among the snakes and lizards."

"Why not camp on the hills back there?" asked Jack.

"We may soon camp anywhere we like," said Ned. "The Zone government
understands that we are a lot of kids out after specimens."

"Specimens of what?" asked Jimmie.

"Tall, slender men with black hair turning gray," replied Frank.

"Quit your kiddin'," grinned Jimmie.

The boys left the train at a modern depot, passed through the train-shed,
crossed a level sward, and looked down into a mighty chasm.

"Great Scott!" cried Frank. "Is that the bottom of the world?"

He pointed below as he spoke.

"There seems to be a thin crust of rock between the bottom and the other
side of the world," laughed George. "See! There are tunnels and pits down
there. The men are still digging. Look like ants, don't they?"

It was a wonderful sight, and the Boy Scouts gazed long at the scene of
activity before turning away toward the Gatun dam itself. This, Peter
Fenton explained, was one of the big cuts of the canal, and ran from the
marshy valley above down through the rocky ridge which held the rains in
check and made a swamp of the upland.

Along the margins of the excavation ran shining steel rails upon which
were mounted tapering structures of steel, from which cables crossed the
gorge, carrying great buckets of concrete for the work below. Heavy walls
were growing out of the depths.

"The ships will come up out of the sea through this cut," Peter
explained.

"Then they'll climb the hill," scorned Jimmie.

"They will stop down there," said Peter, "and the lock gates will be
closed, and the water will lift them to the level of the lake."

"I don't see no lake," observed the skeptical Jimmie.

"The lake will lie where the low land is, over there," replied Peter,
pointing. "The Gatun dam will block the water and make a lake 85 feet
above sea level, covering one hundred and sixty-four square miles of
earth."

"So the most of the canal will be lake?" asked the boy.

"Quite a lot of it," was the reply.

"And if any one should blow up the dam, after it gets on its job, the
ships would have to climb a ladder if they got over to Panama," he
exclaimed.

"Something like that," Peter said.

"Where is the Gatun dam?" asked Jack.

"It is going up over there," Peter replied, pointing out a low, broad
ridge which appeared to link two hills together. "That is what will make
the inland sea, and that is the lump of earth we came here to look
aft