rew them into the receptacle, which he then locked up, and pocketed
his keys. "Which is it, Tom--repentance, or because they are of no use
to the thief?"

"Let's hope it is the first, uncle," replied Tom gravely, and his uncle
uttered a long, deep-toned--

"Hah!" Then, "Come along, and let's think of something pleasanter, my
boy."

They went up into the observatory, where the new diagonal mirror Tom had
ground and silvered was fitted into the telescope; and that night being
gloriously clear, the new addition was tested, and proved to be almost
perfect.

"As nearly perfect as we shall get it, Tom," said Uncle Richard; and
then till quite late a glorious evening was spent, searching the dark
depths of space for twin stars, Tom having a goodly share of the
observations; and when he was not using the glass making shift with the
star-finder, and listening the while to his uncle's comments upon that
which he saw.

The telescope was directed at the double star Castor; which, with
Pollux, was glittering brightly in the black-looking sky, when Uncle
Richard made way for the boy to take his place.

"Wonderfully clear, uncle."

"But do you notice anything particular?"

"Yes; I was going to say, it's like it is sometimes when the moon is
low-down; the air seems to be all in a quiver."

"That is so, Tom. People don't, as a rule, think that they can see the
atmosphere, but you can see it to-night all in motion. I think it means
wind."

"Wind blowing hard a very long way up?"

"Yes, I think so."

"Oh!" ejaculated Tom.

"What's the matter?"

"It was so sudden. A cloud has swept right across."

Uncle Richard stepped up to the opening, and looked out into the night.

"Yes," he said, "we may shut up for the night; there's a dense black
curtain of clouds drawing across the sky. Come and look. Ah! how
brilliant!"

Tom started. He had just taken his eye from the great glass, when the
interior of the observatory was lit up for an instant by a flash of
lightning, and as soon as his dazzled eyes mastered the intense darkness
which followed, he joined his uncle, and looked out of the great shutter
opening, to see the singular sight, of one-half of the heavens
brilliantly illuminated with the countless orbs, while the Milky Way was
clearly defined; the other of an inky blackness, moving steadily,
cutting off star after star, till two-thirds of the sky was darkened,
and in half-an-hour, when the shutter was drawn ov