“What is the danger point in the matter of flexion, captain?” asked Bob, turning to Nemo, junior, whose gray head was bowed forward on his hand, while his gleaming eyes regarded the cool, self-possessed youth with something like admiration.
“Ten millimeters,” was the answer.
“We still have a margin of three millimeters and are at the depth you indicated.”
“Bravo! We are five yards from the bottom. Do a little cruising, Bob. Let us see how the Grampus behaves at this depth.”
The entire shell of the submarine was under an enormous pressure.
Bob gave the order to start the motor, and the popping of the engine soon settled into a low hum of perfectly working cylinders. A forward motion was felt by those in the submarine.
“Not many people have ever had the novel experience of navigating the ocean seventy yards below the surface,” remarked the captain, with a slow smile.
“It’s a wonderful thing!” exclaimed Bob. “The Grampus seems equal to any task you set for her, captain.”
The air of the periscope room was being exhausted by the breathing of Bob, Nemo, junior, and Cassidy. Bob ordered the bulkhead doors opened, in order that fresh oxygen might be admitted from the reservoirs. Just before the doors were opened, Captain Nemo, junior’s, face had suddenly paled, and he had swayed on his seat, throwing a hand to his chest.
“You can’t stand this, captain!” exclaimed Bob, jumping to the captain’s side. “Hadn’t we better ascend?”