Over this chaotic region the travellers were now sweeping, as if borne on the wings of a storm; the peaks defiled beneath them; the yawning chasms revealed their ruin-strewn floors; the fissured cracks untwisted themselves; the ramparts showed all their sides; the mysterious holes presented their impenetrable depths; the clustered mountain summits and rings rapidly decomposed themselves: but in a moment again all had become more inextricably entangled than ever. Everything appeared to be the finished handiwork of volcanic agency, in the utmost purity and highest perfection. None of the mollifying effects of air or water could here be noticed. No smooth-capped mountains, no gently winding river channels, no vast prairie-lands of deposited sediment, no traces of vegetation, no signs of agriculture, no vestiges of a great city. Nothing but vast beds of glistering lava, now rough like immense piles of scoriae and clinker, now smooth like crystal mirrors, and reflecting the Sun's rays with the same intolerable glare. Not the faintest speck of life. A world absolutely and completely dead, fixed, still, motionless--save when a gigantic land-slide, breaking off the vertical wall of a crater, plunged down into the soundless depths, with all the fury too of a crashing avalanche, with all the speed of a Niagara, but, in the total absence of atmosphere, noiseless as a feather, as a snow flake, as a grain of impalpable dust. Careful observations, taken by Barbican and repeated by his companions, soon satisfied them that the ridgy outline of the mountains on the Moon's border, though perhaps due to different forces from those acting in the centre, still presented a character generally uniform. The same bulwark-surrounded hollows, the same abrupt projections of surface. Yet a different arrangement, as Barbican pointed out to his companions, might be naturally expected. In the central portion of the disc, the Moon's crust, before solidification, must have been subjected to two attractions--that of the Moon herself and that of the Earth--acting, however, in contrary directions and therefore, in a certain sense, serving to neutralize each other. Towards the border of her disc, on the contrary, the terrestrial attraction, having acted in a direction perpendicular to that of the lunar, should have exerted greater power, and therefore given a different shape to the general contour. But no remarkable difference had so far been perceived by terrestrial observers; and none could now be detected by our travellers. Therefore the Moon must have found in herself alone the principle of her shape and of her superficial development--that is, she owed nothing to external influences. "Arago was perfectly right, therefore," concluded Barbican, "in the remarkable opinion to which he gave expression thirty years ago: 'No external action whatever has contributed to the formation of the Moon's diversified surface.'"