The Fourth Dimension is only the beginning.

We utilize that to isolate our island.

But the higher dimensions are gradually being conquered, too.

Nearly all of us can pass into the Fifth at will, 'disappearing,' as you have the word, from the lower dimensions.

It is well-known to you that in a land whose people knew length and breadth, but no _up_ and _down_, an object might be pushed, but never lifted _up_ or put _down_.