"The heavens varying in number from three to twelve according to the locality
were imagined as formed by widely spaced concentric hemispheres of solid
material which rested upon the plane of the earth.
In a vertical direction upward the celestial realms would accordingly lie one above the other; but in the horizontal direction they formed circular zones on the earth's surface. Thus a group of islands which considered itself te pito, the navel of the universe, was conceived of as situated at the center of a series of concentric spaces of great but indefinite extent, separated from one another by the walls of the various sky domes which rested on the earth." (Makemson)