Look in what direction one would, countless flashing rainbow islands could be seen whirling and twirling in fantastic manner like giant spinning wheels, forming geometric figures of every conceivable design as they sped on their way, while through them all, in imposing, majestic lines swept the planets.

“What do you say to our first visiting the island of Mercury, that being the one nearest the sun, and then taking the others in order?” said Harold.

They all agreed to this plan.

“Now, I am going to state a few astronomical facts, dull as you may find them, for they are things you all should know, and I think the girls have little conception of the millions of miles distant these planets are, or of their size and the time it takes for light from them to reach us.

“Now, just out of curiosity I am going to ask you how large you think these planets are which you look at every night, and how far away they seem. I advise you to begin your guessing about Venus, as it is best seen from here.”

“Well, let me see,” said Ione; “Venus looks to be about the size of a cheese, but, of course, I know that in reality it is almost as large as the earth.”

“Now, princess, what do you say?”

“It looks to me to be about the size of a barrel-head and that it is twice as large as the earth.”

“You are both wrong, and to show you how much you are in error, here are a few figures. Mercury is thirty-six million miles distant from the sun and it takes eighty-eight days to make one revolution in its orbit round the sun, consequently its year is only eighty-eight days, instead of three hundred, sixty-five and one quarter days as ours is. Wouldn’t you like to live where the years were that long? Then you could have four Christmas Days where now you have but one,” said Harold.

“Mercury,” he continued, “has the shortest year of all of the planets and Neptune the longest, its year being sixty thousand, one hundred and twenty-six days in length. Just think, if you lived upon Neptune you would have a Christmas once in about nineteen years reckoned by our time. The length of year varies with the other planets—but enough of statistics. I know they are uninteresting to girls. How would it please you to hurry on to Mercury’s Satellite Island to see what it looks like and if it is inhabited?”