Godfrey disposed of, Dennis turned to Ross and said, “Just test the atmosphere, Ross, will you?” and in a short time he returned saying the atmosphere was variable, and he thought they had better go across the world to get several samples before they thought of landing. Accordingly, the _Regina_ shot ahead till she came into the sunshine forward and then back into the sunshine at the opposite side, about half a dozen bags being filled with atmospheric air at different points easily located. Whilst Gilbert and Ross were testing these samples, Dennis took measurements of distances, gravity on surface, speed travelled, etc. They had come about 245,000 miles, but having altered their course, it was probable that this measurement was in excess of the actual distance of the object from Earth, as measured on a straight line, which is, of course, the shortest distance between two points. The diameter would be, roughly speaking, about 2160 miles, and the total surface was, as near as could be ascertained without going all round, about 14,500,000 square miles or a little over, or O.074 of Earth, and its volume about 5,300,000,000 cubic miles; its density was about 3.57 of Earth-water, or 0.63 of earth, reckoning earth as 1; it was travelling in its orbit with a velocity of 2273 miles per hour, and had an equatorial velocity of rotation of a little over ten miles an hour. Just as these calculations were complete Gilbert and Ross came in laughing, and asked Dennis, “Where are we, do you think?” “On the shady side of old Luna,” replied Dennis, “or I’ll eat her!” “Right!” said Ross; “we can’t be anywhere else. You, Godfrey, have shot us to Luna instead of Jupiter, and now we know where we are, the positions of the other planets can be fixed also.” “Luna! and after all those elaborate calculations!” exclaimed Godfrey, sarcastically. “What remarkable brain-power there is on board, triad, to discover it at last—but better late than never!” No one on Earth has ever seen the dark side of the moon, owing to the illuminated or convex edge always being turned towards the sun; there is, therefore, continual light on one side of the moon and constant comparative darkness on the other, the crescent altering in shape by becoming increased or diminished as we on Earth see more or less of the illumined side as the moon changes its position; consequently, the dark side is hidden from Earth in almost every phase except occasionally when, owing to libration, it is possible to see those parts beyond the edge, or border, of the lunar disc, which alternately come into view and are hidden. It was, therefore, perhaps not unprofitable, whilst they were there, to gain, a little information on several points about which the scientists of Earth had been in dispute for centuries.