The aeroplane lay just below on the ledge which had been occupied by the Louise on the previous night.

Three lights were in sight. The lamp on the forward framework of the machine was burning brightly, and two men were walking along the ledge with electric searchlights in their hands. They did not appear to be surprised at the appearance of the Louise.

“I wonder what they’ve lost,” said Jimmie, his teeth fairly chattering with the cold. “Suppose we go down and ask.”

Ben circled the Louise into the warmer air of the valley on the other side of the summit, and then moved slowly to the west.

As he did so, the strange aeroplane leaped into the air and darted off to the south. She seemed to be a speedy machine, for she swept away from the Louise with wonderful ease.

“You just wait till I get turned around and get the motors on,” Ben muttered, “and I’ll show you that we can go some!”

The stranger was some distance in the lead before the Louise was well under way. After that it seemed to the boys that they gained, although very slowly. The machines both kept as low down as possible and ran to the full power of their motors.

The rush of wind and the clatter of the motors effectually checked verbal communication, but Jimmie pointed significantly to the machine ahead and then nodded determinedly.

“Let her go,” muttered Jimmie under his breath. “We had a race something like this in Old Mexico, and the other machine brought up in the Pacific ocean. That was a race that ought to have been written up!”

In the meantime, those watching from the camp saw the strange aeroplane dart swiftly over the ridge and head into the succession of valleys running to the west of the range. A few moments later she was followed by the Louise.