"But this is no time for sentiment. I assume that Frederick and Dan are with you, I must be brief, succinct. There are several things which now I must make plain to you three. If there is anything here, Peter, which Dan and you do not understand, Frederick will make it clear." "Hah!" I exclaimed, "a little gibe at us, Dan!" Freddie smiled as Dan gestured. "Go on. Let's hear it." Good old dad! My heart warmed to him. I resumed: "The few astronomical facts concerning Xenephrene which now you should know, are these: It is a globe flattened at the poles, expanded at the equator. Rather more so than the earth. Polar diameter, sixty-five hundred miles. Equatorial diameter, seventy-eight hundred miles. Thus it is similar in size, though slightly smaller than our earth. Its average density, I believe is about that of earth. Its mass, hence, is but little less than earth. Gravitation, about the same. You will notice, in this respect, hardly any difference. "Xenephrene's present orbit about our sun is an ellipse rather more eccentric than earth's--more comparable to that of Mercury. I believe it is not yet stabilized. There may even be a tendency toward a breaking of the ellipse at its aphelion--I sometimes shudder at the thought--if we should all be here on Xenephrene. Frederick will understand--" I glanced at Dan. "Well, if he does, we don't." "Never mind," said Freddie. But he did not smile. I read on: "Xenephrene rotates on its axis once in twenty-two hours, thirty-seven minutes, ten seconds, as we measure time on earth. This is very similar to our earth. This axis is not inclined to the plane of its orbit, but is almost exactly vertical. Hence we have here no change of seasons. And throughout the year, the periods of day and night alternate in exact and unchanging relative lengths. "Here in the country of the Garlands, we are situated at about eight degrees south latitude. Thus, near the equator, our days are always some eleven hours and nineteen minutes long; and our night but a few seconds shorter. "Xenephrene has one moon. Pyrena, we call it. You will already have seen it, even with your small telescope, no doubt. I will not go into the elements of its orbit now, or describe its phases as we nightly see them. A beautiful sight, Peter. It is really the sun for Xenephrene--or at least it was, before Xenephrene came to bathe in our own greater sunlight. It is a small world of incandescent gas--blazing purple. You should see our dim purple nights--strangely beautiful. "You are now to proceed as follows: "I attach herewith a rough map of my own, giving the general conformation of Xenephrene's surface. I drew it from my own sketches made as I came down from outer Space. It is of necessity vague, and inexact.