THEVISIBLE ANDINVISIBLEWORLDS 53
in the scale. Another illustration may perhaps make the
subject clearer.
Let us use a spherical sponge to represent the dense
earth—the Chemical Region. Imagine that sand permeates
every part of the sponge and also forms a layer outside the
sponge. Let the sand represent the Etheric Region, which in
a similar manner permeates the dense earth and extends
beyond its atmosphere.
Let us further imagine this sponge and sand immersed in
a spherical glass vessel filled with clear water, and a little
larger than the sponge and sand. We place the sponge and
sand in the center of the vessel as the yolk is placed in the
center of an egg. We have now a space of clear water
between the sand and the vessel. The water as a whole will
represent the Desir e World, for just as the water percolates
between the grains of sand, through every pore of the
sponge, and forms that clear layer, so the Desire World
permeates both the dense Earth and the ether and extends
beyond both of these substances.
We know there is air in water, and if we think of the air
in the water (in our illustration), as representing the World
of Thought, we s hall ha ve a fair mental picture of the wa y in
which the World of Thought, being finer and more subtle,
interpenetrates the two denser Worlds.
Finally, imagine that the vessel containing the sponge,
sand and water is placed in the center of a large spherical
vessel; then the air in the space between the two vessels
would represent that part of the World of Thought which
extends beyond the Desire World.
Each of the planets in our solar system has three such
interpenetrating Worlds, and if we think of each of the
planets consisting of three Worlds as being individual