I drew my note-book from my pocket and made a careful topographical sketch of the locality within the range of my vision. Due north lay the island, far out upon the shimmering sea. The spot I had chosen for my observations was the top of a large, flat boulder which rose six or eight feet above the turf. This spot I called Greenwich. The boulder was the “Royal Observatory.” I had made a start! I cannot tell you what a sense of relief was imparted to me by the simple fact that there was at least one spot within Pellucidar with a familiar name and a place upon a map. It was with almost childish joy that I made a little circle in my note-book and traced the word Greenwich beside it. Now I felt I might start out upon my search with some assurance of finding my way back again to the prospector. I decided that at first I would travel directly south in the hope that I might in that direction find some familiar landmark. It was as good a direction as any. This much at least might be said of it. Among the many other things I had brought from the outer world were a number of pedometers. I slipped three of these into my pockets with the idea that I might arrive at a more or less accurate mean from the registrations of them all. On my map I would register so many paces south, so many east, so many west, and so on. When I was ready to return I would then do so by any route that I might choose. I also strapped a considerable quantity of ammunition across my shoulders, pocketed some matches, and hooked an aluminum fry-pan and a small stew-kettle of the same metal to my belt. I was ready—ready to go forth and explore a world! Ready to search a land area of 124,110,000 square miles for my friends, my incomparable mate, and good old Perry! And so, after locking the door in the outer shell of the prospector, I set out upon my quest. Due south I traveled, across lovely valleys thick-dotted with grazing herds. Through dense primeval forests I forced my way and up the slopes of mighty mountains searching for a pass to their farther sides. Ibex and musk-sheep fell before my good old revolver, so that I lacked not for food in the higher altitudes. The forests and the plains gave plentifully of fruits and wild birds, antelope, aurochsen, and elk. Occasionally, for the larger game animals and the gigantic beasts of prey, I used my express rifle, but for the most part the revolver filled all my needs. There were times, too, when faced by a mighty cave bear, a saber-toothed tiger, or huge felis spelaea, black-maned and terrible, even my powerful rifle seemed pitifully inadequate—but fortune favored me so that I passed unscathed through adventures that even the recollection of causes the short hairs to bristle at the nape of my neck.