"He's gone down under water!" exclaimed Nat. "Man overboard!" he loudly cried, thinking some one on the dock or aboard the vessels might hear him and come to help aid in rescuing the imperiled one. But there came no answer. The pier seemed to be deserted.
Nat reached the deck of the first barge and rushed across it to the farthermost rail. He tried to peer down into the black space between the two freight boats, but he could see nothing.
"Where are you?" he called again.
"Here! Right here!" was the answer. "I fell down in between the two barges. I got hold of a rope, but it slipped from me a moment ago, and I went under. I managed to get hold of it again when I came up, but I can't last much longer. Hurry and help me!"
"I will!" exclaimed Nat. "I'm coming down as soon as I can find a rope to cling to. There isn't room to swim down there."
"No; that's right. I can hardly move. But I can't hold on much longer."
"Don't give up!" yelled Nat. "I'll be right there. Queer there isn't some of the crew here," he murmured to himself.
He glanced rapidly about him. There was a lantern burning high up on the smokestack of one of the barges, which were of the latest type, with big engines to turn the large propellers. It was the work of but an instant for Nat to loosen the lantern rope from the cleat and lower the light to the deck. Then cutting the rope, as the quickest method of detaching it from the stack, he hurried with it to the space between the two barges. He lowered the light, and by its gleam saw an elderly man clinging to a rope that dangled from the side of the barge the boy was on.
"That's good; show a light!" exclaimed the man. "Now you can see what to do. But please hurry. My arms are nearly pulled from the sockets."
"I'll have to get a rope that will bear my weight," replied Nat. "Hold on a moment more."