Dawes. Mr. Dawes thought that a telescope that could
make such a discovery would be worth having, so he bought the large
lens out of this new telescope. Then he bought other glasses from Mr.
Clark, and sold them again to other astronomers. In this way Mr. Clark
became famous in England.

[Illustration: Telescopic View of the Moon.]

Mr. Clark had given up painting. He put his whole heart into making the
best telescopes in the world. He went to England and saw the great
astronomers, and looked through their telescopes.

They were glad to see the man who made the best lenses in the world.
His telescopes had helped them to find out many new things never seen
before. By this time Mr. Clark was coming to be known in his own
country. He got an order to make the largest glass ever made for a
telescope in the whole world. This was to be put up in America. Nobody
had ever dreamed of making so large and powerful a telescope.

After a long time the great glass for this telescope was ground. Mr.
Clark set it up to try it. His younger son, Alvan, who was helping him,
turned the telescope so as to look at the bright star Sirius. As soon
as he had looked, he cried out in surprise, "Why, father, the star has
a companion!" Sirius is a sun. It has a satellite, a dark star like our
world revolving round it. Nobody had ever been able to see this dark
star before. But this telescope was stronger than any that had ever
been pointed at the sky.

Mr. Clark now looked through the tube himself. Sure enough, there was
the companion of Sirius, never seen before by anybody on the earth. The
large glass which had been a year in making had won its first victory.
But Mr. Clark made much larger glasses even than that one. He had
nobody to show him how. But by patient thought and hard work he had
made the greatest telescopes in the world. Medals and other honors were
sent to him from many countries.

ADVENTURES IN ALASKA.

[Illustration: Scene in Alaska.]

The Copper River of Alaska flows from north to south into the ocean.
The Yukon River, which is farther north, runs from the east toward the
west. It was known that the waters of these two rivers must be near
together at the place from which they started in the mountains, but it
was not known whether anybody could pass from the valley of the Copper
River over the mountains into the valley of the Yukon. A scouting party
was sent to find out whether the crossing from one river to the oth