Chapter 1

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THE OUTLINE OF SCIENCE

A PLAIN STORY SIMPLY TOLD

EDITED BY J. ARTHUR THOMSON REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF ABERDEEN

WITH OVER 800 ILLUSTRATIONS OF WHICH ABOUT 40 ARE IN COLOUR

IN FOUR VOLUMES

G. P. PUTNAM'S SONS NEW YORK AND LONDON The Knickerbocker press

Copyright, 1922 by G. P. Putnam's Sons

_First Printing April, 1922 Second Printing April, 1922 Third Printing April, 1922 Fourth Printing April, 1922 Fifth Printing June, 1922 Sixth Printing June, 1922 Seventh Printing June, 1922 Eighth Printing June, 1922 Ninth Printing August, 1922 Tenth Printing September, 1922 Eleventh Printing Sept., 1922 Twelfth Printing, May, 1924_

Made in the United States of America

INTRODUCTORY NOTE

By Professor J. Arthur Thomson

Was it not the great philosopher and mathematician Leibnitz who said that the more knowledge advances the more it becomes possible to condense it into little books? Now this "Outline of Science" is certainly not a little book, and yet it illustrates part of the meaning of Leibnitz's wise saying. For here within reasonable compass there is a library of little books--an outline of many sciences.

It will be profitable to the student in proportion to the discrimination with which it is used. For it is not in the least meant to be of the nature of an Encyclopædia, giving condensed and comprehensive articles with a big full stop at the end of each. Nor is it a collection of "primers," beginning at the very beginning of each subject and working methodically onwards. That is not the idea.

What then is the aim of this book? It is to give the intelligent student-citizen, otherwise called "the man in the street," a bunch of intellectual keys by which to open doors which have been hitherto shut to him, partly because he got no glimpse of the treasures behind the doors, and partly because the portals were made forbidding by an unnecessary display of technicalities. Laying aside conventional modes of treatment and seeking rather to open up the subject as one might on a walk with a friend, the work offers the student what might be called informal introductions to the various departments of knowledge. To put it in another way, the articles are meant to be clues which the reader may follow till he has left his starting point very far behind. Perhaps when he has gone far on his own he will not be ungrateful to the simple book of "instructions to travellers" which this "Outline of Science" is intended to be. The simple "bibliographies" appended to the various articles will be enough to indicate "first books." Each article is meant to be an invitation to an intellectual adventure, and the short lists of books are merely finger-posts for the beginning of the journey.

We confess to being greatly encouraged by the reception that has been given to the English serial issue of "The Outline of Science." It has been very hearty--we might almost say enthusiastic. For we agree with Professor John Dewey, that "the future of our civilisation depends upon the widening spread and deepening hold of the scientific habit of mind." And we hope that this is what "The Outline of Science" makes for. Information is all to the good; interesting information is better still; but best of all is the education of the scientific habit of mind. Another modern philosopher, Professor L. T. Hobhouse, has declared that the evolutionist's mundane goal is "the mastery by the human mind of the conditions, internal as well as external, of its life and growth." Under the influence of this conviction "The Outline of Science" has been written. For life is not for science, but science for life. And even more than science, to our way of thinking, is the individual development of the scientific way of looking at things. Science is our legacy; we must use it if it is to be our very own.

CONTENTS

INTRODUCTION 3

I. THE ROMANCE OF THE HEAVENS 7

The scale of the universe--The solar system--Regions of the sun--The surface of the sun--Measuring the speed of light--Is the sun dying?--The planets--Venus--Is there life on Mars?--Jupiter and Saturn--The moon--The mountains of the moon--Meteors and comets--Millions of meteorites--A great comet--The stellar universe--The evolution of stars--The age of stars--The nebular theory--Spiral nebulæ--The birth and death of stars--The shape of our universe--Astronomical instruments.

II. THE STORY OF EVOLUTION 53

The beginning of the earth--Making a home for life--The first living creatures--The first plants--The first animals--Beginnings of bodies--Evolution of sex--Beginning of natural death--Procession of life through the ages--Evolution of land animals--The flying dragons--The first known bird--Evidences of evolution--Factors in evolution.

III. ADAPTATIONS TO ENVIRONMENT 113

The shore of the sea--The open sea--The deep sea--The fresh waters--The dry land--The air.

IV. THE STRUGGLE FOR EXISTENCE 135

Animal and bird mimicry and disguise--Other kinds of elusiveness.

V. THE ASCENT OF MAN 153

Anatomical proof of man's relationship with a Simian stock--Physiological proof--Embryological proof--Man's pedigree--Man's arboreal apprenticeship--Tentative men--Primitive men--Races of mankind--Steps in human evolution--Factors in human progress.

VI. EVOLUTION GOING ON 183

Evolutionary prospect for man--The fountain of change; variability--Evolution of plants--Romance of wheat--Changes in animal life--Story of the salmon--Forming new habits--Experiments in locomotion; new devices.

VII. THE DAWN OF MIND 205

A caution in regard to instinct--A useful law--Senses of fishes--The mind of a minnow--The mind and senses of amphibians--The reptilian mind--Mind in birds--Intelligence co-operating with instinct--The mind of the mammal--Instinctive aptitudes--Power of association--Why is there not more intelligence?--The mind of monkeys--Activity for activity's sake--Imitation--The mind of man--Body and mind.

VIII. FOUNDATIONS OF THE UNIVERSE 243

The world of atoms--The energy of atoms--The discovery of X-rays--The discovery of radium--The discovery of the electron--The electron theory--The structure of the atom--The new view of matter--Other new views--The nature of electricity--Electric current--The dynamo--Magnetism--Ether and waves--Light--What the blue "sky" means--Light without heat--Forms of energy--What heat is--Substitutes for coal--Dissipation of energy--What a uniform temperature would mean--Matter, ether, and Einstein--The tides--Origin of the moon--The earth slowing down--The day becoming longer.

ILLUSTRATIONS

FACING PAGE

THE GREAT SCARLET SOLAR PROMINENCES, WHICH ARE SUCH A NOTABLE FEATURE OF THE SOLAR PHENOMENA, ARE IMMENSE OUTBURSTS OF FLAMING HYDROGEN RISING SOMETIMES TO A HEIGHT OF 500,000 MILES _Coloured Frontispiece_

LAPLACE 10

PROFESSOR J. C. ADAMS 10 Photo: Royal Astronomical Society.

PROFESSOR EDDINGTON OF CAMBRIDGE UNIVERSITY 10 Photo: Elliot & Fry, Ltd.

THE PLANETS, SHOWING THEIR RELATIVE DISTANCES AND DIMENSIONS 11

THE MILKY WAY 14 Photo: Harvard College Observatory.

THE MOON ENTERING THE SHADOW CAST BY THE EARTH 14

THE GREAT NEBULA IN ANDROMEDA, MESSIER 31 15 From a photograph taken at the Yerkes Observatory.

DIAGRAM SHOWING THE MAIN LAYERS OF THE SUN 18

SOLAR PROMINENCES SEEN AT TOTAL SOLAR ECLIPSE, MAY 29, 1919. TAKEN AT SOBRAL, BRAZIL 18 Photo: Royal Observatory, Greenwich.

THE VISIBLE SURFACE OF THE SUN 19 Photo: Mount Wilson Observatory.

THE SUN PHOTOGRAPHED IN THE LIGHT OF GLOWING HYDROGEN 19 Photo: Mount Wilson Observatory.

THE AURORA BOREALIS (_Coloured Illustration_) 20 Reproduced from _The Forces of Nature_ (Messrs. Macmillan)

THE GREAT SUN-SPOT OF JULY 17, 1905 22 Yerkes Observatory.

SOLAR PROMINENCES 22 From photographs taken at the Yerkes Observatory.

MARS, OCTOBER 5, 1909 23 Photo: Mount Wilson Observatory.

JUPITER 23

SATURN, NOVEMBER 19, 1911 23 Photo: Professor E. E. Barnard, Yerkes Observatory.

THE SPECTROSCOPE, AN INSTRUMENT FOR ANALYSING LIGHT; IT PROVIDES MEANS FOR IDENTIFYING SUBSTANCES (_Coloured Illustration_) 24

THE MOON 28

MARS 29 Drawings by Professor Percival Lowell.

THE MOON, AT NINE AND THREE QUARTER DAYS 29

A MAP OF THE CHIEF PLAINS AND CRATERS OF THE MOON 32

A DIAGRAM OF A STREAM OF METEORS SHOWING THE EARTH PASSING THROUGH THEM 32

COMET, SEPTEMBER 29, 1908 33 Photo: Royal Observatory, Greenwich.

COMET, OCTOBER 3, 1908 33 Photo: Royal Observatory, Greenwich.

TYPICAL SPECTRA 36 Photo: Harvard College Observatory.

A NEBULAR REGION SOUTH OF ZETA ORIONIS 37 Photo: Mount Wilson Observatory.

STAR CLUSTER IN HERCULES 37 Photo: Astrophysical Observatory, Victoria, British Columbia.

THE GREAT NEBULA IN ORION 40 Photo: Yerkes Observatory.

GIANT SPIRAL NEBULA, MARCH 23, 1914 41 Photo: Lick Observatory.

A SPIRAL NEBULA SEEN EDGE-ON 44 Photo: Mount Wilson Observatory.

100-INCH TELESCOPE, MOUNT WILSON 45 Photo: H. J. Shepstone.

THE YERKES 40-INCH REFRACTOR 48

THE DOUBLE-SLIDE PLATE-HOLDER ON YERKES 40-INCH REFRACTING TELESCOPE 49 Photo: H. J. Shepstone.

MODERN DIRECT-READING SPECTROSCOPE 49 By A. Hilger, Ltd.

CHARLES DARWIN 56 Photo: Rischgitz Collection.

LORD KELVIN 56 Photo: Rischgitz Collection.

A GIANT SPIRAL NEBULA 57 Photo: Lick Observatory.

METEORITE WHICH FELL NEAR SCARBOROUGH AND IS NOW TO BE SEEN IN THE NATURAL HISTORY MUSEUM 57 Photo: Natural History Museum.

A LIMESTONE CANYON 60 Reproduced from the Smithsonian Report, 1915.

GEOLOGICAL TREE OF ANIMALS 61

DIAGRAM OF AMOEBA 61

A PIECE OF A REEF-BUILDING CORAL, BUILT UP BY A LARGE COLONY OF SMALL SEA-ANEMONE-LIKE POLYPS, EACH OF WHICH FORMS FROM THE SALTS OF THE SEA A SKELETON OR SHELL OF LIME 64 From the Smithsonian Report, 1917.

A GROUP OF CHALK-FORMING ANIMALS, OR FORAMINIFERA, EACH ABOUT THE SIZE OF A VERY SMALL PIN'S HEAD 65 Photo: J. J. Ward, F.E.S.

A COMMON FORAMINIFER (POLYSTOMELLA) SHOWING THE SHELL IN THE CENTRE AND THE OUTFLOWING NETWORK OF LIVING MATTER, ALONG WHICH GRANULES ARE CONTINUALLY TRAVELLING, AND BY WHICH FOOD PARTICLES ARE ENTANGLED AND DRAWN IN 65 Reproduced by permission of the Natural History Museum (after Max Schultze).

A PLANT-LIKE ANIMAL, OR ZOOPHYTE, CALLED OBELIA 68 Photo: J. J. Ward, F.E.S.

TRYPANOSOMA GAMBIENSE 69 Reproduced by permission of _The Quart. Journ. Mic. Sci._

VOLVOX 69

PROTEROSPONGIA 69

GREEN HYDRA 72 Photo: J. J. Ward, F.E.S.

DIAGRAM ILLUSTRATING THE BEGINNING OF INDIVIDUAL LIFE 72

EARTHWORM 72 Photo: J. J. Ward, F.E.S.

GLASS MODEL OF A SEA-ANEMONE 72 Reproduced from the Smithsonian Report, 1917.

THIS DRAWING SHOWS THE EVOLUTION OF THE BRAIN FROM FISH TO MAN 73

OKAPI AND GIRAFFE (_Coloured Illustration_) 74

DIAGRAM OF A SIMPLE REFLEX ARC IN A BACKBONELESS ANIMAL LIKE AN EARTHWORM 76

THE YUCCA MOTH 76 Photo: British Museum (Natural History).

INCLINED PLANE OF ANIMAL BEHAVIOUR 76

VENUS' FLY-TRAP 77 Photo: J. J. Ward, F.E.S.

A SPIDER SUNNING HER EGGS 77 Reproduced by permission from _The Wonders of Instinct_ by J. H. Fabre.

THE HOATZIN INHABITS BRITISH GUIANA 82

PERIPATUS 83 Photograph, from the British Museum (Natural History), of a drawing by Mr. E. Wilson.

ROCK KANGAROO CARRYING ITS YOUNG IN A POUCH 83 Photo: W. S. Berridge, F.Z.S.

PROFESSOR THOMAS HENRY HUXLEY (1825-95) 86 Photo: Rischgitz.

BARON CUVIER, 1769-1832 86

AN ILLUSTRATION SHOWING VARIOUS METHODS OF FLYING AND SWOOPING 87

ANIMALS OF THE CAMBRIAN PERIOD 90 From Knipe's _Nebula to Man_.

A TRILOBITE 90 Photo: J. J. Ward, F.E.S.

THE GAMBIAN MUD-FISH, PROTOPTERUS 91 Photo: British Museum (Natural History).

THE ARCHÆOPTERYX 91 After William Leche of Stockholm.

WING OF A BIRD, SHOWING THE ARRANGEMENT OF THE FEATHERS 91

PICTORIAL REPRESENTATION OF STRATA OF THE EARTH'S CRUST, WITH SUGGESTIONS OF CHARACTERISTIC FOSSILS (_Coloured Illustration_) 92

FOSSIL OF A PTERODACTYL OR EXTINCT FLYING DRAGON 94 Photo: British Museum (Natural History).

PARIASAURUS: AN EXTINCT VEGETARIAN TRIASSIC REPTILE 94 From Knipe's _Nebula to Man_.

TRICERATOPS: A HUGE EXTINCT REPTILE 95 From Knipe's _Nebula to Man_.

THE DUCKMOLE OR DUCK-BILLED PLATYPUS OF AUSTRALIA 95 Photo: _Daily Mail_.

SKELETON OF AN EXTINCT FLIGHTLESS TOOTHED BIRD, HESPERORNIS 100 After Marsh.

SIX STAGES IN THE EVOLUTION OF THE HORSE, SHOWING GRADUAL INCREASE IN SIZE 101 After Lull and Matthew.

DIAGRAM SHOWING SEVEN STAGES IN THE EVOLUTION OF THE FORE-LIMBS AND HIND-LIMBS OF THE ANCESTORS OF THE MODERN HORSE, BEGINNING WITH THE EARLIEST KNOWN PREDECESSORS OF THE HORSE AND CULMINATING WITH THE HORSE OF TO-DAY 104 After Marsh and Lull.

WHAT IS MEANT BY HOMOLOGY? ESSENTIAL SIMILARITY OF ARCHITECTURE, THOUGH THE APPEARANCES MAY BE VERY DIFFERENT 105

AN EIGHT-ARMED CUTTLEFISH OR OCTOPUS ATTACKING A SMALL CRAB 116

A COMMON STARFISH, WHICH HAS LOST THREE ARMS AND IS REGROWING THEM 116 After Professor W. C. McIntosh.

THE PAPER NAUTILUS (ARGONAUTA), AN ANIMAL OF THE OPEN SEA 117 Photo: J. J. Ward, F.E.S.

A PHOTOGRAPH SHOWING A STARFISH (_Asterias Forreri_) WHICH HAS CAPTURED A LARGE FISH 117

TEN-ARMED CUTTLEFISH OR SQUID IN THE ACT OF CAPTURING A FISH 118

GREENLAND WHALE 118

MINUTE TRANSPARENT EARLY STAGE OF A SEA-CUCUMBER 119

AN INTRICATE COLONY OF OPEN-SEA ANIMALS (_Physophora Hydrostatica_) RELATED TO THE PORTUGUESE MAN-OF-WAR 119 Photo: British Museum (Natural History).

A SCENE IN THE GREAT DEPTHS 119

SEA-HORSE IN SARGASSO WEED 120

LARGE MARINE LAMPREYS (_Petromyzon Marinus_) 120

THE DEEP-SEA FISH _Chiasmodon Niger_ 120

DEEP-SEA FISHES 120

FLINTY SKELETON OF VENUS' FLOWER BASKET (_Euplectella_), A JAPANESE DEEP-SEA SPONGE 121

EGG DEPOSITORY OF _Semotilus Atromaculatus_ 121

THE BITTERLING (_Rhodeus Amarus_) 124

WOOLLY OPOSSUM CARRYING HER FAMILY 124 Photo: W. S. Berridge.

SURINAM TOAD (_Pipa Americana_) WITH YOUNG ONES HATCHING OUT OF LITTLE POCKETS ON HER BACK 125

STORM PETREL OR MOTHER CAREY'S CHICKEN (_Procellaria Pelagica_) 125

ALBATROSS: A CHARACTERISTIC PELAGIC BIRD OF THE SOUTHERN SEA 128

THE PRAYING MANTIS (_Mantis Religiosa_) 138

PROTECTIVE COLORATION: A WINTER SCENE IN NORTH SCANDINAVIA 138

THE VARIABLE MONITOR (_Varanus_) 139 Photo: A. A. White.

BANDED KRAIT: A VERY POISONOUS SNAKE WITH ALTERNATING YELLOW AND DARK BANDS 140 Photo: W. S. Berridge, F.Z.S.

THE WARTY CHAMELEON 140 Photos: W. S. Berridge, F.Z.S.

SEASONAL COLOUR-CHANGE: SUMMER SCENE IN NORTH SCANDINAVIA 141

PROTECTIVE RESEMBLANCE 142 Photo: J. J. Ward, F.E.S.

WHEN ONLY A FEW DAYS OLD, YOUNG BITTERN BEGIN TO STRIKE THE SAME ATTITUDE AS THEIR PARENTS, THRUSTING THEIR BILLS UPWARDS AND DRAWING THEIR BODIES UP SO THAT THEY RESEMBLE A BUNCH OF REEDS 143

PROTECTIVE COLORATION OR CAMOUFLAGING, GIVING ANIMALS A GARMENT OF INVISIBILITY (_Coloured Illustration_) 144

ANOTHER EXAMPLE OF PROTECTIVE COLORATION (_Coloured Illustration_) 144

DEAD-LEAF BUTTERFLY (_Kallima Inachis_) FROM INDIA 146

PROTECTIVE RESEMBLANCE BETWEEN A SMALL SPIDER (_to the left_) AND AN ANT (_to the right_) 146

THE WASP BEETLE, WHICH, WHEN MOVING AMONGST THE BRANCHES, GIVES A WASP-LIKE IMPRESSION 147 Photo: J. J. Ward, F.E.S.

HERMIT-CRAB WITH PARTNER SEA-ANEMONES 147

CUCKOO-SPIT 147 Photo: G. P. Duffus.

CHIMPANZEE, SITTING 156 Photo: New York Zoological Park.

CHIMPANZEE, ILLUSTRATING WALKING POWERS 156 Photo: New York Zoological Park.

SURFACE VIEW OF THE BRAINS OF MAN AND CHIMPANZEE 157

SIDE-VIEW OF CHIMPANZEE'S HEAD 157 Photo: New York Zoological Park.

PROFILE VIEW OF HEAD OF PITHECANTHROPUS, THE JAVA APE-MAN, RECONSTRUCTED FROM THE SKULL-CAP 157 After a model by J. H. McGregor.

THE FLIPPER OF A WHALE AND THE HAND OF A MAN 157

THE GORILLA, INHABITING THE FOREST TRACT OF THE GABOON IN AFRICA (_Coloured Illustration_) 158

"DARWIN'S POINT" ON HUMAN EAR 160

PROFESSOR SIR ARTHUR KEITH, M.D., LL.D., F.R.S. 161 Photo: J. Russell & Sons.

SKELETONS OF THE GIBBON, ORANG, CHIMPANZEE, GORILLA, MAN 161 After T. H. Huxley (by permission of Messrs. Macmillan).

SIDE-VIEW OF SKULL OF MAN AND GORILLA 164

THE SKULL AND BRAIN-CASE OF PITHECANTHROPUS, THE JAVA APE-MAN, AS RESTORED BY J. H. MCGREGOR FROM THE SCANTY REMAINS 164

SUGGESTED GENEALOGICAL TREE OF MAN AND ANTHROPOID APES 165

THE GIBBON IS LOWER THAN THE OTHER APES AS REGARDS ITS SKULL AND DENTITION, BUT IT IS HIGHLY SPECIALIZED IN THE ADAPTATION OF ITS LIMBS TO ARBOREAL LIFE 166 Photo: New York Zoological Park.

THE ORANG HAS A HIGH ROUNDED SKULL AND A LONG FACE 166 Photo: New York Zoological Park.

COMPARISONS OF THE SKELETONS OF HORSE AND MAN 167 Photo: British Museum (Natural History).

A RECONSTRUCTION OF THE JAVA MAN (_Coloured Illustration_) 168

PROFILE VIEW OF THE HEAD OF PITHECANTHROPUS, THE JAVA APE-MAN--AN EARLY OFFSHOOT FROM THE MAIN LINE OF MAN'S ASCENT 170 After a model by J. H. McGregor.

PILTDOWN SKULL 170 From the reconstruction by J. H. McGregor.

SAND-PIT AT MAUER, NEAR HEIDELBERG: DISCOVERY SITE OF THE JAW OF HEIDELBERG MAN 171 Reproduced by permission from Osborn's _Men of the Old Stone Age_.

PAINTINGS ON THE ROOF OF THE ALTAMIRA CAVE IN NORTHERN SPAIN, SHOWING A BISON AND A GALLOPING BOAR (_Coloured Illustration_) 172

PILTDOWN MAN, PRECEDING NEANDERTHAL MAN, PERHAPS 100,000 TO 150,000 YEARS AGO 174 After the restoration modelled by J. H. McGregor.

THE NEANDERTHAL MAN OF LA CHAPELLE-AUX-SAINTS 175 After the restoration modelled by J. H. McGregor.

RESTORATION BY A. FORESTIER OF THE RHODESIAN MAN WHOSE SKULL WAS DISCOVERED IN 1921 176-177

SIDE VIEW OF A PREHISTORIC HUMAN SKULL DISCOVERED IN 1921 IN BROKEN HILL CAVE, NORTHERN RHODESIA 178 Photo: British Museum (Natural History).

A CROMAGNON MAN OR CROMAGNARD, REPRESENTATIVE OF A STRONG ARTISTIC RACE LIVING IN THE SOUTH OF FRANCE IN THE UPPER PLEISTOCENE, PERHAPS 25,000 YEARS AGO 178 After the restoration modelled by J. H. McGregor.