[Illustration: Showing the five groups considered in the book]
[Illustration: Group of Extinct Animals.]
OUTLINES
OF
CREATION.
BY
ELISHA NOYCE.
AUTHOR OF
"THE BOY'S BOOK OF INDUSTRIAL INFORMATION."
ILLUSTRATED WITH
FOUR HUNDRED ENGRAVINGS,
BY
THE BROTHERS DALZIEL.
LONDON:
WARD & LOCK, 158, FLEET STREET.
1858.
(_The right of Translation is reserved._)
Dalziel, Brothers, Camden Press, London.
CONTENTS.
THE SKY.
PAGE
Sky, definition of 1
Stars, what they are 1
Sun, probable planets of 2
Nebulæ 2
Solar system 3
Planets, list of 3
Sun, the source of light 3
" size, diameter, &c. 3
" spots on 3
" compared with size of planets 4
Orbits, elliptical 5
Ellipse, definition of 5
Earth's orbit, form of 6
Mercury 6
Venus 7
Planets, inferior and superior 7
" conjunction and opposition of 8
The Earth 8
" form of, demonstrated 9
" diurnal motion of 10
" rate of motion of 10
Equinoxes and solstices 12
The Moon 12
" phases of 13
Mars 14
Jupiter 16
" satellites of 18
Saturn 18
" rings of 19
Uranus 21
Neptune 22
The planetoids 22
" supposed origin of 23
The stellar system 24
Stars, number of 24
The Milky Way 24
Nebulæ 24
Constellations 25
Stars, double 26
" variable 27
Comets 27
THE AIR.
Air, how perceived 29
" composition of 29
" weight of 30
Barometer, principle of 30
Winds, course of 31
Vapour, condensation of 31
Snow, hail, and frost 32
" red and green 32
Air, temperature of 32
Dew, cause of 33
" artificial formation of 34
Clouds and fogs 35
Lightning 36
" conductors 37
Thunder-storms 38
Rainbow 39
Air, the source of nourishment 40
" carbonic acid of 41
" the source of coal 41
THE EARTH.
Elements, list of 45
Earths, list of 46
Silica 46
Alumina, Lime, Potassa 47
Soda 48
The Earth, surface of 49
Strata 49
" diagram of 50
" various positions of 51
Faults or dykes 52
Granite 53
Gneiss 54
Strata, primary 54
Earth, primary period of 55
Stalagmites, formation of 58
Terebratula 58
Secondary system 59
Trilobites 59
Mountains, formation of 61
Earth, section of part of 62
Volcanoes, formation of 62
Coral polypi 64
Encrinites 65
Mountain limestone 65
Basalt 66
Tree-ferns, Pines, &c. 66
Air, purification of 67
Coal, formation of 67
" consumption of 68
Coal shales, ferns found in 69
Earth's surface, alterations of 69
Labyrinthodon 70
Red Sandstone, impressions in 70
Saliferous system 71
Lias and oolite 71
Ammonites and pentacrinites 72
Cretaceous system (chalk) 72
Ichthyosaurus and plesiosaurus 73
Coprolites 74
Chalk, organic remains in 75
" flints of 76
Strata, tertiary 78
Alluvium and diluvium 78
" quadrupeds of 78
Dinotherium 79
Mammoth, &c. 80
Irish elk, paleotherium 81
Boulder formation 82
Fossil leaves 83
Man, as yet unformed 83
" his remains only in upper strata 83
Sculptures from Nineveh 84
Earth's surface, always changing 84
" as it is 86
Earth, temperature of 86
Europe 87
Asia and Africa 88
America 88
Australia 89
The Great Desert 89
Oceans 90
THE WATERS.
The waters 91
Sea-weeds, &c. 92
The horizon 93
The cliffs 93
The waters, their divisions 93
The sea, always the same level 94
" waters poured into it 94
Rain, how produced 95
Rivers and streams 96
" causes of their overflowing 97
Lakes 97
Chalk downs, &c., once a sea bottom 98
Sea, its encroachments 98
" waves of 99
" Sargasso 101
Gulf stream 101
Sand, formation of 102
" none in deep seas 102
Diatomaceæ 103
Foraminiferæ 104
Salt, the source of 104
Sea-water, composition of 105
Tides 105
Waters, beneficially arranged 107
Steam navigation 108
Introduction to organic kingdoms 110
THE VEGETABLE KINGDOM.
Quantity, distribution, &c. 112
Forests of Russia and America 113
Sargasso sea, sea-weed 114
Diatomaceæ 114
Fungi, mould, mildew, &c. 116
Coral reef, fertilisation of 118
Vegetables, composition of 118
" feed on the air 119
" the food of animals 119
" mode of growth 120
" action of light and heat on 121
Seeds, germination of 122
Growth, promoted by rain 123
Endosmose, experiment on 123
Carbonic acid decomposed by
plants 124
Sap, course of 124
Vegetables, position they hold 125
" compared with radiata 126
" description of parts of 127
Leaves, forms of 130
Corolla, forms of 132
Stamens, arrangement of 133
Fruit, forms of 134
Inflorescence, forms of 136
Vegetable kingdom, divisions of 139
Acrogenæ 141
Algæ 141
Fungi 143
Lichens, ferns 144
Liverworts 145
Mosses, various 146
Horsetails 147
Endogenæ 147
Bamboo, applications of 152
Endogenæ, orders of 154
Grasses 154
Sedges, Arums 155
Bull-rush, Colchicum 156
Lily, Narcissus 157
Crocus, Orchids 158
Naiads, Flowering rushes 159
Water Plantain 160
Exogens 160
" wood of 161
" age of 162
Baobab 163
Woods, various kinds of 165
Galls, formation of 167
Wood, uses of 167
Exogens, size of 168
Wellingtonia Gigantea 168
Banyan 170
Exogens, sub-classes of 170
Thalamifloræ, orders of 171
White Water Lily 171
Poppies, Monkshood 172
Fumitory, Water-cress 173
Helianthemum, Berberry 174
Violet, Sun-dew 175
Milkwort, Bachelor's Buttons 176
Lime Tree, St. John's Wort 177
Marsh Mallow, Meadow Geranium 178
Flax, Maple Tree 179
Rue, Wood Sorrel 180
Calycifloræ, orders of 181
Spindle Tree, Buckthorn 181
Broom, Garden Pea 182
Pear Tree, Rose, Strawberry, Loose Strife 183
French Willow, Myrtle 184
House-leek, Gooseberry 185
London Pride, Fennel, Hemlock 186
Corollifloræ, orders of 187
Melon, Dogwood 187
Honeysuckle, Guelder Rose, Cross Wort 188
Valerian, Red Valerian, Teasel 189
Coltsfoot, Ox-eye Daisy, Harebell 190
Grey Heath, Gentian, Buck-bean 191
Pimpernel, Primrose, Bindweed 192
Borage, Sage 193
Tobacco 194
Speedwell 195
Butterwort, Plantain 196
Thrift, Holly 197
Monochlamydeæ, orders of 197
Ladies' Mantle 197
Beetroot, Buckwheat 198
Oleaster, Spurge Laurel 199
Sweet Chestnut, Box 200
Hop, White Willow 201
Birch, Alder, Elm 202
Larch, Yew, Bay 203
Plants, list of poisonous 204
Monk's-hood, Wolf's-bane 204
Bryony, Green Hellebore, Stinking Hellebore 205
Mezerium, Meadow Saffron 206
Foxglove, Staves-acre 207
Nightshade 208
Hemlock, Thorn Apple 209
Poppies, Henbane 210
Caper, Wild Lettuce 211
Fungi, poisonous 212
THE ANIMAL KINGDOM.
Animalculæ in water 215
Man, created, not developed 217
Animals, chief division of 217
Animals, invertebrate 217
Infusoria 218
Protozoa 218
Infusoria, higher kinds of 220
Entozoa (intestinal worms) 221
Zoophytes (Sertularia, &c.) 221
Sponge 222
Gorgonia 222
Actinia 223
Corals (Tubipora musica, &c.) 224
Flustra (Sea mats) 225
Echinodermata (Star-fishes, &c.) 225
Sea urchins, &c. 226
Articulata 227
Annellata (Worms, &c.) 227
Cirripeda (Sea acorns) 228
Crustacea 229
Insects 231
" metamorphoses of 231
" parts of 232
" depredations by 234
" orders of 236
Beetles 236
Grasshoppers, Locusts, &c. 237
Dragon-flies, May-flies, &c. 238
Bees, Wasps, &c. 240
Ants, habitations of 240
White Ants 245
Stylops 247
Butterflies, Moths, &c. 248
Silkworm 249
Bugs, Aphides, &c. 250
House-fly, Gnat, &c. 250
Flea, Chigoe 251
Spiders and Scorpions 252
Mollusca 252
Nautilus, mussel, &c. 255
Tunicated molluscs 255
Lingula, Terebratula, &c. 256
Oyster, cockle, scallop, &c. 256
Clio borealis 257
Snail, slug, whelk, &c. 257
Cuttle-fish, nautilus, &c. 258
Vertebrata 259
Fishes, description of 259
Fishes, divisions of 260
Perch, Mackerel, Gurnard, &c. 261
Salmon, Pilchard, Pike, &c. 262
Turbot, Plaice, Soles, &c. 265
Eels 266
Pipe-fish, Sea Horse 267
Sea Porcupine, Sun-fish 268
Sturgeons, Sharks 269
Lamprey 270
Reptiles 271
Frogs and Toads 271
Snakes 272
Lizards, Crocodiles, &c. 274
Turtles and Tortoises 276
Birds 279
" divisions of 280
Eagles, Falcons, &c. 281
King-fisher, Woodpecker, &c. 281
Poultry, Pheasants, &c. 282
Herons, Cranes, &c. 284
Swans, Geese, &c. 285
Mammalia, orders of 286
Kangaroo, Opossum, &c. 287
Duckbill 288
Rat, Beaver, Hare, &c. 289
Anteaters 291
Ox, Deer, &c. 292
Horse, Elephant, Hog, &c. 294
Whale, Narwal, &c. 296
Lion, Tiger, &c. 297
Dogs, Wolves and Jackalls 302
Bears 302
Seals and Walrus 303
Mole, Hedgehog, &c. 303
Bats 304
Monkeys 305
Man 307
Man the only possessor of reason 308
Skeleton, diagram of 309
" parts of 310
Bones, description of 311
Muscles 312
" voluntary and involuntary 313
Ligaments and cartilages 313
Form, affected by age and sex 314
" in infancy 315
" in middle age 315
" in old age 316
" affected by sex 316
Senses, special 317
Sight 317
Eye, structure of 319
Eyes, compound 320
Hearing, smell, taste 321
Touch 322
Digestion 322
Respiration 325
Circulation of Blood 326
Man, his superior faculties 327
" varieties of 328
European race 328
Basks 329
Skiptar, Kelts (or Celts), Greeks and Latins, Sarmatians,
Germans 330
Abyssinians 331
Mongolians 332
Hottentots 333
Malays 334
Papuans, Negrillo 335
Indians, or Telingans, Ethiopians 336
Australians, Negro 337
Races, numerical table of 338
INTRODUCTION.
The object of this work is to bring before the reader a simple and
intelligible description of the whole Creation, without attempting
to enter into minute particulars on any of the subjects more than
is sufficient to present them in a form clear enough to be both
comprehended, and recollected; thus aiming at the production of a
taste for such knowledge, and a desire to enter more minutely into any
or all of the subjects this work embraces, which desire can easily
be gratified by a study of some of the many excellent works devoted
exclusively to the individual parts, which in this work are treated
of collectively. The want of a general knowledge of those works of
the Great Creator which are constantly spread out before us, in these
days of easy acquirement, amounts almost to a sin, for it is by the
study of Nature in all her varied forms and associations, that we learn
to "look from Nature up to Nature's God;" for who can look upon the
works of God without a feeling of awe and admiration? who can look
upwards at "the spacious firmament on high," without a sense of his
own insignificance? who can gaze around upon the beauty and variety
the earth displays, without a strong desire to know more of such a
Great Creator's works?--and he who knows the most, be sure it is he
who will worship Him with the truest and most heartfelt gratitude and
admiration. The works of God (next to the Divine revelation of His
will) are the highest studies to which Man can apply his intellect; it
has required the greatest study of the greatest minds to find out and
record but a few facts to add to the general store, and surely no one
should consider his time misspent who can read over such records, and
trace their truth by comparison with Nature, the more especially as it
is by these means a love of inquiry is engendered, and that ultimately
he may be enabled by diligent perusal of the great Book of Nature, to
add his quota to the store of knowledge already formed and recorded.
It is true that infidels have often brought forward some branch of
Science in confutation of Scripture, but it is also a fact that in
nearly every such case, the very arguments that have been used by these
men, have at last become the strongest arguments on the other side.
Geology was at first adduced as a proof that the world had existed
from all eternity, instead of having been created by an Omnipotent
God, and the question had often been asked, "Can you produce one proof
of the creation of anything?" Now this was a difficult question to
answer, until Geology made manifest the fact that Man was created, by
producing a clear and unimpeachable proof that up to a certain time, he
did _not_ exist on the earth, and that at a period of time, a little
later, he _did_ exist; the space between these epochs is not known,
but it has nothing to do with the argument, for within that period
(whatever it may have been) Man _was_ created, and created as perfect
in his physical organisation as he is at present--no long series of
developments from the higher animals by fortuitous circumstances, as
some pretend--no gradual addition of parts to suit the physical changes
of the earth's surface. There is undoubted proof from the oldest
records, in the form of Sculptures, that Man's appearance has always
been the same, and the records of the Bible (the _antiquity_ of which,
at all events, cannot be disputed) show that the constitution of his
mind was at that time just as it is now--every passion, every desire
the same--the only advance he has made, is in the knowledge of God's
works; the application of that knowledge to his own benefit, and the
glorification of his Maker.
THE SKY.
[Illustration: FIG. 11. TELESCOPIC APPEARANCE OF THE MOON.]
The Sky is the familiar name used to express that wonderful and vast
expanse of space which extends on all sides far beyond our knowledge
or conception, and in which the earth and millions of other orbs move
round suns as their centres. Countless millions of these suns exist
at immense distances apart and of the most prodigious magnitudes
(many thousand times larger than this earth), these are the stars
which on clear nights we see twinkling so brightly in the sky; our
sun is one of them, but being very much nearer to us than the others
it appears proportionately larger and brighter, and is our centre of
attraction and circulation. There is but little doubt that every star
has its circulating worlds or "planets," but these are too small to
be seen even with the best telescopes; this may be understood when it
is considered that the stars themselves, by the most powerful aids,
appear but as bright points or specks, and they are thousands of times
larger than the worlds which would circulate round them. But though
their planets cannot be perceived by the naked eye, yet analogy teaches
us that they in all probability exist, for very many of the heavenly
bodies have satellites revolving round them, of such are our moon and
the moons of Jupiter, and in this sense the planets themselves may
be considered as the satellites of the sun, and as the sun has its
satellites revolving round it, it is fair to conclude that it is not
the only one of all the stars which has. All these thousands of suns
and planets, millions of miles apart, and occupying space, the extent
of which we have no terms to express, form but one system of stars out
of many, for by comparison with infinite space they occupy but a point,
telescopes of the greatest power having revealed that beyond all these
stars, there is an immense space in which are seen other systems of
stars, as great and numerous as our own, to which the name "Nebulæ"
has been given. The mind fails to reach to such magnitude, and it is
certain that the study of these great things, brings us to regard
size and space (like time) as nothing; for it appears that God has
expanded or contracted His works at will to suit His plan of creation
without regard to limit; whether we look at the most minute shell or
the greatest orb, still His marks of design are equally evident. If we
consider it wonderful that God should take up hundreds of millions of
miles for one system, and that He should scatter through space millions
of such systems, then let us lay aside the telescope and, after an
exclamation of adoration, take up the microscope, by which we shall
learn that God has also placed millions of systems equally wonderful
within the compass of an inch! We shall at once acknowledge that he
is "Lord of all," and that size, space, quantity, and time, are mere
fictions of our own imperfect minds, and that to an Infinite God there
is no difficulty from such sources.
THE SOLAR SYSTEM.
This is the name given to that collection of worlds which, with the sun
as a centre, circulate at different distances from and around it. There
have at present been discovered eight large planets and thirty-four
smaller ones called "asteroids" or "planetoids," the larger planets
revolving in the following order from the sun or centre:--
1. MERCURY.
2. VENUS.
3. THE EARTH.
4. MARS.
5. JUPITER.
6. SATURN.
7. URANUS.
8. NEPTUNE.
The Sun, the centre of the solar system, is the great source of light
and heat to our planet and all others which revolve around it, as well
as of another agent not so well understood, namely "actinism," or that
power which produces the chemical changes in many substances exposed to
the sun's rays, and which has been of late turned to such useful and
wonderful account in the art of photography.
The sun is an immense sphere, many thousand times larger than our
earth, or indeed all the planets put together. It turns upon its axis
in twenty-five days, and, like all spheres which rotate, has a slightly
flattened form; it is supposed that the sun itself, carrying its
planets with it, performs a journey round some other centre very far
away, but for all the purposes of explaining the solar system it may
be supposed to be stationary. The diameter of the sun is about 890,000
miles, or nearly 112 times the diameter of our earth, and as the bulk
of spheres is as the cubes of their diameters, it follows that the
sun is about 1,400,000 times the bulk of the earth. Fig. 1 shows the
relative size of the sun and the planets which rotate round it; the
specific gravity of the sun is about a quarter that of our earth or
one-and-a-half times that of water. On its surface irregularities are
seen (by the aid of the telescope) which give it a wavy appearance,
and beside these, black spots or tracts (_maculæ_) which appear to
traverse from west to east, across its face; these however do not
travel on, but are carried round by the sun in its rotation, for
by observing any one of them, it is seen to go across and make its
appearance again at the other side, and the time it takes to arrive at
the place where it was first seen, determines the time of the sun's
rotation, which (as before stated) is twenty-five days or nearly; these
spots alter in size, form, and number from time to time, some of them
remaining permanent for months, others closing in and disappearing in a
few hours.
[Illustration: FIG. 1. PLANETS COMPARED WITH A QUARTER OF THE SUN.]
These black spots have a sort of shadowy fringe (_penumbra_) which
gives them the appearance of being openings through a luminous surface,
discovering a surface less luminous, with openings in it through which
some still darker surface is seen; that this really is the case, and
that these are not merely dark spots or surfaces, is shown by the
fore-shortening of the nearest edge as they arrive at the verge of the
sun's disc, and are consequently presented edgewise to the eye, so that
a spot may have the appearance of fig. 2 when seen in front-view near
the centre, and of fig. 3 when seen fore-shortened near the edge of the
sun's disc. These spots (although but specks in comparison with the
vast surface of the sun) are yet of prodigious magnitude, some having
been calculated to measure 18,000 miles across--large enough for two
such worlds as ours to pass through side by side! From the rapid motion
of the "penumbra" or edges of these spots, which alter, open, and
close up very rapidly, and from some of them being semi-dark, others
quite dark, &c., it has been concluded that the sun has at least two
surrounding atmospheres, that the body of the sun is not luminous, nor
the first atmosphere or that nearest to it, but that the outer one is,
and that the dusky appearance of the inner, as seen through openings
of the luminous outer atmosphere, results from its being very strongly
illuminated by the outer one; this luminosity may be (and probably is)
only comparative, for the spots which appear black may be yet very
bright, appearing black only in comparison with the extreme brilliancy
of the outer atmosphere, just as a bar of red-hot iron appears black
when held up to the sun. The course which the planets take round the
sun is not exactly circular, but deviating from it more or less, never
being quite a circle. The orbit of each planet, if accurately computed
and laid down on paper, proves to be that form of curved line called
an "ellipse," or that form which instead of having one centre, as in
the circle, from which all lines radiating to the circumference are
equal in length, has a longer and shorter diameter, two centres called
"foci," and the circumference or boundary so placed that the sum of
any two lines, drawn one from each centre, and meeting at any part of
the circumference, shall be equal to any two other lines so drawn and
meeting at any other point of the circumference, and to the major axis
or long diameter of the ellipse. In fig. 4, each pair of lines drawn
from A A and meeting repectively at B are each equal.
An ellipse may be very much elongated, or almost circular, but still
have these properties which are essential to it, and in the case of the
orbits of the planets, they are so nearly circular, that if drawn a few
inches wide, would hardly be detected to differ from the circle. The
orbit of the earth is about one thirtieth part longer than broad.
[Illustration: FIG. 2.]
[Illustration: FIG. 3.]
[Illustration: FIG. 4.]
The rate at which the planets revolve round the sun is not equable,
that is, their progress is not through equal distances at equal times,
but a line drawn from the planet to the sun would always pass over
equal spaces or "areas" in equal times, for example, in fig. 5, if the
area of the angle included in A B C be equal to that included in A D E,
then a planet would pass from B to C and from D to E in equal times.
Mercury is the smallest of the greater planets, and the nearest to the
sun. Its diameter is about 3000 miles, and it is about one-fifteenth
part the volume of the earth; its distance from the sun is 36,770,000
miles, and it performs its revolution in eighty-eight days.
[Illustration: FIG. 5.]
This planet is but seldom seen with the naked eye; for, being so
(comparatively) near to the sun, it sets before dark, and does not rise
till the grey of morning makes it scarcely visible. Nothing notable has
been discovered on its surface.
Venus is the second in rotation from the sun, and revolves round it,
at a distance of 68,750,000 miles, in 224-1/2 days. The diameter of
Venus is about 7760 miles, it is therefore nearly the volume of the
earth. This is the brightest planet seen in the heavens, for although
much smaller than many others, its comparative nearness to the sun
and earth causes it to appear larger and brighter to the eye. Venus
is the evening and morning star; for when to the west of the sun, it
rises before it, and is then called "the morning star" (or, formerly,
"Lucifer"), but when it is to the east of the sun, it sets after
twilight is gone, and is called "the evening star," or "Hesperus."
These two planets, Mercury and Venus, have "phases" (like the moon),
or certain positions in which the whole of the side illuminated by the
sun is seen from the earth, and other positions in which it is seen
sideways; the planet is then said to be in "quadrature," as may be seen
at Q Q, fig. 6. Mercury and Venus, being between the sun and the earth,
are called "inferior" planets, while those whose orbits are outside
that of the earth are called "superior" planets. When either of the
inferior planets are between the earth and the sun, they are said to
be in "inferior conjunction" (I C, fig. 6), and when on the
opposite side, or behind the sun, so that a straight line from it to
the earth would have to pass through the sun, then it is called being
in "superior conjunction" (S C); at mid-distance, either east
or west, it is said to be in "eastern" or "western quadrature."
[Illustration: FIG. 6. PLANETS SEEN IN QUADRATURE.]
The third planet from the sun is the Earth, distant about 95,000,000
miles, with a diameter of 7925 miles, so that the most lofty mountains
(five miles high) bear about the same proportion to it as would an
elevation one-fourteenth of an inch in height to a ball of ten feet in
diameter; therefore, with all its valleys and high hills, the surface
of the earth is smoother in proportion to its bulk than the rind of an
orange. The earth is not a perfect sphere, but has a slightly flattened
form, as though it had been compressed at the poles. The diameter at
the poles is the smallest, and is 7899 miles, while that at the equator
(its greatest) is 7925 miles, being a difference of twenty-six miles;
but this is so small, when compared with the size of the earth, that
if an exact model of it were made, four inches in diameter, it would
require the most accurate measurement to determine that it was not a
perfect sphere.
[Illustration: FIG. 7.]
The form of the earth has been demonstrated by accurate experiments and
calculations, but there are many things we may observe, convincing us
of its rotundity; one of the most evident of these is the fact that as
a ship at sea goes from the land, the hull first disappears, then the
lower sails, and lastly the tops, while a ship approaching the shore
shows first the topsails, and lastly the hull; see fig. 7, where A
shows a ship on the horizon, B hull-down, C out of sight. In the same
way, the tops of distant mountains are seen at sea long before the
lower lands. Another proof is drawn from the fact, that ships have been
sailed quite round the earth; by steering as nearly as possible in one
direction, they have arrived at the place from which they started.
A third proof of the earth's rotundity is found in the form of its
shadow, when the moon is eclipsed by it; this shadow, as thrown by the
earth upon the moon, is circular, in whatever position the earth may
be, and a sphere is the only solid form which can in all positions cast
a circular shadow.
The earth turns upon its axis every 23 hours, 56 minutes, and 4
seconds, which constitutes a day, and makes one revolution round the
sun in every 365-1/4 days, which make up a year; but the earth's axis
is not at a right angle to an imaginary line drawn from the earth to
the sun, but at an angle of 23 deg. 28 min. to it, as shown at fig. 8,
where the line from N to S is the earth's axis of rotation, the dotted
line leading to S is the sun's direction, and E Q is the equator.
[Illustration: FIG. 8.]
The earth travels through space at a rate of more than a
million-and-a-half miles per day, besides the distance which each
object upon it is carried in its diurnal rotation (24,000 miles). At
first thought it would seem impossible that such a rapid motion should
not be felt; but as the air and clouds, and every object belonging to
the earth, moves with it, and this motion is perfectly smooth, it can
only be perceived by looking at objects independent of the earth. If
sailing on the water, when it is quite smooth and the land not very
near, the ship seems to be stationary and the objects on shore appear
to pass along in an opposite direction to that in which the ship is
going. It is the same with the earth; the sun, which appears to move,
is stationary, while the earth is going round it; and the result is,
while the earth turns round on its axis the whole firmament appears
to move, we lose sight of those stars which are to the westward,
which are then said to "set," while those to the eastward, constantly
coming into sight, are said to "rise," the whole appearing to pass
from east to west, while in reality the earth's surface is passing
from west to east. At the equator, or that part of the earth which
lies midway between the poles, the sun and stars appear to rise and
set perpendicularly to the horizon and at equal times above and below
it, it is therefore 12 hours day and 12 hours night; in places not
situated on the equator, they do not rise and set perpendicularly to
the horizon, but form portions of circles at greater or less altitudes
in the heavens, and the nearer the observer is to either of the poles,
the smaller the circle, and the more of it is seen; so that, at the
poles, any star situated exactly overhead does not appear to move
at all. This place is called the north pole of the heavens, and the
nearest star to it is called the "polestar," which neither rises nor
sets, and, as it always keeps the same position, serves as a guide to
mariners. All this is the effect of the diurnal motion of the earth,
its annual motion not affecting the position of the stars, they being
at such an immense distance that the circle which the earth forms in
passing round the sun--although nearly 200,000,000 miles across--is as
a mere point in proportion. But not so with the sun: as before stated,
at the equator it is twelve hours above the horizon and the same time
below it; now, as we approach towards the poles, it forms at each
rotation an arc above the horizon, lower and lower, until at the poles
its daily rising and setting is lost altogether, and there would never
be daylight there, provided that the earth was only subject to the
diurnal motion (fig. 9); but as the earth turns upon an oblique axis,
the north and south poles share the blessing of daylight between them,
so that through one-half of the earth's orbit the north pole is towards
the sun, as shown in the figure, and the south pole during the other
half. There is therefore at the poles but one day and one night in
the year--the day being summer and the night winter. In less northern
climates, as England, this exists to a much smaller extent; for half
the year the sun is longer above than below the horizon, constituting
our summer, the other half of the year the sun is longer below the
horizon than above it, and this is winter. Hence, in each case, midway
between, the sun is twelve hours above and twelve below the horizon,
which occurs in spring and autumn, being called the "equinoxes" (equal
nights); the vernal or spring equinox takes place on the 21st of March,
the autumnal on the 21st of September. The times just between these,
when the sun is the longest and shortest time below the horizon, are
called the summer and winter solstices, and occur on the 21st of
December and the 21st of June.
[Illustration: FIG. 9.]
The earth has a smaller sphere or "satellite," circulating round
it, this is the Moon; it is placed at a distance of about 238,000
miles from the earth, is about one-fiftieth of its bulk or volume,
and revolves round it every 27-1/2 days, keeping always the same
side towards it, so that the other side has never been seen. This is
effected by rotation on its axis, which takes place once for every
circuit round the earth; if it did not rotate, or kept the same side
always to the same point of the heavens, then, when it had half-way
revolved, the other side would be turned towards the earth. There are
good reasons for believing that the moon has no atmosphere or air
around it, for the concave edge (when only a small portion of the half
illuminated by the sun is seen) instead of being gradually shaded off
into darkness, as would be the case if there were an atmosphere, is
well defined and uneven, showing the tops of some of the mountains and
their shadows (fig. 10). Nor does there appear to be any clouds, and as
a consequence no water; neither has anything been observed by the aid
of the best telescopes which could be considered sea, on the contrary,
the whole surface seems torn up and rent into chasms and immense
jagged mountains, enclosing circular portions like gigantic walls.
The darkened parts which are always seen on the surface of the moon
were formerly supposed to be seas, but of late, by the use of improved
instruments, they have been seen to be rough like the other parts, and
cannot therefore be water (fig. 11). As there appears to be no water,
it may be confidently inferred that there are no inhabitants.
[Illustration: FIG. 10.]
The moon having always one half illuminated by the sun, while the other
half is dark, presents different "phases" to us on the earth, according
to the position in which we view it; thus, in fig. 12, E represents the
central position of the earth, and S the direction from which the light
of the sun comes, the outer circle of moons represents the various real
positions of that luminary with respect to the earth and sun, and the
inner circle shows its appearance when in these various positions. When
the moon is between the earth and sun, as at _a_, it is said to be in
"conjunction," and as the darkened side is towards the earth, of course
it is not visible, this is "new moon" (a corruption of "no moon"); when
at _b b_, but a small part of the illuminated half is seen, and it is
then said to be "crescentic" (first and last quarter); at _c c_, half
of the bright side is seen, the moon is said to be at "quadrature," and
the appearance is that of a "half-moon;" at _d d_, the greater part of
the bright side is seen, and it is called "gibbous" and appears as a
"three-quarter-moon," and at _e_ the whole of the illuminated side is
seen; it is then "full-moon," and is said to be in "opposition."
[Illustration: FIG. 12.]
Beyond the earth the planet Mars (fig. 13) moves in its orbit round
the sun; it is the smallest, but one, of the larger planets, having
a diameter of but 4085 miles, and being only about one-seventh the
magnitude of the earth; it makes its revolution in 687 days, at a
distance of 144,780,000 miles from the sun.
[Illustration: FIG. 13.]
Owing to the brilliancy and proximity to the sun of Venus and Mercury,
together with other causes, no rotation has been observed in them, but
as this exists in all the other planets there is no doubt they also
rotate, but the nearness of Mars to the earth when in opposition (that
is, when the earth is between it and the sun), has caused its rotation
to be distinctly visible; the observation of this has been from time
to time greatly favoured by certain dark spots which have remained
stationary a sufficient time to determine the question very accurately.
Mars takes 24 hours and 37 minutes to turn on its axis, or pretty
nearly the time the earth does. Its resemblance is still more increased
by the axis of rotation being oblique, from all which it is inferred
that there is a day and night, winter and summer, and variation of
climate very nearly resembling that of our own world, and there are
round bright parts situated at the poles of Mars, which enlarge when it
is winter there and diminish when summer, just as would the snows of
arctic regions, and these are therefore supposed to be portions of the
surface of Mars which are actually covered with snow (fig. 13). As to
the question of the planets being inhabited, of course it can never be
answered with certainty, but it is a great deal more likely that they
are than that the moon is, which, having neither water nor atmosphere,
can hardly be supposed to give habitation to any beings similar or
analogous to those on earth, while Mars possesses a climate not greatly
differing from that of the earth, and has both air and water. Mars
has, at certain positions of the earth with respect to it, a partially
"gibbous" form, that is, a small portion of the non-illuminated part
comes within the lines of our vision it is then of the form seen in
(fig. 14), but this can only occur when the earth and planet occupy
positions somewhat near to that represented in fig. 15, in which S is
the sun, E E opposite positions of the earth, and M Mars.
[Illustration: FIG. 14.]
[Illustration: FIG. 15.]
[Illustration: FIG. 16.]
[Illustration: FIG. 17.]
Jupiter is by far the largest of the planets, it is 87,030 miles
in diameter, and placed at the enormous distance of 494,000,000
miles from the sun. This great planet takes 12 years and 52 days to
perform its circuit; it turns upon its axis in 9 hours 55 minutes, a
surprisingly short time considering the immensity of its bulk. As a
result of this rapid motion Jupiter is very far removed from the form
of a true sphere, for the oblate form of heavenly bodies is caused
by their rotatory motion, and the centrifugal force set up by it. In
fig. 16 is an outline of the earth and Jupiter, showing their relative
size. It has no phases, like those planets which are nearer to the
sun than the earth, its great distance preventing this, as may be
seen in fig. 17, in which the earth (E E) is placed at the
two widest lateral positions of its orbit, but the earth is too near
the sun, in proportion to the great distance of Jupiter, to allow
any part of the latter to come within the range of vision, except
that which is illuminated by the sun. This planet is high up in the
heavens the greater number of nights in the year, and is therefore a
very conspicuous object. It also presents a most beautiful appearance
through a good telescope, its vast size causing it to look larger
than those which are much nearer; it has several shadowy belts across
it, which are supposed to be openings in the strata of clouds which
surround it, drawn into ring-like forms by the rotation of the planet,
these are shown in fig. 18. It being probable that this great planet
is surrounded by strata of the densest clouds which only open in the
tropical region, its inhabitants therefore, (if there be any) get
but a glimpse of the firmanent and its stars through them, in those
situations at or near to the planet's equator. These dense clouds serve
a very useful purpose in regions so very far removed from the source of
heat, for if radiation were permitted to go on freely from the surface
of the planet the sun's rays would be too feeble to compensate for it,
and the cold would be intense; but the clouds reflect back the heat
radiated from the surface and keep in what little heat is received
at that great distance. Jupiter has four satellites or moons, which
revolve round it as our moon does round this earth.
[Illustration: FIG. 18.]
[Illustration: FIG. 19.]
Far beyond Jupiter rolls another stupendous orb called Saturn, not so
large as Jupiter, but still immense, being 847 times the bulk of the
earth. It is placed at the distance of 906 millions of miles from the
sun. An idea of this may be formed from the fact that light, which
travels at the rate of nearly 200,000 miles a second or 12,000,000
a minute, takes about an hour and a quarter to pass from the sun to
Saturn. It performs its journey round the sun only in 29-1/2 years,
which are therefore but as one year, yet all this time it is moving at
the rate of nearly 22,000 miles an hour, so immense is the orbit it
has to traverse, but it revolves on its axis in about 10-1/2 hours,
so that the nights and days are extremely short while the years are
prodigiously long. There is every reason to believe that it has
changes of seasons and variation of climate similar to those in our
world, but, being so far from the sun, they must be altogether more
severe than ours. The most extraordinary part of this great globe is
its possession of three (perhaps more) great flattened rings, which
surround it, one within the other; these rings are of immense size and
width, but very thin, the great breadth through all from the inner to
the outer edges being about 30,000 miles, while their thickness cannot
exceed 250. These rings are placed at a right angle to the planet's
axis of rotation and revolve with it, so that when the planet is at
the equinox, the edge of these rings is turned towards the sun, they
can then be seen only by the most powerful telescopes, forming a faint
streak on each side of the orb of the planet (fig. 19), but as they
become inclined they appear as a very long ellipse, the ends of which
project in loop-like forms on either side, giving rise to the notion of
the planet having two handles (fig. 20). This ellipse becomes broader
and broader as the plane of the rings forms a greater angle with the
line of vision. For a short time before and after the equinoxes of
Saturn, the rings become invisible, owing to the earth and sun being on
opposite sides of them, as may be seen in fig. 21, so that the darkened
side is turned towards the earth and the edge, which is the only part
illuminated, is towards the sun.
[Illustration: FIG. 20.]
[Illustration: FIG. 21.]
The inner ring of Saturn is supposed to be composed of watery vapour,
as it is somewhat transparent, but the outer ones are solid, which
is shown by the shadow they cast upon the planet, and the shadow it
casts upon them in different positions (figs. 22 and 23). Besides
these rings Saturn has eight satellites or moons, which revolve in a
plane nearly parallel to that of the rings and exterior to them. It
has been calculated that Saturn weighs only 100 times more than the
earth, although it is somewhere about 900 times larger, from which it
is concluded that the substance of which Saturn is made must be about
one-ninth the density of this earth, half the density of water, or
about the same as cork. Saturn is very much flattened at the poles, so
much so that the equatorial diameter is a tenth more than the axial
diameter, which difference is distinctly visible through good glasses.
Still further into space, at double the distance of Saturn, or nearly
1822 millions of miles from the sun, another great world or planet
revolves round it, it is called Uranus. This planet is not so large
as either Jupiter or Saturn, but is of considerable magnitude, being
eighty times that of this world, it takes eighty-four of our years to
complete its vast circle round the sun, which are therefore equivalent
to but one year of Uranus.
[Illustration: FIG. 22.]
[Illustration: FIG. 23.]
It has several satellites, four of which have been discerned perfectly,
but it is doubtful whether there have not been two more seen. This orb
was first recognised as a planet by Sir Wm. Herschell, after whom it
was for some time named.
Another, and the most remote planet in our system, is Neptune,
revolving at the immense distance of 2850 millions of miles from the
sun, and taking more than 164 years to perform the journey. This
planet is only to be seen by the most powerful glasses, and was
discovered under very peculiar circumstances, not (like other planets)
by chance; its existence was recognised as necessary to account for
certain "perturbations" or deviations in the orbit of Uranus, which
was found to take a course differing from what it should, according to
computation, and which were only to be accounted for by supposing that
another planet existed far out in space, which affected the course of
Uranus by its attraction. The idea of finding out where this orb should
be, occurred to M. Le Verrier and Mr. Adams, independent of each other;
they both arrived at nearly similar conclusions, for the positions
assigned to the supposed planet so nearly agreed with each other and
with its real position, that their calculations have been looked on as
the greatest feat of astronomical research. It was discovered by Dr.
Galle of Berlin, upon his hearing from Le Verrier the position in which
at that time it should be sought for.
THE PLANETOIDS.
Upon observing the relative distances of the planets from each other in
passing outwards from Mercury, it will be found that each one is placed
about double the distance of the one next before it (not exactly, but
sufficiently near to form a coincidence almost amounting to a law),
they are as follows:--
Mercury 36,700,000
Venus 68,770,000
The Earth 95,000,000
Mars 144,780,000
Jupiter 494,000,000
Saturn 906,000,000
Uranus 1822,000,000
Neptune 2850,000,000
It will be seen, however, that in this table of distances there is
one great exception to the rule, namely the distance between Mars and
Jupiter, which is nearly double what it should be according to this
rule, giving rise to the idea that a planet ought to be placed between
them. Professor Bode was so convinced that something of the kind was
necessary to complete the harmony of the series, that he caused to
be instituted a search for the supposed planet, and according to his
conjecture one was discovered as nearly as possible in the situation
indicated, but upon more accurate information being obtained, this
planet was found to be so small (scarcely 150 miles diameter) that it
could hardly be considered as a planet ranging with the others, and
having so large a space of the heavens to itself; shortly afterwards
another small planet was discovered, having nearly the same orbit. From
time to time others have been discovered, to the number of forty-two,
up to the present date. Dr. Olbers upon discovering the second of
these small bodies, where one great one was anticipated, put forth the
curious hypothesis, that one large planet had really existed there
at some former time, that it had been shattered into pieces by some
accident, such as an internal explosion, and that more of these pieces
would be found; it is curious how accurately this prediction has been
verified.
If we suppose the original planet to have been liquid when shattered
to pieces, it would fully account for the fragments being spherical,
just as globules of mercury assume this form from their own attraction
of gravitation, and that the planets, our own earth amongst them,
are liquid, is very nearly proved by their forms, which are exactly
such as fluid masses rotating on an axis would assume, moreover the
specific gravity of some of the planets is but little more than that of
water, and with respect to our earth, the evidence of internal heat,
increasing as we descend below the surface, &c., show almost beyond
doubt that at the present time it is in a liquid state (molten) covered
over by a few miles' thickness of hardened crust, which bears such
a small proportion to the bulk of the globe, that the whole may be
considered as liquid.
THE STELLAR SYSTEM.
The thousands of stars which spangle the heavens are all part of one
"system;" but it has been found by the aid of the telescope that this
system is but one out of many. Our system of stars occupies a space
somewhat in the form of a thick lens or much-flattened sphere, but
others are of very different forms, and some have but little regularity
of form at all; our sun is one of the stars of this system. It is not
known whether there are planets revolving round the other stars, the
distance being far too great for any telescope to render them visible.
Our sun occupies a somewhat central position in the system. The stars
are classed into sizes, as first magnitude, second magnitude, &c., on
to the thirteenth or fourteenth magnitude, but all beyond the fifth
magnitude (by far the greater number) are only visible by the aid of
the telescope. There are about 5000 stars visible to the naked eye.
But fourteen stars of the first magnitude are in our hemisphere of the
heavens, and about fifty of the second, but the number of stars of each
magnitude increases prodigiously in the higher numbers, so that those
stars capable only of being seen by the aid of powerful telescopes,
amount to many millions; these are chiefly situated in a great belt
which encircles the heavens, called the "Milky Way," which is caused by
the line of vision passing through the breadth of our starry system,
and consequently meeting with a greater number of stars than in other
directions, where it only crosses its thickness.
The other systems of stars, called "nebulæ," from their resemblance
to little clouds, were supposed to consist of luminous matter of but
little density, and which might at some future period be condensed
into stars; but the improved power and construction of telescopes have
enabled astronomers to resolve many of these nebulæ into clusters of
stars, and there is but little doubt that all could be thus resolved,
were the telescope of sufficient power; and thus it appears that in
the infinity of space collections of systems are placed, each one too
distant from the others to be calculated or written in numbers, but
each consisting of thousands of suns many hundred times greater than
this earth, and many millions of miles from each other. What an idea
of space does this afford, and how soon do all our narrow notions of
possibility and impossibility vanish before such facts accomplished by
the hands of God!
[Illustration: FIG. 24.]
[Illustration: FIG. 25.]