When Jack was satisfied with the progress of the caulking and sealing of the great dunce-cap, he ascended the platform—a tinker’s shop and an apothecary-store of ladles, funnels, bottles, and terra-cotta vessels of clove-oil—and was pleased to observe a slight rise in the water-level, followed by a blurp and a collapse as some residual steam forced its way through the water-trap in the U-bend. This happened several more times in the next few minutes as the very last of the moisture was exhaled from the humid cake in the kettle, but then it stopped. There was then an interlude, which grew awkward the longer it went on; but Jack bid them keep stoking the fire and have faith. He was viewing the water level with respect to a wee bubble trapped in the glass pane, and for a while it did not move at all. But then it rose up distinctly, and a moment later a little belch of vapor shimmered up through the water and broke out the top. "It begins!" he announced.