"So, sir, it seems that you've set your heart on learning something of everything?" The man who said this was a tall and rugged professional diver. He to whom it was said was Edgar Berrington, our hero, a strapping youth of twenty-one. "Well-yes, I have set my heart upon something of that sort, Baldwin," answered the youth. "You see, I hold that an engineer ought to be practically acquainted, more or less, with everything that bears, even remotely, on his profession; therefore I have come to you for some instruction in the noble art of diving."