A moment later Captain Jules stood rigged in the same costume as Madge.
“Steady, my girl,” Captain Jules warned her.
“Aye, aye, Captain,” returned Madge quietly, “I’m ready. Let us go down together to the bottom of the bay.”
“Pump away,” ordered the captain.
There was a splash on the surface of the clear water, a long-drawn gasp from Madge’s friends; then a few bubbles rose. Rapidly, skillfully, Madge’s tenders played out her life and pipe lines, and Madge Morton disappeared from the world of men. Captain Jules made his plunge a few seconds in advance of his companion.
In the boat where Tom Curtis and Phyllis Alden sat there was a breathless, intense silence. The boy and girl happened to be in the boat with the men who were looking out for the welfare of Captain Jules. Philip Holt was with Madge’s tenders.
Phyllis knew that there was but one way in which she could follow her chum’s course below the surface of the water. She could watch her life and air lines. Captain Jules had made it plain to Phyllis that all the time the diver is under water small ripples will appear near his air line. These bubbles are caused by the air that the diver breathes out from the valve in the side of his diving helmet.
Phyllis watched the lines doggedly. Captain Jules was to keep Madge under water only about fifteen or twenty minutes, but at that a minute may appear longer than an hour.
Suddenly Phyllis Alden discovered that the man who was tending Madge’s air pump seemed to be working less vigorously. He pumped unevenly. Once he swayed, as though he were about to fall over in his seat.
In a second it flashed over Phyllis that the man was ill. He was a strong, red-faced individual, but his face turned to a kind of ghastly pallor. It was all so quick that Phil had no time to speak from her boat. Philip Holt, who was in the same boat with the man, grasped the situation as quickly as Phyllis did. With a single motion he took the tender’s place at the air-pump. Phil saw that he was pumping away with vigor.