Transcriber’s Notes Obvious typographical errors have been silently corrected. Variations in hyphenation have been standardised but all other spelling and punctuation remains unchanged. Italics are represented thus _italic_, bold thus =bold= and superscripts thus y^{en}. WORLDS IN THE MAKING THE EVOLUTION OF THE UNIVERSE BY SVANTE ARRHENIUS DIRECTOR OF THE PHYSICO-CHEMICAL NOBEL INSTITUTE, STOCKHOLM TRANSLATED BY DR. H. BORNS ILLUSTRATED [colophon] NEW YORK AND LONDON HARPER & BROTHERS PUBLISHERS MCMVIII Copyright, 1908, by HARPER & BROTHERS. _All rights reserved._ Published March, 1908. TABLE OF CONTENTS I. VOLCANIC PHENOMENA AND EARTHQUAKES 1 Destruction caused by volcanism and by earthquakes.—Different kinds of volcanoes.—Vesuvius.—Products of eruption.—Volcanic activity diminishing.—Structure of volcanoes.—Geographical distribution of volcanoes.—Temperature in the interior of the earth.—Significance of water for volcanism.—Composition of the earth’s interior.—Geographical distribution of earthquakes.—Fissures in the earth’s crust.—Groups of earthquakes.—Waves in the sea and in the air accompanying earthquakes.—Their connection with volcanism.—Systems of fissures.—Seismograms. II. THE CELESTIAL BODIES, IN PARTICULAR THE EARTH, AS ABODES OF LIVING BEINGS 39 Manifold character of the worlds.—The earth probably at first a ball of gases.—Formation of the earth crust and its rapid cooling.—Balance between heat received and heat lost by radiation.—Life already existing on the earth for a milliard of years.—The waste of solar heat.—Temperature and habitability of the planets.—Heat-preserving influence of the atmosphere.—Significance of carbon dioxide in the atmosphere.—Warm and cold geological ages.—Fluctuations in the percentage of carbon dioxide of the air.—Combustion, decay, and growth.—Atmospheric oxygen.—Vegetable life more ancient than animal life.—The atmospheres of planets.—Chances of an improvement in the climate. III. RADIATION AND CONSTITUTION OF THE SUN 64