And as fate had it, while they were watching the curious basin, a strange sound began to arise from it.
It was a dull, distant, hollow booming, and then suddenly little channels of water began to appear in the rock galleries.
“Begorra, it’s afther comin’!” cried Barney.
With interest the aerial voyagers watched the phenomenon.
Suddenly from an orifice in the centre of the basin there shot up to the height of fifty feet a great column of water.
Then in an incredibly short space of time from all the galleries there rushed forth great seething volumes, swift as the rush of Niagara.
And once full, the great basin overflowed in a second, sending a mighty tidal wave across the country at race-horse speed.
Small wonder that the ship’s crew had been overtaken and overwhelmed. Nothing could have outstripped that line of swiftly rolling water.
On all the wide earth Frank and his companions thought there could be no phenomenon to equal this.
It was without parallel. Within the incredible space of an hour the Transient Lake, tranquil and placid, was once more restored to its basin.