I had hunted these creatures in Thark as a guest of the great green Jeddak, Tars Tarkas, and I knew something of their cunning and resourcefulness as well as of their ferocity. Extremely man-like in conformation, they also approach man more closely than any other of the lower orders in the size and development of their brain. Occasionally these creatures are captured when young and trained to perform, and so intelligent are they that they can be taught to do almost anything that man can do that lies within the range of their limited reasoning capacity. Man has, however, never been able to subdue their ferocious nature and they are always the most dangerous of animals to handle, which probably accounts more even than their intelligence for the interest displayed by the large audiences which they unfailingly attract. In Hastor I have paid a good price to see one of these and now I found myself in a position where I should very gladly pay a good deal more not to see one, but from the noise he was making in the shaft beneath me it appeared to me that he was determined that I should have a free show and he a free meal. He was hurling himself as best he could against the trap door, above which I stood with some misgivings which were presently allayed when I realized that not even the vast strength of a white ape could avail against the still staunch and sturdy skeel of the ancient door. Finally convinced that he could not come at me by this avenue, I set about taking stock of my situation. Circling the tower I examined its outward architecture by the simple expedient of leaning far outward above each of the four sides. Three sides terminated at the roof of the building a hundred and fifty feet below me, while the fourth extended to the pavement of the courtyard two hundred feet below. Like much of the architecture of ancient Barsoom, the surface of the tower was elaborately carved from top to bottom and at each level there were window embrasures, some of which were equipped with small stone balconies. As a rule there was but a single window to a level, and as the window for the level directly beneath never opened upon the same side of the tower as the window for the level above, there was always a distance of from thirty to forty feet between windows upon the same side, and, as I was examining the outside of the tower with a view to its offering me an avenue of escape, this point was of great importance to me, since a series of window ledges, one below another, would have proved a most welcome sight to a man in my position.