• TABLE OF CONTENTS
HIDE
 Front Cover
 Half Title
 Frontispiece
 Title Page
 Preface
 Table of Contents
 List of Illustrations
 Through magic glasses
 Magic glasses, and how to...
 Fairy rings and how they are...
 The life-history of lichens and...
 The history of a lava stream
 An hour with the sun
 An evening among the stars
 Little beings from a miniature...
 The dartmoor ponies
 The magician's dream of ancient...
 Index
 Advertising
 Back Cover
 Spine






Group Title: Through magic glasses and other lectures : a sequel to The fairyland of science
Title: Through magic glasses and other lectures
CITATION THUMBNAILS PAGE TURNER PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00078569/00001
 Material Information
Title: Through magic glasses and other lectures a sequel to The fairyland of science
Physical Description: xiv, 234 p., 2 leaves of plates : ill., (some col.) ; 19 cm.
Language: English
Creator: Buckley, Arabella B ( Arabella Burton ), 1840-1929
D. Appleton and Company ( Publisher )
Publisher: D. Appleton and Company
Place of Publication: New York
Publication Date: 1890
Edition: "Authorized ed." 1st English ed., 1890.
 Subjects
Subject: Science -- Juvenile literature   ( lcsh )
Natural history -- Juvenile literature   ( lcsh )
Physical sciences -- Juvenile literature   ( lcsh )
Science -- History -- Juvenile literature   ( lcsh )
Textbooks -- 1890   ( rbgenr )
Bldn -- 1890
Genre: Textbooks   ( rbgenr )
non-fiction   ( marcgt )
Spatial Coverage: United States -- New York -- New York
 Notes
Statement of Responsibility: by Arabella B. Buckley (Mrs. Fisher).
General Note: Includes index.
General Note: 10 chapters on astronomy, biology, etc.
 Record Information
Bibliographic ID: UF00078569
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 002222926
notis - ALG3173
oclc - 49265592

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Half Title
        Page i
    Frontispiece
        Page ii
    Title Page
        Page iii
        Page iv
    Preface
        Page v
        Page vi
        Page vii
        Page viii
    Table of Contents
        Page ix
        Page x
    List of Illustrations
        Page xi
        Page xii
        Page xiii
        Page xiv
    Through magic glasses
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
    Magic glasses, and how to use them
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
    Fairy rings and how they are made
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
    The life-history of lichens and mosses
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
    The history of a lava stream
        Page 96
        Page 97
        Page 98
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
        Page 111
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
    An hour with the sun
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
        Page 122
        Page 123
        Page 124
        Page 125
        Page 126
        Page 126a
        Page 127
        Page 128
        Page 129
        Page 130
        Page 131
        Page 132
        Page 133
        Page 134
        Page 135
        Page 136
        Page 137
        Page 138
        Page 139
        Page 140
        Page 141
        Page 142
        Page 143
        Page 144
    An evening among the stars
        Page 145
        Page 146
        Page 147
        Page 148
        Page 149
        Page 150
        Page 151
        Page 152
        Page 153
        Page 154
        Page 155
        Page 156
        Page 157
        Page 158
        Page 159
        Page 160
        Page 161
        Page 162
        Page 163
        Page 164
        Page 165
        Page 166
        Page 166a
        Page 167
        Page 168
        Page 169
        Page 170
        Page 171
    Little beings from a miniature ocean
        Page 172
        Page 173
        Page 174
        Page 175
        Page 176
        Page 177
        Page 178
        Page 179
        Page 180
        Page 181
        Page 182
        Page 183
        Page 184
        Page 185
        Page 186
        Page 187
        Page 188
        Page 189
        Page 190
        Page 191
        Page 192
        Page 193
        Page 194
    The dartmoor ponies
        Page 195
        Page 196
        Page 197
        Page 198
        Page 199
        Page 200
        Page 201
        Page 202
        Page 203
        Page 204
        Page 205
        Page 206
        Page 207
        Page 208
    The magician's dream of ancient days
        Page 209
        Page 210
        Page 211
        Page 212
        Page 213
        Page 214
        Page 215
        Page 216
        Page 217
        Page 218
        Page 219
        Page 220
        Page 221
        Page 222
        Page 223
        Page 224
        Page 225
        Page 226
    Index
        Page 227
        Page 228
        Page 229
        Page 230
        Page 231
        Page 232
        Page 233
        Page 234
    Advertising
        Page 235
        Page 236
        Page 237
        Page 238
    Back Cover
        Back Cover 1
        Back Cover 2
    Spine
        Spine
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THROUGH MAGIC GLASSES































































THE GREAT NEBULA OF ORION
From a .1 .' ,l aken on February 40' 188E
SIsaac Roberts









THROUGH


MAGIC GLASSES


AND OTHER LECTURES



A SEQUEL TO THE FAIRYLAND OF SCIENCE




BY
ARABELLA B. BUCKLEY
(MRS. FISHER)
AUTHOR OF LIFE AND HER CHILDREN, WINNERS IN LIFE S RACE,
A SHORT HISTORY OF NATURAL SCIENCE, ETC.


WITH NUMEROUS ILLUSTRATIONS






NEW YORK
D. APPLETON AND COMPANY
1890



























Authorized Edition.














PREFACE.


THE present volume is chiefly intended for those of
my young friends who have read, and been interested
in, the Fairyland of Science. It travels over a wide
field, pointing out a few of the marvellous facts which
can be studied and enjoyed by the help of optical
instruments. It will be seen at a glance that any
one of the subjects dealt with might be made the
study of a lifetime, and that the little information
given in each lecture is only enough to make the
reader long for more.
In these days, when moderate-priced instruments
and good books and lectures are so easily accessible,
I hope some eager minds may be thus led to take up
one of the branches of science opened out to us by
magic glasses ; while those who go no further will at
least understand something of the hitherto unseen
world which is now being studied by their help.






PREFACE


The two last lectures wander away from this path,
and yet form a natural conclusion to the Magician's
lectures to his young Devonshire lads. They have
been published before, one in the Youth's Companion of
Boston, U.S., and the other in Atalanta, in which the
essay on Fungi also appeared in a shorter form.
All three lectures have, however, been revised and
fully illustrated, and I trust that the volume, as a
whole, may prove a pleasant Christmas companion.
For the magnificent photograph of Orion's nebula,
forming the Frontispiece, I am indebted to the courtesy
of Mr. Isaac Roberts, F.R.A.S., who most kindly lent
me the plate for reproduction; and I have had the
great good fortune to obtain permission from MM.
Henri of the Paris Observatory to copy the illustra-
tion of the Lunar Apennines from a most beautiful
and perfect photograph of part of the moon, taken by
them only last March. My cordial thanks are also
due to Mr. A. Cottam, F.R.A.S., for preparing the
plate of coloured double stars, and to my friend
Mr. Knobel, Hon. Sec. of the R.A.S., for much
valuable .assistance; to Mr. James Geikie for the
loan of some illustrations from his Geology; and to






PREFACE vii

Messrs. Longman for permission to copy Herschel's
fine drawing of Copernicus.
With the exception of these illustrations and a
few others, three of which were kindly given me
by Messrs. Macmillan, all the woodcuts have been
drawn and executed under the superintendence of
Mr. Carreras, jun., who has made my task easier by
the skill and patience he has exercised under the
difficulties incidental to receiving instructions from a
distance.
ARABELLA B. BUCKLEY.


UPCOTT AVENEL, Oct. 1890.




















TABLE OF CONTENTS



CHAPTER I
PAGE
THE MAGICIAN'S CHAMBER BY MOONLIGHT I


CHAPTER II

MAGIC GLASSES AND HOW TO USE THEM 27


CHAPTER III

FAIRY RINGS AND HOW THEY ARE MADE 55


CHAPTER IV

THE LIFE-HISTORY OF LICHENS AND MOSSES 75


CHAPTER V

THE HISTORY OF A LAVA STREAM. 96


CHAPTER VI

AN HOUR WITH THE SUN .








x CONTENTS


CHAPTER VII
PAGE
AN EVENING AMONG THE STARS 145


CHAPTER VIII

LITTLE BEINGS FROM A MINIATURE OCEAN 172


CHAPTER IX

THE DARTMOOR PONIES. 195


CHAPTER X

THE MAGICIAN'S DREAM OF ANCIENT DAYS 209






















LIST OF ILLUSTRATIONS



PLATES

PHOTOGRAPH OF THE NEBULA OF ORION Frontispiece
TABLE OF COLOURED SPECTRA Plate I.facingp. 127
COLOURED DOUBLE STARS II. ,, 167



WOODCUTS IN THE TEXT
PAGE
PARTIAL ECLIPSE OF THE MOON initial letter I
A BOY ILLUSTRATING THE PHASES OF THE MOON 6
COURSE OF THE MOON IN THE HEAVENS .
CHART OF THE MOON 1. .IO
FACE OF THE FULL MOON II
TYCHO AND HIS SURROUNDINGS (from a photograph by De
la Rue) 13
PLAN OF THE PEAK OF TENERIFFE 15
THE CRATER COPERNICUS .17
THE LUNAR APPENNINES (from a photograph by MM. Henri) 19
THE CRATER PLATO SEEN SOON AFTER SUNRISE 20
DIAGRAM OF TOTAL ECLIPSE OF THE MOON 23
BOY AND MICROSCOPE t niial letter 27
EYE-BALL SEEN FROM THE FRONT 30
SECTION OF AN EYE LOOKING AT A PENCIL 3. 31
IMAGE OF A CANDLE-FLAME THROWN ON PAPER BY A LENS. 33
ARROW MAGNIFIED BY A CONVEX LENS 35








xii LIST OF ILLUSTRATIONS
PAGE
STUDENT'S MICROSCOPE .36
SKELETON OF A MICROS OPE 37
FOSSIL DIATOMS SEEN UNDER THE MICROSCOPE 39
AN ASTRONOMICAL TELESCOPE 41
TWO SKELETONS OF TELESCOPES 44
THE PHOTOGRAPHIC CAMERA 47
KIRCHHOFF'S SPECTROSCOPE 5. .
PASSAGE OF RAYS THROUGH THE SPECTROSCOPE 52
A GROUP OF FAIRY-RING MUSHROOMS Initial letter 55
THREE FORMS OF VEGETABLE MOULD MAGNIFIED 6
MUCOR MUCEDO GREATLY MAGNIFIED. 63
YEAST CELLS GROWING UNDER THE MICROSCOPE 65
EARLY STAGES OF THE MUSHROOM 67
LATER STAGES OF THE MUSHROOM 68
MICROSCOPIC STRUCTURE OF MUSHROOM GILLS 69
A GROUP OF CUP LICHENS Initial letter 75
EXAMPLES OF LICHENS FROM LIFE 77
SINGE-CELLED PLANTS GROWING 78
SECTIONS OF LICHENS 8
FRUCTIFICATION OF A LICHEN 83
A STEM OF FEATHERY MOSS FROM LIFE 85
MOSS-LEAF MAGNIFIED 87
POLYTRICHUM COMMUNE, A LARGE HAIR-MOSS 88
FRUCTIFICATION OF A MOSS 89
SPHAGNUM MOSS FROM A DEVONSHIRE BOG .93
SURFACE OF A LAVA-FLOW initial letter 96
VESUVIUS AS SEEN IN ERUPTION 97
TOP OF VESUVIUS IN 1864 00oo
DIAGRAMMATIC SECTION OF AN ACTIVE VOLCANO 105
SECTION OF A LAVA-FLOW 108
VOLCANIC GLASS WITH CRYSTALLITES AND MICROLITHS 109
VOLCANIC GLASS WITH WELL-DEVELOPED MICROLITHS 110
A PIECE OF DARTMOOR GRANITE 2 2
VOLCANIC GLASS SHOWING LARGE INCLUDED CRYSTALS 115
A TOTAL ECLIPSE OF THE SUN .Initial letter 117
FACE OF THE SUN PROJECTED ON A PIECE OF CARDBOARD 120









LIST OF ILLUSTRATIONS xiii

PAGE
PHOTOGRAPH OF THE SUN'S FACE, taken by Mr. Selwyn
(Secchi, Le Soleil) 122
TOTAL ECLIPSE OF THE SUN, SHOWING CORONA AND PRO-
MINENCES (Guillemin, Le Ciel) 124
KIRCHHOFF'S EXPERIMENT ON THE DARK SODIUM LINE .128
THE SPECTROSCOPE ATTACHED TO THE TELESCOPE FOR SOLAR
WORK 32
SUN-SPECTRUM AND PROMINENCE SPECTRUM COMPARED 134
RED PROMINENCES, as drawn by Mr. Lockyer r869 136
A QUIET SUN-SPOT 40
A TUMULTUOUS SUN-SPOT 141
A STAR-CLUSTER Initial leler 145
SOME CONSTELLATIONS SEEN ON LOOKING SOUTH IN MARCH
FROM SIX TO NINE O'CLOCK 148
TIE CHIEF STARS OF ORION, WITII ALDEBARAN 149
TIE TRAPEZIUM 0 ORIONIS 150
SPECTRUM OF ORION'S NEBULA AND SUN-SPECTRUM COM-
PARED 151
SOME CONSTELLATIONS SEEN ON LOOKING NORTH IN MARCH
FROM SIX TO NINE O'CLOCK 156
THE GREAT BEAR, SHOWING POSITION OF THE BINARY STAR 157
DRIFTING OF THE SEVEN STARS OF CHARLES'S WAIN .159
CASSIOPEIA AND THE HEAVENLY BODIES NEAR 162
e LYRIE, A DOUBLE-BINARY STAR 166
A SEASIDE POOL. I itial letter 172
A GROUP OF SEAWEEDS (natural size) 175
ULVA LACTUCA, a piece greatly magnified 176
SEAWEEDS, magnified to show fruits 177
A CORALLINE AND SERTULARIAN COMPARED .179
SERTULARIA TENELLA HANGING IN WATER .IO
7'HURICOLLA FOLLICULATA AND CHILOM ONAS AMYGDALUM 182
A GROUP OF LIVING DIATOMS 84
A DIATOM GROWING 185
CYDIPPE PILEUS, ANIMAL AND STRUCTURE 87
THE SEA-MAT, FLUSTRA FOLIACEA 19
DIAGRAM OF THE FLUSTRA ANIMAL 192









xiv LIST OF ILLUSTRATIONS
PAGE
DARTMOOR PONIES 7 Iitial letter 195
EQUUS H1EMIONUS, THE HORSE-ASS OF TARTARY AND TIBET 201
PRZEVALSKY'S WILD HORSE 202
SKELETON OF AN ANIMAL OF THE HORSE-TRIBE 206
PAL/EOLITHIC MAN CHIPPING FLINT TOOLS Initial letter 209
SCENE IN PALEOLITHIC TIMES. .212
PALEOLITHIC RELICS-NEEDLE, TOOTH, IMPLEMENT 213
MAMMOTH ENGRAVED ON IVORY 216
NEOLITHIC IMPLEMENTS-HATCHET, CELT, SPINDLE WHORL. 219
A BURIAL IN NEOLITHIC TIMES .221
BRITISH RELICS-COIN, BRONZE CELT, AND BRACELET .223
BRITONS TAKING REFUGE IN THE CAVE .224
















THROUGH MAGIC GLASSES


CHAPTER I

THE MAGICIAN'S CHAMBER BY MOONLIGHT

.- HE full moon was shining in all
its splendour one lovely August
night, as the magician sat in
Shis turret chamber bathed in
lier pure white beams, which
streamed upon him through the
,-,pen shutter in the wooden
dome above. It is true a faint
leam of warmer light shone
from below through the open
door, for this room was but an offshoot at the top
of the building, and on looking down the turret
stairs a lecture-room might be seen below where a
bright light was burning. Very little, however, of
this warm glow reached the magician, and the im-
plements of his art around him looked like weird
gaunt skeletons as they cast their long shadows
across the floor in the moonlight.







THROUGH MAGIC GLASSES


The small observatory, for such it was, was a
circular building with four windows in the walls, and
roofed with a wooden dome, so made that it could
be shifted round and round by pulling certain cords.
One section of this dome was a shutter, which now
stood open, and the strip, thus laid bare to the night,
was so turned as to face that part of the sky along
which the moon was moving. In the centre of the
room, with its long tube directed towards the opening,
stood the largest magic glass, the TELESCOPE, and in
the dead stillness of the night, could be heard distinctly
the tick-tick of the clockwork, which kept the instru-
ment pointing to the face of the moon, while the
room, and all in it, was being carried slowly and
steadily onwards by the earth's rotation on its axis.
It was only a moderate-sized instrument, about six
feet long, mounted on a solid iron pillar firmly fixed
to the floor and fitted with the clockwork, the sound
of which we have mentioned; yet it looked like a
giant as the pale moonlight threw its huge shadow
on the wall behind and the roof above.
Far away from this instrument in one of the
windows, all of which were now closed with shutters,
another instrument was dimly visible. This was
a round iron table with clawed feet, and upon it,
fastened by screws, were three tubes, so arranged
that they all pointed towards the centre of the table,
where six glass prisms were arranged in a semicircle,
each one fixed on a small brass tripod. A strange
uncanny-looking instrument this, especially as the
prisms caught the edge of the glow streaming up the
turret stair, and shot forth faint beams of coloured







THE MAGICIAN'S INSTR UMEANTS


light on the table below them. Yet the magician's
pupils thought it still more uncanny and mysterious
when their master used it to read the alphabet of
light, and to discover by vivid lines even the faintest
trace of a metal otherwise invisible to mortal eye.
For this instrument was the SPECTROSCOPE, by
which he could break up rays of light and make them
tell him from what substances they came. Lying
around it were other curious prisms mounted in
-metal rims and fitted with tubes and many strange
devices, not to be understood by the uninitiated, but
magical in their effect when fixed on to the telescope
and used to break up the light of distant stars and
nebula.
Compared with these mysterious glasses the PHOTO-
GRAPHIC CAMERA, standing in the background, with
its tall black covering cloth, like a hooded monk,
looked comparatively natural and familiar, yet it, too,
had puzzling plates and apparatus on the table near
it, which could be fitted on to the telescope, so that
by their means pictures might be taken even in the
dark night, and stars, invisible with the strongest lens,
might be forced to write their own story, and leave
their image on the plate for after study.
All these instruments told of the magician's
power in unveiling the secrets of distant space and
exploring realms unknown, but in another window,
now almost hidden in the shadow, stood a fourth
and highly-prized helpmate, which belonged in one
sense more to our earth, since everything examined
by it had to be brought near, and lie close under its
magnifying-glass. Yet the MICROSCOPE too could







THROUGH MAGIC GLASSES


carry its master into an unseen world, hidden to
mortal eye by minuteness instead of by distance.
If in the stillness of night the telescope was his most
cherished servant and familiar friend, the microscope
by day opened out to him the fairyland of nature.
As he sat on his high pedestal stool on this
summer night with the moonlight full upon him, his
whole attention was centred on the telescope, and
his mind was far away from that turret-room,
wandering into the distant space brought so near to
him; for he was waiting to watch an event which
brought some new interest every time it took place
-a total eclipse of the moon. To-night he looked
forward to it eagerly, for it happened that, just as
the moon would pass into the shadow of our earth,
it would also cross directly in front of a star, causing
what is known as an occultation of the star, which
would disappear suddenly behind the rim of the
dark moon, and after a short time flash out on the
other side as the satellite went on its way.
How he wished as he sat there that he could
have shown this sight to all the eager lads whom he
was teaching to handle and love his magic glasses.
For this magician was not only a student himself,
he was a rich man and the Founder and Principal
of a large public school for boys of the artisan class.
He had erected a well-planned and handsome build-
ing in the midst of the open country, and received
there, on terms within the means of their parents,
working-lads from all parts of England, who, besides
the usual book-learning, received a good technical
education in all its branches. And, while he left to







THE MAGICIAN'S PUPILS


other masters the regular school lessons, he kept for
himself the intense-pleasure of opening the minds of
these lads to the wonders of God's universe around
them.
You had only to pass down the turret stairs, into
the large science class-room below, to see at once
that a loving hand and heart had furnished it. Not
only was there every implement necessary for
scientific work, but numerous rough diagrams cover-
ing the walls showed that labour as well as money
had been spent in decorating them. It was a large
oblong room, with four windows to the north, and four
to the south, in each of which stood a microscope
with all the tubes, needles, forceps, knives, etc.,
necessary for dissecting and preparing objects;
and between the windows were open shelves, on which
were ranged chemicals of various kinds, besides many
strange-looking objects in bottles, which would have
amused a trained naturalist, for the lads collected
and preserved whatever took their fancy.
On some of the tables were photographic plates
laid ready for printing off; on others might be seen
drawings of the spectrum, made from the small
spectroscope fixed at one end of the room; on
others lay small direct spectroscopes which the
lads could use for themselves. But nowhere was
a telescope to be seen. This was not because
there were none, for each table had its small
hand telescope, cheap but good. The truth is
that each of these instruments had been spirited
away into the dormitories that night, and many
heads were lying awake on their pillows, listening







THROUGH MAGIC GLASSES


for the strike of the clock to spring out and see the
eclipse begin.
A mere glance round the room showed that the
moon had been much studied lately. On the black-
board was drawn a rough diagram, showing how a
boy can illustrate for himself the moon's journey
round the earth, by taking a ball and holding it a
little above his head at arm's length, while he turns
slowly round on his heel in a darkened room before
Fig. I.






1, I'2










A boy illustrating the phases of the moon.
a lighted lamp, or better still before the lens of a
magic lantern (Fig. I). The lamp or lens then re-
presents the sun, the ball is the moon, the boy's
head is the earth. Beginning with the ball between
him and the source of light, but either a little above,
or a little below the direct line between his eye and







THE PHASES OF THE MOON


it, he will see only the dark side of the ball, and
the moon will be on the point of being new." Then
as he turns slowly, a thin crescent of light will creep
over the side nearest the sun, and by degrees en-
croach more and more, so that when he has turned
through one quarter of the round half the disc will
be light. When he has turned another quarter,
and has his back to the sun, a full moon will face
him. Then as he turns on through the third quarter
a crescent of darkness creeps slowly over the side
away from the sun; and gradually the bright disc is
eaten away by shadow till at the end of the third
quarter half the disc again only is light ; then, when
he has turned through another quarter and completed
the circle, he faces the light again and has a dark
moon before him. But he must take care to keep
the moon a little above or a little below his eye at
new and full moon. If he brings it exactly on a
line with himself and the light at new moon, he will
shut off the light from himself and see the dark
body of the ball against the light, causing an eclipse
of'the sun ; while if he does the same at full moon
his head will cast a shadow on the ball causing an
eclipse of the moon.
There were other diagrams showing how and why
such eclipses do really happen at different times in
the moon's path round the earth; but perhaps the
most interesting of all was one he had made to
explain what so few people understand, namely, that
though the moon describes a complete circle round
our earth every month, yet she does not describe
a circle in space, but a wavy line inwards and out-







THROUGH MAGIC GLASSES


S- .5 wards across the
-y earth's path round the
S -- sun. This is because
/ the earth is moving

S-ing the moon with it,
S. ~ and it is only by see-
:J .s ,ing it drawn before
). | our eyes that we can
realise how it happens.
S--- S v Thus suppose, in
0 order to make the
-- o dates as simple as
S possible, that there is
M Sa new moon on the
--- Ist of some month.
S Then by the 9th (or
S_ --- roughly speaking in
S7 days) the moon
3 ---- will have described a
: -- E quarter of a circle

;' shown by the plottedd
S: line (Fig. 2), which
Smarks her position
b. ,- night after night with
regard to us. Yet
S because she is carried
S-- g onwards all the while
S... by the earth, she will
i,, really have passed
Along the interrupted







T7HE MOO0'S JOLURA7NEY LV SPACE 9

line --- between us and the sun. During the next
week her quarter of a circle will carry her round be-
hind the earth, so that we see her on the I7th as a
full moon, yet her actual movement has been onwards
along the interrupted line on the farther side of the
earth. During the third week she creeps round
another quarter of a circle so as to be in advance of
the earth on its yearly journey round the sun, and
reaches the end of her third quarter on the 24th.
In her last quarter she gradually passes again
between the earth and the.sun ; and though, as regards
the earth, she appears to be going back round to the
same place where she was at the beginning of the
month, and on the 3 Ist is again a dark new moon,
yet she has travelled onwards exactly as much as
we have, and therefore has really not described a
circle in the heavens but a wavy line.
Near to this last diagram hung another, well loved
by the lads, for it was a large map of the face of
the moon, that is of the side which is always turned
towards us, because the moon turns once on her
axis during the month that she is travelling round
the earth. On this map were marked all the different
craters, mountains, plains and shining streaks which
appear on the moon's face; while round the chart
were pictures of some of these at sunrise and sunset
on the moon, or during the long day of nearly a
fortnight which each part of the face enjoys in its
turn.
By studying this map, and the pictures, they
were able, even in their small telescopes, to recognize
Tycho and Copernicus, and the mountains of the








o1 THROUGH MAGIC GLASSES

moon, after they had once grown accustomed to the


Fig. 3.


i Tycho.
2 Copernicus.
3 Kepler.


4 Arist
5 Erat
6 Arch


Chart of the moon.
Craters-
archus. 7 Plato. io Petavius.
osthenes. 8 Eudoxus. II Ptolemy.


imedes.


9 Aristotle.


Grey plains formerly believed to be seas-
A Mare Crisium. O Mare Imbrium.
C -- Frigoris. Q Oceanus Procellarum.
G -- Tranquillitatis. X Mare Fcecunditatis.
H Serenitatis. T Humorum.


strange changes in their appearance which take








THE FACE OF THIE FULL MOON II
place as daylight or darkness creeps over them.
They could not however pick out more than some of
the chief points. Only the magician himself knew
every crater and ridge under all its varying lights,
Fig- 3a.

























The full moon. (From Ball s Sarland.)

and now, as he waited for the eclipse to begin, he
turned to a lad who stood behind him, almost hidden
in the dark shadow-the one fortunate boy who had
earned the right to share this night's work.







THROUGH MAGIC GLASSES


We have still half an hour, Alwyn," said he,
"before the eclipse will begin, and I can show you the
moon's face well to-night. Take my place here and
look at her while I point out the chief features.
See first, there are the grey plains (A, C, G, etc.)
lying chiefly in the lower half of the moon. You
can often see these on a clear night with the
naked eye, but you must remember that then they
appear more in the upper part, because in the tele-
scope we see the moon's face inverted or upside down.
These plains were once thought to be oceans, but
are now proved to be dry flat regions situated at
different levels on the moon, and much like what
deserts and prairies would appear on our earth if seen
from the same distance. Looking through the
telescope, is it not difficult to imagine how people
could ever have pictured them as a man's face ? But
not so difficult to understand how some ancient
nations thought the moon was a kind of mirror, in
which our earth was reflected as in a looking-glass,
with its seas and rivers, mountains and valleys; for
it does look something like a distant earth, and as
the light upon it is really reflected from the sun it
was very natural to compare it to a looking-glass.
Next cast your eye over the hundreds of craters,
some large, others quite small, which cover the moon's
face with pitted marks, like a man with small-pox ;
while a few of the larger rings look like holes
made in a window-pane, where a stone has passed
through, for brilliant shining streaks radiate from
them on all sides like the rays of a star, covering
a large part of the moon. Brightest of all these







TYCHO AND HIS SURROUNDINGS


starred craters is Tycho, which you will easily find
near the top of the moon (i, Fig. 3), for you have
often seen it in the small telescope. How grand it
looks to-night in the full moon (Fig. 3) It is
true you see all the craters better when the moon
is in her quarters, because the light falls sideways
upon them and the shadows are more sharply defined ;
yet even at the full the bright ray of light on
Tycho's rim marks out the huge cavity, and you can
even see faintly the magnificent terraces which run
round the cup within, one below the other.
"This cavity measures fifty-four miles across,

Fig. 4.


Tycho and his surroundings.
(From a photograph of the moon taken by Mr. De la Rue, 1863.)

so that if it could be moved down to our earth
it would cover by far the largest part of Devon-
shire, or that portion from Bideford on the north,







THROUGH MAGIC GLASSES


to the sea on the south, and from the borders of
Cornwall on the east, to Exeter on the west, and
it is 17,000 feet or nearly three miles in depth.
Even in the brilliant light of the full moon this
enormous cup is dark compared to the bright rim,
but it is much better seen in about the middle of the
second quarter, when the rising sun begins to light
up one side while the other is in black night.
The drawing on the wall (Fig. 4), which is taken
from an actual photograph of the moon's face, shows
Tycho at this time surrounded by the numerous
other craters which cover this part of the moon.
You may recognize him by the gleaming peak in the
centre of the cup, and by his bright rim which is so
much more perfect than those of his companions.
The gleaming peak is the top of a steep cone or hill
rising up 6000 feet, or more than a mile from the base
of the crater, so that even the summit is about two
miles below the rim.
"There is one very interesting point in Tycho,
however, which is seen at its very best at full moon.
Look outside the bright rim and you will see that
from the shadow which surrounds it there spring
on all sides those strange brilliant streaks (see Fig.
3a) which I spoke of just now. There are others
quite as bright, or even brighter, round other craters,
Copernicus (Fig. 6), Kepler, and Aristarchus, lower
down on the right-hand side of the moon ; but
these of Tycho are far the most widely spread, cover-
ing almost all the top of the face.
"What are these streaks ? We do not know.
During the second quarter of the moon, when the sun







LUNAR AND TERRESTRIAL CRATERS 15

is rising slowly upon Tycho, lighting up his peak and
showing the crater beautifully divided into a bright
cup in the curve to the right, while a dense shadow lies
in the left hollow, these streaks are only faint, and
among the many craters around (see Fig. 4) you t
might even have some difficulty at first in finding
the well-known giant. But as the sun rises higher
and higher they begin to appear, and go on increasing
in brightness till they shine with that wonderfully
silvery light you see now in the full moon.
Fig. 5.



i .. lri ,l ] ,, 1 .
.- k ^1 Tl.- .' ' L, ; _.-


:' '. ,
_4K -T2 .


Plan of the Peak of Teneriffe, showing how it resembles
a lunar crater. (A. Geikie.)
Here is a problem for you young astronomers to
solve, as we learn more and more how to use the
telescope with all its new appliances.







THROUGH MAGIC GLASSES


The crater itself is not so difficult to explain, for
we have many like it on our earth, only not nearly
so large. In fact, we might almost say that our earthly
volcanoes differ from those in the moon only by their
smaller size and by forming mountains with the crater
or cup on the top; while the lunar craters lie flat on
the surface of the moon, the hollow of the cup forming
a depression below it. The peak of Teneriffe (Fig. 5),
which is a dormant volcano, is a good copy in minia-
ture on our earth of many craters on the moon The
large plain surrounded by a high rocky wall, broken
in places by lava streams, the smaller craters nestling
in the cup, and the high peak or central crater
rising up far above the others, are so like what we
see on the moon that we cannot doubt that the same
causes have been at work in both cases, even though
the space enclosed in the rocky wall of Teneriffe
measures only eight miles across, while that of Tycho
measures fifty-four.
"But of the streaks we have no satisfactory expla-
nation. They pass alike over plain and valley and
mountain, cutting even across other craters with-
out swerving from their course. The astronomer
Nasmyth thought they were the remains of cracks
made when the volcanoes were active, and filled
with molten lava from below, as water oozes up
through ice-cracks on a pond. But this explana-
tion is not quite satisfactory, for the lava, forcing
its way through, would cool in ridges which ought to
cast a shadow in sunlight. These streaks, however,
not only cast no shadow, as you can see at the full
moon but when the sun shines sideways upon them








THE CRATER COPERNICUS


in the new-or waning moon they disappear as we
have seen altogether. Thus the streaks, so brilliant
at full moon in Tycho, Copernicus, Kepler, and
Aristarchus, remain a puzzle to astronomers still.
Fig. 6.

| I',, P';, ,'la:,:,,,'I ,, l,, u' ,'i.


The crater Copernicus.
(As given in Herschel's Astronomy, from a drawing taken in a
reflecting telescope of 20 feet focal length.)
We cannot examine these three last-named craters
well to-night with the full sun upon them ; but mark
their positions well, for Copernicus, at least, you must







THROUGH MAGIC GLASSES


examine on the first opportunity, when the sun is
rising upon it in the moon's second quarter. It is
larger even than Tycho, measuring fifty-six miles
across, and has a hill in the centre with many peaks;
while outside, great spurs or ridges stretch in all
directions sometimes for more than a hundred miles,
and between these are scattered innumerable minute
craters. But the most striking feature in it is the
ring, which is composed inside the crater of mag-
nificent terraces divided by deep ravines. These
terraces are in some ways very like those of the
great crater of Teneriffe, and astronomers can best
account for them by supposing that this immense
crater was once filled with a lake of molten lava
rising, cooling at the edges, and then falling again,
leaving the solid ridge behind. The streaks are
also beautifully shown in Copernicus (see Fig. 6),
but, as in Tycho, they fade away as the sun sets
on the crater, and only reappear gradually as mid-
day approaches.
And now, looking a little to the left of Copernicus,
you will see that grand range of mountains, the
Lunar Apennines (Fig. 7), which stretches 400 miles
across the face of the moon. Other mountain
ranges we could find, but none so like mountains
on our own globe as these, with their gentle sunny
slope down to a plain on the left, and steep
perpendicular cliffs on the right. The highest
peak in this range, called Huyghens, rises to the
height of 21,ooo feet, higher than Chimborazo in
the Andes. Other mountains on the moon, such as
those called the Caucasus, south of the Apennines,








THE MOUNTAINS Of THE MOON


are composed of disconnected peaks, while others
again stand as solitary pyramids upon the plains.
But we must hasten on, for I want you to observe
those huge walled crater-plains which have no hill
i2. 7.


.L l lJai L lllllllr eb.
(Copied by kind permission of MM. Henri from part of a magnificent photo-
graph taken by them, March 29, 18go, at the Paris Observatory.)
in the middle, but smooth steel-grey centres shining
like mirrors in the moonlight. One of these, called
Archimedes, you will find just below the Lunar
Apennines (Figs. 3 and 7), and another called Plato,
which is sixty miles broad, is still lower down the







THROUGH MAGIC GLASSES


moon's face (Figs. 3 and 8). The centres of these broad
circles are curiously smooth and shining like quick-

Fig. 8.


The crater Plato as seen soon after sunrise. (After Neison.)

silver, with minute dots here and there which are
miniature craters, while the walls are rugged and
crowned with turret-shaped peaks.
It is easy to picture to oneself how these may
once have been vast seas of lava, not surging as
in Copernicus, and heaving up as it cooled into
one great central cone, but seething as molten lead
does in a crucible, little bubbles bursting here and
there into minute craters ; and this is the explanation
given of them by astronomers.







THE CRATER-PLAINS AND THEIR ORIGIN 21

And now that you have seen the curious rugged
face of the moon and its craters and mountains, you
will want to know how all this has come about. We
can only form theories on the point, except that
everything shows that heat and volcanoes have in
some way done the work, though no one has ever yet
clearly proved that volcanic eruptions have taken
place in our time. We must look back to ages long
gone by for those mighty volcanic eruptions which
hurled out stones and ashes from the great crater of
Tycho, and formed the vast seas of lava in Copernicus
and Plato.
And when these were over, and the globe was
cooling down rapidly, so that mountain ranges
were formed by the wrinkling and rending of the
surface, was there then any life on the moon ? Who
can tell? Our magic glasses can reveal what now
is, so far as distance will allow ; but what has
been, except where the rugged traces remain, we
shall probably never know. What we now see is a
dead worn-out planet, on which we cannot certainly
trace any activity except that of heat in the past.
That there is no life there now, at any rate of the
kind on our own earth, we are almost certain ; first,
because we can nowhere find traces of water, clouds,
nor even mist, and without moisture no life like ours is
possible; and secondly, because even if there is, as
perhaps there may be, a thin ocean of gas round
the moon there is certainly no atmosphere such as
surrounds our globe.
One fact which proves this is, that there are
no half-shadows on the moon. If you look some







THROUGH MAGIC GLASSES


night at the mountains and craters during her first
and second quarters, you will be startled to see what
heavy shadows they cast, not with faint edges dying
away into light, but sharp and hard (see Figs. 6-8),
so that you pass, as it were by one step, from shadow
to sunshine. This in itself is enough to show that
there is no air to scatter the sunlight and spread it into
the edges of the shade as happens on our earth ; but
there are other and better proofs. One of these is,
that during an eclipse of the sun there is no reflec-
tion of his light round the dark moon as there
would be if the moon had an atmosphere; another is
that the spectroscope, that wonderful instrument
which shows us invisible gases, gives no hint of air
around the moon ; and another is the sudden dis-
appearance or occultation of a star behind the moon,
such as I hope to see in a few minutes.
See here take the small hand telescope and turn
it on to the moon's face while I take my place at
the large one, and I will tell you what to look for.
You know that at sunset we see the sun for some
time after it has dipped below the horizon, because
the rays of light which come from it are bent in our
atmosphere and brought to our eyes, forming in
them the image of the sun which is already gone.
Now in a short time the moon which we are watching
will be darkened by our earth coming between it
and the sun, and while it is quite dark it will pass
over a little bright star. In fact to us the star will
appear to set behind the dark moon as the sun sets
below the horizon, and if the moon had an atmo-
sphere like ours, the rays from the star would be bent








TOTAL ECLIPSE OF THE MOON


in it and reach our eyes after the star was gone, so
that it would only disappear gradually. Astronomers
have always observed, however, that the star is lost
to sight quite suddenly, showing that there is no
ocean of air round the moon to bend the light-rays."
Here the magician paused, for a slight dimness
on the lower right-hand side of the moon warned
him that she was entering into the p-cmzmbra or

Fig. 9.







R -"m .. ,I jl' II 'll ll, i'


"'P
Diagram of total eclipse of the moon.
S, Sun. E, Earth. M, Moon passing into the earth's shadow
and passing out at M'.
R, R', Lines meeting at a point U, U' behind the earth and
enclosing a space within which all the direct rays of the
sun are intercepted by the earth, causing a black darkness
or umbra.
R, P and R', P', Lines marking a space within which, behind
the earth, part of the sun's rays are cut off, causing a half-
shadow or penumbra, P, P',
a, a, Points where a few of the sun's rays are bent or refracted
in the earth's atmosphere, so that they pass along the path
marked by the dotted lines and shed a lurid light on the
sun's face.

half-shadow (see Fig. 9) caused by the earth cutting
off part of the sun's rays; and soon a deep black







THROUGH MAGIC GLASSES


shadow creeping over Aristarchus and Plato showed
that she was passing into that darker space or
umbra where the body of the earth is completely
between her and the sun and cuts off all his rays.
All, did I say? No! not all. For now was seen a
beautiful sight, which would prove to any one who
saw our earth from a great distance that it has a
deep ocean of air round it.
It was a clear night, with a cloudless sky, and
as the deep shadow crept slowly over the moon's
face, covering the Lunar Apennines and Copernicus,
and stealing gradually across the brilliant streaks of
Tycho till the crater itself was swallowed up in dark-
ness, a strange lurid light began to appear. The
part of the moon which was eclipsed was not wholly
dark, but tinted with a very faint bluish-green light,
which changed almost imperceptibly, as the eclipse
went on, to rose-red, and then to a fiery copper-
coloured glow as the moon crept entirely into the
shadow and became all dark. The lad watching
through his small telescope noted this weird light, and
wondered, as he saw the outlines of the Apennines
and of several craters dimly visible by it, though
the moon was totally eclipsed. He noted, but was
silent. He would not disturb the Principal, for the
important moment was at hand, as this dark copper-
coloured moon, now almost invisible, drew near to
the star over which it was to pass.
This little star, really a glorious sun billions of miles
away behind the moon, was perhaps the centre of
another system of worlds as unknown to us as we to
them, and the fact of our tiny moon crossing between







LURID LIGHT DURING ECLIPSE


it and our earth would matter as little as if a grain
of sand was blown across the heavens. Yet to the
watchers it was a great matter-would the star give
any further clue to the question of an atmosphere
round the moon ? Would its light linger even for
a moment, like the light of the setting sun ? Nearer
and nearer came the dark moon; the star shone
brilliantly against its darkness ; one second and it was
gone. The long looked-for moment had passed, and
the magician turned from his instrument with a sigh.
" I have learnt nothing new, Alwyn," said he, but at
least it is satisfactory to have seen for ourselves
the proof that there is no perceptible atmosphere
round the moon. We need wait no longer, for
before the star reappears on the other side the
eclipse will be passing away."
But, master," burst forth the lad, now the silence
was broken, tell me why did that strange light of
many tints shine upon the dark moon ? "
Did you notice it, Alwyn ? said the Principal,
with a pleased smile. Then our evening's work is
not lost, for you have made a real observation for
yourself. That light was caused by the few rays of
the sun which grazed the edge of our earth passing
through the ocean of air round it (see Fig. 9). There
they were refracted or bent, and so were thrown
within the shadow cast by our earth, and fell upon
the moon. If there were such a person as a 'man
in the moon,' that lurid light would prove to him
that our earth has an atmosphere. The cause of
the tints is the same which gives us our sunset
colours, because as the different coloured waves which







26 THROUGH MAGIC GLASSES

make white light are absorbed one by one, passing
through the denser atmosphere, the blue are cut off
first, then the green, then the yellow, till only the
orange and red rays reached the centre of the shadow,
where the moon was darkest. But this is too diffi-
cult a subject to begin at midnight."
So saying, he lighted his lamp, and covering the
object-glass of his telescope with its pasteboard cap,
detached the instrument from the clockwork, and the
master and his pupil went down the turret stairs and
past through the room below. As they did so they
heard in the distance a scuffling noise like that of rats
in the wall. A smile passed over the face of the
Principal, for he knew that his young pupils, who
had been making their observations in the gallery
above, were hurrying back to their beds.







MAGIC GLASSES, AND HOW TO USE THEM 27


CHAPTER II

MAGIC GLASSES, AND HOW TO USE THEM


HE sun shone brightly in-
to the science class-room
at mid-day. No gaunt
shadows nor ghostly
S moonlight now threw a
1"'spell on the magic cham-
S.". above. The instruments
-' 'l'o-1-:ed bright and business-like,
." a, d the Principal, moving
an,-ngst them, heard the sub-
i.du ,. hum of fifty or more voices
rising from below. It was the
lecture hour, and the subject for the day was,
"Magic glasses, and how to use them." As the
large clock in the hall sounded twelve, the Principal
gathered up a few stray lenses and prisms he had
selected, and passed down the turret stair to his
platform. Behind him were arranged his diagrams,
before him on the table stood various instruments,
and the rows of bright faces beyond looked up with
one consent as the hum quieted down and he began
his lecture.







THROUGH MAGIC GLASSES


I have often told you, boys, have I not ? that I am
a Magician. In my chamber near the sky I work
spells as did the magicians of old, and by the help
of my magic glasses I peer into the secrets of nature.
Thus I read the secrets of the distant stars ; I catch
the light of wandering comets, and make it reveal
its origin ; I penetrate into the whirlpools of the
sun; I map out the craters of the moon. Nor
can the tiniest being on earth hide itself from me.
Where others see only a drop of muddy water, that
water brought into my magic chamber teems with
thousands of active bodies, darting here and whirling
there amid a meadow of tiny green plants floating
in the water. Nay, my inquisitive glass sees even
farther than this, for with it I can watch the eddies
of water and green atoms going on in each of these
tiny beings as they feed and grow. Again, if I want
to break into the secrets of the rock at my feet, I
have only to put a thin slice of it under my micro-
scope to trace every crystal and grain ; or, if I wish
to learn still more, I subject it to fiery heat, and
through the magic prisms of my spectroscope I read
the history of the very substances of which it is
composed. If I wish to study the treasures of the
wide ocean, the slime from a rock-pool teems with
fairy forms darting about in the live box imprisoned
in a crystal home. If some distant stars are in-
visible even in the giant glasses of my telescope, I
set another power to work, and make them print
their own image on a photographic plate and so
reveal their presence.
"All these things you have seen through my magic







THE HUMAN EYE


glasses, and I promised you that one day I would
explain to you how they work and do my bidding.
But I must warn you that you must give all your
attention; there is no royal road to my magician's
power. Every one can attain to it, but only by
taking trouble. You must open your eyes and ears,
and use your intelligence to test carefully what your
senses show you.
"We have only to consider a little to see that we
depend entirely upon our senses for our knowledge
of the outside world. All kinds of things are going
on around us, about which we know nothing, because
our eyes are not keen enough to see, and our ears
not sharp enough to hear them. Most of all we
enjoy and study nature through our eyes, those
windows which let in to us the light of heaven, and
with it the lovely sights and scenes of earth; and
which are no ordinary windows, but most wonderful
structures adapted for conveying images to the brain.
They are of very different power in different people,
so that a long-sighted person sees a lovely land-
scape where a short-sighted one sees only a confused
mist; while a short-sighted person can see minute
things close to the eye better than a long-sighted
one.
Let us try to understand this before we go on to
artificial glasses, for it will help us to explain how
these glasses show us many things we could never
see without them. Here are two pictures of the
human eyeball (Figs. 10 and I i), one as it appears
from the front, and the other as we should see the
parts if we cut an eyeball across from the front to







THROUGH MAGIC GLASSES


the back. From these drawings we see that the
eyeball is round ; it only looks oval, because it is
seen through the oval slit of the eyelids. It is really
Fig. 1o. a hard, shining, white
ball with a thick nerve
cord (on, Fig. I I) pass-
ing out at the back,
and a dark glassy
S mound c, cin the centre
,, n of the white in front.
In this mound we
can easily distinguish
S two parts-first, the
coloured iris or elastic
curtain (i, Fig. I o); and
Eye-ball seen from the front, secondly, the dark spot
(After Le Gros Clark.) or pupils in the centre.
w, White of eye. ,Iris. Pupil. The iris is the part
which gives the eye its colour; it is composed
of a number of fibres, the outer ones radiating to-
wards the centre, the inner ones forming a ring
round the pupil; and behind these fibres is a coat
of dark pigment or colouring matter, blue in some
people, grey, brown, or black in others. When the
light is very strong, and would pain the nerves inside
if too much entered the pupil or window of the eye,
then the ring of the iris contracts so as partly to
close the opening. When there is very little light,
and it is necessary to let in as much as possible, the
ring expands and the pupil grows large. The best
way to observe this is to look at a cat's eyes in the
dusk, and then bring her near to a bright light; for








HOW WE SEE


the iris of a cat's eye contracts and expands much
more than ours does.
"Nowlook at the second diagram (Fig. I ) and notice
the chief points necessary in seeing. First you will

Fig. Ir.














Section of an eye looking at a pencil. (Adapted from Kirke.)
c,c, Cornea. w, White ofeye. cm, Ciliary muscle. a,a, Aque-
ous humour. i, i, Iris. 1, 1, Lens. r, r, Retina. on, Optic nerve.
1, 2, Pencil. I', 2', Image of pencil on the retina.

observe that the pupil is not a mere hole; it is pro-
tected by a curved covering c. This is the cornea, a
hard, perfectly transparent membrane, looking much
like a curved watch-glass. Behind this is a small
chamber filled with a watery fluid a, called the
aqueous humour, and near the back of this chamber
is the dark ring or iris i, which you saw from the
front through the cornea and fluid. Close behind
the iris again is the natural 'magic glass' of our
eye, the crystalline lens 1, which is composed of per-
fectly transparent fibres and has two rounded or







THROUGH MAGIC GLASSES


convex surfaces like an ordinary magnifying glass.
This lens rests on a cushion of a soft jelly-like sub-
stance v, called the vitreous humour, which fills the
dark chamber or cavity of the eyeball and keeps it
in shape, so that the retina r, which lines the chamber,
is kept at a proper distance from the lens. This
retina is a transparent film of very sensitive nerves;
it forms a screen at the back of the chamber, and has
a coating of very dark pigment or colouring matter
behind it. Lastly, the nerves of the retina all meet
in a bundle, called the optic nerve, and passing out
of the eyeball at a point on, go to the brain.
These are the chief parts we use in seeing ; now how
do we use them ?
"Suppose that a pencil is held in front of the
eye at the distance at which we see small objects
comfortably. Light is reflected from all parts of the
surface of the pencil, and as the rays spread, a certain
number enter the pupil of the eye. We will follow
only two cones of light coming from the points r
and 2 on the diagram Fig. I I. These you see enter
the eye, each widely spread over the cornea c. They
are bent in a little by this curved covering, and by
the liquid behind it, while the iris cuts off the rays
near the edges of the lens, which would be too much
bent to form a clear image. The rest of the rays
fall upon the lens 1. In passing through this lens
they are very much bent (or refracted) towards each
other, so much so that by the time they reach the
end of the dark chamber v, each cone of light has
come to a point or focus i' 2', and as rays of this
kind have come from every point all over the pencil,







IMAGE FORMED AT FOCAL DISTANCE 33

exactly similar points are formed on the retina, and
a real picture of the pencil is formed there between
I' and 2.
"We will make a very simple and pretty experi-
ment to illustrate this. Darkening the room I light
a candle, take a square of white paper in my hand,
and hold a simple magnifying glass between the two
(see Fig. I 2) about three inches away from the candle.
Then I shift the paper nearer and farther behind the
lens, till we get a clear image of the candle-flame
Fig. 12.
..........










Image of a candle-flame thrown on paper by a lens.

upon it. This is exactly what happens in our eye.
I have drawn a dotted line c round the lens and the
paper on the diagram to represent the eyeball in
which the image of the candle-flame would be on the
retina instead of on the piece of paper. The first
point you will notice is that the candle-flame is upside
down on the paper, and if you turn back to Fig. 1
you will see why, for it is plain that the cones of
light cross in the lens /, I going to I' and 2 to 2'.
Every picture made on our retina is upside down.







THROUGH MAGIC GLASSES


But it is not there that we see it. As soon as the
points of light from the pencil strike upon the retina,
the thrill passes on along the optic nerve on, through
the back of the eye to the brain; and our mind,
following back the rays exactly as they have come
through the lens, sees a pencil, outside the eye, right
way upwards.
This is how we see with our eyes, which adjust
themselves most beautifully to our needs. For
example, not only is the iris always ready to expand
or contract according as we need more or less light,
but there is a special muscle, called the ciliary muscle
(cm, Fig. I I), which alters the lens for us to see things
far or near. In all, or nearly all, perfect eyes the
lens is flatter in front than behind, and this enables
us to see things far off by bringing the rays from them
exactly to a focus on the retina. But when we look
at nearer things the rays require to be more bent or
refracted, so without any conscious effort on our part
this ciliary muscle contracts and allows the lens to
bulge out slightly in front. Instantly we have a
stronger magnifier, and the rays are brought to the
right focus on the retina, so that a clear and full-size
image of the near object is formed. How little we
think, as we turn our eyes from one thing to another,
and observe, now the distant hills, now the sheep
feeding close by; or, as night draws on, gaze into
limitless space and see the stars millions upon
millions of miles away, that at every moment the
focus of our eye is altering, the iris is contracting
or expanding, and myriads of images are being
formed one after the other in that little dark cham-








FAR SIGHT AND NEAR SIGHT


ber, through which pass all the scenes of the outer
world !
Yet even this wonderful eye cannot show us every-
thing. Some see farther than others, some see more
minutely than others, according as the lens of the eye
is flatter in one person and more rounded in another.
But the most long-sighted person could never have
discovered the planet Neptune, more than 2700
millions of miles distant from us, nor could the keenest-
sighted have known of the existence of those minute
and beautiful little plants, called diatoms, which live
around us wherever water is found, and form delicate
flint skeletons so infinitesimally small that thousands
of millions go to form one cubic inch of the stone
called tripoli, found at Bilin in Bohemia.
It is here that our 'magic glasses' come to our
assistance, and reveal to us what was before invisible.

Fig. 13-
A


C ., --



D


B
Arrow magnified by a convex lens.
a, b, Real arrow. C, D, Magnifying-glass. A, B, Enlarged
image of the arrow.

We learnt just now that we see near things by the
lens of our eye becoming more rounded in front; but







THROUGH MAGIC GLASSES


there comes a point beyond which the lens cannot
bulge any more, so that when a thing is very tiny,
and would have to be held very close to the eye for
us to see it, the lens can no longer collect the rays
to a focus, so we see nothing but a blur. More than
800 years ago an Arabian, named Alhazen, explained
why rounded or convex glasses make things appear
larger when placed before the eye. This glass which
Fig. 4. I hold in my hand is a simple
eep magnifying-glass, such as we
,.-' ^ used for focusing the candle-
flame. It bends the rays in-
/":/' wards from any small object
1/ (see the arrow a, b, Fig. 13) so
/ that the lens of our eye can
S use them, and then, as we
.'P follow out the rays in straight
S' / lines to the place where we
/ see clearly (at A, B), every
point of the object is magni-
S' fied, and we not only see it
much larger, but every mark
upon it is much more distinct.
You all know how the little


Student's microscope.
ep, Eye-piece. o, g, Object-
glass.


shilling magnifying- glasses
you carry show the most
lovely and delicate structures
in flowers, on the wings of


butterflies, on the head of a bee or fly, and, in fact,
in all minute living things.
But this is only our first step. Those diatoms we
spoke of just now will only look like minute specks







THE MICROSCOPE


under even the strongest magnifying-glass. So we
pass on to use two extra
lenses to assist our eyes, Fig. Is.
and come to this com-
pound microscope (Fig. 14)
through which I have be-
fore now shown you the
delicate markings on shells
which were themselves so
minute that you could not
see them with the naked
eye. Now we have to dis-
cover how the microscope
performs this feat. Going
back again for a minute
to our candle and magnify-
ing-glass (Fig. 12), you will
find that the nearer you put
the lens to the candle the
farther away you will have
to put the paper to get a
clear image. When in a
microscope we put a
powerful lens o, I close
down to a very minute
object, say a spicule of a
flint sponge s, s, quite in-
Skeleton of a microscope, showing
visible to the unaided eye, how an object is magnified.
the rays from this spicule o, 1, Object-lens. e,g, Eye-glass.
are brought to a focus a s, s, Spicule. s', s', Magnified
long way behind it at s', sI image of same in the tube.
long way behind it at s s, s, Image again enlarged by
making an enlarged image the lens of the eye-piece.







38 THROUGH MAGIC GLASSES

because the lines of light have been diverging ever
since they crossed in the lens. If you could put a
piece of paper at s' s', as you did in the candle
experiment, you would see the actual image of the
magnified spicule upon it. But as these points of
light are only in an empty tube, they pass on, spread-
ing out again from the image, as they did before from
the spicule. Then another convex lens or eye-
glass e, g is put at the top of the microscope at
the proper distance to bend these rays so that they
enter our eye in nearly parallel lines, exactly as we
saw in the ordinary magnifying-glass (Fig. I 3), and
our crystalline lens can then bring them to a focus
on our retina.
By this time the spicule has been twice magnified;
or, in other words, the rays of light coming from it
have been twice bent towards each other, so that
when otlr eye follows them out in straight lines they
are widely spread, and we see every point of light so
clearly that all the spots and markings on this
minute spicule are as clear as if it were really as
large as it looks to us.
This is simply the principle of the microscope.
When you come to look at your own instruments,
though they are very ordinary ones, you will find that
the object-glass o, I is made of three lenses, flat on the
side nearest the tube, and each lens is composed of
two kinds of glass in order to correct the unequal
refraction of the rays, and prevent fringes of colour
appearing at the edge of the lens. Then again the
eye-piece will be a short tube with a lens at each
end, and halfway between them a black ledge will be







WHAT THE MICROSCOPE REVEALS


seen inside the tube which acts like the iris of our
eye (i, Fig. I I) and cuts off the rays passing through
the edges of the lens. All these are devices to cor-
rect faults in the microscope which our eye corrects
for itself, and they have enabled opticians to make
very powerful lenses.
"Look now at the diagram (Fig. 6) showing a
group of diatoms which you can see under the
microscope after the lecture. Notice the lovely
patterns, the delicate tracery, and the fine lines on
the diatoms shown there. Yet each of these minute
flint skeletons, if laid on a piece of glass by itself,
would be quite in- Fig. 16.
visible to the naked
eye, while hundreds
of them together
only look like a
faint mist on the
slide on which they i
lie. Nor are they
even here shown as
much magnified as
they might be;
under a stronger
power we should
see those delicate
lines on the diatoms Fossil diatoms seen under the microscope.
broken up into The largest of these is an almost imperceptible
speck to the naked eye.
minute round cups.
Is it not wonderful and delightful to think that
we are able to add in this way to the power of our
eyes, till it seems as if there were no limit to the







THROUGH MAGIC GLASSES


hidden beauties of the minute forms of our earth, if
only we can discover them ?
But our globe does not stand alone in the universe,
and we want not only to learn all about everything
we find upon it, but also to look out into the vast
space around us and discover as much as we can
about the myriads of suns and planets, comets and
meteorites, star-mists and nebula, which are to be
found there. Even with the naked eye we can admire
the grand planet Saturn, which is more than 800
millions of miles away, and this in itself is very
marvellous. Who would have thought that our tiny
crystalline lens would be able to catch and focus
rays, sent all this enormous distance, so as actually
to make a picture on our retina of a planet, which,
like the moon, is only sending back to us the light
of the sun ? For, remember, the rays which come to
us from Saturn must have travelled twice 800 millions
of miles-884 millions from the sun to the planet,
and less or more from the planet back to us, according
to our position at the time. But this is as nothing
when compared to the enormous distances over which
light travels from the stars to us. Even the nearest
star we know of, is at least twenty millions of millions
of miles away, and the light from it, though travelling
at the rate of 186,300 miles in a second, takes four
years and four months to reach us, while the light from
others, which we can see without a telescope, is be-
tween twenty and thirty years on its road. Does not
the thought fill us with awe, that our little eye should
be able to span such vast distances ?
But we are not yet nearly at the end of our







THE TELESCOPE


wonder, for the same power which devised our eye
gave us also the mind capable of inventing an instru-
ment which increases the strength of that eye till we
can actually see stars so far off that their light takes
two thousand years coming to our globe. If the
microscope delights us in helping us to see things
invisible without it, because they are so small, surely
the telescope is fascinating beyond all other magic
glasses when we think that it brings heavenly bodies,
thousands of billions of miles away, so close to us
that we can examine them.
"A Telescope (Fig. 17) can, like the microscope, be
made of only two glasses: an object-glass to form
an image in the tube and Fig. 7.
a magnifying eye-piece
to enlarge it. But there
is this difference, that the
object lens of a micro-
scope is put close down
to a minute object, so
that the rays fall upon r
it at a wide angle, and
the image formed in the
tube is very much larger
than the object outside.p ,
In the telescope, on the
contrary, the thing we
look at is far off, so that An astronomical telescope.
the rays fall on the ef, Eye-piece. og, Object-glass.
object-glass at such a / Finder.
very narrow angle as to be practically parallel, and the
image in the tube is of course very, very much smaller







THROUGH MAGIC GLASSES


than the house, or church, or planet it pictures.
What the object-glass of the telescope does for us, is
to bring a small real image of an object very far off
close to us in the tube of the telescope so that we
can examine it.
Think for a moment what this means. Imagine
that star we spoke of (p. 41), whose light, travelling
186,300 miles in one second, still takes 2000
years to reach us. Picture the tiny waves of light
crossing the countless billions of miles of space
during those two thousand years, and reaching us so
widely spread out that the few faint rays which
strike our eye are quite useless, and for us that star
has no existence; we cannot see it. Then go and
ask the giant telescope, by turning the object-glass
in the direction where that star lies in infinite space.
The widespread rays are collected and come to a
minute bright image in the dark tube. You put the
eye-piece to this image, and there, under your eye, is
a shining point: this is the image of the star, which
otherwise would be lost to you in the mighty
distance.
Can any magic tale be more marvellous, or any
thought grander, or more sublime than this? From
my little chamber, by making use of the laws of light,
which are the same wherever we turn, we can pene-
trate into depths so vast that we are not able even
to measure them, and bring back unseen stars to tell
us the secrets of the mighty universe. As far as the
stars are concerned, whether we see them or not
depends entirely upon the number of rays collected
by the object-glass ; for at such enormous distances







HOW THE TELESCOPE MAGNIFIES


the rays have no angle that we can measure, and
magnify as you will, the brightest star only remains
a point of light. It is in order to collect enough
rays that astronomers have tried to have larger and
larger object-glasses; so that while a small good
hand telescope, such as you use, may have an object-
glass measuring only an inch and a quarter across,
some of the giant telescopes have lenses of two and a
half feet, or thirty inches, diameter. These enormous
lenses are very difficult to make and manage, and have
many faults, therefore astronomical telescopes are
often made with curved mirrors to reflect the rays,
and bring them to a focus instead of refracting them
as curved lenses do.
We see, then, that one very important use of the
telescope is to bring objects into view which otherwise
we would never see; for, as I have already said,
though we bring the stars into sight, we cannot
magnify them. But whenever an object is near
enough for the rays to fall even at a very small
perceptible angle on the object-glass, then we can
magnify them ; and the longer the telescope, and the
stronger the eye-piece,the more the object is magnified.
I want you to understand the meaning of this, for
it is really very simple, only it requires a little thought.
Here are skeleton drawings of two telescopes (Fig.
18), one double the length of the other. Let us
suppose that two people are using them to look at
an arrow on a weathercock a long distance off. The
rays of light r, r from the two ends of the arrow will
enter both telescopes at the same angle r, .r, r, cross
in the lens, and passion at exactly the same angle into








THROUGH MAGIC GLASSES


Fig. 18.


Skeletons of telescopes.
A, A one-foot telescope with
a three-inch eye-piece. B, A
two-foot telescope with a three-
inch eye-piece. e,p, Eye-piece.
o,g, Object-glass. r, r, Rays
which enter the telescopes and
crossing at x form an image
at i, i, which is magnified by
the lens e, f. The angles r, x, r
and i, x, i are the same. In
A the angle i, o, i is four times
greater than that of i, x, i. In
B it is eight times greater.


the tubes. So far all is alike,
but now comes the difference.
In the short telescope A the
object-glass must be of such a
curve as to bring the cones of
light in each ray to a focus at
a distance of one foot behind
it,' and there a small image i, i
of the arrow is formed. But B
being twice the length, allows
the lens to be less curved, and
the image to be formed two feet
behind the object-glass; and
as the rays r, r have been di-
verging ever since they crossed
at x, the real image of the
arrow formed at z i is twice the
size of the same image in A.
Nevertheless, if you could put
a piece of paper at i, i in both
telescopes, and look through
the object-glass (which you
cannot actually do, because
your head would block out the
rays), the arrow would appear
the same size in both tele-
scopes, because one would be
twice as far off from you as
the other, and the angle i, x, i
is the same in both.


1 In our Fig. 18 the distances are inchesinstead of feet, but the pro-
portions are the same.







WHIA T SMALL TELESCOPES CAN DO 45

But by going to the proper end of the telescope
you can get quite near the image, and can see and
magnify it, if you put a strong lens to collect the rays
from it to a focus. This is the use of the eye-piece,
which in our diagram is placed at a quarter of a
foot or three inches from the image in both tele-
scopes. Now that we are close to the images, the
divergence of the points i, i makes a great difference.
In the small telescope, in which the image is only
one foot behind the object-glass, the eye-piece being
a quarter of a foot from it, is four times nearer, so
the angle i, o, i is four times the angle i, x, i, and the
man looking through it sees the image magnified
four times. But in the longer telescope the-image
is two feet behind the lens, while the eye-piece is,
as before, a quarter of a foot from it. Thus the eye-
piece is now eight times nearer, so the angle i, o, i is
eight times the angle i, x, i, and the observer sees the
image magnified eigz/t times.
In real telescopes, where the difference between
the focal length of the object-glass and that of the
eye-glass can be made enormously greater, the
magnifying power is quite startling, only the object-
glass must be large, so as to collect enough rays to
bear spreading widely. Even in your small tele-
scopes, with a focus of eighteen inches, and an object-
glass measuring one and a quarter inch across, we
can put on a quarter of an inch eye-piece, and so
magnify seventy-two times; while in my observatory
telescope, eight feet or ninety-six inches long, an
eye-piece of half an inch magnifies 192 times, and I
can put on a --inch eye-piece and magnify 768







THROUGH MAGIC GLASSES


times! And so we can go on lengthening the
focus of the object-glass and shortening the focus
of the eye-piece, till in Lord Rosse's gigantic
fifty-six-foot telescope, in which the image is fifty-
four feet (648 inches) behind the object-glass, an
eye-piece one-eighth of an inch from the image
magnifies 5 84 times These giant telescopes, how-
ever, require an enormous object-glass or mirror, for
the points of light are so spread out in making the
large image that it is very faint unless an enor-
mous number of rays are collected. Lord Rosse's
telescope has a reflecting mirror measuring six feet
across, and a man can walk upright in the telescope
tube. The most powerful telescope yet made is that
at the Lick Observatory, on Mount Hamilton, in
California. It is fifty-six and a half feet long, the
object-lens measures thirty-six inches across. A
star seen through this telescope appears 2000 times
as bright as when seen with the naked eye.
You need not, however, wait for an opportunity
to look through giant telescopes, for my small
student's telescope, only four feet long, which we
carry out on to the lawn, will show you endless
unseen wonders; while your hand telescopes, and
even a common opera-glass, will show many features
on the face of the moon, and enable you to see the
crescent of Venus, Jupiter's moons, and Saturn's
rings, besides hundreds of stars unseen by the naked
eye.
Of course you will understand that Fig. 18 only
shows the principle of the telescope. In all good
instruments the lenses and other parts are more







THE PHOTOGRAPHIC CAMERA


complicated ; and in a terrestrial telescope, for looking
at objects on the earth, another lens has to be put
in to turn them right way up again. In looking at
the sky it does not matter which way up we see a
planet or a star, so the second glass is not needed,
and we lose light by using it.
We have now three magic glasses to work for
us-the magnifying-glass, the microscope, and the
telescope. Besides these, however, we have two other
helpers, if possible even more wonderful. These are
the Photographic camera and the Spectroscope.
Now that we thoroughly understand the use of
lenses, I need scarcely Fig. 19.
explain this photographic .
camera (Fig. 19), for it is -i
clearly an artificial eye. In i
place of the crystalline lens ',
(compare with Fig. I ) the '
photographer uses one, or ,
generally two lenses 1, 1, with '-
a black ledge or stop s be-
tween them, which acts like
the iris in cutting off the
rays too near the edge of the
lens. The dark camera c c
answers to the dark chamber
Photographic camera.
of the eyeball, and the 1, 1, Lenses. s, s, Screen cut-
plate p, p at the back of ting off diverging rays. c c, Slid-
the chamber, which is made ing box. p, p, Picture formed.
sensitive by chemicals, answers our retina. The box
is formed of two parts, sliding one within the other
at c, so as to place the plate at a proper .distance








7THROUGiC MAGIC GLASSES


from the lens, and then a screw adjusts the focus
more exactly by bringing the front lens back or for-
ward, instead of altering the curve as the ciliary
muscle does in our eye. The difference between the
two instruments is that in our eye the message
goes to the brain, and the image disappears when
we turn our eyes away from the object; but in
the camera the waves of light work upon the
chemicals, and the image can be fixed and remain
for ever.
But the camera has at least one weak point. The
screen at the back is not curved like our retina, but
must be flat because of printing off the pictures, and
therefore the parts of the photograph near the edge
are a little out of proportion.
"In many ways, however, this photographic eye is
a more faithful observer than our own, and helps us
to make more accurate pictures. For instance, in-
stantaneous photographs have been taken of a
galloping horse, and we find that the movements are
very different from what we thought we saw with
our eye, because our retina does not throw off one
impression after another quickly enough to be quite
certain we see each curve truly in succession. Again,
the photograph of a face gives minute curves and
lines, lights and shadows, far more perfectly than
even the best artist can see them, and when the
picture is magnified we see more and more details
which escaped us before.
But it is especially when attached to the micro-
scope or the telescope that the photographic
apparatus tells us such marvellous secrets; giving







WHAT PHOTOGRAPHS CAN SHOW


us, for instance, an accurate picture of the most
minute water-animal quite invisible to the naked eye,
so that when we enlarge the photograph any one can
see the beautiful markings, the finest fibre, or the
tiniest granule; or affording us accurate pictures,
such as the one at p. 19 of the face of the moon, and
bringing stars into view which we cannot otherwise
see even with the strongest telescope.
Our own eye has many weaknesses. For ex-
ample, when we look through the telescope at the
sky we can only fix our attention on one part at
once, and afterwards on another; and the picture
which we see in this way, bit by bit, we must draw
as best we can. But if we put a sensitive photo-
graphic plate into the telescope just at the point (i, i,
Fig. 8), where the image of the sky is focused,
this plate gives attention, so to speak, to the whole
picture at once, and registers every point exactly as
it is; and this picture can be kept and enlarged so
that every detail can be seen.
Then, again, if we look at faint stars, they do not
grow any brighter as we look. Each ray sends its
message to the brain, and that is all; we cannot
heap them up in our eye, and, indeed, after a time
we see less, because our nerves grow tired. But on
a photographic plate in a telescope, each ray in its
turn does a little work upon the chemicals, and the
longer the plate remains, the stronger the picture
becomes. When wet plates were used they could
not be left long, but since dry plates have been
invented, with a film of chemically prepared gelatine,
they can be left for hours in the telescope, which is







THROUGH MAGIC GLASSES


kept by clockwork accurately opposite to the same
objects. In this way thousands of faint stars, which
we cannot see with the strongest telescope, creep
into view as their feeble rays work over and over
again on the same spot; and, as the brighter stars
as well as the faint ones are all the time making
their impression stronger, when the plate comes out
each one appears in its proper strength. On the
other hand, very bright objects often become blurred
by a long exposure, so that we have sometimes to
sacrifice the clearness of a bright object in order to
print faint objects clearly.
We now come to our last magic glass-the
Spectroscope; and the hour has slipped by so fast
that I have very little time left to speak of it. But
this matters less as we have studied it before.1 I
need now only remind you of some of the facts. You
will remember that when we passed sunlight through
a three-sided piece of glass called a prism, we broke
up a ray of white light into a line of beautiful
colours gradually passing from red, through orange,
yellow, green, blue, and indigo, to violet, and that
these follow in the same order as we see them in the
rainbow or in the thin film of a soap-bubble. By
various experiments we proved that these colours are
separated from each other because the many waves
which make up white light are of different sizes, so
that because the waves of red light are slow and
heavy, they lag behind when bent in the three-sided
glass, while the rapid violet waves are bent more out
1 Fairyland -of Science, Lecture II.; and Short History of Aatural
science chapter xxxiv.







THE SPECTROSCOPE 51

of their road and run to the farther end of the line,
the other colours ranging themselves between.
"Now when the light falls through the open
window, or through a round hole or large slit, the
images of the hole made by each coloured wave
overlap each other very much, and the colours in
the spectrum or coloured band are crowded together.
But when in the spectroscope we pass the ray of light
through a very narrow slit, each coloured image of the

Fig. 20.













Kirchhoffs spectroscope.
A, The telescope which receives the ray of light
through the slit in 0.

upright slit overlaps the next upright image only
very little. By using several prisms one after the
other (see Fig. 2 ), these upright coloured lines are
separated more and more till we get a very long
band or spectrum. Yet, as you know from our
experiments with the light of a glowing wire or of
molten iron, however much you spread out the light








THROUGH MAGIC GLASSES


given by a solid or liquid, you can never separate
these coloured lines from each other. It is only
when you throw the light of a glowing gas or vapour
into the slit that you get a few bright lines standing
out alone. This is because all the rays of white light
are present in glowing solids and liquids, and they
follow each other too closely to be separated. But
a gas, such as glowing hydrogen for example, gives
out only a few separate rays, which, pouring through
the slit, throw red, greenish-blue, and dark blue lines
Fig. 21. on the screen. Thus
you have seen the
double, orange-yellow
sodium line (3, Plate I.)
which starts out at
once when salt is held
in a flame and its
light thrown into the
spectroscope, and the
red line of potassium
vapour under the same
treatment; and we
Passage of rays through the spectroscope. shall observe these
S, S', Slit through which the light falls again when we study
on the prisms. 1, 2, 3, 4, Prisms ill the colour lihts of
which the rays are dispersed more and the colourd lights of
more. a, b, Screen receiving thespectrum, the sun and stars.
of which the seven principal colours are We see, then, that
marked. the work of our magic
glass, the spectroscope, is simply to sift the waves
of light, and that these waves, from their colour
and their position in the long spectrum, actually tell
us what glowing gases have started them on their







WHAT THE SPECTROSCOPE CAN SHOW 53

road. Is not this like magic? I take a substance
made of I know not what ; I break it up, and, melting
it in the intense heat of an electric spark, throw its
light into the spectroscope. Then, as I examine this
light after it has been spread out by the prisms, I
can actually read by unmistakable lines what metals
or non-metals it contains. Nay, more ; when I catch
the light of a star, or even of a faint nebula, in my
telescope, and pass it through these prisms, there,
written up on the magic-coloured band, I read off
the gases which are glowing in that star-sun or
star-dust billions of miles away.
"Now, boys, I have let you into the secrets of my
five magic glasses-the magnifying-glass, the micro-
scope, the telescope, the photographic camera, and
the spectroscope. With these and the help of
chemistry you can learn to work all my spells. You
can peep into the mysteries of the life of the tiniest
.being which moves unseen under your feet; you
can peer into that vast universe, which we can never
visit so long as our bodies hold us down to our
little earth; you can make the unseen stars print
their spots of light on the paper you hold in your
hand, by means of light-waves, which left them
hundreds of years ago ; or you can sift this light in
your spectroscope, and make it tell you what sub-
stances were glowing in that star when they were
started on their road. All this you can do on one
condition, namely, that you seek patiently to know
the truth.
Stories of days long gone by tell us of true magi-
cians and false magicians, and the good or evil they







54 THROUGH MAGIC GLASSES
wrought. Of these I know nothing, but I do know
this, that the value of the spells you can work with
my magic glasses depends entirely upon whether you
work patiently, accurately, and honestly. If you
make careless, inaccurate experiments, and draw
hasty conclusions, you will only do bad work, which
it may take others years to undo; but if you
question your instruments honestly and carefully,
they will answer truly and faithfully. You may
make many mistakes, but one experiment will correct
the other; and while you are storing up in your
own mind knowledge which lifts you far above this
little world, or enables you to look deep below the
outward surface of life, you may add your little
group of facts to the general store, and help to pave
the way to such grand discoveries as those of Newton
in astronomy, Bunsen and Kirchhoff in spectrum
analysis, and Darwin in the world of life."







FAIRY RINGS AND HOW THEY ARE MADE 55


CHAPTER III

FAIRY RINGS AND HOW THEY ARE MADE

T was a lovely warm day in
S '' September, the golden corn
-.. had been cut and carted,
Sand the waggons of the
farmers around were fice
for the use of the college
the'i r., lads in their yearly autumn
holiday. There they stood
in a long row, one behind
tl! other in the drive round the
-.i .-,iunds, each with a pair of
", -lIek, powerful farm-horses, and
Sthl waggoners beside them with
their long whips ornamented with coloured ribbons ;
and as each waggon drew up before the door, it
filled rapidly with its merry load and went on its
way.
They had a long drive of seven miles before them,
for they were going to cross the wild moor, and then
descend gradually along a fairly good road to the
more wooded and fertile country. Their object that







THROUGH MAGIC GLASSES


day was to reach a certain fairy dell known to a few
only among the party as one of the loveliest spots in
Devon. It was a perfect day for a picnic. As
they drove over the wide stretches of moorland, with
tors to right and tors to the left, the stunted furze
bushes growing here and there glistened with spiders'
webs from which the dew had not yet disappeared,
and mosses in great variety carpeted the ground,
from the lovely thread-mosses, with their scarlet
caps, to the pale sphagnum of the bogs, where a halt
was made for some of the botanists of the party to
search for the little Sundew (Droser-a rotundifolia).
Though this little plant had now almost ceased to
flower, it was not difficult to recognize by its rosette
of leaves glistening with sticky glands which it
spreads out in many of the Dartmoor bogs to catch
the tiny flies and suck out their life's blood, and
several specimens were uprooted and carefully packed
away to plant in moist moss at home.
From this bog onwards the road ran near by one
of the lovely streams which feed the rivers below, and,
passing across a bridge covered with ivy, led through
a small forest of stunted trees round which the wood-
bine clung, hanging down its crimson berries, and the
bracken fern, already putting on its brown and yellow
tints, grew tall and thick on either side. Then, as
they passed out of the wood, they came upon the
dell, a piece of wild moorland lying in a hollow
between two granite ridges, with large blocks of
granite strewn over it here and there, and furze bushes
growing under their shelter, still covered with yellow
blossoms together with countless seed-bearing pods,







FAIRY RINGS IN A DELL


which the youngsters soon gathered for the shiny
black seeds within them.
Here the waggons were unspanned, the horses
tethered out, the food unpacked, and preparations for
the picnic soon in full swing. Just at this moment,
however, a loud shout from one part of the dell called
every one's attention. The fairy rings the fairy
rings! we have found the fairy rings and there
truly on the brown sward might be seen three deli-
cate green rings, the fresh sprouting grass growing
young and tender in perfect circles measuring from
six feet to nearly three yards across.
What are they ?" The question came from many
voices at once, but it was the Principal who answered.
Why, do you not know that they are pixie circles,
where the 'elves of hills, brooks, standing lakes, and
groves' hold their revels, whirling in giddy round,
and making the rings, 'whereof the ewe not bites'?
Have you forgotten how Mrs. Quickly, in the lMerry
Wives of Windsor, tells us that
nightly, meadow-fairies, look you sing,
Like to the Garter's compass, in a ring :
The expressure that it bears, green let it be,
More fertile-fresh than all the field to see' ?
If we are magicians and work spells under magic
glasses, why should not the pixies work spells on the
grass? I brought you here to-day on purpose to
see them. Which of you now can name the pixie
who makes them ? "
A deep silence followed. If any knew or guessed
the truth of the matter, they were too shy to risk
making a mistake.







THROUGH MAGIC GLASSES


Be off with you then," said the Principal, and
keep well away from these rings all day, that you
may not disturb the spell. But come back to me
before we return at night, and perhaps I may show
you the wonder-working pixie, and we may take him
home to examine under the microscope."
The day passed as such happy days do, and the
glorious harvest moon had risen over the distant
tors before the horses were spanned and the waggons
ready. But the Principal was not at the starting
place, and looking round they saw him at the farther
end of the dell.
Gently, gently," he cried, as there was one general
rush towards him ; "look where you tread, for I stand
within a ring of fairies 1"
And then they saw that just outside the green
circle in which he stood, forming here and there a
broken ring, were patches of a beautiful tiny mush-
room, each of which raised its pale brown umbrella
in the bright moonlight.
Here are our fairies, boys. I am going to take
a few home where they can be spared from the ring,
and to-morrow we will learn their history."

The following day saw the class-room full, and
from the benches eager eyes were turned to the
eight windows, in each of which stood one of the
elder boys at his microscope ready for work. For
under those microscopes the Principal always arranged
some object referred to in his lecture and figured in
diagrams on the walls, and it was the duty of each
boy, after the lecture was over, to show and explain







IlPS AND PIXIES OF PLANT-LIFK


to the class all the points of the specimen under
his care. These boys were always specially envied,
for though the others could, it is true, follow all the
descriptions from the diagrams, yet these had the
plant or animal always under their eye. Discussion
was at this moment running high, for there was a
great uncertainty of opinion as to whether a mush-
room could be really called a plant when it had no
leaves or flowers. All at once the hush came, as the
Principal stepped into his desk and began :
"Life is hard work, boys, and there is no being
in this world which has not to work for its living.
You all know that a plant grows by taking in gases
and water, and working them up into sap and living
tissue by the help of the sunshine and the green
matter in their leaves; and you know, too, that
the world is so full of green plants that hundreds
and thousands of young seedlings can never get a
living, but are stifled in their babyhood or destroyed
before they can grow up.
Now there are many dark, dank places in the
world where plants cannot get enough sunlight
and air to make green colouring matter and manu-
facture their own food. And so it comes to pass
that a certain class of plants have found another
way of living, by taking their food ready made
from other decaying plants and animals, and so
avoiding the necessity of manufacturing it for them-
selves. These plants can live hidden away in dark
cellars and damp cupboards, in drains and pipes
where no light ever enters, under a thick covering of
dead leaves in the forest, under fallen trunks and







60 THROUGH MAGIC GLASSES

mossy stones; in fact, wherever decaying matter,
whether of plant or animal, can be found for them
to feed upon.
It is to this class, called fungi, which includes
all mushrooms and moulds, mildews, smuts, and
ferments, that the mushroom belongs which we
found yesterday making the fairy rings. And, in
truth, we were not so far wrong when we called
them pixies or imps, for many of them are indeed
imps of mischief, which play sorry pranks in our
stores at home and in the fields and forest abroad.
They grow on our damp bread, or cheese, or pickles;
they destroy fruit and corn, hop and vine, and even
take the life of insects and other animals. Yet, on
the other hand, they are useful in clearing out un-
healthy nooks and corners, and purifying the air;
and they can be made to do good work by those
who know how to use them; for without ferments
we could have neither wine, beer, nor vinegar, nor
even the yeast which lightens our bread.
I am going to-day to introduce you to this large
vagabond class of plants, that we may see how they
live, grow, and spread, what good and bad work
they do, and how they do it. And before we come
to the mushrooms, which you know so well, we must
look at the smaller forms, which do all their work
above ground, so that we can observe them. For the
fungi are to be found almost everywhere. The film
growing over manure-heaps, the yeast plant, the wine
fungus, and the vinegar plant; the moulds and mil-
dews covering our cellar-walls and cupboards, or
growing on decayed leaves and wood, on stale fruit,







MOULDS AND MILDEWS


bread, or jam, or making black spots on the leaves
of the rose, the hop, or the vine; the potato fungus,
eating into the potato in the dark ground and pro-
ducing disease; the smut filling the grains of wheat
and oats with disease, the ergot feeding on the rye,
the rust which destroys beetroot, the rank toadstools
and puff-balls, the mushroom we eat, and the truffles
which form even their fruit underground,-all these
are fumgi, or lowly plants which have given up mak-
ing their own food in the sunlight, and take it ready
made from the dung, the decaying mould, the root,
the leaf, the fruit, or the germ on which they grow.
Lastly, the diseases which kill the silkworm and the
common house-fly, and even some of the worst skin
diseases in man, are caused by minute plants of this
class feeding upon their hosts.
In fact, the fungi are so widely spread over all
things living and dead, that there is scarcely any-
thing free from them in one shape or another. The

Fig. 22.







Three forms of vegetable mould magnified.
i, Mucor Mucedo. 2, glaucus. 3, Pcnicillium gaucunr.
minute spores, now of one kind, now of another,
float in the air, and settling down wherever they
find suitable food, have nothing more to do than







THROUGH MAGIC GLASSES


to feed, fatten, and increase, which they do with
wonderful rapidity. Let us take as an example
one of the moulds which covers damp leaves, and
even the paste and jam in our cupboard. I have
some here growing upon a basin of paste, and you
see it forms a kind of dense white fur all over the
surface, with here and there a bluish-green tinge
upon it. This white fur is the common mould, Mucor
Mucedo (I, Fig. 2 2), and the green mould happens in
this case to be another mould, Penicillium glaucumi
(3, Fig. 22) ; tbut I must warn you that these minute
moulds look very much. alike until you examine
them under the microscope, and though they are
called white, blue, or green moulds, yet any one of
them may be coloured at different times of its
growth. Another very common and beautiful mould,
Aspergillus glaucus (2, Fig. 22), often grows with
Mucor on the top of jam.
"All these plants begin with a spore or minute
colourless cell of living matter (s, Fig. 23), which
spends its energy in sending out tubes in all direc-
tions into the leaves, fruit, or paste on which it feeds.
The living matter, flowing now this way now that,
lays down the walls of its tubes as it flows, and by
and by, here and there, a tube, instead of working
into the paste, grows upwards into the air and
swells at the tip into a colourless ball in which
a number of minute seed-like bodies called spores are
formed. The ball bursts, the spores fall out, and each
one begins to form fresh tubes, and so little by little
the mould grows denser and thicker by new plants
starting in all directions.







HOW MOULDS GROW


Under the first microscope you will see a slide
showing the tubes which spread through the paste,
and which are called the mycelium (m, Fig. 23), and
amongst it are three upright Fig. 23.
tubes, one just starting a,
another with the fruit ball
farming b, and a third c,
which is bursting and throw-
ing out the spores. The
Aspcrgillus and the Penicil-
lium differ from the Mucor in
having their spores naked
and not enclosed in a spore-
case. In Penicillium they
grow like the beads of a
necklace one above the other
on the top of the upright
tube, and can very easily be
separated (see Fig. 22); while
Aspergillus, a most lovely
silvery mould, is more com-
plicated in the growth of its
spores, for it bears them on Mlfucor Mucedo, greatly magni-
many rows branching out unified. (After Sachs and
Brefeld.)
from the top of the tube like m, Mycelium, or tangle of
the rays of a star. threads. a, b, c, Upright tubes
"I want you to look at in different stages. c, Spore-
case bursting and sending out
each of these moulds care- spores. s, 1, 2, 3, A growing
fully under the microscope, spore, in different stages, start-
for few people who hastily ing a new mycelium.
scrape a mould away, vexed to find it on food or
damp clothing, have any idea what a delicate and







THRO UGH MAGIC GLASSES


beautiful structure lies under their hand. These
moulds live on decaying matter, but many of the
mildews, rusts, and other kinds of fungus, prey upon
living plants such as the snmut of oats (Ustilago carbo),
and the bunt (Tilletia caria) which eats away the
inside of the grains of wheat, while another fungus
attacks its leaves. There is scarcely a tree or herb
which has not one fungus to prey upon it, and many
have several, as, for example, the common lime-tree,
which is infested by seventy-four different fungi, and
the oak by no less than 200.
So these colourless food-taking plants prey upon
their neighbours, while they take their oxygen for
breathing from air. The 'ferments,' however, which
live inside plants or fluids, take even their oxygen
for breathing from their hosts.
If you go into the garden in summer and pluck
an overripe gooseberry, which is bursting like this
one I have here, you will probably find that the pulp
looks unhealthy and rotten near the split, and the
gooseberry will taste tart and disagreeable. This is
because a small fungus has grown inside, and worked
a change in the juice of the fruit. At first this
fungus spread its tubes outside and merely fed upon
the fruit, using oxygen from the air in breathing;
but by and by the skin gave way, and the fungus
crept inside the gooseberry where it could no longer
get any fresh air. In this dilemma it was forced to
break up the sugar in the fruit and take the oxygen
out of it, leaving behind only alcohol and carbonic
acid which give the fermented taste to the fruit.
So the fungus-imp feeds and grows in nature,







THE GROWTH OF YEAST


and when man gets hold of it he forces it to do
the same work for a useful purpose, for the grape-
fungus grows in the vats in which grapes are crushed
and kept away from air, and tearing up the sugar,
leaves alcohol behind in the grape-juice, which in
this way becomes wine. So, too, the yeast-fungus
grows in the malt and hop liquor, turning it into
beer; its .spores floating in the fluid and increasing
at a marvellous rate, as any housewife knows who,
getting yeast for her bread, tries to keep it in a
corked bottle.
"The yeast plant has never been found wild. It
is only known as a cultivated plant, growing on
prepared liquor. The brewer has to sow it by taking
some yeast from other beer, or by leaving the liquor
exposed to air in which yeast spores are floating;
or it will sow itself in the same Fig. 24.
way in a mixture of water, hops,
sugar, and salt, to which a handful
of flour is added. It increases at
a marvellous rate, one cell budding
out of another, while from time to
time the living matter in a cell will
break up into four parts instead of
two, and so four new cells will start Yeast cells growing
and bud. A drop of yeast will very under the microscope.
soon cover a glass slide with this a, Single cells. t, Two
cells forming by division.
tiny plant, as you will see under c, Agroupofcellswhere
the second microscope, where they division is going on in
are now at work (Fig. 24). all directions.
"But perhaps the most curious of all the minute
fungi are those which grow inside insects and destroy







THROUGH MAGIC GLASSES


them. At this time of year you may often see a
dead fly sticking to the window-pane with a cloudy
white ring round it; this poor fly has been killed by
a little fungus called Emnpusa muscle. A spore from
a former plant has fallen perhaps on the window-
pane, or some other spot over which the fly has
crawled, and being sticky has fixed itself under the
fly's body. Once settled on a favourable spot it
sends out a tube, and piercing the skin of the fly,
begins to grow rapidly inside. There it forms little
round cells one after the other, something like the
yeast-cells, till it fills the whole body, feeding on its
juices; then each cell sends a tube, like the upright
tubes of the Mucor (Fig. 23) out again through the
fly's skin, and this tube bursts at the end, and so
new spores are set free. It is these tubes, and the
spores thrown from them, which you see forming a
kind of halo round the dead fly as it clings to the
pane. Other fungi in the same way kill the silk-
worm and the caterpillars of the cabbage butterfly.
Nor is it only the lower animals which suffer. When
we once realise that fungus spores are floating every-
where in the air, we can understand how the terrible
microscopic fungi called bacteria will settle on an
open wound and cause it to fester if it is not properly
dressed.
"Thus we see that these minute fungi are almost
everywhere. The larger ones, on the contrary, are
confined to the fields and forests, damp walls and
hollow trees; or wherever rotting wood, leaves, or
manure provide them with sufficient nourishment.
Few people have any clear ideas about the growth







HOW MUSHROOMS GROW


of a mushroom, except that the part we pick springs
up in a single night. The real fact is, that a whole
mushroom plant is nothing more than a gigantic
mould or mildew, only that it is formed of many
different shaped
cells, and spreads g.
its tubes under-
ground or through b
the trunks of trees
instead of in paste -' '
or jam, as in the i7 '
case of the mould. '" ''
"The part which C-..'
we gather and call a ""
mushroom, a toad-
stool, or a puffball is
only the fruit, answer- Early stes of the mushroom.
only the fuit, answer- (After Sachs.)
ing to the round balls m, Mycelium. b-3, Mushroom budsof
of the mould. The different ages. 14, Button mushroom. g,
rest of the plant is Glls forming inside before lower attach.
ment of the cap gives way at v.
a thick network of
tubes, which you will see under the third micro-
scope. These tubes spread' underground and suck
in decayed matter from the earth; they form the
mycelium (m, Fig. 25) such as we found in the
mould. The mushroom-growers call it 'mushroom
spawn' because they use it to spread over the
ground for new crops. Out of these underground
tubes there springs up from time to time a
swollen round body no bigger at first than a mustard
seed (br, Fig. 25). As it increases in size it comes
above ground and grows into the mushroom or








THROUGH MAGIC GLASSES


spore-case, answering to the round balls which
contain the spores of the mould. At first this
swollen body is egg-shaped, the top half being
largest and broadest, and the fruit is then called
a 'button-mushroom' b4. Inside this ball are
now formed a series of folds made of long cells,
some of which are soon to bear spores just as the

1 Fig. 26.



-I





Later stages of the mushroom. (After Gautier.)
T, Button mushroom stage. c, Cap. v, Veil. g, Gills.
2, Full-grown mushroom, showing veil v after the cap is quite
free, and the gills or Jamella g, of which the structure is shown in
Fig. 27.

tubes in the mould did, and while these are forming
and ripening, a way out is preparing for them. For
as the mushroom grows, the skin of the lower part
of the ball (v, b4) is stretched more and more, till it
can bear the strain no longer and breaks away from
the stalk; then the ball expands into an umbrella,
leaving a piece of torn skin, called the veil (v, Fig. 26),
clinging to the stalk.
All this happens in a single night, and the mush-
room is complete, with a stem up the centre and a







THE GROWTH OF JIUSHROOM[ GILLS -69

broad cap, under which are the folds which bear the
spores. Thus much you can see for yourselves at any
time by finding a place where mushrooms grow and
looking for them late at night and early in the
morning so as to get the different stages. But now

Fig. 27.



,l0' '-







I, One of the gills or lamella of the mushroom slightly magnified,
showing the cells round the edge. c, Cells which do not bear
spores. fc, Fertile cells. 2, A piece of the edge of the same'
powerfully magnified, showing how the spores s grow out of the
tip of the fertile cells fc.

we must turn to the microscope, and cutting off one
of the folds, which branch out under the cap like the
spokes of a wheel, take a slice across it (i, Fig. 27)
and examine.
First, under a moderate power, you will see the
cells forming the centre of the fold and the layer of
long cells (c and fc) which are closely packed all round
the edge. Some of these cells project beyond the
others, and it is they which bear the spores. We
see this plainly under a very strong power when you
can distinguish the sterile cells c and the fertile cells







THROUGH MAGIC GLASSES


fc projecting beyond them, and each bearing four
spore-cells s on four little horns at its tip.
These spores fall off very easily, and you can
make a pretty experiment by cutting off a large
mushroom head in the early morning and putting it
flat upon a piece of paper. In a few hours, if you
lift it very carefully, you will find a number of dark
lines on the paper, radiating from a centre like the
spokes of a wheel, each line being composed of the
spores which have fallen from a fold as it grew ripe.
They are so minute that many thousands would be
required to make up the size of the head of an ordin-
ary pin, yet if you gather the spores of the several
kinds of mushroom, and examine them under a strong
microscope, you will find that even these specks of
matter assume different shapes in the various species.
You will be astonished too at the immense
number of spores contained in a single mushroom
head, for they are reckoned by millions ; and when
we remember that each one of these is the starting
point of a new plant, it reminds us forcibly of the
wholesale destruction of spores and seeds which must
go on in nature, otherwise the mushrooms and their
companions would soon cover every inch of the
whole world.
"As it is, they are spread abroad by the wind, and
wherever they escape destruction they lie waiting in
every nook and corner till, after the hot summer,
showers of rain hasten the decay of plants and leaves,
and then the mushrooms, toadstools, and puffballs,
grow at an astounding pace. If you go into the woods
at this season you may see the enormous deep-red liver







THE FAIRY-RING MUSHROOM


fungus (Fistulina hiepatica) growing on the oak-trees,
in patches which weigh from twenty to thirty pounds ;
or the glorious orange-coloured fungus (Tremella
mesenterica) growing on bare sticks or stumps of
furze; or among dead leaves you may easily chance
on the little caps of the crimson, scarlet, snowy white,
or orange-coloured fungi which grow in almost every
wood. From white to yellow, yellow to red, red to
crimson and purple black, there is hardly any colour
you may not find among this gaily-decked tribe; and
who can wonder that the small bright-coloured caps
have been supposed to cover tiny imps or elves, who
used the large mushrooms to serve for their stools
and tables-?
There they work, thrusting their tubes into twigs
and dead branches, rotting trunks and decaying
leaves, breaking up the hard wood and tough
fibres, and building them up into delicate cells,
which by and by die and leave their remains as food
for the early growing plants in the spring. So we
see that in their way the mushrooms and toadstools
are good imps after all, for the tender shoot of a
young seedling plant could take no food out of a
hard tree-trunk, but it finds the work done for it by
the fungus, the rich nourishment being spread around
its young roots ready to be imbibed.
To find our fairy-ring mushrooms, however, we
must leave the wood and go out into the open
country, especially on the downs and moors and
rough meadows, where the land is poor and the grass
coarse and spare. There grow the nourishing kinds,
most of which we can eat, and among these is the







THROUGH MAGIC GLASSES


delicate little champignon or 'Scotch-bonnet' mush-
room, Marasmins Oreades,1 which makes the fairy-
rings. When a spore of this mushroom begins to
grow, it sucks up vegetable food out of the earth and
spreads its tubes underground, in all directions from
the centre, so that the mycelium forms a round patch
like a thick underground circular cobweb. In the
summer and autumn, when the weather is suitable, it
sends up its delicate pale-brown caps, which we may
gather and eat without stopping the growth of the
plant.
This goes on year after year underground, new
tubes always travelling outwards till the circle widens
and widens like the rings of water on a pond, only
that it spreads very slowly, making a new ring each
year, which is often composed of a mass of tubes as
much as a foot thick in the ground, and the tender
tubes in the centre die away as the new ones form a
larger hoop outside.
"But all this is below ground ; where then are
our fairy rings ? Here is the secret. The tubes, as
we have seen, take up food from the earth and
build it up into delicate cells, which decay very soon,
and as they die make a rich manure at the roots of
the grass. So each season the cells of last year's ring
make a rich feeding-ground for the young grass,
which springs up fresh and green in a fairy ring,
while outside this emerald circle the mushroom tubes
are still growing and increasing underneath the grass,
so that next year, when the present ring is no longer
richly fed, and has become faded and brown like the
1 Shown in initial letter of this chapter.







HOW FAIRY RINGS ARE FORMED


rest of the moor, another ring will spring up outside
it, feeding on the prepared food below.
In bad seasons, though the tubes go on spreading
and growing below, the mushroom fruit does not
always appear above ground. The plant will only
fruit freely when the ground has been well warmed
by the summer sun, followed by damp weather to
moisten it. This gives us a rich crop of mushrooms
all over the country, and it is then you can best
see the ring of fairy mushrooms circling outside the
green hoop of fresh grass. In any case the early
morning is the time to find them ; it is only in very
sheltered spots that they sometimes last through the
day, or come up towards evening, as I found them
last night on the warm damp side of the dell.
This is the true history of fairy rings, and now go
and look for yourselves under the microscopes.
Under the first three you will find the three different
kinds of mould of our diagram (Fig. 22). Under the
fourth the spores of the mould are shown in their
first growth putting out the tubes to form the
mycelium. The fifth shows the mould itself with its
fruit-bearing tubes, one of which is bursting. Under
the sixth the yeast plant is growing; the seventh
shows a slice of one of the folds of the common
mushroom with its spore-bearing horns; and under
the eighth I have put some spores from different
mushrooms, that you may see what curious shapes
they assume.
Lastly, let me remind you, now that the autumn
and winter are coming, that you will find mush-
rooms, toadstools, puffballs, and moulds in plenty







74 THROUGH MAGIC GLASSES
wherever you go. Learn to know them, their differ-
ent shapes and colours, and above all the special
nooks each one chooses for its home. Look around
in the fields and woods and take note of the decay-
ing plants and trees, leaves and bark, insects and
dead remains of all kinds. Upon each of these you
will find some fungus growing, breaking up their
tissues and devouring the nourishing food they pro-
vide. Watch these spots, and note the soft spongy
soil which will collect there, and then when the
spring comes, notice what tender plants flourish upon
these rich feeding grounds. You will thus see for
yourselves that the fungi, though they feed upon
others, are not entirely mischief-workers, but also
perform their part in the general work of life."







THE LIFE-HISTOR Y OF LICHENS AND MOSSES 75


CHAPTER IV

TIE LIFE-HISTORY OF LICHENS AND MOSSES

i':, p P HE autumn has passed away
and we are in the midst
IM of winter. In the long
winter evenings the stars
S.. shine bright and clear, and
'- t..,''lt us to work with the telescope
S.,-II.. its helpmates the spectroscope
and, photographic plates. But at
e. ,' -ight it would seem as though
--: J -.i microscopes would have to stand
S -. i:l o far at least as plants are
:.-.r.:-rned, or be used only to ex-
amine dried specimens and mounted
sections. Yet this is not the fact, as I remembered
last week when walking through the bare and leafless
wood. A startled pheasant rising with a whirr at
the sound of my footsteps among the dead leaves
roused me from my thoughts, and as a young rabbit
scudded across the path and I watched it disappear
among the bushes, I was suddenly struck with the







THROUGH MAGIC GLASSES


great mass of plant life flourishing underfoot and
overhead.
Can you guess what plants these were? I do
not mean the evergreen pines and firs, nor the few
hardy ferns, nor the lovely ivy clothing the trunks
of the trees. Such plants as these live and remain
green in the winter, but they do not grow. If you
wish to find plant life revelling in the cold damp
days of winter, fearing neither frost nor snow and
welcoming mist and rain, you must go to the mosses,
which as autumn passes away begin to cover the
wood-paths, to creep over the roots of the trees, to
suck up the water in the bogs, and even to clothe
dead walls and stones with a soft green carpet.
And with the mosses come the lichens, those curious
grey and greenish oddities which no one but a
botanist would think of classing among plants.
The wood is full of them now: the hairy lichens
hang from the branches of many of the trees, making
them look like old greybearded men; the leafy
lichens encircle the branches, their pale gray, green,
and yellow patches looking as if they were made of
crumpled paper cut into wavy plates ; and the crusty
lichens, scarcely distinguishable from the bark of the
trees, cover every, available space which the mosses
have left free.
As I looked at these lichens and thought of their
curious history I determined that we would study
them to-day, and gathered a basketful of specimens
(see Fig. 28). But when I had collected these I found
I had not the heart to leave the mosses behind. I
could not even break off a piece of bark with lichen







A GROUP OF LICHENS


upon it without some little moss coming too, especi-
ally the small thread-mosses (Bryium) which make a
Fig. 28.









Examples of Lichens. (From life.)
i, A hairy lichen. 2, A leafy lichen. 3, A crustaceous lichen.
Sf the fruit.
home for themselves in every nook and corner of the
branches ; while the feather-mosses, hair-mosses,
cord-mosses, and many others made such a lovely
carpet under my feet that each seemed too beautiful
to pass by, and they found their way into my basket,
crowned at the top with a large mass of the pale-
green Sphagnum, or bog-moss, into which I sank
more than ankle-deep as I crossed the bog in the
centre of the wood on my way home.
So here they all are, and I hope by the help of
our magic glass to let you into some of the secrets
of their lives. It is true we must study the structure
of lichens chiefly by diagrams, for it is too minute
for beginners to follow under the microscope, so we
must trout to drawings made by men more skilful in
microscopic botany, at any rate for the present. But
the mosses we can examine n e for ourselves and admire
their delicate leaves and wonderful tiny spore-cases.







78 THROUGH MAGIC GLASSES

Now the first question which I hope you want to
ask is, how it is that these lowly plants flourish so
well in the depth of winter when their larger and
stronger companions die down to the ground. We
will answer this first as to the lichens, which are such
strange uncanny-looking plants that it is almost
difficult to imagine they are alive at all ; and indeed
they have been a great puzzle to botanists.
Before we examine them, however, look for a
minute at a small drop of this greenish film which I
have taken from the rain-water taken outside. I
have put some under each microscope, and those
Fig. 29. who can look into them will
see the slide almost covered
with small round green cells
very much like the yeast
cells we saw when studying
the Fungi, only that instead
of being colourless they are
a bright green. Some of
these cells will I suspect be
longer than others, and these
Single-celled green plants grow- long cells will be moving
ing and dividing (Pleurococcus). over the slide very rapidly,
After Thuret and Brnet.) swimming hither and thither,
and you will see, perhaps for the first time, that very
low plants can swim about in water. These green
cells are, indeed, the simplest of all plants, and
are merely bags of living matter which, by the help
of the green granules in them, are able to work up
water and gases into nourishing food, and so to live,
grow, and multiply.







WHERE SINGLE-CELLED PLANTS GROW 79

There are many kinds of these single-celled plants
in the world. You may find them on damp paths,
in almost any rain-water butt, in ponds and ditches,
in sparkling waterfalls, along the banks of flowing
rivers, and in the cold clear springs on the bleak
mountains. Some of them take the form of tangled
threads 1 composed of long strings of cells, and these
sometimes .form long streamers in flowing water, and
at other times are gathered together in a shapeless
film only to be disentangled under a microscope.
Other kinds 2 wave to and fro on the water, forming
dense patches of violet, orange-brown, or glossy green
scum shining in the bright sunlight, and these flourish
equally in the ponds of our gardens and in pools in
the Himalaya mountains, i 8,000 feet above the sea.
Others again seize on every damp patch on tree
trunks, rocks, or moist walls, covering them with a
green powder formed of single plant cells. Other
species of this family turn a bright red colour when
the cells are still ; and one, under the name of Gory
Dew,4 has often frightened the peasants of Italy, by
growing very rapidly over damp walls and then
turning the colour of blood. Another 5 forms the
"red snow" of the Arctic regions, where it covers
wide surfaces of snow with a deep red colour. Others 6
form a shiny jelly over rocks and stones, and these
may be found almost everywhere, from the garden
path to the warm springs of India, from the marshes
of New Zealand up to the shores of the Arctic ocean,
and even on the surface of floating icebergs.
1 Conferva. 2 Oscillarlic. Pro/ococcrr s.
4 Pallella cruenta. 5 PI'/otorocirs nivalis. 6 NAosoc.







THROUGH MAGIC GLASSES


The reason why these plants can live in such very
different regions is that they do not take their food
through roots out of the ground, but suck in water
and gases through the thin membrane which covers
their cell, and each cell does its own work. So it
matters very little to them where they lie, so long as
they have moisture and sunlight to help them in
their work. Wherever they are, if they have these,
they can take in carbonic acid from the air and
work up the carbon with other gases which they
imbibe with the water, and so make living material.
In this way they grow, and as a cell grows larger
the covering is stretched and part of the digested
food goes to build up more covering membrane, and
by and by the cell divides into two and each mem-
brane closes up, so that there are two single-celled
plants where there was only one before. This will
sometimes go on so fast that a small pond may be
covered in a few hours with a green film formed of
new cells.
Now we have seen, when studying mushrooms, that
the one difference between these green plants and the
single-celled Fungi is that while the green cells make
their own food, colourless cells can only take it in
ready-made, and therefore prey upon all kinds of
living matter. This is just what happens in the
lichens; and botanists have discovered that these
curious growths are really the result of a partnership
between single-celled green plants and single-celled
fungi. The grey part is a fungus; but when it is
examined under the microscope we find it is not a
fungus only; a number of green cells can be seen







HOW LICHENS SUCCEED


scattered through it, which, when carefully studied,
prove to be some species of the green single-celled
plants.
Here are two drawings of sections cut through
two different lichens, and
Fig. 30.
enormously magnified so
that the cells are clearly ,
seen. I, Fig. 30 is part of \.'-i' J
a hairy lichen (i, Fig. 28), f N
and 2 is part of a leafy i'ligo
lichen (2, Fig. 28). The '4i
hairy lichen as you see has U 11
a row of green cells all round
the tiny branch, with fungus '.I,,' -
cells on all sides of them. .
The leafy lichen, which only
presents one surface to the 2
sun and air while the other
side is against the tree, has a 3. ,,
only one layer of green cells
near the surface, but pro- Sections of Lichens. (Sachs.)
I, Section of a hairy lichen,
tected by the fungus above. Usnea babata. 2, Section of a
The way the lichen has leafy lichen, Slicta fuliginosa.
grown is this. A green cell 3, Early growth of a lichen.
S3, Fig. 3) falling on gc, Green cells. f, Fungus.
(c 3, Fig. 30) falling on
some damp spot has begun to grow and spread,
working up food in the sunlight. To it comes
the spore of the fungus f, first thrusting its tubes
into the tree-bark, or wall, and then spreading
round the green cells, which remain always in
such a position that sunlight, air, and moisture
can reach them. From this time the two classes of







THROUGH MAGIC GLASSES


plants live as friends, the fungus using part of the
food made by the green cells, and giving them in
return the advantage of being spread out to the
sunlight, while they are also protected in frosty or
sultry weather when they would dry up on a bare
surface. On the whole, however, the fungus probably
gains the most, for it has been found, as we should
expect, that the green cells can live and grow if
separated out of the lichen, but the fungus cells die
when their industrious companions are taken from
them.
At any rate the partnership succeeds, as you will
see if you go into the wood, or into an orchard where
the apple-trees are neglected, for every inch of the
branches is covered by lichens if not already taken
up by mosses or toadstools.
There is hardly any part of the world except the
tropics where lichens do not abound. In the Alps
of Scandinavia close to the limits of perpetual snow,
in the sandy wastes of Arctic America, and over the
dreary Tundras of Arctic Siberia, where the ground
is frozen hard during the greater part of the year,
they flourish where nothing else can live.
The little green cells multiply by dividing, as we
saw them doing in. the green film from the water-
butt. The fungus, however, has many different
modes of seeding itself. One of these is by form-
ing little pockets in the lichen, out of which, when
they burst, small round bodies are thrown, which
cover the lichen with a minute green powder. There
is plenty of this powder on the leafy lichen which
you have by you. You can see it with the magnify-








OW- LICHENS FRUIT 83

ing-glass, without putting it under the microscope.
As long as the lichen is dry these round bodies do
not grow, but as soon as moisture reaches them they
start away and become new plants.
A more complicated and beautiful process is shown
in this diagram (Fig. 3 1). If you look carefully at
the leafy lichen (2, Fig. 28) you will find here and
there some. little cups, while others grow upon the

Fig. 3.1


, ; ,' ..



i ,,


-:.


f\


7- ^


Fructification of a lichen. (From Sachs and Oliver.)
Apothecium or spore-chamber of a lichen. I, Closed. 2, Open.
3, The spore-cases and filaments enlarged, showing the spores. f, Fila-
ments. sc, Spore-cases. s, Spores.

tips of the hairy lichen. These cups, or fruits,
were once closed, flask-shaped chambers (r, Fig.
31) inside which are formed a number of oval
cells sc, which are spore-cases, with from four to eight
spores or seed-like bodies s3 inside them. When
these chambers, which are called apothecia, are ripe,
moist or rainy weather causes them to swell at the
9


\


I,







THROUGH MAGIC GLASSES


top, and they burst open and the spore-cases throw
out the spores to grow into new fungi.
In some lichens the chambers remain closed and
the spores escape through a hole in the top, and they
are then called perithecia, while in others, as these
which we have here, they open out into a cup-shape.
This, then, is the curious history of lichens; the
green cells and fungi flourishing together in the damp
winter and bearing the hardest frost far better than
the summer drought, so that they have their good
time when most other plants are dead or asleep.
Yet though some of them, such as the hairy
lichens, almost disappear in the summer, they are by
no means dead, for, like all these very low plants,
they can bear being dried up for a long time, and then,
when moisture visits them again, each green cell sets
to work, and they revive. There is much more to be
learnt about them, but this will be sufficient to make
you feel an interest in their simple lives, and when
you look for them in the wood you will be surprised to
find how many different kinds there are, for it is most
wonderful that such lowly plants should build up such
an immense variety of curious and grotesque forms.

And yet, when we turn to the mosses, I am half
afraid they will soon attract you away from the dull
grey lichens, for of all plant histories it appears to
me that the history of the moss-plant is most
fascinating.
As this history is complicated by the moss having,
as it were, two lives, you must give me your whole
attention, and I will explain it first from diagrams,




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