At that time we, as Afrites, would have flown from our distant planet back to the earth, and have laughed to see the fire or heat driving away part of the water from the surface. We should have danced with glee to see the volcanoes pouring out ashes and cinders, and to watch the cinders crumbling and changing and beginning to form new rocks and lighter soil. And so at last we should have seen our earth formed, a rude earth, rough and bare, its seas warm and muddy, its mountains treeless, its fields without a single blade of green, a veil of mist all about it. And how long did it take to complete all this? No one can answer. No one can number the years of creative ages. Earth-building is not a process that can be hastened. After the globe had reached the state which we have now indicated, vast successive changes took place until our own time. Science has divided the succession of these changes into periods or ages, and at these periods we shall now glance, as at some marvellous panorama. FOOTNOTES: [1] This theory is not universally accepted; some consider that the interior of the earth by cooling and pressure may be in a much harder than molten state. [2] At the present time the interior of the earth has probably become much more solid than in the earlier building ages. We really _know_ little of it below a depth of a few miles from the surface. LESSON II. THE FIRST CONTINENT. “As he who sets his willing feet In Nature’s footprints light and fleet, And follows fearless where she leads.” --LONGFELLOW, _Keramos_. For convenience in study, scientists have divided the story of earth-building into vast epochs, known as times. The times are again divided into ages. At first the names used for these times were derived from the Latin, and simply meant first, second, third, and fourth times.[3] The first time or period was that in which dry land first appeared above the waters. The fourth time meant the period during which mammals, fruit, grain, and man appeared. The second and third periods or times of course divided the interval between these two. Other names, made from Greek words, are now coming into general use to represent these building periods.[4] If we put these new names into plain English, they mean the time of first life, or first living things,--the age of ancient life, when most of the fossils, or petrified plants and animals which we now find, were buried up in the rocks; then the middle time; and finally the “new time,” when man and most of the plants and animals that now belong in the world appeared. Such long hard names make the beginning of science seem dry and dull, but we must not be alarmed: a very beautiful garden has sometimes a rough and ugly gate. [Illustration: LOOKING FROM AFAR.]