As a matter of fact, the cars were nearly touching.

“Keep up your pluck, girls!” Jack called back. “If this map is all right, we’ll make the camp in five minutes more.”

“If we didn’t have an old tub in front of us, we’d make it in four,” sang out Cora.

“If the rain will only hold off,” murmured Belle.

But the prospect grew ever more threatening. The peals of thunder were redoubled and the lightning played so vividly across the sky that Bess covered her face with her hands.

“Suppose the car should be struck!” she exclaimed.

“If it were, we’d probably never know it,” was all the comfort her sister could give.

Just then there was an appalling roar, and a great tree, split from top to bottom, swayed for a moment and then fell with a deafening crash right across the road, about a hundred feet in front of the leading car.

There were shrieks from the girls, and a jumble of shouts came from the boys, as Jack brought his machine to a halt, and Cora, who had not lost her presence of mind, did the same.

All jumped out and ran forward. A glance told them that there was no getting past the tree. It blocked the road completely. Nor was it possible to get around the fallen monarch with the cars, for there was dense undergrowth on both sides of the road.