The most minute search failed to reveal another trace of the presence of the ancient giant, who had left the impress of his foot in the wet sands of the beach here so many millions of years ago that even the imagination of the geologists shrank from the task of attempting to fix the precise period. The Great Footprint. Around this gigantic footprint gathered most of the scientific members of the expedition, wearing their oddly shaped air-tight suits, connected with telephonic wires, and the spectacle, but for the impressiveness of the discovery, would have been laughable in the extreme. Bending over the mark in the rock, nodding their heads together, pointing with their awkwardly accoutred arms, they looked like an assemblage of antediluvian monsters collected around their prey. Their disappointment over the fact that no other marks of anything resembling human habitation could be discovered was very great. Still this footprint in itself was quite sufficient, as they all declared, to settle the question of the former inhabitation of the moon, and it would serve for the production of many a learned volume after their return to the earth, even if no further discoveries should be made in other parts of the lunar world. Expeditions Over the Moon. It was the hope of making such other discoveries that led to the dispatch of the other various expeditions which I have already named. I had chosen to accompany the car that was going to Aristarchus, because, as every one who had viewed the moon from the earth was aware, there was something very mysterious about that mountain. I knew that it was a crater nearly thirty miles in diameter and very deep, although its floor was plainly visible. The Glowing Mountains. What rendered it remarkable was the fact that the floor and the walls of the crater, particularly on the inner side, glowed with a marvellous brightness which rendered them almost blinding when viewed with a powerful telescope. So bright were they, indeed, that the eye was unable to see many of the details which the telescope would have made visible but for the flood of light which poured from the mountains. Sir William Herschel had been so completely misled by this appearance that he supposed he was watching a lunar volcano in eruption. It had always been a difficult question what caused the extraordinary luminosity of Aristarchus. No end of hypotheses had been invented to account for it. Now I was to assist in settling these questions forever. From Cape Heraclides to Aristarchus the distance in an air line was something over 300 miles. Our course lay across the north-eastern part of the Sea of Showers, with enormous cliffs, mountain masses and peaks shining on the right, while in the other direction the view was bounded by the distant range of the lunar Apennines, some of whose towering peaks, when viewed from our immense elevation, appeared as sharp as the Swiss Matterhorn.