Arthur, of course, as an engineer, had studied the construction of the building with great care, and happened to remember that this partly hollow pile was the one nearest the safe-deposit vault. The collapse of the board-room floor had suggested that some change had happened in the building itself, and that was found when he saw that the deposit-vault had actually risen an inch.
He at once connected the rise in the flooring above the hollow pile with the pipe in the pile. Estelle had heard liquid sounds. Evidently water had been forced into the hollow artesian pipe under an unthinkable pressure when the catastrophe occurred.
From the rumbling and the suddenness of the whole catastrophe a volcanic or seismic disturbance was evident. The connection of volcanic or seismic action with a flow of water suggested a geyser or a hot spring of some sort, probably a spring which had broken through its normal confines some time before, but whose pressure had been sufficient to prevent the accident until the failure of its flow.
When the flow ceased the building sank rapidly. For the fact that this “sinking” was in the fourth direction—the Fourth Dimension—Arthur had no explanation. He simply knew that in some mysterious way an outlet for the pressure had developed in that fashion, and that the tower had followed the spring in its fall through time.
The sole apparent change in the building had occurred above the one hollow concrete pile, which seemed to indicate that if access were to be had to the mysterious, and so far only assumed spring, it must be through that pile. While the vault retained its abnormal elevation, Arthur believed that there was still water at an immense and incalculable pressure in the pipe. He dared not attempt to tap the pipe until the pressure had abated.
At the end of a week he found the vault slowly settling back into place. When its return to the normal was complete he dared begin boring a hole to reach the hollow tube in the concrete pile.
As he suspected, he found water in the pile—water whose sulfurous and mineral nature confirmed his belief that a geyser reaching deep into the bosom of the earth, as well as far back in the realms of time, was at the bottom of the extraordinary jaunt of the tower.
Geysers were still far from satisfactory things to explain. There are many of their vagaries which we cannot understand at all. We do know a few things which affect them, and one thing is that “soaping” them will stimulate their flow in an extraordinary manner.
Arthur proposed to “soap” this mysterious geyser when the renewal of its flow should lift the runaway sky-scraper back to the epoch from which the failure of the flow had caused it to fall.
He made his preparations with great care. He confidently expected his plan to work, and to see the sky-scraper once more towering over mid-town New York as was its wont, but he did not allow the fishermen and hunters to relax their efforts on that account. They labored as before, while deep down in the sub-basement of the colossal building Arthur and his volunteers toiled mightily.