sang out Jack. And then turning to his cousins
he added in a low voice: "We mustn't lose a minute of time in getting
back. This blow is going to be a heavy one."

The girls were soon seated in the rowboats, and then the four Rovers
lost no time in casting off from the little dock and in starting to row
towards Clearwater Hall. As they proceeded, the sky kept growing darker
and darker while the wind grew stronger and stronger.

"We're in for a squall all right enough," murmured Randy, as he and
Andy bent to their oars with vigor.

"Gee! I only hope we can reach the shore before it strikes us," was the
response.

"Row for all you're worth, boys!" sang out Jack from the other boat.
"Bend to it just as if you were in a race!"

And then he and Fred, as well as the twins, settled down to the task of
trying to outrace the oncoming squall.

CHAPTER XX

IN GREAT PERIL

As those who have had any experience know, a squall on a lake encircled
by hills sometimes comes up very quickly, and this is what happened in
the present case. Hardly had the two rowboats covered a quarter of the
distance to the shore, when the wind came whistling across the bosom of
the lake, sending the whitecaps tumbling in all directions.

"Oh, dear, just look how rough the water is getting!" remarked Ruth in
alarm.

"And how the wind is blowing!" added May.

In the other boat the girls were even more fearful, and Andy and Randy
had all they could do to make them sit still.

"Don't shift," pleaded Randy. "We don't want to ship any water."

"Oh, dear! If only we were safe on shore!" wailed Alice.

"I didn't think it looked like a storm when we left the school," added
Annie, in dismay.

"This is only a squall. It may blow itself out in a few minutes,"
returned Randy, although to himself he admitted that the squall looked
as though it might last for some time.

Battling as best they could against the wind and the whitecaps, the
Rover boys strove to reach the shore in the vicinity of the girls'
school. But the wind was blowing directly down Clearwater Lake and
threatened more than once to capsize them.

"Gee, Jack, this is getting serious!" panted Fred, as he looked
questioningly at his cousin.

The same thought had come into the minds of each of the boys. Could the
girls swim? They wished they knew, but did not dare to ask any
questions for fear of further alarming their passengers.

"I guess we had better head up into the wind.