Attached to the bottom of our bag, which was open, were a number of long cords, terminating in loops. Through these loops we passed the longest rope that we had made--a rope so long that it entirely encircled the circumference of the tower--when we lowered it below the projecting eaves. We made it fast there, but with a slip knot that could be instantly released with a single jerk. Next, we slid the loops at the end of the ropes attached to the bottom of the bag along the cord that encircled the tower below the eaves until we had maneuvered the opening of the bag directly over the mouth of the flue leading down into the furnace of death in the pits of Ghasta. Standing upon either side of the flue Nur An and I lifted the bag until it commenced to fill with the hot air rushing from the chimney. Presently it was sufficiently inflated to remain in an erect position, whereupon, leaving Nur An to steady it, I moved the loops until they were at equal distances from one another, thus anchoring the bag directly over the center of the flue. Then I passed another rope loosely through the loops and secured its ends together, and to opposite sides of this rope Nur An and I snapped the boarding hooks that are a part of the harness of every Barsoomian warrior, the primary purpose of which is to lower boarding parties from the deck of one ship to that of another directly below, but which in practice are used in countless ways and numerous emergencies. Then we waited; Nur An ready to slip the knot that held the rope around the tower beneath the eaves and I, upon the opposite side, with Sharu's sharp dagger prepared to cut the rope upon my side. I saw the great bag that we had made filling with hot air. At first, loosely inflated, it rocked and swayed, but presently, its sides distended, it strained upward. Its fabric stretched tightly until I thought that it should burst. It tugged and pulled at its restraining cords, and yet I waited. Down in the valley of Hohr there was little or no wind, which greatly facilitated the carrying out of our rash venture. The great bag, almost as large as the room in which we had been confined, bellied above us. It strained upon its guy ropes in its impatience to be aloft until I wondered that they held, and then I gave the word. Simultaneously Nur An slipped his knot and I severed the rope upon the opposite side. Freed, the great bag leaped aloft, snapping us in its wake. It shot upward with a velocity that was astounding until the valley of Hohr was but a little hollow in the surface of the great world that lay below us. Presently a wind caught us and you may be assured that we gave thanks to our ancestors as we realized that we were at last drifting from above the cruel city of Ghasta. The wind increased until it was blowing rapidly in a northeasterly direction, but little did we care where it wafted us as long as it took us away from the river Syl and the valley of Hohr.