Nor was the chamois forgotten. The generous landlord had it brought down to the inn from the spot where it had fallen, and sent an ample equivalent to Hirzel's cottage.
Jack was delighted with the idea. Gus differed from him entirely. Joe and I, being girls, pronounced it--horrid.
"Papa wants us to, you know," said May, who always sets us straight.
Jack, who had recently joined one of the college societies, moved that the Professor be cordially supported. "His lecture last week was exceedingly entertaining," he argued. "That he should be so good as to come here and talk to us about his wonderful science in a pleasant familiar way, simply because he's papa's old friend, shows the interest he takes in the family."
"My dear sister, I can not. What the Professor has to tell us about the heavenly bodies--"
"I hate the heavenly bodies," growls Gus.
"Is it jealousy, Augustus, because they are allowed to stay out late nights, while you are not?"
"Whatever it is, I agree with him," puts in Joe, who always stands by Gus. "I hate astronomy too."
"Feeling as I do, Josephine, that your knowledge in the science is confined to 'Twinkle, twinkle, little star,' and the fact that 'the moon is made of green cheese,' I am surprised at you."
The Professor heard this, for he was just coming up stairs.
"What makes them twinkle, May?" and the Professor seated himself in an easy-chair, as if ready to talk.
"I don't know, Sir. Won't you please tell us?"
"Pooh, May, don't bother the Professor with such juvenile questions. He'll think he's intrusted with the charge of the third form in an infant school."
"But," persisted May, "I would like very much to know, and I don't believe you can tell, if you _have_ been to college. Now there!"
Jack was somewhat nonplussed at this, but after a moment's hesitation said, "Well, anyhow, the books I studied never told anything about the stars twinkling, and I don't believe they do twinkle. It's nothing but a baby notion."
All eyes are now intently fixed upon the Professor, who is expected first to settle the fact, and then to account for it.
"You, Jack, who have been to college," he began, "know that all vision or sight is produced by rays falling upon the eyes. These rays may be broken or turned from their natural course--the word astronomers use is refracted. Now the stars are so far away from us that through the largest telescope they are still only points of light. As the rays come down through space there is nothing to break or refract them, but when they reach our atmosphere, there is the tremulous agitation of the air and ascending vapors. By these the rays coming from the tiny points are at intervals turned aside from the narrow space of the pupil of the eye. When the eye is assisted with the wide opening of the object-glass of a telescope no such thing happens. So Jack is right; the stars don't twinkle. When viewed through a telescope, they are found to shine with a steady brightness, and hence the motion is only in appearance. Recent astronomers have little to say about it; but it is due, doubtless, as Sir Isaac Newton explains in his celebrated _Principia_, to the ascending vapors and tremulous movements of the atmosphere. You have seen how the heated air or gas rising from a stove will sometimes make things behind it tremble and dance. Now if a small candle were burning on the other side of the ascending vapor, its flame, though really steady, would seem to flicker."