Instead, the most extraordinary city that man had ever laid eyes upon was stretched directly beneath. It was grouped about what seemed to be the meeting-point of three great roads, which led to this spot from as many passes through the surrounding hills. And the city seemed thus naturally divided into three segments, of equal size and shape, and each with its own street system. For they undoubtedly were streets. No metropolis on earth ever had its blocks laid out with such unvarying exactness. This Mercurian city contained none but perfect equilateral triangles, and the streets themselves were of absolutely uniform width. The buildings, however, showed no such uniformity. On the outskirts of this brilliantly tan mystery the blocks seemed to contain nothing save odd heaps of dingy, sun-baked mud. On the extreme north, however, lay five blocks grouped together, whose buildings, like those in the middle of the city, were rather tall, square-cut and of the same dusty, cream-white hue. "Down-town" were several structures especially prominent for their height. They towered to such an extent, in fact, that their upper windows were easily made out. Apparently they were hundreds of stories high! Here and there on the streets could be seen small spots, colored a darker buff than the rest of that dazzling landscape. But not one of the spots was moving. "We'll go down further," said the engineer tentatively, in a low tone. There was no comment. He gradually reduced the repelling current, so that the sky-car resumed its descent. They sank down until they were on a level with the top of one of those extraordinary sky-scrapers. The roof seemed perfectly flat, except for a large, round, black opening in its center. No one was in sight. When opposite the upper row of windows, at a distance of perhaps twenty feet, Smith brought the car to a halt, and they peered in. There were no panes; the windows opened directly into a vast room; but nothing was clearly visible in the blackness save the outlines of the opening in the opposite walls. They went down further, keeping well to the middle of the space above the street. At every other yard they kept a sharp lookout for the inhabitants; but so far as they could see, their approach was entirely unobserved. When within fifty yards of the surface, all four men made a search for cross-wires below. They saw none; there were no poles, even. Neither, to their astonishment, was there such a thing as a sidewalk. The street stretched, unbroken by curbing, from wall to wall and from corner to corner. As the cube settled slowly to the ground, the adventurers left the deadlight to use the windows. For a moment the view was obscured by a swirl of dust, raised by the spurt of the current; then this cloud vanished, settling to the ground with astounding suddenness, as though jerked down by some invisible hand.