Unscrewing a cap on the top of the case, he applied a small air-pump, which he had taken out of the box, to the opening, and screwed it firmly on; then, closing the glass door, he placed cement along the junction of the door and sides, from a bottle which he had brought for that purpose. In a few moments, the cement had set, and then, working the air-pump, he soon exhausted the air from the case; finally unscrewing the pump, he replaced the cap and laid the pump in the corner of the chamber. All this being finished to his satisfaction, he announced that the work for the night was completed. Looking at his watch, Cobb said: "It is now four o'clock in the morning, and time that we should get out of this if we don't wish to be seen departing. We have done all that it is possible to do for the present; let us at once start for town; besides, you have to be at the post by six o'clock." "Yes, that is true," returned Hathaway; "we are due at that hour. We have done a good deal of work, but for the life of me, I am totally ignorant of the purposes of all this apparatus. I would like to have you explain some of it to me," and his eyes turned inquiringly toward the large case with its wheels and compass. "All in good time!" and Cobb cautiously opened the swinging panel. The coast was clear; not a single person was in sight. "Now, then, be lively!" and he stepped out, the others following quickly. In another moment the door was closed, and not a sign was left to indicate that the pedestal of the Statue of Liberty held within its interior the apparatus necessary for prolonging the life of a human being. The three friends passed down the hill, and took the Haight-street cars for the city. It was the first car for the day, and not another passenger was on board. Arriving at the Occidental, Cobb said: "You are expected to be at reveille this morning, but I have no duties until retreat. There are a few things that I wish to attend to; so I will leave you here. Be sure to be at my quarters at 9:30 to-night. Good-bye!" and he left them without waiting for a reply. It was nearly eight o'clock, and after a hearty breakfast, when Cobb left the hotel, passed down Montgomery street into Washington, and made his way to a small-sized house at the foot of an alley leading from that thoroughfare. The windows of the house were all closed by shutters, and the whole building bore an aspect of dilapidation. Ascending the four rickety steps that led to the door, he gave a sharp knock, repeating it after a moment, as no answer was obtained. "Who knocks?" "It is I, Colchis! Open the door." The door swung open, and Cobb entered, the door closing behind him with a bang. CHAPTER IV It is necessary to go back a few months in our story, and introduce a new character, the inhabitant of the little old, dilapidated house in the lane.