through, but
would bend, just as you have seen a stick in a glass of water appearing
as though it was bent below the water line. That is refraction."

Two weeks of very vigorous work had now been put in since the yaks had
disappeared, and the wagon was still at the edge of the forest. George
was anxious to recover it, with the new team, and with Harry started out
early in the morning to make up as much as possible lost time, as every
hour was considered valuable in their enterprises.

The yaks could be ridden as well as horses, but the greater part of the
way were driven. One of the guns which had been completed was taken
along, as well as the only pistol which the Professor had saved. In less
than three hours the forest was reached and they were soon within sight
of the wagon.

"What have we there?" cried Harry, as they neared the spot.

"Our yaks! And where do you suppose they have been?"

Close by the wagon were the yaks, as though patiently waiting for the
boys. They made no resistance, nor show of fright, when the boys
approached. One of them, Jack, still had the strap tied to the horns,
and it was the halter which had been attached to the tree at South
River.

A hasty examination was made, but if either of the boys came to any
conclusion concerning it, nothing was said. Without wasting time, the
team brought with them was yoked up and the broken wheel replaced by a
new one. The repairs to the wagon tongue did not take long, and they
were ready for the return.

"What shall we do with Jack and Jill?" Those were the names bestowed on
the first team. "Let us see if they will follow us."

They had gone fully one hundred feet before the yaks made any sign, and
then slowly followed, thus assuring them that no care or attention would
be required in that direction. Both boys were intensely delighted at the
recovery of their favorites and could not get home fast enough to give
the Professor the good news.

Nearing home, the Professor, who was on the watch, came out to meet
them, waving his hat at the sight of Jack and Jill. When the latter came
up he went over and affectionately petted the creatures, who seemed to
realize the welcome.

"I hope they are as glad as we are; I can understand why they got away;
look at the end of this thong." It plainly showed the teeth of some
animal which had gnawed the leather of which it was made.

"So you have been out prospecting, too?" was Harry's query, as he saw
the queer-