TABLE OF CONTENTS
| [I]. | VOLCANIC PHENOMENA AND EARTHQUAKES | 1 |
| Destruction caused by volcanism and by earthquakes.—Differentkinds of volcanoes.—Vesuvius.—Products of eruption.—Volcanicactivity diminishing.—Structure of volcanoes.—Geographicaldistribution of volcanoes.—Temperaturein the interior of the earth.—Significance of waterfor volcanism.—Composition of the earth’s interior.—Geographicaldistribution of earthquakes.—Fissures in theearth’s crust.—Groups of earthquakes.—Waves in the seaand in the air accompanying earthquakes.—Their connectionwith volcanism.—Systems of fissures.—Seismograms. | ||
| [II]. | THE CELESTIAL BODIES, IN PARTICULAR THEEARTH, AS ABODES OF LIVING BEINGS | 39 |
| Manifold character of the worlds.—The earth probably atfirst a ball of gases.—Formation of the earth crust and itsrapid cooling.—Balance between heat received and heatlost by radiation.—Life already existing on the earth fora milliard of years.—The waste of solar heat.—Temperatureand habitability of the planets.—Heat-preserving influenceof the atmosphere.—Significance of carbon dioxide in theatmosphere.—Warm and cold geological ages.—Fluctuationsin the percentage of carbon dioxide of the air.—Combustion,decay, and growth.—Atmospheric oxygen.—Vegetablelife more ancient than animal life.—The atmospheresof planets.—Chances of an improvement in the climate. | ||
| [III]. | RADIATION AND CONSTITUTION OF THE SUN | 64 |
| Stability of the solar system.—Losses and possible gainsof heat by the sun.—Theses of Mayer and of Helmholtz.—Temperaturesof the white, yellow, and reddish stars, andof the sun.—Sun-spots and sun faculæ.—Prominences.—Spectra of the parts of the sun.—Temperature of the sun.—Theinterior of the sun.—Its composition according to themechanical theory of heat.—The losses of heat by the sunprobably covered by the enormous solar energy. | ||
| [IV]. | THE RADIATION PRESSURE | 94 |
| Newton’s law of gravitation.—Kepler’s observation ofcomets’ tails.—The thesis of Euler.—Proof of Maxwell.—Theradiation pressure.—Electric charges and condensation.—Comets’tails and radiation pressure.—Constituentsand properties of comets’ tails.—Weight of the solar corona.—Lossand gain of matter by the sun.—Nature of meteorites.—Electriccharge of the sun.—Electrons drawn into thesun.—Magnetic properties of the sun and appearance of thecorona.—Constituents of the meteors.—Nebulæ and theirheat and light. | ||
| [V]. | THE SOLAR DUST IN THE ATMOSPHERE. POLARLIGHTS AND THE VARIATIONS OF TERRESTRIAL MAGNETISM | 118 |
| The supply of dust from the sun rather insignificant.—Polarizationof the light of the sky.—The upper clouds.—Differentkinds of auroræ.—Their connection with thecorona of the sun.—Polar lights and sun-spots.—Periodicityof polar lights.—Polar lights and magnetic disturbances.—Velocityof solar dust.—Fixation of atmospheric nitrogen.—TheZodiacal Light. | ||
| [VI]. | END OF THE SUN.—ORIGIN OF NEBULÆ | 148 |
| The extinction of the sun.—Collision between two celestialbodies.—The new star in Perseus.—Formation of nebulæ.—Theappearance of nebulæ.—The nebulæ catch wanderingmeteors and comets.—The ring nebula in Lyra.—Variablestars.—Eta in Argus.—Mira Ceti.—Lyra and Algol stars.—Evolutionof the stars. | ||
| [VII]. | THE NEBULAR AND THE SOLAR STATES | 191 |
| The energy of the universe.—The entropy of the universe.—Theentropy increases in the suns, but decreases in thenebulæ.—Temperature and constitution of the nebulæ.—Schuster’scalculations of the condition of a celestial bodyconsisting of gases.—Action of the loss of heat on nebulæand on suns.—Development of a rotating nebula into aplanetary system.—The hypothesis of Kant-Laplace.—Objectionsto it.—The views of Chamberlin and Moulton.—Theradiation pressure balances the effect of Newtoniangravitation.—The emission of gases from the nebulæ balancesthe waste of heat characteristic to the solar systems. | ||
| [VIII]. | THE SPREADING OF LIFE THROUGH THE UNIVERSE | 212 |
| Stability of the species.—Theory of mutation.—Spontaneousgeneration.—Bathybius.—Panspermia.—The stand-pointsof Richter, Ferdinand Cohn, and Lord Kelvin.—Theradiation pressure enables spores to escape.—The effect ofstrong sunlight and of cold on the germinating power.—Transportof spores through the atmosphere into universalspace and through it to other planets.—General conclusions. | ||
EXPLANATION OF ABBREVIATIONS, ETC.
The temperatures are stated in degrees centigrade (° C.), either on the Celsius scale, on which the freezing-point of water is 0°, or on the absolute scale, whose zero lies 273 degrees below the freezing-point of water, at -273° C. The equivalent temperatures on the Fahrenheit scale (freezing-point of water 32° F.) are added in brackets (° F.).
1 metre (m.) = 10 decimetres (dm.) = 100 centimetres (cm.) = 1000 millimetres (mm.) = 3.28 ft.; 1 kilometre (km.) = 1000 metres (m.) = 0.62 miles; 1 mile = 1.6 kilometres (km.).
Light travels in vacuo at the rate of 300,000 km. (nearly 200,000 miles) per second.