"Another part of this machinery," explained the white-haired Adept, "is used to extend the bridge from the island to the mainland. The steel bridge is in a room much like that in which the boats are kept, and at Coo-ce-oh's command it would reach out, joint by joint, until its far end touched the shore of the lake. The same magic command would make the bridge return to its former position. Of course the bridge could not be used unless the island was on the surface of the water."

"But how do you suppose Coo-ee-oh managed to sink the island, and make it rise again?" inquired Glinda.

This the Adepts could not yet explain. As nothing more could be learned from the basement they mounted the steps to the Queen's private suite again, and Ozma showed them to a special room where Coo-ee-oh kept her magical instruments and performed all her arts of witchcraft.

Chapter Twenty-Three

The Magic Words

Many interesting things were to be seen in the Room of Magic, including much that had been stolen from the Adepts when they were transformed to fishes, but they had to admit that Coo-ee-oh had a rare genius for mechanics, and had used her knowledge in inventing a lot of mechanical apparatus that ordinary witches, wizards and sorcerers could not understand.

They all carefully inspected this room, taking care to examine every article they came across.

"The island," said Glinda thoughtfully, "rests on a base of solid marble. When it is submerged, as it is now, the base of the island is upon the bottom of the lake. What puzzles me is how such a great weight can be lifted and suspended in the water, even by magic."

"I now remember," returned Aujah, "that one of the arts we taught Coo-ee-oh was the way to expand steel, and I think that explains how the island is raised and lowered. I noticed in the basement a big steel pillar that passed through the floor and extended upward to this palace. Perhaps the end of it is concealed in this very room. If the lower end of the steel pillar is firmly embedded in the bottom of the lake, Coo-ee-oh could utter a magic word that would make the pillar expand, and so lift the entire island to the level of the water."