That the moon possesses little or no atmosphere is deduced from the undiminished lustre of the stars, at the instant when they emerge from behind her disk. That the ocean of the moon is frozen, is confirmed from there being no appearance of lunar tides; which, if they existed, would cover the part of her disk nearest the earth. See note on Canto III. l. 61.] "GNOMES! how you trembled! with the dreadful force When Earth recoiling stagger'd from her course; 85 When, as her Line in slower circles spun, And her shock'd axis nodded from the sun, With dreadful march the accumulated main Swept her vast wrecks of mountain, vale, and plain; And, while new tides their shouting floods unite, 90 And hail their Queen, fair Regent of the night; Chain'd to one centre whirl'd the kindred spheres, And mark'd with lunar cycles solar years. [_When earth recoiling_. l. 84. On supposition that the moon was thrown from the earth by the explosion of water or the generation of other vapours of greater power, the remaining part of the globe would recede from its orbit in one direction as the moon receded in another, and that in proportion to the respective momentum of each, and would afterwards revolve round their common centre of gravity. If the moon rose from any part of the earth except exactly at the line or poles, the shock would tend to turn the axis of the earth out of its previous direction. And as a mass of matter rising from deep parts of the globe would have previously acquired less diurnal velocity than the earth's surface from whence it rose, it would receive during the time of its rising additional velocity from the earth's surface, and would consequently so much retard the motion of the earth round its axis. When the earth thus receded the shock would overturn all its buildings and forests, and the water would rush with inconceivable violence over its surface towards the new satellite, from two causes, both by its not at first acquiring the velocity with which the earth receded, and by the attraction of the new moon, as it leaves the earth; on these accounts at first there would be but one tide till the moon receded to a greater distance, and the earth moving round a common centre of gravity between them, the water on the side furthest from the moon would acquire a centrifugal force in respect to this common centre between itself and the moon.] IV. "GNOMES! you then bade dissolving SHELLS distil From the loose summits of each shatter'd hill, 95 To each fine pore and dark interstice flow, And fill with liquid chalk the mass below. Whence sparry forms in dusky caverns gleam With borrow'd light, and twice refract the beam; While in white beds congealing rocks beneath 100 Court the nice chissel, and desire to breathe.--