairly distinct regions, separated from each other by 
lanes that look comparatively dark. The most westerly 
of the branches is roughly crescent shaped, and the 
whole of this region appears to be covered by a diffuse, 
but not uniform, faint cloud, which gives the appearance 
of nebulosity, but which is seen to be, if the plate be 
examined under a microscope, not nebulosity, but faint, 
fairly well defined stars. The next region, rather more 
to the east, is smaller, but more striking, since not only 
are the faint stars aggregated so as to suggest, a 
nebulous bed, but brighter stars are also massed 

1 By Annie S. D. Maunder. 











Region of Nebula, Rho Ophiuchi. 
(Photograph by Profi-ssor E. E. Barnard.) 



together, giving the appearance of numerous and super- 
imposed layers of stars, whose brightness diminishes 
with their distance from us. More to the east, again, 
there is a huge region, not seeming to differ in its 
composition, so far as this photograph can show, from 
the first two, except in the greater frequency of its local 
aggregations of both bright and faint stars, and its more 
numerous channels where no stars appear, or only a few 
sporadic ones. 

But the next region to the east is the most interesting 
of all. It is small, and Alpha Cygni lies on its western 
border. To the unassisted eye, this region appears on 
the negative from which this photographic print is 
taken to consist of a dense nebulous patch, intersected 
by extremely fine streaks. Under a magnifying-glass, 
the nebulosity, to some extent, resolves itself into faint 
and fainter streams and bands of stars, these being 
again bound together by still fainter bands, which are 
not always capable of being resolved into separate stars. 
The streaks are some of the spaces where no star or 
connecting-stuff is seen, between the streams and the 
bands that are not capable of being resolved into stars. 
Many of the stars and the bands form themselves 
into connected spirals. There is one due east of 
Alpha Cygni, half superposed on the most brilliant 
of the regions of the Milky Way. An even more 
curious feature on the original negative is a hole. 


slightly elliptical, but about the diameter of the full 
moon, situated about halfway between Alpha and the 
north-east corner of the photograph. But on this 
photograph, though the general form and structure of 
the Milky Way in Cygnus is well shown, there is 
probably no true nebulosity — except perhaps in the 
bright region due east of Alpha — but only apparent 
nebulosity due to the aggregation of small discrete stars 
too faint to be separately perceived by the unaided eye. 
From this photograph alone, then, we cannot judge 
whether the Milky Way is really a connected structure, 
or only appears to be so by the perspective crowding 
of the stars. To judge of this we will examine six 
beautiful photographs taken by Professor E. E. Barnard 
with a telescope whose object-glass measured ten inches 
instead of the one and a half inches of the little lens 
with which the Cygnus photograph was taken. Pro- 
fessor Barnard gave exposures to these photographs 
of from four and a half to five and a half hours. The 
Cygnus plate was taken just at the starting point of the 
two great branches of the Milky Way. These continue 
separately their course southward past the equator, 
where they are most brilliant ; and three of Professor 
Barnard's photographs are taken of the Milky Way's 
western branch where it passes through the constella- 
tion of the Serpent-holder, and three of its eastern 
branch, where it lies in the constellation of the Archer, 



Region of Theta Ophiuchi. 

(Photograph by Professor E. E. Barnard.) 



Photogkapii of the great rift near theta ophiuchi. 
{Pholograph by Professor E. E. Barnard.) 


The first of Prof. Barnard's photographs (Plate 
LXVI.) is of the region where the foot of the Serpent- 
holder is pressing down upon the head of the Scorpion. 
To the west of the picture there are stars in plenty, 
separate stars such as were seen in the Cygnus photo- 
graph. In the centre of the picture there is also a great 
mass of something that is not merely layer on layer of 
stellar points crowded into one ; it seems in part to be 
truly nebulous star mist, and in part to be made up of 
powdered stars. But there is something in this picture 
that is more remarkable than either crowded stars or 
powdered star mist ; there are long and short, straight 
and crookedly winding lanes and rifts that are empty, 
almost entirely empty, of stars, great or small, or of star 
fog, glowing or dim, speckled or curdled. These channels 
run everywhere, cutting through the star crowds and the 
nebula equally, and impressing blackness upon them. 
The next two photographs {Plates LXVI I. and 
LXVIII.) are of the region of the foot of the Serpent- 
holder which is being stung by the tail of the Scorpion. 
Here the stars sometimes appear simply crowded to- 
gether, sometimes they look as if they are powdered into 
a nebulous bedwork. But whichever their condition, 
the narrow or broad rifts and channels plough through 
them. In the north-west of Plate LXVI I. there is 
a broad bow that seems half filled with grey star stuff, 
with a few separate stars sprinkled upon it. A little 


further to the east and south a giant note of interrogation 
is scooped out of the nebulous froth ; this, too, is half 
filled with nebula. Farther to the south, again, there is, 
as it were, a black S imprinted on the stars, but with 
the ink smeared off from its tail towards the east. All 
along the whole south there is an irregular great grey 
patch, but the grey bed of the channel is seamed and 
scored by blacker rifts. On the whole there is more 
nebula here than star dust, and the nebulosity looks 
curdled like whey because of the rifts and channels. 

In Plate LXVIII., which is near the same region as 
the second, we have principally to do with star crowdings 
and with rifts, rather than with nebulosity and rifts. 
Consider the great straight band running from the 
centre to the south-west corner, which is evidently a 
dark channel, across which the stars have drifted just as 
snowflakes cover again a path that has been swept. 
Running from the centre due east there is a broader, 
less regular, band, like a river with flat wet banks, let 
us say, on which the falling snowflakes melt when fallen. 

The next two photographs are parts of the con- 
stellation of the Archer. In Plate LXIX. the stars 
are certainly so crowded together that we cannot see 
between them, yet where they seem to thin we see 
that they lie imbedded in a grey, nebulous mist. The 
whole might almost do for a photograph of a mackerel 
sky. But in Plate LXX. the stars are certainly not 

PLATIl lxix. 


Great Star Cloud in Sagittarius. 

(Pliotograph by Professor E. E. Barnard.] 




Small Star Cloud in Sagittarius. 

(Photograph by Professor E. E. Barnard.) 



so crowded in many places, we can see everywhere 
between them into blackness. There are one or two 
black channels here, or channels that are sprinkled over 
quite thickly. Almost in the centre of the plate there is 
a large, very black hole, with but a star or two upon it, 
and this hole is evidently connected with the principal 
dark channel, which seems to run from the hole towards 
the south-west, behind the stars. But there are other 
bands, bright ones, or bridges, shall we say, in which the 
stars do not seem to be unduly crowded, but they seem 
to be in, or upon, or behind a nebulous ribbon. The 
most noteworthy of these runs from the great star-cloud 
in the centre of the picture in a slightly south-easterly 

The sixth picture is from the little triangular space 
between the constellations of the Archer, the Eagle, and 
the Serpent, which the astronomers of the late middle 
ages devoted to form a new constellation, that of 
Sobieski's shield. This contains a famous cluster of 
stars, visible to the naked eye, and called * the flock 
of wild ducks.* It lies a little to the north of the 
centre of the picture. {See Plate LXXI.) 

The stars are certainly crowded in this picture, 
though not so crowded that they often run together to 
form a continuous cloud-like surface. But here and 
there weirdly shaped channels are seen, some absolutely 
sharp and black, as if engraved and inked in, containing 


no star or nebulous matter. Note the sharp figure, as of 
a 7 (upside down) in the north-west quarter of the photo- 
graph. Note the V (lying sideways) in the north-east 
and very near the eastern edge. One arm of the V 
stops abruptly, as if it dipped down deep below the 
stars, or they had drifted over it, and then continues 
as abruptly farther on. In the very centre of the plate is 
a curious four-branched figure, only slightly obliterated 
by stars, the junction of the four branches being marked 
by a sharp, round hole, and the north-west branch 
straggling broadly into another hole, out of which one 
might have imagined that the ' flock of wild ducks ' had 

Now, what is the meaning of these extraordinary 
va.cant lanes in the Milky Way ? Not only are they 
often devoid of stars, but they seem to be darker even 
than the surrounding sky. Neither stars nor nebulae 
appear in them. Are they really vacant spaces, or do 
they contain some black substance that hides the stars 
and nebulae from our view ? 

How can we answer this question ? We do not yet 
know ; but whether these lanes be empty or full, they 
teach us one thing about the Milky Way, that it is one 
structure; its different parts are not unconnected with 
each other. For, suppose that the channels are really 
vacant of stars and star mist, then some force has acted 
on all the Milky Way in that region to sweep these 


channels bare. The presence of the lanes shows that 
the Milky Way has a definite form and structure of its 
own ; that its parts form a body. 

And suppose that the channels are due to some 
black substance, to an opaque nebula which blots out 
the bright stars and star mist, then consider the black 
hole which we saw in the centre of the fifth of Professor 
Barnard's pictures. It was large and quite black, so 
that it is evident that if there is black stuff there, it is 
between us and the Milky Way, for it blots out the Milky 
Way. But from this hole, we saw that several channels 
ran to the south-west, channels that were not black on 
the whole but overlaid fairly thickly by a layer of stars, 
stars that evidently form part and parcel with those that 
are adjacent and fairly remote from the channels, and 
the farther from the hole, the more thickly do the stars 
lie upon the channel, blotting it out. We can even trace 
the channels out into the comparatively vacant spaces 
to the south-west, out beyond the great star-cloud which 
occupies the centre of the picture. 

Whether the hole and channels, then, be made up of 
emptiness or of black absorbing stuff, it is evident that 
it lies askew to this great star-cloud. The black round 
patch is in the forefront of it, the channels work back 
to its further end. The star-cloud, the ' hole,' and the 
channels are mixed up together ; they form a composite 


The story that the Plough stars told us was that they 
were of one family ; bound upon a common pilgrimage, 
vast and distant. The story that the nebulae of Orion, 
of Andromeda, and of the Pleiades told us, was that 
they each were one also, bound by ties of inconceivable 
attenuateness, but bound securely; wonderful in form, 
vast spiral structures, though how vast or how distant 
we do not know. So, too, the story that the Milky Way 
tells us is, that it is one, vaster than we can conceive, 
more distant than we can conceive, but yet one, because 
of the complicated structure uniting its parts. 

• • • • • 

Such are a few of the stories which ' the heavens are 
telling.' Some of them were read by men thousands of 
years ago ; some we are only just now beginning to spell 
out. But they are all stories of that great building which 
the hands of God have reared. First of all, men learnt 
how the world on which they lived was set amongst the 
shining lights of heaven, and how these seemed to move 
around it. They learned in time the shape and size of 
that world ; then of the size and distance of moon and 
sun and planets. They learned of the different states 
and conditions of the sun and the planets, and their 
relations to each other as members of the same system. 
Then, greatly daring, they have soared upwards to the 
stars, and tried to stretch the line of thought out to the 
uttermost depths of that unfathomable immensity. And 


Region of Cluster, Messier ii. 
(Photograph by Professor E. E. Barnard.) 




The Veil Nebula in Cygnus (New General Cata. No. 6960). 

{From a photograph iahcii at the Yerkes Observatory^ by Professor G. JF. Ritehey.) 

' Frontiers quickening under prophetic motions from God.' 



there they have still found the tokens of structure ; all 
that we see is part of one building. But of its im- 
mensity what can we say ? The only thing that saves 
us from being crushed by the immensity of the pro- 
portions which are here revealed to us, is that the 
human mind refuses to realize the significance of the 
figures by which those distances are expressed. Were 
it otherwise, the human spirit would be overwhelmed^ 
as in the old German rhapsody that De Quincey trans- 

' God called up from dreams a man into the vestibule 
of heaven, saying, " Come thou hither, and see the 
glory of My house." And to the angels which stood 
around His throne, He said, " Take him, strip from him 
his robes of flesh ; cleanse his vision, and put a new 
breath into his nostrils, only touch not with any change 
his human heart, the heart that weeps and trembles." 
It was done ; and with a mighty angel for his guide the 
man stood ready for his infinite voyage; and from the 
terraces of heaven, without sound or farewell, at once 
they wheeled away into endless space. Sometimes 
with the solemn flight of angel wings they passed 
through zaharas of darkness, through wildernesses of 
death, that divided the worlds of life ; sometimes they 
swept over frontiers that were quickening under pro- 
phetic motions from God. Then, from a distance which 
is counted only in heaven, light dawned for a time 


through a shapeless film ; by unutterable pace the light 
swept to them, they by unutterable pace to the light. 
In a moment the rushing of planets was upon them ; 
in a moment the blazing of suns was around them. 

• Then came eternities of twilight, that revealed but 
were not revealed. On the right hand and on the- left 
towered mighty constellations, that by self-repetitions 
and answers from afar, that by counter-positions, built 
up triumphal gates, whose architraves, whose archways, 
horizontal, upright, rested, rose, at altitude, by spans 
that seemed ghostly from infinitude. Without measure 
were the architraves, past number were the archways, 
beyond memory the gates. Within were stairs that 
scaled the eternities around; above was below and 
below was above, to the man stripped of gravitating 
body ; depth was swallowed up in height unsurmount- 
able, height was swallowed up in depth unfathomable. 
Suddenly, as thus they rode from infinite to infinite, 
suddenly, as thus they tilted over abysmal worlds, a 
mighty cry arose that systems more mysterious, that 
worlds more billowy, other heights and other depths, 
were coming, were nearing, were at hand. 

• Then the man sighed and stopped, shuddered and 
wept. His overladen heart uttered itself in tears, and 
he said, " Angel, I will go no farther ; for the spirit of 
man acheth with this infinity. Insufferable is the glory 
of God. Let me lie down in the grave, and hide me 


from the persecution of the Infinite, for end I see there 
is none." And from all the listening stars that shone 
around issued a choral voice, " The man speaketh truly : 
end there is none that ever yet we heard of!" "End 
is there none ? " the angel solemnly demanded ; " is there 
indeed no end ? And is this the sorrow that kills you ? " 
But no voice answered, that he might answer himself. 
Then the angel threw up his glorious hands to the 
heaven of heavens, saying, " End is there none to the 
universe of God. Lo ! also, there is no beginning." ' 

When I consider the heavens, the work of Thy fingers. 

The moon and the stars, which Thou hast ordained ; 

What is man, that Thou art mindful of him? 

And the son of man, that Thou visitest him ? 

For Thou hast made him a little lower than the angels, 

And hast crowned him with glory and honour. 


ACRONYCHAL risings of Stars, 67 

Alcor. See Plough stars. 

Aldebaran, 81 

Alioth. See Plough stars. 

Alpha Centauri. See Centaur. 

Alpha Cygni. See Swan. 

Altair, 299 

'Ancient Mariner,' 57, 278 

Andromeda, great nebula in, 311, 

312, 313, 314, 346 
Antares (The Scorpion's Heart), 75, 

76, 77, 88, 172 
Antoniadi, £. M., 229 
Aquila. See Eagle. 
Archer, the, 76, 77, 78, 79, 87, 89, 90, 

298, 329. 340, 343 
Arcturus, 172 
Argo (The Ship), 329 
Ashtoreth Kamaim (Ashtoreth of 

the Horns), 43 
Astronomers-Royal, 283 
Auriga (The Holder of the Reins),. 

81, 329 

Babylonians, 38, 43, 51, 73. 92 
Bacon, Miss Gertrude, 227 

„ Rev. J. M., 227 
Balasi (Assyrian astronomer), 55 
Barnard, E. E., 314, 336, 339, 345 
Bayeux tapestry, 273 
Benatnasch. See Plough stars. 
Betelgeuse, 8i 
Bradley, third Astronomer - Royal, 

284, 294 
Bull, 65, 81, 82, 90 
Bums, Robert, 225 

Calcium, 175 

Cape Observatory, 124, 287, 288, 

Carbon, 211 
Cassiopeia (The Lady in the Chair), 

6S, 74, 329, 330 
Castor. See Twins. 
Centaur, chief star in (Alpha Cen- 
tauri), 172, 287, 288, 289, 291, 296, 
298, 308,318 
Chart of the Heavens, International, 

320, 323 
Chromosphere, 150, 153, 154 
Circle, 270, 271 
Comet, coma, 265 

„ Donati's, 265, 266 

„ Halley's, 272, 273 

„ nucleus, 265 

„ of 1 882.. 264, 320 

„ orbits of, 270 

„ taU, 26s, 311 

„ „ movement of, 269 
Comets, 263-274 

., 252, 30s 
Corona, the sun's, 150, 153, 154, 264, 

305, 3" 
„ changes of, 153, 158, 161, 

Crab, 82, 88 
Craters. See Moon. 
Crescent. See Moon. 
Croly, 42, 50 
Cygnus. See Swan. 

Dante, 292 
Dayspring, the, 35 




Decrescent. See Moon. 

De Quincey, 349 

' Descent of Istar,' 43, 51, 92 

Distance of moon, how determined, 

Distance of sun, how determined, 

Donati's Comet, 265, 266 
Dubhe. See Plough stars. 

Eagle, 329, 330, 343 
Earth, 226 

„ influence on sun-spots, 191 

„ shape of, 36, 37 

„ size of, 37, 41 

„ support of, 38, 41 
Easton, Dr. C, 330 
Eclipse of Sun, 146, 149 

„ „ 1896.. 149 

„ „ 1900.. 146 

„ „ colours during, 146, 

Ecliptic, 36, 67 
Ellipse, 270, 271 
Equator, 36 

Equinoxes, precession of, 280 
Eratosthenes, 37 
Eros, 127 
Evening stars, 66, 67, 86, 87, 89 

Faculae, 116, 144, 202 
Famines, Indian, 180, 183 
Fishes, the, 80, 86, 87, 90 
Flamsteed, first Astronomer-Royal, 

107, 284 
'Flock of Wild Ducks.' See 

Messier 1 1 
Four Feathers, 71 

Galileo, 107, 213, 214, 215, 255, 

277, 279, 280, 281, 283, 318 
Gemini. See Twins. 
Genesis i. 14 . . 23 
Gill, Sir David, 320 
Goethe, 74 

Great Dog. See Sirius. 
Green, N. E., 233 

Greenwich Observatory, 24, 107, 123, 
221, 273, 288 

Halley, second Astronomer- Royal, 

Halley's comet, 272, 273 
Hampton, Lord, 149 
Heliacal risings of stars, 67 
Henderson, 288 
Herschel, Sir John, 128 

„ Sir William, 283 
Hesperus, 89, 90 
Hilly Fields, 23, 24, 34 
Holder of the Reins, 81, 329 
Holmes, Oliver Wendell, 58 
Hooke, Robert, 211, 283 
Huygens, 215 
Hydrogen, 175 
Hyperbola, 270, 271 

Indian famines, 180, 183 
International Chart of the Heavens, 

320, 323 
Istar, S3 

„ descent of, 43, 51, 92 

Job xxvi. 7 . . 73 
„ xxxviii. 12.. 35 
Jupiter, 197-211 

„ 90, 91, 92, 94, 96, 99, 213, 

214, 216, 219, 225, 261, 

263, 264, 273, 278, 280, 304 

„ apparent path of, 81, 82, 85 

„ attraction of, 240 
' „ bands of, 201, 204 
„ eighth satellite of, 221 
„ great red spot of, 208 
„ influence upon comets, 272 
„ polar caps of, 204, 207 
„ rotation period of, 208, 228 
„ white spots upon, 203, 204 

Kepler, 273 
Kipling, Rudyard, 60 

Lampland, 242 



Laplace, 220 

Lesser Dog. See Procyon. 

Lick Observatory, 317 

Light, refraction of, i66 

Line of sight, motion in, 176, 177 

Linn€ (lunar crater), 261 

Lion, the, 88 

Lodge, Sir Oliver, 281 

Lowell, Percival, 235, 242 

Magnetic needle, 184, 185 

„ „ movements of, 

184, 185, 186 
„ storms, 186, 187, 188, 

189, 190 
Mark Twain, 255 

Mars, 90, 96, 99, 125, 213, 219, 226, 
228, 270 
„ apparent path of, 76, 7T, 78, 

79, 80, 85, 86 
„ atmosphere of, 229, 235, 236, 

239, 261 
„ attraction of, 240 
„ ' canals ' of, 242, 243, 244 
„ markings on, 233, 234 
„ poles of, 230 
„ rotation of, 229, 234 
Mason, A. E. W., 71 
Megrez. See Plough stars. 
Melotte, P., 221 
Merak. See Plough stars. 
Mercury, 91, 93, 106, 108, 213, 219, 
„ period of, 93 
Merodach, 92 
Messier 11 ('Flock of Wild 

Ducks'), 343, 344 
Milky Way, 827-351 

„ „ 81, 320 

„ „ dark holes m, 340, 343, 
344, 345 

„ „ dark rifts in, 339, 340, 
343, 344, 345 
Milton, 52, S3, 89, 25s, 327 
Mizar, See Plough stars. 
Molesworth, Major P. B., 235 
Months, rule for length of, 54 
Moon, 42-57, 246-262 

Moon, 226, 363 

„ bright rays on, 259 

„ cause of phases, 46, 49, 50 

„ crater Linn^, 261 

„ craters on, 259, 260 

„ crescent, 56 

„ decrescent, 56 

„ distance of, 123, 124 

„ markings on, 249, 250, 251 

„ mountain ranges on, 256, 259 

„ no atmosphere on, 252 

„ phases of, 42-46 

„ photographs of, 252 

„ ' seas ' on, 255, 256, 260 

„ spots on, 46 

„ suspected changes on, 261 

„ unequal motion of, 56 

„ walled plains on, 259 
Morning stars, 66, 67, 86, 89 
Motion in line of sight, 176, 177 

Nebulae, The, 305-323 
Newton, Sir Isaac, 269, 270 

Orion, 81, 172 

„ Nebula in, 306, 307, 308, 311, 

Parabola, 270, 271 

Parallax, stellar, 283, 284, 287, 288, 

291, 294 
Perseus, 81, 329 

„ new star in, 314, 317, 318 
Phillips, Rev. T. E. R., 202 
Phoebe, 221 
Phosphorus, 89, 90 
Pickering, Prof. W. H., 220 
Planets, 74-100 

„ 85, 86, 96 

„ elongatioiis of, 89, 93 

„ oppositions of, 96 

„ retrogressions of, 85, 96 

„ ' seven,' 293 

„ stationary points of, 85 
Pleiades, 318, 319, 328, 346 

„ nebulae in, 323, 324 
Plough, 292-304 



Plough, 62, 68, 74, 307, 311, 327, 328, 
„ stars: Alcor, 293, 300 
„ „ Alioth, 293, 299 
„ „ Benatnasch, 293, 295 
„ „ Dubhe, 292, 295 
„ „ Megrez, 293 
„ „ Merak, 292, 295, 296, 

297, 298, 299, 308 
„ „ Mizar, 292, 295, 296, 
297, 298, 299, 300, 
304, 308 
„ „ Phecda, 292, 297 
Pole star, 68, 71, 72, 291, 299, 308 

„ „ height of, 71, 73 
Pollux. See Twins. 
Precession of the equinoxes, 280 
Prism, 165 

Proctor, R. A., 266, 294 
Procyon (Lesser Dog), 81 
Prominences, 150, 153, 154, 175 

„ changes of, 150, 157 

Proper motion, 294 
Psalm viii., 351 
„ xix., 19, 20, 38 

Rainfall, annual, 180 

Ram, 90 

Ritchey, Professor G. W., 314 

Sagittarius. See Archer. 
Saturn, 212-222 

» 90. 96, 99, 225, 261, 263, 273, 
278, 312 

„ apparent path of, 80, 85, 86 

„ period of, 95 

„ rings of, 215, 216, 217, 218, 

„ nature of rings, 219 

„ rotation of, 228 
Scales, 76 

Schiaparelli, Professor G, V., 242 
Scorpio. See Scorpion. 
Scorpion, 88, 89, 329, 339 
Scorpion's Heart. See Antares. 
Seagoat, 79, 87, 94, 298 
Sea-monster, 80 
Serpens, 329, 343 

Serpent-holder, 339 

Shakespeare, 19, 33, 55 

Sinbad the Sailor, 131 

Sirius (The Great Dog), 81, 172,291, 

299. 308, 319 
Sobieski's shield, 343 
Sodium, spectrum of, 172, 173, 174 
Solar system, scale of, 99, 106, 129 
Southern Cross, 71, 329 
Spectroscope^ 168, 171 
Spectrum, 167, 168, 171 

„ explanation of, 174 
„ lines in solar, 171 
„ of sodium, 172, 173, 174 
„ of sun, 168, 171, 172, 173 
Stars, 58-73 
„ acronychal risings of, 67 
„ apparent movement of, 60-62 
„ evening, 66, 67, 86, 87, 89 
„ heliacal risings, 67 
„ in Perseus, new, 314, 317, 318 
„ morning, 66, 67, 86, 89 
Stonehenge, 34 
Sun, 19-41 
„ 225,263,305 
„ appearance of surface, 1 16, 1 17, 

„ atmosphere of, 104 
„ dayspring, 35 
„ distance of, how determmed, 

„ inclination of path of, 27, 28, 

„ methods of observing, 106, 107 
„ midday height, 29, 30 
„ rising points, 27, 28, 29, 30 
„ rotation of, 108, in, 207, 228 
„ spectrum of, 168, 171, 172, 173 
„ surface of, 116 
Sun-spots, 131-143 

103, 105, 178, 179, 188, 
189, 202, 242, 243 
„ appearance of, 112 
„ bridges, 112 
„ changes of, 115 
„ cycle, 138 
„ duration of, 115 
„ influence of, 180, 183, 190 



Sun-spots, latitudes of, 136, 137 
„ movements of, 132, 135 
„ nucleus, 112 
„ penumbra, 112 
„ size of, 129, 178, 179 
„ umbra, 112 
„ zones, 137, 138, 141 

Swan, 329, 330, 331, 339 

„ Alpha, the bright star in, 332, 

„ No. 61 in, 289, 308, 332 

Taurus. See BulL 
Tennyson, 65, 318 
Twins (Castor and Pollux), 81, 82, 
88, 90 • 

Underworld, 38 
Unicom, 330 
Uranus, 225 

Vega, 172 

Venus, 90, 91, 92, 93, 96, 108, 213, 
219, 226, 228, 244, 246, 262 

„ atmosphere of, 239, 240 

„ attraction of, 240 

„ period of, 94 

„ phases of, 278, 279 

„ rotation of, 228, 244 
Virgin, 76, 88, 90 

Waterpourer, 79, 87, 90 
Wolf, Professor Max, 311, 324 

Yerkes Observatory, 314, 317 

Zodiac, 67 

„ constellations of, 67 



Astronomy without a Telescope 




Fully Illustrated with Full-Page Plates, and with Maps and 

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' Mr. Maunder's book is an excellent guide to the naked-eye 
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illustrated with numerous diagrams and maps.' — Journal of the 
British Astronomical Association. 

'A popular book, fully illustrated, by a competent astro- 
nomer.' — Times. 

'An attractive and instructive book, which ought to make 
many amateur astronomers.' — Daily News. 


The Astronomy of the Bible 


With 34 Illustrations 

London : T. SEALEY CLARK & CO., Ltd., i Racquet Court, Fleet Street, E.C. 

410 + xvi pp. Crown 8vo. Price 5J. net. 

Everything that concerns the Bible is of universal and abiding 
interest ; no time or effort is wasted that is devoted to throwing 
further light upon it. 

The Biblical references to the celestial bodies have a special 
attraction. The progress of modern science has revealed such 
marvels concerning them, the natural objects themselves are so 
glorious, and the language in which they are referred to in 
Scripture has such sublimity, that the Astronomy of the Bible 
must appeal to every thoughtful mind. 

Yet hitherto there has been no attempt to treat the subject in 
a sufficiently comprehensive manner. There have been, indeed, 
a few technical papers written on special points, a great deal of 
vague speculation, not a little rhapsodical writing, and much 
barren argument on an alleged 'conflict between religion and 
science ' ; but no simply written, straightforward book, designed 
for the help of the ordinary student and reader. 

The above work is designed to supply this want. The 
author, Mr. Walter Maunder, Superintendent of the Solar 
Department of the Royal Observatory, Greenwich, is well known 
as a practical astronomer of many years' experience, and as a 
successful writer and lecturer on astronomical subjects. 



Book I. The Heavenly Bodies. 

The Hebrew and Astronomy — The Creation — ^The Deep — The Firmament — ^The 
Ordinances of the Heavens — The Sun — The Moon — The Stars — Comets — 
Meteors — Eclipses of the Sun and Moon — Saturn and Astrology. 

Book II. The Constellations. 

The Origin of the Constellations — Genesis and the Constellations — The Story 
of the Deluge — ^The Tribes of Israel and the Zodiac — Leviathan — The 
Pleiades — Orion — Mazzaroth — Arcturus. 

Book III. Times and Seasons. 

The Day and its Divisions— The Sabbath and the Week— The Month— The 
Year — The Sabbatic Year and the Jubilee — The Cycles of Daniel. 

Book IV. Three Astronomical Marvels. 

Joshua's Long Day — The Dial of Ahaz — The Star of Bethlehem, 


From the Rev. Robert Killip, F.R.A.S. (' Methodist Recorder') :— 

' It would be impossible to give to this most fascinating volume too high praise. 
The author is at the head of the Solar Phjrsics Department of our National Observa- 
tory at Greenwich, and is one of the best known and most trusted of our English 
astronomers. Everything he does is characterized by thoroughness, and his qualifica- 
tions for the task accomplished in this volume are beyond question. . . . The book 
is well and beautifully illustrated, and is a pleasure to handle. Preachers and 
teachers will find many hints capable of being expanded into children's addresses, and 
the volume would make a most acceptable gift book to young or old.' 

From the V^^y. A. L. Cortie, F.R.A.S. ('Observatory'), 

Director of the Solar Section of the British Astronomical Association : — 
< This is an admirable book, both for the learning displayed in its pages, and for 
the spirit of reverent piety shown in the treatment of the sacred volume.' 

Fi-om the Rev. R. B. Girdlestone, M. A. (' The Record'), 

Hon. Canon of Christ Church, Oxford: — 

' The whole work is stimulating to the intellect and strengthening to the faith. 

The book abounds in illustrations, which add greatly to its practical value ; but what 

we appreciate most highly in the author is his combination of reverence, learning, and 

good sense.' 

From the Rev. Edmund Ledger, M.A., Gresham Professor of Astronomy : — 

'"The Astronomy of the Bible" is really a wonderful book in its scientific 
accuracy, its archaeological information, its reverent treatment, and in the lucid and 
easy way in which the difficulties of the subject are explained and the interest of the 
reader unceasingly maintained. The unlearned and the learned in matters astronomical 
and theological will alike enjoy it, and cannot fail greatly to profit by its perusal. It 
is eminently suited for presentation. Many readers of it may do well to purchase 
several copies as presents to their friends. In spite of its low price it contains a large 
number of charming illustrations.' 



Royal Observatory, Greenwich 


With 54 Portraits and Illustrations from old Prints 
and original Photographs. 


320 pp. Price i,s. 

'No one who is interested in astronomy can begin this 
charming book without finishing it, time permitting. In it 
Mr. Maunder is at his best. The history of the Greenwich 
Observatory is co-extensive with that of modern astronomy, 
for the institution was founded in Newton's day. It is at 
present pursuing so many lines of research that its activities 
cover nearly all the principal kinds of observations. The book, 
therefore, gives a good view of present-day methods of work. 
The first four chapters are devoted to an historical sketch from 
Flamsteed to Christie, the present Astronomer - Royal ; the 
remaining nine describe the work now going on. The publishers 
have done their part exceedingly well, and the result is a volume 
that is at once a delight to the eye and a feast to the mind.' — 
Prof. Herbert A. Howe in Popular Astronomy. 


The Story of the Sea and Seashore 


W. PERCIVAL WESTELL, f.l.s., m.b.o.u. 


ETC. ; 





Small Medium 8vo. Cloth Gilt. Gilt Top. 

Price Ss. net. 

With 128 beautiful Illustrations and 8 Coloured Plates. 

This is an admirable companion volume to 'The Story of Insect Life.' The 
author has dealt for the most part with all the commoner forms of British marine 
life, such as Whales, Porpoises, Dolphins, Seals, Sea Fishes, Sea Birds j the British 
Crustacea, namely. Lobsters, Crabs, and Shrimps ; the Mollusca, or Shell-fish, such 
as Whelks, Oysters, Cockles, Mussels, Limpets, &c. ; as also Sea Urchins, Star-fishes, 
Jelly-fishes, Sea Anemones, Corals, Sponges, and the lower forms of Animal life, 
with a concluding essay regarding Trees and Plants of the Sea and Seashore. The 
book is one that makes a strong appeal to all observant and intelligent persons who 
wish to know something of the mysteries of the deep and the wild folk who populate 
our seas and seashores. The illustrations are a great feature. Eight coloured plates 
from the talented brushes of Messrs. W. S. Berridge, F.Z.S., and C. F. Newall, ^nd 
128 photos and drawings, combine to make up a vastly interesting and beautiful book 
on a subject that has not received the attention it so richly deserves. 

25-35 City Road, and 26 Paternoster Row, London, E.C. 


The Story of Insect Life 


W. PERCIVAL WESTELL, f.l.s., m.b.o.u. 


ETC. ; 





With 138 beautiful Illustrations from Photographs by 


J. H. CRABTREE, and others; 

and Eight, exquisite Coloured Plates, figuring fifty different species 

of insects, by 


340 pp. Small Medium 8vo. Cloth Gilt. Gilt Top. 
Price 5^. net. 

In this book the Author deals in an interesting, informing, and popular manner 
with the commoner species of British insects, some of which are likely to come under 
the notice of the reader. The style of treatment is intended to encourage the 
intelligent life-study of insects by our younger folk, to discourage collecting, and to 
stimulate the profitable employment of one's eyes and ears in town or country. It 
has been his aim to point out many of the wonders of insect life, and to show how 
even these minute creatures supply a fund of interest and amusement, and teach 
wonderful object-lessons of patience, intelligence, design, and beauty. The illustra- 
tions in this sumptuous volume are very numerous and remarkable. The eight 
coloured plates, from the talented brush of Mr. E. J. Bedford, have been adjudged by 
competent critics as most life-like and beautiful; whilst the fine series of micro- 
photographs and others combine to make this work the best book ever issued dealing 
exclusively with British Insect Life. 

25-35 City Road, and 26 Paternoster Row, London, E.C. 


The Story of Hedgerow and Pond 




306 pp. Small Medium 8vo. 

With Illustrations on nearly every page, and Eight Full-Page 
Coloured Plates by G, E. LODGE. 

Elegantly bound in Cloth Gilt, Gilt Edges, and Bevelled Boards. 

Price SJ. net. 

The Author takes a roadside hedge and pond, such as are within reach of almost 
every one, and describes the birds, beasts, insects, and flowers found therein at the 
various seasons of the year, laying bare some secrets of their lives, so as to stimulate 
his readers to find out more for themselves. 

* The Author has told his story well, in a plain, unvarnished, understandable, and 
informing way, and we very highly commend this volume.' — Naturalists^ Quarterly 


The Birds and Their Story 

Small Medium 8vo. 156 Illustrations and Eight Coloured Plates. 

Some of the Contents: 

The Birds of Prey. The Insect Eaters. Seed and Vegetable Eaters, 

The Wading Birds. Fresh-water Birds. Sea Birds. 

The Flightless Birds. 

' No better book than this of Mr. Lodge's could be put into the hands of a boy 
or girl for stimulating and satisfying one of the most lasting and pleasurable of all 
tastes, the taste for field natural history.' — County Gentleman. 

25-35 City Road, and 26 Paternoster Row, London, E.C. 


The Flowers and Their Story 



With 155 Illustrations of Flowers and Flower Studies from the 
Author's Photographs, and Eight Coloured Plates. 

316 pp. Small Medium 8vo. Cloth Gilt. Gilt Top. 
Price $s. net. 

For nearly a quarter of a century the Author's Mowers and Flower- 
Lore has been a popular and standard work; and in the present 
volume the results of long and patient study have been brought together. 
Such chapters as those on Dame Nature's Tuck-shop, Honey-pots and 
Honey-guides, Moss-troopers, Fairy Gold, Balloons and Floats, Flags 
and Banners, or Acrobats and Steeple-jacks, can hardly fail to appeal 
to the schoolboy ; while the girls will turn with pleasure to those on 
Lords and Ladies, Among the Nobility, the Flowers of Mary, The 
Emerald Chalice, A Visit to the Nursery, or In the Showroom. 

Illustrations have been freely used, because it is felt that readers 
will be able, by their aid, the more easily to recognize the plants when 
they see them growing. The volume has been carefully planned with 
a view to the fostering of the love of Nature among yoimg people. 

25-35 City Road, and 26 Paternoster Row, London, E.G.