How big, you ask, could this heart be? You know it, that with Me in all things that proportion is according to what is necessary; therefore it is also certainly the case with the heart of the earth. As the earth is large, there must also be a relatively large heart or center of gravity in itself, so that in it's innumerable compartments, that power can be generated which is sufficiently powerful to drive out all the various life-juices of the earth into the widely extended organs, and again, when the juices perform their service, to draw them to itself for further saturation. – The Earth, Chapter 2, Paragraph 3